SU93658A1 - Single acting hydraulic presses - Google Patents

Description

The invention relates to devices for clamping sheet blanks for deep drawing on hydraulic presses of simple action.

Existing devices of the same designation have the same status code; that air compensators that require compressed air are used to provide constant clamping force.

The proposed clamping device does not require compressed air. In this device, in order to achieve a constant clamping force, the working cavity of the cylinder (above the piston) is connected to the cavity under the piston and to the oil reservoir by means of an adjustable safety valve.

In order to automatically fill the working cavity of the cylinder with oil during the return stroke of the piston, it is connected to the front cavity and the reservoir by means of a check valve.

Fig. 1 shows schematically a hydraulic device for clamping sheet billet during deep drawing on presses of simple operation; on

FIG. 2 is a schematic of the installation of a prim. YcTpoiicTBa in the press.

The device (Fig. 2) consists of hydraulic dilirov / mounted on a slider 2 iipecca. The plungers 3 are rigidly connected to the folding device 4, which presses the fox blanks 5, which is placed between the punch bar and the punch 6 II l; the atrix 7.

During the working cycle of the press hydraulic cylinders 1 with the necessary force, the value of the TO-jioro can be adjusted by the operator, which is applied to the storage bin.

P) The efficiency of the operation of the clamping device is as follows.

The cavities of the cylinder / (Fig. 1), upper and H11lp, are connected by a pipe line -M aa, in which the safety valve A is installed with an adjustable spring. When lowering, the folding holder reaches the surface of the workpiece a little earlier than the punch. Upon further lowering of the press ram, fluid from the upper cavity of the cylinder 1 is bypassed into the lower cavity through Valve A.

The pressure of the fluid, and therefore the clamping force, depends on the adjustment of the spring tightening of the valve A, since the volume of the upper cavity of the cylinder is larger than the volume of the lower cavity, the excess liquid flows into the tank 8 along

pipeline c. |.

The lower and upper cavities of the cylinder are also connected by an esi pipe with a non-return valve that allows only the liquid to flow to the upper cavity.

When the press creep is returned to the upper position, the piston 2 lowers under its own weight, and the liquid flows through the 0v1 pipeline into the upper cavity. The opening of the valve occurs under the pressure of the fluid created in the lower cavity of the cylinder under the action of the piston weight.

The volume is not sufficiently liquid at the same time into the upper cavity of the cylinder from the tank 8. In addition, the tank 8 is designed to compensate for leakage of fluid from the system.

Subject invention

Claims (2)

1.Hydraulic single-action presser is simultaneously a safety device against water hammer punching for failure, using an oil-filled hydraulic cylinder with a piston, characterized in that, in order to achieve a constant clamping force, the working cavity of the cylinder is connected with front cavity and with oil reservoir by means of an adjustable safety valve. 2. The form of the device according to claim 1, characterized in that, in order to automatically fill the working cavity of the cylinder with oil during reverse of the piston, the working cavity is connected to the front cavity and the reservoir by means of a check valve. hh- r-f fl- I WITH. UN P, J f, „™ l1 t C AND/ p: s: sS V2