SU1250355A1 - Method of producing articles of valve semihousing type - Google Patents

Description

The invention relates to the processing of metals by pressure and relates to methods for the manufacture of blanks for stamped and welded bodies of pipeline fittings, the predominant field of application of which is large-sized pipe fittings operating under high and medium pressure and used in the power engineering, chemical and some other engineering industries.

The purpose of the invention is to increase the quality of the product; reduction of manufacturing labor and metal saving.

FIG. 1 shows the initial hemispherical blank with a central hole; in fig. 2-t :, initial pipe billet; in fig. 3 - dome-shaped billet with a pre-formed outer pipe; in fig. 4 - half-body of pipeline fittings.

The method is carried out as follows.

From a hemispherical with a central hole, a billet, pulled out of a sheet, or a tubular billet, are longitudinally crimped to pre-mold the outer tube with a set of metal and make the billet shaped.

After receiving the dome-shaped billet, the opening of the billet is dispensed at the site of the external pipe and its draft is dispensed with the hole at the forming area of the internal pipe.

An example of a specific implementation of the proposed method is the manufacture of a batch of a valve body with a nominal diameter of DN 175 mm.

From a pipe with an outer diameter of 465 mm and a wall thickness of 42 mm, a blank with a length of 420 mm is cut. Under a press with a force of 80 MN, a longitudinal crimping of the billet section is carried out in the clamp, and a dome-shaped billet with a high cylindrical outer tube is obtained. Outer

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the diameter of the nozzle is 256 mm, and the outer diameter of the spherical part of the surface of the workpiece is equal to the outer diameter of the tube blank. Height of preparation is 450 mm.

Then, on the same press in the same punch, the bore hole is distributed in the area of the outer pipe and the inner pipe is formed by precipitating the outer pipe with simultaneous distribution of the central hole of the workpiece to the cone. In this case, the distribution to the cone is carried out simultaneously with the draft using the backpressure provided by the lower cylinder of the press by means of the self-heating conical backwater.

The result is a semi-hull blank with an outer sphere diameter of 465 mm, a wall thickness of 42 mm, an outer tube diameter of 256 mm, and a total height of 340 mm. The outer diameter of the internal nozzle is 240 mm and the diameter of the conical surface at the end is 170 mm.

The obtained semi-body is processed for welding along the ends of a large diameter, two semi-bodies are welded with each other, and then, after cutting the holes in the spherical part, the neck is welded. The welded body is subjected to heat treatment and final machining.

The use, in accordance with the proposed method, of sludge operation with simultaneous distribution of the aperture in the zone of formation of the internal nozzle between the workpiece and the matrix creates a stable tight fit, and the stamped workpiece receives a shape completely corresponding to the specified one, i.e. is equal without clips and folds in the zone of transition of the external nozzle to the spherical part. This eliminates the need to apply machining on the outer surface of the extruded half-body and in the machining allowance.

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Compiled by I. Lanska

Editor M. PetrovaTekhred I. VeresKorrektor A. Zimokosov

Order 4361/10 Circulation 783 Subscription

VNIIPI USSR State Committee

for inventions and discoveries

113035, Moscow, Zh-35, Raushsk nab. 4/5

Branch PPP "Patent, Uzhgorod, st. Project, 4

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Claims (1)

METHOD FOR PRODUCING A PRODUCT TYPE OF SEMI-HOUSING PIPELINE FITTINGS from a pipe billet, including preliminary formation with a set of metal of the outer pipe and giving the billet a domed shape, subsequent distribution of the billet hole in the section of the external pipe and its upsetting with the formation of the internal pipe, which is different in order to save to reduce the complexity, as well as improve the quality of the product, during the upsetting process, they distribute holes, applying force in the direction opposite the positive direction of the upsetting force, with obtaining a conical surface with a taper angle of 30–80 °. figure 1