JPS64128B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an apparatus for indirectly extruding metal billets, and the purpose thereof is to remove the skin of the billet left on the inner surface of the container by utilizing the time when the billet is loaded into the container. Therefore, the aim is to improve the operating rate.

Conventional technology Unlike the direct extrusion method, conventional methods for indirect extrusion of metal billets do not generate friction between the metal billet and the billet loading hole of the container that holds it, so frictional heat is generated during extrusion molding. There is no risk of causing a confusing flow of metal within the billet, and the pressing force is not related to the length of the billet, so it has the advantage of being able to extrude a large billet with a small force. Therefore, it is widely used. However, on the other hand, there is a risk that oxides, segregation layers, and other impurities in the billet skin may be extruded onto the surface of the profile as part of the product, or may be incorporated into the product, reducing the quality of the product. It has certain drawbacks.

Methods to prevent this include, for example, cutting and removing the skin of the billet by machining before extrusion molding, or attaching the skin of the billet to the inner wall surface of the billet loading hole of the container during extrusion molding. A method has been proposed in which only the high-quality parts are extruded into products. However, the former method requires machining, and the latter method involves inserting a cleanout disk with the same diameter as the billet loading hole after extrusion and before feeding the billet into the billet loading hole. It is necessary to remove the skin of the billet adhering to the inner wall surface of the loading hole, and in both cases, a special process is required in the extrusion process, resulting in poor operating efficiency.

For example, a similar method described in Japanese Utility Model Publication No. 197-197 transmits air pressure directly to the scraping ring, but this method is unstable for the ring to extend uniformly around the plunger. . Furthermore, since air pressure is sent through a flexible tube, it cannot be applied to a mechanism for extruding metal materials.

Configuration The present invention aims to solve the above problems,
The tip of the stem has an outer diameter that has a clearance such that the billet skin remains on the inner wall of the container between it and the inner wall of the container during extrusion, and
A die block having an annular step smaller than the outer diameter of the die block is installed around the side facing the tip of the stem, and the die block elastically contracts into the annular step during extrusion and causes the stem to collapse when returned. A clean-out ring holding device provided around the circumference so as to be able to reciprocate toward the periphery of the annular step by the action of a cylinder presses the ring against the annular step to remove the billet skin remaining on the inner wall of the container from the outside of the container. This is an indirect extrusion device for metal billets, characterized in that a clean-out ring is provided with a protrusion like a disc spring that is close to the inner wall of the container so as to scrape out the billet.

That is, in the present invention, the die block has an outer diameter such that there is a clearance between the die block and the inner wall of the container, and the clean-out ring is elastically contracted within the annular step of the die block so as not to cause any trouble during extrusion. Therefore, during extrusion, the billet skin can be positively left on the inner wall of the container. Therefore, a high-quality extruded material can be obtained without impurities in the billet skin being involved in the extruded material during extrusion, and the clean-out ring is not deformed by extrusion pressure. Therefore, the clean-out ring can always maintain its function of reliably scraping out the billet skin leaving the inner wall of the container.

Furthermore, when returning, the clean-out ring is pressed against the annular stepped portion of the die block uniformly over the entire clean-out ring by the clean-out ring holding device having the above-described structure, so that the ridge around the clean-out ring is The billet skin is uniformly close to the entire circumference of the inner wall of the container, and almost all of the billet skin left on the inner wall of the container can be scraped out of the container, so that during the next extrusion, impurities generated by the previous extrusion are removed. In addition, billets can be loaded smoothly.

Next, examples will be described.

FIG. 1 shows an embodiment of the device of the present invention, in which a clean-out ring 5 is provided with a ridge like a disc spring to form a ridge around a dive block 3 at the tip of a stem 2. This is pressed against the stepped portion of the die block 3 by a clean-out ring holding device 4 provided around the stem 2 so as to be movable by the action of a cylinder 6.

FIG. 1 shows the state during extrusion molding. At this time, the clean-out presser device 4 does not work and the protruding ridge of the clean-out ring 5 has a diameter equal to or less than the outer diameter of the die block 3. As a result, a clearance is created between the die block 3 and the inner wall of the container 1, and the skin portion a of the billet B is left behind on the inner wall of the container 1.

Fig. 2 is a diagram when extrusion is finished and the next billet B is loaded. At this time, the cylinder 6 is operated to move the clean-out ring holding device 4 on the stem 2, and the clean-out ring 5 is held there. The ridge of the clean-out ring 5 is raised against the elastic force, the ridge of the clean-out ring 5 is brought close to the inner wall of the container 1, and the container is moved by the ridge of the clean-out ring 5 relative to the container 1. 1 Scrape off the billet skin part a adhering to the inner wall.

Effects The present invention is as described above, and it is possible to obtain a high-quality extruded material by leaving the billet skin part on the inner wall surface of the container during extrusion molding, and to clean out the billet display part attached to the inner wall of the container. Since it can be carried out without going through any special steps, it is effective in improving the operating rate of extrusion molding.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an embodiment of the present invention during extrusion, and FIG. 2 is a cross-sectional view of the billet when it is loaded. DESCRIPTION OF SYMBOLS 1... Container, 2... Stem, 3... Dive block, 4... Clean out ring holding device, 5... Clean out ring, 6... Cylinder, a... Billet skin part, B... Billet.

Claims (1)

[Claims] 1. The tip of the stem has an outer diameter that has a clearance between it and the inner wall surface of the container during extrusion so that the billet skin remains on the inner wall of the container, and the outer diameter of the die block is placed around the side facing the tip of the stem. A die block with an annular step smaller than the diameter is installed, and when extruded, the die block elastically contracts into the annular step, and when returned, the stem is moved around the circumference of the annular step by the action of a cylinder. A clean-out ring retaining device, which is provided so as to be able to reciprocate, presses against the annular step to scrape out the billet skin remaining on the inner wall of the container out of the container. An indirect extrusion device for metal billets, characterized by installing a clean-out ring with a ridge.