JPS6076233A - Manufacture of outer-shell member of constant-speed universal joint - Google Patents

Abstract

PURPOSE:To eliminate the need for post working and to improve yield, by performing ironing so that the reduction rate of wall-thickness in the vicinity of an axial-direction groove used for engaging itself with a rolling body, is larger than that of wall-thickness of the other part to work precisely an axial-direction groove. CONSTITUTION:A cylindrical member is extruded into a hollow cylindrical stock 2 whose outer peripheral surface 1 is shown by an alternate long and two short dashes line. The stock 2 has an axial-direction groove 3 in its inner peripheral surface, and the groove 3 is formed into approximately the same shape as the groove of a product and is used for engaging itself with a rolling body, and the wall-thickness (t) in the vicinity of groove 3 is made thinner than the wall-thicknesss (t) of the other part (inner- diameter surface) 4. Next, ironing is provided to the stock 2. In the ironing, the relation of (DELTAL>DELTAL1) is required so as to make the value (L+DELTAL) of the cup depth in the vicinity of groove 3 equal to the value (L1+DELTAL1) of the cup depth in the vicinity of surface 4, because the relation between L and L1 is made to L<L1 after working. Then, the relation between the reduction rate (DELTAt/t) of wall thickness in the direction of groove 3 and that (DELTAt1/t1) of wall-thickness of the part of surface 4 is made to DELTAt1/ t>DELTAt1/t1, in order to hold the relation of (DELTAL>DELTAL1).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an outer shell member of a constant velocity universal joint such as a tripod or barfield.

FIGS. 1 and 2 are explanatory diagrams of a tripod type constant velocity universal joint. In the figure, 11 is an outer shell member, 12 is a shaft, and the shaft 12
Branch shafts 13 are provided in three directions. This branch shaft 13
A rolling element 14 is rotatably supported by a clip 15,16. Further, the outer shell member 11 is provided with ball engagement axial grooves 17 at three equal positions, and the rolling elements 14 are fitted into the axial grooves 17. Therefore, the rolling elements 14 are supported in the cylindrical direction and roll in the axial direction, and transmit rotational force between the outer shell member 11 and the shaft 12 at a constant speed and without torque fluctuation.

By the way, as a method of manufacturing the above-mentioned outer shell member, conventionally only machining was relied upon, but since machining has a low yield and imposes restrictions on the shape of the outer shell member, recently plastic processing has mainly been used. proposed a method of manufacturing an outer shell member.

One of them is Special Publication No. 4B-4809 (Special Application No. 44-8
No. 4106) (hereinafter referred to as the first conventional example). This first conventional example uses a cylindrical material in which an axial groove for a pole anchor of approximately the same shape as the product is formed on the inner periphery as a method for manufacturing the outer ring of a universal joint, and the cross-sectional area reduction rate of the entire cross section is reduced to 10 to 10. A method is disclosed in which the thickness is kept at 30%, and the rate of decrease in thickness in other parts is greater than the rate of decrease in thickness in the vicinity of the axial groove. According to this first conventional example, the axial groove is finished with such high precision that no machining is required, and the yield is significantly improved compared to the case of only machining.

However, in the first conventional example, the amount of axial elongation in the vicinity of the axial groove and other parts due to ironing is different,
Since the end face of the outer ring is undulated and becomes irregular, it is ultimately necessary to align the end face by machining. Therefore, there is room for improvement in yield, and since machining cannot be completely eliminated, there is also room for improvement in terms of man-hours and cost.

In addition, as a method for manufacturing the outer shell member of a constant velocity universal joint that is aligned up to the end face by plastic working, Japanese Patent Application Laid-Open No. 57-206537
(Japanese Patent Application No. 56-92873) (hereinafter referred to as the second conventional example). In the second conventional example, as a method for manufacturing the outer member of a tripod type constant velocity universal joint, a tripod type constant velocity universal joint having an outer member whose wall thickness is set almost uniformly with respect to the inner diameter of a hole shape is used. In the joint, in order to manufacture the outer member, the wall thickness of the cup is made to have the same shape and dimensions as the inner diameter of the cup, so that the amount of axial elongation is uniform throughout the entire circumference during ironing. A method is disclosed in which a cup-shaped outer member set according to the law of constant volume is used and ironed using a punch and die formed to have the same shape and dimensions as the product. According to this second conventional example, since the end faces of the outer member are aligned even after ironing, post-processing of the end faces can be reduced, material yield can be improved, and the total manufacturing cost can be reduced.

However, although this second conventional example can be applied when the end faces of the material are aligned, the end faces of the cylindrical material are not aligned, and the thickness of the plate near the axial groove and other parts may be the same. Or, it cannot be applied to objects where the vicinity of the axial groove is thinner.

The present invention has been made in order to solve the problems of the prior art described above, and it is possible to form an axial groove with high precision by plastic working an outer shell member in which the plate thickness near the axial groove is thinner than the plate thickness in other parts.
An object of the present invention is to provide a method for manufacturing an outer shell member of a constant velocity universal joint that can be manufactured with the end faces of the joints aligned.

According to the present invention, this object is achieved by extrusion processing from a cylindrical member, which has an axial groove on the inner periphery for engaging a rolling element having approximately the same shape as the product, and the thickness of the plate near the axial groove is smaller than that of other parts. A method for manufacturing an outer shell member of a constant velocity universal joint by forming a cylindrical material thinner than the plate thickness of the cylindrical material and ironing the cylindrical material. This is achieved by a method for manufacturing the outer shell member of a constant velocity universal joint in which the rate of decrease in plate thickness in the vicinity is greater than the rate of decrease in plate thickness in other parts.

According to the present invention, when forming a cylindrical material by extrusion processing from a cylindrical material, the plate thickness at the axial groove portion is thinner than the other portions, so that the axial groove portion is thinner than the other portions. Extends longer than the part.

Therefore, by performing ironing so that the plate thickness reduction rate near the axial groove is greater than the plate thickness reduction rate in other parts, the amount of elongation in the axial length is opposite to that in extrusion processing. , so that the end faces of the outer shell members are aligned.

Therefore, according to the present invention, the following effects are achieved.

(a) The axial groove is machined with high precision and does not require any post-processing.

(b) Since the end faces of the outer shell member are aligned by ironing, machining in the post-process can be eliminated. Moreover, even if machining is performed, the amount of machining is extremely small.

(c) Since everything from the cylindrical material to the product is manufactured through regular processing, productivity is high and the degree of freedom in design is increased.

(d) Overall yield is improved and costs can be reduced.

Next, embodiments of the present invention will be described with reference to the drawings.

In the present invention, first, by extrusion processing from a cylindrical member, the outer peripheral surface 1 of the outer shell member is shown by the two-dot chain line in FIGS. 3 and 4. A certain cylindrical material 2 is molded.

This cylindrical material 2 has an axial groove 3 for retaining a rolling element having approximately the same shape as the product on its inner periphery, and the plate thickness t near the axial groove 3 is greater than that of the other portion (inner diameter surface) 4. It is formed thinner than the plate thickness t. In extrusion molding of the cylindrical material 2, since the thickness of the axial groove 3 is thinner than the thickness of the inner diameter surface 4, L<L, as shown in FIG.

Next, this cylindrical material 2 is ironed.

The ironing process is carried out by passing the material through the die 6 using a punch 5 and a die 6 as shown in FIG. 5, as is usually done.

The shape of the product after ironing is shown in solid lines in FIGS. 3 and 4. 7 is the outer peripheral surface of the product after ironing. In this ironing process, in order to make the cup depth of the ironed product equal over the entire circumference, the cup depth near the axial groove 3 is L+ΔL, and the cup depth near the inner diameter surface 4 is +ΔL, In order to make them equal, after extrusion, L
<L.

Therefore, it is necessary to set ΔL>ΔL. Therefore,
In the present invention, the plate thickness reduction rate Δ1 of the portion of the axial groove 3 is
/1 and plate thickness reduction rate Δt 1/ t t at inner diameter surface 4
By setting the relationship Δ1/1 > Δt 1 / t 1, the relationship ΔL>ΔL1 is established. The specific values for aligning the end faces after ironing are as follows:
It can be easily determined according to the shape, material, etc. of the product within the relationship ΔL>ΔLi. In this way, as shown in FIG. 4, a product (outer shell member) with substantially even end surfaces is obtained.

In the above example, an example was shown in which the outer shell member is manufactured from a cylindrical member through extrusion processing and ironing processing without machining, but if necessary, alignment can be performed by machining the end face after extrusion processing. be.

In this case, L=L in FIG. 4.

Therefore, in order to make the cup depth uniform all around the circumference after ironing, that is, L+ΔL=L, +ΔL1, it is necessary to set it to ΔL−ΔL1. By the way, generally the plate thickness reduction rate is made equal in the thin and thick parts, that is, Δ1/
When tightening so that 1=Δ1,/1, the amount of expansion of the cup depth becomes ΔL<ΔL1. Therefore, ΔL=ΔL
To make it 1, Δ1 / 1 > ΔL 1/ j 1
It is necessary to do so. From the above, even in the case of L=L, the plate thickness reduction rate near the axial groove is lower than that of other parts (inner diameter surface).
It can be seen that it is advantageous to perform ironing so that the plate thickness reduction rate is greater than that of .

As described above, according to the method for manufacturing the outer shell member of a constant velocity universal joint according to the present invention, the cup depth after ironing can be made almost equal between the axial groove and the inner diameter surface, so that the end area gets better. Therefore, it is possible to eliminate machining or reduce the amount of machining required for machining.

Further, since the axial groove is machined to a high degree of lamination, no post-processing is required.

Furthermore, the overall yield is improved and costs can be reduced.

Although the above explanation was based on the outer shell member of a tripod type constant velocity universal joint, it goes without saying that the manufacturing method according to the present invention can also be applied to the outer ring of a half-yield type constant velocity universal joint. .

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams of a tripod type constant velocity universal joint, with FIG. 1 being an end view and FIG. 2 being a longitudinal sectional view. 3 and 4 are explanatory diagrams showing the amount of deformation before and after ironing in the method for manufacturing a constant velocity universal joint according to the present invention, FIG. 3 is an end view, and FIG. 4 is a longitudinal sectional view. . FIG. 5 is a schematic diagram of the ladder processing device. 1-----One outer circumferential surface (before ironing) 2----One cylindrical material 3---One axial groove 4----One inner diameter surface (other parts) 5--Punch 6 --------Dice 71---Outer surface (after ironing) Applicant: Toyota Motor Corporation Figure 1 ￥; 2 Figure '3 P! 74 figure vase

Claims (1)

[Claims] (1) A cylindrical shape made by extrusion processing from a cylindrical member, with an axial groove on the inner periphery for holding rolling elements that is approximately the same shape as the product, and where the plate thickness near the axial groove is thinner than other parts. A method of manufacturing an outer shell member of a constant velocity universal joint by molding a material and ironing this cylindrical material, the ironing being performed so that the plate thickness reduction rate in the vicinity of the axial groove for engaging the rolling elements is A method of manufacturing an outer shell member of a constant velocity universal joint, characterized in that the reduction rate of the plate thickness is greater than that of other parts.