WO2021235258A1

WO2021235258A1 - Cutting insert, cutting tool, and method for manufacturing cut workpiece

Info

Publication number: WO2021235258A1
Application number: PCT/JP2021/017791
Authority: WO
Inventors: 洋介福原
Original assignee: 京セラ株式会社
Priority date: 2020-05-21
Filing date: 2021-05-11
Publication date: 2021-11-25
Also published as: JP7455964B2; JPWO2021235258A1

Abstract

A cutting insert according to one embodiment comprises a base part and a cutting part. The cutting part includes an upper surface, a tip surface, a first side surface, a second side surface, a first cutting edge, and a second cutting edge. The upper surface has a breaker projection extending along the second side surface. In a view from the first side surface side, a third ridgeline where the breaker projection and the second side surface intersect has a first linear portion that is located on the side toward the tip having the tip surface and that forms a convex curve shape.

Description

Manufacturing methods for cutting inserts, cutting tools and cutting materials

This disclosure relates to cutting inserts and the like used in cutting.

As a cutting insert used when turning a work material such as metal, for example, the throw-away insert described in Patent Document 1 is known. The chips described in Patent Document 1 can be used for post-grinding. The tip includes a main body portion and a cutting portion. The cutting portion has a first ridge line on which a cutting edge is formed, a second ridge line on which a cutting edge is not formed, and a breaker groove located between the first ridge line and the second ridge line. Have. A first cutting edge is formed on the tip side of the cutting portion on the first ridge line, and a second cutting edge is formed on the opposite side of the second ridge line when the rake face of the cutting portion is viewed from above. Is formed.

Japanese Patent Publication "Japanese Patent Laid-Open No. 2012-250296"

The cutting insert according to one aspect of the present disclosure includes a base portion and a cutting portion provided so as to protrude from the base portion, and the cutting portion is a tip located on the side of the tip in the protruding direction. The surface, the upper surface extending from the base portion to the tip surface, the first side surface extending from the base portion to the tip surface and adjacent to the upper surface, and the first side surface extending from the base portion to the tip surface. A second side surface adjacent to the upper surface, a first cutting edge located at the intersection of the upper surface and the tip surface, and a second cutting edge located at the intersection of the upper surface and the first side surface on the opposite side of the above surface. Have. The upper surface has a breaker protrusion extending along the second side surface, and when viewed from the side of the first side surface, the ridgeline where the breaker protrusion and the second side surface intersect is located on the side of the tip end. It has a first line portion having a convex curved shape.

It is a perspective view of the cutting insert in one Embodiment. It is a perspective view which looked at the cutting insert shown in FIG. 1 from another direction. It is a top view of the cutting insert shown in FIG. 1 as viewed from the A1 direction shown in FIG. FIG. 3 is a side view of the cutting insert shown in FIG. 1 as viewed from the A2 direction shown in FIG. It is an enlarged view of the region B1 shown in FIG. It is an enlarged view of the area B2 shown in FIG. It is an enlarged view of the area B3 shown in FIG. FIG. 7 is a cross-sectional view taken along the line YY of FIG. 7. FIG. 7 is a cross-sectional view taken along the line ZZ of FIG. 7. FIG. 7 is a cross-sectional view taken along the line XX of FIG. 7. It is an enlarged view of the area B4 shown in FIG. It is a side view of the cutting insert of another embodiment. It is an enlarged view of the region B5 shown in FIG. It is an enlarged view of the region B6 shown in FIG. It is a perspective view which shows the cutting tool of an embodiment. It is an enlarged view of the region B7 shown in FIG. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment. It is a schematic diagram which shows one process of the manufacturing method of the machined work of embodiment.

Hereinafter, a method for manufacturing a cutting insert (hereinafter, also simply referred to as an insert), a cutting tool, and a cutting work according to an embodiment of the present disclosure will be described in detail with reference to the drawings. However, each figure referred to below is shown in a simplified manner only for the main members necessary for explaining the embodiment for convenience of explanation. Thus, inserts and cutting tools may include any components not shown in each referenced figure. Further, the dimensions of the members in each drawing do not faithfully represent the dimensions of the actual constituent members, the dimensional ratio of each member, and the like.

(1. Outline of insert)
First, the outline of the insert 1 of the embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a perspective view of the insert 1. FIG. 2 is a perspective view of the insert 1 as viewed from another direction. FIG. 3 is a top view of the insert 1 as viewed from the A1 direction shown in FIG. FIG. 4 is a side view of the insert 1 as viewed from the A2 direction shown in FIG.

As shown in FIGS. 1 to 4, the insert 1 includes a base portion 10 and a cutting portion 20 provided so as to protrude from the base portion 10. The substrate portion 10 can be used as a portion restrained by the holder 105 when the insert 1 is attached to the holder 105 (see FIGS. 15 and 16) described later. The cutting portion 20 is a portion that comes into contact with the work material 201 (see FIGS. 17 to 20) to be machined in the cutting process described later, and is a portion that plays a main role in the cutting process. In this example, the insert 1 includes two cutting portions 20, but may include three or more cutting portions 20. In another example, the insert 1 may include only one cutting section 20.

The shape of the substrate portion 10 is not limited to a specific configuration. For example, the shape of the substrate portion 10 may be a rod shape, a polygonal plate shape, or a polygonal prism shape. In this example, as shown in FIG. 4, the substrate portion 10 has a hexagonal plate shape in which two opposing corners of a rectangle are dropped. The substrate portion 10 is located on the opposite side of the first main surface 11 (see FIG. 1), which is hexagonal, and the second main surface 12 (see FIG. 2), which is also hexagonal. It has a through hole 13 that opens at the center of the first main surface 11 and the center of the second main surface 12. The through hole 13 may be used to fix the insert 1 to the holder 105 (see FIGS. 15 and 16) described later. For example, when the insert 1 is attached to the holder 105, the insert 1 can be fixed to the holder 105 by inserting a screw 107 into the through hole 13.

Further, in this example, the substrate portion 10 has an upper side surface 14 and a lower side surface 15. The upper side surface 14 and the lower side surface 15 are flat surfaces, respectively, and are located parallel to each other along the longitudinal direction of the insert 1. As shown in FIGS. 1 and 2, the upper side surface 14 and the lower side surface 15 form a part of the side surface portion located between the first main surface 11 and the second main surface 12 in the substrate portion 10. good.

In addition, in this specification, the description of "flat" or "flat surface" is intended to be not a curved surface at a visible level, or to have no visible unevenness, and is strictly flat. Do not ask to be. Therefore, unevenness to an unavoidable degree may be allowed in the manufacture of the insert 1. Specifically, it may have irregularities with a surface roughness of about 50 μm.

The size of the substrate portion 10 is not particularly limited. The maximum width of the substrate portion 10 in the direction from the first main surface 11 to the second main surface 12 orthogonal to the longitudinal direction of the insert 1 may be set to, for example, about 2.9 to 4.1 mm. Further, the dimension of the substrate portion 10 in the longitudinal direction may be set to, for example, about 8 to 20 mm.

The shape of the two cutting portions 20 is not limited to a specific configuration. The cutting portion 20 may have, for example, a rod shape, a polygonal plate shape, or a polygonal prism shape. The shape of the two cutting portions 20 in this example is a square plate shape in which one corner of a triangle is dropped. The substrate portion 10 and the cutting portion 20 in the insert 1 may be formed separately or integrally.

The width of the cutting portion 20 in the direction from the first main surface 11 orthogonal to the longitudinal direction of the insert 1 toward the second main surface 12 may be smaller than the width of the base portion 10 in the same direction. When the width of the base portion 10 is relatively large, the wall thickness of the base portion 10 is secured, so that the insert 1 can be stably fixed to the holder 105 (see FIGS. 15 and 16). .. Further, when the width of the cutting portion 20 is relatively small, the degree of freedom in the cutting width of the work material 201 in the cutting process can be increased. When the widths of the base portion 10 and the cutting portion 20 are different as described above, the regions of the base portion 10 and the cutting portion 20 in the insert 1 may be divided by the portions having different widths.

In this example, the two cutting portions 20 each project outward from the base portion 10. One of the two cutting portions 20 projects outward from one end in the longitudinal direction of the substrate portion 10 along the longitudinal direction. The other cutting portion 20 of the two cutting portions 20 projects along the longitudinal direction from the other end portion in the longitudinal direction of the substrate portion 10. The two cutting portions 20 project to the opposite sides of each other.

In the insert 1, the two cutting portions 20 may be positioned so as to be rotationally symmetric with respect to the central axis of the through hole 13. In this example, the two cutting portions 20 project toward opposite sides and are positioned so as to be rotationally symmetric with respect to the central axis of the through hole 13, and have substantially the same configuration as each other. Therefore, in the following, of the two cutting portions 20, in FIG. 1, the configuration of the cutting portion 20 protruding toward the right side when the insert 1 is viewed from the side of the first main surface 11 of the base portion 10 will be described in detail. The description of the other cutting portion 20 protruding toward the left side will be omitted.

(2. Details of the cutting part)
Next, the details of the cutting portion 20 will be described with reference to FIGS. 5 to 11. FIG. 5 is an enlarged view of the region B1 shown in FIG. FIG. 6 is an enlarged view of the region B2 shown in FIG. FIG. 7 is an enlarged view of the region B3 shown in FIG. FIG. 8 is a cross-sectional view taken along the line YY of FIG. 7. 9 is a cross-sectional view taken along the line ZZ of FIG. 7. FIG.

As shown in FIGS. 5 to 7, in this example, the cutting portion 20 has an upper surface 21, a tip surface 22, a first side surface 23, a second side surface 24, and a lower surface 25. The tip surface 22 is located on the side of the tip in the direction in which the cutting portion 20 protrudes from the base portion 10.

The upper surface 21 extends from the substrate portion 10 to the tip surface 22 and is adjacent to the tip surface 22. In the case of the other cutting portion 20, the upper surface 21 extends from the lower side surface 15 of the base portion 10 to the tip surface 22.

The first side surface 23 extends from the base portion 10 to the tip surface 22, and more specifically, extends from the second main surface 12 of the base portion 10 to the tip surface 22. In the other cutting portion 20, the first side surface 23 extends from the second main surface 12 of the base portion 10 to the tip surface 22. The first side surface 23 is adjacent to the upper surface 21 and is also adjacent to the tip surface 22.

The second side surface 24 extends from the base portion 10 to the tip surface 22, and more specifically, extends from the stepped surface 16 adjacent to the first main surface 11 of the base portion 10 to the tip surface 22. The step surface 16 is a plane extending in the direction from the first main surface 11 to the second main surface 12. The stepped surface 16 is a surface generated when the width of the cutting portion 20 in the direction from the first main surface 11 to the second main surface 12 is smaller than the width of the base portion 10 in the same direction. In the other cutting portion 20, the second side surface 24 is adjacent to the first main surface 11 of the base portion 10, and is the tip from the stepped surface forming a plane in the direction from the first main surface 11 to the second main surface 12. It extends toward the surface 22. The second side surface 24 is adjacent to the upper surface 21 on the opposite side of the first side surface 23. Further, the second side surface 24 is adjacent to the tip surface 22 on the opposite side of the first side surface 23.

The lower surface 25 extends from the lower side surface 15 of the substrate portion 10 to the tip surface 22. In the case of the other cutting portion 20, the lower surface 25 extends from the upper side surface 14 of the base portion 10 to the tip surface 22. The lower surface 25 is adjacent to the upper surface 21 via the first side surface 23, the tip surface 22, and the second side surface 24.

Further, as shown in FIGS. 5 and 6, in this example, the tip surface 22 and the first side surface 23 each have a substantially planar shape. The tip surface 22 and the first side surface 23 may be directly connected to each other, but a curved surface connecting the two planes may be located between the tip surface 22 and the first side surface 23. Further, the second side surface 24 also has a substantially planar shape. The tip surface 22, the first side surface 23, and the second side surface 24 may have a curved surface shape.

The tip surface 22 may be composed of one plane as long as it has a substantially planar shape, or may be composed of a plurality of planes slightly inclined to each other. For example, in the example shown in FIGS. 5 and 6, the tip surface 22 is composed of two planes. The first side surface 23 may be composed of one plane, or may be composed of a plurality of planes slightly inclined with each other. For example, in the example shown in FIGS. 5 and 6, the second side surface 24 is composed of one plane.

A ridgeline is formed at the intersection of the surfaces such as the upper surface 21, the tip surface 22, the first side surface 23, and the second side surface 24. Of these, the ridgeline where the upper surface 21 and the tip surface 22 intersect is the first ridgeline R1, the ridgeline where the upper surface 21 and the first side surface 23 intersect is the second ridgeline R2, and the ridgeline where the upper surface 21 and the second side surface 24 intersect is the third ridgeline (ridgeline). ) R3. That is, the cutting portion 20 has a first ridge line R1, a second ridge line R2, and a third ridge line R3. Cutting edges for cutting can be formed at the positions of these ridges.

In this example, the cutting portion 20 has a first cutting edge C1 on the first ridge line R1 and a second cutting edge C2 on the second ridge line R2. On the other hand, the third ridge line R3 does not have a cutting edge. Here, the third ridge line R3 is a ridge line where the surface of the breaker protrusion 21d formed on the upper surface 21 and the second side surface 24 intersect. The cutting portion 20 has a breaker protrusion 21d formed so as to include a portion where the third ridge line R3 forms a convex curve when viewed from the first side surface 23 side, which will be described later.

The first cutting edge C1 is located at least a part of the first ridge line R1. The first cutting edge C1 may be located on the entire first ridge line R1, or may be located only on a part of the first ridge line R1. In this example, the first cutting edge C1 is located on the entire first ridge line R1. Further, in this example, the first cutting edge C1 is a wiper blade protruding toward the work material 201 (see FIGS. 17 to 20). By using the first cutting blade C1 as a wiper blade, the finished surface can be improved by the effect of the wiper blade. The wiper blade may be paraphrased as a shaving blade.

The second cutting edge C2 is located at least a part of the second ridge line R2. The second cutting edge C2 may be located on the entire second ridge line R2, or may be located only on a part of the second ridge line R2. In this example, the second cutting edge C2 is located on the entire second ridge line R2 and is connected to the first cutting edge C1. However, when the curved surface connecting the tip surface 22 and the first side surface 23 is located between these surfaces, the first cutting edge C1 and the second cutting edge C2 pass through the ridgeline where the curved surface and the upper surface 21 intersect. It may be connected. At this time, the ridgeline where the curved surface and the upper surface 21 intersect may form a part of the cutting edge.

As shown in FIGS. 5 and 6, in this example, the tip surface 22 and the first side surface 23 have a substantially planar shape. Therefore, the first cutting edge C1 and the second cutting edge C2 also have a substantially linear shape, respectively.

The first cutting edge C1 can be used as a cutting edge that mainly functions in, for example, grooving and parting off. At this time, the second cutting edge C2 may be used as a cutting edge that assists the cutting process by the first cutting edge C1. The second cutting edge C2 can be used, for example, as a cutting edge that mainly functions in post-grinding processing (lateral feed processing). At this time, the first cutting edge C1 may be used as a cutting edge that assists the cutting process by the second cutting edge C2.

While the tip surface 22 and the first side surface 23 have a substantially planar shape, the upper surface 21 has an uneven shape rather than a planar shape as shown in FIGS. 5 and 6. Specifically, as shown in FIG. 7, in this example, the upper surface 21 has a first inclined surface 21a, a second inclined surface 21b, a flat bottom surface 21c, and a breaker protrusion 21d.

The first inclined surface 21a has an inclination extending along the first cutting edge C1 (first ridge line R1) and descending toward the bottom surface 21c. The second inclined surface 21b has an inclination extending along the second cutting edge C2 (second ridge line R2) and descending toward the bottom surface 21c. 5 to 7 show the first inclined surface 21a and the second inclined surface 21b with hatching.

The breaker protrusion 21d extends along the second side surface 24 and rises from the bottom surface 21c toward the second side surface 24. The intersection of the second side surface 24 and the breaker protrusion 21d is the third ridge line R3.

As shown in FIGS. 8 and 9, on the upper surface 21, the third ridge line R3 where the points y1 and z1 are located is located at the upper end of the breaker protrusion 21d. The third ridge line R3 is located higher (above) than the second ridge line R2 where the points y4 and z4 are located.

The detailed shape of the breaker protrusion 21d will be described later. The breaker protrusion 21d has a function of controlling the traveling direction of chips generated in the first cutting edge C1 and the second cutting edge C2 and flowing through the upper surface 21. By bringing the chips into contact with the breaker protrusion 21d, the chips can be curled and the chip dischargeability can be improved.

(3. Shapes of the 3rd ridge and breaker protrusions)
Next, each shape of the third ridge line R3 and the breaker protrusion 21d in the cutting portion 20 will be described with reference to FIGS. 7 to 11. FIG. 10 is a cross-sectional view taken along the line XX of FIG. 7. FIG. 11 is an enlarged view of the region B4 shown in FIG.

As shown in FIG. 11, in the insert 1, when viewed from the side of the first side surface 23, the third ridge line R3 where the surface of the breaker protrusion 21d and the second side surface 24 intersect is the tip side (the side of the tip surface 22). ), It has a first line portion R3-1 having a convex curve shape.

The cutting portion 20 in the insert 1 has the above configuration, and the breaker protrusion 21d can have a convex curved surface-shaped portion extending from the first ridge line R1 having the first cutting edge C1. Actually, as shown by the line connecting x2 and x3 in FIG. 10, the breaker protrusion 21d has a convex curved surface-shaped portion located on the side of the tip end. Hereinafter, the above-mentioned convex curved surface-shaped portion is referred to as a first portion 21d1. Further, the downwardly inclined line connecting x1 and x2 in FIG. 10 is due to the first inclined surface 21a.

Since the breaker protrusion 21d has the first portion 21d1 located on the tip side, the contact area of the chips generated by the second cutting edge C2 with respect to the breaker protrusion 21d can be reduced. Therefore, the contact resistance generated in the chips generated by the second cutting edge C2 can be reduced. As a result, it is possible to prevent the chips from being clogged, and the chip dischargeability is excellent. Due to the excellent chip discharge property, the insert 1 is less likely to be worn and the durability is improved.

In particular, when low cutting is performed, such as when only the tip end side portion of the second cutting edge C2 is used, the distance between the tip end side portion of the second cutting edge C2 and the breaker protrusion 21d is narrow. Therefore, chip clogging is likely to occur. At this time, the chips tend to come into contact with the portion of the breaker protrusion 21d located on the tip side. Further, since the portion where the chips easily come into contact is the first portion 21d1, the contact resistance generated in the chips can be reduced. As described above, it is possible to prevent the chips from being clogged even in the cutting process under the condition that the chips are likely to be clogged. That is, it is possible to perform stable cutting in a wide cutting area.

Since the chips generated by the second cutting edge C2 are brought into contact with the breaker protrusion 21d even when low cutting is performed, such as when only the tip side portion of the second cutting edge C2 is used, the breaker protrusion 21d May extend as close to the tip surface 22 as possible. On the other hand, the distance between the breaker protrusion 21d and the first ridge line R1 becomes narrower as the breaker protrusion 21d extends closer to the tip surface 22 (first ridge line R1). Therefore, the dischargeability of chips generated when the first cutting edge C1 is used becomes an issue. However, when the first portion 21d1 is located on the side of the tip end of the breaker protrusion 21d, the chips generated by the first cutting edge C1 are less likely to come into surface contact at this portion. That is, the contact resistance generated in the chips generated by the first cutting edge C1 can be reduced.

On the other hand, in the above-mentioned tip described in Patent Document 1, the shape of the second ridge line is a straight line when viewed from the side surface with the second cutting edge.

Therefore, in the tip described in Patent Document 1, the chips generated by the second cutting edge tend to come into contact with a wide range of the rising surface in the protruding direction of the cutting portion. Further, in the chip described in Patent Document 1, the chips generated by the second cutting edge may come into surface contact with the rising surface. As a result, the chips were easily clogged, and the dischargeability of the chips was insufficient. Insufficient chip evacuation tends to wear the tip and reduce its durability.

Here, more preferably, as shown in FIG. 11, the first line portion R3-1 has a first end portion P1 located on the side of the tip end and a second end portion P1 located on the opposite side of the first end portion P1. It may have an end portion P2 and a configuration in which the second end portion P2 is located above the first end portion P1.

With the above configuration, as shown in the line connecting x2 and x3 in FIG. 10, the first portion 21d1 of the breaker protrusion 21d has a configuration in which x3 on the side closer to the substrate portion 10 is higher than x2 on the tip side. Is. As a result, the chips generated by the first cutting edge C1 easily come into contact with the first portion 21d1 of the breaker protrusion 21d. Therefore, the flow direction of the chips generated by the first cutting edge C1 is easily controlled, and the chip processing is stable.

Further, in this case, as shown in FIG. 11, the first line portion R3-1 may have a configuration including a first portion R3-1a and a second portion R3-1b. The first portion R3-1a is a portion that inclines upward from the first end portion P1 toward the base portion 10. The second portion R3-1b is a portion that is located closer to the second end portion P2 than the first portion R3-1a and is inclined downward toward the base portion 10.

With the above configuration, as shown in the line connecting x2 and x3 in FIG. 10, the first portion 21d1 of the breaker protrusion 21d rises and rises from x2 toward x3 while having x3 higher than x2. It will have a shape that descends toward x3 from the middle of. As a result, the radius of curvature of the first line portion R3-1 can be reduced, and the bending of the surface of the breaker protrusion 21d at the first portion 21d1 can be increased. Therefore, it is possible to reduce the contact area when the chips generated by the second cutting edge C2 come into contact with the first portion 21d1 of the breaker protrusion 21d. Therefore, the contact resistance generated in the chips generated by the second cutting edge C2 can be further reduced.

Further, in this case, as shown in FIG. 11, the boundary between the first portion R3-1a and the second portion R3-1b is set as the first boundary K1, and the distance from the first end portion P1 to the first boundary K1 is the first. The configuration may be longer than the distance from the second end P2 to the first boundary K1.

With the above configuration, as shown in the line connecting x2 and x3 in FIG. 10, the distance of the portion of the first portion 21d1 of the breaker protrusion 21d that rises from x2 toward x3 becomes x3 from the middle of the climb. It will be longer than the distance of the part going down. As a result, when the chips generated by the first cutting edge C1 come into contact with the first portion 21d1 of the breaker protrusion 21d, the direction in which the chips have advanced and the angle formed by the first portion 21d1 of the breaker protrusion 21d become smaller. easy. Therefore, there is a low possibility that the chips generated by the first cutting edge C1 will collide with the breaker protrusion 21d and become clogged.

Further, as shown in FIG. 11, when viewed from the side of the first side surface 23, the third ridge line R3 where the breaker protrusion 21d and the second side surface 24 intersect is the base portion 10 rather than the first line portion R3-1. It may have a second line portion R3-2 located on the side and forming a convex curve shape.

With the above configuration, the breaker protrusion 21d can have two convex curved surface-shaped portions in a direction extending along the second side surface 24. In fact, as shown in the line connecting x2, x3, x4 in FIG. 10, the breaker projection 21d has a second part 21d2 as another convex curved surface-shaped part in addition to the first part 21d1. .. As a result, when cutting using the second cutting edge C2, stable cutting can be performed even under machining conditions with a large cutting amount.

Specifically, in cutting with a large cutting amount using the portion of the second cutting edge C2 located on the side of the second line portion R3-2, the flow of chips is unstable due to the large width of the chips. It is easy to become. However, when the breaker protrusion 21d has the above-mentioned two convex curved surface-shaped portions (first portion 21d1 and second portion 21d2), these two first portions 21d1 while reducing the contact resistance generated in the chips, Chips can be stably supported at the second portion 21d2. In this way, since the chips can be supported at each of the plurality of convex curved surface-shaped portions and the flow of the chips can be controlled, stable chip processing can be performed in a wide cutting region.

Further, in this case, as shown in FIG. 11, the second line portion R3-2 has a third end portion P3 located on the tip side and a fourth end portion P4 located on the opposite side of the third end portion P3. And may have. At this time, the fourth end portion P4 may be located above the third end portion P3.

With the above configuration, as shown in the line connecting x3 and x4 in FIG. 10, the second portion 21d2 of the breaker protrusion 21d has a higher x4 on the side closer to the base portion 10 than the x3 on the tip side. .. As a result, when the chips generated by the first cutting edge C1 get over the first portion 21d1 of the breaker protrusion 21d, the chips are likely to come into contact with the second portion 21d2. Therefore, the flow direction of the chips generated by the first cutting edge C1 is easily controlled even in the second portion 21d2, and the chip processing is stable.

(3-1. Another example of each shape of the third ridge line and the breaker protrusion)
Here, using FIGS. 12 to 14, the third ridge line R3 and the breaker protrusion 21d in the cutting portion 20A of the insert (cutting insert) 1A of the embodiment different from the insert 1 shown in FIGS. 1 to 11 Each shape of is described. FIG. 12 is a side view of the insert 1A corresponding to FIG. FIG. 13 is an enlarged view of the region B5 shown in FIG. FIG. 14 is an enlarged view of the region B6 shown in FIG. For convenience of explanation, the same reference numerals are given to the parts common to the insert 1 and the insert 1A, the description thereof will be omitted, and the differences will be specifically described.

As shown in FIG. 13, in the insert 1A, the second line portion R3-2 has a configuration including a third portion R3-2a and a fourth portion R3-2b. The third portion R3-2a is a portion that inclines upward from the third end portion P3 toward the base portion 10. The fourth portion R3-2b is a portion located closer to the fourth end portion P4 than the third portion R3-2a and is inclined downward toward the base portion 10.

With the above configuration, explaining with reference to FIG. 10, the second portion 21d2 corresponding to the second line portion R3-2 of the breaker protrusion 21d rises from x3 toward x4 and moves up to x4 from the middle of the climb. It will have a shape that descends toward it. As a result, the radius of curvature of the third portion R3-2a can be reduced, and the bending of the surface of the breaker protrusion 21d at the second portion 21d2 can be increased. Therefore, it is possible to reduce the contact area when the chips generated by the second cutting edge C2 come into contact with the second portion 21d2 of the breaker protrusion 21d. Therefore, the contact resistance generated in the chips generated by the second cutting edge C2 can be further reduced.

Further, in this case, as shown in FIG. 13, the boundary between the third portion R3-2a and the fourth portion R3-2b is set as the second boundary K2, and the distance from the third end portion P3 to the second boundary K2 is the second boundary. The configuration may be longer than the distance from the four-end P4 to the second boundary K2.

With the above configuration, explaining with reference to FIG. 10, the distance of the portion of the second portion 21d2 corresponding to the second line portion R3-2 of the breaker protrusion 21d from x3 to x4 is ascending. It is longer than the distance of the part that descends from the middle toward x4. As a result, when the chips generated by the first cutting edge C1 come into contact with the second portion 21d2 of the breaker protrusion 21d, the direction in which the chips have advanced and the angle formed by the second portion 21d2 of the breaker protrusion 21d become smaller. easy. Therefore, there is a low possibility that the chips generated by the first cutting edge C1 will collide with the breaker protrusion 21d and become clogged.

Further, in this case, as shown in FIG. 14, the second inclination angle θ2 formed by the second straight line L2 with respect to the reference surface D is larger than the first inclination angle θ1 formed by the first straight line L1 with respect to the reference surface D. The larger configuration may be used. The first straight line L1 is a virtual line connecting the first end portion P1 and the second end portion P2 when viewed from the side of the first side surface 23. The second straight line L2 is a virtual line connecting the third end portion P3 and the fourth end portion P4 when viewed from the side of the first side surface 23. The reference surface D may be, for example, a surface on which the cutting portion 20 is projected from the side of the upper surface 21.

With the above configuration, for example, as compared with the case where the first inclination angle θ1 and the second inclination angle θ2 are the same, the cutting portion 20 is connected to the base portion 10 on the base portion 10 side, that is, the base portion 10 in the cutting portion 20. At the end of the side, the thickness tends to increase in the direction from the upper surface 21 to the lower surface 25. During cutting, a main component force is applied to the cutting portion 20 as a cutting load in the direction from the upper surface 21 to the lower surface 25. However, when the second inclination angle θ2 is larger than the first inclination angle θ1, the durability of the insert with respect to the above-mentioned main component force becomes high.

Here, a virtual plane parallel to the direction of protrusion from the base portion 10 of the cutting portion 20 and orthogonal to the first side surface 23 may be used as the reference plane D. The reference surface D may be located between the upper surface 21 and the lower surface 25. Further, instead of the above definition, the reference plane D may be set according to the following definition. That is, when the substrate portion 10 has the upper side surface 14 and the lower side surface 15, a virtual plane parallel to these surfaces and located between the upper surface 21 and the lower surface 25 may be used as the reference surface D.

(4. Insert material, etc.)
Examples of the material of the insert 1 include inorganic materials such as cemented carbide, cermet and ceramics. Examples of the composition of the cemented carbide include WC (tungsten carbide) -Co, WC-TiC (titanium carbide) -Co and WC-TiC-TaC (tantalum carbide) -Co.

Here, WC, TiC and TaC are hard particles, and Co is a bound phase. Cermet is a sintered composite material in which a metal is composited with a ceramic component. Specifically, examples of the cermet include compounds containing TiC or TiN (titanium nitride) as a main component. Needless to say, the material of the insert 1 is not limited to these.

Further, although not particularly shown, the insert 1 may be configured to include a main body containing the above-mentioned material and a coating layer covering the main body. Examples of the material of the coating layer include carbides of titanium, nitrides, oxides, carbonic acid oxides, nitrogen oxides, carbonitrides and carbonic acid nitrogen oxides. The coating layer may contain only one of the above materials, or may contain a plurality of the above materials. Further, the covering layer may be composed of only one layer, or may be a structure in which a plurality of layers are laminated. The material of the coating layer is not limited to these.

The coating layer can be positioned on the substrate by using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. For example, when the coating layer is formed by using the above vapor deposition method while the substrate is held on the inner peripheral surface of the through hole 13, the entire surface of the substrate excluding the inner peripheral surface of the through hole 13 is covered. The coating layer can be located on.

(5. Cutting tool)
Next, with reference to FIGS. 15 and 16, the cutting tool 101 of the embodiment will be described with reference to the drawings. FIG. 15 is a perspective view showing the cutting tool 101 of the embodiment. FIG. 16 is an enlarged view of the region B7 shown in FIG.

As shown in FIG. 15, the cutting tool 101 of the embodiment is a rod-shaped tool having an insert 1 on the tip side. The cutting tool 101 includes a rod-shaped holder 105 having a pocket 103 on the tip end side, and the above-mentioned insert 1 located in the pocket 103.

As shown in FIG. 16, the pocket 103 is a portion to which the insert 1 is mounted, and has a seating surface and a restraining side surface inclined with respect to the seating surface. Further, the pocket 103 is open on the tip end side of the holder 105.

The insert 1 is mounted so that a portion used as a cutting edge in the cutting portion 20, that is, at least a part of the above-mentioned first cutting edge C1 and second cutting edge C2 protrudes outward from the holder 105. In this example, when the insert 1 is attached to the holder 105, the upper side surface 14 of the base portion 10 is the upper end of the insert 1, and the lower side surface 15 of the base portion 10 is the lower end of the insert 1. In this example, the insert 1 is attached to the holder 105 by a screw 107.

Further, with the insert 1 mounted in the pocket 103, the base portion 10 of the insert 1 and the pocket 103 may be in direct contact with each other, and a sheet or the like is interposed between the insert 1 and the pocket 103. You may.

Steel, cast iron, etc. are used as the material of the holder 105. In particular, when steel is used among these materials, the toughness of the holder 105 can be increased.

Such a cutting tool 101 is used for so-called turning and can be used for post-grinding. However, the cutting tool 101 is not limited to post-grinding, and can also be used for, for example, inner diameter machining, outer diameter machining, and grooving.

(6. Manufacturing method of machined products)
Next, a method of manufacturing the machined object of the embodiment will be described with reference to FIGS. 17 to 20. 17 to 20 are schematic views showing one step of a method for manufacturing a machined product according to an embodiment. 17 to 20 are a state in which the cutting tool 101 to which the insert 1 is mounted is viewed from the side of the upper surface 21 of the cutting portion 20.

The work piece is produced by cutting the work material 201. The method for manufacturing a machined product according to an embodiment includes the following steps. That is,
(1) The process of rotating the work material 201 and
(2) The process of bringing the cutting tool 101 into contact with the rotating work material 201,
(3) The process of separating the cutting tool 101 from the work material 201,
Is equipped.

More specifically, first, as shown in FIG. 17, the work material 201 is rotated around the shaft O1 and the cutting tool 101 is relatively close to the work material 201. Next, as shown in FIG. 18, the first cutting edge C1 and the second cutting edge C2, which are the cutting edges of the cutting tool 101, are brought into contact with the work material 201 to cut the work material 201. Further, as shown in FIG. 19, in a state where the cutting edge of the cutting tool 101 is in contact with the work material 201, the cutting tool 101 moves relative to the rotating work material 201 in the axial direction of the shaft O1. The work material 201 is cut. At this time, the second cutting edge C2 faces forward in the moving direction. Then, as shown in FIG. 20, the cutting tool 101 is relatively far from the work material 201.

In the examples of FIGS. 17 and 18, the cutting tool 101 is moved closer to the work material 201 while the shaft O1 is fixed and the work material 201 is rotated around the shaft O1. Further, in the examples of FIGS. 18 and 19, the work material 201 is cut by bringing the cutting edge of the insert 1 into contact with the rotating work material 201. Further, in FIG. 20, the cutting tool 101 is moved away from the work material 201 in a rotated state.

In the cutting process in the manufacturing method of the embodiment, the cutting tool 101 is brought into contact with the work material 201 or the cutting tool 101 is separated from the work material 201 by moving the cutting tool 101 in each step. ing. However, of course, it is not limited to such a form.

For example, in the step (1), the work material 201 may be brought closer to the cutting tool 101. In the step (3), the work material 201 may be moved away from the cutting tool 101. When the cutting process is continued, the process of keeping the work material 201 rotated and bringing the cutting edge of the insert 1 into contact with different parts of the work material 201 may be repeated.

Note that typical examples of the material of the work material 201 include carbon steel, alloy steel, stainless steel, cast iron, non-ferrous metal and the like.

As described above, the cutting insert according to one aspect of the present disclosure includes a base portion and a cutting portion provided so as to project from the base portion, and the cutting portion is the tip of the tip in the projecting direction. A tip surface located on the side, an upper surface extending from the base portion to the tip surface, a first side surface extending from the base portion to the tip surface and adjacent to the upper surface, and extending from the base portion to the tip surface. , A second side surface adjacent to the upper surface on the opposite side of the first side surface, a first cutting edge located at the intersection of the upper surface and the tip surface, and a second surface located at the intersection of the upper surface and the first side surface. It has a cutting edge. The upper surface has a breaker protrusion extending along the second side surface, and when viewed from the side of the first side surface, the ridgeline where the breaker protrusion and the second side surface intersect is located on the side of the tip end. It has a first line portion having a convex curved shape.

In the tip described in Patent Document 1, the distance between the first ridge line and the second ridge line becomes narrower toward the tip end side of the cutting portion. Therefore, the width of the breaker groove becomes narrower at the portion along the second cutting edge toward the tip end side of the cutting portion, and the rising surface of the breaker wall is located in the vicinity of the second cutting edge. Further, the chip is provided with a wide rising surface of the breaker wall in order to cover a wide cutting area when the post-grinding process is performed. With such a tip, when the chip generated at the tip end side portion of the second cutting edge comes into contact with the breaker wall, a large cutting resistance may occur, and there is a possibility that the chip may be clogged. One aspect of the present disclosure is to realize a cutting insert capable of reducing cutting resistance due to chip discharge and reducing the possibility of chip clogging.

According to one aspect of the present disclosure, the ridge line where the breaker protrusion and the second side surface intersect has a first line portion located on the side of the tip end and forming a convex curve shape. That is, the breaker protrusion has a convex curved surface-shaped portion located on the tip side. As a result, the contact area of the chips generated at the tip end side portion of the second cutting edge with respect to the breaker protrusion can be reduced. Therefore, the dischargeability of chips is improved. As a result, the risk of chip clogging can be reduced.

[Appendix]
The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to each of the above-described embodiments. That is, the invention according to the present disclosure can be variously modified within the scope shown in the present disclosure, and the invention according to the present disclosure also relates to an embodiment obtained by appropriately combining the technical means disclosed in different embodiments. Included in the technical scope. That is, it should be noted that those skilled in the art can easily make various modifications or modifications based on the present disclosure. It should also be noted that these modifications or modifications are within the scope of this disclosure.

1, 1A Cutting insert 10 Base part 11 First main surface 12 Second main surface 13 Through hole 14 Upper side surface 15 Lower side surface 16

Step surface

20, 20A Cutting part 21 Upper surface 21a First inclined surface 21b Second inclined surface

21c Bottom surface

21d Breaker protrusion 22 Tip surface 23 1st side surface 24 2nd side surface 25 Bottom surface 101 Cutting tool 103 Pocket 105 Holder 107 Screw 201 Work material C1 1st cutting edge C2 2nd cutting edge K1 1st boundary K2 2nd boundary L1 1st straight line L2 2nd straight line O1 Axis P1 1st end P2 2nd end P3 3rd end P4 4th end R1 1st ridge R2 2nd ridge R3 3rd ridge R3-1 1st line R3-1a 1st Part R3-1b 2nd part R3-2 2nd line part R3-2a 3rd part R3-2b 4th part θ1 1st tilt angle θ2 2nd tilt angle

Claims

The base part and
A cutting portion provided so as to protrude from the substrate portion is provided.
The cutting part is
The tip surface located on the tip side in the direction of protrusion from the substrate portion,
An upper surface extending from the substrate portion to the tip surface and
A first side surface extending from the substrate portion to the tip surface and adjacent to the upper surface,
A second side surface extending from the substrate portion to the tip surface and adjacent to the upper surface on the opposite side of the first side surface.
The first cutting edge located at the intersection of the upper surface and the tip surface,
It has a second cutting edge located at the intersection of the upper surface and the first side surface, and has.
The upper surface has a breaker protrusion extending along the second side surface.
A cutting insert having a first line portion in which the surface of the breaker protrusion and the intersecting ridge line of the second side surface are located on the side of the tip end and form a convex curve shape when viewed from the side of the first side surface.
The first line part is
The first end located on the side of the tip and
It has a second end located on the opposite side of the first end, and has.
The cutting insert according to claim 1, wherein the second end is located above the first end.
The first line part is
A first portion that inclines upward from the first end portion toward the substrate portion, and
The cutting insert according to claim 2, wherein the cutting insert is located closer to the second end portion than the first portion and has a second portion that is inclined downward toward the base portion.
With the boundary between the first part and the second part as the first boundary,
The cutting insert according to claim 3, wherein the distance from the first end to the first boundary is longer than the distance from the second end to the first boundary.
Claims 2 to 4 further include a second line portion that is located closer to the base portion than the first line portion and has a convex curved shape when viewed from the side of the first side surface. The cutting insert according to any one of the above items.
The second line part is
The third end located on the side of the tip and
It has a fourth end located on the opposite side of the third end, and has.
The cutting insert according to claim 5, wherein the fourth end is located above the third end.
The second line part is
A third portion that inclines upward from the third end portion toward the substrate portion, and a third portion.
The cutting insert according to claim 6, wherein the cutting insert is located closer to the fourth end portion than the third portion and has a fourth portion that is inclined downward toward the substrate portion.
With the boundary between the third part and the fourth part as the second boundary,
The cutting insert according to claim 7, wherein the distance from the third end to the second boundary is longer than the distance from the fourth end to the second boundary.
When viewed from the side of the first side surface, the virtual line connecting the first end portion and the second end portion is the first straight line, and the virtual line connecting the third end portion and the fourth end portion is a virtual line. The second straight line
When a plane parallel to the protruding direction of the cutting portion and orthogonal to the first side surface is used as a reference plane,
Any one of claims 6 to 8, wherein the second tilt angle formed by the second straight line with respect to the reference plane is larger than the first tilt angle formed by the first straight line with respect to the reference plane. The cutting insert described in.
A holder with a pocket located on the tip side,
A cutting tool having the cutting insert according to any one of claims 1 to 9, located in the pocket.
The process of rotating the work material and
The step of bringing the cutting tool according to claim 10 into contact with the rotating work material, and
A method for manufacturing a machined product, comprising a step of separating the cutting tool from the work material.