Holder

Abstract

The holder is made of cemented carbide and has a front end surface, a rear end surface, a first side surface, a second side surface, a pressing surface, a first support surface, and a second support surface. The pressing surface presses the upper surface of the cutting insert. The first support surface supports the back surface of the cutting insert. The second support surface supports the bottom surface of the cutting insert. The holder is provided with a slit penetrating between the first side surface and the second side surface. The slit is formed by an upper end surface connected to the pressing surface and a lower end surface connected to each of the first support surface and the upper end surface. When viewed in a direction from the first side surface to the second side surface, the distance between the upper end surface and the upper side in a direction perpendicular to the bottom side increases monotonically from the front end surface to the rear end surface in the range from the first position to the third position.

Description

[Technical field]

[0001] The present disclosure relates to a holder. [Background technology]

[0002] WO 2015 / 029009 (Patent Document 1) discloses a turning cutting tool having a cutting insert and a cutting tool holder blade. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2015 / 029009 Summary of the Invention

[0004] The holder according to the present disclosure is a holder for holding a cutting insert, made of cemented carbide, and includes a front end surface, a rear end surface, a first side surface, a second side surface, a pressing surface, a first support surface, and a second support surface. The rear end surface is opposite the front end surface. The first side surface is continuous with the front end surface. The second side surface is continuous with the front end surface and opposite the first side surface. The pressing surface presses the upper surface of the cutting insert. The first support surface supports the back surface of the cutting insert. The second support surface supports the bottom surface of the cutting insert. The holder is provided with a slit penetrating between the first side surface and the second side surface. The slit is formed by an upper end surface continuous with the pressing surface and a lower end surface continuous with each of the first support surface and the upper end surface. When viewed in a direction from the first side surface to the second side surface, the holder has a linear bottom side and an upper side opposite the bottom side, and the distance between the upper end face and the upper side in a direction perpendicular to the bottom side increases monotonically from the front end face to the rear end face within a specified range. If, in the direction from the front end face to the rear end face, the rear end of the slit is defined as a first position, the front end of the slit is defined as a second position, and a position from the first position to a third position that is 80% of the distance between the first position and the second position is defined as a third position, the specified range is the range from the first position to the third position. [Brief description of the drawings]

[0005] [Figure 1] FIG. 1 is a schematic side view showing the configuration of a holder according to the first embodiment. [Diagram 2] FIG. 2 is a first perspective schematic view showing the configuration of the holder according to the first embodiment. [Diagram 3] FIG. 3 is a second perspective schematic view showing the configuration of the holder according to the first embodiment. [Figure 4] FIG. 4 is an enlarged schematic view of region IV in FIG. [Diagram 5] FIG. 5 is a schematic diagram showing the relationship between the position of the holder in the X direction and T / T0 according to the first embodiment. [Figure 6] FIG. 6 is a schematic side view showing the configuration of the holder according to the second embodiment. [Figure 7] FIG. 7 is an enlarged schematic view of region VII in FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view showing the configuration of a holder according to the third embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view showing the configuration of a holder according to the fourth embodiment. [Figure 10] FIG. 10 is a schematic side view showing a state in which the cutting insert is attached to the holder. [Figure 11] FIG. 11 is a schematic side view showing the configuration of a holder according to a comparative example. [Figure 12] FIG. 12 is a schematic diagram showing the relationship between the position in the X direction and the distance between the upper end surface of the slit and the upper side of the holder. [Figure 13] FIG. 13 is a schematic diagram showing the relationship between the position in the X direction and the stress of the holder. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure (also referred to as the present embodiment) will be listed and described.

[0007] (1) The holder according to the present disclosure is a holder for holding a cutting insert, made of cemented carbide, and includes a front end surface, a rear end surface, a first side surface, a second side surface, a pressing surface, a first support surface, and a second support surface. The rear end surface is opposite the front end surface. The first side surface is continuous with the front end surface. The second side surface is continuous with the front end surface and opposite the first side surface. The pressing surface presses the top surface of the cutting insert. The first support surface supports the back surface of the cutting insert. The second support surface supports the bottom surface of the cutting insert. The holder is provided with a slit penetrating between the first side surface and the second side surface. The slit is formed by an upper end surface continuous with the pressing surface and a lower end surface continuous with each of the first support surface and the upper end surface. When viewed in a direction from the first side surface to the second side surface, the holder has a linear bottom side and an upper side opposite the bottom side, and the distance between the upper end face and the upper side in a direction perpendicular to the bottom side increases monotonically from the front end face to the rear end face within a specified range. If, in the direction from the front end face to the rear end face, the rear end of the slit is defined as a first position, the front end of the slit is defined as a second position, and a position from the first position to a third position that is 80% of the distance between the first position and the second position is defined as a third position, the specified range is the range from the first position to the third position.

[0008] (2) According to the holder according to (1) above, when viewed in a direction from the first side surface to the second side surface, at least a part of the upper end surface may have a first arc region having a first radius of curvature and a second arc region continuing to the first arc region and having a second radius of curvature. In a direction from the front end surface to the rear end surface, the first arc region may be located between the front end surface and the second arc region. The second radius of curvature may be smaller than the first radius of curvature.

[0009] (3) According to the holder according to (1) or (2) above, when the direction parallel to the base is defined as the X direction, the direction perpendicular to the base as viewed from the first side surface toward the second side surface is defined as the Y direction, and the position where the distance in the X direction starts to increase monotonically is defined as the origin, the position in the X direction is defined as X, and the slope of the tangent to the function where the distance is divided by the distance at the position where the distance starts to increase monotonically is defined as Y, is 0 mm. -1 Larger than 3.5mm -1X is in mm and Y is dimensionless.

[0010] (4) According to any one of the holders according to (1) to (3) above, the holder may have a portion in which the distance between the top end face and the bottom side in a direction perpendicular to the bottom side increases monotonically from the front end face to the rear end face. The maximum distance between the top end face and the bottom side may be 29 mm or more and 35 mm or less.

[0011] (5) According to any one of the holders according to (1) to (3) above, the holder may have a portion in which the distance between the top end face and the bottom side in a direction perpendicular to the bottom side decreases monotonically from the front end face to the rear end face. The maximum distance between the top end face and the bottom side may be 20 mm or more and less than 29 mm.

[0012] (6) According to the holder according to (1) above, when viewed in a direction from the first side surface to the second side surface, at least a part of the upper end surface may have a first arc region having a first radius of curvature, and a second arc region that is continuous with the first arc region and has a second radius of curvature. In a direction from the front end surface to the rear end surface, the first arc region may be located between the front end surface and the second arc region. The second radius of curvature may be smaller than the first radius of curvature. When a direction parallel to the base is defined as an X direction, a direction perpendicular to the base when viewed in a direction from the first side surface to the second side surface is defined as a Y direction, and a position in the X direction where the distance begins to increase monotonically is taken as the origin, the position in the X direction is defined as X, and the value Y obtained by dividing the distance by the distance at the position where the distance begins to increase monotonically is taken as the slope of a tangent to a function that is 0 mm -1 Larger than 3.5mm -1 X is in mm and Y is dimensionless.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Specific examples of the embodiments of the present disclosure will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

[0014] (First embodiment) FIG. 1 is a schematic side view showing the configuration of a holder 100 according to the first embodiment. As shown in FIG. 1, the holder 100 according to the first embodiment has a front end face 13, a rear end face 14, a first side face 11, a second side face 12 (see FIG. 2), a top face 30, and a bottom face 40. The front end face 13 is a face facing a workpiece. The front end face 13 is, for example, planar. The rear end face 14 is opposite to the front end face 13. The rear end face 14 is, for example, planar. The rear end face 14 is substantially parallel to the front end face 13.

[0015] The first side surface 11 is continuous with each of the front end surface 13 and the rear end surface 14. The first side surface 11 is, for example, planar. The second side surface 12 is opposite to the first side surface 11. The second side surface 12 is, for example, planar. The second side surface 12 is continuous with each of the front end surface 13 and the rear end surface 14. The second side surface 12 is substantially parallel to the first side surface 11. The holder 100 is made of a cemented carbide. The cemented carbide includes tungsten carbide (WC) and cobalt (Co). The composition of the tungsten carbide is, for example, 84.8% by mass. The composition of the cobalt is, for example, 15.2±0.3% by mass. The grain size of the tungsten carbide is, for example, 4.0 μm.

[0016] FIG. 2 is a first perspective schematic diagram showing the configuration of the holder 100 according to the first embodiment. The bottom surface 40 has a first bottom surface region 41, a second bottom surface region 42, and a bottom edge 43. The first bottom surface region 41 is continuous with each of the first side surface 11 and the front end surface 13. The first bottom surface region 41 is inclined with respect to each of the first side surface 11 and the front end surface 13. The second bottom surface region 42 is continuous with each of the second side surface 12 and the front end surface 13. The second bottom surface region 42 is inclined with respect to each of the second side surface 12 and the front end surface 13. The boundary between the first bottom surface region 41 and the second bottom surface region 42 forms the bottom edge 43.

[0017] As shown in FIG. 1, the direction parallel to the bottom side 43 when viewed from the first side surface 11 toward the second side surface 12 is the X direction. The direction perpendicular to the bottom side 43 when viewed from the first side surface 11 toward the second side surface 12 is the Y direction. The direction from the first side surface 11 toward the second side surface 12 is the Z direction. The Z direction is perpendicular to both the X direction and the Y direction. The X direction is substantially the same as the direction from the front end surface 13 toward the rear end surface 14. The Y direction is substantially the same as the direction from the bottom surface 40 toward the top surface 30. When viewed in the Z direction, the bottom side 43 of the holder 100 is straight.

[0018] 3 is a second perspective schematic diagram showing the configuration of the holder 100 according to the first embodiment. The upper surface 30 has a first upper surface region 31, a second upper surface region 32, a third upper surface region 33, a fourth upper surface region 34, and a fifth upper surface region 35. The first upper surface region 31 is continuous with the first side surface 11. The first upper surface region 31 is inclined with respect to the first side surface 11. The second upper surface region 32 is continuous with the second side surface 12. The second upper surface region 32 is inclined with respect to the second side surface 12.

[0019] The third upper surface region 33 is continuous with each of the first upper surface region 31 and the second upper surface region 32. In the X direction, the third upper surface region 33 is located between each of the first upper surface region 31 and the second upper surface region 32 and the front end surface 13. The third upper surface region 33 is, for example, planar. The fifth upper surface region 35 is continuous with the third upper surface region 33. In the X direction, the fifth upper surface region 35 is located between the third upper surface region 33 and the front end surface 13. The fourth upper surface region 34 is continuous with the fifth upper surface region 35. In the X direction, the fourth upper surface region 34 is located between the fifth upper surface region 35 and the front end surface 13. The fourth upper surface region 34 is, for example, planar.

[0020] As shown in Figures 2 and 3, the holder 100 has a pressing surface 60, a first support surface 90, a second support surface 50, and a front surface 93. The first support surface 90 supports the back surface of the cutting insert. The second support surface 50 supports the bottom surface of the cutting insert. The pressing surface 60 presses the top surface of the cutting insert. The front surface 93 is continuous with each of the pressing surface 60 and the fourth top surface region 34. The front surface 93 faces the workpiece.

[0021] As shown in FIG. 2, the pressing surface 60 has a first pressing surface portion 61, a second pressing surface portion 62, and a third pressing surface portion 63. The first pressing surface portion 61 is continuous with the first side surface 11. The second pressing surface portion 62 is continuous with the second side surface 12. The third pressing surface portion 63 is continuous with each of the first pressing surface portion 61 and the second pressing surface portion 62. In the Z direction, the third pressing surface portion 63 is located between the first pressing surface portion 61 and the second pressing surface portion 62. In the Y direction, each of the first pressing surface portion 61 and the second pressing surface portion 62 is located between the third pressing surface portion 63 and the fourth upper surface region 34.

[0022] As shown in FIG. 3, the second support surface 50 has a first bottom support portion 51, a second bottom support portion 52, and a third bottom support portion 53. The first bottom support portion 51 is connected to the first side surface 11. The second bottom support portion 52 is connected to the second side surface 12. The third bottom support portion 53 is connected to each of the first bottom support portion 51 and the second bottom support portion 52. In the Z direction, the third bottom support portion 53 is located between the first bottom support portion 51 and the second bottom support portion 52. In the Y direction, each of the first bottom support portion 51 and the second bottom support portion 52 is located between the third bottom support portion 53 and the bottom surface 40.

[0023] The holder 100 is plate-shaped. The maximum thickness of the holder 100 in the X direction is greater than the maximum thickness of the holder 100 in the Y direction. The maximum thickness of the holder 100 in the X direction may be at least two times and at most 20 times the maximum thickness of the holder 100 in the Y direction. The maximum thickness of the holder 100 in the Y direction is greater than the maximum thickness of the holder 100 in the Z direction. The maximum thickness of the holder 100 in the Y direction may be at least two times and at most 20 times the maximum thickness of the holder 100 in the Z direction.

[0024] 1, the holder 100 is provided with a through hole 82 and a slit 81. Each of the through hole 82 and the slit 81 penetrates between the first side surface 11 and the second side surface 12. In the Y direction, the through hole 82 is provided between the second support surface 50 and the bottom surface 40. In the Z direction, the through hole 82 is annular. In the Y direction, the slit 81 is provided between the second support surface 50 and the top surface 30. In the Z direction, the slit 81 is not annular, but is partially open.

[0025] Fig. 4 is an enlarged schematic diagram of region IV in Fig. 1. As shown in Fig. 4, the slit 81 is formed by an upper end surface 71 and a lower end surface 72. The upper end surface 71 is continuous with the pressing surface 60. The lower end surface 72 is continuous with the first support surface 90. In the direction from the front end surface 13 to the rear end surface 14, the rear end of the slit 81 is a first position A1, and the front end of the slit 81 is a second position A2. The upper end surface 71 of the slit 81 is continuous with the pressing surface 60 at the first position A1. The lower end surface 72 is continuous with the upper end surface 71 at the second position A2.

[0026] The holder 100 has an upper side 37. The upper side 37 is opposite to the bottom side 43. The upper side 37 is formed by, for example, the third upper surface region 33, the fourth upper surface region 34, the fifth upper surface region 35, and the boundary line 36 between the first upper surface region 31 and the second upper surface region 32. When viewed in the Z direction, the distance T between the upper end surface 71 and the upper side 37 in a direction perpendicular to the bottom side 43 increases monotonically from the front end surface 13 to the rear end surface 14 in a specified range. In the direction from the front end surface 13 to the rear end surface 14, the distance between the first position A1 and the second position A2 is set to a first length L1. In the direction from the front end surface 13 to the rear end surface 14, if a position from the first position A1 to a third position A3 that is 80% of the first distance is set to a third position A3, the specified range is the range from the first position A1 to the third position A3. In the direction from the front end face 13 to the rear end face 14, the length of the specified range is defined as a second length L2.

[0027] As shown in FIG. 4, when viewed in a direction from the first side surface 11 toward the second side surface 12, at least a portion of the upper end surface 71 may have a first arc region 1, a second arc region 2, and a third arc region 3. The first arc region 1 has a first radius of curvature. The second arc region 2 has a second radius of curvature. The third arc region 3 has a third radius of curvature. The second radius of curvature is smaller than the first radius of curvature. The third radius of curvature is smaller than the second radius of curvature.

[0028] The first radius of curvature is, for example, 16 mm. The first radius of curvature may be greater than or equal to 12 mm and less than or equal to 18 mm. The second radius of curvature is, for example, 9 mm. The first radius of curvature may be greater than or equal to 11 mm and less than or equal to 7 mm. The third radius of curvature is, for example, 2.6 mm. The first radius of curvature may be greater than or equal to 1 mm and less than or equal to 4 mm.

[0029] The second arc-shaped region 2 is continuous with the first arc-shaped region 1. In the direction from the front end face 13 to the rear end face 14, the first arc-shaped region 1 is located between the front end face 13 and the second arc-shaped region 2. The third arc-shaped region 3 is continuous with the second arc-shaped region 2. In the direction from the front end face 13 to the rear end face 14, the second arc-shaped region 2 is located between the first arc-shaped region 1 and the third arc-shaped region 3.

[0030] As shown in FIG. 4, when viewed in a direction from the first side surface 11 toward the second side surface 12, at least a portion of the upper end surface 71 may have a fifth arc region 5 and a sixth arc region 6. The fifth arc region 5 has a fifth radius of curvature. The sixth arc region 6 has a sixth radius of curvature. The fifth radius of curvature may be smaller than the sixth radius of curvature. The first radius of curvature may be smaller than the sixth radius of curvature.

[0031] The fifth radius of curvature is, for example, 2 mm. The fifth radius of curvature may be 1 mm or more and 3 mm or less. The sixth radius of curvature is, for example, 11 mm. The sixth radius of curvature may be 9 mm or more and 13 mm or less.

[0032] The fifth arc-shaped region 5 is continuous with both the pressing surface 60 and the sixth arc-shaped region 6. In the direction from the front end face 13 toward the rear end face 14, the fifth arc-shaped region 5 is located between the pressing surface 60 and the sixth arc-shaped region 6. The sixth arc-shaped region 6 is continuous with both the fifth arc-shaped region 5 and the first arc-shaped region 1. In the direction from the front end face 13 toward the rear end face 14, the sixth arc-shaped region 6 is located between the fifth arc-shaped region 5 and the first arc-shaped region 1.

[0033] 4, when viewed in a direction from the first side surface 11 toward the second side surface 12, at least a portion of the lower end surface 72 may have a fourth arc region 4, a seventh arc region 7, an eighth arc region 8, and a ninth linear region 9. The fourth arc region 4 has a fourth radius of curvature. The seventh arc region 7 has a seventh radius of curvature. The eighth arc region 8 has an eighth radius of curvature.

[0034] The fourth radius of curvature may be smaller than the third radius of curvature. The seventh radius of curvature may be larger than the fourth radius of curvature. The eighth radius of curvature may be smaller than the seventh radius of curvature.

[0035] The fourth radius of curvature is, for example, 1.1 mm. The fourth radius of curvature may be 0.5 mm or more and 2 mm or less. The seventh radius of curvature is, for example, 5 mm. The seventh radius of curvature may be 3 mm or more and 7 mm or less. The eighth radius of curvature is, for example, 2.2 mm. The eighth radius of curvature may be 1 mm or more and 4 mm or less.

[0036] The fourth arc region 4 is continuous with both the third arc region 3 and the seventh arc region 7. The fourth arc region 4 is located between the third arc region 3 and the seventh arc region 7. The seventh arc region 7 is continuous with both the eighth arc region 8 and the fourth arc region 4. In the direction from the front end face 13 to the rear end face 14, the seventh arc region 7 is located between the eighth arc region 8 and the fourth arc region 4. The eighth arc region 8 is continuous with both the ninth linear region 9 and the seventh arc region 7. In the direction from the front end face 13 to the rear end face 14, the eighth arc region 8 is located between the ninth linear region 9 and the seventh arc region 7.

[0037] The arc regions are specified in the following manner. First, an image of the slit 81 viewed in the direction from the first side surface 11 toward the second side surface 12 is acquired by an image dimension measuring device. As the image dimension measuring device, for example, an IM series image dimension measuring device manufactured by Keyence Corporation is used. Based on the acquired image, each arc region on the upper end surface 71 and the lower end surface 72 of the slit 81 is specified.

[0038] As shown in FIG. 4, when viewed in a direction from the first side surface 11 toward the second side surface 12, the ninth linear region 9 extends, for example, along the X direction. The first support surface 90 extends, for example, along the Y direction. The ninth linear region 9 is continuous with the first support surface 90. The holder 100 has a recess region 91. In the recess region 91, the boundary between the bottom surface and the back surface of the cutting insert is disposed. The recess region 91 is continuous with each of the second support surface 50 and the first support surface 90. When viewed in a direction from the first side surface 11 toward the second side surface 12, the recess region 91 is arc-shaped.

[0039] 5 is a schematic diagram showing the relationship between the position in the X direction of the holder 100 according to the first embodiment and T / T0. The value on the Y axis is T divided by T0. Here, T is the distance between the upper end surface 71 of the slit 81 and the upper side 37 of the holder 100 in the Y direction. T0 is the distance between the upper end surface 71 and the upper side 37 of the holder 100 at the position where the distance between the upper end surface 71 and the upper side 37 of the holder 100 starts to increase monotonically. The unit of X is mm. The unit of Y is dimensionless.

[0040] The X direction is parallel to the base 43. The Y direction is perpendicular to the base 43 when viewed from the first side surface 11 toward the second side surface 12. In the X direction, the position where T starts to increase monotonically is the origin. As shown in FIG. 5, the slope of a tangent C of a function B where the position in the X direction is X and the value of T / T0 is Y is 0 mm. -1 Larger than 3.5mm -1 The slope of tangent C is 0.1 mm. -1 It can be larger than 0.2 mm -1 The inclination of the tangent line C may be greater than 3 mm. -1 It may be smaller than 2 mm -1 It may be smaller.

[0041] 1, the maximum distance between the top side 37 and the bottom side 43 of the holder 100 is defined as a first distance H1. The first distance H1 is, for example, not less than 20 mm and less than 29 mm. The first distance H1 may be not less than 22 mm, or may be not less than 24 mm. The first distance H1 may be not more than 28 mm, or may be not more than 26 mm.

[0042] In a direction perpendicular to the bottom side 43 of the holder 100, the distance between the top end surface 71 of the slit 81 and the bottom side 43 of the holder 100 is set to a second distance H2. The top end surface 71 of the slit 81 has a first portion 71a and a second portion 71b. The first portion 71a is a portion where the second distance H2 monotonically increases from the front end surface 13 toward the rear end surface 14. The second portion 71b is a portion where the second distance H2 monotonically decreases from the front end surface 13 toward the rear end surface 14.

[0043] In the X direction, the first portion 71a is located between the pressing surface 60 and the second portion 71b. The second portion 71b is continuous with the first position A1. The length of the first portion 71a in the X direction may be 20% or less of the first length L1, or 10% or less of the first length L1. The length of the second portion 71b in the X direction may be 30% or more of the first length L1, or 50% or more of the first length L1, or 70% or more of the first length L1. In the X direction, the length of the second portion 71b is longer than the length of the first portion 71a.

[0044] Second embodiment Next, the configuration of the holder 100 according to the second embodiment will be described. The holder 100 according to the second embodiment differs from the holder 100 according to the first embodiment mainly in that the maximum distance between the upper side 37 and the bottom side 43 is longer, and other configurations are substantially the same as those of the holder 100 according to the first embodiment. Below, the configurations different from the holder 100 according to the first embodiment will be mainly described.

[0045] Fig. 6 is a schematic side view showing the configuration of the holder 100 according to the second embodiment. Fig. 7 is an enlarged schematic view of an area VII in Fig. 6.

[0046] 6, the first distance H1 is, for example, 29 mm or more and 35 mm or less. The first distance H1 may be 30 mm or more, or 31 mm or more. The first distance H1 may be 34 mm or less, or 33 mm or less.

[0047] The upper end surface 71 of the slit 81 has a first portion 71a and a second portion 71b. In the X direction, the length of the first portion 71a is longer than the length of the second portion 71b. The length of the first portion 71a in the X direction may be 30% or more of the first length L1, or may be 40% or more of the first length L1. The length of the second portion 71b in the X direction may be 40% or less of the first length L1, or may be 30% or less of the first length L1.

[0048] Third embodiment Next, the configuration of the holder 100 according to the third embodiment will be described. The holder 100 according to the third embodiment differs from the holder 100 according to the first embodiment mainly in that an oil supply hole for supplying cutting oil is provided, and other configurations are substantially the same as those of the holder 100 according to the first embodiment. Below, the configurations different from the holder 100 according to the first embodiment will be mainly described.

[0049] Fig. 8 is a schematic cross-sectional view showing the configuration of a holder 100 according to a third embodiment. The cross section shown in Fig. 8 is parallel to each of the X and Y directions and intersects with the middle position of the holder in the Z direction.

[0050] As shown in FIG. 8, the holder 100 according to the third embodiment is formed with a first flow passage 21, a second flow passage 22, a third flow passage 23, a fourth flow passage 24, a connecting hole 29, a first oil supply hole 25, and a second oil supply hole 26. The first oil supply hole 25 is located in the fourth upper surface region 34. The first oil supply hole 25 is an opening of the first flow passage 21 in the fourth upper surface region 34. The first flow passage 21 extends toward the third flow passage 23. The first flow passage 21 is connected to the third flow passage 23. The third flow passage 23 extends from the third upper surface region 33 toward the connecting hole 29. The third flow passage 23 is connected to the connecting hole 29.

[0051] The second oil supply hole 26 is located in the front end face 13. The second oil supply hole 26 is an opening of the second flow passage 22 in the front end face 13. The second flow passage 22 extends toward the fourth flow passage 24. The second flow passage 22 is connected to the fourth flow passage 24. The fourth flow passage 24 extends from the front end face 13 toward the connecting hole 29. The fourth flow passage 24 is connected to the connecting hole 29.

[0052] The holder 100 has a first plug 27 and a second plug 28. The first plug 27 closes the opening of the third flow passage 23 in the third upper surface region 33. The second plug 28 closes the opening of the fourth flow passage 24 in the front end surface 13.

[0053] The connection hole 29 is connected to a tool block (not shown). Cutting oil is supplied from the tool block through the connection hole 29 to the third flow path 23 and the fourth flow path 24. The cutting oil is discharged from the first oil supply hole 25 to the outside of the holder 100 via the first flow path 21 and the third flow path 23, and is discharged from the second oil supply hole 26 to the outside of the holder 100 via the second flow path 22 and the fourth flow path 24.

[0054] The cross-sectional shape of each of the first flow path 21, the second flow path 22, the third flow path 23, and the fourth flow path 24 may be a circle, an ellipse, or a polygon. As shown in Fig. 8, when viewed in the Z direction, each of the first flow path 21, the second flow path 22, the third flow path 23, and the fourth flow path 24 may be linear. When viewed in the Z direction, each of the first flow path 21, the second flow path 22, the third flow path 23, and the fourth flow path 24 may be curved. When viewed in the Z direction, the slit 81 may be located between the first flow path 21 and the fourth flow path 24.

[0055] (Fourth embodiment) Next, the configuration of the holder 100 according to the fourth embodiment will be described. The holder 100 according to the fourth embodiment differs from the holder 100 according to the second embodiment mainly in that an oil supply hole for supplying cutting oil is provided, and other configurations are substantially the same as the holder 100 according to the first embodiment. The holder 100 according to the fourth embodiment differs from the holder 100 according to the third embodiment mainly in that the maximum distance between the upper side 37 and the bottom side 43 is long, and other configurations are substantially the same as the holder 100 according to the third embodiment. Below, the configurations different from the holder 100 according to the second embodiment and the holder 100 according to the third embodiment will be mainly described.

[0056] Fig. 9 is a schematic cross-sectional view showing the configuration of a holder 100 according to a fourth embodiment. The cross section shown in Fig. 9 is parallel to each of the X direction and the Y direction, and intersects with the middle position of the holder in the Z direction.

[0057] 9, the holder 100 according to the fourth embodiment is formed with a first flow path 21, a second flow path 22, a third flow path 23, a fourth flow path 24, a connecting hole 29, a first oil supply hole 25, and a second oil supply hole 26. Each of the third flow path 23 and the fourth flow path 24 intersects with an intermediate imaginary plane D located at an intermediate position between the front end face 13 and the rear end face 14 in the X direction. The intermediate imaginary plane D is parallel to the Y direction. In the X direction, the connecting hole 29 is located between the intermediate imaginary plane D and the rear end face 14.

[0058] FIG. 10 is a side schematic diagram showing a state in which the cutting insert is attached to the holder 100. As shown in FIG. 10, the back surface of the cutting insert 70 is supported by the first support surface 90. The bottom surface of the cutting insert 70 is supported by the second support surface 50. The upper surface of the cutting insert 70 is pressed by the pressing surface 60. The cutting insert 70 is clamped to the holder 100 by being sandwiched between the pressing surface 60 and the second support surface 50 with the back surface in contact with the first support surface 90. With the cutting insert 70 clamped to the holder 100, the cutting edge 75 of the cutting insert 70 is pressed against the rotating workpiece, so that the workpiece is turned. Specifically, the cutting insert 70 moves in a direction substantially perpendicular to the rotation direction of the workpiece, so that the workpiece is cut off.

[0059] Next, the effects of the holder 100 according to this embodiment will be described. According to the holder 100 of this embodiment, the distance between the upper end surface 71 of the slit 81 and the upper side 37 of the holder 100 in the direction perpendicular to the bottom side 43 monotonically increases from the front end surface 13 toward the rear end surface 14 within a specified range. In the direction from the front end surface 13 toward the rear end surface 14, if the rear end of the slit 81 is the first position A1, the front end of the slit 81 is the second position A2, and the position from the first position A1 to the third position A3, which is 80% of the distance between the first position A1 and the second position A2, is the specified range is the range from the first position A1 to the third position A3. This makes it possible to suppress the concentration of stress at a specific point of the holder 100 when the cutting insert 70 is attached to the holder 100. Therefore, the cutting insert 70 can be clamped without being damaged by the holder 100.

[0060] Moreover, the holder 100 according to this embodiment has a first support surface 90 that supports the back surface of the cutting insert 70. Therefore, the positional accuracy of the cutting edge of the cutting insert 70 can be improved.

[0061] According to the holder 100 of this embodiment, when viewed in a direction from the first side surface 11 toward the second side surface 12, at least a part of the upper end surface 71 may have a first arc region 1 having a first radius of curvature and a second arc region 2 continuing to the first arc region 1 and having a second radius of curvature. In a direction from the front end surface 13 toward the rear end surface 14, the first arc region 1 may be located between the front end surface 13 and the second arc region 2. The second radius of curvature may be smaller than the first radius of curvature. This makes it possible to make the stress distribution in the holder 100 more uniform. Therefore, it is possible to further suppress the concentration of stress at a specific location of the holder 100.

[0062] According to the holder 100 of this embodiment, there may be a portion in which the distance between the upper end surface 71 of the slit 81 and the bottom side 43 in the direction perpendicular to the bottom side 43 increases monotonically from the front end surface 13 toward the rear end surface 14. This makes it possible to increase the distance between the lower end surface 72 of the slit 81 and the bottom side 43. As a result, the rigidity of the holder 100 can be increased.

[0063] According to the holder 100 of this embodiment, the distance between the upper end surface 71 of the slit 81 and the bottom side 43 in the direction perpendicular to the bottom side 43 may be monotonically decreased from the front end surface 13 to the rear end surface 14. This allows the distance between the upper end surface 71 of the slit 81 and the upper side 37 of the holder 100 to be increased even if the maximum distance between the upper side 37 and the bottom side 43 is small. Therefore, even if the maximum distance between the upper side 37 and the bottom side 43 is small, the holder 100 can clamp the cutting insert 70 without being damaged. EXAMPLES

[0064] Next, examples will be described. Sample 1 is the holder 100 according to the examples. Specifically, sample 1 is the holder 100 according to the first embodiment (see FIG. 1). Sample 2 is the holder 100 according to a comparative example.

[0065] Fig. 11 is a schematic side view showing the configuration of a holder 100 according to a comparative example. Fig. 12 is a schematic view showing the relationship between the position in the X direction and the distance between the upper end surface 71 of the slit 81 and the upper side 37 of the holder 100.

[0066] 11 and 12, in holder 100 of sample 2, the distance between upper end face 71 and upper side 37 in the direction perpendicular to bottom side 43 monotonically increases from front end face 13 to rear end face 14 in the range from first position A1 to third position A3. On the other hand, in holder 100 of sample 1, the distance between upper end face 71 and upper side 37 in the direction perpendicular to bottom side 43 does not monotonically increase from front end face 13 to rear end face 14 in the range from first position A1 to third position A3.

[0067] FIG. 13 is a schematic diagram showing the relationship between the position in the X direction and the stress of the holder 100. The stress was calculated by a simulation using the finite element method. The Young's modulus and Poisson's ratio of the material forming the holder 100 were set to 620 GPa and 0.21, respectively. In order to reproduce the state in which the cutting insert 70 was clamped to the holder 100, the front end of the pressing surface 60 was forcibly displaced in the Y direction while the bottom side 43 of the holder 100 was restrained so as not to rotate in the X direction, Y direction, and Z direction. The amount of forced displacement was set to 0.2 mm. The stress was set to the maximum principal stress.

[0068] 13, the maximum stress value of the holder 100 according to sample 2 was about 2300 MPa. On the other hand, the maximum stress value of the holder 100 according to sample 1 was about 1700 MPa. From the above results, it was confirmed that the holder 100 according to the example can reduce the maximum stress value compared to the holder 100 according to the comparative example.

[0069] The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims, not by the embodiments described above, and is intended to include the equivalent meanings of the claims and all modifications within the scope of the claims. [Explanation of symbols]

[0070] 1 1st arc region, 2 2nd arc region, 3 3rd arc region, 4 4th arc region, 5 5th arc region, 6 6th arc region, 7 7th arc region, 8 8th arc region, 9 9th straight region, 11 1st side, 12 2nd side, 13 front end face, 14 rear end face, 21 1st flow path, 22 2nd flow path, 23 3rd flow path, 24 4th flow path, 25 1st oil supply hole, 26 2nd oil supply hole, 27 1st plug, 28 2nd plug, 29 connection hole, 30 top face, 31 1st top face region, 32 2nd top face region, 33 3rd top face region, 34 4th top face region, 35 5th top face region, 36 boundary line, 37 top edge, 40 bottom face, 41 1st bottom face region, 42 2nd bottom face region, 43 bottom edge, 50 2nd support face, 51 First bottom support portion, 52 second bottom support portion, 53 third bottom support portion, 60 pressing surface, 61 first pressing surface portion, 62 second pressing surface portion, 63 third pressing surface portion, 70 cutting insert, 71 upper end surface, 71a first portion, 71b second portion, 72 lower end surface, 75 cutting edge, 81 slit, 82 through hole, 90 first support surface, 91 recess area, 93 front portion, 100 holder, A1 first position, A2 second position, A3 third position, B function, C tangent, D intermediate virtual surface, H1 first distance, H2 second distance, L1 first length, L2 second length, T distance.

Claims

1. A holder for holding a cutting insert, The holder is made of a cemented carbide alloy, and A front end surface, a rear end surface opposite the front end surface; A first side surface connected to the front end surface; a second side surface connected to the front end surface and opposite the first side surface; A pressing surface that presses an upper surface of the cutting insert; A first support surface that supports a back surface of the cutting insert; and a second support surface that supports a bottom surface of the cutting insert. The holder has a slit penetrating between the first side surface and the second side surface, the slit is formed by an upper end surface connected to the pressing surface and a lower end surface connected to each of the first support surface and the upper end surface, When viewed in a direction from the first side surface to the second side surface, The holder has a linear bottom side and a top side opposite the bottom side, a distance between the upper end surface and the upper side in a direction perpendicular to the base side monotonically increases from the front end surface to the rear end surface within a specified range; in a direction from the front end surface toward the rear end surface, a rear end of the slit is defined as a first position, a front end of the upper end surface is defined as a second position, and a position from the first position to a third position that is 80% of the distance between the first position and the second position is defined as a third position, the specified range being a range from the first position to the third position, A holder, wherein the first support surface is located between the second position and the third position in a direction from the front end surface to the rear end surface.

2. When viewed in a direction from the first side surface to the second side surface, at least a portion of the upper end surface has a first arcuate region having a first radius of curvature and a second arcuate region connected to the first arcuate region and having a second radius of curvature, the first arc-shaped region is located between the front end surface and the second arc-shaped region in a direction from the front end surface to the rear end surface, The holder of claim 1 , wherein the second radius of curvature is smaller than the first radius of curvature.

3. A direction parallel to the base is defined as an X direction, A direction perpendicular to the base when viewed in a direction from the first side surface to the second side surface is defined as a Y direction; In the X direction, when the position where the distance starts to increase monotonically is taken as the origin, The slope of the tangent to a function where the position in the X direction is X and the value obtained by dividing the distance by the distance at the position where the distance starts to increase monotonically is Y, is 0 mm. -1 Larger and 3.5 mm -1 Smaller than 3. A holder according to claim 1 or claim 2, wherein X is in mm and Y is dimensionless.

4. the holder has a portion in which a distance between the top end surface and the bottom side in a direction perpendicular to the bottom side increases monotonically from the front end surface toward the rear end surface, 3. The holder according to claim 1, wherein a maximum distance between the top side and the bottom side is 29 mm or more and 35 mm or less.

5. the holder has a portion in which a distance between the top end surface and the bottom side in a direction perpendicular to the bottom side monotonically decreases from the front end surface to the rear end surface, The holder according to claim 1 or 2, wherein a maximum distance between the top side and the bottom side is equal to or greater than 20 mm and less than 29 mm.

6. When viewed in a direction from the first side surface to the second side surface, at least a portion of the upper end surface has a first arcuate region having a first radius of curvature and a second arcuate region connected to the first arcuate region and having a second radius of curvature, the first arc-shaped region is located between the front end surface and the second arc-shaped region in a direction from the front end surface to the rear end surface, the second radius of curvature is smaller than the first radius of curvature; A direction parallel to the base is defined as an X direction, A direction perpendicular to the base when viewed in a direction from the first side surface to the second side surface is defined as a Y direction; In the X direction, when the position where the distance starts to increase monotonically is taken as the origin, The slope of the tangent to a function where the position in the X direction is X and the value obtained by dividing the distance by the distance at the position where the distance starts to increase monotonically is Y, is 0 mm. -1 Larger and 3.5 mm -1 Smaller than 2. The holder of claim 1, wherein X is in mm and Y is dimensionless.

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