Cutting tool and method for manufacturing cut product

Abstract

Provided is a cutting tool having excellent chip discharge properties and excellent durability. A cutting tool according to one aspect of the present disclosure has a main body part, and a first cutting part and a second cutting part fixed to the main body part. The main body portion has a trunk portion located on the rear end side and a branch portion extending from the trunk portion toward the front end. The branch portion includes: a first branch portion extending rearward in the direction of rotation toward the tip and connected to the stem portion and the first cutting portion; a second branch part which extends forward in the rotation direction as the second branch part faces the front end and is connected with the main part and the first cutting part; a third branch portion extending rearward in the direction of rotation as the third branch portion faces the tip, the third branch portion being connected to the stem portion and the second cutting portion; and a fourth branch part which extends forward in the rotation direction as the fourth branch part faces the front end, and which is connected to the trunk part and the second cutting part. The second branch part and the third branch part intersect and are connected at the intersection part.

Description

Technical Field

[0001] This disclosure relates to a method for manufacturing a cutting tool and a workpiece. Examples of cutting tools include rotary tools such as boring tools. Boring tools can be used for machining the inner circumferential surfaces of cylindrical workpieces. Background Technology

[0002] For example, a boring tool, which is a type of rotary tool, is known as the cutting tool described in Patent Document 1. The cutting tool described in Patent Document 1 has a center tube and an annular cutting ring. The cutting ring has a leading arm (trailing arm) and a cutting head. An opening is formed in the center tube for the purpose of weight reduction.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: US Patent Publication No. 2021 / 0060665 Summary of the Invention

[0006] A cutting tool based on one aspect of this disclosure comprises: a main body extending from a front end toward a rear end along a rotation axis; a first cutting portion fixed to the main body and having a first cutting edge; and a second cutting portion fixed to the main body and having a second cutting edge, wherein the first cutting portion is located in front of the second cutting portion in the rotation direction of the rotation axis. The main body has: a main stem located on the rear end side; and a branch extending from the main stem toward the front end, the branch having: a first branch that extends toward the rear of the rotation axis in the rotation direction as it extends toward the front end. The second branch extends forward toward the front end and in the direction of rotation of the rotating shaft, and connects to the main branch and the first cutting part; the third branch extends backward toward the front end and in the direction of rotation of the rotating shaft, and connects to the main branch and the second cutting part; and the fourth branch extends forward toward the front end and in the direction of rotation of the rotating shaft, and connects to the main branch and the second cutting part, wherein the second branch and the third branch intersect and connect at the intersection. Attached Figure Description

[0007] Figure 1 This is a perspective view of a cutting tool according to an undefined embodiment of the present disclosure, viewed from the rear end.

[0008] Figure 2 Viewed from the front end Figure 1 A three-dimensional view of the cutting tool shown.

[0009] Figure 3 Viewed from the front end Figure 1 The front view of the cutting tool shown.

[0010] Figure 4 From Figure 3 Observe in the direction of arrow A4 as shown. Figure 1 The side view of the cutting tool shown.

[0011] Figure 5 From Figure 3 Observe in the direction of arrow A3 shown. Figure 1 The side view of the cutting tool shown.

[0012] Figure 6 yes Figure 5 The sectional view along line VI-VI is shown.

[0013] Figure 7 yes Figure 4 The sectional view along line VII-VII is shown.

[0014] Figure 8 It is Figure 1 An enlarged perspective view of the locations of the first and second cutting sections in the cutting tool shown.

[0015] Figure 9 This is a schematic diagram illustrating a step of a method for manufacturing a machined object according to an undefined embodiment of the present disclosure. Detailed Implementation

[0016] In machining processes, there is a growing demand for improved chip evacuation. This is particularly true for boring tools, where the space for chip evacuation is limited, creating a greater need for enhanced chip evacuation. On the other hand, simply increasing the opening size for the purpose of weight reduction and / or improved chip evacuation may reduce the overall strength of the cutting tool.

[0017] Hereinafter, a method for manufacturing a cutting tool and a workpiece according to an example embodiment of this disclosure will be described in detail using the accompanying drawings. However, for ease of explanation, the drawings referred to below only show the main components necessary for illustrating the embodiment. Therefore, the cutting tool may include any constituent members not shown in the referenced drawings. In addition, the dimensions of the components in the drawings do not faithfully represent the actual dimensions of the constituent members or the dimensional ratios of each component.

[0018] (Cutting tools)

[0019] use Figures 1 to 7 The structure of a cutting tool 1, which is not limited to one embodiment, will be described below. The cutting tool 1 is, for example, a rotary tool, and as a specific example, a boring tool can be cited. A boring tool can be used for cutting the inner circumferential surface of a cylindrical workpiece.

[0020] like Figure 1 , Figure 2 As shown, the cutting tool 1 has a rotation axis O1. The rotation axis O1 is the axis through which the cutting tool 1 rotates, not something inherent in the cutting tool 1 as a physical object. The cutting tool 1 rotates about the rotation axis O1 in the rotation direction O2, affecting the workpiece 103 (see reference 1) described later. Figure 9 ( ) is used for cutting.

[0021] The cutting tool 1 may have a main body 10 and a cutting portion 20 fixed to the main body 10. The main body 10 may extend from a front end 10A toward a rear end 10B along the rotation axis O1. The main body 10 may have a main stem 11 located on the rear end 10B side and a branch portion 12 extending from the main stem 11. The branch portion 12 may extend toward the front end 10A.

[0022] <Cutting section>

[0023] like Figures 1 to 7 As shown, the cutting tool 1 may have a first cutting portion 21 having a first cutting edge 21a and a second cutting portion 22 having a second cutting edge 22a as a cutting portion 20. The first cutting portion 21 may be located in front of the rotation direction O2 of the rotation axis O1 relative to the second cutting portion 22. The first cutting portion 21 and the second cutting portion 22 may be located at the same distance relative to the rotation axis O1.

[0024] The cutting tool 1 may also have a third cutting part 23 with a third cutting edge 23a as a cutting part 20. The third cutting part 23 may be located on the side closer to the front end 10A than the first cutting part 21 and the second cutting part 22 and closer to the rotation axis O1 than the first cutting part 21.

[0025] The cutting tool 1 may also have a fourth cutting portion 24 having a fourth cutting edge 24a as a cutting portion 20. The fourth cutting portion 24 may be located at a position on the rear end 10B side of the first cutting portion 21 and the second cutting portion 22, and at the same distance from the rotation axis O1 as the first cutting portion 21 and the second cutting portion 22.

[0026] like Figure 8 As shown, the first cutting section 21 may include a cutting insert 201 with a cutting edge, a housing 202, and a holding section 203. The second cutting sections 22 to the fourth cutting sections 24 may also include the same cutting insert 201, housing 202, and holding section 203 as the first cutting section 21.

[0027] A cutting blade 201 is mounted on the housing 202. The housing 202 may have a groove on one side of the front end 10A for mounting the cutting blade 201, in which the cutting blade 201 is mounted. The housing 202 is not limited to a specific shape and may be a rod shape, a polygonal plate shape, or a polygonal prism shape, etc.

[0028] A box 202 is installed in the retaining part 203. The retaining part 203 can be formed as part of the main body 10.

[0029] When the first cutting section 21 to the fourth cutting section 24 are equipped with cutting inserts 201, the cutting insert 201 of the first cutting section 21 has a first cutting edge 21a, and the cutting insert 201 of the second cutting section 22 has a second cutting edge 22a. In addition, the cutting insert 201 of the third cutting section 23 has a third cutting edge 23a, and the cutting insert 201 of the fourth cutting section 24 has a fourth cutting edge 24a.

[0030] The cutting insert 201 is not limited to a specific shape; it can be a diamond-shaped plate, a triangular plate, or the like. The shape of the cutting insert 201 can be different between the first cutting section 21 and the fourth cutting section 24.

[0031] When the cutting insert 201 is a rhomboid plate or a triangular shape, in the first cutting section 21, the first cutting edge 21a can be located at the intersection of the two sides of the apex of the front end 10A of the cutting insert 201. By making the first cutting edge 21a and the workpiece 103 (see reference) Figure 9 ( ) contact, enabling cutting processing.

[0032] The second cutting section 22 to the fourth cutting section 24 are the same as the first cutting section 21. That is, when the cutting insert 201 is a rhomboid plate or a triangular shape, the second cutting edge 22a, the third cutting edge 23a, or the fourth cutting edge 24a can be located at the intersection of the two sides of the apex of the front end 10A of the respective cutting insert 201. By positioning the second cutting edge 22a, the third cutting edge 23a, or the fourth cutting edge 24a with the workpiece 103 (see reference 103)... Figure 9 ( ) contact, enabling cutting processing.

[0033] Materials used for the cutting insert 201 can include, for example, cemented carbide and cermet. Compositions of cemented carbide can include, for example, WC-Co, WC-TiC-Co, and WC-TiC-TaC-Co. Here, WC, TiC, and TaC can be hard particles, and Co can be a bonding phase.

[0034] Cermets can be sintered composite materials made by combining metal and ceramic components. Examples of cermets include titanium compounds with titanium carbide (TiC) or titanium nitride (TiN) as the main component. The material of the cutting insert 201 is not limited to the above composition.

[0035] The surface of the cutting insert 201 can be coated with a film formed using chemical vapor deposition (CVD) or physical vapor deposition (PVD). Examples of the film composition include titanium carbide (TiC), titanium nitride (TiN), titanium carbonitride (TiCN), and aluminum oxide (Al2O3).

[0036] Furthermore, the cutting tool 1 can have multiple sets of the first cutting section 21 and the second cutting section 22 as a group. For example... Figure 3 As shown, in a structure comprising two groups consisting of a first cutting section 21 and a second cutting section 22, the first cutting section 21 and another first cutting section 21 belonging to the other group can be arranged in opposing positions separated by a rotation axis O1. Similarly, the second cutting section 22 and another second cutting section 22 belonging to the other group can be arranged in opposing positions separated by a rotation axis O1.

[0037] Multiple third cutting portions 23 and multiple fourth cutting portions 24 can be provided. In a structure with two third cutting portions 23, the third cutting portion 23 and the other third cutting portion 23 can be arranged in opposite positions separated by the rotation axis O1. Similarly, in a structure with two fourth cutting portions 24, the fourth cutting portion 24 and the other fourth cutting portion 24 can be arranged in opposite positions separated by the rotation axis O1.

[0038] <Main Body>

[0039] like Figures 1 to 7 As shown, the main body 10 of the fixed cutting part 20 may have a main stem 11 located on the rear end 10B side and a branch 12 extending from the main stem. The branch 12 may extend toward the front end 10A. The first cutting part 21, the second cutting part 22 and the third cutting part 23 described above as the cutting part 20 may be fixed to the branch 12.

[0040] By configuring the main body 10 with such a structure, the portion separating the inner and outer sides of the main body 10 in the branch portion 12, i.e., the portion that acts as a barrier when the chips generated by the cutting portion 20 flow toward the rear end 10B, does not exist except in the branch portion 12. Therefore, the chips cut by the first cutting portion 21, the second cutting portion 22, and the third cutting portion 23 flow from the hollowed-out inner side of the main body 10 through the large opening between the branch portions 12 toward the rear end 10B and are discharged.

[0041] Therefore, compared to cutting tools with a shaft extending along the axis of rotation at the center of the main body, chip removal is significantly improved. Furthermore, compared to cutting tools where the shaft of the main body is hollow and an opening communicating with the internal hollow space is provided on the outer periphery of the shaft, the portion that acts as a barrier to chip flow is significantly reduced, thus improving chip removal.

[0042] Furthermore, since the first cutting section 21, the second cutting section 22, and the third cutting section 23 are each supported only by the branch section 12, the generated chips enter the inner side of the main body 10 from between the branch sections 12 and flow inside the main body 10. Therefore, it is possible to reduce the amount of chips in the workpiece 103 (refer to...) Figure 9 The amount of chips flowing on the outer side of the main body 10 with the machined surface can reduce the possibility of damaging the machined surface.

[0043] like Figure 2 , Figure 6 As shown, the main stem 11 can be hollow. That is, the main stem 11 can be hollow inside, with only the outer periphery remaining. For example, the main stem 11 can be a cylindrical shape with a hole 11A formed in its central portion along the rotation axis O1. In addition, the main stem 11 can be located on a part of the outer periphery of the main body 10, and there can be an opening on the outer periphery of the main body 10 where the main stem 11 is not disposed.

[0044] For example, such as Figure 2 , Figure 4 As shown, when from Figure 3 When viewed in the direction of arrow A4, the main stem 11 may have a triangular or trapezoidal opening 14 protruding from the front end 10A towards the rear end 10B. In other words, as... Figure 5 As shown, when from Figure 3 When viewed in the direction of arrow A3, the main stem 11 can be divided into a triangular shape protruding from the rear end 10B towards the front end 10A. For example... Figure 1 , Figure 2 As shown, the parts that form such a triangular shape can be arranged in pairs with the rotation axis O1 facing each other.

[0045] like Figure 3 As shown, the directions of arrows A1 and A3 are orthogonal to the rotation axis O1, and the directions of arrows A1 and A3 differ by 180°. The directions of arrows A2 and A4 are also orthogonal to the rotation axis O1, and the directions of arrows A2 and A4 differ by 180°. The directions of arrows A1, A2, A3, and A4 are all offset by 90° along the rotation direction O2.

[0046] In this way, the main body 11 is also hollowed out, and through the opening 14 that communicates with the outside of the main body 10, the chips cut by the first cutting part 21, the second cutting part 22 and the third cutting part 23 are also discharged to the rear end 10B side through the opening 14. As a result, the chip discharge performance can be made into a structure with better performance.

[0047] In addition, such as Figure 6 As shown, the main stem 11 can be bent inwards with the side containing the rotation axis O1 as the inner side. Furthermore, the main stem 11 can be bulging outwards from the rear end 10B towards the front end 10A in a direction away from the rotation axis O1. The aforementioned opening 14 can open towards the rear end 10B. The thickness of the plate-like portion of the main stem 11 may not be uniform, and the portion connecting to the branch 12 may be formed to be thicker than other portions. Additionally, the outer and inner peripheral surfaces of the main stem 11 can be smooth.

[0048] like Figure 1 , Figure 2 , Figure 4 , Figure 5 As shown, branch 12 may have a first branch 121 to a fourth branch 124. Figure 1 In the diagram, the portions corresponding to the first branch 121 and the second branch 122 are enclosed by dashed lines. Figure 4 In the diagram, the portions corresponding to the first branch 121 to the fourth branch 124 are enclosed by dashed lines. The first branch 121 to the fourth branch 124 can extend toward the front end 10A.

[0049] The first branch 121 can extend rearward toward the rotation direction O2 of the rotation axis O1 along the front end 10A, and connect with the main body 11 and the first cutting part 21 described above. The second branch 122 can extend forward toward the rotation direction O2 of the rotation axis O1 along the front end 10A, and connect with the main body 11 and the first cutting part 21. In this case, the holding part 203 of the first cutting part 21 can be formed at the intersection of the first branch 121 and the second branch 122.

[0050] The third branch 123 can extend rearward toward the rotation direction O2 of the rotation axis O1 along the front end 10A, and connect with the main body 11 and the aforementioned second cutting portion 22. The fourth branch 124 can extend forward toward the rotation direction O2 of the rotation axis O1 along the front end 10A, and connect with the main body 11 and the second cutting portion 22. In this case, the aforementioned holding portion 203 of the second cutting portion 22 can be formed at the intersection of the third branch 123 and the fourth branch 124.

[0051] Furthermore, the second and third branches can intersect and connect at the intersection. Hereinafter, the intersection will be referred to as "intersection P1".

[0052] When the inner cavity of the main body 10 is hollowed out to fix the cutting part 20 to the branch 12, the chip removal performance is excellent, but on the other hand, the holding force of the cutting part 20 may be reduced. By adopting the above structure, the first cutting part 21 is held by both the first branch 121 and the second branch 122, and the second cutting part 22 is held by both the third branch 123 and the fourth branch 124. Therefore, compared with the structure in which the first cutting part 21 is held by only one of the first branch 121 and the second branch 122, and the structure in which the second cutting part 22 is held by only one of the third branch 123 and the fourth branch 124, the holding force of the first cutting part 21 and the second cutting part 22 can be improved.

[0053] Furthermore, during cutting, if the first branch 121 and the second branch 122 are compared, a greater load is applied to the first cutting section 21, which is located in front of the rotation direction O2, than to the second cutting section 22. Also, the load applied to the first cutting section 21 is greater in the second branch 122, which is located behind the first cutting section 21 in the rotation direction O2. As described above, by setting the second branch 122, which applies the greatest load among the first to fourth branches 124, as the intersection P1 that intersects and connects with the third branch 123, the load applied to the second branch 122 can be distributed to the third branch 123. Therefore, the branch 12, which would otherwise become a barrier to chip flow, is not unnecessarily thickened, the first cutting section 21 can be firmly held, and in addition to chip removal, the durability of the cutting tool 1 can be improved.

[0054] like Figure 1 , Figure 4 As shown, the second branch 122 may intersect the third branch 123 at a position closer to the first cutting section 21 and the second cutting section 22 than the main stem 11. Similarly, the third branch 123 may intersect the second branch 122 at a position closer to the first cutting section 21 and the second cutting section 22 than the main stem 11. For example, the intersection P1 of the second branch 122 and the third branch 123 may be located closer to the first cutting section 21 and the second cutting section 22 than the main stem 11.

[0055] In a structure where the intersection P1 is located near the main stem 11, the effect of distributing the load applied to the second branch 122 to the third branch 123 is small. As described above, by bringing the intersection P1 close to the first cutting part 21 and the second cutting part 22, the load applied to the second branch 122 can be effectively distributed to the third branch 123.

[0056] In addition, such as Figure 4 As shown, the second branch 122 can be formed to be thicker than the first branch 121, and the fourth branch 124 can be thicker than the third branch 123. In other words, the area of ​​the cross-section of the first branch 121 and the second branch 122 cut in a direction orthogonal to the extension direction can be formed such that the area of ​​the cross-section of the third branch 123 and the fourth branch 124 cut in a direction orthogonal to the extension direction can be formed such that the area of ​​the cross-section of the third branch 123 and the fourth branch 124 cut in a direction orthogonal to the extension direction can be formed such that the area of ​​the cross-section of the fourth branch 124 is larger than the area of ​​the third branch 123.

[0057] As described above, the load applied to the first cutting section 21 during machining is greater in the second branch 122, which is located behind the first cutting section 21 in the rotational direction O2. By adopting the above structure, the durability of the second branch 122, which is subjected to a large load, can be improved. In addition, in the first branch 121, the portion that becomes a barrier to chip flow is not unnecessarily enlarged, thereby enabling good chip removal.

[0058] It should be noted that when the thickness of the first branch 121 and the second branch 122 is not constant, it is sufficient to compare the area of ​​the cross-section with the smallest cross-sectional area.

[0059] Similar to the first branch 121 and the second branch 122, the load applied during cutting of the second cutting section 22 in the fourth branch 124, which is located behind the second cutting section 22 in the rotational direction O2, is greater than that in the third branch 123. By adopting the above structure, the durability of the fourth branch 124, which is subjected to a large load, can be improved, and in the third branch 123, chip removal can be improved.

[0060] This reduces the portion that becomes a barrier to chip flow and firmly supports the first cutting section 21 and the second cutting section 22, improving durability.

[0061] In addition, such as Figure 4 As shown, the portion 122-1 of the second branch 122 located on the front end 10A side of the intersection portion that intersects with the third branch 123 is formed to be thicker than the portion 122-2 of the second branch 122 located on the rear end 10B side of the intersection portion that intersects with the third branch 123. That is, the portion 122-1 located on the front end 10A side of the intersection portion P1 can be formed to be thicker than the portion 122-2 located on the rear end 10B side of the intersection portion P1.

[0062] When part 122-1 is relatively coarse, the rigidity of the first cutting section 21 can be enhanced relative to the main component force applied in the opposite direction of rotation O2 during cutting. Furthermore, when part 122-2 is relatively fine, space for chip removal is easily ensured.

[0063] Furthermore, in the cutting tool 1, the first branch 121 to the fourth branch 124 can each be a straight line. As for the shape of the branch 12, the straight line shape is more resistant to bending than the flexible shape. Therefore, by adopting the above structure, it is difficult to bend even when a load is applied during cutting.

[0064] Furthermore, in the cutting tool 1, the first branch 121 to the fourth branch 124 can be formed to move away from the rotation axis O1 as they move toward the front end 10A. By adopting such a structure, the overall length can be shortened, and it is difficult to bend even with the same thickness, thus achieving a structure with high load resistance.

[0065] And, as Figures 1-5 As shown, the branch portion 12 may have a fifth branch portion 125 extending toward the front end 10A from the first branch portion 121 and / or the second branch portion 122, or the third branch portion 123 and / or the fourth branch portion 124. In this case, the aforementioned holding portion 203 of the third cutting portion 23 may be formed on the third branch portion 123.

[0066] Based on the above structure, the workpiece 103 (refer to) is cut using the first cutting part 21 and the second cutting part 22. Figure 9 Machining workpiece 103 (refer to) Figure 9 When machining the large-diameter hole 104, the small-diameter hole 105 can be machined using the third cutting part 23. Since the small-diameter hole 105 can be machined simultaneously in the process of machining the large-diameter hole 104, there is no positional offset between the large-diameter hole 104 and the small-diameter hole 105, and it can be formed with good accuracy. In addition, the number of processes can also be reduced.

[0067] Furthermore, in the structure where the fifth branch 125 supporting the third cutting section 23 extends from the main body 11, the fifth branch 125 becomes a barrier to the flow of chips, narrowing the space that serves as a passage for chip flow. By adopting the above structure, the space that serves as a passage for chip flow can be more effectively secured.

[0068] Furthermore, in a structure having two third cutting sections 23, such as Figure 1 , Figure 5 , Figure 6As shown, the third cutting portion 23 and another third cutting portion 23 can be connected to each other via a connecting portion 13, which is part of the main body portion 10. The connecting portion 13 can be a shaft as shown in one example, or it can be a structure formed by connecting the front ends of multiple fifth branch portions 125 to each other.

[0069] And, as Figure 1 , Figure 2 , Figure 5 , Figure 6 As shown, the branch 12 may have a sixth branch 126 extending radially toward the rotation axis O1 on the rear end 10B side of the main stem 11. The aforementioned fourth cutting portion 24 may be fixed to the main stem 11 and the sixth branch 126. In this case, the aforementioned retaining portion 203 of the fourth cutting portion 24 may be formed to span across the main stem 11 and the sixth branch 126.

[0070] Examples of materials that can be used for the main body 10 include stainless steel, cast iron, and aluminum alloys. In particular, when steel is used in these components, the components have high toughness.

[0071] (Methods for manufacturing workpieces that have been machined)

[0072] Next, use Figure 9 The manufacturing method of a workpiece with a non-limiting aspect of this disclosure will be described. The case in which a large-diameter hole 104 is formed on the workpiece 103 using the first cutting part 21, the second cutting part 22 and the fourth cutting part 24 in the cutting tool 1, and a small-diameter hole 105 is formed on the workpiece 103 using the third cutting part 23 will be described.

[0073] The workpiece 101 is manufactured by machining the workpiece 103. The manufacturing method of the workpiece 101 in this embodiment includes the following steps:

[0074] (1) The process of rotating the cutting tool 1;

[0075] (2) The process of bringing the cutting tool 1 into contact with the workpiece 103; and

[0076] (3) The process of moving the cutting tool 1 away from the workpiece 103.

[0077] More specifically, firstly, such as Figure 9 As shown by reference numeral 901 in the accompanying drawing, the cutting tool 1 can be rotated about the rotation axis O1 in the rotation direction O2, and relative to the workpiece 103 being approached. Next, as... Figure 9 As shown by reference numeral 902 in the accompanying drawings, at least a portion of the cutting edge of the cutting tool 1 can be made to contact the workpiece 103 to cut it. Furthermore, as... Figure 9As shown by reference numeral 903 in the attached drawing, the cutting tool 1 can be moved relatively away from the workpiece 103 (workpiece 101).

[0078] like Figure 9 As shown by reference numeral 901 in the attached drawing, the cutting tool 1 can be moved forward in a rotating state ( Figure 9 The cutting tool 1 moves in the downward direction, thereby bringing it closer to the workpiece 103 being cut.

[0079] In addition, such as Figure 9 As shown by reference numeral 902 in the accompanying drawings, the cutting tool 1 can be moved forward while at least a portion of the cutting edge is in contact with the workpiece 103, thereby cutting the workpiece 103.

[0080] In addition, such as Figure 9 As shown by reference numeral 903 in the attached drawing, the cutting tool 1 can be moved backward while rotating ( Figure 9 The cutting tool 1 moves away from the workpiece 103 by moving upwards (in the middle direction).

[0081] In each process, the cutting tool 1 is moved to contact the workpiece 103 or to move away from the workpiece 103, but it is not limited to this situation.

[0082] For example, in step (1), the workpiece 103 can be brought close to the cutting tool 1. In step (3), the workpiece 103 can be moved away from the cutting tool 1. If the cutting process continues, the steps of maintaining the state of rotation of the cutting tool 1 and bringing at least a portion of the cutting edge into contact with different parts of the workpiece 103 can be repeated.

[0083] Representative examples of the material of the workpiece 103 include hardened steel, carbon steel, alloy steel, stainless steel, cast iron, or non-ferrous metals.

[0084] <Summary>

[0085] The cutting tool of embodiment 1 of this disclosure has: a main body extending from a front end toward a rear end along a rotation axis; a first cutting part fixed to the main body and having a first cutting edge; and a second cutting part fixed to the main body and having a second cutting edge. The first cutting part is located in front of the second cutting part in the rotation direction of the rotation axis. The main body has: a main stem located on the rear end side; and a branch extending from the main stem toward the front end. The branch has: a first branch extending toward the rear of the rotation axis in the direction of rotation as it moves toward the front end. The second branch extends forward toward the front end and toward the rotation direction of the rotating shaft, and connects to the main branch and the first cutting part; the third branch extends backward toward the front end and toward the rotation direction of the rotating shaft, and connects to the main branch and the second cutting part; and the fourth branch extends forward toward the front end and toward the rotation direction of the rotating shaft, and connects to the main branch and the second cutting part, wherein the second branch and the third branch intersect and connect at the intersection.

[0086] In Scheme 2 of this disclosure, the cutting tool is based on Scheme 1, and the second branch and the third branch intersect at a position closer to the first cutting part and the second cutting part than the main body.

[0087] In embodiment 3 of this disclosure, the cutting tool is based on embodiment 1 or 2, wherein the second branch is thicker than the first branch, and the fourth branch is thicker than the third branch.

[0088] In embodiment 4 of this disclosure, the cutting tool is based on any one of embodiments 1 to 3, wherein the portion of the second branch located on the front end side of the portion intersecting with the third branch is thicker than the portion of the second branch located on the rear end side of the portion intersecting with the third branch.

[0089] The cutting tool in Scheme 5 of this disclosure is based on any one of Schemes 1 to 4, wherein the first branch, the second branch, the third branch, and the fourth branch are all straight lines.

[0090] The cutting tool in Scheme 6 of this disclosure is based on any one of Schemes 1 to 5, wherein the main body is hollow.

[0091] In embodiment 7 of this disclosure, the cutting tool is based on embodiment 6, wherein the main stem is located on a portion of the outer periphery of the main body, and an opening is provided on the outer periphery of the main body where the main stem is not disposed.

[0092] The method for manufacturing a workpiece in Scheme 8 of this disclosure includes: a step of rotating a cutting tool of any one of Schemes 1 to 7; a step of bringing the cutting tool into contact with the workpiece to be cut; and a step of moving the cutting tool away from the workpiece to be cut.

[0093] [Additional Notes]

[0094] The invention disclosed herein has been described above based on the accompanying drawings and embodiments. However, the invention disclosed herein is not limited to the embodiments described above. That is, the invention disclosed herein can be modified in various ways within the scope shown in this disclosure, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the invention disclosed herein. In other words, it should be noted that anyone skilled in the art can easily make various modifications or alterations based on this disclosure. Furthermore, please note that these modifications or alterations are included within the scope of this disclosure.

[0095] Explanation of reference numerals in the attached figures:

[0096] 1. Cutting tools

[0097] 10 Main Body

[0098] 10B Backend

[0099] 10A Front End

[0100] 11 Key Cadres

[0101] 11A Hole

[0102] 12 Branches

[0103] 14 Opening

[0104] 21 First cutting section

[0105] 21a First cutting edge

[0106] 22 Second cutting section

[0107] 22a Second cutting edge

[0108] 101 Workpiece being machined

[0109] 103 Workpiece to be cut

[0110] 121 First Branch

[0111] 122 Second Branch

[0112] 123 Third Branch

[0113] 124 Fourth Branch

[0114] O1 Rotating Axis

[0115] O2 rotation direction.

Claims

1. A cutting tool, wherein, The cutting tool has: The main body extends from the front end toward the rear end along the axis of rotation; A first cutting part, fixed to the main body, and having a first cutting edge; and The second cutting part is fixed to the main body and has a second cutting edge. The first cutting portion is located in front of the second cutting portion in the rotational direction of the rotating shaft. The main body portion has: The main stem, located on the rear end side; and A branch that extends from the main trunk toward the front end. The branch has: The first branch extends rearward toward the direction of rotation of the rotating shaft as it moves toward the front end, and connects to the main body and the first cutting part; The second branch extends forward toward the direction of rotation of the rotating shaft as it moves toward the front end, and connects to the main body and the first cutting part; The third branch extends rearward toward the direction of rotation of the rotating shaft as it moves toward the front end, and connects to the main body and the second cutting part; as well as The fourth branch extends forward toward the direction of rotation of the rotating axis as it moves toward the front end, and connects to the main body and the second cutting part. The second branch and the third branch intersect and connect at the intersection.

2. The cutting tool according to claim 1, wherein, The second branch and the third branch intersect at a position closer to the first cutting part and the second cutting part than the main stem.

3. The cutting tool according to claim 1 or 2, wherein, The second branch is thicker than the first branch, and the fourth branch is thicker than the third branch.

4. The cutting tool according to any one of claims 1 to 3, wherein, The portion of the second branch located on the front end side of the portion intersecting with the third branch is thicker than the portion of the second branch located on the rear end side of the portion intersecting with the third branch.

5. The cutting tool according to any one of claims 1 to 4, wherein, The first branch, the second branch, the third branch, and the fourth branch are all straight lines.

6. The cutting tool according to any one of claims 1 to 5, wherein, The main stem is hollow.

7. The cutting tool according to claim 6, wherein, The main stem is located on a portion of the outer periphery of the main body. The opening on the outer periphery of the main body is not where the main body is located.

8. A method for manufacturing a workpiece by cutting, wherein, The method for manufacturing the workpiece includes: The process of rotating the cutting tool according to any one of claims 1 to 7; The process of bringing the cutting tool into contact with the workpiece; and The process of moving the cutting tool away from the workpiece.

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