JPH0347689Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a mold for plastic processing such as wire drawing, and more specifically to a mold that allows the set inner diameter of a die insert to be corrected during processing operations. Regarding.

[Prior art]

Wire drawing is a processing method that reduces the cross-sectional area of the material and increases its length by pulling the material through a conical or tapered tool called a die. The product is characterized by extremely accurate dimensions, and recently the accuracy of the outer diameter has increased from the conventional 1/100 to 1/1000.
There is a demand for even higher precision.

However, the wire rod that is the raw material is becoming longer and longer due to continuous casting and continuous wire drawing, and the dimensional difference between the starting and ending ends of the wire rod is decreasing due to wear of the wire drawing die.
It reaches 0.2 to 0.03 m/m, and therefore, even when blanks are cut to a certain length, variations in volume occur, making high-precision plastic working difficult.

By the way, the mold of Utility Model Publication No. 1975 (1975), in which the mold hole of the wire drawing mold can be adjusted, has a hole in the front of the nut-shaped female screw part that has a smaller diameter at the front. A conical hole is formed, and a beak made of carbide with a small diameter inclined portion at the tip is inserted into the conical hole.
The rear end of the beak is received in the socket in the front part of the male through hole which is screwed into the threaded part of the female mold, and by screwing this male mold, the beak is constricted by the taper of the conical hole. The size of the mold hole can be adjusted by compressing the outer periphery toward the axial center to reduce the hole diameter.

[Problem that the invention attempts to solve]

However, the conventional mold has a structure in which the front half of the small diameter side of the beak is in contact with the inner periphery of the truncated conical hole of the female mold, and the beak is directly advanced in the axial direction by the spiral rotation of the male mold. This has the disadvantage that the force generated during wire drawing is applied to the threaded part via the female die.
When this mold is used as a heading mold, not only is it not possible to accurately and uniformly obtain the required front and rear dimensions of the beak, but the resistance between the female mold and the beak causes large friction between the socket and the female mold against the beak. As a result, it is not possible to easily and delicately adjust the mold hole dimensions.

It is an object of the present invention to eliminate the drawbacks of the conventional example described above and to allow correction of processing dimensions to be performed even during the drawing operation.

[Means for solving problems]

The mold according to the present invention has a recess formed on the outer periphery of a right cylindrical die insert, which is housed in a reinforcing ring and restrained in the axial direction, and whose outer circumferential surface is inside the reinforcing ring and has a smaller diameter at the rear. A tapered ring having a tapered shape that matches the tapered inner circumferential surface of the part is fitted so as to be movable rearward in the axial direction of the reduced diameter, and this tapered ring is located in the front part of the reinforcing ring and is fitted with the reinforcing ring. The ring is characterized in that it can be moved rearward via a bearing by means of a screw member which is rotated from outside the ring.

[Effect]

The mold of the present invention can perform a predetermined wire drawing process by drawing out the required wire from the back of the die insert to the front, and during this process, the wire diameter of the drawn wire can be controlled by, for example, a laser beam. When the wear of the die is detected by a measuring means, and when this reaches the allowable limit, the taper ring is pushed axially rearward via the bearing by rotating the screw member, and the outer periphery of the internal die insert is aligned with the axis. By being compressed toward the core, the diameter of the mold hole can be adjusted as desired during the process.

Therefore, in the case of a die insert that has a compressive elasticity of about 0.2 m/m, if correction is performed in units of 0.0005 m/m, the correction can be repeated many times and a highly accurate wire rod can be obtained. .

〔Example〕

Hereinafter, the present invention will be explained with reference to the embodiments shown in the figures.
Reference numeral 1 denotes a reinforcing ring for holding the mold, which is stored in the machine frame 2 from the front part (right side in the drawing) and fixed into the machine frame with a pin lock 3. Inside the ring, there is a necessary carbide tool in the center. A die insert 5 having a diameter of 4 and having a right cylindrical outer periphery is provided on the inner surface of the protrusion 1a that protrudes inward toward the mouth edge of the rear side of the reinforcing ring 1, and on the pressure receiving plate at the front inside the machine frame. The insert spacer 7 is received by the insert spacer 6 and is housed in a state where it is restrained in the axial direction. Reference numeral 8 denotes a tapered ring fitted to the outer periphery of the die insert 5, and the outer periphery of the tapered ring has a tapered shape that matches the tapered inner periphery of the concave portion 9 whose diameter is reduced at the rear of the reinforcing ring 1, and The receiving portion 1a inside the reinforcing ring 1
It is configured to be able to move toward a rear space 9' of a recessed portion 9 formed to surround the holder. 1
Reference numeral 0 denotes a pressing bush fitted to the outer periphery of the insert spacer 7 so as to press the front end of the tapered ring 8.
The taper ring 8 can be moved to the side by rotating a threaded member 12 screwed into the female thread 1b on the inner circumference of the front portion of the reinforcing ring 1 via the reinforcing ring 1. Reference numeral 13 denotes a gear portion formed on the front portion of the screw member 12, and the gear portion meshes with a drive gear 14 which is provided on a shaft so as to be rotatable from the outside of the machine frame 2. Reference numeral 15 denotes a gap provided between the outer periphery of the rear half of the reinforcing ring, where the concave portion 9 is provided, and the machine frame 2 in order to allow expansion of the reinforcing ring as the tapered ring 8 is pressed and moved.

The mold with the above configuration is made by inserting the required wire into the machine frame 1.
A predetermined wire drawing process is performed by passing the die insert 5 through the rear part of the die insert 5 and pulling it forward in the direction of the arrow, but when the die insert 5 wears out and the predetermined hole diameter cannot be obtained, the gear 14 is pulled out from the outside of the machine frame 2.
When the screw member 12 is rotated through the gear portion 13 by driving the
1 and a pressing bush 10, the tapered ring 8 is pressed and moved toward the hollow space 9' at the rear of the concave portion 9 in the reinforcing ring 1, which is opposite to the drawing direction, and for this reason, the die insert 5 is By receiving a constriction force from the outer periphery in the axial direction, the diameter of the hole is reduced and the diameter of the hole is corrected.

[Effect of idea]

According to the present invention, when adjusting the hole diameter of the die insert, the outer periphery of the die insert is compressed by pressing and moving the tapered ring on the outer periphery in the opposite direction to the drawing direction. Axial movement of the die insert, which is inconvenient when used as a mold, can be avoided, and the axial movement of the tapered ring is provided via a bearing at the front of the tapered ring and can be driven from the outside. Since the adjustment is made by rotating the screw member, the adjustment can be made while drawing the wire, and the purpose can be achieved with a relatively light force.

[Brief explanation of drawings]

The figure is a side sectional view of the mold of the present invention. 1 is a reinforcing ring, 5 is a die insert, 8 is a tapered ring, 9 is a concave portion, 11 is a bearing, 1
2 is a screw member.

Claims (1)

[Scope of utility model registration request] A tapered inner periphery of a concave portion 9 whose outer circumferential surface has a smaller diameter at the rear is provided inside the reinforcing ring 1 to the outer periphery of a right cylindrical die insert 5 housed in a restrained state in the axial direction. A tapered ring 8 having a tapered shape matching the surface is fitted so as to be movable rearward in the axial direction of the reduced diameter, and this tapered ring 8 is placed in the front part of the reinforcing ring 1 and outside the reinforcing ring. A correctable mold for plastic working, characterized in that it can be moved rearward via a bearing 11 by a screw member 12 which is rotated from the top.