JPH0724872B2 - Method for forming outer ring of tripod type constant velocity joint - Google Patents

Description

The present invention relates to a method for molding an outer ring of a tripod type constant velocity joint.

[Conventional technology]

As shown in FIGS. 4 and 5, the outer ring of the tripod type constant velocity joint has three cylinders parallel to the axial center of the cup portion on the inner diameter surface of the cylindrical cup portion 2 having the shaft portion 1 at the closed end. A shaped track groove 3 is formed, three axial grooves 4 are provided on the outer diameter surface, and the groove 4 and the track 3 are displaced in the circumferential direction.

Further, since the opening of the cup portion 2 is closed by mounting the boot, the tip of the outer diameter surface of the cup portion 2 is made to be the cylindrical surface 5 for the purpose of facilitating the coupling of the boot and improving the sealing property of the coupling portion. There are quite a few cases.

Such an outer ring is usually made of a forged product, and the forged product is ironed so that the inner diameter portion of the cup portion 2 can be precisely formed. A press machine is used for the ironing process.

6 and 7 show a conventional pressing device for molding an outer ring. In this pressing apparatus, a die base 51 is attached to the lower end of a press slide 50, and a die 52 attached to the lower end of the die base 51 is provided with a shaft insertion hole 53 that opens at the lower surface of the die.

Further, below the press slide 50, a receiving table 54 is arranged and supported by a plurality of springs 55, a work receiving table 56 is attached to the receiving table 54, and a punch insertion hole 57 formed in the work receiving table 56. Insert the ironing punch 58, and insert the ironing punch.
The lower end of 58 is supported by a punch support 59.

At the time of forming the outer ring, the outer ring forged product A having the track surface 6 of the track groove 3 shown in FIG. 6 with an ironing allowance is supported by the work cradle 56, and the forged product A is pushed down by lowering the press slide 50. As shown in FIG. 7, the cup portion 2 is press-fitted onto the outer side of the ironing punch 58, and the inner surface of the cup portion 2 is ironed by the ironing punch 58.

[Problems to be Solved by the Invention]

By the way, in the above-mentioned conventional molding method, the cup portion 2
Since the outer diameter surface of the cup portion 2 is not constrained, and only the inner surface of the cup portion 2 is squeezed by the ironing punch 58, the inner diameter dimension of the cup portion 2 varies, and sometimes the width dimension of the track groove 3 becomes insufficient. It may be a good product, and there is an inconvenience that stable production cannot be achieved. The cause is the track surface 6
It is considered that this is because the inner diameter portion 7 of the cup portion 2 is dragged outward as the material is moved by the ironing.

If the inner diameter surface 7 of the cup portion 2 is provided with an ironing allowance, the opening of the track surface 6 begins to be unsatisfactory and stable accuracy cannot be obtained.

Then, this invention makes it a technical subject to eliminate the said inconvenience and to improve the dimensional accuracy of a molded product.

[Means for Solving the Problems]

In order to solve the above problems, in the present invention, an axial track groove is formed on the inner diameter surface of a cylindrical cup portion having a shaft portion at the closed end, and the inner surface and the outer diameter surface of the cup portion are respectively formed. Using a forged product with a margin of ironing, the inner diameter surface of the cup part is ironed with an inner diameter ironing punch with both ends of the cup part of the forging product axially restrained, and the inner diameter ironing punch is inserted into the cup part. In this state, the outer diameter of the cup is ironed with an outer diameter ironing die.

[Action]

As described above, using a forged product with an ironing allowance on the inner surface and outer diameter surface of the cup part, after ironing the inner surface of the cup part of the forged product, and then ironing the outer diameter surface, extremely high dimensional accuracy You can get the outer ring.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a double-action press machine for carrying out the method of the invention. This press device includes an inner press slide 10 that can be moved up and down, and an outer press slide 20 that can be moved up and down fitted to the outside thereof, and a die base 11 is attached to the lower end of the inner press slide 10 and further A pushing die 12 is attached to the lower end. The pushing die 12 has a cylindrical shape, and the shaft portion 1 of the outer ring forged product A'shown in FIG. 4 can be inserted therein. Also, the die for pushing
A large-diameter shaft portion 13 is provided above the outer periphery of 12.

A cylindrical die holder 21 is attached to the lower end of the outer press slide 20. The die holder 21 becomes movable relative to the die base 11, and the protrusion 22 provided on the upper portion of the inner diameter surface of the flange 14 and the pressing die 12 formed on the upper portion of the outer diameter surface of the die base 11. Large diameter shaft
It can move up and down with respect to the die base 11 within the range of contacting the die 13.

An outer diameter ironing die 23 is attached to the lower end of the die holder 21, and the outer diameter ironing die 23 is the pushing die.
Fitted on the outside of twelve.

A plurality of rods 31 are attached to the upper surface of a support base 30 arranged below the outer diameter ironing die 23, and a support plate 32 supported so as to be vertically movable along the rods 31 is fitted to the outside of the rod 31. It is supported by a combined spring 33.

Further, the work support 34 is supported on the support plate 32, the upper portion of the inner diameter ironing punch 36 is inserted into the punch insertion hole 35 formed in the work support 34, and the lower portion of the inner diameter ironing punch 36 is the support base 30. Supported by.

The double-acting press device shown in the embodiment has the above-mentioned structure. When the outer-ring forged product A'shown in FIG.
34, and then the inner press slide 10 and the outer press slide 20 are sequentially lowered. in this case,
As the outer ring forged product A ′, a cup part 2 having an inner surface and an outer diameter surface with an ironing margin is used.

The ironing allowance of the inner surface of the cup portion 2 is provided on the track surface 6 of the track groove 3, or on the track surface 6, or on the track surface 6 and the inner diameter surface 7.
Any of those attached to

Now, after the cup portion 2 of the outer ring forged product A'is set on the upper surface of the work receiving base 34, the inner press slide 10 is lowered, and the tip of the pushing die 12 comes into contact with the closed end of the cup portion 2 and The outer ring forged product A'is pressed into the outer side of the inner diameter ironing punch 36 (see FIG. 2). Therefore, the inner surface of the cup portion 2 is ironed by the inner diameter ironing punch 36.

At this time, the outer press slide 20 descends together with the inner press slide 10 due to the engagement of the flange 14 of the die base 11 and the protrusion 22 of the die holder 21, and the outer press slide 10 descends after the inner press slide 10 stops descending. Then, the outer diameter ironing die 23 is press-fitted to the outside of the cup portion 2. Since the outer diameter ironing die 23 is restricted in its descending position as shown in FIG. 3 due to the contact between the protruding portion 22 of the die holder 21 and the large diameter shaft portion 13 of the pushing die 12, the outer diameter ironing die 23 is It fits snugly on the outside of the cup portion 2 and can prevent the cylindrical surface 5 at the outer diameter tip of the cup portion 2 from being pushed in the axial direction by the outer diameter ironing die 23.

The outer diameter surface of the cup portion 2 is ironed by press-fitting the outer diameter ironing die 23. At this time, the inner surface of the cup portion 2 is pressed against the outer peripheral surface of the inner diameter ironing punch 36 by the flow of material from the outer diameter portion, As a result, it is possible to obtain an outer ring having a high inner diameter dimension accuracy.

〔The invention's effect〕

As described above, in the present invention, since the inner surface and the outer diameter surface are ironed while the cup portion provided with the ironing allowance on the inner surface and the outer peripheral surface is constrained in the axial direction,
The inner and outer surfaces of the cup can be securely ironed by each ironing process, and since the outer diameter surface is ironed after the inner surface of the cup part is ironed, when ironing the outer diameter surface,
The material reliably flows in the inner diameter direction so that the inner surface of the cup portion is pressed against the outer peripheral surface of the inner diameter punch.

In this way, the inner surface of the cup part is finished by both ironing with the inner diameter ironing punch and ironing with the outer diameter ironing die, and it is possible to obtain an outer ring with extremely high inner diameter dimension accuracy. Post-processing of the inner surface of the cup part can be eliminated.

Moreover, since the outer diameter dimensional accuracy of the cup portion is improved at the same time,
The weight variation of the outer ring is small, and the material yield can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view showing a double-acting press device used in a method according to the present invention, FIGS. 2 and 3 are sectional views showing stepwise operation states of the same press device, and FIG. 4 is outer ring forging. Fig. 5 is a perspective view showing the product, Fig. 5 is a plan view of the same as above, Fig. 6 is a cross-sectional view of a pressing device used in a conventional method, and Fig. 7 is a cross-sectional view showing an operating state of the same. A: Forged outer ring, 1 ... Shaft, 2 ... Cup, 3 ... Track groove.

Claims (1)

[Claims] 1. A forged product in which an axial track groove is formed on an inner diameter surface of a cylindrical cup portion having a shaft portion at a closed end, and an ironing margin is provided on each of the inner surface and the outer diameter surface of the cup portion. The inner diameter of the cup part is ironed with an ironing punch while the both ends of the cup part of the forged product are restrained in the axial direction, and the inner diameter of the cup is the outer diameter of the cup part when the ironing punch is inserted into the cup part. A method for forming the outer ring of a tripod type constant velocity joint in which the outer diameter is ironed with an ironing die.