RU2292976C2 - Method for drawing parts of sheet material (variants) - Google Patents

Abstract

FIELD: sheet forming processes and equipment.

SUBSTANCE: method comprises steps of pressing edge portion of blank and further pulling-in of edge portion of blank to gap between punch and die. According to first variant after pressing edge portion of blank, in central portion of blank recesses are formed at preliminarily defining blank surface due to thinning material. Then at the same transition defined surface of blank is smoothed and pulled-in and simultaneously edge portion of blank is pulled-in to gap between punch and die for forming wall of three-dimensional part. According to second variant edge portion of blank is pressed and further pulled-in to gap between punch and die at press stroke downwards. After pressing edge portion of blank, initial stage of drawing is realized by non-full depth of part. Then recesses are formed in blank central portion and preliminary blank surface is defined due to thinning material. At final stage of drawing defined surface of blank is smoothed and pulled-in and simultaneously edge portion of blank is pulled-in to gap between punch and die for forming wall of three-dimensional part.

EFFECT: lowered labor consumption of drawing process, improved quality of drawn part due to increased limit depth of drawing.

2 cl, 2 dwg

Description

The invention relates to the field of sheet stamping and can be used to extract various parts from sheet materials. The primary area of application is stamping of car body parts, agricultural machines and other equipment.

There is a method of extracting parts with a clamp from a piece of flat workpiece, in which the edge part of the workpiece is pressed first, and then this edge part of the workpiece is pulled into the gap between the punch and the die to form the wall of the spatial part (Romanovsky V.P. Handbook of cold stamping. L .: Mechanical engineering, 1979, p. 86, table 29).

The disadvantage of this method is the small limit depth of the hood, and when you try to pull the part of greater depth, the workpiece ruptures. Dividing the process of drawing a deep part into several transitions increases the complexity, reduces the stamping performance and worsens the surface quality of the drawn part, since there are traces (prints) from the bending and straightening places of the workpiece during shaping.

In addition, when carrying out the known drawing process, the central part of the workpiece after contact with the working surface of the punch practically stops stretching (friction forces prevent this), which leads to the need to unnecessarily increase the size of the workpiece and the rate of consumption of sheet material.

An object of the invention is to reduce the complexity of the drawing process and improve the quality of the manufactured parts.

The technical result of using the proposed technical solution is to increase the maximum depth of the hood and save sheet material.

The specified technical result can be implemented in two ways.

Option 1.

The technical result is achieved due to the fact that when drawing parts from sheet material by a method in which the edge part of the workpiece is pressed first, then this edge part of the workpiece is pulled into the gap between the punch and the die in order to increase the maximum drawing depth and to save sheet material , immediately after pressing the edge of the workpiece, they form the recesses in the central part of the workpiece, providing a preliminary set of the surface of the workpiece due to the thinned Material, and then, at the same transition of the hood, smoothing and retracting the accumulated surface of the workpiece simultaneously pulling the edge of the workpiece into the gap between the punch and the matrix, with the formation of the wall of the spatial part.

Option 2

The technical result is achieved due to the fact that when drawing parts from sheet material by a method in which the edge part of the workpiece is pressed first, then this edge part of the workpiece is pulled into the gap between the punch and the die in order to increase the maximum drawing depth and to save sheet material , pressing the edge of the workpiece and further retracting the edge of the workpiece into the gap between the punch and the die is carried out during the slide of the press down, while after pressing the edge hour and the blanks carry out the initial stage of drawing to an incomplete depth of the part, and then forming the recesses in the central part of the workpiece, providing a preliminary set of the surface of the workpiece by thinning the material, and then at the final stage of drawing, smoothing and retracting the accumulated surface of the workpiece, while simultaneously retracting the edge of the workpiece into the gap between the punch and the die, with the formation of the wall of the spatial part.

A preliminary set of surface in the central part of the workpiece allows you to increase the maximum depth of drawing, and additional thinning of the central part of the workpiece during the formation of recesses and a set of surfaces allows you to reduce the size of the workpiece and thereby save sheet material.

The essence of the proposed method is illustrated by drawings.

Option 1.

On figa shows an axial longitudinal section of a stamp for implementing the method on a press of simple action at the time of completion of the formation of the recesses in the Central part of the workpiece 1 (to the left of the axis of the stamp) and at the end of the drawing process (to the right of the axis of the stamp).

In Fig. 1c, the punch is fixed at the top on the slider of a simple-action press, and the matrix is fixed below, on a stationary table of the press.

Option 2

On figa shows an axial longitudinal section of a stamp for implementing the method on a press of simple action at the time of completion of the formation of the recesses in the Central part of the workpiece 1 (to the left of the axis of the stamp) and at the end of the drawing process (to the right of the axis of the stamp).

On figv the punch is fixed at the top on the slider of a press of simple action, and the matrix is below, on a stationary table of the press.

The stamp for carrying out the method comprises: a blank 1, a punch 2, fixed at the bottom on a stationary table of the press, a matrix 3, mounted at the top on the slider of the press, a clamp 4, which, through the pusher 5, rests on the pillow of the press (not shown), the piston 6 and the auxiliary punch 7 .

The method is as follows.

Option 1.

During the slide of the press down, the edge of the workpiece 1 is pressed between the pressing surfaces of the matrix 3 and the clamp 4. At this moment, under the action of a high-pressure liquid (compressed air, levers or other means), the piston 6 and the auxiliary punch 7 rigidly connected with it are moved, which carries out the formation of recesses in the Central part of the workpiece 1 due to plastic stretching and thinning of the material (figa, b, left). Next, the auxiliary punch 7 is returned to its original position and, during the further course of the press slide, downward, smoothing and retracting the accumulated surface of the workpiece while pulling the edge of the workpiece into the gap between the punch 2 and the matrix 3, with the formation of the wall of the spatial part.

During the press slide upward, the elongated part is removed from the punch 2 by the clamp 4 and pushed out of the matrix 3 using the piston 6 and the auxiliary punch 7 (Fig. 1a, c, to the right).

Option 2

When the press slider moves down, the edge of the workpiece 1 is clamped between the pressing surfaces of the matrix 3 and the clamp 4 and the initial stage of drawing to an incomplete depth of the part. Then, under the action of a high-pressure liquid (compressed air, levers, or other means), the piston 6 and the auxiliary punch 7 rigidly connected with it are moved, which performs the formation of recesses in the central part of the workpiece 1 due to plastic stretching and thinning of the material (Fig.2a, left). Next, the auxiliary punch 7 is returned to its original position and, during the further course of the press slider down at the final drawing stage, smoothing and retraction of the gathered workpiece surface is carried out simultaneously with retraction of the edge part of the workpiece into the gap between the punch 2 and matrix 3, with the formation of the wall of the spatial part.

During the press slide upward, the elongated part is removed from the punch 2 by the clamp 4 and pushed out of the matrix 3 using the piston 6 and the auxiliary punch 7 (Fig. 2a, c, to the right).

Instead of the auxiliary punch 7, the depressions can be formed in the central part of the preform by other methods, for example, using elastic media (rubber, polyurethane, liquid, compressed air, gas, etc.) or a magnetic field.

Thus, this method, in comparison with the known, provides an increase in the ultimate degree of deformation of the workpiece and the possibility of using the workpiece of smaller sizes.

Similarly, this drawing method is implemented on double and triple action presses.

Claims (2)

1. A method of extracting parts from sheet material, including clamping the edge of the workpiece and further retracting the edge of the workpiece into the gap between the punch and the die, characterized in that after pressing the edge of the workpiece, the depressions are formed in the central part of the workpiece with a preliminary set of the workpiece surface for due to thinning of the material, and then at the same transition of the hood, smoothing and retracting the accumulated surface of the workpiece and simultaneously retracting the edge part blanks in the gap between the punch and the matrix with the formation of the wall of the spatial part. 2. A method of extracting parts from sheet material, including clamping the edge of the workpiece and further retracting the edge of the workpiece into the gap between the punch and the die, characterized in that the pressure of the edge of the workpiece and further retracting the edge of the workpiece into the gap between the punch and the die is carried out during the press slider down, while after pressing the edge of the workpiece, the initial stage of drawing to an incomplete depth of the part is carried out, then the depressions are formed in the central part of the workpiece with By preliminarily collecting the surface of the workpiece by thinning the material, and then at the final stage of drawing, smoothing and retracting the accumulated surface of the workpiece and simultaneously pulling the edge of the workpiece into the gap between the punch and the matrix with the formation of the wall of the spatial part.

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