WO2015137509A1

WO2015137509A1 - Cutting insert, tool body, and cutting tool

Info

Publication number: WO2015137509A1
Application number: PCT/JP2015/057600
Authority: WO
Inventors: 岳志山口
Original assignee: 株式会社タンガロイ
Priority date: 2014-03-14
Filing date: 2015-03-13
Publication date: 2015-09-17
Also published as: JPWO2015137509A1; JP6025088B2

Abstract

An approximately square, flat cutting insert (1) that includes approximately square first and second end surfaces (2,3) having a hole (19) for fixation to a cutting tool passing therebetween. Four successively adjacent surfaces that connect the two end surfaces (2, 3) are third to sixth end surfaces (4-7). A rake surface (8) is formed on the fourth end surface (5). A first cutting edge (11) is formed at an intersecting ridge line of the rake surface (8) and the first end surface (2). When viewed from the side of the rake surface (8), a second cutting edge (12) is formed at an intersecting ridge line of the third end surface (4) and the fourth end surface (5). When viewed from the side of the rake surface (8), the angle between the first cutting edge (11) and the second cutting edge (12) is 10-85° inclusive. The formation of a protrusion (16) or a recess, which contacts a tip seat of the cutting tool, on the fifth end surface (6) that is on the opposite side to the third end surface (4) enables stable fixation to the cutting tool.

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 and cutting tools include those shown in Patent Document 1. FIG. 1 and FIG. 2 of the same document describe a cutting insert having a substantially rectangular plate shape having two opposing end faces having a substantially square shape and having a hole penetrating the two end faces. On each of the four side surfaces connecting the two end surfaces, a rake surface is formed at a connection portion with each end surface. That is, a total of eight rake faces are formed, and a cutting edge is formed at the intersection ridgeline between each rake face and each end face.

Japanese Laid-Open Patent Publication No. 57-27603

The conventional cutting insert of Patent Document 1 is placed in a state where one end face is in contact with the bottom surface of the tip seat of the cutting tool, and is fixed to the tip seat by screwing a screw through the through hole. At this time, it is set as the structure which the flat surface of a side surface contacts with the wall surface of the chip seat of a cutting tool. For this reason, in the cutting insert as described in Patent Document 1, when a cutting force acts on the cutting edge, the flat surface may float from the wall surface of the chip seat. In other words, the cutting insert may move during cutting, and fixing stability may be insufficient.

The present invention has been made to solve such a problem. To this end, according to the first embodiment of the present invention, the cutting insert has a substantially polygonal plate shape, and has a hole penetrating two polygonal end faces. The two polygonal end surfaces are defined as a first end surface and a second end surface, and one of a plurality of surfaces connecting the first and second end surfaces is defined as a third end surface, If one surface adjacent to the third end surface is defined as a fourth end surface, and a surface located on the opposite side or substantially opposite to the third end surface with respect to the hole is defined as a facing end surface, the fourth end surface In addition, a rake face is formed, a first cutting edge is formed at a crossing ridge line between the rake face and the first end face, and the third end face and the fourth edge are viewed from the rake face 8 side. A second cutting edge is formed at the intersecting ridge line with the end face, and when viewed from the rake face side, The angle formed by one cutting edge and the second cutting edge is in the range of 10 ° to 85 °, and a convex portion or a concave portion that contacts the tip seat of the cutting tool is formed on the opposed end surface. A cutting insert is provided.

Further, in the second aspect of the present invention, the tool body of the cutting tool to which the cutting insert is mounted, the first wall surface of the tip seat that contacts the convex portion or the concave portion of the cutting insert, A tool body is provided that includes an inclined surface that inclines toward the inside of the tip seat as the first wall surface comes into contact with the first end surface or the second end surface and moves away from the bottom surface of the tip seat. Is done.

Further, in a third embodiment of the present invention, a cutting tool provided with the above cutting insert is provided.

The cutting insert of the present invention is in contact with the tip seat of the cutting tool at the convex portion or concave portion of the opposed end surface located on the opposite side or almost opposite side of the third end surface. For this reason, it is prevented that the cutting insert floats up from the chip seat. As a result, the cutting insert is prevented from shifting in the tip seat. For this reason, the stability of fixing of the cutting insert is high. As a result, the quality of the machined surface is improved and the tool life is greatly improved.

FIG. 1 is a perspective view of a cutting insert according to the first embodiment. FIG. 2 is a right side view of the cutting insert shown in FIG. FIG. 3 is a plan view of the cutting insert shown in FIG. FIG. 4 is a front view of the cutting insert shown in FIG. FIG. 5 is a rear view of the cutting insert shown in FIG. FIG. 6 is a perspective view of a cutting tool equipped with the cutting insert shown in FIG. FIG. 7 is an enlarged perspective view around the tip seat of the cutting tool shown in FIG. FIG. 8 is a perspective view of a cutting insert according to the second embodiment. FIG. 9 is a right side view of the cutting insert shown in FIG. FIG. 10 is a plan view of the cutting insert shown in FIG. FIG. 11 is a front view of the cutting insert shown in FIG. 12 is a rear view of the cutting insert shown in FIG.

First Embodiment A first embodiment of a cutting insert, a tool body, and a cutting tool to which the present invention is applied will be described with reference to FIGS.

As shown in FIGS. 1 to 3, the cutting insert 1 of this embodiment has a substantially rectangular plate shape. Moreover, the cutting insert 1 has the hole 19 which penetrates the two

end surfaces

2 and 3 which each have a substantially square shape and oppose. The hole 19 comes into contact with a clamping member 40 such as a tightening screw or a lever when the cutting insert 1 is mounted on the cutting tool 30. The hole 19 is therefore also called a clamping hole. The cutting insert 1 has four

end faces

4, 5, 6 and 7 which are connected between the two

end faces

2 and 3 and are sequentially adjacent to each other. The end faces 2 and 3 of the cutting insert 1 of this embodiment are substantially square as shown in FIGS. Accordingly, the four end faces 4, 5, 6 and 7 have substantially the same shape.

Here, the two substantially

square end surfaces

2 and 3 are referred to as a first end surface 2 and a second end surface 3, respectively. Further, the remaining end faces 4, 5, 6 and 7 are referred to as a third end face 4, a fourth end face 5, a fifth end face 6 and a sixth end face 7, respectively. That is, the end face adjacent to the third end face 4 is the fourth end face 5. The end face adjacent to the fourth end face 5 on the side opposite to the third end face 4 is the fifth end face 6. In this embodiment, the fifth end face 6 has a hole 19 from the third end face 4. It becomes the opposing end surface located on the opposite side across. The end face adjacent to the fifth end face 6 on the side opposite to the fourth end face 5 is the sixth end face 7. The sixth end face 7 is also adjacent to the third end face 4. Therefore, the

end surfaces

4 and 6 are end surfaces facing each other, and the

end surfaces

5 and 7 are end surfaces facing each other. Note that the end faces 4, 5, 6 and 7 correspond to the sides of a substantially square forming the basic shape of the

end faces

2 and 3. Accordingly, a fillet surface, a chamfered surface, or the like (a honing surface or the like) may be formed at a connection portion between the

end surfaces

4, 5, 6, and 7. In this case, the adjacent end faces 4, 5, 6 and 7 mean end faces substantially corresponding to sides of a polygon (in this embodiment, a square) except for a fillet surface and a chamfered surface.

As shown in FIG. 6, the cutting insert 1 of this embodiment is mounted on the cutting tool 30 so that the fourth end face 5 becomes the rake face 8, for example. The cutting insert 1 of the present embodiment is rotated by 90 ° around the axis O of the hole 19 (for example, from the state shown in FIG. 3 to the state shown in FIG. 4) or an axis orthogonal to the axis O of the hole 19. Can be used eight times by rotating 180 degrees around (for example, from the state shown in FIG. 4 to the state shown in FIG. 5) and reattaching to the cutting tool 30. That is, it is an economical cutting insert 1. That is, the third to sixth end faces 4 to 7 are all 90 ° rotationally symmetric around the axis O. Accordingly, the third to sixth end faces 4 to 7 can all function as the rake face 8. Similarly, the first end surface 2 and the second end surface 3 have a 180 ° rotationally symmetric shape around an axis orthogonal to the axis O of the hole 19.

Hereinafter, in order to simplify the description, the surface acting as the rake face 8 is defined as the fourth end face 5 and will be described. The description when the other three end faces 4, 6, and 7 act as the rake face 8 is omitted. As described above, since the end faces 4, 5, 6 and 7 have a 90 ° rotationally symmetric shape around the axis O, they function in the same manner even when the orientation is changed and the chip seat of the cutting tool 30 is mounted. Because. The fourth end face 5 can be used twice as a rake face, but for the sake of simplicity, only one explanation is given and the other explanation is omitted. The end faces 2 and 3 have a 180 ° rotationally symmetric shape around an axis orthogonal to the axis O of the hole 19. Even if the end face 2 and the end face 3 are replaced and mounted on the chip seat of the cutting tool 30, the same applies. Because it works. A chip breaker is preferably formed on the rake face 8. Various known shapes are applied as the shape of the chip breaker.

Hereinafter, the fourth end surface 5 is referred to as the upper surface 5, and the third end surface 4 is referred to as the front surface 4. Similarly, the first end face 2 is called a right face 2, the second end face 3 is called a left face 3, the fifth end face 6 is called a back face 6, and the sixth end face 7 is called a lower face 7. These names correspond to the cutting insert 1 of the present embodiment when viewed from the end as shown in FIG. 4 as a front view, and in order to make the explanation easy to understand, space such as up, down, left, right, etc. This term is used for convenience, and is intended to specify the absolute orientation and positional relationship in the space of each surface. is not. Unless otherwise noted, the same applies to terms representing orientations and positional relationships in other spaces. As best shown in FIG. 2, a cutting edge 10 is formed at the intersecting ridge line between the upper surface 5 and the right surface 2. A cutting edge 10 is also formed on the intersecting ridge line between the upper surface 5 and the front surface 4. Here, the portion of the cutting edge 10 formed at the intersecting ridge line between the upper surface 5 and the right surface 2 is referred to as a first cutting edge 11. Further, the portion of the cutting edge 10 formed at the intersecting ridge line between the upper surface 5 and the front surface 4 is referred to as a second cutting edge 12. The corners of the first cutting edge 11 and the second cutting edge 12 are smoothly connected by the arc cutting edge 13.

A flank 9 is formed on the right surface 2 connected to the first cutting edge 11. A flank 9 is also formed on the front surface connected to the second cutting edge 12. A curved relief surface 9 is also formed on the connection surface between the right surface and the front surface connected to the arc cutting edge 13. The flank 9 is a surface formed by smoothly connecting these three surfaces. In the cutting insert 1 of this embodiment, the angle α between the first cutting edge 11 and the second cutting edge 12 when viewed from the direction facing the rake face 8 is about 80 ° (see FIG. 3). . If it does in this way, this cutting insert 1 can use both the 1st cutting edge 11 and the 2nd cutting edge 12 as a main cutting edge. For example, as shown in FIG. 6, when the cutting tool 30 of this embodiment is an outer diameter tool for lathe, the first cutting edge 11 is a main cutting for cutting the outer diameter side of the workpiece. It is considered a blade. The second cutting edge 12 is a main cutting edge for cutting the end face side of the workpiece.

That is, the cutting tool 30 and the cutting insert 1 of this embodiment are easy to use because a single cutting tool 30 can be turned in two directions on the outer diameter side and the end face side. However, the angle α formed by the first cutting edge 11 and the second cutting edge 12 is not limited to this and may be in the range of 10 ° or more and 85 ° or less. The angle α is preferably in the range of 50 ° or more and 85 ° or less. With such an angle, the lathe cutting tool 30 and the cutting insert 1 are very easy to use. The ease of use mentioned here means that replacement with a conventional cutting tool is easy, and that lathe machining in two directions on the outer diameter side and the end face side is possible. That is, the conventional lathe cutting tool in which the angle α formed by the first cutting edge 11 and the second cutting edge 12 is about 80 ° can be used four times by reattaching the cutting insert (first time) And when the second end face is a rhombus) or six times (when the first and second end faces are hexagonal) are often used. On the other hand, the cutting tool 30 of this embodiment is economical because the number of times the cutting insert 1 can be used is increased to eight.

The cutting insert 1 of this embodiment is made to be a substantially square plate shape so that it can be used eight times, but is not limited thereto. For example, if it is a substantially polygonal plate shape such as a substantially pentagonal plate shape or a substantially hexagonal plate shape, it is possible to further increase the number of times it can be used. However, by making it a substantially square plate shape, the cutting insert 1 becomes small and economical and is very easy to use.

The left surface 3, the rear surface 6 and the lower surface 7 of the cutting insert 1 of this embodiment come into contact with the chip seat 32 when the cutting insert 1 is mounted on the cutting tool 30. FIG. 7 shows an enlarged perspective view around the chip seat 32 of the cutting tool 30 of this embodiment. As shown in FIG. 7, the bottom surface 33 and the wall surface 34 of the chip seat 32 are portions formed so as to be in contact with the left surface 3, the back surface 6, and the bottom surface 7. The wall surface 34 includes a first wall surface 34 a that contacts the back surface 6 and a second wall surface 34 b that contacts the lower surface 7. The left surface 3 of the cutting insert 1 is preferably formed as a flat surface. When the left surface 3 is a flat surface, the bottom surface 33 of the chip seat 32 can also be a flat surface, so that machining can be easily performed and the shape of the chip seat 32 can be fixed with high stability. However, it is not limited to this. The left surface 3 and the bottom surface 33 of the chip seat 32 may have any shape as long as they can contact each other and fix the cutting insert 1.

The back surface 6 of the cutting insert 1 has the convex part 14, as shown in FIG.1 and FIG.5. The convex portion 14 has two inclined portions 16, and at least one inclined portion 16 contacts the wall surface 34 of the chip seat 32 when the cutting insert 1 is mounted on the cutting tool 30. The cutting insert 1 of this embodiment has eight cutting edges 10 as described above, and can be used eight times. Accordingly, the cutting insert 1 has eight inclined portions 16 and four convex portions 14. Here, when the first cutting edge 11, the second cutting edge 12, and the arc cutting edge 13 are the working cutting edges (that is, the first end face, the third end face, and the fourth end face are respectively the right face 2). The inclined portion 16 that comes into contact with the wall surface 34 of the chip seat 32 when the front surface 4 and the upper surface 5 are formed is referred to as a first inclined portion 16a. In addition, although the convex part 14 is formed in the cutting insert 1 of this embodiment, it replaces with the convex part 14 and the recessed part 15 may be formed so that it may mention later about FIG.

The first inclined portion 16a is inclined so as to gradually protrude outwardly from the upper surface 5 toward the lower surface 7, and is inclined so as to gradually protrude outwardly as the distance from the right surface 2 increases. When the second cutting edge 12 or the like acts as a working cutting edge, the first inclined portion 16a formed on the back surface 6 opposite to the second cutting edge 12 is formed by the first wall surface 34a of the tip seat 32. Contact with. When the second cutting edge 12 or the like acts as a working cutting edge, the first inclined portion 16a on the side opposite to the second cutting edge 12 tends to float by the main component of the cutting force. Since the chip seat 32 is pressed downward from the first wall surface 34a of the tip seat 32, it does not rise. Further, although it tends to float in the direction away from the bottom surface 33 of the tip seat 32 by the feed force of the cutting force, that is, on the right surface 2 side, it does not float in that direction because it is pressed from the first wall surface 34a of the tip seat 32. . Therefore, the stable cutting insert 1 can be restrained. This prevents the cutting insert 1 from moving during cutting.

The convex portion 14 of the cutting insert 1 is preferably formed so as to extend in an oblique direction with respect to the lower surface 7 in the end surface view of FIG. That is, the convex portion 14 is preferably formed so as to extend in an oblique direction with respect to the intersecting ridge line between the lower surface 7 and the rear surface 6 when viewed from the direction facing the rear surface 6. When the convex portion 14 is formed in this way, the first inclined portion 16a is inclined so as to gradually protrude outwardly from the upper surface 5 toward the lower surface 7, and gradually outwards as it is separated from the right surface 2. It is easy to form it so as to be raised. Therefore, the direction in which the convex portion 14 extends is preferably the direction from the right surface 2 to the left surface 3 as it goes from the lower surface 7 to the upper surface 5. The direction in which the convex portion 14 extends is easy to understand if it is considered as the following direction.

When there is a ridge line portion 17 formed by two inclined portions 16 on the top of the convex portion 14, the direction in which the ridge line portion 17 extends is defined as the direction in which the convex portion 14 extends. When the ridge line portion 17 does not clearly appear on the top of the convex portion 14 (when the two inclined portions 16 are connected by a curved surface), the two inclined portions 16 formed on the convex portion 14 are approximated and extended 2 respectively. The direction in which the intersecting ridge lines of the two virtual surfaces extend is defined as the direction in which the convex portion 14 extends. Note that the convex portion 14 “extends in an oblique direction with respect to the lower surface 7” means that the direction in which the convex portion 14 extends when viewed from the direction facing the rear surface 6, that is, when the rear surface 6 is viewed from the end surface, It means that the intersection ridge line with the back surface 6 intersects with an acute angle.

When the ridge line portion 17 is on the top of the convex portion 14, the direction in which the ridge line portion 17 extends as viewed from the direction facing the back surface 6 is a direction that intersects at an acute angle with the direction in which the intersecting ridge line between the bottom surface 7 and the back surface 6 extends. It is preferable that If the convex part 14 is formed in such a shape and direction, the cutting insert 1 will be firmly pressed by the wall surface 34a of the chip seat 32, and the cutting insert 1 will be prevented from shifting during cutting. More preferably, the range of the angle β formed by the direction in which the convex portion 14 extends and the direction in which the intersecting ridgeline between the lower surface 7 and the rear surface 6 extends is 5 ° or more and 40 ° or less. In general, the cutting force is greater in the main component than in the feed component. Therefore, in order to further enhance the restraining effect on the main component force of the cutting force, such an angle range is preferable.

The lower surface 7 of the cutting insert 1 comes into contact with the second wall surface 34 b of the tip seat 32 of the cutting tool 30 when the cutting insert 1 is mounted on the cutting tool 30. That is, the lower surface 7 includes a contact surface that comes into contact with the second wall surface 34 b of the chip seat 32. As described above, the left surface 3 of the cutting insert 1 is in contact with the bottom surface 33 of the chip seat 32. Further, the back surface 6 of the cutting insert 1 is in contact with the first wall surface 34 a of the chip seat 32. As described above, the cutting insert 1 is firmly fixed to the cutting tool 30 when the hole 19 comes into contact with the clamp member 40.

As described above, the direction in which the convex portion 14 extends is preferably an angle range of 5 ° or more and 40 ° or less with respect to the direction in which the intersecting ridge line between the lower surface 7 and the back surface 6 extends. On the other hand, the direction in which the convex portion 14 extends is preferably an angle range of 50 ° or more and 70 ° or less with respect to the direction in which the intersecting ridge line between the lower surface 7 and the back surface 6 extends. The direction in which the convex portion 14 of the cutting insert 1 of this embodiment extends is about 60 ° with respect to the direction in which the intersecting ridge line between the lower surface 7 and the rear surface 6 extends. The contact surface of the lower surface 7 is preferably provided immediately below the cutting edge 10. Therefore, when the direction in which the convex portion 14 extends is an angle range of 50 ° or more and 70 ° or less with respect to the direction in which the intersecting ridge line between the lower surface 7 and the rear surface 6 extends, the convex portion 14 is formed on the cutting edge 10. Since it can extend to just below and abut on the 2nd wall surface 34b, in cutting insert 1 of this embodiment, convex part 14 can be combined with a contact surface to the 2nd wall surface 34b. That is, when the cutting insert 1 is attached so that the fifth end surface shown as the back surface 6 in the above description becomes the lower surface 7, the convex portion 14 can function as a contact surface with respect to the second wall surface 34b. it can.

As shown in FIG. 7, the tip seat 32 of the cutting tool 30 in this embodiment has a screw hole 35 formed in the direction of the axis O ′ in order to fix the clamping screw which is the clamp member 40. The screw hole 35 opens to the bottom surface 33. A female screw is formed on the inner surface of the screw hole 35. The wall surface 34 basically consists of two surfaces. That is, as described above, the first wall surface 34 a that contacts the convex portion 14 of the cutting insert and the second wall surface 34 b that contacts the lower surface 7 are formed.

The first wall surface 34 a has a complementary shape corresponding to the first inclined portion 16 a formed by the convex portion 14. In other words, the first wall surface 34a is an inclined surface that is inclined so as to approach (protrude) inward of the chip seat 32 as the distance from the second wall surface 34b increases. If the 1st wall surface 34a of the chip seat 32 is formed in such a shape, the cutting insert 1 will be firmly restrained by the 1st wall surface 34a via the 1st inclination part 16a, and the cutting insert 1 will be a chip seat. It is possible to prevent floating from the second wall surface 34b of 32. It is more preferable that the first wall surface 34 a be an inclined surface that is inclined so as to approach the inside of the chip seat 32 as it is separated from the bottom surface 33 of the chip seat 32. When the first wall surface 34a of the chip seat 32 is formed in such a shape, the cutting insert 1 is more firmly restrained by the first wall surface 34a via the first inclined portion 16a, and the cutting insert 1 is inserted into the chip. It is possible to prevent the floating from the bottom surface 33 from the seat 32 more effectively.

The second wall surface 34 b of the tip seat 32 in the cutting tool 30 of this embodiment is in contact with the convex portion of the lower surface 7 of the cutting insert 1. As described above, the convex portion of the lower surface 7 has the same shape as the convex portion 14 of the back surface 6. That is, as described above, the convex portion 14 of the back surface 6 can also serve as the contact surface of the lower surface 7. That is, when the cutting insert 1 is attached so that the fifth end surface shown as the back surface 6 in the above description becomes the lower surface 7, the convex portion 14 can function as a contact surface with respect to the second wall surface 34b. it can.

A thin portion 37 or the like is provided at the intersection between the bottom surface 33 and the wall surface 34 of the chip seat 32 as necessary. The chip seat 32 of the cutting tool 30 of this embodiment is provided with a storage space 39 for protecting the cutting edge 10 when the cutting insert 1 is not used.

Second Embodiment As shown in FIGS. 8 to 12, the cutting insert 1 of the second embodiment has a substantially square plate shape. In order to simplify the description, members or portions having the same function as the cutting insert 1 of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

The back surface 6 of the cutting insert 1 of this embodiment has a recess 15. In the recess 15, when the cutting insert 1 is mounted on the cutting tool 30, at least one inclined portion 16 comes into contact with the wall surface 34 of the chip seat 32. The cutting insert 1 of this embodiment also has eight cutting edges 10 and can be used eight times. Accordingly, the cutting insert 1 is formed with eight inclined portions 16 and four concave portions 15. Here, when the first cutting edge 11, the second cutting edge 12 and the arc cutting edge 13 are the working cutting edges (that is, the first end face 2, the third end face 4 and the fourth end face 5 are the right side, respectively. The inclined portion 16 that comes into contact with the wall surface 34 of the tip seat 32 when the tip seat of the cutting tool shown in FIG. 7 is attached so as to be the front surface and the upper surface 5 is referred to as a first inclined portion 16a.

The first inclined portion 16a is inclined so as to gradually protrude outward from the upper surface 5 toward the lower surface 7. However, the first inclined portion 16a of the cutting insert in this embodiment is not inclined in the direction from the right surface 2 toward the left surface 3. When the second cutting edge 12 or the like acts as a working cutting edge, the first inclined portion 16a formed on the back surface 6 opposite to the second cutting edge 12 is formed by the first wall surface 34a of the tip seat 32. Contact with. When the second cutting edge 12 or the like acts as a working cutting edge, the first inclined portion 16a on the side opposite to the second cutting edge 12 tends to float by the main component of the cutting force. Since the chip seat 32 is pressed downward from the first wall surface 34a of the tip seat 32, it does not rise. Therefore, the stable cutting insert 1 can be restrained. This prevents the cutting insert 1 from moving during cutting.

The inclined portion 16a of the cutting insert 1 in this embodiment is formed so as not to be inclined in the direction from the right surface 2 to the left surface 3, but is not limited thereto. The inclined portion 16a is preferably inclined outward as it is separated from the right surface 2. When the inclined portion 16a is formed in this way, when the second cutting edge 12 or the like acts as the working cutting edge, the first inclined portion 16a opposite to the second cutting edge 12 The force tends to float away from the bottom surface 33 of the chip seat 32, that is, the right surface 2 side, but does not float because it is pressed from the first wall surface 34 a of the chip seat 32. Therefore, the stable cutting insert 1 can be restrained. This prevents the cutting insert 1 from moving during cutting.

The recess 15 of the cutting insert 1 in this embodiment extends in a direction substantially parallel to the lower surface 7 as shown in FIG. However, the recess 15 of the cutting insert 1 is preferably formed so as to extend in an oblique direction with respect to the lower surface 7. When the recess 15 is formed in this way, the first inclined portion 16a is inclined outwardly so as to protrude from the upper surface 5 toward the lower surface 7, and further protrudes outward as it is separated from the right surface 2. It is easy to form it with a slant. The inclination direction of the recess 15 is preferably a direction from the right surface 2 to the left surface 3 as it goes from the lower surface 7 to the upper surface 5.

The direction in which the recess 15 extends refers to the direction in which the valley of the recess 15 extends. When the valley line portion 18 is present in the valley portion of the recess 15, the direction in which the valley line portion 18 extends is defined as the direction in which the recess 15 extends. When the valley line portion 18 does not clearly appear in the valley portion of the recess 15, the intersecting ridge lines of the two virtual surfaces of the two virtual surfaces obtained by approximating and extending the two inclined portions 16 formed in the recess 15 respectively. The extending direction is the direction in which the recess 15 extends. Note that “the concave portion 15 extends in an oblique direction with respect to the lower surface 7” means that the direction in which the concave portion 15 extends is the lower surface when viewed from the direction facing the fifth end surface 6 as shown in FIG. It means that the intersecting ridgeline between the end face 7 and the fifth end face 6 serving as the back surface extends at an acute angle. When the valley line portion 18 exists in the valley portion of the recess 15, the direction in which the valley line portion 18 extends from the direction facing the fifth end surface 6 is the intersection of the first end surface 2 and the fifth end surface 6. A direction in which the ridgeline extends and a direction intersecting with an acute angle are preferable. When the concave portion 15 is formed in such a shape and direction, the cutting insert 1 is firmly pressed against the wall surface 34 of the chip seat 32, and the cutting insert 1 is prevented from being displaced during cutting.

As described above, the recess 15 of the cutting insert 1 in this embodiment extends in a direction substantially parallel to the lower surface 7. That is, the first inclined portion 16 a is not inclined in the direction from the right surface 2 toward the left surface 3. Therefore, the cutting insert 1 of this embodiment has a somewhat low restraining effect on the feed force of the cutting force. However, when the recess 15 is provided so as to extend in a direction substantially parallel to the lower surface 7 as described above, the manufacturing becomes easy and the manufacturing cost can be suppressed. That is, since the lower surface 7 and the hole 19 and the concave portion 15 are in a substantially parallel direction, the hole 19 and the concave portion 15 can be formed by ordinary powder pressure molding and sintering.

As shown in FIG. 7, the wall surface of the chip seat in the cutting tool to which the cutting insert 1 of this embodiment is mounted is the first wall surface 34 a that contacts the recess 15 of the cutting insert 1 and the first wall surface that contacts the lower surface 7. 2 wall surfaces 34b. However, in the case of this embodiment, the first wall surface 34 a has a complementary shape corresponding to the recess 15. That is, the first wall surface is an inclined surface that is inclined so as to approach the inside of the chip seat and come into contact with the inclined portion 16a as the distance from the second wall surface 34b increases. Since other shapes are the same as the shape corresponding to the convex portion 14 of the first embodiment, the description thereof is omitted. That is, by replacing the convex portion 14 of the first embodiment with the concave portion 15 of the second embodiment and considering the first embodiment, application and deformation to various shapes can be understood.

In any other embodiment, the material around the cutting edge 10 of the cutting insert 1 is a hard material such as cemented carbide, cermet, ceramic, cubic boron nitride, or a PVD or CVD coating film on the surface of these hard materials. It is selected from those coated. Further, the material other than the cutting edge 10 is preferably made of the same hard material.

Note that the cutting insert and the cutting tool of the present invention are not limited to the above-described embodiment and the modifications described in various places, and various modifications and additions can be made without departing from the gist of the present invention. It is. For example, the clamping member may be a cutting tool that simultaneously presses a surface other than the hole while contacting the hole of the cutting insert.

Further, in the first embodiment, the convex portion 14 can be provided substantially parallel to the lower surface 7. Thereby, manufacture becomes easy similarly to 2nd Embodiment, and manufacturing cost can be suppressed.

Furthermore, the manufacturing method of the cutting insert 1 is not limited to normal powder pressure molding and sintering as described in the second embodiment. Grinding may be applied after powder pressing and sintering. In particular, when the convex portion 14 or the concave portion 15 is provided in a direction inclined with respect to the lower surface 7, grinding is effective. However, the manufacturing method of the cutting insert 1 is not limited to this. For example, it is possible to employ a manufacturing method in which a die that is a mold for powder pressure molding is divided.

In addition, the shape of the cutting insert is not limited to a substantially square plate. That is, the shape of the first and second end faces is not limited to a substantially square shape. It may be a quadrilateral other than a square, or may be another polygon. However, it is preferable that the cutting insert has a substantially regular polygonal plate shape from the viewpoint of enabling economical use multiple times. Further, from the viewpoint of improving the stability of fixing the cutting insert, it is preferable that a convex portion or a concave portion is formed on the end surface (opposing end surface) located on the side opposite to the third end surface.

Considering these things, the basic shape of the cutting insert is a regular 2n square columnar shape having first and second end faces of a regular 2n square (n is an integer of 2 or more) and 2n end faces connecting them. When one end face of the 2n end faces is the third end face, it is preferable that a convex portion or a concave portion is formed on the end face located on the side opposite to the third end face. For example, in a regular hexagonal plate-shaped cutting insert, when the first and second end faces of a regular hexagon and the five adjacent faces connecting them are the third to eighth end faces, the third end face The sixth end face located substantially on the opposite side can be used as an opposing end face, and a convex portion or a concave portion can be formed here.

However, if an effect capable of effectively constraining the cutting insert is obtained, for example, a regular (2n + 1) rectangular plate shape such as a regular pentagonal plate shape is adopted, and the end surface located on the substantially opposite side to the third end surface is projected. The part or the recessed part should just be formed. For example, in a regular pentagonal plate-shaped cutting insert, when the first and second end faces of the regular pentagon and the five adjacent faces connecting them are the third to seventh end faces, the third end face A convex part or a concave part can be formed in the 5th or 6th end surface located in the substantially opposite side.

Claims

A substantially polygonal plate-shaped cutting insert (1),
Having a hole (19) through two polygonal end faces (2, 3);
The two polygonal end faces are defined as a first end face (2) and a second end face (3),
One of a plurality of surfaces connecting between the first and second end surfaces (2, 3) is a third end surface (4),
One surface adjacent to the third end surface (4) is a fourth end surface (5),
When the third end face (4) is defined as a facing end face (6), a face located on the opposite side or substantially opposite side across the hole (19),
A rake face (8) is formed on the fourth end face (5),
A first cutting edge (11) is formed at the intersecting ridge line between the rake face (8) and the first end face (2),
A second cutting edge (12) is formed at the intersecting ridge line between the third end surface (4) and the fourth end surface (5) when viewed from the rake face (8) side,
The angle formed by the first cutting edge (11) and the second cutting edge (12) when viewed from the rake face (8) side is in the range of 10 ° or more and 85 ° or less,
The cutting insert in which the convex part (14) or recessed part (15) which contacts the chip seat (32) of a cutting tool (30) is formed in the said opposing end surface (6).
The convex portion (14) or the concave portion (15) of the opposed end surface (6) is an inclined portion (16) that gradually protrudes outward as it is separated from one surface (5) adjacent to the opposed end surface (6). The cutting insert of Claim 1 containing.
The projecting portion (14) or the recessed portion (15) of the opposed end surface (6) includes an inclined portion (16) that gradually protrudes outward as it is separated from the first end surface (2). 2. The cutting insert according to 2.
The angle formed by the first cutting edge (11) and the second cutting edge (12) when viewed from the rake face (8) side is in the range of 50 ° or more and 85 ° or less. The cutting insert in any one of 3 to 3.
The substantially polygonal plate shape is a substantially square plate shape, eight first cutting edges (11) are formed, and four convex portions (14) or four concave portions (15) are formed. The cutting insert according to any one of claims 1 to 4.
The convex part (14) has a ridge part (17),
When the opposed end surface (6) is viewed in an end view, the direction in which the ridge line portion (17) extends is the direction in which the intersecting ridge line between the opposed end surface (6) and the surface (7) of one surface adjacent thereto extends. The cutting insert according to any one of claims 1 to 5, which is a direction intersecting an acute angle.
The recess (15) has a trough (18),
When the opposed end surface (6) is viewed in an end view, the direction in which the valley line portion (18) extends is a direction in which an intersecting ridge line between the opposed end surface (6) and one surface (7) of the adjacent surface extends. The cutting insert according to any one of claims 1 to 5, which is a direction intersecting an acute angle.
The cutting insert according to claim 6 or 7, wherein an inclination direction of the convex portion (14) or the concave portion (15) is an angle range of 5 ° or more and 40 ° or less with respect to a direction in which the intersecting ridge line extends.
The cutting insert according to claim 6 or 7, wherein an inclination direction of the convex portion (14) or the concave portion (15) is an angle range of 50 ° or more and 70 ° or less with respect to a direction in which the intersecting ridge line extends.
A tool body (31) of a cutting tool (30) to which the cutting insert (1) according to any one of claims 1 to 9 is mounted, wherein the convex portion (14) or the concave portion of the cutting insert (1). (15) having a first wall surface (34a) of the chip seat (32) in contact with,
The first wall surface (34a) comes into contact with the first end surface (2) or the second end surface (3), and the tip seat ( 32) A tool body including an inclined surface inclined inward.
The tip seat (32) is in contact with one surface (7) located on the opposite side or substantially opposite the hole (19) with respect to the fourth end surface (5) of the cutting insert (1). A second wall surface (34b)
The tool body according to claim 10, wherein the first wall surface (34a) includes an inclined surface that inclines toward the inside of the tip seat (32) as it is separated from the second wall surface (34b).
The tool body according to claim 11, wherein the second wall surface (34b) is in contact with the convex portion (14) or the concave portion (15) of the cutting insert (1).
A cutting tool comprising the cutting insert (1) according to any one of claims 1 to 9.