Milling tool and method for designing a milling tool of this type
Patent Information
- Application Number
- EP2023736030
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-30
- Filing Date
- 2023-06-26
- Publication Date
- 2025-05-07
Smart Images
Figure 1.1
Abstract
Description
[0001]MAPAL Fabrik für Präzisionswerkzeuge Dr. Kress KG DESCRIPTION Milling tool and method for designing such a milling tool The invention relates to a milling tool and a method for designing such a milling tool. When milling - particularly in contrast to drilling or reaming - there is the challenge that the cutting edges of a milling tool are not permanently in engagement with a machined workpiece, but rather cyclically enter and exit the workpiece. For example, when using a wide finishing knife as one cutting edge of the milling tool, the wide finishing knife engages the machined workpiece less deeply than the other cutting edges, resulting in a smaller metal removal volume than the average metal removal volume per cutting edge assigned to the milling tool.At a constant feed rate of the milling tool, a cutting edge lagging behind the wide finishing knife must therefore remove more material from the workpiece; in particular, this results in a larger metal removal volume for the cutting edge than the average metal removal volume assigned to the milling tool. As a result, the cutting edge lagging behind the wide finishing knife is subjected to excessive load, resulting in increased wear on this cutting edge. This, in turn, leads to uneven wear and different service lives of the various cutting edges. The object of the invention is to provide a milling tool and a method for designing such a milling tool, wherein the aforementioned disadvantages are at least partially eliminated. This object is achieved by providing the present technical teaching, in particular the teaching of the independent claims and the embodiments disclosed in the dependent claims and the description.The object is achieved in particular by providing a milling tool with a plurality of first cutting edges and at least one second cutting edge, wherein the plurality of first cutting edges and the at least one second cutting edge are arranged offset on the milling tool in the circumferential direction of the milling tool. The first cutting edges are arranged at a nominal position in the axial direction of the milling tool. Furthermore, the plurality of first cutting edges comprises a compensation group with at least one compensation cutting edge and at least one non-compensation cutting edge. A nominal cutting circle is assigned to the at least one non-compensation cutting edge. A compensation cutting circle is assigned to the at least one compensation cutting edge. Furthermore, the nominal cutting circle and the compensation cutting circle are different from one another.The at least one second cutting edge is offset in the axial direction of the milling tool by a pre-offset relative to the nominal position in the direction of a machining face. Additionally, the at least one second cutting edge is assigned a surface machining cutting circle, wherein the surface machining cutting circle is smaller than the nominal cutting circle and the compensation cutting circle. The at least one second cutting edge leads the plurality of first cutting edges in the circumferential direction. In this way, the different machining volumes per cutting edge, which are due to the at least one second cutting edge, can advantageously be adjusted to one another. The machining volume per cutting edge is a measure of the machining performance achieved by the respective cutting edge.In particular, a lateral, i.e., radial, alignment of the compensation cutting edges can be adjusted such that the metal removal volumes per cutting edge are at least substantially equal, preferably equal, for each cutting edge. This also results in a more even force distribution on the cutting edges, which thus also have more even and, in particular, longer service lives. In particular, a metal removal volume not achieved by the second cutting edge due to the radial offset resulting from the surface machining flight circle is distributed among the cutting edges of the compensation group. This increases the metal removal volume of the at least one compensation cutting edge and the at least one non-compensation cutting edge compared to a first cutting edge not assigned to the compensation group.In particular, it is possible, for a fixed metal removal volume not achieved by the second cutting edge, to reduce the additional metal removal volume per cutting edge of the compensation group the larger the number of cutting edges in the compensation group. Furthermore, the metal removal volume achieved by the second cutting edge depends on the radial setback of the second cutting edge, with the metal removal volume of the second cutting edge decreasing as the setback increases. In particular, the metal removal volume of the second cutting edge is zero as soon as the radial setback is equal to a threshold setback. Thus, the metal removal volume not achieved by the second cutting edge is constant – in particular, corresponds to a maximum metal removal volume – for a radial setback that is greater than or equal to the threshold setback.Therefore, with a fixed additional metal removal rate per cutting edge of the compensation group, it is possible to increase the metal removal rate not achieved by the second cutting edge, in particular until the maximum metal removal rate is reached, the greater the number of cutting edges in the compensation group. Milling is understood here in particular to be a machining process using a rotating tool. The cutting edges of the milling tool generate the cutting movement by rotating around a tool center axis of the milling tool as the axis of rotation. At the same time, a feed movement is effected between the milling tool and a machined workpiece. The feed movement can be carried out on the milling tool and / or on the workpiece. The axial direction extends in the direction of the tool center axis, i.e. the intended axis of rotation of the milling tool. The circumferential direction encompasses the tool center axis concentrically.A radial direction is perpendicular to the tool center axis. The cutting edges, in particular, comprise cutting edges of the milling tool. The cutting edges can be formed directly on a base body of the milling tool, or on cutting inserts, in particular knife plates or indexable inserts, which are attached to the base body, for example, screwed to the base body or soldered into the base body. In particular, the cutting edges are main cutting edges of an associated cutting edge geometry. The cutting edges are, in particular, offset from one another in the circumferential direction on the base body of the milling tool, i.e., arranged in pairs with a finite angular distance from one another on the base body.A cutting edge leading a cutting edge is understood to be a cutting edge which, as viewed in the direction of rotation of the milling tool, leads the cutting edge in question, i.e., is arranged in front of the cutting edge in question as viewed in the direction of rotation of the milling tool and, when machining a workpiece, preferably comes into engagement with the material of the workpiece before the cutting edge in question. Furthermore, a cutting edge immediately leading a cutting edge is understood to be a cutting edge which, as viewed in the direction of rotation of the milling tool, leads the cutting edge in question, i.e., is arranged in front of the cutting edge in question as viewed in the direction of rotation of the milling tool and, when machining a workpiece, preferably comes into engagement with the material of the workpiece immediately before the cutting edge in question.A flight circle is, in particular, an imaginary circle defined by the path described by a point on a cutting edge of a cutting edge that, along the cutting edge geometry, has the greatest distance from the tool center axis, during the rotation of the milling tool around the tool center axis. The fact that a cutting edge is assigned a flight circle means, in particular, that the cutting edge on the milling tool has the flight circle, or – expressed in other words – that the cutting edge, in particular its cutting edge, is arranged with the corresponding flight circle on the milling tool. The nominal flight circle is therefore, in particular, a flight circle predetermined for the milling tool that determines a nominal machining diameter of the milling tool. In addition, the compensation flight circle is, in particular, determined and / or calculated based on the nominal flight circle.In particular, the at least one second cutting edge is offset radially inwards relative to the plurality of first cutting edges, i.e. offset back in the direction of the tool center axis, since the surface machining cutting circle is smaller than the nominal cutting circle and the compensation cutting circle. The nominal position is in particular a position predetermined for the milling tool along the axial direction, at which position the first cutting edges, in particular the cutting edges of the first cutting edges, are to be arranged. The fact that the at least one second cutting edge is offset in the axial direction of the milling tool by a pre-offset relative to the nominal position in the direction of a machining end face means that the at least one second cutting edge projects in the axial direction towards a workpiece to be machined relative to a cutting edge arranged in the nominal position.In particular, the plurality of first cutting edges and the at least one second cutting edge differ in an arrangement of the cutting edges both in the axial direction of the milling tool and in the radial direction of the milling tool. In particular, a material removal in the radial direction of the milling tool on a workpiece by means of one of the first cutting edges is greater than the material removal in the radial direction of the milling tool on the workpiece by means of the at least one second cutting edge. In particular, a material removal in the axial direction of the milling tool on a workpiece by means of the at least one second cutting edge is greater than the material removal in the axial direction of the milling tool on the workpiece by means of one of the first cutting edges. In particular, the compensation flight circle is smaller than the nominal flight circle.In particular, the nominal cutting circle is assigned to at least one first cutting edge of the plurality of first cutting edges that is not assigned to the compensation group. In particular, at least one first cutting edge arranged on the nominal cutting circle leads the at least one second cutting edge, in particular directly ahead. In a further embodiment, a second cutting edge of the at least one second cutting edge and a compensation cutting edge of the at least one compensation cutting edge are directly adjacent to one another in the circumferential direction. Furthermore, the one second cutting edge of the at least one compensation cutting edge leads the at least one compensation cutting edge directly ahead in the circumferential direction. In particular, a machining direction of the milling tool is orthogonal to the axial direction of the milling tool. During milling, the milling tool is displaced perpendicular to the tool center axis, in particular in the machining direction.A specific feed rate per revolution of the milling tool is set, which is the quotient of the linear feed rate divided by the speed of the milling tool. In particular, the at least one second cutting edge is designed as a wide finishing knife. According to a further development of the invention, the compensation group has at least two compensation cutting edges, with different compensation cutting circles being assigned to the at least two compensation cutting edges. In addition, the at least two compensation cutting edges are directly adjacent to one another. Advantageously, this makes it possible to distribute the machining volume not achieved by the at least one second cutting edge between a plurality of first cutting edges and thus reduce the additional loads on the first cutting edges assigned to the compensation group.In particular, in this way, the cutting performance and the metal removal volume are evened out among the cutting edges, so that their load, metal removal performance, wear, and service life are advantageously homogenized. In one embodiment, a first compensation cutting edge is assigned a first compensation cutting edge, and a second compensation cutting edge is assigned a second compensation cutting edge. The first compensation cutting edge immediately lags behind the at least one second cutting edge in the circumferential direction. Furthermore, the second compensation cutting edge and the non-compensation cutting edge are immediately adjacent to one another. In particular, the first compensation cutting circle is smaller than the second compensation cutting circle, and the second compensation cutting circle is smaller than the nominal cutting circle. According to a further development of the invention, the at least one non-compensation cutting edge immediately lags behind the at least one compensation cutting edge.In one embodiment, the non-compensating cutting edge immediately lags behind the first compensating cutting edge in the circumferential direction. Alternatively, the non-compensating cutting edge preferably immediately lags behind the second compensating cutting edge in the circumferential direction. In particular, the non-compensating cutting edge immediately lags behind the compensating cutting edge with the largest compensation cutting circle in the circumferential direction. According to a further development of the invention, it is provided that the plurality of first cutting edges are designed for pre-machining the workpiece, in particular as roughing cutting edges. Preferably, the at least one second cutting edge is additionally designed for finish machining the workpiece, in particular as finishing cutting edges. In a particularly advantageous embodiment, roughing and finishing operations can be carried out with the same milling tool, since the surface quality is increased.This in turn results in time and cost savings due to fewer tool changes and setup work. Due to the arrangement of the plurality of first cutting edges and the at least one second cutting edge, the milling tool is configured to primarily machine a first workpiece surface orthogonal to the machining direction using the plurality of first cutting edges and to primarily machine a second workpiece surface orthogonal to the axial direction using the at least one second cutting edge. In particular, a workpiece is milled flat using the milling tool, and the particularly flat surface of the workpiece is machined and / or finished during the face milling using the at least one second cutting edge.Alternatively or additionally, in particular by means of the at least one second cutting edge, a bottom surface of a groove produced by the milling tool in the workpiece is machined and / or finished during the introduction of the groove, which in particular is carried out primarily by means of the plurality of first cutting edges. According to a further development of the invention, it is provided that a first compensation cutting edge of the at least one compensation cutting edge is offset radially inwards relative to the nominal flight circle by a first setback and is arranged on a first compensation flight circle. According to a further development of the invention, it is provided that a second compensation cutting edge of the at least two compensation cutting edges is offset radially inwards relative to the nominal flight circle by a second setback and is arranged on a second compensation flight circle.The first offset of the first compensation flight circle relative to the nominal flight circle is greater than the second offset of the second compensation flight circle relative to the nominal flight circle. According to a further development of the invention, the first cutting edges each enclose a pitch angle in pairs, wherein the pitch angles have a relative size difference of at most 15%. A pitch angle α enclosed in pairs by two first cutting edges. iis understood to mean an angle that two first cutting edges immediately adjacent in the circumferential direction enclose with each other. In one embodiment, a target pitch angle α is predetermined, with all pitch angles αi having at least the value 0.925*α and at most the value 1.075*α. Thus, the pitch angles αi have a relative size difference of at most 15% with respect to the target pitch angle α. Alternatively, all pitch angles α i at most the value 1.15*min(αi). Thus, the pitch angles αi have a relative size difference of at most 15% with respect to a minimum pitch angle. Alternatively, all pitch angles α i at least the value 0.85*max(α i). The pitch angles αi therefore have a relative size difference of at most 15% with respect to a maximum pitch angle. The object is also achieved by providing a method for designing, preferably for manufacturing, a milling tool according to the invention or a milling tool according to one of the previously described embodiments, wherein an angular position for the plurality of first cutting edges and the at least one second cutting edge is defined in the circumferential direction on the milling tool. In addition, the nominal cutting circle of the at least one non-compensating cutting edge is defined. A first compensating cutting edge of the at least one compensating cutting edge is radially set back by a first setback relative to the nominal cutting circle.The first setback for the first compensation cutting edge of the at least one compensation cutting edge is preferably selected depending on at least one parameter that is selected from a predetermined additional load on the compensation cutting edges and a tooth feed per revolution for the milling tool. In connection with the method, the advantages that have already been explained in connection with the milling tool arise in particular. In particular, a nominal position of the first cutting edges, in particular of the cutting edges of the first cutting edges, is furthermore defined along the axial direction of the milling tool. In addition, in particular a pre-offset of the at least one second cutting edge in the axial direction of the milling tool relative to the nominal position in the direction of a machining end face is furthermore defined. In particular, the at least one compensation cutting edge and the at least one non-compensation cutting edge are furthermore determined and / or defined.In particular, a first compensation cutting circle is determined using the nominal cutting circle and the first offset. In particular, a surface machining cutting circle is further defined for the at least one second cutting edge such that the surface machining cutting circle is smaller than the first compensation cutting circle and the nominal cutting circle. In particular, the positions of the first cutting edges and the at least one second cutting edge in the circumferential direction are defined such that the at least one second cutting edge leads the first cutting edges, in particular the at least one compensation cutting edge. In particular, a value of at most 20%, in particular at most 25%, in particular at most 33%, in particular at most 33.33%, in particular at most 50%, is selected for the predetermined additional load q of the compensation cutting edges.In particular, a value of at least 0.01 mm to at most 0.5 mm, in particular 0.1 mm, in particular 0.111 mm, in particular 0.125 mm, in particular 0.139 mm, in particular 0.15 mm, in particular 0.153 mm, in particular 0.167 mm, in particular 0.181 mm, in particular 0.194 mm, in particular 0.200 mm, in particular 0.222 mm, in particular 0.236 mm, in particular 0.25 mm, is selected for the tooth feed per revolution fz for the milling tool. According to a development of the invention, it is provided that a second compensation cutting edge of the at least two compensation cutting edges is radially set back relative to the nominal flight circle by a second setback, wherein the first setback is greater than the second setback.Furthermore, the second setback for the second compensation cutting edge is preferably selected depending on at least one parameter selected from the predetermined additional load of the compensation cutting edge and a tooth feed per revolution for the milling tool. According to a further development of the invention, it is provided that firstly the tooth feed per revolution for the milling tool and the predetermined additional load of the compensation cutting edge are determined. Subsequently, a machining compensation is determined based on the tooth feed and the predetermined additional load. Based on the machining compensation, a number of compensation cutting edges is determined. Subsequently, a setback is determined for each cutting edge of the number of compensation cutting edges. Subsequently, the compensation cutting edges are each offset radially inward by the assigned setback with respect to the nominal cutting circle.In particular, the machining compensation Kzer is calculated using the equation ^^. ^^ ^^ ^^ = ^^ ^^ ∗ ^^ (1) is calculated from the additional load q of the compensation cutting edges and the feed per revolution fz. In particular, the number of compensation cutting edges is determined using equation (2) from the tooth feed per revolution fz, the machining compensation Kzer and a minimum manufacturing compensation K mincalculated. In particular, the number of first cutting edges is determined using the minuend in equation (2). In particular, the subtrahend is chosen to be 1, since the milling tool, in particular the compensation group, has at least one non-compensating cutting edge. In particular, a value of at most 0.04 mm, in particular at most 0.05 mm, in particular at most 0.06 mm, in particular at most 0.07 mm, in particular at most 0.08 mm, in particular at most 0.09 mm, in particular at most 0.1 mm, is selected for the minimum manufacturing compensation Kmin. Preferably, the minimum manufacturing compensation Kmin is determined using the equation ^^ ^^ ^^ ^^ = 2 ∗ ( ^^ ^^ ^^ + ^^ ^^ ) (3) is calculated from a manufacturing tolerance of the tool TWZ and a manufacturing tolerance of the cutting edges TS. In particular, the respective setback ri for i=1 to nk is calculated using the equation ^^ ^^ = ^^ ^^− ^^ ∗ max{ ^^ ^^ ^^ ^^ , ^^ ^^ ^^ ^^} (4) is calculated from the feed per revolution fz, the machining compensation Kzer, and the minimum manufacturing compensation Kmin. In particular, Table 1 summarizes the predetermined and / or calculated values from equations (1) to (4) for various configurations, with all values in columns 3 to 9 being given in millimeters. Table 1: Overview of a plurality of different configurations of the milling tool according to the invention with calculated setbacks r i . The invention is explained in more detail below with reference to the drawings. Figure 1 shows a schematic representation of a first exemplary embodiment of a milling tool, Figure 2 shows a schematic representation of a second exemplary embodiment of the milling tool, Figure 3 shows a schematic representation of a third exemplary embodiment of the milling tool, and Figure 4 shows a flow chart of an exemplary embodiment of a method for designing the milling tool. Figure 1 shows a schematic representation of a first exemplary embodiment of a milling tool 1. The milling tool 1 has a plurality of first cutting edges 3.1, in particular three first cutting edges 3.1, and at least one second cutting edge 3.2, in particular designed as a wide finishing knife, in particular exactly one second cutting edge 3.2. The cutting edges 3 are arranged offset on the milling tool 1 in the circumferential direction 5 of the milling tool 1 – the arrow at 5 indicates its intended direction of rotation.The plurality of first cutting edges 3.1 are arranged at a nominal position 9 in the axial direction 7 of the milling tool 1. The plurality of first cutting edges 3.1 comprises a compensation group 11 with at least one compensation cutting edge 13, in particular precisely one compensation cutting edge 13, and at least one non-compensation cutting edge 15. A nominal cutting circle 17.1 is assigned to the at least one non-compensation cutting edge 15. A compensation cutting circle 17.2 is assigned to the at least one compensation cutting edge 13, wherein the nominal cutting circle 17.1 and the compensation cutting circle 17.2 are different. The at least one second cutting edge 3.2 is offset in the axial direction 7 of the milling tool 1 by a pre-offset 19 relative to the nominal position 9 in the direction of a machining face 21. A surface machining cutting circle 17.3 is assigned to the at least one second cutting edge 3.2. The surface machining cutting circle 17.3 is smaller than the nominal flight circle 17.1 and the compensation flight circle 17.2. Furthermore, the at least one second cutting edge 3.2 of the plurality of first cutting edges 3.1 leads in the circumferential direction 5. In particular, the nominal flight circle 17.1 is assigned to at least one first cutting edge 3.1 of the plurality of first cutting edges 3.1 that is not assigned to the compensation group 11. In particular, at least one first cutting edge 3.1 arranged on the nominal flight circle 17.1 leads, in particular, directly ahead of the at least one second cutting edge 3.2. Furthermore, in particular, the at least one non-compensation cutting edge 15 leads directly behind the at least one compensation cutting edge 13. Fig.1 a) shows a view in the direction of a z-axis from below of the machining end face 21 of the first embodiment of the milling tool 1. Here, the different flight circles 17 of the cutting edges 3 can be clearly seen.In particular, the compensation cutting edge 13 is radially offset inward relative to the nominal cutting circle 17.1 by a first offset r1 and arranged on the compensation cutting circle 17.2. Furthermore, the second cutting edge 3.2 is radially offset inward relative to the nominal cutting circle 17.1 by a surface finishing offset 23 and arranged on the surface finishing cutting circle 17.3. In particular, the first cutting edges 3.1 each enclose a pitch angle α in pairs, wherein the pitch angles α. i, in particular the first pitch angle α1 and the second pitch angle α2, have a relative size difference of at most 15%. Fig. 1 b) shows a side view of the first embodiment of the milling tool 1. The nominal position 9 and the pre-offset 19 of the at least one second cutting edge 3.2 can be clearly seen. In particular, the plurality of first cutting edges 3.1 are designed for pre-machining the workpiece 25. Alternatively or additionally, the at least one second cutting edge 3.2 is preferably designed for finish-machining the workpiece 25. In particular, the milling tool is moved along a machining direction 26. Fig. 2 shows a schematic representation of a second embodiment of the milling tool 1. Identical and functionally identical elements are provided with the same reference numerals in all figures, so that reference is made to the preceding description.The second embodiment according to Figure 2, analogous to the first embodiment according to Figure 1, has exactly one second cutting edge 3.2, designed in particular as a wide finishing knife. Furthermore, the milling tool 1 has in particular seven first cutting edges 3.1. In particular, the compensation group 11 has two compensation cutting edges 13, in particular a first compensation cutting edge 13' and a second compensation cutting edge 13''. Different compensation cutting circles 17.2 are assigned to the at least two compensation cutting edges 13, in particular a first compensation cutting circle 17.2' is assigned to the first compensation cutting edge 13' and a second compensation cutting circle 17.2'' is assigned to the second compensation cutting edge 13''. In addition, the at least two compensation cutting edges 13 are arranged directly adjacent to one another. Preferably, the first compensation cutting edge 13' is relative to the nominal flight circle 17.1 is offset radially inwards by a first offset r1 and is arranged on the first compensation cutting circle 17.2'. Furthermore, the second compensation cutting edge 13" is preferably offset radially inwards relative to the nominal cutting circle 17.1 by a second offset r2 and is arranged on the second compensation cutting circle 17.2', wherein the first offset r1 is preferably greater than the second offset r2. Fig. 3 shows a schematic representation of a third exemplary embodiment of the milling tool 1. In particular, the third exemplary embodiment of the milling tool 1 has three second cutting edges 3.2, which are designed in particular as wide finishing knives. In addition, the milling tool 1 has three compensation groups 11, each with at least one compensation cutting edge 13 and at least one non-compensation cutting edge 15.With regard to the arrangement of the cutting edges 3 in the axial direction 7 and a radial direction in an xy plane, all three compensation groups 11 are preferably designed identically. Furthermore, every second cutting edge 3.2 of the three second cutting edges 3.2 is arranged on the milling tool 1 analogously to the first exemplary embodiment according to Figure 1 or the second exemplary embodiment according to Figure 2. In addition, each compensation group 11 of the three compensation groups 11 is designed and arranged on the milling tool 1 analogously to the first exemplary embodiment according to Figure 1 or the second exemplary embodiment according to Figure 2. Fig. 4 shows a flowchart of an exemplary embodiment of a method for designing the milling tool 1. In a first step S1, an angular position for the plurality of first cutting edges 3.1 and the at least one second cutting edge 3.2 in the circumferential direction 5 on the milling tool 1 is determined. In a second step S2, the nominal cutting circle 17 is determined.1 of the at least one non-compensating cutting edge 15 is determined. In a third step S3, the first compensating cutting edge 13' of the at least one compensating cutting edge 13 is radially set back relative to the nominal flight circle 17.1 by the first setback r1. Preferably, the first setback r1 for the first compensating cutting edge 13' of the at least one compensating cutting edge 13 is selected depending on at least one parameter selected from a predetermined additional load q of the compensating cutting edge 13 and a tooth feed per revolution f. zfor the milling tool 1. Preferably, in the third step S3, the second compensation cutting edge 13'' of the at least two compensation cutting edges 13 is additionally radially set back relative to the nominal flight circle 17.1 by the second setback r2, wherein the first setback r1 is greater than the second setback r2. In addition, the second setback r2 for the second compensation cutting edge 13'' is preferably selected depending on at least one parameter which is selected from the predetermined additional load q of the compensation cutting edges 13 and the tooth feed per revolution fz for the milling tool 1. In particular, in a first third step a) the tooth feed per revolution f z for the milling tool 1 and the predetermined additional load q of the compensation cutting edges 13. Subsequently, in a second third step b), a machining compensation K zer based on the tooth feed f zand the predetermined additional load q, in particular by means of equation (1). Then, in a third step c), based on the machining compensation Kzer, a number nk of compensation cutting edges 13 is determined, in particular by means of equation (2). Furthermore, in a fourth step d), for each cutting edge 3 of the number n k a setback ri is determined for each compensation cutting edge 13, in particular by means of equation (4). Then, in a fifth third step e), the compensation cutting edges 13 are each offset by the assigned setback r i offset radially inwards with respect to the nominal flight circle 17.1.
Claims
CLAIMS 1. Milling tool (1), with a plurality of first cutting edges (3.1) and at least one second cutting edge (3.2), which are arranged offset on the milling tool (1) in the circumferential direction (5) of the milling tool (1), wherein ^ the plurality of first cutting edges (3.1) are arranged in the axial direction (7) of the milling tool (1) at a nominal position (9), wherein ^ the plurality of first cutting edges (3.1) comprises a compensation group (11) with at least one compensation cutting edge (13) and at least one non-compensation cutting edge (15), wherein ^ the at least one non-compensation cutting edge (15) is assigned a nominal flight circle (17.1), wherein ^ the at least one compensation cutting edge (13) is assigned a compensation flight circle (17.2), wherein ^ the nominal flight circle (17.1) and the compensation flight circle (17.2) are different, wherein ^ the at least one second cutting edge (3.2) is offset in the axial direction (7) of the milling tool (1) by a pre-offset (19) relative to the nominal position (9) in the direction of a machining end face (21), wherein ^ a surface machining flight circle (17.3) is assigned to the at least one second cutting edge (3.2), wherein ^ the surface machining flight circle (17.3) is smaller than the nominal flight circle (17.1) and than the compensation flight circle (17.2), wherein ^ the at least one second cutting edge (3.2) leads the plurality of first cutting edges (3.1) in the circumferential direction (5).
2. Milling tool (1) according to claim 1, wherein the compensation group (11) has at least two compensation cutting edges (13), wherein different compensation flight circles (17.2) are assigned to the at least two compensation cutting edges (13), wherein the at least two compensation cutting edges (13) are directly adjacent to one another.Milling tool (1) according to one of the preceding claims, wherein the at least one non-compensating cutting edge (15) immediately lags behind the at least one compensating cutting edge (13).
4. Milling tool (1) according to one of the preceding claims, wherein the plurality of first cutting edges (3.1) is designed for pre-machining the workpiece (25), and wherein preferably the at least one second cutting edge (3.2) is designed for finish-machining the workpiece (25).
5. Milling tool (1) according to one of the preceding claims, wherein a first compensation cutting edge (13') of the at least one compensation cutting edge (13) is offset radially inward relative to the nominal cutting circle (17.1) by a first setback (r1) and is arranged on a first compensation cutting circle (17.2').
6. Milling tool (1) according to claim 5, wherein a second compensation cutting edge (13") of the at least two compensation cutting edges (13) is offset radially inwards relative to the nominal flight circle (17.1) by a second setback (r2) and is arranged on a second compensation flight circle (17.2"), wherein the first setback (r1) of the first compensation flight circle (17.2') relative to the nominal flight circle (17.1) is greater than the second offset (r2) of the second compensation flight circle (17.2") relative to the nominal flight circle (17.1).
7. Milling tool (1) according to one of the preceding claims, wherein the first cutting edges (3.1) each enclose a pitch angle (α) in pairs, wherein the pitch angles (αi) have a relative size difference of at most 15%.
8. Method for designing a milling tool (1) according to one of claims 1 to 7, wherein ^ an angular position for each of the plurality of first cutting edges (3.1) and the at least one second cutting edge (3.2) in the circumferential direction (5) on the milling tool (1) is defined, wherein ^ the nominal flight circle (17.1) of the at least one non-compensating cutting edge (15) is defined, wherein ^ a first compensating cutting edge (13') of the at least one compensating cutting edge (13) is positioned relative to the nominal flight circle (17.1) is radially set back by a first setback (r1), and wherein ^ the first setback (r1) for the first compensation cutting edge (13') of the at least one compensation cutting edge (13) is preferably selected depending on at least one parameter which is selected from a predetermined additional load (q) of the compensation cutting edges (13) and a tooth feed per revolution (fz) for the milling tool (1).
9. Method for designing a milling tool (1) according to claim 8, wherein a second compensation cutting edge (13") of the at least two compensation cutting edges (13) is radially set back relative to the nominal flight circle (17.1) by a second setback (r2), wherein the first setback (r1) is greater than the second setback (r2), and wherein the second setback (r2) for the second compensation cutting edge (13") is preferably selected depending on at least one parameter which is selected from the predetermined additional load (q) of the compensation cutting edges (13) and the tooth feed per revolution (f z) for the milling tool (1).
10. The method according to claim 8 or 9, wherein a) the tooth feed per revolution (fz) for the milling tool (1) and the predetermined additional load (q) of the compensation cutting edges (13) are determined, wherein b) a machining compensation (Kzer) is determined based on the tooth feed (fz) and the predetermined additional load (q), wherein c) based on the machining compensation (K zer ) a number (n k ) of compensation cutting edges (13), wherein d) for each cutting edge (3) of the number (nk) of compensation cutting edges (13) a respective offset (ri) is determined, wherein e) the compensation cutting edges (13) are each offset by the associated offset (r i ) are displaced radially inwards with respect to the nominal flight circle (17.1).