Patent Application
20150050169
The present invention relates to a high-pressure washing device.
Conventionally, as a high-pressure washing device for cleaning an outer wall such as a concrete wall or a tile wall, or a car, there is commonly used a stationary type washing device which includes a pump driven by electric power supplied from a commercial power supply, and, which compresses water (cleaning liquid) supplied from a tap (water source) by means of the pump and ejects the water (For example, refer to Japan Patent Application Publication No. 2005-313008).
However, cleaning operation performed by the high-pressure washing device requires both the commercial power supply and water source. Further, even if both the commercial power supply and water source can be ensured, a cleaning area of the high-pressure washing device is limited by a length of a power cable or a water hose. Further, if an ejection pressure is low (e.g., less than 0.3 MPa equivalent to a pressure of waterworks), as in the case of a spray, tough stains cannot be removed.
In view of forgoing, it is an object of the present invention to provide a high-pressure washing device capable of performing high-pressure cleaning over a wide area. Another object of the present invention is to provide a high-pressure washing device excellent in portability and capable of performing high-pressure cleaning.
In order to attain above and other object, the present invention provide a high-pressure washing device. The high-pressure washing device includes a nozzle, a motor, a battery, and a pump. The nozzle is configured to eject a high-pressure cleaning liquid. The battery is configured to supply electric power to the motor. The pump is configured to be driven by the motor to eject the cleaning liquid from the nozzle. An ejection pressure of the cleaning liquid from the nozzle is set to more than or equal to 3 Mpa.
This configuration allows a high ejection pressure to be obtained even when driven by the battery. Thus, even a cordless type washing device can exert cleaning capability equivalent to that of a conventional high-pressure washing device driven by a commercial power supply. Further, a power cable for acquiring power from the commercial power supply is not required, so that high-pressure cleaning can be performed over a wide area without being restricted by a length of the power cable.
According to still another aspect, the present invention provides a high-pressure washing device. The high-pressure washing device includes a nozzle, a motor, and a pump. The nozzle is configured to eject a high-pressure cleaning liquid. The motor is configured to be driven by an external power. The pump is configured to be driven by the motor to eject the cleaning liquid from the nozzle. An ejection pressure of the cleaning liquid from the nozzle is set to more than or equal to 3 Mpa.
This allows the high-pressure washing device to be used over a wide area without being restricted in terms of a location where the device is used and allows 3.0 MPa or more high-pressure cleaning.
According to the present invention, a high-pressure washing device can perform high-pressure cleaning over a wide area. Further, a battery-driven high-pressure washing device can obtain an ejection pressure equivalent to that of a high-pressure washing device driven by a commercial power supply.
A high-pressure washing device 1 according to a first embodiment of the present invention will be described with reference to
As illustrated in
As illustrated in
The upper housing 4 includes a main body 41, a lid portion 42, an upper latch 43, a pair of lower latches 44, and a pressing portion 45 serving as a connecting portion to the tank 6. The pressing portion 45 may be provided in the lower housing 5.
That is, in the high-pressure washing device 1 according to the present embodiment, the lid portion 42, the main body 41, and the lower housing 5 (drive section) are aligned downward from above in this order. The tank 6 containing cleaning liquid is accommodated in the main body 41, so that the main body 41 functions as a tank accommodating portion. With this configuration, even if the high-pressure washing device 1 is overturned or dropped, the tank 6 is protected by the tank accommodating portion 41, preventing breakage of the tank 6. Further, even if the connecting portion (pressing portion 45, etc., to be described later, serving as a water-feed inlet from the tank 6) between the tank 6 and drive section is broken due to the overturn, the cleaning liquid can be prevented from leaking outside the tank accommodating portion 41, which in turn prevents the cleaning liquid from being introduced into the drive section. Further, the high-pressure washing device 1 can be used with the tank 6 accommodated therein, eliminating the need to supply the cleaning liquid from waterworks using a water hose. Thus, the high-pressure washing device 1 can be used without limiting a location, allowing use over a wide area.
The lid portion 42 can be opened and closed by releasing the upper latch 43, and opening the lid portion 42 about a support shaft 43a as illustrated in
That is, the lid portion 42 is connected to the tank accommodating portion 41 so as to be openable and closable, so that when an opening portion of the tank accommodating portion 41 is closed by the lid portion 42, the high-pressure washing device 1 can easily be carried by hand by means of the handle 42a, and when the lid portion 42 is opened, the tank 6 can be taken out from the tank accommodating portion 41. Further, when the lid portion 42 is closed in a state where the tank 6 has been taken out, foreign matters can be prevented from entering the tank accommodating portion 41 to thereby prevent the inlet for the cleaning liquid from being clogged. Further, in a case where a water hose is connected, a hose connecting portion where the water hose is connected is protected by the tank accommodating portion 41, preventing the connection from being released by an external force.
Further, the upper housing 4 (tank accommodating portion 41) and lower housing 5 (drive section) can be attached to and detached from each other. When the lower housing 5 is separated from the upper housing 4, the lower housing 5 can be connected to another tank larger than the tank 6 accommodated in the tank accommodating portion 41. That is, tanks of various sizes can be used depending on intended use.
As illustrated in
As shown in
The outflow port 62 extends in the vertical direction, and the pressed portion 63 is disposed in the outflow port 62 so as to be movable in the vertical direction by being spring-biased downward. The check valve 64 is provided at an upper end of the pressed portion 63 so as to be able to close the outflow port 62. The fitting portion 65 has a tubular shape and is coaxially disposed with the outflow port 62 at a portion below the outflow port 62. As illustrated in
When attaching the tank 6 to the upper housing 4, as illustrated in
The outflow port 62 and the inlet 451 are substantially the same in diameter. When the pressed portion 63 and the pressing portion 45 are in contact with each other, the outflow port 62 and inlet 451 are coaxially connected to each other, so that the cleaning liquid from the outflow port 62 flows in the inlet 451 stably. Assuming that a leading end of the outflow port 62 may be made smaller in diameter than a leading end of the inlet 451 so as to be fittingly inserted into the inlet 451, the cleaning liquid can flow in the inlet 451 more reliably.
An outer peripheral surface of the tank 6 and an inner peripheral portion of the main body 41 are substantially the same in dimension. When the tank 6 is attached to the upper housing 4, front-rear and left-right sides (near-far and left-right sides in
Ejection of the cleaning liquid from the tank 6 during use of the high-pressure washing device 1 causes an inside of the tank 6 to generate a negative pressure. The negative pressure inside the tank 6 may prevent smooth supply of the cleaning liquid to a pump 576 described later or may cause the tank 6 to shrink. In order to avoid this, as illustrated in
In a state illustrated in
On the other hand, in a state illustrated in
Further, the air inlet 6d and inlet valve 6a need not always be disposed in the bottom surface 6A of the tank 6 but may be disposed in a side surface thereof. In a case where the air inlet 6d and inlet valve 6a are disposed in the side surface of the tank 6, the valve can automatically be opened upon attachment of the tank 6 to the main body 41.
In the present embodiment, the connecting portion 61 to be connected to the pressing portion 45 is provided in the adapter (lid) 67 to be connected to the opening portion 68 of the tank 6, and the inlet valve 6a is provided in a portion (bottom surface 6A) of the tank 6 that is not connected to the adapter 67. However, the connecting portion 61 may be provided in the tank 6, not in the adapter 67, and the inlet valve 6a may be provided in the adapter 67. Further alternatively, the connecting portion 61 may provided in a prescribed surface of the tank 6 and the inlet valve 6a may be provided in different surfaces from the prescribed surface. In this case, since the opening portion 68 needs to be provided, one of the connecting portion 61 and inlet valve 6a is preferably provided in the adapter 67.
As illustrated in
Further, as illustrated in
The battery chamber 55 detachably accommodates a battery pack 7 (battery). The battery pack 7 can be attached also to a power tool such as an impact driver and accommodates a rechargeable battery. In the present embodiment, eight lithium ion batteries (4 in series×2 in parallel) each with a rated voltage of 3.6 V and a capacity of 1.5 Ah are accommodated in the battery pack 7, resulting in the battery pack 7 with a rated voltage of 14.4 V and a capacity of 3.0 Ah. As illustrated in
Further, as illustrated in
The motor chamber 56 accommodates therein a control circuit 561 (
As illustrated in
As illustrated in
As illustrated in
The valves 574 and 575 each incorporate a spring and are each closed by the spring biasing force in a normal state. The intake-side valve 574 includes a valve portion 574A. When the valve portion 574A moves downward in
The pump chamber 57 accommodates a pump 576. The pump 576 is a reciprocating pump, especially, a plunger pump, and more specifically, a single plunger-type pump (provided with one plunger) having a smaller number of plungers than that in a conventional three-plunger type pump. The pump 576 includes a plunger 576A serving as a reciprocating member made of aluminum alloy and a crank 576B. Further, the pump 576 includes a rubber packing 576C, a metal 576D, and a grease leak preventing member 576E. The rubber packing 576C serving as a seal member is brought into contact with an outer periphery of the plunger 576A to prevent the cleaning liquid from leaking from the compression chamber 573 to the crank 576B side. The metal 576D is in sliding contact with the outer periphery of the plunger 576A to improve the sliding ability of the plunger 576A. The grease leak preventing member 576E serving a seal member is brought into contact with the outer periphery of the plunger 576A to prevent grease for lubricating the crank 576B from leaking to the compression chamber 573 side. The plunger 576A is supported by a casing 576F of the pump 576.
Although the plunger pump (driven by the plunger 576A) is used as the pump 576 in the present embodiment, a piston pump may be used in place of the plunger pump. The pump 576 has the seal member 576C on a housing side (on a side of a member that slidably supports the plunger 576A). On the other hand, the piston pump has a seal member (e.g., an O-ring) provided on a piston side (member corresponding to the plunger 576A of the plunger pump) to be driven to prevent leakage of the cleaning liquid (pressure). That is, a pump of any type may be used as the pump 576 as long as the pump can prevent leakage of the cleaning liquid (pressure) and can achieve high-pressure ejection.
The plunger 576A is of substantially a columnar shape and has one end connected to the crank 576B and the other end constituting a part of the compression chamber 573.
As illustrated in
As illustrated in
The motor 562 and the pump 576 are oriented so as to cross each other. As illustrated in
In a case of the conventional three-plunger system, the three plunger system employs a rotating swash plate having a non-uniform thickness in the plunger axial direction to transmit the rotation of the motor, in place of the crank 576B of the embodiment. The rotating swash plate has an inclined surface facing and in contact with the one end portion of the three plungers. Upon rotating the rotating swash plate, the plungers contacting the thickened portion of the rotating swash plate is sequentially pushed whereby the three-plungers are reciprocatingly moved in order. In this configuration, the rotating swash plate needs to be provided in the axial direction of the motor, so that the plunger needs to be provided in parallel to the motor shaft and on an extension thereof. Accordingly, the motor and plunger are disposed so as to face the same direction, resulting in an increase in dimension in the motor shaft direction. Further, since the three plungers are used, a size of the pump becomes relatively large.
On the other hand, according to the present embodiment in which a single plunger 576A is used, the size of the pump 576 can be reduced, and further, the motor 562 and the pump 576 are disposed substantially perpendicularly (in an L-shape) to each other, so that a dimension of the drive section in the motor axial direction can be reduced as compared to the conventional three-plunger system. Further, since the battery pack 7 is arranged in a space between the motor 562 and the pump 576, a space (dead space) created by the arrangement of the motor and pump can be effectively used, and the drive section can become compact even in a configuration in which the battery pack 7 is provided. When
Operation of the pump 576 will concretely be described. In an initial state, i.e., in a state where the plunger 576A is located at the top dead point, the valves 574 and 575 are closed. When the plunger 576A moves to the bottom dead point side, a capacity of the compression chamber 573 increases to bring the inside of the compression chamber 573 into a negative pressure. The intake-side valve 574 is pulled by the negative pressure to be opened, and the ejection-side valve 575 is pulled by the negative pressure to maintain a closed state thereof. When the intake-side valve 574 is opened, the cleaning liquid from the intake port 571 flows in the compression chamber 573 through the intake-side valve 574.
When the plunger 576A further moves to reach the bottom dead point (state of
When the plunger 576A further moves to reach the top dead point (state of
The pressurized cleaning liquid is supplied to the gun 3 through the ejection port 572 and high-pressure hose 2. A distal end of the gun 3 is formed with the nozzle 31 having an extremely small diameter of about 0.6 mm, and thus the cleaning liquid is further pressurized by the nozzle 31 before the ejection thereof. As described above, high-pressure ejection can be achieved since the diameter of the nozzle 31 (diameter of an ejection port of the gun 3) is as extremely small as 0.6 mm. In order to achieve an output of about 7.0 MPa in consideration of the dimension of the compression chamber 573 or plunger 576A and flow rate, 0.6 mm is optimum as the diameter of the nozzle 31. When an amount of the cleaning liquid to be pushed in one reciprocating motion of the plunger 576A is large, the nozzle diameter can be designed more than 0.6 mm. On the other hand, when the amount of the cleaning liquid to be pushed in one reciprocating motion of the plunger 576A is small, the nozzle diameter needs to be reduced from 0.6 mm. That is, the nozzle diameter needs to be designed in consideration of the amount of the cleaning liquid to be pushed in the reciprocating motion of the plunger 576A or the like.
The seal part 576C is provided so as to be in contact with the outer periphery of the plunger 576A, the valves 574 and 575, and the O-rings 574a and 575a fitted in the valves prevent the cleaning liquid in the compression chamber 573 from leaking outside, that is, do not interfere with a pressure rise in the compression chamber 573 associated with the movement of the plunger 576A, with the result that the cleaning liquid (pressure) pushed by the plunger 576A is ejected unchangedly from the nozzle 31, thereby achieving high-pressure (e.g., about 3.0 MPa) cleaning. Note that the pressure of 3.0 MPa has experimentally been calculated as the lowest pressure at which stains are actually washed out with a nozzle diameter of 0.6 mm. However, the lowest pressure is not limited to the above value, but may be appropriately set in accordance with the diameter of the ejection port of the nozzle 31.
The pump system includes not only the plunger system, but also a rotary pump system and the like. In the rotary pump system, when a pressure in the rotary pump is increased, the cleaning liquid is returned (flows back) between a rotating body and a casing thereof to prevent pressure rise. Thus, the rotary pump type is not suitable for high-pressure cleaning but for an atomizer (operating at a pressure of about 0.5 MPa) that does not require high-pressure.
Conventional common type high-pressure washing devices adopt the three-plunger system (provided with three plungers). In the three-plunger system, three plungers are made to reciprocate with a phase difference of 120 degree with each other to eject the cleaning liquid. Thus, as illustrated in solid line of
The high-pressure washing device 1 according to the present embodiment, adopting the single plunger system as described above, can resolve the above drawback of the three-plunger system. Theoretically, in the single plunger system, the cleaning liquid ejected from the nozzle 31 during one reciprocating motion of the plunger 576A (one rotation of the crank 576B) varies in amount so as to have 100% pulsation (variation in flow rate), as illustrated in
In the present embodiment, the high-pressure cleaning is performed using the cleaning liquid accommodated in the tank 6, that is, there is a limit to the amount of cleaning liquid to be used. On the other hand, most conventional high-pressure washing device is used by connecting to the waterworks, that is, the cleaning liquid is supplied substantially unlimitedly. Thus, in the case where the cleaning liquid is supplied from the waterworks as in the conventional way, the use of the three-plunger system is not problematic. However, in the case where there is a limit to the amount of the cleaning liquid to be used as in the present embodiment, there occurs a problem that the cleaning liquid in the tank 6 is used up early. Therefore, in the tank system where there is a limit to the amount of the cleaning liquid to be used, the single plunger system capable of performing high-pressure ejection equivalent to that in the three-plunger system and suppressing the waste of the cleaning liquid is more suitably used. The use of such a single plunger system can prolong operation time.
Further, the single plunger system, having only one plunger 576A, can reduce a sliding resistance caused by the reciprocating motion to about one-third of that in the three-plunger system. On the other hand, the three-plunger system drives the three plungers, casing a large sliding resistance between the plungers and a member supporting the plungers, resulting in an increase in power consumption. The single-plunger system is, as described above, capable of reducing the sliding resistance to about one-third due to existence of only one plunger, thus suppressing the waste of power. Thus, the high-pressure washing device 1 according to the present embodiment can increase efficiency of the reciprocating motion of the plunger 576A, i.e., rotating efficiency of the motor 562, which in turn results in suppression of electric power of the battery pack 7.
In the present embodiment, the motor 562 is driven by power supplied from the battery pack 7, that is, there is a limit to the amount of power to be used. On the other hand, conventional high-pressure washing devices receive power supply from a commercial power supply, that is, the power is supplied substantially unlimitedly. Thus, if the power is supplied from the commercial power supply as in the conventional way, the use of the three-plunger system not effective in power saving is not problematic. However, if there is a limit to the amount of the power to be used as in the present embodiment, the power of the battery pack 7 may be used up immediately to fail to drive the motor 562. Therefore, in a cordless type (battery-driven type) having a limit to the amount of the power to be used, the single plunger system is more appropriately used because of increasing the rotating efficiency of the motor 562 to suppress the waste of the power of the battery pack 7 while performing high-pressure ejection equivalent to that in the three-plunger system. The use of such a single plunger system can prolong operation time.
Further, in the three-plunger system, a motor having a high rated output is required in order to overcome the sliding resistance of the three plungers, disadvantageously increasing a size of the entire apparatus, which results in an increase in weight thereof. On the other hand, in the single plunger system, the sliding resistance can be suppressed since only one plunger is provided, so that a small-sized motor suffices. Further, the number of parts can be reduced to thereby reduce the size and weight of the entire apparatus. Thus, adoption of the single plunger system allows the use of a cordless type (connection to the commercial power supply is not required) high-pressure washing device 1 that is driven by the small-sized and light-weighted battery pack 7. Thus, there can be provided a user-friendly high-pressure washing device 1 capable of being carried/operated by hand and thus not restricted in terms of working area.
Actually, the ejection port 572 (compression chamber 573) is subject to a pressure that prevents ejection of the cleaning liquid from the high-pressure hose 2 side. That is, the nozzle 31 has a diameter of as small as 0.6 mm, so that the cleaning liquid is difficult to eject. When a pressure in the ejection port 572 is increased, the high-pressure hose 2 is expanded to function in the same manner as the compression chamber 573 to suppress pulsation, so that 100% pulsation (variation in flow rate) as illustrated in
In an extreme case, the pulsation of the cleaning liquid ejected from the nozzle 31 approaches to substantially 0% (pulsation becomes small) in a case where the plunger 576A is made to reciprocate at high-speed and approaches to substantially 100% (pulsation becomes large) in a case where the plunger 576A is made to reciprocate at low-speed. However, in reciprocating motion of the plunger 576A at extremely high-speed, the cleaning liquid and electric power are wasted as in the case of the three-plunger system, whereas in the reciprocating motion at extremely low-speed, cleaning capability may become insufficient, and vibration due to the pulsation may be increased.
In order to cope with this, in the high-pressure washing device 1 according to the present embodiment, the reciprocating motion (the number of reciprocations) of the plunger 576A, that is, a rotating speed of the motor 562 is controlled such that the pulsation of the cleaning liquid ejected from the nozzle 31 becomes 20% or more, preferably, in a range of 20% to 60% as illustrated in
As a result, the cleaning liquid can be ejected from the nozzle 31 at a pressure having sufficient cleaning capability while suppressing the waste of the cleaning liquid. In the present embodiment, the cleaning liquid is configured to be ejected at a pressure of about 3.0 MPa to 7.0 MPa from the nozzle 31 by reciprocatingly moving the plunger 576A at a speed range of 1,000 rpm to 5,000 rpm. The term high-pressure used in the present embodiment refers to a pressure higher than that (e.g., 0.3 MPa) of common waterworks (specifically, 3.0 MPa or more, in the present embodiment).
In the pump 576 of the single plunger system, setting of a diameter D, a stroke S, and the reciprocation number N (rotating speed of the motor) of the plunger 576A for obtaining an ejection pressure of 3.0 MPa with a nozzle diameter of 0.6 mm will be described in detail. Performance of the pump 576 depends upon the diameter D, the stroke S, and the reciprocation number N of the plunger 576A, and a flow rate V of water ejected in one minute is represented by the following equation 1.
V (L/min)=D (mm)×S (mm)×N (rpm)×a (equation 1)
In equation 1, the diameter D is a diameter of the plunger 576A of
When the diameter D is increased, an area where the plunger 576A pushes the cleaning liquid is correspondingly increased. For example, if the cleaning liquid is ejected at 3.0 MPa by the plunger 576A having 10 mm diameter D, a thrust force of 236 kg is required generally calculated by radius×radius×p×pressure. If the diameter D is increased by 2 mm, a thrust force of 339 kg is required. That is, an increase of only 2 mm in the diameter D requires an increase in a thrust force by 103 kg. In order to increase the thrust force, the motor 562 needs to be replaced with a higher-output (larger) motor and, further, a bearing and a housing each subjected to reaction force need to be reinforced. This leads to an increase in the size of the entire high-pressure washing device 1 and cost.
On the other hand, when the stroke S is increased, a travel amount of the plunger 576A is correspondingly increased. For example, if the stroke S is 5 mm, a clearance of the compression chamber 573 corresponding to a radius of 2.5 mm of the crank 576B and a 5 mm stroke is required. In order to further increase the stroke S by 5 mm, a clearance of the compression chamber 573 corresponding to a radius of 5 mm of the crank 576B and a 10 mm stroke is required. That is, an increase of 5 mm in the stroke requires an extended structure of 7.5 mm in total, leading to an increase in the size of the entire high-pressure washing device 1.
Further, in a case where the reciprocation number N of the plunger 576A is constant, Dt seconds which is time required for one stroke is constant. Thus, an average plunger speed U is calculated by the following equation 2.
U (m/s)=N (rpm)/60×S (m)×2 (equation 2)
If the reciprocation number N of the plunger 576A is set to a constant value of 3,000 rpm, the speed U is 0.5 m/s when the stroke S is 5 mm and, when the stroke S is increased to 10 mm, the speed U is doubled (1.0 m/s). The plunger 576A reciprocatingly moves while slidingly contacting the seal part 576C and the metal 576D. When the stroke S is increased to increase the speed U, a material having higher abrasion resistance is necessary, leading to an increase in cost.
Next, a case is considered where the reciprocation number N (rotating speed of the motor 562) of the plunger 576A is variable. If the reciprocation number N is set to a given value, the reciprocation number N and a displacement volume J need to be adjusted in order to realize a predetermined flow rate V. The displacement volume J is defined by multiplying a cross-section area of the plunger 576A by the stroke S.
An increase in the reciprocation number N allows a reduction of the displacement volume J while maintaining the predetermined flow rate V, thereby allowing a reduction in a size of the plunger 576A. The high-pressure hose 2 extends from the plunger 576A to the nozzle 31, and the expansion/contraction of the high-pressure hose 2 suppresses the pulsation. That is, when the cleaning liquid is ejected at high-speed with a small volume, ejection pulsation becomes smaller than a theoretical ejection waveform (
On the other hand, if the reciprocation number N is reduced while maintaining the predetermined flow rate V, the displacement volume J is correspondingly increased and the size of the plunger 576A is also increased. In this case, the ejection pulsation is relatively larger so as to become generally the theoretical ejection waveform (
Thus, the diameter D, the stroke S, and the reciprocation number N of the plunger 576A each need to be set to an optimum value in consideration of the size of the apparatus, cost, flow rate, or the like. In the present embodiment, the optimum range of use of each setting values is experimentally calculated in terms of suppressing an increase in the size of the apparatus and cost, the use amount of electric power and water, and the vibration. Specifically, in the present embodiment, the plunger diameter D is set to 5 mm to 20 mm, the stroke S is set to 3 mm to 10 mm, and the reciprocation number N of the plunger 576A is set to 1,000 rpm to 5,000 rpm. More specifically, in the present embodiment, in order to obtain an ejection pressure of up to about 7.0 MPa with the nozzle diameter of 0.6 mm, the plunger diameter D is set to 12 mm, the stroke S is set to 5 mm (eccentricity of the crank 576B is 2.5 mm), and the reciprocation number N of the plunger is set to 3,000 rpm, as optimum values.
In the single plunger system, the ejection pulsation reaches 100% as illustrated in
A peak time during which the cleaning liquid is ejected at the maximum pressure is a certain time period (momentary) within one reciprocating motion of the plunger 576A. In other word, a time period during which the cleaning liquid is ejected at a pressure other than the maximum pressure is extremely longer than the peak time. As illustrated in
Thus, in the single plunger system, the ejection pressure is raised to a peak value equivalent to that in the conventional three-plunger system for each stroke of the plunger 576A, thereby allowing achievement of the high-pressure cleaning. At this time, the ejection pressure (water amount) pulsates, so that the cleaning can be performed while saving the amount of the cleaning liquid to be used as compared to the continuous ejection in the conventional three plunger system.
Further, the conventional three-plunger system employs the rotating swash plate having a non-uniform thickness in the plunger axial direction instead of the crank 576B. In detail, the inclined surface of the rotating swash plate is in confrontation with the three plungers. That is, the rotation of the rotating swash plate in this state causes the plungers contacting the thickened portion of the rotating swash plate to sequentially be pushed, whereby the plungers can be made to reciprocate.
However, in such a configuration, the rotating swash plate and the plunger are in sliding contact with each other, and the sliding resistance therebetween consumes more electric power.
On the other hand, in the present embodiment, the plunger 576A is made to reciprocate by means of the crank 576B, reducing the sliding resistance (there is no sliding resistance between the rotating swash plate and plunger) as compared to the three-plunger system. Also in this regard, the power consumption can be saved. Although the single plunger system is adopted in the present embodiment, a two-plunger system in which the number of the plungers to be provided is smaller than in the three-plunger system may be adopted, provided that the ejection pressure equivalent to that in the three-plunger system can be obtained while suppressing the amount of water to be ejected. In the case of the two-plunger system, two plungers are made to reciprocate with a phase difference of 180 degree. Thus, the cleaning liquid is not always ejected, so that the two-plunger system is more effective in water-saving and power-saving than the three-plunger system, although less effective than the single plunger system.
The following describes selection of a capacity of the battery pack 7 by which the high-pressure ejection can be achieved in the cordless type high-pressure washing device 1 of the present embodiment which is provided with the tank 6 and driven by the battery pack 7.
As illustrated in
Conversion efficiency is considered among the battery pack 7, the motor 562, and the pump 576. As illustrated in
First, a motor output required to drive the pump 576 based on the second efficiency (h2) will be discussed. Assuming that P stands for an ejection pressure and Q stands for an ejection flow rate, a power W2 (motor output, second power) required to drive the pump 576 can be generally calculated by the following equation 3.
W2 (W)=P (MPa)×Q (L/min)×1,000/60/h2 (equation 3)
Assuming that the second efficiency h2 is 50% to 80% which is a pump efficiency of the common type high-pressure washing device, the power W2 of about 60 W to 100 W is obtained from
The motor 562 is driven by power supplied from the battery pack 7. Here, battery pack power W1 (first power) will be considered in order to attain about 60 W to 100 W as the power W2 (motor output). The power W2 is a value obtained by multiplying the battery pack power W1 by the first efficiency h1 and, accordingly, the battery pack power W1 can be obtained by dividing the power W2 by the first efficiency h1 and represented as shown in a graph of
Assume here that the motor 562 is a commonly-used DC motor. In this case, motor efficiency of the motor 562 is 50% to 80%. As show in the graph of
The battery pack 7 will next be described in detail. According to the above description, the power of the battery pack 7 is required at 200 W. Assuming that the tank 6 can accommodate the cleaning liquid of 4 liters. It is preferable that the battery pack 7 is required to supply enough power for the cleaning liquid of 4 liters to be ejected completely in one cleaning operation (one charging of the battery pack 7). Thus, assuming that the ejection flow rate Q of the nozzle 31 is 1 liter per minute, the battery pack 7 is required to have a capacity of about 13.3 Wh (200 (W)×4 (Liters)/1=800 (W/min)).
To obtain an output power of 200 W from the battery pack 7 (a lithium ion battery) whose battery cell has 3.6 V rated voltage and 20 A discharge current, at least three battery cells are required (3.6 V×3 (series or parallel connected cells)×20 A=216 W). That is, when the three cells are connected in series, the battery pack 7 of 10.8 V or more can be applied. Three or more cells are connected in parallel, an output power equal to or greater than that of the battery pack of 10.8 V can be obtained. Examples of a rated voltage of the battery pack 7 used in a power tool include 3.6 V, 10.8 V, 14.4 V, 18.0 V, 25.2 V, and 36.0 V, and examples of a battery capacity thereof include 1.5 Ah, 2.0 Ah, and 3.0 Ah. The battery voltage and battery capacity differs depending on the number of series-connected battery cells and the number of parallel-connected battery cells, respectively. For example, when three 3.6 V battery cells are connected in series, 10.8 V is obtained as the battery pack, and when two 1.5 Ah battery cells are connected in parallel, 3.0 Ah is obtained as the battery pack. The voltage and the capacity per battery cell differ depending on manufacturers. Although, the present embodiment employs a battery pack having a rated voltage of 3.6 V and a capacity of 1.5 Ah, various types of battery cells is available.
The battery pack 7 having a rated voltage of 10.8 V and a capacity of 1.5 Ah achieves a capacity of 16.2 Wh. A battery pack having a rated voltage of 10.8 V or more satisfies the required capacity of 13.3 Wh. Alternatively, a battery in which three battery cells each having a rated voltage of 3.6 V are connected in parallel can satisfy the required capacity.
Next, cleaning operation time of the high-pressure washing device 1 will be considered. For example, in a case where the battery pack 7 has a rated voltage of 10.8 V and a capacity of 1.5 Ah, a battery energy of 16.2 Wh is obtained. Assuming that a minimum power of the battery pack 7 is 200 W, cleaning operation can be performed for about five minutes. The cleaning liquid (4 liters) in the tank 6 can be consumed within this five minutes. That is, cleaning operation time can be ensured during which at least the cleaning liquid (4 liters) in the dedicated tank 6 of the high pressure washing device 1 can be consumed.
From above, a relationship among the rated voltage (V), the battery capacity (Ah), the battery energy (Wh), and the cleaning operation time (minute) is obtained as shown in Table 1 below. At this time, the ejection pressure is set to 3.0 MPa, the ejection flow rate Q is to 1 liter per minute, the battery power is to 200 W, and the average discharge current is to 20 A (per battery cell). In the case of the lithium battery, applying overcurrent may cause degradation of the battery. Thus, the average discharge current is preferably reduced to 30 A or less. For example, the battery pack 7 or the control circuit 561 may be provided with a current detection section for detecting a current value every predetermined time interval. In this case, for example, when the detected current value exceeds 30 A at a predetermined number of times for, e.g., 10 seconds, overcurrent is determined to stop the discharge. In this case, the gun 3 may be provided with a display section for indicating, using an LED, that the discharge is stopped by the overcurrent. Further, the display section may display a residual capacity of the battery pack 7.
In the present embodiment, the battery pack 7 has a rated voltage of 14.4 V and a battery capacity of 3.0 Ah, and thus a battery energy and output power of the battery pack 7 are 43.2 Wh and 288 W, respectively. Then an operation time is about 13 minutes, which allows consumption of water corresponding to two dedicated tanks 6. This operation time (13 minutes) is a time, for example, capable of cleaning all windows in the second floor of a typical house. Further, the cleaning operation can be performed while raising or dropping the battery voltage.
The high-pressure washing device 1 has cleaning capability of 1 liter per minute in the present embodiment. However, the cleaning capability may be increased in a case where the cleaning capability needs to be increased at the expense of weight of the device 1, or in a case where light weight is preferred over the cleaning capability, and the like. For example, for obtaining an ejection pressure of 3.0 MPa and an ejection flow rate of 3 liter per minute, the battery power requires 600 W calculated from the above equation 3 in case where the efficiency h1 and the efficiency h2 are set to 50%. In this case, a battery pack having a rated voltage of 36.0 V should be selected with reference to Table 1. The 36.0 V battery is used recently in gardening tools and has a weight (about 1.4 kg) that an operator can carry. Further, when cleaning capability is set to 5 liters per minute (battery power 1,000 W) equivalent to conventional devices or 6 liters per minute, two 36.0 V batteries should be used in combination. The battery pack having a rated voltage of 14.4 V and a capacity of 3.0 Ah has a weight of about 530 g, and a battery pack having a rated voltage of 18.0 V and a capacity of 3.0 Ah has a weight of about 700 g. That is, even when more battery power is required and thus a one-size-bigger battery is used, the weight does not become so great that portability is not impaired.
Assuming that the ejection pressure is set to 7 MPa: approximate 450 W battery power is required if the flow rate is set to 1 liter per minute; 1400 W battery power is required if the flow rate is set to 3 liter per minute; and approximate 2300 W battery power is required if the flow rate is set to 5 liter per minute. When the required power is thus increased, a plurality of battery packs may be selected from Table 1 and used in combination. When a plurality of battery packs 7 are used in combination, the weight of the entire product is increased. In this case, however, wheels are provided in the high-pressure washing device 1 so as to allow the device 1 to be dragged, which prevents portability from being impaired.
Further, although the single plunger system is adopted in the present embodiment, the conventional three-plunger system may be adopted if the cleaning capability is prior rather than the consumption of the cleaning liquid, the consumption of power, and the weight. Even in this case, the high-pressure washing device 1 can be driven by the battery pack 7. For example, when the ejection pressure is set to 3 Mpa and the ejection flow rate is set to 1 liter per minute, a battery power of 600 W is required. This 600 W is three times that the required power in the single-plunger system is required simply because the number of the plunger is tripled. In this case, a 36.0 V battery may be used. That is, either the single plunger type or the three-plunger type may be used according to the purpose of usage as long as the high-pressure washing device 1 is driven by the battery pack 7 and performs high-pressure ejection.
Next, the weight of the high-pressure washing device 1 will be considered. Unlike the conventional device, the high-pressure washing device 1 according to the present embodiment uses the battery pack 7 as a drive source of the motor 562. In such a cordless type in which the tank 6 can be carried together with the main body, the weight of the high-pressure washing device 1 is preferably kept as low as possible in terms of portability. In particular, the weight of the battery pack 7 is directly reflected in the weight of the high-pressure washing device 1, and thus the weight of the battery pack 7 is desirably reduced. On the other hand, the present applicant sells FAW-SA series which is the conventional high-pressure washing device driven by a commercial power supply and which has a weight of about 4.5 kg. Thus, the weight of the high-pressure washing device 1 excluding the tank 6, i.e., the weight of the drive section (substantially corresponding to the lower housing 5 of
In the high-pressure washing device 1 according to the present embodiment, the weight of the drive section including the battery pack 7, the pump 576, and the motor 562 is about 4 kg equivalent to the weight of the conventional device. When the weight (4 kg) of the tank 6 (containing the cleaning liquid of 4 liters) is added to the weight of the drive section, the entire weight of the high-pressure washing device 1 is not much more than 8 kg. Thus, the portable high-pressure washing device 1 of the cordless type can be achieved.
From above, the minimum power W2 (100 W) and the minimum battery pack power W1 (200 W) each required for the cordless type high-pressure washing device 1 (3.0 MPa, 1 liter per minute) driven by the battery pack 7 are calculated in consideration of the efficiency h1 (50% to 80%) from the battery pack 7 to the motor 562 and efficiency h2 (50% to 80%) from the motor 562 to the pump 576. That is, according to the present embodiment, when the power W2 is set to 100 W or more and the battery pack power W1 is set to 200 W or more, the cordless type high-pressure washing device 1 can be provided. Further, when the battery pack 7 has more than or equal to 200 W output power and more than or equal to 13.3 Wh battery capacity, the cleaning liquid in the dedicated tank 6 can be ejected completely. Furthermore, even when the weight of the high-pressure washing device 1 becomes equivalent to that of the conventional device, existing battery packs can be used. In the present embodiment, a commutator DC motor is employed as the motor 562 and, thus, the conversion efficiency is settled at 50% to 80%. However, when a brushless motor is employed as the motor 562, the conversion efficiency is increased (80% or more), providing power reduction required from the battery pack 7.
As described above, in the high-pressure washing device 1 according to the first embodiment of the present invention, since the motor 562 is driven by power from the battery pack 7, the device 1 can be used without a commercial power supply. This configuration eliminates the need for a power cable to be connected to the high-pressure washing device 1, allowing wide range high-pressure cleaning to be performed without restriction of a length of the power cable. Further, a voltage drop due to presence of the power cable does not occur, providing a stable high-pressure cleaning.
Since the plunger 576A is disposed so as to constitute a part of the compression chamber 573, the plunger 576A is constantly cooled by the cleaning liquid. In addition, in the high-pressure washing device 1 according to the present embodiment, the plunger 576A and the crank 576B connected to the plunger 576A are each made of an aluminum alloy having high heat conductivity. Thus, cooling effect by the cleaning liquid is transmitted over a wide area, thereby preventing a temperature inside the high-pressure washing device 1 from being increased due to heat generated in the motor 562.
Further, the inside of the lower housing 5 is divided by a partitioning plate 54 into the battery chamber 55, the motor chamber 56, and the pump chamber 57, thereby preventing the cleaning liquid in the pump chamber 57 from flowing into the battery chamber 55 and the motor chamber 56. Thus, water damage to components provided in the pump chamber 57, and the battery chamber 55 can be avoided. Further, the tank 6 is provided above the drive section (pump chamber 57 and the like), so that the cleaning liquid flows down into the drive section by its own weight, thereby eliminating the need to additionally provide a pump for pumping up the cleaning liquid.
Further, the battery pack 7 can be detachably attached to the lower housing 5, facilitating charging and replacement of the battery pack 7.
Further, since the battery pack 7 can be used for a power tool, the battery pack 7 used for the power tool can also be applied to the high-pressure washing device 1.
Further, since the battery pack 7 supplies more than or equal to 40 Wh electric power to the motor 562, cleaning operation with a high ejection pressure can be performed for ten minutes or longer.
Further, an average discharge current flowing to the battery cell of the lithium ion battery is set to more than or equal to 20 A, suppressing a degradation thereof.
Further, an average discharge current flowing to the battery cell of the lithium ion battery is set to less than or equal to 30 A, suppressing a degradation thereof.
Further, since the nozzle 31 is formed with an outlet port having a diameter at 0.6 mm, high pressure cleaning with at least 3 Mpa can be achieved.
Further, since the valves 574 and 575 as a check valve are provided respectively at the intake port 571 and the ejection port 572 each connected to the compression chamber 573, a pressure inside the compression chamber 573 is prevented from leaking or decreasing, thereby allowing the pressure of the cleaning liquid to be raised stably in the pump.
Further, since the pump 576 is provided with a single plunger 576A, a consumption of the cleaning liquid can be saved.
A high-pressure washing device 1A according to a second embodiment of the present invention will be described with reference to
As illustrated in
Hereinafter, the same reference numerals are given to the same components as in the first embodiment to avoid duplicated description.
As illustrated in
As illustrated in
As illustrated in
As illustrated in
When the battery cover 53 is closed, the engaging protrusion 53A is engaged with the engaged portion 55A and, at the same time, the waterproof protrusion 53B is brought into abutment with the seal portion 55B. This prevents more reliably the cleaning liquid from flowing into the battery chamber 55 from outside.
The battery chamber 55 is provided with a guide rail 55C and a latched portion 55D as illustrated in
As illustrated in
As described above, in the high-pressure washing device 1A according to the present embodiment, the battery chamber 55 and the motor chamber 56 are accommodated in the housing 5A disposed above the tank 6A. Even if the cleaning liquid has leaked from the tank 6A, the cleaning liquid is unlikely to flow in the battery chamber 55 and the motor chamber 56. This prevents the battery pack 7 accommodated in the battery chamber 55, the control circuit 561, and the motor 562 accommodated in the motor chamber 56 from breaking down due to introduction of the cleaning liquid thereinto.
Further, the seal members 54A are mounted to the partitioning plate 54, thereby preventing more reliably the inflow of the cleaning liquid into the battery chamber 55 and the motor chamber 56. Further, the seal portion 55B is provided also in the battery chamber 55, thereby preventing the cleaning liquid or rainwater from being introduced into the battery chamber 55.
The battery pack 7 to be attached to and detached from the battery chamber 55 is guided by the guide rail 55C formed in the battery chamber 55, facilitating attachment of the battery pack 7 to the battery chamber 55.
Further, the battery pack 7 has the latching portion 7B engaged with the latched portion 55D of the battery chamber 55, thereby reliably and easily fixing the battery pack 7 in the battery chamber 55.
A high-pressure washing device 1B according to a third embodiment of the present invention will be described with reference to
Hereinafter, the same reference numerals are given to the same components as in the first and second embodiments to avoid duplicated description.
As illustrated in
More specifically, the first engagement portion 5a is formed into a cylindrical shape and has, in an inner peripheral surface thereof, a female screw portion corresponding to a male screw formed in a spout of the plastic tank 6B (
As described above, the high-pressure washing device 1B according to the present embodiment does not require the dedicated tank such as the tank 6 of the first embodiment and tank 6A of the second embodiment and can perform high-pressure cleaning by using a commercially-available container.
A high-pressure washing device 1C according to a fourth embodiment of the present invention will be described with reference to
Hereinafter, the same reference numerals are given to the same components as in the first to third embodiments to avoid duplicated description.
As illustrated in
The adapter 8 includes an engagement portion 8a, a fitting part 8b, and a pair of locking portions 8c serving as a fixing portion.
The engagement portion 8a is formed into a cylindrical shape and has, in an inner peripheral surface thereof, a female screw portion meshingly engageable with a male screw formed in a spout of the commercially-available container (in the present embodiment, PET bottle 6C).
The fitting part 8b is provided above the engagement portion 8a and has a concave shape opening upward.
Each of the locking portions 8c is pivotally movable about a shaft 8d and has a locking protrusion 8e protruding inward from an upper end of the locking portion 8c. Further, each of the locking portions 8c is biased by a not-illustrated spring so as to cause the locking protrusion 8e to travel inward. The locking portion 8c may be provided on a pressing portion 45A side, not the adapter 8 side as long as the container 6C does not come off from the high-pressure washing device 1C.
The housing 5B includes, at a lower portion thereof, a pressing portion 45A similar to the pressing portion 45 of the first embodiment.
The pressing portion 45A extends in the vertical direction and is formed with the inlet 451 extending in the vertical direction. Further, the pressing portion 45A is formed with a locked portion 45a having a concave shape opening outward at an upper end thereof.
As illustrated in
As described above, in the present embodiment, the high-pressure washing device 1C and commercially-available container can be connected to each other through the adapter 8. That is, the use of a plurality of types of adopters 8 allows the high-pressure cleaning to be performed in various scenes with the high-pressure washing device 1C.
The high-pressure washing device according to the present invention is not limited to the above-described embodiments, but may be variously changed and modified within the scope of the claims of the invention.
For example, as illustrated in
Further, as illustrated in
Further, as illustrated in
Further, as illustrated in
For the similar reason, as illustrated in
Further, in the second embodiment, an additional seal member 54B (third seal member) may be provided between the electrode 551 of the battery chamber 55 and the battery pack 7, as illustrated in
Further, as illustrated in
The pump 576 is not limited to a type described in the above embodiments but may be, e.g., a piston pump.
Although the cleaning liquid to be ejected from the nozzle 31 has a pressure of 3 MPa to 7 MPa in the above embodiments, the minimum pressure need not be 3.0 MPa but may be any value as long as cleaning operation can be effectively performed. Although the pressure of 3.0 MPa has experimentally been calculated as the lowest pressure at which stains can be removed, this value can be changed in accordance with a diameter of the nozzle. For example, the minimum pressure may be set to 2.5 MPa, provided that cleaning can be effectively performed.
Further, attaching a shoulder belt to the high-pressure washing device according to the present invention facilitates wide area high-pressure cleaning. For example, as illustrated in
Although the cleaning liquid container is provided above or below the housing in the above embodiments, the container may be provided on a side of the housing. In this case, when an opening portion (outlet port) of the container faces downward, the pump may have a configuration as illustrated in
| Number | Date | Country | Kind |
|---|---|---|---|
| 2012-033402 | Feb 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2013/000778 | 2/13/2013 | WO | 00 |
