JP2884028B2 - Forming method of gear with meshing hole for meshing clutch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a gear (driven gear) with a meshing hole (generally referred to as a female dog) for a meshing clutch used exclusively in a transmission for a motorcycle or a cultivator.

[0002]

2. Description of the Related Art A gear with a meshing hole for a meshing clutch is formed in advance by forming a tooth profile by cutting and then forming a meshing hole for a meshing clutch, and conversely, it is described in Japanese Patent Publication No. Sho 60-2134. As shown in the figure, the meshing hole for the meshing clutch is extruded forward from one side so that the excess thickness protrudes only to the portion corresponding to the meshing hole for the meshing clutch, and the meshing hole for the meshing clutch is formed. There have been attempts to form

[0003]

Conventionally, not only two steps, a step of forming a tooth profile and a step of forming a meshing hole for a meshing clutch, are required, but also the excess is pressed locally in the punching direction of the punch. Because of the overhang, the flow of meat in the radial direction was poor.

[0004]

SUMMARY OF THE INVENTION The present invention has been developed for the purpose of reducing the number of steps by effectively utilizing the cutting means, focusing on the fact that there is a cutting step at the end. A donut-shaped material is press-fitted into a cavity provided with a tooth-forming tooth mold on the inner periphery to form a tooth profile around the material, and at the same time, a bottomed hole serving as a meshing hole for a clutch is formed on one side by driving a punch. It is intended to form the surplus material so as to protrude uniformly to the other side surface and to cut off the other side surface together with the surplus thickness up to the bottom surface of the bottomed hole.

[0005]

[Function] Since the tooth shape and the bottomed hole are formed at the same time, the volume corresponding to the bottomed hole is applied to the tooth shape, and the flesh flows in the radial direction because it protrudes uniformly to the other side as surplus thickness. When the excess thickness is removed, a through hole is formed as a meshing hole for a meshing clutch.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gear with a meshing hole for a meshing clutch according to the present invention will be described with reference to the drawings. Reference numeral 1 denotes a die having a cavity 3 provided with a tooth form forming tooth mold 2 on the inner periphery, and reference numeral 4 denotes a punch for press-fitting a donut-shaped material 5 into the cavity 3. On the bottom surface of the cavity 3, there is formed a recessed recess 6 having a height that becomes lower by one step, and a mandrel 7 is vertically provided at the center thereof. On the other hand, punch 4 has 6
A punch 8.8... Having a fan shape in section has a projecting overhang 9, and the punches 8.8... Have a length corresponding to the thickness of the material.

According to the device thus formed, a bottomed hole 11 serving as a meshing hole for a meshing clutch is formed at one side of the punching portion of the punch 8 of the material press-fitted into the cavity, and at the same time, is formed around the periphery. A tooth profile 10 is formed.
In addition, the excess material 12 corresponding to the bottomed hole 11 is pushed forward,
Overhang into the escape recess 6 to a uniform thickness. When the material thus formed is taken out and finish-cut, if the overhanging excess material 12 is cut off, the bottomed hole is opened at the bottom surface,
The meshing hole 13 for the meshing clutch penetrates.

As described above, the formation of the tooth profile and the formation of the bottomed hole are performed at the same time, and the bottomed hole is penetrated at the time of finish cutting. Labor saving is realized. In addition, since the volume corresponding to the bottomed hole is applied to the tooth profile, the tooth profile has good overhang, and a gear with high precision can be obtained.

The size, number of teeth, number, size, shape, etc. of the meshing holes for the meshing clutch may be changed as appropriate, and the shaft hole is not formed simultaneously with the meshing hole for the meshing clutch but is post-processed. be able to.

[0010]

According to the present invention, since the tooth profile and the bottomed hole serving as the meshing hole for the meshing clutch are formed at the same time, only one process is required, and the reliability and accuracy using the forging means are high. Gears can be formed.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an apparatus for carrying out a molding method of the present invention.

FIG. 2 is an explanatory view showing steps of a molding method.

FIG. 3 is a partially cutaway explanatory view showing a product immediately after molding in which a surplus wall is formed overhanging.

FIG. 4 is an explanatory diagram of a completed product.

[Explanation of symbols]

1. Die, 2. Tooth profile forming die, 3. Cavity, 4. Punch, 5. Material, 6. Recessed recess, 7.
・ Mandrel, 8 ・ ・ Punch, 9 ・ ・ Overhang, 10
··· Tooth profile, 11 ·· Bottomed hole, 12 ·· Overfill, 13 ·· Meshing hole for meshing clutch.

Claims (1)

(57) [Claims] At the same time, a donut-shaped material is press-fitted into a cavity provided with a tooth-form forming tooth mold on an inner periphery to form a tooth shape around the material, and at the same time, a meshing hole for a meshing clutch is formed by driving a punch from one side. A method of forming a gear with a meshing hole for a meshing clutch in which a bottomed hole is formed to allow the surplus to protrude uniformly to the other side surface, and the other side is cut off together with the surplus to the bottom surface of the bottomed hole to form a through hole. .