JP2000334541A - Outer ring of constant-velocity universal joint and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an outer ring for a constant-velocity universal joint which is combined with a cylindrical part formed with a press working for obtaining the lightening and a shaft part and has both of the strong bonding force and the high bonding precision, and the production thereof. SOLUTION: The outer ring for a constant-velocity universal joint which is composed of the cylindrical part 2 formed with the press-working and the shaft part 3 and formed of a through-hole 16 at the center in the bottom part 5 of the cylindrical part 2 and fits a small diameter part 6 in the shaft part 3 into the through-hole 16 arranging a ruggedness part 10 on this inner peripheral surface, is produced by plastically working an annular groove 9 on the end surface of the small diameter part 6 so as to plastically fluidize the material of the small diameter part 6 into the recessed part on the inner peripheral surface of the through-hole 16 and combining the cylindrical part 2 with the shaft part 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer race formed by press working in a constant velocity joint used for a drive system of an automobile, and a method of manufacturing the outer race.

[0002]

2. Description of the Related Art Conventionally, an outer ring for a constant velocity joint is manufactured by annealing and surface lubrication, forward extrusion, upsetting, annealing and surface lubrication, rear extrusion from a cylindrical material,
In general, the cylindrical part and the shaft part are integrally press-formed by a multi-step cold forging process such as annealing and surface lubrication processing and forming processing of an engagement portion of the cylindrical part with an inner bearing. Met.

However, in recent years, in order to reduce the weight of the outer ring for a constant velocity joint, the outer ring for a constant velocity joint has been divided into a cylindrical part and a shaft part, formed by press working, joined together and integrated. The way to do it is attracting attention. In particular, attempts have been made on how to join the cylindrical part and the shaft part.

For example, in Japanese Patent Application Laid-Open No. Hei 7-317792, a pipe is formed as a raw material, and an outer ring (cylindrical part),
An outer ring of a constant velocity joint in which a shaft and a shell-type outer ring including a joint portion and a cylindrical portion are connected to each other and a method of manufacturing the same are disclosed. That is, a serration groove is formed in the cylindrical portion, or the cylindrical portion is formed in a polygonal shape, and one end of the shaft is connected to the cylindrical portion. Further, as another embodiment, an embodiment in which a joining member is interposed between a cylindrical portion and a shaft is disclosed.

[0005] However, in connecting the shaft with the shell-type outer ring formed from the pipe material, the thickness of the pipe material determines the bonding force, and a large bonding force cannot be expected. Further, in the case where the joining member is press-fitted into the cylindrical portion, extra costs are required for manufacturing a joining member having a plurality of grooves or flat surfaces in the axial direction on the inner and outer peripheral surfaces, and for press-fitting the joining member to the cylindrical portion. Required. Further, since the constant velocity joint is formed by coupling the three components of the outer ring, the joining member, and the shaft, there remains uncertainty in the coupling accuracy between the joint portion of the outer ring and the shaft.

In JP-A-8-49727, a hole is formed in a shell-type outer ring (cylindrical part) press-formed from a plate material, and a plurality of grooves or flat surfaces are formed in the inner peripheral surface of the hole in the axial direction. A constant velocity joint having a structure in which a formed outer ring and a shaft are integrally joined by press-fitting a protrusion of the shaft and press-fitting the end of the protrusion is disclosed.

However, in such a coupling method,
There is a possibility that the coupling force generated at the press-fitting portion between the outer ring and the shaft is reduced by swaging the end face of the protruding portion. Further, since only the plate thickness of the outer ring is the fitting portion with the shaft, a large coupling force cannot be expected. On the other hand, when the shaft is press-fitted into the outer ring, the fitting length is short because the fitting part is only the thickness of the plate of the outer ring, and the outer ring may be deformed. I'm worried.

[0008]

SUMMARY OF THE INVENTION An outer ring for a constant velocity joint, which is formed by joining a cylindrical part formed by press working with a shaft part to reduce weight, and has both a strong joining force and a high joining accuracy, and It is intended to provide a manufacturing method.

[0009]

In order to solve the above-mentioned problems, an outer race for a constant velocity joint according to the present invention comprises a cylindrical part and a shaft part formed by press working, and a center of a bottom part of the cylindrical part. A small diameter portion of the shaft part is fitted into a through hole having irregularities on its inner peripheral surface, and a ring-shaped groove is plastically worked on the end surface of the small diameter portion, thereby reducing the material of the small diameter portion. The cylindrical component and the shaft component were joined by plastically flowing into the recess on the inner peripheral surface of the through hole.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the shapes of a cylindrical part (FIG. 1) and a shaft part (FIG. 2) will be described. The tubular part 2 and the shaft part 3 are later joined to form the outer race 1 for a constant velocity joint.
The tubular part 2 is composed of a tubular part 4 and a bottom part 5 and is formed by pressing from a columnar or cylindrical material or a thick plate material.

A through-hole 16 is formed at the center of the bottom 5, and the unevenness 10 is provided on the inner peripheral surface thereof. The lower end of the bottom portion 5 has a cylindrical shape having a through hole 16 and is connected to the cylindrical portion 4 above.

As shown in FIG. 3A, the cylindrical portion 4 has an inner peripheral shape 13 in which engagement portions 8 with three bearings and arcs 12 connecting them are arranged at equal intervals in the circumferential direction. I have.
The outer peripheral shape 14 is similar to the inner peripheral shape 13 as shown in FIG. 4, or a part 15 in the axial direction from the end face of the cylindrical portion 4 is a circular shape 15 as shown in FIG. 5. Therefore, the outer diameter of the cylindrical portion 4 is lighter than that of a conventional outer ring for a constant velocity joint in which all the outer diameters are circular.

On the other hand, the shaft part 3 comprises a small diameter portion 6 and a stepped portion 7 having different diameters as shown in FIG. 2, and is formed by pressing a columnar material. The small diameter portion 6 is formed on the end face of the shaft component 3 and
And has a diameter substantially the same as that of the through hole 16 and is connected to the large diameter portion 11 of the stepped portion 7 having a different diameter. The small-diameter portion 6 is so dimensioned that its tip does not protrude above the through-hole 16 when inserted into the through-hole 16.

Next, a method of connecting the cylindrical part 2 and the shaft part 3 will be described. First, the small diameter portion 6 is inserted into the through hole 16 until the lower end surface of the cylindrical component 2 and the stepped portion 7 are in close contact. Then, a ring-shaped groove 9 is formed on the upper end surface of the small diameter portion 6 as shown in FIG. 4 or FIG.

By forming the groove 9, the small diameter portion 6 is formed.
The outer diameter of the small diameter portion 6 tends to increase due to plastic deformation.
The material of the small diameter portion 6 flows into the space between the outer diameter of the cylindrical member 2 and the concave portion (10) of the inner peripheral surface of the through hole 16, so that the cylindrical component 2 and the shaft component 3 are plastically connected. As a result, the tubular part 2 and the shaft part 3 are connected without any play to the rotational force (torque) in the circumferential direction and the pulling force in the axial direction.

The unevenness 1 provided on the inner peripheral surface of the through hole 16
Instead of 0, a spline 17 may be provided as shown in FIG. At this time, the spline 17 is located at the bottom 5
Must be formed partway through the thickness of Further, the width and depth of the ring-shaped groove 9 need to be sufficiently set so that the material of the small-diameter portion 6 flows into the axial end of the spline 17 so that no gap is generated. As a result, the torque resistance at the time of joining the cylindrical component 2 and the shaft component 3 becomes stronger.

Further, as shown in FIG. 7, a triangular notch 37 having a small diameter of the spline 17 as a base and a vertex of a diameter equal to or less than the large diameter as a vertex is provided in advance in the axial direction of the spline 17. The coupling force in the axial direction between the cylindrical part 2 and the shaft part 3 becomes stronger. The shape of the notch 37 is not limited to a triangle, but may be, for example, an arc or a square.

Next, the spline 17 on the bottom 5 of the cylindrical part 2
Will be described. FIG. 8 shows a mold structure for forming the spline 17. The upper die 18 is mounted on a slide of the press, and the lower die 19 is mounted on a bolster.
The punch 20 is fixed to the upper die 18 and has the shape of the spline 17.

The holder 21 is also fixed to the upper die 18 and guides the punch 20 at the inner diameter portion. The outer peripheral portion has a tip shape slightly smaller than the inner peripheral shape 13 of the tubular part 2 and has a similar shape. . Stripper 24 outside holder 21
Is urged downward by a spring 22. The guide 23 is fixed to the upper die 18 and guides the stripper 24 up and down.

The block 25 is fixed to the lower mold 19, and the cavity has substantially the same outer peripheral shape as the cylindrical portion 4 and the bottom portion 5. Inside the block 25, there is a cylindrical counter punch 26, which can be moved up and down freely. First, the tubular part 2 is put into the block 25. At this time, the outer peripheries of the cylindrical portion 4 and the bottom portion 5 are restrained by the block 25, and the lower end of the bottom portion 5 is held by the counter punch 26.

After positioning the tubular part 2 in this way,
In a state where the stripper 24 urges the end face of the tubular portion 4 downward, the holder 21 is lowered while fitting to the inner peripheral shape 13 of the tubular component 2. Punch 2 while maintaining such a state
The spline 17 is formed by lowering 0.

Since the punch 20 is guided by the through hole 16 of the cylindrical part 2 and the inner diameter of the counter punch 26, the spline 17 is formed at the center of the cylindrical part 2 with high precision. After the molding is completed, the cylindrical part 2 is discharged from the block 25 by the counter punch 26.

Next, a method of forming the groove 9 by press working will be described. FIG. 9 shows a mold structure when a spline 17 is provided on the inner periphery of the through hole 16 and the groove 9 is formed by press working. The upper mold 28 is used for the press slide and the lower mold 2
9 is mounted on the bolster. The punch 30 is the upper mold 28
, And has a ring-shaped groove 9 at the tip.

A stripper 33 is provided outside the punch 30 and is urged downward by a spring 31. The guide 32 is fixed to the upper mold 28, and guides the stripper 33 up and down freely. The inner diameter of the stripper 33 guides the punch 30, and the tip of the outer peripheral portion has a similar shape slightly smaller than the inner peripheral shape 13 of the tubular part 2.

The block 34 is fixed to the lower mold 29, and the cavity has substantially the same outer peripheral shape as the cylindrical part 2 and the shaft part 3. Inside the block 34, there is a counter punch 35, which can be moved up and down freely. First, the shaft component 3 is put into the block 34, and the outer periphery and the lower end of the large diameter portion 11 are restrained and held by the block 34. At the same time, the lower end of the shaft component 3 is held by the counter punch 35.

Next, the tubular part 2 is put into the block 34. At this time, the insertion is performed so that the lower end surface of the tubular part 2 and the stepped part 7 are in close contact with each other while the through hole 16 and the small diameter part 6 are fitted. At the same time, the outer circumference of the cylindrical part 4 and the bottom part 5 of the cylindrical part 2 are restrained or held by the block 34.

After the positioning of the cylindrical part 2 and the shaft part 3 in this manner, the stripper 33 moves the inner peripheral shape 1 of the cylindrical part 2.
The lower part 5 is fitted to the lower part 3 and is urged downward by contacting the upper surface of the bottom part 5. While maintaining such a state, the punch 30
Is lowered to form a ring-shaped groove 9 in the end face of the small diameter portion 6. After the molding is completed, the joined tubular part 2 and shaft part 3 are discharged from the block 34 by the counter punch 35.

In the joining by such a method, the outer peripheral portion and the lower end of the bottom portion 5 and the outer peripheral portion and the lower end of the large-diameter portion 11 are restrained or held by the block 34. A strong tension is generated between the material of the outer diameter 1 and the material of the small-diameter portion 6, so that the outer ring 1 for a constant velocity joint can endure a high torque strength particularly required, and the cylindrical part 2
Good coupling accuracy between the shaft component 3 and the shaft component 3 can be obtained.

Further, since such plastic deformation due to the formation of the groove 9 occurs only in the vicinity of the spline 17 and the small-diameter portion 6, a portion previously worked by press working or machine before joining, for example, a cylindrical part The engagement part 8 with the bearing in the inner peripheral shape 13 of the cylindrical part 4 and the shaft part 3
The deterioration of the accuracy of the serration 38 at the tip of is very small.

[0030]

According to the above operation, in the outer race 1 for a constant velocity joint, which is composed of the tubular part 2 and the shaft part 3 and is connected,
It is possible to manufacture a light-weight product having both a strong coupling force and a high coupling accuracy. In particular, the required torque strength can be satisfied in the torque strength of the joint between the tubular part 2 and the shaft part 3 which has been a problem so far.

[Brief description of the drawings]

Fig. 1 Cylindrical part before plastic coupling

Fig. 2 Shaft parts before plastic coupling

FIG. 3 is a cylindrical part having a spline provided on an inner peripheral surface of a through hole before plastic coupling.

FIG. 4 is an outer race diagram for a constant velocity joint in which a cylindrical part and a shaft part are plastically connected.

FIG. 5 is an outer ring diagram for a constant velocity joint in which a cylindrical part and a shaft part having a round part at the tip are plastically connected.

FIG. 6 is a detailed view of a connecting portion between a cylindrical part and a shaft part.

FIG. 7 is a detailed view of a coupling portion between a cylindrical component and a shaft component having a notch in a spline portion.

FIG. 8 is an explanatory view of a mold structure for spline molding.

FIG. 9 is an explanatory view of a mold structure for groove forming.

[Explanation of symbols]

1 is an outer ring for a constant velocity joint, 2 is a cylindrical part, 3 is a shaft part, 4 is a cylindrical part, 5 is a bottom part, 6 is a small diameter part, 7 is a stepped part, 8 is an engaging part, 9 is a groove, 10 Is an irregular shape, 11 is a large diameter portion, 12 is an arc shape, 13 is an inner peripheral shape, 14 is an outer peripheral shape, 15 is a circular shape,
16 is a through hole, 17 is a spline, 18 is an upper die, 19 is a lower die, 20 is a punch, 21 is a holder, 22 is a spring, 23 is a guide, 24 is a stripper, 25 is a block, 26 is a counter punch, and 27 is a counter punch. Knockout pin,
28 is an upper mold, 29 is a lower mold, 30 is a punch, 31 is a spring, 32 is a guide, 33 is a stripper, 34 is a block, 35 is a counter punch, 36 is a knockout pin,
37 is a nod, 38 is a serration

Claims (6)

[Claims] An outer ring for a constant velocity joint comprising a cylindrical part having a cylindrical part and a bottom part and a shaft part having a small diameter part at an end surface and a step part having a different diameter is provided. A cylindrical part is formed by fitting a small-diameter part of the shaft part into a through hole formed at the center of the bottom part and having irregularities on the inner peripheral surface thereof, and plastically processing a ring-shaped groove on an end face of the small-diameter part. An outer ring for a constant velocity joint, characterized by combining a shaft component with a shaft component. 2. The outer race for a constant velocity joint according to claim 1, wherein said unevenness is a spline formed from an inner peripheral surface of said through hole to a middle part from a cylindrical portion side. 3. The outer race for a constant velocity joint according to claim 2, wherein said spline is formed by press working. 4. An outer race for a constant velocity joint comprising a cylindrical part having a cylindrical part and a bottom part and a shaft part having a small diameter part at an end face and having a stepped part having a different diameter. A cylindrical part is formed by fitting a small-diameter part of the shaft part into a through hole formed at the center of the bottom part and having irregularities on the inner peripheral surface thereof, and plastically processing a ring-shaped groove on an end face of the small-diameter part. A method of manufacturing an outer race for a constant velocity joint, comprising: coupling an outer ring with a shaft part. 5. The method for manufacturing an outer race for a constant velocity joint according to claim 4, wherein said unevenness is a spline formed from an inner peripheral surface of said through hole to a middle part of said through hole. 6. The method for manufacturing an outer race for a constant velocity joint according to claim 5, wherein said spline is formed by press working.