SU1310111A1 - Injection mould for hydrostatic compacting of hollow blanks from powder - Google Patents

Abstract

The invention relates to the field of powder metallurgy, in particular to the equipment for the hydrostatic pressing of blanks of metal powders. The invention improves the quality of the pressed blanks. The shell and mandrel of the mold are made with reinforcing rods in the form of tightly wound springs. When loading the mold, the shell and mandrel have the ability to vary in cross section without decreasing in the longitudinal direction. As a result, when pressure is removed from the pressing in the billet, tensile stresses do not occur. 3 hp f-ly, 2 ill. with about

Description

-

eleven

The invention relates to powder metallurgy, in particular, to devices for hydrostatic pressing of metal powder blanks.

The purpose of the invention is to improve the quality of the pressed blanks by reducing the level of residual tensile stresses by increasing the longitudinal rigidity of the shell and mandrel.

Fig. 1 is a diagram of a mold for hydrostatic pressing of hollow cylindrical tube type blanks; Fig. 2 is a diagram of a mold for hydrostatic pressing of hollow blanks with screw outer and inner surfaces.

The mold for hydrostatic pressing of cylindrical hollow products consists of an elastic shell 1 reinforced by an element, for example, in the form of a tightly wound steel spring 2, an elastic mandrel 3 made with a through cylindrical bore, reinforced similarly to the shell 1, sealing rings 4 and a cover 5, made with a cylindrical through hole equal to the hole in the mandrel. The lid 5 is made with a working annular protrusion 6 and with two annular recesses 7 and 8 for accommodating the ends of the shell 1 and the mandrel 3. At the other end of the mandrel 2 there is a flange 9, the diameter of which is equal to the inner diameter of the shell 1.

Mold for hydrostatic pressing hollow screw blanks

consists of elastic shell 10,

made with an internal screw surface and axially reinforced elements 11, having the form of a tightly wound spring, elastic mandrel 12, made with an external screw surface and profile equidistant profile of the internal surface of the shell having a through cylindrical hole, also reinforced with elements similar to the shell, elastic screw caps 13 made with through cylindrical holes equal to the hole in the mandrel. Elastic screw caps provide the centering of the screw sheath relative to the screw mandrel, as well as the tightness of the mold.

to

t5

20 35

25

thirty

45

40

„55

The pressing of the powders using the proposed mold is carried out as follows.

For pressing the cylindrical hollow articles into the elastic shell 1, an elastic mandrel 3 is installed with a seal 4. The cavity between the shell and the mandrel is filled with compressible powder. For uniform filling of the press-fo;: 1M 1 powder filling is carried out on a vibrating table (not shown). After loading is completed, install the cover 5 with pre-worn sealing rings 4.

For hydrostatic pressing of hollow screw blanks, an elastic screw mandrel 12 is screwed into an elastic screw sheath 10. Then, an elastic screw cap 13 is screwed into the gap between the sheath and the mandrel. Powder is filled into the helical cavity between the shell and mandrel. After loading is complete, install another elastic screw.

The assembled mold is placed in a hydrostat, where they create high pressure. The process of compaction of the powder in the mold is carried out only in the transverse direction, since the elastic shells 10 and the mandrel 12 reinforced by elastic elements have an increased axial rigidity under compression. In the transverse direction, the elements do not prevent the deformation of the elastic shell and mandrel. Therefore, when hydrostatic pressure is removed in a hollow compact, tensile stresses do not occur and, as a result, the product is of high quality without cracks and with uniformly distributed density along the length and wall thickness, i.e. by product volume. The hollow billet is removed by removing or unscrewing the die from the mold and then removing the pipe or screwing the hollow helical billet from the mandrel.

Claims (4)

1. A mold for hydrostatic pressing of a hollow billet with a straight linear axis containing an elastic shell and a mandrel, characterized in that, in order to increase the quality of the pressed billets by reducing 313 the level of residual tensile stresses due to an increase in the longitudinal rigidity of the shell and mandrel, the latter are provided with longitudinal reinforcing elements. 2. The mold according to claim 1, about the t l and is determined by the fact that each reinforcing element is made in the form of a tightly wound steel spring. 3. The mold according to claims 1 and 2, which is equipped with a sealing lid with a working annular protrusion and annular grooves on both sides of the protrusion to accommodate one end of the casing and the mandrel, the mandrel and the casing 4 Yen in cylinders} 1drichnyh bushings, and at the end of the mandrel, opposite the lid, made the flange, the diameter of which is equal to the inner diameter of the shell. 4. The mold according to claim. characterized in that it is provided with two screw caps disposed on both sides of the mandrel and the shell, the outer surface of the mandrel and the inner surface of the shell are screwed and equidistant, facing one another, and placed with a gap of one relative to another. X figure 1 Editor N. Kisttuliney Compiled by V. Grigoriev Tehred L. Oleink Corrector M.Sharoshi Order 1825/10 Circulation 74 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and printing company, Uzhgorod, Projecto st., 4 FI.2