SU1245444A2 - Apparatus for pressing articles of polymeric materials - Google Patents

Description

The invention relates to powder metallurgy, in particular, devices for compressing articles from powder materials (filter elements), and is an improvement of the invention according to the main author. St. No. 461848.

The purpose of the invention is to expand the technological capabilities of the device by providing products with a variable density across the section.

The drawing shows the proposed device, the cut.

The device consists of an upper pressing body 1, made in the form of a screw with trapedeidal cutting, a lower pressing body 2 made in the form of a detachable sleeve, an intermediate shaft 3, the diameter of which is equal to the internal diameter of the cutting screw 1. The upper part and the lower pressing bodies are enclosed in the housing 4. Axial The movement of the liner 2 is controlled by the device 5. In the upper part of the body, hoppers are located. The dimensions of the trapedia are in relation to each other.

0.35 4 I 1,

where b and (x are the lengths of the smaller and larger bases of the trapezium, respectively.

The device works as follows. .

When the screw 1 is rotated, the powder from the hopper is fed to the compaction zone. Since the screw grooves in the normal section have the shape of a trapezoid, the powder, advancing along the thread, takes the form of an element in the form of a helical spring, whose profile coincides with the profile of the screw groove. In the forming zone turns the screw element

2

d6

dM

de dM

54.7 54.7

47.9 53.2 47.9 50.0

five

0

five

0

five

they are joined and pressed together to form a lengthy tubular product, with those sections of coils that are large in the direction of pressing being the most compact. The pressure required for pressing provides device 5. As the sleeve is pressed, together with the pressed part of the product, the flashes out of the housing 4. The pressing is completed when the sleeve is completely out of the housing. After that, the block consisting of the sleeve with the product and the intermediate shaft 3 enclosed in it is disconnected. From the device 5 and the screw 1. The pressed product is removed from the block. The length of the product corresponds to the length of the sleeve 2.

In the case when the smaller base of the trapezium of the groove of the screw is located on the inner diameter of its cutting, the density of the filter element manufactured by the device increases from the inner surface to the outer one. In the case of a smaller base of the trapedia of the screw groove on the outer diameter of its cutting, the density of the filter element decreases from the inner surface to the outer one. ,

B. In the case where d- - 1, i.e., the bases of the trapezoid are equal to each other, it is impossible to obtain a variable density over the section of the product.

Jl

When 0.35, the powdered material is compacted to a maximum value in most of the screw grooves and consequently, the excess material is compressed in the radial stress, which leads to a leveling of the density over the cross section of the product.

60.3 68 o 75.458.7

56.9 58.8 60.758.2.

61.4 69.652.9

51.7 53,252,6

Note: dg is the diameter of the filter corresponding to the larger trapezoid base of the auger groove profile; d is the diameter of the filter corresponding to the smaller base; To the trapezium profile of the screw groove.

Change geometric parameters

 the rank of the ratio g the density difference of the profile of the screw groove, can be obtained by the diameter of the filters increases

The required density distribution over the cross section of the product (filter element).

The table shows the experimental data on the variation of the density of the filter diameter depending on the geometrical parameters of the screw groove for different materials.

From the analysis of experimental data it can be seen that with a decrease in the size A.

Compiled by G. Zagorsk

Tehred O. Sopko Proofreader S. Shekmar

Order 3947/9 Circulation 597 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Manufacturing and printing company, Uzhgorod, Projecto st., 3

Table continuation.

and the maximal value of the density difference corresponds to the minimum value of the ratio g - when h. S, 35. Thus, using the proposed device, it is possible to obtain filters with a variable density across the section, which ensures their higher operating parameters.

Claims (1)

DEVICE FOR PRESSING PRODUCTS FROM POWDER MATERIALS by ed. St. No. 461848, with the proviso that, in order to expand the technological capabilities of the device by providing products with a variable cross-sectional density, the screw grooves are made trapezoidal in the following ratio: 0.35 _x <t <T, where b is the length of the smaller base of the trapezoid; the length of the larger base of the trapezoid. SU _m , 1245444