JPWO2018180157A1 - Brooch tool - Google Patents

Abstract

One embodiment of the broaching tool of the present invention includes a plurality of processing blade portions arranged along a central axis extending in a vertical direction. Each of the processing blades has a plurality of teeth protruding radially outward. The plurality of teeth are arranged along the circumferential direction for each machining blade, and are arranged along the axis with the teeth of the other machining blades. Among the processing blade portions adjacent in the axial direction, the processing blade portion arranged on the upper side has a larger circumferential dimension of the tooth portion than the processing blade portion arranged on the lower side, and the radial outer end of the tooth portion has At least one of which is located radially outward. The circumferential dimension of the tooth portion of the first processing blade arranged at the uppermost position among the plurality of processing blades is the largest among the plurality of processing blades. At least one of the plurality of processing blades, which is disposed below the first processing blade, has a radially outer end of the tooth portion at a radially outer end of the tooth at the first processing blade. Located radially outwardly.

Description

The present invention relates to a broaching tool.

2. Description of the Related Art A broach tool that has a plurality of blade portions along an axial direction and a circumferential direction and processes a spline, an internal gear, and the like is known. For example, Patent Literature 1 describes a broach tool in which a plurality of cutting edges are made of a cemented carbide.

JP-A-2004-345050

In the cutting processing using the broach tool as described above, the broach tool is moved in the axial direction, and the processing target is gradually cut by a plurality of blades arranged in the axial direction in order to approximate the final processing shape. At this time, the blade part that lastly cuts the processing target is a blade part that finishes to a final processing shape, and greatly contributes to the processing accuracy of the broach tool. For this reason, there is a problem in that the machining accuracy of the broaching tool is reduced when the blade portion for shaving the object to be machined last is worn.

In view of the above circumstances, an object of the present invention is to provide a broach tool that can suppress wear of a processing blade part that cuts a processing target last.

One embodiment of the broach tool of the present invention includes a plurality of processing blades arranged along a central axis extending in a vertical direction, and each of the processing blades has a plurality of teeth protruding radially outward. The plurality of tooth portions are arranged along the circumferential direction for each of the processing blade portions, and each is arranged along the axial direction with the tooth portion of the other one of the processing blade portions. The processing blade portion arranged on the upper side among the processing blade portions adjacent to each other has a larger circumferential dimension of the tooth portion than the processing blade portion disposed on the lower side, and a radial direction of the tooth portion. The outer end is located radially outward, and at least one of the plurality of machining blades has a circumferential dimension of the tooth portion in a first machining blade disposed at an uppermost position. The first processing blade among the plurality of processing blade portions, which is the largest among the blade portions; At least one of the processing blade portion which is disposed below the radially outer end of the tooth portion is positioned radially outward from the radially outer end of the teeth in the first processing blade unit.

According to one aspect of the present invention, there is provided a broaching tool capable of suppressing abrasion of a processing blade portion for cutting a processing target last.

FIG. 1 is a side view showing the broach tool of the first embodiment. FIG. 2 is a side view showing the processing blade portion and the rake portion of the first embodiment. FIG. 3 is a perspective view showing the processing blade portion and the rake portion of the first embodiment. FIG. 4 is a diagram in which the processing blade portion of the first embodiment is viewed from below. FIG. 5 is a diagram in which a part of the processing blade portion of the first embodiment is viewed from below. FIG. 6 is a partial cross-sectional side view schematically illustrating the processing blade portion of the first embodiment. FIG. 7 is a view of a part of the broach tool of the first embodiment as viewed from below. FIG. 8 is a diagram illustrating a part of a cutting procedure using the broach tool of the first embodiment. Drawing 9 is a figure which looked at the processing blade part of a 2nd embodiment from the lower side. FIG. 10 is a perspective view showing a processing blade part of the third embodiment. Drawing 11 is a figure which looked at the processing blade part of a 3rd embodiment from the lower side. FIG. 12 is a sectional view showing an example of a speed reducer having an internal gear manufactured using the broach tools of the first embodiment and the second embodiment.

The Z-axis direction appropriately shown in each drawing is a direction parallel to the vertical direction. The positive side in the Z-axis direction is defined as “upper”, and the negative side in the Z-axis direction is defined as “lower”. In addition, the center axis J appropriately shown in each drawing extends in the Z-axis direction, that is, the up-down direction. In the following description, the axial direction of the central axis J, that is, the vertical direction parallel to the Z-axis direction is simply referred to as “axial direction”. The radial direction about the central axis J is simply called “radial direction”, and the circumferential direction about the central axis J is simply called “circumferential direction”. The terms “upper and lower”, “upper” and “lower” are simply names for describing the relative positional relationships of the respective components, and the actual positional relationships and the like are positional relationships and the like other than the positional relationships and the like indicated by these names. You may.

1ST EMBODIMENT The broach tool 10 shown in FIG. 1 is a tool which processes the tooth part of an internal gear. The broaching tool 10 has a rod shape extending in the axial direction about the central axis J. The broach tool 10 includes a lower guide portion 11, a processing portion 12, an upper guide portion 13, and a handle portion 14 in order from the lower side to the upper side.

The processing unit 12 is a part that cuts the processing target OP. The processing section 12 has a plurality of processing blade sections 30 and a plurality of rake sections 40. That is, the broach tool 10 includes a plurality of processing blade portions 30 and a rake portion 40. The plurality of processing blade portions 30 are arranged along a central axis J extending in the up-down direction. In the present embodiment, for example, eight processing blade portions 30A to 30H are provided as the processing blade portions 30A. The processing blade portions 30A to 30H are arranged in order from the lower side to the upper side.

The processing blade portions 30A to 30H have similar shapes, although some dimensions are different from each other. In the following description, the processing blade parts 30A to 30H are simply referred to as the processing blade parts 30 unless otherwise distinguished.

As shown in FIGS. 2 and 3, the processing blade part 30 has a tapered part 31 and a main body part 32. The tapered portion 31 has a truncated cone shape whose outer diameter increases from the upper side to the lower side around the center axis J. The main body 32 has an external gear shape centered on the central axis J. The main body portion 32 is connected to a lower end of the tapered portion 31 below the tapered portion 31. A plurality of teeth 33 projecting radially outward are provided on the outer peripheral surface of the main body 32. That is, each of the processing blade portions 30 has a plurality of tooth portions 33 protruding radially outward.

As shown in FIG. 4, the plurality of tooth portions 33 are arranged along the circumferential direction for each processing blade portion 30. The plurality of teeth portions 33 are arranged at equal intervals over one circumference in the circumferential direction. The tooth shape of the tooth portion 33 is, for example, a cycloid tooth shape. Thus, the outer shape of the main body 32 viewed from below is a cycloid curve. Note that the tooth shape of the tooth portion 33 may be a trochoidal tooth shape or an involute tooth shape.

Each of the teeth 33 has a rake face 35 facing downward. In the present embodiment, the rake face 35 is a part of the lower surface of the processing blade 30 and is orthogonal to the axial direction. The lower surface of the processing blade portion 30 is a flat surface facing the lower side and orthogonal to the axial direction. That is, the rake faces 35 of the plurality of tooth portions 33 are arranged on the same plane orthogonal to the axial direction for each processing blade portion 30. In the present embodiment, the rake face 35 of each tooth 33 is connected to the rake face 35 of the tooth 33 adjacent in the circumferential direction. As a result, the rake face 35 is provided on the radial outer edge of the lower surface of the processing blade portion 30 over one circumference in the circumferential direction. The rake face 35 of each of the teeth 33 connected to each other has an annular shape extending in the circumferential direction.

As shown in FIG. 2, each of the tooth portions 33 has a flank 36 provided on the circumferential side surface of the tooth portion 33 over the entire circumference. In the present embodiment, the flank 36 of each tooth 33 is connected to the flank 36 of the tooth 33 adjacent in the circumferential direction. Thus, the flank 36 is provided on the circumferential side surface of the processing blade portion 30 over the entire circumference. The flank 36 of each of the teeth 33 connected to each other has an annular shape extending in the circumferential direction. The lower end of the flank 36 is connected to the radial outer edge of the rake face 35. The ridge between the rake face 35 and the flank 36 is a cutting edge 38 of the processing blade portion 30. In addition, in this specification, the "circumferential side surface" is a surface along the circumferential direction, and is a surface facing radially outward.

The flank 36 is inclined with respect to the axial direction at the clearance angle θ. More specifically, the flank 36 inclines toward the inside of the cutting edge 38 as viewed from the up-down direction from the lower side to the upper side. The clearance angle θ is the same angle at any position in the circumferential direction. Thereby, as shown by the broken line in FIG. 5, the radial outer edge of the flank 36 in the cross section passing through the flank 36 and orthogonal to the axial direction is formed inside the radial outer edge of the rake face 35, that is, the cutting edge 38. They are located at equal distances.

In the present embodiment, the clearance angle θ of the clearance surface 36 is larger than 0 ° and equal to or smaller than θmax shown in FIG. As shown in FIG. 6, θmax is represented by tan (θmax) = L1 / L2. As illustrated in FIG. 7, L1 is the other of the teeth 33 adjacent to each other in the circumferential direction of the uppermost processing blade 30H among the plurality of processing blades 30 when viewed from below. Of the tangents in contact with the part on the tooth part 33 side, the tangents TL1 and TL2 with which the angle φ formed with the virtual line CL is the minimum are the distances between the contacts TP1 and TP2 in contact with the tooth 33. The imaginary line CL is a line connecting the center in the circumferential direction of the teeth 33 adjacent to each other in the circumferential direction and the central axis J. The tangent to the tooth portion 33 is a tangent to the radial outer edge of the rake face 35, that is, the tangent to the cutting edge 38 when viewed from below.

In the example shown in FIG. 7, the tangent line TL1 is a tangent line having the smallest angle φ among the tangent lines in contact with the other tooth portion 33 side of the left tooth portion 33 in FIG. 7, that is, the right portion. The tangent line TL2 is a tangent line having the smallest angle φ among tangent lines that contact the other tooth portion 33 side of the right tooth portion 33 in FIG. 7, that is, the left portion.

As shown in FIG. 6, L2 is an axial distance between the lower end of the tooth 33 of the processing blade 30H and the lower end of the tooth 33 of the processing blade 30G adjacent to the lower side of the processing blade 30H. is there. In other words, L2 is the axial distance between the rake face 35 of the processing blade 30H and the rake face 35 of the processing blade 30G. The clearance angle θ is, for example, 2 ° or more and 5 ° or less, and preferably 3 °. By setting the clearance angle θ to such a value, it is possible to sufficiently reduce the clearance of the flank 36 and to suppress a decrease in the strength of the tooth portion 33.

In the present embodiment, the processing blade 30H corresponds to a first processing blade, and the processing blade 30G corresponds to a second processing blade. The first processing blade part is the uppermost processing blade part among the substantially functioning processing blade parts, and the second processing blade part is the first processing blade part among the substantially functioning processing blade parts. It is a 2nd processing blade part adjacent to the lower side of the processing blade part. That is, for example, even if the processing blade portion disposed at the uppermost position does not substantially function, it does not correspond to the first processing blade portion. Further, even if the processing blade portion adjacent to the lower side of the first processing blade portion does not substantially function, it does not correspond to the second processing blade portion. In the present specification, the “substantially functioning processing blade portion” is a processing blade portion that can cut off at least a part of the processing target OP when processing the processing target OP with a broach tool.

The plurality of tooth portions 33 are provided side by side with the tooth portions 33 of the other processing blade portions 30 along the axial direction. That is, as shown in FIG. 7, the teeth 33 of the processing blade 30A, the teeth 33 of the processing blade 30B, the teeth 33 of the processing blade 30C, the teeth 33 of the processing blade 30D, The teeth 33 of the blade 30E, the teeth 33 of the processing blade 30F, the teeth 33 of the processing blade 30G, and the teeth 33 of the processing blade 30H overlap in the axial direction.

Of the processing blades 30 that are adjacent in the axial direction, the teeth 33 of the processing blade 30 disposed on the upper side do not overlap with the teeth 33 of the processing blade 30 disposed on the lower side when viewed from below. With parts. Here, as shown in FIG. 8, the broach tool 10 is inserted into the through hole H provided in the processing object OP from the upper side and moved downward, so that the inner edge of the through hole H is cut by the cutting edge 38. The surface is cut and cut. At this time, the plurality of processing blade portions 30 pass through the through hole H from the upper side to the lower side in order from the lowermost processing blade portion 30A to the uppermost processing blade portion 30H. The inner peripheral surface of the hole H is cut.

For this reason, the tooth portion 33 of the processing blade portion 30 disposed on the upper side has a portion that does not overlap in the axial direction with the tooth portion 33 of the processing blade portion 30 disposed on the lower side. After the inner peripheral surface of the through hole H is cut, the inner peripheral surface of the through hole H can be further cut by the upper processing blade portion 30. In this manner, the inner peripheral surface of the through hole H can be gradually cut by the plurality of processing blade portions 30 arranged in the axial direction, and the processing load on each processing blade portion 30 can be reduced. Further, since each of the processing blade portions 30 of the present embodiment can cut off at least a part of the processing target OP in this manner, it corresponds to the above-described substantially functioning processing blade portion.

As shown in FIG. 7, in the present embodiment, among the processing blade portions 30 that are adjacent in the axial direction, the processing blade portion 30 disposed on the upper side is more toothed than the processing blade portion 30 disposed on the lower side. Is larger in the circumferential direction, and at least one of the radially outer ends of the tooth portions 33 is located radially outward of the processing blade portion 30 arranged below. Thereby, the processing object OP can be cut while distributing the processing load in the radial direction and the circumferential direction.

In the present embodiment, in at least one set of the processing blade portions 30 adjacent in the axial direction, the circumferential dimension of the tooth portion 33 of the processing blade portion 30 disposed on the upper side is the same as that of the processing blade portion 30 disposed on the lower side. Is larger than the circumferential dimension of the toothed portion 33 at. Further, in the present embodiment, in at least one set of the processing blade portions 30 adjacent in the axial direction, the radially outer end of the tooth portion 33 of the processing blade portion 30 disposed on the upper side is the processing blade disposed on the lower side. It is located radially outward of the radially outer end of the tooth portion 33 in the portion 30.

Since the circumferential dimension of the tooth portion 33 differs depending on the radial position of the tooth portion 33, the comparison of the circumferential size of the tooth portion 33 is performed at the same radial position. That is, in the present specification, "the circumferential dimension of the tooth portion is large" means that when the circumferential dimension of the tooth portion is compared at the same radial position, the tooth is located at any radial position on the tooth portion. This includes a large circumferential dimension of the part.

The processing blade portion 30B has a circumferential dimension of the tooth portion 33 larger than that of the processing blade portion 30A disposed on the lower side, and a radially outer end of the tooth portion 33 is located radially outward. In the processing blade portion 30C, the circumferential dimension of the tooth portion 33 is larger than the processing blade portion 30B disposed on the lower side, and the radial outer end of the tooth portion 33 is located radially outward. In the processing blade portion 30D, the radially outer end of the tooth portion 33 is positioned radially outward from the processing blade portion 30C disposed below. The circumferential dimension of the tooth portion 33 in the processing blade 30D is equal to or less than the circumferential dimension of the tooth 33 in the processing blade 30C.

In the processing blade portion 30E, the radially outer end of the tooth portion 33 is positioned radially outside of the processing blade portion 30D arranged below. The circumferential dimension of the tooth 33 in the processing blade 30E is equal to or less than the circumferential dimension of the tooth 33 in the processing blade 30D. In the processing blade portion 30F, a radially outer end of the tooth portion 33 is positioned radially outward with respect to the processing blade portion 30E arranged below. The circumferential dimension of the tooth portion 33 in the processing blade 30F is equal to or less than the circumferential dimension of the tooth 33 in the processing blade 30E.

In the processing blade portion 30G, the radially outer end of the tooth portion 33 is positioned radially outward of the processing blade portion 30F disposed below. The circumferential dimension of the tooth 33 in the processing blade 30G is equal to or smaller than the circumferential dimension of the tooth 33 in the processing blade 30F. The position of the radially outer end of the tooth portion 33 in the processing blade portion 30G is located at the outermost position in the radial direction among the plurality of processing blade portions 30.

The processing blade portion 30H has a larger circumferential dimension of the tooth portion 33 than the processing blade portion 30G disposed on the lower side. The circumferential dimension of the tooth portion 33 in the processing blade portion 30H is the largest among the plurality of processing blade portions 30. The radially outer end of the tooth portion 33 in the processing blade portion 30H is located radially inward from the radially outer end of the tooth portion 33 in the processing blade portion 30G. That is, at least one of the plurality of processing blade portions 30 disposed below the processing blade portion 30H has a radially outer end of the tooth portion 33 of the tooth portion 33 in the processing blade portion 30H. It is located radially outward from the radially outer end.

Therefore, in the radial direction, the finishing cutting is performed by the processing blade 30 other than the processing blade 30H. Thereby, the processing load on the processing blade portion 30H that lastly cuts the processing target OP can be reduced. Therefore, according to the present embodiment, it is possible to suppress the wear of the processing blade portion 30H that cuts the processing target OP last. Thereby, the frequency of re-grinding the processing blade portion 30H and the frequency of replacing the broach tool 10 can be reduced, and the production cost of products manufactured by processing with the broach tool 10 can be reduced.

On the other hand, in the circumferential direction, finishing cutting is performed by the processing blade portion 30H. The tooth portions of the internal gear manufactured by the broaching tool 10 are in contact with the tooth portions of the external gear that meshes with the internal gear on both sides in the circumferential direction. Therefore, in the meshing of the gears, the accuracy of the side surfaces on both sides in the circumferential direction in the tooth portion of the internal gear is important. Therefore, by performing the finishing cutting in the circumferential direction by the processing blade portion 30H lastly, it is easy to accurately machine the side surfaces on both sides in the circumferential direction in the tooth portion of the internal gear, and to smooth the meshing between the gears. Can be.

Further, according to the present embodiment, the position of the radially outer end of the tooth portion 33 in the processing blade portion 30G adjacent to the lower side of the processing blade portion 30H is the radially outermost of the plurality of processing blade portions 30. Since it is located, in the radial direction, finishing cutting is performed by the processing blade portion 30G. Thereby, the finishing in the radial direction and the finishing in the circumferential direction are finally performed by the two processing blade portions 30G and the processing blade portion 30H. Therefore, for example, it is easier to improve the finishing accuracy in each direction than in the case where a cutting step by another processing blade portion is included between the radial finishing and the circumferential finishing. Therefore, in both the circumferential direction and the radial direction, the processing accuracy of the tooth portion of the manufactured internal gear is easily improved. In the present embodiment, the radially outer end of the tooth portion 33 in the processing blade portion 30H is located radially outward from the radially outer end of the tooth portion 33 in the processing blade portion 30F.

In the case where the circumferential dimension of the tooth portion 33 of the machining blade portion 30 arranged above the machining blade portion 30 arranged lower than the machining blade portion 30 arranged below in the axially adjacent machining blade portion 30 increases, The amount of increase in the circumferential dimension is larger than the circumferential dimensional tolerance of the tooth portion 33. For this reason, after the processing object OP is shaved by the processing blade 30 having the tooth 33 having an error in the circumferential dimension, the processing blade 30 having a larger circumferential dimension of the tooth 33 than the processing blade 30. By removing the processing target OP by using, the deviation in the circumferential direction due to an error can be eliminated. Therefore, it is possible to suppress accumulation of errors in the circumferential direction of the cutting performed by the respective processing blade portions 30, and it is possible to improve processing accuracy in the circumferential direction.

Specifically, an increase amount DC1 in the circumferential direction of the tooth portion 33 from the processing blade portion 30A to the processing blade portion 30B, and an increase in the circumferential size of the tooth portion 33 from the processing blade portion 30B to the processing blade portion 30C. The amount DC2 and the increase DC3 in the circumferential dimension of the tooth portion 33 from the processing blade portion 30G to the processing blade portion 30H are larger than the circumferential dimensional tolerance of the tooth portion 33. In FIG. 7, the increments DC1, DC2, DC3 are substantially the same as each other. The increments DC1, DC2, DC3 are, for example, about 0.01 mm or more and 0.1 mm or less. The dimensional tolerance in the circumferential direction of the tooth portion 33 is, for example, about ± 0.005 mm or more and ± 0.01 mm or less.

In the processing blade part 30 adjacent in the axial direction, when the radial outer end of the tooth part 33 in the processing blade part 30 disposed above the processing blade part 30 disposed below is positioned radially outward, The radial distance between the radially outer end of the tooth portion 33 of the processing blade portion 30 disposed on the upper side and the radially outer end of the tooth portion 33 of the processing blade portion 30 disposed on the lower side is Larger than the dimensional tolerance in the radial direction. Therefore, after the processing target OP is shaved by the processing blade portion 30 having the tooth portion 33 in which the radial dimension has an error, the radial outer end of the tooth portion 33 is positioned radially outside of the processing blade portion 30. The displacement in the radial direction due to the error can be eliminated by cutting the processing object OP with the processing blade portion 30 to be processed. Therefore, it is possible to suppress the accumulation of errors in the radial direction of the cutting performed by the processing blade portions 30, and to improve the processing accuracy in the radial direction.

Specifically, the distances DR1 to DR6 between the radially outer ends of the tooth portions 33 in the processing blade portions 30 adjacent in the axial direction are larger than the radial dimensional tolerance of the tooth portions 33. The distance DR1 is a radial distance between a radially outer end of the tooth portion 33 in the processing blade portion 30A and a radially outer end of the tooth portion 33 in the processing blade portion 30B. The distance DR2 is a radial distance between a radially outer end of the tooth portion 33 in the processing blade portion 30B and a radially outer end of the tooth portion 33 in the processing blade portion 30C. The distance DR3 is a radial distance between a radially outer end of the tooth portion 33 in the processing blade portion 30C and a radially outer end of the tooth portion 33 in the processing blade portion 30D. The distance DR4 is a radial distance between a radially outer end of the tooth portion 33 of the processing blade portion 30D and a radially outer end of the tooth portion 33 of the processing blade portion 30E. The distance DR5 is the radial distance between the radially outer end of the tooth portion 33 in the processing blade portion 30E and the radially outer end of the tooth portion 33 in the processing blade portion 30F. The distance DR6 is a radial distance between the radially outer end of the tooth portion 33 in the processing blade portion 30F and the radially outer end of the tooth portion 33 in the processing blade portion 30G.

In the present embodiment, the distance DR2, the distance DR3, and the distance DR5 are the same. The distance DR1 is smaller than the distance DR2, the distance DR3, and the distance DR5. The distance DR4 is larger than the distance DR3 and the distance DR5. The distance DR6 is smaller than the distance DR1. That is, the amount of change in the radial position of the radially outer end of the tooth portion 33 between the processing blade portions 30 adjacent in the axial direction is the same or increases from the processing blade portion 30A to the processing blade portion 30E. However, it decreases between the processing blade portion 30E and the processing blade portion 30G.

As shown in FIG. 4, the outer diameter D of the processing blade portion 30 is a circular diameter centered on the central axis J and passing through the radially outer end of the tooth portion 33. The outer diameter D of the processing blade 30 increases in the order of the processing blade 30A, the processing blade 30B, the processing blade 30C, the processing blade 30D, the processing blade 30E, the processing blade 30F, and the processing blade 30G. The outer diameter D of the processing blade 30H is smaller than the processing blade 30G and larger than the processing blade 30F. The outer diameter D of each processing blade portion 30 is, for example, 20 mm or less. The change amount of the outer diameter D between the processing blade portions 30 adjacent in the axial direction changes in the same manner as the change amount of the radial position of the radial outer end of the tooth portion 33 described above.

In the present embodiment, the plurality of processing blade portions 30 are separate members. Therefore, after manufacturing a plurality of processing blade parts 30 separately, broach tool 10 can be assembled by connecting a plurality of processing blade parts 30 along the axial direction. Thereby, for example, when processing the flank surface 36 using a grindstone, by performing the processing before assembling the processing blade part 30, the grinding stone does not interfere with the other processing blade parts 30, which is preferable. The flank 36 having the clearance angle θ is obtained. Further, since the processing blade portions 30 are separate members from each other, there is no need to process the flank surface 36 using a grindstone. For example, the machining blade portion 30 can be manufactured by cutting out the flank surface 36 from the plate member by wire electric discharge machining. Therefore, according to this embodiment, even if the broaching tool 10 is relatively small, it is possible to suitably provide the clearance angle θ over the entire circumference of the circumferential side surface of the tooth portion 33 in the processing blade portion 30. is there. In the present embodiment, each of the plurality of processing blade portions 30 is a single member.

As used herein, the term "relatively small broach tool" refers to a broach tool having an outer diameter of a processing blade portion of 20 mm or less, a broach tool having a distance L1 of 2 mm or less, a broach tool having a distance L2 of 10 mm or less, and the like. including.

Further, in the conventional broaching tool, there is a problem that it is particularly difficult to provide the clearance angle θ at the contact point of the tooth portion 33 with the tangent having the smaller angle φ described above. On the other hand, according to the present embodiment, the clearance angle θ can be suitably provided even at the contact points TP1 and TP2 where the angle φ is the minimum, so that the clearance is provided over the entire circumferential side surface of the tooth portion 33. The angle θ can be suitably provided.

In addition, since the plurality of processing blades 30 are separate members, when some of the plurality of processing blades 30 are worn, only some of the processing blades 30 can be replaced. Therefore, it is not necessary to replace the entire broaching tool 10 when a part of the processing blade portion 30 is worn, and the production cost of a product processed and manufactured by the broaching tool 10 can be reduced.

Further, for example, in the case of the internal gear and the external gear that mesh with each other, when the tooth shape of the tooth portion is a cycloid tooth shape or a trochoid tooth shape, the tooth portion and the external tooth of the internal gear are compared with the case where the tooth shape is an involute tooth shape. The range of the circumferential side surface in contact with the tooth portion of the gear is large. Therefore, when the tooth profile is a cycloid tooth profile or a trochoid tooth profile, it is important that the processing accuracy is high over the entire circumference of the circumferential side surface of the tooth portion.

On the other hand, by using the broach tool 10 in which the clearance angle θ is preferably provided in the entire circumferential side surface of the tooth portion 33 as in the present embodiment, the circumferential side surface of the tooth portion of the internal gear is used. Can be machined accurately over the entire circumference. Therefore, the effect of suitably providing the clearance angle θ on the entire circumference of the circumferential side surface of the tooth portion 33 is particularly useful when the tooth shape of the tooth portion of the processing target OP is a cycloid tooth shape or a trochoid tooth shape. is there.

Further, in the present embodiment, the rake face 35 is a part of the lower surface of the processing blade portion 30 orthogonal to the axial direction. Therefore, the plate surface of the plate member can be used as the rake face 35 by cutting the plate member by wire electric discharge machining or the like to manufacture the machining blade portion 30. Thus, the rake face 35 can be easily and accurately formed by using a plate member having a relatively high flatness of the plate surface. Thereby, the cutting edge 38 can be made with high accuracy, and the cutting performance of the broach tool 10 can be improved. Further, since the rake face 35 can be polished by polishing the lower surface of the flat processing blade portion 30 and the cutting edge 38 can be polished, it is easy to re-polish the cutting edge 38 when the cutting edge 38 is worn. is there.

As shown in FIG. 3, each of the processing blade portions 30 includes a first through hole 34 a penetrating the processing blade portion 30 in the axial direction, and a plurality of second through holes 34 b penetrating the processing blade portion 30 in the axial direction. And The shape viewed from above the first through hole 34a is a circular shape centered on the central axis J. The shape as viewed from above the second through hole 34b is a circular shape. The inner diameter of the second through hole 34b is smaller than the inner diameter of the first through hole 34a. In the present embodiment, two second through holes 34b are provided in each of the processing blade portions 30. The two second through-holes 34b are arranged on the radially outer side of the first through-holes 34a on opposite sides of the center axis J. The first through hole 34a and the second through hole 34b open on the upper surface of the tapered portion 31.

The rake portion 40 has a column shape centered on the central axis J. As shown in FIG. 1, each of the plurality of rake sections 40 is connected to the lower end of each processing blade section 30 below each processing blade section 30. The rake portion 40 is provided in the same number as the number of the processing blade portions 30, and in the present embodiment, eight rake portions are provided. The rake sections 40 other than the rake section 40 arranged at the lowermost side among the plurality of rake sections 40 connect the processing blade sections 30 adjacent in the axial direction between the processing blade sections 30 adjacent in the axial direction. .

As shown in FIG. 2, the outer diameter of the rake portion 40 is smaller than the portion where the teeth 33 are provided in each of the processing blade portions 30 adjacent in the axial direction, that is, the outer diameter of the main body portion 32. Therefore, a relief portion 37 that is depressed radially inward is provided between the processing blade portions 30 that are adjacent in the axial direction. As a result, as shown in FIG. 8, chips MS generated when the inner peripheral surface of the through hole H of the processing target OP is cut by the processing blade portion 30 connected to the upper side of the rake portion 40 are released into the release portion 37. Can be. Therefore, when the processing object OP is cut by the broach tool 10, it is possible to suppress chips MS from being clogged between the broach tool 10 and the inner peripheral surface of the through hole H, and it is easy to perform cutting by the broach tool 10.

The relief portion 37 has an annular shape extending in the circumferential direction. The inner surface of the relief portion 37 is configured by the rake face 35, the outer peripheral surface of the rake portion 40, and the outer peripheral surface of the tapered portion 31. In the present embodiment, since the tapered portion 31 has a truncated conical shape whose outer diameter increases from the upper side to the lower side, the inside of the escape portion 37 can be easily widened below the rake face 35, and the chip MS escapes. Easy to escape inside. Further, when the escape portion 37 comes out from the through hole H to the lower side, the chips MS are easily removed from the escape portion 37 along the tapered portion 31.

As shown in FIG. 2, the outer diameter of the rake portion 40 increases upward at the upper end portion of the rake portion 40. As a result, the chips MS that have been scooped by the rake face 35 and escaped in the escape portion 37 can be easily rolled and guided downward as shown in FIG. Therefore, the chips MS can be easily released into the release portion 37, and the cutting by the broach tool 10 can be more easily performed.

The outer diameter of the lower end of the rake portion 40 is equal to or larger than the outer diameter of the upper end of the processing blade portion 30 connected to the lower side of the rake portion 40, that is, the outer diameter of the upper end of the tapered portion 31. Therefore, chips MS guided downward along the outer circumferential surface of the rake portion 40 can be suppressed from being caught in the boundary between the rake portion 40 and the lower processing blade portion 30. Thereby, it is easy to remove the chips MS from the escape portion 37.

As shown in FIG. 3, the rake portion 40 is a separate member from the machining blade portion 30. That is, the plurality of processing blade portions 30 and the plurality of rake portions 40 are separate members. Therefore, as described above, the rake portion 40 can be similarly manufactured by hollowing out the plate member, while manufacturing the processing blade portion 30 by hollowing out the plate member. Thereby, the machining blade portion 30 and the rake portion 40 can be easily manufactured, and the chips MS can be easily released by the rake portion 40. In addition, for example, since the plurality of rake portions 40 may have the same shape and dimensions, when the rake portions 40 are manufactured with the same shape and the same dimensions, the manufacture of the rake portions 40 can be facilitated. In the present embodiment, for example, the shapes and dimensions of the plurality of rake portions 40 are the same.

Further, since the processing blade portion 30 and the rake portion 40 are separate members, the material of the processing blade portion 30 and the material of the rake portion 40 can be different from each other. Thereby, the processing blade part 30 and the rake part 40 can be manufactured with suitable materials. Specifically, the cutting by the broach tool 10 can be facilitated by using a relatively hard material for the processing blade portion 30 that performs the processing. Further, by making the material of the rake portion 40 a relatively inexpensive material, the manufacturing cost of the broach tool 10 can be reduced.

As an example, as a material of the processing blade part 30, a high-speed tool steel material (JIS G4403: 2015) such as SKH51, and a cemented carbide may be used. Examples of the material of the rake portion 40 include carbon steel materials for machine structures such as S50C (JIS G 4051: 2009) and SUS420.

Each of the rake sections 40 has a third through-hole 41a penetrating the rake section 40 in the axial direction, and a plurality of fourth through-holes 41b penetrating the rake section 40 in the axial direction. The shape viewed from above the third through-hole 41a is a circular shape centered on the central axis J. The shape as viewed from above the fourth through hole 41b is a circular shape. The inner diameter of the fourth through hole 41b is smaller than the inner diameter of the third through hole 41a. In the present embodiment, two fourth through holes 41 b are provided in each of the rake portions 40. The two fourth through-holes 41b are arranged on the radially outer side of the third through-hole 41a on opposite sides of the center axis J. The inside diameter of the third through hole 41a is the same as the inside diameter of the first through hole 34a. The inner diameter of the fourth through hole 41b is the same as the inner diameter of the second through hole 34b.

As shown in FIG. 1, the broaching tool 10 further includes a shaft 21 disposed along the central axis J. The shaft 21 has a cylindrical shape extending in the axial direction. The shaft 21 connects the lower guide portion 11, the processing portion 12, the upper guide portion 13, and the handle portion 14. The lower guide portion 11, the processing portion 12, the upper guide portion 13, and the handle portion 14 are connected to each other by passing a shaft 21 through an axially provided through hole provided in each portion.

A male screw portion is provided on the outer peripheral surface of the lower end of the shaft 21 and the outer peripheral surface of the upper end of the shaft 21. The nut 15 is screwed into the male screw portion at the lower end of the shaft 21. The nut 16 is screwed into the male screw portion at the upper end of the shaft 21. As a result, the lower guide portion 11, the processed portion 12, the upper guide portion 13, and the handle portion 14 are axially sandwiched between the nuts 15 and 16 and fixed to the shaft 21.

The shaft 21 connects the plurality of processing blades 30 and the plurality of rakes 40 that constitute the processing unit 12. More specifically, the plurality of processing blade portions 30 are connected by passing the shaft 21 through the first through hole 34a. Thereby, each processing blade part 30 can be arranged along the axial direction with high axial accuracy. Therefore, the processing accuracy by the broach tool 10 can be improved.

The plurality of rake sections 40 are connected to each other by passing the shaft 21 through the third through hole 41a. As described above, in the present embodiment, the plurality of processing blade portions 30 and the plurality of rake portions 40 are connected to the first through-hole 34a and the third through-hole 41a by passing the shaft 21 therethrough. Thereby, the plurality of processing blade portions 30 and the plurality of rake portions 40 can be arranged with high axial accuracy along the axial direction.

In the present embodiment, the material of the processing blade portion 30 and the material of the shaft 21 are different from each other. Thereby, the processing blade part 30 and the shaft 21 can be manufactured with suitable materials, respectively. Specifically, by setting the material of the shaft 21 to a material having high toughness, the shaft 21 connecting the plurality of processing blade portions 30 and the plurality of rake portions 40 can be hardly broken. As the material of the shaft 21, for example, as in the case of the rake portion 40, a carbon steel material for machine structure such as S50C (JIS G 4051: 2009) and SUS420 are exemplified. The material of the shaft 21 may be different from the material of the rake portion 40.

As shown in FIG. 3, the broaching tool 10 further includes a rotation stopper 50 that suppresses relative rotation between the processing blades 30. Therefore, it is possible to prevent the processing blade portions 30 that are separate members from shifting from each other in the circumferential direction, and it is possible to suppress a reduction in processing accuracy of the broach tool 10. The rotation stopping portion 50 includes a plurality of second through holes 34b provided in each of the processing blade portions 30, a plurality of fourth through holes 41b provided in each of the rake portions 40, and a plurality of pins 22. Have. That is, the broach tool 10 further includes a plurality of pins 22.

In the present embodiment, for example, two pins 22 are provided. Further, for example, two second through holes 34 b are provided for each processing blade portion 30. Further, for example, two fourth through holes 41 b are provided for each rake portion 40.

The pin 22 has a cylindrical shape extending in the axial direction. The outer diameter of the pin 22 is smaller than the outer diameter of the shaft 21. As shown in FIG. 1, the lower end of the pin 22 is fixed to the lower guide 11. The pin 22 is passed across the second through holes 34b of the plurality of processing blade portions 30. Thereby, the rotation stopper 50 can suppress the relative rotation of the plurality of processing blades 30 in the circumferential direction. In the present embodiment, since the rotation stopper 50 has the configuration using the second through-hole 34b and the pin 22, the labor and cost for manufacturing the rotation stopper 50 can be reduced, and the manufacturing cost of the broach tool 10 can be reduced.

In the present embodiment, since the outer diameter of the pin 22 is smaller than the outer diameter of the shaft 21, the second through hole 34b through which the pin 22 passes can be made relatively small. Thereby, it can suppress that the rigidity of the processing blade part 30 falls.

Further, the pins 22 pass through the fourth through holes 41b of the plurality of rake portions 40. That is, in the present embodiment, the pin 22 passes through the second through holes 34b of the plurality of processing blade portions 30 and the fourth through holes 41b of the plurality of rake portions 40. Thereby, the rotation stopper 50 can suppress the relative rotation of the plurality of processing blades 30 and the plurality of rakes 40 in the circumferential direction.

Further, for example, a clearance is provided between the inner peripheral surface of the first through hole 34a and the outer peripheral surface of the shaft 21. As a result, for example, the processing blade portion 30 may move in the radial direction with respect to the shaft 21 by the clearance. On the other hand, for example, when the radial position between the pin 22 and the shaft 21 or the radial position between the first through hole 34a and the second through hole 34b deviates within the tolerance, the first through hole 34
The radial movement of the processing blade part 30 due to the clearance between the shaft a and the shaft 21 is suppressed by the contact between the inner peripheral surface of the second through hole 34b and the outer peripheral surface of the pin 22. Thereby, it is possible to prevent the processing blade portion 30 from moving in the radial direction with respect to the shaft 21 due to the clearance between the first through hole 34a and the shaft 21.

For example, when the tolerance of the radial position of the second through hole 34b with respect to the first through hole 34a is relatively small and the radial position of the pin 22 with respect to the shaft 21 is shifted within the range of the tolerance, the first through hole is formed. The direction in which the shaft 21 shifts in the radial direction due to the clearance in the portion 34a is easily determined uniquely. Therefore, the displacement of the plurality of processing blade portions 30 with respect to the shaft 21 can be aligned in the radial direction, and each tooth portion 33 can be accurately aligned in the axial direction.

In the present embodiment, a plurality of pins 22 are provided, and a plurality of second through holes 34 b are provided for each processing blade 30. Therefore, the rotation stopper 50 can suppress the circumferential rotation of the processing blade 30 at a plurality of positions in the circumferential direction for each processing blade 30.

For example, a clearance is provided between the inner peripheral surface of the second through hole 34b and the outer peripheral surface of the pin 22. Accordingly, for example, when the rotation of the processing blade 30 is stopped by one pin 22 and one second through hole 34b, the processing blade 30 may move in the circumferential direction with respect to the shaft 21 by the clearance. is there.

On the other hand, when the processing blade portion 30 is stopped from rotating by the plurality of pins 22 and the plurality of second through holes 34b, for example, the first through hole 34a of the plurality of second through holes 34b in each processing blade portion 30 is used. May be shifted within the respective tolerances. Therefore, when the plurality of pins 22 are respectively passed through the plurality of second through holes 34b, the circumferential movement of the processing blade portion 30 due to the clearance between the second through holes 34b and the pins 22 causes the other pins 22 to move. And the inner peripheral surface of the second through hole 34b is suppressed. Thereby, it is possible to prevent the processing blade portion 30 from moving in the circumferential direction with respect to the shaft 21 due to the clearance between the pin 22 and the second through hole 34b.

Further, for example, when the tolerance of the circumferential position of the plurality of second through holes 34b with respect to the first through hole 34a is relatively small, and the circumferential position of the plurality of pins 22 with respect to the shaft 21 is shifted within the range of the tolerance, The direction in which the pin 22 shifts in the circumferential direction due to the clearance in the second through hole 34b is likely to be uniquely determined. Therefore, the displacement of the plurality of processing blade portions 30 with respect to the shaft 21 can be aligned on one side in the circumferential direction, and the tooth portions 33 can be accurately aligned in the axial direction.

The effect of suppressing the movement of the processing blade portion 30 in the radial direction and the circumferential direction due to the clearance described above is the same for the rake portion 40. That is, according to the present embodiment, it is possible to suppress the rake portion 40 from moving in the radial direction and the circumferential direction due to each clearance.

In the present embodiment, the material of the processing blade 30 and the material of the pin 22 are different from each other. Thereby, the processing blade part 30 and the pin 22 can be manufactured with suitable materials, respectively. Specifically, by setting the material of the pin 22 to a material having high tenacity, the pin 22 functioning as a rotation stopper of the plurality of processing blade portions 30 and the plurality of rake portions 40 can be hardly broken. Examples of the material of the pin 22 include a carbon steel material for machine structure such as S50C (JIS G 4051: 2009) and SUS420, like the rake portion 40 and the shaft 21. The material of the pin 22 may be different from the material of the rake portion 40 and the material of the shaft 21. The material of the pin 22 may be, for example, a high-speed tool steel material such as SKH51 (JIS G4403: 2015) or a cemented carbide as in the case of the machining blade portion 30.

The present invention is not limited to the above embodiment, and other configurations can be adopted. In the following description, the same components as those described above may be omitted from the description by assigning the same reference numerals as appropriate.

The processing blade portion 30 and the rake portion 40 may be a single member. The rake section 40 may not be provided. Further, the plurality of processing blade portions 30 may not be separate members from each other, and may be portions of a single member. In this case, the processing unit 12 or the broach tool 10 can be a single member having a plurality of processing blades. The method of connecting the plurality of processing blade portions 30 is not particularly limited, and may be, for example, welding. The rotation stopper 50 is not particularly limited as long as the rotation of the machining blade 30 with respect to the shaft 21 in the circumferential direction can be suppressed. The rotation stopper 50 may not be provided. The processing blade part 30, the rake part 40, the shaft 21, and the pin 22 may be made of the same material. The number of the processing blade portions 30 is not particularly limited as long as it is plural.

If the flank 36 having the clearance angle θ larger than 0 ° is provided on the entire circumferential surface of each tooth 33, the flank 36 of each tooth 33 may not be connected to each other. Further, the clearance angle θ may change depending on the position of the clearance surface 36. Further, the tooth portion 33 may be provided with a straight land (JIS B 0175-1996) in which the clearance angle θ is 0 °. The radial outer surface of the straight land is orthogonal to the radial direction. The straight land connects the flank 36 and the rake face 35 between the flank 36 and the rake face 35.

Further, a plurality of processing blade portions 30H having the largest circumferential dimension of the tooth portions 33 may be provided side by side in the axial direction. According to this configuration, even if the cutting of the processing object OP cannot be completed by the processing blade portion 30H disposed at the lowermost side among the plurality of processing blade portions 30H, another processing blade portion is further formed on the upper side. Since 30H is provided, it is possible to improve the reliability of the finishing of the cutting process of the processing object OP. Further, for example, even when the lowermost processing blade portion 30H among the plurality of processing blade portions 30H is worn, the finishing of the cutting process is performed by another processing blade portion 30H disposed above. Therefore, the frequency of replacement of the processing blade portion 30H can be reduced. In this case, the plurality of processing blade portions 30H only need to have the same circumferential dimension of the tooth portions 33 and be the largest among the processing blade portions 30. The position of the radially outer end of the tooth portion 33 is The processing blades 30G may be different from each other within a range radially inward of the teeth 33.

<2nd Embodiment> As shown in FIG. 9, in the processing blade part 130 of the broach tool 110 of 2nd Embodiment, the rotation stop part 150 has the outer peripheral surface of the shaft 121 and the inner peripheral surface of the 1st through-hole 134a. A concave portion that is provided on one of them and is radially depressed, and a convex portion that is provided on the other of the outer peripheral surface of the shaft 121 and the inner peripheral surface of the first through hole 134a and protrudes in the radial direction. Have. In the present embodiment, the recess is a recess 134c that is recessed radially outward from the inner peripheral surface of the first through hole 134a. The protrusion is a protrusion 121a that protrudes radially outward from the outer peripheral surface of the shaft 121.

The protrusion 121a is fitted into the recess 134c. Accordingly, the rotation stopping portion 150 can suppress the processing blade portion 130 from rotating in the circumferential direction with respect to the shaft 121. The shaft 121 is a single member having the convex portion 121a. Therefore, the rotation stopper 150 can be configured without increasing the number of parts, and the manufacturing cost of the broach tool 110 can be reduced.

Note that, for example, a configuration may be adopted in which a second concave portion that is depressed inward in the radial direction is provided at a position radially opposed to the concave portion 134c on the outer peripheral surface of the shaft 121, and a key member is fitted into the concave portion 134c and the second concave portion. Good. In this case, the key member corresponds to “a protrusion provided on the other of the outer peripheral surface of the shaft and the inner peripheral surface of the first through hole and protruding in the radial direction”. Further, the concave portion may be a concave portion recessed radially inward from the outer peripheral surface of the shaft 121, and the convex portion may be a convex portion projecting radially inward from the inner peripheral surface of the first through hole 134a. Good.

Third Embodiment As shown in FIGS. 10 and 11, each of the processing blade portions 230 of the present embodiment has a plurality of tooth portions 233 protruding radially outward. The plurality of tooth portions 233 are arranged at equal intervals over one circumference along the circumferential direction. In this embodiment, the tooth profile of the tooth portion 233 is an involute tooth profile, unlike the above-described embodiments.

<Example of Reducer with Internal Gears to be Manufactured> The internal gear G1 of the reducer GR shown in FIG. 12 is a broach tool of the first and second embodiments of the broach tools of the above-described embodiments. It is an example of an internal gear manufactured using the above. The reduction gear GR has an internal gear G1, an external gear G2, and an output member OM. The internal gear G1 is formed in an annular shape around the rotation axis O1 of the motor shaft S. On the inner peripheral surface of the internal gear G1, there are provided a plurality of teeth T1 arranged in the circumferential direction of the rotation axis O1. The internal gear G1 is fixed to a housing of the speed reducer GR.

The external gear G <b> 2 is formed in an annular shape to be fitted on the outer peripheral surface of the eccentric portion Se of the motor shaft S. The eccentric axis O2 of the eccentric part Se is eccentric with respect to the rotation axis O1 of the motor shaft S. The inner peripheral surface of the external gear G2 functions as a slide bearing, and is rotatable relative to the eccentric portion Se. On the outer peripheral surface of the external gear G2, there are provided a plurality of teeth T2 arranged along the circumferential direction of the eccentric shaft O2. The tooth part T2 meshes with the tooth part T1 at a part of the outer periphery of the external gear G2. The tooth shape of the tooth portion T1 and the tooth shape of the tooth portion T2 are, for example, cycloid tooth shapes.

The external gear G2 has a plurality of holes PH penetrating the external gear G2 in the axial direction of the eccentric shaft O2. The plurality of holes PH are arranged at equal intervals over one circumference along the circumferential direction of the eccentric axis O2. The output member OM has a plurality of support pins P inserted into the holes PH. The outer diameter of the support pin P is smaller than the inner diameter of the hole PH.

When the motor shaft S is rotated around the rotation axis O1, the eccentric portion Se revolves around the rotation axis O1. As a result, the external gear G2 swings while the position at which the inner peripheral surface of the hole PH is in contact with the outer peripheral surface of the support pin P changes, and the position at which the tooth portion T1 and the tooth portion T2 mesh with each other is changed by the rotation shaft. It changes in the circumferential direction of O1. Therefore, the internal gear G1 and the external gear G2 rotate relatively. In FIG. 12, since the internal gear G1 is fixed to the housing of the speed reducer GR, the external gear G2 rotates. When the external gear G2 rotates, the output member OM rotates via the hole PH and the support pin P. The rotation of the output member OM is reduced with respect to the rotation of the motor shaft S.

According to the broach tools of the first and second embodiments described above, the internal gear G1 of such a speed reducer GR can be manufactured. More specifically, the internal gear G1 can be manufactured by forming a plurality of teeth T1 by cutting using the broach tools of the first and second embodiments described above.

In addition, the application of the broach tool of each embodiment mentioned above is not specifically limited. In addition, the above-described configurations can be appropriately combined as long as they do not conflict with each other.

10, 110: broaching tool, 21, 121: shaft, 22: pin, 30, 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 130, 230 ... machining blade part, 33, 233 ... tooth part, 34a, 134a: first through hole, 34b: second through hole, 40: rake portion, J: central axis

Claims (7)

A plurality of processing blades arranged along a central axis extending in a vertical direction, each of the processing blades has a plurality of teeth protruding radially outward, and the plurality of teeth are the processing blades. Each part is arranged along the circumferential direction, and each is arranged along the axial direction with the tooth part of the other processing blade part, and is disposed on the upper side of the processing blade parts adjacent in the axial direction. The processing blade portion to be disposed has a larger circumferential dimension of the tooth portion than the processing blade portion disposed below, and a radially outer end of the tooth portion is located radially outward. At least one of the plurality of processing blades, a circumferential dimension of the tooth portion in the first processing blade disposed at an uppermost position is the largest of the plurality of processing blades, A processing blade disposed below the first processing blade part in the processing blade part At least one, radially outer end of the tooth portion is positioned radially outward from the radially outer end of the teeth in the first processing blade portion, broach tool. The position of the radially outer end of the tooth portion in the second processing blade portion adjacent to the lower side of the first processing blade portion of the plurality of processing blade portions is the most radial position of the plurality of processing blade portions. The broaching tool according to claim 1, wherein the broaching tool is located outside. In the processing blade portion adjacent in the axial direction, when the circumferential dimension of the tooth portion in the processing blade portion disposed above the processing blade portion disposed below is increased, The broaching tool according to claim 1, wherein an increase in a circumferential dimension is larger than a circumferential dimensional tolerance of the tooth portion. In the processing blade portion adjacent in the axial direction, in the case where the radial outer end of the tooth portion in the processing blade portion disposed above the processing blade portion disposed below is located radially outward, The radial distance between the radially outer end of the tooth portion in the processing blade portion disposed on the upper side and the radially outer end of the tooth portion in the processing blade portion disposed on the lower side is the toothed portion. 4. The broaching tool according to claim 1, wherein the broaching tool is larger than a dimensional tolerance in a radial direction. The broaching tool according to any one of claims 1 to 4, wherein the plurality of processing blades are separate members. A shaft disposed along the central axis; and a plurality of pins extending in an axial direction, wherein each of the processing blade portions includes a first through-hole that axially penetrates the processing blade portion; A plurality of second through holes penetrating the blade portion in the axial direction; and the plurality of processing blade portions are connected by passing the shaft through the first through hole. The broaching tool according to claim 5, wherein the broaching tool is passed over the second through hole of the processing blade portion. The broaching tool according to claim 6, wherein a material of the processing blade portion, a material of the shaft, and a material of the pin are different from each other.

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