Manufacturing method of cutting insert, cutting tool, and machined product

Abstract

This cutting insert has a top surface, a front lateral surface, a first corner lateral surface, a front cutting edge, and a first corner cutting edge. The top surface has: a front land surface that extends along the front cutting edge; a first corner land surface that extends along the first corner cutting edge; a front groove that extends inward from the front land surface side; and a first corner groove that extends inward from a first corner land surface side. The first corner groove has a length shorter than that of the front groove.

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] Examples of cutting inserts used when cutting a workpiece include those described in Patent Documents 1 and 2. During cutting, a coolant (cooling solvent) is usually sprayed toward the cutting insert to remove chips and cool the cutting insert. In order to enhance the cooling effect of the coolant on the cutting edge, the cutting inserts described in Patent Documents 1 and 2 are provided with grooves. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication "JP Patent Publication No. 2014-018891" [Patent Document 2] Japanese Patent Publication No. 2002-502711 Summary of the Invention

[0004] The cutting insert according to the present disclosure has an upper surface having a first corner, a second corner, and a first side connected to the first corner and the second corner. The cutting insert according to the present disclosure has a front side surface connected to the first side, a first corner side surface connected to the first corner, a front cutting edge located on the first side, and a first corner cutting edge located at the first corner. The upper surface further has a front land surface located on the outer edge of the upper surface and extending along the front cutting edge, a first corner land surface located on the outer edge of the upper surface and extending along the first corner cutting edge, a front groove extending inward from a side of the front land surface, and a first corner groove extending inward from a side of the first corner land surface. The length of the first corner groove is shorter than the length of the front groove. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic perspective view of a cutting tool according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is an enlarged view of part II in FIG. [Diagram 3] FIG. 1 is a schematic perspective view of a cutting insert according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a schematic top view of the cutting insert shown in FIG. 3. [Diagram 5] FIG. 4 is a schematic right side view of the cutting insert shown in FIG. 3. [Figure 6] FIG. 4 is a schematic left side view of the cutting insert shown in FIG. 3. [Figure 7] FIG. 4 is a schematic front view of the cutting insert shown in FIG. [Figure 8] FIG. 4 is an enlarged view of a portion VIII in FIG. 3, and is a schematic enlarged perspective view of a part of the cutting insert according to an embodiment of the present disclosure. [Figure 9] FIG. 2 is a schematic enlarged top view of a portion of a cutting insert according to an embodiment of the present disclosure. [Figure 10] FIG. 11 is a schematic enlarged perspective view of a portion of a cutting insert according to a first modified example of an embodiment of the present disclosure. [Figure 11] FIG. 11 is a schematic enlarged perspective view of a portion of a cutting insert according to a second modified example of an embodiment of the present disclosure. [Figure 12] FIG. 11 is a schematic enlarged perspective view of a portion of a cutting insert according to a third modified example of an embodiment of the present disclosure. [Figure 13] FIG. 11 is a schematic enlarged perspective view of a portion of a cutting insert according to a fourth modified example of an embodiment of the present disclosure. [Figure 14] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment of the present disclosure. [Figure 15] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment of the present disclosure. [Figure 16] 1A to 1C are schematic diagrams illustrating a manufacturing method of a machined product according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] The cutting inserts described in Patent Documents 1 and 2 have grooves that enhance the cooling effect of the cutting edge by the coolant, but the durability of the cutting insert may be reduced. In other words, there is a demand for both a good cooling effect and improved durability of the cutting insert.

[0007] According to the present disclosure, it is possible to improve the durability of the cutting insert while enhancing the cooling effect of the cutting edge by the coolant.

[0008] Hereinafter, the cutting insert, cutting tool, and manufacturing method of the machined product according to the embodiment of the present disclosure will be described in detail with reference to the drawings. However, for the convenience of explanation, each of the drawings referred to below shows only the components necessary for explaining the embodiment in a simplified manner. Therefore, the cutting insert according to the embodiment of the present disclosure may include any components not shown in each of the drawings referred to. The dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of each member. In addition, in this disclosure, parallel does not mean strictly parallel, but means that an error of about ±5 degrees is allowed.

[0009] <Cutting tools> A cutting tool 10 according to an embodiment of the present disclosure will be described with reference to Figures 1 and 2. Figure 1 is a schematic perspective view of the cutting tool 10 according to an embodiment of the present disclosure. Figure 2 is an enlarged view of part II in Figure 1.

[0010] 1 and 2, a cutting tool 10 according to an embodiment of the present disclosure is a turning tool used in turning of a workpiece W (see FIG. 14). The cutting of the workpiece W includes outer diameter machining, inner diameter machining, grooving, cut-off, and the like. The cutting tool 10 may have a holder 12 attached to a tool rest of a lathe and a cutting insert 14 held by the holder 12.

[0011] The holder 12 may have a square bar shape extending from a front end 12a, which is a first end, to a rear end 12b, which is a second end. The holder 12 may have a bar shape other than a square bar shape, such as a round bar shape. Examples of the material of the holder 12 include metals such as stainless steel, carbon steel, cast iron, and aluminum alloy. A pocket 16 for holding the cutting insert 14 may be located on the front end 12a side of the holder 12. The length of the holder 12 may be set to, for example, 100 mm to 400 mm.

[0012] An injection port 18 for injecting a coolant (cooling medium) toward the cutting insert 14 may be provided on the side of the tip 12a of the holder 12. The coolant may be, for example, a water-insoluble oil or a water-soluble oil, and may be appropriately selected and used depending on the material of the workpiece W. Examples of water-insoluble oils include oil-based, inactive extreme pressure, and active extreme pressure cutting oils. Examples of water-soluble oils include cutting oils such as emulsions, solubles, and solutions. The coolant is not limited to a liquid, and may be a gas such as an inert gas.

[0013] The cutting insert 14 may be located in a pocket 16 of the holder 12. The cutting insert 14 may be fixed to the pocket 16 of the holder 12 by a fixing screw 20. The cutting insert 14 may be fixed to the pocket 16 of the holder 12 by a clamp member instead of the fixing screw 20.

[0014] <Cutting insert> The configuration of the cutting insert 14 according to the embodiment of the present disclosure will be described with reference to Figs. 3 to 7. Fig. 3 is a schematic perspective view of the cutting insert 14 according to the embodiment of the present disclosure. Fig. 4 is a schematic top view of the cutting insert 14 shown in Fig. 3. Fig. 5 is a schematic right side view of the cutting insert 14 shown in Fig. 3. Fig. 6 is a schematic left side view of the cutting insert 14 shown in Fig. 3. Fig. 7 is a schematic front view of the cutting insert 14 shown in Fig. 3.

[0015] 3 to 7, the cutting insert 14 according to the embodiment of the present disclosure may have a base portion 22 for mounting in the pocket 16 of the holder 12. The base portion 22 may have a first main surface 24 having a substantially polygonal shape, such as a substantially triangle, and a second main surface 26 located opposite the first main surface 24. The first main surface 24 and the second main surface 26 may each have a substantially polygonal shape, such as a substantially triangle. In other words, the base portion 22 may have a substantially polygonal plate shape, such as a substantially triangular plate shape.

[0016] The base portion 22 may have a plurality of side surfaces located between the first main surface 24 and the second main surface 26, and any of the plurality of side surfaces may be a flat base upper surface 28. The base portion 22 may have a through hole 30 in the center thereof for inserting the fixing screw 20 therethrough. The through hole 30 may be open on the first main surface 24 side and the second main surface 26 side.

[0017] The cutting insert 14 according to the embodiment of the present disclosure may have a cutting portion 32 that comes into contact with the workpiece W to perform cutting. The cutting portion 32 may be provided at only one of the multiple corners of the base portion 22. The cutting portion 32 may be provided at each of the multiple corners of the base portion 22. The cutting portion 32 may be provided in a notch 34 provided at the corner of the base portion 22.

[0018] Examples of the material of the base portion 22 include cemented carbide and cermet. Examples of the composition of cemented carbide include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co is produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering the mixture. WC-TiC-Co is produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is produced by adding tantalum carbide (TaC) to WC-TiC-Co. The cermet is a sintered composite material in which a ceramic component is combined with a metal. Specifically, examples of the cermet include those mainly composed of titanium compounds such as titanium carbide (TiC) and titanium nitride (TiN).

[0019] Examples of the material of the cutting portion 32 include hard materials such as cBN (Cubic Boron Nitride) and PCD (PolyCrystalline Diamond). When the material of the cutting portion 32 is different from the material of the base portion 22, the cutting portion 32 may be joined to the base portion 22 with a brazing material. When the material of the cutting portion 32 is the same as the material of the base portion 22, the cutting portion 32 may be formed integrally with the base portion 22.

[0020] A coating may be applied to the surface of the cutting insert 14 using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the material of the coating include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al2O3).

[0021] A specific configuration of the cutting portion 32 of the cutting insert 14 according to the embodiment of the present disclosure will be described with reference to Fig. 8 and Fig. 9. Fig. 8 is an enlarged view of part VIII in Fig. 3, and is a schematic enlarged perspective view of a part of the cutting insert 14 according to the embodiment of the present disclosure. Fig. 9 is a schematic enlarged top view of a part of the cutting insert 14 according to the embodiment of the present disclosure.

[0022] 8 and 9, the cutting portion 32 of the cutting insert 14 may have an upper surface 36, and the upper surface 36 may function as a rake surface for flowing chips. The upper surface 36 of the cutting portion 32 may constitute the upper surface of the cutting insert 14 together with the base upper surface 28 of the base portion 22.

[0023] The upper surface 36 of the cutting portion 32 may have a first corner 38, a second corner 40, and a first side 42 connected to the first corner 38 and the second corner 40. The first corner 38 and the second corner 40 may each be curved. The first side 42 may be straight or slightly curved. The first side 42 being slightly curved means that the first side 42 is not limited to a strictly straight shape. Therefore, when the first side 42 is slightly curved, the radius of curvature of the first side 42 is 10 times or more the radius of curvature of the first corner 38 and the second corner 40, and compared with the first corner 38 and the second corner 40, the first side 42 may be considered to have a straight shape macroscopically. The upper surface 36 of the cutting portion 32 may also have a second side 44 connected to the first corner 38 and a third side 46 connected to the second corner 40. The second side 44 and the third side 46 may be parallel to each other, or may gradually approach each other as they move away from the first side 42.

[0024] The cutting portion 32 may have a front side surface 48 connected to the first side 42, and the front side surface 48 may function as a clearance surface. The cutting portion 32 may have a first corner side surface 50 connected to the front side surface 48 and the first corner 38, and a second corner side surface 52 connected to the front side surface 48 and the second corner. The first corner side surface 50 and the second corner side surface 52 may each function as a clearance surface. The first corner side surface 50 and the second corner side surface 52 may each be narrowed in width as they move away from the upper surface 36. The cutting portion 32 may have a first lateral side surface 54 connected to the first corner side surface 50 and the second side 44, and a second lateral side surface 56 connected to the second corner side surface 52 and the third side 46. The first lateral side surface 54 and the second lateral side surface 56 may each function as a clearance surface.

[0025] The cutting portion 32 may have a front cutting edge FB located on a first side 42 where the top surface 36 and the front side surface 48 intersect. The front cutting edge FB may be located in the entire area or a part of the area of ​​the first side 42. The cutting portion 32 may also have a first corner cutting edge CB1 located on a first corner 38 where the top surface 36 and the first corner side surface 50 intersect. The first corner cutting edge CB1 may be located on the entire area or a part of the area of ​​the first corner 38. Furthermore, the cutting portion 32 may have a second corner cutting edge CB2 located on a second corner 40 where the top surface 36 and the second corner side surface 52 intersect. The second corner cutting edge CB2 may be located on the entire area or a part of the area of ​​the second corner 40.

[0026] The cutting portion 32 may have a first side cutting edge SB1 located on the second side 44, which is the intersection of the top surface 36 and the first lateral side surface 54. The first side cutting edge SB1 may be located in the entire area or a part of the area of ​​the second side 44. The first side cutting edge SB1 may have a function of finishing the machined surface of the workpiece W. The first side cutting edge SB1 may be omitted from the cutting portion 32 to avoid interference between the second side 44 and the machined surface of the workpiece W. The cutting portion 32 may also have a second side cutting edge SB2 located on the third side 46, which is the intersection of the top surface 36 and the second lateral side surface 56. The second side cutting edge SB2 may be located in the entire area or a part of the area of ​​the third side 46. The second side cutting edge SB2 may have a function of finishing the machined surface of the workpiece W. The second side cutting edge SB2 may be omitted from the cutting portion 32 to avoid interference between the third side 46 and the machined surface of the workpiece W.

[0027] The upper surface 36 of the cutting part 32 may have a front land surface 58 for increasing the strength of the front cutting edge FB. The front land surface 58 may be located on the outer edge of the upper surface 36 of the cutting part 32 and extend along the front cutting edge FB. The front land surface 58 may be connected to the front cutting edge FB. The upper surface 36 of the cutting part 32 may also have a first corner land surface 60 for increasing the strength of the first corner cutting edge CB1. The first corner land surface 60 may be located on the outer edge of the upper surface 36 of the cutting part 32 and extend along the first corner cutting edge CB1. The first corner land surface 60 may be connected to the first corner cutting edge CB1. Furthermore, the upper surface 36 of the cutting part 32 may have a second corner land surface 62 for increasing the strength of the second corner cutting edge CB2. The second corner land surface 62 may be located on the outer edge of the upper surface 36 of the cutting part 32 and extend along the second corner cutting edge CB2. The second corner land surface 62 may be connected to the second corner cutting edge CB2.

[0028] The upper surface 36 of the cutting portion 32 may have a first lateral land surface 64 for increasing the strength of the first side cutting edge SB1. The first lateral land surface 64 may be located on the outer edge of the upper surface 36 of the cutting portion 32 and extend along the first side cutting edge SB1. The first lateral land surface 64 may be connected to the first side cutting edge SB1. The upper surface 36 of the cutting portion 32 may have a second lateral land surface 66 for increasing the strength of the second side cutting edge SB2. The second lateral land surface 66 may be located on the outer edge of the upper surface 36 of the cutting portion 32 and extend along the second side cutting edge SB2. The second lateral land surface 66 may be connected to the second side cutting edge SB2.

[0029] The front land surface 58, the first corner land surface 60, the second corner land surface 62, the first lateral land surface 64, and the second lateral land surface 66 may each be set as a band-shaped area having a width of, for example, approximately 0.03 mm to 0.5 mm when viewed from above.

[0030] The upper surface 36 of the cutting portion 32 may have a flat upper end surface 68 located on the side of the base portion 22. The upper surface 36 of the cutting portion 32 may have a rising wall surface 70 located between the outer edge of the upper surface 36 and the upper end surface 68. The rising wall surface 70 may be inclined with respect to the upper end surface 68, and may have the function of curling chips to improve chip dischargeability.

[0031] The upper surface 36 of the cutting part 32 may have a front groove 72 extending inward from the front land surface 58 toward the center of the upper surface 36. The front groove 72 may function as a coolant reservoir (gap) for storing coolant. The front groove 72 may be spaced apart from the front land surface 58 and the front cutting edge FB. The front groove 72 may be connected to the front land surface 58 instead of being spaced apart from the front land surface 58.

[0032] The front groove 72 may be connected to the rising wall surface 70. Also, the front groove 72 may be connected to the upper end surface 68. While chips are likely to come into contact with the rising wall surface 70, chips are unlikely to come into contact with the upper end surface 68. Therefore, when the front groove 72 is connected to the upper end surface 68, coolant is likely to flow from the upper end surface 68 into the front groove 72. As a result, coolant is likely to accumulate in the front groove 72.

[0033] 8 and 9, the number of front grooves 72 is multiple, but may be one. When the number of front grooves 72 is multiple, the multiple front grooves 72 may include a first front groove 72A and a second front groove 72B located closer to the first corner 38 than the first front groove 72A. The length of the first front groove 72A may be the same as the length of the second front groove 72B.

[0034] The upper surface 36 of the cutting portion 32 may have a first corner groove 74 extending inward from the side of the first corner land surface 60. The first corner groove 74 may function as a coolant reservoir for storing coolant. The first corner groove 74 may be spaced apart from the first corner land surface 60 and the first corner cutting edge CB1. The first corner groove 74 may be connected to the first corner land surface 60 instead of being spaced apart from the first corner land surface 60.

[0035] The first corner groove 74 may be connected to the rising wall surface 70. Also, the first corner groove 74 may be connected to the upper end surface 68. When the first corner groove 74 is connected to the upper end surface 68, the coolant tends to flow from the upper end surface 68 into the first corner groove 74. As a result, the coolant tends to accumulate in the first corner groove 74. In the examples of FIGS. 8 and 9, the number of first corner grooves 74 is one, but there may be more than one.

[0036] The first corner groove 74 may extend inward from the side of the boundary between the front land surface 58 and the first corner land surface 60. The first corner groove 74 may be separated from the boundary between the front land surface 58 and the first corner land surface 60, but may be connected to the boundary. The first corner groove 74 may extend parallel to the front groove 72. Also, the length of the first corner groove 74 may be shorter than the length of the front groove 72. The width of the first corner groove 74 may be narrower than the width of the front groove 72. The depth of the first corner groove 74 may be the same as the depth of the front groove 72.

[0037] The upper surface 36 of the cutting portion 32 may have a second corner groove 76 extending inward from the side of the second corner land surface 62. The second corner groove 76 may function as a coolant reservoir. The second corner groove 76 may be spaced apart from the second corner land surface 62 and the second corner cutting edge CB2. The second corner groove 76 may be connected to the second corner land surface 62 instead of being spaced apart from the second corner land surface 62.

[0038] The second corner groove 76 may be connected to the rising wall surface 70. The second corner groove 76 may also be connected to the upper end surface 68. When the second corner groove 76 is connected to the upper end surface 68, the coolant tends to flow from the upper end surface 68 into the second corner groove 76. As a result, the coolant tends to accumulate in the second corner groove 76. In the examples of FIGS. 8 and 9, the number of second corner grooves 76 is one, but there may be more than one.

[0039] The second corner groove 76 may extend inward from the side of the boundary between the front land surface 58 and the second corner land surface 62. The second corner groove 76 may be separated from the boundary between the front land surface 58 and the second corner land surface 62, but may be connected to the boundary. The second corner groove 76 may extend parallel to the front groove 72. Also, the length of the second corner groove 76 may be shorter than the length of the front groove 72. The width of the second corner groove 76 may be narrower than the width of the front groove 72. The depth of the second corner groove 76 may be the same as the depth of the front groove 72.

[0040] The upper surface 36 of the cutting portion 32 may have a first lateral groove 78 extending inward from the side of the first lateral land surface 64. The first lateral groove 78 may function as a coolant reservoir. The first lateral groove 78 may be spaced apart from the first lateral land surface 64 and the first lateral cutting edge SB1. The first lateral groove 78 may be connected to the first lateral land surface 64.

[0041] The first lateral groove 78 may be connected to the rising wall surface 70. Also, the first lateral groove 78 may be connected to the upper end surface 68. When the first lateral groove 78 is connected to the upper end surface 68, the coolant tends to flow from the upper end surface 68 into the first lateral groove 78. As a result, the coolant tends to accumulate in the first lateral groove 78. The length of the first lateral groove 78 may be longer than the length of the first corner groove 74. In the example of FIGS. 8 and 9, the number of first lateral grooves 78 is multiple, but there may be only one.

[0042] The upper surface 36 of the cutting portion 32 may have a second lateral groove 80 extending inward from the side of the second lateral land surface 66. The second lateral groove 80 may function as a coolant reservoir. The second lateral groove 80 may be spaced apart from the second lateral land surface 66 and the second lateral cutting edge SB2. The second lateral groove 80 may be connected to the second lateral land surface 66.

[0043] The second lateral groove 80 may be connected to the rising wall surface 70. Also, the second lateral groove 80 may be connected to the upper end surface 68. When the second lateral groove 80 is connected to the upper end surface 68, the coolant easily flows from the upper end surface 68 into the second lateral groove 80. As a result, the coolant easily accumulates in the second lateral groove 80. The length of the second lateral groove 80 may be longer than the length of the second corner groove 76. In the examples of FIGS. 8 and 9, the number of the second lateral grooves 80 is plural, but there may be only one.

[0044] The cross-sectional shapes of the front groove 72, the first corner groove 74, the second corner groove 76, the first lateral groove 78, and the second lateral groove 80 along the width direction may be V-shaped or rectangular. The lengths of the front groove 72, the first corner groove 74, the second corner groove 76, the first lateral groove 78, and the second lateral groove 80 may be set to, for example, 0.3 mm to 3 mm. The widths of the front groove 72, the first corner groove 74, the second corner groove 76, the first lateral groove 78, and the second lateral groove 80 may be set to, for example, 0.05 mm to 0.5 mm. The depths of the front groove 72, the first corner groove 74, the second corner groove 76, the first lateral groove 78, and the second lateral groove 80 may be set to, for example, 0.05 mm to 0.5 mm.

[0045] 3 to 8, when the upper surface 36 of the cutting part 32 has the front groove 72 and the first corner groove 74, the coolant can be efficiently supplied to the front cutting edge FB and the first corner cutting edge CB1. This enhances the cooling effect of the coolant on the front cutting edge FB and the first corner cutting edge CB1.

[0046] A larger cutting load is applied to the first corner cutting edge CB1 than to the front cutting edge FB, and cracks are likely to occur at the first corner cutting edge CB1 if the first corner groove 74 has the same shape (same width, same length) as the front groove 72. In contrast, as in the example shown in Figures 3 to 8, if the length of the first corner groove 74 is shorter than the length of the front groove 72, the strength of the first corner cutting edge CB1 is increased, making it less likely to crack.

[0047] In other words, according to the examples shown in Figures 3 to 8, the cooling effect of the coolant on the leading cutting edge FB and the first corner cutting edge CB1 can be increased while improving the durability of the first corner cutting edge CB1, in other words, the durability of the cutting insert 14.

[0048] 3 to 8, when the width of the first corner groove 74 is narrower than the width of the front groove 72, the strength of the first corner cutting edge CB1 is increased, making it more difficult for cracks to occur in the first corner cutting edge CB1. This can further improve the durability of the cutting insert 14.

[0049] As in the examples shown in Figs. 3 to 8, when the depth of the first corner groove 74 is the same as the depth of the front groove 72, the amount of coolant stored in the first corner groove 74 can be sufficiently secured. This can further enhance the cooling effect of the first corner cutting edge CB1 by the coolant. When the depths of the front groove 72 and the first corner groove 74 are not constant, the maximum value of the depth of the front groove 72 and the maximum value of the depth of the first corner groove 74 may be compared. The depth of the first corner groove 74 is not required to be the same as the depth of the front groove 72 in the strict sense. If the depth of the first corner groove 74 is about 97% to 103% of the depth of the front groove 72, they may be considered to be the same.

[0050] It has been found that the leading cutting edge BF or the first corner cutting edge CB1 is easily deteriorated around the boundary between the first side 42 and the first corner 38 on the upper surface 36 of the cutting part 32. As shown in the example of FIG. 3 to FIG. 8, when the first corner groove 74 extends inward from the boundary between the front land surface 58 and the first corner land surface 60, the coolant can be efficiently supplied to the boundary. As a result, the leading cutting edge BF or the first corner cutting edge CB1 is less likely to deteriorate around the boundary between the first side 42 and the first corner 38 on the upper surface 36 of the cutting part 32, and the durability of the cutting insert 14 can be further improved. In particular, when the first corner groove 74 extends parallel to the front groove 72, the interval between the first corner groove 74 and the front groove 72 is prevented from becoming locally small, and the durability of the cutting insert 14 can be further improved.

[0051] 3 to 8, when the length of the first front groove 72A is the same as the length of the second front groove 72B, the variation in the amount of coolant supplied to the entire front cutting edge FB can be reduced. This can further improve the durability of the first corner cutting edge CB1, in other words, the durability of the cutting insert 14.

[0052] 3 to 8, when the length of the second corner groove 76 is shorter than the length of the front groove 72, the strength of the second corner cutting edge CB2 is increased, making it less likely for cracks to occur in the second corner cutting edge CB2. This improves the durability of the second corner cutting edge CB2.

[0053] 3 to 8, when the length of the first lateral groove 78 is longer than the length of the first corner groove 74, a sufficient amount of coolant can be secured in the first lateral groove 78. This enhances the cooling effect of the coolant on the first lateral cutting edge SB1.

[0054] <First Modification of the Embodiment> A configuration of a cutting insert 14A according to Modification 1 of the embodiment of the present disclosure will be described with reference to Fig. 10. Fig. 10 is a schematic enlarged perspective view of a portion of the cutting insert 14A according to Modification 1 of the embodiment of the present disclosure.

[0055] 10, the cutting insert 14A according to the first modified example of the embodiment of the present disclosure has the same configuration as the cutting insert 14, except for a part. Among the configuration of the cutting insert 14A, differences from the configuration of the cutting insert 14 will be described. For convenience of explanation, the same reference numerals will be used to denote members having the same functions as the members described in the embodiment.

[0056] The upper surface 36 of the cutting portion 32 may have two first corner grooves 74 extending inward from the side of the first corner land surface 60. One of the first corner grooves 74 may extend inward from the side of the boundary between the front land surface 58 and the first corner land surface 60. The other first corner groove 74 may extend inward from the side of the center of the first corner land surface 60.

[0057] The upper surface 36 of the cutting portion 32 may have two second corner grooves 76 extending inward from the side of the second corner land surface 62. One of the second corner grooves 76 may extend inward from the side of the boundary between the front land surface 58 and the second corner land surface 62. The other second corner groove 76 may extend inward from the side of the center of the second corner land surface 62.

[0058] As in the example shown in Figure 10, when the upper surface 36 of the cutting portion 32 has two first corner grooves 74, it is possible to supply a sufficient amount of coolant to the first corner cutting edge CB1, thereby enhancing the cooling effect of the coolant on the first corner cutting edge CB1.

[0059] <Modification 2 of the embodiment> A configuration of a cutting insert 14B according to Modification 2 of the embodiment of the present disclosure will be described with reference to Fig. 11. Fig. 11 is a schematic enlarged perspective view of a part of the cutting insert 14B according to Modification 2 of the embodiment of the present disclosure.

[0060] 11, the cutting insert 14B according to the second modification of the embodiment of the present disclosure has the same configuration as the cutting insert 14, except for some parts. Among the configuration of the cutting insert 14B, differences from the configuration of the cutting insert 14 will be described. For convenience of explanation, the same reference numerals will be used to denote members having the same functions as the members described in the embodiment.

[0061] The upper surface 36 of the cutting portion 32 may have one first lateral groove 78 extending inwardly from the side of the first lateral land surface 64. The first lateral groove 78 may extend inwardly from the side of the boundary between the first lateral land surface 64 and the first corner land surface 60.

[0062] The upper surface 36 of the cutting portion 32 may have one second lateral groove 80 extending inward from the side of the second lateral land surface 66. The second lateral groove 80 may extend inward from the side of the boundary between the second lateral land surface 66 and the first corner land surface 60.

[0063] The first corner side 50 and the second corner side 52 may each become narrower moving away from the top surface 36 .

[0064] 11, when the first lateral groove 78 extends inward from the side of the boundary between the first lateral land surface 64 and the first corner land surface 60, coolant can be efficiently supplied to the boundary. This makes it difficult for the first lateral cutting edge CF or the first corner cutting edge CB1 to deteriorate around the boundary between the second side 44 and the first corner 38 on the upper surface 36 of the cutting portion 32, and the durability of the cutting insert 14 can be further improved.

[0065] <Modification 3 of the embodiment> A configuration of a cutting insert 14C according to Modification 3 of the embodiment of the present disclosure will be described with reference to Fig. 12. Fig. 12 is a schematic enlarged perspective view of a part of the cutting insert 14C according to Modification 3 of the embodiment of the present disclosure.

[0066] As shown in Fig. 12, the cutting insert 14C according to the third modification of the embodiment of the present disclosure has the same configuration as the cutting insert 14B, except for some parts. The following describes the configuration of the cutting insert 14C that is different from the configuration of the cutting insert 14B. For convenience of explanation, the same reference numerals are used for members having the same functions as the members described in the second modification of the embodiment.

[0067] The multiple front grooves 72 may include a first front groove 72A and a second front groove 72B located closer to the first corner 38 than the first front groove 72A. The length of the first front groove 72A may be longer than the length of the second front groove 72B.

[0068] 12, when the length of the first front groove 72A is longer than the length of the second front groove 72B, the coolant can be efficiently supplied to the center of the front cutting edge bF, which is difficult to dissipate heat, thereby further improving the cooling effect of the coolant on the front cutting edge FB.

[0069] <Fourth Modification of the Embodiment> A configuration of a cutting insert 14D according to Modification 4 of the embodiment of the present disclosure will be described with reference to Fig. 13. Fig. 13 is a schematic enlarged perspective view of a part of a cutting insert 14D according to Modification 4 of the embodiment of the present disclosure.

[0070] As shown in Fig. 13, the cutting insert 14D according to the fourth modification of the embodiment of the present disclosure has the same configuration as the cutting insert 14C, except for some parts. The following describes the configuration of the cutting insert 14D that is different from the configuration of the cutting insert 14C. For convenience of explanation, the same reference numerals are used for members having the same functions as those described in the third modification of the embodiment.

[0071] The upper surface 36 of the cutting portion 32 may have a plurality of first lateral grooves 78 extending inwardly from the side of the first lateral land surface 64. One first lateral groove 78 may extend inwardly from the side of the boundary between the first lateral land surface 64 and the first corner land surface 60.

[0072] The upper surface 36 of the cutting portion 32 may have a plurality of second lateral grooves 80 extending inward from the side of the second lateral land surface 66. One second lateral groove 80 may extend inward from the side of the boundary between the second lateral land surface 66 and the first corner land surface 60.

[0073] <Other embodiments> As in the examples shown in FIGS. 3 to 13, the technical ideas applied to the cutting tool 10 (10A, 10B, 10C, 10D) may be applied to a cutting tool used in a cutting process.

[0074] <Method of manufacturing machined products> A method for manufacturing a machined product according to an embodiment of the present disclosure will be described with reference to Fig. 14 to Fig. 16. Fig. 14 to Fig. 16 are schematic views for explaining a method for manufacturing a machined product according to an embodiment.

[0075] As shown in the examples of Figs. 14 to 16, the manufacturing method of the machined product according to the embodiment is a method for manufacturing a machined product M, which is a workpiece W that has been machined, and includes a first step, a second step, and a third step. The first step is a step of rotating the workpiece W around its axis S. The second step is a step of bringing the cutting insert 14 of the cutting tool 10 into contact with the rotating workpiece W. The third step is a step of separating the cutting tool 10 from the workpiece W. Examples of the material of the workpiece W include stainless steel, carbon steel, alloy steel, cast iron, and non-ferrous metals. The specific content of the manufacturing method of the machined product according to the embodiment is as follows.

[0076] First, the cutting tool 10 is attached to the tool rest of the lathe, and the workpiece W is attached to the chuck of the lathe. Next, as shown in the example of FIG. 14, the chuck is rotated to rotate the workpiece W around its axis S (first step). Then, as shown in the example of FIG. 15, the cutting tool 10 is moved in the direction of the arrow D1 to approach the workpiece W, and the cutting portion 32 of the cutting insert 14 is brought into contact with the outer peripheral surface Wf of the rotating workpiece W, thereby providing a cut in the workpiece W (second step). As a result, the workpiece W is cut, and a machining groove Wg can be formed in the outer peripheral surface Wf of the workpiece W.

[0077] 16, the cutting tool 10 is moved in the direction of the arrow D2 to separate the cutting tool 10 from the workpiece W (third step). This completes the cutting of the workpiece W, and a machined product M can be manufactured, which is the workpiece W that has been machined. Since the cutting insert 14 has excellent cutting ability for the reasons described above, a machined product M with excellent machining accuracy can be manufactured.

[0078] When cutting is continued, the cutting portion 32 of the cutting insert 14 may be repeatedly brought into contact with different locations of the workpiece W while rotating the workpiece W. In the embodiment of the present disclosure, the cutting tool 10 is brought close to the workpiece W, but since it is only necessary that the cutting tool 10 and the workpiece W are brought relatively close to each other, for example, the workpiece W may be brought close to the cutting tool 10. In this regard, the cutting tool 10 is also moved away from the workpiece W in the same manner.

[0079] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-mentioned 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 the embodiments obtained by appropriately combining the technical means disclosed in the 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.

[0080] For example, the front land surface 58, the first corner land surface 60, the second corner land surface 62, the first lateral land surface 64, and the second lateral land surface 66 may each be a honing surface formed by a so-called honing process. Also, the rising wall surface 70 may be a land surface. In such a case, the honing surface has a curved shape, while the land surface has a flat shape, so that it is possible to distinguish between the two. [Explanation of symbols]

[0081] 10 cutting tools 12 Holder 12a Tip (1st end) 12b Rear end (2nd end) 14 Cutting insert (cutting insert according to embodiment) 16 Pockets 18 Nozzle 20 Fixing screw 22 Base 24 First main surface 26 Second main surface 28 Base top surface 30 Through hole 32 Cutting part 34 Notch 36 Top 38 First corner 40 2nd corner 42 Side 1 44 Side 2 46 Third Side 48 Front side 50 First corner side 52 Second corner side 54 1st side surface 56 2nd lateral side 58 Front Land Surface 60 First corner land surface 62 2nd corner land surface 64 First horizontal land surface 66 Second horizontal land surface 68 Upper end surface 70 Rising Wall 72 Anterior groove 72A 1st front groove 72B 2nd front groove 74 First corner groove 76 2nd corner groove 78 First Yokomizo 80 Second Yokomizo FB front cutting edge CB1 First corner cutting edge CB2 2nd corner cutting edge SB1 1st side blade SB2 2nd side blade 14A Cutting insert (cutting insert according to modified example 1 of the embodiment) 14B Cutting insert (cutting insert according to modified example 2 of the embodiment) 14C Cutting insert (Cutting insert according to modified example 3 of the embodiment) 14C Cutting insert (cutting insert according to the fourth modification of the embodiment)

Claims

1. a top surface having a first corner, a second corner, and a first side connected to the first corner and the second corner; A front side surface connected to the first side; a first corner side connected to the first corner; A front cutting edge located on the first side; a first corner cutting edge located at the first corner, The upper surface is a front land surface located at an outer edge of the upper surface and extending along the front cutting edge; a first corner land surface located at an outer edge of the upper surface and extending along the first corner cutting edge; a front groove extending inward from the front land surface side; a first corner groove extending inward from the first corner land surface side, The length of the first corner groove is shorter than the length of the front groove, The cutting insert, wherein a width of the first corner groove is equal to or smaller than a width of the front groove.

2. The cutting insert according to claim 1 , wherein the first corner groove extends inward from a boundary between the front land surface and the first corner land surface.

3. The cutting insert according to claim 2 , wherein the first corner groove extends parallel to the front groove.

4. The cutting insert according to claim 1 or 2, wherein a width of the first corner groove is narrower than a width of the front groove.

5. The cutting insert according to claim 4 , wherein a depth of the first corner groove is the same as a depth of the front groove.

6. The front groove is A first front groove; a second front groove located closer to the first corner than the first front groove, The cutting insert according to claim 1 or 2, wherein a length of the first front groove is the same as a length of the second front groove.

7. The front groove is A first front groove; a second front groove located closer to the first corner than the first front groove, The cutting insert according to claim 1 or 2, wherein a length of the first front groove is longer than a length of the second front groove.

8. a second corner side connected to the second corner; a second corner cutting edge located at the second corner, The upper surface is a second corner land surface located at an outer edge of the upper surface and extending along the second corner cutting edge; and a second corner groove extending inward from the second corner land surface side, The length of the second corner groove is shorter than the length of the front groove, The cutting insert according to claim 1 or 2, wherein a width of the second corner groove is narrower than a width of the front groove.

9. The upper surface is A second side connected to the first corner; a lateral land surface located at an outer edge of the upper surface and extending along the second side; A lateral groove extending inward from the lateral land surface side, The cutting insert according to claim 1 or 2, wherein a length of the lateral groove is longer than a length of the first corner groove.

10. The front groove is spaced from the front cutting edge, The cutting insert according to claim 1 or 2, wherein the first corner groove is spaced from the first corner cutting edge.

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; A cutting tool comprising: a cutting insert according to claim 1 or 2 located in the pocket.

12. Rotating the workpiece; contacting the rotating workpiece with the cutting tool according to claim 11; and removing the cutting tool from the workpiece.

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