SU827266A1 - Apparatus for pressing powder articles - Google Patents

Description

one

The invention relates to powder metallurgy, in particular, to devices for pressing articles from powder.

A known mold for two-sided pressing, including a movable die, an upper movable and a lower fixed-punches 1.

In this solution, the upper punch, moving Down, compacts the powder layer under the punch more strongly than at the opposite end of the pressed product. Therefore, in the upper part between the walls of the matrix and the pressed powder, greater friction forces appear than in the lower part, and then thanks to the difference in these forces, movement occurs until the friction forces at the bottom exceed the friction forces in the upper part. Then re-starts the re1, ats punch. This alternate mixing, the upper punch and die, continues until the pressing process is completed.

In this construction, the disadvantage is the possibility of the destruction of a matrix of low-strength materials, ainpHMep graphite, under the conditions necessary to overcome the friction forces, but exceeding their matrix material tensile strength, and greater unevenness of properties along the height of the workpiece.

The closest to the proposed invention to the technical essence, and the achieved effect is a device for pressing products made of loroshka, including a mobile matrix And a mobile and stationary iunsans 2.

The device also comprises springs, on which a die, a sleeve and a rod are installed for forming a floor in the workpiece.

However, in the known device of uniform compression with two old ones. With one-sided application of force does not occur, since the matrix begins to move (and therefore, pressing will come from the other side) only when the friction forces between the pressed material and the matrix of the moving punch will be more pressing. When the density of the lorosque billet of the basement material increases, the concentration of force increases over a small area, which causes the matrices to rupture. In addition, the blanks are made in different heights in height.

The aim of the invention is to increase the durability of the matrix and ensure uniform density.

The goal is achieved by the fact that the fixed punch is made of a height equal to or greater than the height of the movable

poinsoya, and the height of the latter is determined from the condition

pp B Lee .27p

where hn.li is the height of the movable punch; Lee - the height of the product; ui is the density of the product; Vn is the bulk density of the powder.

The execution of a mobile Luanson you: a honeycomb, derived from the proposed dependence, and a fixed punch of the same or greater height allows for even pressing on both sides: first from the side of the moving punch, and then from the other side, from the side of the fixed punch, which the matrix itself moves with the powder and with another punch to which the force is applied.

Such pressing allows the force to be evenly distributed over the entire working surface of the die and thereby increases its durability.

FIG. 1 shows the proposed device before pressing. Powder; in fig. 2 - the same, after the approach of the lower punch; in fig. 3 - the same, after pressing.

The device consists of a movable matrix 1, an upper punch 2 and a lower movable punch 3. At the bottom of the device there is a shoulder 4 for holding the lower punch during transporting the device, which prevents the powder from being expelled. The device also contains a fixed support 5, a stand 6 and a rod 7.

The operation of the device is dried in the following way.

After installing the lower punch 3, the required amount of powder is poured into the die and the device is installed above the rod 7 on the stand 6. At the top of the powder is set the upper punch 2 and the fixed 5.

After the pressure is applied to the lower punch 3, the powder in the matrix condenses mainly in the lower part, and after entering the lower punch matrix (Fig. 2), the matrix itself begins to rise, and the upper punch already compresses the upper layers of the powder. Upper fixed punch

It has an upper furnace lid as a stop, the lower movable punch receives and transmits the pressing force from the furnace cylinder rod.

The proposed device allows to obtain products with uniform density in height (the difference in the density of beryllium blanks was no more than 1%).

The device can receive products with

a certain density, i.e. porous. For this, the height of the fixed punch must be equal to the height of the movable punch. The proposed device has high reliability (the matrix withstands

tearing

specific pressing pressure to

PO kg / cm2).

In your own way, the proposed device allows pressing on both sides while applying pressure to one punch with less effort to overcome friction, which, in turn, allows for greater pressure on the powder and to obtain products with more uniform properties.

Claims (2)

Invention Formula A device for pressing products from powder, including its movable matrix and movable and stationary punches, is characterized in that, in order to increase the durability of the matrix and ensure uniform density, the stationary punch is made equal to or greater than the height of the movable punch, the latter being determined of condition  7i where / 1pp - the height of the movable punch; / g „- product height; ui is the density of the product; 7n - the bulk density of the powder. Information sources, taken into account during the examination 1. Cypress S. S., Libenson G. A. Poroshkova metallurgists, M., Metallurgists, 1972, p. 220-221. 2. Belov S.V. Porous metals in mechanical engineering, M., “Mechanical Engineering, 1976, p. 14, fig. 7 //////  I //////