JPH0380574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a method of manufacturing a clutch gear, particularly for an automobile, having a chamfer portion and a reverse tapered portion for preventing gear disengagement.

Conventional technology In the past, clutch gears for automobiles were machined from hot or cold forged material into a pre-toothed shape, machined with a gear cutter, and then machined with a chamfer ring machine or the like. Above, it is manufactured by adding a reverse taper to the tooth profile by rolling, etc.

The problems with this conventional technology are that the tooth profile is processed using a cutter, which not only results in a low yield, but also requires a variety of processes, which necessitates the installation of a large number of machines of various types. In addition, a large amount of investment and operating costs are required for building buildings to accommodate them and maintaining these machines. Furthermore, the manufacturing takt time is around 30 to 60 seconds due to the use of various machines, which also poses problems in terms of production.

Purpose The present invention provides a highly accurate automotive gear that solves the above problems, and aims to improve the yield of tooth profile processing, shorten the tact time of press work, and reduce the area of equipment and buildings. It is.

Structure The present invention involves a first step of simultaneously forming a straight tooth profile portion and a chamfer portion on the outer circumferential surface of a predetermined annular body by cold forging. The second step is to invert and press in the axial direction to form a reverse taper on the tooth profile by cold forging, and the third step is to grip the reverse taper part at three or more points and process the inner diameter part. This is a manufacturing method for automobile clutch gears.

To explain this in detail based on the drawings, a tooth-shaped material is placed in a mold that has a molding part for molding the straight tooth-shaped part 1 of an automobile clutch gear on the inner surface of the die, and a molding part for molding the chamfer part 3 on the bottom of the die. is inserted, and cold forging is performed by pressing a cold forging punch with the same diameter as the tooth bottom diameter or slightly smaller, thereby forming an annular body having a tooth profile portion 1 and a tapered portion 2 as shown in Fig. 1. to form. At this time, the chamfer part 3 is also molded at the same time, but the tooth profile part 1 at this time is straight 4.

In the present invention, the metal of the annular body is flowed in the radial direction of the annular body during cold forging, and at the same time as the tooth profile 1 is formed, the excess metal is released in the longitudinal direction of the upper part of the annular body. In the first step, it became possible to mold the straight tooth profile and the chimney part at the same time.

Next, in order to form a reverse taper into the straight 4 of the tooth profile part 1 of the intermediate automobile clutch gear formed in the first step, the chamber part is placed in the mold of a coining press for forming a reverse taper with the chamfer part facing up, and the punch is inserted into the mold. Then, as shown in FIG. 2, a reverse tapered portion 5 is formed in the straight portion 4 of the tooth profile portion 1 by cold working.

Thereafter, as shown in FIG. 3, the reverse tapered portion 5 of the toothed portion 1 is gripped by a chuck at at least three points a, b, and c, and the inner diameter portion 6 is machined.

Effects According to the method of the present invention, since the tooth profile and the chamfer are simultaneously formed by cold forging, it is no longer necessary to use a large number of machines of various types that were required to cut the tooth profile, thereby reducing material loss. As a result, the yield is improved. In addition, when machining the inner diameter, the inverted tapered portion of the tooth profile is gripped at at least three points with a chuck, thereby ensuring reliable chucking and allowing machining of the inner diameter with less tooth groove runout. Furthermore, according to the present invention, the forging tact for tooth profile forming is shortened to a few seconds, and productivity is improved as described above, which reduces the number of machines compared to conventional equipment, reduces the area of the storage building, and ultimately reduces the investment amount. This has the advantage of reducing working capital.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams of the process order of an embodiment of the present invention. 1...Tooth profile part, 2...Tapered part, 3...Channfer part, 4...Straight, 5...Reverse tapered part, 6...Inner diameter part.

Claims (1)

[Claims] 1. A first step in which a straight tooth profile and a chamfer are simultaneously formed on the outer peripheral surface of a predetermined annular body by cold forging. A second step of forming a reverse taper in the tooth profile by cold forging by pressing in a direction, and a third step of gripping the reverse taper at three or more points and machining the inner diameter part. Clutch gear manufacturing method.