Cutting inserts for recess machining, cutting insert kits comprising two such cutting inserts, cutting insert holders for such cutting inserts and a method for producing a recess

Abstract

The present invention relates to a cutting insert holder (29), comprising a central axis (M), at least one first mounting portion (31) for mounting a first cutting insert (1.1) to the cutting insert holder (29), and at least one second mounting portion (33) for mounting at least one second cutting insert (1.2) to the cutting insert holder (29), the first mounting portion (31) and the second mounting portion (33) being arranged offset from each other in a circumferential direction around the central axis (M), and the first mounting portion (31) and the second mounting portion (33) being arranged within the first mounting portion (31). the first cutting insert (1.1) is configured and arranged such that a first cutting surface (21.1) assigned to an effective main cutting edge (9.1) of the mounted first cutting insert (1.1) has a first orientation along the circumferential direction and a second cutting surface (21.2) assigned to an effective main cutting edge (9.2) of a second cutting insert (1.2) arranged in the second mounting part (33) has a second orientation along the circumferential direction, the first orientation being opposite to the second orientation when the first cutting insert (1.1) and the second cutting insert (1.2) are mounted in the cutting insert holder (29).

Description

Technical Field

[0001] The present invention relates to a cutting insert for recess machining, a cutting insert kit comprising two such cutting inserts, in particular a cutting insert holder and a recess for such a cutting insert, and in particular a method for producing a groove.

[0002] During recess (recess) machining, especially during groove production, burr formation problems often occur at the recess edges. This problem becomes even more pronounced when machining hard, quenched or hardened materials. In particular, problems occur, for example, in the recess machining of a toothed shaft for producing a groove for a retaining ring. This is because the formed burrs prevent the toothed shaft from being joined to a gear or a corresponding shaft to transmit torque. In this case, in particular, the discontinuous cutting conditions resulting from the tooth portions are problematic. Under such cutting conditions, conventional cutting tools (Stechmeissel) in a radially supported configuration, in particular, have excessively low stability and thus tend to chatter. This makes the problems described herein even more pronounced.

[0003] The formed burrs have to be removed laboriously, for example by grinding. This leads to a great deal of post-processing effort. Therefore, overall, problems related to recess machining, especially the production of such grooves, in particular a large number of defective products and / or a great deal of production effort and high production costs occur.

[0004] Therefore, the underlying problem of the present invention is to provide a cutting insert for recess machining, a cutting insert kit comprising two such cutting inserts, in particular a cutting insert holder and a recess for such a cutting insert, and in particular a method for producing a groove, in which the above-mentioned disadvantages do not occur.

[0005] This problem is solved by providing the technical teachings of the present invention, in particular the teachings of the independent claims as well as the teachings of the dependent claims and the teachings of the embodiments disclosed in the specification.

[0006] The problem is solved, in particular, by providing a cutting insert for recess machining. The cutting insert has a substrate and a cutting projection protruding radially from the substrate. The cutting projection has a main cutting edge at the working end opposite to the substrate. The cutting projection has a trimming edge on at least one side at the transition end on the substrate side in the transition region to the substrate. Advantageously, when machining a workpiece with the cutting insert, first, the main cutting edge engages with the workpiece. During the process of producing a recess, in particular a groove, when the target recess depth or groove depth is reached in particular, finally, the trimming edge arranged at the base of the cutting projection also engages with the workpiece. In this case, in the same working step as the machining of the recess in the workpiece, the edge of the recess is trimmed. Thus, the problem of burr formation is solved simply, accurately and inexpensively, and the production labor related to recess machining is significantly reduced. Thereby, in particular, the production cost is also reduced.

[0007] The cutting insert is configured to carry out a method according to the invention for producing a recess, in particular a groove, or a method according to one or more of the embodiments described below. To carry out such a method, the cutting insert is formed, in particular, by a trimming edge arranged on the cutting projection at the transition end in the transition region to the substrate.

[0008] The main cutting edge is preferably formed integrally with the cutting projection, in particular with a uniform material. However, alternatively, in a suitable configuration, it is also possible that the main cutting edge is formed from a material different from that of the cutting projection and is attached to the cutting projection, in particular bonded, in particular joined, to the cutting projection.

[0009] The chamfering edge is preferably formed integrally with, in particular uniformly in material with, the cutting-in projection. However, alternatively, in a preferred configuration, it is also possible that the chamfering edge is formed from a material different from that of the cutting-in projection and is attached to the cutting-in projection, in particular bonded, in particular joined, to the cutting-in projection.

[0010] Preferably, the cutting-in projection is formed integrally with, in particular uniformly in material with, the base body.

[0011] Preferably, the cutting-in projection and the main cutting edge are preferably formed integrally with, in particular uniformly in material with, the base body together with the chamfering edge.

[0012] In a preferred configuration, the cutting insert has, in the base body, mounting holes for mounting the cutting insert in a cutting insert holder, in particular a cutting insert holder according to the present invention or a cutting insert holder according to one or more of the embodiments described below. The mounting holes preferably penetrate the base body and are configured to be penetrated by mounting means, in particular mounting screws. The cutting insert holder, in particular a cutting insert holder according to the present invention described below or a cutting insert holder preferred according to the present invention, preferably has, according to at least one embodiment, corresponding mounting means, preferably threads, and mounting means, in particular mounting screws, engage with these threads, whereby the cutting insert can be mounted in the cutting insert holder.

[0013] According to an improved form of the present invention, it has been specified that the plunge protrusion has one burr-removing blade on each side at its transition end. In this case, the concept of "on each side" is particularly related to the extension of the main cutting edge, and thus particularly related to the width direction of the recess formed by the cutting insert, particularly the groove width of the formed groove. That is, in the plunge protrusion, one burr-removing blade is assigned to each end of the main cutting edge in particular. In this way, it becomes possible to simultaneously remove burrs from both recess edges of the formed recess, particularly both groove edges. In this case, one burr-removing blade is assigned to each recess edge respectively. Therefore, advantageously, the production effort is particularly reduced, and the cutting insert can be used particularly efficiently.

[0014] According to an improved aspect of the present invention, it has been specified that the plunge protrusion and the main cutting edge are configured such that the cutting force is introduced in a tangential direction to the base body during the recess machining of the workpiece and are arranged relative to the base body. Therefore, the cutting force introduced to the main cutting edge is supported in a tangential direction by the cutting insert. In this case, the entire cross-section of the cutting insert is provided to support the cutting force. In this way, extremely high stability of the cutting insert is obtained during recess machining. As a result, the quality of the formed recess is improved and at the same time burr formation is reduced. In particular, the chattering tendency is significantly reduced compared to the support in the radial direction with respect to the cutting insert.

[0015] The support in the tangential direction is particularly understood to mean that the main cutting edge extends perpendicular to the main plane of the base body. In this case, the main plane is particularly the plane in which the base body has the largest extent, particularly the plane serving as a reference for the vertically positioned mounting hole. Therefore, the main cutting edge preferably extends parallel to the mounting hole. Therefore, the cutting force is particularly introduced in a tangential direction with respect to the virtual circumferential line centered on the axial direction defined by the mounting hole. In particular, the main cutting edge preferably extends in the axial direction.

[0016] According to an improved form of the present invention, it has been identified that the cutting insert contains at least one material selected from the group consisting of cemented carbide and cubic boron nitride, especially PcBN. Thus, the cutting insert is particularly advantageously configured to also machine hard materials, especially tempered or quenched materials. Preferably, the cutting insert consists of a material selected from the group consisting of cemented carbide and cubic boron nitride, especially PcBN. According to a preferred configuration, it is possible for the cutting insert to be substantially formed from cemented carbide and have a layer or layers consisting of cubic boron nitride. However, alternatively, it is also preferably possible for the cutting insert to consist entirely of cemented carbide. According to another preferred configuration, it is possible for the cutting insert to consist entirely of cubic boron nitride.

[0017] Alternatively or additionally, the cutting insert is preferably coated, at least in the region of the main cutting edge, preferably at least in the region of the cutting projection. In particular, the coating can advantageously contribute to the cutting insert being suitable for machining hard materials, especially tempered or quenched materials. The coating material for preferably coating the cutting insert is preferably selected from the group consisting of TiAlN, TiAlSiN, TiSiN, TiCN, TiN, AlCrN and Al2O3.

[0018] Alternatively or additionally, the cutting insert is preferably coated, at least in the region of the chamfering edge.

[0019] According to a preferred configuration, the cutting insert is coated only in the region of the main cutting edge, or only in the region of the chamfering edge, or on the one hand in the region of the main cutting edge and on the other hand in the region of the chamfering edge, or only in the region of the cutting projection. However, in a preferred configuration, it is also alternatively possible for the entire cutting insert to be coated.

[0020] According to an improved form of the present invention, it has been identified that at least one cutting edge stability geometry is assigned to the main cutting edge. This cutting edge stability geometry can advantageously enhance the stability of the cutting insert, and thus the machining quality and lifespan. In particular, the main cutting edge is protected by the cutting edge stability geometry. This is particularly advantageous when machining hard materials, especially tempered or quenched materials. The cutting edge stability geometry particularly reduces the need to replace the cutting insert so frequently, thereby lowering the production costs.

[0021] Preferably, the cutting insert has a cutting edge stability geometry. Alternatively or additionally, the cutting edge stability geometry is preferably arranged in the transition region from the main cutting edge to the flank face. In particular, the transition from the main cutting edge to the flank face is not formed so abruptly based on the cutting edge stability geometry, whereby the main cutting edge is formed to be less vulnerable to damage.

[0022] At least one cutting edge stability geometry is preferably selected from the group consisting of a rounding and a chamfer. These geometries have been found to be particularly suitable for stabilizing the main cutting edge. It is possible for the cutting edge stability geometry to have only one rounding or only one chamfer. However, it is also possible for the cutting edge stability geometries to be arranged one behind the other, especially starting from the main cutting edge, and to have a combination of one rounding and one chamfer. Also, the cutting edge stability geometry may have a plurality of roundings, a plurality of chamfers, or a combination of a plurality of roundings and a plurality of chamfers.

[0023] According to an improved form of the present invention, the cutting insert is formed as a throw-away tip, and the cutting insert is specified to have at least two cutting projections that are offset from each other in the circumferential direction of the base body, particularly located opposite each other in the diametrical direction. Thereby, a particularly economical configuration of the cutting insert is obtained. Because the cutting insert can first be rotated when the first cutting projection among the plurality of cutting projections is worn, and thereby, for further workpiece machining, the second cutting projection among the plurality of cutting projections is used. In this case, the cutting insert must be replaced only when all the cutting projections are worn. That is, the cutting insert does not necessarily have to be replaced particularly when the first, and in some cases only one, cutting projection is worn.

[0024] The problem is also solved by providing a cutting insert kit having a cutting insert according to the first aspect of the present invention or a first cutting insert according to one or more of the above-described embodiments. This cutting insert kit further has a cutting insert according to the second aspect of the present invention or a second cutting insert according to one or more of the above-described embodiments. The cutting projection of the first cutting insert has a first working width. The cutting projection of the second cutting insert has a second working width. This second working width is larger than the first working width. In relation to the cutting insert kit, in particular, the advantages already described in relation to the cutting insert are obtained.

[0025] The cutting insert kit is particularly configured to perform a method according to the present invention for producing a recess, particularly a groove, or a method according to one or more of the following-described embodiments. To perform such a method, the cutting insert kit is particularly formed by a first cutting insert and a second cutting insert each having one burring blade disposed on a cutting projection at each transition end in the transition region to the base body.

[0026] A cutting insert kit is understood, in particular, as an assembly of a plurality of cutting inserts, in particular a set of at least two cutting inserts.

[0027] The working width of the plunge projection is understood, in particular, as the extent of the main cutting edge assigned to the plunge projection in the width direction of the recess to be formed or formed by the plunge projection, in particular in the direction of the groove width to be formed.

[0028] Due to the second working width being larger than the first working width, the first cutting insert is configured to rough machine or initially machine a workpiece, in particular a recess, in particular a groove, and the second cutting insert is configured to finish machine or finish a workpiece, in particular a recess, in particular a groove. Rough machining or initial machining is also referred to simply as roughing, and finish machining or finishing is also referred to simply as finish turning. The difference between the first working width and the second working width is also called the oversize and defines the amount of material to be removed relative to the initial machining during finishing. That is, the second plunge projection has an oversize relative to the first plunge projection.

[0029] The cutting insert kit enables the complete recess machining and finishing of a workpiece to be carried out simply, quickly and inexpensively. This is because, in particular, the initial machining and the finishing can be carried out directly and continuously in a similar manner by the same cutting inserts, in particular cutting inserts that are similar to each other except for their different working widths. This is particularly efficient when the first cutting insert and the second cutting insert of the cutting insert kit are arranged in the same cutting insert holder, in particular a cutting insert holder according to the invention or a cutting insert holder according to one or more of the following embodiments described below.

[0030] The problem is also solved by providing a cutting insert holder having a central axis and at least one first mounting portion for mounting a first cutting insert to the cutting insert holder. The cutting insert holder has at least one second mounting portion for mounting at least one second cutting insert to the cutting insert holder. The first mounting portion and the second mounting portion are arranged offset from each other in the circumferential direction about the central axis. The first mounting portion and the second mounting portion are configured and arranged such that a first rake face assigned to an effective major cutting edge of a first cutting insert disposed within the first mounting portion has a first orientation along the circumferential direction, and a second rake face assigned to an effective major cutting edge of a second cutting insert disposed within the second mounting portion has a second orientation along the circumferential direction. When the first cutting insert and the second cutting insert are mounted to the cutting insert holder, in particular when the effective major cutting edges are arranged at engagement positions for machining a workpiece, the first orientation is opposite to the second orientation. In connection with the cutting insert holder, in particular, the advantages already described in connection with cutting inserts and cutting insert kits are obtained.

[0031] The effective major cutting edge is understood in particular to be a major cutting edge that is arranged and oriented in the cutting insert holder such that machining of the workpiece can be carried out by the major cutting edge. In particular, when the cutting insert is formed as a throwaway tip, the cutting insert has at least one ineffective major cutting edge in the sense that it is arranged not at a machining position or engagement position, but rather at a rest position or standby position, in addition to the effective major cutting edge.

[0032] The first cutting insert is also called a roughing insert and is provided for initial machining or roughing. The second cutting insert is also called a finishing insert and is provided for finish machining or finish turning.

[0033] The cutting insert holder is configured to carry out the method according to the invention, in particular for producing recesses, in particular grooves, or a method according to one or more of the embodiments described below. The cutting insert holder is in particular configured to carry out such a method. This is because the first cutting insert and the second cutting insert can be arranged in the cutting insert holder in corresponding first and second orientations, whereby the workpiece can be machined first by the first cutting insert in a first rotational direction while reversing the rotational direction of the relative rotation between the workpiece and the cutting insert holder within the scope of the method, and then by the second cutting insert in a second rotational direction opposite to the first rotational direction.

[0034] In particular, based on the reverse rotational directions of the relative rotation between the workpiece and the cutting insert holders for the different cutting inserts, by arranging both the cutting protrusions of the cutting inserts in opposite directions with respect to the circumferential direction and thus simultaneously, it is possible to carry out a particularly efficient, rapid and thus inexpensive recess machining of the workpiece while scraping off the produced recesses using the cutting insert holder.

[0035] The axial direction with respect to the cutting insert holder is in particular a direction that extends parallel to or coincides with the central axis of the cutting insert holder. The radial direction is perpendicular to the axial direction, and the circumferential direction concentrically surrounds the axial direction.

[0036] Both mounting parts for the cutting inserts are preferably arranged on the cutting insert holder such that, in the state where the cutting insert is assembled to the cutting insert holder, the axial direction of the cutting insert is oriented parallel to the axial direction of the cutting insert holder. In particular, preferably, the mounting holes of the cutting insert extend in the axial direction of the cutting insert holder. Thus, in this case, ultimately, the main cutting edges of each cutting insert also extend along the axial direction of the cutting insert holder, and the circumferential direction is locally perpendicular to the rake face of the cutting insert.

[0037] The mounting portion for the first cutting insert and the mounting portion for the second cutting insert are preferably arranged on the cutting insert holder such that when the cutting inserts are arranged on their respective mounting portions, the plunge protrusions are directed radially inwardly and towards the central axis. In particular, the mounting portions are arranged on the outer peripheral side of the cutting insert holder. Thus, in particular, the workpiece is placed in the inner machining area, particularly in the area of the central axis of the cutting insert holder, and in particular, by first feeding the first cutting insert and then the second cutting insert radially towards the workpiece, the workpiece can be machined first by the first cutting insert and then by the second cutting insert. This is particularly understood as the relative movement between the workpiece and the cutting insert. This includes the workpiece being moved and the cutting insert holder being kept stationary, or the cutting insert holder being moved and the workpiece being kept stationary, or both the cutting insert holder and the workpiece being relatively moved with respect to each other.

[0038] In particular, a configuration of the cutting insert holder in which the first cutting insert, particularly the cutting insert according to the present invention or the cutting insert according to one or more of the above-described embodiments, is arranged on the first mounting portion and the second cutting insert, particularly the cutting insert according to the present invention or the cutting insert according to one of the above-described embodiments, is arranged on the second mounting portion is suitable. A configuration of the cutting insert holder in which a cutting insert kit, particularly the cutting insert kit according to the present invention or the cutting insert kit according to one or more of the above-described embodiments, is arranged on the cutting insert holder and in particular the first cutting insert of the cutting insert kit is arranged on the first mounting portion and the second cutting insert of the cutting insert kit is arranged on the second mounting portion is particularly suitable.

[0039] The fact that a certain cutting insert is disposed in a certain mounting portion includes the fact that a specific cutting insert is disposed in a specific mounting portion.

[0040] In a preferred configuration, it is possible for the cutting insert holder to have more than one first mounting portion for a plurality of first cutting inserts. Alternatively or additionally, the cutting insert holder preferably has more than one second mounting portion for a plurality of second cutting inserts.

[0041] Also, it is possible for at least one additional mounting portion for at least one additional cutting insert to be disposed in the cutting insert holder. In this case, the at least one additional mounting portion and the at least one additional cutting insert are provided for at least one intermediate machining step between the rough machining and the finish machining.

[0042] If the cutting insert holder has exactly one first mounting portion and exactly one second mounting portion, both mounting portions are preferably arranged to face each other in the diametrical direction, in particular shifted relative to each other by 180° in the circumferential direction and disposed in the cutting insert holder. If the cutting insert holder has a plurality of first mounting portions and / or a plurality of second mounting portions, the angular spacing between adjacent mounting portions is preferably smaller. For example, in the case of a total of four mounting portions, it is 90° each.

[0043] According to an improved form of the present invention, the cutting insert holder is such that a first cutting insert arranged on at least one first mounting part and a second cutting insert arranged on at least one second mounting part are separated from each other, and in particular are adjusted according to this workpiece so as to be feedable towards the workpiece to be machined one after the other in time. In this way, advantageously, continuous machining of the workpiece can be easily and quickly carried out first by the first cutting insert and then by the second cutting insert. In particular, preferably, the radius of the circumferential line of the cutting insert holder on which the mounting parts are arranged can be arranged in the region of the central axis inside the circumference of the cutting insert holder with respect to the workpiece, and thus, first, the first cutting insert can be engaged with the workpiece, during which the second cutting insert is not engaged with the workpiece, and then a relative radial feed of the cutting insert holder with respect to the workpiece can be carried out, so that the second cutting insert is engaged with the workpiece, during which the first cutting insert is selected not to be engaged with the workpiece.

[0044] The cutting insert holder preferably has an interface for attaching this cutting insert holder to a machine tool. This interface can in particular be formed in various different forms. In particular, it is also possible for the interface to be replaceable with respect to the cutting insert holder. In this case, the cutting insert holder can preferably be used with various different machine tools.

[0045] The interface can be formed, for example, as a VDI40 mounting part, a steep taper interface, a Morse taper interface, an HSK interface or in another suitable form.

[0046] The cutting insert holder is preferably configured to cooperate with a machine tool selected from the group consisting of a vertical lathe, a horizontal lathe and a machining center.

[0047] The problem is finally solved by providing a method for producing a recess, in particular a groove, in particular an annular groove, in particular a retaining ring groove, in a workpiece, in particular a toothed shaft, in particular a shaft having teeth. This method has the following steps. An initial recess, in particular an initial groove, having a first width is milled into the workpiece using a first cutting insert, in particular a first cutting insert according to the first aspect of the present invention or a first cutting insert according to one or more of the above-described embodiments, thereby initially machining the workpiece. At this time, a relative rotation of the workpiece with respect to the first cutting insert is caused in a first rotational direction. This machining step is also called roughing. The initial recess is widened to a second width greater than the first width using a second cutting insert, in particular a second cutting insert according to the second aspect of the present invention or a second cutting insert according to one or more of the above-described embodiments, thereby finishing the workpiece. At this time, a relative rotation of the workpiece with respect to the second cutting insert is caused in a second rotational direction. This machining step is also called finishing. Thus, a recess, in particular a groove, is produced. The second rotational direction is opposite to the first rotational direction. The burr formed in the recess is removed, in particular by the second cutting insert, during finishing. In particular, the advantages already described in connection with the cutting insert, the cutting insert kit and the cutting insert holder are obtained in relation to the method.

[0048] By changing the rotational direction between roughing and finishing, in particular by changing the rotational direction of the relative rotation, the burrs formed can be removed particularly efficiently, so that at the same time a high working speed and a high machining quality are achieved. In particular, the burrs formed during roughing are removed in the finishing direction opposite to the roughing direction, i.e. in the finishing direction opposite to the roughing direction.

[0049] Deburring of the recess, in particular the groove, is made particularly easy and accurate by means of a cutting insert according to the present invention or a cutting insert according to one or more of the above-described embodiments. This is because the cutting insert has a deburring edge in the transition region of the cutting protrusion to the substrate at the base or transition end of the cutting protrusion.

[0050] The relative rotation between the workpiece and the cutting insert can be caused by rotating the workpiece relative to the cutting insert. However, preferably, it is also possible to rotate at least the currently effective cutting insert, preferably both cutting inserts, relative to the workpiece. Also, in a preferred configuration, it is possible to cause a relative rotation in which both the workpiece and the cutting insert move appropriately relative to each other, particularly during machining in a machining center.

[0051] Preferably, the initial machining can be carried out by a plurality of first cutting inserts. Alternatively or additionally, preferably, the finishing machining can be carried out by a plurality of second cutting inserts. Alternatively or additionally, it is possible to carry out at least one intermediate step between the initial machining and the finishing machining by at least one further cutting insert. Importantly, in particular, the direction of rotation of the relative rotation between the workpiece and the cutting insert engaged with the workpiece respectively is changed with respect to the direction of rotation during the immediately preceding working step at least before the last finishing machining step, preferably before the first finishing machining step or before a single finishing machining step.

[0052] According to an improved form of the present invention, it is specified to cause a first relative rotation between the workpiece and a tool having a first cutting insert and a second cutting insert, particularly a cutting insert holder according to the present invention or a cutting insert holder according to one or more of the foregoing embodiments. A second relative rotation is caused between the workpiece and the same tool, particularly the cutting insert holder, and during the initial machining, the first cutting insert is engaged with the workpiece, and during the finishing machining, the second cutting insert is engaged with the workpiece. This is made possible particularly based on arranging the first cutting insert in a first orientation and the second cutting insert in a second orientation in the cutting insert holder by the cutting insert holder according to the present invention or a cutting insert holder according to one or more of the foregoing embodiments.

[0053] According to an improved form of the present invention, for initial machining, a first cutting insert is fed to the workpiece, and for finish machining, a second cutting insert is fed to the workpiece. This includes any possibility of relative movement between the workpiece and the cutting insert, in particular whether the cutting insert is moved and the workpiece is stationary, whether the workpiece is moved and the cutting insert is stationary, or whether both the workpiece and the cutting insert are moved.

[0054] According to an improved form of the present invention, it is specified that a toothed shaft is machined as the workpiece. In particular, in this case, the already described advantages based on discontinuous cutting conditions, especially interrupted ones, are realized.

[0055] According to an improved form of the present invention, it is specified that a recess, in particular a groove, is machined in the workpiece in the hardened or quenched state. In particular, in this case, the already described advantages are realized. The workpiece preferably has a hardness of at least 36 HRC and at most 60 HRC. Note that HRC represents the Rockwell hardness on the C scale.

[0056] According to an improved form of the present invention, it is specified that the method is carried out on a vertical lathe, a horizontal lathe or a machining center. These machine tools have been found to be particularly suitable for the method. Preferably, when using a vertical lathe and a horizontal lathe, relative rotation is generated by rotating the workpiece. In this case, the cutting insert may be kept stationary or is only fed towards the workpiece, especially in the radial direction. In the case of a machining center, preferably, in order to generate relative rotation, a complex relative rotation is carried out by appropriately moving both the workpiece and the cutting insert.

[0057] The present invention will be described in detail with reference to the drawings.

Brief Description of the Drawings

[0058]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0059] FIG. 1 shows a first figure of an embodiment of a cutting insert 1. The cutting insert 1 is formed for recess machining and has a substrate 3 and a cutting projection 5 that projects radially from the substrate 3. In the embodiment shown in the figure, the cutting insert 1 is formed as a throw-away tip and has two cutting projections 5 that are offset from each other in the circumferential direction of the substrate 3. Since these two cutting projections 5 are preferably formed identically to each other, hereinafter, only one of the two cutting projections 5 will be described in detail.

[0060] The cutting projection 5 has a main cutting edge 9 at the working end 7 on the side opposite to the substrate 3.

[0061] FIG. 2 shows a second figure of the cutting insert 1 shown in FIG. 1.

[0062] For the same elements and functionally identical elements, the same reference numerals are assigned in all the drawings. Therefore, regarding this point, please refer to the above-described explanations respectively.

[0063] As is apparent from the second figure, the chamfered protrusion 5 has deburring blades 15 on at least one side, and in both sides in the illustrated embodiment, at the transition end 11 on the base 3 side in the transition region 13 to the base 3. The transition end 11 is also called the base of the chamfered protrusion 5.

[0064] By the deburring blades 15, it is possible to efficiently remove burrs generated on the workpiece during the recess machining with less labor.

[0065] In the illustrated embodiment, the chamfered protrusion 5 and the main cutting edge 9 are integrally formed with the base 3, particularly with a uniform material.

[0066] Also shown are the main plane 17 of the base 3 and the mounting hole 19 that penetrates the base 3 perpendicular to the main plane 17 and along the axial direction of the base 3 and thus simultaneously along the axial direction of the cutting insert 1.

[0067] The chamfered protrusion 5 and the main cutting edge 9 are preferably configured such that the cutting force is introduced in the tangential direction to the base 3 during the recess machining of the workpiece and are arranged relative to the base 3. In particular, the main cutting edge 9 extends perpendicular to the main plane 17, particularly in the axial direction, and particularly parallel to the mounting hole 19.

[0068] The cutting insert 1 preferably contains at least one material selected from the group consisting of cemented carbide and cubic boron nitride. Alternatively or additionally, the cutting insert 1 is coated at least in the region of the chamfered protrusion 5.

[0069] In the region of the main cutting edge 9, in particular, the rake face 21 of the cutting insert 1 is adjacent to the flank face 23. Preferably, the main cutting edge 9 forms the intersection line between the rake face 21 and the flank face 23.

[0070] Preferably, a cutting edge stability geometry 25 is assigned to the main cutting edge 9. This cutting edge stability geometry 25 is preferably selected from the group consisting of rounding portions and chamfered portions.

[0071] Figure 3 shows a view of an embodiment of the cutting insert kit 27. The cutting insert kit 27 has a first cutting insert 1.1 and a second cutting insert 1.2. Both cutting inserts 1.1, 1.2 are each preferably formed according to the embodiments described above in connection with FIGS. 1 and 2. However, the first cutting depth protrusion 5.1 of the first cutting insert 1.1 has a first working width B1 that is smaller than the second working width B2 of the second cutting depth protrusion 5.2 of the second cutting insert 1.2. Thus, while the first cutting insert 1.1 is preferably formed for roughing or initial machining, the second cutting insert 1.2 is formed for finish cutting or finish machining.

[0072] Figure 4 shows a first view of an embodiment of the cutting insert holder 29. The cutting insert holder 29 has a central axis M and a first attachment portion 31 for attaching the first cutting insert 1.1, in particular the first cutting insert 1.1 of the cutting insert kit 27 shown in FIG. 3, to the cutting insert holder 29. Further, the cutting insert holder 29 has a second attachment portion 33 for attaching the second cutting insert 1.2, in particular the second cutting insert 1.2 of the cutting insert kit 27 shown in FIG. 3, to the cutting insert holder 29. The central axis M defines the axial direction of the cutting insert holder 29. The cutting inserts 1.1, 1.2 are held in the attachment portions 31, 33 respectively assigned to them such that, in particular their respective axial directions, in particular the attachment holes 19, are oriented parallel to the axial direction of the cutting insert holder 29, i.e., the central axis M.

[0073] It is also shown that the cutting inserts 1.1, 1.2 are preferably attached to the cutting insert holder 29 by attachment means 35 formed as attachment screws.

[0074] The first mounting portion 31 and the second mounting portion 33 are arranged so as to be shifted from each other in the circumferential direction about the central axis M, and are particularly located opposite to each other in the diametrical direction.

[0075] The cutting insert holder 29 has an interface 37 configured to couple the cutting insert holder 29 to a machine tool.

[0076] FIG. 5 shows a second view of the cutting insert holder 29 shown in FIG. 4. As is apparent from the figure, the first mounting portion 31 and the second mounting portion 33 are such that the first rake face 21.1 assigned to the effective main cutting edge 9.1 of the first cutting insert 1.1 disposed within the first mounting portion 31 has a first orientation along the circumferential direction, and the second rake face 21.2 assigned to the effective main cutting edge 9.2 of the second cutting insert 1.2 disposed within the second mounting portion 33 has a second orientation along the circumferential direction. In this case, the first orientation is opposite to the second orientation along the circumferential direction. The effective main cutting edges 9.1, 9.2 are disposed at an engagement position for machining a workpiece. In the embodiment shown in the figure, the chip pockets 5.1, 5.2 assigned to the effective main cutting edges 9.1, 9.2 are directed radially inward in the direction of the central axis M. In this case, the workpiece is disposed in the region of the central axis M of the cutting insert holder 29 for machining by the cutting inserts 1.1, 1.2.

[0077] Based on the different orientations of the rake faces 21.1, 21.2 with respect to each other, first, a change in the rotational direction of the relative rotation between the workpiece and the cutting insert holder 29 is required between the machining of the workpiece by the first cutting insert 1.1 and then the machining of the workpiece by the second cutting insert 1.2. In this case, in particular, the workpiece can be initially machined by the first cutting insert 1.1 and then finished by the second cutting insert 1.2. At that time, the burrs generated during the initial machining are efficiently removed simultaneously in the direction opposite to the preceding cutting direction.

[0078] In particular, the cutting insert holder 29 separates the first cutting insert 1.1 and the second cutting insert 1.2 from each other, and is adjusted according to the workpiece to be machined so that they can be fed toward the workpiece in the radial direction in a time - staggered manner, especially one after the other.

[0079] FIG. 6 shows a third view of the cutting insert holder shown in FIGS. 4 and 5. In this figure, on the one hand, the different orientations of the first rake face 21.1 and the second rake face 21.2 along the circumferential direction are again clearly visible. On the other hand, as shown in this figure, the interface 37 may be formed as a VDI 40 mounting part in a preferred configuration. However, the interface 37 may alternatively be formed in a preferred configuration as, in particular, a steep taper interface, a Morse taper interface, an HSK interface or in another suitable form.

[0080] FIG. 7 shows a view of a workpiece 39 for machining using the cutting insert 1 shown in FIG. 1 and the cutting insert holder shown in FIG. 4. The workpiece 39 is formed in particular as a toothed shaft. Using the cutting insert 1, in particular the first cutting insert 1.1 and the second cutting insert 1.2, in particular the cutting insert kit 27, and in particular the cutting insert holder 29, a recess 40, in particular an annular groove 41, in particular a groove for a retaining ring, is preferably machined in the workpiece 39. In this case, in particular the aforementioned advantages are obtained. This is because, based on the discontinuous cutting conditions that occur precisely in the region of the tooth part, high stability is important for the cutting inserts 1.1, 1.2, especially because burr formation occurs.

[0081] FIG. 8 shows a schematic view of an embodiment of a method for producing a recess 40, in particular a groove, in particular an annular groove 41, in the workpiece 39 shown in FIG. 7.

[0082] Within the scope of the method, first, the workpiece 39 is initially machined by cutting an initial recess having a first width using a first cutting insert 1.1 having a first working width B1. This is also called roughing. In this case, the relative rotation of the workpiece 39 with respect to the first cutting insert 1.1, in particular the tool 43, in particular the cutting insert holder 29, occurs in a first rotational direction. For this purpose, the workpiece 39 is preferably arranged in the region of the central axis M of the cutting insert holder 29. In this case, first, the first cutting insert 1.1 is fed radially towards the workpiece 39.

[0083] Thereafter, the workpiece is finish-machined by widening the initial recess to a second width greater than the first width using a second cutting insert 1.2 having a second working width B2. This is also called finish cutting. This is possible because the second working width B2 is greater than the first working width B1. In this way, a recess 40, in particular an annular groove 41, is produced. During finish machining, the relative rotation of the workpiece 39 with respect to the second cutting insert 1.2 occurs in a second rotational direction opposite to the first rotational direction of the roughing machining. In particular, the relative rotation in the second rotational direction occurs relative to the same tool 43, in particular the cutting insert holder 29, and the first relative rotation in the first rotational direction also occurs relative to the tool 43. The recess 40 formed, in particular the annular groove 41, is burr-removed by the second cutting insert 1.2, in particular its burr-removing edge 15.2, during finish machining, that is, during finish cutting. This is done particularly efficiently because the burr is separated in a direction opposite to its forming direction. For finish machining, the second cutting insert 1.2 is fed radially towards the workpiece 39.

[0084] Relative rotation occurs, in particular, between the cutting insert holder 29 and the workpiece 39. Since the cutting inserts 1.1, 1.2 are arranged in the cutting insert holder 29 in opposite directions to each other, it is possible to reverse the direction of rotation of the relative rotation between the initial machining by the first cutting insert 1.1 and the finish machining by the second cutting insert 1.2, whereby the burr can be cut off in the direction opposite to its formation direction. In particular, during the initial machining, only the first cutting insert 1.1 engages with the workpiece 39, and the second cutting insert 1.2 does not engage with the workpiece 39. During the finish machining, only the second cutting insert 1.2 engages with the workpiece 39, and the first cutting insert 1.1 does not engage with the workpiece 39.

[0085] The recesses 40, in particular the annular groove 41, are preferably machined in the workpiece 39 which is in a hardened or quenched state. The workpiece 39 preferably has a hardness of at least 36 HRC and at most 60 HRC.

[0086] Preferably, the method is carried out on a vertical lathe, a horizontal lathe or a machining center.

Claims

Claim 1 A cutting insert holder (29), comprising a central axis (M), at least one first mounting portion (31) for mounting a first cutting insert (1.1) to the cutting insert holder (29), and at least one second mounting portion (33) for mounting at least one second cutting insert (1.2) to the cutting insert holder (29), wherein the first mounting portion (31) and the second mounting portion (33) are arranged offset from each other in the circumferential direction about the central axis (M), and the first mounting portion (31) and the second mounting portion (33) are configured and arranged such that a first rake face (21.1) assigned to an effective major cutting edge (9.1) of the first cutting insert (1.1) disposed within the first mounting portion (31) has a first orientation along the circumferential direction, and a second rake face (21.2) assigned to an effective major cutting edge (9.2) of the second cutting insert (1.2) disposed within the second mounting portion (33) has a second orientation along the circumferential direction, and when the first cutting insert (1.1) and the second cutting insert (1.2) are mounted to the cutting insert holder (29), the first orientation is opposite to the second orientation. Furthermore, the first and second mounting portions (31, 33) are arranged on the cutting insert holder (29) such that when the first and second cutting inserts (1.1, 1.2) are respectively disposed in the first and second mounting portions (31, 33), the plunge protrusions of the first and second cutting inserts (1.1, 1.2) are directed radially inwards towards the central axis (M). And the first and second mounting portions (31, 33) are arranged on the outer periphery of the cutting insert holder (29). And it is possible to arrange a workpiece (39) in the region of the central axis (M). Moreover, the first cutting insert (1.1) disposed on the at least one first mounting portion (31) and the second cutting insert (1.2) disposed on the at least one second mounting portion (33) can be individually fed toward the workpiece (39) in a separated state from each other. Thereby, when the first and second cutting inserts (1.1, 1.2) are respectively disposed on the mounting portions (31, 33), the workpiece (39) can be first machined by the first cutting insert (1.1) and then machined by the second cutting insert (1.2). A cutting insert holder (29) characterized by this.

2. When the first and second cutting inserts (1.1, 1.2) are respectively disposed on the first and second mounting portions (31, 33), the first cutting insert (1.1) disposed on the at least one first mounting portion (31) and the second cutting insert (1.2) disposed on the at least one second mounting portion (33) can be fed toward the workpiece (39) to be machined in a time - sequential front - and - rear relationship with each other. The cutting insert holder (29) according to Claim 1.

3. At least one cutting insert (1) for recess machining disposed on the first and second mounting portions (31, 33), wherein the at least one cutting insert (1) - a base body (3); - a cutting - in protrusion (5) protruding radially from the base body (3); is provided with; - the cutting - in protrusion (5) has a main cutting edge (9) at the working end (7) on the side opposite to the base body (3); - the cutting - in protrusion (5) has a burring - removing edge (15) on at least one side at the transition end (11) on the base - body (3) side in the transition region (13) to the base body (3). The cutting insert holder (29) according to Claim 1.

4. The cutting - in protrusion (5) has one burring - removing edge (15) on each of both sides at the transition end (11). The cutting insert holder (29) according to Claim 3.

5. The chip-breaking protrusion (5) and the main cutting edge (9) are configured such that cutting force is introduced in a tangential direction to the substrate (3) during recess machining of the workpiece (39), and are disposed relative to the substrate (3). The cutting insert holder (29) according to claim 3 or claim 4.

6. - The cutting insert (1) contains at least one material selected from the group consisting of cemented carbide and cubic boron nitride, and / or - The cutting insert (1) is coated at least in the region of the chip-breaking protrusion (5). The cutting insert holder (29) according to any one of claims 3 to 5.

7. At least one cutting edge stability geometry (25) is assigned to the main cutting edge (9), and the at least one cutting edge stability geometry (25) is preferably selected from the group consisting of a rounded portion and a chamfered portion. The cutting insert holder (29) according to any one of claims 3 to 6.

8. The cutting insert (1) is formed as a throw-away tip, and the cutting insert (1) has at least two chip-breaking protrusions (5) arranged offset from each other in the circumferential direction of the substrate (3). The cutting insert holder (29) according to any one of claims 3 to 7.

9. The insert holder (29) has the first cutting insert (1.1) disposed in the first mounting portion (31) and the second cutting insert (1.2) disposed in the second mounting portion (33). The chip-breaking protrusion (5.1) of the first cutting insert (1.1) has a first working width (B1), and the chip-breaking protrusion (5.2) of the second cutting insert (1.2) has a second working width (B2). The second working width (B2) is larger than the first working width (B1). The cutting insert holder (29) according to any one of claims 3 to 8.

10. A method for producing a recess (40), particularly a groove, particularly an annular groove (41) in a workpiece (39), particularly a toothed shaft, using the cutting insert holder (29) according to any one of claims 1 to 9. - A step of initially machining the workpiece (39) by cutting an initial recess having a first width using the first cutting insert (1.1), wherein at this time, a relative rotation of the workpiece (39) with respect to the first cutting insert (1.1) is caused in a first rotation direction, the step of initially machining; - A step of finishing the workpiece (39) by widening the initial recess to a second width larger than the first width using the second cutting insert (1.2), and thus manufacturing the recess (40), wherein at this time, a relative rotation of the workpiece (39) with respect to the second cutting insert (1.2) is caused in a second rotation direction, the step of finishing and thus manufacturing; comprising; - The second rotation direction is opposite to the first rotation direction; - The formed recess (40) is chamfered by the second cutting insert (1.2) during the finishing process; Method.

11. Causing the first relative rotation between the workpiece (39) and the cutting insert holder (29), causing the second relative rotation between the workpiece (39) and the same cutting insert holder (29), during the initial machining, engaging the first cutting insert (1.1) with the workpiece (39), and during the finishing machining, engaging the second cutting insert (1.2) with the workpiece (39), the method according to claim 10.

12. Feeding the first cutting insert (1.1) to the workpiece (39) for the initial machining, and feeding the second cutting insert (1.2) to the workpiece (39) for the finishing machining, the method according to claim 10 or claim 11.

13. Machining a toothed shaft as the workpiece (39), the method according to any one of claims 10 to 12.

14. Machining the recess (40) in the workpiece (39) in a hardened or quenched state, and the workpiece (39) preferably has a hardness of at least 36 HRC to at most 60 HRC, the method according to any one of claims 10 to 13.

15. Implementing the method on a vertical lathe, a horizontal lathe or a machining center, the method according to any one of claims 10 to 14.

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