Gear machining tool and method of manufacturing the same

Abstract

To provide a gear machining tool having abrasive grains and preventing waste of the abrasive grains.SOLUTION: The gear machining tool 1 is a gear machining tool for polishing a tooth surface formed on a workpiece, and includes an annular base material blade part 12 having a plurality of blades 14 on an outer peripheral surface at one end of a shaft-like base material body part 11. And a plurality of abrasive grains provided on the rake face 14a so as to overlap a ridge line portion 15 which is a boundary between the flank face and the rake face 14a when viewed from the direction of the rotation axis C of the substrate 10, in which the abrasive grains are not provided in a region other than the ridge line portion 15 on the flank face. 14a.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a gear cutting tool and a method for manufacturing the same. [Background technology]

[0002] As a conventional gear cutting tool for processing tooth surfaces, Patent Document 1 discloses a finishing cutting tool in which abrasive grains are blended into the base material of a pinion cutter, and Patent Document 2 discloses an electroplated abrasive tool in which abrasive grains are fixed to the surface of a base material by electrodeposition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-303715 [Patent Document 2] Japanese Patent Publication No. 2022-129415 Summary of the Invention [Problem to be solved by the invention]

[0004] A gear cutting tool having abrasive grains on its surface can be configured to use a gear skiving cutter as a base material, which is a gear cutting tool having a configuration in which an annular base cutting portion with multiple blades on its outer peripheral surface is provided at one end of a shaft-shaped base body, and abrasive grains are provided on the surface of the base cutting portion. However, the flank face of the gear skiving cutter does not come into contact with the tooth surface of the workpiece to be machined during machining in areas other than the ridge line that forms a ridge with the rake face, so even if abrasive grains are placed on the flank face in areas other than the ridge line, the abrasive grains do not substantially participate in machining the tooth surface and are wasted.

[0005] The present invention has been made in view of the above-mentioned problems, and aims to provide a gear cutting tool that is equipped with abrasive grains and that prevents the abrasive grains from being wasted. [Means for solving the problem]

[0006] One aspect of the present invention is A gear cutting tool for polishing a tooth surface formed on a workpiece, a substrate provided at one end of a shaft-shaped substrate main body with an annular substrate blade portion having a plurality of blades on its outer peripheral surface, the substrate blade portion having a flank surface located on the outer peripheral side of the substrate blade portion, and a rake surface located on an end side of the substrate blade portion in the direction of the rotation axis C; a plurality of abrasive grains provided on the rake face so as to overlap a ridge portion that is a boundary between the flank face and the rake face when viewed from the rotation axis direction of the base material; Equipped with In the gear cutting tool, no abrasive grains are provided on the flank surface except in the area of ​​the ridge line portion.

[0007] Another aspect of the present invention is A method for manufacturing a gear cutting tool for polishing a tooth surface formed on a workpiece, comprising: a preparation step of preparing a substrate having an annular substrate blade portion having a plurality of blades on an outer peripheral surface at one end of a shaft-shaped substrate main body, the substrate having a flank surface facing the outer peripheral surface of the substrate blade portion, a rake surface facing an end side in the rotation axis direction, and a ridge portion that is a boundary between the flank surface and the rake surface; a base material arranging step of arranging the base material inside an annular jig to form a gap between the ridge line portion and a ridge line opposing portion opposing the ridge line portion in the annular jig; an abrasive grain arranging step of arranging a plurality of abrasive grains on the rake face along the ridge line opposing portion so as to overlap the ridge line portion when viewed from the rotation axis direction of the base material; and an abrasive grain fixing step of fixing the abrasive grains to the rake face. [Effects of the Invention]

[0008] In the gear cutting tool of the above embodiment, a plurality of abrasive grains are provided on the rake face of the substrate so as to overlap the ridge line portion when viewed from the direction of the rotation axis of the substrate. This allows the gear cutting tool to polish the tooth surface of the workpiece with the abrasive grains. Furthermore, since no abrasive grains are provided on the flank face of the substrate other than the ridge line portion, waste of abrasive grains is prevented.

[0009] In the method for manufacturing a gear cutting tool of the other aspect described above, an annular jig is used to arrange a plurality of abrasive grains along the ridgeline-facing portion of the annular jig as viewed from the direction of the rotation axis of the base material, with a gap formed between the ridgeline portion of the base material and the ridgeline-facing portion on the inside of the annular jig. This allows the plurality of abrasive grains to be easily arranged so as to overlap the ridgeline portion with high precision, reducing the workload for arranging the plurality of abrasive grains and preventing abrasive grain waste by reducing the provision of abrasive grains that are not involved in processing.

[0010] As described above, according to the above aspect, it is possible to provide a gear cutting tool that includes abrasive grains and prevents the abrasive grains from being wasted. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view of a gear cutting tool according to a first embodiment. [Figure 2] FIG. 1 is a vertical cross-sectional view of a gear cutting tool according to a first embodiment. [Figure 3] FIG. 2 is a flowchart showing a method for manufacturing a gear cutting tool according to the first embodiment. [Figure 4] FIG. 2 is a longitudinal cross-sectional view of the gear cutting tool according to the first embodiment, illustrating a method for manufacturing the gear cutting tool. [Figure 5] FIG. 2 is a view of the gear cutting tool according to the first embodiment, seen from the direction of the rotation axis, illustrating a method for manufacturing the gear cutting tool. [Figure 6] FIG. 6 is an enlarged view of the area indicated by VI in FIG. 5. [Figure 7] FIG. 7 is an enlarged view of the area indicated by VII in FIG. 5. [Figure 8]FIG. 10 is a view of a gear cutting tool according to a second embodiment, seen from the direction of its rotation axis, illustrating a method for manufacturing the gear cutting tool. [Figure 9] FIG. 10 is a longitudinal cross-sectional view of a gear cutting tool according to a third embodiment, illustrating a method for manufacturing the gear cutting tool. [Figure 10] FIG. 10 is a view of a gear cutting tool according to a third embodiment, seen from the direction of its rotation axis, illustrating a method for manufacturing the gear cutting tool. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment 1) 1. Gear cutting tool 1 configuration The shape of the gear cutting tool 1 of the first embodiment will be described below with reference to the drawings. The gear cutting tool 1 of the first embodiment is a tooth polishing tool for polishing the tooth surface formed on a workpiece (not shown). The gear cutting tool 1 includes a substrate 10 shown in FIGS. 1 and 2 and a plurality of abrasive grains 20 shown in FIG. 6.

[0013] 2. Base material 10 As shown in Figures 1 and 2, the substrate 10 includes a substrate main body 11 and a substrate blade portion 12. The substrate main body 11 and the substrate blade portion 12 are configured as an integral member. A gear skiving cutter can be used as the substrate 10. The substrate main body 11 is formed in a hollow cylindrical shape. Alternatively, the substrate main body 11 may be formed in a columnar shape.

[0014] The substrate blade portion 12 has a substrate blade portion main body 13 formed in an annular shape and coaxially connected to one end of the substrate main body 11, and a plurality of blades 14 on the outer peripheral surface of the substrate blade portion main body 13. The number of the plurality of blades 14 is not limited, but should be different from the number of teeth formed on the workpiece (not shown) to be machined, and the number of teeth formed on the workpiece should not be an integer multiple of the number of teeth on the substrate blade portion 12. As a result, two or more of the plurality of blades 14 will machine one tooth surface formed on the workpiece. In this embodiment, the number of teeth on the workpiece to be machined (not shown) is, for example, 100, and as shown in Figure 5, the number of teeth on the substrate blade portion 12 is 22.

[0015] As shown in FIG. 2, the substrate cutting portion 12 has a rake face 14a at an end face of the substrate cutting portion 12 in the direction Y of the rotation axis C, the rake face 14a having a rake angle θ with respect to a plane perpendicular to the rotation axis C. The outer peripheral surfaces of the multiple blades 14 of the substrate cutting portion 12 are formed in a truncated cone shape, and the tip surfaces of the multiple blades 14 form front clearance faces 14b having a predetermined front clearance angle with respect to the rake face 14a, and surfaces extending radially inward from the front clearance faces 14b form side clearance faces 14c. The outer peripheral surfaces of the multiple blades 14 of the substrate cutting portion 12 may also be cylindrical. In this specification, the front clearance faces 14b and the side clearance faces 14c are collectively referred to as clearance faces 14bc. In the cross-sectional views of the substrate 10 shown in Figure 2 and Figures 4 and 9 described below, the tooth bottom of the substrate cutting portion 12 is shown schematically so that it can be seen from the top to the bottom in the direction Y of the rotation axis C. However, in reality, since the blade 14 has a twist angle with respect to the direction of the rotation axis C, the tooth bottom of the substrate cutting portion 12 may not be seen from the top to the bottom in the direction Y of the rotation axis C in the cross-sectional views.

[0016] As shown in Fig. 2, a ridge portion 15 is formed between the rake face 14a and the front flank 14b and the side flank 14c, forming a boundary between the two. In this embodiment, as shown in Figs. 6 and 7, the ridge portion 15 includes a first ridge portion 151 that forms a boundary between the rake face 14a and the front flank 14b (see Fig. 2), and a second ridge portion 152 that forms a boundary between the rake face 14a and the side flank 14c (see Fig. 2).

[0017] 2, the substrate cutting portion 12 has a step portion 16 facing the opposite side to the rake face 14a in the direction Y of the rotation axis C of the substrate 10. The step portion 16 is annular and forms a surface parallel to the radial direction X.

[0018] 3. Abrasive grain 20 6, the plurality of abrasive grains 20 are provided on the rake face 14a so as to overlap the ridge line portion 15 when the substrate cutting portion 12 is viewed from the direction Y of the rotation axis C. In this embodiment, the plurality of abrasive grains 20 are provided on the rake face 14a so as to overlap the first ridge line portion 151 when viewed from the direction Y of the rotation axis C, and are also provided on the rake face 14a so as to overlap the second ridge line portion 152. On the other hand, the abrasive grains 20 are not provided on the flank face 14bc.

[0019] The type of abrasive grains 20 is not limited, and can be general abrasive grains made of ceramic materials such as alumina or silicon carbide, or superabrasive grains made of diamond or CBN. The average particle size of the abrasive grains 20 is not limited, and grains having any average particle size can be used. Note that, although the abrasive grains 20 are shown as spherical in FIG. 6 for convenience, the abrasive grains 20 do not have to be spherical.

[0020] The abrasive grains 20 may be provided on the ridge lines 15 of at least two of the blades 14, but on the ridge lines 15 of the remaining blades 14. In this embodiment, as shown in FIG. 5 , the abrasive grains 20 are not provided on the ridge lines 15 of three of the blades 14 (the first blade 141, the second blade 142, and the third blade 143), but on the ridge lines 15 of the remaining blades 14. In this embodiment, when viewed from the direction Y of the rotation axis C of the substrate 10, the rotation axis C of the substrate 10 is located inside a virtual triangle formed by virtual lines L1, L2, and L3 connecting the first blade 141, the second blade 142, and the third blade 143.

[0021] 4. Manufacturing method of gear cutting tool 1 Next, a detailed description will be given of a method for manufacturing the gear cutting tool 1. As shown in Fig. 3, the method for manufacturing the gear cutting tool 1 includes a preparation step S1, a base material arrangement step S2, an abrasive grain arrangement step S3, and an abrasive grain fixing step S4.

[0022] In the preparation step S1, the above-described base material 10 is prepared. In the present embodiment 1, further, in the preparation step S1, the blades 14 to be in contact with the radial contact portions 311 to 313 are determined from among the multiple blades 14 of the base material 10 based on the number of teeth of the workpiece and the number of teeth of the base material 10. In the present embodiment 1, as described above, the first blade 141, the second blade 142, and the third blade 143 shown in FIG. 5 are determined as the blades 14 to be in contact with the radial contact portions 311 to 313.

[0023] Next, in the substrate placement step S2, an annular jig 30 is used, as shown in Figures 4 and 5. The annular jig 30 is annular, and is configured so that the substrate 10 is placed inside the annular jig 30. A ridge line opposing portion 31 that faces the ridge line portion 15 of the substrate 10 in the radial direction X is formed inside the annular jig 30.

[0024] As shown in Figure 5, when the substrate 10 is placed inside the annular jig 30, the ridge opposing portion 31 abuts against the ridge portions 15 of at least two of the multiple blades 14 of the substrate 10 (in this embodiment, the first blade 141, the second blade 142, and the third blade 143), and forms a gap P between it and the ridge portions 15 of the other blades 14.

[0025] 6, the width D2 of the gap P is set to a value smaller than the average grain size D1 of the abrasive grains 20, and can be set to preferably equal to or less than half, and more preferably equal to or less than one-fifth, of the average grain size D1 of the abrasive grains 20. By making the width D2 of the gap P sufficiently smaller than the average grain size D1 of the abrasive grains 20, it is possible to prevent the abrasive grains 20 from entering the gap P.

[0026] 5, portions of the ridgeline opposing portion 31 that come into contact with the ridgeline portions 15 of the first blade 141, the second blade 142, and the third blade 143 are designated as a first radial contact portion 311, a second radial contact portion 312, and a third radial contact portion 313, respectively. In this embodiment, as shown in FIG. 7, the ridgeline portion 15 of the first blade 141 includes a first ridgeline portion 151 and a second ridgeline portion 152. The first ridgeline portion 151 comes into contact with the first radial contact portion 311 to restrict movement in a direction parallel to the radial direction X, and the second ridgeline portion 152 comes into contact with the first radial contact portion 311 to restrict movement in a rotational direction about the rotation axis C. Similarly, the ridge portions 15 of the second blade 142 and the third blade 143 each include a first ridge portion 151 and a second ridge portion 152, which abut against the second radial abutment portion 312 and the third radial abutment portion 313, respectively, thereby restricting movement in a direction parallel to the radial direction X and movement in a rotational direction around the rotation axis C.

[0027] 4, a step abutting portion 32 is formed on the inside of the annular jig 30 to face the step 16 of the substrate 10 in the direction Y of the rotation axis C and abut against the step 16. In the annular jig 30, an upper surface 33, which is the end portion of the substrate 10 on the side of the rake face 14a in the direction Y of the rotation axis C, is configured to be located outward in the direction Y of the rotation axis C of the substrate 10 when the substrate 10 is placed inside the annular jig 30. As a result, the ridge line facing portion 31 on the inside of the annular jig 30 extends upward in the direction Y of the rotation axis C beyond the substrate 10.

[0028] Then, in the substrate placement process S2, as shown in FIG. 5, the substrate 10 placed inside the annular jig 30 is positioned in the radial direction X by the ridge portions 15 of the first blade 141, the second blade 142, and the third blade 143 abutting against the first radial abutment portion 311, the second radial abutment portion 312, and the third radial abutment portion 313, and is also positioned in the direction Y of the rotation axis C by the step portion 16 of the substrate 10 abutting against the step abutment portion 32.

[0029] Next, in the abrasive grain arrangement step S3, for each of the plurality of blades 14 other than the first blade 141, the second blade 142, and the third blade 143, the plurality of abrasive grains 20 are arranged on the rake face 14a along the ridge line facing portion 31 so as to overlap the ridge line portion 15 when viewed from the direction of the rotation axis C of the substrate 10, as shown in FIG. 6. At this time, the width D2 of the gap P is sufficiently smaller than the average particle size D1 of the abrasive grains 20. Therefore, simply by arranging the abrasive grains 20 along the ridge line facing portion 31, the abrasive grains 20 can be arranged on the rake face 14a so as to overlap the ridge line portion 15 but not enter the gap P.

[0030] 6, in the present embodiment, in the blades 14 other than the first blade 141, the second blade 142, and the third blade 143 among the plurality of blades 14, the abrasive grains 20 are arranged on the rake face 14a along the ridge opposing portion 31 so as to overlap both the first ridge portion 151, which is the boundary between the rake face 14a and the front relief surface 14b, and the second ridge portion 152, which is the boundary between the rake face 14a and the side relief surface 14c, of the ridge portion 15. Note that, in the first blade 141, the second blade 142, and the third blade 143, the abrasive grains 20 are not arranged, as shown in FIG.

[0031] Thereafter, in the abrasive grain fixing step S4, the abrasive grains 20 arranged on the rake face 14a are fixed. The method for fixing the abrasive grains 20 in the abrasive grain fixing step S4 is not limited, but the abrasive grains 20 can be fixed by electrodeposition via a plating layer formed by electroless plating. When fixing the abrasive grains 20 by electrodeposition, it is preferable to roughen the surface of the substrate 10 to form a base plating layer (not shown) before the abrasive grain placement step S3, and then place the abrasive grains 20 on the base plating layer on the rake face 14a to form a main plating layer for fixing the abrasive grains 20. The base plating layer and the main fixing plating layer can be, for example, nickel plating. The thickness of the base plating layer and the main fixing plating layer is not particularly limited, but can be appropriately set so as not to completely cover the abrasive grains 20 with the plating layer.

[0032] 5. Effects The effects of the gear cutting tool 1 and the manufacturing method for the gear cutting tool 1 according to the first embodiment will be described in detail below. According to the gear cutting tool 1 according to the first embodiment, a plurality of abrasive grains 20 are provided on the rake face 14a of the substrate 10 so as to overlap with the ridge line portion 15 when viewed from the direction Y of the rotation axis C of the substrate 10. This makes it possible to polish the tooth surface of the workpiece with the abrasive grains 20 by using the gear cutting tool 1. Furthermore, since the abrasive grains 20 are not provided in areas of the flank face 14bc of the substrate 10 other than the ridge line portion 15, waste of the abrasive grains 20 is prevented.

[0033] In addition, in this embodiment 1, a process similar to gear skiving is performed in which the rotation axis of the gear cutting tool 1 is inclined at an axis crossing angle relative to the rotation axis of the workpiece, and the workpiece and the gear cutting tool 1 are rotated synchronously while the gear cutting tool 1 is repeatedly moved in the tool feed direction at a predetermined feed rate. This allows the workpiece to be machined at a higher rotation speed than in hobbing. The tip portion of the rake face (ridge portion 15) first comes into contact with the workpiece, allowing the tooth surface of the workpiece to be polished efficiently.

[0034] Furthermore, in the gear cutting tool 1 of the first embodiment, the multiple abrasive grains 20 are not provided on the ridge lines 15 of the first blade 141, the second blade 142, and the third blade 143 among the multiple blades 14, but are provided on the ridge lines 15 of the other blades 14. When viewed from the direction of the rotation axis C of the substrate 10, the rotation axis C of the substrate 10 is located inside an imaginary triangle formed by imaginary lines L1, L2, and L3 connecting the first blade 141, the second blade 142, and the third blade 143 among the multiple blades 14. This allows the abrasive grains 20 to be provided on many of the multiple blades 14 while ensuring reliable positioning in the radial direction X in the manufacturing process described below, thereby enabling the tooth surface of the workpiece to be sufficiently polished.

[0035] In the gear cutting tool 1 of the first embodiment, the flank 14bc includes a front flank 14b located on the outer peripheral surface of the plurality of cutting edges 14 and a side flank 14c extending from the front flank 14b at an angle radially inward, and the ridge 15 includes a first ridge 151 that forms the boundary between the rake face 14a and the front flank 14b and a second ridge 152 that forms the boundary between the rake face 14a and the side flank 14c. The plurality of abrasive grains 20 are provided on the rake face 14a so as to overlap with the first ridge 151 and the second ridge 152, as viewed from the direction Y of the rotation axis C. This further improves the polishing effect of the gear cutting tool 1 on the tooth surface of the workpiece.

[0036] Furthermore, according to the manufacturing method of the gear cutting tool 1 of the first embodiment, a circular jig 30 is used to arrange a plurality of abrasive grains 20 along the ridgeline-facing portion 31 of the circular jig 30 as viewed from the direction of the rotation axis C of the substrate 10, with a gap P formed between the ridgeline portion 15 of the substrate 10 and the ridgeline-facing portion 31 inside the circular jig 30. This allows the abrasive grains 20 to be easily and accurately arranged so as to overlap the ridgeline portion 15, reducing the workload for arranging the abrasive grains 20 and preventing waste of abrasive grains 20 by reducing the amount of abrasive grains 20 not involved in machining. Furthermore, the tooth surface of the workpiece can be polished effectively. Furthermore, the accuracy of the arrangement of the abrasive grains 20 on the gear cutting tool 1 is improved, thereby improving the machining accuracy of the gear cutting tool 1.

[0037] Furthermore, in the manufacturing method of the gear cutting tool 1 of the first embodiment, the annular jig 30 has radial contact portions 311-313 that come into contact with parts of the ridge portions 15 in the radial direction X perpendicular to the direction Y of the rotation axis C of the substrate 10 when the substrate 10 is placed inside. Then, in the substrate placement step S2, parts of the ridge portions 15 come into contact with the radial contact portions 311-313, thereby positioning the substrate 10 in the radial direction X. This makes it easy to position the substrate 10 in the radial direction X.

[0038] Furthermore, in the manufacturing method of the gear cutting tool 1 of the first embodiment, the flank 14bc includes the front flank 14b and the side flank 14c, and the ridge 15 includes a first ridge 151 that is the boundary between the rake face 14a and the front flank 14b, and a second ridge 152 that is the boundary between the rake face 14a and the side flank 14c. Then, in the base material positioning step S2, the first ridge 151 and the second ridge 152 abut against the radial abutment portions 311 to 313, thereby positioning the base material 10 in the radial direction. This restricts movement of the base material 10 placed inside the annular jig 30 in a direction parallel to the radial direction X and in a rotational direction about the rotation axis C, thereby reliably positioning the base material 10.

[0039] Furthermore, in the manufacturing method of the gear cutting tool 1 of this embodiment 1, the annular jig 30 includes a first radial abutment portion 311 that abuts against the ridge portion 15 of a first blade of the plurality of blades 14, a second radial abutment portion 312 that abuts against the ridge portion 15 of a second blade of the plurality of blades, and a third radial abutment portion 313 that abuts against the ridge portion of the second blade of the plurality of blades, and when viewed from the direction Y of the rotation axis C of the substrate 10, the rotation axis C of the substrate 10 is located inside a virtual triangle formed by virtual lines L1, L2, and L3 that connect the first blade 141, the second blade 142, and the third blade 143, which do not have abrasive grains 20 provided on the ridge portion 15 of the plurality of blades 14. Then, in the abrasive grain arrangement step S3, the first blade 141, the second blade 142, and the third blade 143 among the plurality of blades 14 are not provided with the abrasive grains 20, but the other blades 14 are provided with the abrasive grains 20. This allows the abrasive grains 20 to be provided on many of the plurality of blades 14 while ensuring positioning in the radial direction X, thereby enabling the tooth surface of the workpiece to be sufficiently polished.

[0040] Furthermore, in the manufacturing method of the gear cutting tool 1 of the first embodiment, the flank 14bc includes a front flank 14b and a side flank 14c, and the ridge 15 includes a first ridge 151 that forms the boundary between the rake face 14a and the front flank 14b, and a second ridge 152 that forms the boundary between the rake face 14a and the side flank 14c. Then, in the abrasive grain arrangement step S3, a plurality of abrasive grains 20 are provided on the rake face 14a so as to overlap with the first ridge 151, and are also provided on the rake face 14a so as to overlap with the second ridge 152, as viewed from the direction Y of the rotation axis C. This further improves the polishing effect of the gear cutting tool 1 on the tooth surface of the workpiece.

[0041] Furthermore, in the manufacturing method of the gear cutting tool 1 of the first embodiment, in the preparation step S1, the blades 141-143 that will come into contact with the radial contact portions 311-313 are determined from the plurality of blades 14 of the base material 10 based on the number of teeth of the workpiece and the number of teeth of the base material 10. This makes it clear in advance which blades 141-143 will come into contact with the radial contact portions 311-313, improving workability.

[0042] Furthermore, in the manufacturing method of the gear cutting tool 1 of the first embodiment, the substrate cutting portion 12 of the substrate 10 has a step portion 16 facing the side opposite to the rake face 14a in the direction of the rotation axis C of the substrate 10, and the annular jig 30 has a step abutment portion 32 that abuts against the step portion 16 when the substrate 10 is placed inside. Then, in the substrate placement step S2, the step portion 16 abuts against the step abutment portion 32, thereby positioning the substrate 10 in the direction Y of the rotation axis C. This makes it easy to position the substrate 10 in the direction Y of the rotation axis C.

[0043] Furthermore, the manufacturing method of the gear cutting tool 1 of the first embodiment allows positioning in the radial direction X. When the substrate 10 is arranged inside, the upper surface 33, which is the end of the substrate 10 on the rake face 14a side in the direction Y of the rotation axis C, is configured to be located outward of the rake face 14a in the direction Y of the rotation axis C. This causes the ridge line facing portion 31 on the inside of the annular jig 30 to extend above the substrate 10 in the direction Y of the rotation axis C, making it easier to arrange the abrasive grains 20 along the ridge line facing portion 31, improving workability.

[0044] As described above, according to this embodiment, it is possible to provide a gear cutting tool 1 that includes abrasive grains 20 and prevents the abrasive grains 20 from being wasted.

[0045] (Embodiment 2) In the above-described first embodiment, as shown in Fig. 5, three blades 141-143 are in contact with radial contact portions 311-313 on the substrate 10, and abrasive grains 20 are not provided on the ridge portions 15 of the three blades 141-143, while abrasive grains 20 are provided on the other blades 14. In the second embodiment, instead, as shown in Fig. 8, two blades (a first blade 141 and a second blade 142) are in contact with the first radial contact portion 311 and the second radial contact portion 312 on the substrate 10, and abrasive grains 20 are not provided on the ridge portions 15 of the first blade 141 and the second blade 142, while abrasive grains 20 are provided on the other blades 14. When viewed from the direction Y of the rotation axis C, the rotation axis C is located on an imaginary line L4 connecting the first blade 141 and the second blade 142. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0046] According to the gear cutting tool 1 of the second embodiment, the number of blades 14 provided with abrasive grains 20 can be increased, and therefore the polishing effect on the tooth surface of the workpiece can be further enhanced.

[0047] Furthermore, according to the manufacturing method of the gear cutting tool 1 of the second embodiment, the annular jig 30 includes a first radial contact portion 311 that contacts the ridge portion 15 of the first blade 141 and a second radial contact portion 312 that contacts the ridge portion 15 of the second blade 142. When viewed from the direction Y of the rotation axis C, the rotation axis C of the substrate 10 is located on an imaginary line L4 connecting the first blade 141 and the second blade 142. This allows positioning in the radial direction X to be performed in the substrate placement step S2. Note that the second embodiment also provides the same effects as the first embodiment.

[0048] (Embodiment 3) In the first embodiment described above, the annular jig 30 has radial contact portions 311-313 that contact parts of the ridgeline portion 15 in the radial direction X when the substrate 10 is disposed inside. In the third embodiment, instead, as shown in FIG. 9, the annular jig 30 has radial contact portions 341 and 342 that contact the front clearance surface 14b of the substrate 10 and the side clearance surface 14c. In the third embodiment, as shown in FIG. 10, a gap P is formed between the ridgeline portion 15 of each of the blades 14 and the ridgeline-facing portion 31 of the annular jig 30. Therefore, as in the case shown in FIG. 6, abrasive grains 20 are provided on the rake faces 14a of each of the blades 14 so as to overlap the ridgeline portion 15. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and a description thereof will be omitted.

[0049] According to the manufacturing method of the gear cutting tool 1 of the third embodiment, in the substrate placement step S2, the radial contact portions 341, 342 of the annular jig 30 contact parts of the flanks 14bc of the substrate 10, thereby restricting movement of the substrate 10 in a direction parallel to the radial direction X and in a rotational direction about the rotation axis C, thereby ensuring reliable positioning of the substrate 10. Furthermore, the abrasive grains 20 are provided on the rake faces 14a of all the cutting edges 14 so as to overlap the ridges 15, thereby further enhancing the polishing effect on the tooth surface of the workpiece. Note that the third embodiment also provides the same effects as the first embodiment.

[0050] In the third embodiment, the annular jig 30 abuts against the flank 14bc of the substrate 10 at two locations, the radial abutment portions 341 and 342, but the number of abutting portions is not limited, and three or more locations in a region of the flank 14bc of the substrate 10 other than the portion forming the ridge line portion 15, or the entire region other than the portion forming the ridge line portion 15, may abut against the flank 14bc of the substrate 10. In this case, the same effects as those of the third embodiment are also achieved.

[0051] Note that, since the position of the flank surface 14bc in the radial direction X varies depending on the position in the direction of the rotation axis C, it may be difficult to design the radial contact portions 341, 342 that come into contact with the flank surface 14bc in the annular jig 30. From this perspective, since the position of the ridge portion 15 in the radial direction X is fixed, it is easier to design the annular jig 30 in the first and second embodiments than the annular jig 30 in the third embodiment.

[0052] The present invention is not limited to the above-described first to third embodiments and the modified embodiments, and can be applied to various embodiments without departing from the gist of the present invention. [Explanation of symbols]

[0053] 1 Gear processing tools 10 Base material 11 Base material body part 12 Base material blade part 13 Base material blade body 14 blades 141~143 1st~3rd blades 14a Rake face 14b Front relief 14c Side relief 14bc relief face 15 Ridgeline 151 First Ridge 152 Second Ridge 16 Step 20 abrasive grains 30 Annular jig 31 Ridgeline facing part 311 to 313 First to third radial contact portions 32 Step contact part 33 Top surface 341 Radial contact part 342 Radial contact part C Rotation axis L1~L4 virtual lines P Gap

Claims

1. A gear cutting tool for polishing a tooth surface formed on a workpiece, a substrate provided at one end of a shaft-shaped substrate body with an annular substrate blade portion having a plurality of blades on its outer peripheral surface, the substrate having a flank surface located on the outer peripheral side of the substrate blade portion and a rake surface located on an end side of the substrate blade portion in the direction of the rotation axis; a plurality of abrasive grains provided on the rake face so as to overlap a ridge portion that is a boundary between the flank face and the rake face when viewed from the rotation axis direction of the base material; Equipped with The gear cutting tool, wherein the flank face is not provided with abrasive grains in an area other than the ridge line portion.

2. the plurality of abrasive grains are not provided on the ridge line portions of at least two of the plurality of blades, and are provided so as to overlap the ridge line portions of the remaining blades; 2. The gear cutting tool according to claim 1, wherein, when viewed from the direction of the rotation axis of the base material, the rotation axis of the base material is located on an imaginary line connecting a first blade and a second blade, of the plurality of blades, whose ridges do not have the abrasive grains.

3. the plurality of abrasive grains are not provided on the ridge line portions of at least three blades among the plurality of blades, and are provided on the ridge line portions of the remaining blades, 3. The gear cutting tool according to claim 2, wherein, when viewed from the direction of the rotation axis of the base material, the rotation axis of the base material is located inside an imaginary triangle formed by imaginary lines connecting a first blade, a second blade, and a third blade, among the plurality of blades, which have no abrasive grains provided on their ridge lines.

4. the flanks include front flanks located on outer peripheral surfaces of the plurality of blades, and side flanks extending radially inwardly and inclined from the front flanks, the ridge line portion includes a first ridge line portion that is a boundary between the rake face and the front flank face, and a second ridge line portion that is a boundary between the rake face and the side flank face, 4. The gear cutting tool according to claim 1, wherein the plurality of abrasive grains are provided on the rake face so as to overlap with the first ridge portion and also so as to overlap with the second ridge portion when viewed from the rotation axis direction of the base material.

5. A method for manufacturing a gear cutting tool for polishing a tooth surface formed on a workpiece, comprising: a preparation step of preparing a substrate having an annular substrate blade portion having a plurality of blades on an outer peripheral surface at one end of a shaft-shaped substrate main body, the substrate having a flank surface facing the outer peripheral surface of the substrate blade portion, a rake surface facing an end side in the rotation axis direction, and a ridge portion that is a boundary between the flank surface and the rake surface; a substrate placement step of placing the substrate inside an annular jig and forming a gap between a ridge line portion that is a boundary between the flank face and the rake face in the annular jig and a ridge line opposing portion that is opposing the ridge line portion; an abrasive grain arranging step of arranging a plurality of abrasive grains on the rake face along the ridge line opposing portion so as to overlap the ridge line portion when viewed from the rotation axis direction of the base material; and an abrasive grain fixing step of fixing the abrasive grains to the rake face.

6. the annular jig has a radial abutment portion that abuts against a part of the ridge portion or at least a part of the relief surface in a radial direction perpendicular to a rotation axis direction of the base material when the base material is disposed inside the annular jig, 6. The method for manufacturing a gear cutting tool according to claim 5, wherein in the base material positioning step, a part of the ridge line portion or at least a part of the flank face abuts on the radial abutment portion, thereby positioning the base material in the radial direction.

7. the flanks include front flanks located on outer peripheral surfaces of the plurality of blades, and side flanks extending radially inwardly and inclined from the front flanks, the ridge line portion includes a first ridge line portion that is a boundary between the rake face and the front flank face, and a second ridge line portion that is a boundary between the rake face and the side flank face, 7. The method for manufacturing a gear cutting tool according to claim 6, wherein in the base material positioning step, the first ridge portion and the second ridge portion abut against the radial abutment portion, thereby positioning the base material in the radial direction.

8. the flanks include front flanks located on outer peripheral surfaces of the plurality of blades, and side flanks extending radially inwardly and inclined from the front flanks, 7. The method for manufacturing a gear cutting tool according to claim 6, wherein in the base material positioning step, the front relief surface and the side relief surface abut against the radial abutment portion, thereby positioning the base material in the radial direction.

9. the radial abutment portion includes a first radial abutment portion that abuts against the ridge portion of a first blade of the plurality of blades, and a second radial abutment portion that abuts against the ridge portion of a second blade of the plurality of blades, When viewed from the rotation axis direction of the base material, the rotation axis of the base material is located on an imaginary line connecting the first blade and the second blade, 9. The method for manufacturing a gear cutting tool according to claim 6, wherein in the abrasive grain arrangement step, the plurality of abrasive grains are not arranged on the first blade and the second blade, and the plurality of abrasive grains are arranged on the other blades of the plurality of blades.

10. the radial abutment portion includes a first radial abutment portion that abuts against the ridge portion of a first blade of the plurality of blades, a second radial abutment portion that abuts against the ridge portion of a second blade of the plurality of blades, and a third radial abutment portion that abuts against the ridge portion of a third blade of the plurality of blades, When viewed from the rotation axis direction of the base material, the rotation axis of the base material is located inside an imaginary triangle formed by imaginary lines connecting the first blade, the second blade, and the third blade, 9. The method for manufacturing a gear cutting tool according to claim 6, wherein in the abrasive grain arrangement step, the plurality of abrasive grains are not arranged on the first blade, the second blade, and the third blade among the plurality of blades, and the plurality of abrasive grains are arranged on the other blades.

11. the flanks include front flanks located on outer peripheral surfaces of the plurality of blades, and side flanks extending radially inwardly and inclined from the front flanks, the ridge line portion includes a first ridge line portion that is a boundary between the rake face and the front flank face, and a second ridge line portion that is a boundary between the rake face and the side flank face, 9. The method for manufacturing a gear cutting tool according to claim 5, wherein in the abrasive grain arranging step, the plurality of abrasive grains are provided on the rake face so as to overlap with the first ridge portion and also so as to overlap with the second ridge portion, as viewed from the rotation axis direction of the base material.

12. 9. The method for manufacturing a gear cutting tool according to claim 6, wherein in the preparation step, a blade to be in contact with the radial abutment portion, out of the plurality of blades of the base material, is determined based on the number of teeth of the workpiece and the number of teeth of the base material.

13. the substrate blade portion of the substrate has a step portion facing the opposite side to the rake face in a rotation axis direction of the substrate, the annular jig has a step abutting portion that abuts against the step portion when the base material is placed inside the annular jig, 9. The method for manufacturing a gear cutting tool according to claim 5, wherein in the base material arranging step, the base material is positioned in the rotation axis direction by the step portion abutting on the step abutment portion.

14. 9. The method for manufacturing a gear cutting tool according to claim 5, wherein the annular jig is configured such that, when the base material is placed inside, an upper surface of the base material, which is an end portion of the base material on the cutting face side in the rotation axis direction, is positioned outward in the rotation axis direction from the cutting face.

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