RU2370336C2 - Method of producing hollow parts - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metal forming and can be used in production of hollows parts via forging. After upsetting the billet is subjected to recrystallisation annealing. Then first extrusion, second extrusion, recrystallisation annealing, bottom stamping and reduction are successively performed. In first and second extrusions male moulds are used with face surface representing a truncated cone. Half-stuff bottom thickness during second extrusion is taken to equal the strain region height. Half-stuff bottom thickness during stamping is taken to equal the half-stuff bottom thickness during second extrusion.

EFFECT: reduced specific pressure on tool increasing its durability.

7 dwg

Description

The invention relates to the processing of metals by pressure, in particular to the technology of die forging, and can be used for the manufacture of hollow products.

A known method of manufacturing hollow parts, including operations: cutting the workpiece, its sediment, extrusion, drawing with thinning the wall (US 3614816, 26 10, 1971, B21K 21/04).

The disadvantage of this method is the low resistance of the tool to the extrusion operations, since the deformation obtained on the draft is added to the deformation obtained during the extrusion operation.

An object of the invention is to increase tool life.

The problem is solved due to the fact that in the method of manufacturing hollow parts, including cutting the workpiece, its precipitation, extrusion, drawing with thinning the wall, recrystallization annealing is carried out after precipitation and the first extrusion operation is performed sequentially, the second extrusion operation, recrystallization annealing, and the bottom chasing operation and reduction, while the first and second extrusion operations use punches, the end surface of which is made in the form of a truncated cone, the bottom floor thickness the finished product of the second extrusion operation is taken equal to the height of the deformation zone, and the bottom thickness of the semi-finished embossing operation is taken equal to the thickness of the bottom of the semi-finished second extrusion operation.

Figure 1 shows the technological scheme of the operation of sediment.

Figure 2 shows the technological scheme of the operation of extrusion 1.

Figure 3 shows the technological scheme of the operation of extrusion 2.

Figure 4 shows the technological scheme of the operation hood.

Figure 5 shows the technological scheme of the operation of chasing the bottom.

Figure 6 shows the technological scheme of the turning operation.

Figure 7 shows the technological scheme of the operation of reduction.

The proposed method consists of a sequence of the following operations: cutting the workpiece (not described), precipitate (Fig. 1), recrystallization annealing, which significantly reduces the specific pressure on the tool of the 1st and 2nd extrusion, since the summation of the deformations of operations by 1- m and the 2nd extrusion, with deformation obtained on the lees (in comparison with the prototype), increases the ductility of the processed material.

After annealing of the recrystallization semifinished product, the precipitate goes to the 1st extrusion operation, where an angle equal to 2 ° ± 10 is introduced at the end of the punch, that is, the end surface of the punch has a conical shape (see Fig. 2), to ensure metal gain in the transition zone of the bottom surface in the wall of the housing (see figure 5).

At the 2nd extrusion, for the same purpose as at the 1st extrusion operation, an angle equal to 3 ° ± 10 is introduced at the end of the punch, that is, the end surface of the punch has a conical shape (see Fig. 3) and the bottom thickness the semi-finished product of the 2nd extrusion is taken equal to the height of the deformation zone.

After annealing, the recrystallization semi-finished product of the 2nd extrusion is fed to the operation “drawing" (figure 4).

Due to the fact that the bottom thickness was taken to be equal to the thickness of the second extrusion product during the embossing of the bottom, the metal is displaced from the bottom when chasing notches into the wall, the excess metal recovered during the 1st and 2nd extrusion operations is the transition zone of the bottom part to the wall of the body is redistributed to form a spherical concave outer surface of the bottom (see Fig. 5), which significantly reduces the specific pressure on the punch tool and provides a complete imprint of the shape of the notches at the bottom of the punch.

Subsequent operations - turning (Fig.6) and reduction (Fig.7) - are not described.

The invention is industrially applicable.

The manufacture of hollow parts is used at the FSUE "Plant named after Sergo", so the invention meets the requirements of industrial applicability. The applicant believes that the sign of “conicity of punches” is significant, as in the literature: Handbook, “Forging and stamping”, volume 3, edited by G. A. Navrotsky. 1987, p. 137, on line 11, the taper of the punch is introduced to reduce the degree of destruction of the coating layer and lubricant, in our case, the taper at the end of the punch of the 1st and 2nd extrusion is introduced to set the metal in the zone of transition of the bottom to the wall case, in order to ensure the complete formation of notches, taking into account the tolerance on the thickness of the bottom of the semi-finished products of the 2nd extrusion and embossing of the bottom, therefore this symptom is significant. The combination of features set forth in the claims is not found by the authors from the prior art, therefore, the authors believe that the invention meets the requirement of materiality of differences, since they provide the formation of the bottom of the semi-finished product and significantly reduce the specific pressure on the tool.

Claims (1)

A method of manufacturing hollow parts, including cutting a workpiece, its sediment, extruding, drawing with thinning the wall, characterized in that after precipitation they recrystallize and subsequently perform the first extrusion operation, the second extrusion operation, the recrystallization annealing, the operation of chasing the bottom and reduction in the first and second extrusion operations, punches are used, the end surface of which is made in the form of a truncated cone, and the bottom thickness of the semi-finished product of the second operation extrusion is taken equal to the height of the deformation zone, and the thickness of the bottom of the semi-finished operation of minting is taken equal to the thickness of the bottom of the semi-finished operation of the second extrusion.

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