Cutting insert for use in face milling and face milling cutter comprising such cutting insert

Abstract

A cutting insert for use in face milling and rotatable to different working positions. The cutting insert comprises a peripheral surface (10) extending around the cutting insert between a rake face (2) and an opposite abutment face (3), where a portion of the peripheral surface is provided with ridges (11) and intermediate valleys (12) such that a peripheral cutting edge (20) between the rake face and the peripheral surface has the shape of a toothed ring with external teeth (21). A main cutting edge (30), a surface smoothing cutting edge (31) and an auxiliary corner cutting edge (32) are provided along each tooth (21), wherein the main cutting edge (30) has an entry angle of 75 DEG or more in at least one point along its extension. Each tooth (21) is asymmetric about a reference line extending perpendicular to the surface sleeking cutting edge (31) of the tooth and intersecting a center of the surface sleeking cutting edge, the center being half between two opposite end points of the surface sleeking cutting edge.

Description

Technical Field

[0001] This invention relates to a cutting insert for use in face milling as described in the preamble of claim 1. The invention also relates to a face milling cutter comprising at least one such cutting insert. Background Technology

[0002] A face milling cutter is a rotary cutting tool used to perform face milling operations on a workpiece. In face milling, a flat surface is cut by rotating the tool body perpendicular to its central axis. A face milling cutter can have several cutting inserts, which are detachably mounted in corresponding insert holders within the tool body. Each individual insert can have several identical sets of cutting edges, allowing each insert to rotate to different working positions. When the cutting edges of an insert wear, the insert can be repositioned in its insert holder and installed in a new working position where another set of cutting edges is in the active cutting position.

[0003] The face milling cutter of the above type can be equipped with cutting inserts configured to perform so-called roughing, i.e., chip removal with a considerable depth of cut, via the main cutting edge or primary cutting edge of each cutting insert. Alternatively, the face milling cutter of the above type can be equipped with cutting inserts configured to perform so-called finishing, i.e., shallow surface smoothing of the workpiece surface, via the surface finishing cutting edge of each cutting insert.

[0004] The cutting inserts of the present invention are intended for finishing by face milling, particularly for finishing components of turbocharger housings. Purpose of the invention

[0005] The object of the present invention is to provide a cutting insert having a novel and advantageous design and suitable for finishing with face milling cutters of the type described above. Summary of the Invention

[0006] According to the present invention, the objective is achieved by a cutting blade having the features defined in claim 1.

[0007] The cutting insert according to the present invention is rotatable to different working positions and includes: - A rake face and an abutment face, the rake face and the abutment face being arranged on opposite sides of the cutting insert, the cutting insert having a central axis extending between the rake face and the abutment face, wherein the abutment face includes an abutment surface configured to serve as a tangential abutment surface of the cutting insert in the working position of the cutting insert, and abutting against a corresponding tangential support surface in the insert holder in the tool body of the face milling cutter when the cutting insert is mounted in the insert holder in either of its working positions; - An outer peripheral surface extending around the cutting insert between the rake face and the abutment face, wherein a first portion of the outer peripheral surface adjacent to and abutting the rake face is provided with at least eight radially projecting ridges evenly distributed around the central axis, and each ridge extending from the rake face in a direction toward the abutment face, each pair of adjacent ridges forming a valley extending from the rake face in a direction toward the abutment face in the first portion of the outer peripheral surface, such that, viewed in a plan view along the central axis, the outer peripheral edge formed at the intersection between the rake face and the outer peripheral surface has the shape of a substantially circular toothed ring, wherein the outer teeth of the toothed ring are congruent to each other and correspond in number to the number of ridges, wherein each of these teeth comprises: • A straight or convex first edge segment, the first edge segment forming the tooth tip and having a first endpoint at the front end and a second endpoint at the opposite tail end, as seen in a counterclockwise direction around the central axis when the rake face is viewed in a plan view along the central axis. • A second edge segment, which connects to the first edge segment at the first endpoint and forms the anterior ventral edge of the tooth, as seen in the counterclockwise direction, and • A third edge segment, which connects to the first edge segment at the second endpoint and forms the tail ventral edge of the tooth, as seen in the counterclockwise direction; and - A plurality of cutting edges, wherein each of these plurality of cutting edges is formed by a portion of a corresponding tooth of the teeth.

[0008] Each of the plurality of cutting edges includes a surface finishing cutting edge, a main cutting edge, and an auxiliary corner cutting edge, wherein the surface finishing cutting edge is formed by a first edge segment of an associated tooth and extends between a first endpoint and a second endpoint of the first edge segment; the auxiliary corner cutting edge is formed by a portion of a third edge segment of an associated tooth and connects to the surface finishing cutting edge of the same group of cutting edges at the second endpoint of the surface finishing cutting edge of the same group of cutting edges; and the main cutting edge is formed by a portion of the second edge segment of an associated tooth, the portion extending from a first reference plane to a second reference plane, the first reference plane being parallel to the central axis and including the first endpoint and the second endpoint of the first edge segment of the surface finishing cutting edge of the same group of cutting edges; the second reference plane being parallel to the first reference plane and including the tangent of the auxiliary corner cutting edge of the adjacent group of cutting edges associated with the adjacent tooth immediately preceding the main cutting edge in the counterclockwise direction.

[0009] Each of the plurality of cutting edges has a primary cutting edge with an approach angle of 75° or more at at least one point along its extension, as seen relative to the first reference plane associated with the same primary cutting edge. This large approach angle means reduced burr formation. Furthermore, when the primary cutting edge of the face milling cutter's insert has an approach angle of 75° or more, the axial force on the workpiece can be kept low during face milling. Due to the fact that the cutting insert of the present invention is provided with a primary cutting edge having an approach angle of 75° or more, the cutting insert is suitable for finishing very thin workpieces that can only withstand face milling with low axial forces.

[0010] Furthermore, the first distance between the third edge segment of each tooth and the reference line along the second reference plane is greater than the second distance between the second edge segment of the tooth and the reference line along the second reference plane, preferably by at least 10%, more preferably by at least 20%, wherein the reference line extends perpendicularly to the first reference plane of the tooth and intersects the center of the first edge segment of the tooth, the center being located halfway between the first endpoint and the second endpoint of the first edge segment. This reference line can be considered as the centerline of the associated tooth, where the difference between the aforementioned first and second distances means that each tooth is asymmetrical about its centerline. Thus, the front ventral edge of each tooth can be designed with its primary focus on achieving a large approach angle for the associated main cutting edge, while the tail ventral edge of each tooth can be designed with a slope different from the slope of the opposite front ventral edge of the same tooth and its primary focus on achieving a robust cutting insert.

[0011] The central axis of the cutting insert extends between the center point of the rake face and the center point of the contact face. The center point refers to the centroid or geometric center. The cutting insert may be provided with a through hole that extends centrally through the cutting insert between the rake face and the contact face, wherein the central axis of the through hole coincides with the central axis of the cutting insert.

[0012] In each working position of the cutting insert, when properly mounted in the dedicated insert holder of the face milling cutter, one set of cutting edges from different groups will be in an active cutting position, wherein the surface finishing cutting edges of the active group face forward axially and extend beyond the front of the face milling cutter body, and such that the straight line connecting the first and second endpoints of the surface finishing cutting edges is included in a plane substantially perpendicular (i.e., perpendicular to the central axis of the tool body within manufacturing tolerances), wherein the main cutting edge of the active group faces radially outward away from the central axis of the tool body, and wherein the auxiliary corner cutting edges of the active group face radially inward toward the central axis of the tool body.

[0013] The front end of the first edge segment refers to the lower end of the first edge segment, which is disposed in the cutting insert and is circumferentially in front of the opposite end of the same first edge segment, as seen in the aforementioned counterclockwise direction. Conversely, the tail end of the first edge segment refers to the lower end of the first edge segment, which is disposed in the cutting insert and is circumferentially behind the opposite end of the same first edge segment, as seen in the aforementioned counterclockwise direction.

[0014] The front ventral edge of a tooth refers to the lower ventral edge of the tooth, which is located in the cutting insert and circumferentially in front of the opposite ventral edge of the same tooth, as seen in the aforementioned counterclockwise direction. Conversely, the tail ventral edge of a tooth refers to the lower ventral edge of the tooth, which is located in the cutting insert and circumferentially behind the opposite ventral edge of the same tooth, as seen in the aforementioned counterclockwise direction.

[0015] The primary cutting edge of each of the plurality of cutting edges preferably has an entry angle of 80° or more at at least one point along its extension, as seen relative to a first reference plane associated with the same primary cutting edge. Furthermore, the primary cutting edge of each of the plurality of cutting edges preferably has a maximum entry angle of less than or equal to 90°, as seen relative to a first reference plane associated with the same primary cutting edge.

[0016] According to one embodiment of the invention, the second edge segment of each tooth intersects the third edge segment of the adjacent tooth at its radially innermost point on the portion of the outer peripheral edge located between the first endpoint of the first edge segment connecting to the second edge segment and the second endpoint of the first edge segment connecting to the third edge segment of the adjacent tooth, wherein, viewed from the central axis, the angular distance between the radially innermost point and the second endpoint is greater than the angular distance between the radially innermost point and the first endpoint, preferably at least 50% greater. Therefore, the deepest point of the gap between two consecutive teeth, i.e., the point of the gap closest to the central axis of the cutting insert, is closer to the first edge segment connected to the second edge segment facing the gap, rather than to the first edge segment connected to the third edge segment facing the gap.

[0017] According to another embodiment of the invention, the ridges on the first portion of the outer peripheral surface, and thus the number of teeth is at least ten, preferably at least twelve.

[0018] According to another embodiment of the invention, the first edge segment of each tooth is convex and the radius of curvature of the first edge segment is greater than the radius of the circumcircle of the toothed ring. The radius of curvature is advantageously 20 mm or more, preferably 30 mm or more, and more preferably 50 mm or more. Further, the radius of the circumcircle of the toothed ring is preferably 5-13 mm, more preferably 7-10 mm.

[0019] According to another embodiment of the present invention, the vertical distance between the first reference plane and the second reference plane is less than 1 mm, preferably less than 0.8 mm, and more preferably at least 0.5 mm.

[0020] According to another embodiment of the invention, a plurality of indexing devices are provided on a second portion of the outer peripheral surface adjacent to and abutting the abutting surface. These indexing devices are evenly distributed around the central axis and their number corresponds to the number of ridges. Therefore, the number of indexing devices also corresponds to the number of teeth on the toothed ring, and thus to the number of cutting edge groups and alternative working positions of the cutting insert. Each of the plurality of indexing devices is preferably formed by a corresponding abutting surface on the second portion of the outer peripheral surface, the abutting surface being substantially flat or concave, as seen in any plane extending across the abutting surface and perpendicular to the central axis. In each working position of the cutting insert, two of these abutting surfaces are designed to abut against a corresponding support surface in a dedicated insert holder in the tool body of the face milling cutter, thereby ensuring correct and stable positioning of the cutting insert in the insert holder. Each of the abutting surfaces on the second portion of the outer peripheral surface is preferably configured to serve as an axial abutting surface of the cutting blade in one of the working positions of the cutting blade, and to serve as a radial abutting surface of the cutting blade in another of the working positions of the cutting blade.

[0021] According to another embodiment of the invention, all regions on the ridges and valleys of the first portion of the outer peripheral surface protrude radially beyond the outer periphery of the second portion of the outer peripheral surface. Therefore, the ridges and valleys protruding radially beyond the second portion of the outer peripheral surface and the abutment surface thereon is advantageous in avoiding the active cutting edge of the cutting insert when the cutting insert is mounted in a dedicated insert holder in the tool body of the face milling cutter in either of its working positions.

[0022] According to another embodiment of the invention, the cutting insert has a rotational symmetry of 360° / n about the central axis, where n is an integer corresponding to the number of ridges. In this case, even if any of the rake face, abutment face, or outer peripheral surface is provided with one or more auxiliary markings (which lack the image of 360° / n rotational symmetry about the central axis), for example in the form of a recess, the cutting insert is still considered to have a rotational symmetry of 360° / n about the central axis, provided that these one or more markings are irrelevant to the function of the cutting insert.

[0023] Further advantageous features of the cutting insert according to the invention will become apparent from the following description.

[0024] The present invention also relates to a face milling cutter comprising at least one cutting insert of the type described above.

[0025] According to an embodiment of the invention, a face milling cutter includes a tool body having an insert holder configured to receive the at least one cutting insert, wherein a set of surface-finishing cutting edges of one of the plurality of sets of cutting edges of the cutting insert is configured in an active cutting position, i.e., such that the surface-finishing cutting edges extend beyond the front face of the tool body of the face milling cutter, and such that when the cutting insert is mounted in the insert holder in one of its working positions, a straight line connecting the first and second endpoints of the surface-finishing cutting edges is included in a plane substantially perpendicular to the central axis of the tool body (i.e., perpendicular within the manufacturing tolerances of the tool body and the cutting insert), and wherein the active surface-finishing cutting edge has a positive clearance angle, as seen in any plane extending across the active surface-finishing cutting edge and containing the central axis of the cutting insert.

[0026] The face milling cutter body preferably includes a plurality of insert holders, each insert holder being configured to receive a cutting insert of the type described above, wherein the first and second endpoints of the active surface finishing cutting edge of each cutting insert are substantially included in the plane perpendicular to the central axis of the cutter body, i.e., included within the manufacturing tolerances of the cutter body and the cutting insert.

[0027] Other advantageous features of the face milling cutter according to the invention will become apparent from the following description. Attached Figure Description

[0028] Referring to the accompanying drawings, the following is a detailed description of embodiments of the present invention, cited by way of example. In the drawings:

[0029] Figure 1a This is a perspective view of a cutting blade according to an embodiment of the present invention.

[0030] Figure 1b yes Figure 1a Side view of the cutting blade.

[0031] Figure 1c This is viewed from below. Figure 1a A plan view of the cutting insert.

[0032] Figure 1d It is viewed from above. Figure 1a A plan view of the cutting insert.

[0033] Figure 1e It is based on Figure 1d A sectional view of line Ie-Ie in the middle.

[0034] Figure 2 Is Figure 1a A plan view of the outer peripheral edge formed at the intersection between the rake face and the outer peripheral surface of the cutting insert.

[0035] Figure 3 yes Figure 2 Enlarged detail of a portion of the outer perimeter edge.

[0036] Figure 4 It is set according to the following: Figures 1a to 1e The perspective view of the face milling cutter with cutting inserts shown in the embodiment is as follows.

[0037] Figure 5 yes Figure 4 Front view of a face milling cutter.

[0038] Figure 6 yes Figure 4 Side view of a face milling cutter.

[0039] Figure 7 It is based on Figure 6 The sectional view of line VII-VII in the middle.

[0040] Figure 8 yes Figure 4 A magnified view of a portion of a face milling cutter.

[0041] Figure 9 yes Figure 4 A side view of a portion of a face milling cutter, and

[0042] Figure 10 It is based on Figure 9 A sectional view of line XX in the diagram. Detailed Implementation

[0043] Figures 1a to 1e An embodiment of the cutting insert 1 according to the present invention is shown. The cutting insert 1 is configured for use in a face milling cutter, for example... Figures 4 to 10 The type of face milling cutter shown is 40.

[0044] The cutting insert 1 is rotatable to different working positions. The cutting insert 1 includes a rake face 2 and a contact face 3 arranged on opposite sides of the cutting insert 1. The cutting insert 1 has a central axis C extending between the rake face 2 and the contact face 3.

[0045] The contact surface 3 includes a contact surface 4, which is configured to serve as a tangential contact surface for the cutting insert 1 in the said working positions, and when the cutting insert 1 is mounted in the insert holder 46 in the tool body 41 of the face mill 40 in any of its working positions, the contact surface 4 abuts against the corresponding tangential support surface 50 in the insert holder 46 (see...). Figure 8 and Figure 10Therefore, the abutment surface 4 on the abutment surface 3 is configured to serve as the tangential abutment surface of the cutting blade 1 in all working positions of the cutting blade. In the illustrated embodiment, the abutment surface 4 on the abutment surface 3 is flat, or at least substantially flat, and extends perpendicular to the central axis C.

[0046] In the illustrated embodiment, the cutting insert 1 is provided with a through-hole 6 that extends centrally through the cutting insert between the rake face 2 and the abutment face 3. The through-hole 6 is configured to receive a fastening element 7, for example a screw, through which the cutting insert can be releasably secured to the insert holder 46 of the face mill 40. The central axis C of the cutting insert 1 coincides with the central axis of the through-hole 6. Alternatively, the cutting insert 1 may not have a through-hole 6, wherein the cutting insert is configured to be releasably secured to the insert holder of the face mill by a suitable clamping device.

[0047] An outer peripheral surface 10 extends around the cutting insert 1 between the rake face 2 and the contact face 3. The outer peripheral surface 10 includes a first portion 10a adjacent to and abutting the rake face 2 and a second portion 10b adjacent to and abutting the contact face 3. The first portion 10a of the outer peripheral surface 10 is provided with a plurality of radially projecting ridges 11 evenly distributed around a central axis C, wherein each ridge 11 extends from the rake face 2 in a direction toward the contact face 3. Each pair of adjacent ridges 11 defines a central valley 12 that extends from the rake face 2 in the first portion 10a of the outer peripheral surface along the adjacent ridges 11 in a direction toward the contact face 3. An outer peripheral edge 20 is formed at the intersection between the rake face 2 and the outer peripheral surface 10. As seen in a plan view along the central axis C, the outer peripheral edge 20 has the shape of a substantially circular toothed ring having external teeth 21 that are congruent to each other and evenly distributed around the central axis C. The number of teeth 21 corresponds to the number of ridges 11.

[0048] The number of the aforementioned ridges 11 and thus the aforementioned teeth 21 is at least eight, preferably ten or more. In the illustrated embodiment, the cutting blade 1 is provided with twelve such ridges 11, which means that the outer peripheral edge 20 has twelve teeth 21.

[0049] Each tooth 21 on the outer peripheral edge 20 includes: - The first edge segment E1, which is straight or convex (see...) Figure 2 and Figure 3 The first edge segment E1 forms the tip of tooth 21 and has a first endpoint P1 at the front end and a second endpoint P2 at the opposite tail end, as seen in the counterclockwise direction R1 around the central axis C when the rake face 2 is viewed in a plan view along the central axis C. - A second edge segment E2, which connects to the first edge segment E1 at its first endpoint P1 and forms the front tooth vent edge of tooth 21, as seen in the counterclockwise direction R1; and - The third edge segment E3 connects to the first edge segment E1 at the second end point P2 and forms the tail tooth ventral edge of tooth 21, as seen in the counterclockwise direction R1.

[0050] The first edge segment E1 forms the so-called top kerf at the tooth tip.

[0051] In the illustrated embodiment, the first edge segment E1 of each tooth 21 is slightly convex, and its radius of curvature is greater than the circumcircle 22 of the toothed ring formed by the outer peripheral edge 20 (see [reference]). Figure 2 The radius r of the circumcircle 22. In this case, the radius of curvature of the first edge segment E1 is advantageously 20 mm or more, preferably 30 mm or more, and more preferably 50 mm or more. The radius r of the circumcircle 22 can be 5-13 mm, preferably 7-10 mm. Therefore, the cutting insert 1 in Figures 1a to 1e It is shown at a greatly magnified scale.

[0052] The innermost point 23 of the second edge segment E2 of each tooth 21 is located on the outer peripheral edge 20 between the first endpoint P1 of the first edge segment E1 connected to the second edge segment E2 and the second endpoint P2 of the first edge segment E1 connected to the third edge segment E3 of the adjacent tooth (see...). Figure 2 and Figure 3 The third edge segment E3 of the adjacent tooth is joined at the point where the innermost radial point 23 and the second endpoint P2 are viewed from the central axis C. The angular distance between the innermost radial point 23 and the second endpoint P2 is greater than the angular distance between the innermost radial point 23 and the first endpoint P1, preferably at least 50% greater.

[0053] The cutting insert 1 includes several sets of cutting edges, each set of cutting edges being formed by a portion of a corresponding tooth in the teeth 21, and includes a main cutting edge 30, a surface finishing cutting edge 31, and an auxiliary corner cutting edge 32, which are sequentially positioned along a portion of the outer peripheral edge 20, wherein: - The surface finishing cutting edge 31 is formed by the first edge segment E1 of the associated tooth and extends between the first end point P1 and the second end point P2 of the first edge segment E1. - The auxiliary corner cutting edge 32 is formed by a portion of the third edge segment E3 of the associated tooth, and is connected to the surface-finishing cutting edge 31 of the same set of cutting edges at the second end point P2 of the surface-finishing cutting edge 31 of the same set of cutting edges; and - The main cutting edge 30 is formed by a portion of the second edge segment E2 of the associated tooth, which extends from the imaginary first reference plane RP1 (see...). Figure 2 and Figure 3 The first reference plane RP1 extends to a hypothetical second reference plane RP2, which is parallel to the central axis C and includes the first endpoint P1 and the second endpoint P2 of the first edge segment E1 of the surface-finished cutting edge 31 forming the same set of cutting edges. The hypothetical second reference plane RP2 is parallel to the first reference plane RP1 and includes the tangent of the auxiliary corner cutting edge 32 of the adjacent set of cutting edges associated with the adjacent tooth 21 in front of the main cutting edge 30 when viewed in the counterclockwise direction R1.

[0054] Since these sets of cutting edges are associated with a corresponding tooth among the teeth 21 on the outer peripheral edge 20, the number of these sets corresponds to the number of teeth 21. Therefore, in the illustrated embodiment, the cutting insert 1 is provided with 12 sets of cutting edges.

[0055] In each working position of the cutting insert 1, one set of cutting edges from different groups of cutting edges is in an active cutting position. Therefore, the number of working positions corresponds to the number of cutting edge groups. Thus, in each of the twelve different working positions of the cutting insert 1 shown, the cutting edges 30, 31, and 32 of one set of cutting edges from the twelve different groups of cutting edges constitute the active cutting edge of the cutting insert.

[0056] The vertical distance D between the first reference plane RP1 and the second reference plane RP2 (see...) Figure 3 Advantageously, the thickness is less than 1 mm, preferably less than 0.8 mm, and more preferably at least 0.5 mm.

[0057] As seen in the plan view along the central axis C, the main cutting edge 30 of each set of cutting edges has a convex shape or at least a substantially convex shape. Furthermore, each main cutting edge 30 has an approach angle α of 75° or more, preferably 80° or more, at at least one point along its extension, as seen relative to a first reference plane RP1 associated with the same main cutting edge 30. The maximum approach angle α of the main cutting edge 30 is preferably less than or equal to 90°, as seen relative to the first reference plane RP1 associated with the same main cutting edge 30. In the illustrated embodiment, the main cutting edge 30 of each set of cutting edges has a maximum approach angle α of approximately 82°, as... Figure 3 As shown by line L1, which represents the steepest slope tangent to the main cutting edge 30, as seen relative to the associated first reference plane RP1.

[0058] The distance d1 between the third edge segment E3 of each tooth 21 and the imaginary reference line RL along the second reference plane RP2 (see...) Figure 3 The distance d2 between the second edge segment E2 of tooth 21 and the reference line RL along the second reference plane RP2 is greater than, preferably at least 10%, more preferably at least 20%, wherein the hypothetical reference line RL extends perpendicularly to the first reference plane RP1 of tooth 21 and intersects the center of the first edge segment E1 of tooth 21, which is located halfway between the first endpoint P1 and the second endpoint P2 of the first edge segment E1. Therefore, tooth 21 is asymmetrical with respect to the reference line RL. Compared to the third edge segment E3 of the same tooth, the second edge segment E2 of each tooth 21 has a steeper slope with respect to the first reference plane RP1 of the tooth.

[0059] The second portion 10b of the outer peripheral surface 10, i.e., the portion of the outer peripheral surface 10 adjacent to and abutting the abutment surface 3, is provided with a plurality of indexing devices 14 evenly distributed around the central axis C and corresponding in number to the number of ridges 11. In the illustrated embodiment, each of the indexing devices 14 is formed by a corresponding abutment surface 15 on the second portion 10b of the outer peripheral surface 10. In the illustrated example, each such abutment surface 15 is slightly concave, as seen in any cross-sectional plane extending across the abutment surface 15 and perpendicular to the central axis C. However, as an alternative, each such abutment surface 15 may be flat or at least substantially flat. Each of these abutment surfaces 15 on the second portion 10b of the outer peripheral surface 10 is configured to serve as an axial abutment surface of the cutting insert 1 in one of the working positions of the cutting insert, wherein the abutment surface 15 abuts against a corresponding axial support surface 52 in the insert holder 46 in the tool body 41 of the face mill 40 (see Figure 7 and Figure 8 ), and is configured to serve as a radial abutment surface of the cutting blade 1 in another working position of the cutting blade, wherein the abutment surface 15 abuts against the corresponding radial support surface 51 in the blade holder 46.

[0060] In the illustrated embodiment, each of the abutment surfaces 15 on the second portion 10b of the outer peripheral surface 10 is slightly inclined outward away from the central axis C, as seen in any plane extending across the abutment surfaces 15 and encompassing the central axis C in the direction from the abutment surface 3 toward the rake face 2. Furthermore, as seen in any such plane, the ridges 11 on the first portion 10a of the outer peripheral surface 10 are inclined outward away from the central axis C, as seen in the direction from the second portion 10b of the outer peripheral surface 10 toward the rake face 2, wherein the inclination angle of each ridge 11 is greater than the inclination angle of each abutment surface 15, such as... Figure 1e As shown.

[0061] In the illustrated embodiment, all regions on the ridges 11 and valleys 12 of the first portion 10a of the outer peripheral surface 10 project radially beyond the outer periphery of the second portion 10b of the outer peripheral surface 10, such as... Figure 1c As shown.

[0062] The cutting insert 1 preferably has a rotational symmetry of 360° / n about a central axis C, where n is an integer corresponding to the number of ridges 11. In the illustrated embodiment with twelve ridges 11, the cutting insert 1 has a rotational symmetry of 30° about the central axis C. This rotational symmetry of the cutting insert 1 about the central axis C means that: - Within manufacturing tolerances, ridges 11 are identical to each other; - Within manufacturing tolerances, the teeth 21 on the outer peripheral edge 20 are identical to each other; - Within manufacturing tolerances, the main cutting edges 30 of different groups of cutting edges are identical to each other; - Within manufacturing tolerances, the surface-finished cutting edges 31 of different groups of cutting edges are the same as each other; - Within manufacturing tolerances, the auxiliary corner cutting edges 32 of different groups of cutting edges are identical to each other; and - Within manufacturing tolerances, the abutting surfaces 15 on the second portion 10b of the outer peripheral surface 10 are identical to each other.

[0063] In the illustrated embodiment, the rake face 2 is provided with a recessed mark 8. The mark 8 is located in front of one of the teeth 21 and facilitates identification of different working positions of the cutting insert 1. In addition to the mark 8, the rake face 2 has a rotational symmetry of 30° about the central axis C.

[0064] Figures 4 to 10 A milling cutter in the form of a face mill 40 is shown. The face mill 40 includes a cutter body 41 and is configured to rotate about a rotation axis 42 in a desired rotational direction R. The cutter body 41 has a rear end 41b and an opposite front end 41a. A central axis 43 of the cutter body 41 extends between the rear end 41b and the front end 41a, wherein the central axis 43 coincides with the rotation axis 42 of the face mill 40. A connecting member 44 is formed at the rear of the cutter body 41, through which the cutter body 41 can be mounted directly or via an intermediate tool holder to the rotary spindle or similar component of a machine tool (e.g., a milling machine).

[0065] The front portion of the tool body 41 is provided with a plurality of insert holders 46, which are evenly or at least substantially evenly distributed in the circumferential direction of the tool body 41 and configured to receive corresponding cutting inserts 1. Thus, the insert holders 46 are evenly or at least substantially evenly distributed around the central axis 43 of the tool body 41. Each insert holder 46 is located at the transition between the front end 41a and the periphery 47 of the tool body 41, wherein each insert holder 46 is open toward the front end 41a of the tool body 41 to allow the cutting insert 1 mounted in the insert holder to protrude beyond the front end 41a of the tool body 41 in the axial direction, and is also open toward the periphery 47 of the tool body 41 to allow the cutting insert 1 mounted in the insert holder to protrude beyond the periphery of the tool body 41 in the radial direction. As seen in the intended rotational direction R of the tool body 41, a recess 48 is provided in front of each insert holder 46 in the tool body 41.

[0066] In the illustrated embodiment, the tool body 41 is provided with seven insert holders 46 spaced apart in the circumferential direction of the tool body. However, as an alternative, the tool body 41 may be provided with any other suitable number of insert holders 46, depending particularly on the diameter of the tool body. A tool body with a smaller diameter may, for example, be provided with two insert holders, while a tool body with a larger diameter may be provided with more than seven insert holders.

[0067] Cutting inserts 1 are mounted in each insert holder 46 within the tool body 41. In the illustrated embodiment, the face mill 40 is provided with... Figures 1a to 1e Cutting inserts 1 of the type shown. Each cutting insert 1 is configured to be releasably mounted to an associated insert holder 46. In the illustrated embodiment, each cutting insert 1 is secured to the associated insert holder 46 by a fastening element 7 in the form of a screw, the fastening element 7 extending through a through-hole 6 in the cutting insert 1 and engaging a threaded hole 48 in a tangential support surface 50 in the insert holder (see [link]). Figure 8 and Figure 10 Each blade holder 46 is also provided with a radial support surface 51 and an axial support surface 52.

[0068] Each cutting insert 1 is mounted in its associated insert holder 46 in one of its working positions: - Wherein, the abutting surface 4 on the abutting surface 3 serves as the tangential abutting surface of the cutting blade 1 and abuts against the tangential support surface 50 in the blade holder 46. - Wherein, one of the abutting surfaces 15 on the second portion 10b of the outer peripheral surface 10 serves as the radial abutting surface of the cutting insert 1 and abuts against the radial support surface 51 in the insert holder 46. - Among them, another abutting surface 15 on the second part 10b of the outer peripheral surface 10 serves as the axial abutting surface of the cutting insert 1 and abuts against the axial support surface 52 in the insert holder 46. - Wherein, the first portion 10a of the outer peripheral surface 10 is received in the blade holder 46 with a certain clearance, that is, it does not contact any surface of the blade holder 46, and - In this context, one of the teeth 21 on the outer peripheral edge 20 forms the foremost part of the cutting insert 1 in the axial direction and protrudes beyond the front end 41a of the tool body 41 in the axial direction. The main cutting edge 30, the surface finishing cutting edge 31 and the auxiliary corner cutting edge 32 arranged along the tooth 21 are in the working cutting position, and thus constitute the working cutting edge of the cutting insert 1 in the effective working position of the cutting insert.

[0069] The active main cutting edge 30 of each cutting insert 1 faces outward radially away from the central axis 43 of the tool body 41, while the active auxiliary corner cutting edge 32 of each cutting insert 1 faces inward radially toward the central axis 43 of the tool body 41.

[0070] When the cutting insert 1 is mounted in the associated insert holder 46 in one of its working positions, the surface finishing cutting edge 31 in the active cutting position has a positive clearance angle, as seen in any plane extending across the active surface finishing cutting edge 31 and containing the central axis C of the cutting insert 1.

[0071] When any of the working cutting edges 30, 31, 32 of the cutting insert 1 have been worn, the cutting insert 1 can be repositioned in its insert holder 46 and installed in a new working position, in which another set of cutting edges of the cutting insert is in a working cutting position.

[0072] Of course, the present invention is not limited in any way to the embodiments described above. Rather, many possibilities for modifications to the above embodiments will be apparent to those skilled in the art without departing from the basic concept of the invention as defined in the appended claims.

Claims

1. A cutting insert for face milling, the cutting insert (1) being rotatable to different working positions and comprising: - A rake face (2) and an abutment face (3) arranged on opposite sides of the cutting insert (1), the cutting insert (1) having a central axis (C) extending between the rake face (2) and the abutment face (3), wherein the abutment face (3) includes an abutment surface (4) configured to serve as a tangential abutment surface of the cutting insert (1) in the working position of the cutting insert, and abutting against a corresponding tangential support surface (50) in the insert holder (46) of the tool body (41) of the face milling cutter when the cutting insert (1) is mounted in any of its working positions. - An outer peripheral surface (10) extending around the cutting insert (1) between the rake face (2) and the abutment face (3), wherein a first portion (10a) of the outer peripheral surface (10) adjacent to and abutting the rake face (2) is provided with at least eight radially projecting ridges (11) evenly distributed around the central axis (C), and each ridge extends from the rake face (2) in a direction toward the abutment face (3), and each pair of adjacent ridges (11) of the at least eight ridges forms a valley (12). The valley (12) extends from the rake face (2) toward the abutment surface (3) in the first portion (10a) of the outer peripheral surface, such that, in a plan view along the central axis (C), the outer peripheral edge (20) formed at the intersection between the rake face (2) and the outer peripheral surface (10) has the shape of a substantially circular toothed ring, wherein the outer teeth (21) of the toothed ring are equal to each other and correspond in number to the number of the ridges (11), wherein each of these teeth (21) includes: • A straight or convex first edge segment (E1), which forms the tip of the tooth (21) and has a first endpoint (P1) at the front end and a second endpoint (P2) at the opposite tail end, as seen in a plan view of the rake face (2) along the central axis (C) in a counterclockwise direction (R1) around the central axis (C). • The second edge segment (E2), which connects to the first edge segment (E1) at the first endpoint (P1), forms the anterior ventral edge of the tooth, as seen in the counterclockwise direction (R1). • A third edge segment (E3), which connects to the first edge segment (E1) at the second endpoint (P2) and forms the tail ventral edge of the tooth, as seen in the counterclockwise direction (R1); and - A plurality of cutting edges, wherein each of these plurality of cutting edges is formed by a portion of a corresponding tooth of the teeth (21). Its features are: - Each of the plurality of cutting edges includes a surface finishing cutting edge (31), a main cutting edge (30), and an auxiliary corner cutting edge (32), wherein the surface finishing cutting edge (31) is formed by a first edge segment (E1) of an associated tooth and extends between a first endpoint (P1) and a second endpoint (P2) of the first edge segment (E1), the auxiliary corner cutting edge (32) is formed by a portion of a third edge segment (E3) of an associated tooth, and is connected to the surface finishing cutting edge (31) of the same group of cutting edges at the second endpoint (P2), and the main cutting edge (30) It is formed by a portion of the second edge segment (E2) of the associated teeth, the portion extending from the first reference plane (RP1) to the second reference plane (RP2), the first reference plane (RP1) being parallel to the central axis (C) and including the first endpoint (P1) and the second endpoint (P2) of the first edge segment (E1) of the surface finishing cutting edge (31) forming the same set of cutting edges, the second reference plane (RP2) being parallel to the first reference plane (RP1) and including the tangent of the auxiliary corner cutting edge (32) of the adjacent set of cutting edges associated with the adjacent tooth in the counterclockwise direction (R1) immediately in front of the main cutting edge (30); - The main cutting edge (30) of each of the plurality of cutting edges has an approach angle (α) of more than 75° at at least one point along its extension, as seen relative to the first reference plane (RP1) associated with the same main cutting edge (30); and - The distance (d1) between the third edge segment (E3) of each tooth (21) and the reference line (RL) along the second reference plane (RP2) is greater than the distance (d2) between the second edge segment (E2) of the tooth (21) and the reference line (RL) along the second reference plane (RP2), preferably by at least 10%, more preferably by at least 20%, wherein the reference line (RL) extends perpendicularly to the first reference plane (RP1) of the tooth (21) and intersects the center of the first edge segment (E1) of the tooth (21), the center being located halfway between the first endpoint (P1) and the second endpoint (P2) of the first edge segment (E1).

2. The cutting insert according to claim 1, characterized in that, The main cutting edge (30) of each of the plurality of cutting edges has an approach angle (α) of more than 80° at at least one point along its extension, as seen relative to the first reference plane (RP1) associated with the same main cutting edge (30).

3. The cutting insert according to claim 1 or 2, characterized in that, The main cutting edge (30) of each of the plurality of cutting edges has a maximum entry angle (α) of less than or equal to 90° at at least one point along its extension, as seen relative to the first reference plane (RP1) associated with the same main cutting edge (30).

4. The cutting insert according to any one of claims 1-3, characterized in that, The second edge segment (E2) of each of the teeth (21) meets the third edge segment (E3) of the adjacent tooth at the radial innermost point (23) of the portion of the outer peripheral edge (20) located between the first endpoint (P1) of the first edge segment (E1) connected to the second edge segment (E2) and the second endpoint (P2) of the first edge segment (E1) connected to the third edge segment (E3) of the adjacent tooth, wherein, viewed from the central axis (C), the angular distance between the radial innermost point (23) and the second endpoint (P2) is greater than the angular distance between the radial innermost point (23) and the first endpoint (P1), preferably at least 50% greater.

5. The cutting insert according to any one of claims 1-4, characterized in that, The number of ridges (11) on the first portion (10a) of the outer peripheral surface (10) is at least ten, preferably at least twelve.

6. The cutting insert according to any one of claims 1-5, characterized in that, The first edge segment (E1) of each of the teeth (21) is convex and the radius of curvature of the first edge segment (E1) is greater than the radius (r) of the circumcircle (22) of the toothed ring.

7. The cutting blade according to claim 6, characterized in that, The radius of curvature is 20 mm or more, preferably 30 mm or more, and more preferably 50 mm or more.

8. The cutting insert according to any one of claims 1-7, characterized in that, The radius (r) of the circumcircle (22) of the toothed ring is 5-13 mm, preferably 7-10 mm.

9. The cutting insert according to any one of claims 1-8, characterized in that, The vertical distance (D) between the first reference plane (RP1) and the second reference plane (RP2) is less than 1 mm, preferably less than 0.8 mm.

10. The cutting insert according to any one of claims 1-8, characterized in that, The vertical distance (D) between the first reference plane (RP1) and the second reference plane (RP2) is 0.5-1 mm.

11. The cutting insert according to any one of claims 1-10, characterized in that, The second part (10b) of the outer peripheral surface (10) adjacent to and adjacent to the contact surface (3) is provided with a plurality of rotation devices (14), which are evenly distributed around the central axis (C) and correspond in number to the number of the ridges (11).

12. The cutting blade according to claim 11, characterized in that, Each of the plurality of indexing devices (14) is formed by a corresponding abutting surface (15) on the second portion (10b) of the outer peripheral surface (10), the abutting surface (15) being substantially flat or concave, as seen in any plane extending across the abutting surface (15) and perpendicular to the central axis (C).

13. The cutting insert according to claim 12, characterized in that, Each of the abutting surfaces (15) on the second portion (10b) of the outer peripheral surface (10) is configured to serve as an axial abutting surface of the cutting blade (1) in one of the working positions of the cutting blade, and is configured to serve as a radial abutting surface of the cutting blade (1) in another working position of the cutting blade.

14. The cutting insert according to any one of claims 11-13, characterized in that, All regions on the ridge (11) and valley (12) of the first portion (10a) of the outer peripheral surface (10) protrude radially beyond the outer periphery of the second portion (10b) of the outer peripheral surface (10).

15. The cutting insert according to any one of claims 1-14, characterized in that, The cutting blade (1) has a rotational symmetry of 360° / n about the central axis (C), where n is an integer corresponding to the number of the ridges (11).

16. A face milling cutter comprising at least one cutting insert (1) according to any one of claims 1 to 15.

17. The face milling cutter according to claim 16, characterized in that, The face milling cutter (40) includes a cutter body (41) having a insert holder (46) configured to receive the at least one cutting insert (1), wherein the surface finishing cutting edge (31) of one of the plurality of cutting edges of the cutting insert (1) is configured to be in an active cutting position when the cutting insert (1) is mounted in the insert holder (46) in one of its working positions, and wherein the active surface finishing cutting edge (31) has a positive clearance angle, as seen in any plane extending across the active surface finishing cutting edge (31) and containing the central axis (C) of the cutting insert (1).

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