Cutting tools, cutting inserts

Abstract

To provide a cutting tool in which a cutting insert can be stably attached to a tool body and positional deviation of the cutting insert during cutting can be prevented, and also provide the cutting insert and the tool body.SOLUTION: A cutting tool in the present invention is a tool in which a cutting insert is attached to a tool body. The cutting insert has a rake face and a seating face, and the rake face and the seating face are connected by a side face including a flank. The tool body has one or more pockets at one end thereof, and includes a fitting seat and one or more fitting side faces angled with respect to the fitting seat in the pocket. The seating face, the side face, the fitting seat, and the fitting side face respectively have a restraining part. Processing streaks at a constant cycle are formed with 0.05 μm≤Ra≤6.30 μm on all restraining parts. In the state where the cutting insert is attached to the tool body, an angle θ between a processing streak of the cutting insert in each restraining part and a processing streak of the tool body is 0°≤θ≤5°.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cutting tool, a cutting insert and a tool body. [Background technology]

[0002] In a cutting insert in which an interchangeable cutting insert is attached to a tool body, the cutting insert is attached to the tool body by bringing the seating surface (restraining portion) of the cutting insert into contact with the mounting surface (restraining portion) of the tool body and screwing a clamp screw inserted into the mounting hole of the cutting insert into a screw hole formed in the tool body.

[0003] In this case, if the seating surface of the cutting insert and the mounting surface of the tool body are flat surfaces, the cutting insert is likely to slip relative to the tool body due to the cutting load during cutting. Therefore, a configuration is known in which multiple convex ridge portions each measuring several millimeters are provided on one side of either the seating surface of the cutting insert or the mounting surface of the tool body, and multiple concave ridge portions each measuring several millimeters are provided on the other side, and these are meshed with each other to suppress the slippage of the cutting insert. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Fumihiko Inagaki, Noboru Morita, Hirofumi Hidai, Sota Matsuzaka, Shinji Shimizu, Akira Chiba, Yuichiro Matsumoto, “Effect of Bonding Surface Properties on the Insert Grip Characteristics of Indexable Cutting Tools”, Journal of the Japan Society for Abrasive Machining, 2020, pp.380-387 Summary of the Invention [Problem to be solved by the invention]

[0005] When the cutting insert is attached to the tool body, not only the seating surface but also a part of the side surface is restrained by the tool body. Therefore, if an uneven shape is provided on the side surface of the cutting insert to suppress slippage, the uneven shape may affect the shape of the cutting edge because the unevenness dimension is in the order of several millimeters. In other words, it is difficult to provide an uneven shape on the side surface other than the seating surface because there is a risk that the uneven shape of the side surface will be reflected in the cutting edge shape.

[0006] In addition, when the seating surface and side surface of the cutting insert are formed with uneven shapes, it is difficult to fit each unevenness into the unevenness on the tool body when attaching the cutting insert to the tool body. Therefore, the uneven shape can only be applied to the seating surface, which has the largest contact area with the tool body and does not affect the cutting edge.

[0007] The present invention has been made against this background, and aims to provide a cutting tool, a cutting insert, and a tool body that can stably attach a cutting insert to the tool body and prevent the cutting insert from shifting from its position during cutting. [Means for solving the problem]

[0008] A cutting tool according to one embodiment of the present invention is a cutting tool in which a cutting insert is attached to a tool body that rotates around a rotation axis, the cutting insert having a cutting face and a seating surface, the cutting face and the seating surface being connected by a side including a clearance surface, the tool body having one or more pockets at one end, the pocket having a mounting seat and one or more mounting side surfaces angled relative to the mounting seat, the seating surface, the side surfaces, the mounting seat and the mounting side surfaces each having a constraint portion, all of the constraint portions having constant periodic machining marks formed at 0.05 μm≦Ra≦6.30 μm, and when the cutting insert is attached to the tool body, an angle θ between the machining marks of the insert at each constraint portion and the machining marks of the tool body is 0°≦θ≦5°.

[0009] A cutting insert according to one embodiment of the present invention has a pair of cutting faces and a seating surface, the cutting faces and the seating surfaces are connected by a side surface including a clearance surface, the seating surface and the side surface each have a restraining portion, and the restraining portion is formed with a constant periodic machining marking of 0.05 μm≦Ra≦6.30 μm.

[0010] A tool body according to one embodiment of the present invention is a tool body that rotates around a rotation axis, the tool body having one or more pockets at one end, the pocket having a mounting seat and one or more mounting side surfaces angled relative to the mounting seat, the mounting seat and the mounting side surfaces each having a restraining portion, and the restraining portions are formed with machining marks at a constant period within the range of 0.05 μm≦Ra≦6.30 μm.

[0011] According to this configuration, the present invention has two or more constraining portions on each of the cutting insert and the tool body, and the machining streaks are intentionally formed on each of the constraining portions. Furthermore, the machining streaks are formed at a constant period and the arithmetic mean height Ra is also formed within a certain range, so that the width and height difference of the machining streaks formed on the constraining portion of the cutting insert and the machining streaks provided on the constraining portion of the tool body can be made close to each other. In addition, when the cutting insert is attached to the tool body, the angle between the machining streaks in the constraining portion between the cutting insert and the tool body is 0°≦θ≦5°, so that the directions of the machining streaks are approximately the same. Therefore, the machining streaks mesh well with each other and the contact area between them is large. This increases the constraining force in each of the constraining portions, making it possible to suppress the slippage of the cutting insert relative to the tool body. In addition, by forming machining streaks with a microscopic orientation on each of the constraining portions, the cutting insert can be easily positioned relative to the tool body, and macroscopic attachment is possible.

[0012] In this case, the arithmetic mean height Ra was set to 0.05 μm≦Ra≦6.30 μm, but it is preferable to set it to 0.10 μm≦Ra≦2.00 μm. Also, the angle between the processed streaks in the restraint portion was set to 0°≦θ≦5°, but it is preferable to set it to 0°≦θ≦2°.

[0013] The period of the processed streaks may be 0.05 mm to 0.50 mm, and preferably 0.05 mm to 0.20 mm.

[0014] In addition, the present invention makes it possible to form machining streaks in a plurality of constraint parts facing different directions on the cutting insert and the tool body, and to make it possible for the machining streaks to mesh with each other at all of the constraint parts. In the above configuration, the range of the arithmetic mean height Ra is specified as a parameter of the surface roughness, but it is not desirable from the viewpoint of meshing if there are places where the height of the machining streaks is extremely high or extremely low. Therefore, in the present invention, the maximum height Rz of the machining streaks formed on the cutting insert and the tool body may be 0.10 μm≦Rz≦25.00 μm, and preferably 0.50 μm≦Rz≦12.00 μm.

[0015] The machining streaks in the cutting tool, cutting insert, and tool body according to one embodiment of the present invention may be formed by grinding.

[0016] In the present invention, the processing streaks are formed by grinding. It is possible to form the processing streaks when manufacturing the cutting insert and the tool body, but it is difficult to obtain processing streaks with a constant period due to waviness caused by sintering. In contrast, by forming the processing streaks by grinding, it is possible to obtain a minute uneven shape with a constant period. Effect of the Invention

[0017] According to the present invention, it is possible to provide a cutting tool, a cutting insert, and a tool body that enable the cutting insert to be stably attached to the tool body and prevent the cutting insert from shifting from its original position during cutting. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing one embodiment of a cutting tool. [Diagram 2] FIG. 2 is a diagram showing one embodiment of a tool body, and is a partially enlarged perspective view of an insert pocket. [Diagram 3] FIG. 3 is a perspective view showing one embodiment of a cutting insert. [Figure 4] FIG. 4 is a diagram illustrating each restraining portion of the cutting insert in one embodiment. [Diagram 5] FIG. 5 is a diagram illustrating each restraining portion of a tool body in one embodiment. [Figure 6] FIG. 6(a) is an enlarged view showing the processing streaks of each restraining portion of the cutting insert, and (b) is an enlarged view showing the processing streaks of each restraining portion of the cutting insert. [Figure 7] FIG. 7 is a schematic diagram of a part of the verification machine, where FIG. 7(a) shows the measurement when a radial component force is applied to the cutting insert, and FIG. 7(b) shows the measurement when an axial load is applied to the cutting insert. [Figure 8] 8(a) to (d) are schematic diagrams showing the tool body used in the evaluation and the direction of the processed lines (line angles θ4 to θ6: 90°) at each restraint portion. [Figure 9] 9(a) to (d) are diagrams showing the cutting insert 10A used in the evaluation and the streak directions (streak angles θ1 to θ3: 90°) of the processed streak at each restraint portion. [Figure 10] FIG. 10(a) is a partial diagram of a cutting tool in which a cutting insert is attached to a tool body, and is a diagram for explaining the verification results; (b) is a cross-sectional view along line A-A' in FIG. 11; (a) to (c) are diagrams showing schematic views of the engagement state between each constraint portion of the cutting insert and each constraint portion of the tool body for each surface roughness. [Figure 11] FIG. 11 is a diagram showing the direction in which a load is applied. [Figure 12]Figures 12(a) to (c) are graphs showing the relationship between the rotational displacement amount of the cutting insert (displacement amount, vertical axis of the graph, unit of μm) and the load (horizontal axis of the graph, unit of N) for (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. [Figure 13] Figures 13(a) to (c) are graphs showing the relationship between the axial load (horizontal axis of the graph, unit of N) and the rotational displacement of the cutting insert (vertical axis of the graph, unit of μm) for (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. [Figure 14] Figures 14(a) to (c) are graphs showing the relationship between the radial component force (horizontal axis of the graph, unit of N) and the rotational displacement amount of the cutting insert (vertical axis of the graph, unit of μm) at (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. [Figure 15] Figures 15(a) to (c) are graphs showing the relationship between the axial load (horizontal axis of the graph, unit of N) and the rotational displacement of the cutting insert (vertical axis of the graph, unit of μm) for (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. [Figure 16] Figure 16 is a diagram showing the relationship between the shear direction acting on the short side restraint portion and the processed lines, where (a) shows the line angle θ3 on the cutting insert side being 45°, and (b) shows the line angle θ3 on the cutting insert side being 135°. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may omit non-characteristic parts for convenience in order to make the characteristic parts easier to understand.

[0020] <Cutting tools> FIG. 1 is a perspective view of one embodiment of a cutting tool 100. 1, the cutting tool 100 of the present embodiment has a plurality of cutting inserts 10 and a tool body 30. The cutting tool 100 performs milling by rotating the tool body 30 about a rotation axis JO in a rotation direction TD.

[0021] (tool body) FIG. 2 is a diagram showing one embodiment of the tool body 30, and is a partially enlarged perspective view of the insert pocket 31. As shown in FIG. As shown in Fig. 2, the tool body 30 is formed into a cylindrical shape from a metal material such as steel. The tool body 30 has a plurality of (e.g., three) insert pockets (pockets) 31 at a tip portion. An insert mounting seat 33 is formed in the insert pocket 31. The insert mounting seat 33 is a base on which the cutting insert 10 is attached. The insert mounting seat 33 has a mounting seat 33a, a long side mounting side surface (mounting side surface) 33b, and a short side mounting side surface (mounting side surface) 33c.

[0022] The mounting seat 33a is a surface facing the rotation direction TD. The mounting seat 33a is a surface facing a seating surface 13 of the cutting insert 10 described later, and has an area substantially equal to that of the seating surface 13. A screw hole 32 is formed in substantially the center of the mounting seat 33a. The mounting seat 33a comes into contact with the seating surface 13 of the attached cutting insert 10.

[0023] The long-side mounting side surface (mounting side surface) 33b extends from the long side of the mounting seat 33a along the rotation axis JO toward the rotation direction TD. The long-side mounting side surface 33b faces the long-side side surface of the cutting insert 10 described later and has an area substantially equal to that of the long-side side surface. The long-side mounting side surface 33b contacts the flank surface of the long-side side surface of the mounted cutting insert 10.

[0024] The short-side mounting side surface (mounting side surface) 33c extends from a short side of the mounting seat 33a perpendicular to the rotation axis JO toward the rotation direction TD. The short-side mounting side surface 33c faces a short-side side surface of the cutting insert 10 described later and has an area substantially equal to that of the short-side side surface. The short-side mounting side surface 33c contacts a relief surface of the short-side side surface of the mounted cutting insert 10.

[0025] As shown in Fig. 1, the cutting insert 10 is attached to each insert mounting seat 33 of the tool body 30 shown in Fig. 2 by using a clamp screw 38. As shown in Fig. 1, the cutting insert 10 is attached to the insert mounting seat 33 by tightening the clamp screw 38 inserted into the mounting hole 7 of the cutting insert 10 into the screw hole 32 formed in the center of the mounting seat 33a of the tool body 30 shown in Fig. 2.

[0026] (Cutting insert) FIG. 3 is a perspective view illustrating one embodiment of the cutting insert 10. As shown in FIG. As shown in FIG. 3, the cutting insert 10 is made of a hard material such as cemented carbide. The cutting insert 10 has a polygonal plate shape (rectangular plate shape in this embodiment) that is rotationally symmetric by 180° with respect to a center line CO extending in the thickness direction. In the following description, the direction along the center line CO may be simply referred to as the thickness direction. Also, the direction perpendicular to the center line CO may be simply referred to as the width direction. Similarly, the circumferential direction around an axis centered on the center line CO may be simply referred to as the circumferential direction.

[0027] The cutting insert 10 includes a rake face 12 forming one of a pair of polygonal faces, a seating face 13 forming the other of the pair of polygonal faces, and a side face 14 connecting the rake face 12 and the seating face 13. The cutting insert 10 of this embodiment has a rectangular or parallelogram shape in a plan view when viewed from a direction along the center line CO. The seating face 13 is smaller in size than the rake face 12 in a plan view, and is included inside the projection area of ​​the rake face 12 in the center line direction.

[0028] A cutting edge 20 is provided at the intersection ridge between the rake face 12 and the side surface 14 . Since the cutting insert 10 of this embodiment is a positive-type cutting insert, the relief surface constituting the side surface 14 is an inclined surface substantially following the relief angle.

[0029] The cutting insert 10 shown in Fig. 3 is detachably attached to the tool body 30 which rotates around the rotation axis JO shown in Fig. 2 by the clamp screw 38 shown in Fig. 1. The cutting insert 10 is seated with its seating surface 13 in close contact (abutment) with the mounting seat 33a of the tool body 30 and with two circumferentially adjacent long side side surfaces 14b and short side side surfaces 14c in close contact (abutment) with the long side mounting side surfaces 33b and short side mounting side surfaces 33c, respectively. That is, the seating surface 13 of the cutting insert 10 is restrained by the mounting seat 33a of the insert mounting seat 33 on the tool body 30, and the long side side surface 14b and short side side surface 14c of the cutting insert 10 are restrained by the long side mounting side surface 33b and short side mounting side surface 33c on the tool body 30.

[0030] Next, the detailed configurations of the cutting insert 10 and the tool body 30 will be described.

[0031] As shown in FIGS. 4(a) to (c) and 5(a) to (c), the cutting insert 10 and the tool body 30 of this embodiment have restraining portions 15a to 15c and 35a to 35c, respectively, which are restrained relative to each other. 4(a)-(c) are diagrams showing schematic diagrams of the restraining portions 15a-15c of the cutting insert 10 in one embodiment. FIG. 4(a) shows the restraining portion 15a formed on the seating surface 13 of the cutting insert 10. FIG. 4(b) is a diagram seen from the -X direction of FIG. 3, showing the long side restraining portion 15b formed on the long side surface 14b. FIG. 4(c) is a diagram seen from the -Z direction of FIG. 3, showing the short side restraining portion 15c formed on the short side surface 14c.

[0032] 5(a)-(c) are diagrams showing schematic diagrams of the respective restraining portions 35a-35c of the tool body 30 in one embodiment. Fig. 5(a) shows the restraining portion 35a formed on the mounting seat 33a of the tool body 30. Fig. 5(b) is a diagram seen from the radially outer side (X direction) of Fig. 2, showing the long side restraining portion 35b formed on the long side mounting side surface 33b. Fig. 5(c) is a diagram seen from the tip side (Z direction) of Fig. 2, showing the short side restraining portion 35c formed on the short side mounting side surface 33c.

[0033] FIG. 6(a) is an enlarged view of a portion of the restraining portions 15a-15c (machining marks 16a-16c) of the cutting insert 10, and FIG. 6(b) is an enlarged view of a portion of the restraining portions 35a-35c (machining marks 36a-36c) of the tool body 30.

[0034] (Restraint part of cutting insert) As shown in Fig. 4(a), the cutting insert 10 of this embodiment has a bottom restraint portion 15a on the seating surface 13. In this embodiment, the bottom restraint portion 15a is formed on the entire seating surface 13. The bottom restraint portion 15a is a portion that is restrained by a bottom restraint portion 35a (Fig. 5(a)) described below that is formed on the mounting seat 33a of the insert mounting seat 33 of the tool body 30 shown in Fig. 2.

[0035] As shown in Fig. 4(b), the cutting insert 10 has a long side restraint portion 15b on the long side surface 14b. In this embodiment, the long side restraint portion 15b is formed on the entire long side surface 14b. The long side restraint portion 15b of the cutting insert 10 is a portion that is restrained by a later-described long side restraint portion 35b (Fig. 5(b)) formed on the long side mounting side surface 33b of the insert mounting seat 33 of the tool body 30 shown in Fig. 2.

[0036] Furthermore, as shown in Fig. 4(c), the cutting insert 10 has a short side restraint portion 15c on the short side surface 14c. In this embodiment, the short side restraint portion 15c is formed on the entire short side surface 14c. The short side restraint portion 15c of the cutting insert 10 is a portion that is restrained by a short side restraint portion 35c (Fig. 5(c)) described later, which is formed on the short side mounting side surface 33c of the insert mounting seat 33 of the tool body 30 shown in Fig. 2.

[0037] The restraining portions 15a to 15c of the cutting insert 10 are respectively formed with processed streaks 16a to 16c having a fine (several μm) uneven shape at a constant period (see FIG. 6(a)). In this embodiment, the processed streaks 16a to 16c extending in one direction are respectively formed over the entire area of ​​each of the restraining portions 15a to 15c. Each of the processed streaks 16a to 16c is formed, for example, by grinding using a grindstone.

[0038] As shown in Fig. 4(a), in a plan view seen from the axial direction of the cutting insert 10, the processed streaks 16a formed on the seating surface 13 of the cutting insert 10 extend in a direction along the longitudinal direction or in a direction forming a predetermined angle (streak angle θ1) with respect to the longitudinal direction. In this embodiment, for example, the streaks angle θ1 when the processed streaks 16a extend along the longitudinal direction of the cutting insert 10 is set to 0°. In addition, the streaks angles θ1 of the processed streaks 16a with respect to the longitudinal direction of the cutting insert 10 are illustrated as 45°, 90°, and 135°. The streak angle θ1 of the processed streak 16a relative to the longitudinal direction of the cutting insert 10 is not limited to the above-mentioned value.

[0039] As shown in Fig. 4(b), in a side view seen from the -X direction in Fig. 3, the processed streaks 16b formed in the long side restraint portion 15b of the cutting insert 10 extend in a direction along the center line CO or in a direction forming a predetermined angle (streak angle θ2) with respect to the center line CO. In this embodiment, for example, the streak angle θ2 when the processed streaks 16b extend along the center line CO of the cutting insert 10 is set to 0°. In addition, examples are shown in which the streak angle θ2 of the processed streaks 16b with respect to the center line CO of the cutting insert 10 is 45°, 90°, and 135°. In addition, the streak angle θ2 of the processed streak 16b with respect to the center line CO of the cutting insert 10 is not limited to the above-mentioned numerical value.

[0040] As shown in Fig. 4(c), in a side view seen from the -Z direction in Fig. 3, the processed streaks 16c formed in the short side restraint portion 15c of the cutting insert 10 extend in a direction along the center line CO (thickness direction) or in a direction forming a predetermined angle (streak angle θ3) with respect to the center line CO. In this embodiment, for example, the streaks angle θ3 when the processed streaks 16c extend along the center line CO of the cutting insert 10 is set to 0°. In addition, examples are shown in which the streaks angles θ3 of the processed streaks 16c with respect to the center line CO of the cutting insert 10 are 45°, 90°, and 135°.

[0041] Here, it is preferable that the streak angles θ1 to θ3 of the processed streak 16a to 16c formed in each of the restraining portions 15a to 15c of the cutting insert 10 are equal to each other. For example, when the streak angle θ1 of the processed streak 16a on the seating surface 13 side is 0°, the streak angle θ2 of the processed streak 16b on the long side and the streak angle θ3 of the processed streak 16c on the short side are also 0°.

[0042] (Restraint part of tool body) As shown in Figures 5(a) to 5(B), the restraining portions 35a to 35c of the tool body 30 are also formed with machining streaks 36a to 36c each having a fine (several μm) uneven shape at a constant period (see Figure 6(b)). In this embodiment, the machining streaks 36a to 36c are formed in one direction over the entire area of ​​the restraining portions 35a to 35c. The machining streaks 36a to 36c are formed, for example, by grinding using an end mill.

[0043] 5(a), the processed streaks 36a formed on the mounting seat 33a of the tool body 30 extend in a direction along the rotation axis JO of the tool body 30 (Z direction) or in a direction forming a predetermined streak angle θ4 with respect to the rotation axis JO (Z direction) when viewed from the circumferential direction. In this embodiment, for example, the streak angle θ4 is set to 0° when the processed streaks 36a extend along the rotation axis JO (Z direction) of the tool body 30. Alternatively, the streak angle θ4 of the processed streaks 36a with respect to the rotation axis JO (Z direction) of the tool body 30 may be 45°, 90°, or 135°.

[0044] 5(b), in a side view seen from the radial outside (X direction) in FIG. 2, the processed streaks 36b formed in the long side restraint portion 35b of the cutting insert 10 extend in a direction along the rotation axis JO (Z direction) or in a direction forming a predetermined angle (streak angle θ5) with respect to a direction perpendicular to the rotation axis JO (Z direction). In this embodiment, for example, the streaks angle θ5 is set to 0° when the processed streaks 16b extend in a direction perpendicular to the rotation axis JO (Z direction) of the tool body 30. In addition, the streaks angle θ5 of the processed streaks 16b with respect to the center line CO (Y direction) of the cutting insert 10 may be 45°, 90°, or 135°.

[0045] As shown in Fig. 5(c), in a side view seen from the tip side (Z direction) in Fig. 5(a), the processed streaks 16c formed in the short side restraint portion 15c of the cutting insert 10 extend in a direction along the rotation axis JO (Z direction) or in a direction forming a predetermined angle (streak angle θ6) with respect to the center line CO (Y direction). In this embodiment, for example, the streaks angle θ6 when the processed streaks 16c extend along the center line CO (Y direction) of the cutting insert 10 is set to 0°. In addition, the streaks angle θ6 of the processed streaks 16c with respect to the center line CO (Y direction) of the cutting insert 10 may be 45°, 90°, or 135°.

[0046] Here, the score angles θ4 to θ6 of the processed scores 36a to 36c formed in the restraining portions 35a to 35c of the tool body 30 are equal to each other. For example, when the score angle θ4 of the processed score 36a on the mounting seat 33a side is 0°, the score angle θ5 of the processed score 36b on the long side and the score angle θ6 of the processed score 36c on the short side are also 0°.

[0047] In a state where the cutting insert 10 is attached to the tool body 30, the extending directions of the processing streaks 16a-16c, 36a-36c formed in the constraint parts 15a-15c on the cutting insert 10 side and the corresponding constraint parts 35a-35c on the tool body 30 side are the same. Specifically, between the constraint parts 15a-15c, 35a-35c facing each other on the cutting insert 10 and the tool body 30, the angle θ formed between the processing streaks 16a-16c of the cutting insert 10 and the processing streaks 36a-36c of the tool body 30 is within the range of 0°≦θ≦5°.

[0048] Figure 6(a) is an enlarged view of the machining lines 16a-16c of each restraining portion 15a-15c in the cutting insert 10, and Figure 6(b) is an enlarged view of the machining lines 36a-36c of each restraining portion 35a-35c in the tool body 30. In this embodiment, the processed streaks 16a-16c and the processed streaks 36a-36b are formed so that the maximum height Rz is 6.30 μm or less. Specifically, it is preferable that the maximum height Rz is within the range of 0.10 μm≦Rz≦6.30 μm. Due to such processed streaks 16a-16c and the processed streaks 36a-36b, the restraining portions 15a-15c of the cutting insert 10 and the restraining portions 35a-35c of the tool body 30 have minute irregularities microscopically as shown in, for example, Figures 6(a) and (b), but form a flat surface macroscopically.

[0049] As described above, the restraining portions 15a to 15c of the cutting insert 10 and the restraining portions 35a to 35c of the tool body 30 are all formed by grinding. When using a grindstone to form the processed streaks 16a-16c on each of the restraining portions 15a-15c of the cutting insert 10, it is possible to form the processed streaks 16a-16c in a predetermined size and uneven shape by changing the grain size of the grindstone. It is possible to form the processed streaks 16a-16c at a constant period by grinding while moving the grindstone in one direction.

[0050] An end mill can be used to form the processed streaks 36a-36c on each of the restraining portions 35a-35c of the tool body 30, and a ball end mill with the largest cusp height (theoretical surface roughness) for forming the streaks during processing can be used for such grinding. For example, a ball end mill with a tool blade diameter of 1.5 mm can be used to perform finish processing on each of the restraining portions 35a-35c, thereby forming the processed streaks 36a-36c with minute irregularities. By grinding while moving the end mill in one direction, it is possible to form the processed streaks 36a-36b at a constant period.

[0051] As a method for forming the processing streaks 36a-36c on the respective restraining portions 35a-35c of the tool body 30, it is possible to use a grindstone as in the case of the cutting insert 10, but depending on the size of the grindstone, it may be difficult to process each of the restraining portions 35a-35c of the insert mounting seat 33 in the tool body 30. For this reason, it is preferable to use an end mill capable of processing a minute area.

[0052] As another method, forming the processing streaks 16a-16c, 36a-36c when sintering the cutting insert 10 or the tool body 30 is considered, but the sintered surface is prone to waviness. Therefore, if the processing streaks 16a-16c, 36a-36c with fine irregularities are formed in the restraint portion made of such a sintered surface, it is considered that the unevenness will become large due to the waviness of the sintered surface. Therefore, it is preferable to use an end mill that can grind the sintered surface to flatten it while forming the fine processing streaks 16a-16c, 36a-36c. By using an end mill, it is possible to uniformly finish each of the processing streaks 36a-36c with a constant period.

[0053] During grinding with an end mill, cutter marks may be formed on the machined surface. However, by processing the cutter marks so that they have periodicity, it is also possible to form machining streaks 16a-16c, 36a-36c with a constant period.

[0054] In this embodiment, the machining streaks 16a-16c of the cutting insert 10 are finished by a grindstone, and the machining streaks 36a-36c of the tool body 30 are finished by an end mill, but other methods may be used as long as they can form the machining streaks 16a-16c, 36a-36c with minute irregularities within the above-mentioned range. For example, laser patterning or electric discharge machining may be used.

[0055] In addition, it is preferable that the processed streaks 16a-16c and the processed streaks 36a-36b have similar maximum heights Rz. Since the surface roughness, i.e., the periodicity of the projections and recesses, of the processed streaks 16a-16c and the processed streaks 36a-36b are similar, the contact area between them can be increased, and the fitting strength can be increased.

[0056] In this embodiment, the cutting insert 10 and the tool body 30 each have two or more surfaces of the restraint parts 15a-15c, 35a-35c, and the processing streaks 16a-16c, 36a-36c are intentionally formed in each of the restraint parts 15a-15c, 35a-35c. In addition, the processing streaks 16a-16c are formed at a constant period in each of the restraint parts 15a-15c of the cutting insert 10 with 0.05 μm≦Ra≦6.30 μm, and the processing streaks are formed at a constant period in each of the restraint parts 35a-35c of the tool body 30 with 0.05 μm≦Ra≦6.30 μm, so that the width and height difference of the processing streaks 16a-16c formed in the restraint parts 15a-15c of the cutting insert 10 and the processing streaks 36a-36c provided in the restraint parts 35a-35c of the tool body 30 can be made close to each other. In addition, when the cutting insert 10 is attached to the tool body 30, the angles between the processing streaks 16a-16c, 36a-36c in the respective restraining portions 15a-15c, 35a-35c are 0°≦θ≦5° between the cutting insert 10 and the tool body 30, so that the directions of the opposing processing streaks 16a-16c, 36a-36c are approximately the same. Therefore, the processing streaks 16a-16c, 36a-36c mesh well with each other, and the contact area between them is increased. This increases the restraining force in the respective restraining portions 15a-15c, 35a-35c, and makes it possible to suppress the slippage of the cutting insert 10 relative to the tool body 30. Furthermore, by forming the machining streaks 16a to 16c, 36a to 36c having a microscopic orientation in each of the restraining portions 15a to 15c, 35a to 35c, the cutting insert 10 can be easily positioned relative to the tool body 30, and macroscopic attachment can be achieved.

[0057] The arithmetic mean height Ra is set to 0.05 μm≦Ra≦6.30 μm, but is preferably set to 0.10 μm≦Ra≦2.00 μm. The angle between the processed streaks 16a-16c, 36a-36c in the restraint portions 15a-15c, 35a-35c may be set to 0°≦θ≦5°, and is preferably set to 0°≦θ≦2°.

[0058] The period of the processed streaks 16a to 16c, 36a to 36c may be 0.05 mm to 0.50 mm, and preferably 0.05 mm to 0.20 mm.

[0059] In addition, in this embodiment, the machining streaks 16a-16c, 36a-36c are formed in the multiple constraint parts 15a-15c, 35a-35c facing different directions on the cutting insert 10 and the tool body 30, respectively, and it is possible to mesh the machining streaks 16a-16c, 36a-36c in all the constraint parts 15a-15c, 35a-35c. In the above-mentioned configuration, the range of the arithmetic mean height Ra is specified as a parameter of the surface roughness, but it is not desirable from the viewpoint of meshing if there are any places where the height of the machining streaks 16a-16c, 36a-36c is extremely high or extremely low. Therefore, in this embodiment, the maximum heights Rz of the processed streaks 16a to 16c, 36a to 36c formed in the cutting insert 10 and the tool body 30 may be set to 0.10 μm≦Rz≦25.00 μm, and preferably 0.50 μm≦Rz≦12.00 μm.

[0060] According to this embodiment, it is possible to provide a cutting tool 100 including a cutting insert 10 and a tool body 30, which can stably attach the cutting insert 10 to the tool body 30 and prevent the cutting insert 10 from shifting out of position during cutting.

[0061] The present invention will be specifically described below with reference to Examples 1 and 2. However, the present invention is not limited to these Examples 1 and 2.

[0062] In Examples 1 and 2, when performing cutting processing using the cutting insert and tool body described in the above embodiment, it was verified to what extent the surface roughness and knot direction at each restraint portion of the cutting insert and the tool body affect the slippage (displacement amount) of the cutting insert relative to the tool body. Here, taking into consideration the cases of vertical wall machining, which is performed in the axial direction, and seating surface machining, which is performed in the radial direction, verification was conducted separately for each load direction (radial component force, axial load).

[0063] 7(a) and (b) are schematic diagrams of a part of the verification machine, where FIG. 7(a) shows the measurement state when a radial component force is applied to the cutting insert, and FIG. 7(b) shows the measurement state when an axial load is applied to the cutting insert. As shown in Figures 7(a) and (b), an external force simulating the cutting resistance against the cutting insert was applied by pressing a jig 51 fixed on a dynamometer against a cutting tool (cutting insert) for evaluation attached to the spindle of a machine tool in the radial or axial direction. The displacement and behavior of the cutting insert were measured by a dial gauge 52 placed on the outer periphery of the cutting insert, and the displacement of the insert alone was calculated by subtracting the displacement of the tool body alone measured by a separate dial gauge 52. EXAMPLES

[0064] [Verification of the effect of surface roughness] First, we verified the extent to which the relationship between the arithmetic mean height Ra of the restraint portion in the cutting insert and the arithmetic mean height Ra of the restraint portion in the tool body affects the amount of rotational displacement of the cutting insert relative to the tool body for each of the radial and axial force components. As an example, a cutting insert and a tool body in which grooves were applied to each of the restraining portions were prepared. As a comparative example, a cutting insert was prepared in which the long side and short side restraint portions were sintered surfaces, and the bottom surface restraint portion was planetary ground. The cutting insert of the comparative example had no machining streaks on any of the restraint portions.

[0065] 8(a)-(d) are diagrams showing the tool body 30A used in the evaluation and the streak directions (streak angles θ4-θ6: 90°) of the processed streaks 36a-36c in each of the restraining parts 35a-35c. FIG. 9(a)-(d) are diagrams showing the cutting insert 10A used in the evaluation and the streak directions (streak angles θ1-θ3: 90°) of the processed streaks 16a-16c in each of the restraining parts 15a-15c. FIG. 10(a) is a diagram showing a part of a cutting tool in which the cutting inserts 10A-10D are attached to the tool body 30A, and is a diagram for explaining the verification results. FIG. 10(b) is a cross-sectional view taken along the line A-A' in FIG. 11.

[0066] [Table 1]

[0067] As a sample of the tool body, one tool body 30A under the conditions shown in Table 1 and in FIGS. 8(a) to (d) was prepared. "Tool body 30A" Arithmetic mean height Ra of restraint portions 35a to 35c: 1.10 μm · Processing line period: 0.13mm - Angle of processing lines 36a to 36c: Uniform at 90°

[0068] As samples of the cutting insert of Example 1, three cutting inserts 10A to 10C having the conditions shown in Table 1 and FIGS. 9(a) to (d) were prepared. "Cutting insert 10A" Arithmetic mean height Ra: 0.16μm · Processing streak cycle: 0.05mm - The angle of the processing lines 36a to 36c is unified as θ1:90° "Cutting insert 10B" Arithmetic mean height Ra: 1.00μm · Processing line period: 0.12mm · The angle of the grooves in the restraint sections 15a to 15c is unified at θ2: 90° "Cutting insert 10C" Arithmetic mean height Ra: 3.10μm · Processing streak cycle: 0.21mm · The angle of the processing ridges 36a to 36c is unified as θ3: 90°

[0069] In a state in which the cutting inserts 10A to 10C are attached to the tool body 30A, the restraining portions 15a to 15c on the cutting inserts 10A to 10D side are restrained by the restraining portions 35a to 35c on the tool body 30A side.

[0070] 10(a) to (c) are diagrams that show schematic views of engagement between the restraining portions 15a to 15c of the cutting inserts 10A to 10D and the restraining portions 35a to 35c of the tool body 30A for each surface roughness. As shown in FIG. 10(b), when the surface roughness of each of the restraint portions 15a-15c of the cutting inserts 10A-10C is closest to the surface roughness of each of the restraint portions 35a-35c of the tool body 30A, the contact area between the machining marks 16a-16c, 36a-36c is maximized.

[0071] <Radial component force> First, the effect of surface roughness on the radial component force is examined. Three cutting inserts 10A-10C were sequentially attached to the tool body 30A, and as shown in Figure 7(a), a jig was pressed against the long side surface of the cutting inserts 10A-10C from the radial outside to apply a predetermined load, which was an external force simulating the cutting resistance on the cutting inserts 10A-10C during vertical wall machining, and the effect of surface roughness was evaluated from the degree of misalignment of each cutting insert 10A-10C relative to the tool body 30A.

[0072] Figures 12(a) to (c) are graphs showing the relationship between the rotational displacement amount (displacement amount, vertical axis of the graph, unit μm) of cutting inserts 10A to 10C and the load (horizontal axis of the graph, unit N) at (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. As shown in FIGS. 12(a) to (c), in any of the cutting inserts 10A to 10C, a change (deviation) occurred with respect to the tool body 30A when the load exceeded 200N, and the amount of displacement reached a maximum at approximately 600N.

[0073] The seating side restraint portions 15a, 35a are surfaces along the radial direction (direction indicated by arrow P in FIG. 11) along which the load is applied, and a force perpendicular to the direction of fitting acts on them. Therefore, for the bottom restraint portions 15a, 35a, as shown in FIG. 12(b), the amount of displacement differed depending on the surface roughness of the cutting inserts 10A to 10C. The amount of displacement (rotational displacement) of the bottom restraint portion 15a increased in the order of 1.00 μm, 0.16 μm, and 3.10 μm in terms of the arithmetic mean height Ra.

[0074] In addition, for the short side constraint portions 15c and 35c, when a load is applied from the direction indicated by the arrow P in Fig. 11, it is considered that the load acts from the diagonal direction indicated by the arrow Q in Fig. 11. For the short side constraint portions 15c and 35c as well, as shown in Figs. 12(b) and (c), the displacement amount (rotational displacement amount) increases in the order of arithmetic mean height Ra of 0.16 μm, 1.00 μm, and 3.10 μm.

[0075] With regard to the long side constraint portions 15b, 35b, as shown in FIG. 12(a), regardless of the surface roughness of the cutting inserts 10A to 10C (regarding the surface roughness of the long side constraint portions 15b, 35b), there was no significant difference in the amount of displacement between the cutting inserts 10A to 10C (arithmetic mean heights Ra: 0.16 μm, 1.00 μm, 3.10 μm) relative to the tool body 30A. The reason for this is that the cutting inserts 10A to 10C exhibited a clockwise behavior when viewed from the front, and the long side constraint side rose up due to the radial component force, which reduced the contact area between the long side constraint portion 15b of the cutting inserts 10A to 10C and the long side constraint portion 35b of the tool body 30A, thereby reducing the effect of surface roughness.

[0076] Among the cutting inserts 10A to 10C, the cutting insert 10B had the smallest displacement in each of the long side constraint portion 15b, the bottom surface constraint portion 15a, and the short side constraint portion 15c. The arithmetic mean height Ra of each constraint portion 15a to 15c of the cutting insert 10B was 1.00 μm, which was closest to the arithmetic mean height Ra (1.10 μm) on the tool body 30A side. Therefore, it is considered that the contact area with the tool body 30A was increased and the fitting strength was increased, resulting in the smallest displacement. Among the cutting inserts 10A to 10C, the cutting insert 10C had the largest displacement, with an arithmetic mean height Ra of 3.10 μm.

[0077] <Axial load> Next, the effect of surface roughness on the axial load will be examined. As shown in Figure 7(b), a jig was pressed against the tip of the cutting insert from the tip side of the cutting tool 100 to apply a load in the axial direction, creating an external force that simulated the cutting resistance on the cutting inserts 10A to 10C, and the effect of surface roughness was evaluated from the degree of deviation of each cutting insert 10A to 10C relative to the tool body 30A.

[0078] Figures 13(a) to (c) are graphs showing the relationship between the rotational displacement amount (vertical axis of the graph, unit of μm) of cutting inserts 10A to 10C and the axial load (horizontal axis of the graph, unit of N) in (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion, respectively. As shown in FIGS. 13(a) to (c), in any of the cutting inserts 10A to 10C, a change (deviation) occurred with respect to the tool body 30A when the load exceeded 200N, and the amount of displacement reached a maximum at approximately 600N.

[0079] As shown in FIG. 13(a), regarding the long side restraint portion 15b, no significant difference was observed in the displacement amount of each of the cutting inserts 10A to 10C (arithmetic mean heights Ra: 0.16 μm, 1.00 μm, 3.10 μm). As shown in Fig. 13(b), for the restraint portions 15a, 35a on the seating surface side, the amount of displacement varied depending on the surface roughness of the cutting inserts 10A to 10C. The amount of displacement increased in the order of the arithmetic mean heights Ra of the long side restraint portion 15b and the bottom surface restraint portion 15a, 1.00 µm, 0.16 µm, and 3.10 µm.

[0080] On the other hand, no significant difference in the surface roughness was observed between the short side restraint portions 15c of the cutting inserts 10A to 10C and the short side restraint portions 35c of the tool body 30A. As shown in Fig. 13(c), in the cutting inserts 10A to 10C (in any surface roughness of the short side restraint portions 15c and 35c), there was no significant difference in the amount of displacement between the cutting inserts 10A to 10C (arithmetic mean heights Ra: 0.16 μm, 1.00 μm, and 3.10 μm) relative to the tool body 30A.

[0081] The reason for this is that the cutting inserts 10A to 10C exhibit a behavior in which the short side constraint portion 15c rises up when rotated counterclockwise when viewed from the front due to the axial component force, and therefore the contact area between the short side constraint portion 15c of the cutting inserts 10A to 10C and the short side constraint portion 35c of the tool body 30A is reduced, thereby reducing the effect of surface roughness.

[0082] Among the cutting inserts 10A-10C, the cutting insert 10B had the smallest displacement in each of the long side constraint portion 15b, the bottom surface constraint portion 15a, and the short side constraint portion 15c. The arithmetic mean height Ra of each constraint portion 15a-15c of the cutting insert 10B is 1.00 μm, which is closest to the arithmetic mean height Ra (1.10 μm) on the tool body 30A side, as shown in FIG. 10(b). In addition, the streak angles θ1-θ3 of each processing streak 16a-16c of the cutting insert 10B are all 90°, which is equal to the streak angles θ4-θ6 of each processing streak 36a-36c of the tool body 30A. For this reason, the depth of engagement of the projections and recesses becomes larger, and the contact area between each of the restraining portions 15a-15c of the cutting inserts 10A-10C and each of the restraining portions 35a-35c of the tool body 30A increases, and the mutual engagement strength (fixed limit resistance) increases, which is thought to be the reason for the smallest displacement. Note that, among the cutting inserts 10A-10C, the cutting insert 10C with an arithmetic mean height Ra of 3.10 μm had the largest displacement. This is thought to be because the depth of engagement of the projections and recesses is the smallest.

[0083] From the above results, in both the radial component force and the axial load, the rotational displacement amount of the cutting inserts 10A-10C relative to the tool body 30A was best when the arithmetic mean heights Ra of the respective constraint portions 15a-15c, 35a-35c were close to each other. That is, when the arithmetic mean height Ra of the respective constraint portions 35a-35c of the tool body 30A was 1.10 μm, the displacement amount relative to the tool body 30A was smallest for the cutting insert 10B, whose arithmetic mean heights Ra of the respective constraint portions 15a-15c were 1.00 μm.

[0084] In addition, regardless of the load from the radial direction or the load from the axial direction, it was found that the displacement amount of the cutting inserts 10A to 10C of the above-mentioned Example 1 with respect to the tool body 30A was significantly suppressed in all of the restraining parts compared to the cutting inserts of the comparative example (conventional product) without processing streaks. When a radial component force is loaded, the displacement amount is suppressed as much as the cutting insert (Ra: 1.10 μm) close to the arithmetic mean height (Ra: 1.00 μm) on the tool body 30A side. In addition, when an axial load is loaded, the difference from the comparative example was remarkable in all of the restraining parts 15a to 15c regardless of the surface roughness value. In addition, when a load acts from the same direction as the fitting direction of the restraining parts, the displacement amount was significantly smaller than that of the comparative example regardless of the surface roughness value.

[0085] In the cutting insert of the comparative example, the amount of displacement increased from about a load of 200 N regardless of the radial and axial directions, and in particular, when the radial component force exceeded 500 N, the amount of displacement relative to the tool body 30A rapidly increased compared to the cutting inserts 10A to 10C. In both the radial component force and the axial load, the amount of displacement was confirmed to be approximately the same in all of the long side constraint portion, short side constraint portion and bottom surface constraint portion of the cutting insert of the comparative example without machining streaks.

[0086] Therefore, in order to suppress the displacement of the cutting inserts 10A-10C relative to the tool body 30A, it was found that it is more effective to provide machining marks 36a-36c, 16a-16c that form surface roughness on the respective restraint portions 35a-35c, 15a-15c of the tool body 30A and the cutting inserts 10A-10C, and to make the surface roughness on the cutting inserts 10A-10c side closer to the arithmetic mean height (Ra: 1.00 μm) on the tool body 30A side. When the arithmetic mean height Ra of the cutting inserts 10A-10C and the tool body 30A is about 1.0, the tool body 30A and the cutting inserts 10A-10C are restrained by minute irregularities (machined streaks 36a-36c, 16a-16c) that can be macroscopically engaged with each other in the restraining parts 35a-35c, 15a-15c, and a high fitting force is obtained even against a load acting from a direction different from the fitting direction of each restraining part 35a-35c, 15a-15c. In addition, since the streaks angles θ1-θ3 on the cutting inserts 10A-10C side are equal to the streaks angles θ4-θ6 on the tool body 30A, the fitting depth of the irregularities between the processed streaks 16a-16c, 36a-36c becomes large, and the rotational displacement amount on the cutting inserts 10A-10C side is further suppressed. EXAMPLES

[0087] [Verification of the effect of processing grain direction] Next, we verified the extent to which the relationship between the line direction (line angles θ1 to θ3) of the processed lines 16a to 16c in the cutting inserts 10D, 10E, 10F, and 10G of the present invention and the line direction (line angles θ4 to θ6) of the processed lines 36a to 36c in the tool body 30A affects the shifting movement (displacement amount) of the cutting inserts 10D to 10G relative to the tool body 30A.

[0088] [Table 2]

[0089] As samples of the cutting insert of Example 2, cutting inserts 10D to 10G were prepared under the conditions shown in Table 2. Here, four cutting inserts were prepared in which the streak directions (streak angles θ1 to θ4) of the processed streaks 16a to 16c were different from one another. "Cutting insert 10D~10G" Arithmetic mean height Ra: Uniform at 1.00μm - Direction of the processed streaks 16a to 16c (streaking angles θ1 to θ3): 0°, 45°, 90°, 135°

[0090] <Radial component force> The four prepared cutting inserts 10D-10G were attached in order to the tool body 30A, and as shown in Figure 7(a), a jig 51 was pressed against the long side surface of the cutting inserts 10D-10G from the radial outside to apply a predetermined load, thereby reproducing the load applied to each cutting insert 10D-10G during cutting processing, and the effect of the grain direction was evaluated from the degree of misalignment of each cutting insert 10D-10G relative to the tool body 30A.

[0091] Figures 14(a) to (c) are graphs showing the relationship between the rotational displacement amount (vertical axis of the graph, unit of μm) of cutting inserts 10D to 10G and the radial component force (horizontal axis of the graph, unit of N) at (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion, respectively. 14(a), in the long side restraint portion 15b of the cutting inserts 10D-10G, the amount of displacement of the cutting inserts 10A-10D relative to the long side restraint portion 35b of the tool body 30A is small regardless of the streak angle θ2 (0°, 45°, 90°, 135°) that indicates the streak direction of the processed streak 16b, and the variation between the cutting inserts 10D-10G is small. In other words, it can be said that the degree to which the streak direction between the processed streaks 16b, 36b (magnitude of the streak angle θ2) affects the amount of displacement of the cutting inserts 10D-10G is small with respect to the long side restraint portions 15b, 35b.

[0092] On the other hand, as shown in Figure 14(b), in the bottom restraint portions 15a of the cutting inserts 10D to 10G, regardless of the magnitude of the load, the amount of displacement relative to the tool body 30A increased as the groove angle θ1, which represents the groove direction of the processed groove 16a, was changed in the order of 90°, 135°, 45°, and 0°. Also, as shown in FIG. 14(c), in the short side constraint portions 15c of the cutting inserts 10D to 10G, the amount of displacement relative to the tool body 30 increased as the streak angle θ3, which represents the streak direction of the processed streak 16c, increased in the order of 90°, 135°, 0°, and 45°.

[0093] In this way, it was found that even if the surface roughness of the restraint parts 35a-35c, 15a-15c between the tool body 30A and the cutting inserts 10D-10G is similar, if the groove directions are misaligned, the contact area decreases and sufficient restraint force cannot be obtained. In both the bottom surface restraint parts 35a, 15a and the short side restraint parts 35c, 15c, regardless of the magnitude of the load, when the groove angles θ1, θ3 are 90°, which is the same as the groove angles θ4, θ6 of the bottom surface restraint part 35a and the short side restraint part 35c in the tool body 30A, the displacement amount relative to the tool body 30A is small. In other words, it is considered that the smaller the difference in the groove directions (angles) between the cutting inserts 10D-10G and the restraint parts 15a-15c, 35a-35c of the tool body 30A, the deeper the engagement of the concaves and convexes becomes, the larger the contact area becomes, the higher the restraint force becomes, and the smaller the degree of influence on the displacement amount of the cutting insert 10 becomes.

[0094] <Axial load> As shown in Figure 7(b), a jig 51 was pressed against the tips of the cutting inserts 10D to 10G from the tip side of the cutting tool 100 to apply a load in the axial direction, creating an external force that simulated the cutting resistance on the cutting inserts 10D to 10G, and the effect of surface roughness was evaluated from the degree of deviation of each cutting insert 10D to 10G relative to the tool body 30A.

[0095] Figures 15(a) to (c) are graphs showing the relationship between the rotational displacement amount (vertical axis of the graph, unit of μm) of cutting inserts 10D to 10G and the axial load (horizontal axis of the graph, unit of N) at (a) the long side constraint portion, (b) the bottom surface constraint portion, and (c) the short side constraint portion. As shown in FIGS. 15(a) to (c), in any of the cutting inserts 10D to 10G, a change (deviation) occurred with respect to the tool body 30A when the load exceeded 200N, and the amount of displacement reached a maximum at approximately 600N.

[0096] As shown in Fig. 15(c), no significant difference was observed depending on the groove angles θ1 to θ3 for the short side restraint portion 15c of the cutting inserts 10D to 10G. As described above, the short side restraint portion 15c of the cutting inserts 10D to 10G exhibits a behavior of floating up when rotated counterclockwise in front view due to the axial component force, and therefore it is considered that the influence of the groove angle is reduced due to the reduction in the contact area between the short side restraint portion 15c of the cutting inserts 10D to 10G and the short side restraint portion 35c of the tool body 30A.

[0097] On the other hand, in the long side restraint parts 15b, 35b and the bottom surface restraint parts 15a, 35a, the grain direction on the tool body 30A side and the load direction acting on each long side restraint part 15b, 35b and each bottom surface restraint part 15a, 35a became closer to an orthogonal relationship, which is considered to have caused the difference depending on the joint angle. The amount of displacement became smallest when the joint direction was 135°, 0°, and 45°, in that order, and the amount of displacement was smallest mainly when the joint direction was 90°.

[0098] From the above results, regardless of whether the radial component force or the axial load is applied, the degree of deviation (displacement amount) of the cutting inserts 10D-10G relative to the tool body 30A was smallest when the grain directions of each of the restraint portions 15a-15c, 35a-35c were the same (here, when they were 90° to each other).

[0099] Furthermore, when compared with cutting inserts of comparative examples (conventional products) having no machining marks, it was found that the amount of displacement of cutting inserts 10D to 10G of Example 2 described above with respect to the tool body 30A was significantly reduced at all restraining portions, regardless of whether a radial load or an axial load was applied.

[0100] 16 is a diagram showing the relationship between the shear direction acting on the short side restraint portions 15c, 35c and the processed streaks 16c, 36c, where (a) shows the streaks angle θ3 on the cutting inserts 10D-10G side being 45°, and (c) shows the streaks angle θ3 on the cutting inserts 10D-10G side being 135°. The streaks angle θ6 of the tool body 30 is 90°.

[0101] As shown in Figure 14(c) above, when a load was applied from the radial outside of the cutting inserts 10D to 10G, the amount of displacement relative to the tool body 30A having a groove angle θ6 of 90° was largest when the groove angle θ3 of the short side restraint portion 15c was 45°. This is thought to be because, as shown in Figure 16(a), when the groove angle θ3 of the short side restraint portion 15c on the cutting insert 10D-10G side is 45° relative to the short side restraint portion 35c on the tool body 30A side (groove angle θ6: 90°), the shear direction acting on the short side restraint portions 15c, 35c (direction indicated by arrow Q in the figure) and the direction of the machining grooves 16c of the cutting inserts 10D-10G become approximately parallel, reducing the depth of engagement of the concaves and convexes and weakening the restraining force between the short side restraint portions 15c, 35c.

[0102] On the other hand, as shown in Fig. 16(b), when the streak angle θ3 on the cutting inserts 10D to 10G side is 135°, the amount of displacement with respect to the tool body 30A is smaller than when the streak angle θ3 is 45°. This is thought to be because when the streak angle θ3 is 135°, the fitting depth of the concaves and convexes is greater than when it is 45°, and the fitting area between the processed streaks 16c, 36c in the direction perpendicular to the shear direction increases, increasing the binding force between the short side binding portions 15c, 35c.

[0103] According to the above-mentioned Examples 1 and 2, when there are no machining streaks as in the comparative example, and the constraint of the cutting insert and the constraint part of the tool body are flat surfaces, the cutting insert is likely to slip relative to the tool body due to the cutting load during cutting. Therefore, it is possible to form an uneven shape on the seating surface or side of the cutting insert to increase the constraint force, but for example, if the uneven shape formed on the side of the cutting insert is large (several mm), the unevenness may affect the cutting edge shape. In addition, between the cutting insert and the tool body, it is necessary to ensure the fitting strength by fitting the uneven shapes of the constraint parts of each other. In other words, the cutting insert must be attached to the tool body with high precision so that the unevenness between the constraint part of the cutting insert and the constraint part of the tool body fits with each other. However, it is difficult to precisely mate the three constraint portions of the cutting insert with the three constraint portions of the tool body. If there is even one pair of surfaces that does not mate precisely, the cutting insert will tilt relative to the tool body.

[0104] Therefore, as in the above embodiment, the machining streaks 16a-16c, which are microscopically oriented and have minute uneven shapes, are formed with minute dimensions of several μm for each of the restraining parts 15a-15c, 35a-35c of the cutting inserts 10A-10G and the tool body 30A, and the angle between the machining streaks 16a-16c is set to be within the range of 0°≦θ≦5°, thereby increasing the area in which the unevenness fits with each other. This makes it easy to position the cutting inserts 10A-10G relative to the tool body 30A, and allows the cutting inserts 10A-10G to be macroscopically attached to the tool body 30A. Therefore, it is possible to easily replace the cutting inserts 10A-10G.

[0105] As a result of the above-mentioned Examples 1 and 2, when the surface roughness values ​​of the restraint portions 15a-15c, 35a-35c between the cutting inserts 10A-10G and the tool body 30A are close to each other, the contact area of ​​the contact surface roughness increases and the static friction coefficient becomes maximum, so that it is possible to suppress the amount of rotational displacement of the cutting inserts 10A-10G relative to the tool body 30A.

[0106] Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the examples. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present invention. The configurations of each embodiment may be appropriately combined.

[0107] For example, the shape of the cutting insert is not limited to the shapes shown in the above embodiments, and may be a square shape, a parallelogram shape, or the like other than a rectangular shape when viewed from above. [Explanation of symbols]

[0108] 10(10A, 10B, 10C, 10D, 10E, 10F, 10G)…Cutting insert 13…Seating surface 12...Scooping surface 14…Side 15a, 15b, 15c...Restraint portion of cutting insert 35a, 35b, 35c...Restraint portion of tool body 16a, 16b, 16c... Machining marks of cutting insert 36a, 36b, 36c…Processing lines on tool body 30(30A)...Tool body 31…Insert pocket (pocket) 33a…Mounting seat 33b...Long side mounting surface (mounting surface) 33c…Short side mounting surface (mounting surface) 100...Cutting tools JO…Rotation axis θ…The angle between the cutting insert's machining marks and the tool body's machining marks

Claims

1. A cutting tool in which a cutting insert is attached to a tool body that rotates around a rotation axis, The cutting insert has a rake face and a seating surface, and the rake face and the seating surface are connected by a side surface including a flank surface, the tool body has one or more pockets at one end, the pockets having a mounting seat and one or more mounting sides angled relative to the mounting seat; The seating surface, the side surface, the mounting seat, and the mounting side surface each include a restraining portion, All of the restraint portions are formed with constant periodic processing streaks of 0.05 μm≦Ra≦6.30 μm, In a state in which the cutting insert is attached to the tool body, The angle θ between the machining line of the cutting insert and the machining line of the tool body in each restraint portion is 0°≦θ≦5°; A cutting tool characterized by:

2. The processing streaks are formed by grinding.

2. The cutting tool according to claim 1 .

3. A pair of rake faces and seat faces are provided, and the rake faces and the seat faces are connected by a side surface including a flank, The seating surface and the side surface each include a restraining portion, The restraint portion is formed with a constant period of processing streaks of 0.05 μm≦Ra≦6.30 μm. A cutting insert characterized by:

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