Cutting tool and method for manufacturing cut workpiece

Abstract

The present invention achieves a cutting tool, or the like, having a cutting insert with high durability and seating stability. The cutting insert of the cutting tool has a through-hole that is open so as to penetrate from a first surface-side to a second surface-side, and a pocket of the cutting tool has a screw hole that is open in a first groove. A screw is inserted into the through-hole and screwed into the screw hole.

Description

Cutting tool and method for manufacturing machined product

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

[0002] Examples of cutting tools used when cutting a workpiece include those described in Patent Documents 1 and 2.

[0003] The cutting tools described in Patent Documents 1 and 2 each have a holder (main body) and a cutting insert (cartridge). The cutting insert has a cutting edge and a through hole, and is fixed to the holder by a screw (bolt) inserted into the through hole. The holder has a pocket in which the cutting insert is fixed, and the pocket has a seat surface provided with a threaded hole in which the screw is fixed.

[0004] Japanese Patent Publication No. 2000-042820 and Japanese Patent Publication No. 2017-535439

[0005] A cutting tool according to one aspect of the present disclosure includes a holder extending from a front end to a rear end and having a pocket located on the front end side, a cutting insert located in the pocket, and a screw for fixing the cutting insert to the holder. The cutting insert has a first surface, a second surface located opposite the first surface, a first side surface located between the first surface and the second surface and connected to the first surface, a cutting edge located at an intersection of the first surface and the first side surface, and a through hole opening so as to penetrate from the first surface side to the second surface side. The pocket has first and second constraint surfaces abutting the second surface, respectively, a first groove extending between the first and second constraint surfaces, and a threaded hole opening in the first groove. The screw is inserted into the through hole and threaded into the threaded hole.

[0006] 15A and 15B are a first perspective view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure; a second perspective view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure; a side view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure; an enlarged view of a range IV in FIG. 3; a bottom view showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure; a sectional view taken along VI-VI in FIG. 3 showing a schematic configuration of a cutting tool according to a first embodiment of the present disclosure; an enlarged view of a range VII in FIG. 6; a first perspective view showing a schematic configuration of a holder; a second perspective view showing a schematic configuration of a holder; a side view showing a schematic configuration of a holder; an enlarged view of a range XI in FIG. 10; a bottom view showing a schematic configuration of a holder; a sectional view taken along XIII-XIII in FIG. 10 showing a schematic configuration of a holder; an enlarged view of a range XIV in FIG. 13; a perspective view showing a schematic configuration of a cutting insert; a plan view of the cutting insert as viewed in a direction XVI in FIG. 15; a plan view of the cutting insert as viewed in a direction XVII in FIG. 15; a plan view of the cutting insert as viewed in a direction XVIII in FIG. 15. Fig. 16 is a plan view of the cutting insert as viewed in the XIX direction of Fig. 15. Fig. 16 is a plan view of the cutting insert as viewed in the XX direction of Fig. 15. Fig. 16 is a perspective view showing a first step in a method for manufacturing a machined product according to embodiment 2 of the present disclosure. Fig. 16 is a perspective view showing a second step in a method for manufacturing a machined product according to embodiment 2 of the present disclosure. Fig. 16 is a perspective view showing a third step in a method for manufacturing a machined product according to embodiment 2 of the present disclosure.

[0007] When the cutting insert is fixed to the holder, the cutting insert is pressed against the holder by the screw, and a relatively large force is likely to be applied to the area of ​​the seating surface near the screw hole compared to the area away from the screw hole.

[0008] When the cutting edge of the cutting insert is located near the screw hole, the seating stability of the cutting insert is high, but the durability is reduced due to the narrow distance between the cutting edge and the through hole.When the cutting edge of the cutting insert is located away from the screw hole, the durability of the cutting insert is high, but the seating stability is reduced.

[0009] For the above reasons, there is a demand for a cutting tool that combines high durability and seating stability of the cutting insert.

[0010] A cutting tool according to one aspect of the present disclosure has high durability and seating stability of the cutting insert.

[0011] 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.

[0012] For the sake of convenience, the drawings referred to below show only the main components necessary for explaining each embodiment in a simplified manner. Therefore, for example, the cutting tool 101 may include any components not shown in the drawings. The dimensions of the components in the drawings do not faithfully represent the dimensions and dimensional ratios of the actual components. These points are the same for all cutting tools 101 and methods for manufacturing machined products 301.

[0013] [Embodiment 1] Fig. 1 is a first perspective view showing a schematic configuration of a cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 2 is a second perspective 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. Fig. 4 is an enlarged view of range IV in Fig. 3. Fig. 5 is a bottom view showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 3 showing a schematic configuration of the cutting tool 101 according to embodiment 1 of the present disclosure. Fig. 7 is an enlarged view of range VII in Fig. 6. The cutting tool 101 may have a holder 1, a cutting insert 2, and a screw 3.

[0014] Fig. 8 is a first perspective view showing the schematic configuration of the holder 1. Fig. 9 is a second perspective view showing the schematic configuration of the holder 1. Fig. 10 is a side view showing the schematic configuration of the holder 1. Fig. 11 is an enlarged view of range XI in Fig. 10. Fig. 12 is a bottom view showing the schematic configuration of the holder 1. Fig. 13 is a cross-sectional view taken along line XIII-XIII in Fig. 10 showing the schematic configuration of the holder 1. Fig. 14 is an enlarged view of range XIV in Fig. 13.

[0015] The holder 1 may extend from a leading end 4 to a trailing end 5 along the rotation axis A. The holder 1 may have a pocket 6 located on the leading end 4 side. Examples of materials for the holder 1 include steel, cast iron, and cemented carbide. The leading end 4 and the trailing end 5 are the leading end and the trailing end of the holder 1, respectively.

[0016] Fig. 15 is a perspective view showing a schematic configuration of the cutting insert 2. Fig. 16 is a plan view of the cutting insert 2 as viewed in the XVI direction of Fig. 15. Fig. 17 is a plan view of the cutting insert 2 as viewed in the XVII direction of Fig. 15. Fig. 18 is a plan view of the cutting insert 2 as viewed in the XVIII direction of Fig. 15. Fig. 19 is a plan view of the cutting insert 2 as viewed in the XIX direction of Fig. 15. Fig. 20 is a plan view of the cutting insert 2 as viewed in the XX direction of Fig. 15.

[0017] The cutting insert 2 may be positioned in the pocket 6. The cutting insert 2 may have a first surface 7, a second surface 8, a first side surface 9, a cutting edge 10, and a through hole 11. The second surface 8 may be positioned opposite the first surface 7. The first side surface 9 may be positioned between the first surface 7 and the second surface 8. The first side surface 9 may be connected to the first surface 7. The cutting edge 10 may be positioned at the intersection of the first surface 7 and the first side surface 9. The through hole 11 may open so as to penetrate from the first surface 7 side to the second surface 8 side. Examples of materials for the cutting edge 10 include hard materials such as CBN (Cubic Boron Nitride) and PCD (Polycrystalline Diamond). The surface of the cutting edge 10 may be coated with a film formed using a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method. Examples of the coating material include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and alumina (Al ２ O ３ Examples of materials for the portions of the cutting insert 2 other than the cutting edge 10 include stainless steel, carbon steel, and tool steel.

[0018] 8 to 14 , the pocket 6 may have a first restraint surface 12, a second restraint surface 13, a first groove 14, and a threaded hole 15. The first restraint surface 12 may abut against the second surface 8. The second restraint surface 13 may abut against the second surface 8. The first groove 14 may extend between the first restraint surface 12 and the second restraint surface 13. The threaded hole 15 may open in the first groove 14.

[0019] The screw 3 may fix the cutting insert 2 to the holder 1. The screw 3 may be inserted into the through hole 11 and screwed into the threaded hole 15.

[0020] According to the cutting tool 101, the cutting edge 10 can be separated from the screw hole 15 by the amount of the first constraining surface 12 or the second constraining surface 13, thereby realizing high durability of the cutting insert 2. According to the cutting tool 101, the cutting insert 2 can be seated on two surfaces, the first constraining surface 12 and the second constraining surface 13, thereby realizing high seating stability of the cutting insert 2.

[0021] The first constraining surface 12 and the second constraining surface 13 may be located on the same plane. The plane S1 in Fig. 11 may be the plane on which the first constraining surface 12 and the second constraining surface 13 are located. The plane may be the same plane. This makes the first constraining surface 12 and the second constraining surface 13 mutually planar, thereby further increasing the seating stability of the cutting insert 2.

[0022] The first constraining surface 12 may be located closer to the tip 4 than the second constraining surface 13, and may be wider than the second constraining surface 13. This allows the cutting edge 10 to be spaced apart from the screw hole 15 by the amount of the first constraining surface 12, which is wider than the second constraining surface 13, on the tip 4 side where it is often desired to position the cutting edge 10, thereby increasing the durability of the cutting insert 2.

[0023] The cutting edge 10 may be located closer to the tip 4 than the first groove 14. This allows the first constraining surface 12 and the second constraining surface 13, which are closer to the tip 4, to stably receive the feed force during cutting by the cutting tool 101.

[0024] The cutting insert 2 may have a second side surface 16. The second side surface 16 may be located between the first surface 7 and the second surface 8. The second side surface 16 may be connected to the second surface 8. The pocket 6 may have a third constraining surface 17, a fourth constraining surface 18, and a second groove 19. The third constraining surface 17 may abut against the second side surface 16. The fourth constraining surface 18 may abut against the second side surface 16. The second groove 19 may extend between the third constraining surface 17 and the fourth constraining surface 18. This allows the load to be released during cutting by the cutting tool 101, so that even if the holder 1 bends, the cutting insert 2 can be stably supported on both the leading end 4 side and the trailing end 5 side of the side surface of the pocket 6.

[0025] The third constraining surface 17 and the fourth constraining surface 18 may be located on the same straight line in a cross section parallel to the rotation axis A. This makes it difficult for a step to occur between the third constraining surface 17 and the fourth constraining surface 18, thereby improving the seating stability of the cutting insert 2. As long as the above relationship is satisfied, the third constraining surface 17 and the fourth constraining surface 18 may be flat or curved.

[0026] At least a portion of the third constraining surface 17 and at least a portion of the fourth constraining surface 18 may be located on the same plane. A plane S2 in Fig. 8 may be the plane on which the above-mentioned portions of the third constraining surface 17 and the fourth constraining surface 18 are located. This plane may be the same plane. As a result, the third constraining surface 17 and the fourth constraining surface 18 are mutually planar, thereby further increasing the seating stability of the cutting insert 2.

[0027] The third constraining surface 17 may be located closer to the tip 4 than the fourth constraining surface 18, and may be wider than the fourth constraining surface 18. This allows the cutting edge 10 to be spaced apart from the screw hole 15 by the amount of the third constraining surface 17, which is wider than the fourth constraining surface 18, on the tip 4 side where it is often desired to position the cutting edge 10, thereby increasing the durability of the cutting insert 2.

[0028] The cutting edge 10 may be located closer to the tip 4 than the second groove 19. This allows the third constraining surface 17 and the fourth constraining surface 18, which are closer to the tip 4, to stably receive the main component force during cutting by the cutting tool 101.

[0029] The first side surface 9 may have a rake surface, or the entire first side surface 9 may be a rake surface. The first surface 7 may have a flank surface, or the entire first surface 7 may be a flank surface. The second groove 19 may be deeper than the first groove 14. This allows the cutting insert 2 to be stably supported even if the holder 1 is significantly deflected on the sides of the third constraining surface 17 and the fourth constraining surface 18 due to the principal component force during cutting by the cutting tool 101.

[0030] [Embodiment 2] Fig. 21 is a perspective view showing a first step in a method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure. Fig. 22 is a perspective view showing a second step in the method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure. Fig. 23 is a perspective view showing a third step in the method for manufacturing a machined product 301 according to embodiment 2 of the present disclosure.

[0031] The first step is a step of rotating the cutting tool 101. The cutting tool 101 may be rotated around a rotation axis A of the cutting tool 101.

[0032] The second step is a step of bringing the cutting tool 101 into contact with the workpiece 201. The rotating cutting tool 101 may be moved to bring the cutting tool 101 closer to the workpiece 201. The cutting blade 10 may be brought into contact with the workpiece 201 to cut the workpiece 201. Examples of materials for the workpiece 201 include carbon steel, alloy steel, stainless steel, cast iron, and non-ferrous metals.

[0033] 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.

[0034] According to the manufacturing method of the machined product 301, the cutting tool 101 having a cutting insert 2 with high durability is used, which reduces the number of times the cutting insert 2 is replaced, thereby improving the efficiency of manufacturing the machined product 301. According to the manufacturing method of the machined product 301, the cutting tool 101 having a cutting insert 2 with high seating stability is used, which makes it possible to cut the workpiece 201 with excellent machining accuracy, and to obtain the machined product 301 having a machined surface with high accuracy.

[0035] 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 cutting tool 101 may be kept rotating, and the step of bringing the cutting blade 10 into contact with different locations on the workpiece 201 may be repeated.

[0036] Although 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.

[0037] The cutting tool 101 may be a turning tool, but may also be, for example, a turning tool. When the cutting tool 101 is a turning tool, the workpiece 201 may be rotated in the first step of the manufacturing method of the machined product 301.

[0038] [Summary] A cutting tool according to aspect 1 of the present disclosure comprises a holder extending from a front end to a rear end and having a pocket located on the front end side, a cutting insert located in the pocket, and a screw for fixing the cutting insert to the holder, wherein the cutting insert has a first surface, a second surface located opposite the first surface, a first side surface located between the first surface and the second surface and connected to the first surface, a cutting edge located at the intersection of the first surface and the first side surface, and a through hole opening so as to penetrate from the side of the first surface to the side of the second surface, wherein the pocket has first and second constraint surfaces abutting the second surface, respectively, a first groove extending between the first and second constraint surfaces, and a threaded hole opening in the first groove, and wherein the screw is inserted into the through hole and screwed into the threaded hole.

[0039] A cutting tool according to a second aspect of the present disclosure is the cutting tool of the first aspect, wherein the first constraint surface and the second constraint surface are located on the same plane.

[0040] A cutting tool according to aspect 3 of the present disclosure is the same as aspect 1 or 2, wherein the first constraint surface is located closer to the tip than the second constraint surface and is wider than the second constraint surface.

[0041] A cutting tool according to a fourth aspect of the present disclosure is the cutting tool of any one of the first to third aspects, wherein the cutting edge is located closer to the tip than the first groove.

[0042] A cutting tool according to aspect 5 of the present disclosure is any one of aspects 1 to 4, wherein the cutting insert is located between the first surface and the second surface and further has a second side surface connected to the second surface, and the pocket further has a third constraint surface and a fourth constraint surface abutting the second side surface, respectively, and a second groove extending between the third constraint surface and the fourth constraint surface.

[0043] A cutting tool according to a sixth aspect of the present disclosure is the cutting tool of the fifth aspect, wherein at least a portion of the third constraint surface and at least a portion of the fourth constraint surface are located on the same plane.

[0044] A cutting tool according to aspect 7 of the present disclosure is the cutting tool of aspect 5 or 6, wherein the third constraint surface is located closer to the tip than the fourth constraint surface and is wider than the fourth constraint surface.

[0045] A cutting tool according to aspect 8 of the present disclosure is the cutting tool of any one of aspects 5 to 7, wherein the cutting edge is located closer to the tip than the second groove.

[0046] A cutting tool according to aspect 9 of the present disclosure is any one of aspects 5 to 8, wherein the first side surface has a cutting face, the first surface has a relief face, and the second groove is deeper than the first groove.

[0047] A manufacturing method for a machined product according to aspect 10 of the present disclosure is a method in any one of aspects 1 to 9, comprising the steps of rotating the cutting tool, bringing the cutting tool into contact with a workpiece, and moving the cutting tool away from the workpiece.

[0048] 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.

[0049] REFERENCE SIGNS LIST 1 Holder 2 Cutting insert 3 Screw 4 Tip 5 Rear end 6 Pocket 7 First surface 8 Second surface 9 First side surface 10 Cutting edge 11 Through hole 12 First constraint surface 13 Second constraint surface 14 First groove 15 Screw hole 16 Second side surface 17 Third constraint surface 18 Fourth constraint surface 19 Second groove 101 Cutting tool 201 Workpiece 301 Machined product

Claims

1. A cutting tool having a holder extending from a front end to a rear end and having a pocket located on the side of the front end, a cutting insert located in the pocket, and a screw for fixing the cutting insert to the holder, wherein the cutting insert has a first surface, a second surface located opposite to the first surface, a first side surface located between the first surface and the second surface and connected to the first surface, a cutting edge located at the intersection of the first surface and the first side surface, and a through hole opening so as to penetrate from the side of the first surface to the side of the second surface, and the pocket has a first restraining surface and a second restraining surface respectively abutting on the second surface, a first groove extending between the first restraining surface and the second restraining surface, and a screw hole opening in the first groove, and the screw is inserted into the through hole and screwed into the screw hole.

2. The cutting tool according to claim 1, wherein the first restraining surface and the second restraining surface are located on the same plane.

3. The cutting tool according to claim 1 or 2, wherein the first restraining surface is located on the side of the front end relative to the second restraining surface and is wider than the second restraining surface.

4. The cutting tool according to any one of claims 1 to 3, wherein the cutting edge is located on the side of the front end relative to the first groove.

5. The cutting tool according to any one of claims 1 to 4, wherein the cutting insert further has a second side surface located between the first surface and the second surface and connected to the second surface, and the pocket further has a third restraining surface and a fourth restraining surface respectively abutting on the second side surface, and a second groove extending between the third restraining surface and the fourth restraining surface.

6. The cutting tool according to claim 5, wherein at least a part of the third restraining surface and at least a part of the fourth restraining surface are located on the same plane.

7. The cutting tool according to claim 5 or 6, wherein the third restraining surface is located on the side of the front end relative to the fourth restraining surface and is wider than the fourth restraining surface.

8. The cutting tool according to any one of claims 5 to 7, wherein the cutting edge is located on the side of the front end relative to the second groove.

9. The cutting tool according to any one of claims 5 to 8, wherein the first side surface has a rake face, the first surface has a flank face, and the second groove is deeper than the first groove.

10. A method for manufacturing a machined product, comprising the steps of rotating the cutting tool according to any one of claims 1 to 9, bringing the cutting tool into contact with a workpiece, and separating the cutting tool from the workpiece.

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