GRINDING MACHINE FOR GRINDING A SURFACE OF AN OBJECT

Abstract

A grinding machine for grinding a surface of an object has at least one grinding tool with a movably mounted abrasive carrier, and a plurality of abrasive elements attached to the abrasive carrier. An abrasive driving device drives the grinding tool in a first relative movement to the object. A conveying device conveys the object with a second relative movement to the grinding tool through the grinding machine. The plurality of abrasive elements each have 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 direction of movement of the abrasive carrier. The abrasive drive device is adapted to be operated 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.

Claims

1. 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, an abrasive drive device for driving the grinding tool in a first relative movement to the object, a conveying device for conveying the object through the grinding machine with a second movement relative to the grinding tool, wherein the plurality of abrasive elements comprise a plurality of first surfaces provided with first abrasive bodies for lying against a 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, wherein the second direction of movement of the abrasive carrier is opposite to the first direction of movement of the abrasive carrier, and wherein the abrasive drive device is adaptable to be operated in the first direction of movement, in which the first surfaces of the plurality of abrasive elements are in grinding engagement with the surface of the object, and wherein the abrasive drive device is adaptable to be operated in the second direction of movement, in which the second surfaces of the plurality of abrasive elements are in grinding engagement with the surface of the object, and a control device in signalling communication with the abrasive drive device that is adapted to switch the abrasive drive device back and forth between the first direction of movement and the second direction of movement.

2. The grinding machine according to claim 1, wherein the abrasive drive device is adapted to drive the at least one grinding tool in a rotational movement as a first relative movement, and wherein the control device is adapted to switch the rotational movement back and forth between a clockwise rotation and a counterclockwise rotation.

3. The grinding machine according to claim 1, wherein the abrasive drive device is adapted to set the at least one grinding tool in rotation about an abrasive rotation axis, wherein 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.

4. The grinding machine according to claim 3 wherein the guide axis of the grinding tool guide element is arranged parallel to and at a distance from the abrasive rotation axis.

5. The grinding machine according to claim 1 wherein the conveying device is adapted to convey the object through the grinding machine in a translatory movement.

6. The grinding machine according to claim 5 wherein the translatory movement is linear.

7. The grinding machine according to claim 1 wherein at least 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.

8. The grinding machine according to claim 1 wherein the plurality of abrasive elements comprises: 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 wherein each of which is not coated with abrasive bodies on a rear surface, a plurality of second plane abrasive body carrier elements, each of which is not coated with abrasive bodies on a front surface, and wherein each of which is coated with the second abrasive bodies on a rear surface forming the second surface; and wherein the first abrasive body carrier elements and the second abrasive body carrier elements are each arranged on the abrasive carrier such that in the first direction of movement the front surfaces of the first abrasive body carrier elements and the second abrasive body carrier elements lie against the surface of the object, and wherein in the second direction of movement the rear surfaces of the first abrasive body carrier elements and the second abrasive body carrier elements lie against the surface of the object.

9. The grinding machine according to claim 8, wherein the first abrasive body carrier elements and the 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 an adjacent second abrasive body carrier element t on a first side and the rear surface of the first abrasive body carrier element faces a front surface of an adjacent second abrasive body carrier element on a second side.

10. The grinding machine according to claim 9, wherein the first abrasive body carrier element and the second abrasive body carrier element 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 adjacent second abrasive body carrier element.

11. The grinding machine according to claim 8, wherein one or more first groups of several first abrasive body carrier elements are arranged next to one another on the abrasive carrier and one or more second groups of several second abrasive body carrier elements are arranged next to one another on the abrasive carrier and at least one first group of the one or more first groups and at least one second group of the one or more second groups are fastened to the abrasive carrier.

12. The grinding machine according to claim 11 wherein the one or more first groups includes a plurality of first groups and the one or more second groups includes a plurality of second groups, and wherein several first groups of the plurality of first groups and several second groups of the plurality of second groups are fastened alternately adjacent to one another on the abrasive carrier.

13. The grinding machine according to claim 1 wherein the plurality of abrasive elements is in a form of a plurality of abrasive paper sections which are flexible, and the abrasive carrier is adapted as a plate-shaped or ring-shaped carrier which has an axial end face to which a majority of the abrasive paper sections are attached, or is adapted as a cylindrical carrier which has a circumferential surface to which the majority of the abrasive paper sections are attached, wherein the first and second directions of movement are formed by a clockwise and counterclockwise rotation of the carrier, and wherein the abrasive paper sections are fixed to the carrier such that when the carrier rotates clockwise, the abrasive paper sections lie with a front side against a workpiece onto which the abrasive elements are pressed, and when the direction of rotation is reversed, the abrasive paper sections fold over so that a rear side of the abrasive paper sections lies against the workpiece instead of the front side.

14. The grinding machine according to claim 1 wherein 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, wherein the second grain size is different from the first grain size.

15. 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 wherein the plurality of abrasive elements has 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, wherein the second direction of movement is opposite to the first direction of movement.

16. The grinding tool according to claim 12, wherein at least some or each of the plurality of 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.

17. The grinding tool according to claim 15 wherein the plurality of abrasive elements comprises: 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 wherein each of the plurality of first plane abrasive body carrier element is not coated with abrasive bodies on a rear surface, a plurality of second plane abrasive body carrier elements, each of which is not coated with abrasive bodies on a front surface, and wherein each of the plurality of second plane abrasive body carrier elements is coated with the second abrasive bodies on a rear surface forming the second surface, and wherein the first abrasive body carrier elements and the second abrasive body carrier elements are arranged on the abrasive carrier such that in the first direction of movement the front surfaces of the first abrasive body carrier elements and the second abrasive body carrier elements are lying against the surface of the object, and wherein in the second direction of movement the rear surfaces of the first abrasive body carrier elements and the second abrasive body carrier elements are lying against the surface of the object.

18. The grinding tool according to claim 18, wherein the first abrasive body carrier elements and the 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 of the first abrasive body carrier elements faces the rear surface of and adjacent second abrasive body carrier element of the second body carrier elements on a first side and the rear surface of the first abrasive body carrier element of the first abrasive body carrier elements faces a front surface of an adjacent second abrasive body carrier element of the second abrasive body carrier elements on a second side.

19. The grinding tool according to claim 18, wherein the first abrasive body carrier element and the second abrasive body carrier element 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.

20. The grinding tool according to claim 19, wherein one or more first groups of several first abrasive body carrier elements are arranged next to one another on the abrasive carrier and one or more second groups of several second abrasive body carrier elements are arranged next to one another on the abrasive carrier, and wherein at least one first group and at least one second group are fastened to the abrasive carrier.

21. The grinding tool according to claim 20 wherein the one or more first groups includes a plurality of first groups and the one or more second groups includes a plurality of second groups, and wherein several first groups of the plurality of first groups and several second groups of the plurality of second groups are fastened alternately adjacent to one another on the abrasive carrier.

22. Grinding tool according to claim 15 wherein the plurality of abrasive elements is formed as a plurality of abrasive paper sections, and wherein the abrasive carrier is adapted as a plate-shaped or ring-shaped carrier which has an axial end face to which the majority of the abrasive paper sections are attached, or is adapted as a cylindrical carrier which has a circumferential surface to which the majority of the abrasive paper sections are attached, wherein the first direction of movement and the second direction of movement are formed by a clockwise and counterclockwise rotation of the carrier, respectively, and wherein the abrasive paper sections are fixed to the carrier such that when the carrier rotates clockwise, the abrasive paper sections lie with a front side against a workpiece onto which the abrasive elements are pressed, and when the direction of rotation is reversed, the abrasive paper sections fold over so that a rear side of the abrasive paper sections lies against the workpiece instead of the front side.

23. The grinding tool according to claim 15 wherein 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, and wherein the second grain size is different from the first grain size.

24. A method of grinding a surface of an object, comprising: grinding the surface of the object by 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 the one or more grinding tools comprise a first surface 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, wherein the second direction of movement is opposite to the first direction of movement; and moving the grinding tool in a first machining step in the first direction of movement in grinding engagement over the surface of the object, and moving the grinding tool in a subsequent second machining step in the second direction of movement in grinding engagement over the surface of the object.

25. The method according to claim 24, wherein 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, and wherein the grinding and moving steps are performed so as to achieve rough grinding of the surface in a first processing step, and fine grinding of the surface in a second processing step.

Description

DESCRIPTION OF THE DRAWINGS

[0051] 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:

[0052] FIG. 1: a schematic representation of a preferred embodiment of a grinding tool according to the invention in a first direction of movement, and

[0053] FIG. 2: a schematic representation of the preferred embodiment according to FIG. 1 in a second direction of movement.

[0054] FIG. 3a-d: schematic representations of the lower end face of four different grinding tools according to the invention,

[0055] FIG. 4: a schematic representation of a preferred embodiment of a grinding machine according to the invention.

[0056] FIG. 5A, B: a first and a second advantageous sequence of a grinding process according to the invention.

DESCRIPTION

[0057] Referring first of all to FIG. 1, an grinding tool according to the invention is designed in the preferred embodiment as a disk brush and comprises an abrasive carrier 10 which is formed in the shape of a disk and has a central opening 11 for receiving a drive shaft which defines the axis of rotation 12 of the grinding tool. A plurality of abrasive elements 20a, b, c, d, e, . . . are attached to an end face 10a of the abrasive carrier 10 over the entire circumference, only some of which are shown. Each abrasive element is formed by a rectangularly cut textile carrier section covered with abrasive grains on both sides. These abrasive elements are flexible and, depending on the direction of rotation of the grinding tool about the axis of rotation 12, can bend due to the frictional effect acting on these abrasive elements at their outer end when they are pressed onto a surface of a workpiece to be machined, thereby bringing either a first surface 21a-e or a second surface 22a-e, depending on the direction of rotation A or B, into grinding engagement with this surface. In FIG. 1, the grinding tool is driven in the direction of rotation A (clockwise when viewed from above on the side 10a) and the abrasive elements are bent backwards against this direction of rotation and lie with the first surfaces against a workpiece (not shown). In FIG. 2, the grinding tool is driven in the direction of rotation b (counterclockwise when viewed from above on the grain side 10a) and the abrasive elements 21a-e are bent backwards against this direction of rotation and lie with the second surfaces 22a-e against the workpiece (not shown).

[0058] FIG. 3a shows an abrasive carrier 110, on the end face of which a plurality of abrasive paper sections 120a, b, c, . . . coated on both sides 121a, b, c, 122a, b, c with abrasive bodies such as corundum grains are fastened via an annular circumferential region.

[0059] In a variant shown in FIG. 3b, the abrasive carrier 210 also has a plurality of abrasive elements 220a, b, c, d, . . . , which, however, in this embodiment are only coated on one side 221a, c, 222b, d with abrasive bodies. The abrasive elements are arranged in such a way that alternating abrasive elements with different orientations are distributed around the circumference of the abrasive carrier so that the abrasive surfaces 221a, c face clockwise and the abrasive surfaces 222b, d face counterclockwise.

[0060] In a variant shown in FIG. 3c, the abrasive carrier 310 also has a plurality of abrasive elements 320a, b, c, 320a, b, c, which, however, in this embodiment are coated with abrasive bodies on one side only. The abrasive elements are arranged in such a way that groups 323a, b, c of five abrasive elements aligned in the same direction are combined and these groups are distributed alternately with different orientations around the circumference of the abrasive carrier. As a result, this plurality of abrasive elements also has first surfaces 321a-c, which come into grinding engagement with the surface of a workpiece onto which the grinding tool is pressed in a first direction of rotation, and second surfaces 322a-c, which come into grinding engagement with the surface when the grinding tool is moved in a second direction of rotation opposite thereto.

[0061] FIG. 3d shows a fourth variant which, like FIG. 3b, is equipped with abrasive elements 420a, b, c, d, . . . coated on one side. In this embodiment, the abrasive elements are also, as in FIG. 3b, alternately distributed around the circumference in the first and second orientation. The sides 424b,d, 425a,c of the abrasive elements that are not coated with abrasive bodies are in direct contact with one another and may be bonded together if necessary.

[0062] FIG. 4 shows a section of a grinding machine which has a disk brush grinding module 500. Several grinding tools 530a, b, c, . . . are arranged on this disk brush grinding module in a satellite-like arrangement, the design of which can correspond to that of FIGS. 1 and 2 and FIG. 3a, 3b or 3c.

[0063] These grinding tools 530 are rotated within the disk brush grinding module about their respective disk brush rotation axis 530a, 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.

[0064] 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 540 a, b, c, . . . , which in turn is rotatably mounted about a satellite carrier axis 540a, b, c, . . . and thereby causes a superimposed rotation about the disk brush rotation axes 530a, b, c, . . . about a satellite carrier axis 540a. 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.

[0065] 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.

[0066] FIG. 5A shows a first sequence of the grinding method according to the invention. In a first processing step 1000, the workpiece is grinded by the first surfaces of the grinding tools by moving the grinding tools in a first direction of movement relative to the surface. In this first processing step, the workpiece is moved through the grinding machine in a first conveying direction by means of the endless conveyor belt and is thereby guided under the grinding tools while the grinding operation is carried out.

[0067] 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.

[0068] FIG. 5B shows a second, alternative sequence of the grinding process according to the invention. Again, as in the first process sequence, a workpiece is first machined in a first machining pass 2000 by the grinding tools with the first surfaces of the abrasive elements, in that the workpiece is guided through the conveying device under the disk brushes and the disk brushes rotate in a first direction of rotation and consequently bring the first surfaces of the abrasive elements into grinding engagement.

[0069] 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.

[0070] 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.