SU1002092A1 - Apparatus for hydrostaic pressing of powder - Google Patents

Description

This invention relates to the field of powder metallurgy, in particular, to devices for hydrostatic pressing of powder.

A device for hydrostatic pressing of a powder is known, comprising a press, a high-pressure chamber with a working cavity mounted on a press table, a plunger mounted on a press traverse and a pumping station for creating a pre-pressure in chamber C11.

The disadvantage of this device is the low working pressure in the chamber in the form of the absence of a multiplier and the presence of leaks from the working medium due to the imperfect design of the plunger seal.

The closest to the invention according to the technical essence and the achieved result is a device for hydrostatic pressing of a powder, comprising a coaxially mounted high pressure chamber, a multiplier with a piston and a rod, a seal containing ring elements installed between the chamber walls and the stem and forming a closed sealing cavity, and elastic elements located in the sealing cavity between the annular elements 23.

The disadvantage of this device is low technological capabilities due to low working pressure due to leakage of working medium into the gap with seals when the chamber expands during pressing.

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The aim of the invention is to expand the technological capabilities of the device by increasing the operating pressure.

The goal is achieved by the fact that a device for hydrostatic pressing of a powder, including coaxially mounted high pressure chambers, a multiplier with a piston and a rod, a seal containing annular

20 elements mounted between the walls of the chamber and the stem and. forming a closed sealing cavity, and elastic elements located in the sealing cavity between the ring elements are equipped with a hydroaccumulator mounted on the chamber, the ring elements are made in the form of movable and fixed pistons with thin-walled protrusions adjacent to the wall of the chamber and the rod, the elastic elements are made in the form of springs, and a through hole is made in the chamber wall between the hydroaccumulator and the sealing cavity. The hydroaccumulator and the sealing cavity are filled with a viscous liquid. u, for example grease. Figure 1 shows the device, a general view; Fig. 2 shows the seal of the multiplier rod and the hydroaccumulator torus before the creation of the preliminary pressure in the chamber; in FIG. 3, the seal of the multiplier rod and the hydroaccumulator at the final moment of the creation of the preliminary pressure in the chamber. The device contains guides 1 of lock 2, upper seal 3, high pressure chamber 4, multiplier 5 with piston 6, current 7 of which is located in channel 8 and covered with a seal consisting of movable piston 9 and fixed piston 10 interconnected The springs 11, Inside the battery 12, a piston 13 is mounted, spring-loaded by a spring 14 and provided with a sealing ring 15. The cavity 16 of the battery 12 is filled with an expanding medium. The accumulator is provided with a check valve 17. The piston 9 is made with a thin-walled protrusion 18, and the piston 10 with two thin-walled protrusions 19 and 20. On the piston, they are provided with sealing rings 21, 22, 23, 24, 25 and 26, Sealed torus 12 and cavity 27 communicate between each other by channel 28. The end of thin-walled protrusion 1.8 is separated from channel 28 by a distance H equal to i

where P is the pressure in the cavity of the hydrocumulus of the torus; K - spring stiffness coefficient,

hydroaccumor torus;

C3 is the diameter of the cavity of the chamber; dj is the diameter of the rod of the multiplier; p - the number of springs between

piston m.50

A grease, such as grease, is used as a viscous medium.

The device works as follows.55

After loading the powder into the channel 8 of the chamber 4, an upper seal 3 is installed and locked with a lock 2 moving along the guides 1. A compressor (no noKasaH-h, Q creates a preliminary pressure in the channel 8, the piston 9 moves down, expels a portion of the viscous fluid from the cavity 27 through channel 28 into cavity 16 and moving piston 13 accumulator - j

Claims (2)

1. A device for hydrostatic pressing of a powder, comprising coaxially mounted high pressure chambers, a multiplier with a piston and a rod, a seal containing ring elements installed between the chamber walls and a rod n forming a closed sealing cavity, and elastic elements located in the sealing cavity between the ring elements It is supposed that, in order to expand technological capabilities by increasing the working pressure, it is equipped with a hydraulic valve that is installed on the chamber, annular elements are made in the form of movable and stationary pistons with thin-walled protrusions adjacent to the wall of the chamber and the rod, the elastic elements are made in the form of a tube;.;.; -; and JB to the wall of the chamber between the hydraulic adapter 12. After closing the channel 28 with the thin-walled protrusion 18, the liquid overflows, with a further increase in the pressure in the channel, the liquid in the cavity 27 closes, ensuring reliable sealing of the rod 7 of the multiplier 5. Then the compressor turns off , the channel connecting it with the chamber overlaps, a further increase in pressure is carried out by the multiplier 5 when its stem 7 enters the channel 8 of the high pressure chamber 4. The distance H from the end of the thin-walled protrusion 18 to the channel 28 of the chamber 4 is selected from those conditions that the channel. 28 closes at a pressure of EC-kg / cm. After the pressure in channel 8 is removed, the viscous medium in the cavity 27 expands and starts to lift the piston 9. As soon as the channel 28 is open, the spring 14 will move the piston 13 of the accumulator 12, a portion of the viscous liquid Moves from cavity 16 to cavity 27, replenishing the minimum leaks that will still occur. In this case, the springs 11 fix the upper position of the piston 9. To unload the pressed product, lock 2 and seal 3 are removed. After that, the device is ready for further pressing. The device allows to obtain higher working pressures by reducing leakage of fluid through the gaps, expanding technological capabilities and increasing density compressible products by 10%. The economic effect from the introduction of the invention is 30 thousand rubles. in year. the through hole and the multiplier and sealing cavity are made .. 2. The apparatus of claim 1, wherein the sealing cavity and the hydroaccumulator are filled with a viscous liquid, for example, a solid oil. Sources of information taken into account in the examination 1. Authors certificate of USSR 423572, cl. B 22 F 3/04, 1976. 2. Tsiklis D.S. Technique of physicochemical studies at high pressures x, GHI. 1958, p. 96, p.54