Patent Application
20240391058
The invention relates to a grinding machine for grinding a surface of an object, comprising at least one grinding tool with a movably mounted abrasive carrier and a plurality of abrasive elements attached to the abrasive carrier, and an abrasive drive device for driving the grinding tool in a first relative movement to the object, a conveying device for conveying the object in a second relative movement to the grinding tool through the grinding machine. Another aspect of the invention is a grinding tool for grinding a surface of an object and a method for grinding a surface of an object.
Such grinding machines and grinding tools are used to process the surfaces of workpieces. On the one hand, the processing can involve macroscopic smoothing, in which the surfaces are ground plane and macroscopic unevenness is removed. Surface treatment by grinding can also be used to produce a certain roughness, in which microscopic surface roughness from previous machining processes is reduced and a higher quality surface is produced in terms of surface quality and roughness.
Another aim of grinding a surface can be to achieve a specific optical pattern through the grinding process. A desired, predetermined grinding pattern is created on the surface by a relative movement between the grinding tool and the workpiece surface. The movement is often generated by a rotation of the grinding tool, superimposed on a translational movement of the workpiece and possibly other superimposed swivel or rotational movements around other axes between the grinding tool and the workpiece.
Different shapes of grinding tools can be used for such grinding processes. One versatile form, for example, is the disk brush, in which a disk-shaped abrasive carrier is used, which has a large number of abrasive elements on an axial end face facing the workpiece, which can be formed as abrasive bristles or abrasive paper sections, for example. The plate-shaped abrasive carrier is then rotated about a central axis, which is perpendicular or slightly inclined to the perpendicular to the surface of the workpiece to be machined, thereby generating a component of the relative movement between the grinding tool or the abrasive elements and the surface. Another design of a grinding tool is the roller brush, in which a cylindrical circumferential surface faces the workpiece and the rotation of the grinding tool takes place around a central axis, which corresponds to the cylindrical center axis.
The abrasive elements are thereby often formed by an abrasive element carrier coated with abrasive elements such as corundum grains or other sharp-edged grains made of suitable hard materials. The abrasive elements are bonded to a surface of the abrasive element carrier or integrated into the abrasive element carrier. The fact that these abrasive elements have a certain length means that the wear caused by abrasion or breakage of the grains can be compensated for over a longer processing period by shortening the abrasive elements accordingly, allowing new, sharp-edged grains to be continuously brought into grinding engagement with the surface of the workpiece.
Due to their design, the abrasive elements are flexible to a certain degree and are moved over the surface of the workpiece with a rotating drag movement during machining. Consequently, they are not exactly axially aligned and protruding from the abrasive carrier, but are bent backwards against the direction of movement due to a force caused by the rotational movement in the circumferential direction, so that an end section of the forward-facing surface of the abrasive elements, which is covered with the abrasive elements, rests on the surface.
Such an abrasive element can be formed by an abrasive paper section. For the purposes of the invention, an abrasive paper section is to be understood as a flexible abrasive paper-like element which, on the one hand, has a flexible carrier material which can, for example, be in the form of paper or textile and to which the abrasive grains can be attached by means of a suitable bonding material. The end section, which rests on the surface to be grinded, can form an at least linear, preferably plane, contact between part of the overall surface of the abrasive paper section and the surface of the workpiece.
Despite the very long service life of such disk brushes, one problem with grinding is that the grinding result is affected by the wear of the disk brush, i.e. either the optical properties of the surface change or the qualitative properties of the surface, i.e. the evenness and roughness, change, and in particular no longer fall within the desired tolerance range. This can include both an insufficient grinding effect, resulting in insufficient material removal and a possibly undesirable polishing result instead of effective grinding removal. As a result, the effect achieved by the processing can lead to inadequate smoothing with a roughness of the processed surface that does not correspond to the desired target value.
It is known to optically detect the surface of the workpiece in order to incorporate such changes into the control of grinding parameters or to conclude from such changes that the disk brush needs to be replaced and to initiate a corresponding replacement. For example, DE 102018105133A1 and DE102018105134A1 already disclose corresponding grinding machines with such detection systems. It is true that a desired surface quality can be set much better with such technology, even if the disk brush is subject to wear during processing. However, on the one hand, there are certain limits to the compensation of the wear of the disk brush by adjusting the grinding parameters, and on the other hand, the adjustment of grinding parameters depending on the measurement of the surface properties can often only insignificantly extend the service life of the disk brush, so that even with these previously known solutions it is necessary to replace the disk brush or the several disk brushes used in the grinding machine at regular intervals, thereby reducing the economic efficiency of the grinding machine and necessitating downtime and investment.
The invention is based on the task of providing a grinding machine and a grinding process with which a more economical processing of surfaces can be achieved.
This problem is solved in accordance with the invention in that the plurality of abrasive elements has a plurality of first surfaces provided with first abrasive bodies for lying against the surface of the object in a first direction of movement of the abrasive carrier and a plurality of second surfaces provided with second abrasive bodies for lying against the surface of the object in a second direction of movement of the abrasive carrier opposite to the first, and in that the abrasive drive device is adapted to drive the grinding tool in the first direction of movement, in which the first surfaces of the abrasive elements are in grinding engagement with the surface of the object, and in the second direction of movement, in which the second surfaces of the abrasive elements are in grinding engagement with the surface of the object, and further in that a control device is provided which is coupled to the abrasive drive device by means of signals and is adapted to switch the abrasive drive device back and forth between the first and the second direction of movement.
According to the invention, first and second surfaces are provided on the abrasive carrier by the plurality of abrasive elements, each of which is provided with abrasive elements. The first surfaces are aligned in such a way that they point in a first direction of movement of the grinding tool and thus come into contact with the surface of the object in this first direction of movement of the abrasive carrier. This can be realized, for example, by abrasive elements designed in the manner of abrasive paper sections, which have a surface provided with abrasive elements that are bent by the abrasive force in the opposite direction to the direction of movement and thus come into contact with the surface of the object to be grinded. In the case of disk brushes, for example, this can be achieved by the abrasive elements being adapted as abrasive paper sections and extending axially from the disk with the first surfaces facing in a first circumferential direction.
According to the invention, a plurality of second surfaces, which are also provided with corresponding abrasive elements, is further provided by the plurality of abrasive elements on the abrasive carrier. These second surfaces lie point in a second direction of movement, which is opposite to the first direction of movement, and lie against the surface of the object in this direction of movement, which in turn, as explained above, can be achieved by correspondingly bending and conforming sections of abrasive paper sections which form these second surfaces.
The second surfaces preferably do not lie against the surface of the object in the first direction of movement and, accordingly, the first surfaces are do not lie against the surface of the object in the second direction of movement. In the case of disk brushes, for example, this can be achieved by the abrasive elements being designed as abrasive paper sections and extending axially from the disk and the second surfaces pointing in a second circumferential direction opposite to the first.
According to the invention, the abrasive drive device is further adapted to move the abrasive elements selectively both in the first and in the second direction of movement relative to the surface of the object, i.e. to reverse the direction of movement accordingly, for which purpose, according to the invention, a corresponding control device for the abrasive drive device is further provided, which controls a corresponding reversal between the first and the second direction of movement, i.e. switches the movement from the movement along the first direction of movement to a movement along the second direction of movement and vice versa.
Consequently, the invention makes it possible for the grinding tool used to achieve a grinding effect in two different directions of movement of the abrasive carrier and for different surfaces of the grinding tool to come into grinding engagement. As a result, the service life of the grinding tool can be extended compared to previously known grinding tools; furthermore, it is achieved that the abrasive effect can be changed by correspondingly reversing the direction of movement, thereby enabling the desired optical abrasive results to be achieved over a longer period of time or previously unattainable optical results caused by reversing the direction of movement to be achieved.
According to a first preferred embodiment, it is provided that the abrasive drive device is adapted to drive the grinding tool in a rotational movement as a first relative movement and the control device is adapted to switch the rotational movement back and forth between a clockwise rotation and a counterclockwise rotation. This type of further development of the abrasive drive device makes it possible, on the one hand, to achieve a relative movement between the grinding tool and the surface that is efficient for processing the surface and well suited for many desired surface structures and, on the other hand, to use grinding tools adapted for such a rotational movement, such as disk brushes.
It is even more preferred if the abrasive drive device is adapted to set the grinding tool in rotation about an abrasive rotation axis and the abrasive rotation axis is formed on a grinding tool guide element which is pivotably or rotatably mounted about a guide axis which is not coaxially aligned with the abrasive rotation axis and which is preferably arranged parallel to and distanced from the abrasive rotation axis. According to this embodiment, in addition to the rotation of the grinding tool about the grinding rotation axis itself, a superimposed movement of the grinding rotation axis about a distanced guide axis is carried out, which has various advantages. On the one hand, this allows several grinding tools to be used simultaneously and next to each other in the manner of satellites for grinding processing and to be pivoted or rotated about a common guide axis. This not only increases the processing area covered by the grinding tools, but also makes it possible to enlarge it even further by swiveling or rotating it around the guide axis and thus, in conjunction with the conveying device that conveys the object through the grinding machine, to perform a movement in three axes and thus, on the one hand, to perform a variably configurable grinding movement and, on the other hand, to cover a large surface with the grinding tools. In this mode of use, the extended service life achieved by the invention is therefore particularly beneficial and the additional possibility of reversing the rotational movement of the grinding tools about the axis of rotation means that particularly economical processing can be achieved.
It is preferred that the control device is adapted to control at least two mutually independent relative movements between the grinding tool and the surface of the workpiece in such a way that the superposition of these relative movements causes the first surfaces to engage with the surface of the workpiece in an area swept by the grinding tool and the second surfaces to engage with the surface of the workpiece in another area swept by the grinding tool, which in turn allows special grinding patterns to be produced that could not be achieved with previous grinding machines.
It is further preferred that the conveying device is adapted to convey the object through the grinding machine in a translatory, in particular linear, movement. In particular, the conveying device can be designed as an endless conveyor belt on which the objects can be placed, wherein the support surface of the conveying device is preferably adapted for high static friction with respect to the objects or has fastening means such as vacuum suction cups for holding the objects. A relative movement in relation to the surface of the workpiece basically corresponds to a real movement in relation to the support surface of the conveying device, i.e. in this case the endless conveyor belt
According to a further preferred embodiment, it is provided that some or each of the abrasive elements has a plane abrasive body carrier element which is coated on a front surface with the first abrasive bodies and is coated on a rear surface with the second abrasive bodies. In this embodiment, some of the abrasive elements or each of the abrasive elements are designed in such a way that they are coated on both sides with abrasive bodies such as corundum grains or the like and thereby form a front surface and rear surface which are effective for the abrasive action and which accordingly form the first surfaces and the second surfaces. The grinding tool can then be designed such that a plurality of such double-sided abrasive elements coated with abrasive grains are provided thereon, in particular such that all abrasive elements are coated on both sides in such a manner or that some of the abrasive elements are coated on both sides and other abrasive elements are only coated on one side. The abrasive elements coated on one side can be arranged on the abrasive carrier in such a way that they all face the same side with the surface coated with abrasive elements and consequently only come into engagement with the surface in one direction of movement, or they can be arranged in such a way that some of the abrasive elements coated on one side face the abrasive surface in one direction and some in the other direction, so that the abrasive elements coated on one side also exert an abrasive effect in both directions of movement of the grinding tool.
According to a further preferred embodiment, it is provided that the plurality of abrasive elements has a plurality of first plane abrasive body carrier elements, each of which is coated with the first abrasive bodies on a front surface forming the first surface and is not coated with abrasive bodies on a rear surface, has a plurality of second plane abrasive body carrier elements, each of which is not coated with abrasive bodies on a front surface and is coated with the second abrasive bodies on a rear surface forming the second surface, and the first and second abrasive body carrier elements are arranged on the abrasive carrier in such a way that in the first direction of movement the front surfaces of the first and second abrasive body carrier elements lie against the surface of the object and in the second direction of movement the rear surfaces of the first and second abrasive body carrier elements lie against the surface of the object. According to this embodiment, the grinding tool comprises a plurality of abrasive elements coated with abrasive bodies on one side only. These are divided into first and second abrasive body carrier elements, which are aligned differently. The first abrasive body carrier elements are arranged on the abrasive carrier in such a way that their surface coated with abrasive bodies comes into contact with the surface of the object in the first direction of movement and grinds this surface. The second abrasive body carrier elements are attached to the abrasive carrier in such a way that their surface coated with abrasive bodies engages with the surface of the object in the second direction of movement and grinds it. In this way, the grinding tool can be constructed from conventional abrasive paper sections coated on one side by attaching them to the abrasive carrier in two different orientations, thereby generating an abrasive effect in both directions of movement.
It is particularly preferred if the first and second abrasive body carrier elements are fastened alternately adjacent to one another on the abrasive carrier, so that the front surface of a first abrasive body carrier element faces the rear surface of a second abrasive body carrier element adjacent on a first side and the rear surface of the first abrasive body carrier element faces a front surface of a second abrasive body carrier element adjacent on a second side. In such an alternating arrangement of the two differently aligned abrasive body carrier elements, one abrasive element is thus fastened to the abrasive body carrier in such a way that its surface provided with abrasive bodies is aligned for machining the surface in the first direction of movement, and an abrasive element whose surface coated with abrasive bodies is aligned in such a way that it performs abrasive machining of the surface in the second direction of movement is arranged adjacent thereto. Consequently, two sides of the abrasive elements provided with abrasive bodies and two surfaces of the abrasive elements not provided with abrasive bodies alternately face each other on the grinding tool. This arrangement achieves a uniform abrasive effect of the abrasive elements over the entire processing length of the grinding tool, i.e. in the case of disc brushes over the entire circumference of the grinding tool in both directions of movement, and a favorable absorption of detached abrasive grains within the grinding tool is achieved.
This embodiment can be further developed by connecting the first and second abrasive body carrier elements to one another by partially or fully bonding the rear surface of the first abrasive body carrier element to the front surface of the second abrasive body carrier element. According to this embodiment, the surfaces of the abrasive elements that face each other and are not coated with abrasive bodies are joined together, in particular bonded together over their entire surface. On the one hand, this connection enables the grinding tool to be manufactured efficiently and, on the other hand, reduces the bending slackness of the abrasive elements, which is advantageous for abrasive machining, by creating a sandwich element consisting of two abrasive elements coated on both sides with abrasive bodies, which has a well-adapted rigidity against bending and thus avoids an unfavorable large-area contact of the surface provided with abrasive media on the surface of the object, even at higher contact pressures of the grinding tool on the surface, whereby an economically efficient grinding operation is better achieved.
As an alternative to the previously explained alternately adjacent arrangement of the abrasive elements, it is preferably provided in another embodiment that a first group of a plurality of first abrasive body carrier elements are arranged next to one another on the abrasive carrier and a second group of a plurality of second abrasive body carrier elements are arranged next to one another on the abrasive carrier and at least one first group and one second group are fastened to the abrasive carrier, preferably several first and second groups are fastened alternately adjacent to one another on the abrasive carrier. According to this embodiment, the abrasive elements are not alternately fastened to the abrasive carrier in different orientations, but several abrasive elements forming a group, whose surface provided with abrasive bodies faces the same side and consequently produces an abrasive effect on the surface of the object in the same direction of movement, are combined and arranged, whereas in turn several abrasive elements combined to form a second group are fastened to the abrasive carrier in such a way that their surface provided with abrasive bodies faces in the opposite direction and consequently comes into engagement with the surface of the object in the second direction of movement. This can be implemented, for example, in such a way that only the first and second groups of abrasive body carrier elements are present on the grinding tool, i.e. in the case of a disk brush, for example, the first and second groups each extend over 180° of the circumference. However, the embodiment can also be adapted in such a way that a plurality of first and second groups are present on the grinding tool, for example in each group only two, three, four or more abrasive elements attached to the abrasive carrier with the same orientation are provided and then a plurality of the first and second groups form the plurality of abrasive elements.
Such an arrangement in groups achieves, on the one hand, an advantageous grinding effect due to several successive surfaces of the abrasive elements in one section of the grinding tool that are provided with abrasive bodies and, on the other hand, an advantageous cleaning and wiping effect due to several successive surfaces of the abrasive elements in another section of the grinding tool that are provided without abrasive bodies, thereby reducing the risk of broken abrasive bodies having a detrimental effect on the grinding result.
In a further preferred embodiment, it is provided that the plurality of abrasive elements is in the form of a plurality of abrasive paper sections which are flexible, and the abrasive carrier
Finally, according to a further preferred embodiment of the grinding machine according to the invention, it is provided that the first abrasive bodies of the first surfaces have a first grain size and the second abrasive bodies of the second surfaces have a second grain size which is different from the first grain size. According to this embodiment, the first surfaces and second surfaces are provided with abrasive bodies of different grain sizes, so that in the first direction of movement of the grinding tool, abrasive bodies with a first grain size are brought to the surface for grinding and in the second direction of movement, abrasive bodies with a different grain size are brought to the surface for grinding. This embodiment can be designed in particular in accordance with the preferred embodiments explained above with abrasive body carrier elements coated on one side or on both sides with abrasive bodies, i.e. in that an abrasive body carrier element is either coated on one side with a first grain size and coated on a second side with a second grain size different therefrom, or in that abrasive elements are used which are coated on one side with abrasive bodies, a first type of the abrasive elements being formed by abrasive body carrier elements, which are coated on one side with abrasive bodies of a first grain size and which are aligned on the grinding tool in such a way that they come into grinding engagement with the surface in the first direction of movement, and a second type of abrasive element is formed by abrasive body carrier elements which are coated on one side with abrasive bodies of a second, different grain size and whose surface coated with abrasive bodies is aligned in the opposite direction to the abrasive elements of the first group, so that these come into grinding engagement with the surface when the grinding tool is moved relative to the surface in the second direction of movement.
In this preferred embodiment, it is therefore advantageously possible to carry out a grinding operation with two different grit sizes and consequently, for example, to carry out a first grinding operation on the surface with a coarse grain in order to smooth out larger surface irregularities by moving the grinding tool in the first direction of movement relative to the surface, and then to carry out a subsequent operation with the same grinding tool with a finer grain size in order to achieve a higher surface quality and lower roughness by moving the grinding tool in the second direction of movement relative to the surface of the object. Consequently, this embodiment avoids the need to change the grinding tool to achieve this grinding finish with coarse and fine grain, and the two-stage grinding finish can be carried out by a single grinding unit without changing the grinding tool in the grinding machine, so that the provision of a further grinding unit in the grinding machine is also not necessary.
A further aspect of the invention is a grinding tool for grinding a surface of an object, comprising an abrasive carrier and a plurality of abrasive elements attached to the abrasive carrier, wherein the plurality of abrasive elements has a first surface provided with first abrasive bodies for lying against the surface of the object in a first direction of movement of the abrasive carrier and a second surface provided with second abrasive bodies for lying against the surface of the object in a second direction of movement of the abrasive carrier opposite to the first direction of movement. The grinding tool according to this aspect of the invention is particularly suitable for use in a grinding machine of the design according to the invention described above. The grinding tool has a plurality of abrasive elements which form first surfaces for lying against a surface machined with the grinding tool when the grinding tool is moved over this surface with a first direction of movement, and second surfaces which are provided with second abrasive bodies which lie against a surface of a workpiece when the grinding tool is moved over this surface with a second direction of movement which is different from the first direction of movement. The first surfaces therefore face in a different direction than the second surfaces, in particular in an opposite direction.
The grinding tool is therefore suitable for use as explained above, i.e. to exert an abrasive effect on the surface when the grinding tool is guided over the surface in a first direction of movement and subsequently in a second direction of movement, and the grinding tool according to the invention thus has a longer service life.
The grinding tool according to the invention can be further formed in that some or each of the abrasive elements has a plane abrasive body carrier element which is coated with the first abrasive bodies on a front surface and is coated with the second abrasive bodies on a rear surface.
Furthermore, the grinding tool according to the invention can be further formed in that the plurality of abrasive elements has a plurality of first plane abrasive body carrier elements, each of which is coated with the first abrasive bodies on a front surface forming the first surface and is not coated with abrasive bodies on a rear surface, has a plurality of second plane abrasive body carrier elements, each of which is not coated with abrasive bodies on a front surface and is coated with the second abrasive bodies on a rear surface forming the second surface, and the first and second abrasive body carrier elements are arranged on the abrasive carrier in such a way that in the first direction of movement, the front surfaces of the first and second abrasive body carrier elements are lying against the surface of the object and, in the second direction of movement, the rear surfaces of the first and second abrasive body carrier elements are lying against the surface of the object.
Furthermore, the grinding tool according to the invention can be further formed in that the first and second abrasive body carrier elements are each fastened alternately adjacent to one another on the abrasive carrier, so that the front surface of a first abrasive body carrier element faces the rear surface of a second abrasive body carrier element adjacent on a first side and the rear surface of the first abrasive body carrier element faces a front surface of a second abrasive body carrier element adjacent on a second side.
Furthermore, the grinding tool according to the invention can be further formed in that the first and second abrasive body carrier elements are connected to one another by the rear surface of the first abrasive body carrier element being partially or fully connected to the front surface of the second abrasive body carrier element.
Furthermore, the grinding tool according to the invention can be further formed in that a first group of several first abrasive body carrier elements are arranged next to one another on the abrasive carrier and a second group of several second abrasive body carrier elements are arranged next to one another on the abrasive carrier and at least one first group and one second group are fastened to the abrasive carrier, preferably several first and second groups are fastened alternately adjacent to one another on the abrasive carrier.
Furthermore, the grinding tool according to the invention can be further developed in that the plurality of abrasive elements is formed as a plurality of abrasive paper sections,
Furthermore, the grinding tool according to the invention can be further formed in that the first abrasive bodies of the first surfaces have a first grain size and the second abrasive bodies of the second surfaces have a second grain size which is different from the first grain size.
These further embodiments of the grinding tool according to the invention correspond to those further embodiments of the grinding tool which is used in the grinding machine according to the invention explained above, and with regard to the variants and advantages of these further embodiments for the grinding tool according to the invention, reference is made to the variants and advantages of the grinding machine according to the invention with the correspondingly advanced grinding tool explained above.
Finally, a further aspect of the invention is a method of grinding a surface of an object, with the steps of: grinding the surface of the object by means of one or more grinding tools, each of which comprises a plurality of abrasive elements attached to at least one movably mounted abrasive carrier, wherein the plurality of abrasive elements of a grinding tool has a first surface provided with first abrasive elements for lying against the surface of the object in a first direction of movement of the abrasive carrier and a second surface provided with second abrasive elements for lying against the surface of the object in a second direction of movement of the abrasive carrier opposite to the first direction of movement, and that the grinding tool is moved in a first machining step in the first direction of movement in grinding engagement over the surface of the object and is moved in a subsequent second machining step in the second direction of movement in grinding engagement over the surface of the object.
The method according to the invention can be carried out in particular with a grinding machine or a grinding tool of the previously explained embodiment. The grinding method according to the invention is characterized by a long service life of the grinding tool and thus a possible economical grinding operation and has the further advantage that it can produce a greater variety of surface structures and patterns due to the possibility of reversing the direction of movement of the grinding tool and a grinding operation in both directions of movement.
In particular, the grinding method according to the invention can be further developed in that the first abrasive bodies of the first surfaces have a first grain size and the second abrasive bodies of the second surfaces have a second grain size which is different from the first grain size, with the steps:
With this type of grinding process, a grinding tool is used in a two-stage machining process to efficiently smooth out larger irregularities in the surface of the workpiece in a first machining step, followed by fine machining of the surface to achieve a low roughness in a second machining step, without the need to use two different grinding tools or two different grinding units with correspondingly different grinding tools within one grinding machine. This considerably increases the processing speed and the processing variance.
In addition to this two-stage machining, a further preferred embodiment of the grinding method according to the invention is that a first workpiece is machined by means of the grinding tool with a first direction of movement through the first surface and a second workpiece is machined in a subsequent machining process by means of the second direction of movement through the second surface of the grinding tool. On the one hand, this allows any contamination of the grinding tool that has occurred on the first surface due to the machining of the first workpiece, such as a layer of paint removed during the grinding process, to have no effect on the subsequent second machining process of the second workpiece, because different surfaces of the grinding tool are used here. Furthermore, this processing method makes it possible to process workpieces of different hardness by using abrasive bodies of different grain sizes on the first and second surfaces of the grinding tool, as explained above, and thereby enabling the abrasive effect to be adapted to workpieces with different properties by selecting the direction of movement of the grinding tool accordingly.
A preferred embodiment of a grinding tool according to the invention and a grinding machine according to the invention is explained with reference to the following figures. They show:
Referring first of all to
In a variant shown in
In a variant shown in
These grinding tools 530 are rotated within the disk brush grinding module about their respective disk brush rotation axis 530′a, b, c, . . . on the one hand, wherein this rotational movement can be performed clockwise and counterclockwise by the grinding machine in order to bring the first and second surfaces of the abrasive elements into corresponding engagement with a surface to be processed.
The workpieces to be processed are conveyed through the grinding machine on an endless conveyor belt 550 under the disk brushes. The disk brushes of the disk brush grinding module are attached as a triple satellite arrangement to a disk brush carrier 540a, b, c, . . . , which in turn is rotatably mounted about a satellite carrier axis 540′a, b, c, . . . and thereby causes a superimposed rotation about the disk brush rotation axes 530′a, b, c, . . . about a satellite carrier axis 540′a. As a result, even a workpiece with a large surface area and a width corresponding to the width of the endless conveyor belt can be grinded evenly by the disk brush grinding module.
In principle, the grinding machine according to the invention can be operated in such a way that the speed of the disk brushes around the disk brush rotation axes is many times greater than the speed at which the disk brush rotation axes are rotated around the satellite carrier axis. In this case, the speed of the disk brushes around the disk brush rotation axis determines the bending direction of the flexible abrasive elements and this is uniform. However, if the ratio of the speed around the disk brush rotation axis to the speed around the satellite carrier axis is reduced to a certain level or even the speed around the satellite carrier axis is increased to a multiple of the speed around the rotation axis, the relative speed of the abrasive elements to the workpiece surface is reversed in the course of a full revolution of the grinding tool around the disk brush rotation axis, which causes the abrasive elements to flip from grinding with the first surface to grinding with the second surface. In this case, the direction of contact of the abrasive elements with the first surface is changed twice during one revolution of the grinding tool around the axis of rotation and the abrasive elements grind with the first surface in a first section and with the second surface in a second section during this revolution. This can be advantageous in certain applications to achieve certain grinding patterns on the surface of the workpiece.
In a subsequent second processing step 1100 of a second workpiece, this second workpiece is moved under the grinding tool in the same direction of movement of the conveyor. However, the direction of movement of the grinding tools is reversed and the grinding tools therefore machine the second workpiece with the second surfaces. Any soiling or wear of the first surfaces of the abrasive elements by the first workpiece therefore has no effect on the processing quality of the second workpiece.
After the workpiece has passed completely under the disk brushes, either the direction of movement of the conveying device is reversed in a second processing step 2100 and the workpiece is guided under the disk brushes in the opposite direction. In this case, the direction of rotation of the disk brushes is reversed and the disk brushes are consequently guided over the surface in the second direction of movement, whereby the second surfaces of the abrasive elements come into grinding engagement with the surface. These second surfaces preferably have a finer grain than the first surfaces, so that finer processing and production of a high-quality surface with low roughness is achieved in this second processing step.
Alternatively, instead of reversing the direction of movement of the conveying device, the workpiece can also be removed from the grinding machine in an intermediate step 2200, fed to the grinding machine again at the front end and fed to the disk brush grinding unit again in the second processing step 2100 with the conveying device in the same direction of movement. As before, the disk brushes are then driven in the second direction of movement during this second machining operation, so that the second machining operation is performed with the second surfaces of the abrasive elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023113967.3 | May 2023 | DE | national |
