Cutting insert, cutting tool, and method for manufacturing machined product

Abstract

This cutting insert has an upper surface and a lower surface. The upper surface has a first corner, a first edge, a rake surface, and a rising surface. The rising surface has: a first recessed part that is sunken from the first edge; a first protruding part positioned further away from the first corner than is the first recessed part; a second protruding part positioned between the first protruding part and the first edge; and a first stepped part positioned between the first and second protruding parts. The first protruding part has a first distal-end section positioned closest to the first edge. A cross-section that is orthogonal to the first edge and includes the first distal-end section is designated as a first cross-section. In the first cross-section, the second protruding part is positioned closer to the lower surface than is the first protruding part.

Description

[Technical Field]

[0001] The present disclosure relates to a cutting insert used in cutting a workpiece, a cutting tool, and a method for manufacturing a machined product. [Background technology]

[0002] For example, a cutting insert described in Patent Document 1 is known as a cutting tool used when cutting workpieces such as metals. In the cutting insert described in Patent Document 1, a recess is formed in the direction along the main cutting edge on the peripheral surface (rising surface, breaker wall surface) of the convex portion rising from the breaker groove. In semi-rough cutting, chips generated by the main cutting edge pass through the recess without coming into contact with the bottom surface of the recess, reducing the contact area between the chip and the peripheral surface. This reduces the contact area of ​​the chip with the peripheral surface in the chip's traveling direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-447 Summary of the Invention

[0004] In order to solve the above-described problems, a cutting insert according to one aspect of the present disclosure includes an upper surface, a lower surface, a side surface located between the upper surface and the lower surface, and a cutting edge located at an intersection of the upper surface and the side surface, wherein the upper surface includes a first corner, a first side extending from the first corner, a cutting surface located along the first corner and the first side and approaching the lower surface as it moves away from the first corner and the first side, and a rising surface located along the cutting surface and moving away from the lower surface as it moves away from the rake surface, The metal plate has a first recess that is recessed relative to the first side, a first convex portion that is located farther from the first corner than the first recess and that protrudes toward the first side, a second convex portion that is located between the first convex portion and the first side and that protrudes toward the first side, and a first step portion that is located between the first convex portion and the second convex portion, wherein the first convex portion has a first tip portion that is located closest to the first side, and a cross section that is perpendicular to the first side and includes the first tip portion is a first cross section, and in the first cross section, the second convex portion is located closer to the lower surface than the first convex portion. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a perspective view showing a cutting insert according to an embodiment. [Figure 2] 2 is a plan view of the cutting insert shown in FIG. 1 as viewed from above. FIG. [Figure 3] FIG. 2 is an enlarged view of an area A1 shown in FIG. [Figure 4] FIG. 3 is an enlarged view of an area A2 shown in FIG. [Figure 5] 4. FIG. 4 is a cross-sectional view of the cutting insert taken along line IV-A in FIG. [Figure 6] 4. FIG. 4 is a cross-sectional view of the cutting insert taken along line IV-B in FIG. [Figure 7] 4. FIG. 4 is a cross-sectional view of the cutting insert taken along line IV-C in FIG. [Figure 8] 4. FIG. 4 is a cross-sectional view of the cutting insert taken along the line IV-D in FIG. [Figure 9]4. FIG. 4 is a cross-sectional view of the cutting insert taken along the line IV-E in FIG. [Figure 10] 9A is a cross-sectional view of the cutting insert shown in FIG. [Figure 11] FIG. 11 is an enlarged view of an area A3 shown in FIG. [Figure 12] 9A is a cross-sectional view of the cutting insert shown in FIG. 9 taken along line IXB. [Figure 13] FIG. 13 is an enlarged view of an area A4 shown in FIG. [Figure 14] 10 is an explanatory view showing a deformed shape of a first cross section of the cutting insert shown in FIG. 9 and a fourth cross section of a cutting insert of a modified example. FIG. [Figure 15] 2 is an explanatory view schematically showing contact of chips with a rising surface of the cutting insert shown in FIG. 1. FIG. [Figure 16] 1 is a perspective view showing a cutting tool according to an embodiment; [Figure 17] 1A to 1C are schematic diagrams illustrating a method for manufacturing a machined product according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] Hereinafter, a cutting insert 1 according to an embodiment (hereinafter simply referred to as the insert 1) will be described in detail with reference to the drawings. However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining the embodiment in a simplified form. Therefore, the insert 1 may include any components not shown in the drawings referred to in this disclosure. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0007] Cutting can be performed by using a cutting tool having the insert 1 of the embodiment. Examples of cutting tools include turning tools and milling tools.

[0008] <Cutting insert> The configuration of a cutting insert 1 according to this embodiment, which is an example, will be described with reference to Figures 1 to 15. As shown in Figure 1, the insert 1 according to this embodiment has an upper surface 3, a lower surface 5 located opposite to the upper surface 3, and a side surface 7 located between the upper surface 3 and the lower surface 5.

[0009] As shown in Figures 1 and 2, the upper surface 3 has a polygonal shape, specifically, the upper surface 3 is a rectangle. The lower surface 5 may also have a polygonal shape like the upper surface 3. The lower surface 5 may be the same size as the upper surface 3, or may be smaller than the upper surface 3. The lower surface 5 may have a shape similar to the upper surface 3 but slightly smaller than the upper surface 3. The insert 1 has a polygonal plate shape.

[0010] When a virtual line passing through the center of the upper surface 3 and the center of the lower surface 5 is defined as a central axis R1, the upper surface 3 may have a shape that is rotationally symmetrical by 180° about the central axis R1, as shown in Fig. 2. The shape of the insert 1 is not limited to the above configuration. The upper surface 3 may be, for example, triangular or hexagonal rather than rectangular.

[0011] An imaginary plane that is perpendicular to the central axis R1 and located between the upper surface 3 and the lower surface 5 is defined as the reference surface R2 (see Figures 5 to 9 and 14). The reference surface R2 can be used as a height reference when comparing the heights of the various parts that make up the upper surface 3. "Approaching the reference surface R2" can be rephrased as "approaching the lower surface 5." "Moving away from the reference surface R2" can be rephrased as "moving away from the lower surface 5." "Located near the reference surface R2" can be rephrased as "located near the lower surface 5."

[0012] The top surface 3 is quadrilateral and has four corners. One of these four corners is designated as a first corner 9. The top surface 3 has the first corner 9 and a first side 11 and a second side 13 extending from the first corner 9. In other words, the first corner 9 is located between the first side 11 and the second side 13.

[0013] As shown in FIG. 4, the first corner 9 does not need to be sharp, and in the insert 1, the first corner 9 has a curved shape that is convex outward. When the top surface 3 is viewed from the front, the radius of curvature of the first corner 9, which has a convex curved shape, may be constant or may vary. When the top surface 3 is viewed from the front, the first corner 9 in the insert 1 has an arc shape with a constant radius of curvature. The radius of curvature of the first corner 9, which has a convex curved shape, is set to be smaller than the maximum width of the top surface 3.

[0014] The first side 11 and the second side 13 of the upper surface 3 need only be a generally straight line when viewed visually, and do not need to be strictly straight. In other words, the first side 11 and the second side 13 of the upper surface 3 may be, for example, a slightly curved convex or concave shape. Note that if the first side 11 and the second side 13 are curved, the radii of curvature of the first side 11 and the second side 13 are set to be larger than the maximum width of the upper surface 3.

[0015] The side surface 7 located between the upper surface 3 and the lower surface 5 may be connected to each of the upper surface 3 and the lower surface 5. In the insert 1, since the upper surface 3 is polygonal, the side surface 7 has a plurality of surface regions connected to each side and first corner 9 of the upper surface 3. In the insert 1, the side surface 7 has a first side surface 7a, a second side surface 7b, and a corner side surface 7c as these plurality of surface regions.

[0016] The first side surface 7a is located along the first edge 11 of the top surface 3. The second side surface 7b is located along the second edge 13 of the top surface 3. The corner side surface 7c is located along the first corner 9 of the top surface 3. The corner side surface 7c is located between the first side surface 7a and the second side surface 7b, and is adjacent to each of the first side surface 7a and the second side surface 7b. The first side surface 7a and the second side surface 7b may be flat. The corner side surface 7c may also be convexly curved.

[0017] A cutting edge 15 may be located on at least a portion of the ridge where the top surface 3 and the side surface 7 intersect. In the insert 1, the cutting edge 15 is located on the ridge where the top surface 3 and the side surface 7 intersect, at the first corner 9, a portion of the first side 11, and a portion of the second side 13. The cutting edge 15 may be located on the entire first side 11 and the second side 13. Here, the portion of the cutting edge 15 located on the first corner 9 is conveniently referred to as a corner cutting edge 15c. The portion of the cutting edge 15 located on the first side 11 is conveniently referred to as a first cutting edge 15a. Furthermore, the portion of the cutting edge 15 located on the second side 13 is conveniently referred to as a second cutting edge 15b.

[0018] As shown in Fig. 4, the upper surface 3 of the insert 1 has a rake face 17 and a rising surface (blade wall surface) 19. As shown in Fig. 4, the rake face 17 is located along the first corner 9, the first side 11, and the second side 13. As shown in Figs. 5 to 9, the rake face 17 approaches the reference plane R2 as it moves away from the first corner 9, the first side 11, and the second side 13.

[0019] On the other hand, as shown in Fig. 4, the rising surface 19 is located along the rake face 17. As shown in Figs. 5 to 9, the rising surface 19 moves away from the reference surface R2 as it moves away from the rake face 17. When the chips come into contact with the rising surface 19, they are curled, which makes it easier to discharge them.

[0020] The boundary between the rake face 17 and the rising face 19 is the lowest point. The slope that descends to the lowest point closest to the reference plane R2, in other words, approaches the reference plane R2, is the rake face, and the slope that ascends from the lowest point, in other words, moves away from the reference plane R2, is the rising face. A horizontal surface may exist between the rake face 17 and the rising face 19. In other words, the lowest point on the boundary between the rake face 17 and the rising face 19 may be indicated by a line rather than a point in the cross-sectional view. In this case, the horizontal surface may function as the bottom surface.

[0021] 4, the top surface 3 may have a land surface 21 extending toward the center of the top surface 3 between the first side 11, the second side 13, and the first corner 9 and the rake face 17. In the insert 1, the land surface 21 is inclined so as to approach the reference surface R2 with increasing distance from the first corner 9, the first side 11, and the second side 13, as shown in FIGS.

[0022] If the inclination angle is defined as the inclination with respect to the reference plane R2, when the land surface 21 is inclined, the inclination angle of the rake face 19 is larger than the inclination angle of the land surface 21. The land surface 21 may be a surface parallel to the reference plane R2, or may be inclined so as to move away from the reference plane R2 with increasing distance from the first corner 9, the first side 11, and the second side 13.

[0023] Furthermore, the upper surface 3 may further have an upper end surface 31 located along the rising surface 19 .

[0024] (Rising surface) The following describes the rising surface 19. Here, as shown in Fig. 4, the rising surface 19 close to the first side 11, which contributes to the discharge of chips generated by the first cutting edge 15a, will be described. Although a detailed description will be omitted, the same applies to the rising surface 19 close to the second side 13, which contributes to the discharge of chips generated by the second cutting edge 15b.

[0025] As shown in FIG. 4 , in the insert 1, the raised surface 19 has a first recess 23, a first protrusion 25, a second protrusion 27, and a first step 29. The first recess 23 is recessed with respect to the first side 11. The first protrusion 25 is located farther from the first corner 9 than the first recess 23 and protrudes toward the first side 11. The second protrusion 27 is located between the first protrusion 25 and the first side 11 and protrudes toward the first side 11. The first step 29 is located between the first protrusion 25 and the second protrusion 27.

[0026] The first protrusion 25 has a first tip 25A located closest to the first side 11. In FIG. 4, the first tip 25A is highlighted by a black dot. A cross section perpendicular to the first side 11 and including the first tip 25A is a first cross section D1. FIG. 9 corresponds to the first cross section D1. As shown in FIG. 9, in the first cross section D1, the second protrusion 27 is located closer to the reference plane R2 than the first protrusion 25.

[0027] 14 is an explanatory diagram showing a deformed first cross section of the insert 1 shown in FIG. 9 and a deformed fourth cross section of the insert of the modified example. The first cross section D1' is a cross section obtained by deforming the first cross section D1. The fourth cross section of the insert of the modified example will be described later.

[0028] As shown in FIG. 14 , chips generated by the first cutting edge 15a pass through the land surface 21 and the rake face 17 and come into contact with the second convex portion 27 of the rising surface 19. Here, when the insert 1 is used for medium-rough machining and the chips generated by the first cutting edge 15a are relatively thick, the chips come into contact with the first convex portion 25 without coming into contact with the first step portion 29. Therefore, the contact area between the rising surface 19 and the chips in the direction of travel is reduced. This makes it possible to reduce contact of the chips with the rising surface 19 over a wide area in the direction of travel of the chips in medium-rough machining.

[0029] Thin chips generated when the feed rate is small also come into contact with the first step portion 29. The thin chips come into sliding contact with the second protrusion 27, the first step portion 29, and the first protrusion 25.

[0030] 15 is an explanatory diagram schematically illustrating contact of chips with the rising surface 19 of the insert 1 shown in FIG. 1. As shown in FIG. 15, the first convex portion 25 and the second convex portion 27 protrude toward the first side 11. Therefore, the chips K come into contact with the central portions of the first convex portion 25 and the second convex portion 27, and are unlikely to come into contact with both ends of the first convex portion 25 and the second convex portion 27. In particular, when the chips K are relatively thick, as occurs in medium-rough machining, they are unlikely to come into contact.

[0031] In this way, by providing the first convex portion 25 and the second convex portion 27 that protrude toward the first side 11 on the rising surface 19, the contact area between the chip and the rising surface 19 is also reduced in the width direction of the chip. This makes it possible to reduce contact of the chip with the rising surface 19 over a wide range in the width direction of the chip.

[0032] 4, in the insert 1, the first recess 23 is formed closer to the first corner 9 than the first protrusion 25. Therefore, as shown in FIG. 15, one end in the width direction of the chip K that has contacted the first protrusion 25 and the chip K that has contacted the second protrusion 27 contacts the first recess 23. This makes it possible to stabilize the behavior of the chip compared to a configuration in which only the inner side of the chip in the width direction contacts the first protrusion 25 or the second protrusion 27.

[0033] 10 and 11, the first protrusion 25 may have a curved shape in the second cross section D2. As shown in Fig. 9, the second cross section D2 is a cross section of the insert 1 that is parallel to the upper end surface 31 and includes the first protrusion 25, and is a cross section taken along line IX-A of the insert 1 shown in Fig. 9.

[0034] If the shape of the first protrusion 25 in the second cross section D2 is polygonal, wear tends to progress at the corners, but by using a curved shape, the progress of wear of the first protrusion 25 can be suppressed.

[0035] 12 and 13, the second convex portion 27 may have a curved shape in the third cross section D3. As shown in Fig. 9, the third cross section D3 is a cross section of the insert 1 that is parallel to the upper end surface 31 and includes the second convex portion 27, and is a cross section taken along line IX-B of the insert 1 shown in Fig. 9. In this case, too, the curved shape can suppress the progression of wear of the second convex portion 27.

[0036] Furthermore, in the insert 1, as shown in FIG. 4, the first recess 23 may have an end 23A closest to the first corner 9, and the end 23A may be located closer to the first side 11 than the first tip 25A. That is, as shown in FIG. 4, when the distance from the first side 11 to the end 23A is L1 and the distance from the first side 11 to the first tip 25A is L2, L1 < L2. In FIG. 4, the end 23A is highlighted by a black dot.

[0037] As shown in FIG. 15, since the end 23A is closer to the first side 11 than the first tip 25A, the chip K contacts the end 23A before the first tip 25A, and the behavior of the chip K can be controlled at the end 23A. The corner cutting edge 15c located at the first corner 9 is more prone to chipping and finer than the first cutting edge 15a. Therefore, chip clogging at the corner cutting edge 15c directly leads to the loss of the corner cutting edge 15c. According to the above configuration, since the behavior of the chip near the corner cutting edge 15c can be stably controlled, it is difficult to cause the corner cutting edge 15c to be damaged.

[0038] Also, the second protrusion 27 may have a second tip 27A located closest to the first side 11, and the end 23A may be located closer to the first side 11 than the second tip 27A. That is, as shown in FIG. 4, when the distance from the first side 11 to the end 23A is L1 and the distance from the first side 11 to the second tip 27A is L3, L1 < L3. In FIG. 4, the second tip 27A is highlighted by a black dot.

[0039] Also in this case, as shown in FIG. 15, since the end 23A is closer to the first side 11 than the second tip 27A, the behavior of the chip K can be controlled at the end 23A, and it is difficult to cause the corner cutting edge 15c to be damaged.

[0040] 14, in the insert 1, the first convex portion 25 may have a first straight portion 25-1, and the second convex portion 27 may have a second straight portion 27-2 in the first cross section D1'. By adopting such a configuration, it is easy to ensure the function of the first convex portion 25 and the second convex portion 27 to guide the chips while reducing the contact area between the chips and the rising surface 19.

[0041] 14, the first convex portion 25 has a first straight portion 25-1 located along the upper end surface 31 and a first concave curved portion 25-2 located along the first step portion 29. The first straight portion 25-1 may be a convex curved portion.

[0042] The second convex portion 27 has a first convex curved portion 27-1, a second concave curved portion 27-3, and a second straight portion 27-2. The first convex curved portion 27-1 is located along the first step portion 29. The second concave curved portion 27-3 is located along the rake face 17. The second straight portion 27-2 is located between the first convex curved portion 27-1 and the second concave curved portion 27-3.

[0043] The first step portion 29 is a concave-convex curve having an inflection point. The position close to the second convex portion 27 is a convex curve, and the position close to the first convex portion 25 is a concave curve. The first step portion 29 may be a straight line. The first step portion 29 may be parallel to the reference plane R2. The boundary between the first step portion 29 and the first concave curve portion 25-2 may be curved or have a corner. In addition, the boundary between the first step portion 29 and the first convex curve portion 27-1 may also be curved or have a corner.

[0044] Furthermore, in the insert 1, as shown in Figure 14, in the first cross section D1', the inclination angle θ1 of the first straight portion 25-1 may be greater than the inclination angle θ2 of the second straight portion 27-2, and the first straight portion 25-1 may be shorter than the second straight portion 27-2.

[0045] According to the above configuration, the first straight portion 25-1, which has a larger inclination angle and a higher braking effect than the second straight portion 27-2, is set to be short, thereby ensuring the chip guiding function of the first convex portion 25 and the second convex portion 27 and improving chip discharge performance.

[0046] The inclination angle θ3 of the first step portion 29 is smaller than the inclination angle θ1 of the first straight portion 25-1 and the inclination angle θ2 of the second straight portion 27-2. The inclination angle θ1 is, for example, 30° to 60°, the inclination angle θ2 is, for example, 30° to 60°, and the inclination angle θ3 is, for example, 10° to 25°.

[0047] Furthermore, in the insert 1, as shown in Figure 14, the rising surface 19 may have a second recess 33 located between the first recess 23 and the upper end surface 31, and a second step portion 35 located between the first recess 23 and the second recess 33.

[0048] With this configuration, even between the first recess 23 and the second recess 33, relatively thick chips generated by the first cutting edge 15a during medium-rough machining come into contact with the second recess 33 without coming into contact with the second step portion 35. This reduces the contact area between the rising surface 19 and the chips in the direction of travel. This reduces contact of the chips with the rising surface 19 over a wide area in the direction of travel of the chips during medium-rough machining.

[0049] Thin chips generated when the feed rate is small also come into contact with the second step portion 35 and slide against the first recess 23 , the second step portion 35 and the second recess 33 .

[0050] 14, the first recess 23 may have a third straight portion 23-2, and the second recess 33 may have a fourth straight portion 33-1 in the fourth cross section D4. The fourth cross section D4 is a cross section that is perpendicular to the first side 11 and intersects with the first recess 23 and the second recess 33. With this configuration, it is easy to ensure the function of guiding chips by the first recess 23 and the second recess 33 while reducing the contact area between the chips and the rising surface 19.

[0051] 14, the first recess 23 has a second convex curved portion 23-1, a third concave curved portion 23-3, and a third straight portion 23-2. The second convex curved portion 23-1 is located along the second step portion 35. The third concave curved portion 23-3 is located along the rake face 17. The third straight portion 23-2 is located between the second convex curved portion 23-1 and the third concave curved portion 23-3.

[0052] The second recess 33 has a fourth linear portion 33-1 located along the upper end surface 31 and a fourth concave curved portion 33-2 located along the second step portion .

[0053] The second step portion 35 is a concave-convex curve having an inflection point. The portion close to the first recess 23 is a convex curve, and the portion close to the second recess 33 is a concave curve. The second step portion 35 may be a straight line. The second step portion 35 may be parallel to the reference plane R2. The boundary between the second step portion 35 and the fourth concave curve portion 33-2 may be curved or have a corner. In addition, the boundary between the second step portion 35 and the second convex curve portion 23-1 may also be curved or have a corner.

[0054] Furthermore, in this case, in the fourth cross section D4, the inclination angle θ1 of the fourth straight portion 33-1 may be larger than the inclination angle θ2 of the third straight portion 23-2, and the fourth straight portion 33-1 may be shorter than the third straight portion 23-2.

[0055] According to the above configuration, the fourth straight portion 33-1, which has a larger inclination angle and a higher braking effect than the third straight portion 23-2, is set to be short, thereby ensuring the chip guiding function of the first recessed portion 23 and the second recessed portion 33 and improving chip discharge performance.

[0056] (Other configurations) The insert 1 has through holes 37 that open on the upper surface 3 and the lower surface 5. The through holes 37 may be formed from the center of the upper surface 3 toward the center of the lower surface 5. The through holes 37 may also be open in surface regions located on opposite sides of the side surface 7. The through holes 37 can be used to fix the insert 1 to a holder for a cutting tool. For example, the insert 1 can be fixed to the holder by inserting a screw into the through hole 37 and screwing the insert 1.

[0057] The extending direction of the through hole 37, in other words, the penetration direction, may be perpendicular to the upper surface 3 and the lower surface 5, as shown in one example in Figure 1. Furthermore, since the through hole 37 is formed from the center of the upper surface 3 toward the center of the lower surface 5, the central axis of the through hole 37 coincides with the central axis R1.

[0058] The size of the insert 1 is not particularly limited. The maximum width of the upper surface 3 may be set to, for example, about 6 mm to 25 mm. The height from the upper surface 3 to the lower surface 5 may be set to about 1 mm to 10 mm. Here, the height from the upper surface 3 to the lower surface 5 refers to the length in the direction parallel to the central axis R1 between the upper end of the upper surface 3, i.e., the upper end surface 31, and the lower end of the lower surface 5.

[0059] The insert 1 is made of a material such as cemented carbide or cermet. The cemented carbide has a composition such as WC-Co, WC-TiC-Co, or WC-TiC-TaC-Co. Here, WC, TiC, and TaC are hard particles, and Co is a binder phase.

[0060] Cermet is a sintered composite material in which a ceramic component is combined with a metal. An example of a cermet is a titanium compound whose main component is titanium carbide (TiC) or titanium nitride (TiN). However, it goes without saying that the material of the insert 1 is not limited to the above composition.

[0061] The surface of the insert 1 may be coated with a coating by chemical vapor deposition (CVD) or physical vapor deposition (PVD), and the coating may have a composition such as titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), or alumina (Al2O3).

[0062] <Cutting tools> Next, a cutting tool 101 according to an embodiment will be described with reference to the drawings. The cutting tool 101 shown in Fig. 16 is rod-shaped and extends from a first end to a second end. It includes a holder 105 having a pocket 103 located on the first end side, and the insert 1 described above located in the pocket 103. In the cutting tool 101 of the present disclosure, the insert 1 is attached so that the portion used as the cutting edge protrudes from the first end of the holder 105. Usually, the first end is called the leading end, and the second end is called the trailing end.

[0063] The holder 105 has a long, thin rod shape. A pocket 103 is provided on the first end side of the holder 105. The pocket 103 is a portion where the insert 1 is attached, and is open to an end face of the holder 105 located on the first end side. At this time, the pocket 103 is also open to the side face of the holder 105, which makes it easy to attach the insert 1. Specifically, the pocket 103 has a seating surface parallel to the bottom face of the holder 105 and a restraining side face inclined relative to the seating surface.

[0064] The insert 1 is positioned in the pocket 103. At this time, the lower surface 5 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.

[0065] The insert 1 is attached so that a portion used as a cutting edge protrudes outward from the holder 105. In the present disclosure, the insert 1 is attached to the holder 105 by a clamp member (lever lock) 39. The member for attaching the insert 1 to the holder 105 is not limited to the clamp member 39, and a fixing screw, for example, may be used. That is, the insert 1 may be attached to the holder 105 by inserting a fixing screw into the through hole 37 of the insert 1 and inserting the tip of the fixing screw into a threaded hole (not shown) formed in the pocket 103 to screw the threaded portions together.

[0066] Steel, cast iron, etc. may be used for the holder 105. Among these materials, steel, which has high toughness, may be used in particular.

[0067] In the present disclosure, a cutting tool used for so-called turning is exemplified. Examples of turning include internal diameter machining, external diameter machining, and grooving. The cutting tool is not limited to that used for turning. For example, the insert 1 of the above embodiment may be used in a cutting tool used for milling.

[0068] <Method of manufacturing machined products> Next, a method for manufacturing a machined product according to an embodiment will be described with reference to the drawings. The machined product is produced by cutting a workpiece 201. The method for manufacturing a machined product according to the present disclosure includes the following steps: (1) rotating the workpiece 201; (2) bringing a cutting tool 101, such as that typified by the above-described embodiment, into contact with a rotating workpiece 201; (3) separating the cutting tool 101 from the workpiece 201; It is equipped with:

[0069] More specifically, first, as shown in the diagram of reference numeral 1700 in Fig. 17, the workpiece 201 is rotated around the axis R3, and the cutting tool 101 is brought relatively close to the workpiece 201. Next, as shown in the diagram of reference numeral 1701 in Fig. 17, the cutting edge of the cutting tool 101 is brought into contact with the workpiece 201 to cut the workpiece 201. Then, as shown in the diagram of reference numeral 1702 in Fig. 17, the cutting tool 101 is moved relatively away from the workpiece 201.

[0070] In the present disclosure, the axis R3 is fixed and the workpiece 201 is rotated around the axis R3 while the cutting tool 101 is moved to approach the workpiece 201. In addition, in the diagram indicated by reference numeral 1701 in FIG. 17, the cutting edge of the insert 1 is brought into contact with the rotating workpiece 201 to cut the workpiece 201. In addition, in the diagram indicated by reference numeral 1702 in FIG. 17, the cutting tool 101 is moved away from the rotating workpiece 201 to move the workpiece 201 away.

[0071] In each step of the cutting process in the manufacturing method of the present disclosure, the cutting tool 101 is moved to bring the cutting tool 101 into contact with the workpiece 201 or to move the cutting tool 101 away from the workpiece 201. However, it is not limited to this configuration.

[0072] For example, in step (1), the workpiece 201 may be brought closer to the cutting tool 101. In addition, in step (3), the workpiece 201 may be moved away from the cutting tool 101. To continue the cutting process, the workpiece 201 may be kept rotating, and the step of bringing the cutting edge of the insert into contact with different locations on the workpiece 201 may be repeated.

[0073] Typical examples of the material of the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0074] The invention according to the present disclosure has been described based on various drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure. [Explanation of symbols]

[0075] 1 Cutting insert 3 Top surface 5 Bottom side 7 Side 15 cutting edge 17 Rake face 19 Rising surface 23 First recess 23-2 3rd straight line section 23A end 25 First convex part 25-1 1st straight line section 25A 1st tip 27 Second convex part 27-2 2nd straight line section 27A 2nd tip 29 First step 31 Upper end surface 33 Second recess 33-1 4th straight line section 35 Second step 37 Through hole 39 Clamping member 101 Cutting tools 103 Pocket 105 Holder 201 Work material D1 1st cross section D2 2nd cross section D3 Third cross section D4 4th section θ1 Tilt angle θ2 Tilt angle

Claims

1. The top surface and The underside and a side surface located between the upper surface and the lower surface; a cutting edge located at an intersection of the top surface and the side surface, The upper surface is The first corner, a first side extending from the first corner; a cutting surface located along the first corner and the first side and approaching the lower surface as it moves away from the first corner and the first side; a rising surface located along the rake face and moving away from the lower surface as it moves away from the rake face; The rising surface is a first recess recessed relative to the first side in a front view of the top surface; a first protrusion located farther from the first corner than the first recess and protruding toward the first side in a front view of the top surface; a second protrusion located between the first protrusion and the first side and protruding toward the first side in a front view of the top surface; a first step portion located between the first convex portion and the second convex portion, the first recess has an end closest to the first corner; the first protrusion has a first tip located closest to the first side, the second protrusion has a second tip located closest to the first side, a cross section perpendicular to the first side and including the first tip portion is a first cross section, In the first cross section, the second convex portion is located closer to the lower surface than the first convex portion, The cutting insert, wherein the end portion is located closer to the first side than the first tip portion and the second tip portion.

2. the upper surface further has an upper end surface located along the rising surface, a cross section that is parallel to the upper end surface and includes the first protrusion is a second cross section, The cutting insert according to claim 1 , wherein the first convex portion has a curved shape in the second cross section.

3. the upper surface further has an upper end surface located along the rising surface, a cross section that is parallel to the upper end surface and includes the second protrusion is a third cross section, The cutting insert according to claim 1 , wherein the second convex portion has a curved shape in the third cross section.

4. In the first cross section, the first convex portion has a first linear portion, The cutting insert according to claim 1 , wherein the second protrusion has a second linear portion.

5. In the first cross section, the inclination angle of the first straight line portion is larger than the inclination angle of the second straight line portion, The cutting insert according to claim 4 , wherein the first linear portion is shorter than the second linear portion.

6. the upper surface further has an upper end surface located along the rising surface, The rising surface is a second recess located between the first recess and the upper end surface; The cutting insert according to claim 1 , further comprising: a second step portion located between the first recess and the second recess.

7. a cross section perpendicular to the first side and intersecting with the first recess and the second recess is a fourth cross section, In the fourth cross section, the first recess has a third linear portion; The cutting insert according to claim 6 , wherein the second recess has a fourth linear portion.

8. In the fourth cross section, the inclination angle of the fourth straight line portion is greater than the inclination angle of the third straight line portion, The cutting insert according to claim 7 , wherein the fourth linear portion is shorter than the third linear portion.

9. The top surface and The underside and a side surface located between the upper surface and the lower surface; a cutting edge located at an intersection of the top surface and the side surface, The upper surface is The first corner, a first side extending from the first corner; a cutting surface located along the first corner and the first side and approaching the lower surface as it moves away from the first corner and the first side; a rising surface located along the rake face and moving away from the lower surface as it moves away from the rake face; The rising surface is a first recess recessed relative to the first side in a front view of the top surface; a first protrusion located farther from the first corner than the first recess and protruding toward the first side in a front view of the top surface; a second protrusion located between the first protrusion and the first side and protruding toward the first side in a front view of the top surface; a first step portion located between the first convex portion and the second convex portion, the first protrusion has a first tip located closest to the first side, a cross section perpendicular to the first side and including the first tip portion is a first cross section, In the first cross section, the second convex portion is located closer to the lower surface than the first convex portion, the first convex portion has a first linear portion, the second convex portion has a second linear portion, the inclination angle of the first straight line portion is larger than the inclination angle of the second straight line portion, The cutting insert, wherein the first linear portion is shorter than the second linear portion.

10. The top surface and The underside and a side surface located between the upper surface and the lower surface; a cutting edge located at an intersection of the top surface and the side surface, The upper surface is The first corner, a first side extending from the first corner; a cutting surface located along the first corner and the first side and approaching the lower surface as it moves away from the first corner and the first side; a rising surface located along the rake face and moving away from the lower surface as it moves away from the rake face; an upper end surface located along the rising surface, The rising surface is a first recess recessed relative to the first side in a front view of the top surface; a second recess located between the first recess and the upper end surface; a first protrusion located farther from the first corner than the first recess and protruding toward the first side in a front view of the top surface; a second protrusion located between the first protrusion and the first side and protruding toward the first side in a front view of the top surface; a first step portion located between the first convex portion and the second convex portion; a second step portion located between the first recess and the second recess, the first protrusion has a first tip located closest to the first side, a cross section perpendicular to the first side and including the first tip portion is a first cross section, In the first cross section, the second convex portion is located closer to the lower surface than the first convex portion, a cross section perpendicular to the first side and intersecting with the first recess and the second recess is a fourth cross section, In the fourth cross section, the first recess has a third linear portion; The second recess has a fourth linear portion.

11. a holder having a rod shape extending from a first end to a second end and having a pocket located at the first end; and the cutting insert according to claim 1 located in the pocket.

12. rotating the workpiece; bringing the cutting tool according to claim 11 into contact with the rotating workpiece; and removing the cutting tool from the workpiece.

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