JPH01197038A - Method for forming flanged spline - Google Patents

Abstract

PURPOSE:To control the flow of a material to a spline part and to form the spline shaft of enough length by simultaneously forming hollows on the upper part of a flange by providing a projection at the tip of a punch. CONSTITUTION:A preform 4 is inserted into a forming die 1 and when it is pressed by a punch 2, the forming of the spline part of a preform 4 is started at the spline forming part 5 of a die 1 first and a hollow 7 is simultaneously formed at the flange upper part 6 because of a projection 3 being located on the punch 2. With further progress of the forming a flange part 8 is abutted to the die 1 and upsetting of the flange part is started. Due to the projection 3 being located on the punch 2, the material is flowed in succession in not only the direction 10 of the flange but also the direction of the spline shaft 11 by this projection, hence a spline shaft 9 of sufficient length can be obtd. at the forming completion time of the flange part 8.

Description

Detailed Description of the Invention (Objective of the Invention) (Industrial Application Field) The present invention relates to a method for forming a spline shaft or a gear shaft with a spline, and is intended for use in transmitting power such as an automobile transmission. It is used for parts that have been manufactured.

(Prior art) As a prior art related to the present invention, when a spline shaft or a gear shaft with a collar is formed at the same time as the upsetting of the collar, a second
The material shown in the figure is punch-formed as shown in FIG. 9 using a forming die 1 and punch 12 as shown in FIG.
(Patent Application No. 107539/1982).

(Problem to be solved by the invention) However, in the above-mentioned forming method, when extruding the spline shaft and upsetting the collar are performed simultaneously with a punch, the collar 8 hits the die 1 and the molding of the collar begins. As shown in FIG. 9, the material flows only in the direction 10, and the material does not flow in the direction of the spline shaft 9. When the forming of the collar is completed, a satisfactory spline is formed as shown in FIG. There is a problem that the length cannot be obtained.

This is because when comparing the force to push the material forward and the force to upset the collar, the force to upset the collar is smaller, so when the collar begins to be formed, the force to push the material forward When comparing the force for upsetting the brim, the force for upsetting the brim is smaller. Therefore, once the forming of the brim begins, there is no force pushing the material forward, and only the brim is uprooted. It is.

The technical object of the present invention is to provide a forming method in which the material flows also in the direction of the spline axis.

[Structure of the invention]

(Means for solving the problem) The technical means taken to solve the above technical problem are as follows. In other words, when a spline shaft or gear shaft with a flange is extruded at the same time as upsetting molding of the flange, forming a spline shaft or gear shaft with a flange involves providing a protrusion at the tip of a punch and forming a recess at the top of the flange at the same time. It's a method.

(Operation) The technical means operates as follows. That is, by providing a protrusion on the tip of the punch and simultaneously forming a recess on the upper part of the collar, the flow of material to the spline portion is controlled and a spline shaft or gear shaft of sufficient length is formed.

(Example) Examples will be described below.

Figure 1 shows the mold structure for molding a spline shaft or gear shaft with a bevel, and Figure 2 shows the shape of the rough material before molding.

In Fig. 1, 1 is a forming die, 2 is a punch, and 3 is a protrusion that forms a recess on the top of the pot.The rough profile 4 shown in Fig. 2 is formed from a round bar through a cold forging process. It is what was done.

The processing method will be explained with reference to FIGS. 3 to 6.

When the rough shaped material 4 is inserted into the forming die 1 and pressurized with the punch 2, the spline section of the rough shaped material begins to be formed in the spline forming section 5 of the die, and since the punch 2 has protrusions, A recess 7 is formed in the upper part 6 of the brim. At this time, the upsetting of the collar portion 8 is not yet performed as shown in FIG.

As the molding progresses further, the collar 8 hits the die 1 and upsetting of the collar begins as shown in FIG.

Since the punch 2 has a protrusion 3, this protrusion allows the material to flow not only in the direction of the collar lO as shown in FIG. At the end it is possible to obtain a spline shaft 9 of sufficient length, which is shown in FIG.

FIG. 7 shows experimental data on the correlation between the depth of the recess and the length of the spline shaft. (A) shows the shape of the material before forming. All A-sized ships (A = 30 m) shown in Fig. 2 are the same, and the spline shaft length B and recess depth C are measured after forming the rough-shaped material. The results are shown in (b).

Regarding the relationship between the spline shaft length and the recess depth shown in (b), (compared to when the recess depth is 3 and there is no recess, the spline shaft is elongated by 10++n, and even with the recess depth of 3 fi, the spline shaft direction is sufficiently extended. It can be seen that material flow can be obtained. □ The target product has a shape that requires a hole with a depth of 17.5 mm at the top of the brim, so the protrusion was molded to this length at the same time, and drilling was also performed. could be omitted.

〔Effect of the invention〕

The present invention has the following effects. In other words, when simultaneously forming the collar using a conventional punch and extruding the spline shaft, the length of the spline shaft is insufficient, so in order to obtain a sufficient spline shaft length, it is necessary to Two steps are required: a forward extrusion step and a collar upsetting step. However, according to the forming method of the present invention, a sufficient spline shaft length can be obtained while forming the collar.
There is no need for re-forming, resulting in a significant cost reduction, and since the spline forming process is the final process, the spline accuracy is not affected by the upsetting process at the end of the next process, unlike in the past.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the mold structure of this example, Fig. 2 is an external view of the material before molding, Figs. 3 to 6 are explanatory diagrams of the process according to this embodiment, and Fig. 7 (a) is It is a diagram showing the relationship between the depth of the depression and the length of the spline shaft in (B) with the material before molding turned red. FIGS. 8 to 10 are explanatory diagrams of the prior art. 2...Punch, 3...Protrusion. 8...Brim, 9...Spline shaft. Tumor 1 Diagram 3 Diagram 40 parrots 5 squares
Parrot 6 figure 47 figure + Jh46 (""')

Claims (1)

[Claims] In a molding method in which a spline shaft or gear shaft with a flange is extruded at the same time as the upsetting of the flange, a protrusion is provided at the tip of the punch and a recess is formed at the same time at the top of the flange to obtain a sufficient length of the spline. A method for forming a spline shaft with a collar or a gear shaft to obtain a shaft or gear shaft.