SU980961A1 - Injection mould for hydrostatic extrusion of powder articles - Google Patents

Description

The invention relates to powder metallurgy, in particular, to molds for hydrostatic pressing of articles made of metal powders, preferably with an internal cavity of complex shape.

A known mold for hydrostatic pressing of powders, comprising a perforated matrix with an elastic cover, a central core, a cover with an opening for filling powder, and a cover for sealing the cavity of the cover 1.

The disadvantages of this mold include the limited shape and size of the pressed blanks.

Closest to the invention is a mold for hydrostatic pressing of articles from powders, comprising a perforated matrix, a central core, an elastic shell that is installed inside the matrix, and a diaphragm. In this case, the central rod is made solid and fixed on the matrix with the help of covers 2.

The disadvantages of this mold include the low quality of products with an internal cavity of a complex shape, which is associated with the destruction of the pressed blanks due to their disassembly.

by broadening after hydrostatic pressure has been removed.

The purpose of the invention is to improve the quality of products, with an internal cavity of complex shape.

This goal is achieved by the fact that in a mold for hydrostatic pressing of products from powders, including a perforated matrix,

10, the central rod, the elastic shell installed inside the matrix, and the diaphragm, the rod is made in the form of two components, the lower part of which is fixed in the matrix, and the upper part 15 is mounted on the lower part with the possibility of axial movement.

The drawing shows a diagram of the mold.

The perforated die 1 of the mold 20, inside of which the elastic case 2 is placed, contains the upper 3 and lower 4 flanges. An intermediate cover 5 is fixed to the upper Flange 3 for filling the powder material. , with which its upper part 8 is telescopically assembled. An elastic diaphragm 10 is fixed on the intermediate cover 5 with a cover 9. For

thirty

Vibro-vacuum sealing is done by installing the mold into a vacuum chamber rigidly mounted on the shaker table (not shown), and for hydrostatic pressing into a high-pressure container of the installation (not shown). In the process of thinning and vibrating compaction of the powder material, instead of the cover 9, a kshashka has a slightly different design, additionally centering and holding the rod (its upper part 8).

The mold works in the following way.

The mold without the elastic diaphragm 10 and with the lid additionally centering the rod is installed in a vacuum chamber rigidly mounted on the table of the shaker. Under the influence of vacuum, the elastic cover 2 lays the inner surface of the perforated matrix 1. The shaker comes on. When vibrated, the powder material is pressed into the mold. The vibrostend is switched off, the elastic diaphragm 10 is set. And the cover 9. The powder material is evacuated. If necessary, an operation {and vibration compaction of the vacuum powder is carried out. The mold is transferred to a high pressure container and is lifted by fluid pressure. During the period of pressure increase, the elastic diaphragm 10 presses the upper, part 8 of the rod to its lower part 7, and through the elastic case 2 this pressure is transferred to the powder material, which results in its shrinkage (drawing, to the left of the axis). Then there is a reduction in pressure, in the process of which a comprehensive uniform elastic expansion of the compressible product is ensured, as the pressure of the upper part 8 of the rod gradually decreases to its lower part 7. Under the influence of the elastic expansion forces, the upper part B with elastic diaphragm 10 rises up by

Axis, centering in the lower part 7 and freeing the product (drawing, to the right of the axis). The mold is removed from the container, installed in a vacuum chamber. The cover 9 with the diaphragm 10 is removed; The vacuum pump is turned on. Under the influence of vacuum, the elastic cover 2 peels off from the product and lines the inner surface of the matrix 1. The product is removed together with the upper Part 8 of the rod. Then press; the mold is reassembled and the pressing cycle is repeated.

When testing the proposed mold when pressing products of complex shape, for example, an immersion cup with a central channel in the form of two conjugated cones, it was found that the marriage is practically absent.

. Thus, the use of the described mold allows improving the quality of pressed products with an internal cavity of a complex shape.

Claims (2)

1. Author's certificate of the USSR 461847, cl. B 22 F 3/04, 1976. 2. Lobashov V.P. Hydrostatic pressing. Sat works ZNIICHM Poroshkova metallurgists. Issue 43.K., Metallurgists, 1965, p. 26 Jlohtm i / 5 // vf pressure Schlenz II and t t f t YazZelie