JPS6210771B2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a method of processing a universal joint for an input/output shaft of an automobile. The present invention relates to a method for manufacturing a universal joint.

(Prior art) In the conventional processing of a universal joint, first, the blank 1 shown in Fig. 1 is manufactured from a coil material M by punching the layout shown in Figs. 2 to 4, and then the process shown in Figs. The ear members on both sides of the blank shown in Figure 1 are bent toward the hub member to form the hub member into a cylindrical shape, and at the same time, the bent ear members are protruded from opposite sides of the cylindrical hub member, and two fork members are formed. The molded product 10 of the universal joint was formed through a bending process in which the cylindrical hub member was made to protrude in parallel from the upper end of the cylindrical hub member in a direction orthogonal to the ear member. Next, as shown in FIGS. 6A and 6B, the molded product is subjected to a cutting process F to flatten the end surface of the hub member 2, and a pin hole 6 is drilled to connect the cruciform joint to the fork member. The universal joint 10 is finished by processing, drilling holes 5 for tightening bolts for tightening the ear members, and applying spline processing S to the inner peripheral surface of the cylindrical hub member to match the input/output shaft of the automobile. was.

(Problems to be Solved by the Invention) The blank 1 shown in FIG. 1 is punched out of a coil material M by the punching process having the layout shown in FIGS. 2 to 4. For example, sagging and burrs occur in the valleys E, F, and G as shown in FIG. 12I. In order to reduce droop and burrs occurring in the blank 1, the feed width α and the edge width δ are required to be at least 1.5 times the thickness of the material. Therefore, in the conventional method, the material yield was limited to approximately 61%, 49%, and 59% in the layouts shown in FIGS. 2 to 4, respectively.
In addition, the sag or burr on the fracture surface is a collection of fine cracks, and some of the fine cracks may become enlarged when used for a long period of time under constant load, depending on the component part of the universal joint. There is a concern that it may cause damage. Universal joints for automobile input/output shafts are important parts, and damage during use is unacceptable for safety reasons. Further, the two fork members 4, 4 protruding from the cylindrical hub member are provided at positions facing each other in parallel with a constant interval,
Compared to the spacing between the fork members in the punched blank, the fork members are expanded 3 to 4 times, and the troughs F and G at the proximal ends of the fork members are in the most tensioned state,
Fine cracks on the fracture surface that occurred during blank punching often remained in the final product. Furthermore, since stress is concentrated in the valley E provided midway between the hub member 2 and the ear member 3 after bending, there is a problem in that fine cracks remain on the fracture surface.

(Means for Solving the Problems) The present invention has been made for the purpose of correcting sag and burrs that occur during the punching process of the blank 1 by coining process and improving the material yield. Specifically, the present invention makes the feed width α and the edge width δ zero when punching the blank 1 from the coil material M, and as a result, the sagging and burrs that occur in the blank 1 are eliminated by the coining process. In addition to repairing small cracks, the blank width is expanded from its original length by coining the side edges B and B of the blank 1, thereby improving the material yield. Next, the same bending process as in the conventional method is performed to form a universal joint molded product as shown in FIG. At this time, the side edge of the coined blank 1 is formed to become a part of the cylinder as shown in Figure B, making it possible to perform high-quality spline processing. This is what we are trying to provide.

(effect) The present invention will be explained in detail below with reference to Examples.

In Fig. 1, 1 is a universal joint blank punched from coil material M;
The hub member 2 has a cylindrical shape when it becomes the product shown in the figure, the ear members 3, 3 on both sides of the hub member 2 have a protruding shape when bent, and the ear members 3, 3 protrude parallel to the upper end of the cylindrical hub member 2. The two fork members 4, 4 forming the shape are both continuously formed from one metal plate. Although the blank 1 of the present invention is punched from a coil material M with the layout shown in FIGS. 7 to 9 and the feed width α and edge width δ set to zero, sagging and burrs naturally occur. Regarding this part, the parts of the burrs that are problematic in terms of the structure of the universal joint, and the burrs, see Chapter 10.
It is corrected by the coining process shown in FIGS.

In the first coining process shown in FIG. 10, the sag or burr on the side edge of the ear member 3 is corrected by coining the upper part 31, and a smooth side edge B' is formed. As a result of the coining process of the upper portions 31, 31, the width A between the side edges B' and B' is formed wider than that of conventional blanks of the same type. In other words, the material yield can be improved by the increased width. Then the 11th
In the second coining process shown in Fig. 12, I
The trough E provided in the middle of connecting the hub member 2 and the ear member 3 shown in FIG.
As shown in the figure, the peripheral portions 21 of the troughs F and G are coined to form troughs E', F' and G' with smooth convex cross sections. Tanibe E, F, G
This coining process corrects small cracks and improves the quality of the structural parts after bending.

After the two-step coining process shown in FIGS. 10 and 11, the blank 1 is processed in the same manner as in the conventional processing sequence shown in FIGS.
B' is bent toward the hub member 2 with B' inside, and then the hub member 2 is bent into a cylindrical shape, and the ear members 3, 3 are made to protrude from the cylindrical hub member 2, and at the same time, the fork members 4, 4 are bent. are formed so that they protrude parallel to each other at a constant interval L. The inside of the hub member 2 is splined to fit the input/output main shaft of an automobile, and holes 5, 5 for tightening bolts are bored in the ear members 3, 3.
Furthermore, by drilling pin holes 6, 6 in the fork members 4, 4 to connect with the cruciform joint, a universal joint 20 shown in FIG. 13 can be obtained. In the present invention, as shown in FIG. 13, the ear members 3, 3 are bent and formed oppositely so that they become part of the cylindrical inner surface of the hub member 2, thereby improving quality.

(Effects of the Invention) The present invention has the above-described configuration, and when according to the present invention, the valley part in the middle of connecting the hub member and the ear member of the blank of the universal joint, and the two fork members protruding from the hub member. The sagging and burrs that occur during the punching process in the valley at the base end of the universal joint are corrected by coining before the bending process is performed, thereby preventing damage caused by sagging and burrs in the important structural parts of the universal joint. It has the effect of improving quality.

Furthermore, in the present invention, since the side edges of the ear member are coined and then bent, the sagging and burrs on the side edges are corrected, and the width of both side edges is expanded, which improves the material yield. There is. Moreover, since the coined side edges are bent oppositely so as to become part of the inner surface of the cylindrical hub member, high quality spline processing can be performed.

As described above, when blanks are punched from coil material, even if the layout is such that the feed width and edge width are set to zero, all the adverse effects of burrs and burrs that occur in the punched blank can be corrected by coining. Material yield can be dramatically improved. The overall yield according to the present invention has an effect of improving by about 16% compared to the conventional method.

[Brief explanation of the drawing]

Fig. 1 is a plan view of a blank used in the processing method of the present invention, Figs. 2 to 4 are explanatory diagrams of the layout when punching a conventional blank from coil material, and Fig. 5 to Fig. Fig. 6 is a perspective view of a universal joint manufactured by a conventional processing method, and Figs. 7 to 9 show a blank of the present invention as a coil material. 10 and 11 are illustrations of the coining process for blanks according to the present invention. FIG. 12I is an illustration of the valleys and burrs. FIG. 13, which is an explanatory diagram of the corrected convex portion, is a perspective view of a universal joint manufactured by the processing method of the present invention. 1 is a blank, 2 is a hub member, 3 is an ear member, 4
5 is a fork member, 5 is a tightening bolt hole, 6 is a pin hole, M is a coil material, B is a side edge, E, F, G are valleys, and S is a spline process.

Claims (1)

[Claims] 1. A blank having a hub member, ear members provided on both sides of the hub member, and two fork members protruding in parallel from the end face of the hub member in a direction perpendicular to the ear member is fed from a coil material to determine the width and edge width. After continuous punching with a width of zero, the side edge of the ear member of the blank is coined to make the width of the blank wider than the original dimension, and to connect the hub member, fork member, and ear member of the blank. The troughs are coined to correct droop and burrs during punching, and then the ear members on both sides of the blank are bent toward the hub member.The hub member is then formed into a cylindrical shape, and at the same time, the above-mentioned bending is performed. making the ear members protrude from the side surface of the cylindrical hub member, and forming the ear members so as to face each other with a certain gap,
Further, two fork members opposed in parallel with a certain interval are made to protrude from the upper end of the cylindrical hub member in a direction perpendicular to the ear member to form a molded product of the universal joint; Next, a pin hole for connecting the cruciform joint was drilled in the fork member of the molded product, a hole for a tightening bolt was drilled in the ear member, and a main shaft for input/output was formed on the inner peripheral surface of the cylindrical hub member. A method of processing a universal joint characterized by applying a compatible spline processing.