SU837440A1 - Method of producing branches on thin-walled tubes - Google Patents

Description

(54) METHOD OF MANUFACTURING TUBES ON THIN WALLED PIPES

one

The invention relates to the processing of metals by pressure and can be used in the preparation of elements of pipeline systems.

There is a known method of making waste on thin-walled pipes, inclusive of the simultaneous impact on the pipe billet by the internal pressure of an elastic medium and axial compression I.

However, due to the high friction forces between the workpiece and the die in the process of stamping with increased internal pressure in the deformation zone. additional tensile stresses appear, reducing the plasticity of the material and increasing the thinning of the workpiece. In addition, the need for axial compression of the workpiece leads to the complication of die tooling and, consequently, to an increase in the cost of the part.

The purpose of the invention is to expand technological capabilities and reduce the cost of parts.

This goal is achieved by the fact that the pipe billet is crimped in the transverse direction before stamping with the internal pressure of an elastic medium.

FIG. 1 shows a tube blank formed in the transverse direction; FIG. 2 shows a process of stamping outlets; FIG. 3 - stamped part.

The stamping method is carried out in the following manner.

On a thin-walled tubular billet, cross corrugations are performed.

0 by fluid or rubber pressure, rollers or another known method. The workpiece is placed in the die so that the ends of the workpiece cannot move in the axial direction.

5 towards the center. The internal cavity of the workpiece and the cavity are filled with fluid in the corrugations and the wall of the matrix. To prevent outflow of fluid outside

0 workpieces, and to create a backpressure in the process of stamps1 and in the places of stamping the taps, movable plugs are installed to which a counterpressure force Q is applied.

5 creating the necessary pressure q on the inner surface of the workpiece is performed by stamping outlets, accompanied by the distribution of transverse corrugations. By distributing corrugations

G generates axial compression allowing

increase the ductility of the metal billet.

Reducing the contact area of the workpiece With the matrix allows, for a given pressure q, to reduce friction forces and reduce their harmful effects. The presence of fluid between the outer surface of the workpiece and the die leads to a decrease in friction forces. If necessary, a grease is laid in the corrugations on the outer surface of the workpiece before punching. At the end of the punching process, if necessary, an increased calibrating pressure is created to increase the precision of the part.

The proposed method was tested on pipes AMGBM 040x1.0. The transverse corrugations were created by rolling the workpiece in the rollers. The height of the corrugations was 3 mm, pitch 6 mm. Corrugations were not formed at the place of punching of taps to facilitate metal flow in the cavity of the matrix during the initial punching period. The workpiece was deformed in a rigid split matrix by fluid pressure.

The stamping of the proposed method allows an increase in the height of the outlet by 9-11% as compared with that provided by the known methods of stamping.

Claims (1)

1. USSR author's certificate fb05b59, cl. B 21 C 37/29, 1978. in.i