Abrasive for the production of a grinding tool, grinding tool and method for operating a grinding tool of this type

Abstract

A grinding tool (1) has a replaceable abrasive (4). A grinding layer (9) of the abrasive (4) faces a drive shaft (2) of the grinding tool (1). This enables a grinding of a workpiece (W) while exerting a tensile force (F). Surface areas (O) of the workpiece (W) facing away from a processor may thus be processed easily and flexibly.

Claims

1. An abrasive for the production of a grinding tool comprising a grinding layer (9) for grinding a workpiece (W), and a connecting element (13) for connecting to an abrasive holder (3), characterized in that the grinding layer (9) and the connecting element (13) are arranged on a common side (S.sub.1) for grinding while exerting a tensile force (F).

2. An abrasive according to claim 1, characterized by a supporting body (8) on which the grinding layer (9) and the connecting element (13) are arranged.

3. An abrasive according to claim 1 or 2, characterized in that the grinding layer (9) is attached directly to a supporting body (8) by means of an adhesive (10).

4. An abrasive according to at least one of the preceding claims, characterized in that the grinding layer (9) is configured to be curved.

5. An abrasive according to at least one of the preceding claims, characterized by a second grinding layer (17) which is arranged on the supporting body (8) and is opposite the first grinding layer (9).

6. An abrasive according to at least one of the preceding claims, characterized in that the grinding layer (9) comprises abrasive grains (11).

7. An abrasive according to at least one of the preceding claims, characterized in that the connecting element (13) is designed as a rotary connecting element.

8. A grinding tool comprising a drive shaft (2) for driving the grinding tool (1) in rotation, an abrasive holder (3) arranged on the drive shaft (2), and an abrasive (4) replaceably arranged on the abrasive holder (3), with a grinding layer (9), characterized in that the grinding layer (9) faces the drive shaft (2) for grinding while exerting a tensile force (F).

9. A grinding tool according to claim 8, characterized in that the abrasive (4) comprises a connecting element (13) for connecting to the abrasive holder (3).

10. A grinding tool according to claim 9, characterized in that the abrasive holder (3) comprises a counter-connecting element (7) for connecting to the connecting element (13).

11. A grinding tool according to at least one of claims 8 to 10, characterized in that the abrasive (4) comprises a supporting body (8) on which the grinding layer (9) and/or a connecting element (13) are arranged.

12. A grinding tool according to at least one of claims 8 to 11, characterized in that the abrasive holder (3) for supporting the abrasive (4) is arranged at least partially on a side (S.sub.2) of the abrasive (4) facing away from the drive shaft (2).

13. A grinding tool according to at least one of claims 8 to 12, characterized in that the abrasive holder (3) comprises a first holder component (20) and a second holder component (21), between which the abrasive (4) is arranged.

14. A method for operating a grinding tool comprising the steps of: providing a grinding tool (1) according to at least one of claims 8 to 13, and grinding a workpiece (W) by means of the grinding layer (9) while exerting a tensile force (F).

Description

[0026] Further features, advantages and details of the invention will be apparent from the following description of several embodiments. In the drawings:

[0027] FIG. 1 shows an axial section through a grinding tool with an abrasive holder and an abrasive replaceably attached thereto, according to a first embodiment,

[0028] FIG. 2 shows a top view onto the abrasive in FIG. 1,

[0029] FIG. 3 shows an axial section through a grinding tool with an abrasive holder and an abrasive replaceably attached thereto, according to a second embodiment,

[0030] FIG. 4 shows an axial section through a grinding tool with an abrasive holder and an abrasive replaceably attached thereto, according to a third embodiment, and

[0031] FIG. 5 shows an axial section through a grinding tool with a two-part abrasive holder and an abrasive replaceably attached thereto, according to a fourth embodiment.

[0032] In the following, a first embodiment of the invention is described with reference to FIGS. 1 and 2. A grinding tool 1 comprises a drive shaft 2, an abrasive holder 3 and an abrasive 4. The drive shaft 2 defines an axis of rotation 5 for driving the grinding tool 1 in rotation by means of a hand-held tool drive not shown in more detail. The drive shaft 2 and the abrasive holder 3 are connected to each other by means of a common threaded connection 6. The abrasive holder 3 further comprises a counter-connecting element 7, which is described in more detail below in connection with the abrasive 4.

[0033] The abrasive 4 comprises a supporting body 8 on which a grinding layer 9 is arranged. The grinding layer 9 is arranged on a first side S.sub.1 facing the abrasive holder 3 in a fixed state of the abrasive 4. Furthermore, the abrasive 4 has a second side S.sub.2 facing away from the abrasive holder 3. The grinding layer 9 comprises abrasive grains 11 directly attached to the supporting body 8 by means of an adhesive 10. The grinding layer 9 additionally comprises a cover bond 12 applied to the abrasive grains 11.

[0034] The abrasive 4 is replaceably connected to the abrasive holder 3. The abrasive 4 comprises a connecting element 13, which is fixed to the supporting body 8 concentrically to the axis of rotation 5 of the grinding tool 1 or of the abrasive 4. The connecting element 13 is arranged on the first side S.sub.1 of the supporting body 8 or of the abrasive 4 and faces the abrasive holder 3. The connecting element 13 is connected to the supporting body 8 in a material-fit and/or form-fit manner.

[0035] The connecting element 13 forms a circular attachment region B, which is arranged concentrically with regard to the axis of rotation 5. The attachment region B is surrounded by an annular inner working region A.sub.1, which in turn is surrounded by an annular outer working region A.sub.2. The inner working region A.sub.1 and the outer working region A.sub.2 are collectively referred to as the working region A. The abrasive 4 has a diameter D for which the following applies: 10 mm≤D≤230 mm, in particular 35 mm≤D≤135 mm.

[0036] The supporting body 8 and the grinding layer 9 arranged thereon are formed in three dimensions. In the inner working region A.sub.1, the grinding layer 9 is formed to be planar. In contrast, in the outer working region A.sub.2, the grinding layer 9 is formed to be curved in a radial direction R and in a circumferential direction U. When viewed from the first side S.sub.1, the grinding layer 9 is concavely curved in the radial direction R. The supporting body 8 is formed to be rigid and/or elastically deformable.

[0037] The connecting element 13 is designed as a rotary connecting element. For this purpose, the connecting element 13 has a plurality of projections 14 which are arranged as to be rotationally symmetrical about the axis of rotation 5 and bound a receiving opening 15 in certain regions. The receiving opening 15 serves for inserting and receiving the counter-connecting element 7. The counter-connecting element 7 is formed as a rotary counter-connecting element and has a plurality of counter-projections 16 extending in the radial direction R. The counter-projections 16 can be inserted into the connecting element 13 in the region outside the projections 14 through the receiving opening 15 by a movement along the axis of rotation 5. By a subsequent rotation about the axis of rotation 5, the counter-projections 16 are clamped to the projections 14 in a form-fit and friction-fit manner.

[0038] The operating principle of the grinding tool 1 is as follows:

[0039] The grinding tool 1 serves for processing a surface area O of the workpiece W which is difficult to access and faces away from a processor of the workpiece W. The abrasive holder 3 is first connected to the drive shaft 2, which has a length suitable for processing the workpiece W. The drive shaft 2 is clamped in a manually guided tool drive, which is not shown in more detail. The abrasive 4 is connected to the counter-connecting element 7 of the abrasive holder 3 by means of the connecting element 13.

[0040] The abrasive 4 is now driven in rotation about the axis of rotation 5 by means of the tool drive. By exerting a tensile force F in the direction of the axis of rotation 5, the processor guides the grinding layer 9 to the surface area O facing away, such that the latter is processed or ground in the desired manner. Unwanted material projections M can be easily and flexibly removed in this way. Due to the fact that the grinding layer 9 is configured to be curved in the outer working region A.sub.2, it is also possible to process fillet welds K of the workpiece W which are facing away.

[0041] The abrasive 4 is replaceable so that, for example, after a rough processing, a fine processing can be carried out in an easy and flexible manner. For this purpose, the abrasive 4 is detached from the abrasive holder 3 by means of the connecting element 13 and a new abrasive 4 is attached to the abrasive holder 3. The new abrasive 4 is configured in accordance with FIGS. 1 and 2, but has a grinding layer 9 and abrasive grains 11 which are suitable for fine processing.

[0042] Hereinafter, with reference to FIG. 3, a second embodiment of the invention is described. In contrast to the first embodiment, the supporting body 8 has a second grinding layer 17 on the second side S.sub.2, which is substantially opposite the first grinding layer 9. The supporting body 8 is thus arranged between the first grinding layer 9 and the second grinding layer 17. The second grinding layer 17 is configured corresponding to the first grinding layer 9. By means of the second grinding layer 17, the workpiece W can be processed at a surface area O′ facing the processor. For this purpose, the processor guides the grinding tool 1 to the surface area O′ and processed it by exerting a compressive force F′ with the second grinding layer 17. The grinding tool 1 may thus also process or remove material projections M′ which face the processor. With regard to the further construction and the further operational principle, reference is made to the preceding embodiment.

[0043] In the following, with reference to FIG. 4, a third embodiment of the invention is described. In contrast to the preceding embodiment, the abrasive 4 comprises an abrasive body 18 formed of abrasive grains 11 bonded with synthetic resin 19. The abrasive body 18 thus forms a first grinding layer 9 on the first side S.sub.1 due to its surface, and forms a second grinding layer 17 on the second side S.sub.2 due to its surface. With regard to the further construction and the further operational principle, reference is made to the preceding embodiments.

[0044] Hereinafter, with reference to FIG. 5, a fourth embodiment of the invention is described. In contrast to the preceding embodiments, the abrasive 4 does not have a connecting element and the abrasive holder 3 does not have an associated counter-connecting element. The abrasive holder 3 comprises a first holder component 20 and a second holder component 21. The first holder component 20 is connected to the drive shaft 2 by means of the threaded connection 6. The first holder component 20 has a threaded bore 22, which is arranged concentrically to the axis of rotation 5. An associated threaded pin 23, which is part of the second holder component 21, can be screwed into the threaded bore 22. For passing the threaded pin 23 therethrough, the abrasive 4 comprises a central opening 24. The abrasive 4 is clamped between the holder components 20, 21 by screwing the threaded pin 23 into the threaded bore 22. For this purpose, the first holder component 20 forms a first annular region K.sub.1 having a diameter D.sub.1. On the other hand, the second holder component 21 forms an annular region K.sub.2 having a diameter D.sub.2. The following applies: 0.1.Math.D≤D.sub.1≤0.5.Math.D. Furthermore, it applies that: 0.1.Math.D≤D.sub.2≤1.1.Math.D, in particular 0.2.Math.D≤D.sub.2≤1.Math.D, in particular 0.3.Math.D≤D.sub.2≤0.5.Math.D. The smaller D.sub.1, the larger the working region A. The larger D.sub.2, the better the abrasive 4 is supported on the second side S.sub.2 when a processor, exerting a tensile force F, is processing the workpiece W. For example, the following applies: D.sub.1=D.sub.2. With regard to the further construction and the further operational principle, reference is made to the preceding embodiments.

[0045] In general:

[0046] The drive shaft 2 may be formed integrally with the abrasive holder 3 or with the first holder component 20 of the abrasive holder 3. The shape and design of the grinding layer 9 and/or the grinding layer 17 can be combined in any desired way with a connecting element 13 and an associated counter-connecting element 7 of the abrasive holder 3 or with an abrasive holder 3 comprising a plurality of holder components 20, 21.

[0047] The supporting body 8 may be configured to be rigid and/or elastically deformable. Furthermore, the second holder component 21 may be configured to be rigid and/or elastically deformable. If the second holder component 21 is rigid, the abrasive 4 may also be configured to be flexible or bendable, for example as an abrasive on a backing.