WO2016093275A1

WO2016093275A1 - Cutting insert, tool body, and cutting tool

Info

Publication number: WO2016093275A1
Application number: PCT/JP2015/084516
Authority: WO
Inventors: 晋也間嶋; 桂望月
Original assignee: 株式会社タンガロイ
Priority date: 2014-12-10
Filing date: 2015-12-09
Publication date: 2016-06-16
Also published as: JP6528781B2; JPWO2016093275A1

Abstract

Provided are: a cutting insert for which fixing on a cutting tool is stabilized; a tool body; and a cutting tool. This cutting insert has two opposite end faces and a peripheral side surface connecting the end faces. The peripheral side surface is provided with at least one holding section. The holding section comprises first and second contact surfaces that are separated from each other in the peripheral direction of the cutting insert and a protruding section or flat section formed between the first and second contact surfaces. The first contact surface is inclined in the peripheral direction so as to dip towards the inside of the cutting insert when proceeding from one end of the holding section towards the protruding section or flat section. The second contact surface is inclined in the peripheral direction so as to dip towards the inside of the cutting insert when proceeding from the other end of the holding section towards the protruding section or flat section.

Description

Cutting inserts, tool bodies and cutting tools

The present invention relates to a cutting insert that is attached to a cutting tool so as to be freely attached and used for cutting a metal material, etc., a tool body to which the cutting insert is attached, and a cutting tool.

Conventional cutting inserts, tool bodies, and cutting tools include those shown in Patent Document 1. That is, it is a cutting insert and a cutting tool suitable for a small lathe also called an automatic lathe, and the contour shape of the cutting insert is a substantially parallelogram. Since the cutting edge is formed in two portions corresponding to the acute angle portion of the parallelogram, it has two cutting edges. That is, the cutting insert can be used twice by reattaching it to the cutting tool. This cutting insert has two opposing end surfaces and a peripheral side surface connecting these end surfaces, and two surface portions of the peripheral side surfaces are formed into a wall shape of a chip seat when mounted on a cutting tool. Abuts against the rising surface. In this cutting tool, a part of the wall surface of the chip seat is recessed (relieved), so that one wall surface is divided into two spaced apart parts, and the other wall surface is separated. Three surface portions abut against the cutting insert together with one surface portion. The contact portion on the peripheral side surface of the cutting insert is basically constituted by four flat portions, and two of the flat portions act as contact surfaces.

Further, conventional cutting inserts, tool bodies and cutting tools include those shown in Patent Document 2. That is, the cutting insert is used for turning, grooving, parting, or threading, and has a plurality of cutting edges. The cutting insert has two opposing end surfaces and a peripheral side surface connecting the end surfaces. The peripheral side surface has four contact areas (contact surfaces). Each of the four contact areas is connected by two concave portions to form two contact recesses. When the cutting insert is attached to the holder of the cutting tool, at least three of the four contact areas contact the reaction area (holding surface) of the holder.

JP-A-11-123603 Special table 2013-540058 gazette

The conventional cutting insert, tool body and cutting tool of Patent Document 1 have a certain improvement effect in enhancing the fixing property of the cutting insert by denting a part of the wall surface of the chip seat. However, since the peripheral side surface of the cutting insert is planar, it cannot be prevented from moving in a direction parallel to the plane, and the fixability may still be insufficient. Also, in order to bring the peripheral side surface, which is the short side of the parallelogram, into contact with the wall surface of the chip seat, when using cutting inserts with different lengths of the long side of the parallelogram, that is, in parting off processing, etc. When using cutting inserts with different protruding lengths, it is necessary to prepare corresponding tool holders (bites) in accordance with the entire length of the cutting insert. Further, if the cutting edge portion of the cutting insert is greatly damaged during the cutting process, the contact surface formed on the short side of the parallelogram may be damaged, and the opposite cutting edge may not be usable.

The conventional cutting insert, tool body, and cutting tool of Patent Document 2 have high fixability because at least three of the four contact areas formed on the cutting insert are in contact with the tip seat of the cutting tool. However, if the distance between the two surface portions where the contact area of the peripheral side surface is formed becomes short, the two concave surface portions approach each other, and the strength of the cutting insert may be reduced. For this reason, there is a limit to the distance between the two surface portions of the peripheral side surface where the contact area is formed, and there is a problem that it cannot be applied to a small cutting tool for a small lathe.

The cutting insert, tool body and cutting tool of the present invention solve at least one of these problems.

The cutting insert of the present invention is a cutting insert having two opposing end surfaces and a peripheral side surface connecting between the end surfaces, and the peripheral side surface includes at least one holding portion. The holding portion includes first and second contact surfaces that are spaced apart from each other in the circumferential direction of the cutting insert, and a convex surface portion or a flat surface portion that is formed between the first and second contact surfaces. In the circumferential direction, the first contact surface is inclined so as to be recessed inward of the cutting insert from the one end side of the holding portion toward the convex surface portion or the flat surface portion side. In the circumferential direction, the second contact surface is inclined so as to be recessed inward of the cutting insert from the other end side of the holding portion toward the convex surface portion or the flat surface portion side.

The tool body of the present invention is a tool body of a cutting tool to which the cutting insert of the present invention is detachably mounted, and includes a tip seat. The tip seat has a main surface and a sub surface extending so as to stand up from the main surface and capable of contacting a part of the peripheral side surface. The sub surface includes a wall surface portion with which the holding portion of the cutting insert can come into contact. The wall surface portion has a first holding surface with which the first contact surface of the cutting insert can come into contact, and a second holding surface with which the second contact surface can come into contact.

The cutting tool of the present invention is a cutting tool provided with the cutting insert of the present invention.

In the cutting insert of the present invention, the holding portion has a convex surface portion or a flat surface portion formed between the two abutting surfaces, so that the distance between the two surfaces of the peripheral side surface on which the holding portion is formed is shortened. However, the strength of the cutting insert does not decrease. For this reason, the cutting insert, tool body, and cutting tool which do not generate | occur | produce defects, such as a defect | deletion of a cutting insert, are provided.

FIG. 1 is a perspective view of a cutting insert according to the first embodiment. FIG. 2 is a left side view of the cutting insert shown in FIG. FIG. 3 is a partially enlarged view of the left side view of FIG. 4 is another partially enlarged view of the left side view of FIG. FIG. 5 is a plan view of the cutting insert shown in FIG. FIG. 6 is a front view of the cutting insert shown in FIG. FIG. 7 is a right side view of the cutting insert shown in FIG. FIG. 8 is a perspective view of the cutting tool in the first embodiment equipped with the cutting insert shown in FIG. FIG. 9 is a plan view of the cutting tool shown in FIG. FIG. 10 is a left side view of the cutting tool shown in FIG. FIG. 11 is a partially enlarged view of FIG. FIG. 12 is a front view of the cutting tool shown in FIG. FIG. 13 is an enlarged perspective view of the periphery of the tip seat with the cutting insert and the clamp member removed from the cutting tool shown in FIG. FIG. 14 is a perspective view of a cutting insert according to the second embodiment. FIG. 15 is a plan view of a cutting tool in the second embodiment in which the cutting insert shown in FIG. 14 is mounted. FIG. 16 is a partially enlarged view of the plan view of FIG. FIG. 17 is an enlarged perspective view of the periphery of the chip seat in a state where the cutting insert, the clamp member, and the deposit are removed from the cutting tool shown in FIG.

The cutting insert, tool body, and cutting tool of the first embodiment to which the present invention is applied will be described with reference to the drawings. As shown in FIGS. 1 to 7, the cutting insert 1 in this embodiment has two

opposing end surfaces

2 and 3 and a peripheral side surface 4. The peripheral side surface 4 connects between the two

end surfaces

2 and 3. As shown in FIGS. 2 and 7, the contour shapes of the two

end surfaces

2 and 3 are substantially parallelograms. Each of the parallelograms of the end faces 2 and 3 has two long sides and two short sides. Since the short side portion is bent in the vicinity of the acute angle portion of the substantially parallelogram, the contour shape of each of the

end faces

2 and 3 can be regarded as a substantially hexagonal shape. However, the explanation here assumes that the bent side is regarded as one side and is regarded as a substantially parallelogram. Therefore, the peripheral side surface 4 basically includes two long side surface portions 4a corresponding to the long side portions and two short side surface portions 4b corresponding to the short side portions. Note that the terms “long” and “short” as used herein only mean a relative relationship in length or size, and do not mean an absolute degree. At the center of each of the two

end surfaces

2 and 3, a mounting hole 15 penetrating the

end surfaces

2 and 3 is formed. When the cutting insert 1 is mounted on the cutting tool 20, the mounting hole 15 comes into contact with a clamp member 30 such as a tightening screw or a lever. The attachment hole 15 can also be called a clamp hole 15. The cutting insert 1 is 180 ° rotationally symmetric with respect to the central axis of the mounting hole 15. As shown in FIGS. 1 and 2, in the cutting insert 1 in this embodiment, a substantially cylindrical portion 15 a having a substantially constant diameter d is formed in a part of the mounting hole 15.

A rake face 6 and a flank face 7 are formed on a part of the peripheral side surface 4 of the cutting insert 1. A cutting edge 5 is formed at the intersecting ridge line portion between the rake face 6 and the flank face 7. That is, at least a part of the cutting edge 5 is formed on a part of the peripheral side surface 4. Another part of the cutting edge 5 may also be formed on a part of the intersecting ridge line portion between the two

end surfaces

2 and 3 and the peripheral side surface 4. Therefore, a part of the flank 7 may be formed on a part of the two end faces 2 and 3. In the cutting insert 1 in this embodiment, at least two cutting edges 5 are formed. That is, it is an economical cutting insert 1 that can be used at least twice by reattaching it to the cutting tool. The two cutting edges 5 are arranged and shaped to be 180 ° rotationally symmetrical with respect to the central axis of the mounting hole 15. Hereinafter, in order to simplify the description, only the case where one cutting edge 5 is used as the working cutting edge 5a will be described, and the description when the other cutting edge is used as the working cutting edge will be substantially omitted. That is, only the case where the cutting edge 5 shown on the upper right side in FIG. 2 is used as the working cutting edge 5a will be described, and the explanation on the case where the cutting edge 5 shown on the lower left side is used as the working cutting edge is the same. Therefore, it is omitted. Here, the long side surface portion 4a on which the rake face 6a of the working cutting edge 5a is formed is referred to as an upper side surface portion 4a1. The upper side surface portion 4a1 can also be referred to as a first side surface portion 4a1. Similarly, the short side surface portion 4b where the flank 7a of the working cutting edge 5a is formed is referred to as a front side surface portion 4b1. The long side surface portion 4a facing the upper side surface portion 4a1 is called a lower side surface portion 4a2, and the short side surface portion 4b facing the front side surface portion 4b1 is called a rear side surface portion 4b2. The lower side surface portion 4a2 may be referred to as a second side surface portion 4a2, the front side surface portion 4b1, the third side surface portion 4b1, and the rear side surface portion 4b2 may be referred to as a fourth side surface portion 4b2. In FIG. 1, the left end surface 2 is referred to as a first end surface 2, and the right end surface 3 is referred to as a second end surface 3. For ease of explanation, terms indicating directions in space such as up, down, front, back, left, and right are used, but this does not intend to indicate an absolute position or direction in the space. For example, when the working cutting edge is replaced and the other cutting edge on the opposite side of 180 ° is used as the working cutting edge, the direction in the space can be switched between the up and down directions shown here. Further, for example, when the cutting insert 1 is a reverse cutting insert (not shown), the left and right directions can be interchanged in space.

A chip breaker is formed on the rake face 6. Various known shapes are applied as the shape of the chip breaker. In the cutting insert 1 of this embodiment, one chip breaker groove is formed along each cutting edge 5. The chip breaker gives a positive rake angle and reduces cutting resistance.

As shown in FIGS. 8 to 13, the second end surface 3 abuts on the main surface 23 of the tip seat 22 when the cutting insert 1 is mounted on the cutting tool 20, and the peripheral side surface 4 is the auxiliary seat of the tip seat. Abuts against the surface 24. The main surface 23 of the chip seat is the surface that contacts the cutting insert 1 most widely, and can also be referred to as the bottom surface 23. The sub-surface 24 of the chip seat is a surface that rises in a wall shape from the main surface 23 and can also be referred to as a side wall surface 24. The 2nd end surface 3 of the cutting insert 1 is good to be formed in planar shape. If the second end face 3 is formed in a planar shape, the corresponding main surface 23 of the chip seat can also be formed in a flat shape, so that the main surface 23 of the chip seat can be formed with high accuracy and easily. Can do. If the 2nd end surface 3 of the cutting insert 1 is formed in planar shape, the contact with the 2nd end surface 3 and the main surface 23 of a chip seat will be ensured with a wide area. The peripheral side surface 4 of the cutting insert 1 has first and

second holding portions

8a and 8b which are holding portions 8 that come into contact with the sub-surface 24 of the chip seat. Here, the holding portion 8 formed on the lower side surface portion 4a2 is referred to as a first holding portion 8a, and the holding portion 8 formed on the upper side surface portion 4a1 is referred to as a second holding portion 8b. Accordingly, the holding portion 8 that mainly receives the main component force among the cutting resistance applied to the working cutting edge 5a becomes the first holding portion 8a. That is, the main component force of the cutting force acts on the working cutting edge 5a from the upper side surface portion 4a1 side toward the lower side surface portion 4a2 side, and thus the first holding portion 8a formed on the lower side surface portion 4a2. The main component of cutting force is received. The second holding portion 8 b is a holding portion 8 that fixes the cutting insert 1 to the tip seat 22 of the cutting tool 20 by cooperating with the first holding portion 8 a. The first holding portion 8 a has at least two contact surfaces 9 that are spaced apart from each other in the circumferential direction of the cutting insert 1. Here, the contact surface 9 on the side close to the working cutting edge 5a is defined as a first contact surface 9a, and the contact surface 9 on the far side is defined as a second contact surface 9b. As shown in FIGS. 1 to 3, a convex surface portion 10 is formed between two contact surfaces 9 in the circumferential direction of the cutting insert 1.

Here, the end of the first holding portion 8a on the working cutting edge 5a side is a first end 11a, and the other end is a second end 11b. The first contact surface 9a is inclined so as to be recessed inward of the cutting insert 1 from the first end 11a side toward the convex surface portion 10 side. That is, in the circumferential direction of the cutting insert 1, the first contact surface 9 a is inclined so as to approach the upper side surface portion 4 a 1 side from the front side surface portion 4 b 1 side toward the rear side surface portion 4 b 2 side. The second contact surface 9b is inclined so as to be recessed inward of the cutting insert 1 from the second end 11b side of the first holding portion 8a toward the convex surface portion 10 side. That is, the second contact surface 9b is inclined in the circumferential direction of the cutting insert 1 so as to approach the upper side surface portion 4a1 side from the rear side surface portion 4b2 side toward the front side surface portion 4b1 side.

The second holding portion 8b has at least one abutting surface 9. Here, the contact surface 9 of the second holding portion 8b is referred to as a third contact surface 9c. Further, the end of the second holding portion 8b on the side far from the working cutting edge 5a is referred to as a third end 11c, and the end close to the working cutting edge 5a is referred to as a fourth end 11d. The third contact surface 9c is inclined so as to be recessed inward of the cutting insert 1 from the third end 11c side to the fourth end 11d side of the second holding portion 8b. That is, the third contact surface 9c is inclined so as to approach the lower side surface portion 4a2 side from the rear side surface portion 4b2 side toward the front side surface portion 4b1 side. As described above, the cutting insert 1 has a 180 ° rotationally symmetric shape with respect to the central axis of the mounting hole 15. Therefore, the third contact surface 9 c of the second holding portion 8 b is rotationally symmetric with each other by 180 ° with respect to the first contact surface 9 a of the first holding portion 8 a and the central axis of the mounting hole 15. Arranged and shaped. The second holding portion 8b is formed with a fourth contact surface 9d that is 180 ° rotationally symmetric with respect to the second contact surface 9b and the central axis of the mounting hole 15. However, as will be described later, the fourth contact surface 9d does not function as a contact surface with respect to the working cutting edge 5a, and functions as a contact surface when another cutting blade 5 acts. This relationship also holds for the second contact surface 9b.

A raised portion 12 is formed on the working cutting edge 5a side of the second holding portion 8b. Here, the raised portion 12 is referred to as a forward raised portion 12. That is, the fourth end 11 d of the second holding portion 8 b is formed on the front raised portion 12 that is raised outward from the cutting insert 1. A forward curved portion 14 that is smoothly connected from the fourth end 11d of the second holding portion 8b toward the working cutting edge 5a is formed.

A raised portion 13 is also formed on the side of the second holding portion 8b away from the working cutting edge 5a. Here, the raised portion 13 is referred to as a rear raised portion 13. That is, the third end 11 c of the second holding portion 8 b is formed in the rear raised portion 13 that is raised outward from the cutting insert 1.

The material around the cutting edge 5 of the cutting insert 1 is a hard material such as cemented carbide, cermet, ceramics, and sintered body containing cubic boron nitride, or the surface of these hard materials coated with a PVD or CVD coating film. Or a single crystal diamond or a sintered body containing diamond. The material of the cutting insert 1 other than the cutting edge 5 is preferably a similar hard material.

As shown in FIGS. 8 to 12, the cutting tool 20 in this embodiment is a turning tool. More specifically, it is a small tool for a small lathe, also called an automatic lathe, that is, a small turning tool. The cutting insert 1 in this embodiment is suitable for grooving and parting off. Therefore, the cutting tool 20 in this embodiment is suitable for grooving and parting off. However, it is not limited to this. The present invention can be applied to cutting tools for various uses such as for threading. The tool body 21 of the cutting tool 20 in this embodiment is a square whose cross-sectional shape of the shank is 12 mm on each side. In order to enable highly efficient cutting, a small lathe is mounted so that a large number of cutting tools are concentrated on a comb-type tool post or the like. Therefore, it is preferable that the cutting tool used is a small cutting tool having a cross-sectional shape of the shank of about 10 mm to 16 mm on each side.

The clamping member 30 of the cutting tool 20 in this embodiment is a fastening screw 30. However, the clamp member 30 is not limited to this embodiment. Various known mounting methods of the cutting insert 1 such as a lever lock type can be applied.

As shown in FIG. 13, the tip seat 22 of the cutting tool 20 of this embodiment has a main surface (bottom surface) 23 and a sub surface (side wall surface) 24. As described above, the main surface 23 is formed in a planar shape. Further, a screw hole 29 into which a fastening screw 30 that is a clamp member 30 is screwed opens in the main surface 23. The sub-surface 24 of the chip seat 22 basically consists of two surface portions. In other words, the cutting insert 1 includes a first wall surface portion 25a that comes into contact with the first holding portion 8a and a second wall surface portion 25b that comes into contact with the second holding portion 8b. The first wall surface portion 25 a and the second wall surface portion 25 b are separated by the opening portion 28. When the cutting insert 1 protrudes from the open portion 28, the working cutting edge 5 is protruded with respect to the tool body 21. The first and second

wall surface portions

25a and 25b have shapes corresponding to the first and

second holding portions

8a and 8b, respectively. That is, the sub-surface 24 of the tip seat 22 may have any shape as long as it is in contact with the first and

second holding portions

8a and 8b of the cutting insert 1 and can fix the cutting insert 1. The sub-surface 24 of the tip seat 22 is preferably in contact with the cutting insert 1 at least at two locations so that the lower first wall surface portion 25a does not move even when receiving cutting force applied to the cutting edge 5. At least one location of the second wall surface portion 25b on the upper side may be in contact with the cutting insert 1. In this way, if the cutting insert 1 and the tip seat 22 come into contact with each other at three positions that are arranged at positions away from each other and that have different contact surface orientations, the cutting insert 1 is firmly and securely attached to the tip seat 22. Fixed. The first wall surface portion 25a of the cutting tool 20 in this embodiment has two convex curved surface portions, and a connecting surface 27 is formed between the two convex curved surface portions. A holding surface 26 that contacts the holding portion 8 is formed on each convex curved surface portion. Here, the holding surface 26 corresponding to the first contact surface 9a is referred to as a first holding surface 26a, and the holding surface 26 corresponding to the second contact surface 9b is referred to as a second holding surface 26b. Of the two end portions of the first wall surface portion 25a, when the end portion on the first holding surface 26a side is one end and the end portion on the second holding surface 26b side is the other end, the first holding surface 26a. Is inclined so that the first wall surface portion 25a protrudes toward the main surface 23 as it goes from one end side to the other end side of the first wall surface portion 25a. Further, the second holding surface 26b is inclined so that the first wall surface portion 25a protrudes toward the main surface 23 side from the other end side of the wall surface portion 25a toward the one end side. The second holding surface 26b faces the open portion 28 corresponding to the working cutting edge 5a.

The connecting surface 27 between the first and second holding surfaces 26 a and 26 b is a concave portion 27. The concave surface portion 27 has a shape corresponding to the convex surface portion 10 or the flat surface portion. That is, the connecting surface 27 may include a flat portion.

The second wall surface portion 25b has two convex curved surface portions, and a connecting surface is formed between the two convex curved surface portions. However, as shown in FIG. 11, one convex curved surface portion at a position corresponding to the fourth contact surface 9 d of the second holding portion 8 b is retreated upward and does not contact the cutting insert 1. Are arranged as follows. That is, one convex curved surface portion at a position corresponding to the fourth contact surface 9d is formed as the non-holding surface 26d. A holding surface 26 that contacts the holding portion 8 is formed on the other convex curved surface portion. Here, the holding surface 26 corresponding to the third contact surface 9c is referred to as a third holding surface 26c. Of the two end portions of the second wall surface portion 25b, when the end portion on the side far from the opening portion 28 corresponding to the working cutting edge 5a is one end and the end portion on the side close to the opening portion 28 is the other end, The third holding surface 26c is inclined so that the second wall surface portion 25b protrudes toward the main surface 23 side from the other end side of the second wall surface portion 25b toward the one end side.

Next, the operation and effect of each component will be described. The first contact surface 9a is inclined so as to be directed inward of the cutting insert 1 from the first end 11a side to the second end 11b side, and the second contact surface 9b is formed on the first end 11a side. Since it inclines so that it may go to the outward of the cutting insert 1 as it goes to the 2nd end 11b side, the 1st contact surface 9a and the 2nd contact surface 9b are formed so that it may face. In other words, the two extension surfaces that extend the two contact surfaces of the cutting insert 1 and the chip seat 22 intersect each other. For this reason, the cutting insert 1 is firmly fixed to the sub-surface 24 of the chip seat 22 and does not move even if only the two abutting surfaces abut. Furthermore, the third contact surface 9c of the second holding portion 8b is inclined so as to go inward of the cutting insert 1 from the third end 11c side to the fourth end 11d side of the second holding portion 8b. Therefore, the third contact surface 9c is disposed facing the working cutting edge 5a side, that is, is disposed facing the open portion 28 side, and the first contact surface 9a and the second contact surface 9b are arranged. They are arranged in different directions. More specifically, the third holding surface 26c that contacts the third contact surface 9c is disposed so as to face the second holding surface 26a that contacts the second contact surface 9b, and the second holding surface The second contact surface 9b that contacts the surface 26b is disposed so as to face the first contact surface 9a that contacts the first holding surface 26a. Therefore, the cutting insert 1 is firmly fixed by coming into contact with the sub-surface 24 of the chip seat 22 at the first to

third contact surfaces

9a, 9b, 9c. That is, the cutting insert 1 is pressed against the sub-surface 24 of the chip seat 22 because the direction of the fixing force received from the third abutting surface 9c is directed to the first and second abutting

surfaces

9a and 9b, and thus the cutting insert 1 is pressed. Is more effectively suppressed. Here, the third contact surface 9c is preferably formed at a position as far as possible from the working cutting edge 5a. When the third contact surface 9c is formed sufficiently away from the working cutting edge 5a, a cutting resistance is applied to the working cutting edge 5a during the cutting process, and the portion of the working cutting edge 5a opposite to the floating side is lifted. When trying to do so, the third abutment surface 9c can be effectively pressed down. As described above, the cutting insert 1 of this embodiment has a 180 ° rotationally symmetric shape and has two cutting edges 5. That is, the third contact surface 9c is arranged and shaped 180 degrees rotationally symmetrical with the first contact surface 9a, so that when the other cutting edge 5 is used, the first contact surface 9a Change. However, it is not limited to this. The third abutment surface 9c cooperates with the first and second abutment surfaces to abut against the sub-surface 24 of the chip seat 22 so that the cutting insert 1 can be fixed in any arrangement and shape. It does not matter.

When the clamp member 30 is the tightening screw 30, it is preferable to match the rotation direction when the screw is tightened with the direction in which the cutting insert 1 tries to rotate by the cutting resistance. In this embodiment, the fastening screw 30 is preferably a right-hand thread. When the cutting tool 20 is a right hand that is the opposite of this embodiment, the fastening screw is preferably a left-handed screw. When the rotation direction of the tightening screw is selected in this way, the cutting insert 1 can be stopped during the cutting process from the state in which the cutting insert 1 is tightened with the tightening screw.

The convex surface portion 10 of the first holding portion 8a prevents the strength of the cutting insert 1 from being reduced. If this is a concave curved surface, stress concentrates on the concave surface portion, which may be the starting point of the fracture of the cutting insert 1. Therefore, when the concave surface portion is provided, the distance from the attachment hole 15 is increased. In the case of the cutting insert 1 suitable for the small cutting tool 20 for a small lathe, the maximum dimension from the upper side surface portion 4a1 to the lower side surface portion 4a2 is preferably 12 mm or less. As described above, since the shank of the cutting tool 20 for a small lathe has a side of 16 mm or less, it is preferable to suppress it to a size smaller than this. In order to provide the attachment hole 15 in a dimension of 12 mm or less and further provide the first and

second holding portions

8a and 8b, it is effective to provide the convex surface portion 10. Here, the convex surface portion 10 includes a case where the convex surface portion 10 is a flat surface portion 40 as shown in a cutting insert of a second embodiment described later. Since the convex surface portion 10 is at least the flat surface portion 40, stress concentration does not occur, and it can be prevented from becoming a starting point of fracture. That is, by attaching the cutting insert 1 to the chip seat 22 so that the portion where the stress is concentrated does not become a concave curved surface, excessive stress concentration can be prevented and the stress distribution can be dispersed. Moreover, when the convex surface part 10 or the flat surface part 40 is provided, the effect of ensuring the thickness of the cutting insert 1 between the peripheral side surface 4 and the attachment hole 15 is also acquired. In order to ensure the thickness of the cutting insert 1 around the mounting hole 15, for example, the convex surface portion 10 can be formed on a cylindrical surface concentric with the mounting hole 15. However, the convex portion 10 is not limited to being formed concentrically with the attachment hole 15. The cutting insert 1 in this embodiment brings the center position of the curvature radius of the convex surface portion 10 closer to the first holding portion 8a side so that the dimension A in FIG. 2 can be made as large as possible.

Further, the first holding portion 8a may be formed as a smooth curved surface as a whole. Since the entire first holding portion 8a is formed as a smooth curved surface, stress concentration can be further prevented and the wall thickness can be appropriately ensured, so that the cutting insert 1 is prevented from being damaged and suitable for a small lathe. It can be applied to a small cutting tool 20. In that case, the curved portion of the joint between the contact surface 9 and the convex surface portion 10 or the flat surface portion 40 includes a concave curved surface at a position away from the attachment hole 15 to the extent that it does not become a starting point of fracture due to stress concentration. Do not exclude that. What is necessary is just to adjust suitably so that the whole 1st holding | maintenance part 8a may become a smooth curved surface, considering so that stress may not concentrate.

The convex surface portion 10 or the flat surface portion 40 may be formed so as to contact the sub surface 24 of the chip seat 22. When the convex surface portion 10 or the flat surface portion 40 and the sub surface 24 are further in contact with each other, the contact area is increased, the arrangement directions of the contact surfaces are diversified, and the force in more directions can be received. That is, when the convex surface portion 10 or the flat surface portion 40 is formed so as to contact the sub surface 24 of the chip seat 22 in addition to the first and second contact surfaces 9a and 9b, the fixing property of the cutting insert 1 is further improved. To do. Although the number of the convex surface part 10 of this embodiment is one, it is not limited to this. Although not shown, a plurality of convex surface portions 10 may be formed. When the plurality of convex portions 10 are formed so as to abut against the sub-surfaces 24 of the chip seats 22, the fixing property of the cutting insert 1 is further improved. However, in order to bring all of the contact surface 9 and the plurality of convex surface portions 10 into contact with the corresponding holding surfaces 26 of the sub-surface 24 of the chip seat 22, these curved surfaces are ground. It is important to form with precision. On the other hand, in order to form the contact surface 9 at low cost, only the first and second contact surfaces 9a and 9b are used as the first holding portion in the case where the contact surface 9 is formed only by powder pressing and sintering. The two contact surfaces 9 in 8a may be in contact with the sub surface 24 of the chip seat 22.

Here, the thickness of the cutting insert 1 around the mounting hole 15 is a distance A in FIG. That is, from the outermost peripheral portion of the mounting hole 15 in the direction perpendicular to the lower surface portion 4a2 (that is, the direction perpendicular to the long side of the substantially parallelogram when the cutting insert 1 is opposed to the first or second end surface). The distance to the peripheral side surface 4 of the cutting insert 1 is a distance A. It is preferable that the distance A between the attachment hole 15 and the convex surface portion 10 is secured to a required dimension or more. The convex portion 10 is shaped here so as to ensure at least a predetermined thickness over the entire circumference of the mounting hole 15. A distance A is defined as a dimension representative of the thickness. When the diameter of the substantially cylindrical portion 15a of the mounting hole 15 is d, the distance A is preferably in the range of 10% to 80% with respect to the diameter d. When the distance A is less than 10% with respect to the diameter d, there is a concern that the wall thickness is insufficient and the cutting insert 1 is damaged. When the distance A exceeds 80% with respect to the diameter d, there is a concern that the hole diameter of the mounting hole 15 is too small and the tightening screw is too thin to be damaged. The tightening screw is appropriately selected in consideration of cutting conditions and the size of the cutting insert 1. It is preferable that the tightening screw has a diameter of 1.5 mm or the like even if it is small. In the case of the cutting insert 1 for a small lathe, the larger one is preferably up to about 6 mm in diameter. Therefore, the diameter d is preferably in the range of 2 mm or more and 8 mm or less.

Since the contour shapes of the first and second end surfaces 2 and 3 are substantially parallelograms each composed of two long sides and short sides, a small lathe can be obtained by reducing the size of the short sides. The present invention can be applied to a small cutting tool 20 that can be attached to the head. On the other hand, the cutting tool 20 with different protruding lengths can be easily manufactured by appropriately setting the dimension on the long side portion side. This protrusion length is related to the maximum depth of cut which is the cutting condition of the cutting insert 1 and the cutting tool 20. For example, if the cutting tool 20 is for grooving, this overhang length is related to the maximum groove depth constraint that can be machined. The cutting tool 20 of this embodiment has a plurality of types of cutting inserts 1 having different lengths on the side of one type of tool body 21 only by making the shapes of the first and

second holding portions

8a and 8b common. Can be installed. That is, when providing a plurality of cutting tools 20 having different protruding lengths, the tool body 21 can be shared by one type, and only the cutting insert 1 provides a plurality of types. Further, when used for cutting, the periphery of the cutting edge 5 of the cutting insert 1 may be greatly damaged. In the cutting tool 20 of this embodiment, even when the periphery of the cutting edge 5 is greatly damaged, the shapes of the first and

second holding portions

8a and 8b are not damaged, and the opposite cutting edge 5 can be used. It is possible and economical. That is, even if the shape around the cutting edge 5 of the cutting insert 1 on the side opposite to the working cutting edge 5a is damaged, the structure for mounting on the tool body 21 is not affected. The cutting insert 1 of this embodiment has a 180 ° rotationally symmetric shape with respect to the central axis of the mounting hole 15, but is not limited thereto. The shape of the cutting insert 1 may be any shape as long as it can be attached to the tool body 21 and has a cutting edge 5.

As shown in FIG. 2, the distance from the first contact surface 9a to the second contact surface 9b in the direction parallel to the long side portion of the substantially parallelogram is B, and the long side portion of the substantially parallelogram When the total length of the cutting insert 1 in the direction parallel to the length L is L, the interval B is preferably in the range of 15% or more and 50% or less with respect to the total length L. When the interval B is less than 15% of the total length L, the sitting stability of the cutting insert 1 is insufficient, the distance between the fulcrum and the action point becomes long, and the cutting insert 1 is caused by the cutting resistance received by the cutting edge 5. Easier to move. Or there exists a possibility that plastic deformation may arise in the chip seat 22 of the cutting tool 20 by cutting resistance. When the interval B exceeds 50% with respect to the total length L, the protruding length of the cutting insert 1 when mounted on the cutting tool 20 is insufficient, and the use of the cutting tool is greatly limited. Alternatively, the size of the cutting insert 1 is increased as a whole, and cannot be applied to a small lathe.
Since the cutting insert 1 of the present embodiment has a 180 ° rotationally symmetric shape, in FIG. 2, for the sake of convenience, the interval B from the first contact surface 9a to the second contact surface 9b is set to a third value. The distance from the contact surface 9c to the fourth contact surface 9d is shown.
In the present embodiment, the first to fourth contact surfaces 9a to 9d are all flat, and the interval B from the first contact surface 9a to the second contact surface 9b is the first The distance between the end of the contact surface 9a on the first end 11a side and the end of the second contact surface 9b on the second end 11b side is defined as the distance. Similarly, the distance B from the third contact surface 9c to the fourth contact surface 9d is equal to the end of the third contact surface 9c on the third end 11c side and the fourth contact surface 9d. The distance to the end on the 4th end 11d side.

The front raised portion 12 and the front curved portion 14 protect the holding portion 8 from collisions such as chips during cutting. Further, the front raised portion 12 and the front curved portion 14 are effective for forming a suitable chip breaker. Further, the front raised portion 12 and the front curved portion 14 act so that the shape of the second holding portion 8b is not damaged when the periphery of the cutting edge 5 is largely damaged during the cutting process. That is, since the height of the cutting insert 1 in the vicinity of the front raised portion 12 is high, the cross-sectional area increases, and the influence of breakage around the cutting edge 5 reaches the second holding portion 8b beyond the front raised portion 12. To prevent. The front bending portion 14 is connected to the rake face 6a of the working cutting edge 5a. The front curved portion 14 may be a concave curved surface. The front bending portion 14 may be formed integrally with the chip breaker shape. Further, the rake face 6a of the working cutting edge 5a may be formed integrally with the front bending portion 14 so that the boundary is not known.

The rear raised portion 13 is located below the cutting edge 5 when the opposite cutting edge 5 is the working cutting edge, so that the cross-sectional area increases, the rigidity of the cutting insert 1 is increased, and the cutting resistance is increased. Even if it is received, it has the effect of making it difficult to break. The rear raised portion 13 acts so that the shape of the first holding portion 8a is not damaged when the periphery of the cutting edge 5 is greatly damaged during the cutting process. A curved portion that smoothly connects from the rear ridge 13 toward the rear side may be formed.

As shown in FIG. 8 and FIG. 9, the cutting tool 20 in this embodiment has a thin tip. That is, the cutting insert 1 is not disposed on the extended surface of the left side surface, but is disposed at a position greatly shifted to the right side surface side. When the cutting tool 20 is formed in such a shape, it is suitable for cutting on the sub spindle side of the small lathe. Here, the sub-spindle is a sub-spindle with respect to the main spindle in a lathe having two main axes. In a general small lathe, the sub spindle is disposed so as to face the main spindle. That is, in the processing on the sub spindle side, the longitudinal direction (Z direction) is opposite to the main spindle. Therefore, if the cutting tool 20 is not thinned at the tip end side, the area where cutting can be performed on the sub spindle side becomes narrow. In the cutting tool 20 in this embodiment, the tip end side is thin, but since the periphery of the holding surface 26 protrudes, a decrease in rigidity is suppressed. Therefore, the cutting tool 20 of this embodiment has a high rigidity and is easy to use as compared with a cutting tool whose tip side is thin. That is, the cutting tool 20 of this embodiment is resistant to breakage, and the occurrence of chatter vibration is also suppressed.

As described above, each holding surface 26 comes into contact with the corresponding contact surface 9 and cooperates to fix the cutting insert 1. The first and second holding surfaces 26 a and 26 b support the cutting resistance transmitted through the cutting insert 1. The third holding surface 26c that comes into contact with the third contact surface 9c is disposed so as to face the second holding surface 26a that comes into contact with the second contact surface 9b, and the second holding surface 26b has By arranging the second contact surface 9b that contacts the first contact surface 9a that contacts the first holding surface 26a so that the cutting insert 1 is in contact at three locations, Fixed. As described above, the concave surface portion 27 or the flat surface portion of the sub surface 24 may be formed so as to contact the convex surface portion 10 or the flat surface portion 40 of the cutting insert 1. When the concave surface portion 27 or the flat surface portion is formed so as to contact the convex surface portion 10 or the flat surface portion 40, the area of the contact surface increases, and the arrangement direction of the contact surface becomes more diverse, so that the fixing property is improved. Further improve. On the contrary, if the concave surface portion 27 or the flat surface portion is formed so as not to contact the convex surface portion 10 or the flat surface portion 40, it is surely desired even if the shape accuracy of the holding surface 26 or the contact surface 9 is not as high as that of grinding. Therefore, the cutting tool 20 with high fixability can be obtained while suppressing the manufacturing cost.

The cutting insert 1 of the present invention can be manufactured by powder pressure molding and sintering. Further, grinding can be performed after sintering to obtain a cutting insert with high dimensional accuracy. The tool body 21 of the present invention can be manufactured by cutting. The peripheral edge of the second end face 3 of the cutting insert 1 in this embodiment is chamfered to form a narrow band-like plane. When the second end face 3 has such a shape, it prevents the chipping of the cutting insert 1 when mounted on the cutting tool 20, and reduces the grinding allowance when the blade width is finished by grinding. Cost can be reduced. Note that the peripheral edge of the first end surface 2 may also be chamfered.

Next, the cutting insert 1, the tool body 21, and the cutting tool 20 in the second embodiment to which the present invention is applied will be described. In order to simplify the description, the same components as those of the cutting insert 1, the tool body 21 and the cutting tool 20 in the first embodiment are denoted by the same member numbers, and the description thereof is omitted. As shown in FIGS. 14 and 15, the cutting insert 1 of this embodiment is suitable for threading. The cutting insert 1 has two

opposite end surfaces

end surfaces

2 and 3. As shown in FIG. 14, the contour shapes of the two end faces 2 and 3 are substantially triangular. At the center of each of the two

end surfaces

2 and 3, a mounting hole 15 penetrating the end surfaces 2 and 3 is formed. The cutting insert 1 has a shape that is 120 ° rotationally symmetric with respect to the central axis of the mounting hole 15.

A rake face 6 is formed on a part of the first end face 2 of the cutting insert 1. A clearance surface is formed on the peripheral side surface 4 of the cutting insert 1. A cutting edge 5 is formed at the intersection ridgeline between the rake face 6 and the flank face. That is, the cutting edge 5 is formed on at least a part of the intersecting ridge line between the first end surface 2 and the peripheral side surface 4. The cutting insert 1 in this embodiment is formed with three angle-shaped cutting edges 5 for threading. The three cutting edges 5 are arranged and shaped to be 120 ° rotationally symmetrical to each other.

When the cutting insert 1 is mounted on the cutting tool 20, the second end surface 3 contacts the main surface 23 of the tip seat 22, and the peripheral side surface 4 contacts the sub-surface 24 of the tip seat. The 2nd end surface 3 of the cutting insert 1 is good to be formed in planar shape. The peripheral side surface 4 of the cutting insert 1 has first and

second holding portions

8a and 8b which are holding portions 8 that come into contact with the sub-surface 24 of the chip seat. Here, in a plan view, the holding portion 8 that is closest to the working cutting edge 5a in the clockwise direction is referred to as a second holding portion 8b, and the second holding portion 8 in the clockwise direction is referred to as a first holding portion 8a. . Therefore, the holding portion 8 that mainly receives the back component force of the three component forces of the cutting force applied to the working cutting edge 5a becomes the first holding portion 8a. The first holding portion 8 a has at least two contact surfaces 9. Here, the contact surface 9 on the side farther in the circumferential direction of the cutting insert 1 from the second holding portion 8b is the first contact surface 9a, and the contact surface 9 on the closer side is the second contact surface 9b. To do. As shown in FIG. 14, a flat portion 40 is formed between the two contact surfaces 9. In FIG. 14, the flat portion 40 is formed so that a valley line appears between the two contact surfaces 9 so that the flat portion 40 can be easily understood. In practice, it is preferable to form a connection portion that smoothly connects the contact surface 9 and the flat portion 40 so that the valley line does not appear.

Here, the end of the first holding portion 8a on the working cutting edge 5a side is one end, and the other end is the other end. The first contact surface 9a is inclined so as to go inward of the cutting insert 1 from the one end side toward the flat surface portion 40 side. The second contact surface 9b is inclined so as to go inward of the cutting insert 1 from the other end side of the first holding portion 8a toward the flat surface portion 40 side.

The second holding portion 8b has at least one abutting surface 9. Here, the contact surface 9 of the second holding portion 8b is referred to as a third contact surface 9c. The end of the second holding portion 8b on the side away from the working cutting edge 5a is the third end, and the end on the working cutting edge 5a side is the fourth end. The third contact surface 9c is inclined so as to go inward of the cutting insert 1 from the third end side to the fourth end side of the second holding portion 8b. As described above, the cutting insert 1 has a 120 ° rotationally symmetric shape with respect to the central axis of the mounting hole 15. Accordingly, the third contact surface 9 c of the second holding portion 8 b is rotationally symmetrical with respect to each other by 120 ° with respect to the first contact surface 9 a of the first holding portion 8 a and the central axis of the mounting hole 15. Arrangement and shape.

As shown in FIGS. 15 and 16, the cutting tool 20 in this embodiment is a turning tool. The cutting tool 20 in this embodiment is suitable for thread cutting. However, it is not limited to this. The clamping member 30 of the cutting tool 20 in this embodiment is a fastening screw 30. However, the clamp member 30 is not limited to this embodiment.

As shown in FIG. 17, the tip seat 22 of the cutting tool 20 of this embodiment has a main surface (bottom surface) 23 and a sub surface (side wall surface) 24. The main surface 23 is formed in a planar shape. Further, a screw hole into which a fastening screw 30 that is a clamp member 30 is screwed opens in the main surface 23. The sub-surface 24 of the chip seat 22 basically consists of two surface portions. In other words, the cutting insert 1 includes a first wall surface portion 25a that comes into contact with the first holding portion 8a and a second wall surface portion 25b that comes into contact with the second holding portion 8b. The first wall surface portion 25 a and the second wall surface portion 25 b are separated by the opening portion 28. The first and second

wall surface portions

25a and 25b have shapes corresponding to the first and

second holding portions

8a and 8b of the cutting insert 1 and can fix the cutting insert 1. The sub-surface 24 of the tip seat 22 has at least two first wall portions 25a on the opposite side to the cutting edge 5 so that they do not move even when receiving cutting resistance applied to the cutting edge 5. It is good to abut. The second wall surface portion 25b may be in contact with the cutting insert 1 at least at one place. If it makes contact at three places in this way, the cutting insert 1 is firmly and securely fixed. The first wall surface portion 25a of the cutting tool 20 in this embodiment has one convex curved surface portion. A holding surface 26 that contacts the contact surface 9 is formed on the convex curved surface portion. Here, the holding surface 26 corresponding to the first contact surface 9a is referred to as a first holding surface 26a, and the holding surface 26 corresponding to the second contact surface 9b is referred to as a second holding surface 26b. The second wall surface portion 25b of the cutting tool 20 has one convex curved surface portion. A holding surface 26 that contacts the contact surface 9 is also formed on the convex curved surface portion. Here, the holding surface 26 corresponding to the third contact surface 9c is referred to as a third holding surface 26c. The cutting tool 20 of this embodiment has a fourth holding surface 26e corresponding to the fourth contact surface 9d. That is, the sub-surface 24 of the tip seat 22 is configured to abut on the peripheral side surface 4 of the cutting insert 1 at four locations. However, it is not limited to this. The fourth holding surface 26e may be a non-holding surface.

The cutting insert and the cutting tool of the present invention are not limited to the embodiment described above, and various changes and additions can be made without departing from the gist of the present invention. For example, the present invention is not limited to a lathe cutting tool, and can be applied to a rotary cutting tool.

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 1st end surface 3 2nd end surface 4 Peripheral side surface 4a Peripheral side surface part 4a1 by the side of a long side Upper side surface part (1st side surface part)
4a2 Lower side surface portion (second side surface portion)
4b Short side peripheral side surface portion 4b1 Front side surface portion (third side surface portion)
4b2 Rear side surface portion (fourth side surface portion)
5 Cutting edge 5a Action cutting edge 6 Rake face 6a Action cutting edge rake face 7 Relief face 7a Action cutting edge relief face 8 Holding part 8a First holding part 8b Second holding part 9 Abutting face 9a First Contact surface 9b Second contact surface 9c Third contact surface 9d Fourth contact surface 10 Convex surface portion 11a One end of the first holding portion (first end)
11b The other end (second end) of the first holding portion
11c 3rd end 11d 4th end 12 Front raised part 13 Back raised part 14 Front curved part 15 Attachment hole 15a Substantially cylindrical part 20 Cutting tool 21 Tool body 22 Tip seat 23 Main surface (bottom face) of tip seat
24 Sub-surface (side wall surface) of chip seat
25a First wall surface portion 25b Second wall surface portion 26 Holding surface 26a First holding surface 26b Second holding surface 26c Third holding surface 26d Non-holding surface 26e Fourth holding surface 27 Concave portion 28 Opening portion 29 Screw hole 30 Clamp member 40 Plane portion

Claims

A cutting insert (1) having two opposite end faces (2, 3) and a peripheral side face (4) connecting between the end faces (2, 3),
The peripheral side surface (4) comprises at least one holding part (8a),
The holding portion (8a) includes first and second contact surfaces (9a, 9b) spaced apart in the circumferential direction of the cutting insert, and the first and second contact surfaces (9a, 9b). A convex surface portion (10) or a flat surface portion (40) formed between
The first abutting surface (9a) has a cutting insert (as viewed from the one end (11a) side of the holding portion (8a) toward the convex surface portion (10) or the flat surface portion (40) in the circumferential direction. 1) Inclined to dent inward,
The second abutment surface (9b) is formed in the circumferential direction from the other end (11b) side of the holding portion (8a) toward the convex surface portion (10) or the flat surface portion (40). (1) The cutting insert which inclines so that it may dent inward.
A rake face (6), a flank face (7), and at least one cutting edge (5) at the intersection ridge line of the rake face (6) and the flank face (7),
The peripheral side surface (4) has a plurality of side surface portions, and a second holding portion is provided on a first side surface portion (4a1) different from the second side surface portion (4a2) on which the holding portion (8a) is disposed. (8b)
The second holding portion (8b) has a third contact surface (9c),
When the cutting edge (5) located between the first side surface portion (4a1) and the second side surface portion (4a2) in the circumferential direction of the cutting insert is a working cutting blade,
In the circumferential direction, the end of the second holding portion (8b) far from the working cutting edge is defined as a third end (11c), which is close to the working cutting edge of the second holding portion (8b). When the end on the side is the fourth end (11d),
The third abutting surface (9c) is formed in the cutting insert (1) as it goes from the third end (11c) side to the fourth end (11d) side of the second holding portion (8b). The cutting insert according to claim 1, wherein the cutting insert is inclined so as to be recessed.
The peripheral side surface (4) is provided between the first and second contact surfaces (9a, 9b) and the convex surface portion (10) or the flat surface portion (40). The cutting insert according to claim 1 or 2, wherein each curved portion that smoothly connects the contact surface (9a, 9b) and the convex surface portion (10) or the flat surface portion (40) is formed.
When viewed from the direction facing the end faces (2, 3), the contour shape of each of the end faces (2, 3) is a substantially parallelogram,
A rake face (6), a flank face (7), and at least one cutting edge (5) at the intersection ridge line of the rake face (6) and the flank face (7),
The cutting insert according to any one of claims 1 to 3, wherein the rake face (6) is formed on the peripheral side face (4).
The substantially parallelogram that is the contour shape of each of the end faces (2, 3) has two long sides and two short sides,
The peripheral side surface (4) includes two long side surface portions (4a) corresponding to the two long side portions and two short side surface portions (4b) corresponding to the two short side portions, respectively. Have
The rake face (6) is formed on one (4a1) of the two long side face parts (4a),
At least a part of the flank (7) is formed on one (4b1) of the two short side portions (4b);
The holding portion (8a) on which the first and second contact surfaces (9a, 9b) are formed is formed on the other (4a2) of the two long side surface portions (4a),
The second holding portion (8b) is formed at a position farther from the working cutting edge than the rake face (6) in the one (4a1) of the two long side face portions (4a). The cutting insert according to claim 4.
The first contact surface (9a) and the third contact surface (9c) are arranged and shaped rotationally symmetrical to each other with respect to an axis passing through the two end surfaces (2, 3). The cutting insert according to any one of claims 2 to 5.
A mounting hole (15) passing through the two end faces (2, 3);
The cutting insert according to any one of claims 1 to 6, wherein the contour shape of the cutting insert (1) is 180 ° rotationally symmetric with respect to the central axis of the mounting hole (15).
A mounting hole (15) passing through the two end faces (2, 3);
The mounting hole (15) has a substantially cylindrical portion (15a) whose diameter d is substantially constant,
The distance A from the mounting hole (15) to the convex surface portion (10) or the flat surface portion (40) is in a range of 10% to 80% with respect to the diameter d. The cutting insert according to claim 1.
When viewed from the direction facing the end faces (2, 3), the contour shape of each end face (2, 3) is a substantially parallelogram, and the substantially parallelogram has two long sides and two short sides. Consisting of sides,
The distance B from the first contact surface (9a) to the second contact surface (9b) in the direction parallel to the long side portion and the cutting insert (1 in the direction parallel to the long side portion ) And the total length L of
The cutting insert according to any one of claims 1 to 8, wherein the interval B is in a range of 15% to 50% with respect to the total length L.
The rake face (6) is formed on the peripheral side face (4),
10. The raised portion (12) is formed at the fourth end (11 d), which is the end portion on the cutting edge (5) side of the second holding portion (8 b). The cutting insert according to Item.
A concave curved portion (14) is formed between the second holding portion (8b) and the working cutting edge, and the curved portion (14) is the fourth end of the second holding portion (8b). The cutting insert according to claim 10, wherein the cutting insert is smoothly connected to (11d).
A tool body (21) of a cutting tool (20) for detachably mounting the cutting insert (1) according to any one of claims 1 to 11,
A tip seat (22) is provided, and the tip seat (22) is erected from the main surface (23) on which one of the two end faces (2, 3) can abut, and the main surface (23). And has a secondary surface (24) with which a part of the peripheral side surface (4) can contact,
The secondary surface (24) includes a wall surface portion (25a) with which the holding portion (8a) of the cutting insert (1) can abut,
The wall surface portion (25a) is in contact with the first holding surface (26a) on which the first contact surface (9a) of the cutting insert (1) can contact, and the second contact surface (9b). A tool body having a contactable second holding surface (26b).
Of the two end portions of the wall surface portion (25a), when the end portion on the first holding surface (26a) side is one end and the end portion on the second holding surface (26b) side is the other end,
The first holding surface (26a) is inclined so that the wall surface portion (25a) protrudes toward the main surface (23) as it goes from the one end side to the other end side of the wall surface portion (25a). ,
The second holding surface (26b) is inclined so that the wall surface portion (25a) protrudes toward the main surface (23) as it goes from the other end side to the one end side of the wall surface portion (25a). The tool body according to claim 12.
The tool body according to claim 12 or 13, wherein the wall surface portion (25a) has a concave surface portion (27) or a flat surface portion formed between the first and second holding surfaces (26a, 26b).
The sub-surface (24) of the tip seat (22) has an opening (28),
The secondary surface (24) is separated from the wall surface portion (25a) by the open portion (28), and a second holding portion (8b) of the cutting insert (1) can contact the second surface. A wall surface portion (25b),
The second wall surface portion (25b) has a third holding surface (26c),
Of the two end portions of the second wall surface portion (25b), an end portion on the side far from the opening portion (28) is one end, and an end portion on the side close to the opening portion (28) is the other end. ,
The third holding surface (26c) is arranged so that the second wall surface portion (25b) is closer to the main surface (23) as it goes from the other end side to the one end side of the second wall surface portion (25b). The tool body according to any one of claims 12 to 14, which is inclined so as to protrude.
The sub-surface (24) of the tip seat (22) has an opening (28),
The tool body according to any one of claims 12 to 15, wherein the wall surface portion (25a) has the second holding surface (26b) facing the open portion (28).
A cutting tool comprising the cutting insert (1) according to any one of claims 1 to 11. *