SU863179A1 - Press mould for pressing metal powders - Google Patents

Description

The invention relates to porous metallurgy, in particular to molds for pressing long bales and blanks such as bodies of revolution made of metal powders. A known mold for pressing metal powders, comprising a die, a carcass and a punch, made in the form of an elastic sleeve and a plug, with a nut, pressing the edge of the elastic sleeve to a rigid frame. At the same time, the mold is placed in a container filled with liquid and connected to a source of pressure I. The disadvantage of this mold is its low productivity, due to the need to assemble and work all the elements of the mold after each pressing cycle. The closest to the technical essence and the achieved effect to the proposed is a mold D for pressing metal portions, including a die, a holder and punches with guides. In this case, the cage is made with a conical inner surface, and the punches are made with a scoop support surface. , in the pressed powder and the absence of the possibility of relative movement of poro-particles during the pressing process. The purpose of the invention is to increase the density of the pressed blanks and ensure uniform density distribution throughout their volume. This goal is achieved by the fact that the mold, which includes the die, holder and punches with guides, is provided with a copier 1, made in the form of cores of profiled elements located on the inner surface with alternating cyclically repeated shape of the surface that is out of phase by 0.25 -0.5 periods for each of the neighboring elements, with the guide punches made in the form of sectors interconnected by a common base, and the closing washer installed above the sectors j profiled elements are made in de groove or bead.

FIG. 1 shows the mold layout / section A-A in FIG. 2, in FIG. 2 shows a section BB in FIG. 1 in FIG. 3 shows a section B-B in FIG. 2; in fig. 4 - section G-Y in FIG. 2

Metal Compression Mold

powders consists of the top 1, bottom 2 and side 3-8 punches located along the perimeter of the pressed workpiece at an angle of no more than 60 ° to each other and made with the working surface, the curvature of which corresponds to the curvature of the corresponding section of the pressed workpiece guides consisting of sectors connected by a common base 10, the yoke 11, on the working surface of which a copier 12 is made in the form of profiled elements (grooves or shoulder) with alternating cyclically repeating pho The surface area, which is shifted in phase by 0, is the period for each of the adjacent elements (see Fig. 3 and 4), where the value of the profiled element, in this case the depth of the groove, is indicated by an index.

Side punches are installed in the gaps between sectors 9 and profiled elements.

The mold works as follows.

Powder is loaded into the matrix in the extreme upper position. With the help of vertical punches, the powder is compressed, as a result of which the side punches are extracted to their copier (profiled elements). When a given density is reached, the upper punch rests on the end face 10 of the base and moves the die downward (relative to the yoke with profiled elements). When this occurs, the movement of the radial punches according to the law given by the geometry of the surface of the profiled elements. The latter define the alternating law of motion with a phase shift of 0.25-0.5 periods on each of the neighboring elements. At the same time, in the pressed workpiece, the workpieces, the deformation centers, are sequentially displaced along the perimeter of the workpiece. A phase shift of less than 0.25 period does not cause a noticeable effect, and a shift of more than 0.5 period causes a slowdown.

Local foci of deformation of the powder material.

When the matrix is lowered, the side punches come out of the copier, and the pressing process ends.

The impact of shear deformations in the pressed powder leads to an increase in the density of the compacted billets up to 95-97%, and the compression of the billet using side punches ensures a uniform density throughout the billet regardless of the ratio of its height and diameter.

Thus, the use of the proposed mold increases the density of pressed long-length blanks and blanks such as rotation bodies, for example, in the form of a ball, ellipse, etc., and also ensures uniform density distribution over their volume.

Claims (2)

1. A mold for pressing metal powders, including a die, a holder and punches with guides, characterized in that, in order to increase the density of the pressed blanks and ensure uniform density distribution throughout their volume, it is equipped with a copier made in the form of the inner surface of the cage. The profiled elements with alternating cyclically repeating surface shape, are shifted in phase by 0.25-0.5 periods for each of the adjacent elements, while the punch guides are enes in the form of sectors interconnected by a common base, and a locking washer installed above the sectors. 2. The mold according to claim 1, wherein it is molded with the fact that the profiled elements are made in the form of a groove or shoulder. Sources of information taken into account in the examination 1. USSR Author's Certificate No. 379315, cl. B 22 P 3/04, 1971. 2. Radomysylsky I.D. and others. Molds for powder metallurgy. Calculation and design. Kiev, Technique - 1970, p. 10-11, fig. four.