SU774717A1 - Method of producing thin walled fittings - Google Patents

Description

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The invention relates to the field of metal forming and can be used in the manufacture of nozzles in various ways of mechanical engineering.

A known method of manufacturing single-pipe nozzles, the shaping of which is carried out by pushing the workpiece into internal pressure nozzles, is created by an elastic medium or liquid 1J

The disadvantage of this method is the impossibility of manufacturing thin-walled pipes with small radii of curvature.

There is also known a method of manufacturing thin-walled pipes with molding them by pneumatic-thermal method in the matrix 2j. The method allows to obtain thin-walled, steeply bent nozzles by creating an effect of superplasticity.

The disadvantage of this method is the complexity of the subsequent welding of flanges due to the small thickness of the end sections of the nozzle.

The aim of the invention is to obtain thin-walled nozzles with welded ends.

This goal is achieved by the fact that before forming the tubular billet they sit down with the formation of local thickenings, bend into a ring and weld a tee with a choke to the ends of the pipe of an open ring, and after forming the ring is cut into places of thickening of the pipe into several pipes.

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FIG. 1 shows a pipe billet; in fig. 2 — preparation with the obtained local thickenings; in fig. 3 - billet, bent into a ring with a welded tee; in fig. 4 - billet after pnevmo15 thermal forming; in fig. 5 cutting the pipes at an angle of 90 °.

According to the proposed method, cutting and technological preparation of the billet are performed (Fig. 1), local thickeners are picked up by axial compression with heating of individual pipe sections (Fig. 2), then the billet is bent into a ring,

welded to the ends of the tee (Fig. 3) inflate the billet with gas over the matrix in the superplasticity mode (Fig. 4) after which the ring is cut into 30 three nozzles (Fig. 5).

Example. For the manufacture of a nozzle with a relative thickness of 0.5 mm, a diameter of 100 mm and a radius of 75 mm, a tubular billet of 25 2 -2 mm from material QT4 is taken. Subsequently receive: four thickenings (Fig. 2) of 5 mm. Then the pipe is bent with a radius of 100 mm axis, the tee is welded to the ends, put into the matrix, heated to 950 ° C and inflated with argon heated to the same temperature, pressure P 10 -14 MPa, after the workpiece is cooled, cut into three nozzles with angles of 90 ° (Fig. 5), thus obtaining a sheet thickness in the joint for welding of the flange 1 mm.

Using the proposed method will allow to obtain branch pipes with thickened ends, which allow to obtain a high-quality weld. It has a lightweight product with a high utilization rate of the material.

This improves the quality and reliability of the product in operation.

Claims (2)

1. Ershov A.G. The manufacture of pipes from solid pipes. Aviation industry, 1976, No. b, p. 4346. 2. USSR author's certificate No. 633635, cl. B 21 D 41/02, 03/30/76