SU1430141A1 - Method of manufacturing hollow articles from sheet blank - Google Patents

Abstract

The invention relates to the processing of metals by pressure and can be used in mechanical engineering in the drawing of new products from sheet blank. The goal is to increase the height of the stretchable product by reducing the frictional forces on the surface of contact of the workpiece with the clamp. Before filling the central part of the workpiece 1 with lubricant on its edge part, on the side opposite to the existing thickening, an additional annular thickening forms, the size of which is 0.1-0.25 of the thickness of the blank 1. When stretched due to an increase in pressure, the lubricant separates the contact surface of the workpiece 1 with the clamp 4, reducing the force of friction on this surface. The lubricant has a viscosity that prevents it from running off the workpiece prior to the start of the stretching process. 1 hp f-ly, 5 ill.

Description

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The invention relates to the processing of metals by pressure and relates to methods for drawing hollow articles from sheet blank.

The purpose of the invention is to increase the height of the stretchable products by reducing the frictional forces on the surfaces of contact of the workpiece with the clamp.

FIG. 1 shows schematically a device for carrying out the method, a longitudinal section (to the left of the axis of symmetry, the initial position, to the right, at an intermediate drawing time); in fig. 2 - initial blank; in fig. 3 - billet with a curled edge; in fig. 4 is a diagram of the formation of nodules; in fig. 5 - billet with thickening, filled with lubricant.

In the drawings, the following notation is accepted: the workpiece being stretched 1; finished product 2; extension matrix 3; clamp 4; stop 5; pulling punch 6; seal 7; 8 holes in the clamp; cavity 9 in the clamp; calibration punch C); calibration matrix 11.

The method is carried out in the following manner.

Before starting the stretching process, the initial flat billet 1 having dimensions So and Do is cut down (Fig. 2). Then, along the contour of the workpiece 1, one-sided embedding by curling (Fig. 3) is formed by its edge part. After that, using the calibration punch 10 and the calibration matrix 11 on the edge h, the parts of the workpiece 1 on both sides form colpeal thickenings. The size of the plate P1 on one side is equal to two or three tarpards of the workpiece 1, and on the other - 0.1-0.25 of its thickness. The thickening on the workpiece 1 can also be obtained, for example, by applying a paint coating, a low-melting solder, and polyethylene on a lathe. Next, the central part of the workpiece 1 is filled on both sides with lubricant, the viscosity of which excludes the free flow of the lubricant from the workpiece 1 before the start of the stretching process (Fig. 5). Wax, oxidized petrolatum, asphalt bitumen, paraffin and similar lubricant viscosity can be used as lubricants. After that, the workpiece 1 with the lubricant filled on both sides is placed on the matrix, with a thickening equal to two to three thicknesses of the workpiece facing the matrix 3 and pressing it down with the clamp 4. Due to the fact that the height of the support 5 is 10-15 / o less than thickening on the workpiece 1, it may nroizhodit his additional height calibration. When the punch 6 is exposed to the central part of the workpiece 1, the lubricant, filled with it from the side of the die 3, closes along the outer diameter and along the exhaust edge of the die 3, and the grease is filled

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and the central part of the workpiece 1 on the side of the clamp 4, closes along the outer diameter and but the surface of the seal 7. With further movement of the punch 6, the outer size of the peripheral part of the workpiece 1 continues to decrease and, accordingly, the areas of the workpiece 1, filled with with lubricant, which leads to an increase in pressure in the indicated volumes. As a result of the increase in pressure, the lubricant filling the central part of the workpiece 1 on the side of the matrix 3 is squeezed out of the floor in the workpiece 1 and separates the surface of the matrix 3 and the stretchable part 2, reducing the friction force on the contact of the matrix 3 - workpiece 1.

Simultaneously, the lubricant filling the central part of the workpiece 1 on the side of the presser 4, as a result of the growth in it, the pressure starts to be squeezed out onto the upper plane of the presser 4 through the openings 8, collected in the cavity 9 for reuse. The lubricant 7 prevents the lubricant from entering the gap between the clamp 4 and the punch 6. The holes 8 are located evenly around the clamp 4 of the punch 6, and they are located above the rounding hole of the die 3. This prevents the workpiece 1 from contacting the clamp 4 in the area of the holes 8 and, accordingly, the possibility of scoring in this area, even in those cases when the central part of the workpiece 1 is not filled with the lubricant for any reason (for example, when the worker is damaged) from the side of the clamp 4. During the normal process as the periphery of the workpiece 1 moves toward the center of the section. The lubricant is squeezed out through the holes 8, at the same time separating the surface of the presser 4 and the extruded part 2.

The proposed method compared with the known method provides an increase in the height of the parts to be pulled out by reducing the frictional forces on the surfaces of contact of the workpiece with the clamp.

Claims (2)

Invention Formula . A method of manufacturing hollow articles from sheet billet having an annular thickening on the edge portion equal to two to three thicknesses of the blank by filling its central part with a lubricant, pressing its peripheral part and exposing its central part to an elongating force. increasing the height of the stretchable products by reducing the friction forces on the surface of the contact of the workpiece with the clamp, before filling the central part of the workpiece with lubricant on its edge part on the side opposite to having eniyu form further circumferential thickening and filled it with grease having a viscosity excluding lubricant runoff prior to stretching. 2. Method of claim. 1, characterized in that the value of the additional thickening is 0.1-0.25 thickness of the workpiece. .2 fie.Z