Holder, cutting tool, and method for manufacturing cut workpiece

Abstract

The present invention achieves, inter alia, a holder where replacement work of a first member is facilitated while having a high level of holding stability. The holder is such that a protruding part has a first side, a second side, a first projection, and a second projection, and a hole has a third side and a fourth side. The first projection abuts the third side, the first side is separated from the third side, the second projection abuts the fourth side, and the second side is separated from the fourth side.

Description

Holder, cutting tool, and method for manufacturing machined product

[0001] The present disclosure relates to a holder, a cutting tool, and a method for manufacturing a machined product.

[0002] 2. Description of the Related Art A holder disclosed in Patent Document 1, for example, is known as a holder for a cutting tool used when cutting a workpiece such as a metal member.

[0003] The holder described in Patent Document 1 has a head located on the tip side and a shank located on the rear end side. The head has a pin protruding toward the shank, and the shank has an insertion hole into which the pin is inserted. In a cross section perpendicular to the central axis, the pin and the insertion hole are shown as simple polygonal shapes. In this cross section, the entire outer circumferential surface of the pin and the entire inner circumferential surface of the insertion hole abut against each other, thereby fixing the head to the shank.

[0004] International Publication No. 2019 / 034620

[0005] A holder according to one aspect of the present disclosure has a shape extending from a front end to a rear end along a reference axis and includes a first member and a second member located closer to the rear end than the first member. The first member has a first front end surface located closer to the front end, a rear end surface located closer to the rear end, an upper surface located between the first front end surface and the rear end surface, a lower surface located opposite the upper surface, a first side surface located between the first front end surface and the rear end surface and adjacent to the upper surface, a second side surface located opposite the first side surface, a pocket opening from the first front end surface to the first side surface, the upper surface, and the first side surface, into which a cutting insert can be attached, and a protrusion protruding from the rear end surface toward the second member. The second member has a second front end surface located closer to the front end and a hole opening in the second front end surface and into which the protrusion is inserted.

[0006] In a cross section perpendicular to the reference axis, the protrusion has a first corner located closer to the bottom surface and the second side surface than the reference axis, a first side extending from the first corner toward the top surface, a first convex portion protruding outward from the first side, a second side extending from the first corner toward the first side surface, and a second convex portion protruding outward from the second side, and the hole has a second corner opposite the first corner, a third side opposite the first side, and a fourth side opposite the second side. The first convex portion abuts against the third side and the first side is separated from the third side, and the second convex portion abuts against the fourth side and the second side is separated from the fourth side.

[0007] 1 is a perspective view showing a schematic configuration of a cutting tool according to each of the first and second embodiments of the present disclosure; FIG. 2 is a top view showing a schematic configuration of a cutting tool according to each of the first and second embodiments of the present disclosure; FIG. 3 is a side view showing a schematic configuration of a cutting tool according to each of the first and second embodiments of the present disclosure; FIG. 4 is a perspective view showing a schematic configuration of a holder; (a) is a top view showing a schematic configuration of the holder, and (b) is an enlarged perspective view of a portion of the tip side in (a) being enlarged; FIG. 5 is a side view showing a schematic configuration of the holder; FIG. 6 is a first exploded perspective view showing a schematic configuration of the holder; FIG. 7 is a second exploded perspective view showing a schematic configuration of the holder; FIG. 8 is a developed view showing a schematic configuration of a first member; FIG. 9 is a top view showing a schematic configuration of the first member; FIG. 10 is a side view showing a schematic configuration of the first member; FIG. 11 is a rear view showing a schematic configuration of the first member; FIG. 12 is a front view showing a schematic configuration of the second member; FIG. 13 is a top view showing a first step in a method for manufacturing a machined product according to the third embodiment of the present disclosure; FIG. 14 is a top view showing a second step in a method for manufacturing a machined product according to the third embodiment of the present disclosure;

[0008] When the entire outer peripheral surface of the pin abuts the entire inner peripheral surface of the insertion hole in a cross section perpendicular to the central axis, the head can be fixed to the shank. However, in this case, a large load may be required when attaching or detaching the head from the shank. This may result in a time-consuming process, such as replacing the head from the shank, which may hinder improvement of work efficiency.

[0009] A holder according to one aspect of the present disclosure has high holding stability and allows for easy replacement of the first member.

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present disclosure. For convenience of explanation, the same reference numerals are used to designate components having the same functions as those previously described, and the description thereof may not be repeated.

[0011] For the sake of convenience, the figures referred to below show only the main components necessary for explaining each embodiment in a simplified manner. Therefore, for example, the holder 1 may include any components not shown in the figures referred to. The dimensions and dimensional ratios of the components in the figures do not faithfully represent the dimensions and dimensional ratios of the actual components. These points are the same for all of the holder 1, cutting tool 101, and method for manufacturing machined product 301.

[0012] [Embodiment 1] Fig. 1 is a perspective view showing a schematic configuration of a cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 2 is a top view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 3 is a side view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. The cutting tool 101 is used in cutting a workpiece 201 to produce a machined product 301. The cutting tool 101 may have a holder 1 and a cutting insert 2.

[0013] Fig. 4 is a perspective view showing a schematic configuration of the holder 1. Fig. 5(a) is a top view showing a schematic configuration of the holder 1, and Fig. 5(b) is an enlarged perspective view of a part of the tip 3 side in Fig. 5(a). Fig. 6 is a side view showing a schematic configuration of the holder 1. Fig. 7 is a first exploded perspective view showing a schematic configuration of the holder 1. Fig. 8 is a second exploded perspective view showing a schematic configuration of the holder 1.

[0014] The holder 1 may have a shape extending from the front end 3 to the rear end 4 along the reference axis A1. The shape may be a rod shape. In this application, the term "along" is not limited to two members extending parallel to each other, and the two members may extend at an inclination of 5° or less relative to each other. The holder 1 can be used to hold the cutting insert 2. The holder 1 may have a first member 5 and a second member 6. The second member 6 may be located closer to the rear end 4 than the first member 5. The front end 3 and the rear end 4 may be the front end and the rear end of the holder 1, respectively. The first member 5 may also be called a head, and the second member 6 may also be called a shank.

[0015] The first member 5 may have a first front end surface 7, a rear end surface 8, an upper surface 9, a lower surface 10, a first side surface 11, a second side surface 12, a pocket 13, and a protrusion 14. The first front end surface 7 may be located on the side of the front end 3. The rear end surface 8 may be located on the side of the rear end 4. The upper surface 9 may be located between the first front end surface 7 and the rear end surface 8. The lower surface 10 may be located on the side opposite the upper surface 9. The first side surface 11 may be located between the first front end surface 7 and the rear end surface 8. The first side surface 11 may be adjacent to the upper surface 9. The second side surface 12 may be located on the side opposite the first side surface 11. The pocket 13 may be open across the first front end surface 7, the upper surface 9, and the first side surface 11. The pocket 13 may be capable of receiving the cutting insert 2. The protrusion 14 may protrude from the rear end surface 8 toward the second member 6.

[0016] Examples of the shape of the first member 5 include a cylindrical shape and a polygonal prism shape. Examples of the material of the first member 5 include steel, cast iron, and aluminum alloy.

[0017] The second member 6 may have a second tip surface 15 and a hole 16. The second tip surface 15 may be located on the side of the tip 3. The hole 16 may be open at the second tip surface 15. The protrusion 14 may be inserted into the hole 16.

[0018] Examples of the shape of the second member 6 include a cylindrical shape and a polygonal prism shape. Examples of the material of the second member 6 include steel, cast iron, and aluminum alloy. The shape of the rear end face 8 and the shape of the second tip face 15 may correspond to each other, for example, the shape of the rear end face 8 and the shape of the second tip face 15 may be congruent.

[0019] The protrusion 14 may have a through hole 51. The second member 6 may have a through hole 52. With the protrusion 14 inserted into the hole 16, the first member 5 may be attached to the second member 6 by screwing screws 53 through both the through holes 51 and 52.

[0020] Examples of the material of the cutting insert 2 include cemented carbide and cermet.

[0021] Examples of cemented carbide compositions include WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. WC-Co may be produced by adding cobalt (Co) powder to tungsten carbide (WC) and sintering the mixture. WC-TiC-Co may be produced by adding titanium carbide (TiC) to WC-Co. WC-TiC-TaC-Co may be produced by adding tantalum carbide (TaC) to WC-TiC-Co.

[0022] The cermet may be a sintered composite material in which a ceramic component is combined with a metal. Specifically, the cermet may be a cermet containing a titanium compound as a main component. Examples of the cermet containing a titanium compound as a main component include titanium carbide (TiC) and titanium nitride (TiN).

[0023] 1 to 8, a plane S is shown as a reference for a cross section perpendicular to the reference axis A1. The cross section perpendicular to the reference axis A1 is a cross section cut through the plane S itself or a cross section cut through a plane parallel to the plane S.

[0024] Fig. 9 is a development view showing a schematic configuration of the first member 5. Fig. 10 is a top view showing a schematic configuration of the first member 5. Fig. 11 is a side view showing a schematic configuration of the first member 5. Fig. 12 is a rear view showing a schematic configuration of the first member 5. Fig. 13 is a front view showing a schematic configuration of the second member 6.

[0025] In a cross section perpendicular to the reference axis A1, the protrusion 14 may have a first corner 17, a first side 18, a first convex portion 19, a second side 20, and a second convex portion 21. The first corner 17 may be located closer to the lower surface 10 and the second side surface 12 than the reference axis A1. The first side 18 may extend from the first corner 17 toward the upper surface 9. The first convex portion 19 may protrude outward from the protrusion 14 from the first side 18. The second side 20 may extend from the first corner 17 toward the first side surface 11. The second convex portion 21 may protrude outward from the protrusion 14 from the second side 20.

[0026] In a cross section perpendicular to the reference axis A1, the hole 16 may have a second corner 22, a third side 23, and a fourth side 24. The second corner 22 may be opposite the first corner 17. The third side 23 may be opposite the first side 18. The fourth side 24 may be opposite the second side 20.

[0027] In the holder 1, the first protrusion 19 may abut against the third side 23 while the first side 18 is separated from the third side 23, and the second protrusion 21 may abut against the fourth side 24 while the second side 20 is separated from the fourth side 24.

[0028] According to the holder 1, when the first member 5 is attached to the second member 6, gaps are generated between the first side 18 and the third side 23 and between the second side 20 and the fourth side 24. When the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, these gaps serve to cushion the load, reducing the risk of a large load being required. Therefore, it is possible to realize a holder 1 that has high holding stability and allows for easy replacement of the first member 5. For example, the time required for replacement of the first member 5 can be shortened, improving work efficiency.

[0029] In a cross section perpendicular to the reference axis A1, the second corner 22 may be spaced apart from the first corner 17. As a result, when the first member 5 is attached to the second member 6, a gap is generated between the first corner 17 and the second corner 22. When the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, the gap serves to buffer the load, thereby reducing the risk of a large load being required. Furthermore, as a result, when the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, the risk of the first corner 17 being chipped can be reduced.

[0030] In a cross section perpendicular to the reference axis A1, the first convex portion 19 may have a first top surface 25 that is linear and abuts against the third side 23. Furthermore, in a cross section perpendicular to the reference axis A1, the second convex portion 21 may have a second top surface 26 that is linear and abuts against the fourth side 24. As a result, the first convex portion 19 abuts against the third side 23 in a planar manner, and the second convex portion 21 abuts against the fourth side 24 in a planar manner, so that when the first member 5 is attached to the second member 6, the second member 6 can stably hold the first member 5.

[0031] In a cross section perpendicular to the reference axis A1, the first top surface 25 may approach the first side surface 11 as it approaches the upper surface 9. This makes it possible to reduce the risk of the first member 5 rotating when the first member 5 is attached to the second member 6, and also to receive the feed force during cutting by the cutting tool 101.

[0032] In a cross section perpendicular to the reference axis A1, the second top surface 26 may be parallel to the lower surface 10. This allows the second top surface 26 to fully receive the principal component force during cutting by the cutting tool 101.

[0033] In a cross section perpendicular to the reference axis A1, the width W2 of the second top surface 26 may be larger than the width W1 of the first top surface 25. This improves the durability of the second convex portion 21 against a large principal component force during cutting with the cutting tool 101.

[0034] Furthermore, in a cross section perpendicular to the reference axis A1, the width W2 of the second top surface 26 may be smaller than the width W1 of the first top surface 25. With this configuration, the location where the second protrusion 21 holds the object is less likely to shift in response to the principal component force, thereby improving holding stability.

[0035] In a cross section perpendicular to the reference axis A1, the distance D1 between the second convex portion 21 and the first side surface 11 may be smaller than the distance D2 between the second convex portion 21 and the second side surface 12. This allows the second convex portion 21 to be positioned as close as possible to directly below the cutting edge of the cutting insert 2, which corresponds to the tip of the principal component of force during cutting by the cutting tool 101.

[0036] In a cross section perpendicular to the reference axis A1, the distance D3 between the first convex portion 19 and the upper surface 9 may be smaller than the distance D4 between the first convex portion 19 and the lower surface 10. This allows the second convex portion 21 to be positioned as close as possible to the side of the cutting edge of the cutting insert 2, which corresponds to the tip of the feed force during cutting by the cutting tool 101.

[0037] The above may be combined appropriately to improve the balance of the contact between the first convex portion 19 and the third side 23 and the contact between the second convex portion 21 and the fourth side 24. This makes it possible to minimize the load when the first member 5 is attached to the second member 6.

[0038] The protrusion 14 may include a first portion 27. The first portion 27 may have a tapered shape whose outer shape decreases with increasing distance from the rear end face 8. The hole 16 may include a second portion 28. The second portion 28 may have a tapered shape whose outer shape decreases with increasing distance from the second tip face 15. The difference between the outer shape of a bottom portion 29 of the first portion 27 that contacts the rear end face 8 and the outer shape of an end portion 30 of the first portion 27 that is distant from the rear end face 8 may be greater than the height H1 of the first protrusion 19 and the height H2 of the second protrusion 21. This allows the first portion 27 to have a so-called tapered shape without losing the abutting function between the first protrusion 19 and the third side 23 and the abutting function between the second protrusion 21 and the fourth side 24. Therefore, when inserting the protrusion 14 into the hole 16, the first portion 27 can be easily inserted into the second portion 28. This also allows the projection 14 to be more easily inserted into the hole 16 since the insertion of the first portion 27 into the second portion 28 is loose.

[0039] Here, "outer shape" refers to the radius of a circumscribing circle in a cross section perpendicular to the reference axis A1 of the target region. For example, the radius of the circumscribing circle in a cross section perpendicular to the reference axis A1 at the bottom 29 of the first region 27 that is in contact with the rear end surface 8, and the radius of the circumscribing circle in a cross section perpendicular to the reference axis A1 at the end 30 of the first region 27 that is remote from the rear end surface 8 are identified. The difference between the radii of these two circumscribing circles refers to the "difference in outer shape" mentioned above.

[0040] The protrusion 14 may include a first portion 27. The first portion 27 may have a tapered shape whose outer shape decreases with increasing distance from the rear end face 8. The hole 16 may include a second portion 28. The second portion 28 may have a tapered shape whose outer shape decreases with increasing distance from the second tip face 15. The difference between the outer shape of a bottom portion 29 of the first portion 27 that contacts the rear end face 8 and the outer shape of an end portion 30 of the first portion 27 that is distant from the rear end face 8 may be smaller than the height H1 of the first protrusion 19 and the height H2 of the second protrusion 21. This allows the first portion 27 to have a so-called tapered shape without losing the abutting function between the first protrusion 19 and the third side 23 and the abutting function between the second protrusion 21 and the fourth side 24. Therefore, when inserting the protrusion 14 into the hole 16, the first portion 27 can be easily inserted into the second portion 28. This also allows the first part 27 to be tightly inserted into the second part 28, so that the first convex part 19 can be brought into sufficient contact with the third side 23, and the second convex part 21 can be brought into sufficient contact with the fourth side 24.

[0041] In a cross section perpendicular to the reference axis A1, the protruding portion 14 may have a third corner 31, a fifth side 32, and a third convex portion 33. The third corner 31 may be connected to the second side 20. The fifth side 32 may extend from the third corner 31 toward the top surface 9. The third convex portion 33 may protrude outward from the protruding portion 14 from the fifth side 32.

[0042] In a cross section perpendicular to the reference axis A1, the hole 16 may have a fourth corner 34 and a sixth side 35. The fourth corner 34 may be opposite the third corner 31. The sixth side 35 may be opposite the fifth side 32.

[0043] In the holder 1, the third protrusion 33 may abut against the sixth edge 35, and the fifth edge 32 may be spaced apart from the sixth edge 35. As a result, when the first member 5 is attached to the second member 6, a gap is generated between the fifth edge 32 and the sixth edge 35. When the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, the gap serves to buffer the load, thereby reducing the risk of a large load being required. Furthermore, as a result, the triangular abutment between the first protrusion 19, the second protrusion 21, and the third protrusion 33 reduces the risk of the first member 5 rotating when the first member 5 is attached to the second member 6.

[0044] In a cross section perpendicular to the reference axis A1, the fourth corner 34 may be spaced apart from the third corner 31. As a result, when the first member 5 is attached to the second member 6, a gap is generated between the third corner 31 and the fourth corner 34. When the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, the gap serves to buffer the load, thereby reducing the risk of a large load being required. Furthermore, as a result, when the first member 5 is attached to the second member 6 or when the first member 5 is removed from the second member 6, the risk of the third corner 31 being chipped can be reduced.

[0045] In a cross section perpendicular to the reference axis A1, the third convex portion 33 may have a third top surface 36 that is linear and abuts against the sixth side 35. As a result, the third convex portion 33 abuts against the sixth side 35 in a planar manner, so that when the first member 5 is attached to the second member 6, the second member 6 can stably hold the first member 5.

[0046] In a cross section perpendicular to the reference axis A1, the third top surface 36 may approach the second side surface 12 as it approaches the top surface 9. This allows the third top surface 36 to receive reaction forces against the main component force and the feed component force during cutting with the cutting tool 101, thereby reducing so-called chatter vibrations.

[0047] A cross section perpendicular to the reference axis A1 has the following configuration: the first convex portion 19 has a linear first top surface 25 abutting the third side 23, and the second convex portion 21 has a linear second top surface 26 abutting the fourth side 24, and the width W2 of the second top surface 26 may be greater than the width W3 of the third top surface 36. This makes it possible to reduce the reaction to the main component force and the feed component force during cutting with the cutting tool 101, thereby reducing so-called chatter vibrations.

[0048] Furthermore, the width W2 of the second top surface 26 may be smaller than the width W3 of the third top surface 36. With this configuration, the durability of the third convex portion 33 can be ensured while improving the holding stability of the second convex portion 21 against the principal component force.

[0049] The width W1 of the first top surface 25 may be larger than the width W3 of the third top surface 36. This reduces the reaction to the main component force and the feed component force during cutting with the cutting tool 101, thereby reducing so-called chatter vibrations.

[0050] By appropriately combining the above, it is possible to improve the balance between the contact between the first convex portion 19 and the third side 23, the contact between the second convex portion 21 and the fourth side 24, and the contact between the third convex portion 33 and the sixth side 35. This makes it possible to minimize the load when the first member 5 is attached to the second member 6.

[0051] [Embodiment 2] Fig. 1 is also a perspective view showing a schematic configuration of a cutting tool 101 according to embodiment 2 of the present disclosure. Fig. 2 is also a top view showing a schematic configuration of the cutting tool 101 according to embodiment 2 of the present disclosure. Fig. 3 is also a side view showing a schematic configuration of the cutting tool 101 according to embodiment 2 of the present disclosure.

[0052] The cutting tool 101 may include the holder 1 and the cutting insert 2 positioned in the pocket 13. This makes it possible to realize the cutting tool 101 that has high holding stability and allows the first member 5 to be easily replaced.

[0053] [Embodiment 3] Fig. 14 is a top view showing a first step in a manufacturing method of a machined product 301 according to embodiment 3 of the present disclosure. Fig. 15 is a top view showing a second step in a manufacturing method of a machined product 301 according to embodiment 3 of the present disclosure. Fig. 16 is a top view showing a third step in a manufacturing method of a machined product 301 according to embodiment 3 of the present disclosure.

[0054] The first step is a step of rotating the workpiece 201. The workpiece 201 may be rotated around a rotation axis A2 of the workpiece 201. Examples of materials for the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0055] The second step is a step of bringing the cutting tool 101 into contact with the rotating workpiece 201. The cutting tool 101 may be moved to bring the cutting tool 101 relatively close to the rotating workpiece 201. The cutting edge of the cutting insert 2 of the cutting tool 101 may be brought into contact with the workpiece 201 to cut the workpiece 201.

[0056] The third step is a step of separating the cutting tool 101 from the workpiece 201. The cutting tool 101 may be moved to separate the cutting tool 101 from the workpiece 201, thereby obtaining a machined product 301.

[0057] According to the manufacturing method of the machined product 301, the cutting tool 101 having high holding stability is used, so that the workpiece 201 can be cut with excellent processing accuracy, and the machined product 301 having a highly accurate processed surface can be obtained. According to the manufacturing method of the machined product 301, the cutting tool 101 that allows easy replacement of the first member 5 is used, so that the manufacturing efficiency of the machined product 301 can be improved.

[0058] In the second step, the workpiece 201 may be brought closer to the cutting tool 101. In the third step, the workpiece 201 may be moved away from the cutting tool 101. To continue the cutting process, the workpiece 201 may be kept rotating, and the step of bringing the cutting edge of the cutting insert 2 of the cutting tool 101 into contact with different locations on the workpiece 201 may be repeated.

[0059] Although the holder 1, the cutting tool 101, and the method for manufacturing the machined product 301 have been exemplified above, this aspect is not limited to the above-described embodiment, and any method may be used as long as it does not deviate from the gist of this aspect.

[0060] The cutting tool 101 may be a turning tool, but may also be, for example, a milling tool. When the cutting tool 101 is a milling tool, the cutting tool 101 may be rotated in the first step of the manufacturing method of the machined product 301.

[0061] [Summary] A holder according to a first aspect of the present disclosure has a shape extending from a front end to a rear end along a reference axis, and includes a first member and a second member located closer to the rear end than the first member, wherein the first member has a first front end surface located closer to the front end, a rear end surface located closer to the rear end, an upper surface located between the first front end surface and the rear end surface, a lower surface located on the opposite side of the upper surface, a first side surface located between the first front end surface and the rear end surface and adjacent to the upper surface, a second side surface located on the opposite side of the first side surface, a pocket that opens across the first front end surface, the upper surface, and the first side surface, and into which a cutting insert can be attached, and a protruding portion that protrudes from the rear end surface towards the second member, and the second member has a second front end surface located closer to the front end, and a hole portion that opens at the second tip surface and into which the protrusion is inserted, and in a cross section perpendicular to the reference axis, the protrusion portion has a first corner located closer to the lower surface and the second side surface than the reference axis, a first side extending from the first corner toward the upper surface, a first convex portion protruding outward from the first side, a second side extending from the first corner toward the first side surface, and a second convex portion protruding outward from the second side, and the hole portion has a second corner opposite the first corner, a third side opposite the first side, and a fourth side opposite the second side, and the first convex portion abuts against the third side and the first side is spaced apart from the third side, and the second convex portion abuts against the fourth side and the second side is spaced apart from the fourth side.

[0062] A holder according to a second aspect of the present disclosure is the holder of the first aspect, wherein the second angle is spaced apart from the first angle in a cross section perpendicular to the reference axis.

[0063] In a holder according to aspect 3 of the present disclosure, in aspect 1 or 2, in a cross section perpendicular to the reference axis, the first convex portion has a first top surface that is linear and abuts the third side, and the second convex portion has a second top surface that is linear and abuts the fourth side.

[0064] A holder according to a fourth aspect of the present disclosure is the holder of the third aspect, wherein in a cross section perpendicular to the reference axis, the first top surface approaches the first side surface as it approaches the upper surface.

[0065] A holder according to aspect 5 of the present disclosure is the holder of aspect 3 or 4, wherein in a cross section perpendicular to the reference axis, the second top surface is parallel to the lower surface.

[0066] A holder according to a sixth aspect of the present disclosure is the holder of any one of the third to fifth aspects, wherein the width of the second top surface is greater than the width of the first top surface in a cross section perpendicular to the reference axis.

[0067] A holder according to aspect 7 of the present disclosure is any of aspects 1 to 6, wherein in a cross section perpendicular to the reference axis, the distance between the second convex portion and the first side surface is smaller than the distance between the second convex portion and the second side surface.

[0068] A holder according to aspect 8 of the present disclosure is any one of aspects 1 to 7, wherein in a cross section perpendicular to the reference axis, the distance between the first convex portion and the upper surface is smaller than the distance between the first convex portion and the lower surface.

[0069] A holder according to aspect 9 of the present disclosure is one in which, in any of aspects 1 to 8, the protrusion includes a first portion having a tapered shape whose outer shape becomes smaller as it moves away from the rear end face, and the hole portion includes a second portion having a tapered shape whose outer shape becomes smaller as it moves away from the second tip face, and the difference between the outer shape at the bottom of the first portion that contacts the rear end face and the outer shape at the end of the first portion that is away from the rear end face is greater than the height of the first convex portion and the height of the second convex portion, respectively.

[0070] A holder according to aspect 10 of the present disclosure is one in which, in any of aspects 1 to 8, the protrusion includes a first portion having a tapered shape whose outer shape becomes smaller as it moves away from the rear end face, and the hole portion includes a second portion having a tapered shape whose outer shape becomes smaller as it moves away from the second tip face, and the difference between the outer shape at the bottom of the first portion that contacts the rear end face and the outer shape at the end of the first portion that is away from the rear end face is smaller than the height of the first convex portion and the height of the second convex portion, respectively.

[0071] A holder according to aspect 11 of the present disclosure is, in any of aspects 1 to 10, such that in a cross section perpendicular to the reference axis, the protrusion further has a third corner to which the second side is connected, a fifth side extending from the third corner toward the upper surface, and a third convex portion protruding outward from the fifth side, and the hole further has a fourth corner opposite the third corner and a sixth side opposite the fifth side, the third convex portion abutting the sixth side and the fifth side being spaced apart from the sixth side.

[0072] A holder according to a twelfth aspect of the present disclosure is the holder of the eleventh aspect, wherein the fourth angle is spaced apart from the third angle in a cross section perpendicular to the reference axis.

[0073] A holder according to aspect 13 of the present disclosure is the holder of aspect 11 or 12, wherein in a cross section perpendicular to the reference axis, the third convex portion has a third top surface that is linear and abuts against the sixth side.

[0074] A holder according to aspect 14 of the present disclosure is in accordance with aspect 13, wherein in a cross section perpendicular to the reference axis, the third top surface approaches the second side surface as it approaches the upper surface.

[0075] A holder according to aspect 15 of the present disclosure is the holder of aspect 13 or 14, wherein in a cross section perpendicular to the reference axis, the first convex portion has a first top surface that is linear and abuts the third side, the second convex portion has a second top surface that is linear and abuts the fourth side, and the width of the second top surface is greater than the width of the third top surface.

[0076] A holder according to Aspect 16 of the present disclosure is similar to Aspect 15, wherein the width of the first top surface is greater than the width of the third top surface.

[0077] A cutting tool according to a seventeenth aspect of the present disclosure is the cutting tool of any one of the first to sixteenth aspects, and includes the holder and a cutting insert positioned in the pocket.

[0078] The method for manufacturing a machined product according to aspect 18 of the present disclosure is a method in accordance with aspect 17, comprising the steps of rotating a workpiece, bringing the cutting tool into contact with the rotating workpiece, and moving the cutting tool away from the workpiece.

[0079] The invention according to the present disclosure has been described above based on the drawings and examples. However, the invention according to the present disclosure is not limited to the above-described embodiments. In other words, the invention according to the present disclosure can be modified in various ways within the scope of the present disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention according to the present disclosure. In other words, it should be noted that a person skilled in the art can easily make various modifications or corrections based on the present disclosure. It should also be noted that these modifications or corrections are included in the scope of the present disclosure.

[0080] DESCRIPTION OF SYMBOLS 1 Holder 2 Cutting insert 3 Tip 4 Rear end 5 First member 6 Second member 7 First tip surface 8 Rear end surface 9 Top surface 10 Bottom surface 11 First side surface 12 Second side surface 13 Pocket 14 Protrusion 15 Second tip surface 16 Hole 17 First corner 18 First side 19 First convex portion 20 Second side 21 Second convex portion 22 Second corner 23 Third side 24 Fourth side 25 First top surface 26 Second top surface 27 First portion 28 Second portion 29 Bottom 30 End 31 Third corner 32 Fifth side 33 Third convex portion 34 Fourth corner 35 Sixth side 36 Third top surface 101 Cutting tool 201 Workpiece 301 Machined product A1 Reference axis D1 Distance between the second convex portion and the first side surface D2 Distance between the second convex portion and the second side surface D3 Distance between the first convex portion and the upper surface D4 Distance between the first convex portion and the lower surface H1 Height of the first convex portion H2 Height of the second convex portion W1 Width of the first top surface W2 Width of the second top surface W3 Width of the third top surface

Claims

1. A shape extending from the tip to the rear end along a reference axis, having a first member and a second member located on the rear end side of the first member. The first member has a first front surface located on the tip side, a rear surface located on the rear end side, an upper surface located between the first front surface and the rear surface, a lower surface located on the opposite side of the upper surface, a first side surface located between the first front surface and the rear surface and adjacent to the upper surface, a second side surface located on the opposite side of the first side surface, a pocket that opens over the first front surface, the upper surface and the first side surface and can attach a cutting insert, and a protrusion protruding from the rear surface toward the second member. The second member has a second front surface located on the tip side and a hole that opens at the second front surface and into which the protrusion is inserted. In a cross-section perpendicular to the reference axis, the protrusion has a first corner located closer to the lower surface and the second side surface than the reference axis, a first side extending from the first corner toward the upper surface, a first convex portion protruding outward from the first side, a second side extending from the first corner toward the first side surface, and a second convex portion protruding outward from the second side. The hole has a second corner facing the first corner, a third side facing the first side, and a fourth side facing the second side. A holder in which the first convex portion abuts against the third side and the first side moves away from the third side, and the second convex portion abuts against the fourth side and the second side moves away from the fourth side.

2. The holder according to claim 1, wherein in a cross-section perpendicular to the reference axis, the second corner is farther from the first corner.

3. The holder according to claim 1 or 2, wherein in a cross-section perpendicular to the reference axis, the first convex portion has a first top surface that is linear and abuts against the third side, and the second convex portion has a second top surface that is linear and abuts against the fourth side.

4. The holder according to claim 3, wherein in a cross-section perpendicular to the reference axis, the first top surface approaches the first side surface as it approaches the upper surface.

5. The holder according to claim 3 or 4, wherein in a cross-section orthogonal to the reference axis, the second top surface is parallel to the bottom surface.

6. The holder according to any one of claims 3 to 5, wherein in a cross-section orthogonal to the reference axis, the width of the second top surface is larger than the width of the first top surface.

7. The holder according to any one of claims 1 to 6, wherein in a cross-section orthogonal to the reference axis, the distance between the second convex portion and the first side surface is smaller than the distance between the second convex portion and the second side surface.

8. The holder according to any one of claims 1 to 7, wherein in a cross-section orthogonal to the reference axis, the distance between the first convex portion and the upper surface is smaller than the distance between the first convex portion and the bottom surface.

9. The protruding portion includes a first portion having a tapered shape whose outer shape becomes smaller as it moves away from the rear end surface, the hole portion includes a second portion having a tapered shape whose outer shape becomes smaller as it moves away from the second tip surface, and the difference between the outer shape at the bottom surface in contact with the rear end surface in the first portion and the outer shape at the end portion away from the rear end surface in the first portion is larger than the heights of the first convex portion and the second convex portion respectively. The holder according to any one of claims 1 to 8.

10. The protruding portion includes a first portion having a tapered shape whose outer shape becomes smaller as it moves away from the rear end surface, the hole portion includes a second portion having a tapered shape whose outer shape becomes smaller as it moves away from the second tip surface, and the difference between the outer shape at the bottom surface in contact with the rear end surface in the first portion and the outer shape at the end portion away from the rear end surface in the first portion is smaller than the heights of the first convex portion and the second convex portion respectively. The holder according to any one of claims 1 to 8.

11. In a cross-section orthogonal to the reference axis, the protruding portion further has a third corner to which the second side is connected, a fifth side extending from the third corner toward the upper surface, and a third convex portion protruding outward from the fifth side, the hole portion further has a fourth corner facing the third corner and a sixth side facing the fifth side, and the third convex portion abuts against the sixth side and the fifth side is away from the sixth side. The holder according to any one of claims 1 to 10.

12. The holder according to claim 11, wherein, in a cross-section orthogonal to the reference axis, the fourth corner is away from the third corner.

13. The holder according to claim 11 or 12, wherein, in a cross-section orthogonal to the reference axis, the third convex portion has a linear shape and has a third top surface that abuts against the sixth side.

14. The holder according to claim 13, wherein, in a cross-section orthogonal to the reference axis, the third top surface approaches the second side surface as it approaches the upper surface.

15. The holder according to claim 13 or 14, wherein, in a cross-section orthogonal to the reference axis, the first convex portion has a linear shape and has a first top surface that abuts against the third side, the second convex portion has a linear shape and has a second top surface that abuts against the fourth side, and the width of the second top surface is larger than the width of the third top surface.

16. The holder according to claim 15, wherein the width of the first top surface is larger than the width of the third top surface.

17. A cutting tool comprising the holder according to any one of claims 1 to 16 and a cutting insert positioned in the pocket.

18. A method for manufacturing a machined product, comprising the steps of rotating a workpiece, bringing the cutting tool according to claim 17 into contact with the rotating workpiece, and separating the cutting tool from the workpiece.

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