1. Field of the Invention
The present invention generally relates to a solid cleaning medium that removes, without using water or solvent, dust and fine particles attached to an object used in an electrophotographic apparatus (such as a copier and a laser printer), such as toner particles attached to a component of a complex shape; and a dry-type cleaning apparatus using the solid cleaning medium; and particularly relates to solid cleaning medium and a dry-type cleaning apparatus that achieve higher cleaning efficiency by allowing continuous introduction of objects to be cleaned.
2. Description of the Related Art
Office equipment makers that manufacture copiers, facsimile machines, printers, and the like are actively engaged in recycling activities in which used products and component units are collected from users and then disassembled, cleaned, and assembled again for recycle use as components or as resin material in order to bring about a resource-recycling society. In order to recycle the components used in these products and component units, there is a need for a process that removes fine toner particles attached to the disassembled components and units for the cleaning purpose. The important issue is to reduce the cost and environmental impact associated with such cleaning.
In the case of a wet-type cleaning method that uses water or solvent to remove contaminants such as toner attached to components and units, the need for processing the waste fluid containing toner and energy consumption associated with a drying process after cleaning may lead to a cost increase in terms of environmental measures and energy conservation measures.
In the case of a dry-type cleaning method that uses air blowing forced air, the cleaning power is not high enough to remove highly adhesive toner, so that subsequent process steps are required such as manual wiping. Thus, cleaning is recognized as one of the bottleneck process steps in recycling and reusing the products. In the case of blast cleaning using dry ice, use of a large amount of dry ice may result in high running costs and a significant environmental impact.
As a solution to these problems, Patent Document 1 discloses a dry cleaning apparatus that discharges a charged object to be cleaned through stirring with an elastically deformable contact member in a rotating cylinder so as to lower the adhesion of dust attached to the object, and thus removes the dust from the object.
Patent Document 2 discloses a cleaning method using a dry cleaning medium. In this method, a developer (carrier) used in electrophotographic processes is used as a cleaning medium, and toner particles adhering to the object to be cleaned are removed by being attaching to the cleaning medium, thereby achieving dry cleaning.
Shot blasting techniques as disclosed in Patent Document 3 and Patent Document 4 are also used. The technique disclosed in Patent Document 3 is to remove extraneous substances from an object to be cleaned by blasting stainless microspheres or small stainless pieces onto the object. The technique disclosed in Patent Document 4 is to remove dirt from a resin container by causing granular solids to collide with the surface of a resin container with a high-speed air current.
Patent Document 5 discloses a dry cleaning apparatus. According to Patent Document 5, particulate cleaning media that attract particles are introduced into a vessel to be cleaned, and then a cleaning nozzle is inserted into an opening of the vessel. The cleaning nozzle provides a high-speed air current in the cleaning vessel to propel the cleaning media, which remove particles adhering to the inner surface of the cleaning vessel. The cleaning media collide with a mesh attached to an end of the cleaning nozzle, so that the mesh separates the particles adhering to the cleaning media by filtering and thus regenerates the cleaning media. The air blows up the regenerated median thereby cleaning the vessel repeatedly.
The apparatus of Patent Document 5 performs the process of blowing up the cleaning media and the process of regenerating the cleaning media by suction at the same time.
Further, Patent Documents 6 though 10 disclose blast cleaning techniques that use flexible cleaning media in order to prevent damage to or deformation of objects to be cleaned during cleaning.
Patent Document 11 discloses a cleaning method using thin cleaning media for higher cleaning efficiency.
Patent Document 1: Japanese Patent Registration No. 3288462
Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-122123
Patent Document 3: Japanese Patent Registration No. 2889547
Patent Document 4: Japanese Patent Registration No. 3468995
Patent Document 5: Japanese Patent Laid-Open Publication No. 2005-329292
Patent Document 6: Japanese Patent Laid-Open Publication No. 2004-106100
Patent Document 7: Japanese Patent Laid-Open Publication No. 60-188123
Patent Document 8: Japanese Patent Laid-Open Publication No. 04-059087
Patent Document 9: Japanese Utility Model Registration No. 2515833
Patent Document 10: Japanese Patent Laid-Open Publication No. 07-088446
Patent Document 11: Japanese Patent Laid-Open Publication No. 2007-29945
In the dry cleaning apparatus of Patent Document 1, the impact power of the contact member on the object due to stirring is not high enough to remove highly adhesive dust.
The dry cleaning apparatus of Patent Document 2 needs to improve the cleanliness of the cleaning medium in order to improve the cleaning quality. The centrifugal separation effect of air circulation (cyclone method) is not sufficient for this purpose in terms of separation power. Further, in order to improve cleaning quality, there is a need to replace the cleaning media again and again after the cleaning media attract and hold toner, resulting in cleaning inefficiency and the need for a large amount of cleaning media.
The dry cleaning apparatuses of Patent Document 3 and 4 use metal microspheres, small metal pieces, or granular solids as cleaning media, which scrape and roughen the surface of the objects to be cleaned while removing dirt from the objects, and therefore cannot be used in the case damage to the objects to be cleaned is not allowed.
The dry cleaning apparatus of Patent Document 5 that performs the process of blowing up the cleaning media and the process of regenerating the cleaning media by suction at the same time is effective for cleaning a small vessel. However, in the case of cleaning in a large cleaning tank such as one in which the cleaning media are introduced and moved, the cleaning media do not fly around but stay in the same place because of dispersed energy of flying the cleaning media. Thus the performance of flying and regenerating the cleaning media is lowered, which results in a lower cleaning performance.
The dry cleaning apparatuses of Patent Documents 6 through 10 require long time for cleaning, and have difficulty in removing highly adhesive particles.
In the dry cleaning apparatus of Patent Document 11, the cleaning media adhere to the wall of the cleaning tank, so that the amount of cleaning media available for cleaning is reduced, which results in lower cleaning efficiency. Further, in the step of removing cleaning media from the object after the cleaning process, the cleaning media adhering to the object increase the time required for removal of the cleaning media. Moreover, the cleaning media are often stuck in joints and seams in the object or in joints and seams in the cleaning tank, which also increases the time required for removal of the cleaning media.
In view of the foregoing, the present invention aims to improve cleaning quality and cleaning efficiency by improving the motion speed and degree of cleanliness of a dry cleaning medium. The present invention is directed to provide a cleaning medium for use in dry cleaning that is capable of cleaning a component without damaging the component and without leaving unclean areas even if the component has a complex shape; and a dry cleaning apparatus using the cleaning medium.
The present invention also aims to facilitate removal of the cleaning medium attached to the cleaned component so as to reduce time required for operations associated with the cleaning process.
According to an aspect of the present invention, there is provided a cleaning medium that flies in an air current in a cleaning tank to collide with an object to be cleaned so as to remove an extraneous substance attached to the object. The cleaning medium comprises an outer surface that comes into contact with the object and an inner surface that remains out of contact with the object. The cleaning medium is flexible and formed in a shape that allows the air current to flow from the outside onto the inner surface of the cleaning medium.
According to another aspect of the present invention, there is provided a dry cleaning apparatus that uses the above-described cleaning medium and comprises a circulating air current generating unit to generate a high-speed air current to cause the cleaning medium to fly in a cleaning tank; a cleaning medium accelerating unit to deliver a high-speed air current to cause the flying cleaning medium to collide with an object to be cleaned so as to remove an extraneous substance such as dust or a particle attached to the object; and a cleaning medium regenerating unit to take suction on and remove the extraneous substance attached to the cleaning medium that has collided with the object.
According to still another aspect of the present invention, there is provided a cleaning medium that flies with an air current to collide with an object to be cleaned so as to remove an extraneous substance attached to the object. The cleaning medium comprises a flexible thin piece including an upright portion extending from a flat base portion.
In an embodiment of the present invention, a flexible cleaning medium is caused to fly with an air current in a cleaning tank to collide with an object to be cleaned so as to remove an extraneous substance attached to the object. The collision of the cleaning medium with the object is an inelastic collision, and therefore a single collision can cover a wide contact area. Further, when the impact force upon collision with the object is large, the cleaning medium is bent along the shape of the object. Thus the cleaning medium can clean the object even if the object has a complex shape, resulting in improving the cleaning quality and cleaning efficiency.
Further, when the impact force upon collision with the object is large, the cleaning medium is bent to absorb the energy. Thus the cleaning medium dose not damage the object, thereby achieving stable cleaning, reuse of the object, and contribution to energy saving.
FIGS. 53A through 53C-2 are diagrams showing examples of a cleaning medium according to an embodiment of the present invention;
An air blowing unit that provides the air current to propel the cleaning medium 1 to fly is disposed in a position spaced away from the fixed position of the object 3 by a predetermined distance. Examples of the air blowing unit include a blower, a compressed air source, air tube, an air blowing nozzle, and a spray device. Any method may be used to propel the cleaning medium 1 to fly in the air current 2 provided by the air blowing unit. For example, the cleaning medium 1 may be mixed with the air in advance so as to be blown out with the air current 2. Alternatively, the cleaning medium 1 may be placed at the outlet of the air blowing unit.
Thus a number of cleaning media 1 in the passage of the air current 2 fly with the air current 2. Many of the cleaning media 1 come into contact or collide with the object 3 to scrape off the extraneous substances 4, thereby cleaning the surface of the object 3. Unlike stationary cleaning units such as a brush, wire, and scraper, the cleaning media 1 can move around and enter every corner of the object 3, resulting in an improved cleaning effect.
An air blowing nozzle connected to the compressed air source may be used as the air blowing unit that generates the air current 2 for propelling the cleaning media 1. The use of such an air blowing nozzle makes it possible to provide a high-speed air current 2 and improve the cleaning performance of the cleaning media 1. The higher the speed of the air current 2, the more frequently the cleaning media 1 come into contact with the object 3, resulting in a reduction of time required for cleaning the object 3 and an increase of the cleaning efficiency.
As described above, since the cleaning medium 1 for cleaning the object 3 is flexible and therefore bendable upon contact or collision with the object 3, it is possible to reduce the impact concentration on the object 3 and improve the cleaning efficiency. Further, if the force of the impact on the object 3 is large, the cleaning medium 1 can bend to absorb a shock due to its flexibility as shown in
The use of the tubular cleaning medium 1 can significantly increase the cleaning performance compared with the cleaning media of other shapes. This is because the tubular cleaning medium 1 is superior over the cleaning media of other shapes in terms of the capacity to follow the air current 2 (i.e., the capacity to fly at high speed and the capacity to perform complex motions) and the behavior at the time of contact or collision (e.g., the effect of the edges, sliding contact, bending effect).
In the following, the capacity to follow the air current 2 is described. The flexible tubular cleaning medium 1 flies at high speed when receiving the force of an air current in the direction in which its projected area is large. This is because its weight is extremely small with respect to the air force. Further, the flexible tubular cleaning medium 1 has a small air resistance in the direction in which its projected area is small. When flying in such a direction, high-speed motion can be maintained for a long distance. The higher the speed of the cleaning medium 1, the greater the energy of the cleaning medium 1, resulting in a larger force being applied to the object 3 upon contact and a higher cleaning quality. Further, the higher the speed of the cleaning medium 1, the greater the frequency of contact with the object 3, resulting in improved cleaning efficiency. Moreover, because the air resistance of the flexible tubular cleaning medium 1 varies significantly depending on its orientation, the flexible tubular cleaning medium 1 can not only move along with the air current 2 but also perform complex motions such as a sudden change in the flight direction. Due to the effect of the high-speed air current 2, air turbulence is generated around the object 3. Further, the flexible tubular cleaning media 1, which are rather susceptible to air resistance for their weights, rotate around themselves and revolve due to the eddies of the air turbulence to contact the object 3 repeatedly. Therefore the cleaning media 1 can provide high cleaning performance and high cleaning efficiency even when the object 3 has a relatively complex shape.
In the following, behavior upon contact or collision is described. When the flexible tubular cleaning medium 1 collides at its end first as shown in
On the other hand, typical shot material or elastic sponge material is likely to bounce back upon collision, which means that the contact efficiency with the object 3 upon collision is not as high as that of the flexible tubular cleaning medium 1. Further, in the case of the flexible tubular cleaning medium 1, its wiping motion and scraping motion associated with the sliding contact at the time of contact or collision tend to exert a force on the extraneous substances 4 in the direction parallel to the contact surface. It is known that, in general, a small force can remove the extraneous substances 4 if the force is applied in the direction parallel to the surface on which the extraneous substances 4 are attached rather than if the force is applied in the direction perpendicular to the surface on which the extraneous substances 4 are attached. Conventional granular sponge and granular foam are deformable due to their flexibilities and therefore can have a greater contact area with the object 3 upon collision, but are likely to bounce back or roll over and fail to provide wiping motion and scraping motion associated with sliding contact. Therefore, shear force for removing the extraneous substances 4 is not produced, which makes the cleaning performance of the granular sponge and the granular foam for highly adhesive extraneous substances 4 lower than that of the flexible tubular cleaning medium 1.
What is described above are believed to be the reasons why the flexible tubular cleaning media 1 exhibit higher cleaning performance and higher cleaning efficiency with respect to components of relatively complex shapes compared with the cleaning media of other shapes. These are outstanding features that are not provided by the conventional blast shot materials, barreling media materials, granular sponge, or granular foam.
The shape suitable for the flexible tubular cleaning medium 1 may be of a lateral area of 1 through 1000 mm2 and a tube wall thickness of 1 to 500 μm. Examples of the material suitable for cleaning medium 1 include a resin tube, a thermoplastic elastomer tube, a rubber tube, a cloth tube, a paper tube, and a metal tube. However, without being limited thereto, as mentioned above, the material, weight, size, shape, etc., of the cleaning medium 1 may be determined according to the properties of the object 3 (e.g., shape and material) and the properties of the extraneous substances 4 on the object 3 (e.g., the particle size and adhesion force).
Although various flexible materials may be used as the cleaning medium 1, the Young's modulus according to ASTM D882 of the materials may preferably be 4 GPa or less in terms of enhancing the cleaning efficiency due to inelastic collision resulting from bending motion. In terms of overcoming the resistance during wiping motion resulting from sliding contact, the Young's modulus may preferably be 0.2 GPa or greater. For example, the use of general resin proves flexibility and durability, ensuring that the cleaning medium 1 can be used repeatedly for a long time without damaging the object 3. The use of polyethylene is cost-effective, allowing cost reduction. In the case where plural types of extraneous substances 4 are present on the object 3, plural materials may used for cleaning the plural types of extraneous substances 4. For example, a resin tube is not suitable for adsorbing and removing greasy dirt, but is easily regenerated by dry cleaning because of its low adsorption performance. On the other hand, cloth is suitable for adsorbing and removing greasy dirt, but is not easily regenerated by dry cleaning and cannot withstand repeated use. Especially in the case of repeatedly using the cleaning medium 1, because mechanical strength is required, resin and metal materials are advantageous over paper and cloth materials. Metal materials are plastically deformed by repetitive application of strains, and therefore compounds of micro polymers linked or connected together such as resin tubes, thermoplastic elastomer tubes, and rubber tubes are advantageous over the metal materials. Especially, resin tubes are more likely to cause inelastic collision with the object 3 compared with thermoplastic elastomer tubes and rubber tubes and are therefore advantageous in terms of the cleaning efficiency. As can be understood from the above, because the performance of cleaning the object 3 varies depending on the material, the total cleaning performance can be enhanced by using cleaning media 1 made of various different materials.
One problem with the cleaning medium 1 configured to fly with the air current 2 is that the cleaning medium 1 is charged due to friction with the wall of a cleaning tank, the object 3 to be cleaned, or other cleaning media 1 during cleaning. Especially, when the cleaning medium 1 is flying at higher speed for reducing cleaning time, more friction is produced, so that the amount of charge is increased in a short time. As a result, the cleaning media 1 are often attached to the wall of the cleaning tank or the object 3 to be cleaned due to the electrostatic effect. Especially in the case of flexible plate-shape cleaning media 1p, the shapes of the cleaning media 1p can follow the shape of the object 3 in contact therewith, and the cleaning media 1p can come into tight contact with the wall of the cleaning tank or the surface of the object 3 as shown in
With reference to
The amount of the cleaning media 1p available for cleaning in the cleaning process is therefore reduced, which results in lower cleaning efficiency and longer cleaning time. Moreover, in the process of removing the cleaning media 1p from the cleaned object 3, more time is required to remove the cleaning media 1p.
To solve these problems, the tubular cleaning medium 1 is used. Since the air current can flow onto the inner surface of the cleaning medium 1, the cleaning medium can fly again with the air current that has flowed onto the inner surface of the cleaning medium 1 even if the cleaning medium 1 is attached to or stuck in the object 3 to be cleaned or the cleaning tank as described above.
More specifically, in the cleaning process, even if the tubular cleaning medium 1 is attached to the cleaning tank (or the object 3 as shown in
Even if the tubular cleaning medium 1 is stuck in a gap 5 as shown in
Further, in the process of removing the cleaning medium 1 from the cleaned object 3, when an air current is generated to flow onto the inner surface of the tubular cleaning medium 1 and the force of the air current separating the cleaning medium 1 from the surface of the object 3 is greater than the electrostatic attraction force, the cleaning medium 1 is separated from object 3 and thus can be easily removed. A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium 1 in contact with the object 3 so as to discharge the cleaning medium 1, thereby enhancing the effect of removing the cleaning medium 1.
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media 1 that contribute to cleaning and to allow new contact of the cleaning media 1 with the object 3 due to prevention of accumulation of the cleaning media 1 in the gaps in the object 3, thereby maintaining a constant cleaning efficiency. Further, in the process of removing the cleaning media 1 from the cleaned object 3, when an air current is generated to flow into the cleaning medium 1 and hit the cleaning medium 1 the cleaning medium 1 flies again and thus can easily be removed.
To facilitate the repeated flight of the cleaning medium 1, the width of the cleaning medium 1 is not especially limited as long as it is greater than the widths and depths of the gaps at the joints and seams in the object 3 and the joints and seams of the cleaning tank. The cleaning medium 1 may be produced by cutting a tube into a segment of a predetermined length.
The tubular cleaning medium 1 may have any shape as long as it provides flexibility. Examples of the shape of the tubular cleaning medium 1 include, in addition to the cylindrical shape as shown in
In an embodiment, as shown in
In an embodiment, as shown in
In an embodiment, as shown in
In an embodiment, as shown in
Although the embodiments described above are directed to the case where the tubular cleaning media 1 are used for removing the extraneous substances 4 attached to the object 3, a cleaning medium 1a formed in the shape of a bag having an opening at one end may be used for removing the extraneous substances 4 attached to the object 3.
An air blowing unit that provides the air current to propel the cleaning medium 1a is disposed in a position spaced away from the fixed position of the object 3 by a predetermined distance. Examples of the air blowing unit include a blower, a compressed air source, air tube, an air blowing nozzle, a spray device. Any method may be used to propel the cleaning medium 1a with the air current 2 provided by the air blowing unit. For example, the cleaning medium 1a may be mixed with the air in advance so as to be blown out with the air current 2. Alternatively, the cleaning medium 1a may be placed at the outlet of the air blowing unit.
Thus a number of cleaning media 1a in the passage of the air current 2 fly with the air current 2. Many of the cleaning media 1a come into contact with or collide with the object 3 to scrape off the extraneous substances 4, thereby cleaning the surface of the object 3. Unlike stationary cleaning units such as a brush, wire, and scraper, the cleaning media 1a can move around and enter every corner of the object 3, resulting in improved cleaning effect.
An air blowing nozzle connected to the compressed air source may be used as the air blowing unit that generates the air current 2 for flying the cleaning media 1a. The user of such an air blowing nozzle makes it possible to provide a high-speed air current 2 and improve the cleaning performance of the cleaning media 1a. The higher the speed of the air current 2, the more frequently the cleaning media 1a come into contact with the object 3, resulting in a reduction of time required for cleaning the object 3 and an increase of the cleaning efficiency.
As described above, since the cleaning medium 1a for cleaning the object 3 is flexible and therefore bendable upon contact or collision with the object 3, it is possible to reduce the impact concentration on the object 3 and improve the cleaning efficiency. Further, if the force of the impact on the object 3 is large, the cleaning medium 1a can bend to absorb a shock due to its flexibility as shown in
The use of the bag-shaped cleaning medium 1a can significantly increase the cleaning performance compared with the cleaning media of other shapes. This is because the bag-shaped cleaning medium 1a is superior over the cleaning media of other shapes in terms of the capacity to follow the air current 2 (i.e., the capacity to fly at high speed and the capacity to perform complex motions) and the behavior at the time of contact or collision (e.g., the effect of the edges, sliding contact, bending effect).
In the following, the capacity to follow the air current 2 is described. The flexible bag-shaped cleaning medium 1a flies at high speed when receiving the force of an air current from the open end side. When flying in such a condition, high-speed motion can be maintained for a long distance. The higher the speed of the cleaning medium 1a, the greater the energy of the cleaning medium 1a, resulting in a larger force being applied to the object 3 upon contact and higher cleaning quality. Further, the higher the speed of the cleaning medium 1a, the greater the frequency of contact with the object 3, resulting in improved cleaning efficiency. Moreover, because the air resistance of the flexible bag-shaped cleaning medium 1a varies significantly depending on its orientation, the flexible bag-shaped cleaning medium 1a can not only move along with the air current 2 but also perform complex motions such as a sudden change in the flight direction. Due to the effect of the high-speed air current 2, air turbulence is generated around the object 3. Further, the flexible bag-shaped cleaning media 1a rotate around themselves and revolve due to the eddies of the air turbulence to come into contact with the object 3 repeatedly. Therefore the cleaning media 1a can provide high cleaning performance and high cleaning efficiency even when the object 3 has a relatively complex shape.
In the following, behavior upon contact or collision is described. When the flexible bag-shaped cleaning medium 1a collides at its end first as shown in
Further, in the case of the flexible bag-shaped cleaning medium 1a, its wiping motion and scraping motion associated with the sliding contact at the time of contact or collision tend to exert a force on the extraneous substances 4 in the direction parallel to the contact surface.
What is described above are believed to be the reasons why the flexible bag-shaped cleaning media 1a exhibit higher cleaning performance and higher cleaning efficiency with respect to components of relatively complex shapes compared with the cleaning media of other shapes. These are outstanding features that are not provided by the conventional blast shot materials, barreling media materials, granular sponge, or granular foam.
The shape suitable for the flexible bag-shaped cleaning medium 1a may be of a lateral area of 1 through 1000 mm2 and a tube wall thickness of 1 to 500 μm. Examples of the material suitable for the cleaning medium 1a include a resin tube, a thermoplastic elastomer tube, a rubber tube, a cloth tube, a paper tube, and a metal tube. However, without being limited thereto, as mentioned above, the material, weight, size, shape, etc., of the cleaning medium 1a may be determined according to the properties of the object 3 (e.g., shape and material) and the properties of the extraneous substances 4 on the object 3 (e.g., the particle size and adhesion force).
Although various flexible materials may be used as the cleaning medium 1a, the Young's modulus according to ASTM D882 of the materials may preferably be 4 GPa or less in terms of enhancing the cleaning efficiency due to inelastic collision resulting from bending motion. In terms of overcoming the resistance during wiping motion resulting from sliding contact, the Young's modulus may preferably be 0.2 GPa or greater. For example, the use of general resin proves flexibility and durability, ensuring that the cleaning medium 1 can be used repeatedly for a long time without damaging the object 3. The use of polyethylene is cost-effective, allowing cost reduction. In the case where plural types of extraneous substances 4 are present on the object 3, plural materials may be used for cleaning the plural types of extraneous substances 4. For example, a resin tube is not suitable for adsorbing and removing greasy dirt, but is easily regenerated by dry cleaning because of its low adsorption performance. On the other hand, cloth is suitable for adsorbing and removing greasy dirt, but is not easily regenerated by dry cleaning and cannot withstand repeated use. Especially in the case of repeatedly using the cleaning medium 1a, because mechanical strength is required, resin and metal materials are advantageous over paper and cloth materials. Metal materials are plastically deformed by repetitive application of strains, and therefore compounds of micro polymers linked or connected together such as resin tubes, thermoplastic elastomer tubes, and rubber tubes are advantageous over the metal materials. Especially, resin tubes are more likely to cause inelastic collision with the object 3 compared with thermoplastic elastomer tubes and rubber tubes and are therefore advantageous in terms of the cleaning efficiency. As can be understood from the above, because the performance of cleaning the object 3 varies depending on the material, the total cleaning performance can be enhanced by using cleaning media 1a made of various different materials.
In the cleaning process, even if the bag-shaped cleaning media 1a are attached to the cleaning tank (or the object 3 as shown in
Even if the bag-shaped cleaning medium 1a is stuck in a gap 5 as shown in
Further, in the process of removing the cleaning medium 1a from the cleaned object 3, when an air current is generated to flow into the bag-shaped cleaning medium 1a and the force of the air current separating the cleaning medium 1a from the surface of the object 3 is greater than the electrostatic attraction force, the cleaning medium 1a is separated from object 3 and thus can be easily removed. A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium 1a in contact with the object 3 so as to discharge the cleaning medium 1a, thereby enhancing the effect of removing the cleaning medium 1a.
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media 1a that contribute to cleaning and to allow new contact of the cleaning media 1a with the object 3 due to prevention of accumulation of the cleaning media 1a in the gaps in the object 3, thereby maintaining a constant cleaning efficiency. Further, in the process of removing the cleaning media 1a from the cleaned object 3, when an air current is generated to flow into the cleaning medium 1a and hit the cleaning medium 1a, the cleaning medium 1a flies again and thus can easily be removed.
To facilitate the repeated flight of the cleaning medium 1a, the width of the cleaning medium 1a is not especially limited as long as it is greater than the widths and depths of the gaps at the joints and seams in the object 3 and the joints and seams of the cleaning tank. This cleaning medium 1a may be produced by, for example as shown in
The bag-shaped cleaning medium 1a may have any shape as long as it provides flexibility. Examples of the shape of the bag-shaped cleaning medium 1a include, in addition to the conical shape as shown in
In an embodiment, as shown in
Each of the cleaning media 1 and 1a may preferably be made of or include an antistatic material. To achieve effective antistatic performance, the surface resistance of the cleaning medium 1 (1a) may preferably be 1010 Ω/sq. or less. In the case where the cleaning medium 1 (1a) is made of metal, the cleaning medium 1 (1a) itself is antistatic. In the case where the cleaning medium 1 (1a) is made of resin, any of the following types of antistatic techniques may be used, which are generally classified into three categories, namely, a kneading type, a coating type, a combination of the these two types.
The kneading type is for kneading an antistatic agent into resin in advance. The kneading type is subdivided into a non-stretching type, a biaxial stretching type, and an inflation type. In the case of utilizing ion conduction, examples of an antistatic agent include surfactants (anion surfactant, cationic surfactant, nonionic surfactant, ampholytic surfactant) and hydrophilic macromolecules, which are well known in the art. In the case of utilizing electron conduction, metal particles, conductive particles (conductive carbon, oxide semiconductor, etc.) conductive polymer that are well known in the art can be used as a conductive filler. The coating type is for coating the surface of the cleaning medium 1 (1a) with an antistatic agent, thereby forming a layer that provides an antistatic effect. The antistatic agent that can be used is one suitable for coating, which may be selected from aqueous, oily, organic, inorganic, and polymeric antistatic agents that are well known in the art. The layer is generally of submicron thickness, but may be 0.1 μm or less to exert the effect.
The use of this cleaning medium 1 (1a) can prevent increase of charges due to friction and can reduce the electrostatic effect of the cleaning medium 1 (1a) being attracted to the wall of the cleaning tank or the object 3 to be cleaned. Thus, the cleaning medium 1 (1a) can be separated from the wall of the cleaning tank or the object 3 with reduced air current 2, which allows downsizing of the air current generation equipment and leads to reduction of energy consumption. A corona discharging unit may be used in conjunction to improve the effect of making the cleaning media 1 and 1a fly repeatedly.
At least a part of the inner surface of the cleaning medium 1 (1a) may be covered with a ferromagnetic material. For example, a mixture of magnetic powder (e.g., y iron oxide and cobalt doped ion oxide) and synthetic resin serving as a binder may be applied to the inner surface of the cleaning medium 1 (1a). Alternatively, cobalt is deposited on the outer surface of the cleaning medium 1 (1a), and then the cleaning medium 1 (1a) is turned inside out. Other magnetically-attractable materials that can be formed into a film may be used as the ferromagnetic material for covering the inner surface. In the case of the cleaning medium 1 (1a) of this configuration, a magnetic force generated by a magnetic force generating unit can exert a force that separates the cleaning medium 1 (1a) from the wall of the cleaning tank or the object 3. Further, in the process of removing the cleaning media 1 from the cleaned object 3, even if the cleaning medium 1 (1a) is attached to the object 3 or stuck in a gap in the object 3, when the magnetic force generated by the magnetic force generating unit such as a permanent magnet and an electromagnet together with the force of the air current that has flowed into the cleaning medium 1 (1a) for separating the cleaning medium 1 (1a) from the object 3 are greater than the electrostatic attraction force, the cleaning medium 1 (1a) is separated from the wall of the cleaning tank and thus can fly again. Thus, the cleaning medium 1 (1a) can be separated from the wall of the cleaning tank or the object 3 with reduced air current 2, which allows downsizing of the air current generation equipment and leads to reduction of energy consumption. A corona discharging unit may be used in conjunction to improve the effect of making the cleaning media 1 (1a) fly repeatedly. It is to be noted that the magnetic material on the inner surface of the cleaning medium 1 (1a) does not come into direct contact with the object 3, which prevents the object 3 from being contaminated with the magnetic material.
At least a part of the inner surface of the cleaning medium 1 (1a) may be covered with a luminescent material or a light reflection material. In this case, the cleaning medium 1 (1a) may be made of a material that can transmit the light from the luminescent material or the light reflection material. For example, if a light storing material is used to cover at least a part of the inner surface of the cleaning medium 1 (1a), the pigment may be subjected to ultraviolet radiation before the cleaning process such that the cleaning medium 1 (1a) can emit light. Thus, the cleaning medium 1 (1a) remaining on the object 3 can be quickly determined through detection of the light from the cleaning medium 1 (1a). Further, the lights of the cleaning media 1 (1a) are blocked by the extraneous substances 4 such as toner, so that the amount of light detected by a light detecting unit varies. Therefore, it is possible to determine the dirtiness of the cleaning media 1 (1a) and the progress of the cleaning process based on the degree of the change in the amount of the light of the cleaning media 1 (1a) between before and after the cleaning. If a fluorescent material is used to cover at least a part of the inner surface of the cleaning medium 1 (1a), ultraviolet radiation is performed upon light detection so as to detect a visible light, thereby determining the dirtiness of the cleaning media 1 (1a) and the progress of the cleaning process. If a light reflection material is used to cover at least a part of the inner surface of the cleaning medium 1 (1a), radiation of light is performed upon light detection so as to detect a reflection light, thereby determining the dirtiness of the cleaning media 1 (1a) and the progress of the cleaning process. It is to be noted that the luminescent material or the light reflection material on the inner surface of the cleaning medium 1 (1a) does not come into direct contact with the object 3, which prevents the object 3 from being contaminated with the luminescent material or the light reflection material.
In the following, a dry cleaning apparatus 11 that uses the cleaning medium 1 or the cleaning media 1a (hereinafter referred to as the cleaning medium 1) is described.
The cleaning tank 12 has a box shape for accommodating the object 3 to be cleaned and the cleaning media 1 (neither shown), and includes a lid 12a, which is opened and closed for placement and removal of the object 3. To make the cleaning media 1 fly easily with air currents from the Type 1 nozzles 14 having a function of propelling and dispersing the cleaning media 1, it is preferable to eliminate right angle corners and acute angle corners at the joints between a bottom surface 12b and walls 12c as shown in
An outlet port 12e for ejecting the extraneous substances 4, which has been removed from the object 3, from the cleaning tank 12 is provided in one of walls 12c. The outlet port 12e is connected to a filter and a dust collector (neither shown). The outlet port 12e is provided with a cylindrical mesh 13 that prevents the cleaning media 1 from being ejected from the cleaning tank 12. The cylindrical mesh 13 may be made of a metal net or the like that have a number of openings sized to allow the extraneous substances 4 such as dust removed from the object 3 to pass through but not the cleaning media 1. The mesh 13 may be preferably one that has little air resistance and to which the extraneous substances 4 are not easily attached. When the cleaning media 1 are attracted to and come into contact with the cylindrical mesh 13, the extraneous substances 4 such as dust attached to the cleaning media 1 are scraped off or beaten off to be separated from the cleaning media 1. Then the extraneous substances 4 pass through the cylindrical mesh 13 to be ejected from the outlet port 12e to the outside of the cleaning tank 12.
The Type 1 nozzles 14 provide a function of preventing clogging of the mesh 13 as well as the function of making the cleaning media 1 fly and scatter. More specifically, each nozzle 14 is formed of an air blowing nozzle that has a large number of small holes aligned in the axial direction of the hollow cylinder so as to make the cleaning media 1 fly and scatter in the cleaning tank 12. The nozzle 14 includes a nozzle position and orientation changing unit and is configured to be driven by a motor (not shown) so as to rotate or swing reciprocally during the cleaning operation. When the nozzles 14 are provided with compressed air through the rotating joints and rotated in the direction indicated by the arrows A of
The Type 2 nozzles 16 provide a function of accelerating the cleaning media 1 as well as the function of making the cleaning media 1 fly and scatter. A large number of Type 2 nozzles 16 are provided inside the cleaning tank 12 so as to accelerate the cleaning media 1 flying inside the cleaning tank 12 toward the object 3 to be cleaned. Although general purpose air blowing nozzles can be used as the nozzles 16, injection nozzles utilizing the Coanda effect are preferably used in order to reduce air consumption by a large number of the nozzles 16. The air nozzles utilizing the Coanda effect can generate the air current of a volume of a few times through twenty times the volume of the consumed air, and therefore can accelerate a large number of the cleaning media 1 with little air consumption. Various types of injection nozzles utilizing the Coanda effect have been known.
To change the positions and orientations of the Type 2 nozzles 16, the nozzles 16 disposed on the bottom surface 12b and the walls 12c of the cleaning tank 12 as shown in
The work holding unit 19 includes, e.g., five work holders 19a on a rotating shaft 19b for holding the object 3 to be cleaned. The work holding unit 19 is held by a rotatable hollow shaft 29 and is rotated in a horizontal plane by a rotary torque of the work horizontally-rotating motor 20, which is attached to the bottom surface 12b of the cleaning tank 12, transmitted through the timing belt 22 to the hollow shaft 29. A torque of the work swing motor 21 is transmitted through the timing belt 23 to a coaxial shaft 30 inside the hollow shaft 29, and then swings the work holders 19a as indicated by the arrow D of
The following describes the cleaning operation performed by the dry cleaning apparatus 11 for removing the extraneous substances 4 from the object 3 using the cleaning media 1 in the order of steps. Step of flying, scattering, accelerating and bringing into collision the cleaning media
(1) The cleaning media 1 are placed into the cleaning tank 12. The object 3 is held by the work holding unit 19, and the lid 12a of the cleaning tank 12 is closed. Then, compressed air is supplied to the nozzles 14 and the nozzles 16 facing the bottom surface 12b of the cleaning tank 12 such that the cleaning media 1 on the bottom surface 12b are blown up along the bottom surface 12b and the walls 12c of the cleaning tank 12 to fly and scatter.
(2) As illustrated in
(3) The nozzle 16 facing the object 3 is oscillated or reciprocally moved for varying its position and orientation (blowing direction), thereby uniformly cleaning the entire surface of the object 3. Since the position or the orientation (the blowing position or the blowing direction) of the nozzle 16 is changed, the nozzle 16 can provides both the function of propelling and scattering the cleaning media 1 and the function of accelerating and bringing into collision the cleaning media 1.
(4) The work holding unit 19 is horizontally rotated and swung for varying the positional relationship between the nozzle 16 and the object 3, thereby causing the cleaning media 1 to uniformly come into contact or collide with the entire surface of the object 3.
Step of cleaning with contact by the cleaning media
(5) The cleaning media 1 come into contact or collide with the object 3 to be cleaned at high speed, thereby beating off the extraneous substances 4 attached to the object 3. The extraneous substances 4 that have been beaten off enter the cylindrical mesh 13, are carried inside the cylindrical mesh 13 by the air current flowing toward the outlet port 12e, and are ejected from the cleaning tank 12.
(6) Due to the contact or collision of the cleaning media 1 with the object 3 to be cleaned, some of the extraneous substances 4 on the object 3 are attached to the cleaning media 1. These cleaning media 1 are carried toward the cylindrical mesh 13 by the air current flowing toward the outlet port 12e.
Step of removing the dust attached to the cleaning media
(7) The cleaning media 1 that have been carried toward the cylindrical mesh 13 come into contact or collide with the mesh 13, so that the extraneous substances 4 attached to the cleaning media 1 are separated from the cleaning media 1 and are ejected from the cleaning tank 12. A discharging unit (e.g. an ionizer for generating ionized air) may be provided in the vicinity of the mesh 13. If the cleaning media 1 are discharged by the discharging unit, an electrostatic attraction force between the cleaning media 1 and the extraneous substances 4 is weakened, resulting in an easier separation of the extraneous substances 4.
(8) The cleaning media 1 that have been attached to the mesh 13 due to the suction force of the outlet port 12e are made to fly again inside the cleaning tank 12 due to the rotation of the nozzles 14.
The steps described above are repeated, so that the cleaning media 1 circulate inside the cleaning tank 12, thereby efficiently removing the extraneous substances 4 from the object 3. Even if the dust is relatively highly adhesive and is thus hard to be removed by relying only on an air blower, the contact or collision of the cleaning media 1 flying at high speed makes it possible to remove the dust from the object 3. Further, the cylindrical mesh 13 effectively removes the extraneous substances 4 attached to the cleaning media 1 so as to maintain a high degree of cleanliness of the cleaning media 1. This prevents the extraneous substances 4 attached to the cleaning media 1 from adhering to the object 3 again, thereby achieving high quality cleaning.
The step (1) and the step (2) may be performed either alternately or simultaneously. In the case where the step (1) and the step (2) are performed simultaneously, because the compressed air is not used at the same time for propelling and scattering the cleaning media 1 and for accelerating the cleaning media 1, a sufficient effect of propelling and scattering the cleaning media 1 and a sufficient effect of accelerating the cleaning media 1 can be obtained even if the capacity of supplying compressed air is limited. If the capacity of supplying compressed air is high enough, the step of propelling and scattering the cleaning media 1 and the step of accelerating the cleaning media 1 may be performed simultaneously. Thus a large amount of the cleaning media 1 can be easily supplied, thereby making it possible to uniformly clean the object 3 in a shorter time.
One problem which might occur during cleaning using the flying cleaning media 1 is that the cleaning medium 1 may be charged due to friction with the walls 12c of the cleaning tank 12, the object 3 to be cleaned, or other cleaning media 1. Especially, when the cleaning medium 1 is flying at higher speed for reducing cleaning time, more friction is produced, so that the amount of charge is increased in a short time. As a result, the cleaning media 1 are attached to the walls 12c of the cleaning tank 12 or the object 3 to be cleaned due to the electrostatic effect. Especially in the case of the cleaning media 1 that provide flexibility, the shapes of the cleaning media 1 can follow the shape of an object in contact therewith, and the cleaning media 1 can come into tight contact with the walls 12c of the cleaning tank 12 or the surface of the object 3 to be cleaned. Once the cleaning media 1 are in tight contact with the walls 12c of the cleaning tank 12 or the surface of the object 3, the space where the air current can enter is reduced between the cleaning media 1 and the walls 12c of the cleaning tank 12 or the surface of the object 3. This makes it difficult to discharge the cleaning media 1 using a corona discharging unit, because ions cannot enter the space between the cleaning media 1 and the walls 12c of the cleaning tank 12 or the surface of the object 3. As a result, the cleaning media 1 remain attached to the walls 12c of the cleaning tank 12 or the surface of the object 3. The amount of the cleaning media 1 available for cleaning in the cleaning process is therefore reduced, which results in lower cleaning efficiency and longer cleaning time. Moreover, in the process of removing the cleaning media 1 from the object 3 after the cleaning process, more time is required to remove the cleaning media 1. With use of one of the cleaning media 1 shown in
The work holding unit 19 is horizontally rotated, and the work holders 19a holding the object 3 is swung. Further, the nozzles 16 facing the object 3 are oscillated or reciprocally moved for varying their positions and orientations (blowing directions). This makes it possible to cause the cleaning media 1 to come into contact with or collide with the entire surface of the object 3 from various directions, thereby uniformly cleaning the object 3 in a shorter time even if the object 3 has a complex shape. Optionally, the work holding unit 19 holding the object 3 may be slowly moved up and down.
Although the nozzles 16 described above are configured to be rotated or moved, a large number of nozzles 16 with different blowing directions and positions may alternatively be provided. A selective use of such nozzles 16′ can provide the same effect as in the case of rotating and moving the nozzles 16.
The following describes a second dry cleaning apparatus 11a using the flexible cleaning medium 1. Referring to
The cleaning tank 41 is a hollow structure of substantially rectangular shape. The cleaning tank 41 includes an object inlet 45 in the top surface through which the object 3 to be cleaned is placed and has an opening in the bottom. The cleaning tank 41 is provided with a lid 46 that opens and closes the object inlet 45. The cleaning medium regenerating unit 44 is disposed at the bottom opening of the cleaning tank 41. A circulating air current generating unit 42 is provided on the inner surface of one of the side walls of the cleaning tank 41 as shown in
Although general purpose air blowing nozzles can be used as the nozzles 16, injection nozzles utilizing the Coanda effect such as one shown in
Referring to
Referring to the perspective view of
Referring to the block diagrams of FIG. 29, 30A and 30B, a control unit 50 of the dry cleaning apparatus 11 is connected to each of an air current circulating electromagnet valve 52 that opens and closes an air pipe of the compressed air to be supplied from a compressed gas supply unit 56 to the circulating air current generating unit 42; an accelerating electromagnet valve 53 that opens and closes an air pipe of the compressed air to be supplied to the cleaning medium accelerating unit 43; an accelerated air current switching control valve 54 that switches the destination of the compressed air between the accelerating nozzles 431a and 431b provided on the opposing surfaces of the cleaning medium accelerating unit 43; and a regenerating electromagnet valve 55 that opens and closes the suction duct 47 connecting the cleaning medium regenerating unit 44 and a dust collecting unit 57. The control unit 50 controls the operations of each electromagnet valve according to drive signals provided from an activating unit 51.
In the dry cleaning apparatus 11a, the object 3 held by a work holding unit 48 is placed into the cleaning tank 41 by a work transport unit 49. Then the extraneous substances 4 such as toner attached to the object 3 are removed by circulating the flexible cleaning media 1 in the cleaning tank 41. These operations are described below with reference to the time chart of
The flexible cleaning media 1 are placed into the cleaning tank 41 and accumulated on the separating member 441 of the cleaning medium regenerating unit 44. Then the object 3 being held by the work holding unit 48 is placed into the cleaning tank 41 through the object inlet 45 and positioned in the initial position by the work transport unit 49. The lid 46 of the object inlet 45 is closed, so that the cleaning tank 41 is sealed. Then the activating unit 51 is operated to input a cleaning start signal to the control unit 50. The control unit 50 first opens the air current circulating electromagnet valve 52 to supply, e.g., compressed air from the compressed gas supply unit 56 such as a compressor to the circulating air current generating unit 42, so that the circulating air current generating unit 42 generates a circulating air current that flows along the circulation path formed by the inner surfaces of the cleaning tank 41. The circulating air current flows along the separating member 441 of the cleaning medium regenerating unit 44; hits the flexible tubular cleaning media 1 accumulated on the separating member 441 from the lateral direction as shown in
One problem which might occur during cleaning is that the cleaning medium 1 may be charged due to friction with the wall of the cleaning tank 41, the object 3 to be cleaned, or other cleaning media 1. Especially, when the cleaning medium 1 is flying at higher speed for reducing cleaning time, more friction is produced, so that the amount of charge is increased in a short time. As a result, the cleaning media 1 are attached to the wall of the cleaning tank 41 or the object 3 to be cleaned due to the electrostatic effect. Especially in the case of the cleaning media 1 that provide flexibility, the shapes of the cleaning media 1 can follow the shape of an object in contact therewith, and the cleaning media 1 can come into tight contact with the wall of the cleaning tank 41 or the surface of the object 3 to be cleaned. Once the cleaning media 1 are in tight contact with the wall of the cleaning tank 41 or the object 3, the space where the air current can enter is reduced between the cleaning media 1 and the walls 12c of the cleaning tank 41 or the surface of the object 3. This makes it difficult to discharge the cleaning media 1 using a corona discharging unit, because ions cannot enter the space between the cleaning media 1 and the wall of the cleaning tank 41 or the surface of the object 3. As a result, the cleaning media 1 remain attached to the wall of the cleaning tank 41 or the object 3. The amount of the cleaning media 1 available for cleaning in the cleaning process is therefore reduced, which results in lower cleaning efficiency and longer cleaning time. Moreover, in the process of removing the cleaning media 1 from the object 3 after the cleaning process, more time is required to remove the cleaning media 1. With use of one of the cleaning media 1 shown in
In the case of making the accumulated flexible cleaning media 1 fly by carrying the cleaning media 1 with an air current, if, for example as shown in
The circulating air current generating unit 42 for generating the circulating air current is disposed with its suction port facing upward and its ejection port facing downward on one of the side walls of the cleaning tank 41, which side walls form the circulation path of the circulating air current, in the vicinity of the bottom surface. Therefore, it is possible to apply a great force of the air current along the bottom surface to the cleaning media 1 accumulated on the separating member 441 at the bottom of the cleaning tank 41 even if the cleaning media 1 are spaced apart from the ejection port, and thus to carry a large amount of the cleaning media 1 along the wall of the cleaning tank 41. Further, the cleaning media 1 coming into the suction port are dispersed and have a low space density, and therefore do not clog the suction port. Thus the circulating air current generating unit 42 can stably generate the circulating air current. That is, if the circulating air current generating unit 42 is disposed with its suction port facing downward in the vicinity of the bottom surface of the cleaning tank 41, it is difficult to carry a large amount of the cleaning media 1 accumulated at the bottom of the cleaning tank 41. Further, if a large amount of the accumulated cleaning media 1 is suctioned from the suction port, the space density of the cleaning media 1 at the suction port is increased, resulting in clogging the suction port. Disposing the circulating air current generating unit 42 with its suction port facing upward can prevent these problems.
When a predetermined time has elapsed, the control unit 50 closes the air current circulating electromagnet valve 52 to stop generation of the circulating air current by the circulating air current generating unit 42. Then, as shown in
The dust removed from the object 3 and the cleaning media 1, to which the dust is attached as a result of collision with the object 3, fall due to the gravity onto separating member 441 of the cleaning medium regenerating unit 44 that provides suction due to the negative pressure inside the hood 442. The dust that have fallen together with or without the cleaning media 1 on the separating member 441 is suctioned into the food 442 due to the negative pressure inside the hood 442 and collected by the dust collecting unit 57. Thus the cleaning media 1 to which the dust had been attached are efficiently regenerated.
After performing the injection of compressed air by the accelerating nozzles 431a for a predetermined time period, the control unit 50 closes the accelerating electromagnet valve 53 and the regenerating electromagnet valve 55 to stop operations of the cleaning medium accelerating unit 43 and the cleaning medium regenerating unit 44. When the regenerating electromagnet valve 55 is closed, the negative pressure inside the hood 442 is lost. Thus the force of suctioning the cleaning media 1 toward the hood 442 is lost, so that the cleaning media 1 are carried away from the separating member 441 by the circulating air current to come. It is thus possible to continuously separate the dust from the cleaning media 1 while preventing the cleaning media 1 from covering and sealing the mesh or the like of the separating member 441. There is therefore no need to replace the cleaning media 1. If the cleaning media 1 are broken and thus the amount of the cleaning media 1 is reduced, new cleaning media 1 may be added. In this way, it is possible to efficiently use the cleaning media 1 and facilitate maintenance work.
After that, control unit 50 opens the air current circulating electromagnet valve 52 again to cause the circulating air current generating unit 42 to generate a circulating air current, thereby causing the regenerated cleaning media 1 on the separating member 441 of the cleaning medium regenerating unit 44 to fly for a predetermined time period T1. Then the control unit 50 opens the accelerating electromagnet valve 53 and the regenerating electromagnet valve 55, and controls the accelerated air current switching control valve 54 to switch to the accelerating nozzle 431b. Thus, the operation of removing dust from the object 3 and the operation of regenerating the cleaning media 1 are performed for a predetermined time period. The predetermine time period for removing dust from the object 3 and regenerating the cleaning media 1 may be made longer than the time period for generating the circulating air current, thereby allowing cleaning a large area of the object 3. Since the compressed air is delivered alternately by the accelerating nozzles 431a and the accelerating nozzles 431b, it is possible to prevent the interference between the air currents delivered from the accelerating nozzles 431a and the accelerating nozzles 431b and therefore to surely cause collision of the cleaning media 1 with object 3, thereby enhancing the effect of cleaning by the cleaning media 1.
The operation of generating the circulating air current and the operations of removing dust from the object 3 and regenerating the cleaning media 1 are repeatedly and alternately performed, while the object 3 is gradually moved down from the initial position. When the object 3 reaches a return position shown in
In the above embodiment, the accelerating nozzles 431a and 431b alternately deliver compressed air to clean the entire surface of the object 3. However, if the injection angles of the accelerating nozzles 431a and 431b are properly adjusted as shown in
In the above embodiment, the flat inner surfaces of the cleaning tank 41 form the circulation path of the circulating air current generated by the circulating air are flat. In an alternative embodiment, as shown in
The wall surface 411 of the cleaning tank 41 forming the circulation path of the circulating air current may have a curved surface with a concave shape as shown in
Further, as shown in
The cleaning tank 41 may not be a substantially rectangular shape and may include a slope 412 forming a bottom surface having an opening as shown in
In the above embodiment, one circulating air current generating unit 42 is provided in the cleaning tank 41. In an alternative embodiment shown in
In the above embodiment, one cleaning medium regenerating unit 44 is provided in the cleaning tank 41. In an alternative embodiment, as shown in
Further it is possible to prevent the flying cleaning media 1 from falling without being accelerated by the accelerating nozzles 431a and 431b and to provide a large amount of cleaning media 1 between the accelerating nozzles 431a and 431b and the object 3 while the compressed air is delivered from the accelerating nozzles 431a and 431b, resulting in enhancing the cleaning efficiency. That is, in the case of cleaning through collision of the flexible cleaning media 1 with the object 3, the cleaning quality is substantially proportional to the frequency of the collisions of the cleaning media 1 with the object 3 at a speed higher than a predetermined speed. Accordingly, increasing the amount of the cleaning media 1 can improve the cleaning quality and reduce the cleaning time, resulting in a reduction of energy use.
In an embodiment, rough cleaning using the acceleration nozzles 431a and 431b and the cleaning medium regenerating units 44a through 44d may be performed before the usual cleaning of the used cleaning media 1. The process including the rough cleaning is described with reference to the timing chart of
The flexible cleaning media 1 are placed into the cleaning tank 41 and accumulated on the separating member 441 of the cleaning medium regenerating unit 44. Then the object 3 being held by the work holding unit 48 is placed into the cleaning tank 41 through the object inlet 45 and positioned in the initial position by the work transport unit 49. The lid 46 of the object inlet 45 is closed, so that the cleaning tank 41 is sealed. Then the activating unit 51 is operated to input a cleaning start signal to the control unit 50. The control unit 50 opens the accelerating electromagnet valve 53 to switch on and off the accelerated current switching control valve 54 on a predetermined cycle, thereby causing the accelerating nozzles 431a and 431b to alternately deliver compressed air. In synchronization with the switching between the compressed air delivery by the accelerating nozzles 431a and the compressed air delivery by the accelerating nozzles 431b, the control unit 50 controls the suction air current switching control valve 63 to switch between suction by the cleaning medium regenerating units 44a and 44b disposed on the surface facing the accelerating nozzles 431b for compressed air delivery and suction by the cleaning media regenerating units 44c and 44d disposed on the surface facing the accelerating nozzles 431a for compressed air delivery. More specifically, when the accelerating nozzles 431a on the front surface of the cleaning tank 41 delivers compressed air, the cleaning medium regenerating units 44c and 44d perform suction. With this operation, when the compressed air delivered from the accelerating nozzles 431a hits the object 3, the dirt and the extraneous substances 4 adhering to the object 3 with low adhesion force are removed, so that the object 3 is roughly cleaned. Then the circulating air current generating unit 42 is caused to generate the circulating current, thereby carrying and propelling the cleaning media 1 accumulated on the separating member 441 to of the cleaning media regenerating unit 44, thereby cleaning is performed using the flying cleaning media 1. When the cleaning operation by the flying cleaning media 1 is completed, the accelerating nozzles 431a and 431b are again caused to alternately deliver compressed air. In synchronization with the switching between the compressed air delivery by the accelerating nozzles 431a and the compressed air delivery by the compressed air delivery by the accelerating nozzles 431b, the control unit 50 controls the suction air current switching control valve 63 to switch between suction by the cleaning medium regenerating units 44a and 44b disposed on the surface facing the accelerating nozzles 431b for compressed air delivery and suction by the cleaning media regenerating units 44c and 44d disposed on the surface facing the accelerating nozzles 431a for compressed air delivery. Thus the cleaning media attached to the object 3 due to the electrostatic action are blown off, and the cleaning operation is completed. The lid 46 of the cleaning tank 41 is opened to take out the object 3 held by the work holding unit 48 with use of the work transport unit 49 so as to be replaced with another object 3 to be cleaned. Then the cleaning operation is started again. With the rough cleaning operation and the operation of blowing off the cleaning media 1, the cleaning speed and the cleaning quality can be improved.
In the above embodiment, the cleaning medium regenerating units 44a and 44b and the cleaning medium regenerating units 44c and 44d are disposed on the front surface and the back surface of the cleaning tank 41, respectively. In an alternative embodiment, as shown in
During cleaning, by causing the cleaning media 1 to fly and collide with the object 3, some cleaning media 1 may be broken down due to the collision with the object 3 and pass through the mesh of the separating member 441 of the cleaning medium regenerating unit 44 to be ejected into the dust collecting unit 57, resulting in a reduced amount of the cleaning media 1 in the cleaning tank 41. If the amount of the cleaning media 1 in the cleaning tank 41 is reduced and thus the amount of the cleaning media 1 flying in the cleaning tank 41 is reduced, the cleaning effect is lowered. In some cases, plural objects 3 may be held by the work holding unit 48 and placed into the cleaning tank 41 so as to be cleaned. In such cases, as shown in
The cleaning operation to be performed in the case where the flying cleaning media amount measuring unit 64 and the object detecting units 65a and 65b are provided is described below with reference to the timing chart of
As shown in
Since the amount of the flying cleaning media 1 is detected and the cleaning operation is performed using the predetermined amount of the flying cleaning media 1 or greater, high quality cleaning can be performed. The amount of the cleaning media 1 that collide with the object 3 is proportional to the amount of the flying cleaning media 1. Therefore, the control unit 50 can evaluate the cleaning quality based on the flying amount in each predetermined time period. Further, if the fluctuation of the amount of the flying cleaning media 1 is recorded, it is possible to accurately quantify the cleaning quality and cleaning performance.
When the cleaning operation starts, the work transport unit 49 moves down the plural objects 3. When the first object 3 reaches a position to block the optical beam of the object detecting unit 65a disposed above the accelerating nozzles 431a and 431b, the object detecting unit 65a inputs an object detection signal to the control unit 50. With a delay of a time required for the object 3 to reach the position of the accelerating nozzles 431a and 431b, which is calculated based on the travel speed of the object 3 and the distance between the object detecting unit 65a and the accelerating nozzles 431a and 431b, the control unit 50 stops generation of circulating air current and starts delivery of the compressed air by the accelerating nozzles 431a and suction by the cleaning medium regenerating unit 44 so as to clean the first object 3. When the object detection signal is not input from the object detecting unit 65a any longer, with a delay of the time required for the object 3 to reach the position of the accelerating nozzles 431a and 431b, the control unit 50 stops the delivery of the compressed air by the accelerating nozzles 431a and suction by the cleaning medium regenerating unit 44 and starts generation of circulating air current by the circulating air current generating unit 42. This control operation is performed every time the object detecting unit 65a inputs an object detecting signal, so that the plural objects 3 are sequentially cleaned. When the objects 3 reach the return point, the objects 3 start moving up. While the objects 3 move up, the control unit 50 performs a control operation similar to the above-described control operation every time the object detecting unit 65a inputs an object detecting signal, thereby cleaning the entire surfaces of the objects 3 while causing the accelerating nozzles 431b to deliver compressed air.
With this configuration, since the delivery of the compressed air from the accelerating nozzles 431a and 431b, which use a large amount of compressed air, is performed according to the position of the object 3, the use of compressed air by the accelerating nozzles 431a and 431b can be reduced, thereby reducing energy consumption.
In the above embodiment, the flying cleaning media amount measuring unit 64 including the photoelectric sensor 641 is used. In an alternative embodiment, a method of integrating the power of impact of the cleaning media 1 on the object 3 with use of a force sensor, or a method of measuring weight at the end of process with use of a weight sensor, a method of measuring the amount of the accumulated cleaning media 1 at the bottom of the cleaning tank 41 with use of the distance sensor may be used. In the case of integrating the power of the impact of the cleaning media 1, cleaning quality can be evaluated based on the integrated number of times of the impact.
Referring to
The above embodiments are designed for removing dry toner (average diameter in a range about 5 through 10 μm) as the extraneous substances 4, which is used in electrophotographic apparatuses such as copiers and laser printers. This is not a limiting example, and the present invention is applicable to a cleaning apparatus for removing attached particles or dust in general. The type of the cleaning medium 1 and the speed and volume of the air current are selected as appropriate in accordance with the characteristics of the object 3 and the extraneous substances 4. If the object 3 to be cleaned is easily damaged, for example, a tubular cleaning medium 1 made of a flexible material such as resin and having a thin wall thickness may be used. The easily bendable cleaning medium 1 does not damage the object 3 to be cleaned.
In order to observe the effects of the adhesion force of toner as the extraneous substance 4 to be removed by dry cleaning, a toner cartridge of a copier with toner attached was heated for one hour, and thus three types of samples were prepared having the toner adhering thereto with different adhesion forces (low adhesion force, medium adhesion force, and high adhesion force). The samples were cleaned by the dry cleaning apparatus 11 to remove the toner adhering to the samples. Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa.
The following four types of flexible tubular cleaning media 1 were used.
(1) cylindrical polyethylene tube having a wall thickness of 30 μm, an outer diameter of 5 mm, and a length of 10 mm
(2) cylindrical PET (polyethylene terephthalate) tube having a wall thickness of 30 μm, an outer diameter of 5 mm, and a length of 10 mm
(3) cylindrical polyethylene tube having a wall thickness of 100 μm, an outer diameter of 5 mm, and a length of 10 mm
(4) cylindrical PET tube having a wall thickness of 100 μm, an outer diameter of 5 mm, and a length of 10 mm
As comparative examples, performed were:
(5) dry cleaning by air blow without using cleaning media, and
dry cleaning by air blow using the following four types of granular cleaning media:
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
(9) non-flexible PET cylinder having a diameter of 5 mm and a length of 10 mm
Table 1 shows the cleaning results.
As is understood from Table 1 the dry cleaning methods using the flexible tubular cleaning media 1 exhibited better cleaning results than the related-art dry cleaning methods using granular cleaning media. Among the flexible tubular cleaning media 1, the higher the flexibility of the cleaning medium 1, the better the cleaning result.
The following shows experimental results of dry cleaning using the cleaning media 1 repeatedly.
A toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with medium adhesion force. Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa. The same cleaning media 1 were continuously used without being replaced. Thus transitions of the cleaning results along with the increase of the number of the samples subjected to the cleaning process were compared. The following five types of flexible tubular cleaning media 1 were used.
(1) cylindrical polyethylene tube having a wall thickness of 30 μm, an outer diameter of 5 mm, and a length of 10 mm
(2) cylindrical PET tube having a wall thickness of 30 μm, an outer diameter of 5 mm, and a length of 10 mm
(3) cylindrical nylon-cloth tube having a wall thickness of 100 μm, an outer diameter of 5 mm, and a length of 10 mm
(4) cylindrical paper tube having a wall thickness of 100 μm, an outer diameter of 5 mm, and a length of 10 mm
(5) cylindrical aluminum tube having a wall thickness of 100 μm, an outer diameter of 5 mm, and a length of 10 mm
Table 2 shows the cleaning results.
As is understood from Table 2, the cleaning media 1 made of resin materials exhibited better cleaning results in the case of repeated use.
In order to observe the difference in the cleaning performance, a toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with increased adhesion force (medium adhesion force). The samples were cleaned by the dry cleaning apparatus 11a. Each sample was cleaned for one minute by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa. The following three types of flexible tubular cleaning media 1 were used.
(1) cylindrical PET tube formed in the shape shown in
(2) quadrangular PET tube formed in the shape shown in
(3) cylindrical PET tube including flexible thin pieces on the side surface formed in the shape shown in
As comparative examples, cleaning was performed using the following six types of cleaning media:
(4) PET film having a thickness of 30 μm and sides of 5 mm by 5 mm
(5) dry cleaning by air blow without using cleaning media
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
(9) non-flexible PET cylinder having a diameter of 5 mm and a length of 10 mm
Table 3 shows the cleaning results. In Table 3, the double circle mark indicates very clean as a result of toner cleaning; the single circle mark indicates fairly clean; the triangle mark indicates partly unclean; and the x mark indicates unclean.
As is understood from Table 3, the dry cleaning methods using the flexible tubular cleaning media 1 exhibited better cleaning results than the related-art cleaning methods. The flexible tubular cleaning media 1 having different shapes showed good results in different evaluation items. Therefore, the cleaning medium 1 having the shape that shows a good result in the item on which importance is placed may be selected so as to achieve the desired cleaning result. It is possible to use different shapes of the flexible tubular cleaning media 1 at the same time or to use different shapes of the cleaning media 1 at different steps of the cleaning process.
In order to observe the effects of the adhesion force of toner as the extraneous substance 4 to be removed by dry cleaning, a toner cartridge of a copier with toner attached was heated for one hour, and thus three types of samples were prepared having the toner adhering thereto with different adhesion forces (low adhesion force, medium adhesion force, and high adhesion force). The samples were cleaned by the dry cleaning apparatus 11a to remove the toner adhering to the samples. Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa.
The following four types of flexible bag-shaped cleaning media 1a were used.
(1) polyethylene cone having a wall thickness of 30 μm, a bottom diameter of 5 mm, and a length of 10 mm
(2) PET (polyethylene terephthalate) cone having a wall thickness of 30 μm, a bottom diameter of 5 mm, and a length of 10 mm
(3) polyethylene cone having a wall thickness of 100 μm, a bottom diameter of 5 mm, and a length of 10 mm
(4) PET cone having a wall thickness of 100 μm, a bottom diameter of 5 mm, and a length of 10 mm
As comparative examples, performed were:
(5) dry cleaning by air blow without using cleaning media, and
dry cleaning by air blow using the following four types of granular cleaning media:
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
(9) non-flexible PET cone having a bottom diameter of 5 mm and a length of 10 mm
Table 4 shows the cleaning results.
As is understood from Table 4, the dry cleaning methods using the flexible bag-shaped cleaning media 1a exhibited better cleaning results than the related-art dry cleaning methods using granular cleaning media. Among the flexible bag-shaped cleaning media 1a, the higher the flexibility of the cleaning medium 1a, the better the cleaning result.
The following shows experimental results of dry cleaning using the flexible bag-shaped cleaning media 1a repeatedly.
A toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with medium adhesion force. Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa. The same cleaning media 1a were continuously used without being replaced. Thus transitions of the cleaning results along with the increase of number of the cleaned samples were compared. The following five types of flexible bag-shaped cleaning media 1a were used.
(1) polyethylene cone having a wall thickness of 30 μm, a bottom diameter of 5 mm, and a length of 10 mm
(2) PET cone having a wall thickness of 30 μm, a bottom diameter of 5 mm, and a length of 10 mm
(3) nylon-cloth cone having a wall thickness of 100 μm, a bottom diameter of 5 mm, and a length of 10 mm
(4) paper cone having a wall thickness of 100 μm, a bottom diameter of 5 mm, and a length of 10 mm
(5) aluminum cone having a wall thickness of 100 μm, a bottom diameter of 5 mm, and a length of 10 mm
Table 5 shows the cleaning results.
As is understood from Table 5, the cleaning media 1a made of resin materials exhibited better cleaning results in the case of repeated use.
In order to observe the difference in the cleaning performance, a toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with increased adhesion force (medium adhesion force). The samples were cleaned by the dry cleaning apparatus 11a. Each sample was cleaned for one minute by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa. The following three types of flexible bag-shaped cleaning media 1a were used.
(1) PET cone formed in the shape shown in
(2) PET four-sided pyramid formed in the shape shown in
(3) PET cone including folds on the side surface formed in the shape shown in
As comparative examples, cleaning was performed using the following six types of cleaning media:
(4) PET film having a thickness of 30 μm and sides of 5 mm by 5 mm
(5) dry cleaning by air blow without using cleaning media
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
(9) non-flexible PET cone having a bottom diameter of 5 mm and a length of 10 mm
Table 6 shows the cleaning results. In Table 6, the double circle mark indicates very clean as a result of toner cleaning; the single circle mark indicates fairly clean; the triangle mark indicates partly unclean; and the x mark indicates unclean.
As is understood from Table 6, the dry cleaning methods using the flexible bag-shaped cleaning media 1a exhibited better cleaning results than the related-art cleaning methods. The flexible bag-shaped cleaning media 1a having different shapes showed good results in different evaluation items. Therefore, the cleaning medium 1a having the shape that shows a good result in the item on which importance is placed may be selected so as to achieve the desired cleaning result. It is possible to use different shapes of the flexible bag-shaped cleaning media 1a at the same time or to use different shapes of the cleaning media 1a at different steps of the cleaning process.
In an embodiment of the present invention, a cleaning medium is configured to fly with an air current to collide with an object to be cleaned and remove extraneous substances attached to the object. The cleaning medium includes a flexible thin piece having an upright portion extending from a flat base portion.
According to an embodiment of the present invention, a cleaning medium M is configured to have a space where an air current can enter between the wall of a cleaning tank and the cleaning medium M attached thereto and between the surface of an object to be cleaned and the cleaning medium M attached thereto. The cleaning medium M is also configured to not enter greater than a predetermined depth in joints and seams in the cleaning tank or joints and seams in the object.
More specifically, the cleaning medium M is modified from a flexible thin cleaning medium to include one or more upright portions extending from a flat base portion so as to have a three dimensional shape.
With this configuration, in the cleaning process, even if the cleaning medium M is attached to the wall of the cleaning tank, there is a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from the wall of the cleaning tank is greater than the electrostatic attraction force, the cleaning medium M is separated from the wall of the cleaning tank and thus can fly again.
Thus, it is possible to prevent a reduction in the amount of cleaning media M that contributes to cleaning, thereby maintaining a constant cleaning efficiency.
A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the wall of the cleaning tank so as to discharge the cleaning medium M, thereby enhancing the effect of making the cleaning medium M fly repeatedly.
In a process of removing the cleaning medium M from the cleaned object, even if the cleaning medium M is attached to the object, there is a space where an air current can enter between the cleaning medium M and the object.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from object is greater than the electrostatic attraction force, the cleaning medium M is separated from the object and thus can easily be removed.
A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the object so as to discharge the cleaning medium M, thereby enhancing the effect of removing the cleaning medium M.
Further, even if there is a gap having the substantially same width as the width of the thin cleaning medium M at a joint or a seam in the object or a joint or a seam in the cleaning tank, the bent portion (upright portion) of the cleaning medium M prevents complete insertion of the cleaning medium M into the gap. The air current hits a part of the cleaning medium M exposed outside the gap to make the cleaning medium M fly again, thereby preventing accumulation of the cleaning media M.
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media M that contribute to cleaning and to allow new contact of the cleaning media M with the object due to prevention of accumulation of the cleaning media M in gaps in the object, thereby maintaining constant cleaning efficiency.
Further, in the process of removing the cleaning media M from the cleaned object, when an air current is generated to flow into the space to hit a part of the cleaning medium M exposed outside the gap, the cleaning medium M flies again and thus can easily be removed.
The following describes the shape of the cleaning medium M.
In an embodiment, a cleaning medium M includes, as one or more bent portions M1, one or more upright portions formed by bending a flat base portion as shown in
The position and number of the bent portions M1 are not especially limited as long as it is possible to form a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank or the surface of the object, and as long as the height of the three dimensional shape defined by the bent portion M1 is greater than the widths of the gaps that have been known from use of unprocessed thin cleaning media.
An example of a cleaning medium M shown in
In the case of the cleaning medium having the bent portions M1 bent in the same direction, the space is formed between the base portion and the bent portions M1. In the case of the cleaning medium having the bent portions M1 and M2 bent in the opposite directions, spaces are formed between the base portion M1 and the surface of the base portion and between the base portion M2 and the opposite surface of the base portion. Although the cleaning media N shown in
Cleaning media M shown in
As shown in
With this configuration, in the cleaning process, even if the cleaning medium M is attached to the wall of the cleaning tank, there is a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank. Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from the wall of the cleaning tank is greater than the electrostatic attraction force, the cleaning medium M is separated from the wall of the cleaning tank and thus can fly again.
Thus, it is possible to prevent a reduction in the amount of cleaning media M that contributes to cleaning, thereby maintaining a constant cleaning efficiency.
A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the wall of the cleaning tank so as to discharge the cleaning medium M, thereby enhancing the effect of making the cleaning medium M fly repeatedly.
In a process of removing the cleaning medium M from the cleaned object, even if the cleaning medium M is attached to the object, there is a space where an air current can enter between the cleaning medium M and the object.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from object is greater than the electrostatic attraction force, the cleaning medium M is separated from the object and thus can easily be removed.
A corona discharging unit cleaning unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the object so as to discharge the cleaning medium M, thereby enhancing the cleaning efficiency.
In this embodiment, in the case of the surface shape including one or more bent portions M1 (and M2) as the upright portions, the provision of plural bent portions M1 (and M2) as shown in
Further, as shown in
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media M that contribute to cleaning and to allow new contact of the cleaning media M with the object due to prevention of accumulation of the cleaning media M in gaps in the object, thereby maintaining constant cleaning efficiency.
Further, in the process of removing the cleaning media M from the cleaned object, when an air current is generated to flow into the space to hit a part of the cleaning medium M exposed outside the gap, the cleaning medium M flies again and thus can easily be removed.
In an embodiment, a cleaning medium M including an upright portion has a curved shaped as shown in
The curvature is not especially limited as long as it is possible to form a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank or the surface of the object, and as long as the height of the three dimensional shape defined by the curved portion is greater than the widths of the gaps that have been known from use of unprocessed thin cleaning media.
As shown in
This production method is only an example, and any production method may be used that can produce the cleaning medium M having a curved shape. For example, the cleaning medium M may be produced by the following methods:
cutting a tube in the circumferential direction and the axial direction winding a tape around a cylindrical core to make the tape curved, and then cutting the tape.
applying friction to one surface of a tape to make the tape stretched and warped, and then cutting the tape.
applying heat to one surface of a tape to make the tape stretched and warped due to thermal expansion, and then cutting the tape.
applying heat to a tape including layers of materials of different thermal expansion to make the tape warped due to the difference in thermal expansion, and then cutting the tape.
With this configuration, in the cleaning process, even if the cleaning medium M is attached to the wall of the cleaning tank, there is a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from the wall of the cleaning tank is greater than the electrostatic attraction force, the cleaning medium M is separated from the wall of the cleaning tank and thus can fly again.
Thus, it is possible to prevent a reduction in the amount of cleaning media M that contributes to cleaning, thereby maintaining a constant cleaning efficiency.
A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the wall of the cleaning tank so as to discharge the cleaning medium M, thereby enhancing the effect of making the cleaning medium M fly repeatedly.
In a process of removing the cleaning medium M from the cleaned object, even if the cleaning medium M is attached to the object, there is a space where an air current can enter between the cleaning medium M and the object due to the above-described configuration of the cleaning medium M.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from object is greater than the electrostatic attraction force, the cleaning medium N is separated from the object and thus can easily be removed.
In the case of the curved surface shape, when the cleaning medium M is in line contact with the object to be cleaned or the wall of the cleaning tank when attached thereto as shown in
Further, as shown in
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media M that contributes to cleaning and to allow new contact of the cleaning media M with the object due to prevention of accumulation of the cleaning media M in the gap in the object, thereby maintaining constant cleaning efficiency.
Further, in the process of removing the cleaning media M from the cleaned object, when an air current is generated to flow into the space to hit a part of the cleaning medium M exposed outside the gap, the cleaning medium M flies again and thus can easily be removed.
In an embodiment, a cleaning medium M includes raised and recessed portions on both surfaces as shown in
The positions and the number of the raised and recessed portions P1 and P2 are not especially limited as long as it is possible to form a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank or the surface of the object, and as long as the height of the three dimensional shape defined by the raised and recessed portions is greater than the widths of the gaps that have been known from use of unprocessed thin cleaning media.
As shown in
This production method is only an example, and any production method may be used that can produce the cleaning medium M including the raised and recessed portions on both surfaces. For example, the cleaning medium M may be produced by depositing droplets of an adhesive agent in some positions to form raised portions and then cutting the tape by a tape cutter.
With this configuration, in the cleaning process, even if the cleaning medium M is attached to the wall of the cleaning tank, there is a space where an air current can enter between the cleaning medium M and the wall of the cleaning tank.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from the wall of the cleaning tank is greater than the electrostatic attraction force, the cleaning medium M is separated from the wall of the cleaning tank and thus can fly again.
Thus, it is possible to prevent a reduction in the amount of cleaning media M that contributes to cleaning, thereby maintaining a constant cleaning efficiency.
A corona discharging unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the wall of the cleaning tank so as to discharge the cleaning medium M, thereby enhancing the effect of making the cleaning medium M fly repeatedly.
In a process of removing the cleaning medium M from the cleaned object, even if the cleaning medium M is attached to the object, there is a space where an air current can enter between the cleaning medium M and the object.
Then, when an air current is generated to flow into the space and the force of the air current separating the cleaning medium M from object is greater than the electrostatic attraction force, the cleaning medium M is separated from the object and thus can easily be removed.
A corona discharging unit cleaning unit may be used in conjunction to provide ions on the surface of the cleaning medium M in contact with the object so as to discharge the cleaning medium M, thereby enhancing the cleaning efficiency.
In the case of the surface shape including the raised and recessed portions on both surfaces, the cleaning medium M as shown for example in
It should be noted that the cleaning medium can be in surface contact with the object due to its bending motion upon collision during cleaning.
Further, as shown in
Thus, in the cleaning process it is possible to prevent a reduction in the amount of the cleaning media M that contribute to cleaning and to allow new contact of the cleaning media M with the object due to prevention of accumulation of the cleaning media M in the gap in the object, thereby maintaining constant cleaning efficiency.
Further, in the process of removing the cleaning media M from the cleaned object, when an air current is generated to flow into the space to hit a part of the cleaning medium M exposed outside the gap, the cleaning medium M flies again and thus can easily be removed.
The cleaning medium M may preferably be made of or include an antistatic material.
To achieve effective antistatic performances the surface resistance of the cleaning medium M may preferably be 1010 Ω/sq. or less.
In the case where the cleaning medium M is made of metal, the cleaning medium M itself is antistatic. In the case where the cleaning medium M is made of resin, any of the above-described antistatic techniques used may be used as in the case of the cleaning media 1 and 1a.
The use of this cleaning medium M can prevent increase of charges due to friction and can reduce the electrostatic effect of making the cleaning medium M be attracted to the wall of the cleaning tank or the object to be cleaned.
Thus, the cleaning medium M can be separated from the wall of the cleaning tank or the object with reduced air current. This allows downsizing of the air current generation equipment and leads to reduction of energy consumption. A corona discharging unit may be used in conjunction to improve the effect of making the cleaning medium M fly repeatedly.
The above described dry cleaning apparatuses may use the cleaning medium M as well as the cleaning media 1 and 1a.
The following shows experimental results based on the above-described embodiments.
First, for the purpose of obtaining the experimental results, in order to observe the effects of the adhesion force of the extraneous substances (toner) to be removed by dry cleaning, a toner cartridge of a copier with toner attached was heated for one hour, and thus three types of samples were prepared having the toner adhering thereto with different adhesion forces (low adhesion force, medium adhesion force, and high adhesion force). Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa.
The following four types of flexible thin cleaning media as described in the above embodiments were used.
(1) polyethylene film having a thickness of 30 μm and sides of 5 mm by 5 mm
(2) PET (polyethylene terephthalate) film having a thickness of 30 μm and sides of 5 mm by 5 mm
(3) polyethylene film having a thickness of 100 μm and sides of 5 mm by 5 mm
(4) PET film having a thickness of 100 μm and sides of 5 mm by 5 mm
As comparative examples, performed were:
(5) dry cleaning by air blow without using cleaning media, and
dry cleaning using the following types of granular cleaning media:
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
(9) non-flexible PET circular plate having a thickness of 2 mm and a diameter of 5 mm
Table 7 shows the experimental results.
As is understood from Table 7, the dry cleaning methods using the flexible thin cleaning media of the embodiments of the present invention exhibited better cleaning results than the related-art dry cleaning methods using granular cleaning media.
Among the flexible thin cleaning media 1, the higher the flexibility of the film, the better the cleaning result.
The following shows experimental results of dry cleaning using the cleaning media repeatedly.
A toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with medium adhesion force. Each sample was cleaned for two minutes by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa. The same cleaning media were continuously used without being replaced. Thus transitions of the cleaning results along with the increase of number of the cleaned samples were compared.
The following four types of flexible thin cleaning media as described in the above embodiments were used.
(1) polyethylene film having a thickness of 100 μm and sides of 5 mm by 5 mm
(2) PET film having a thickness of 100 μm and sides of 5 mm by 5 mm
(3) a piece of nylon cloth having a thickness of 100 μm and sides of 5 mm by 5 mm
(4) a piece of paper cloth having a thickness of 100 μm and sides of 5 mm by 5 mm
(5) a piece of aluminum foil having a thickness of 100 μm and sides of 5 mm by 5 mm
Table 8 shows the experimental results.
As is understood from Table 8, the cleaning media made of resin materials exhibited better cleaning results in the case of repeated use.
In the above embodiments, the extraneous substances to be removed from the object to be cleaned was dry toner (average diameter in a range about 5 through 10 μm), which is used in electrophotographic apparatuses such as copiers and a laser printers. This is not a limiting example, and the present invention is applicable to cleaning for removing particles and dust in general attached to the object. The type (sizer shape, material, etc.) of the cleaning medium and the speed and volume of the air current are selected as appropriate in accordance with the characteristics of the object to be cleaned and the extraneous substances.
(An Experiment Showing the Effects of the Embodiment of the Present Invention)
Table 9 shows an example of cleaning results.
In order to observe the difference in the cleaning performance, a toner cartridge of a copier with toner attached was heated for one hour, and thus samples were prepared having the toner adhering thereto with increased adhesion force (medium adhesion force). The cleaning apparatus having the configuration shown in FIG. 42 was used.
Each sample was cleaned for one minute by using plural air nozzles SL-920A made by Silvent as an air blowing unit while maintaining a constant compressed air pressure of 0.2 MPa.
The following flexible thin cleaning media M were used.
(1) PET film including bent portions as shown in
(2) PET film having a curved surface as shown in
(3) PET film including raised and recessed portions on both surfaces as shown in
As a comparative example, cleaning was performed using the following cleaning medium:
(4) PET film with no bent portions, having a thickness of 30 μm and sides of 5 mm by 5 mm As other comparative examples, performed were:
(5) dry cleaning by air blow without using cleaning media, and
dry cleaning using the following types of granular cleaning media in place of the thin cleaning media M:
(6) nylon cube of 2 mm on a side
(7) nylon ball having a diameter of 2 mm
(8) urethane sponge ball having a diameter of 5 mm
The following is an explanation of symbols used in Table 9.
As is understood from Table 9, the dry cleaning methods using the thin cleaning media modified from the thin cleaning media to have three-dimensional shapes exhibited better cleaning results than the related-art cleaning methods.
The flexible thin cleaning media having different three-dimensional shapes showed good results in different evaluation items. Therefore, the cleaning medium having the shape that shows a good result in the item on which importance is placed may be selected so as to achieve the desired cleaning result. It is possible to use different three-dimensional shapes of the flexible thin cleaning media at the same time or to use different three-dimensional shapes of the cleaning media at different steps of the cleaning process.
The present application is based on Japanese Priority Application No. 2006-339126 filed on Dec. 15, 2006, Japanese Priority Application No. 2007-192888 filed on Jul. 25, 2007, and Japanese Priority Application No. 2007-297415 filed on Nov. 16, 2007, with the Japanese Patent Office, the entire contents of which are hereby incorporated by reference.
Number | Date | Country | Kind |
---|---|---|---|
2006-339126 | Dec 2006 | JP | national |
2007-192888 | Jul 2007 | JP | national |
2007-297415 | Nov 2007 | JP | national |