JP4837598B2 - Forging equipment - Google Patents

Description

  The present invention relates to a forging device for forming a bottomed hole substantially coaxial with a shaft main body in a head portion having an uneven thickness portion.

The bottomed hole for engagement formed in the head of the shaft has a flat side surface on a part of the peripheral surface or a square cross section, so it is difficult to machine with a rotary tool such as a drill or end mill Therefore, it must be formed by a forging device. In this case, when the head is coaxial with the shaft main body, a bottomed hole coaxial with the shaft main body can be easily formed in the head by arranging the punch coaxially with the shaft main body. However, in the case where the head has an uneven thickness portion projecting to one side, the molding pressure is biased in the radial direction when the punch is driven into the head even if the punch is arranged coaxially with the main shaft. The punch is bent and the bottomed hole is not formed coaxially with the shaft main body.
JP 2002-263775 A

  An object of this invention is to obtain the forging apparatus which can form the bottomed hole substantially coaxial with the shaft main body in the head with an uneven thickness part with high precision.

The present invention is configured as follows to achieve the above object. That is, the shaft main body is provided with a shaft material having an uneven wall portion projecting to one side, the shaft material is fitted into a die forming hole, and a punch disposed substantially coaxially with the shaft main body is disposed on the head. When forming a bottomed hole substantially coaxial with the shaft main body in the head, a pressing surface on the tip side of the punch is provided with a slope that generates a component force in the direction of the anti-thickness portion upon receiving molding pressure. It is a thing.
According to a second aspect of the present invention, the slope is formed by chamfering a portion that is a part of the periphery of the pressure surface and is located on the side of the uneven thickness portion of the head.
In the invention according to claim 3, the inclined surface is formed by inclining the pressing surface upward from the anti-thickness portion side toward the uneven thickness portion side.

  When the punch is driven into the head portion of the shaft material, the material flow toward the uneven thickness portion tends to increase and the punch tends to be dragged in the direction of the uneven thickness portion. The component force (reaction force) acting in the direction of the meat part prevents the punch from bending in the direction of the uneven part. For this reason, the punch is fitted into the head while being held coaxially with respect to the shaft main body. As a result, a bottomed hole having a high degree of coaxiality with the main shaft is formed in the head.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is a sectional view of a forging device according to the present invention, FIG. 2 is a partial side view showing a first embodiment of a punch according to the present invention, FIG. 3 is a bottom view of FIG. 2, and FIG. 5 is a plan view of FIG. 4, FIG. 6 is a partially sectional side view of a shaft with a bottomed hole, FIG. 7 is a plan view of FIG. 6, and FIG. 8 is a second view of a punch according to the present invention. It is a partial side view which shows an Example.

  In FIG. 1, reference numeral 1 denotes a forging device, which includes a die unit 2 and a punch unit 10. The die unit 2 is mounted on the upper surface of the central portion of the receiver 3 with the die 4 divided into three parts in the vertical direction, that is, the upper die 4a, the middle die 4b, and the lower die 4c. The clamp 5 is press-fitted into the upper clamp 5 a and the lower clamp 5 b and fixed to the receiver 3.

  A molding hole 6 is formed vertically through the center of the die 4. The forming hole 6 is a stepped hole that reduces in diameter stepwise from the upper part to the lower part, and a bulging part 6a that bulges rightward is formed in the upper part.

  A punch unit 10 is provided above the die unit 2. The punch unit 10 has a columnar punch 12 disposed on the lower surface of the axial center of a punch head 11 that is moved up and down by a ram so as to be suspended and fixed coaxially with the molding hole 6 described above. That is, the upper part of the punch 12 is press-fitted and fixed to the punch holder 15, and the punch holder 15 is fixed to the punch head 11 by the holding ring 16.

  The punch 12 has a small-diameter and prismatic insertion portion 12a integrally therewith. As shown in FIGS. 2 and 3, the fitting portion 12 a has a tip (lower end) having a slightly larger diameter, and a pressing surface 13 and a slope 14 are formed on the lower surface of the tip. The pressing surface 13 is formed on a smooth surface orthogonal to the axis of the punch 12.

  The slope 14 has an end edge portion of the pressure surface 13, that is, an end edge portion on the side facing the bulging portion 6a of the molding hole 6 (right end portion in FIGS. 2 and 3) having a height H1. It is formed by chamfering so that the inclination angle α1 is about 45 degrees and about 1.6 mm.

  Reference numeral 20 denotes a shaft material to be fitted into the molding hole 6, and as shown in FIG. 4, a head having an uneven portion 22 a on the upper portion of a shaft-shaped shaft main body 21 whose diameter decreases stepwise downward. 22 integrally. The uneven thickness portion 22a is fitted into the bulging portion 6a of the molding hole 6 described above, and the front and rear width W1 projects rightward with the width of the reference diameter of the head portion 22 as shown in FIG. The right end portion is formed in a square shape when viewed from the plane, and a linear protrusion 22b is formed on the right end portion.

  According to the embodiment, when the punch 12 is lowered and the insertion portion 12 a is driven into the head portion 22 of the shaft material 20, the component force (reverse force) acting in the direction of the anti-thickness portion of the inclined surface 14 formed on the pressing surface 13. Force) prevents the fitting portion 12a from bending in the direction of the uneven thickness portion 22a. For this reason, the fitting portion 12 a, that is, the punch 12 is fitted into the head portion 22 while being held coaxially with respect to the shaft main body 21. As a result, as shown in FIGS. 6 and 7, a rectangular bottomed hole 23 having a high degree of coaxiality with the shaft main body 21 is formed in the head portion 22 of the material 20.

  FIG. 8 shows a second embodiment of the punch 12. In this, the entire lower surface (pressure surface) of the fitting portion 12a described above is inclined upward from the left end (on the side of the uneven thickness portion 22a) toward the right end (on the side of the uneven thickness portion 22a), and the lower surface is inclined 14 '. It is what. In this case, the angle α2 of the inclined surface 14 'is an angle at which the height H2 of the right end with respect to the left end of the fitting portion 12a is about 1.6 mm.

  The heights H1 and H2 and the inclination angles α1 and α2 of the inclined surfaces are appropriately set according to the amount of the uneven thickness portion 22a, the hole shape, and the like.

It is sectional drawing of the forging apparatus by this invention. It is a partial side view which shows 1st Example of the punch by this invention. FIG. 3 is a bottom view of FIG. 2. It is a partial cross section side view of a shaft raw material. FIG. 5 is a plan view of FIG. 4. It is a partial cross section side view of the shaft in which the bottomed hole was formed. FIG. 7 is a plan view of FIG. 6. It is a partial side view which shows 2nd Example of the punch by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Forging device 2 Die unit 3 Receipt 4 Die 5 Clamp 6 Molding hole 6a Expansion part 10 Punch unit 11 Punch head 12 Punch 12a Insertion part 13 Pressurization surface 14 (14 ') Slope 15 Punch holder 16 Holding ring 20 Shaft material 21 Shaft main body 22 Head 22a Uneven portion 23 Bottomed hole

Claims (3)

  A shaft material having an uneven thickness portion projecting to one side is provided on the head of the shaft main body, the shaft material is fitted into a molding hole of the die, and a punch disposed substantially coaxially with the shaft main body is driven into the head. When the bottomed hole substantially coaxial with the shaft main body is formed in the head, the pressurizing surface on the punch tip side is provided with a slope that generates a component force in the direction of the anti-thickness portion under molding pressure. A forging device that is characterized.   2. The forging device according to claim 1, wherein the inclined surface is formed by chamfering a portion which is a part of the periphery of the pressing surface and is located on the side of the uneven thickness portion of the head.   The forging device according to claim 1, wherein the inclined surface is formed by inclining the pressing surface upward from the opposite thickness side toward the thickness side.

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