SU1761353A1 - Method of manufacturing hollow products from welded tubular intermediate products - Google Patents

Abstract

Use: manufacture of hollow cylindrical parts from thin-walled welded tubular blanks, such as sleeves cups milking machines. Summary of the invention: simultaneously with the crimping, the pipe wall is clamped at the border of the compressed and uncompressed parts, an annular section is formed and it is pushed against the end of the mandrel. silt

Description

The invention relates to the processing of metals by pressure and can be used for the manufacture of hollow cylindrical parts from thin-walled welded tubular billets, such as sleeves of milking machines.

A known method of manufacturing cylindrical hollow parts from tubular blanks, in which one end of the tubular billet is crimped in a die with a sliding support to obtain a curvilinear shape.

A disadvantage of the known method is that it does not provide the required quality of parts when crimping welded pipe billets that have reinforcement of a weld on the inner surface. In this connection, between the inner surface of the pipe and the mandrel it is necessary to provide a gap, the value of which must be greater than the height of the reinforcement of the weld. The presence of the gap and the axial force leads to the loss of stability of the tubular billet during crimping, which is expressed in the formation of bumps on the cylindrical part near the crimped end of the pipe.

The closest to the proposed invention of the technical essence and the achieved positive effect is the method of making cylindrical hollow parts from tubular blanks, in which one end of the blank is compressed at several technological transitions before obtaining the bottom of a curvilinear form in dies with a radial external support.

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The disadvantage of the known method is that it does not provide the quality of processing of thin-walled welded pipes due to the formation of corrugations on the cylindrical part of the part. This is due to the fact that the axial force arising during the shaping of the curvilinear bottom exceeds the carrying capacity of the cylindrical shell.

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The aim of the invention is to improve the quality of processing by eliminating corrugated formation by reducing the force acting on the non-deformed section of the pipe.

This goal is achieved by the fact that in a known method of manufacturing hollow parts from welded pipe blanks, in which a pipe is installed in a die with a radial external support, the end portion of the pipe is compressed using a mandrel to obtain a curved shape according to the invention. The pressed and uncompressed areas are clamped, and the reduction is performed from the side of the deformable pipe end, forming a thickened annular section with its abutment at the end of the mandrel.

Fig. 1 shows the implementation of the proposed method for manufacturing hollow articles from welded tubular billets; in fig. 2 - pipe to crimp; in fig. 3 the same, at the time of the beginning of crimping; in fig. M is the same at the time of crimping.

Example. According to the proposed method, the teat cup sleeve OD00.815 is manufactured from a welded pipe with a diameter of 2 mm. Material - 08X17T stainless steel. The sleeve has the following dimensions: the outer diameter of the cylindrical part is k2 mm, the wall thickness is 2 mm, the inner diameter of the cylindrical part is 38 mm, the part height is 1 mm, the radius of the spherical part is 20 mm, the diameter of the central hole in the bottom is 18 mm, diameter side opening 7.5 mm. The pipe is cut into workpieces 172 mm long. The punching is carried out on a SIL 160 crank press with a force of 1600 to

The blank 1, which is a 2 "2 piece of pipe with a length of 172 mm, is mounted on the base 2 and fixed along the inner surface by a mandrel 3 with a clearance of 0.55 mm. External radial backing is carried out with the aid of a sectional holder "Closure of sections of the dowel M occurs with the help of wedges moving from the upper plate of the stamp, and opening for

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the effect of springs (lower, upper die plate and springs are not shown in figure 1). When the press ram moves downward, the crimping die 5 first moves the yoke C downwards and then begins to crimp the end of the workpiece 1. When the pipe wall is crimped in the plastic deformation center, it bends along an arc of a circle having a radius equal to the radius of the spherical surface of the die 5, i.e. 20 mm (fig.). Upon further downward movement of the matrix, the volume of the metal (in Fig. 4, hatching) is displaced in the radial direction onto the flat end of the mandrel, forming an annular section 6. The annular section 6 perceives a part of the crimping force, transferring it to the mandrel 3. In this case, the undeformed wall is unloaded pipes, which eliminates the formation of corrugations, i.e. improves processing quality.

Thus, the proposed method provides, in comparison with the prototype, the possibility of obtaining hollow cylindrical parts with one of the thin-walled welded pipe blanks, eliminates the loss of stability, which consists in forming corrugations on the cylindrical part of the part, i.e., improves the quality of machining of parts and reduces scrap by 6-7% .

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Claims (1)

Invention Formula A method of manufacturing hollow parts from welded tubular billets in which the pipe is installed in a die with a radial external support and compresses the end portion of the pipe using a mandrel to obtain a curved shape, characterized in that, in order to improve the quality of processing by eliminating corrugation by reducing effort, acting on the non-deformable section of the pipe, the wall at the border of the compressed and uncompressed sections is clamped, and the compression is performed from the side of the deformable end of the pipe, forming a thickened circular section Stock focusing it in the end face of the mandrel, FIG. I FIG. 2 Fig.Z