Cutting tool, cutting tool manufacturing method, and tip manufacturing method

Abstract

To enhance production efficiency of a cutting tool with a tip arranged on an attachment seat.SOLUTION: A cutting tool 10 comprises: a tool body 12 rotatable relatively to a workpiece around an axis A; cutting edges 22 formed at a tip of the tool body 12; attachment seats 24 each with a rake face 18 adjacent to the cutting edge 22 formed cut off in a recessed shape; tips 14 each embedded in the attachment seat 24 and joined to the tool body 12; first positioning parts 36 each including a first engaging part 34 formed on a side surface of the tip 14, and a first locking part 30 formed in a step part 28 of the attachment seat 24 and fitted to the first engaging part 34; and second positioning parts 40 each including a second engaging part 38 formed on a side surface of the tip 14 at a part different from the first positioning part 36, and a second locking part 32 formed in the step part 28 of the attachment seat 24 and fitted to the second engaging part 38.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cutting tool that cuts a workpiece by rotating the workpiece relative to its axis, a method for manufacturing the cutting tool, and a method for manufacturing a tip. [Background technology]

[0002] Among tools such as drills that rotate around their axis, cutting tools (also called tipped tools) are known that have a tip made of a hard material attached to the tip of the tool body. In such cutting tools, an uneven structure called a breaker may be provided on the rake face of the tip to break chips and improve chip discharge (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 209460 Summary of the Invention [Problem to be solved by the invention]

[0004] The cutting tool of Patent Document 1 was manufactured by forming a recessed mounting seat on the rake face at the tip of the tool body, placing a tip on the mounting seat, and joining it by brazing or other methods. Conventional manufacturing methods are prone to misalignment between the tip and the tool body. Therefore, structures requiring high positional accuracy, such as breakers, were formed by precision machining after joining the tip to the tool body. However, this manufacturing method required a long processing time and resulted in poor production efficiency.

[0005] An object of the present invention is to solve the above-mentioned problems. [Means for solving the problem]

[0006] One aspect of the following disclosure is a cutting tool comprising: a tool body that rotates relative to a workpiece around an axis; a cutting edge formed at the tip of the tool body; a mounting seat with a concave notch in the cutting face of the cutting edge; a tip that is disposed in the mounting seat and joined to the tool body; a first positioning portion that has a first engaging portion formed on a side of the tip and a first locking portion formed on a step of the mounting seat and locking the first engaging portion; and a second positioning portion that has a second engaging portion formed on the side of the tip at a location different from the first engaging portion and a second locking portion formed on the step of the mounting seat and locking the second engaging portion.

[0007] According to another aspect, there is provided a second positioning part including: a tool body that rotates relative to a workpiece about an axis; a cutting edge formed at a tip of the tool body; a mounting seat in which a rake face of the cutting edge is recessed; a tip that is disposed in the mounting seat and joined to the tool body; a first positioning part that includes a first engaging portion formed on a side surface of the tip; and a first locking portion that is formed on a step of the mounting seat and locks the first engaging portion; a second engaging portion that is formed on a side surface of the tip at a position different from the first engaging portion; and a second locking portion that is formed on the step of the mounting seat and locks the second engaging portion. a positioning unit, the method comprising the steps of: preparing the tip having the first engaging portion and the second engaging portion; preparing the tool body on which the mounting seat having the first locking portion and the second locking portion is formed; a positioning step of locking the first engaging portion with the first locking portion and locking the second engaging portion with the second locking portion to position the tip on the mounting seat; and a joining step of brazing the tip positioned on the mounting seat to the tool body.

[0008] According to another aspect, there is provided a tool for cutting a workpiece by using a tool body that rotates relative to the workpiece around an axis, a cutting edge formed at a tip of the tool body, a mounting seat in which a rake face of the cutting edge is notched in a concave shape, a tip that is disposed on the mounting seat and joined to the tool body, a first positioning part having a first engaging portion formed on a side surface of the tip and a first locking portion formed on a step of the mounting seat and locking the first engaging portion, a second positioning part having a second engaging portion formed on a side surface of the tip at a position different from the first engaging portion and a second locking portion formed on the step of the mounting seat and locking the second engaging portion, and a chip manufacturing method for use in a cutting tool, the chip having a breaker formed on the chip surface of the chip for breaking chips, the method comprising: a step of preparing a thin-plate chip base material having a plurality of chip forming regions in which the chips are formed; a breaker forming step of forming the breakers for breaking chips by forming an uneven structure in each of the chip forming regions of the chip base material; and a chip cutting step of forming the chips by cutting out the chip forming regions while forming the first engaging portion and the second engaging portion after the breaker forming step.

[0009] The cutting tool, the method of manufacturing a cutting tool, and the method of manufacturing a tip from the above viewpoints can form a concave-convex structure on the tip before it is joined to the tool body, thereby improving production efficiency compared to conventional methods. [Effects of the Invention]

[0010] According to the present disclosure, since the concave-convex structure can be formed on the tip before it is joined to the tool body, production efficiency can be improved compared to conventional methods. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a cutting tool according to a first embodiment. [Figure 2] FIG. 2 is an enlarged perspective view of the tip of the cutting tool of FIG. [Figure 3] 3 is a front view of the tip surface of the cutting tool of FIG. 1. FIG. [Figure 4]FIG. 4 is a perspective view of the tip of the cutting tool without a tip attached. [Figure 5] FIG. 5 is an explanatory diagram of the method for manufacturing the cutting tool according to the first embodiment. [Figure 6] Fig. 6A is a plan view of a chip base material, Fig. 6B is a plan view showing a breaker and a chip forming region formed on the chip base material of Fig. 6A, and Fig. 6C is a plan view of a chip cut out from the chip base material of Fig. 6B. [Figure 7] FIG. 7 is an explanatory diagram showing an example of positioning of the tip and the tool body when the radius of curvature of the curved portion of the step is larger than the radius of curvature of the corner portion of the tip. [Figure 8] FIG. 8 is a side view of the cutting tool according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] (First embodiment) The cutting tool 10 according to this embodiment shown in FIGS. 1 to 3 is a drill that is rotated about an axis A (axial center) in a rotational direction B1 to cut a workpiece (not shown). Alternatively, cutting may be performed by fixing the cutting tool 10 to a jig and rotating the workpiece about the axis A in a rotational direction B2. Such a cutting tool 10 is used to drill holes in the workpiece. In this specification, the direction perpendicular to the axis A is referred to as the radial direction. In the radial direction, the direction approaching the axis A is referred to as the inward direction, and the direction away from the axis A is referred to as the outward direction. Arrows A0 and A1 are directions parallel to the axis A, and the end located in the direction indicated by arrow A0 is referred to as the tip, and the end located in the direction indicated by arrow A1 is referred to as the base.

[0013] The cutting tool 10 has a tool body 12 and a tip 14. The tool body 12 has a cylindrical rod-shaped shank portion 12a and a body 12b located at the tip of the shank portion 12a. The body 12b has multiple grooves 16 on its outer periphery. The grooves 16 discharge chips generated during cutting. The grooves 16 are provided at predetermined intervals in the circumferential direction centered on the axis A. The tool body 12 shown in FIG. 1 has two grooves 16 arranged 180° apart from each other. The grooves 16 extend parallel to the axis A. However, the extension direction of the grooves 16 is not limited to being parallel to the axis A, and the grooves 16 may have a twisted shape inclined at a predetermined angle relative to the direction of the axis A.

[0014] The groove 16 is formed in a V-shape or an L-shape in a cross section of the tool body 12 cut perpendicular to the axis A. The groove 16 has a first inner surface 16a and a second inner surface 16b. The first inner surface 16a is located closer to the rotation direction B2, and the second inner surface 16b is located closer to the rotation direction B1. As shown in FIG. 3, the first inner surface 16a forms a cutting face 18 at the tip of the cutting tool 10.

[0015] The tool body 12 has a relief surface 20 at its tip. The relief surface 20 constitutes at least a part of the tip surface 12d of the tool body 12. The relief surface 20 may be perpendicular to the axis A. Alternatively, the relief surface 20 may be formed along a conical surface inclined with respect to the axis A. The relief surface 20 forms a sharp cutting edge 22 on a ridge line intersecting with the rake face 18. The cutting edge 22 extends from near the axis A toward the outer periphery of the tool body 12. In the example of FIG. 2, the cutting edge 22 extends linearly in the radial direction. Note that the orientation of the cutting edge 22 is not limited to the radial direction. Furthermore, the cutting edge 22 is not limited to a linear shape and may extend along a curve.

[0016] As shown in FIG. 4 , the cutting tool 10 of this embodiment has a mounting seat 24 near the cutting edge 22. The mounting seat 24 is formed by cutting out a concave portion of the first inner surface 16 a of the tool body 12. The tip 14 is attached to the mounting seat 24. The mounting seat 24 has a planar bottom surface 26 and a step 28 formed between the bottom surface 26 and the rake face 18. The bottom surface 26 is formed as a surface parallel to the rake face 18. The height of the step 28 (the distance between the bottom surface 26 and the rake face 18 in a direction perpendicular to the rake face 18) is approximately the same as the thickness of the tip 14.

[0017] The step portion 28 has a first linear portion 28a, a second linear portion 28b, a curved portion 28c, a first locking portion 30, and a second locking portion 32. The first linear portion 28a extends linearly parallel or substantially parallel to the axis A. The second linear portion 28b extends in a direction intersecting with the first linear portion 28a. In the example shown in FIG. 4, the extension direction of the second linear portion 28b is parallel to the radial direction of the tool body 12, but is not limited thereto. The curved portion 28c is a portion that connects the first linear portion 28a and the second linear portion 28b with a smooth curve. The curved portion 28c may be a concavely curved arc-like curve. The curved portion 28c distributes local loads on the mounting seat 24 to prevent the tip 14 from peeling off.

[0018] The first locking portion 30 is formed on the first linear portion 28a. The first locking portion 30 is formed in a portion corresponding to a first engagement portion 34 of the tip 14, which will be described later, and locks the first engagement portion 34. The first locking portion 30, together with the first engagement portion 34, constitutes a first positioning portion 36. In the example shown in FIG. 4, the first locking portion 30 is formed as a recess that is recessed into the first linear portion 28a. However, the first locking portion 30 is not limited to this and may be a protrusion that protrudes from the first linear portion 28a.

[0019] The second locking portion 32 is formed on the second linear portion 28b. The second locking portion 32 is formed in a portion corresponding to a second engagement portion 38 of the tip 14, which will be described later, and locks the second engagement portion 38. The second locking portion 32, together with the second engagement portion 38, constitutes the second positioning portion 40. The second locking portion 32 is formed as a recess that is recessed into the second linear portion 28b. However, the second locking portion 32 is not limited to this and may be a protrusion that protrudes from the second linear portion 28b.

[0020] As shown in FIG. 2, the tip 14 is disposed in a mounting seat 24 and joined to the tool body 12. That is, the tip 14 is embedded in the mounting seat 24. In the example shown in FIG. 2, the cutting edge 22A of the tip 14, together with the tool body 12, constitutes the cutting edge 22. Note that the entire cutting edge 22 of the cutting tool 10 may be constituted only by the cutting edge 22A of the tip 14. The tip 14 is formed of a material that is harder than the material (e.g., tool steel or high-speed steel) that constitutes the tool body 12, thereby extending the life of the cutting tool 10. The tip 14 is located near the outer periphery of the tool body 12, where the relative speed with respect to the workpiece is greater, and is responsible for most of the cutting of the workpiece.

[0021] 4, the tip 14 is thin and has, as its main outer surfaces, a tip mating surface 14a, a tip surface 14b, a tip front surface 14c, a tip outer peripheral surface 14d, a first side surface 14e, a second side surface 14f, and a corner portion 14g. The tip mating surface 14a is the surface that abuts and is mated with the bottom surface 26 of the mounting seat 24. The tip surface 14b is located on the opposite side of the tip mating surface 14a and constitutes the rake face 18A of the tip 14.

[0022] As shown in FIG. 2, the tip surface 14b is flush with the first inner surface 16a of the tool body 12, forming the same plane. That is, the tip surface 14b and the first inner surface 16a of the tool body 12 are flush with each other. The tip surface 14b, together with the first inner surface 16a of the tool body 12, forms the rake face 18 of the cutting tool 10. The tip 14 of this embodiment has a breaker 42 formed with an uneven structure on the tip surface 14b. The breaker 42 breaks chips generated by the cutting edge 22A of the workpiece, improving chip discharge. Details of the breaker 42 are described, for example, in International Publication No. WO 2022 / 209460.

[0023] The tip tip surface 14c is located at the tip of the tip 14. The tip tip surface 14c is formed by polishing or the like so as to be flush with the tip surface 12d of the tool body 12, and constitutes the relief surface 20 of the cutting tool 10. A cutting edge 22A of the tip 14 is formed at the intersection of the tip tip surface 14c and the tip surface 14b.

[0024] 2, the tip outer peripheral surface 14d is exposed to the outer periphery of the cutting tool 10 when the tip 14 is joined to the mounting seat 24. The tip outer peripheral surface 14d is formed by polishing or the like so as to be connected without any steps to the outer peripheral surface 12c of the tool body 12 and as a curved surface having the same curvature as the outer peripheral surface 12c.

[0025] The first side surface 14e abuts against the first linear portion 28a of the mounting seat 24. The first side surface 14e extends linearly. The second side surface 14f extends linearly in a direction intersecting with the first side surface 14e and abuts against the second linear portion 28b of the mounting seat 24. The corner portion 14g connects the first side surface 14e and the second side surface 14f with a smooth curved surface. The corner portion 14g prevents stress concentration on the chip 14 and prevents damage to the chip 14. The radius of curvature of the corner portion 14g may be the same as or different from the radius of curvature of the curved portion 28c.

[0026] Note that making the radii of curvature of curved portion 28c and corner portion 14g extremely small facilitates positioning of tip 14. However, if the radii of curvature are extremely small, the load during cutting will be concentrated locally on corner portion 14g and curved portion 28c, causing wear and other problems that may lead to peeling of tip 14. Therefore, it is preferable that the radii of curvature of curved portion 28c and corner portion 14g be, for example, 0.1 mm or greater.

[0027] The tip 14 of this embodiment further includes a first engagement portion 34 and a second engagement portion 38. The first engagement portion 34 is a protrusion formed protruding from the first side surface 14e. The first engagement portion 34 mates with a first locking portion 30 formed as a recess in the first linear portion 28a of the mounting seat 24. The first engagement portion 34 may be a recess recessed from the first side surface 14e. In this case, the first engagement portion 34 mates with the first locking portion 30 formed as a protrusion in the first linear portion 28a of the mounting seat 24. The first engagement portion 34, together with the first locking portion 30, constitutes a first positioning portion 36. The first positioning portion 36 prevents displacement of the tip 14 in directions along the first side surface 14e and the first linear portion 28a. In one example, the first positioning portion 36 positions the tip 14 in the axial direction.

[0028] The second engagement portion 38 is a protrusion formed to protrude from the second side surface 14f and engages with a second locking portion 32 formed as a recess in the second linear portion 28b of the mounting seat 24. The second engagement portion 38 may be a recess recessed from the second side surface 14f. In this case, the second engagement portion 38 mates with the second locking portion 32 formed as a protrusion in the second linear portion 28b of the mounting seat 24. The second engagement portion 38, together with the second locking portion 32, constitutes a second positioning portion 40. The second positioning portion 40 prevents displacement of the tip 14 in directions along the second side surface 14f and the second linear portion 28b. In one example, the second positioning portion 40 positions the tip 14 in the radial direction.

[0029] The cutting tool 10 described above is used to cut a workpiece by rotating in the direction of rotation B1 indicated by the arrow in Figure 3. A tip 14 disposed at the tip of the cutting tool 10 comes into contact with the surface of the workpiece to cut the workpiece and form a hole of a predetermined size in the workpiece.

[0030] A method for manufacturing the cutting tool 10 according to this embodiment will now be described.

[0031] 5, the method for manufacturing cutting tool 10 includes steps of machining tool body 12 (S10 to S30), steps of manufacturing tip 14 (S40 to S60), steps of joining tip 14 to tool body 12 (S70, S80), and finishing steps (S90 to S100). Each step will be described below in the above order.

[0032] The machining process for the tool body 12 begins with an outer diameter grinding step (S10) of the tool body 12 in Fig. 5. First, the tool body 12 is prepared. This tool body 12 has a structure in which a rod-shaped body 12b made of a hard metal material such as tool steel is joined to a rod-shaped shank portion 12a (see Fig. 1). Next, the tool body 12 is ground into a cylindrical rod shape. This step (step S10) forms an outer peripheral surface 12c, and the tool body 12 is formed into a cylindrical rod shape extending in the axial direction.

[0033] Next, the machining process of the tool body 12 proceeds to a groove machining step (S20) shown in Fig. 5. In the groove machining step (S20), grooves 16 (see Fig. 1) are formed by engraving the outer peripheral surface 12c of the tool body 12 by grinding. In this step (S20), a plurality of grooves 16 spaced apart in the circumferential direction of the tool body 12 are formed, as in the example of Fig. 1.

[0034] Next, the machining process for the tool body 12 proceeds to the mounting seat machining step (S30) of FIG. 5. The mounting seat machining step (S30) is a grinding process using a grindstone tool. In the mounting seat machining step (S30), the first inner surface 16a of the recessed groove 16 is ground to form the mounting seat 24. This step forms the mounting seat 24 having the step portion 28 and bottom surface 26 shown in FIG. 4. In addition, the step portion 28 is formed with a first straight portion 28a, a second straight portion 28b, a curved portion 28c, a first locking portion 30, and a second locking portion 32. This completes the machining process for the tool body 12.

[0035] Next, the manufacturing process of the tip 14 will be described. The manufacturing process of the tip 14 begins with a tip base material preparation step (S40). For example, a thin plate-shaped substrate as shown in FIG. 6A is used as the tip base material 44. The tip base material 44 has a thickness of several hundred μm to several mm. The tip base material 44 has an area where multiple tips 14 can be formed simultaneously, and multiple tip forming regions 46 are defined on its surface 44a. Examples of materials used for the tip base material 44 include sintered diamond (PCD), cubic boron nitride (CBN), ceramics, cermet, and tungsten carbide alloy. The surface 44a of the tip base material 44 will later become the tip surface 14b. The back surface 44b of the tip base material 44 will later become the tip bonding surface 14a.

[0036] Next, the manufacturing process for the chip 14 proceeds to the breaker forming step (S50). In the breaker forming step (S50), as shown in FIG. 6B, each chip forming region 46 of the chip base material 44 is machined to carve the chip surface 14b. This step forms a breaker 42 including a plurality of groove-like uneven structures. This step is performed, for example, by laser processing. In this step, breakers 42 are formed simultaneously for a plurality of chip forming regions 46, eliminating the need for steps such as positioning and chip transport for individual chips 14, and allowing the breaker 42 to be formed efficiently.

[0037] Next, as shown in FIG. 5, the manufacturing process of the tip 14 proceeds to a tip cutting step (S60). In the tip cutting step (S60), each tip forming region 46 of the tip base material 44 shown in FIG. 6B is cut out, and the tip 14 is cut out from the tip base material 44. The tip cutting step (S60) is performed by, for example, laser processing. By this step, the tip 14 having the breaker 42 on the tip surface 14b is completed, as shown in FIG. 6C. In this step, the first engagement portion 34 and the second engagement portion 38 are formed at predetermined positions on the tip 14. This completes the manufacturing process of the tip 14. The manufacturing process of the tip 14 can be performed regardless of the progress of machining of the tool body 12.

[0038] Next, the process of joining the tip 14 and the tool body 12 will be described. The process of joining the tip 14 and the tool body 12 begins with a tip mounting process (S70) shown in FIG. 5. In the tip mounting process (S70), the tip 14 is placed on the mounting seat 24 of the tool body 12, and the tip 14 is positioned relative to the tool body 12, as shown in FIG. 7. If the radius of curvature of the curved portion 28c of the mounting seat 24 is larger than the radius of curvature of the corner portion 14g of the tip 14, as shown in FIG. 7, the tip 14 is likely to rotate around the contact point T between the corner portion 14g of the tip 14 and the curved portion 28c, causing the tip 14 to tilt. Therefore, if the tip 14 and mounting seat 24 do not have the first positioning portion 36 and the second positioning portion 40, the tip 14 may rattle in the mounting seat 24, resulting in positional and angular misalignment.

[0039] In contrast, in the tip 14 and tool body 12 of this embodiment, the first engagement portion 34 of the tip 14 and the first locking portion 30 of the mounting seat 24 are fitted together at the first positioning portion 36. Furthermore, the second engagement portion 38 of the tip 14 and the second locking portion 32 of the mounting seat 24 are fitted together at the second positioning portion 40. The first positioning portion 36 and the second positioning portion 40 allow the tip 14 to be accurately positioned on the mounting seat 24 without rattling. Since the mounting seat 24 has a depth equal to the thickness of the tip 14, the tip surface 14b of the tip 14 placed on the mounting seat 24 forms the same plane as the first inner surface 16a of the tool body 12.

[0040] Thereafter, the process of joining the tip 14 and the tool body 12 proceeds to a brazing process (step S80) shown in Figure 5. In the brazing process (S80), the tip 14 positioned in the mounting seat 24 is joined to the tool body 12 by brazing. This embodiment is preferable because the tip surface 14b and the first inner surface 16a are flush with each other, making it easy to detect any tilt or lift of the tip 14 during brazing. This completes the process of joining the tip 14 and the tool body 12.

[0041] Next, a finishing process is performed on the tool body 12 to which the tip 14 is joined. The finishing process includes a finishing process (S90) of the tip outer peripheral surface, as shown in Fig. 5. The finishing process (S90) of the tip outer peripheral surface involves grinding the outer peripheral surface 12c of the tool body 12 and the tip outer peripheral surface 14d. This process forms the tip outer peripheral surface 14d so that it is connected smoothly to the outer peripheral surface 12c of the tool body 12, as shown in Fig. 2.

[0042] The finishing process includes a relief face machining process (S100) shown in FIG. 5. The relief face machining process (S100) is a process of grinding the tip tip surface 14c and the tip surface 12d of the tool body 12 to form the relief face 20 of the cutting tool 10. As shown in FIG. 2, this process forms the relief face 20 in which the tip tip surface 14c is seamlessly connected to the tip surface 12d of the tool body 12. Furthermore, a ridge appears where the relief face 20 intersects with the rake faces 18, 18A (see FIG. 2), forming sharp cutting edges 22, 22A (see FIG. 2). Note that the order of the relief face machining process (S100) and the tip outer peripheral surface finishing process (S90) shown in FIG. 5 may be reversed from the order shown in FIG. 5. The cutting tool 10 according to the embodiment is completed through the above processes.

[0043] In conventional manufacturing methods, tilt and misalignment of the tip 14 occurs, so it is necessary to form the breaker 42 while adjusting the position and uneven surface in accordance with the tilt and misalignment of the tip 14, which takes time to manufacture the breaker 42. In addition, since machining of the tool body 12 and forming the breaker 42 on the tip surface 14b cannot be performed in parallel, it takes time to manufacture one cutting tool, which increases manufacturing costs.

[0044] In contrast, the method for manufacturing the cutting tool 10 of this embodiment allows the tip 14 to be joined to the tool body 12 with high positional accuracy, so the breaker 42 can be formed on the tip 14 before it is joined to the tool body 12. This allows the formation of the breaker 42 to be performed separately and in parallel with the processing of the tool body 12, significantly shortening the time required to manufacture the cutting tool 10 and reducing manufacturing costs. Furthermore, the breakers 42 of multiple tips 14 can be formed simultaneously, effectively reducing the manufacturing costs of the breakers 42.

[0045] (Second embodiment) The cutting tool 10A of this embodiment shown in Fig. 8 is a stepped reamer. In the configuration of the cutting tool 10A of this embodiment, the same components as those of the cutting tool 10 described with reference to Figs. 1 to 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0046] The cutting tool 10A includes a tool body 12A having cutting edges formed on its tip and outer periphery. The tool body 12A has a step 48 whose diameter changes at a predetermined position in the axial direction. The tool body 12A is formed with a plurality of grooves 16A that extend spirally and are inclined relative to the axial direction. In the illustrated example, each groove 16A has a tip surface 12d or the step 48 as its tip-side end. The grooves 16A do not have to be divided by the step 48, and may be formed to straddle the step 48 in the axial direction.

[0047] A mounting seat 24 for mounting a tip 14 is formed near the tip of each recessed groove 16A. In this embodiment, a tip 14 is disposed in an adjacent portion of the tip surface 12d and in an adjacent portion of each step 48. Each tip 14 is embedded in the mounting seat 24 and joined by brazing. The mounting seat 24 and tip 14 are as described with reference to FIGS. 1 to 3.

[0048] In the cutting tool 10A of this embodiment, the tip 14 is fixed to the tool body 12A with high positioning accuracy, so the breaker 42 can be formed on the tip 14 before it is joined to the tool body 12A. This allows the breaker 42 to be formed separately from the processing of the tool body 12A, significantly shortening the time required to manufacture the cutting tool 10A and reducing manufacturing costs.

[0049] In addition to the above disclosure, the following additional notes are disclosed.

[0050] (Appendix 1) One aspect of the above disclosure is a cutting tool (10, 10A) comprising: a tool body (12, 12A) that rotates relative to a workpiece around an axis; a cutting edge (22, 22A) formed at the tip of the tool body; a mounting seat (24) in which a cutting face (18, 18A) of the cutting edge is recessed; a tip (14) that is disposed in the mounting seat and joined to the tool body; a first positioning portion (36) that has a first engagement portion (34) formed on a side of the tip and a first locking portion (30) formed on a step portion (28, 48) of the mounting seat and locking the first engagement portion; and a second positioning portion (40) that has a second engagement portion (38) formed on a side of the tip at a position different from the first engagement portion and a second locking portion (32) formed on the step portion of the mounting seat and locking the second engagement portion.

[0051] In the cutting tool described above, the tip can be joined to the tool body with high positional accuracy, so a breaker can be formed on the tip before it is joined to the tool body. This allows the breaker to be formed separately from the machining of the tool body, significantly shortening the time required to manufacture the cutting tool and reducing manufacturing costs.

[0052] (Appendix 2) In the cutting tool described in Appendix 1, the first positioning unit may position the tip axially relative to the tool body, and the second positioning unit may position the tip radially relative to the tool body. This cutting tool can reduce errors when joining the tip to the tool body, and can join the tip at an accurate position.

[0053] (Appendix 3) In the cutting tool according to Supplementary Note 1 or 2, the step portion may have a first straight portion (28a) that intersects with the cutting edge, a second straight portion (28b) that extends in a direction intersecting with the first straight portion, and a curved portion (28c) that connects the first straight portion and the second straight portion with a curved surface, and the first locking portion may be located on the first straight portion, and the second locking portion may be located on the second straight portion. This cutting tool has excellent productivity because the first locking portion and the second locking portion can be formed simultaneously with grinding the mounting seat.

[0054] (Appendix 4) In the cutting tool described in Appendix 3, the tip may have a first side surface (14e) abutting the first linear portion, a second side surface (14f) abutting the second linear portion, and a corner portion (14g) connecting the first side surface and the second side surface with a curved surface, and the first engagement portion may be located on the first side surface, and the second engagement portion may be located on the second side surface. This cutting tool has excellent productivity because the first engagement portion and the second engagement portion of the tip can be formed simultaneously with the tip cutting step.

[0055] (Appendix 5) In the cutting tool according to any one of Supplementary Notes 1 to 4, the thickness of the tip may be the same as the height of the mounting seat, and the tip surface (14b) of the tip may be flush with the rake face of the tool body. This cutting tool makes it easy to detect any tilt or lift of the tip when joining the tip.

[0056] (Appendix 6) In the cutting tool according to any one of Supplementary Notes 1 to 5, the tip may have a chip-breaking breaker (42) on the tip surface (14b). This cutting tool allows the breaker to be formed efficiently.

[0057] (Appendix 7) Another aspect of the above disclosure is a tool having: a tool body that rotates relative to a workpiece about an axis; a cutting edge formed at a tip of the tool body; a mounting seat in which a rake face of the cutting edge is notched in a concave shape; a tip that is disposed in the mounting seat and joined to the tool body; a first positioning portion that has a first engaging portion formed on a side surface of the tip; and a first locking portion that is formed on a step of the mounting seat and locks the first engaging portion; a second engaging portion that is formed on a side surface of the tip at a position different from the first positioning portion; and a second locking portion that is formed on the step of the mounting seat and locks the second engaging portion. and a second positioning portion configured to engage the first engaging portion and the second engaging portion, the method comprising the steps of: preparing the tip having the first engaging portion and the second engaging portion; preparing the tool body on which the mounting seat having the first locking portion and the second locking portion is formed; a positioning step of locking the first engaging portion with the first locking portion and locking the second engaging portion with the second locking portion to position the tip on the mounting seat; and a joining step of brazing the tip positioned on the mounting seat to the tool body.

[0058] The above-described method for manufacturing a cutting tool allows the tip to be joined to the tool body with high positional accuracy, thereby significantly reducing the time required to manufacture the cutting tool and reducing manufacturing costs.

[0059] (Appendix 8) The method for manufacturing a cutting tool according to Appendix 7 may further include a breaker forming step of forming a breaker for breaking chips on the rake face of the tip, the breaker forming step being performed before the positioning step. This method for manufacturing a cutting tool can form a breaker on the tip before it is joined to the tool body. This significantly reduces the time required to manufacture the cutting tool and reduces manufacturing costs.

[0060] (Appendix 9) Another aspect of the above disclosure provides a tool body that rotates relative to a workpiece around an axis, a cutting edge formed at a tip of the tool body, a mounting seat in which a rake face of the cutting edge is recessed, a tip that is disposed on the mounting seat and joined to the tool body, a first positioning portion having a first engaging portion formed on a side surface of the tip and a first locking portion formed on a step of the mounting seat and locking the first engaging portion, a second positioning portion having a second engaging portion formed on a side surface of the tip at a position different from the first positioning portion and a second locking portion formed on the step of the mounting seat and locking the second engaging portion, A method for manufacturing a chip used in a cutting tool, the chip having a breaker formed on the chip surface for breaking chips, the method comprising the steps of: preparing a thin-plate chip base material (44) having a plurality of chip forming regions (46) in which the chips are formed; a breaker forming process for forming the breakers for breaking chips by forming a concave-convex structure in each of the chip forming regions of the chip base material; and a chip cutting process for forming the chips by cutting out the chip forming regions while forming the first engaging portion and the second engaging portion after the breaker forming process.

[0061] The above-described method for manufacturing inserts allows breakers for multiple inserts to be formed simultaneously on the surface of a single insert base material, thereby reducing the time required to machine cutting tools and the manufacturing costs of cutting tools.

[0062] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0063] 10, 10A…Cutting tool 12, 12A…Tool body 14...Chip 14b...Chip surface 14e…1st side 14f…2nd side 14g...Corner part 18, 18A...Scooping face 22, 22A...Cutting edge 24...Mounting seat 28...Stepped part 28a...First straight part 28b...second straight section 28c...curved section 30...First locking portion 32...Second locking portion 34...First engaging part 36...First positioning part 38...Second engaging part 40...Second positioning part 42...Breaker 44...Chip base material 46: Chip forming region 48: Step portion

Claims

1. a tool body that rotates relative to the workpiece around an axis; a cutting edge formed at a tip of the tool body; a recessed groove for discharging chips generated by the cutting blade; a mounting seat formed by cutting out a tip of a first inner surface of the recessed groove that is positioned closer to the rotational direction; a tip disposed in the mounting seat and joined to the tool body, the tip having a second cutting edge continuous with the cutting edge, and a breaker formed on a surface adjacent to the second cutting edge to break chips; a first positioning portion having a first engaging portion formed on a side surface of the tip and a first locking portion formed on a step between a bottom surface of the mounting seat and a rake face of the tool body, the first engaging portion being locked; A cutting tool comprising: a second engagement portion formed on a side surface of the tip at a location different from the first engagement portion; and a second locking portion formed on the step portion and locking the second engagement portion, the second positioning portion performing positioning in a direction intersecting the direction in which the first positioning portion performs positioning.

2. 2. The cutting tool according to claim 1, wherein the first positioning portion positions the tip axially relative to the tool body, and the second positioning portion positions the tip radially relative to the tool body.

3. 2. The cutting tool according to claim 1, wherein the step portion is a first linear portion intersecting the cutting edge; a second linear portion extending in a direction intersecting the first linear portion; a curved portion connecting the first linear portion and the second linear portion with a curved surface, The cutting tool, wherein the first engaging portion is located at the first linear portion and the second engaging portion is located at the second linear portion.

4. 4. The cutting tool according to claim 3, wherein the tip comprises: a first side surface abutting the first linear portion; a second side surface abutting the second linear portion; a corner portion connecting the first side surface and the second side surface with a curved surface, The first engagement portion is located on the first side surface, and the second engagement portion is located on the second side surface.

5. 2. The cutting tool according to claim 1, wherein the thickness of the tip is the same as the height of the mounting seat, and the tip surface of the tip is flush with the rake face of the tool body.

6. a tool body that rotates relative to a workpiece around an axis; a cutting edge formed at a tip of the tool body; a recessed groove for discharging chips generated by the cutting edge; a mounting seat formed by concavely cutting out a tip of a first inner surface of the recessed groove that is closer to the rotation direction; a tip that is disposed on the mounting seat and joined to the tool body, and has a second cutting edge continuous with the cutting edge; and a breaker formed on a surface adjacent to the second cutting edge for breaking up chips; a first positioning part that has a first engaging portion formed on a side surface of the tip and a first locking portion that is formed on a step between a bottom surface of the mounting seat and a rake face of the tool body and locks the first engaging portion; and a second positioning part that has a second engaging portion formed on a side surface of the tip at a position different from the first positioning part and a second locking portion that is formed on the step and locks the second engaging portion, preparing the tip having the first engaging portion and the second engaging portion; preparing the tool body on which the mounting seat having the first locking portion and the second locking portion is formed; a positioning step of positioning the tip on the mounting seat by locking the first engaging portion with the first locking portion and locking the second engaging portion with the second locking portion; and a joining step of brazing the tip positioned in the mounting seat to the tool body.

7. 7. The method for manufacturing a cutting tool according to claim 6, further comprising a breaker forming step of forming the breaker for breaking chips on a rake face of the insert, the breaker forming step being performed before the positioning step.

8. a tool body that rotates relative to a workpiece around an axis, a cutting edge formed at a tip of the tool body, a recessed groove for discharging chips generated by the cutting edge, a mounting seat formed by concavely cutting out a tip of a first inner surface of the recessed groove that is positioned closer to the rotation direction, a second cutting edge that is disposed on the mounting seat and joined to the tool body, and that continues to the cutting edge, and a breaker that is formed on a surface adjacent to the second cutting edge and that breaks chips, a first positioning part that has a first engaging portion formed on a side surface of the tool body and a first locking portion that is formed on a step between a bottom surface of the mounting seat and a rake face of the tool body and that locks the first engaging portion, and a second positioning part that has a second engaging portion formed on a side surface of the tool body at a position different from the first positioning part, and a second locking portion that is formed on the step and that locks the second engaging portion, and that performs positioning in a direction intersecting a direction in which the first positioning part positions the tool body, preparing a thin-plate-shaped chip base material having a plurality of chip forming regions in which the chips are to be formed; a breaker forming step of forming the breaker for breaking chips by forming a concave-convex structure in each of the chip forming regions of the chip base material; a chip cutting step, which is performed after the breaker forming step, by cutting out the chip forming region while forming the first engaging portion and the second engaging portion, to form the chip; A method for manufacturing a chip having the above structure.

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