JP2019130647A - Cutting insert, cutting tool and manufacturing method of cutting work object - Google Patents

Abstract

To solve the problem of requiring a cutting insert having an excellent cutting discharge property.SOLUTION: An insert of one mode comprises a corner of a convex curve shape, an upper surface having the first side and the second side respectively extended from the corner, an undersurface positioned on the opposite side of the upper surface and a side surface positioned between the upper surface and the undersurface. The upper surface comprises a first surface positioned along the corner, a second surface separated from the first surface and separately positioned from the undersurface more than the first surface and a third surface positioned between the first surface and the second surface and inclined to respective ones of the first surface and the second surface. In a top view, the third surface comprises a first inclined plane positioned on the side of the first side and a second inclined plane positioned on the side of the second side more than the first inclined plane, and in the top view, the first inclined plane contacts with the corner.SELECTED DRAWING: Figure 4

Description

  This aspect relates to a cutting insert, a cutting tool, and a manufacturing method of a cut workpiece.

  For example, a cutting insert having a chip breaker described in Patent Document 1 is known as a cutting tool used when cutting a work material such as metal. The chip breaker in the cutting insert described in Patent Document 1 has two breaker surfaces that are symmetrical with respect to the nose bisector.

International Publication No. 2005/068117

  Since the chip breaker in the cutting insert described in Patent Document 1 has two breaker surfaces located away from the nose, the behavior of the chips may become unstable during cutting with a low depth of cut.

  The insert according to one aspect includes a convex curve-shaped corner, an upper surface having first and second sides extending from the corner, a lower surface located on the opposite side of the upper surface, the upper surface and the lower surface, respectively. And a side surface located between them. Further, the upper surface is a first surface located along the corner, a second surface that is separated from the first surface and is further away from the lower surface than the first surface, and And a third surface that is located between the first surface and the second surface and is inclined with respect to each of the first surface and the second surface. In the top view, the third surface has a first inclined surface located on the first side and a second inclined surface located on the second side from the first inclined surface. In the top view, the first inclined surface is a cutting insert in contact with the corner.

  The cutting insert of the said aspect has favorable chip discharge | emission property.

It is a perspective view showing a cutting insert of an embodiment of this indication. It is an enlarged view which shows area | region A1 in FIG. It is a top view of the cutting insert shown in FIG. It is an enlarged view which shows area | region A2 in FIG. It is a modification of the cutting insert shown in FIG. It is the side view which looked at the cutting insert shown in FIG. 3 from B1 direction. It is an enlarged view which shows area | region A3 in FIG. It is the side view which looked at the cutting insert shown in FIG. 3 from the B2 direction. It is an enlarged view which shows area | region A4 in FIG. It is the side view which looked at the cutting insert shown in FIG. 3 from B3 direction. It is an enlarged view which shows area | region A5 in FIG. It is sectional drawing which shows the C1-C1 cross section in FIG. It is sectional drawing which shows the C2-C2 cross section in FIG. It is a top view showing a cutting tool of an embodiment of this indication. It is the figure which showed one process in the manufacturing method of the cut workpiece of embodiment of this indication. It is the figure which showed one process in the manufacturing method of the cut workpiece of embodiment of this indication. It is the figure which showed one process in the manufacturing method of the cut workpiece of embodiment of this indication.

<Cutting insert>
Hereinafter, the cutting insert 1 of various embodiment of this indication is demonstrated in detail using drawing. However, for convenience of explanation, the drawings referred to below show only main members necessary for explaining the cutting insert 1 of the embodiment in a simplified manner. Therefore, the cutting insert 1 according to the present disclosure may include any constituent member that is not shown in each of the referenced drawings. Moreover, the dimension of the member in each figure does not represent the dimension of an actual structural member, the dimension ratio of each member, etc. faithfully.

  As shown in FIG. 1, the cutting insert 1 of the embodiment has an upper surface 9, a lower surface 11 positioned on the opposite side of the upper surface 9, and a side surface 13 positioned between the upper surface 9 and the lower surface 11. Moreover, as shown in FIG. 3 which is a top view, the top surface 9 includes a corner 3 having a convex curve shape, and a first side 5 and a second side 7 respectively extending from the corner 3.

  In the embodiment, the upper surface 9 has a polygonal shape, and in the example shown in FIG. Therefore, the upper surface 9 in the example shown in FIG. 3 has four corners and four sides. Moreover, since the upper surface 9 is a rhombus, the side surface 13 is comprised by four surface area | regions. The shape of the upper surface 9 is not limited to the configuration shown in FIG. For example, there is no problem even if the upper surface 9 is not a quadrangle, but a pentagon, a hexagon, or an octagon.

  In FIG. 3, the corner 3 is one of the four corners of the upper surface 9. The first side 5 and the second side 7 are two of the four sides of the upper surface 9.

  The upper surface 9 in the embodiment may be generally polygonal and need not be polygonal in a strict sense. That is, the sides on the polygonal upper surface 9 do not have to be strictly linear, and may be, for example, a convex curve shape or a concave curve shape. Moreover, the corner | angular in the polygonal upper surface 9 is not limited to the structure where two straight lines crossed, For example, the shape rounded outward may be sufficient.

  As in the example illustrated in FIGS. 3 and 4, the first side 5 and the second side 7 may be linear when viewed from above. The convex curve shape of the corner 3 may have a constant radius of curvature.

  Although the magnitude | size of the cutting insert 1 is not specifically limited, For example, the length of the one side of the upper surface 9 may be set to about 3-20 mm. Moreover, the height from the upper surface 9 to the lower surface 11 may be set to about 5 to 20 mm.

  The cutting insert 1 may have a cutting edge located on at least a part of a ridge line where the upper surface 9 and the side surface 13 intersect. The cutting blade can cut the work material when the work material is cut. For example, the cutting edge may be located on the upper surface 9 at the corner 3, a part of the first side 5 following the corner 3, and a part of the second side 7 following the corner 3. In the example shown in FIG. 4, the cutting edge is located in the entire corner 3, a partial region adjacent to the corner 3 on the first side 5, and a partial region adjacent to the corner 3 on the second side 7. .

  Further, the cutting insert 1 may have a hole 35 that opens in the upper surface 9. The hole 35 may penetrate to the lower surface 11. In addition, the hole 35 is not limited to the above-described form, and may be open to the side surface 13, for example, and may be another surface region located on the opposite side of the surface region from one surface region of the side surface 13. It may penetrate through the surface area.

  The hole 35 can be used as an insertion hole for a fixture when the cutting insert 1 is mounted on a holder. Examples of the fixture include a screw, a clamp member, and a wedge.

  As shown in FIGS. 4 and 7, the upper surface 9 in the present disclosure has a first surface 15, a second surface 17, and a third surface 19. The first surface 15 is located along the corner 3. In addition, you may have the inclined surface which inclines with respect to each of the 1st surface 15 and the side surface 13 between the corner 3 and the 1st surface 15. FIG. The inclined surface may be a flat surface or a curved surface. When the inclined surface is flat, the inclined surface is a so-called chamfer. Moreover, when the said inclined surface is a curved surface, the said inclined surface is what is called a land.

  Further, the second surface 17 is separated from the first surface 15 and is located farther from the lower surface 11 than the first surface 15. The third surface 19 is located between the first surface 15 and the second surface 17 and is inclined with respect to each of the first surface 15 and the second surface 17 as shown in FIG. Yes.

  In addition, as in the example illustrated in FIG. 4, in the top view, the third surface 19 includes a first inclined surface 21 located on the first side 5 side and the second side 7 side from the first inclined surface 21. The first inclined surface 21 is in contact with the corner 3.

  Since the first inclined surface 21 is in contact with the corner 3, for example, chips generated from the corner 3 at the time of low-cut cutting using the entire corner 3 easily come into contact with the first inclined surface 21, so that chip discharge is stable. To do. Further, since the first inclined surface 21 is in contact with the corner 3, the first inclined surface 21 is easily located near the center of the corner 3. Therefore, for example, chips are likely to come into contact with the first inclined surface 21 even at the time of ultra-low cutting using a part of the corner 3. Therefore, since the cutting insert 1 in the embodiment can stabilize the behavior of the chips even at the time of low cutting, the cutting insert 1 has a good chip discharging property.

  Further, as in the example illustrated in FIG. 4, the first inclined surface 21 may be in contact with the first side 5 in the top view. When the first inclined surface 21 is in contact with the first side 5, a predetermined space can be provided between the first inclined surface 21 and the corner 3. Therefore, chips generated from the corner 3 are not easily clogged in the first inclined surface 21. Therefore, the cutting insert 1 in the example shown in FIG. 4 has better chip dischargeability.

  5, the third surface 19 has a third inclined surface 25 that is adjacent to the first inclined surface 21 and extends along the first side 5 in a top view. You may do it. Stress tends to concentrate in the vicinity of the intersection where the three surfaces of the side surface 13, the second surface 17, and the first inclined surface 21 intersect. However, since the third surface 19 has the third inclined surface 25 adjacent to the first inclined surface 21 and extending along the first side 5 in the top view, Stress concentration is relaxed. Therefore, the cutting insert 1 in the embodiment has high durability. In addition, in the top view, the third inclined surface 25 may be a flat surface or a curved surface.

Further, the upper surface 9 may have a convex curve portion having a radius of curvature different from that of the corner 3 between the corner 3 and the first side 5 and between the corner 3 and the second side 7. . As shown in an example in FIG. 4 which is a top view, the second inclined surface 23 may be in contact with a convex curve-shaped portion located between the corner 3 and the second side 7.

  For example, when cutting is performed by cutting the corner 3 to a position closest to the second side 7, the second inclined surface 23 is not located on the corner 3, and therefore, a predetermined interval is set between the second inclined surface 23 and the corner 3. Space can be provided. Therefore, chips generated from the corner 3 are not easily clogged in the second inclined surface 23. Therefore, when the 2nd inclined surface 23 is said structure, chip discharge | emission property becomes further favorable. When viewed from above, when the second inclined surface 23 is in contact with the convex curve portion located between the corner 3 and the second side 7, the second inclined surface 23 is in point contact with the corner 3. Also good.

  Further, as shown in FIG. 4 which is a top view, the second inclined surface 23 may be separated from the corner 3. When the second inclined surface 23 is away from the corner 3, the space of the first surface 15 is easily secured. Therefore, it is hard to clog chips.

  Further, the second inclined surface 23 may be in contact with the second side 7 in a top view. For example, when cutting is performed using the second side 7 in addition to the corner 3, the chips are stable and easily come into contact with the second inclined surface 23. Therefore, it is possible to treat chips well on the second inclined surface 23.

  The first inclined surface 21 and the second inclined surface 23 in the example shown in FIG. 4 are flat surfaces. The first inclined surface 21 and the second inclined surface 23 may each have a convex curved surface shape or a concave curved surface shape.

  Moreover, the 1st inclined surface 21 and the 2nd inclined surface 23 may cross like the example shown in FIG. That is, as in the example illustrated in FIG. 4, the upper surface 3 may have a ridge line 27 between the first inclined surface 21 and the second inclined surface 23. Furthermore, as shown in FIG. 4, the ridge line 27 may be parallel to the bisector M of the corner 3 or may be inclined. In the example shown in FIG. 4, the ridge line 27 is located closer to the second side than the bisector M of the corner 3 and approaches the bisector M as the distance from the corner 3 increases. .

  In the example shown in FIG. 4, the bisector M of the corner 3 is indicated by a line that bisects the angle formed by the virtual extension line L1 of the first side 5 and the virtual extension line L2 of the second side 7. Has been.

  When the ridgeline 27 is inclined with respect to the bisector M when viewed from above, the work surface of the work material is improved as described below.

  For example, as shown in FIG. 4, when the ridge line 27 is inclined so as to approach the first side 5 as it moves away from the corner 3, end face machining mainly using a portion on the second side 7 side in the corner 3. The work surface of the work material in the is improved. This is because, when the ridge line 27 is inclined as described above, the chips are likely to come into contact with the first inclined surface 21, and thus are easily discharged in the feed direction of the cutting insert 1 and are not easily discharged in the direction of the processed surface. Because.

  In the end face processing described above, the cutting insert 1 moves in a direction substantially along the second side 7 and toward the corner 3 from the second side 7. Therefore, the feeding direction in the above-described end face machining is a direction substantially along the second side 7 and a direction from the second side 7 toward the corner 3.

Further, when the ridge line 27 is inclined so as to approach the second side 7 as the distance from the corner 3 increases, the machining in the inner diameter processing or the outer diameter processing mainly using the portion on the second side 7 side in the corner 3 is performed. The machined surface of the material is improved. This is because, when the ridge line 27 is inclined as described above, chips coming into contact with the second inclined surface 23 are easily discharged in the feed direction of the cutting insert and are not easily discharged in the direction of the processed surface. .

  In the inner diameter processing and outer diameter processing described above, the cutting insert 1 moves in a direction substantially perpendicular to the second side 7 and from the first side 5 toward the second side 7. Therefore, the feed direction in the end face processing is a direction that is substantially perpendicular to the second side 7 and is directed from the first side 5 toward the second side 7.

  The ridge line 27 is a portion to which the first inclined surface 21 and the second inclined surface 23 are connected, and does not need to be a strict line. For example, an elongate curved surface connecting these surfaces may exist between the first inclined surface 21 and the second inclined surface 23. That is, if such a curved surface is generally linear when viewed with the naked eye, this curved surface may be regarded as the ridge line 27.

  Further, as in the example illustrated in FIG. 4, the ridge line 27 may be located closer to the second side 7 than the bisector M of the corner 3 in a top view. When the ridge line 27 is positioned as described above, the width of the first inclined surface 21 in the direction orthogonal to the bisector M is wide. Therefore, chips are likely to come into contact with the first inclined surface 21 in the end face processing mainly using the portion on the second side 7 side in the corner 3.

  Further, as in the example illustrated in FIG. 5, the ridge line 27 may be located closer to the first side 5 than the bisector M of the corner 3 in a top view. When the ridge line 27 is positioned as described above, the width of the second inclined surface 23 in the direction orthogonal to the bisector M is wide. Therefore, chips are likely to come into contact with the second inclined surface 23 in inner diameter processing or outer diameter processing mainly using the portion on the second side 7 side in the corner 3.

  Further, the ridge line 27 may intersect the bisector M of the corner 3 in a top view. When the ridge line 27 is positioned as described above, the first inclined surface 21 and the second inclined surface in the direction orthogonal to the bisector M while the ridge line 27 is inclined with respect to the bisector M. The width of each of 23 is secured widely. Therefore, the processed surface is good in any of the end surface processing, the inner diameter processing, and the outer diameter processing mainly using the portion on the second side 7 side in the corner 3.

  Further, as in the example illustrated in FIG. 4, the upper surface 9 may have a fourth surface 29 that is adjacent to the second inclined surface 23 and is positioned along the second side 7. When the upper surface 9 has the above-described fourth surface 29, for example, the processed surface of the work material in the end face lifting processing using mainly the portion on the second side 7 side in the corner 3 is improved. This is because the portion of the second surface 17 along the second side 7 is less likely to contact the work material. Therefore, even when the cutting insert 1 in the example shown in FIG. 4 is used for the above-described end face lifting process, it is difficult to damage the work material and can provide a good processed surface.

  In the end face lifting process, the cutting insert 1 moves in a direction substantially along the second side 7 and toward the second side 7 from the corner 3. Therefore, the feeding direction in the end face lifting process is a direction substantially along the second side 7 and directed from the corner 3 to the second side 7.

Further, as in the example illustrated in FIG. 5, the fourth surface 29 may be in contact with the corner 3. When the fourth surface 29 is in contact with the corner 3, the portion along the second side 7 in the second surface 17 becomes more difficult to contact the work material when performing the pulling process. Therefore, even when the cutting insert 1 in the example shown in FIG. 5 is used for the end face lifting process,
It is difficult to damage the work material and can provide a good machined surface.

  Further, as in the example illustrated in FIG. 5, the second inclined surface 23 may be separated from the second side 7 in the top view. When the second inclined surface 23 is separated from the second side 7 in a top view, a predetermined space can be provided between the second inclined surface 23 and the second side 7. Therefore, chips generated from the second side 7 are not easily clogged between the second side 7 and the second inclined surface 23. Therefore, the cutting insert 1 in an example shown in FIG. 5 has a good chip discharging property.

  In the example shown in FIGS. 12 and 13, a virtual plane orthogonal to the central axis P passing through the centers of the upper surface and the lower surface is used as the reference surface S. FIG. 12 is a cross-sectional view showing a C1-C1 cross section in FIG. 4 and a cross-sectional view orthogonal to the first side 5. In FIG. 12, an angle formed by the first inclined surface 21 and the reference surface S is defined as a first angle θ1. FIG. 13 is a cross-sectional view showing a C2-C2 cross section in FIG. 4, and is a cross-sectional view orthogonal to the second side 7. In FIG. 13, an angle formed by the second inclined surface 23 and the reference surface S is a second angle θ2. However, FIGS. 12 and 13 do not faithfully represent the positional relationship between various members and the central axis P.

  At this time, the second angle θ2 may be smaller than the first angle θ1. When the second angle θ <b> 2 is smaller than the first angle θ <b> 1, the resistance generated when the chips come into contact with the second inclined surface 23 is small. Therefore, the durability of the cutting insert 1 is high.

  When the virtual straight line orthogonal to the first side 5 does not pass through the first inclined surface 21 in the top view, it is orthogonal to the virtual extension line L1 of the ridge line 27 in the top view, and the first You may evaluate 1st angle (theta) 1 in the cross section which passes along the inclined surface 21. FIG.

  Examples of the material of the cutting insert 1 include cemented carbide, cermet, ceramics, PCD (polycrystal diamond), cBN (cubic boron nitride), and the like.

  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 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 mainly composed of TiC or TiN (titanium nitride). Note that the material of the cutting insert 1 is not limited to these.

  The cutting insert 1 may be constituted by only one member constituted by the material exemplified above, or may be constituted by a plurality of members constituted by the material exemplified above.

  For example, the cutting insert 1 is comprised by the main-body part 31 and the cutting part 33, as shown in FIG. 1, and may have a polygonal plate shape as a whole. The main body 31 may have a substantially polygonal plate shape, and may have a portion cut out at a part of a corner. The cutting part 33 may be joined to the notched part using a brazing material or the like. Here, in the example shown in FIG. 1, the corner 3, a part of the first side 5, and a part of the second side 7 are located in the cutting part 33.

As the material of the cutting part 33, for example, a material having a relatively high hardness such as PCD and cBN is used. Although it is possible, it becomes the cutting insert 1 with high durability with respect to cutting load. What is necessary is just to evaluate the hardness of the main-body part 31 and the cutting part 33 by measuring the Vickers hardness of each site | part.

  Moreover, although the cutting insert 1 may be comprised only by said main-body part 31 and the cutting part 33, in addition to the site | part of the main-body part 31 and the cutting part 33, the coating | cover which covers the surface of these parts, for example A layer (not shown) may be provided. The coating layer may cover the entire surface of the base body constituted by the main body portion 31 and the cutting portion 33, or may cover only a part of the surface of the base body.

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

  Moreover, the coating layer may be configured by only one layer, or may be configured by laminating a plurality of layers. The material of the covering layer is not limited to these. The covering layer can be positioned on the substrate, for example, by using chemical vapor deposition (CVD) or physical vapor deposition (PVD).

<Cutting tools>
Next, the cutting tool 101 of embodiment is demonstrated using drawing.

  As shown in FIG. 14, the cutting tool 101 of the embodiment includes a holder 105 that extends from the first end 105 a toward the second end 105 b. The holder 105 has a pocket 103 (cutting insert pocket) on the first end 105a side. The cutting tool 101 includes the cutting insert 1 located in the pocket 103. In the cutting tool 101 of the embodiment, the cutting insert 1 is mounted such that at least a part of the first side, the second side, and the corner used as a cutting edge protrudes from the first end 105 a of the holder 105. ing.

  The holder 105 has an elongated bar shape. One pocket 103 is provided on the first end 105 a side of the holder 105. The pocket 103 is a portion to which the cutting insert 1 is attached, and is open to the end surface of the holder 105 on the first end 105a side. At this time, when the pocket 103 is also open to the side surface of the holder 105, the cutting insert 1 can be easily mounted. The pocket 103 in the example shown in FIG. 14 has a seating surface parallel to the lower surface of the holder 105 and a restraining side surface that is inclined with respect to the seating surface.

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

  In the example shown in FIG. 14, the cutting insert 1 is attached to the holder 105 by a clamp member 107. That is, the head of the clamp member 107 is pressed against the inner wall of the hole of the cutting insert 1 to restrain the cutting insert 1 in the pocket 103.

  As the holder 105, steel, cast iron, or the like can be used. In particular, it is preferable to use steel having high toughness among these members.

In the embodiment, a cutting tool used for so-called turning is illustrated. Examples of the turning process include an inner diameter process, an outer diameter process, an end face process, and a grooving process. The cutting tool is not limited to that used for turning. For example, you may use the cutting insert 1 of said embodiment for the cutting tool used for a turning process.

<Manufacturing method of cut product>
Next, the manufacturing method of the cut workpiece of embodiment is demonstrated using drawing.

The cut workpiece is produced by cutting the work material 201. The manufacturing method of the cut workpiece in the embodiment includes the following steps. That is,
(1) rotating the work material 201;
(2) contacting the rotating work material 201 with at least a part of the first side, the second side, and the corner used as the cutting edge in the cutting tool 101 represented by the above embodiment;
(3) a step of separating the cutting tool 101 from the work material 201;
It has.

  More specifically, first, as shown in FIG. 15, the work material 201 is rotated around the axis O <b> 1, and the cutting tool 101 is relatively brought closer to the work material 201. Next, as shown in FIG. 16, at least a part of the first side, the second side, and the corner of the cutting tool 101 used as a cutting blade is brought into contact with the work material 201, and the work material 201 is moved. To cut. Then, as shown in FIG. 17, the cutting tool 101 is relatively moved away from the work material 201.

  In the embodiment, the cutting tool 101 is moved in the Y1 direction in a state where the axis O1 is fixed and the work material 201 is rotated, thereby bringing the work tool 201 closer to the work material 201. In FIG. 16, the rotating work material 201 is brought into contact with at least a part of the first side, the second side, and the corner of the cutting insert 1 that are used as cutting edges, and is moved in the X1 direction. Thus, the work material 201 is cut. Further, in FIG. 17, the cutting tool 101 is moved away in the Y2 direction while the work material 201 is rotated.

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

  For example, the work material 201 may be brought close to the cutting tool 101 in the step (1). Similarly, in the step (3), the work material 201 may be moved away from the cutting tool 101. When cutting is continued, the state in which the work material 201 is rotated is maintained and used as a cutting edge among the first side, the second side, and the corner of the cutting insert 1 at different locations of the work material 201. What is necessary is just to repeat the process which contacts at least one part of the part to be made.

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

DESCRIPTION OF SYMBOLS 1 ... Cutting insert 3 ... Corner 5 ... 1st edge 7 ... 2nd edge 9 ... Upper surface 11 ... Lower surface 13 ... Side surface 15 ... 1st surface 17 ... -2nd surface 19 ... 3rd surface 21 ... 1st inclined surface 23 ... 2nd inclined surface 25 ... 3rd inclined surface 27 ... Ridge line 29 ... 4th surface 31 ...・ Main body 33 ... Cutting part 35 ... Hole 101 ... Cutting tool 103 ... Pocket 105 ... Holder 107 ... Clamp member 201 ... Work material P ... Center axis θ1 ... 1st angle θ2 ... 2nd angle M ... Bisecting line L1 ... Virtual extension line L2 ... Virtual extension line S ... Reference plane

Claims (9)

A convex curve-shaped corner, and an upper surface provided with a first side and a second side respectively extending from the corner;
A lower surface located on the opposite side of the upper surface;
A side surface located between the upper surface and the lower surface;
The upper surface is
A first surface located along the corner;
A second surface that is separated from the first surface and is located farther from the lower surface than the first surface;
A third surface positioned between the first surface and the second surface and inclined with respect to each of the first surface and the second surface;
In the top view, the third surface is
A first inclined surface located on the side of the first side;
A second inclined surface located closer to the second side than the first inclined surface;
In the top view, the first inclined surface is a cutting insert in contact with the corner.   The cutting insert according to claim 1, wherein the first inclined surface is in contact with the first side in a top view.   The cutting insert according to claim 1 or 2, wherein the second inclined surface is separated from the corner when viewed from above.   4. The ridge line is provided between the first inclined surface and the second inclined surface in a top view, and the ridge line intersects with a bisector of the corner. 5. Cutting insert as described in.   The top view has a ridge line between the first inclined surface and the second inclined surface, and the ridge line is located on the second side with respect to a bisector of the corner. The cutting insert according to any one of 1 to 3.   The cutting insert according to any one of claims 1 to 5, wherein the upper surface has a fourth surface that is adjacent to the second inclined surface and is positioned along the second side. When a virtual plane orthogonal to the central axis passing through the center of the upper surface and the lower surface is a reference plane,
The second angle formed by the second inclined surface and the reference surface in a cross section orthogonal to the second side in a top view is the second angle formed by the first inclined surface in the cross section orthogonal to the first side in the top view. The cutting insert according to any one of claims 1 to 6, wherein the cutting insert is smaller than a first angle formed by the reference surface. A holder extending from the first end toward the second end and having a pocket located on the first end side;
A cutting tool having a cutting insert according to any one of claims 1 to 7 located in the pocket. A step of rotating the work material;
Contacting the cutting tool according to claim 8 with the rotating work material;
The manufacturing method of the cut workpiece provided with the process of separating the said cutting tool from the said workpiece.

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