Cutting tool and method for manufacturing machined product

Abstract

There is a need for a holder having a high holding stability. A holder according to the present invention has a rod shape that extends along a reference axis, and comprises a first member and a second member, wherein: the first member includes a first end surface, a second end surface, a first upper surface, a first lower surface, a first lateral surface, a protruding portion, and a pocket; the second member includes a third end surface and a hole portion; the second end surface includes a first projecting portion; the first projecting portion includes a first tip end surface and a first outside surface; the third end surface includes a first recessed portion; the first recessed portion includes a first bottom surface and a first inside surface; the first outside surface includes a first outer region with a convex curved surface shape that projects out toward the first inside surface; and the first inside surface includes a first inner region facing the first outer region.

Description

[Technical Field]

[0001] The present disclosure relates to a holder, a cutting tool, and a method for manufacturing a machined product, and more particularly to a holder having two members, a cutting tool, and a method for manufacturing a machined product. [Background technology]

[0002] Known examples of holders for cutting tools used when cutting a workpiece include the holder described in Patent Document 1. The holder for the cutting tool described in Patent Document 1 is a holder made up of two members: a first component and a second component. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-516600 Summary of the Invention

[0004] A holder according to one embodiment of the present disclosure has a rod shape extending from a first end to a second end along a reference axis, and includes a first member located near the first end and a second member located closer to the second end than the first member. The first member has a first end face located near the first end, a second end face located near the second end, a first upper face located between the first end face and the second end face, a first lower face located opposite the first upper face, a first lateral face located between the first upper face and the first lower face, a protrusion extending from the second end face toward the second end, and a pocket located near the first end and opening across the first end face, the first upper face, and the first lateral face. The second member has a third end face located near the first end and facing the second end face, and a hole into which the protrusion is inserted. The second end face has a first protrusion extending toward the second end. The first protrusion has a first tip surface facing the second end and a first outer surface connected to the first tip surface, and the third end surface has a first recess recessed toward the second end. The first recess has a first bottom surface facing the first tip surface and a first inner surface facing the first outer surface. The first outer surface has a first outer region of a convex curved surface shape facing the first lower surface and protruding toward the first inner surface. The first inner surface has a first inner region abutting the first outer region. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 2 is a top view showing a holder according to an embodiment. [Figure 2] 2 is a perspective view of the holder shown in FIG. 1 as viewed from the A1 direction. [Figure 3] 3 is a perspective view of a state in which the first member and the second member shown in FIG. 2 are disassembled. FIG. [Figure 4] 4 is a perspective view of the first member, the second member, etc. shown in FIG. 3 as viewed from the A2 direction. [Figure 5] FIG. 4 is a plan view of the first member as viewed from the second end side. [Figure 6] FIG. 4 is a plan view of the second member as viewed from the first end side. [Figure 7]6 is a plan view of the first member as seen from the A3 direction shown in FIG. 5. [Figure 8] 7 is an enlarged view of the first end side of the second member when viewed from the A3 direction shown in FIG. 6. [Figure 9] 6 is a plan view of the first member as seen from the A4 direction shown in FIG. 5. [Figure 10] 7 is an enlarged view of the first end side of the second member when viewed from the A4 direction shown in FIG. 6. FIG. [Figure 11] 7 is an enlarged view of the cross section XX shown in FIG. 1, corresponding to the region B shown in FIGS. 5 and 6. FIG. [Figure 12] 7 is an enlarged view of the cross section XX shown in FIG. 1, corresponding to the region C shown in FIGS. 5 and 6. FIG. [Figure 13] FIG. [Figure 14] 6 is a plan perspective view of the first member and the second member before the fixing tool is inserted, as viewed from the A3 direction shown in FIG. 5. FIG. [Figure 15] 6 is a plan perspective view of the first member and the second member before the fixing device is inserted, as viewed from the A4 direction shown in FIG. 5. FIG. [Figure 16] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. [Figure 17] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. [Figure 18] FIG. 2 is a schematic explanatory view showing one step of a method for manufacturing a machined product according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] When a holder is made up of a plurality of members, it is required to improve the stability of the connections between these members.

[0007] According to the present disclosure, the holder has high holding stability.

[0008] The holder 1 of the embodiment will be described in detail below with reference to the drawings. However, for the sake of convenience, the drawings referred to below show only the main components necessary for explaining each embodiment in a simplified form. Therefore, the holder 1 of the present disclosure may include any components not shown in the drawings referred to. Furthermore, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the components and the dimensional ratios of each component.

[0009] As shown in FIGS. 1 to 4, the holder 1 of the present disclosure may be rod-shaped and extend from a first end 1a to a second end 1b along a reference axis O1. The reference axis O1 is an axis passing through the center of the holder 1. Hereinafter, for convenience of explanation, the first end 1a will be referred to as the front end 1a, and the second end 1b will be referred to as the rear end 1b. The holder 1 may have a first member 3 located closer to the front end 1a, and a second member 5 located closer to the rear end 1b than the first member 3. In a non-limiting example shown in FIGS. 1 to 4, the first member 3 may include the front end 1a, and the second member 5 may include the rear end 1b.

[0010] 1 is a plan view of the holder 1 from above, FIG. 2 is an oblique view of the holder 1 as viewed from the A1 direction shown in FIG. 1, FIG. 3 is an oblique view showing the first member 3 shown in FIG. 2 separated from the second member 5, and FIG. 4 is an oblique view of the holder 1 shown in FIG. 3 as viewed from the A2 direction, showing the first member, second member, and fixing device disassembled.

[0011] 3 and 4, the first member 3 may have a first end face 7 located on the front end 1a side, a second end face 9 located on the rear end 1b side, a first upper face 11 located between the first end face 7 and the second end face 9, a first lower face 13 located on the opposite side of the first upper face 11, a first lateral face 15 adjacent to the first upper face 11, a protrusion 17 extending from the second end face 9 toward the rear end 1b side, and a pocket 19 located on the front end 1a side and opening in the first end face 7, the first upper face 11, and the first lateral face 15. In an example shown in FIG. 4, the first member 3 may have a second lateral face 21 located on the opposite side of the first lateral face 15.

[0012] The first end face 7, the first upper face 11, the first lower face 13, the first lateral face 15, and the second lateral face 21 may be flat. The protrusion 17 may be cylindrical and extend along the central axis N3. Here, the cylindrical shape does not necessarily have to be a strict cylinder, and may have holes as shown in FIG. 4.

[0013] 3 and 4, the second member 5 may have a third end face 23 located on the side of the tip end 1a and facing the second end face 9, and a hole 25 into which the protrusion 17 is inserted. The hole 25 extends along the central axis N4. The protrusion 17 is inserted into the hole 25, thereby positioning the first member 3 relative to the second member 5. Note that, to make it easier to insert the protrusion 17 into the hole 25, the inner diameter of the hole 25 may be slightly larger than the outer diameter of the protrusion 17, i.e., a slight "play" may be provided between the hole 25 and the protrusion 17.

[0014] In addition, in the example shown in Figure 4, the second member 5 may have a second upper surface 27 located next to the third end surface 23, a second lower surface 29 located opposite the second upper surface 27, a third horizontal surface 31 located between the second upper surface 27 and the second lower surface 29, a fourth horizontal surface 33 located opposite the third horizontal surface 31, and a fourth end surface 34 located opposite the third end surface 23.

[0015] 3 and 4, the second upper surface 27, the second lower surface 29, the third lateral surface 31, the fourth lateral surface 33, and the fourth end surface 34 may each be flat. In this case, in the example shown in FIGS. 3 and 4, the second upper surface 27 may be parallel to the second lower surface 29, and the third lateral surface 31 may be parallel to the fourth lateral surface 33. In this case, in the example shown in FIG. 1, an imaginary line passing through the center of the fourth end surface 34 and parallel to the second upper surface 27, the second lower surface 29, the third lateral surface 31, and the fourth lateral surface 33 may be the reference axis O1.

[0016] 1 to 4, the directions in which the second upper surface 27, the second lower surface 29, the third lateral surface 31, and the fourth lateral surface 33 face may be the same as the directions in which the first upper surface 11, the first lower surface 13, the first lateral surface 15, and the second lateral surface 21 face, respectively. For ease of explanation, the direction in which the first upper surface 11 faces will be referred to as the upper side, the direction in which the first lower surface 13 faces will be referred to as the lower side, the direction in which the first lateral surface 15 faces will be referred to as the foreside, and the direction in which the second lateral surface 21 faces will be referred to as the backside.

[0017] As shown in Figures 4, 5, 7, and 9, the second end surface 9 may have a first protrusion 35 protruding toward the rear end 1b. The first protrusion 35 may have a first tip surface 37 facing the rear end 1b and a first outer surface 39 connected to the first tip surface 37. In the example shown in Figure 7, the first tip surface 37 may have a flat shape, and the first outer surface 39 may be located closer to the front end 1a than the first tip surface 37. Note that Figure 5 is a plan view of the first member 3 seen from the rear end 1b side, Figure 7 is a plan view of the first member 3 seen from the front side, and Figure 9 is a plan view of the first member 3 seen from the back side.

[0018] As shown in Figures 3, 6, 8, and 10, the third end surface 23 may have a first recess 41 recessed toward the rear end 1b. The first recess 41 may have a first bottom surface 43 facing the first front end surface 37 and a first inner surface 45 facing the first outer surface 39. The first bottom surface 43 may have a flat shape and face toward the front end 1a, and the first inner surface 45 may be located closer to the front end 1a than the first bottom surface 43. Note that Figure 6 is a plan view of the second member 5 as seen from the side of the front end 1a, Figure 8 is a plan view of the second member 5 as seen from the front side, and Figure 10 is a plan view of the second member 5 as seen from the back side.

[0019] 11 and 12 are cross-sectional views of the holder 1 taken along line XX in FIG. 1 etc. The XX cross section is a cross section passing through the center of the first protrusion 35 in the direction in which the reference axis O1 extends and perpendicular to the reference axis O1. FIG. 11 is an enlarged view corresponding to region B shown in FIGS. 5 and 6. FIG. 12 is an enlarged view corresponding to region C shown in FIGS. 5 and 6.

[0020] The first outer surface 39 may have a first outer region 47 that faces the first lower surface 13 and has a convex curved shape that protrudes toward the first inner surface 45. Here, the convex curved shape may be a convex curved shape that protrudes toward the first inner surface 45 in a cross section perpendicular to the reference axis O1, as shown in FIG. 5 . In the example shown in FIG. 5 , the first outer region 47 may be connected to the first lateral surface 15.

[0021] In the example shown in FIG. 11, the entire surface of the first outer surface 39 facing downward may be configured from a single first outer region 47 having a convex curved shape.

[0022] The first inner surface 45 may have a first inner region 61 facing the first outer region 47. In an example shown in Fig. 8, the first inner region 61 may face upward. In an example shown in Fig. 11, the first outer region 47 may abut against the first inner region 61.

[0023] As shown in Fig. 4, the holder 1 of the present disclosure may have a fixture 49 that fixes the first member 3 to the second member 5. In an example shown in Fig. 13, the fixture 49 may have a shaft portion 51 extending along the fixture axis O2, a head portion 53 that is fixed, and a tapered portion 55 located between the shaft portion 51 and the head portion 53. In the example shown in Fig. 13, the tapered portion 55 may have a diameter that gradually increases from the shaft portion 51 to the head portion 53.

[0024] 14 and 15, the protrusion 17 may have a first hole 57 into which the fastener 49 is inserted, and the second member 5 may penetrate from the fourth lateral surface 33 to the hole 25 and may have a second hole 59 into which the fastener 49 is inserted. FIGS. 14 and 15 are views showing the state of the holder 1, with the protrusion 17 of the first member 3 inserted into the hole 25 of the second member 5, and before the fastener 49 is inserted. FIG. 14 is a planar perspective view of the first member 3 and the second member 5 seen from the front side, and FIG. 15 is a planar perspective view of the first member 3 and the second member 5 seen from the back side.

[0025] In the holder 1 of the present disclosure, the second hole 59 located on the rear side may be larger than the head 53 of the fixing device 49, and the head 53 may be larger than the first hole 57. Furthermore, since the fixing device 49 is inserted from the rear side, the efficiency of the work of attaching the first member 3 to the second member 5 is improved. This is also true when the fixing device 49 is inserted from the front side.

[0026] In the holder 1 of the present disclosure, the first member 3 rotates around the central axis N3 and the first outer region 47 is pressed against the first inner surface 45, thereby stably holding the first member 3 to the second member 5. The mechanism for this rotation is as follows.

[0027] First, the fastener 49 is inserted into the second hole 59 and the first hole 57 from the rear side, causing the tapered portion 55 of the fastener 49 to abut against the upper portion of the first hole 57. Furthermore, as the fastener 49 is tightened, the tapered portion 55 presses the upper portion of the first hole 57 from the rear side toward the front side, and as shown in FIG. 5, when the first member 3 is viewed from the rear end 1b toward the front end 1a, the first member 3 rotates slightly in the counterclockwise direction Y1 around the central axis N3.

[0028] The rotation presses the first outer region 47 against the first inner surface 45 located below it, thereby stably holding the first outer region 47. As a result, even if a large cutting load is applied to the first member 3 during cutting, misalignment between the first member 3 and the second member 5 is suppressed, allowing for stable cutting. When the fixing tool 49 is tightly tightened, the first outer region 47 may move slightly in the Y2 direction shown in FIG. 11 due to play between the hole 25 and the protrusion 17. If the first outer region 47 has a convex curved surface shape, the first member 3 is stably held by the second member 5 even if the first outer region 47 moves slightly.

[0029] Note that the above mechanism is merely an example and is not limited to the above mechanism. For example, the fastener 49 may be inserted from the front side toward the rear side, in which case the tapered portion 55 may come into contact with a lower portion of the first hole 57, causing the first member 3 to rotate counterclockwise around the central axis N3.

[0030] Furthermore, in the holder 1 of the present disclosure, the fixing device 49 is a screw, and therefore the first member 3 is fixed to the second member 5 by tightening the fixing device 49 at the same time as the above-mentioned insertion, but the mechanism may also be such that after the fixing device 49 is inserted, the first member 3 is fixed to the second member 5 by a fixing member other than the fixing device 49.

[0031] 5, the first protrusion 35 is connected to the first upper surface 11. In this case, the width W1 of the first protrusion 35 in the up-down direction shown in FIG. 5 can be made larger.

[0032] 5, the first convex portion 35 is located on the side of the first upper surface 11 on the second end surface 9. Here, the first convex portion 35 being located on the side of the first upper surface 11 means that the distance from the center of the first convex portion 35 to the first upper surface 11 on the second end surface 9 is shorter than the distance from the center of the first convex portion 35 to the first lower surface 13. In such a case, as shown in FIG. 6, the width W2 in the vertical direction of the second member 5 that receives the cutting load from the first convex portion 35 is ensured, so that the second member 5 can more stably receive the cutting load applied to the first member 3.

[0033] The first inner region 61 may have a planar shape. In the example shown in FIG. 1 , the entire upward-facing surface of the first inner surface 45 is the first inner region 61. The first inner region 61 may also approach the second upper surface 27 as it approaches the third lateral surface 31. In the above case, the first outer region 47 becomes more likely to move in the Y2 direction, and the first member 3 is more likely to be stably held by the second member 5. In the example shown in FIG. 6 , the first inner region 61 is connected to the third lateral surface 31.

[0034] 11 , the first outer region 47 may contact the first inner region 61 at a first contact point P1. As shown in FIG. 11 , in a direction parallel to the first upper surface 11, a distance W3 from the first contact point P1 to an end S1 of the first outer region 47 closer to the first horizontal surface 15 may be smaller than a distance W4 from the first contact point P1 to an end S2 of the first outer region 47 farther from the first horizontal surface 15. Note that when the first outer region 47 is in surface contact with the first inner region 61 and the first contact point P1 cannot be identified at a single point, the midpoint of the contact portion may be defined as the first contact point P1.

[0035] When the cutting insert 103 is attached to the pocket 19 of the holder 1 of the present disclosure, the cutting edge 107 of the cutting insert 103 is located on the side of the first lateral surface 15. Therefore, when the holder 1 has the above-described configuration, the cutting load can be stably received in the portion of the first outer region 47 closer to the first lateral surface 15, where the cutting load is likely to be applied.

[0036] 5, in a direction parallel to the first upper surface 11, the first outer region 47 may be located between the protrusion 17 and the first lateral surface 15. In such a case, the cutting load can be stably received by the portion of the second end surface 9 closer to the first lateral surface 15, which is more likely to receive the cutting load.

[0037] 5 and 12, the first outer surface 39 may have a second outer region 63 facing the opposite side to the first horizontal surface 15. In other words, the second outer region 63 faces the second horizontal surface 21. The second outer region 63 may also have a planar shape. In the example shown in FIGS. 5 and 12, the entire surface of the first outer surface 39 facing the back side may be the second outer region 63.

[0038] 6 and 12, the first inner surface 45 may have a second inner region 65 facing the second outer region 63. In the example shown in FIGS. 6 and 12, the second inner region 65 faces the third lateral surface 31. The second inner region 65 may have a planar shape. In the example shown in FIGS. 6 and 12, the entire surface of the first inner surface 45 facing the front side may be the second inner region 65.

[0039] 12, the second outer region 63 may be in contact with the second inner region 65. In the example shown in FIG. 12, the second outer region 63 may be in surface contact with the second inner region 65. Here, surface contact does not require the entire second outer region 63 to be in contact with the entire second inner region 65; it is sufficient that one-fifth or more of one region is in contact with the other region. When the second outer region 63 is in contact with the second inner region 65, the second outer region 63 may be spaced apart from the second inner region 65 as it moves from the contact point toward the first upper surface 11.

[0040] Here, when the fixing device 49 is inserted into the second hole 59 and the first hole 57, the first outer region 47 moves in the Y2 direction shown in Fig. 5, so that the entire first protrusion 35 moves toward the rear surface and the second outer region 63 is pressed against the second inner region 65. As a result, when a cutting load is applied to the first member 3 in the rear surface direction, the second member 5 can stably receive the load.

[0041] 5, the first protrusion 35 is connected to the first lateral surface 15. In this case, the width W5 of the first protrusion 35 can be made larger.

[0042] In the example shown in Fig. 5, the first convex portion 35 is located on the side of the first lateral surface 15 on the second end surface 9. Here, the fact that the first convex portion 35 is located on the side of the first lateral surface 15 means that the center of the first convex portion 35 is located on the side of the first lateral surface 15 on the second end surface 9. In such a case, as shown in Figs. 5 and 6, the width W6 of the second member 5 that receives the cutting load from the first convex portion 35 in the direction parallel to the first upper surface 11 is ensured, and the second member 5 can stably receive the cutting load applied to the first member 3.

[0043] 14 and 15, when the central axis of the first hole 57 is defined as the first central axis N1 and the central axis of the second hole 59 is defined as the second central axis N2, the second central axis N2 is located closer to the rear end 1b than the first central axis N1. In this case, when the fixing device 49 is inserted, the first member 3 moves closer to the rear end 1b. As a result, the second end face 9 is pressed against the third end face 23, which tends to improve the accuracy of the cutting edge position of the cutting insert attached to the holder 1.

[0044] 14 and 15, the second central axis N2 may be located above the first central axis N1. When the second central axis N2 is located above the first central axis N1, the tapered portion 55 comes into contact with the upper portion of the first hole 57 when the fastener 49 is inserted, allowing the first member 3 to rotate slightly, making it easier for the first member 3 to be stably held by the second member 5.

[0045] The positional relationship between the first center axis N1 and the second center axis N2 indicates the positional relationship immediately before the protrusion 17 of the first member 3 is inserted into the hole 25 of the second member 5 and the fixing device 49 is inserted, as shown in Figures 14 and 15.

[0046] In the example shown in Figure 5, when the first member 3 is viewed from the rear end 1b side, the central axis N3 of the protrusion 17 is spaced apart from the reference axis O1. In the example shown in Figure 6, when the second member 5 is viewed from the front end 1a side, the central axis N4 of the hole 25 is spaced apart from the reference axis O1. In such a case, since the protrusion 17 is not positioned at the center of the first member 3, it is possible to prevent mistakes such as attaching the first member 3 upside down to the second member 5 when attaching the first member 3 to the second member 5.

[0047] In the example shown in FIGS. 5 and 7 , the second end surface 9 may have a connecting portion 67 connected to the first outer surface 39 and located closer to the tip 1 a than the first outer surface 39. In the example shown in FIG. 7 , the connecting portion 67 has a concave curved surface shape. In the example shown in FIGS. 5 and 7 , the second end surface 9 has a flat surface 69 connected to the connecting portion 67 and located closer to the tip 1 a than the connecting portion 67. In the example shown in FIG. 7 , the flat surface 69 faces the rear end 1 b. When the second end surface 9 has the connecting portion 67 with a concave curved surface shape, chipping is less likely to occur in the portion of the third end surface 23 facing the connecting portion 67 when the first member 3 is attached to the second member 5.

[0048] The second end surface 9 may have a second protrusion 71 that protrudes toward the rear end 1b. In the example shown in Fig. 5, the second protrusion 71 may be located on the lower back side of the second end surface 9. In the example shown in Fig. 5, the second protrusion 71 may have a second tip surface 73 that faces the rear end 1b and a second outer surface 75 that is connected to the second tip surface 73. In the example shown in Fig. 9, the second outer surface 75 may have a third outer region 83 that faces upward.

[0049] The third end surface 23 may have a second recess 77 recessed toward the rear end 1b. In the example shown in FIG. 6, the second recess 77 may have a second bottom surface 79 facing the second front end surface 73 and a second inner surface 81 facing the second outer surface 75. In the example shown in FIG. 10, the second bottom surface 79 faces the front end 1a. In the example shown in FIG. 6, the second inner surface 81 may have a third inner region 85 facing the third outer region 83. In the example shown in FIG. 10, the third inner region 85 may face downward.

[0050] In the holder 1 of the present disclosure, the second tip surface 73, the second bottom surface 79, the third outer region 83, and the third inner region 85 may be planar. Of the second outer surface 75, a portion of the surface facing upward may be the third outer region 83, or the entire surface facing upward may be the third outer region 83. Also, of the second inner surface 81, a portion of the surface facing downward may be the third inner region 85, or the entire surface facing downward may be the third inner region 85.

[0051] In the holder 1 of the present disclosure, the third outer region 83 is separated from the third inner region 85, but may be in contact with them. In the holder 1 of the present disclosure, the third outer region 83 is separated from the first upper surface 11 as it approaches the second lateral surface 21. In the example shown in FIG. 6 , the length L1 of the first inner region 61 is smaller than the length L2 of the third inner region 85 in the direction parallel to the first upper surface 11. In such a case, the configuration of the second end surface 9 becomes asymmetric, which can prevent errors in attaching the first member 3 to the second member 5.

[0052] In the example shown in FIG. 5 , the second outer surface 75 has a fourth outer region 87 facing the front side, and the second inner surface 81 may have a fourth inner region 89 facing the fourth outer region 87, and the fourth inner region 89 may face the rear side. In the example shown in FIG. 5 , the fourth outer region 87 and the fourth inner region 89 may be planar. Of the second outer surface 75, a portion of the surface facing the front side may be the fourth outer region 87, or the entire surface facing the front side may be the fourth outer region 87. Of the second inner surface 81, a portion of the surface facing the rear side may be the fourth inner region 89, or the entire surface facing the rear side may be the fourth inner region 89. In the holder 1 of the present disclosure, the fourth outer region 87 may be separated from the fourth inner region 89.

[0053] The sizes of the first member 3 and the second member 5 are not particularly limited. For example, the length from the front end 1a to the second end face 9 may be 10 to 100 mm. The length from the first upper face 11 to the first lower face 13 may be 5 to 50 mm. The length from the third end face 23 to the rear end 1b may be 50 to 200 mm. The length from the second upper face 27 to the second lower face 29 may be 5 to 50 mm.

[0054] Furthermore, the length of the first convex portion in the vertical direction may be 2 to 18 mm. The length of the first convex portion in a direction parallel to the first upper surface may be 2 to 18 mm. The length of the second convex portion in the vertical direction may be 2 to 18 mm. The length of the second convex portion in a direction parallel to the first upper surface may be 2 to 18 mm.

[0055] The holder 1 can be made of a material such as steel, cast iron, or cemented carbide.

[0056] <Cutting tools> Next, a cutting tool according to an embodiment of the present disclosure will be described with reference to the drawings.

[0057] 16 to 18, a cutting tool 101 according to the present disclosure has a rod shape extending from a front end 1a to a rear end 1b. The cutting tool 101 includes a holder 1 and a cutting insert 103 positioned in a pocket 19 in the holder 1. The cutting insert 103 may have a through hole 105.

[0058] 16 to 18 may include an insert screw 109 that can be used to fix the cutting insert 103 in the pocket 19. In the example shown in FIG. 1, the pocket 19 may have a pocket hole 111 that extends from the first upper surface 11 side toward the first lower surface 13 side. The cutting insert 103 can be fixed to the pocket 19 by inserting the insert screw 109 into the through hole 105 in the cutting insert 103 and the pocket hole 111 in the pocket 19.

[0059] Examples of materials for the cutting insert 103 include cemented carbide and cermet. Examples of cemented carbide compositions include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co is produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering the mixture. WC-TiC-Co is produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co is produced by adding tantalum carbide (TaC) to WC-TiC-Co.

[0060] Cermets are sintered composite materials in which a ceramic component is combined with a metal. Specifically, cermets include materials containing titanium compounds such as titanium carbide (TiC) and titanium nitride (TiN) as their main components.

[0061] The surface of the cutting insert 103 may be coated with a coating by chemical vapor deposition (CVD) or physical vapor deposition (PVD), and the coating may have a composition such as titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al2O3).

[0062] <Method of manufacturing machined products> Next, a method for manufacturing a machined product according to an embodiment of the present disclosure will be described with reference to the drawings.

[0063] The machined product is produced by cutting a workpiece. The manufacturing method of the machined product according to the present disclosure includes the following steps: (1) rotating the workpiece 201; (2) contacting the cutting tool 101 with the rotating workpiece 201; (3) separating the cutting tool 101 from the workpiece 201; It is equipped with:

[0064] More specifically, first, as shown in Fig. 16, workpiece 201 is rotated around rotation axis O3, and cutting tool 101 is brought relatively close to workpiece 201. Next, as shown in Fig. 17, cutting edge 107 of cutting tool 101 is brought into contact with rotating workpiece 201 to cut workpiece 201. Then, as shown in Fig. 18, cutting tool 101 is moved relatively away from workpiece 201.

[0065] In this embodiment, the rotation axis O3 is fixed and the cutting tool 101 is moved in the Y3 direction while the workpiece 201 is being rotated, thereby bringing the cutting tool 101 closer to the workpiece 201. In addition, in FIG. 17, the cutting edge 107 of the insert is brought into contact with the rotating workpiece 201 to cut the workpiece 201. In addition, in FIG. 18, the cutting tool 101 is moved in the Y4 direction while the workpiece 201 is being rotated, thereby moving the cutting tool 101 away from the workpiece 201.

[0066] In the cutting process in the manufacturing method of the embodiment, the cutting tool 101 is moved in each step to bring the cutting tool 101 into contact with the workpiece 201 or to move the cutting tool 101 away from the workpiece 201, but of course, this is not limited to this form.

[0067] For example, in step (1), the workpiece 201 may be brought closer to the cutting tool 101. Similarly, in step (3), the workpiece 201 may be moved away from the cutting tool 101. To continue the cutting process, the workpiece 201 may be kept rotating, and the step of bringing the cutting edge 107 of the insert into contact with different locations on the workpiece 201 may be repeated.

[0068] The material of the workpiece 201 may be, for example, carbon steel, alloy steel, stainless steel, cast iron, or non-ferrous metal.

[0069] In one embodiment, (1) a rod-shaped holder extending from a first end to a second end along a reference axis includes a first member located on the first end side and a second member located closer to the second end than the first member, the first member including a first end face located on the first end side, a second end face located on the second end side, a first upper face located between the first end face and the second end face, a first lower face located opposite to the first upper face, a first lateral face located between the first upper face and the first lower face, a protrusion extending from the second end face toward the second end, and a pocket located on the first end side and opening across the first end face, the first upper face, and the first lateral face; the third end surface may have a third end surface located on a side of the first end surface facing the second end surface and facing the second end surface, and a hole into which the protrusion is inserted, the second end surface having a first convex portion extending toward the second end side, the first convex portion having a first tip surface facing the second end side and a first outer surface connected to the first tip surface, the third end surface having a first recess recessed toward the second end, the first recess having a first bottom surface facing the first tip surface and a first inner surface facing the first outer surface, the first outer surface facing the first lower surface and having a first outer region having a convex curved surface shape protruding toward the first inner surface, and the first inner surface having a first inner region abutting the first outer region.

[0070] (2) In the holder of (1) above, the first protrusion may be located on the second end face, closer to the first upper face.

[0071] (3) In the holder of (1) or (2) above, the first interior area may have a planar shape.

[0072] (4) In any of the holders (1) to (3) above, when the contact point between the first outer region and the first inner region is defined as a first contact point, the distance from the first contact point to the end of the first outer region closer to the first lateral surface in a direction parallel to the first upper surface may be smaller than the distance from the first contact point to the end of the first outer region farther from the first lateral surface.

[0073] (5) In the holder according to any one of (1) to (4) above, the first outer area may be located between the protrusion and the first lateral surface in a direction parallel to the first upper surface.

[0074] (6) In any of the holders (1) to (5) above, the first outer surface may further have a second outer area having a planar shape facing the opposite side of the first horizontal surface, and the first inner surface may further have a second inner area having a planar shape facing the second outer area.

[0075] (7) In the holder of (6) above, the second outer region may be in surface contact with the second inner region.

[0076] (8) In any of the holders (1) to (7) above, the holder may further have a fixing device for fixing the first member to the second member, the protrusion portion having a first hole into which the fixing device is inserted, the hole portion having a second hole into which the fixing device is inserted, and the central axis of the second hole being located closer to the second end than the central axis of the first hole and closer to the first upper surface.

[0077] (9) In the holder according to any one of (1) to (8) above, when the first member is viewed from the second end side, the central axis of the protrusion may be spaced apart from the reference axis.

[0078] (10) In any of the holders (1) to (9) above, the second end face may have a first connection portion having a concave curved shape connected to the first outer surface and located closer to the first end than the first outer surface, and a flat surface connected to the first connection portion, located closer to the first end than the first connection portion, and facing the second end.

[0079] (11) In any of the holders (1) to (10) above, the second end surface further has a second convex portion protruding toward the second end, the second convex portion having a second tip surface facing the second end and a second outer surface connected to the second tip surface, the third end surface further having a second recess recessed toward the second end, the second recess having a second tip surface facing the second tip surface and a second inner surface facing the second outer surface, the second outer surface having a third outer region facing the first upper surface and separated from the second inner surface, the second inner surface having the third inner region of a planar shape facing the third outer region, and the length of the second inner region in a direction parallel to the first upper surface is shorter than the length of the third inner region.

[0080] In one embodiment, (12) a cutting tool may have the holder of any one of (1) to (11) above, and a cutting insert positioned in the pocket.

[0081] In one embodiment, (13) a method for manufacturing a machined product may include the steps of rotating a workpiece, bringing any of the cutting tools described above in (13) into contact with the rotating workpiece, and removing the cutting tool from the workpiece.

[0082] The above provides examples of embodiments of the present disclosure, but it goes without saying that the present disclosure is not limited to the above-described embodiments and can be any embodiment as long as it does not deviate from the gist of the present disclosure. [Explanation of symbols]

[0083] 1. Holder 1a...1st end (tip) 1b...Second end (rear end) 3. First member 5. Second member 7...First end surface 9...Second end face 11...1st top surface 13...1st bottom surface 15···First side 17...Protrusion 19. Pocket 21 Second side 23...Third end face 25...Hole 27...2nd top surface 29...2nd bottom surface 31 Third side 33···4th side 34...4th end face 35···First convex part 37...1st tip surface 39...1st outer surface 41... First recess 43...1st bottom surface 45...1st inner surface 47...1st outer area 49...fixture 51 Shaft 53...Head 55 Tapered section 57···1st hole 59...2nd hole 61...1st inner area 63...Second outer area 65...Second inner area 67 Connection 69...Flat surface 71 Second convex part 73...2nd tip surface 75...Second outer surface 77···Second recess 79...2nd bottom surface 81...Second inner surface 83...Third outer area 85...Third inner area 87...4th outer area 89...4th inner area 101·Cutting tools 103··Cutting insert 105··Through hole 107··Cutting edge 109··Insert screw 111··Pocket hole 201...Work material O1 Reference axis O2...fixture shaft O3 Rotation axis Y1: Rotation direction Y2~Y4: Direction of movement W1~W6...Width (interval) P1: First contact S1, S2...ends N1~N4...center axis L1, L2...length

Claims

1. a first member having a rod shape extending from a first end to a second end along a reference axis, the first member being located on the side of the first end, and a second member being located on the side of the second end relative to the first member; The first member is a first end surface located on the first end side; a second end surface located on the second end side; a first upper surface located between the first end surface and the second end surface; a first lower surface located opposite the first upper surface; a first lateral surface located between the first upper surface and the first lower surface; a protrusion extending from the second end surface toward the second end; a pocket located on the first end side and opening across the first end surface, the first top surface, and the first lateral surface; The second member is a third end surface located on the first end side and facing the second end surface; a hole into which the protrusion is inserted, The second end surface is a first protrusion extending toward the second end, The first protrusion is a first tip surface facing the second end; a first outer surface connected to the first tip surface, The third end surface is a first recess recessed toward the second end; The first recess is a first bottom surface facing the first tip surface; a first inner surface opposite to the first outer surface, the first outer surface faces the first lower surface and has a first outer region having a convex curved surface shape that protrudes toward the first inner surface, The first inner surface has a first inner region that abuts the first outer region.

2. The holder according to claim 1 , wherein the first protrusion is located on the second end surface on a side closer to the first upper surface.

3. The holder of claim 1 , wherein the first interior region is planar.

4. When a contact point between the first outer region and the first inner region is defined as a first contact point, 2. The holder of claim 1, wherein in a direction parallel to the first upper surface, the distance from the first contact point to the end of the first outer region closer to the first lateral surface is smaller than the distance from the first contact point to the end of the first outer region farther from the first lateral surface.

5. In a direction parallel to the first upper surface, The holder of claim 1 , wherein the first outer region is located between the protrusion and the first lateral surface.

6. The first outer surface is a second outer area having a planar shape facing away from the first lateral surface; The first inner surface is The holder according to claim 1 , further comprising a second inner area having a planar shape facing the second outer area.

7. The holder according to claim 6 , wherein the second outer region is in surface contact with the second inner region.

8. a fastener for fastening the first member to the second member; the protrusion has a first hole into which the fastener is inserted; the hole portion has a second hole into which the fastener is inserted, The holder according to claim 1 , wherein a central axis of the second hole is located closer to the second end than a central axis of the first hole and closer to the first upper surface.

9. The holder according to claim 1 , wherein when the first member is viewed from the second end side, a central axis of the protrusion is spaced apart from the reference axis.

10. The second end surface is a first connection portion having a concave curved surface shape connected to the first outer surface and positioned closer to the first end than the first outer surface; The holder according to claim 1 , further comprising a flat surface connected to the first connection portion, positioned closer to the first end than the first connection portion, and facing the second end.

11. The second end surface is a second protrusion protruding toward the second end, The second protrusion is a second tip surface facing the second end; a second outer surface connected to the second tip surface; The third end surface is a second recess recessed toward the second end, The second recess a second tip surface opposite to the second tip surface; a second inner surface opposite to the second outer surface, the second outer surface has a third outer region facing the first upper surface and spaced apart from the second inner surface; the second inner surface has a third inner region having a planar shape facing the third outer region, In a direction parallel to the first upper surface, The holder of claim 6 , wherein the length of the second interior region is less than the length of the third interior region.

12. A holder according to any one of claims 1 to 11; a cutting insert located in the pocket.

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

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