SU863182A1 - Apparatus for , centrifugal extrusion of hollow articles from powder - Google Patents

Description

(54) DEVICE FOR CENTRIFUGAL PRESSING HOLLOW PRODUCTS OF POWDER

one

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

A device for centrifugal pressing of products from powder materials is known, consisting of a feeder and a device for creating additional pressure on the product, made in the form of an elastic sealed chamber filled with filler, and fixed on the drive shaft fli.

The disadvantages of this device are the uneven height of the walls of the hollow cylinder in height and the possibility of separating the powder material during use, the mixture of components.

The closest to the technical drying and the achieved effect to the proposed is a device for the centrifugal pressing of hollow articles made of powder, including a split matrix, pressing rollers and a rotational drive. The rollers are enclosed in guide bearings 2.

The drawbacks of the device are the uneven wall thickness of the product, low density, the need for

considerable energy to obtain centrifugal force, capable of pressing metal powders into sufficiently durable products suitable for transportation.

The purpose of the invention is to improve the accuracy of the geometry and strength of the product.

This goal is achieved by the fact that the device for centrifugal

0 pressing of hollow powder articles, including a split matrix, pressing the rollers and a vrszen drive, is provided with an elastic annular forming element and a tool for

15, the axis of the valtsor moves along an alternating trajectory of a logarithmic spiral and a circle connecting the rollers with the drive, the forming element being made in dimensions corresponding to the initial contour of the product and placed between the inner wall of the matrix and the valds.

FIG. 1 shows a device diagram: FIG. 2 - section aa

25 in FIG.

The device consists of a detachable matrix 1, a pressing roller 2, an elastic forming element 3, a latch 4 and a rotational drive with a cone for movement of the axis of the rollers.

thirty

along alternating trajectories of a logarithmic spiral and a circle (not shown in Fig.).

The forming element 3 can be made, for example, of steel tape with a thickness of 0.3-0.8 mm. For. The provision of the specified trajectory of movement of the pressing rollers is suitable for any mechanical device, making it possible to vary the radius of rotation of the axes of the rollers relative to the center of the axis of the drive.

The device ensures the movement of the rollers along the trajectory of the logarithmic spiral with alternation of a circle according to the program given by the dependence:

5 (n + n,). k,

where p is the density coefficient of the material to be pressed;

n is the number of spirals;

PL - the number of circles;

k is the number of cycles, including P and AP.

The device works as follows.

Powder material is poured into the cavity formed by the matrigl 1 wall and the forming element 3. Then, after removing the excess powder, close the matrix K {x 4. At the same time, the wall of the forming element is the initial contour of the product prior to knurling. When the drive is switched on, the pressing roll 2 moves along the back side of the forming element, pressing down the powder material by gradually changing the position of the easor between the roller and the die. The compaction of the powder material continues in a certain cyclical rhythm of movement of the axis of the drum, which describes alternately the logarithmic spiral

and a circle, and the pitch of the helix depends on the compressibility of the source material. The presence of the forming element allows to keep the contours of the original form permanently, and this sealing system increases the mechanical strength of the product.

When forming a cylinder product with a wall thickness of 50 mm with an internal diameter of 340 mm and a height of 100 mm using the proposed device

technological time is reduced by a factor of 3–4 and, accordingly, labor productivity increases. Mechanical strength is increased by 1.5-2 times, which allows the product to be transported to the site of subsequent heat treatment without breakage and damage.

Claims (1)

Invention Formula A device for centrifugal pressing of hollow articles made of powder, including a split matrix, pressing rollers and a rotation drive, characterized in that, in order to increase the accuracy of the geometry. of the product’s strength and strength, it is provided with an elastic annular forming element and a device for moving the axes of the rollers along an alternating trajectory of a logarithmic spiral and a circle connecting the rollers with the drive, the forming element being sized according to the original wall of the product and rollers. Sources of information taken into account in the examination 1. Copyright testimony of the USSR. 441102, CP. B 22 F 3/06, 1973. 2, USSR author's certificate. 422534, class B 22 F 3/06, 1972. -i Powdered powder /