JPH08112624A - Spline forming press die device - Google Patents

Abstract

PURPOSE: To precisely press the circumferential wall part of a circular-cylinder shaped work in a spline shape without generating dull parts on the dedendum. CONSTITUTION: Plural numbers of a punch 4 are arranged around a die 3 by dividing it to the circumferential direction at a place matching to a corner part of the addendum of a spline. On the top end of each punch 4, a projecting part 11 corresponding to the dedendum part of the spline, and a shoulder part 12 forcibly pressing over the total width of the addendum part adjoining to the dedendum part are formed. The punch 4 is made freely advancing and retreating along a line B of the radiation direction passing through the center of the die 3 and the center of the width direction of each dedendum part 3a of the tooth form on the outer circumference of the die 3, the projecting part 11 is made to be advanced straight against the dedendum part 3a. The circumferential wall part of the work W is pressed uniformly along the left and right both side faces of the dedendum part 3a of the die 3, and the generation of the large roll over part caused by being one-sided to one side of the dedendum part is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spline molding press die apparatus for press-molding a peripheral wall portion of a cylindrical work into a spline shape.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus has a die having a tooth profile corresponding to a spline shape formed on an outer peripheral surface thereof, and a die which is fitted into a work, and is circumferentially divided around the die.
A plurality of punches capable of advancing and retracting in the radial direction are provided, and these punches are advanced toward a die to form a spline on the outer periphery of the work.

Then, the punch is divided by a radial dividing surface passing through the widthwise central portion of each tooth crest portion of the tooth profile formed in a die, and a convex portion corresponding to the root portion of the spline is formed at the tip of each punch. Formed on both sides of the convex portion are shoulder portions that press against the half of the tooth portion of the spline, and advance these punches to the die along a radial line connecting the center of the die and the center of the root portion. A method in which the peripheral wall portion of a work is press-formed into a spline shape is known from Japanese Utility Model Publication No. Sho 61-30747.

In this case, since the punch dividing surface is provided in the radial direction passing through the widthwise center of the tooth crest portion of the die as described above, the shoulder portion of one punch and the other portion of the punch adjacent to each other when forming the spline are formed. The peripheral wall portion of the work is pushed by the shoulder portion of the punch and bulges along the dividing surface to cause burrs at the tooth crest center portion of the spline, which requires deburring in a later step.

Therefore, in order to prevent burrs from being generated in the tooth portions of the spline, the punch is divided by a radial dividing surface passing through the corner portions of the tooth portions of the spline, and the spline teeth are provided at the tips of the punches. A convex portion corresponding to the valley portion and a shoulder portion which presses the tooth crest portion adjacent to the tooth valley portion over its entire width are formed, and each punch passes through the center in the width direction of the punch and the center of the die. Japanese Patent Application Laid-Open No. 4-251616 discloses a work in which a peripheral wall of a work is press-formed into a spline shape by advancing to a die along a radial line.

[0006]

In the latter conventional device described above, since the dividing surface of the punch coincides with the corner portion of the tooth crest of the spline, there is no burr in the tooth crest portion of the spline. However, as shown in FIG. 4 (a), the spline a formed by this conventional device has a small sag at the upper and lower corners of the right side surface of the tooth trough located on the dividing surface side of the punch b, The sagging that occurs at the upper and lower corners of the left side surface facing these increases, and the accuracy of forming the root portion of the spline a decreases.

This point will be described with reference to FIG.

The moving direction of the punch b of the conventional apparatus is the direction of the radiation A passing through the center of the punch b in the width direction and the center of the die C. This radiation A is the width of the root portion C ₁ of the die C. A slight angle is formed to the left with respect to the radiation B passing through the center of the direction and the center of the die C. Then, when the punch b is advanced toward the die C side along the radiation A to form the spline a, the convex portion b _{1 of the} punch b is also advanced similarly to the root portion C ₁ of the tooth C of the die C. It moves diagonally to the right at the above angle, and the peripheral wall portion of the work is the tooth trough portion C ₁
It will be pushed toward the right side of the. Then, the sagging on the left side surface of the root portion of the spline located on the opposite side to the pushing direction becomes large.

In view of the above points, an object of the present invention is to provide an apparatus capable of press-molding a peripheral wall portion of a work into a spline shape with high accuracy.

[0010]

In order to achieve the above object,
The present invention is a device for press-molding a peripheral wall portion of a cylindrical work into a spline shape, in which a tooth profile corresponding to the spline shape is formed on an outer peripheral surface, and a die to be fitted into the work,
A plurality of punches which are divided in the circumferential direction around the die and can move back and forth in the radial direction are provided, and these punches match one corner portion in the circumferential direction of each tooth crest portion of the tooth profile formed on the die. It is divided in the circumferential direction at each location, and a convex portion that can be inserted into each root portion of the tooth profile formed on the die of each punch and each tooth peak portion adjacent to one of the root portions in the circumferential direction spans the entire width. And forming a shoulder portion facing each other, each punch is movable back and forth along a radial line that passes through the center of the die and the center of the tooth trough in the width direction.

[0011]

The peripheral wall portion of the work is pushed into the root of the die by the convex portion of the punch, and pressed against the root portion of the die by the shoulder portion of the punch to press-form into a spline shape. At this time, the convex portion of the punch moves along a radial line passing through the center of the die and the center of the tooth trough in the width direction and goes straight to the tooth trough. The parts are pressed evenly. Therefore, it is possible to prevent a large amount of sagging from being generated on one side of the root portion of the tooth and to form the root portion of the spline with high accuracy.

[0012]

In the illustrated embodiment, a peripheral wall portion of a work W having a bottomed cylindrical shape is press-formed into a spline shape. As shown in FIG. 1, a lower mold 1 and an upper mold 2 which can be raised and lowered are provided. Lower mold 1
A die 3 which can be fitted into the work W and a plurality of punches 4 which are circumferentially divided as shown in FIG. 2 are arranged in the central portion of the work W, while the upper die 2 holds the work pressing member facing the die 3. 5 was urged downward by a urethane spring 5a, and a cam driver 6 was arranged around it.

The die 3 has a tooth profile corresponding to the spline shape on the outer peripheral surface thereof, and the die 3 is fixed to a recess formed in the center of the upper surface of the circular guide block 7 provided in the lower die 1. A knockout 8 biased upward by a spring 8a is inserted in the die 3. A plurality of guide grooves 7a are formed on the upper surface of the guide block 7 along a radial line B passing through the center of the die 3 and the center of each tooth trough 3a of the outer peripheral tooth profile. Each punch 4 is slidably supported in the guide groove 7a, and a pin member 4a extending outward through a stay 7b fixed to the guide block 7 is attached to the tail end of each punch 4 so that the pin member 4a Spring 4 compressed between the end and stay 7b
Each punch 4 was urged radially outward by b. Also,
A wedge piece 9 that abuts from below on the lower edge of the tip of each punch 4 and pushes the punch 4 outward is provided so as to be vertically movable, and a sliding rod 10 that pushes up the wedge piece 9 is provided. The guide block 7 is provided so as to be slidable in the radial direction and biased inward by a spring 10a. Each wedge piece 9 is provided so as to cooperate with a plurality of, for example, five punches 4, and each sliding rod 1 is attached to a lower end of a rod 9a vertically provided at a central portion in the circumferential direction of each wedge piece 9.
The wedge piece 9 is pushed up by the inward movement of 0.

The cam driver 6 comes into contact with an inclined edge on the upper side of the tail end portion of each punch 4 from above and pushes the punch 4 inwardly, and an annular first cam 6a having a tapered inner circumference.
And a cam hole 10b formed at the tail end of each sliding rod 10
And a second cam 6b that pushes the sliding rod 10 outward when it descends and pushes it inward when it descends. Then, when the work W is set downward on the die 3 and then the upper die 2 is lowered, the work retainer 5 first comes into contact with the work W and the work W is clamped between the work 3 and the die 3, and then the second die is pressed. The sliding rod 10 is pushed outward by the cam 6b and the wedge piece 9
Is released, and in this state, each punch 4 is pushed inward by the first cam 6a, and the peripheral wall portion of the work W is press-formed into a spline shape.

As clearly shown in FIG. 3, the punch 4 is divided in the circumferential direction at a position that coincides with the tooth crest of the spline, and a convex portion 11 corresponding to the root of the spline is formed at the tip of each punch 4. A shoulder portion 12 that is pressed against the tooth crest portion adjacent to the tooth trough over its entire width is formed.

When the upper die 2 is lowered, the punch 4 is guided by the cam driver 6 in the guide groove 7a, and the punch 4 passes through the center of the die 3 and the widthwise center of the tooth trough 3a of the outer peripheral tooth profile. Along the line B, the peripheral wall portion of the workpiece W is pushed into the tooth trough portion 3a by the convex portion 11 of the punch 4 to form the tooth trough portion of the spline, and the tooth of the die 3 is formed. The peripheral wall portion of the work W that matches the mountain portion 3b is pressed by the shoulder portion 12 of the punch 4 to form the tooth crest portion of the spline. At this time, the convex portion 11 of the punch 4 moves straight with respect to the root portion 3a of the die 3, so that the peripheral wall portion of the work W is uniformly pushed along the left and right side surfaces of the root portion 3a. At the same time, the pressing force of the peripheral wall portion on both the left and right side surfaces is also equalized, and the valley portion of the spline is not biased to one side and a large sag does not occur, so that the valley portion of the spline is molded with high accuracy. Also, the shoulder 12 of the punch 4
Is pressed against the peripheral wall portion of the work W, which is the tooth portion of the spline, over its entire width, and the tooth portion is formed with high precision without causing burrs. Further, at the corner portion of the tooth flank of the spline that coincides with the division surface of the punch 4, the peripheral wall portion of the work W is pushed into the root portion 3a of the die 3 by the convex portion 11 of the adjacent punch 4 when the spline is formed. There is no flash along the dividing plane.

If the upper mold 2 is raised after press molding, the first
The inward pressing of the punch 4 by the cam 6a is released, then the second rod 6b pushes the sliding rod 10 inward to push up the wedge piece 9, and the wedge piece 9 pushes outward. The pressure causes the punch 4 to release the bite from the work W and open outward, and the knockout 8 pushes the work W onto the die 3.

[0018]

As is apparent from the above description, according to the present invention, the occurrence of a large sag that occurs on one side of the root portion of the spline and the occurrence of flash in the tooth crest portion can be prevented.
The peripheral wall of the work can be press-formed into a spline shape with high accuracy.

[Brief description of drawings]

FIG. 1 is a cutaway side view of an example of a device of the present invention.

FIG. 2 is a plan view of a part of the lower mold.

FIG. 3 is an enlarged plan view of a main part.

4A and 4B are enlarged plan views of a main part of a conventional apparatus, in which FIG. 4A shows a pressed state, and FIG. 4B shows a moving direction of a punch.

[Explanation of symbols]

3 dice, 3a tooth root part, 3b tooth crest part, 4 punch, 11 convex part, 1
2 shoulder

Claims (1)

[Claims] 1. A device for press-molding a peripheral wall portion of a cylindrical work into a spline shape, the die having a tooth profile corresponding to the spline shape formed on an outer peripheral surface thereof and a die surrounding the die. Equipped with a plurality of punches that can be moved forward and backward in the radial direction and are divided in the direction, and these punches are divided in the circumferential direction at the points that match one corner of the tooth profile of the tooth profile formed in the die in the circumferential direction. With the convex portion that can be inserted into each tooth trough portion of the tooth profile formed in the die for each punch, and a shoulder portion that is opposed to each tooth crest portion adjacent to one of the tooth trough portions in the circumferential direction over its entire width. The press die device for spline forming, wherein each punch is movable back and forth along a radial line passing through the center of the die and the center of the tooth trough in the width direction.