JPS62252618A - Forming method for outside ring of tripode type constant velocity joint - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy and the material yield by sequentially ironing inside and outside diameter parts of a forging provided with respective ironing allowances on inside and outside surfaces of the cup part. CONSTITUTION:After a cup part 2 of an outside ring forging A' is set on the top of a work table 34, an inner press slide 10 is moved down to abut the top of a push die 12 on the closed end of the cup part 2, to insert an inside ironing punch into the forging A', and to perform an ironing on the cup part 2. After the slide 10 is stopped from moving down, an outer press slide 20 is moved down to insert the cup part 2 into an outside ironing die 23 to perform an ironing on the outside part. In that method, the dimensional accuracy and the material consumption are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of forming an outer ring of a tripod type constant velocity joint.

[Conventional technology]

As shown in Figures 7 and 8, the outer ring of the tripod type constant velocity joint has three cylinders parallel to the axis of the cup part on the inner diameter surface of a cylindrical cup part 2 having a shaft part 1 at the closed end. A shaped track groove 3 is formed, and three axial grooves 4 are also provided on the outer diameter surface, and the grooves 4 and the track groove 3 are shifted in position in the circumferential direction.

Further, since the opening of the cup portion 2 is closed by attaching the boot, the tip of the outer diameter surface of the cup portion 2 is connected to the cylindrical surface in order to facilitate the connection of the boot and to improve the sealing performance of the joint. Very often it is Toshi.

Such an outer ring is usually made of a forged product, and the forged product is ironed to obtain the accuracy of the inner diameter portion of the cup portion 2. A press device is used during the ironing process.

9 and 10 show a conventional press apparatus for forming an outer ring. In this press device, 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 guide space 51 is provided with a shaft insertion hole 53 that opens at the lower surface of the die.

Further, a pedestal 54 is arranged below the press slide 50 and supported by a plurality of springs 55, and a workpiece holder 56 is attached to the pedestal 54. Insert a 5-day iron punch into hole 57,
The lower end of the ironing punch 5B is supported by a punch support stand 59.

When forming the outer ring, the outer ring forged product A, in which the track surface 6 of the track groove 3 shown in FIG.
As shown in FIG.

[Problem that the invention seeks to solve]

By the way, in the above conventional molding method, the cup portion 2
Since only the inner surface of the cup portion 2 is squeezed by the ironing punch 58 without restraining the outer diameter surface of the cup portion 2, variations occur in the inner diameter dimension of the cup portion 2, and sometimes the width dimension of the track groove 3 is insufficient, resulting in defects. Although the product may be of good quality, it has the disadvantage that stable production cannot be achieved. The reason for this is thought to be that the inner diameter portion 7 of the cup portion 2 is dragged outward as the material moves due to the straining of the track surface 6.

Note that if a straining allowance is provided on the inner diameter surface 7 of the cup portion 2, the opening of the track surface 6 will begin to be insufficient, making it impossible to obtain stable precision.

Therefore, the technical object of the present invention is to eliminate the above-mentioned disadvantages and improve the dimensional accuracy of molded products.

[Means for solving problems]

In order to solve the above problems, the present invention forms an axial track groove on the inner diameter surface of a cylindrical cup portion having a shaft portion at the closed end, and forms an axial track groove on each of the inner surface and outer diameter surface of the cup portion. A forged product provided with an ironing allowance is ironed by ironing the inner diameter portion and the outer diameter portion of the cup portion in an orderly manner.

Here, the straining allowance on the inner surface of the cup portion may be provided only once on both track surfaces of the track groove, or may be provided on the right side of the track surface and on the inner diameter surface of the cup portion.

In addition, ironing in order means ironing either the inner surface or the outer diameter surface of the cup part first, and then ironing the other after that, and ironing both at the same time. It is not something to be processed.

Note that if the inner surface and outer diameter surface of the cup are ironed at the same time, the history of plastic deformation will be different between the opening of the cup and the closed end of the cup, so the amount of elastic recovery after unloading will be different. , the width dimension of the track groove and the pitch circle dimension of the track groove are unstable.

〔Example〕

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

FIG. 1 shows a double-acting press apparatus for carrying out the method of the invention. This press device includes an inner press slide 10 that is movable up and down, and an outer press slide 20 that is fitted on the outside of the slide and that is movable up and down.
A die base 11 is attached to the lower end of the 0, and a pushing die 12 is further attached to the lower end of the die base 11. This pushing die 12 has a cylindrical shape, and the shaft portion 1 of the outer ring forged product A shown in FIG. 7 can be inserted into the inside thereof. Further, a large diameter shaft portion 13 is provided on the upper outer periphery of the pushing die 12.

A cylindrical die holder 21 is attached to the lower end of the outer press slide 20. This die holder 21 is movable relative to the die base 11, and the protrusion 22 provided at the upper part of the inner diameter surface is connected to the die base 11.
It can move up and down with respect to the die base 11 within the range where it comes into contact with the large-diameter shaft portion 13 of the pushing die 12 and the seven flange 14 formed on the upper part of the outer diameter surface of the pushing die 12 .

At the lower end of the die holder 21 is an outer diameter ironing die 23.
is attached, and its outer diameter ironing die 23 is fitted on the outside of the pushing die 12.

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

Further, a workpiece holder 34 is supported on the support plate 32, the upper part of the inner diameter ironing punch 36 is inserted into the punch insertion hole 35 formed in the workpiece holder, and the lower part of the inner diameter ironing punch 36 is supported by the support plate 32. It is supported by a stand 30.

The double-acting press device shown in the embodiment has the above-mentioned structure, and when ironing the outer ring forged product A shown in FIG.
From there, the inner press slide 10$ and the outer press slide 20 are lowered in order. In this case, the outer ring forged product A is one in which a rubbing allowance is provided on the inner and outer diameter surfaces of the cup portion 2.

The straining allowance on the inner surface of the cup portion 2 may be either applied to the track surface 6 of the track groove 3 or applied to the track surface 6 and the inner diameter surface 7.

Now, after setting the cup part 2 of the outer ring forged product A on the upper surface of the workpiece holder 34, when the inner press slide 10 is lowered, the tip of the pushing die 12 comes into contact with the closed end of the cup part 2, and the Outer ring forged product A is ironed with inner diameter punch 36
(See Figure 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 is attached to the die base 1.
When the outer press slide 20 is lowered after the inner press slide 10 has stopped descending, the outer diameter ironing die 23 is lowered into the cup portion 2. Press it on the outside. At this time, the outer diameter ironing die 2
3, the protrusion 22 of the die holder 21 and the pushing die 1
As shown in FIG. 3, the lowering position is limited by the contact with the large diameter shaft part 13 of the outer diameter ironing die 23, so that the outer diameter ironing die 23 fits snugly on the outside of the cup part 2, and the outer diameter tip of the cup part 2 It is possible to prevent the cylindrical surface 5 of the section 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, and at this time, the inner surface of the cup portion 2 is ironed by the inner diameter ironing punch 3 due to the flow of material from the outer diameter portion.
As a result, an outer ring with high inner diameter dimensional accuracy can be obtained.

In the embodiment shown in FIGS. 1 to 3, a forming method is shown in which the outer diameter surface of the cup portion 2 is ironed after the inner diameter surface is ironed. After machining, the inner diameter surface may be ironed.

4 to 6 show a double-acting press device in which the inner diameter surface of the cup portion 2 is ironed after the outer diameter surface thereof is ironed. In this press device, an outer diameter ironing die 41 is attached to the upper surface of a fixed die holder 40, and the outer diameter ironing die 41. After setting the forged product A with the cup part 2 facing upward as shown in FIG. (See Fig. 85), then lower the inner press slide 44, press the inner ironing punch 45 attached to the lower end of the inner press slide 44 into the inside of the cup part 2, and press the outer and inner diameter surfaces of the cup part 2. I try to iron them in order. In this case, the inner diameter ironing punch 45 is the outer diameter ironing die 4.
1, the inner surface of the cup portion 2 comes into close contact with the outer circumferential surface of the inner diameter ironing punch 45, resulting in extremely high dimensional accuracy on the inner diameter surface of the cup portion 2. can be obtained.

In addition, when ironing is performed using a double-acting press shown in FIGS. 4 to 6, an ironing allowance is provided on each of the entire inner surface and outer diameter surface of the cup portion 2. A difference is made between the ironing allowance on the inner surface and the ironing allowance on the outer diameter surface,
By lowering the inner diameter ironing punch 45 shown in FIG.
The outer diameter surface and inner surface of the cup portion can be ironed in sequence using a so-called single-acting press device in which the part 2 is omitted.

〔effect〕

As described above, in this invention, ironing allowances are provided on the inner surface and outer diameter surface of the cup portion of the forged outer ring product, and the inner surface and outer diameter surface of the cup portion are ironed in order, so that the inner diameter dimension accuracy is improved. A good outer ring can be obtained, and post-processing of the inner surface of the cup portion can be made unnecessary after the ironing process.

In addition, the accuracy of the outer diameter of the cup part is improved at the same time.
There is little variation in the weight of the outer ring, and the material yield can also be improved.

[Brief explanation of drawings]

FIG. 1 shows a double-acting diagram used in the method according to the present invention;
The figure is a cross-sectional view showing another embodiment of the double-acting press device as described above, FIG. 5 right and FIG. Figure, 8th
9 is a sectional view of the press device used in the conventional method, and FIG. 10 is a sectional view showing the operating state of the same. A: Forged outer ring, 1: Shaft portion, 2: Cup portion, 3: Track groove. Patent Applicant: NCN Toyo Bearing Co., Ltd. Agent: Kama 1) Text 2 Figure 10

Claims (1)

[Claims] A forged product in which an axial track groove is formed on the inner diameter surface of a cylindrical cup portion with a shaft portion at the closed end, and ironing allowances are provided on each of the inner and outer diameter surfaces of the cup portion is used. A method for forming the outer ring of a tripod type constant velocity joint in which the inner diameter part and the outer diameter part are ironed in an orderly manner.