SU1524966A1 - Device for compacting articles from powder - Google Patents

Abstract

The invention relates to powder metallurgy, in particular, devices for compressing articles from powders, preferably carbon graphite. The aim of the invention is to improve the quality of products by increasing the stability of the physicomechanical characteristics. The layer of powder remaining after filling the chamber 5 of the matrix 4 is removed when running the feeder, which is 0.25-0.60 in height from the width of the pressing chamber in the direction of the feeder to the bunker 1, with the front wall 3 of the feeder inclined at an angle of 40-85 ° to the plane of movement of the feeder 2. Improved stability of the hardness and strength of the carbon brushes. 2 ill., 1 tab.

Description

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The invention relates to powder metallurgy, in particular to devices for pressing, and can be used for the manufacture of products, for example, electro-coal, from powdered materials.

The purpose of the invention is to improve the quality of products by increasing the stability of the physicomechanical characteristics.

FIG. 1 shows a device, a general view; in fig. 2 - the same, top view.

The device contains a hopper 1 filled with powder, a feeder 2 with a height / g, including a front wall 3 located at an angle of 40-85 ° to the plane of movement of the feeder, a matrix 4 with pressing chamber 5 of width b, an upper punch 6, a lower punch 7. The height of the feeder h is 0.25-0.60 of the width h of the die pressing chamber.

The device works as follows.

In the bunker 1 fall asleep powder. The feeder 2 is mixed along the matrix 4 under the hopper 1, under which it is filled with a thin layer equal to the height h of the feeder 2. Then the feeder 2 is mixed in the direction of the pressing chamber 5 of the matrix 4.

In the process of mixing the feeder 2 above the pressing chamber 5 of the matrix 4, a layer of powder is destroyed under its own weight with the formation of an open cavity for air to escape from the pressing chamber 5 and filling it with a powder with a density equal to the bulk density of the powder. The layer of powder remaining after filling the matrix chamber is removed when the feeder 2 moves to the bunker 1 with its front wall 3 inclined at an angle of 40-85 ° to the mixing plane of the feeder 2. The inclined wall cuts off the remaining powder layers in the pressing chamber 5 of the matrix 4, and The small thickness of the layer contributes to the fact that in the process of removing the powder there is no distortion in the uniformity of the filling chamber of the pressing 5 of the matrix 4 with the powder.

By moving the upper punch 6 downward, pressing is carried out by the punch 7.

For experimental studies in the device used interchangeable feeders. The size of the press. My product 5X8X16 mm. The size of the die compression chamber is 8x16 mm. The width b of the chamber of the matrix in the direction of premesh, eni feeder 8 mm.

Example 1. The height of the titrator 2 was 3.2 mm or 0.40 of the width of the extrusion chamber. The angle of inclination of the front wall of the feeder to the plane of movement of the feeder was 65 °. The extrusion of electrical wires is carried out.

Example 2. A 2.0 mm high feeder is inserted into the device, which is 0.25 of the width b of the matrix chamber. The process is carried out similarly to proimer 1.

Example 3. A 4.8 mm high feeder is inserted into the device, which is 0.60 times the width b of the matrix chamber.

Example 4. A 1.2 mm high feeder is inserted into the device, which is 0.15 of the width b of the die chamber.

Example 5. A 5.6 mm high feeder is inserted into the device, which is 0.7 of the width b of the matrix chamber.

Example 6 The remaining powder is removed by moving the feeder with the front wall inclined at 40 °.

Example 7 The remaining powder is removed by moving the feeder with the front wall inclined at an angle of 85 °.

Example 8. Remove the remaining powder by moving the feeder with the front wall inclined at an angle of 35 °.

Example 9. The remaining powder is removed by moving the feeder with the front wall 1 inclined at an angle of 90 °.

Example 10. Pressing is carried out on a known device. Hardness and compressive strength are measured on pressed brushes and the variation of these characteristics is determined.

The physicomechanical properties of the product Opt) are given in the Fi table.

From the table it can be seen that the powder filling of the matrix pressing chamber with a feeder, whose height is 0.25-0.60 from the width b of the matrix chamber, provides stable physicomechanical characteristics of the rods, which leads to improved product quality (examples 1-3) .

Powder filling of the matrix pressing chamber with a feeder, the height of which is 0.15 times the width b of the matrix, provides stable characteristics of the brushes, but it is impractical to use the feeder due to the low productivity of the device (Example 4).

Filling the matrix pressing chamber with a feeder, whose height is 0.7 of the matrix width b, does not provide stable physicomechanical characteristics of the brushes, since an increased powder layer leads to a loss of the ability of self-destruction in the feeder above the matrix chamber (example 5).

The powder filling of the matrix pressing chamber with a tester with an angle of inclination of the front wall to the plane of movement of the feeder, equal to 40-85 °, provides stable physical and mechanical characteristics of the products (examples 6, 7).

When the matrix chamber is filled with powder by a feeder with a 35 ° angle of inclination of the front wall to the plane of movement of the feeder, the powder hangs on the wall, since yi OT of the repose of the carbon graphite powder is 33-36 °, which leads to uneven backfilling of the matrix chamber and thus to obtain unstable physico-mechanical characteristics of the brushes (example 8).

When the matrix chamber is filled with powder by a feeder with a front wall inclined at an angle of 90 ° to the plane of movement of the feeder, the upper layers are compacted in the feeder chamber when the feeder is moved to the bunker, as a result of which the brushes do not provide stable physical and mechanical characteristics, which leads to the deterioration of the quality of products (example 9).

When pressing products on a known device, stable

Compiled by L. Tumanov

Editor I. Segl nikTechrel I. Veres Corrector M. Sharoshm

Sunset 7173/8 Circulation 711 Subscription

VNIIPI State Committee for Inventions and Discoveries of the State Committee on Science and Technology of the USSR

113035. Moscow. W - 35. Raushsk nab. D. 4/5 Production and publishing combine “Patent, Uzhgorod, ul. Gagarin. 101

physico-mechanical characteristics of brushes (example 10).

Claims (1)

Invention Formula A device for pressing products from a powder, mainly a carbon graphite, containing a hopper, a die with an extrusion chamber, upper and lower punches and placed between the hopper and the die with the possibility of moving the feeder, in order to improve the quality of the articles by increasing the stability of the physical - mechanical characteristics, front wall of the feeder is made inclined with respect to the plane of movement of the feeder at an angle of 40-85 °, and the height of the feeder is 0.25-0.60 from the width of the pressing chamber. FIG. 2