TOOL PART AND METHOD FOR PRODUCING A TOOL PART OF THIS KIND

Abstract

The invention relates to a tool part (1) having a main body (3) and at least one cutting zone (5) formed on the main body (3), wherein the cutting zone (5) has a clearance face (7) and a rake face (9) which adjoin each other at a cutting edge (11), wherein the rake face (9) has a coating (13) applied to a main body material of the main body (3) and extending as far as the cutting edge (11), which coating is harder than the main body material. According to the invention, the clearance face (7) is free of the coating (13) in a clearance zone (15) proceeding from the cutting edge (11).

Claims

1. A tool part (1) comprising a main body (3) and at least one cutting zone (5) formed on the main body (3), wherein the cutting zone (5) has a clearance face (7) and a rake face (9) which adjoin each other at a cutting edge (11), wherein the rake face (9) has a coating (13) applied to a main body material of the main body (3) and extending as far as the cutting edge (11), which coating is harder than the main body material, wherein the clearance face (7) is free of the coating (13) in a clearance zone (15) proceeding from the cutting edge (11).

2. The tool part (1) of claim 1, wherein the main body material is exposed in the clearance zone (15).

3. The tool part (1) of claim 1, wherein a coating zone (17) of the clearance face (7) adjoins the clearance zone (15) contrary to a cutting direction, in which coating zone the clearance face (7) has the coating (13).

4. The tool part (1) of claim 1, wherein the clearance zone (15) extends along the cutting edge (11) only over a clearance length (33) which is shorter than a cutting length of the cutting edge (11).

5. The tool part (1) of claim 1, wherein the tool part (1) is designed as a cutting tool (2), in particular as a drilling tool (4), in particular a drill, or as a milling tool (6), in particular for cutting abrasive materials, the cutting edge (11) preferably being a front cutting blade of the drill or a peripheral cutting blade (41) of the milling tool (6).

6. The tool part (1) according to claim 5, wherein the clearance zone (15), proceeding from a cutting corner (19) of the cutting edge (11), extends radially inward only along part of the cutting edge (11).

7. The tool part (1) of claim 5, wherein the cutting edge (11) has a central cutting blade (25) and a main cutting edge (23), the clearance zone (15) only extending along the main cutting blade (23), preferably only in certain zones along the main cutting blade (23).

8. The tool (1) of claim 1, wherein the tool part (1) is designed as a cutting plate (8), in particular as an indexable cutting plate (10).

9. A method for producing a tool part (1), comprising: coating a cutting zone (5), which is formed on a main body (3) for the tool part (1) and has a clearance face (7) and a rake face (9) which adjoin each other at a cutting edge (11), with a coating (13) that is harder than a main body material of the main body (3), and removing the coating (13) at least in certain zones on the clearance face (7).

10. The method of claim 9, wherein the coating (13) is removed by means of a laser method.

11. The method of claim 9, wherein the cutting zone (5) is produced on the main body (3) prior to coating.

12. The method of claim 9, wherein, prior to coating, a cutout (29) is introduced into the clearance face (7) at a distance from the cutting edge (11), the coating (13) preferably being removed only in a clearance zone (15) which is delimited on the one hand by the cutting edge (11) and on the other hand by the cutout (29).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The invention is explained in greater detail below with reference to the drawing. In the drawing:

[0058] FIG. 1 is a perspective view of a first embodiment of a tool part;

[0059] FIG. 2 is a front plan view of the tool part according to FIG. 1;

[0060] FIG. 3 is a side view of the tool part according to FIGS. 1 and 2;

[0061] FIG. 4 is a perspective detailed view of a second embodiment of a tool part, and

[0062] FIG. 5 is a perspective view of a third embodiment of a tool part.

[0063] FIG. 1 is a view of a first embodiment of a tool part 1 which is designed in this case in a preferred embodiment as a cutting tool 2, in this case in particular as a drilling tool 4, in particular as a drill. The tool part 1 is set up in particular for machining abrasive workpieces, which preferably comprise fiber-reinforced plastics material or an aluminum alloy, in particular workpieces which comprise carbon-fiber-reinforced plastics material or carbon-fiber-reinforced plastics material.

[0064] The tool part 1 has a main body 3 having at least one cutting zone 5 formed on the main body 3, in this case exactly two cutting zones 5. The two cutting zones 5 are designed identically to one another, so that only one of the cutting zones 5 is explained in more detail below, it not being important which of these cutting zones 5 it is.

[0065] The cutting zone 5 comprises a clearance face 7 and a rake face 9 which adjoin each other at a cutting edge 11. The rake face 9 has a coating 13 which is applied to a main body material of the main body 3 and extends as far as the cutting edge 11 and is harder than the main body material. The main body material is preferably hard metal and the coating is a hard material layer, in particular a diamond layer.

[0066] Proceeding from the cutting edge 11, the clearance face 7 is free of the coating in a clearance zone 15. This advantageously provides different wear conditions when machining a workpiece for the clearance face 7 on the one hand and the rake face 9 on the other hand, with the clearance face 7 being removed more quickly. As a result, the cutting edge 11 loses mechanical support in the zone of the clearance face 7 and breaks off successively, becoming sharp again at the breaking edge, so that the tool part 1 advantageously has a self-sharpening effect. In this way, the wear of the tool part 1 can be reduced overall and its service life can be extended. This applies in particular to the machining of abrasive materials such as fiber-reinforced plastics material or aluminum alloys.

[0067] The main body material is preferably exposed or uncovered in the clearance zone 15.

[0068] To machine a workpiece, a relative rotation is preferably effected between the tool part 1 and the workpiece about a central axis M of the tool part 1, in this case counterclockwise according to FIG. 1, this defining a cutting direction for the cutting edge 11 indicated by an arrow P.

[0069] Contrary to the cutting direction, the clearance zone 15 is adjoined by a coating zone 17 in which the clearance face 7 has the coating.

[0070] It is clear from FIG. 1 that the cutting edge 11 is in particular a front cutting blade of the drill. It is also clear that the clearance zone 15 extends radially inward, proceeding from a cutting corner 19 of the cutting edge 11, i.e. toward the central axis M, only along part of the cutting edge 11. The clearance face 7 is coated along the remaining part. In the zone of the transition between the uncoated part, i.e. the clearance zone 15, and the coated part, an axial cutting step 21 is formed in particular, seen along the cutting edge 11. This embodiment has the particular advantage that when the tool part 1 passes through a workpiece made of fiber-reinforced plastics material, fibers protruding beyond the wall of a bore are reliably cut off by the sharp cutting step 21 while they slide along the cutting edge 11, where they finally land on the cutting step 21 and get cut there.

[0071] The cutting edge 11 is divided in particular into a main cutting blade 23, which is arranged radially on the outside and extends as far as the cutting corner 19, and a central cutting blade 25, which is produced in particular by sharpening the drill. The clearance zone 15 extends only along the main cutting blade 23, in particular—as can be seen in FIG. 1—only in certain zones along the main cutting blade 23, namely proceeding from the cutting corner 19 radially inward and not as far as a transition 27 into the central cutting blade 25. In this way in particular, homogeneous wear and thus homogeneous self-sharpening of the cutting edge 11 can be ensured.

[0072] FIG. 2 is a plan view of a front side of the tool part 1 according to FIG. 1.

[0073] Identical and functionally identical elements are provided with the same reference numbers, so that in this respect reference is made to the preceding description.

[0074] For the sake of simplicity, the majority of the reference numbers are given in this case only on one of the cutting zones 5; the other cutting zone 5 is—as stated—designed to be identical. Again only for the sake of greater clarity, some reference numbers are only assigned to the other cutting zone 5.

[0075] FIG. 2 clearly shows the different cutting blade portions of the cutting zone 5, with a crosscutting blade 26, then the central cutting blade 25, and then the main cutting blade 23 being provided radially outward proceeding from the central axis M toward the cutting corner 19. A circular ground bevel 31 preferably adjoins the cutting corner 19 in the circumferential direction.

[0076] FIG. 2 also shows that the clearance zone 15 extends along the cutting edge 11 only over a clearance length 33 which is shorter than a cutting length, in particular than a total length, of the cutting edge 11.

[0077] FIG. 2 also shows that the clearance face 7 has a first clearance face portion 35 and a second clearance face portion 37, the first clearance face portion 35 comprising the clearance zone 15 and the cutout 29. The second clearance face zone 37 is arranged obliquely to the first clearance face zone 35, in particular to the cutout 29. The cutout 29, together with the second clearance face portion 37, forms the coating zone 17.

[0078] The cutting step 21 is also clearly visible in FIG. 2. In particular, the clearance length 33 extends between the cutting corner 19 on the one hand and the cutting step 21 on the other. In particular, the clearance length 33 is delimited by the cutting corner 19 on the one hand and the cutting step 21 on the other.

[0079] FIG. 3 is a side view of the tool part 1 according to FIGS. 1 and 2. The viewer's gaze in FIG. 3 falls on the rake face 9 in the left-hand cutting zone 5, which is concealed from the viewer in the right-hand cutting zone 5. In the right-hand cutting zone 5, the different portions of the clearance face 7 and in particular also the clearance zone 15 can be seen very well.

[0080] A flute 39 is preferably assigned to each of the cutting zones 5, the rake face 9 also being a wall of the flute 39. The drill shown in this case is in particular a helical drill, with the flutes 39 being helical.

[0081] FIG. 4 is a perspective view of a second embodiment of a tool part 1. In this second embodiment, the tool part 1 is designed in the form of a cutting tool 2, in this case specifically a milling tool 6, in particular a milling cutter. As in the first embodiment, the tool part 1 is also set up in this case, in particular, for machining abrasive materials. The milling tool 6 has, in particular, a plurality of preferably identically designed cutting zones 5, for which, for the sake of better clarity, reference numbers are only provided in this case on two cutting zones 5 and divided between the cutting zones 5. The cutting edge 11 in the cutting zones 5 is in this case in particular a peripheral cutting blade 41 of the milling tool 6. Furthermore, FIG. 4 shows the main body 3, the clearance face 7, the position of the rake face 9, the arrangement of the coating 13, the clearance zone 15, and the coating zone 17. The milling tool 6 also has flutes 39, of which only one is marked with the corresponding reference number for the sake of better clarity. These flutes 39 are in this case in particular formed in a straight line.

[0082] FIG. 5 is a perspective view of a third embodiment of a tool part 1. In this third embodiment, the tool part 1 is designed as a cutting plate 8, in particular as an indexable cutting plate 10, preferably having two cutting zones 5. In the same way as in the previous embodiments, the tool part 1 in this embodiment is also set up for machining abrasive materials. In FIG. 5, in particular the main body 3, the clearance face 7, the rake face 9, the cutting edge 11, the arrangement of the coating 13, the clearance zone 15, the coating zone 17, and also the cutting corner 19 can be clearly seen.

[0083] The tool part 1 is preferably produced, regardless of its specific embodiment, by providing the main body 3—in particular in the form of a hard metal rod or a hard metal plate—and by forming at least one cutting zone 5 on the main body 3. Subsequently, the cutting zone 5 is coated with the coating 13, in particular the hard material layer, in particular the diamond layer. Subsequently, the coating 13 is removed—preferably by means of a laser method—at least in certain zones on the clearance face 7 or from the clearance face 7, so that the clearance zone 15 is ultimately formed. It is also possible that the main body 3 is already provided with a finished cutting zone 5 so that only the coating 13 is applied and subsequently removed again from the clearance face 7 at least in certain zones. The provision of the intact main body 3 and the production of the at least one cutting zone 5 are therefore not necessarily part of the production method.

[0084] Prior to coating, a cutout 29 is preferably introduced into the clearance face 7 at a distance from the cutting edge 11. The coating 13 is then preferably only removed in the clearance zone 15 which is delimited on the one hand by the cutting edge 11 and on the other hand by the cutout 29. In this way, the cutout 29 ultimately defines the clearance zone 15.