JPH0510999Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Field of Application> The present invention relates to a tooth profile sizing mold for finishing a roughly processed intermediate forming material to a predetermined precision by ironing.

<Conventional technology> In the forging process to form a member having multiple tooth profiles along the axial direction on the outer circumferential surface, such as the inner ring of a constant velocity joint or a spur gear, the overall shape is prepared in advance. In order to finish a moderately rough-processed intermediate molding material to a predetermined tooth profile accuracy, sizing molding is performed in which the tooth portions are ironed (ioning).

In this sizing molding, for example,
As disclosed in Publication No. 110831, it is common to push an intermediate forming material positioned and mounted on a finishing forming die from its axial end face toward the die using a punch. .

<Problems to be solved by the invention> However, since the above-mentioned method simply pushes the intermediate forming material into the die with a punch, it can be used, for example, for materials whose center of gravity is high and whose posture is difficult to stabilize. In the case of a material whose end face has not been sufficiently perpendicular to the axis in the previous process, there may be a misalignment between the die and the intermediate forming material during initial setting, or there may be a misalignment between the punch and the intermediate forming material. There was a problem that the parallelism of the contact surface with the material became inaccurate, resulting in uneven contact, falling, or uneven thickness, making it impossible to obtain the initial accuracy.

It is also possible to provide a guide part on the die side to match the tooth profile between the die and the intermediate molding material, but this would increase the size of the die, and in particular, a flange part would be formed at one axial end, making it impossible to pull out. There is a drawback that it cannot be applied to gears having a shape.

In view of the problems of the prior art, the main purpose of the present invention is to provide an improved tooth profile sizing mold that suppresses the occurrence of precision defects and provides stable quality.

<Means for Solving the Problems> According to the present invention, the purpose is to provide a rough-processed intermediate forming machine that includes a punch and a die that are provided so as to be able to approach and separate from each other along the same axis. A punch holder, which is a tooth profile sizing mold for ironing a material, and elastically supports the punch so that the punch can tilt its axis and can be displaced in the axial direction toward the die; , a spherical seat having substantially the same curvature formed on opposing end surfaces of the punch and the punch holder in the axial direction; and a spherical seat having substantially the same curvature formed on the die-side end of the intermediate forming material on the inner peripheral side of the die. a guide ring elastically supported so as to be able to engage closely and to be displaceable substantially only in the axial direction toward the punch, and when it comes into contact with the intermediate forming material prior to processing, the intermediate forming For tooth profile sizing, the punch is displaceable following the punch contact surface of the material, and the intermediate forming material is pushed into the die while being held between the guide ring and the punch. This is achieved by providing a mold.

<Function> In this way, the axis of the punch with respect to the punch holder is self-aligned in the same way as a spherical bearing, so that the opposing end surfaces of the punch and the intermediate forming material are accurately brought into close contact with each other prior to ironing. Furthermore, since the stroke axis of the intermediate molding material is restrained by the guide ring, eccentricity or tilting between the intermediate molding material and the die is prevented.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 schematically show the main parts of a sizing device constructed based on the present invention.
This sizing device consists of a push-in punch 2 provided on a movable platen 1 of a forging press, and a die 4 and a knock-out punch 5 also provided on a fixed platen 3.

The push punch 2 is fixed to the movable platen 1 via a punch holder 6, and is displaced along a predetermined axis by driving the movable platen 1. The push-in punch 2 and the punch holder 6 are engaged so that they can be relatively displaced to some extent in the axial direction (dimension C in Fig. 1), and the push-in punch 2 is pressed downward between them. A cushion member 6a made of urethane resin or the like is interposed for biasing. These push punches 2 and punch holders 6
Spherical seats with substantially the same curvature that complementarily engage with each other are formed on the axial end surfaces 2b and 6b that engage with each other, and the inner surface of the punch holder 6 that guides the outer periphery of the push punch 2 is formed. The peripheral edge 6c is formed in a partially circular cross section that is inwardly convex over the entire circumference.

The die 4 has a finished tooth profile 7 formed on its inner peripheral surface, and is fixed to the fixed platen 3 via a die holder 8.

The knockout punch 5 includes a guide ring 9 that is slidably engaged with the die 4 and the die holder 8 in the axial direction, a knockout 10 that is received in the guide ring 9 so as to be slidable in the axial direction, and a knockout 10 that is axially slidably engaged with the die 4 and the die holder 8. It consists of a knockout pin 11 for protruding in the direction.

The upper end 9a of the guide ring 9 in FIG.
3 in a relatively tight manner.
Further, a cushion member 14 having a larger spring constant than the cushion member 6a provided on the pushing punch 2 side is interposed between the guide ring 9 and the fixed platen 3, so that the guide ring 9 is always resiliently biased upward in FIG.

Next, the ironing process in the above embodiment will be explained.

First, while the movable platen 1 is sufficiently raised together with the push punch 2, the material 1 having the rough tooth profile 12a whose external contour has been prepared in advance and which has been roughly machined is
2 is fitted into the upper end 9a of the guide ring 9, and the tooth profile 12a of the material 12 is aligned with the finishing tooth profile 7 of the die 4. At this time, the lower end of the rough tooth profile 12a of the material 12 and the upper end of the finished tooth profile 7 of the die 4 may be slightly engaged or may have a slight gap, but at least the inner surface of the material 12 and the guide It is better that the upper end surface of the ring 9 is in close contact with the ring 9 from the beginning.

Next, when the push punch 2 is lowered together with the movable platen 1, the lower surface 2a of the push punch 2 and the upper surface 12b of the material 12 come into contact. At this time, the material 12 is elastically supported floating in the axial direction via the guide ring 9, and at the same time, the push punch 2 is elastically supported in the axial direction with a relatively small spring constant relative to the punch holder 6. Since the inner circumferential edge 6c of the punch holder 6, which is floatingly supported and restrains the outer circumferential surface of the push-in punch 2, is a convex surface, the material 12 is attached to the die 4.
Before being pushed into the material 12, the axis of the push-in punch 2 is tilted to follow the upper surface 12b of the material 12, and the lower surface 2a of the push-in punch and the upper surface 12b of the material are accurately brought into close contact (FIG. 1).

From this, when the pushing punch 2 is further lowered against the pressing force of both the cushion members 6a and 14, the spherical end surfaces 2b and 6b of the pushing punch 2 and the punch holder 6 come into close contact with each other, and the material 12 is pushed into the die 4 while being held between the push-in punch 2 and the guide ring 9 (FIG. 2). Therefore,
The sliding axis of the material 12 is held correctly, and at the same time,
Since the inner periphery of the center hole 13 is restrained by the upper end 9a of the guide ring 9, the toothed portion is prevented from being distorted inward.

After the pushing is completed, the movable platen 1 is moved together with the pushing punch 2.
When the material 12 is raised, the material 12 is detached from the die 4 due to the reaction force of the cushion member 14. Next, by pushing out the knockout pin 11 using a drive means (not shown), the blank 12 is removed from the guide ring 9 as a finished product.

Conventionally, in such ironing, the axial movement of the material was guided only by the inner circumferential surface of the die. Therefore, if the center of gravity of the material is high or unstable, positioning with respect to the die tends to become unstable. It is not hard to imagine that if the material is pushed into the die with unstable positioning, it will be difficult to obtain the desired accuracy. Also,
If the perpendicularity between the abutment surface of the material against the punch and the tooth profile axis is low, the distribution of the pressing force of the punch acting on the material will be uneven, which will also lead to deterioration of the cylindricity of the tooth profile outer periphery. .

According to the present invention, the sliding axis of the material can be maintained accurately and the push punch 2 can be accurately brought into close contact with the material 12, so that the above-mentioned problems can be prevented.

In the above embodiment, the load for bringing the material 12 and the push-in punch 2 into close contact was obtained by the elastic force of the cushion members 6a and 14, but this could also be done by a hydraulic device. good.

<Effects of the Invention> As described above, according to the present invention, it is possible to effectively prevent the material from becoming eccentric or tipping over relative to the punch and die, and since the required tooth profile accuracy can be obtained even if the tolerance for the perpendicular accuracy between the axis and end face of the intermediate molding material is increased, it is possible to obtain molded products of high precision and stable quality.
Therefore, it is possible to achieve a very large effect in increasing productivity and greatly reducing the rate of occurrence of processing defects.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing a state in which a material is set in a tooth profile sizing device based on the present invention. FIG. 2 is a cross-sectional view similar to FIG. 1 showing the state when processing is completed. 1...Movable plate, 2...Press punch, 2a...Bottom surface, 2b...End surface, 3...Fixed plate, 4...Die,
5...Knockout punch, 6...Punch holder, 6a...Cushion member, 6b...End face, 6
c... Inner peripheral edge, 7... Finished tooth profile, 8... Die holder, 9... Guide ring, 9a... Upper end, 1
0...Knockout, 11...Knockout pin, 12...Material, 12a...Rough tooth profile, 12b...
...Top surface, 13...Center hole, 14...Cushion member.

Claims (1)

[Claims for Utility Model Registration] A tooth profile for ironing a roughly processed intermediate forming material 12, comprising a punch 2 and a die 4, which are provided so as to be able to move toward and away from each other along the same axis. A punch holder 6 which is a sizing mold and elastically supports the punch in a floating manner so that its axis can be tilted and can be displaced in the axial direction toward the die; and a mutual relationship between the punch and the punch holder. spherical seats 2b, 6b having substantially the same curvature formed on opposing end surfaces in the axial direction of the die; A guide ring 9 is elastically supported so as to be able to be displaced substantially only in the axial direction toward the punch, and when the guide ring 9 comes into contact with the intermediate forming material prior to processing, the punch abutting surface of the intermediate forming material 12b, the punch is capable of displacement, and the intermediate forming material is pushed into the die while being held between the guide ring and the punch.