JPS6043818B2 - Cold forging method for alternator rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for processing products having claw-like protrusions, such as alternator rotors, by cold forging.

There are three conventional processing methods. (Figure 1,
(See Figure 7) Figure 1 shows the case of cold forging, in which a cut round bar 1 is upset to form 2, a claw part 3a is formed,
The claw portion 3a was set to 4 by pending. This process had the following drawbacks. A shape of the claw 4a,
In order to improve dimensional accuracy, it is necessary to make the claw 3a flat (no change in thickness), so a large pressing force was required in the forming process from step 2 to step 3.

Therefore, the life of the mold was short due to this large pressure. Figure 7 shows how to make a similar product using sheet metal.

A plate is punched to make 19 pieces, and then bent to make 20 pieces. Although this method has a long mold life and is economical, it has a poor material yield and is an uneconomical processing method as a whole. The third conventional method is hot or warm forging. This method results in poor material yield, poor product precision, and unbalanced products. Furthermore, there are difficulties in die life, workability, and automation, which are disadvantages specific to hot and warm forging. The present invention provides a processing method that has a high yield, requires a small pressing force, has a simple mold structure, and has a long mold life.

The present invention will be explained below with reference to the drawings.

FIG. 2 shows one embodiment of the invention. 6 is the preformed material 5 cut from a round bar, and 7 is the molded material 6.
, 7 are eyeloned and then 8, 8 are molded to form 9 and the claw portion 9a is formed. Next, the nail 9a is flattened to form a nail 10a, and then a pending process is performed and the process moves to step 11. If the shape and precision of the pawl 11a may be rough, the process of forming the pawl 10a described above may be skipped and the pending process from 9 to 11 may be performed directly.

Furthermore, for products with a simple shape, steps 7 and 8 above may also be skipped. If the arbitrary cross-section of the claw 9a, that is, the cross-sectional area of the P-P and Q-Q cross sections in FIG.
The molding pressure (to thicken the tip of the nail) is approximately 112. According to this embodiment, when the claw is flat, it is approximately 1700 tf.
When the cross-sectional area of one claw is kept constant, the pressing force is about 1000 tf. Furthermore, since the pressure required to form the claw 9a into the claw 10a is about 300 tf, it is more economical to go through the stage of forming the claw 9a once, and the life of the mold is also extended due to the pressure. Next, burrs will be explained.

If the dimensions of the material are strictly regulated, burrs will hardly occur and can be ignored, but if managing the material becomes uneconomical, burrs can be generated in advance and trimmed later. FIG. 4 shows a method of generating burrs at the base of the claw portion and trimming it later. FIG. 5 shows a method of generating burrs around the entire circumference of the claw portion and trimming it afterwards. Furthermore, FIG. 6 shows a method in which the nail portion is generated near the tip and then trimmed. The method of the present invention can also be applied to products with holes, as shown in FIG.

As disclosed above, the effects of the present invention are as follows.

B. Material yield is good.

Mouth: Low pressurizing force and long mold life.

C. Easy to automate and has good work efficiency.

[Brief explanation of the drawing]

FIG. 1 shows a conventional processing method. FIG. 2 shows one embodiment of the invention. 9a is a nail with a constant cross section, 10a is a flat nail, and 11a is a protrusion. Figure 3 is a plan view of the semi-finished product. 9a is a nail with a constant cross section. Figure 4 is a plan view of the semi-finished product. 12 is Bali. Figure 5 is a plan view of the semi-finished product. 13 is the burr. Figure 6 is a plan view of the semi-finished product. 18 is Bali. FIG. 7 shows a conventional processing method. Figure 8 is a cross-sectional view of a product with holes. 21 is the hole part.

Claims (1)

[Claims] 1. Using a straight or stepped slug, a claw portion having a substantially constant cross-sectional area is formed on the main body in a forming process, and then the claw part is bent in a bending process to form a protrusion. A method for cold forging an alternator rotor, characterized by forming. 2. The method for cold forging an alternator rotor according to claim 1, wherein the claw portions are formed by trimming after burrs are generated in the forming process. 3. A method for cold forging an alternator rotor, etc. according to claim 1, characterized in that the cross-sectional area of the claw portion is formed to be substantially constant in the forming process. 4. A method for cold forging an alternator rotor or the like according to claim 1, characterized in that the cross-sectional area of the claw portion is formed to be substantially constant in the forming process, and then the claw portion is formed into a flat shape. 5. A method for cold forging an alternator rotor, etc. according to claim 2, characterized in that trimming is performed after generating burrs on the claw portions. 6. A method for cold forging an alternator rotor, etc. according to claim 3, characterized in that trimming is performed after generating burrs on the claw portions.