JPH0469009B2 - - Google Patents

Description

[Detailed description of the invention] Industrial applications This invention relates to a male porthole die.

Conventional technology and its problems Conventionally, male porthole dies have been made of die steel, but the surface quality of the extruded material, dimensional accuracy in the cross section of the extruded material, and male die life are not satisfactory. The desired performance could not be obtained.
Therefore, in order to improve the surface quality of the extruded mold material, improve the dimensional accuracy in the cross section of the extruded mold material, and improve the life of the male mold, we added a bearing surface to the outer peripheral surface of the mandrel part of the die steel male mold. It was considered to fit and cover a cemented carbide ring. However, if the gap between the outer circumferential surface of the mandrel part and the inner circumferential surface of the cemented carbide ring is small, the thermal expansion coefficient of the die steel is larger than that of the cemented carbide, which causes the die steel to be heated during extrusion. In some cases, there was a problem that cracks occurred in the cemented carbide ring. In addition, if the gap between the outer circumferential surface of the mandrel part and the inner circumferential surface of the cemented carbide ring is large, the cemented carbide ring will shift and its center will deviate from the center of the mandrel part, causing the extrusion opening to have the desired shape. There was a problem in that, unlike the conventional method, there were errors in the cross-sectional dimensions of the extruded material.

An object of the present invention is to provide a male porthole die that solves the above problems.

Means for Solving the Problems In the male porthole die according to the present invention, a cemented carbide ring having a bearing surface on the outer circumferential surface is fitted over the mandrel, and there is a gap between the mandrel and the ring that is larger than the mandrel. A heat-resistant sleeve made of soft material is interposed.

In the above, the heat-resistant sleeve used is one that will not melt or burn at the temperature during extrusion processing.

Also. The above-mentioned male porthole die is applied to an extrusion processing apparatus for aluminum and amminium alloys, as well as other metal materials and plastic materials that can be extruded.

Embodiment In the following description, front and rear refer to FIG. 1, the front refers to the left side of FIG. 1, and the rear refers to the opposite side.

FIGS. 1 and 2 show a porthole die for producing aluminum extrusion materials using a male porthole die according to the present invention. The porthole die 1 includes a male porthole die 10 made of die steel and a male porthole die 20 also made of die steel.

A front protrusion 11 is integrally provided at the center of the front surface of the male porthole die 10, and a plurality of ports 12 are formed around the front protrusion 11 at predetermined intervals in the circumferential direction. A mandrel 13 having a smaller diameter than this is integrally provided on the front surface of the mandrel so as to protrude forward. An annular recess 14 that is open toward the front is formed over the entire circumference at a portion of the front surface of the front protrusion 11 that connects with the circumferential surface of the mandrel portion 13 . A male thread 15 is formed in the front half of the outer peripheral surface of the mandrel portion 13. Further, a cemented carbide ring 17 having a bearing surface 16 on its outer peripheral surface is fitted over the rear half of the mandrel portion 13, and is fixed in front thereof by a nut 18 screwed into the male thread 15. The distance between the outer peripheral surface of the mandrel portion 13 and the inner peripheral surface of the ring 17 is determined by the amount of deformation of the mandrel portion 13 and the amount of deformation of the ring 17 during thermal expansion caused by the difference in coefficient of thermal expansion between die steel and cemented carbide. greater than half the difference. A sleeve 19 made of pure aluminum (heat-resistant sleeve that is softer than the mandrel part 13) is interposed between the mandrel part 13 and the ring 18 so as to fill the gap between them. The nut 18 is made of a material having almost the same coefficient of thermal expansion as die steel, and is lightly tightened when the porthole die 1 is not used for extrusion.

A welding chamber forming recess 22 is provided in the rear surface of the female porthole die 20 around the central opening 21, and a welding chamber 23 is formed between this recess 22 and the front surface of the male mold 10. ing. The front end of each port 12 of the male mold 10 is opened into a welding chamber 23, respectively. Also, opening 2
A recess 24 is formed in the rear end of the peripheral surface of the ring 1, and a cemented carbide ring 26 having a bearing surface 25 on the inner peripheral surface is fitted into the recess 24 by shrink fitting. The bearing surface 25 of the ring 26 fixed to the female die 20 faces the bearing surface 16 of the ring 17 attached to the male die 10 at a predetermined distance, and an extrusion opening 2 is formed between both bearing surfaces 16 and 25.
9 is formed.

The method for manufacturing an aluminum extrusion molding using such a porthole die 1 is as follows.

First, after preheating the porthole die 1, the nut 18 is tightened to prevent the ring 17 from shaking. Then, an aluminum billet is inserted into the billet insertion hole 31 of the container 30 and kept heated by the heating device of the container 30. The extruder stem then pushes the billet forward, and the aluminum material separates into the ports 12 of the male mold 10 and flows through them into the welding chamber 23. The aluminum materials that have flowed into the welding chamber 23 are joined together in the welding chamber 23 and welded together, and then extruded as a shape material through the extrusion opening 29.

In the above, the male die 10 is also heated by the heat transmitted from the marminium material during preheating before extrusion and during extrusion. Then, the amount of radial deformation of the mandrel portion 13 becomes larger than the amount of radial deformation of the cemented carbide ring 17 due to the fact that the coefficient of thermal expansion of the die steel is larger than that of the cemented carbide. When the sleeve 19 is compressed and deformed, no force is applied to the ring 17 to expand it radially outward, thereby preventing the ring 17 from cracking.

After the extrusion process is completed, the sleeve 19 is removed and the male mold 10 and female mold 20 are washed with caustic.
Attach a new sleeve 19 and perform extrusion again in the same order as above.

In the above embodiment, the heat-resistant sleeve 19 is made of pure aluminum, but is not limited to this, and is made of a material that does not melt or burn at the temperature during extrusion processing and is softer than the mandrel portion 13. It can be changed as appropriate to consist of
For example, it may be made of a heat-resistant elastic material.

Effects of the Invention According to the male porthole die of this invention,
Even if heated during extrusion, the mandrel part 1
3 is absorbed by the sleeve 19, thereby preventing the cemented carbide ring 17 from cracking. Moreover, since alignment is achieved through deformation of the sleeve 19, the axial center of the cemented carbide ring 17 is prevented from shifting from the axial center of the mandrel portion 13, and an extruded molded material with very small thickness deviation and high dimensional accuracy can be obtained. It will be done. Furthermore, the life of the male mold 10 is extended and the dimensional accuracy of the cross section of the extruded mold material is maintained at a high level. Furthermore, the surface quality of the extruded profile is also improved.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a porthole die using a male porthole die according to the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1. 10... Porthole die male mold, 13... Mandrel part, 16... Bearing surface, 17... Cemented carbide ring, 19... Pure aluminum sleeve (heat-resistant sleeve made of a material softer than the mandrel part).

Claims (1)

[Claims] 1 A cemented carbide ring 17 having a bearing surface 16 on the outer peripheral surface is fitted onto the mandrel portion 13, and a heat-resistant sleeve 19 made of a material softer than the mandrel portion 13 is interposed between the mandrel portion 13 and the ring 17. A male type porthole die.