Cutting insert and machining method

Abstract

The cutting insert includes a rake face, a flank face, and a cutting edge formed by a ridge line between the rake face and the flank face. The cutting edge has a first cutting edge section for corner machining, a second cutting edge section for drawing machining, a third cutting edge section for finish machining, a first connecting cutting edge section, and a second connecting cutting edge section. The third cutting edge portion is disposed between the first cutting edge portion and the second cutting edge portion. The first cutting edge portion has a curved shape. The radius of curvature of the first cutting edge portion is 0.1 mm or more and 2.4 mm or less. The second cutting edge portion has a linear shape or a curved shape having a radius of curvature of 3 mm or more. The third cutting edge portion has a linear shape or a curved shape having a radius of curvature of 3 mm or more. Each of the first connecting cutting edge portion and the second connecting cutting edge portion has a curved shape.

Description

Technical Field

[0001] The present invention relates to a cutting blade and a machining method. This application claims priority based on Japanese Patent Application No. 2022-178143 filed on November 7, 2022. All the descriptions recorded in the Japanese patent application are incorporated herein by reference. Background Art

[0002] In International Publication No. 2019 / 087496 (Patent Document 1), a cutting blade having a rake face, a flank face, and a chamfer disposed between the rake face and the flank face is disclosed.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: International Publication No. 2019 / 087496 Summary of the Invention

[0006] The cutting blade according to one aspect of the present invention includes a rake face, a flank face, and a cutting edge formed by the ridge line between the rake face and the flank face. The surface participating in cutting is composed of at least any one of a cBN-based sintered body, a diamond-based sintered body, ceramics, cermets, and cemented carbide. The cutting edge has a first cutting edge portion for angular machining, a second cutting edge portion for drawing machining, a third cutting edge portion for finish surface machining, a first connecting cutting edge portion connecting the first cutting edge portion and the third cutting edge portion, and a second connecting cutting edge portion connecting the second cutting edge portion and the third cutting edge portion. The third cutting edge portion is disposed between the first cutting edge portion and the second cutting edge portion. The first cutting edge portion has a curved shape. The radius of curvature of the first cutting edge portion is 0.1 mm or more and 2.4 mm or less. The second cutting edge portion has a straight shape or a curved shape with a radius of curvature of 3 mm or more. The third cutting edge portion has a straight shape or a curved shape with a radius of curvature of 3 mm or more. The first connecting cutting edge portion and the second connecting cutting edge portion each have a curved shape. Brief Description of the Drawings

[0007] Figure 1 It is a perspective schematic view showing the configuration of the cutting blade according to the present embodiment.

[0008] Figure 2 It is a plan schematic view showing the configuration of the cutting tool according to the present embodiment.

[0009] Figure 3 Is Figure 1 An enlarged schematic view of Region III of

[0010] Figure 4 Is along Figure 2Schematic cross-sectional view of the IV-IV line.

[0011] Figure 5 It is a schematic view showing a cross-section perpendicular to the tangent line with respect to the first cutting edge portion.

[0012] Figure 6 It is a schematic view showing a cross-section perpendicular to the tangent line with respect to the second cutting edge portion.

[0013] Figure 7 It is a schematic view showing a cross-section perpendicular to the tangent line with respect to the third cutting edge portion.

[0014] Figure 8 It is a three-dimensional schematic view showing the first retraction area.

[0015] Figure 9 It is a three-dimensional schematic view showing the second retraction area.

[0016] Figure 10 It is a schematic view showing the first processing method according to this embodiment.

[0017] Figure 11 It is an enlarged schematic view showing the processing state.

[0018] Figure 12 It is a side schematic view showing the transverse rake angle of the second cutting edge portion.

[0019] Figure 13 It is a schematic view showing the second processing method according to this embodiment. Detailed implementation mode

[0020] Problems to be solved by the invention

[0021] For example, in the case of high-efficiency machining of quenched steel, since the cutting resistance becomes high, chipping of the cutting edge is likely to occur. Therefore, it is difficult to improve the tool life of the cutting insert.

[0022] An object of the present invention is to provide a cutting insert capable of improving the tool life.

[0023] [Effects of the present invention]

[0024] According to the present invention, a cutting insert capable of improving the tool life can be provided.

[0025] [Description of the embodiment of the present invention]

[0026] First, the embodiments of the present invention will be listed and described.

[0027] (1) The cutting blade 100 according to one aspect of the present invention includes a rake face 50, a flank face 30, and a cutting edge 10 formed by the ridge line 20 of the rake face 50 and the flank face 30. The surface participating in cutting is composed of at least any one of a cBN-based sintered body, a diamond-based sintered body, ceramics, cermets, and cemented carbide. The cutting edge 10 has a first cutting edge portion 1 for corner machining, a second cutting edge portion 2 for drawing machining, a third cutting edge portion 3 for finish surface machining, a first connecting cutting edge portion 11 connecting the first cutting edge portion 1 and the third cutting edge portion 3, and a second connecting cutting edge portion 12 connecting the second cutting edge portion 2 and the third cutting edge portion 3. The third cutting edge portion 3 is disposed between the first cutting edge portion 1 and the second cutting edge portion 2. The first cutting edge portion 1 has a curved shape. The radius of curvature of the first cutting edge portion 1 is 0.1 mm or more and 2.4 mm or less. The second cutting edge portion 2 has a straight shape or a curved shape with a radius of curvature of 3 mm or more. The third cutting edge portion 3 has a straight shape or a curved shape with a radius of curvature of 3 mm or more. The first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 each have a curved shape.

[0028] (2) For the cutting blade 100 according to (1) above, the radius of curvature of each of the first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 may also be 0.2 mm or more.

[0029] (3) For the cutting blade 100 according to (1) or (2) above, the clearance angle of each of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 may also be 3° or more and 20° or less.

[0030] (4) For the cutting blade 100 according to any one of (1) to (3) above, the cutting edge 10 may also have a fourth cutting edge portion 4 connected to the first cutting edge portion 1. The first cutting edge portion 1 may also be located between the third cutting edge portion 3 and the fourth cutting edge portion 4. The flank face 30 may also have a first relief area 71 and a second relief area 72. The first relief area 71 may also be connected to the fourth cutting edge portion 4. The second relief area 72 may also be connected to the first cutting edge portion 1, the second cutting edge portion 2, the third cutting edge portion 3, the first connecting cutting edge portion 11, and the second connecting cutting edge portion 12. The clearance angle of the first relief area 71 may also be 0°. The clearance angle of the second relief area 72 may also be 3° or more and 20° or less. When the area of the first relief area 71 is the first area and the area of the second relief area 72 is the second area, the value obtained by dividing the first area by the sum of the first area and the second area may also be 0.05 or more and 0.95 or less.

[0031] (5) For the cutting blade 100 according to any one of (1) to (3) above, the cutting edge 10 may also have a fourth cutting edge portion 4 connected to the first cutting edge portion 1. The first cutting edge portion 1 may also be located between the third cutting edge portion 3 and the fourth cutting edge portion 4. The ridge line 20 may also have a first ridge line region 81 and a second ridge line region 82. The first ridge line region 81 may also include the fourth cutting edge portion 4. The second ridge line region 82 may also include the first cutting edge portion 1, the second cutting edge portion 2, the third cutting edge portion 3, the first connecting cutting edge portion 11, and the second connecting cutting edge portion 12. The clearance angle of the first ridge line region 81 may also be 0°. The clearance angle of the second ridge line region 82 may also be 3° or more and 20° or less. When the length of the first ridge line region 81 is the first length and the length of the second ridge line region 82 is the second length, the value obtained by dividing the first length by the sum of the first length and the second length may also be greater than 0.05 and 0.95 or less.

[0032] (6) For the cutting blade 100 according to any one of (1) to (3) above, the cutting edge 10 may also have a fourth cutting edge portion 4 connected to the first cutting edge portion 1. The first cutting edge portion 1 may also be located between the third cutting edge portion 3 and the fourth cutting edge portion 4. The first cutting edge portion 1 may also be composed of a first region 1a and a second region 1b connected to the first region 1a. The cutting edge 10 may also be composed of a first cutting portion 91 and a second cutting portion 92. The first cutting portion 91 may also be composed of the first region 1a, the second cutting edge portion 2, the third cutting edge portion 3, the first connecting cutting edge portion 11, and the second connecting cutting edge portion 12. The second cutting portion 92 may also be composed of the second region 1b and the fourth cutting edge portion 4 connected to the second region 1b.

[0033] (7) The machining method according to one aspect of the present invention is a machining method using the cutting blade 100 described in any one of (1) to (6) above. In the drawing process of machining a workpiece using the second cutting edge portion 2, the transverse rake angle of the second cutting edge portion 2 may also be -20° or more and 10° or less.

[0034] (8) The machining method according to one aspect of the present invention is a machining method using the cutting blade 100 described in any one of (1) to (6) above. In the extrusion process, the transverse cutting edge angle of the first cutting edge portion 1 may also be 30° or more and less than 70°. In the drawing process, the transverse cutting edge angle of the second cutting edge portion 2 may also be 70° or more and less than 89°.

[0035] [Details of the Embodiment of the Present Invention]

[0036] The following describes a specific example of a cutting blade according to an embodiment of the present invention with reference to the accompanying drawings. The same or corresponding parts in the following drawings are denoted by the same reference numerals, and their descriptions are not repeated.

[0037] Figure 1 FIG. is a perspective view showing the configuration of the cutting blade 100 according to the present embodiment. As Figure 1 shown, the cutting blade 100 according to the present embodiment has a cutting edge member 6 and a substrate 7. The cutting edge member 6 is mounted on the substrate 7. The cutting edge member 6 participates in cutting. The top view shape of the substrate 7 is not particularly limited, for example, it is a rhombus. At the acute-angled corner portion of the substrate 7, the cutting edge member 6 is joined. The substrate 7 is made of, for example, cemented carbide or cermet. The cutting blade 100 according to the present embodiment is formed by joining the cutting edge member 6 to the acute-angled corner portion of the substrate 7, or the entire cutting blade 100 may be formed of the cutting edge member 6.

[0038] The present invention is also applicable to cutting blades 100 having polygons other than rhombuses. Since the tool tip shapes are common, only the rhombus-shaped cutting blade 100 is illustrated. At the acute-angled corner portion of the substrate 7, a counterbore portion 8 is formed by partially recessing a part of the upper surface. The cutting edge member 6 is joined to the substrate 7 at the counterbore portion 8 by brazing or other joining means.

[0039] The cutting edge member 6 is made of a cBN-based sintered body, a diamond-based sintered body, ceramics, cermet, or cemented carbide. The cBN-based sintered body is a sintered body containing 10% or more and 99.9% or less cBN (cubic boron nitride) by volume ratio. The diamond-based sintered body is a sintered body containing 10% or more and 99.9% or less diamond by volume ratio. There is no particular limitation on the ceramics. For example, ceramics such as alumina (Al2O3), silicon nitride (Si3N4), and titanium carbide (TiC) can be preferably used. There is no particular limitation on the cermet. For example, nitride-based cermet and carbide-based cermet can be preferably used.

[0040] The cutting blade 100 according to the present embodiment has a rake face 50, a flank face 30, a cutting edge 10, and a bottom face 60. The cutting edge 10 is formed by the ridge line 20 of the rake face 50 and the flank face 30. The ridge line 20 has a cutting edge 10, a first ridge line portion 21, and a second ridge line portion 22. The cutting edge 10 is a part of the ridge line 20. The cutting edge 10 has a first cutting edge portion 1 for corner machining, a second cutting edge portion 2 for drawing machining, a third cutting edge portion 3 for finish surface machining, a first connecting cutting edge portion 11, a second connecting cutting edge portion 12, and a fourth cutting edge portion 4.

[0041] The first connecting cutting edge portion 11 connects the first cutting edge portion 1 and the third cutting edge portion 3. The first connecting cutting edge portion 11 is located between the first cutting edge portion 1 and the third cutting edge portion 3. The second connecting cutting edge portion 12 connects the second cutting edge portion 2 and the third cutting edge portion 3. The second connecting cutting edge portion 12 is located between the second cutting edge portion 2 and the third cutting edge portion 3. The third cutting edge portion 3 is disposed between the first cutting edge portion 1 and the second cutting edge portion 2. The third cutting edge portion 3 connects the first connecting cutting edge portion 11 and the second connecting cutting edge portion 12. The fourth cutting edge portion 4 is connected to the first cutting edge portion 1. The first cutting edge portion 1 is located between the third cutting edge portion 3 and the fourth cutting edge portion 4.

[0042] Figure 2 It is a plan view showing the configuration of the cutting tool according to the present embodiment. Figure 2 The shown plan view shows a state observed along a straight line perpendicular to the rake face 50. The viewing point is located at a position opposed to the rake face 50. The viewing direction D is a direction from the rake face 50 toward the bottom face 60.

[0043] As Figure 2 shown, the first cutting edge portion 1 has a curved shape. The first cutting edge portion 1 is curved so as to be convex toward the outside. The first cutting edge portion 1 is a corner cutting edge portion. When observed along a straight line perpendicular to the rake face 50, the radius of curvature of the first cutting edge portion 1 is 0.1 mm or more and 2.4 mm or less. There is no particular limitation on the radius of curvature of the first cutting edge portion 1, and it may be 0.2 mm or more and 2.2 mm or less, it may be 0.4 mm or more and 2.0 mm or less, or it may be 0.6 mm or more and 1.8 mm or less.

[0044] As Figure 2 shown, when observed along a straight line perpendicular to the rake face 50, the second cutting edge portion 2 has a straight shape or a curved shape with a radius of curvature of 3 mm or more. When the second cutting edge portion 2 has a curved shape, the radius of curvature of the second cutting edge portion 2 may be 5 mm or more, it may be 10 mm or more, it may be 30 mm or more, or it may be 50 mm or more. The radius of curvature of the second cutting edge portion 2 may be 150 mm or less, it may be 130 mm or less, or it may be 100 mm or less.

[0045] As Figure 2 shown, when observed along a straight line perpendicular to the rake face 50, the third cutting edge portion 3 has a straight shape or a curved shape with a radius of curvature of 3 mm or more. When the third cutting edge portion 3 has a curved shape, the radius of curvature of the third cutting edge portion 3 may be 5 mm or more, it may be 10 mm or more, it may be 20 mm or more, or it may be 40 mm or more. The radius of curvature of the third cutting edge portion 3 may be 80 mm or less, it may be 70 mm or less, or it may be 60 mm or less.

[0046] The length of the second cutting edge portion 2 may also be greater than the length of the third cutting edge portion 3. The length of the second cutting edge portion 2 may be more than 1.5 times the length of the third cutting edge portion 3, or may be more than 2 times. The length of the second cutting edge portion 2 may be 10 times or less the length of the third cutting edge portion 3, or may be 5 times or less. It should be noted that in the case where the cutting edge portion is curved, the length of the cutting edge portion refers to the length in the case where the curve is regarded as a straight line.

[0047] The first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 are each curved in a manner that forms a convex portion toward the outside, for example. When observed along a straight line perpendicular to the rake face 50, the radius of curvature of each of the first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 is, for example, 0.2 mm or more. The radius of curvature of each of the first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 may be 0.3 mm or more, or may be 0.5 mm or more. The radius of curvature of each of the first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 may be less than 3 mm, or may be less than 2 mm. The first connecting cutting edge portion 11 and the adjacent first cutting edge portion 1 and third cutting edge portion 3 preferably have different radii of curvature respectively. The second connecting cutting edge portion 12, the adjacent second cutting edge portion 2, and the third cutting edge portion 3 preferably have different radii of curvature respectively. The first connecting cutting edge portion 11 and the second connecting cutting edge portion 12 do not participate in cutting in terms of structure and function.

[0048] As Figure 2 shown, the first ridge line portion 21 and the second ridge line portion 22 each have a linear shape. The first ridge line portion 21 is connected to the fourth cutting edge portion 4. The second ridge line portion 22 is connected to the second cutting edge portion 2. The length of the first ridge line portion 21 may also be greater than the length of the second ridge line portion 22. The length of the first ridge line portion 21 may also be greater than the length of the fourth cutting edge portion 4. The length of the second ridge line portion 22 may also be greater than the length of the second cutting edge portion 2. The first ridge line portion 21 and the second ridge line portion 22 are each composed of the base body 7. The cutting edge 10 is composed of the blade member 6.

[0049] The rake face 50 has a first rake face portion 51 and a second rake face portion 52. The first rake face portion 51 is composed of the blade member 6. The second rake face portion 52 is composed of the base body 7. A through hole 5 is formed in the second rake face portion 52. The cutting edge 10 may also be formed at two locations on the diagonal of the rhombus. The shape of the cutting edge 10 may also be bilaterally symmetric with respect to the axis passing through the through hole 5. The angle (the apex angle θ8 of the first cutting edge portion 1) formed by the straight line along the first ridge line portion 21 and the straight line along the second ridge line portion 22 is, for example, 30° or more and 90° or less. The apex angle θ8 of the first cutting edge portion 1 may also be, for example, 35°, 55°, 60°, 70°, or 80°.

[0050] Figure 3 is Figure 1 an enlarged schematic view of Region III. As Figure 3 shown, the flank 30 has a first flank portion 31, a second flank portion 32, a third flank portion 33, a fourth flank portion 34, a fifth flank portion 35, a sixth flank portion 36, a seventh flank portion 37, and a side surface portion 40. The first flank portion 31 is connected to the first cutting edge portion 1. The second flank portion 32 is connected to the second cutting edge portion 2. The third flank portion 33 is connected to the third cutting edge portion 3.

[0051] The fourth flank portion 34 is connected to the fourth cutting edge portion 4. The fifth flank portion 35 is connected to the first connecting cutting edge portion 11. The sixth flank portion 36 is connected to the second connecting cutting edge portion 12. The seventh flank portion 37 is connected to the first flank portion 31 and the fourth flank portion 34 respectively. The first flank portion 31, the second flank portion 32, the third flank portion 33, the fourth flank portion 34, the fifth flank portion 35, the sixth flank portion 36, and the seventh flank portion 37 are formed by the blade member 6.

[0052] The side surface portion 40 has a first side surface region 41, a second side surface region 42, a third side surface region 43, a fourth side surface region 44, a fifth side surface region 45, a sixth side surface region 46, and a seventh side surface region 47. The first side surface region 41 is connected to the first flank portion 31 and the bottom surface 60 respectively. The second side surface region 42 is connected to the second flank portion 32, the second ridge portion 22, and the bottom surface 60 respectively. The third side surface region 43 is connected to the third flank portion 33 and the bottom surface 60 respectively.

[0053] The fourth side surface region 44 is connected to the seventh flank portion 37. The fifth side surface region 45 is connected to the fifth flank portion 35 and the bottom surface 60 respectively. The sixth side surface region 46 is connected to the sixth flank portion 36 and the bottom surface 60 respectively. The seventh side surface region 47 is connected to the fourth flank portion 34, the first ridge portion 21, and the bottom surface 60 respectively. The side surface portion 40 is formed by the base body 7.

[0054] As Figure 3 shown, the cutting edge 10 is composed of a first cutting portion 91 and a second cutting portion 92. The first cutting portion 91 is composed of a first region 1a of the first cutting edge portion 1, the second cutting edge portion 2, the third cutting edge portion 3, the first connecting cutting edge portion 11, and the second connecting cutting edge portion 12. The second cutting portion 92 is composed of a second region 1b of the first cutting edge portion 1 and the fourth cutting edge portion 4. The first cutting edge portion 1 is composed of the first region 1a and the second region 1b. The first region 1a is connected to the second region 1b. The first ridge portion 21 and the second ridge portion 22 do not form the cutting edge 10 respectively.

[0055] Figure 4 is a schematic cross-sectional view along the IV-IV line of Figure 2 . As shown in Figure 4 , the through-hole 5 penetrates the substrate 7. The through-hole 5 opens on the rake face 50 and the bottom face 60 respectively. The seventh side surface area 47 is inclined perpendicularly with respect to the rake face 50. The fourth side surface area 44 is inclined with respect to the seventh side surface area 47. The inclination angle (the fourth angle θ4) of the fourth side surface area 44 with respect to the seventh side surface area 47 is, for example, 3° or more and 20° or less.

[0056] Figure 5 is a schematic view showing a cross-section perpendicular to the tangent line of the first cutting edge portion 1. As shown in Figure 5 , the first flank face portion 31 is inclined inward with respect to the plane perpendicular to the rake face 50. The clearance angle (the first angle θ1) of the first cutting edge portion 1 is the inclination angle of the first flank face portion 31 with respect to the plane perpendicular to the rake face 50. The first angle θ1 can be, for example, 3° or more and 20° or less, can be 5° or more and 18° or less, or can be 7° or more and 15° or less.

[0057] Figure 6 is a schematic view showing a cross-section perpendicular to the tangent line of the second cutting edge portion 2. As shown in Figure 6 , the second flank face portion 32 is inclined inward with respect to the plane perpendicular to the rake face 50. The clearance angle (the second angle θ2) of the second cutting edge portion 2 is the inclination angle of the second flank face portion 32 with respect to the plane perpendicular to the rake face 50. The second angle θ2 can be, for example, 3° or more and 20° or less, can be 5° or more and 18° or less, or can be 7° or more and 15° or less.

[0058] Figure 7 is a schematic view showing a cross-section perpendicular to the tangent line of the third cutting edge portion 3. As shown in Figure 7 , the third flank face portion 33 is inclined inward with respect to the plane perpendicular to the rake face 50. The clearance angle (the third angle θ3) of the third cutting edge portion 3 is the inclination angle of the third flank face portion 33 with respect to the plane perpendicular to the rake face 50. The third angle θ3 can be, for example, 3° or more and 20° or less, can be 5° or more and 18° or less, or can be 7° or more and 15° or less.

[0059] Figure 8 is a three-dimensional schematic view showing the first retraction region 71. As shown in Figure 8 , the flank face 30 has a first retraction region 71 and a second retraction region 72. The first retraction region 71 is composed of the fourth flank face portion 34 and the seventh side surface area 47. In Figure 8The area shaded in the figure corresponds to the first relief area 71. The back angle of the first relief area 71 is 0°. In other words, the first relief area 71 is perpendicular to the rake face 50. The back angle of the first relief area 71 is the inclination angle of the first relief area 71 with respect to the plane perpendicular to the rake face 50.

[0060] The cutting edge 20 has a first cutting edge area 81 and a second cutting edge area 82. The first cutting edge area 81 is composed of the fourth cutting edge part 4 and the first cutting edge part 21. In Figure 8 the case of the shape of the cutting insert 100 described, the length of the first cutting edge area 81 is the length from one corner part of the cutting insert 100 to the end of the fourth cutting edge part 4. The first cutting edge area 81 is connected to the first relief area 71. The back angle of the first cutting edge area 81 is 0°. The back angle of the first cutting edge area 81 is the inclination angle of the first relief area 71 in the cross section perpendicular to the tangent of the first cutting edge area 81.

[0061] Figure 9 It is a three-dimensional schematic diagram showing the second relief area 72. As Figure 9 shown, the second relief area 72 is composed of the area other than the first relief area 71 in the flank face 30. The second relief area 72 is composed of the first flank face part 31, the second flank face part 32, the third flank face part 33, the fifth flank face part 35, the sixth flank face part 36, the seventh flank face part 37, the first side area 41, the second side area 42, the third side area 43, the fourth side area 44, the fifth side area 45, and the sixth side area 46. In Figure 9 the area shaded in the figure corresponds to the second relief area 72. The back angle of the second relief area 72 is 3° or more and 20° or less. The back angle of the second relief area 72 is the inclination angle of the second relief area 72 with respect to the plane perpendicular to the rake face 50. The back angle of the second relief area 72 corresponds to the fourth angle θ4 (refer to Figure 4 ).

[0062] The second cutting edge area 82 is composed of the first cutting edge part 1, the second cutting edge part 2, the third cutting edge part 3, the first connecting cutting edge part 11, the second connecting cutting edge part 12, and the second cutting edge part 22. In Figure 9 the case of the shape of the cutting insert 100 described, the length of the second cutting edge area 82 is the length from another corner part of the cutting insert 100 to the end of the first cutting edge part 1. The second cutting edge area 82 is connected to the second relief area 72. The back angle of the second cutting edge area 82 is 3° or more and 20° or less. The back angle of the second cutting edge area 82 is the inclination angle of the second relief area 72 in the cross section perpendicular to the tangent of the second cutting edge area 82.

[0063] When the area (surface area) of the first retraction region 71 is the first area and the area (surface area) of the second retraction region 72 is the second area, the value obtained by dividing the first area by the sum of the first area and the second area is, for example, 0.05 or more and 0.95 or less. The value obtained by dividing the first area by the sum of the first area and the second area may be 0.1 or more and 0.9 or less, or may be 0.2 or more and 0.8 or less.

[0064] When the length of the first ridge line region 81 is the first length and the length of the second ridge line region 82 is the second length, the value obtained by dividing the first length by the sum of the first length and the second length is, for example, greater than 0.05 and 0.95 or less. The value obtained by dividing the first length by the sum of the first length and the second length may be 0.1 or more and 0.9 or less, or may be 0.2 or more and 0.8 or less.

[0065] Next, the processing method according to the present embodiment will be described. In the processing method according to the present embodiment, the cutting blade 100 according to the present embodiment is used to process the workpiece to be cut.

[0066] Figure 10 is a schematic diagram showing the first processing method according to the present embodiment. As Figure 10 shown, the cutting blade 100 is mounted on the cage 150 using the pressing member 160. The pressing member 160 has a main body portion 162 and an insertion portion 161. The insertion portion 161 is inserted into the through hole 5 of the cutting blade 100. An installation hole 163 is formed in the main body portion 162. A fastening screw 170 is inserted into the installation hole 163. Thus, the pressing member 160 is fixed to the cage 150. The pressing member 160 pulls the cutting blade 100 closer to the cage 150, and the cutting blade 100 is fixed to the cage 150.

[0067] The cutting blade 100 according to the present embodiment can perform outer diameter processing. The workpiece to be cut 200 has an outer peripheral surface 201. The extrusion processing is performed while moving the cutting blade 100 in the first feed direction A1. The first feed direction A1 is the direction from the cage 150 toward the cutting blade 100. In the extrusion processing, the workpiece to be cut 200 is processed using the first cutting edge portion 1. The drawing processing is performed while moving the cutting blade 100 in the second feed direction A2. The second feed direction A2 is the direction from the cutting blade 100 toward the cage 150. In the drawing processing, the workpiece to be cut 200 is processed using the second cutting edge portion 2. The first feed direction A1 and the second feed direction A2 are each parallel to the rotation axis X of the workpiece to be cut 200. The workpiece to be cut 200 rotates about the rotation axis X in the rotation direction R.

[0068] Figure 11 is an enlarged schematic diagram showing the processing state.Figure 11 The enlarged schematic view shown represents the state observed along a straight line perpendicular to the rake face 50. The cutting edge 10 cuts into the workpiece 200 with a cutting depth H. In the extrusion process, the cross-cutting edge angle of the first cutting edge portion 1 is the fifth angle θ5. The fifth angle θ5 is the angle formed by the tangent line of the first cutting edge portion 1 at the contact point between the outer peripheral surface 201 of the workpiece 200 and the first cutting edge portion 1 and a straight line perpendicular to the rotation axis X of the workpiece 200. The fifth angle θ5 is, for example, 30° or more and less than 70°. The fifth angle θ5 can be 35° or more and less than 65°, or can be 40° or more and less than 60°.

[0069] As Figure 11 shown, in the drawing process, the cross-cutting edge angle of the second cutting edge portion 2 is the sixth angle θ6. The sixth angle θ6 is the angle formed by the tangent line of the second cutting edge portion 2 at the contact point between the outer peripheral surface 201 of the workpiece 200 and the second cutting edge portion 2 and a straight line perpendicular to the rotation axis X of the workpiece 200. The sixth angle θ6 is, for example, 70° or more and less than 89°. The sixth angle θ6 can be 73° or more and less than 86°, can be 76° or more and less than 83°. The sixth angle θ6 can also be greater than the fifth angle θ5.

[0070] Figure 12 is a side schematic view showing the transverse rake angle of the second cutting edge portion 2. Figure 12 The side schematic view shown represents the state observed along a straight line perpendicular to the rotation axis X of the workpiece 200.

[0071] In the drawing process of machining the workpiece 200 using the second cutting edge portion 2, the cutting blade 100 is fed in the second feed direction A2 along a direction parallel to the rotation axis X of the workpiece 200. As Figure 12 shown, when observed from a direction perpendicular to the rotation axis X of the workpiece 200, the transverse rake angle θ7 of the second cutting edge portion 2 is the inclination angle of the second cutting edge portion 2 with respect to a straight line C parallel to the rotation axis X of the workpiece 200. The transverse rake angle of the second cutting edge portion 2 is the seventh angle θ7. The seventh angle θ7 can also be, for example, -20° or more and 10° or less. The seventh angle θ7 can be -15° or more and 8° or less, or can be -10° or more and 5° or less. It should be noted that during cutting, when the cutting edge 10 is ahead of the rake face 50, the transverse rake angle is a positive angle. On the contrary, during cutting, when the cutting edge 10 lags behind the rake face 50, the transverse rake angle is a negative angle.

[0072] Figure 13 is a schematic view showing the second processing method according to the present embodiment. As Figure 13As shown, in the second machining method according to the present embodiment, end face machining and outer diameter machining can also be performed. The workpiece 200 has an outer peripheral surface 201 and an end face 202. The outer peripheral surface 201 is parallel to the rotation axis X of the workpiece 200. The end face 202 is perpendicular to the rotation axis X of the workpiece 200. The extrusion machining and the corner machining are performed while moving the cutting blade 100 in the third feed direction B1. In the extrusion machining and the corner machining, the workpiece 200 is machined using the first cutting edge portion 1. The drawing machining is performed while moving the cutting blade 100 in the fourth feed direction B2. In the drawing machining, the workpiece 200 is machined using the second cutting edge portion 2. The third feed direction B1 is perpendicular to the rotation axis X of the workpiece 200. The fourth feed direction B2 is parallel to the rotation axis X of the workpiece 200.

[0073] Next, the effects of the cutting blade 100 and the machining method according to the present embodiment will be described.

[0074] According to the cutting blade 100 according to the present embodiment, the cutting edge 10 has a first cutting edge portion 1 for corner machining, a second cutting edge portion 2 for drawing machining, a third cutting edge portion 3 for finish surface machining, a first connecting cutting edge portion 11 connecting the first cutting edge portion 1 and the third cutting edge portion 3, and a second connecting cutting edge portion 12 connecting the second cutting edge portion 2 and the third cutting edge portion 3. The third cutting edge portion 3 is disposed between the first cutting edge portion 1 and the second cutting edge portion 2. The first cutting edge portion 1 has a curved shape. The radius of curvature of the first cutting edge portion 1 is 0.1 mm or more and 2.4 mm or less.

[0075] Since the cutting blade 100 according to the present embodiment has the first cutting edge portion 1 for corner machining, corner machining and profile machining can be performed. Further, since the cutting blade 100 according to the present embodiment has the second cutting edge portion 2 for drawing machining, drawing machining can be performed.

[0076] By enlarging the cross cutting edge angle θ6 of the second cutting edge portion 2, the feed component force in the drawing machining can be reduced. Therefore, chipping of the cutting edge 10 can be suppressed. As a result, the tool life can be improved. Further, in the drawing machining, the situation where the cutting blade 100 is pulled out from the cage 150 can be suppressed.

[0077] Further, since the cutting blade 100 according to the present embodiment has the third cutting edge portion 3 for finish surface machining, the finish surface roughness can be greatly improved. Therefore, in high-efficiency machining, good surface roughness can be stably obtained. It should be noted that high-efficiency machining means that the volume of the workpiece 200 that can be removed per unit time is, for example, 10 cm 3 / min or more.

[0078] According to the cutting blade 100 according to the present embodiment, the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 may each be 3° or more and 20° or less. By making the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 positive angles, the cutting resistance in the direction of the thrust component force can be reduced. Therefore, the dimensional accuracy can be stably improved.

[0079] According to the cutting blade 100 according to the present embodiment, the flank face 30 may also have a first retracted area 71 and a second retracted area 72. The clearance angle of the first retracted area 71 may be 0°. The clearance angle of the second retracted area 72 may be 3° or more and 20° or less. When the area of the first retracted area 71 is the first area and the area of the second retracted area 72 is the second area, the value obtained by dividing the first area by the second area may be 0.2 or more and 1 or less.

[0080] The first retracted area 71 and the second retracted area 72 are portions that come into contact with the cage 150. Compared with the second retracted area 72, the contact area between the first retracted area 71 and the cage 150 is larger. If the area of the cutting blade 100 that comes into contact with the cage 150 becomes larger, the constraint performance between the cage 150 and the cutting blade 100 becomes higher. As a result, the cutting blade 100 is less likely to be pulled out from the cage 150. By using a value obtained by dividing the first area by the second area of 0.2 or more and 1 or less, the cutting blade 100 can be further inhibited from being pulled out from the cage 150.

[0081] According to the cutting blade 100 according to the present embodiment, the ridge line 20 may also have a first ridge line area 81 and a second ridge line area 82. The clearance angle of the first ridge line area 81 may be 0°. The clearance angle of the second ridge line area 82 may be 3° or more and 20° or less. When the length of the first ridge line area 81 is the first length and the length of the second ridge line area 82 is the second length, the value obtained by dividing the first length by the second length may be greater than 0.5 and 1 or less. Thereby, the cutting blade 100 can be further inhibited from being pulled out from the cage 150, and chatter and undulations can be suppressed during the high-efficiency machining of quenched steel.

[0082] According to the machining method according to the present embodiment, in the drawing machining of the workpiece 200 using the second cutting edge portion 2, the transverse rake angle θ7 of the second cutting edge portion 2 may be -20° or more and 10° or less. Thereby, the load on the second cutting edge portion 2 can be reduced. As a result, the chipping of the second cutting edge portion 2 can be suppressed. Therefore, the cutting blade 100 can be further made to have a long life.

[0083] According to the processing method according to this embodiment, in the extrusion process, the transverse cutting edge angle θ5 of the first cutting edge portion 1 may also be 30° or more and less than 70°. In the drawing process, the transverse cutting edge angle θ6 of the second cutting edge portion 2 may also be 70° or more and less than 89°. Thereby, the load applied to the first cutting edge portion 1 and the second cutting edge portion 2 can be reduced. As a result, chipping of the first cutting edge portion 1 and the second cutting edge portion 2 can be suppressed. Therefore, the cutting blade 100 can be further extended in service life.

[0084] Example

[0085] The present embodiment will be further specifically described by way of examples. However, the present embodiment is not limited by these examples.

[0086] Cutting blades 100 (specimens S1 to S32) having the shapes described in Tables 1 and 2 were trial-produced, and cutting evaluations were performed under the following conditions. The cutting blades 100 of specimens S1 to S32 have a cutting edge member 6 and a substrate 7 (refer to Figure 1 ). In the cutting blades 100 of specimens S1 to S32, the material of the cutting edge member 6 is a cBN-based sintered body.

[0087] In Tables 1 and 2, the first cutting edge, the second cutting edge, the third cutting edge, the first connecting portion, and the second connecting portion respectively correspond to the first cutting edge portion 1, the second cutting edge portion 2, the third cutting edge portion 3, the first connecting cutting edge portion 11, and the second connecting cutting edge portion 12. The clearance angle refers to the clearance angle of each of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3. The seventh angle θ7 is the transverse rake angle of the second cutting edge portion 2 (refer to Figure 12 ). The fifth angle θ5 is the transverse cutting edge angle of the first cutting edge portion 1 (refer to Figure 11 ). The sixth angle θ6 is the transverse cutting edge angle of the second cutting edge portion 2 (refer to Figure 11 ).

[0088] The cutting blades 100 of specimens S1 to S22 and specimens S26 to S32 are examples. In the cutting blades 100 of specimens S1 to S22 and specimens S26 to S32, the radius of curvature of the first cutting edge portion 1 is 0.1 mm or more and 2.4 mm or less. The second cutting edge portion 2 is a straight shape or a curved shape with a radius of curvature of 3 mm or more. The third cutting edge portion 3 is a straight shape or a curved shape with a radius of curvature of 3 mm or more.

[0089] The cutting blades 100 of specimens S23 to S25 are comparative examples. In the cutting blade 100 of specimen S23, the radius of curvature of the first cutting edge portion 1 is 0.09 mm. In the cutting blade 100 of specimen S24, the second cutting edge portion 2 has a curved shape with a radius of curvature of 2 mm. In the cutting blade 100 of specimen S25, the third cutting edge portion 3 has a curved shape with a radius of curvature of 2 mm.

[0090] With the cutting blade 100 assembled to the cage 150, the following workpiece 200 was machined under the following cutting conditions. The shorter cutting time (tool life) was evaluated when the cutting edge 10 of the cutting blade 100 was damaged or when the ten-point mean roughness Rz of the machined surface exceeded 12.5 μm.

[0091] (Cutting geometry)

[0092] Cutting edge inclination angle = -5°, rake angle = 5°, side rake angle = 5°, front cutting edge angle = 5°

[0093] (Workpiece)

[0094] High-hardness steel SUJ2 (HRC62), diameter = 85 mm, length = 200 mm

[0095] (Cutting conditions)

[0096] Cutting speed: V = 200 m / minute, feed rate: f = 0.5 mm / revolution, depth of cut: ap = 0.2 mm, wet

[0097] (Machining method)

[0098] Outer diameter machining (extrusion machining and drawing machining)

[0099] The results are summarized in Tables 1 and 2.

[0100]

[0101] As shown in Table 1, it was confirmed that the cutting blades 100 of specimens S1 to S22 had a longer tool life compared to the cutting blades 100 of specimens S23 to S25.

[0102] In the cutting blades 100 of specimens S8 and S19, the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 were 3° and 2°, respectively. As shown in Table 1, it was confirmed that when the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 were 3° or more, the cutting blade 100 had a longer tool life.

[0103] In the cutting blades 100 of specimens S9 and S20, the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 are 20° and 21° respectively. As shown in Table 1, it was confirmed that: when the clearance angles of the first cutting edge portion 1, the second cutting edge portion 2, and the third cutting edge portion 3 are 20° or less, the cutting blade 100 has a long tool life.

[0104] In the cutting blades 100 of specimens S10 and S21, the transverse rake angles (seventh angle θ7) of the second cutting edge portion 2 are 10° and 11° respectively. As shown in Table 1, it was confirmed that: when the seventh angle θ7 is 10° or less, the cutting blade 100 has a long tool life.

[0105] In the cutting blades 100 of specimens S11 and S22, the transverse rake angles (seventh angle θ7) of the second cutting edge portion 2 are -20° and -21° respectively. As shown in Table 1, it was confirmed that: when the seventh angle θ7 is -20° or more, the cutting blade 100 has a long tool life.

[0106] In the cutting blades 100 of specimens S12 and S13, the transverse cutting edge angles (fifth angle θ5) of the first cutting edge portion 1 are 30° and 70° respectively. As shown in Table 1, it was confirmed that: when the fifth angle θ5 is 30° or more and 70° or less, the cutting blade 100 has a long tool life.

[0107] In the cutting blades 100 of specimens S14 and S15, the transverse cutting edge angles (sixth angle θ6) of the second cutting edge portion 2 are 70° and 89° respectively. As shown in Table 1, it was confirmed that: when the sixth angle θ6 is 70° or more and 89° or less, the cutting blade 100 has a long tool life.

[0108] In the cutting blades 100 of specimens S26 to S32, the clearance angle of the first retraction region 71 is 0°. The clearance angle of the second retraction region 72 is 3° or more and 20° or less. The area of the first retraction region 71 is the first area SN. The area of the second retraction region 72 is the second area SP. The value obtained by dividing the first area SN by the sum of the first area SN and the second area SP is 0.05 or more and 0.95 or less. The clearance angle of the first ridge region 81 is 0°. The clearance angle of the second ridge region 82 is 3° or more and 20° or less. The length of the first ridge region 81 is the first length LN. The length of the second ridge region 82 is the second length LP. The value obtained by dividing the first length LN by the sum of the first length LN and the second length LP is 0.05 or more and 0.95 or less.

[0109]

[0110] In the cutting blades 100 of the specimens S27 and S28, the clearance angles of the second retraction region 72 are 3° and 20°, respectively. As shown in Table 2, it was confirmed that when the clearance angle of the second retraction region 72 is 3° or more and 20° or less, the cutting blade 100 has a long tool life.

[0111] As shown in Table 2, it was confirmed that when the value obtained by dividing the first area SN by the sum of the first area SN and the second area SP is 0.05 or more and 0.95 or less, the cutting blade 100 has a long tool life.

[0112] As shown in Table 2, it was confirmed that when the value obtained by dividing the first length LN by the sum of the first length LN and the second length LP is 0.05 or more and 0.95 or less, the cutting blade 100 has a long tool life.

[0113] The embodiments and examples disclosed herein should be considered illustrative in all respects and not restrictive. The scope of the present invention is represented not by the above embodiments and examples but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0114] Description of Reference Numerals

[0115] 1: First cutting edge part;

[0116] 1a: First region;

[0117] 1b: Second region;

[0118] 2: Second cutting edge part;

[0119] 3: Third cutting edge part;

[0120] 4: Fourth cutting edge part;

[0121] 5: Through hole;

[0122] 6: Blade member;

[0123] 7: Substrate;

[0124] 8: Counterbore part;

[0125] 10: Cutting edge;

[0126] 11: First connecting cutting edge part;

[0127] 12: Second connecting cutting edge part;

[0128] 20: Ridge line;

[0129] 21: First ridge line part;

[0130] 22: Second ridge line part;

[0131] 30: Rear flank;

[0132] 31: First rear flank part;

[0133] 32: Second rear flank part;

[0134] 33: Third rear flank part;

[0135] 34: Fourth rear flank part;

[0136] 35: Fifth rear flank part;

[0137] 36: Sixth rear flank part;

[0138] 37: Seventh rear flank part;

[0139] 40: Side face;

[0140] 41: First side face area;

[0141] 42: Second side face area;

[0142] 43: Third side face area;

[0143] 44: Fourth side face area;

[0144] 45: Fifth side face area;

[0145] 46: Sixth side face area;

[0146] 47: Seventh side face area;

[0147] 50: Front flank;

[0148] 51: First front flank part;

[0149] 52: Second front flank part;

[0150] 60: Bottom surface;

[0151] 71: First retraction area;

[0152] 72: Second retraction area;

[0153] 81: First ridge line area;

[0154] 82: Second ridge line area;

[0155] 91: First cutting part;

[0156] 92: Second cutting part;

[0157] 100: Cutting insert;

[0158] 150: Cage;

[0159] 160: Pressing member;

[0160] 161: Insertion part;

[0161] 162: Main body part;

[0162] 163: Mounting hole;

[0163] 170: Fastening screw;

[0164] 200: Workpiece to be cut;

[0165] 201: Outer peripheral surface;

[0166] 202: End face;

[0167] A1: First feed direction;

[0168] A2: Second feed direction;

[0169] B1: Third feed direction;

[0170] B2: Fourth feed direction;

[0171] C: Straight line;

[0172] D: Line of sight direction;

[0173] LN: First length;

[0174] LP: Second length;

[0175] R: Rotation direction;

[0176] SN: First area;

[0177] SP: Second area;

[0178] X: Rotation axis;

[0179] θ1: First angle;

[0180] θ2: Second angle;

[0181] θ3: Third angle;

[0182] θ4: Fourth angle;

[0183] θ5: Fifth angle;

[0184] θ6: Sixth angle;

[0185] θ7: Transverse rake angle;

[0186] θ8: Tip angle.

Claims

1. A cutting blade, wherein a surface of the cutting blade that participates in cutting is composed of at least any one of a cBN-based sintered body, a diamond-based sintered body, ceramics, cermets, and cemented carbide, and the cutting blade includes a rake face, a flank face, and a cutting edge formed by a ridge line between the rake face and the flank face, wherein, The cutting edge has: a first cutting edge portion for angular machining; a second cutting edge portion for drawing machining; a third cutting edge portion for finish surface machining; a first connecting cutting edge portion connecting the first cutting edge portion and the third cutting edge portion; and a second connecting cutting edge portion connecting the second cutting edge portion and the third cutting edge portion, the third cutting edge portion is disposed between the first cutting edge portion and the second cutting edge portion, the first cutting edge portion has a curved shape, the radius of curvature of the first cutting edge portion is 0.1 mm or more and 2.4 mm or less, the second cutting edge portion has a straight shape or a curved shape with a radius of curvature of 3 mm or more, the third cutting edge portion has a straight shape or a curved shape with a radius of curvature of 3 mm or more, the first connecting cutting edge portion and the second connecting cutting edge portion each have a curved shape.

2. The cutting blade according to claim 1, wherein, The radius of curvature of each of the first connecting cutting edge portion and the second connecting cutting edge portion is 0.2 mm or more.

3. The cutting blade according to claim 1 or 2, wherein, The clearance angle of each of the first cutting edge portion, the second cutting edge portion, and the third cutting edge portion is 3° or more and 20° or less.

4. The cutting blade according to any one of claims 1 to 3, wherein, The cutting edge has a fourth cutting edge portion connected to the first cutting edge portion, the first cutting edge portion is located between the third cutting edge portion and the fourth cutting edge portion, the flank face has a first relief area and a second relief area, the first relief area is connected to the fourth cutting edge portion, the second relief area is connected to the first cutting edge portion, the second cutting edge portion, the third cutting edge portion, the first connecting cutting edge portion, and the second connecting cutting edge portion, the clearance angle of the first relief area is 0°, the clearance angle of the second relief area is 3° or more and 20° or less, When the area of the first relief area is the first area and the area of the second relief area is the second area, the value obtained by dividing the first area by the sum of the first area and the second area is 0.05 or more and 0.95 or less.

5. The cutting blade according to any one of claims 1 to 3, wherein, The cutting edge has a fourth cutting edge portion connected to the first cutting edge portion, the first cutting edge portion is located between the third cutting edge portion and the fourth cutting edge portion, the cutting edge has a first cutting edge region and a second cutting edge region, the first cutting edge region includes the fourth cutting edge portion, the second cutting edge region includes the first cutting edge portion, the second cutting edge portion, the third cutting edge portion, the first connecting cutting edge portion, and the second connecting cutting edge portion, the clearance angle of the first cutting edge region is 0°, the clearance angle of the second cutting edge region is 3° or more and 20° or less, When the length of the first cutting edge region is the first length and the length of the second cutting edge region is the second length, the value obtained by dividing the first length by the sum of the first length and the second length is greater than 0.05 and 0.95 or less.

6. The cutting insert according to any one of claims 1 to 3, wherein, The cutting edge has a fourth cutting edge portion connected to the first cutting edge portion, the first cutting edge portion is located between the third cutting edge portion and the fourth cutting edge portion, The first cutting edge portion is composed of a first region and a second region connected to the first region. The cutting edge is composed of a first cutting portion and a second cutting portion. The first cutting portion is composed of the first region, the second cutting edge portion, the third cutting edge portion, the first connecting cutting edge portion, and the second connecting cutting edge portion. The second cutting portion is composed of the second region and the fourth cutting edge portion connected to the second region.

7. A machining method, which is a machining method using the cutting insert according to claim 1 or 2, wherein, In the drawing process of machining a workpiece using the second cutting edge portion, the transverse rake angle of the second cutting edge portion is -20° or more and 10° or less.

8. A machining method, which is a machining method using the cutting insert according to claim 1 or 2, wherein, In the extrusion process, the transverse cutting edge angle of the first cutting edge portion is 30° or more and less than 70°, and in the drawing process, the transverse cutting edge angle of the second cutting edge portion is 70° or more and less than 89°.

Images