SU858977A1 - Apparatus for flanging holes in sheet materials - Google Patents

Description

(54) DEVICE FOR DRAWING HOLES IN SHEET MATERIAL

one

The invention relates to the processing of metals by pressure, in particular, to devices for flanging holes in a sheet material.

A device for flanging a hole pre-punched in a sheet material is known in which radial compressive loads are applied to the hole edge by a cone in contact with the edge of the workpiece and moving towards the punch 1.

A disadvantage of this device is the small height of the flanged part of the part to be stamped, due to the fact that it does not allow obtaining large degrees of deformation. Due to the action of tangential tensile stresses, destruction along the edge of the hole can occur, and the workpiece can be turned in the area of the hole.

The closest to the proposed by its technical essence and the achieved effect is a device for flanging holes in the sheet material, containing a matrix and a punch with hydraulic

A cavity in which a high-pressure plunger is placed, with which a preformed billet with a punched hole is beaded by the pressure of a liquid applied radially to the edge of the hole 2.

The disadvantage of this device is the low height of the flanged part of the shaded part. This is due to the fact that for a given area of the plunger and a certain pressure of the fluid, a definite amount (volume) of working fluid during the flanging can be fO displaced, thereby producing a part with a certain bead height. In order to increase the height of the bead, it is necessary to displace an additional volume of liquid, which is not allowed to make this device 15.

The purpose of the invention is to increase the height of the flanged part of the stamped part.

This goal is achieved by the fact that a device for flanging holes in the sheet material, containing a matrix and

A punch with a hydraulic cavity in which a high-pressure plunger is placed is provided with an additional container filled with pressurized fluid and connected through a non-return valve to the hydraulic cavity, and the plunger is spring-loaded to the punch in the axial direction.

The drawing shows the device, General view, in longitudinal section.

The device comprises a matrix 1, a plunger 2 with a hydraulic cavity 3, a high-pressure plunger 4 housed therein, spring-loaded with a spring 5 in the axial direction, and an additional container 6 filled with an overpressure fluid and connected through a non-return valve 7 with the cavity 3.

The device works as follows.

The preformed billet 8 with a hole in the bottom part is clamped between the die 1 and the punch 2. With a working stroke of the press slide (not shown) under the action of the plunger 4, the fluid, acting on the edge of the hole, dispenses the latter. At the same time, the material of the bottom of the molded area is squeezed out into the annular gap between the die 1 and the punch 2. Then, when the press slide is raised, the plunger 4 returns to its original position under the action of the spring 5. Due to the formation of a discharge in the cavity 3, the check valve 7 is activated and the fluid in the tank 6 under a certain excess pressure P enters the cavity 3. The process is repeated until then.

until the required depth is obtained.

In the proposed device for several strokes of the plunger can be displaced the required volume of fluid, which provides an increase in the height of the flanged part of the stamped part.

Claims (2)

1.Glazkov V.I., Ershov V.I., Kashchirin M.F., Pashkevich A.G. and Khropusov V.S. Catalog of special stamps for bending, dispensing and crimping. Perm book publishing house, 1977, p. 21-23. 2. USSR author's certificate No. 719749, cl. In 21 D 19/00, 1978 (prototype).