RU1803222C - Method for bending sheet blanks - Google Patents

Abstract

Usage: when bending sheets of ship skin. SUMMARY OF THE INVENTION: Radial crimping on stops is used along edges prone to side curvature. The stops are beveled towards the middle of the workpiece. 2 C.p. f-ls, 2 ill.

Description

The invention relates to the processing of metals by pressure and can be used in the manufacture of sheet metal parts on bending presses.

The purpose of the invention is to improve the quality by reducing the curvature of the generatrix and preventing cracking on. ends of the product.

In FIG. 1 shows a diagram of bending in a stamp; in FIG. 2 - longitudinal section of the stamp.

The following notation is adopted in the drawings: 1 — matrix supports; 2 - base; 3 - punch; 4 - blank; 5 - coasters; and - a corner of a bevel of coasters.

The sheet blank 4 is placed on the matrix supports 1, placed on the base 2, interacting with the punch 3. From the bottom of the workpiece between the matrix supports 1 along the bend line, on the end sections on the base 2, supports 5 are installed that create back pressure at the final moment of the deformation cycle.

. Bending is performed as follows. The blank 4 is laid on the matrix supports 1 and cyclic deformation is carried out. First, by pressing the punch 3 a little less (2-3 mm) than required, check for the presence of curvature and dents on the generatrix, then adjust the installation height of the supports 5 and make the specified curvature with the final pressure, creating back pressure at the end sections , bringing it to plastic crimping, getting the product without warping generators. Then the workpiece progressively moves along its longitudinal axis by a step approximately equal to 1/4 of the distance between the matrix supports and the bending process is repeated.

Usage Example. A sheet of steel with a size of 42x2000x9000 mm is bent to a cylindrical shape with a radius of 2.7 m. In the usual method of bending, the reverse bending of the butt edges of parts reaches 5-6 mm, which requires fine-tuning with the use of gaskets to straighten the generators along the edges. Finishing each detail takes up to 50% of the labor intensity of bending. When used on a universal stamp with a distance between supports of 420 mm, supports 60 mm high with a bevel of 6 °, the deviation of the generators from the ruler did not exceed 1 mm, the edges were wrinkled

ate

with

Ltd

SA) GO GO YOU

less than 1 mm. Lapping is completely eliminated.

Claims (3)

SUMMARY OF THE INVENTION 1. A method of bending sheet blanks, comprising stepwise movement and cyclic deformation of the sheet blank with a punch on two backpressure matrix supports along the bend line, characterized in that, in order to improve quality by reducing the curvature of the generatrix and eliminating formation cracks at the ends of the article, back pressure along the bending line is applied at the final moment of the deformation cycle at the end sections of the bending line, leading to plastic crimping. 2. The method according to claim 1, characterized in that the back pressure is smoothly reduced from the maximum value at the edges of the workpiece to zero. 3. The method according to claim 2, characterized in that the crimping at the end sections is carried out on a length of not more than 2 mm.