Chamfering tool

Abstract

The chamfering tool rotates around an axis. The chamfering tool has a rake face, a front flank, a rear flank, a front cutting edge, and a rear cutting edge. The front flank is continuous with the rake face. The rear flank is located axially rearward of the front flank and is continuous with the rake face and the front flank. The front cutting edge is formed by the ridge line between the rake face and the front flank. The rear cutting edge is formed by the ridge line between the rake face and the rear flank. In the radial direction of the chamfering tool, the front end of the front cutting edge is located more inward than the rear end of the front cutting edge. In the radial direction of the chamfering tool, the front end of the rear cutting edge is located more outward than the rear end of the rear cutting edge. The true rake angle of the front cutting edge is greater than 0°. The true rake angle of the rear cutting edge is greater than 0°.

Description

[Technical Field]

[0001] The present disclosure relates to a chamfering tool. [Background technology]

[0002] Japanese Patent Application Laid-Open No. 2021-74798 (Patent Document 1) discloses a chamfering tool that can chamfer the edge of the upper surface of a workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-74798 Summary of the Invention

[0004] The chamfering tool according to the present disclosure rotates around an axis. The chamfering tool includes a rake face, a leading flank, a trailing flank, a leading cutting edge, and a trailing cutting edge. The leading flank is continuous with the rake face. The trailing flank is located axially rearward of the leading flank and is continuous with the rake face and the leading flank. The leading cutting edge is formed by a ridge line between the rake face and the leading flank. The trailing cutting edge is formed by a ridge line between the rake face and the trailing flank. In the radial direction of the chamfering tool, the leading end of the leading cutting edge is located more inward than the trailing end of the leading cutting edge. In the radial direction of the chamfering tool, the leading end of the trailing cutting edge is located more outward than the trailing end of the trailing cutting edge. The true rake angle of the leading cutting edge is greater than 0°. The true rake angle of the trailing cutting edge is greater than 0°. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a front view of a chamfering tool according to a first embodiment. [Figure 2] FIG. 2 is a side view of the chamfering tool according to the first embodiment. [Figure 3] FIG. 3 is a partially enlarged side view of region III in FIG. [Figure 4]FIG. 4 is a perspective view showing the true rake angle of the leading cutting edge. [Figure 5] FIG. 5 is a perspective view showing the true rake angle of the trailing cutting edge. [Figure 6] FIG. 6 is a schematic diagram showing how the top surface of a workpiece is chamfered using the front cutting edge. [Figure 7] FIG. 7 is a schematic diagram showing how the rear cutting edge is used to chamfer the bottom surface of a workpiece. DETAILED DESCRIPTION OF THE INVENTION

[0006] [Problem to be solved by this disclosure] Chamfering tools have been known that have a front cutting edge that chamfers the edge of the upper surface of a workpiece and a rear cutting edge that chamfers the edge of the lower surface of the workpiece. In such chamfering tools, the radial rake angle is generally less than 0° and the axial rake angle is greater than 0°. However, when chamfering is performed using such a chamfering tool, cutting resistance is high.

[0007] An object of the present disclosure is to provide a chamfering tool with reduced cutting forces. [Effects of this disclosure] According to the present disclosure, it is possible to provide a chamfering tool with reduced cutting resistance.

[0008] [Outline of the embodiment] First, an overview of the embodiment of the present disclosure will be described.

[0009] (1) A chamfering tool according to the present disclosure rotates around an axis. The chamfering tool includes a rake face, a front flank, a rear flank, a front cutting edge, and a rear cutting edge. The front flank is continuous with the rake face. The rear flank is located axially rearward of the front flank and is continuous with the rake face and the front flank. The front cutting edge is formed by a ridge between the rake face and the front flank. The rear cutting edge is formed by a ridge between the rake face and the rear flank. In the radial direction of the chamfering tool, the front end of the front cutting edge is located more inward than the rear end of the front cutting edge. In the radial direction of the chamfering tool, the front end of the rear cutting edge is located more outward than the rear end of the rear cutting edge. The true rake angle of the front cutting edge is greater than 0°. The true rake angle of the rear cutting edge is greater than 0°.

[0010] The chamfering tool according to the present disclosure reduces cutting resistance when chamfering a workpiece. As a result, it is possible to suppress the generation of secondary burrs and work-affected layers during chamfering. Furthermore, the reduced cutting resistance improves the life of the chamfering tool.

[0011] (2) According to the chamfering tool of (1) above, the radial rake angle may be greater than 0°. This makes the true rake angle of the leading cutting edge and the true rake angle of the trailing cutting edge both greater than 0°.

[0012] (3) According to the chamfering tool of (1) or (2) above, the radial rake angle may be 1° or more, so that the true rake angle of the leading cutting edge and the true rake angle of the trailing cutting edge are both greater than 0°.

[0013] (4) In the chamfering tool according to any one of (1) to (3) above, the rake angle in the axial direction may be between −10° and 10°, inclusive, so that the true rake angle of the leading cutting edge and the true rake angle of the trailing cutting edge are both greater than 0°.

[0014] (5) In the chamfering tool according to any one of (1) to (4) above, the rake angle in the axial direction may be between −5° and 5°, so that the true rake angle of the leading cutting edge and the true rake angle of the trailing cutting edge are both greater than 0°.

[0015] (6) In the chamfering tool according to any one of (1) to (5) above, the number of front cutting edges may be 3 or more and 6 or less. This reduces cutting resistance when chamfering the top surface of the workpiece.

[0016] (7) According to the chamfering tool of any one of (1) to (6) above, the number of rear cutting edges may be 3 or more and 6 or less. This reduces cutting resistance when chamfering the lower surface of the workpiece.

[0017] [Details of the embodiment] Hereinafter, details of an embodiment of the present disclosure (hereinafter also referred to as the present embodiment) will be described with reference to the drawings. Note that in the following drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0018] (First embodiment) First, a chamfering tool 100 according to a first embodiment will be described.

[0019] Fig. 1 is a front view of a chamfering tool 100 according to a first embodiment. Fig. 2 is a side view of the chamfering tool 100 according to the first embodiment. Fig. 3 is a partially enlarged side view of a region III in Fig. 2.

[0020] The chamfering tool 100 rotates around an axis A. Specifically, as shown in FIG. anti The chamfering tool 100 rotates clockwise around an axis A. A direction perpendicular to the axis A and directed radially outward from the axis A is defined as a radial direction.

[0021] As shown in FIG. 2 , the chamfering tool 100 has a front end 4 and a rear end 5. An axis A extends from the front end 4 along the rear end 5. The direction from the front end 4 to the rear end 5 is referred to as the rearward axial direction. The direction from the rear end 5 to the front end 4 is referred to as the forward axial direction. The front end 4 and the rear end 5 are planes perpendicular to the axis A.

[0022] The chamfering tool 100 has a cutting portion 1 and a main body portion 2. The cutting portion 1 is connected to the main body portion 2. The cutting portion 1 is located axially forward of the main body portion 2. Specifically, the main body portion 2 includes a shank region 2a and a narrow region 2b. In the radial direction, the diameter of the narrow region 2b is smaller than the diameter of the shank region 2a.

[0023] The rear end portion 5 is formed by the shank region 2a. The narrow region 2b is continuous with the shank region 2a. The narrow region 2b is located axially forward of the shank region 2a. The cutting portion 1 is continuous with the narrow region 2b. The cutting portion 1 is located axially forward of the narrow region 2b. The front end portion 4 is formed by the cutting portion 1.

[0024] 3, the chamfering tool 100 has a front flank 10, a rear flank 20, a rake face 30, a front cutting edge 13, and a rear cutting edge 23. The front flank 10, the rear flank 20, the rake face 30, the front cutting edge 13, and the rear cutting edge 23 are formed on the cutting portion 1.

[0025] The rake face 30 is continuous with the front flank 10, the rear flank 20, and the front end portion 4. The front flank 10 is continuous with the front end portion 4, the rake face 30, and the rear flank 20. The rear flank 20 is continuous with the rake face 30 and the front flank 10.

[0026] 3, the front flank 10 is disposed so as to be sandwiched between the front end portion 4 and the rear flank 20 in the axial direction. In other words, the front flank 10 is located forward of the rear flank 20 in the axial direction. The rear flank 20 is located rearward of the front flank 10 in the axial direction.

[0027] The front flank 10 includes a first front flank 11 and a second front flank 12. The first front flank 11 is located forward of the second front flank 12 in the direction of rotation (see FIG. 1). The rear flank 20 includes a first rear flank 21 and a second rear flank 22. The first rear flank 21 is located forward of the second rear flank 22 in the direction of rotation.

[0028] The front cutting edge 13 is formed by the ridgeline between the rake face 30 and the first front flank 11 of the front flank 10. By bringing the front cutting edge 13 into contact with the end 201 on the top surface of the workpiece 200 while rotating the chamfering tool 100 according to the first embodiment, the end 201 on the top surface of the workpiece 200 can be chamfered (see FIG. 6).

[0029] The rear cutting edge 23 is formed by the ridgeline between the rake face 30 and the first rear flank 21 of the rear flank 20. By bringing the rear cutting edge 23 into contact with the end 202 on the underside of the workpiece 200 while rotating the chamfering tool 100 according to the first embodiment, the end 202 on the underside of the workpiece 200 can be chamfered (see FIG. 7).

[0030] 1, the chamfering tool 100 has an outer peripheral end 40. The outer peripheral end 40 is disposed at a position in the cutting portion 1 farthest from the axis A in the radial direction.

[0031] 3, the front end 13a of the leading cutting edge 13 is continuous with the front end portion 4. The rear end 13b of the leading cutting edge 13 is continuous with the outer peripheral edge 40. In other words, in the radial direction of the chamfering tool 100, the front end 13a of the leading cutting edge 13 is disposed more inward than the rear end 13b of the leading cutting edge 13.

[0032] A front end 23a of the rear cutting edge 23 is continuous with the outer peripheral edge 40. That is, in the radial direction of the chamfering tool 100, the front end 23a of the rear cutting edge 23 is disposed outward of the rear end 23b of the rear cutting edge 23.

[0033] In this way, the front cutting edges 13 and the rear cutting edges 23 are connected via the outer peripheral end 40. As a result, the number of each of the front cutting edges 13 and the rear cutting edges 23 can be three or more. In addition, the strength of the chamfering tool 100 is improved.

[0034] The number of each of the leading cutting edges 13 and the trailing cutting edges 23 configured as described above may be 3 or more and 6 or less. In the chamfering tool 100 according to the first embodiment, the number of each of the leading cutting edges 13 and the trailing cutting edges 23 is 3. In this way, by increasing the number of each of the leading cutting edges 13 and the trailing cutting edges 23, the cutting resistance of each cutting edge when chamfering the workpiece 200 is reduced.

[0035] FIG. 4 is a perspective view showing the true rake angle θ1 of the leading cutting edge 13. FIG. 5 is a perspective view showing the true rake angle θ2 of the trailing cutting edge 23. As used herein, the "true rake angle θ1 of the leading cutting edge 13" refers to the angle between the axis A and the trailing cutting edge 23 when viewed from a direction perpendicular to the trailing cutting edge 23 (the direction along arrow D1 in FIG. 3) at a position where the outer peripheral edge 40 (the rear end 13b of the leading cutting edge 13) overlaps with the axis A, as shown in FIG. 4. As used herein, the "true rake angle θ2 of the trailing cutting edge 23" refers to the angle between the axis A and the leading cutting edge 13 when viewed from a direction perpendicular to the leading cutting edge 13 (the direction along arrow D2 in FIG. 3) at a position where the outer peripheral edge 40 (the front end 23a of the trailing cutting edge 23) overlaps with the axis A, as shown in FIG.

[0036] As shown in Figure 4, when the rear end 23b of the rear cutting edge 23 is located rearward in the direction of rotation with respect to the axis A, the true rake angle θ1 is positive. As shown in Figure 5, when the front end 13a of the front cutting edge 13 is located rearward in the direction of rotation with respect to the axis A, the true rake angle θ2 is positive.

[0037] In the chamfering tool 100 according to the first embodiment, as shown in FIG. 4, the true rake angle θ1 of the leading cutting edge 13 is greater than 0°. The true rake angle θ1 may be 3° or greater, or even 7° or greater. In the chamfering tool 100 according to the first embodiment, as shown in FIG. 5, the true rake angle θ2 of the trailing cutting edge 23 is greater than 0°. The true rake angle θ2 may be 3° or greater, or even 7° or greater. When the true rake angle θ1 and the true rake angle θ2 are both greater than 0°, the cutting resistance is reduced when chamfering the top end 201 and the bottom end 202 of the workpiece 200. As a result, the generation of secondary burrs and work-affected layers during chamfering can be suppressed. Furthermore, the reduced cutting resistance reduces the wear of the leading cutting edge 13 and the trailing cutting edge 23. As a result, the life of the chamfering tool 100 is improved.

[0038] The true rake angle θ1 of the leading cutting edge 13 and the true rake angle θ2 of the trailing cutting edge 23 are determined by the radial rake angle θr and the axial rake angle θz of the chamfering tool 100.

[0039] 1, the "radial rake angle θr" in this specification is the angle between the leading cutting edge 13 and a line passing from the axis A through the outer peripheral end 40 when viewed from the direction along the axis A. When the leading end 13a of the leading cutting edge 13 is located rearward in the rotational direction relative to the outer peripheral end 40 (rear end 13b of the leading cutting edge 13) when viewed from the direction along the axis A, the radial rake angle θr is positive. In the chamfering tool 100 according to the first embodiment, the radial rake angle θr is 10°.

[0040] In this specification, the "axial rake angle θz" is the angle between the axis A and the rake face 30. When the rear cutting edge 23 is located forward in the rotation direction relative to the front cutting edge 13 as viewed from the direction along the axis A, the axial rake angle θz is positive. In the chamfering tool 100 according to the first embodiment, the axial rake angle θz is 0°, and the rake face 30 and the axis A are parallel to each other.

[0041] The radial rake angle θr may be greater than 0° or may be equal to or greater than 1°. The axial rake angle θz may be greater than or equal to -10° and less than or equal to 10°, or greater than or equal to -5° and less than or equal to 5°. In this way, the true rake angle θ1 of the leading cutting edge 13 and the true rake angle θ2 of the trailing cutting edge 23 are both greater than 0°.

[0042] <Operation> Fig. 6 is a schematic diagram showing how the top surface of the workpiece 200 is chamfered using the front cutting edge 13. Fig. 7 is a schematic diagram showing how the bottom surface of the workpiece 200 is chamfered using the rear cutting edge 23.

[0043] When chamfering the end 201 on the top surface of the workpiece 200, first, the chamfering tool 100 according to the first embodiment is rotated and the front cutting edge 13 is brought into contact with the end 201 on the top surface of the workpiece 200. Next, as shown in Fig. 6, the chamfering tool 100 is moved in the direction of arrow D3, thereby chamfering the end 201.

[0044] When chamfering the end 202 on the underside of the workpiece 200, first, the chamfering tool 100 according to the first embodiment is rotated and the rear cutting edge 23 is brought into contact with the end 202 on the underside of the workpiece 200. Next, as shown in Fig. 7, the chamfering tool 100 is moved in the direction of arrow D4, thereby chamfering the end 202.

[0045] Next, the effects of the chamfering tool 100 according to the present disclosure will be described. Conventionally, when chamfering a workpiece 200 using a chamfering tool 100, cutting resistance has been large. In addition, with the demand for high finish accuracy of the workpiece 200 after chamfering, there is a need to suppress secondary burrs.

[0046] The chamfering tool 100 according to this embodiment rotates around an axis A. The chamfering tool 100 includes a rake face 30, a leading flank 10, a rear flank 20, a leading cutting edge 13, and a rear cutting edge 23. The leading flank 10 is continuous with the rake face 30. The rear flank 20 is located rearward of the leading flank 10 in the axial direction and is continuous with the rake face 30 and the leading flank 10. The leading cutting edge 13 is formed by the ridgeline between the rake face 30 and the leading flank 10. The rear cutting edge 23 is formed by the ridgeline between the rake face 30 and the rear flank 20. In the radial direction of the chamfering tool 100, the leading end 13a of the leading cutting edge 13 is located more inward than the rear end 13b of the leading cutting edge 13. In the radial direction of the chamfering tool 100, the leading end 23a of the rear cutting edge 23 is located more outward than the rear end 23b of the rear cutting edge 23. The true rake angle θ1 of the leading cutting edge 13 is greater than 0°. The true rake angle θ2 of the trailing cutting edge 23 is greater than 0°. This reduces the cutting resistance when chamfering both the upper and lower end portions 201, 202 of the workpiece 200. As a result, the generation of secondary burrs and work-affected layers during chamfering can be suppressed. Furthermore, the reduced cutting resistance improves the life of the chamfering tool 100.

[0047] According to the chamfering tool 100 of this embodiment, the number of front cutting edges 13 is equal to or greater than 3 and equal to or less than 6. This reduces cutting resistance when the top surface of the workpiece 200 is chamfered.

[0048] According to the chamfering tool 100 of this embodiment, the number of rear cutting edges 23 is equal to or greater than 3 and equal to or less than 6. This reduces cutting resistance when the lower surface of the workpiece 200 is chamfered.

[0049] <Example> (Sample preparation) First, chamfering tools 100 of Samples 1 to 4 were prepared. In the chamfering tools 100 of Samples 1 to 4, the number of front cutting edges 13 and rear cutting edges 23 was all 3. The cutting diameter of the chamfering tools 100 of Samples 1 to 4 was 6 mm.

[0050] The chamfering tools 100 of Samples 1 to 4 are made of cemented carbide. A coating film is formed on the surface of the chamfering tools 100 of Samples 1 to 4. The coating film of the chamfering tool 100 of Sample 1 is a TiAlCrN coating containing titanium (Ti), aluminum (Al), chromium (Cr), and nitrogen (N). The coating film of the chamfering tool 100 of Sample 2 is a TiAlN coating containing Ti, Al, and N. The coating film of the chamfering tool 100 of Sample 3 is a CrN coating containing Cr and N.

[0051] Samples 1 to 3 are comparative examples. In the comparative examples, either the true rake angle θ1 or the true rake angle θ2 is less than 0°. Sample 4 is an example. In the example, both the true rake angle θ1 and the true rake angle θ2 are greater than 0°. The radial rake angle θr, axial rake angle θz, true rake angle θ1, and true rake angle θ2 for each sample are as shown in Table 1.

[0052] [Table 1]

[0053] (Processing conditions 1) Next, in the case where the workpiece 200 was a titanium alloy plate, the chamfering tools 100 of Samples 1 to 4 were used to chamfer an edge 201 on the upper surface of the workpiece 200 and an edge 202 on the lower surface of the workpiece 200. The edge 201 on the upper surface was chamfered by the front cutting edge 13. The edge 202 on the lower surface was chamfered by the rear cutting edge 23. The width of the chamfered workpiece 200 was 220 mm.

[0054] A BT30 machine was used as a vertical machining center. The cutting speed Vc was 100 m / min. The feed rate f was 0.033 mm / revolution. The chamfering amount was 0.5 mm so that the end 201 and the end 202 were C-chamfered.

[0055] The workpiece 200 is a titanium (Ti) alloy plate, which is mainly used in the aviation industry. The titanium alloy plate contains 6 mass percent aluminum and 4 mass percent vanadium (V). Under machining condition 1, the cemented carbide used in the chamfering tool 100 of sample 4 is a cemented carbide alloy with a grade of KH26 (manufactured by Sumitomo Electric Industries, Ltd.).

[0056] (Test result 1) The height of the burrs generated on the end 201 on the upper surface and the end 202 on the lower surface, the amount of wear on the front cutting edge 13 and the rear cutting edge 23, and the cutting resistance acting on the chamfering tool 100 were evaluated. Note that the cutting resistance is the resultant force of the cutting resistance in the x and y directions, and the cutting resistance in the axial direction (z direction) is not taken into consideration. Table 2 shows the test results under machining condition 1, where the workpiece 200 was a titanium alloy plate.

[0057] [Table 2]

[0058] As shown in Table 2, when each of the chamfering tools 100 of Samples 1 to 3 was used, the height of the burrs generated on the upper surface end 201 and the lower surface end 202 was 5 μm or more. On the other hand, when the chamfering tool 100 of Sample 4 was used, the height of the burrs generated on the upper surface end 201 and the lower surface end 202 was 0 μm. Thus, by using the chamfering tool 100 in which the true rake angle θ1 and the true rake angle θ2 are both greater than 0°, the finish of the workpiece 200 after chamfering is improved.

[0059] As shown in Table 2, when each of the chamfering tools 100 of Samples 1 to 3 was used, the wear amount of the leading cutting edge 13 and the trailing cutting edge 23 was 10 μm or more. On the other hand, when the chamfering tool 100 of Sample 4 was used, the wear amount of the leading cutting edge 13 and the trailing cutting edge 23 was 5 μm. Thus, by using a chamfering tool 100 in which both the true rake angle θ1 and the true rake angle θ2 are greater than 0°, the wear amount of the leading cutting edge 13 and the trailing cutting edge 23 is reduced.

[0060] As shown in Table 2, when each of the chamfering tools 100 of Samples 1 to 3 was used, the cutting resistance applied to the leading cutting edge 13 when the end 201 of the upper surface was chamfered and the cutting resistance applied to the trailing cutting edge 23 when the end 202 of the lower surface was chamfered were both 25 N or greater. On the other hand, the cutting resistance applied to the leading cutting edge 13 when the end 201 of the upper surface was chamfered and the cutting resistance applied to the trailing cutting edge 23 when the end 202 of the lower surface was chamfered were both less than 25 N. Thus, by using a chamfering tool 100 in which the true rake angle θ1 and the true rake angle θ2 are both greater than 0°, the cutting resistance of the leading cutting edge 13 and the trailing cutting edge 23 is reduced.

[0061] (Processing conditions 2) Next, in the case where the workpiece 200 is Inconel (registered trademark) 718, the chamfering tools 100 of Samples 1 to 4 were used to chamfer an edge 201 on the upper surface of the workpiece 200 and an edge 202 on the lower surface of the workpiece 200. The edge 201 on the upper surface is chamfered by the front cutting edge 13. The edge 202 on the lower surface is chamfered by the rear cutting edge 23. The width of the chamfered workpiece 200 is 220 mm.

[0062] The vertical machining center used was an NVX5100 manufactured by DGM Mori Seiki Co., Ltd. The cutting speed Vc was set to 30 m / min. The feed rate f was set to 0.033 mm / revolution. The chamfering amount was set to 0.5 mm so that the end 201 and the end 202 were C-chamfered.

[0063] The workpiece 200 is Inconel 718. In the processing condition 2, the cemented carbide in the chamfering tool 100 of Sample 4 is an AFU cemented carbide (manufactured by Sumitomo Electric Industries, Ltd.).

[0064] (Test result 2) The height of the burrs generated on the end 201 on the upper surface and the end 202 on the lower surface, the amount of wear on the front cutting edge 13 and the rear cutting edge 23, and the cutting resistance acting on the chamfering tool 100 were evaluated. Note that the cutting resistance is the resultant force of the cutting resistance in the x and y directions, and the cutting resistance in the axial direction (z direction) is not taken into consideration. Table 3 shows the test results under machining condition 2, where the workpiece 200 was a titanium alloy plate.

[0065] [Table 3]

[0066] As shown in Table 3, when each of the chamfering tools 100 of Samples 1 to 3 was used, the height of the burrs generated at the end 201 of the upper surface was 8 μm or more. On the other hand, when the chamfering tool 100 of Sample 4 was used, the height of the burrs generated at the end 201 of the upper surface was 5 μm. The height of the burrs generated at the end 202 of the lower surface was 30 μm or more. On the other hand, when the chamfering tool 100 of Sample 4 was used, the height of the burrs generated at the end 202 of the lower surface was 11 μm. As such, by using the chamfering tool 100 in which both the true rake angle θ1 and the true rake angle θ2 are greater than 0°, the finish of the workpiece 200 after chamfering is improved.

[0067] As shown in Table 3, when each of the chamfering tools 100 of Samples 1 to 3 was used, the wear amounts of the leading cutting edge 13 and the trailing cutting edge 23 were 40 μm or more. On the other hand, when the chamfering tool 100 of Sample 4 was used, the wear amounts of the leading cutting edge 13 and the trailing cutting edge 23 were 35 μm or less. Thus, by using a chamfering tool 100 in which both the true rake angle θ1 and the true rake angle θ2 are greater than 0°, the wear amounts of the leading cutting edge 13 and the trailing cutting edge 23 are reduced.

[0068] As shown in Table 3, when each of the chamfering tools 100 of Samples 1 to 3 was used, the cutting resistance applied to the leading cutting edge 13 when the end 201 of the upper surface was chamfered and the cutting resistance applied to the trailing cutting edge 23 when the end 202 of the lower surface was chamfered were both 90 N or greater. On the other hand, the cutting resistance applied to the leading cutting edge 13 when the end 201 of the upper surface was chamfered and the cutting resistance applied to the trailing cutting edge 23 when the end 202 of the lower surface was chamfered were both less than 80 N. Thus, by using a chamfering tool 100 in which the true rake angle θ1 and the true rake angle θ2 are both greater than 0°, the cutting resistance of the leading cutting edge 13 and the trailing cutting edge 23 is reduced.

[0069] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The basic scope of the present disclosure is defined by the claims, not the above-described embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0070] 1 cutting part, 2 body part, 2a shank area, 2b narrow area, 4 front end, 5 rear end, 10 front flank, 11 first front flank, 12 second front flank, 13 front cutting edge, 13a, 23a front end, 13b, 23b rear end, 20 rear flank, 21 first rear flank, 22 second rear flank, 23 rear cutting edge, 30 rake face, 40 peripheral edge, 100 chamfering tool, 200 workpiece, 201, 202 end, A axis, D1, D2, D3, D4 arrows, θ1, θ2 true rake angle, θr radial rake angle, θz axial rake angle.

Claims

1. A chamfering tool that rotates around an axis, The scooping surface and a front flank surface connected to the rake surface; a rear flank located rearward of the front flank in the axial direction and continuous with the rake face and the front flank; a front cutting edge formed by a ridge line between the rake face and the front flank; a rear cutting edge formed by a ridge line between the rake face and the rear flank, In the radial direction of the chamfering tool, a front end of the front cutting edge is disposed more inward than a rear end of the front cutting edge, In the radial direction of the chamfering tool, a front end of the rear cutting edge is disposed outward of a rear end of the rear cutting edge, The true rake angle of the leading cutting edge is greater than 0°, A chamfering tool, wherein the true rake angle of the trailing cutting edge is greater than 0°.

2. A chamfering tool as described in claim 1, wherein the radial rake angle is greater than 0°.

3. A chamfering tool as described in claim 1 or claim 2, wherein the radial rake angle is 1° or more.

4. The rake face is a flat surface, 3. The chamfering tool according to claim 1, wherein a rake angle in the axial direction is between −10° and 10°.

5. The rake face is a flat surface, The chamfering tool according to claim 1 or 2, wherein a rake angle in the axial direction is not less than −5° and not more than 5°.

6. The chamfering tool according to claim 1 or 2, wherein the number of the front cutting edges is 3 or more and 6 or less.

7. The chamfering tool according to claim 1 or 2, wherein the number of the rear cutting edges is 3 or more and 6 or less.

Images