JP7304989B2 - Manufacturing method of cutting insert, cutting tool and cutting work - Google Patents

Description

Cross-reference to related applications

This application claims priority from Japanese Patent Application No. 2017-208929 filed on October 30, 2017, and the entire disclosure of this earlier application is incorporated herein for reference.

This aspect relates generally to cutting inserts used in cutting operations. More specifically, it relates to cutting tools made of materials with relatively high hardness, such as PCD and cBN.

BACKGROUND ART As a cutting tool used for cutting a work material such as metal, for example, a cutting insert (throwaway tip) described in Japanese Patent Application Laid-Open No. 8-155702 (Patent Document 1) is known. In the cutting insert described in Patent Document 1, the upper surface has a land surface (chamfered portion) positioned along the cutting edge and a chip breaker positioned inside the land surface.

In particular, as in the cutting insert described in Patent Document 1, when the cutting edge portion is composed of an ultra-hard sintered body containing cubic boron nitride (CBN) as a main component, The land surface tends to be set wide. The land surface can be formed, for example, by honing with a brush, by hand or by blasting.

If the land surface is formed only by honing with a brush or by hand, the surface of the land surface may become rough and the arithmetic mean height Sa may become large. As a result, the cutting resistance on the land surface increases, and chipping of the cutting edge may occur. Further, although it is possible to reduce the arithmetic mean height Sa of the land surface only by blasting, in this case, the arithmetic mean height Sa of the chip breaker is also reduced. Therefore, there is a possibility that breaking of chips in the chip breaker may be insufficient.

A cutting insert according to one aspect has a first surface, a second surface, a third surface and a cutting edge. The second surface is located opposite the first surface. The third surface is located between the first surface and the second surface. A cutting edge is located at least part of the intersection of the first surface and the third surface. The first surface has a first area , a second area and a third area . The first region is located along the intersection and at least partially includes a flat first plane. The second region is located inside the first surface relative to the first region, is inclined so as to approach the second surface as the distance from the first region increases, and at least partially includes a flat second plane. there is The third region is located inside the first surface relative to the second region, and is inclined away from the second surface as the distance from the second region increases. It has a flat fourth plane spaced apart from the second surface. The arithmetic mean height Sa3 on the third plane is greater than the arithmetic mean height Sa4 on the fourth plane.

It is a perspective view showing a cutting insert of an embodiment. It is the front view which looked at the cutting insert shown in FIG. 1 from the 1st surface side. It is the side view which looked at the cutting insert shown in FIG. 2 from A1 direction. It is the side view which looked at the cutting insert shown in FIG. 2 from A2 direction. 3 is an enlarged view of a region B1 shown in FIG. 2; FIG. FIG. 6 is a cross-sectional view of the VI cross section in the cutting insert shown in FIG. 5 ; FIG. 6 is a sectional view of the VII section in the cutting insert shown in FIG. 5; 6 is a cross-sectional view of the VIII cross section in the cutting insert shown in FIG. 5; FIG. It is a perspective view showing a cutting tool of an embodiment. FIG. 10 is an enlarged view of a region B2 shown in FIG. 9; It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of embodiment. It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of embodiment. It is the schematic which shows 1 process of the manufacturing method of the cut workpiece of embodiment.

Hereinafter, cutting inserts 1 (hereinafter also simply referred to as inserts 1) of a plurality of embodiments will be described in detail with reference to the drawings. However, for convenience of explanation, each drawing referred to below shows only the main members necessary for explaining each embodiment in a simplified manner. Accordingly, the insert 1 may comprise any components not shown in the referenced figures. Also, the dimensions of the members in each drawing do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the respective members, and the like.

<Cutting insert>
The insert 1 of the embodiment has a first surface 3 (upper surface in FIG. 1), a second surface 5 (lower surface in FIG. 1), a third surface 7 (side surface in FIG. 1), and a cutting edge. It is generally polygonal plate-shaped.

The first surface 3 may be polygonal, as shown in FIG. The second surface 5 may be located opposite the first surface 3, as shown in FIG. The third surface 7 may be located between the first surface 3 and the second surface 5, as shown in FIG. The cutting edge may be located at least part of the intersection of the first surface and the third surface.

The first surface 3 is not limited to a specific shape. The first surface 3 may have, for example, a polygonal shape when viewed from the front. In the example insert 1 shown in FIG. 2, the first face 3 is rhomboidal. Therefore, the first surface 3 in the example shown in FIG. 2 has four corners and four sides. At this time, one of the four corners is the first corner 9 and the two sides connected to the first corner 9 are the first side 11 and the second side 13 . The first corner 9 may be located between the first side 11 and the second side 13 at the outer peripheral edge of the first surface 3 .

Here, the polygonal shape is not strictly limited to a polygonal shape. For example, when the first surface 3 is viewed from the front, the four corners of the first surface 3 may each be rounded and slightly convex outward. Moreover, when the first surface 3 is viewed from the front, the four sides are not limited to strictly linear shapes. These sides may have a slightly convex shape or a slightly concave shape toward the outside when the first surface 3 is viewed from the front.

The second surface 5 may be polygonal, for example rhomboid like the first surface 3 . In this case, the third surface 7 has four generally flat planes and four curved surfaces connecting these planes.

In addition, the shape of the 1st surface 3 and the 2nd surface 5 is not limited to said form. In one embodiment of the insert 1, the shape of the first surface 3 and the second surface 5 is square. However, the shape of the first surface 3 and the second surface 5 may also be triangular or hexagonal, for example.

The size of the insert 1 is not particularly limited. For example, the length of one side of the first surface 3 can be set to approximately 3 mm or more and 20 mm or less. Also, the height from the first surface 3 to the second surface 5 can be set to approximately 5 mm or more and 20 mm or less.

The insert 1 of the embodiment has a cutting edge 15 located at least part of the intersection (ridgeline) L1 between the first surface 3 and the third surface 7 . The cutting edge 15 can be used when cutting a work material. The cutting edge 15 may be positioned over the entire intersection L1, in other words, the entire outer edge portion of the first surface 3, or may be positioned only at a portion of the intersection L1. In the example shown in FIG. 5 , the cutting edges 15 are positioned at the first corner 9 , part of the first side 11 and part of the second side 13 .

The first surface 3 has a first area 17 and a second area 19 . The first region 17 is located along the intersection L1. At this time, the first region 17 may be in contact with the intersection L1 or may be separated therefrom. The first region 17 in the example shown in FIG. 5 touches the intersection L1. The second region 19 is located inside the first surface 3 relative to the first region 17 and is inclined with respect to the first region 17 .

The first region 17 has a flat first plane 21 . Here, the first plane 21 may be located in the entire first region 17 or may be located only in part of the first region 17 . The second region 19 has a flat second plane 23 . The second plane 23 may be located in the entire second region 19 or may be located only in part of the second region 19 .

The first regions 17 in the example shown in FIG. 5 are located along the first corner 9 , the first side 11 and the second side 13 . Also, the first region 17 in the example shown in FIG. 5 has a belt-like configuration in which the width in the direction orthogonal to the intersection L1 is narrower than the width in the direction along the intersection L1.

At least a portion of the first region 17 may be positioned along the cutting edge 15 . A portion of the first region 17 located along the cutting edge 15 can be used as a so-called land surface. When the first region 17 is used as a land surface, the durability of the cutting edge 15 is improved. The first region 17 may be in contact with the cutting edge 15 or may be separated therefrom. The first region 17 in the example shown in FIG. 5 is in contact with the cutting edge 15 .

1 and the like is a central axis passing through the center of the first surface 3 and the center of the second surface 5. FIG. 4 and the like denotes a virtual plane S that is orthogonal to the central axis O1 and positioned between the first surface 3 and the second surface 5. As shown in FIG. The first plane may be parallel to the virtual plane S or may be inclined. The first plane of the example shown in FIGS. 6-8 is parallel to the imaginary plane S. In FIG.

The second region 19 in the insert 1 of the embodiment is slanted with respect to the first region 17 . At this time, the second region 19 may be inclined so as to approach the virtual plane S as it separates from the first region 17 , or it may be inclined so as to separate from the virtual plane S as it separates from the first region 17 . good too. In the example shown in FIGS. 6 to 8, the second area 19 is inclined so as to approach the virtual plane S as the distance from the first area 17 increases.

In the insert 1 of the embodiment, the arithmetic mean height Sa2 on the second plane 23 is greater than the arithmetic mean height Sa1 on the first plane 21 . Since the arithmetic mean height Sa1 in the first plane 21 of the first region 17 positioned along the cutting edge 15 is relatively small in this manner, the cutting resistance during cutting can be reduced. In addition, since the arithmetic mean height Sa2 on the second plane 23 of the second region 19 located inside the first surface 3 is relatively larger than that of the first region 17, it is good for chips scraping the second plane 23 can be braked.

In order to make the arithmetic mean height Sa2 larger than the arithmetic mean height Sa1, for example, the insert 1 may be produced by the following steps. However, the means for making the arithmetic mean height Sa2 larger than the arithmetic mean height Sa1 is not limited to the following steps.

First, a molded body to be the insert 1 is prepared. Next, the second plane 23 is formed by honing with a brush or by hand. At this time, the brush may contact not only the second plane 23 but also the first plane 21 . Next, a protective film is applied on the second plane 23 so that the first plane 21 is exposed. Next, the first plane 21 is formed by blasting. Next, the protective film is removed. Through the above steps, the arithmetic mean height Sa2 can be made larger than the arithmetic mean height Sa1.

Also, the order of creating the first plane 21 and the second plane 23 may be reversed. First, a molded body to be the insert 1 is prepared. Next, the first plane 21 is formed by blasting. At this time, the blasting process may be performed not only on the first plane 21 but also on the second plane 23 . Next, a protective film is applied on the first plane 21 so that the second plane 23 is exposed. Next, the second plane 23 is formed by honing with a brush or by hand. Next, the protective film is removed. Through the above steps, the arithmetic mean height Sa2 can be made larger than the arithmetic mean height Sa1.

Further, when the insert 1 is produced by laser processing, the arithmetic mean height Sa2 can be made larger than the arithmetic mean height Sa1 by adjusting the laser conditions. That is, when the first plane 21 is formed by irradiating the first laser and the second plane 23 is formed by irradiating the second laser, the conditions of the first laser and the second laser are adjusted. It is possible to make the arithmetic mean height Sa2 larger than the arithmetic mean height Sa1.

Further, when the insert 1 is produced by laser processing, the arithmetic mean height Sa2 can be made larger than the arithmetic mean height Sa1 by adjusting the moving speed of the laser instead of adjusting the laser conditions. is possible.

The arithmetic mean height Sa is a surface property parameter defined in ISO25178-6:2010, and is a parameter obtained by extending the arithmetic mean roughness Ra of lines to a surface. Specifically, the arithmetic average height Sa represents the average of the absolute values of the difference in height of each point on the target surface with respect to the average surface of the measurement target surface.

Sa1 and Sa2 are not limited to specific values. For example, Sa1 can be set to approximately 0.1 to 0.3 μm. Also, Sa2 can be set to about 0.2 to 1 μm.

When Sa1 is 0.1 μm or more, it is easy to apply an appropriate brake to chips. Therefore, it is easy to control the flow of chips on the second plane. When Sa1 is 0.3 μm or less, wear of the first flat surface 21 is easily suppressed. Moreover, when Sa2 is 0.2 μm or more, it is easy to control the flow of chips on the second plane. When Sa2 is 1 μm or less, it is easy to suppress wear of the second plane 23 .

The arithmetic mean height Sa1 of the first plane 21 is calculated by measuring the surface shape of the first plane 21 according to the ISO25178-6:2010 standard except that the cutoff value is fixed at 0.03 mm. good. In addition, the arithmetic mean height Sa2 of the second plane 23 is calculated by measuring the surface shape of the second plane 23 according to the ISO25178-6:2010 standard except that the cutoff value is fixed at 0.03 mm. do it.

However, the above cut-off value is merely an example, and may be appropriately set according to the device used for measurement and the measurement conditions. The surface shapes of the first plane 21 and the second plane 23 may be measured using, for example, a contact surface roughness measuring machine using a stylus or an optical non-contact surface roughness measuring machine.

In addition, that the first plane 21 is flat means that the first plane 21 is not curved. Therefore, the first plane 21 need not be parallel to the virtual plane S, and may be inclined with respect to the virtual plane S. Further, that the second plane 23 is flat means that the second plane 23 is not curved. Therefore, the second plane 23 also need not be parallel to the virtual plane S, and may be inclined with respect to the virtual plane S.

In the example shown in FIGS. 6 to 8, the second area 19 is inclined so as to approach the virtual plane S as the distance from the first area 17 increases. In other words, the second region 19 inclines so as to approach the second surface 5 as it separates from the first region 17 .

When the second region 19 is inclined as described above, it is possible to use the second region 19 as a so-called rake face. When the arithmetic mean height Sa2 of the second plane 23 in the second region 19 capable of functioning as a rake face is relatively large, chips are likely to avoid colliding with the second region 19, resulting in chipping. While it is difficult, it can moderately brake against chips.

Moreover, as shown in FIG. 5, the first surface 3 may further have a third region 25 in addition to the first region 17 and the second region 19 . The third region 25 in the example shown in FIGS. 6 to 8 is positioned inside the first surface 3 relative to the second region 19 and is inclined away from the second surface 5 as the distance from the second region 19 increases. .

The third region 25 has a flat third plane 27 . Here, the third plane 27 may be located in the entire third region 25 or may be located only in part of the third region 25 .

The third area 25 can be used as a so-called breaker wall. If the third region 25 is used as a breaker wall, good bending of the chips can be achieved in this third region 25 . As a result, the chips are easily divided into appropriate lengths, and the discharge of the chips is improved.

The surface roughness of the third plane 27 in the third region 25 is not particularly limited. For example, the arithmetic mean height Sa3 on the third plane 27 may be greater than the arithmetic mean height Sa1 on the first plane 21 . When the arithmetic mean height Sa3 is relatively large, the chips scraping the third plane 27 can be well braked, so that the chips can be stably curved.

In particular, when the arithmetic mean height Sa3 on the third plane 27 is greater than the arithmetic mean height Sa2 on the second plane 23, the durability of the insert 1 is improved. If Sa3 is greater than Sa2, excessive braking of chips in the second plane 23, which is closer to the cutting edge 15 than in the third plane 27, is avoided. Therefore, the second plane 23 is less likely to be worn, and the second plane 23 and the third plane 27 can be braked against chips in a well-balanced manner.

Sa3 is not limited to a specific value. For example, Sa3 can be set to approximately 0.2 μm or more and 1 μm or less.

Also, the third region 25 in the example shown in FIGS. 6-8 further has a fourth plane 29 . The fourth plane 29 is positioned farther from the second surface 5 than the third plane 27 and has a flat shape. The arithmetic mean height Sa4 on the fourth plane 29 may be greater than the arithmetic mean height Sa3 on the third plane 27 and may be smaller than the arithmetic mean height Sa3 on the third plane 27.

When the third plane 27 and the fourth plane 29 are used as breaker walls and the arithmetic mean height Sa4 in the fourth plane 29 is greater than the arithmetic mean height Sa3 in the third plane 27, the and the fourth plane 29 can be braked against chips in a well-balanced manner.

The arithmetic mean height Sa3 of the third plane 27 and the arithmetic mean height Sa4 of the fourth plane 29 are the third plane 27 and the surface shape of the fourth plane 29 may be measured. However, the above cut-off value is merely an example, and may be appropriately set according to the device used for measurement and the measurement conditions.

Further, while using the third plane 27 as a breaker wall, the fourth plane 29 is used as a plane for controlling the direction of chip flow, and the arithmetic mean height Sa4 in the fourth plane 29 is the arithmetic mean height in the third plane 27 When it is smaller than Sa3, chips braked on the second plane 23 and the third plane 27 tend to flow smoothly in the direction along the fourth plane 29 on the fourth plane 29 .

In the example shown in FIGS. 6 to 8, the second region 19 is inclined so as to approach the second surface 5 as the distance from the first region 17 increases. It is inclined away from the second surface 5 . Therefore, a so-called breaker groove is formed by the second region 19 and the third region 25 .

When the insert 1 has a breaker groove, chips tend to scrape in the breaker groove. Therefore, the chips are easily braked when flowing through the breaker groove, and the flowing direction is easily controlled when flowing outside the breaker groove.

If the third plane 27 is located closer to the second surface 5 than the intersection L1, then the third plane 27 will be located within the breaker groove. Therefore, it is easy to brake chips in the breaker groove. Further, when the fourth plane 29 is positioned farther from the second surface 5 than the intersection L1, the fourth plane 29 is positioned outside the breaker groove. Therefore, chips tend to flow smoothly in the direction along the fourth plane 29 .

The maximum height Sz2 on the second plane 23 may be greater than the maximum height Sz1 on the first plane 21 . Thus, when the maximum height Sz1 on the first plane 21 of the first region 17 located along the cutting edge 15 is relatively small, similarly to when the arithmetic mean height Sa1 is relatively small, Cutting resistance during cutting can be reduced.

Further, when the maximum height Sz2 on the second plane 23 of the second region 19 positioned along the cutting edge 15 is relatively large, the second Chips scraping the plane 23 can be braked well.

The maximum height Sz is a surface property parameter defined in ISO25178-6:2010, and is a parameter obtained by extending the maximum line height Rz to the surface. Specifically, the maximum height Sz represents the maximum absolute value of the difference in height of each point on the target surface with respect to the average surface of the target surface.

Sz1 and Sz2 are not limited to specific values. For example, Sz1 can be set to approximately 0.5 μm or more and 2.5 μm or less. Also, Sz2 can be set to approximately 2.2 μm or more and 20 μm or less.

The maximum height Sz1 of the first plane 21 may be calculated by measuring the surface shape of the first plane 21 according to the ISO25178-6:2010 standard except that the cutoff value is fixed at 0.03 mm. . Further, the maximum height Sz2 of the second plane 23 is calculated by measuring the surface shape of the second plane 23 according to the ISO25178-6:2010 standard except that the cutoff value is fixed at 0.03 mm. Just do it. However, the above cut-off value is merely an example, and may be appropriately set according to the device used for measurement and the measurement conditions.

Materials for the insert 1 include, for example, cemented carbide, cermet, ceramics, PCD (polycrystalline diamond), and cBN (cubic boron nitride).

Examples of compositions of 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 the hard particles and Co is the binder phase. A cermet is a sintered composite material in which a metal is combined with a ceramic component. Specifically, the cermet includes a compound containing TiC or TiN (titanium nitride) as a main component. In addition, the material of the insert 1 is not limited to these.

Moreover, the insert 1 may have only one member made of the material exemplified above, or may have a plurality of members made of the material exemplified above.

For example, as shown in FIG. 1, the insert 1 may have a body portion 31 and a cutting portion 33 and may have a polygonal plate shape as a whole. The body portion 31 in the example shown in FIG. 1 has a substantially polygonal plate shape, and has a concave shape with a part notched. The cut portion 33 may be joined to the notched recessed portion using brazing material or the like.

Here, as in the example shown in FIG. 1, the first corner 9, the first side 11 and the second side 13 may be positioned at the cutting portion 33. As shown in FIG. To facilitate visual understanding, the cutting portion 33 is hatched with oblique lines in FIG.

The cutting portion 33 may be made of a material with relatively high hardness such as PCD and cBN, and the body portion 31 may be made of cemented carbide, cermet, or ceramics, for example. When the body portion 31 and the cutting portion 33 are made of the above materials, the insert 1 can be manufactured at low cost. In addition, the insert 1 has high durability against cutting load. The hardness of the body portion 31 and the cutting portion 33 may be evaluated by measuring the Vickers hardness of each portion.

The insert 1 may have only the cutting portion 33 and the main body portion 31, but for example, in addition to the cutting portion 33 and the main body portion 31, a coating layer that covers the surfaces of these portions may be provided. The coating layer may cover the entire surface of the substrate constituted by the cutting portion 33 and the body portion 31, or may cover only a portion of the surface of the substrate.

Examples of the material of the coating layer include aluminum oxide (alumina), titanium carbide, nitride, oxide, carbonate, nitroxide, carbonitride and carbonitride. The coating layer may contain only one of the above materials, or may contain a plurality of them.

Moreover, the coating layer may be composed of only one layer, or may be composed of a plurality of laminated layers. In addition, the material of the coating layer is not limited to these. The coating layer can be placed over the substrate by using, for example, chemical vapor deposition (CVD) or physical vapor deposition (PVD) methods.

The example insert 1 shown in FIG. 1 has a through hole 35 . The through holes 35 in the embodiment are formed from the first surface 3 to the second surface 5 and are open on these surfaces. The through hole 35 may extend along the central axis O<b>1 passing through the center of the first surface 3 and the center of the second surface 5 .

The through holes 35 may be used to attach fixing screws or clamping members when holding the insert 1 in the holder. It should be noted that there is no problem even if the through holes 35 are configured to open in regions on the third surface 7 opposite to each other.

<Cutting tool>
Next, the cutting tool 101 of the embodiment will be described with reference to the drawings.

A cutting tool 101 of the embodiment comprises a holder 105 having a pocket 103 (insert pocket) on the tip side, and the insert 1 located in the pocket 103, as shown in FIGS. In the cutting tool 101 of the embodiment, the insert 1 is attached so that at least part of the cutting edge protrudes from the tip of the holder 105 .

The holder 105 has an elongated bar shape. One pocket 103 is provided on the tip side of the holder 105 . The pocket 103 is a portion to which the insert 1 is attached, and is open to the distal end surface of the holder 105 .

At this time, since the pocket 103 is also open to the side surface of the holder 105, the insert 1 can be easily mounted. Specifically, the pocket 103 has a seating surface parallel to the lower surface of the holder 105 and a restraining side surface inclined with respect to the seating surface.

The insert 1 is located in the pocket 103 . At this time, the lower surface of the insert 1 may be in direct contact with the pocket 103, or a sheet may be sandwiched between the insert 1 and the pocket 103.

The insert 1 is mounted such that at least part of the cutting edge protrudes outward from the holder 105 . In one example shown in FIG. 10, the insert 1 is attached to the holder 105 by the clamping member 107 . The insert 1 may be attached to the holder 105 by inserting the clamp member 107 into the through hole of the insert 1 and fixing the clamp member 107 to the holder 105 .

Steel, cast iron, or the like can be used as the holder 105 . In particular, from the viewpoint of increasing the toughness of the holder 103, steel may be used in these members.

An example of the cutting tool shown in FIG. 9 is a cutting tool used for so-called turning. Turning includes, for example, inner diameter machining, outer diameter machining, and grooving. The cutting tools are not limited to those used for turning. For example, the insert 1 of the above embodiment may be used for a cutting tool used for milling.

<Manufacturing method for cutting products>
Next, a method for manufacturing a machined product according to the embodiment will be described with reference to the drawings.

The cutting work is produced by cutting the work material 201 . A method for manufacturing a cut product according to an embodiment includes the following steps. i.e.
(1) a step of rotating the work material 201;
(2) a step of contacting the rotating work material 201 with the cutting tool 101 represented by the above embodiment;
(3) separating the cutting tool 101 from the work material 201;
It has

More specifically, first, as shown in FIG. 11, the workpiece 201 is rotated around the axis O2, and the cutting tool 101 is moved relatively close to the workpiece 201. As shown in FIG. Next, as shown in FIG. 12, the cutting edge of the cutting tool 101 is brought into contact with the work material 201 to cut the work material 201 . Then, as shown in FIG. 13, the cutting tool 101 is moved away from the work material 201 relatively.

In the example shown in FIG. 11, the cutting tool 101 is brought closer to the work material 201 by moving the cutting tool 101 in the Y1 direction while the work material 201 is rotated while the axis O2 is fixed. In FIG. 12, the work material 201 is cut by bringing the cutting edge of the cutting tool 101 into contact with the rotating work material 201 . In FIG. 13, the cutting tool 101 is moved in the Y2 direction while the workpiece 201 is being rotated, thereby moving the cutting tool 101 away.

11 to 13, in each step, the cutting tool 101 is brought into contact with the work material 201 by moving the cutting tool 101, or the cutting tool 101 is brought into contact with the work material 201. Although it is separated from the cutting material 201, it is of course not limited to such a form.

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

Representative examples of the material of the work material 201 include carbon steel, alloy steel, stainless steel, cast iron, non-ferrous metals, and the like.

1 ... cutting insert (insert)
3 First surface 5 Second surface 7 Third surface 9 First corner 11 First side 13 Second side 15 Cutting edge 17 1st region 19 2nd region 21 1st plane 23 2nd plane 25 3rd region 27 3rd plane 29 4th plane 31 Main body portion 33 Cutting portion 35 Through hole 101 Cutting tool 103 Pocket 105 Holder 107 Fixing screw 201 Work material

Claims (9)

a first surface;
a second surface located on the opposite side of the first surface;
a third surface located between the first surface and the second surface;
a cutting edge located at least part of the intersection of the first surface and the third surface;
The first surface is
a first region located along the intersection and having a flat first plane;
a second region located inside the first surface relative to the first region and inclined to approach the second surface as the distance from the first region increases, the second region having a flat second plane ;
A flat third plane located inside the first surface relative to the second region, inclined away from the second surface as the distance from the second region increases, and a flat third plane and the second surface relative to the third plane a third region having a flat fourth plane spaced from the
has
A cutting insert , wherein the arithmetic mean height Sa3 in the third plane is greater than the arithmetic mean height Sa4 in the fourth plane . In a cross-sectional view perpendicular to the cutting edge,
When a direction orthogonal to a central axis passing through the center of the first surface and the center of the second surface is defined as a first direction,
The cutting insert according to claim 1, wherein the length of the third plane along the first direction is shorter than the length of the fourth plane along the first direction. In a cross-sectional view perpendicular to the cutting edge,
When a direction along a central axis passing through the center of the first surface and the center of the second surface is defined as a second direction,
The cutting insert according to claim 1 or 2, wherein the length of the third plane along the second direction is shorter than the length of the fourth plane along the second direction. 4. The cutting insert according to claim 2 or 3, wherein the arithmetic mean height Sa2 in the second plane is greater than the arithmetic mean height Sa1 in the first plane. The cutting insert according to any one of claims 2 to 4 , wherein the arithmetic mean height Sa3 in the third plane is greater than the arithmetic mean height Sa2 in the second plane. 6. Any one of claims 2 to 5, wherein the fourth plane is located farther from the second surface than the intersection, and the third plane is located closer to the second surface than the intersection. A cutting insert according to one . The cutting insert according to any one of claims 2 to 6, wherein the maximum height Sz2 in the second plane is greater than the maximum height Sz1 in the first plane. a holder having a pocket located on the tip side;
A cutting tool comprising a cutting insert according to any one of claims 1 to 7, located in said pocket. rotating the work material;
A step of bringing the cutting tool according to claim 8 into contact with the rotating work material;
and separating the cutting tool from the work material.

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