JP2889867B2 - Manufacturing method of shaft parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a shaft-shaped part in which one large-diameter portion of a material having large-diameter portions near both ends of a shaft portion has a predetermined contour.

[0002]

2. Description of the Related Art As shown in FIG. 22, in a certain type of apparatus, one polyhedron part A2 is fitted through a shaft-like part A having polyhedron parts A2 and A3 near both ends of a shaft part A1. In some cases, power is transmitted from the member B to the other polyhedron part A3 to the member C fitted to the other polyhedron part A3. If the corners are rounded, a gap is formed between the corners of the concave portion to be fitted with the corners and the corners do not adhere to each other. As a result, a problem arises in that power is not transmitted from the member B to the member C due to idling.

Therefore, in this type of shaft-shaped part A,
It is necessary to make the contours of the polyhedral portions A2 and A3 sharp and not to have rounded corners. Therefore, conventionally, it is necessary to cut unnecessary portions by cutting a polyhedral bar having sharp corners. Thus, the shaft-shaped part A is formed. However, in this case, since unnecessary portions of the bar are cut off, there is a problem that the material loss increases and the cost increases.

On the other hand, for example, Japanese Patent Application Laid-Open No. Hei 6-126
It is conceivable to form the shaft-shaped component A by using a cold multi-stage press forming machine as disclosed in Japanese Patent No. 371. However, when trying to form a polyhedral part near both ends, the number of stages of the forging machine increases and it is not realistic,
Only one polyhedron part is formed into the final shape, and the other is manufactured into a large semi-finished shaft-shaped semi-finished product before being formed into a polyhedron. It is conceivable to form a polyhedral part having sharp corners by performing the processing. In this case, the other polyhedral portion may be formed by punching out a large-diameter portion of a semi-finished product into a sharp polyhedral portion using a press molding machine.

[0005]

However, when a large diameter portion of a semi-finished product is stamped and formed into a sharp polyhedral portion by using a press molding machine as described above, the following problems occur.

That is, as shown in FIG. 23, in a state where the semi-finished product D is held by a holding member E at the opposite end of the semi-finished product D having a large diameter portion D1 on one end side, a concave portion F1 having a predetermined shape is formed.
The large diameter portion D1 is punched out by the punch F having a shape and is formed into a polyhedral portion. However, in this case, since the punching load is received at the opposite end, the semi-finished product D
When the length of the shaft portion D2 is long, there is a problem that the shaft portion D2 cannot withstand the punching load and buckles.

On the other hand, in order to prevent the shaft portion D2 from buckling, as shown in FIG. 24, it is possible to separate the large-diameter portion D1 while holding the opposite end portion with the holding member G. It is conceivable that the shaft portion D2 is gripped by the pair of receiving members H1 and H2, and in this state, the large diameter portion D1 is punched out by a punch J having a concave portion J1 of a predetermined shape to form a polyhedral portion. However, in this case, since the large-diameter portion D1 is completely punched into a predetermined contour shape, the punch J and the pair of receiving members H1 and H2 come into contact with each other. There is a problem that the members H1 and H2 wear quickly and must be replaced frequently.

In any of the methods shown in FIGS. 23 and 24, the semi-finished product D has large-diameter portions D1 and D3 near both ends of the shaft portion. When one of the large diameter portions is punched into a predetermined contour shape by punching, the punched chips are discharged and left on the shaft portion D2. Therefore, an operation of removing the punched chips from the shaft portion D2 is separately performed. Required.

In view of the above, the present invention has been made to avoid the above-mentioned problem and to form one large diameter portion of a material having a large diameter portion near both sides of a shaft portion into a predetermined contour shape using a press molding machine. It is an object to provide a manufacturing method which can be formed.

[0010]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized in that it is configured as follows.

That is, the invention of the present application relates to a method of manufacturing a shaft-like component for forming one large-diameter portion of a material having large-diameter portions near both ends of a shaft portion into a predetermined contour shape. Using a receiving member provided with a punching blade portion on one side and a depressing member, an end surface of the one large-diameter portion of the material on the other large-diameter portion side is supported by a receiving member, and in this state, the material is By moving the push-down member from the shaft end on the one large-diameter portion side to a position immediately before coming into contact with the receiving member, the large-diameter portion has a predetermined contour in a state where punched chips are left in the one large-diameter portion. Formed into a shape, and then gripping the other large-diameter portion side of the material, and in this state, moving a movable die having a forming hole having the same shape as the blade portion on the end face side of one large-diameter portion. From the shaft end to the end And removing the.

According to the above construction, the receiving member having at least one of the punching blades and the pushing-down member is used, and the end surface of the one large-diameter portion of the material on the other large-diameter portion side is supported by the receiving member. Then, in this state, when the pressing member is moved from the shaft end on the one large-diameter portion side of the material to form a predetermined contour, the movement of the pressing member is to a position immediately before contact with the receiving member. As a result, the pushing-down member and the receiving member do not come into contact with each other, and since the one end surface is supported, the shaft does not buckle.

In a state where the other large-diameter portion of the material is gripped, a movable die having a forming hole having the same shape as that of the blade is moved to move one of the large-diameter portions from the end face side. Since the punching waste is removed to the shaft end side, the punching waste is discharged to the opposite side of the shaft portion and does not remain on the shaft portion, so that there is no need to remove the punching waste from the shaft portion.

[0014]

Embodiments of the present invention will be described below. An apparatus for manufacturing a shaft-shaped component according to the present embodiment implements the method of the present invention.

FIG. 1 shows a first example of the method according to this embodiment.
It is a press device that performs the process.

The press apparatus 10 has a machine base 11 and a frame 12 erected from the machine stand 11.
A processing table 13 is provided above. A ram 14 is provided above the frame 12 so as to face the processing table 13.
And a cylinder 15 for raising and lowering the ram 14 is provided above the ram 14.

As shown in FIGS. 2 to 4, a rectangular base member 16 is provided on the upper surface of the processing table 13, and a pair of rail members 17a are provided on both sides of the base member 16 in the longitudinal direction. 17b, a pair of slide members 18a, 18b are provided on the base member 16. Each of these slide members 18a, 18b is a cam member 19a, 19b and a base member 20a, 2b.
0b, and a pair of slide members 18a, 18b are formed on the base member 16 by engaging both sides of the base members 20a, 20b with the pair of rail members 17a, 17b. Are movably supported in the longitudinal direction. Also, both slide members 18a, 18
b, semicircular grooves 21a and 21b extending in the vertical direction are provided at the center of the mutually facing surfaces (hereinafter referred to as front surfaces), respectively. When these slide members 18a and 18b come into contact with each other on the front surface, A hole for gripping the shaft portion is formed.
The cam members 19a and 19b of a and 18b are provided with inclined cam surfaces 22a and 22b at rear ends thereof.

Further, spring receiving members 23, 23 are provided upright at both ends in the longitudinal direction of the processing table 13, and the spring receiving members 23, 23 are provided on the rear end surfaces of the base members 20a, 20b. Bolts 24 projecting rearward through
.. 24 are screwed. And these bolts 24
... between the head of 24 and the spring receiving members 23, 23
25 are mounted, and the base members 20a, 20b of the slides 18a, 18b are mounted by the springs 25 ... 25.
The rear end portion is pulled and stopped to a position where it comes into contact with the spring receiving members 23, 23. As a result, the pair of slide members 18a and 18b are held in a state where they are farthest from each other.

In the center of the base member 16, a concave portion 26 for holding one end of the material and erecting the material is provided.
The standing member 26 having a is embedded.

On the other hand, as shown in FIGS. 2 and 4, a mounting plate 27 is fixed to the lower end surface of the ram 14, and a punch 28 is mounted at the center of the mounting plate 27. The mounting plate 2 is positioned so that the punch 28 is located directly above the concave portion 26a of the standing member 26.
7 is attached.

The punch 28 has a recess 28a corresponding to the polyhedron of the finished product to be formed.
The periphery is a blade portion 28b.

A pair of drive members 29a and 29b are hung down on both sides in the longitudinal direction of the mounting plate 27, and the lower end of the surfaces of the drive members 29a and 29b facing each other has an inclined cam surface. 30a and 30b are provided. And a pair of drive members 29a,
29b is a cam surface 22 of the cam members 19a and 19b in a state where the pair of slide members 18a and 18b are farthest apart.
The cam members 30a and 30b of the drive members 29a and 29b are suspended from the mounting plate 27 such that the cam surfaces 30a and 30b of the drive members 29a and 29b are located above the a and 22b.

Next, a press apparatus for performing the second step of the method according to this embodiment will be described with reference to FIG.

The press device 40 has a machine base 41 and a frame 42 erected from the machine base 41.
A processing table 43 is provided on the upper side. Then, a ram 44 is provided above the frame 42 so as to face the processing table 43.
And a cylinder 45 for raising and lowering the ram 44 is provided above the ram 44.

As shown in FIGS. 9, 10, and 12, a pair of rail members 46 are provided on the upper surface of the processing table 43.
a, 46b are provided in parallel,
The slide member 47 is installed between a and 46b. The slide member 47 includes a base member 48, a die member 49, and a pair of cam members 50a and 50b.
By being engaged with 6a and 46b, the slide member 47 is supported on the worktable 43 so as to be movable in the rail direction.

A plate-shaped die member 49 is erected at the end of the base member 48 on a flat plate-shaped but U-shaped base member 48, and a pair of cam members 50a, 50b is fixed. In the center of the die member 49, a groove portion 49a corresponding to a half hexagonal shape as a finished product is provided penetrating forward and backward, and an end side surface (hereinafter referred to as a front surface) of the base member 48. Groove 4
The periphery of 9a is a blade portion 49b. In addition, inclined cam surfaces 51 are provided at rear ends of both cam members 50a and 50b.
a and 51b are provided respectively.

Further, on the processing table 43, spring receiving members 52, 52 are provided in front of the slide member 47, and stopper members 53, 53 are provided in the rear, respectively.
Springs 54, 54 are mounted between the front end of the slide member 47 and the spring receiving members 52, 52, and the rear ends of the slide member 47 are moved by the springs 54, 54 to the stopper members 53, 53. And is held pressed down to a position where it abuts.

The worktable 43 is provided between the pair of cam members 50a and 50b of the slide member 47 at a position between the gripping member 55 and the pair of first material receiving members 56a and 56a.
6b are erected. On the upper surface of the gripping member 55, a semicircular groove 5 for gripping the shaft of the material is provided.
5a is provided. The groove formed by the pair of first material receiving members 56a and 56b is shaped to engage with the polyhedral portion of the material.

Further, on the processing table 43, a second receiving member 57 is provided upright in front of the slide member 47. In the upper surface of the second receiving member 57, holes 57a, 57
b and a semicircular groove 57c for receiving one end of the material.

The working table 43 has drive receiving members 58, 58 standing behind the slide member 47.

On the other hand, as shown in FIG. 9, FIG. 11, and FIG.
A plate member 61 is suspended from the mounting base 59 so as to be vertically movable via guide rods 60. And, so as to be penetrated by the guide rods 60.
A spring 6 is provided between the mounting table 59 and the plate member 61.
62 are mounted, and the plate member 61 is pressed down and held to a predetermined position by the springs 62.

On the lower surface of the plate member 61, a pair of rail members 4 installed on the upper surface of the worktable 43 are provided.
A pair of rail members 63 extending in the same direction as 6a and 46b
a, 63b are provided in parallel,
The slide member 64 is provided between a and 63b. The slide member 64 includes a base member 65, a die member 66, and a pair of cam members 67a and 67b.
By being engaged with 3a and 63b, the slide member 64 is supported on the lower surface of the plate member 61 so as to be movable in the rail direction.

A plate-shaped die member 66 is erected at the end of the base member 65, and a pair of cam members 67a is provided on both sides of the base member 65 on the lower surface of the base member 65. , 67b are fixed. A groove 66a corresponding to a half hexagonal shape as a finished product is provided in the center of the die member 66 so as to penetrate back and forth, and a periphery of the groove 66a on the end side surface of the base member 65 is provided. The blade 66b is provided. When the die member 66 on the ram 44 comes into contact with the die member 49 on the processing table 43, a hole is formed to make the large-diameter portion into a hexagonal shape.

Further, on the lower surface of the plate member 61, a spring receiving member 68 is provided in front of the slide member 64.
A stopper member 69 is provided upright on the rear side. Then, springs 70, 70 are mounted between the front end of the slide member 64 and the spring receiving members 68, 68, and the slide members 64 are mounted by the springs 70, 70.
The rear end portion is pressed and held to a position where it comes into contact with the stopper members 69, 69. The position where the slide member 64 is held is right above in the same direction as the slide member 47 installed on the upper surface of the processing table 43.

The lower surface of the plate member 61 is located at a position between the pair of cam members 67a and 67b.
A holding member 71 is provided upright, and a semicircular groove 71 a for holding a shaft portion of the material is provided on a lower surface of the holding member 71. The position of the holding member 71 is
3 and in the same direction as the gripping member 55 installed on the upper surface thereof.

On the lower surface of the plate member 61,
A receiving member 72 is provided upright in front of the slide member 64, and holes 72 a and 72 b and a semicircular groove 72 c for receiving one end of the material are provided on the lower surface of the receiving member 72. The position of the receiving member 72 is right above in the same direction as the second receiving member 57 installed on the upper surface of the processing table 43.

A pair of drive members 73a and 73b are hung down on one side in the longitudinal direction of the mounting table 59, and the lower ends of the surfaces of the drive members 73a and 73b on the slide member 64 side are inclined. Cam surface 74a,
74b is provided. Also, a pair of drive members 7
The supporting member 75 for supporting 3a, 73b is
Hanged at 9. Then, the drive member 73a,
73b is a cam surface 51 of both cam members 50a, 50b at a position where the rear end of the slide member 47 installed on the upper surface of the processing table 43 comes into contact with the stopper members 53, 53.
The mounting table 59 so that the cam surfaces 74a, 74b of the drive members 73a, 73b are located above the mounting members 59a, 51b.
Hanged on.

Further, circular concave portions 76a, 76b are provided on the upper surfaces of the cam members 50a, 50b of the slide member 47 installed on the upper surface of the processing table 43. On the lower surface of the cam members 67a and 67b of the slide member 64 on the ram 44 side, cylindrical projections 77a and 77b are provided. The positions of the protrusions 77a and 77b are right above the positions corresponding to the recesses 76a and 76b. When the ram 44 descends, these protrusions 77a, 7
7b fits into the concave portions 76a, 76b, whereby the upper and lower slide members 47, 64 are integrated.

The mounting table 59 has a pair of punches 78a for forming one end of the material on two parallel surfaces.
78b is hung. And these punches 78
The a and 78b penetrate the holes 72a and 72b of the receiving member 72, and are hung down on the mounting base 59 at a position where they protrude into the holes 57a and 57b of the second receiving member 57.

Next, a press device 10 for performing the first step
The operation of will be described.

The material a shown in FIG.
The material a is supplied to the concave portion 26a of the standing member 26 with the polyhedron portion a1 of the material a facing down, and the material a is set in a standing state.

Then, as shown in FIG.
As a result, the ram 14 is lowered, and the cam surfaces 30a, 30b of the pair of drive members 29a, 29b are moved to the cam members 19a, 1b of the pair of slide members 18a, 18b.
It descends toward the cam surface 19a, 19b of 9b. The cam surfaces 30a, 3b of the drive members 29a, 29b
0b is the cam surfaces 22a, 22b of the cam members 19a, 19b.
, The front surfaces of the slide members 18a and 18b are brought into contact with each other while the springs 25... 25 are compressed.

Thus, the pair of slide members 18
The shaft portions a3 of the material a are gripped by the grooves 21a and 21b provided on the front surfaces of the slide members 18a and 18b such that the lower end surfaces of the large diameter portions a2 of the material a are supported on the upper surfaces of the materials a and 18b. You.

When the ram 14 further descends in this state, as shown in FIGS. 6 and 7, the punch 28 protrudes to a position immediately before the punch 28 comes into contact with the upper surfaces of the pair of slide members 18a and 18b. The outer shape of the large-diameter portion a2 of the material a is formed into a hexagonal shape with the punch 28 leaving punched chips on the lower end surface of the large-diameter portion a2, thereby forming an intermediate product b shown in FIG.

Next, a press 40 for performing the second step
The operation of will be described.

The intermediate product b is transferred to the press device 40 by the polyhedral portion b1 of the intermediate product b.
The intermediate product b is supplied laterally so as to engage with the grooves of the material receiving members 56a and 56b, and the end of the intermediate part b on the side of the shaft part b2 and the part of the large diameter part b3 are respectively connected to the second holding part 55 and the second part of the processing table 43 side. It is set in a state of being placed on the material receiving member 57.

As shown in FIGS. 13 and 14, the ram 44 is lowered by the operation of the cylinder 45,
The slide member 64 on the ram 44 side descends toward the slide member 47 on the processing table 43 side. The projections 7 of the pair of cam members 67a, 67b of the slide member 64 on the ram 44 side.
7a and 77b are fitted into the concave portions 76a and 76b of the cam members 50a and 50b of the slide member 47 on the processing table 43 side, and the upper and lower slide members 47 and 64 are integrated. Further, the shaft portion b2 of the intermediate product b is gripped by the gripping member 71 on the ram 44 contacting the gripping member 55 on the processing table 43 side. When the material receiving member 72 on the ram 44 comes into contact with the second material receiving member 55 on the processing table 43, the end on the large diameter portion b3 side of the intermediate product b is gripped.

In this state, when the ram 44 further descends, the cam surfaces 74a, 74b of the pair of drive members 73a, 73b are brought into contact with the slide member 47 on the worktable 43 side, as shown in FIGS. Cam members 50a, 50
b, by contacting the cam surfaces 51a, 51b, the springs 54, 54 on the processing table 43 side and the springs 70, 7 on the ram 44 side.
While the 0 is compressed, the upper and lower slide members 47 and 64 move forward integrally.

Thus, the polyhedral part b of the intermediate product b
1 is a pair of first material receiving members 56a, 5
Since the intermediate product b does not move because it is engaged with the groove of the intermediate product 6b, the punching waste b4 of the intermediate product b is removed by the upper and lower dice members 49 and 66 of the upper and lower slide members 47 and 64, and the opposite side of the shaft portion b2 is removed. Is discharged.

The pair of punches 78a, 78b pass through the holes 72a, 72b of the receiving member 72 on the ram 44 side and the holes 57a, 57b of the second receiving member 57 on the processing table 43 side.
, The shaft end on the large diameter portion b3 side of the intermediate product b is formed in two parallel surfaces, and the final product c shown in FIG.
Is formed.

Therefore, according to the press apparatus 10 for performing the first step, the lower end surface of the large diameter portion a2 of the material a is supported by the upper surfaces of the pair of slide members 18a and 18b.
Since the punch 28 is gripped by the slide members 18a and 18b, and in this state, the punch 28 is pushed into a position immediately before coming into contact with the slide members 18a and 18b, the punch 28 and the slide members 18a and 18b do not come into contact with each other. Since the lower end surface of the diameter portion a2 is supported, the shaft portion a3 does not buckle.

Further, a press device 40 for performing the second step
According to this, the polyhedral part b1 side of the intermediate product b is gripped, and in this state, the upper and lower die members 49, 66 of the upper and lower slide members 47, 64 are moved forward to remove the punched waste part b4 of the intermediate product b. Since it is removed, the punched waste part b4 becomes the shaft part b2.
Is discharged to the opposite side and does not remain on the shaft portion b2, and there is no need to remove the punched waste b4 from the shaft portion b2.

In the press apparatus 10 for the first step in the above-described embodiment, the punch 28 is provided with the blade 28b,
The punch 28 is lowered to a position immediately before coming into contact with the receiving member, so that the punched chips are left on the end face of the large diameter portion a2 on the shaft portion a3 side. You may change to the structure which provided the blade part in the member side or the both sides of a receiving member and a punch.

That is, in the press device 80 according to the second embodiment shown in FIG. 17, a pair of receiving members 82 a, while the polyhedral portion a 1 having the final shape of the material a is held by the material receiving member 81, The end portions of the large diameter portion a2 on the shaft portion a3 side before being formed into the polyhedron of the material a are supported by the blade portions 83a and 83b of the material a, and in this state, the punch 84 makes the blade portions of the receiving members 82a and 82b. The large diameter portion a2 is formed into a hexagonal shape with the punched waste a4 left on the shaft end side end surface of the large diameter portion a2 by descending to a position immediately before coming into contact with the large diameter portions 83a and 83b. A spring 85 is provided below the material receiving member 81, and the spring 8
When the material 5 is compressed, the material a is lowered.

Further, in the pressing device 90 according to the third embodiment shown in FIG. 18, a pair of receiving members 92a, 92b is held in a state where the polyhedral portion a1 having the final shape of the material a is held by the material receiving member 91. Of the large diameter portion a2 before being formed into the polyhedron of the material a is supported by the blade portions 93a and 93b of the material a, and in this state, the punch 94 moves the blade portion 93a of the receiving members 92a and 92b. , 93b, and the receiving member 92 from below by the blade portion 94a of the punch 94 from above.
a, 92b, the cutting parts a
The large-diameter portion a2 is formed in a hexagonal shape with 4 and a4 left in the center of the large-diameter portion a2. In addition, a spring 95 is provided below the material receiving member 91, and the material a is lowered by the compression of the spring 95.

[0056]

As described above, according to the method of the present invention, the receiving member provided with the punching blade portion on at least one side and the pushing-down member are used, and the other large-diameter portion in one large-diameter portion of the material is used. When the pressing member is moved from the one large-diameter portion side of the material to form a predetermined contour shape in this state, the end surface of the lower portion is supported by a receiving member. Since the push-down member and the receiving member do not come into contact with each other just before the contact, the shaft portion does not buckle because the one end surface is supported.

Further, while holding the other large-diameter portion of the material, a movable die having a forming hole having the same shape as the blade portion is moved to move the one large-diameter portion from the end face side. Since the punching waste is removed to the shaft end side, the punching waste is discharged to the opposite side of the shaft portion and does not remain on the shaft portion, eliminating the need to remove the punching waste from the shaft portion, using a press molding machine. Thus, it is possible to efficiently manufacture a shaft-shaped part.

[Brief description of the drawings]

FIG. 1 is a front view of a press device for performing a first step according to the present invention.

FIG. 2 is a partially enlarged view of FIG.

FIG. 3 is a view as seen from an arrow line in FIG. 2;

FIG. 4 is a sectional view taken along the line II in FIG. 2;

FIG. 5 is a longitudinal sectional view showing a state where a slide member in a first step is closed.

FIG. 6 is a vertical cross-sectional view showing a state in which the punch in the first step has protruded to a position immediately before contacting the slide member.

FIG. 7 is an enlarged view of a main part of FIG. 6;

FIG. 8 is a front view of a press device that performs a second step according to the present invention.

FIG. 9 is a partially enlarged view of FIG. 8;

FIG. 10 is a view as viewed from the direction of the arrows U-W in FIG. 9;

FIG. 11 is a view taken along the line AA in FIG. 9;

FIG. 12 is a sectional view taken along the line O-O of FIG. 9;

FIG. 13 is a longitudinal sectional view showing a state where the slide member in the second step is closed.

FIG. 14 is a cross-sectional view taken along the line of dashed lines in FIG.

FIG. 15 is a longitudinal sectional view showing a state where the die member has moved forward with the slide member in the second step closed.

FIG. 16 is a sectional view taken along a key line in FIG. 15;

FIG. 17 is an enlarged longitudinal sectional view of a main part of a press device according to a second embodiment.

FIG. 18 is an enlarged longitudinal sectional view of a main part of a press device according to a third embodiment.

FIG. 19 is a view showing the shape of a material processed by a press device that performs the first step.

FIG. 20 is a diagram showing a shape of an intermediate product processed by a press device that performs the first step.

FIG. 21 is a diagram showing a shape of a final product processed by a press device that performs a second step.

FIG. 22 is an explanatory view showing a use state of a shaft-shaped component.

FIG. 23 is a longitudinal sectional view showing a conventional method for manufacturing a shaft-shaped part.

FIG. 24 is a longitudinal sectional view showing another conventional manufacturing method of the shaft-shaped part.

[Explanation of symbols]

18a, 18b Receiving member (slide member) 28, 84, 94 Depressing member (punch) 28b, 94a Blade portion of pressing member (punch blade portion) 49, 66 Dice (die member) 82a, 82b Receiving member 83a, 83b Receiving member 83a, 83b Blade portion 92a, 92b of member Receiving member 93a, 93b Blade portion of receiving member

Claims (1)

(57) [Claims] 1. A method for manufacturing a shaft-like component, wherein one large-diameter portion of a material having large-diameter portions near both ends of a shaft portion is formed into a predetermined contour shape, wherein at least one of the shaft-forming parts has a punching blade portion. Using the provided receiving member and the depressing member, the end face of the one large-diameter portion of the material on the other large-diameter portion side is supported by the receiving member, and in this state, the one large-diameter portion side of the material is By moving the push-down member from the shaft end to a position immediately before contacting the receiving member, the large-diameter portion is formed into a predetermined contour shape while leaving punched waste on the one large-diameter portion, and then Then, the other large-diameter portion side of the material is gripped, and in this state, a movable die having a forming hole having the same shape as the blade portion is moved from the end surface side of one large-diameter portion to the shaft end side. By removing the punched waste The method of manufacturing the part.