JPH0718448Y2 - Split punch - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split punch used for hot forming or the like, which is composed of a head made of a super hard material and a main body made of a different material.

[0002]

2. Description of the Related Art Conventionally, in this type of division punch,
A female part is formed on one of the tip of the body part and the tail end of the head part, and a male part is formed on the other side, and the body part and the head part are fitted in the female part and the male part, and both are friction welded or It is generally welded by brazing or fastened by bolts in the radial direction.

[0003]

[Problems to be Solved by the Invention] In the welding method by friction welding or brazing, when hot forming is carried out, the welded portions of the main body and the head are exfoliated at an early stage due to a difference in thermal expansion between them, Further, in the fastening method using bolts, the forming load in the axial direction of the punch acts as a shearing load on the bolts, and the bolts are likely to break, resulting in inferior durability. In view of the above points, the present invention has an object to provide a split punch having excellent durability.

[0004]

[Means for Solving the Problems] In order to achieve the above object,
The present invention is a split punch composed of a head made of a super hard material and a main body made of a different material, and the female punch is provided at one of the tip of the main body and the tail end of the head. In which the main body and the head are fitted in the female part and the male part, the inner peripheral surface of the female part and the outer peripheral surface of the male part are radially opposed to each other. Is provided with a key member that fits in the groove of the female portion with radial play, and a pressing member that presses the key member inward in the radial direction. It is characterized in that the key member is fitted over the concave groove of the male portion.

[0005]

The key member is fitted over the concave groove of the female portion and the concave groove of the male portion to prevent the head portion from coming off the main body portion. Even when performing hot forming, unlike the welding method, it is not adversely affected by the difference in thermal expansion between the main body and the head, and by using a key member, it is possible to obtain a large shearing surface area in the punch axial direction, Increased strength against molding load. When the head is worn, the pressing by the pressing member is released, the key member is immersed in the concave groove of the female portion, and the head can be replaced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 is a main body made of steel material, 2 is a head made of super hard material, and a stepped female portion 3 is provided at the tip of the main body 1. And a stepped male part 4 corresponding to the female part 3 at the tail end of the head 2, the male part 4 is press-fitted into the female part 3, and the head 2 is attached to the tip of the main body part 1. Installation,
Configured a split punch.

The outer peripheral surfaces of the main body 1 and the head 2 are substantially flush with each other, but in order to reduce the sliding resistance during billet molding, the outer periphery of the front end of the main body 1 has a small diameter.

The inner peripheral surface of the female portion 3 and the outer peripheral surface of the male portion 4 are located at a plurality of positions in the circumferential direction, and as shown in FIG. Is formed, and there is radial play in the concave groove 5 of the female portion 3, the key member 7 is formed.
And a screw hole 8 in the radial direction facing the groove 5
Is formed on the female portion 3, a push screw 9 as a pressing member is screwed into the screw hole 8, the male portion 4 is press-fitted into the female portion 3, and then the key member 7 is pushed out radially inward by the push screw 9. Then, the key member 7 is fitted over the concave groove 5 of the female portion 3 and the concave groove 6 of the male portion 4 to fix the male portion 4 in the press-fitting position. The sizes of the concave grooves 5 and 6 and the key member 7 are set so as to have a sufficient shearing cross-sectional area with respect to the forming load in the punch axial direction.

A radial threaded hole 7a is formed in the central portion of the key member 7, and when the head 2 is replaced, the push screw 9 is pulled out and the draw pin 10 is attached to the tip of the draw pin 10 as shown in FIG. Screwed into the screw hole 7a at the screw part of
Thus, the key member 7 is inserted into the concave groove 5 of the female portion 3 and separated from the concave groove 6 of the male portion 4, and the head portion 2 is separated from the main body portion 1 in this state.

[0010]

As is apparent from the above description, according to the present invention, the head can be firmly connected to the main body by the key member, and the adverse effect due to the difference in thermal expansion between the main body and the head is not exerted and the durability is improved. It has the effect of obtaining a split punch having excellent properties.

[Brief description of drawings]

FIG. 1 is a partially cut side view of an example of a punch of the present invention.

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is an explanatory diagram showing a key member removal operation at the time of head replacement.

[Explanation of symbols]

 1 Main Body 2 Head 3 Female 4 Male 5 and 6 Groove 7 Key Member 9 Push Screw

Claims (1)

[Scope of utility model registration request] 1. A split punch comprising a head made of cemented carbide and a main body made of a different material, wherein the split punch is provided on one of the tip of the main body and the tail end of the head. In a case where a female part and a male part are formed on the other side and the main body part and the head part are fitted in the female part and the male part, in the radial direction on the inner peripheral surface of the female part and the outer peripheral surface of the male part. The pressing member is provided with a key member that forms concave grooves facing each other and is fitted into the concave groove of the female portion with radial play, and a pressing member that presses the key member inward in the radial direction. The split punch is characterized in that the key member is fitted over the concave groove of the male part.