METHOD FOR PARTIALLY GRINDING A SURFACE AND GRINDING DEVICE FOR CARRYING OUT THE METHOD

Abstract

A method for removing a flaw on a treated, finally painted surface by grinding involves, after the flaw has been detected, moving a flexible abrasive sheet to the surface and pressing it against the flaw to be machined in such a way that the flaw is detected by a sensor system, which is operatively connected to a robotic arm carrying the grinding plate. The abrasive sheet, which is designed as an abrasive belt, is fed to the grinding plate and the abrasive sheet being pressed against the flaw.

Claims

1-26. (canceled)

27. A method for removing a flaw of a treated finish-painted surface by grinding, the method comprising: detecting, by a sensor system, the flaw, wherein the sensor system is operationally connected to a robot arm supporting a grinding disk; moving a flexible abrasive sheet toward the treated finish-painted surface by supplying the flexible abrasive sheet to the grinding disk; and pressing the flexible abrasive sheet against the flaw, wherein the flexible abrasive sheet is an abrasive belt.

28. The method of claim 27, wherein the flexible abrasive sheet is detachably connected in an integrally-joined or friction-locked manner to the grinding disk.

29. The method of claim 27, wherein the flexible abrasive belt is held on the grinding disk by a hook-and-loop connection, adhesive bond, or suction.

30. The method of claim 27, wherein the grinding disk having the flexible abrasive belt fastened thereon is moved in a rotating, vibrating, or orbital manner.

31. The method of claim 27, further comprising: detaching the flexible abrasive belt from the grinding disk after the grinding of the flaw.

32. The method of claim 31, wherein the flexible abrasive belt is moved further cyclically by an associated longitudinal extension of the flaw after being detached from the grinding disk.

33. A grinding device configured to remove a flaw of a treated finish-painted surface by grinding, the grinding device comprising: a sensor system configured to detect the flaw; a robot arm operationally connected in a computer-controlled manner to the sensor system; a grinding disk fastened on the robot arm; and a flexible abrasive belt that is held on the grinding disk.

34. The grinding device of claim 33, further comprising: an ejector, associated with the grinding disk, configured to detach the flexible abrasive belt held on the grinding disk.

35. The grinding device of claim 33, wherein the flexible abrasive belt is mounted in a dispenser.

36. The grinding device of claim 33, wherein at least one of the longitudinal edges of the flexible abrasive belt is contoured.

37. The grinding device of claim 35, wherein the dispenser comprises a cassette arranged in a region of the robot arm.

38. The grinding device of claim 33, wherein the grinding disk is configured to be drivable in an orbital, vibrating, or rotating manner in relation to the treated finish-painted surface.

39. The grinding device of claim 37, wherein the cassette comprises a winding shaft and an unwinding shaft, which are respectively configured to wind and unwind the flexible abrasive belt.

40. The grinding device of claim 39, wherein the cassette further comprises two chambers separate from one another, wherein the unwinding shaft is arranged in a first one of the two chambers and the winding shaft is arranged in a second one of the two chambers.

41. The grinding device of claim 39, wherein the winding shaft is configured to be cyclically drivable.

42. The grinding device of claim 39, wherein the winding shaft is configured to be drivable via a motor and the unwinding shaft is nondriven.

43. The grinding device of claim 39, further comprising: a sensor configured to detect an end of the flexible abrasive belt is associated with the unwinding shaft.

44. The grinding device of claim 37, wherein the sensor configured to detect the end of the flexible abrasive belt comprises a laser emitter, wherein the flexible abrasive belt comprises a passage in an end region, which corresponds to a laser beam of the laser emitter.

45. The grinding device of claim 39, further comprising: a sensor system associated with the unwinding shaft and configured to detect a tear in the flexible abrasive belt.

46. The grinding device of claim 45, wherein the sensor system comprises a movement sensor and a follower, wherein the follower moves synchronously with the flexible abrasive belt or the unwinding shaft, and the follower includes markings detectable by the movement sensor.

47. The grinding device of claim 46, wherein the follower comprises a gear wheel.

48. The grinding device of claim 37, further comprising: tensioning means configured to tension the flexible abrasive belt.

49. The grinding device of claim 48, wherein the tensioning means consist of hydraulically or pneumatically operated cylinders.

50. The grinding device of claim 48, wherein the tensioning means comprises a first tensioning means on an intake side of the grinding disk and a second tensioning means on an outlet side of the grinding disk.

51. The grinding device of claim 50, wherein the first tensioning means is a hydraulically or pneumatically operated cylinder that is pressable against a deflection roller.

52. The grinding device of claim 51, wherein the second tensioning means is a second a hydraulically or pneumatically operated cylinder, which presses against the flexible abrasive sheet between two deflection rollers.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0035] In the figures:

[0036] FIGS. 1 and 2 each show a schematic side view of a portion of a grinding device according to the invention

[0037] FIG. 3 shows a detail of the grinding device in different embodiment variants

[0038] FIGS. 4-7 each show further embodiment variants of the grinding device in schematic side views

[0039] FIG. 8 shows a grinding device according to the invention in a front view

[0040] FIG. 9 shows a part of the grinding device in a perspective view.

DETAILED DESCRIPTION

[0041] FIGS. 1 and 2 show a part of a grinding device 1 for removing a flaw, for example, in a finish-treated, in particular finish-painted surface, by grinding, wherein after an optical detection of the flaw by means of an optical sensor system (not shown), a flexible abrasive belt 5 is moved transversely in relation to the surface and pressed against the flaw to be treated.

[0042] A robot arm 2 supporting a grinding disk 3, which is moved accordingly by the sensor system to the flaw, is operationally connected to the sensor system.

[0043] In this case, the abrasive belt 5 is held on the grinding disk 3, which is movable in relation to the surface, for example, in an orbital, vibrating, or rotating manner, for grinding the flaw.

[0044] The abrasive belt 5 is held in a dispenser in the form of a cassette 4 and wound onto a roll 6 on an unwinding shaft 7 and is wound onto a winding shaft 8, preferably cyclically, in accordance with the grinding procedure.

[0045] The abrasive belt 5 is mounted on the grinding disk 3 in an integrally-joined or friction-locked manner, for example, by a detachable adhesive bond or by a hook-and-loop connection or suction connection. For the latter, a suction device (not shown) is provided, which is connected to the grinding disk 3.

[0046] The abrasive belt 5, which is recognizable as a portion in each of various embodiment variants in FIG. 3, can comprise various contoured edges. Thus, in FIG. 3a), one edge of the abrasive belt 5 is formed wavy and the other edge is formed linear. In FIG. 3b), both opposing longitudinal edges are formed linear, while FIG. 3c) shows a variant in which both longitudinal edges are zigzagged.

[0047] To detach the abrasive belt 5 from the grinding disk 3, ejectors 9 are provided in the region of the grinding disk 3, in accordance with the illustrations in FIGS. 5 to 7.

[0048] In this case, ejectors 9 are provided on both sides of the grinding disk 3 in the example shown in FIG. 5, wherein the passage direction of the abrasive belt 5 is identified by an arrow.

[0049] In FIGS. 6 and 7, the grinding disk 3 is overlapped by the ejector 9. Functionally, the grinding disk 3 is raised in relation to the ejector 9 in such a manner that the ejector 9 detaches the connection of the grinding disk 3 to the abrasive belt 5 by way of an abutment.

[0050] In FIG. 4, the cassette 4 accommodating the abrasive belt 5 is shown as a detail, wherein the unwinding and winding shafts 7, 8 are separated by an intermediate wall 10 in such a way that grinding dust accumulating during the grinding does not reach the region in which the unused abrasive belt 5 is arranged in the form of the roll 6, on the left side in the figure.

[0051] FIG. 8 shows a grinding device equipped with the abrasive belt 5, wherein the passage of the abrasive belt 5 is identified by arrow indications.

[0052] The winding shaft 8 is driven and draws the abrasive belt 5 off of the unwinding shaft 7, wherein the abrasive belt 5 is guided via a plurality of deflection rollers 13.

[0053] To be able to detect the end of the abrasive belt after completed usage, a laser source 14 is provided downstream of the unwinding shaft 7, which detects a passage (not shown) introduced at the end of the abrasive belt 5 during its production with the aid of a laser beam 15, so that the useful length of the abrasive belt 5 can be optimally utilized.

[0054] Since the cassette 4 is fixedly connected to the robot arm 2 in the exemplary embodiment, but the grinding disk 3, in contrast, is held using associated assemblies via a movable contact flange on the robot arm 2, the abrasive belt 5 has to be kept under constant tension in the region of the grinding disk 3.

[0055] Two tensioning elements are provided for this purpose in the example, specifically in the form of pneumatically or hydraulically actuated cylinders 11, 12, wherein one cylinder 11 presses the abrasive belt 5 against a deflection roller 13 before the entry of the abrasive belt 5 toward the grinding disk 3.

[0056] On the outlet side, i.e., downstream of the grinding disk 3, the abrasive belt 5 is tensioned by the cylinder 12, which engages on the abrasive belt 5 between two deflection rollers 13, via which the abrasive belt 5 is guided.

[0057] A sensor system is shown as a detail in FIG. 9, using which tearing of the abrasive belt 5 is detected.

[0058] This sensor system consists of a movement sensor 16 and a follower 17 corresponding thereto, which is designed as a gear wheel and is held in a rotationally-fixed manner on the unwinding shaft 7, so that it executes a synchronous movement with the freely rotating unwinding shaft 7.

[0059] Since the unwinding shaft 7 is quasi-entrained with the abrasive belt upon actuation of the winding shaft 8, which is connected to a motor, the follower 17 is also pivoted accordingly. In the event of a tear of the abrasive belt 5, the unwinding shaft 7 stands still, as does the follower 17, which is detected by the movement sensor 16, so that the drive of the winding shaft 8 is interrupted.

[0060] Although the invention has been illustrated and described in detail by way of preferred embodiments, the invention is not limited by the examples disclosed, and other variations can be derived from these by the person skilled in the art without leaving the scope of the invention. It is therefore clear that there is a plurality of possible variations. It is also clear that embodiments stated by way of example are only really examples that are not to be seen as limiting the scope, application possibilities or configuration of the invention in any way. In fact, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete manner, wherein, with the knowledge of the disclosed inventive concept, the person skilled in the art is able to undertake various changes, for example, with regard to the functioning or arrangement of individual elements stated in an exemplary embodiment without leaving the scope of the invention, which is defined by the claims and their legal equivalents, such as further explanations in the description.

LIST OF REFERENCE NUMERALS

[0061] 1 grinding device [0062] 2 robot arm [0063] 3 grinding disk [0064] 4 cassette [0065] 5 abrasive belt [0066] 6 roll [0067] 7 unwinding shaft [0068] 8 winding shaft [0069] 9 ejector [0070] 10 intermediate wall [0071] 11 cylinder [0072] 12 cylinder [0073] 13 deflection roller [0074] 14 laser source [0075] 15 laser beam [0076] 16 movement sensor [0077] 17 follower