Finishing blade and indexable blade milling cutter

Abstract

In the dressing blade, three first corners and three second corners are alternately arranged along the circumferential direction of the blade on the polygonal surface, the cutting edge has a first cutting edge and a second cutting edge, the first cutting edge performs finish machining on a workpiece, the outer peripheral surface has a first relief surface, a second relief surface, and a first constraint surface disposed at a position further outward in the radial direction of the blade than the second cutting edge, and the blade shape is rotationally symmetrical by 180° with respect to the rotational center axis of the second corner adjacent to one side of the circumferential direction of the blade of the specified first corner and the center axis of the blade when viewed in the axial direction of the blade.

Description

Technical Field

[0001] This invention relates to a finishing insert and an indexable insert milling cutter.

[0002] This application claims priority based on Japanese patent application No. 2020-152217, filed on September 10, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] Indexable insert end mills, such as those described in Patent Documents 1 to 3, are known by convention. An indexable insert end mill includes: a tool body having multiple insert mounts; and multiple cutting inserts mounted in each insert mount. Each cutting insert has: a primary cutting edge protruding radially outward from the tool body; and a secondary cutting edge protruding radially outward from the tool body towards the tool tip.

[0004] In Patent Document 1, cutting edges are provided on the edges of the polygonal face of the cutting insert. A portion of these cutting edges are polishing edges (waipers) protruding outwards from the outer periphery of the polygonal face, while the remaining cutting edges are ordinary cutting edges. Furthermore, one type of cutting insert can be used as a cutting insert for general cutting (roughing) and also as a polishing edge insert for finishing. In Patent Document 1, multiple insert mounts have the same shape, allowing the insert to be mounted on any insert mount, whether the cutting insert is used for roughing or as a polishing edge insert for finishing. Additionally, in Patent Document 1, the main cutting edge adjacent to the polishing edge in the cutting insert used as a polishing edge insert is also used for cutting.

[0005] In Patent Document 2, the tool body has multiple identical insert mounts. Among the multiple cutting inserts mounted on each mount are: a standard machining insert for standard machining (roughing); and a finishing insert, which has a different shape from the standard machining insert and is used for finishing. The finishing insert has a finishing cutting edge and a main cutting edge adjacent to it. During machining, both the finishing cutting edge and the main cutting edge cut into the workpiece. Furthermore, the finishing insert has a front-back symmetrical shape, allowing the use of the cutting edges located on the front and back edges of the insert, thus extending tool life.

[0006] In Patent Document 3, the cutting insert is in the shape of a generally triangular hexagonal plate. This cutting insert has a pair of hexagonal faces. The six corners of each hexagonal face have: a first corner where the included angle between a pair of edges is approximately 90°; and a second corner where the included angle between a pair of edges is an obtuse angle larger than the included angle of the first corner. Three first corners and three second corners are alternately arranged along the circumference of each hexagonal face. Furthermore, six side faces are formed on the outer circumferential surface of the cutting insert. When the cutting insert is mounted on the insert holder, two of the six side faces contact the two walls of the insert holder. As described above, the cutting insert of Patent Document 3 has a special shape, therefore the shape of the insert holder is also complex.

[0007] Patent Document 1: Japanese Patent Application Publication No. 2008-23660

[0008] Patent Document 2: Japanese Patent Application Publication No. 2015-150661

[0009] Patent Document 3: Japanese Patent Application Publication No. 2020-32499

[0010] In Patent Document 3, when two types of cutting inserts, roughing inserts and finishing inserts, are arbitrarily installed on multiple insert mounts that are identical in shape, the following problem arises.

[0011] If the insert mount has a complex shape, as in Patent Document 3, the shape of the finishing insert that can be mounted on the insert mount will also be a roughly triangular hexagonal plate shape, similar to the shape of the roughing insert. For example, in order to further improve the machining accuracy of the finishing edge of the finishing insert or to suppress cutting edge defects, it is considered to suppress the contact between the cutting edge (especially the main cutting edge) other than the finishing edge and the workpiece. To this end, it is only necessary to configure the main cutting edge of the finishing insert to be further radially inward than the rotation trajectory of the main cutting edge of the roughing insert around the tool's central axis.

[0012] However, if the main cutting edge of the finishing insert is retracted, the side face of the flank face constituting the main cutting edge of the finishing insert is also retracted. Therefore, when the finishing insert is mounted in the insert holder with its front and back sides reversed, this side face is positioned away from the wall of the insert holder, that is, it does not contact the wall, thus making it impossible to constrain the finishing insert to the insert holder. Therefore, it is impossible to make the finishing insert symmetrical in both front and back sides (i.e., double-sided), and it must be made into a single-sided finishing insert with a short tool life. Summary of the Invention

[0013] One of the objectives of this invention is to provide a finishing insert and an indexable insert milling cutter using the finishing insert. The finishing insert can be arbitrarily mounted on multiple insert holders of the same shape, and can suppress the contact between the cutting edge other than the finishing edge and the workpiece while performing finishing with the finishing edge. It also has a front-back reverse symmetrical shape, which can improve machining accuracy and extend tool life.

[0014] One aspect of the finishing blade of the present invention comprises: a pair of polygonal faces facing opposite sides along a blade axial direction extending from the blade's central axis; an outer peripheral face connected to the pair of polygonal faces and facing radially outward from the blade; and a cutting edge disposed at an edge portion connecting the polygonal faces and the outer peripheral face. The polygonal faces have: a plurality of sides disposed along the outer periphery of the polygonal face; a first corner portion located between a pair of sides arranged along the blade circumferential direction; and a second corner portion disposed at a different position from the first corner portion in the blade circumferential direction, located between a pair of sides arranged along the blade circumferential direction. Three of each of the first and second corner portions are alternately arranged on the polygonal face along the blade circumferential direction. When viewed from the blade axial direction, a first included angle between a pair of sides located on either side of the first corner portion in the blade circumferential direction is greater than the angle between the first and second corner portions. The second included angle between a pair of sides on both sides of the blade circumferential direction of the two corners is small. The cutting edge has: a first cutting edge, which is disposed on one side of the blade circumferential direction of the designated first corner in one of the three first corners, for finishing the workpiece; and a second cutting edge, which is disposed on the other side of the blade circumferential direction of the designated first corner. The outer circumferential surface has: a first flank face, which is connected to the first cutting edge; a second flank face, which is connected to the second cutting edge; and a first constraint face, which is located on the side opposite to the second cutting edge on the second flank face in the blade axial direction and is disposed further radially outward than the second cutting edge. When viewed from the blade axial direction, the blade shape is rotationally symmetrical about 180° around the rotation center axis of the second corner adjacent to one side of the blade circumferential direction of the designated first corner and the blade central axis.

[0015] Furthermore, one embodiment of the indexable insert milling cutter of the present invention comprises: a tool body having a plurality of insert mounting seats arranged at intervals along the circumferential direction of the tool at the front end of the tool axis extending from the tool center axis; the aforementioned finishing insert being disposed in at least one of the plurality of insert mounting seats; and a roughing insert being disposed in an insert mounting seat different from the insert mounting seat on which the finishing insert is disposed, the roughing insert having: a main cutting edge protruding radially outward from the tool body; and a secondary cutting edge protruding radially outward from the tool body towards the front end side of the tool axis, the plurality of insert mounting seats having the same shape, the first cutting edge being disposed further towards the front end side of the tool axis than the secondary cutting edge, and the second cutting edge being disposed further towards the inner side of the tool axis than the main cutting edge.

[0016] In this indexable insert milling cutter, both roughing (standard machining) inserts and finishing inserts can be arbitrarily mounted on multiple insert mounts of the same shape.

[0017] According to the finishing insert of the present invention, the second cutting edge is positioned further radially inward of the insert than the first constraint surface, thus suppressing contact between the second cutting edge and the workpiece. Specifically, in the indexable insert milling cutter of the present invention, the second cutting edge of the finishing insert is configured to retract radially inward of the tool than the rotation trajectory of the main cutting edge of the roughing insert around the tool's central axis. Therefore, the finishing insert cuts into the workpiece only with the first cutting edge (finishing edge), consistently improving the accuracy of finishing.

[0018] Furthermore, when the finishing insert is mounted on the insert mount in a 180° rotational orientation around the central axis, the first constraint surface contacts the first support surface of the insert mount. Therefore, even when using the first cutting edge of either of the two polygonal faces, the finishing insert can be stably fixed to the insert mount. In other words, the finishing insert can be made double-sided, extending tool life.

[0019] As described above, the finishing insert according to the present invention can be arbitrarily mounted on multiple insert holders of the same shape, and can suppress the contact between the cutting edge other than the finishing edge and the workpiece while performing finishing with the finishing edge. Moreover, it has a front-back reverse symmetrical shape, which can improve machining accuracy and extend tool life.

[0020] Furthermore, the indexable insert milling cutter of the present invention has the above-mentioned finishing insert, thus increasing the degree of freedom in insert configuration on multiple insert mounts, which can improve machining accuracy while extending tool life.

[0021] Preferably, in the above-mentioned finishing insert, the second flank face is an inclined surface that is tilted relative to the central axis of the insert, and is located radially outward of the insert as it moves away from the second cutting edge in the insert axial direction. The first constraint surface is connected to the second flank face and is a plane parallel to the central axis of the insert.

[0022] At this point, as described above, the second cutting edge can be retracted, and the structure of the second flank face and the first constraint face can be simplified. The simplified first constraint face improves the stability of the finishing insert on the insert mount, and also simplifies insert manufacturing.

[0023] Preferably, in the above-mentioned finishing insert, the polygonal surface has: a first rake face connected to the first cutting edge; and a seat face disposed further radially inward of the insert than the first rake face. The first rake face is an inclined surface that moves axially from the polygonal surface toward the other polygonal surface as it moves radially inward from the first cutting edge toward the insert. The seat face protrudes axially more than the first cutting edge and the first rake face.

[0024] At this point, the first rake face is tilted towards the positive angle, thus stably improving the sharpness of the first cutting edge. Furthermore, the chips generated by the first cutting edge collide with the step (stepped portion) between the first rake face and the seat surface and are easily separated, thus improving chip handling. Moreover, the first cutting edge and the first rake face do not protrude more than the seat surface in the insert axial direction, therefore, when the finishing insert is mounted in the insert holder with its front and back sides reversed, interference between the first cutting edge and the first rake face and the insert holder can be suppressed.

[0025] Preferably, in the above-mentioned finishing insert, the polygonal surface has a second rake face connected to the second cutting edge, and the seat surface is disposed further radially inside the insert than the second rake face, and protrudes further axially into the insert than the second cutting edge and the second rake face.

[0026] At this time, the second cutting edge and the second rake face will not protrude more than the seat surface in the axial direction of the insert. Therefore, when the finishing insert is installed in the insert mounting seat in a forward and backward manner, the interference of the second cutting edge and the second rake face with the insert mounting seat can be suppressed.

[0027] Preferably, in the above-mentioned finishing blade, the cutting edge has an angular cutting edge, which is connected to the end of the first cutting edge on the other side of the blade circumference and the end of the second cutting edge on one side of the blade circumference. When viewed from the blade axial direction, the included angle between the first cutting edge and the angular cutting edge and the included angle between the second cutting edge and the angular cutting edge are both obtuse angles.

[0028] For example, compared with a structure in which the first cutting edge and the second cutting edge are directly connected, the structure according to the present invention can improve the strength of the cutting edge and suppress edge defects, etc.

[0029] Preferably, in the above-mentioned finishing blade, when viewed from the blade axial direction, the first cutting edge has a convex curve that bulges outward radially from the blade.

[0030] At this point, for example, even if the tool center axis of the tool body with the finishing insert is slightly tilted relative to the workpiece due to cutting resistance during cutting, the machining surface accuracy of the first cutting edge can be stably ensured.

[0031] Preferably, in the above-mentioned polishing blade, the outer peripheral surface has a second constraint surface adjacent to the other side of the blade circumference direction of the first constraint surface.

[0032] Preferably, in the above-mentioned indexable insert milling cutter, the outer peripheral surface of the finishing insert has a second constraint surface, the second constraint surface being disposed at a different position from the first constraint surface in the circumferential direction of the insert, and the insert mounting base having: a bottom surface that contacts the sitting surface of the polygonal surface; a first support surface that contacts the first constraint surface; and a second support surface that contacts the second constraint surface.

[0033] At this point, the finishing blade is constrained to the blade mounting base by the first and second constraint surfaces in both the radial and circumferential directions. This further improves the stability of the finishing blade's placement on the blade mounting base.

[0034] According to one aspect of the present invention, the finishing insert can be arbitrarily mounted on multiple insert holders of the same shape, and can suppress the contact between the cutting edge other than the finishing edge and the workpiece while performing finishing with the finishing edge. It also has a front-back reverse symmetrical shape, which can improve machining accuracy and extend tool life.

[0035] Furthermore, the indexable insert milling cutter of one aspect of the present invention has the aforementioned finishing insert, thus increasing the degree of freedom in insert configuration on multiple insert mounts, thereby improving machining accuracy while extending tool life. Attached Figure Description

[0036] Figure 1 This is a perspective view showing the polishing blade of this embodiment.

[0037] Figure 2 This is a top view of the finishing blade viewed from the blade axis.

[0038] Figure 3 This is a side view of a polishing blade.

[0039] Figure 4 Viewed from the direction of arrow IV Figure 2 Side view of the polishing blade.

[0040] Figure 5 This is a perspective view showing the indexable insert milling cutter of this embodiment, with the roughing insert omitted.

[0041] Figure 6 This is a side view of an indexable insert milling cutter, omitting the illustration of the roughing insert.

[0042] Figure 7 This is a side view of an indexable insert milling cutter, omitting the illustration of the roughing insert.

[0043] Figure 8 It is a magnified 3D view showing the area near the blade mounting base of the tool body.

[0044] Figure 9 It is a side view showing a portion of an indexable insert milling cutter, and a diagram showing the polygonal face of the roughing insert viewed from the front in the direction of tool rotation.

[0045] Figure 10 This is a perspective view showing a roughing insert mounted on an insert mount. Detailed Implementation

[0046] Referring to the accompanying drawings, a finishing insert 1 and an indexable insert milling cutter 10 according to an embodiment of the present invention will be described.

[0047] [Simplified structure of indexable insert milling cutter]

[0048] The indexable insert milling cutter 10 of this embodiment is a cutting tool (rotary cutting tool) for performing milling operations such as planar milling on workpieces made of metal. The indexable insert milling cutter 10 may also be called, for example, an indexable insert planar milling cutter, an indexable insert milling cutter, an indexable insert face milling cutter, etc.

[0049] like Figures 5 to 7 , Figure 9 and Figure 10 As shown, the indexable insert milling cutter 10 includes a tool body 2, a finishing insert 1, a roughing insert 3 for roughing (for standard machining), and screw components such as clamping screws 4. Additionally, Figures 5 to 7 The illustration of the roughing tool 3 is omitted.

[0050] The tool body 2 is cylindrical or similar in shape, centered on the tool's central axis O. The tool body 2 is detachably mounted to the spindle of a machine tool (not shown). The tool body 2 rotates around the tool's central axis O via the machine tool's spindle. At both ends of the tool body 2 along the tool axis, which extends in the direction of the tool's central axis O, the machine tool's spindle is connected at the first end, and a finishing insert 1 and a roughing insert 3 are disposed at the second end. The first end of the tool body 2 may also be referred to as the spindle mounting section, and the second end may also be referred to as the cutting edge.

[0051] In this embodiment, at least one finishing insert 1 is provided on the indexable insert milling cutter 10. A plurality of roughing inserts 3 are provided on the indexable insert milling cutter 10.

[0052] like Figures 1 to 4 As shown, the finishing blade 1 is a roughly triangular hexagonal plate centered on the blade's central axis A. The finishing blade 1 includes: a pair of polygonal faces 11 and 12, which face opposite sides in the direction extending along the blade axis A; an outer peripheral face 13 connected to the pair of polygonal faces 11 and 12; a cutting edge 14 disposed on the edge portion connecting the polygonal faces 11 and 12 and the outer peripheral face 13; and a through hole 15, which opens on the pair of polygonal faces 11 and 12.

[0053] [Definition of direction]

[0054] In this embodiment, the direction extending from the blade center axis A of the polishing blade 1, that is, the direction along the blade center axis A, is called the blade axis. The blade axis can also be called the thickness direction of the polishing blade 1. In the blade axis, the direction from one polygonal face (first polygonal face) 11 of the polishing blade 1 to another polygonal face (second polygonal face) 12 is called the back side of the blade axis, and the direction from the other polygonal face 12 to one polygonal face 11 is called the front side of the blade axis.

[0055] The direction orthogonal to the blade's central axis A is called the blade radial direction. Within the blade radial direction, the direction closest to the blade's central axis A is called the inner radial direction, and the direction furthest from the blade's central axis A is called the outer radial direction.

[0056] The direction of rotation around the central axis A of the blade is called the blade circumferential direction. Within the blade circumferential direction, a defined direction is called one side C1 of the blade circumferential direction, and the direction opposite to the defined direction is called the other side C2 of the blade circumferential direction. In this embodiment, as... Figure 2 As shown, when viewing a polygonal surface 11 from the front of the blade axis, the clockwise direction centered on the blade's central axis A corresponds to one side C1 of the blade's circumference, and the counterclockwise direction corresponds to the other side C2 of the blade's circumference.

[0057] And, as Figure 5 As shown in the figure, in this embodiment, the direction in which the tool center axis O of the tool body 2 extends, that is, the direction along the tool center axis O, is called the tool axis. In the tool axis, the direction from the first end (spindle mounting part) of the tool body 2 toward the second end (cutting part) is called the front end side, and the direction from the second end toward the first end is called the rear end side.

[0058] The direction orthogonal to the tool's central axis O is called the tool radial direction. Within the tool radial direction, the direction closer to the tool's central axis O is called the inner radial direction, and the direction farther from the tool's central axis O is called the outer radial direction.

[0059] The direction of rotation around the tool's central axis O is called the tool's circumferential direction. Within the tool's circumferential direction, the direction in which the tool body 2 rotates through the spindle during milling is called the tool's rotation direction T, and the opposite direction of rotation is called the direction opposite to the tool's rotation direction T, or simply the opposite direction of the tool's rotation direction.

[0060] [Polishing blade]

[0061] First, refer to Figures 1 to 4 The finishing insert 1 will be described below. The finishing insert 1 is, for example, made of cemented carbide. The finishing insert 1 has a symmetrical shape with opposite sides. That is, the finishing insert 1 is a double-sided cutting insert.

[0062] [Explanation of polygonal faces 1]

[0063] The finishing blade 1 has a front-back symmetrical shape, so the pair of polygonal faces 11 and 12 have the same structure. Therefore, in the following description, one polygonal face 11 will be described, and the description of the other polygonal face 12 will be omitted. In addition, although not specifically illustrated, at least one of the pair of polygonal faces 11 and 12 may be provided with an identification mark for identifying each polygonal face 11 and 12.

[0064] The polygonal face 11 faces the blade axis. The polygonal face 11 is hexagonal. The polygonal face 11 has: a plurality of sides 11a, 11b, 11c, 11d, 11e, 11f, arranged along the outer periphery of the polygonal face 11; a first corner 16, located between a pair of sides arranged along the circumferential direction of the blade; and a second corner 17, arranged at a different position from the first corner 16 in the circumferential direction of the blade, and located between a pair of sides arranged along the circumferential direction of the blade.

[0065] like Figure 2As shown, corresponding to the case where the polygonal surface 11 is hexagonal, six sides 11a, 11b, 11c, 11d, 11e, and 11f are arranged on the outer periphery of the polygonal surface 11. Three first corner portions 16 and three second corner portions 17 are alternately arranged on the polygonal surface 11 along the circumferential direction of the blade.

[0066] Specifically, the three first corner portions 16 are disposed between a pair of sides 11a and 11b, a pair of sides 11c and 11d, and a pair of sides 11e and 11f arranged along the circumferential direction of the blade. The three second corner portions 17 are disposed between a pair of sides 11b and 11c, a pair of sides 11d and 11e, and a pair of sides 11f and 11a arranged along the circumferential direction of the blade.

[0067] Furthermore, in this embodiment, the polygonal surface 11 has a plurality of connecting edges 11m, 11n, 11p, and 11q, which are disposed on the outer periphery of the polygonal surface 11, and the length of these edges is shorter than the length of the edges 11a, 11b, 11c, 11d, 11e, and 11f. Additionally, the "connecting edges" can also be referred to as chamfered edges. Therefore, the finishing blade 1 can also be described as a roughly triangular decagonal plate.

[0068] The connecting edge 11m is disposed in the designated first corner 16A of the three first corners 16, connecting a pair of edges 11a and 11b to each other. The two ends of the connecting edge 11m are connected to the end of the edge 11a on the other side C2 in the circumferential direction of the blade and the end of the edge 11b on one side C1 in the circumferential direction of the blade.

[0069] A connecting edge 11n is disposed in another first corner 16B, which is adjacent to the other side C2 of the blade circumference direction of the designated first corner 16A, and connects a pair of edges 11c and 11d to each other. The two ends of the connecting edge 11n are connected to the ends of the edges 11c on the other side C2 of the blade circumference direction and the ends of the edges 11d on one side C1 of the blade circumference direction.

[0070] A connecting edge 11p is disposed in another first corner 16C of the three first corners 16, excluding the first corners 16A and 16B, connecting a pair of edges 11e and 11f to each other. The two ends of the connecting edge 11p are connected to the end of the edge 11e on the other side C2 in the circumferential direction of the blade and the end of the edge 11f on one side C1 in the circumferential direction of the blade.

[0071] The connecting edge 11q is disposed in one of the three second corner portions 17, which is adjacent to one side C1 of the blade circumferential direction of the designated first corner portion 16A, and connects a pair of edges 11f and 11a to each other. The two ends of the connecting edge 11q are connected to the ends of the edges 11f and 11a respectively, on the other side C2 of the blade circumferential direction and on the side C1 of the blade circumferential direction of the edge 11a.

[0072] like Figure 2 As shown, when viewed from the blade axis, the first included angle θ1 between a pair of sides of the blade on both sides of the first corner 16 in the circumferential direction is smaller than the second included angle θ2 between a pair of sides of the blade on both sides of the second corner 17 in the circumferential direction. The first included angle θ1 is, for example, approximately 90°. The second included angle θ2 is an obtuse angle greater than 90°, for example, approximately 150°.

[0073] The structures of polygonal face 11 other than those described above will be described separately later.

[0074] [Cutting edge]

[0075] A pair of cutting edges 14 are provided at the edge connecting one polygonal face 11 to the outer peripheral face 13 and at the edge connecting another polygonal face 12 to the outer peripheral face 13. The finishing blade 1 has a front-back symmetrical shape, so the pair of cutting edges 14 have the same structure. Therefore, in the following description, one cutting edge 14A of the pair of cutting edges 14, which is located at the outer periphery of one polygonal face 11, will be described, while the description of the other cutting edge 14B, which is located at the outer periphery of the other polygonal face 12, will be omitted.

[0076] A cutting edge 14A includes: a first cutting edge 14a, disposed at one side C1 of the blade circumferential direction of the first corner 16A among the three first corners 16 of the polygonal face 11, for finishing workpiece; a second cutting edge 14b, disposed at the other side C2 of the blade circumferential direction of the first corner 16A; and a corner cutting edge 14c, connected to the end of the first cutting edge 14a at the other side C2 of the blade circumferential direction and the end of the second cutting edge 14b at one side C1 of the blade circumferential direction. Figure 2 As shown, when viewed from the axial direction of the blade, the cutting edge 14A is roughly L-shaped.

[0077] The first cutting edge 14a can also be called a finishing edge, finishing cutting edge, or secondary cutting edge. The first cutting edge 14a extends along the edge 11a adjacent to one side C1 of the blade circumference of the defined first corner 16A. Figure 2As shown, when viewed from the axial direction of the insert, the first cutting edge 14a extends in a generally straight line along the edge 11a. Specifically, in this embodiment, when viewed from the axial direction of the insert, the first cutting edge 14a has a convex curve that bulges radially outward from the insert. The first cutting edge 14a bends with a large radius of curvature (e.g., R500mm) when viewed from the axial direction of the insert, and bulges slightly radially outward from the insert. Furthermore, as... Figure 4 As shown, when viewed radially from the blade, the first cutting edge 14a extends in a straight line.

[0078] Regarding the second cutting edge 14b, based on its cutting edge layout, it can also be referred to as the main cutting edge. However, as described later, the second cutting edge 14b is a surface cutting edge that is not used for cutting, and therefore does not actually function as a main cutting edge. The second cutting edge 14b extends along the edge 11b adjacent to the other side C2 of the insert circumference of the defined first corner 16A. Figure 2 As shown, when viewed from the axial direction of the blade, the second cutting edge 14b extends in a straight line on the edge 11b.

[0079] An angled cutting edge 14c is positioned at the connecting edge 11m of a designated first corner 16A. Viewed axially from the insert, the angled cutting edge 14c extends in a straight line along the connecting edge 11m. Viewed axially from the insert, the angles between the first cutting edge 14a and the angled cutting edge 14c, and between the second cutting edge 14b and the angled cutting edge 14c, are both obtuse angles. Figure 3 and Figure 4 As shown, when viewed radially from the insert, the angular cutting edge 14c has a concave curve that curves inward toward the insert axially (on the back side). The cutting length of the angular cutting edge 14c is shorter than the cutting lengths of the first cutting edge 14a and the second cutting edge 14b.

[0080] [Explanation of polygonal faces 2]

[0081] like Figure 1 and Figure 2 As shown, the polygonal surface 11 has a first rake face 11g, a second rake face 11h, a corner rake face 11i, a seating surface 11j, and a stepped portion 11k.

[0082] The first rake face 11g is connected to the first cutting edge 14a. The first rake face 11g is disposed radially inward of the first cutting edge 14a. The first rake face 11g is inclined in the axial direction of the insert from the polygonal face 11 toward the other polygonal face 12 (i.e., the back side of the insert) as it moves radially inward from the first cutting edge 14a toward the insert's central axis. That is, the first rake face 11g is inclined toward the positive angle side relative to an imaginary plane perpendicular to the insert's central axis A. In this embodiment, the first rake face 11g is planar.

[0083] The second rake face 11h is connected to the second cutting edge 14b. The second rake face 11h is disposed radially inside the insert of the second cutting edge 14b. The second rake face 11h has an inclined surface that slopes towards the back side of the insert axially as it moves from the second cutting edge 14b toward the radially inward side of the insert. That is, the second rake face 11h is inclined at a positive angle relative to an imaginary plane perpendicular to the insert's central axis A. In this embodiment, the second rake face 11h is planar.

[0084] The angular rake face 11i is connected to the angular cutting edge 14c. The angular rake face 11i is disposed radially inside the insert of the angular cutting edge 14c. The angular rake face 11i has an inclined surface that slopes towards the back side of the insert axially as it moves radially inside the insert from the angular cutting edge 14c. That is, the angular rake face 11i is inclined at a positive angle relative to an imaginary plane perpendicular to the insert's central axis A. In this embodiment, the angular rake face 11i has a concave curved surface. The end of the angular rake face 11i on one side C1 in the insert circumferential direction is connected to the end of the first rake face 11g on the other side C2 in the insert circumferential direction. The end of the angular rake face 11i on the other side C2 in the insert circumferential direction is connected to the end of the second rake face 11h on one side C1 in the insert circumferential direction.

[0085] The seat surface 11j is located further radially inward of the insert than the first rake face 11g, the second rake face 11h, and the angular rake face 11i. The seat surface 11j is a planar shape that extends in a direction perpendicular to the insert's central axis A.

[0086] like Figure 1 , Figure 3 and Figure 4 As shown, the seat surface 11j protrudes further along the insert axis than the first cutting edge 14a and the first rake face 11g. That is, the seat surface 11j of the polygonal surface 11 is located on the front side of the insert axis, which is closer to the insert axis than the first cutting edge 14a and the first rake face 11g.

[0087] The seat surface 11j protrudes further along the insert axis than the second cutting edge 14b and the second rake face 11h. That is, the seat surface 11j of the polygonal surface 11 is located on the front side of the insert axis, which is closer to the insert axis than the second cutting edge 14b and the second rake face 11h.

[0088] The seat surface 11j protrudes further along the insert axis than the angular cutting edge 14c and the angular rake face 11i. That is, the seat surface 11j of the polygonal surface 11 is located on the front side closer to the insert axis than the angular cutting edge 14c and the angular rake face 11i.

[0089] A stepped portion 11k is radially disposed between the first rake face 11g, the second rake face 11h, the angular rake face 11i, and the seat surface 11j. The stepped portion 11k is an inclined surface relative to the insert's central axis A, and is located on the front side of the insert's axial direction as it faces radially inward. The stepped portion 11k is also an inclined surface facing radially outward. Figure 2 As shown, when viewed from the blade axis, the stepped portion 11k extends in a roughly L-shape along the cutting edge 14.

[0090] [Outer peripheral surface]

[0091] like Figure 1 , Figure 3 and Figure 4 As shown, the outer peripheral surface 13 faces the radially outward side of the blade and extends along the circumference of the blade. The outer peripheral surface 13 is annular with the blade's central axis A as the center.

[0092] The outer peripheral surface 13 has a first flank face 13a, a second flank face 13b, a corner flank face 13c, a first constraint surface 13d, and a second constraint surface 13e. The finishing blade 1 has a front-back symmetrical shape, so a pair (i.e., two) of the first flank face 13a, the second flank face 13b, the corner flank face 13c, the first constraint surface 13d, and the second constraint surface 13e are provided on the outer peripheral surface 13.

[0093] The first flank face 13a is connected to the first cutting edge 14a. The first flank face 13a is disposed on the back side of the first cutting edge 14a in the insert axial direction. The first flank face 13a is generally planar and parallel to the insert central axis A. Specifically, in this embodiment, the first flank face 13a is a cylindrical surface that is parallel to the insert central axis A and slightly convex outward in the radial direction of the insert. The first flank face 13a is disposed in the insert axial direction between the first cutting edge 14a and one side of another polygonal surface 12 (corresponding to the side of the side 11f of a polygonal surface 11), that is, it is disposed along the entire length of the insert axial direction of the outer peripheral surface 13.

[0094] The second flank face 13b is connected to the second cutting edge 14b. The second flank face 13b is disposed on the back side of the second cutting edge 14b in the insert axial direction. The second flank face 13b is an inclined surface that is inclined relative to the insert's central axis A, and is located radially outward of the insert as it moves away from the second cutting edge 14b in the insert axial direction. The second flank face 13b is disposed on the front side portion of the outer peripheral surface 13 in the insert axial direction. Specifically, the second flank face 13b is disposed from the second cutting edge 14b toward the back side of the insert axial direction, for example, covering a range of 1 / 3 to 1 / 2 of the total length of the outer peripheral surface 13 in the insert axial direction.

[0095] The angular relief face 13c is connected to the angular cutting edge 14c. The angular relief face 13c is disposed on the back side of the angular cutting edge 14c in the insert axial direction. The angular relief face 13c is a plane parallel to the insert's central axis A. The angular relief face 13c is disposed in the insert axial direction between the angular cutting edge 14c and a connecting edge of another polygonal face 12 (equivalent to the connecting edge 11p of a polygonal face 11), that is, it is disposed in the insert axial direction along the entire length of the outer peripheral surface 13. The angular relief face 13c is located in the insert circumferential direction between the first relief face 13a, the second relief face 13b, and the first constraint surface 13d.

[0096] The first constraint surface 13d is located on the side of the second flank face 13b opposite to the second cutting edge 14b in the insert axial direction, that is, on the back side of the second flank face 13b in the insert axial direction. The first constraint surface 13d is connected to the second flank face 13b and is a plane parallel to the insert central axis A. The first constraint surface 13d is disposed in the insert axial direction between the second flank face 13b and a side of another polygonal face 12 (corresponding to the side of the side 11e of a polygonal face 11). The first constraint surface 13d is disposed on the back side portion of the outer peripheral surface 13 in the insert axial direction. Specifically, the first constraint surface 13d is disposed from the side of the other polygonal face 12 toward the front side of the insert axial direction, for example, covering a range of 1 / 2 to 2 / 3 of the total length of the outer peripheral surface 13 in the insert axial direction.

[0097] like Figure 2 and Figure 4 As shown, the first constraint surface 13d is positioned further radially outward from the insert than the second cutting edge 14b. In other words, the second cutting edge 14b is configured to recede radially inward from the insert than the first constraint surface 13d.

[0098] like Figure 2 As shown, the first constraint surface 13d is located in the circumferential direction of the blade between the designated first corner 16A and the second corner 17 adjacent to the other side C2 of the blade circumferential direction of the designated first corner 16A.

[0099] like Figure 1 and Figure 3 As shown, the second constraint surface 13e is positioned at a different location from the first constraint surface 13d in the circumferential direction of the cutting tool. The second constraint surface 13e is adjacent to the second flank face 13b and the other side C2 of the first constraint surface 13d in the circumferential direction of the cutting tool. The second constraint surface 13e is a plane parallel to the central axis A of the cutting tool. The second constraint surface 13e is arranged along the axial direction of the cutting tool between a side 11c of a polygonal face 11 and a side 11d of another polygonal face 12 (corresponding to the side 11d of a polygonal face 11), that is, it is arranged along the entire axial length of the outer circumferential surface 13 of the cutting tool.

[0100] like Figure 2 As shown, the second constraint surface 13e is located in the circumferential direction of the blade between the first corner portion 16B and the second corner portion 17 adjacent to one side C1 of the first corner portion 16B in the circumferential direction of the blade.

[0101] like Figure 2 and Figure 3 As shown, the portion 13f of the outer peripheral surface 13 that connects to the connecting edge 11n of the first corner 16B, i.e., the portion 13f located on the back side of the connecting edge 11n along the blade axial direction, is planar and parallel to the blade's central axis A. Therefore, portion 13f can also be referred to as planar portion 13f. The portion 13f of the outer peripheral surface 13 is disposed along the blade axial direction between the connecting edge 11n and a connecting edge of another polygonal surface 12 (corresponding to the connecting edge 11n of polygonal surface 11), i.e., it is disposed along the entire length of the outer peripheral surface 13 along the blade axial direction. The portion 13f of the outer peripheral surface 13 is located between a pair of second constraint surfaces 13e, 13e in the blade circumferential direction.

[0102] like Figures 1 to 4 As shown, the portion 13g of the outer peripheral surface 13 that connects to the connecting edge 11q of the second corner 17A, i.e., the portion 13g of the outer peripheral surface 13 located on the back side of the connecting edge 11q in the blade axial direction, is planar and parallel to the blade central axis A. Therefore, portion 13g can also be called planar portion 13g. The portion 13g of the outer peripheral surface 13 is disposed in the blade axial direction between the connecting edge 11q and a connecting edge of another polygonal surface 12 (corresponding to the connecting edge 11q of the polygonal surface 11), that is, it is disposed along the entire length of the outer peripheral surface 13 in the blade axial direction. The portion 13g of the outer peripheral surface 13 is located between a pair of first flank faces 13a, 13a in the blade circumferential direction.

[0103] [Through-through hole]

[0104] like Figure 1 and Figure 2 As shown, the through hole 15 penetrates the finishing blade 1 along the blade axis. The through hole 15 extends along the blade axis inside the finishing blade 1 and opens at the center of each of the polygonal faces 11 and 12. The through hole 15 is a multi-stage circular hole centered on the blade's central axis A. The inner diameter of the through hole 15 is different at different positions along the blade axis. Specifically, the inner diameter of the two ends of the through hole 15 along the blade axis, i.e., the pair of openings, is larger than the inner diameter of the central portion of the through hole 15 along the blade axis.

[0105] Furthermore, regarding the polishing blade 1 in this embodiment, as... Figure 2As shown, when viewed from the blade axial direction, the blade shape is rotationally symmetrical about 180° around the second corner 17A adjacent to one side C1 of the blade circumference of the designated first corner 16A, the blade central axis A, and the rotational central axis B of the first corner 16B, which is different from the designated first corner 16A. That is, the finishing blade 1 has a front-back symmetrical shape centered on the rotational central axis B. Furthermore, the rotational central axis B can also be called the axis of rotational symmetry. When viewed from the blade axial direction, the rotational central axis B does not pass through the designated first corner 16A where the cutting edge 14 is located.

[0106] The rotation center axis B is orthogonal to the blade center axis A. That is, the rotation center axis B extends radially along the blade. Figure 1 As shown, the rotation center axis B passes through the central portion of the blade axis in the outer peripheral surface 13. Specifically, the rotation center axis B passes through the central portions of the blade axes of the planar portions 13f and 13g of the outer peripheral surface 13.

[0107] [Roughing blades]

[0108] Next, refer to Figure 9 and Figure 10 The roughing insert 3 will be described below. The roughing insert 3 is, for example, made of carbide. The roughing insert 3 has a symmetrical shape with opposite sides. That is, the roughing insert 3 is a double-sided cutting insert.

[0109] As the roughing insert 3 in this embodiment, for example, the cutting insert described in Patent Document 3 (Japanese Patent Application Publication No. 2020-32499) cited in the prior art can be used. Therefore, in the following description, only the basic structure of the roughing insert 3 will be described, and detailed descriptions will be omitted.

[0110] like Figure 9 and Figure 10 As shown, the roughing insert 3 is roughly triangular-hexagonal plate-shaped. The roughing insert 3 includes: a pair of polygonal faces 31 and 32, which face opposite sides in the insert axis; an outer peripheral face 33, which is connected to the pair of polygonal faces 31 and 32; a cutting edge 34, which is disposed on the edge portion connecting the polygonal faces 31 and 32 and the outer peripheral face 33; and a through hole 35, which opens on the pair of polygonal faces 31 and 32.

[0111] The roughing blade 3 has a front-back symmetrical shape, so a pair of polygonal faces 31 and 32 have the same structure. Therefore, one polygonal face 31 will be described here, and the description of the other polygonal face 32 will be omitted.

[0112] The polygonal face 31 has a seat surface 31a. The seat surface 31a is a plane extending in a direction perpendicular to the central axis of the cutting tool (not shown). The cutting edge 34 is disposed on the outer periphery of the polygonal face 31. The cutting edge 34 has a main cutting edge 34a, a secondary cutting edge 34b, and a corner cutting edge 34c.

[0113] The outer peripheral surface 33 has multiple constraint surfaces 33a. Six constraint surfaces 33a are arranged along the circumference of the blade on the outer peripheral surface 33. Each constraint surface 33a is a plane parallel to the central axis of the blade.

[0114] [Tool Body]

[0115] Next, refer to Figures 5 to 8 The tool body 2 will be described below. The tool body 2 is made of metal, such as steel. The tool body 2 is cylindrical or cylindrical. Figure 5 As shown, in this embodiment, the tool body 2 is cylindrical or cylindrical. Alternatively, the tool body 2 may also be disc-shaped, etc. The outer diameter of the front end of the tool body 2 along the tool axis is larger than the outer diameter of the rear end. That is, regarding the tool body 2, the outer diameter of the second end (cutting edge) is larger than the outer diameter of the first end (spindle mounting portion).

[0116] The tool body 2 has a blade mounting seat 21, a chip groove 22 and a cooling hole 23.

[0117] [Blade Mount]

[0118] The blade mounting seat 21 is disposed at the front end of the tool body 2 along the tool axis. The blade mounting seat 21 is concave in shape, recessed from the front end face and outer peripheral surface of the tool body 2. A plurality of blade mounting seats 21 are provided on the tool body 2. The plurality of blade mounting seats 21 are arranged at intervals along the circumferential direction of the tool. In this embodiment, five blade mounting seats 21 are arranged at unequal intervals along the circumferential direction of the tool. One of the finishing blade 1 and the roughing blade 3 is mounted on each blade mounting seat 21.

[0119] Multiple blade mounts 21 are identical in shape. Therefore, finishing blades 1 and roughing blades 3 can be mounted on any blade mount 21.

[0120] like Figure 8 As shown, the blade mounting base 21 has a bottom surface 21a, an internal threaded hole 21b, a first support surface 21c, and a second support surface 21d.

[0121] The bottom surface 21a is a plane oriented towards the tool rotation direction T. In this embodiment, the bottom surface 21a is a circular annular plane. Figure 7As shown, the bottom surface 21a is inclined relative to the tool's central axis O. Specifically, the bottom surface 21a is an inclined surface located in the tool's rotation direction T as it faces the rear end of the tool's axis. That is, the bottom surface 21a is a negative inclined surface with the axial rake set as a negative angle.

[0122] like Figure 8 As shown, the internally threaded hole 21b opens inside (at the center) of the bottom surface 21a. The internally threaded hole 21b is a hole extending in a direction substantially perpendicular to the direction of expansion of the bottom surface 21a. In this embodiment, the internally threaded hole 21b is a bottomed stop hole. Alternatively, the internally threaded hole 21b may also be a through hole. The internally threaded portion is present on the inner circumferential surface of the internally threaded hole 21b.

[0123] The first support surface 21c is disposed further along the tool rotation direction T than the bottom surface 21a. The first support surface 21c is a planar surface facing radially outward from the tool. In this embodiment, the first support surface 21c is a quadrilateral planar surface. The first support surface 21c is inclined relative to the tool's central axis O. Specifically, the first support surface 21c is an inclined surface located radially outward from the tool as it faces the rear end side of the tool's axial direction.

[0124] The second support surface 21d is disposed further along the tool rotation direction T than the bottom surface 21a. The second support surface 21d is disposed further along the tool's axial rear end than the first support surface 21c. A pair of second support surfaces 21d are provided on the tool mount 21. The pair of second support surfaces 21d are arranged radially along the tool. Each second support surface 21d is planar. In this embodiment, each second support surface 21d is a quadrilateral planar surface.

[0125] One of the pair of second support surfaces 21d, located radially outward of the tool, faces radially inward of the tool. One second support surface 21d is inclined relative to the tool's central axis O. Specifically, one second support surface 21d is an inclined surface located radially inward of the tool, facing towards the rear end of the tool's axial direction.

[0126] Of a pair of second support surfaces 21d, the other second support surface 21d, located radially inner to the tool, faces radially outer to the tool. This other second support surface 21d is inclined relative to the tool's central axis O. Specifically, the other second support surface 21d is an inclined surface located radially outer to the tool, facing towards the rear end of the tool's axial direction. The amount of radial displacement of the other second support surface 21d per unit length along the tool's axial direction, i.e., the inclination angle of the other second support surface 21d relative to the tool's central axis O, is greater than the inclination angle of the first support surface 21c relative to the tool's central axis O.

[0127] [The installation of each cutting insert on the insert mount]

[0128] like Figures 5 to 7 As shown, a finishing insert 1 is disposed on at least one of the plurality of insert mounts 21. In this embodiment, a finishing insert 1 is disposed on an indexable insert milling cutter 10. The finishing insert 1 is fixed to the insert mount 21 by screwing the screw member 4, which is inserted into the through hole 15 of the finishing insert 1, into the internal threaded hole 21b. That is, the finishing insert 1 is detachably mounted on the insert mount 21.

[0129] One of the pair of polygonal faces 11 and 12 of the finishing blade 1 disposed on the blade mount 21 (polygonal face 11 in the example) faces the tool rotation direction T, and the other (polygonal face 12 in the example) faces the opposite direction of the tool rotation direction. The sitting surface of the polygonal face 12 facing the opposite direction of the tool rotation direction (equivalent to the sitting surface 11j of polygonal face 11) is in contact with the bottom surface 21a.

[0130] Although not specifically illustrated, the central axis A of the finishing blade 1, disposed in the blade mount 21, is located on the front end side along the tool rotation direction T. Furthermore, the central axis B of the finishing blade 1, disposed in the blade mount 21, is located in the opposite direction to the tool rotation direction along the front end side. That is, the central axis B is tilted relative to the tool central axis O towards a negative angle (see reference). Figure 7 ).

[0131] like Figure 5 As shown, in a pair of first constraint surfaces 13d of the finishing blade 1 disposed on the blade mounting base 21, one of the first constraint surfaces 13d facing the radially inner side of the tool contacts the first support surface 21c.

[0132] In the pair of second constraint surfaces 13e of the finishing blade 1 disposed in the blade mount 21, one of the second constraint surfaces 13e located radially outward and facing radially outward of the tool contacts the other of the pair of second support surfaces 21d facing radially inward of the tool.

[0133] In the pair of second constraint surfaces 13e of the finishing blade 1 disposed in the blade mount 21, the other second constraint surface 13e located radially inward of the tool and facing radially inward of the tool contacts the other second support surface 21d of the pair of second support surfaces 21d facing radially outward of the tool. Alternatively, the other second constraint surface 13e and the other second support surface 21d may be a structure in which they do not contact each other.

[0134] like Figure 6 and Figure 7As shown, the first cutting edge (finishing edge) 14a of the finishing insert 1, which is disposed in the insert mounting base 21, protrudes from the tool body 2 toward the front end side in the tool axial direction. That is, the first cutting edge 14a is configured to protrude further toward the front end side in the tool axial direction than the front end face of the tool body 2. The first cutting edge 14a extends radially along the tool.

[0135] Furthermore, regarding the finishing insert 1 mounted on the insert mount 21, the axial rake angle of the first cutting edge 14a is a positive angle. That is, relative to a "reference plane" (not shown) that includes the tool's central axis O and passes through a portion of the first cutting edge 14a, the first rake face 11g of the first cutting edge 14a is inclined towards the positive angle side. Specifically, the first rake face 11g is a positively inclined surface located in the opposite direction of the tool's rotation direction as it moves from the first cutting edge 14a toward the rear end side of the tool's axial direction.

[0136] The second cutting edge 14b of the finishing insert 1, which is mounted on the insert holder 21, protrudes radially outward from the tool body 2. That is, the second cutting edge 14b is configured to protrude radially outward from the tool body 2 beyond the outer circumferential surface of the tool body 2. The second cutting edge 14b extends along the tool axis.

[0137] The angular cutting edge 14c of the finishing insert 1, which is mounted on the insert holder 21, protrudes from the tool body 2 toward the front end side in the tool axial direction and the outer side in the tool radial direction. The angular cutting edge 14c extends toward the rear end side in the tool axial direction as it moves toward the outer side of the tool radially.

[0138] The roughing insert 3 is disposed in a different insert mounting base 21 than the insert mounting base 21 on which the finishing insert 1 is disposed. The roughing insert 3 is disposed in at least two of the plurality of insert mounting bases 21. That is, a plurality of roughing inserts 3 are provided on the indexable insert milling cutter 10.

[0139] like Figure 9 and Figure 10 As shown, the roughing insert 3 is fixed to the insert mounting base 21 by screwing the screw component 4, which is inserted into the through hole 35 of the roughing insert 3, into the internal threaded hole 21b. That is, the roughing insert 3 can be detachably mounted on the insert mounting base 21.

[0140] One of the pair of polygonal faces 31 and 32 of the roughing insert 3 disposed in the insert mount 21 (polygonal face 31 in the example) faces the tool rotation direction T, and the other (polygonal face 32 in the example) faces the opposite direction of the tool rotation direction. The sitting surface of the polygonal face 32 facing the opposite direction of the tool rotation direction (equivalent to the sitting surface 31a of the polygonal face 31) is in contact with the bottom surface 21a.

[0141] Although not specifically illustrated, the central axis of the roughing insert 3, which is mounted on the insert holder 21, is located on the front end side of the tool axis as it faces the tool rotation direction T. That is, similar to the finishing insert 1, the central axis of the roughing insert 3 is inclined to the negative angle side relative to an imaginary plane perpendicular to the tool central axis O.

[0142] Of the six constraint surfaces 33a of the roughing insert 3 disposed in the insert mount 21, one constraint surface 33a facing the radially inward side of the tool contacts the first support surface 21c.

[0143] Of the six constraint surfaces 33a of the roughing insert 3 disposed in the insert mount 21, another constraint surface 33a facing the radially outward side of the tool contacts one of the pair of second support surfaces 21d facing the radially inward side of the tool.

[0144] Of the six constraint surfaces 33a of the roughing insert 3 disposed in the insert mount 21, another constraint surface 33a facing the radially inner side of the tool contacts another second support surface 21d of a pair of second support surfaces 21d facing the radially outer side of the tool. Alternatively, the constraint surface 33a and the other second support surface 21d can be a structure in which they do not contact each other.

[0145] The main cutting edge 34a of the roughing insert 3, which is mounted on the insert holder 21, protrudes radially outward from the tool body 2. That is, the main cutting edge 34a is configured to protrude radially outward from the tool body 2 beyond the outer circumferential surface of the tool body 2. The main cutting edge 34a extends along the tool axis.

[0146] Although not specifically illustrated, the rotation trajectory of the main cutting edge 34a around the tool's central axis O is located further outward in the tool's radial direction than the rotation trajectory of the second cutting edge 14b of the finishing insert 1 around the tool's central axis O. That is, the main cutting edge 34a is positioned further outward in the tool's radial direction than the second cutting edge 14b. In other words, the second cutting edge 14b is positioned further inward in the tool's radial direction than the main cutting edge 34a. The radial distance between the rotation trajectory of the main cutting edge 34a and the rotation trajectory of the second cutting edge 14b around the tool's central axis O, i.e., the difference in radius between the two rotation trajectories, is, for example, 0.4 mm or less.

[0147] Furthermore, the rotational trajectories of the second flank face 13b and the first constraint face 13d of the finishing insert 1 around the tool center axis O are located further radially inside the tool than the rotational trajectory of the main cutting edge 34a of the roughing insert 3 around the tool center axis O.

[0148] The secondary cutting edge 34b of the roughing insert 3, which is mounted on the insert holder 21, protrudes from the tool body 2 toward the front end of the tool in the axial direction. That is, the secondary cutting edge 34b is configured to protrude further toward the front end of the tool in the axial direction than the front end face of the tool body 2. The secondary cutting edge 34b extends radially along the tool.

[0149] Although not specifically illustrated, the rotational trajectory of the secondary cutting edge 34b around the tool's central axis O is located further along the tool axis towards the rear end than the rotational trajectory of the first cutting edge 14a of the finishing insert 1 around the tool's central axis O. That is, the secondary cutting edge 34b is positioned further along the tool axis towards the rear end than the first cutting edge 14a. In other words, the first cutting edge 14a is positioned further along the tool axis towards the front end than the secondary cutting edge 34b.

[0150] The corner cutting edge 34c of the roughing insert 3, which is mounted on the insert holder 21, protrudes from the tool body 2 toward the front end side in the tool axial direction and the outer side in the tool radial direction. The corner cutting edge 34c extends toward the rear end side in the tool axial direction as it moves toward the outer side of the tool radially.

[0151] [Chip groove]

[0152] like Figures 5 to 10 As shown, the chip groove 22 is disposed at the front end of the tool body 2 along the tool axis. The chip groove 22 is concave, recessed from the front end face and outer peripheral face of the tool body 2. Multiple chip grooves 22 are provided on the tool body 2. The multiple chip grooves 22 are arranged at intervals along the circumferential direction of the tool. In this embodiment, five chip grooves 22 are arranged at unequal intervals along the circumferential direction of the tool. Each chip groove 22 is arranged adjacent to each other in the tool rotation direction T of each blade mount 21 and is connected to each blade mount 21.

[0153] The length of the chip groove 22 recessed from the front end of the tool body 2 towards the rear end of the tool axis, i.e., its depth in the tool axis, is greater than the length of the insert mount 21 recessed from the front end of the tool body 2 towards the rear end of the tool axis. The length of the chip groove 22 recessed from the outer periphery of the tool body 2 towards the inner radial side of the tool, i.e., its depth in the tool radial side, is greater than the length of the insert mount 21 recessed from the outer periphery of the tool body 2 towards the inner radial side of the tool.

[0154] [Cooling holes]

[0155] Cooling holes 23 extend inside the tool body 2. Multiple cooling holes 23 are provided on the tool body 2. These cooling holes 23 are spaced apart from each other along the circumference of the tool. The number of cooling holes 23 is the same as or a multiple of the number of insert mounts 21. Each cooling hole 23 penetrates the tool body 2. Although not specifically shown, the cooling holes 23 are connected to a coolant supply mechanism such as a pump via internal flow paths and pipes within the machine tool spindle. Coolant such as cutting fluid or compressed air is supplied from the coolant supply mechanism to the cooling holes 23.

[0156] At least the portion of the cooling hole 23 including the spray nozzle is located in the opposite direction to the tool's rotation direction, facing radially outward. At least the portion of the cooling hole 23 including the spray nozzle is located on the front end side of the tool's axial direction, facing radially outward. The radially outward end of the cooling hole 23, i.e., the spray nozzle, opens on the chip groove 22. The cooling hole 23 sprays coolant toward the cutting edges 14, 34 of each cutting insert 1, 3 mounted on the insert mount 21, and the machining area of ​​the workpiece.

[0157] [Effects of this implementation method]

[0158] Regarding the indexable insert milling cutter 10 of this embodiment, both roughing (standard machining) inserts 3 and finishing inserts 1 can be arbitrarily mounted on a plurality of insert mounting seats 21 that are identical in shape.

[0159] According to the finishing insert 1 of this embodiment, the second cutting edge 14b is positioned further radially inward than the first constraint surface 13d, thus suppressing contact between the second cutting edge 14b and the workpiece. Specifically, in the indexable insert milling cutter 10 of this embodiment, the second cutting edge 14b of the finishing insert 1 is positioned further radially inward than the rotation trajectory of the main cutting edge 34a of the roughing insert 3 around the tool's central axis O. Therefore, the finishing insert 1 primarily cuts into the workpiece using only the first cutting edge (finishing edge) 14a, which can stably improve the accuracy of finishing.

[0160] Furthermore, when the finishing blade 1 is mounted on the blade mounting base 21 in a 180° rotational orientation around the rotation center axis B, the first constraint surface 13d contacts the first support surface 21c of the blade mounting base 21. Therefore, even when using the first cutting edge 14a of either of the pair of polygonal faces 11 and 12, the finishing blade 1 can be stably fixed to the blade mounting base 21. That is, the finishing blade 1 can be made double-sided, thereby extending tool life.

[0161] As described above, the finishing blade 1 according to this embodiment can be arbitrarily mounted on multiple blade mounting seats 21 of the same shape. It can suppress the contact between the cutting edge other than the finishing blade 14a and the workpiece while performing finishing with the finishing blade 14a. Furthermore, it has a front-back reverse symmetrical shape, which can improve machining accuracy and extend tool life.

[0162] Furthermore, the indexable insert milling cutter 10 of this embodiment has the above-mentioned finishing insert 1, so the degree of freedom of insert arrangement on the multiple insert mounting seats 21 is increased, which can improve machining accuracy and extend tool life.

[0163] Furthermore, in this embodiment, the second flank face 13b is an inclined surface that is tilted relative to the blade central axis A, and the first constraint surface 13d is connected to the second flank face 13b in the blade axial direction and is a plane parallel to the blade central axis A.

[0164] At this point, as described above, the second cutting edge 14b can be retracted, and the structure of the second flank face 13b and the first constraint surface 13d can be simplified. The simplified first constraint surface 13d improves the stability of the finishing insert 1 on the insert mount 21, and also makes insert manufacturing easier.

[0165] Furthermore, in this embodiment, the first rake face 11g is an inclined surface that moves from the first cutting edge 14a toward the radially inner side of the blade toward the axially back side of the blade, and the seat surface 11j is configured to protrude further toward the axially front side of the blade than the first cutting edge 14a and the first rake face 11g.

[0166] At this time, the first rake face 11g is tilted towards the positive angle, thus stably improving the sharpness of the first cutting edge 14a. Furthermore, the chips generated by the first cutting edge 14a collide with the step (stepped portion 11k) between the first rake face 11g and the seat surface 11j and are easily separated, thus improving chip handling. Moreover, the first cutting edge 14a and the first rake face 11g do not protrude more than the seat surface 11j in the insert axial direction; therefore, when the finishing insert 1 is mounted on the insert mounting base 21 in a reverse orientation, interference between the first cutting edge 14a and the first rake face 11g and the insert mounting base 21 can be suppressed.

[0167] Furthermore, in this embodiment, the seating surface 11j is configured to protrude further toward the front side of the insert axial direction than the second cutting edge 14b and the second rake face 11h.

[0168] At this time, the second cutting edge 14b and the second rake face 11h will not protrude more than the seat surface 11j in the insert axial direction. Therefore, when the finishing insert 1 is installed on the insert mounting base 21 in a forward and backward manner, the interference of the second cutting edge 14b and the second rake face 11h with the insert mounting base 21 can be suppressed.

[0169] Furthermore, in this embodiment, the seating surface 11j is configured to protrude further toward the front side of the insert axial direction than the angular cutting edge 14c and the angular rake face 11i.

[0170] At this time, the angular cutting edge 14c and the angular rake face 11i will not protrude more than the seat surface 11j in the insert axial direction. Therefore, when the finishing insert 1 is installed on the insert mounting base 21 in a forward and backward manner, the interference of the angular cutting edge 14c and the angular rake face 11i with the insert mounting base 21 can be suppressed.

[0171] Furthermore, in this embodiment, the cutting edge 14 has an angular cutting edge 14c, which connects the first cutting edge 14a and the second cutting edge 14b, such as... Figure 2 As shown, when viewed from the axial direction of the blade, the included angle between the first cutting edge 14a and the corner cutting edge 14c, and the included angle between the second cutting edge 14b and the corner cutting edge 14c are both obtuse angles.

[0172] Unlike this embodiment, for example, compared to a structure in which the first cutting edge 14a and the second cutting edge 14b are directly connected, the structure described above according to this embodiment can improve the strength of the cutting edge 14 and suppress edge defects.

[0173] Furthermore, in this embodiment, as Figure 2 As described above, when viewed from the axial direction of the blade, the first cutting edge 14a has a convex curve that bulges outward radially from the blade.

[0174] At this time, for example, even if the tool center axis O of the tool body 2 with the finishing insert 1 is slightly tilted relative to the workpiece due to cutting resistance during cutting, the machining surface accuracy of the first cutting edge 14a can be stably ensured.

[0175] Furthermore, in this embodiment, as Figure 1 As shown, the outer peripheral surface 13 of the finishing blade 1 has a first constraint surface 13d and a second constraint surface 13e. Furthermore, as... Figures 5 to 8 As shown, the blade mounting base 21 has: a bottom surface 21a that contacts the seating surface 11j of the polygonal surfaces 11 and 12; a first support surface 21c that contacts the first constraint surface 13d; and a second support surface 21d that contacts the second constraint surface 13e.

[0176] At this time, the finishing blade 1 is constrained to the blade mounting base 21 by the first constraint surface 13d and the second constraint surface 13e in both the radial and circumferential directions. The stability of the finishing blade 1 on the blade mounting base 21 is further improved.

[0177] [Other structures included in this invention]

[0178] Furthermore, the present invention is not limited to the above-described embodiments. For example, as described below, structural modifications can be made without departing from the spirit of the present invention.

[0179] The foregoing embodiments provide the following examples: Figure 2As shown, when viewing a polygonal surface 11 from the front of the insert axial direction, the clockwise direction centered on the insert's central axis A corresponds to one side C1 of the insert's circumferential direction, and the counterclockwise direction corresponds to the other side C2 of the insert's circumferential direction. However, this is not a limitation. That is, it can be as follows: when viewing a polygonal surface 11 from the front of the insert axial direction, the counterclockwise direction centered on the insert's central axis A corresponds to one side C1 of the insert's circumferential direction, and the clockwise direction corresponds to the other side C2 of the insert's circumferential direction. In other words, the present invention can also be applied to finishing inserts and indexable insert milling cutters that differ from the aforementioned embodiments.

[0180] In the foregoing embodiments, an example is given where a pair of polygonal faces 11, 12 of the polishing blade 1 have multiple connecting edges 11m, 11n, 11p, 11q at the outer periphery of each polygonal face 11, 12, but this is not a limitation. At least one or more of the multiple connecting edges 11m, 11n, 11p, 11q may not be provided.

[0181] Without departing from the spirit of the invention, the various structures described in the foregoing embodiments and variations can be combined, and structural additions, omissions, substitutions, or other modifications can be made. Furthermore, the invention is not limited to the foregoing embodiments, but only to the claims.

[0182] Industrial availability

[0183] The finishing insert of the present invention can be arbitrarily mounted on multiple insert holders of the same shape, suppressing contact between the cutting edge (other than the finishing edge) and the workpiece while performing finishing with the finishing edge. Furthermore, its symmetrical shape improves machining accuracy and extends tool life. Since the indexable insert milling cutter of the present invention includes the aforementioned finishing insert, the degree of freedom in insert arrangement on multiple insert holders increases, further improving machining accuracy and extending tool life. Therefore, it has industrial applicability.

[0184] Symbol Explanation

[0185] 1… Polishing blade

[0186] 2…Tool Body

[0187] 3…Roughing (Standard Machining) Inserts

[0188] 10…Indexable insert milling cutter

[0189] 11, 12... polygonal faces

[0190] 11a, 11b, 11c, 11d, 11e, 11f… edge

[0191] 11g…First rake face

[0192] 11h…Second rake face

[0193] 11j…sitting surface

[0194] 13… outer perimeter

[0195] 13a…First back face

[0196] 13b…Second back face

[0197] 13d…First Constraint Surface

[0198] 13e…Second Constraint Surface

[0199] 14 (14A, 14B)...cutting edge

[0200] 14a…First cutting edge

[0201] 14b…Second cutting edge

[0202] 14c… Angle cutting edge

[0203] 16 (16A, 16B, 16C)... First corner

[0204] The first corner specified in 16A…

[0205] 17(17A)...Second corner

[0206] 21…blade mount

[0207] 21a…bottom surface

[0208] 21c…First support surface

[0209] 21d…Second support surface

[0210] 34a…Main cutting edge

[0211] 34b…Secondary cutting edge

[0212] A…blade center axis

[0213] B… Rotation center axis

[0214] C1…One side of the blade circumference

[0215] C2…The other side of the blade circumference

[0216] O…Tool Center Axis

[0217] θ1…First included angle

[0218] θ2…Second included angle

Claims

1. A finishing blade, comprising: a pair of polygonal surfaces facing opposite each other in a blade axial direction along which a blade center axis extends; an outer peripheral surface connected to the pair of polygonal surfaces and facing a blade radial direction outside; and a cutting edge provided at a ridge line portion connecting the polygonal surfaces and the outer peripheral surface, the polygonal surfaces each having: a plurality of edge portions arranged along an outer periphery of the polygonal surface; a first corner portion between a pair of the edge portions arranged in a blade circumferential direction; and a second corner portion arranged at a position different from the first corner portion in the blade circumferential direction and between a pair of the edge portions arranged in the blade circumferential direction, three of the first corner portions and the second corner portions being alternately arranged along the blade circumferential direction, a first included angle between the pair of the edge portions on both sides of the first corner portion in the blade circumferential direction being smaller than a second included angle between the pair of the edge portions on both sides of the second corner portion in the blade circumferential direction, the cutting edge having: a first cutting edge provided at the edge portion on one side of the blade circumferential direction of a prescribed first corner portion among the three first corner portions to finish a workpiece; and a second cutting edge provided at the edge portion on the other side of the blade circumferential direction of the prescribed first corner portion, the first cutting edge being in a convex curved line shape bulging toward the blade radial direction outside when viewed in the blade axial direction, the second cutting edge extending in a straight line shape, the outer peripheral surface having: a first relief surface connected to the first cutting edge; a second relief surface connected to the second cutting edge; and a first constraint surface located on a side opposite to the second cutting edge of the second relief surface in the blade axial direction and provided at a position further toward the blade radial direction outside than the second cutting edge, a blade shape being 180° rotationally symmetrical about a center axis of rotation of the second corner portion adjacent to the one side of the blade circumferential direction of the prescribed first corner portion and the blade center axis when viewed in the blade axial direction, the second relief surface being in an inclined surface shape inclined with respect to the blade center axis and located further toward the blade radial direction outside as it is away from the second cutting edge in the blade axial direction, the first constraint surface being connected to the second relief surface in the blade axial direction and being in a plane shape parallel to the blade center axis.

2. The finishing blade according to claim 1, wherein the polygonal surface has: a first rake surface connected to the first cutting edge; and a seating surface provided at a position further toward a blade radial direction inside than the first rake surface, the first rake surface being in an inclined surface shape inclined toward a side of another polygonal surface from the polygonal surface as it is toward a blade radial direction inside from the first cutting edge in the blade axial direction, the seating surface being more protruded toward the blade axial direction than the first cutting edge and the first rake surface.

3. The finishing blade according to claim 2, wherein the polygonal surface has a second rake surface connected to the second cutting edge, the seating surface being provided at a position further toward a blade radial direction inside than the second rake surface and being more protruded toward the blade axial direction than the second cutting edge and the second rake surface. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 4. The finishing blade according to claim 1, wherein the cutting edge has a corner cutting edge connected to an end portion on the other side in the blade circumferential direction of the first cutting edge and an end portion on the one side in the blade circumferential direction of the second cutting edge, the included angle between the first cutting edge and the corner cutting edge and the included angle between the second cutting edge and the corner cutting edge are obtuse angles, respectively, when viewed in the blade axial direction.

5. The finishing blade according to claim 1, wherein the outer peripheral surface has a second restraining surface adjacent to the other side in the blade circumferential direction of the first restraining surface.

6. An indexable blade milling cutter, comprising: a tool body having, at a front end portion in a tool axial direction in which a tool center axis extends, a plurality of blade mounting seats arranged at intervals from each other in a tool circumferential direction; The finishing blade according to any one of claims 1 to 5, configured in at least one blade mounting seat among a plurality of the blade mounting seats; and a roughing blade arranged at a blade mounting seat different from the blade mounting seat in which the finishing blade is arranged, the roughing blade having: a main cutting edge protruding from the tool body to a tool radial direction outer side; and a sub cutting edge protruding from the tool body to a front end side in the tool axial direction, the plurality of blade mounting seats are in the same shape as each other, the first cutting edge is arranged at a position further toward the front end side in the tool axial direction than the sub cutting edge, the second cutting edge is arranged at a position further toward a tool radial direction inner side than the main cutting edge.

7. The indexable blade milling cutter according to claim 6, wherein the outer peripheral surface of the finishing blade has a second restraining surface arranged at a position different from the first restraining surface in the blade circumferential direction, the blade mounting seat has: a bottom surface in contact with a seating surface of the polygonal surface; a first supporting surface in contact with the first restraining surface; and a second supporting surface in contact with the second restraining surface. ​ ​

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