RU2710616C1 - Method of extrusion of shell sheet parts by plastic medium - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention is intended for use in machine building and in aerospace engineering in production of shell parts from sheet blanks by deep drawing. Workpiece end surface is exposed to preformed lead to form a hole therein, causing workpiece deformation in the direction of the well. At further action of lead on central part of punching, it is turned into working cavity of rigid matrix until formation of part.

EFFECT: higher quality of parts due to reduced thinning in part wall.

1 cl, 5 dwg

Description

The invention relates to the processing of metals by pressure, and in particular, to methods for manufacturing hollow shell parts from sheet blanks with deep drawing and can be used in various industries.

There is a method of stamping hollow shell parts in which, in order to reduce thinning of the wall of the stamped part, the preform is preliminarily stamped on the fungus, the fungus is removed and the central part of the preform is turned out by pressing it against the working cavity of a rigid matrix (1, P. 79). The working cavity of the rigid matrix is the carrier of the shape of the part. The known method can significantly reduce thinning in the domed part of the part. However, the maximum depth of the stamped parts does not exceed the depth of the hemisphere. The flange part has a large length to prevent loss of stability of the non-pressed part of the workpiece.

The closest technical solution is the method of stamping-drawing of shell parts with plastic metal that we have chosen as a prototype (2). In the known method, pre-in the process of smoothing the lead profile it, forming a cavity. The workpiece is mounted on the surface of the rigid matrix, and during the working stroke of the press, the lead and the workpiece are pressed into the working cavity of the matrix. When the cavity collapses during stamping, additional useful friction forces are created between the lead and the workpiece, which unload the dangerous section, preventing its destruction.

However, the ingress of lubricant on the surface of lead by an order of magnitude reduces the friction coefficient and, as a result, the effect of pushing the workpiece into the working cavity of the matrix, which leads to thinning of the workpiece in a dangerous section and its subsequent destruction.

To solve the problem in the known method of stamping-drawing shell parts with plastic metal, the lead is pre-smoothed, it is profiled at the same time to form holes in it, the workpiece is laid on the surface of the rigid matrix, and during the working stroke of the press, the lead and the workpiece are pressed into the working cavity of the matrix, with exposure to lead it is squeezed onto the side part of the preform in the direction of the hole with the formation of a stamping, and then it is turned out by lead into the working cavity of the matrix.

The proposed technical solution allows you to pre-assemble the material in the central part of the stamped part, and then turn it out, thereby reducing thinning in the part walls when stamping conical animated spherical parts.

The essence of the technical solution is illustrated by the drawing, which shows:

- in FIG. 1 moment of the end of the profiling of the hole;

- in FIG. 2 moment of the beginning of stamping of the workpiece;

- in FIG. 3 moment of formation bulging into blanks;

- in FIG. 4 the end of the stamping process, after turning the stamping;

- in FIG. 5 stamped conical billet;

According to the proposed method of stamping-drawing shell sheet parts with a plastic medium, the stamping process is as follows.

Initially, ductile metal - lead 4 located in the container 1 is smoothed out and simultaneously profiled by a punch 2 having the shape of a working surface 3 corresponding to the shape of a hole during a working stroke of the press (see Fig. 1). The hole is formed so that the diameter of its base D is equal to the diameter Do of the workpiece, and the height of the cylindrical part of the hole S is equal to the thickness So of the stamped workpiece.

In FIG. 2 shows a stamp for implementing the proposed method in its initial position. In the initial position, the matrix 5 is installed and fixed on the table of the press (press conditionally not shown). The blank 6 is located on the matrix 5 and enters the cylindrical cavity D of the hole, because the diameter of the workpiece and its thickness are equal to the dimensions of the cylindrical part of the hole. The implementation of the working stroke of the press leads to deformation of the lead and its impact on the side part of the workpiece, that is, on the cylindrical surface of the end face of the workpiece and a narrow strip of the flat surface of the workpiece adjacent to the end face of the workpiece. As a result of this effect, the workpiece begins to bulge in the direction of the hole and form a stamping 7 in the workpiece (see Fig. 3). With a further working stroke of the press (not shown conditionally), the lead begins to press on the central part of the stamping 7, turning it into the working cavity of the matrix 5. In FIG. Figure 4 shows the stamp at the time of stamping, after the stamping process is completed, the stamp is opened and the part is removed from the matrix.

For example, stamping a conical part with a height of 70 mm, a diameter of a smaller base 50 mm. and a larger base of 70 mm from 08kp material, we consider the stamping-drawing process according to the proposed technical solution. The estimated diameter Do of the workpiece 6 is 300 mm, the thickness of the workpiece is 0.8 mm. We preliminary stamp the conical hole in the lead, the diameter of the base of which D is equal to the diameter of the workpiece Do, and the height of its cylindrical part at the base is equal to the thickness of the workpiece, i.e. 0.8 mm. Lubricate the workpiece on both sides with grease, for example, with I20 machine oil. Set the workpiece on the matrix 5 (Fig. 2) positioning it with an extruded hole. During the working stroke of the press, lead 4 begins to act on the side part of the workpiece 6, i.e. on the end face of the workpiece and a narrow strip of the flat surface of the workpiece adjacent to the end face of the workpiece, the size of which is not more than 1 mm, causing the process of buckling the workpiece 8 into the cavity of the hole. With the further course of the press, the buckling process stops, and the lead begins to contact the central part of the workpiece, turning the stamping out into the working cavity of the die 5. The stamping process is carried out until the workpiece is completely pressed against the work surface of the die 5. As shown by numerical calculations, if not lubricate the workpiece from the side of lead, then the flange is pinched with lead, which is the reason for the thinning of the part wall and its destruction. In FIG. 5 shows a stamped conical part.

Thus, the proposed technical solution allows to reduce thinning in the walls of the stamped part, to improve the quality of the part by stamping the workpiece into a hole in lead and then turning the workpiece into the working cavity of the matrix.

1. Melnikov EP Cold stamping bottoms. M.: Mechanical Engineering, 1986. 192 p.

2. E.S. Sizov, M.A. Baburin, Stamping of sheet parts of complex shape with plastic-elastic media KShP No. 8, 1994, from 9-11

Claims (1)

A method of stamping and drawing out shell sheet parts with a plastic medium, which is used as lead, including preliminary smoothing of lead, its simultaneous profiling with the formation of an extruded hole in it, placing a workpiece on the surface of a rigid matrix and pressing lead and a workpiece into the working cavity of the matrix during the working stroke of the press , characterized in that the lead is applied to the side part of the preform, squeezed out in the direction of the hole with the formation of stamping, and then twisted it was lead into the working cavity of the matrix by exposing the central portion vyshtampovki.

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