RU1778010C - Hydraulic press drive - Google Patents

Abstract

Usage: in hydraulic presses for the shoe and leather goods industry. SUBSTANCE: press drive contains working and return cylinders, accelerator, distributor with pilot pilot and control pump. In order to increase reliability and reduce energy costs, the control pump is connected to the cavity of the return cylinders by means of a check valve line, and the pump is connected to the accelerator cavity by means of a line with a charge valve. 1 ill.

Description

The invention relates to presses for the shoe and leather goods industry, and can also be used for other hydraulic presses.

A known hydraulic press control system comprising a pump with a drain tank, connected by a pressure line through a distributor with return cylinders and a boost cavity of a pressure transducer, a pressure cavity of which is connected to power cylinders, a pressure spool with a check valve, connected by an inlet to the forming and an outlet to the working cavity pressure transducer, as well as a control pump, with a hydraulic lock and an additional pressure spool with a check valve in series Credited on the line between the distributor and the cylinder return stroke, nasosupravleni connected through a check valve with a discharge pressure transducer and a cavity through the booster valve with the boost pressure transducer cavity and control cavity quick fit, and the working cavity is connected via a pressure transducer dvuhpozi- insulating valve with a drain tank.

The disadvantage of this system is the complexity of the circuit, the presence of a constant overpressure equal to the pressure necessary to control the valve, which leads to energy losses during the return stroke, and leaks in the return cylinder system (even within the permissible limits) lead to lowering the beam.

A hydraulic press is also known for punching shoe parts and other leather products and artificial materials.

In this press, it is difficult to adjust (spring selection) a controlled spring-loaded valve through which recharge in the open position is fed

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(replenishment of leaks), and when the viscosity of the working fluid changes, inevitable deviations from the normal operation of the system are observed.

The purpose of the invention is to eliminate the noted drawbacks., Increase reliability and reduce energy costs.

This goal is achieved in that, in the hydraulic press drive, the control pump is connected to the cavity of the return cylinders via a check valve line, and the pump is connected to the accelerator cavity through the line with a charge valve.

The drawing shows a diagram of a hydraulic press drive.

The hydraulic press drive comprises a main pump 1 with a safety valve 2, connected through a distributor 3 and a pressure hydraulic valve with a check valve 4 to the return cylinders 5, forming the cavity 6 of the accelerator 7 and through the valves of sequences 8 and 9 with the working cylinders 10.

The control pump 11 with the safety valve 12 through the filter 13 is connected with the control of the distributor 3 and through the check valve 14 with the return cylinders 5.

The working cylinders 10 are connected through a shut-off valve 15 to the working cavity 16 of the accelerator 7.

The hydraulic press drive operates as follows.

In the initial position, when the main pump 1 is turned on, the working fluid is supplied to the safety valve 2 and is discharged through the distributor 3. From the control pump 11, liquid is supplied to the safety valve 12, the distributor 3 and through the check valve 14 to the return cylinders 5.

When the left electromagnet of the distributor 3 is turned on, the working fluid from the pump 1 is supplied to the boost cavity b of the accelerator 7. From the working half 15, the fluid is displaced through the shut-off valve 15 into the working cylinders 10. From the return cylinders 5, the working fluid through the pressure hydraulic valve with check valve 4 and the distributor 3 enters the drain. There is an accelerated traverse 17 down.

When the cross member 17 reaches the working element (cutter), the pressure in the pressure line of the main pump 1 — distributor 3 — forcing cavity 6 of the accelerator 7 increases, the valve of sequence 8 adjusted to a pressure of 4-6 MPa opens, and the shut-off valve 15

tuned to a pressure of 2-2.5 MPa, disconnects the working cavity 16 of the accelerator 7 from the working cylinders 10 and the liquid from the pump 1 through the distributor 3, the valve of the sequence 8 is fed into the working cylinders 10. A working stroke occurs with maximum force.

After the end of the technological process, the left and right solenoid valves of the distributor 3 are turned off, as a result of which the distributor 3 is switched and the working fluid through the pressure hydraulic valve 6 with a check valve 4 enters the return cylinders 5.

From the working cylinders 10, liquid is supplied through the shut-off valve 15 to the working cavity 16 of the accelerator 7, thereby moving the movable piston 18 to the lower (according to the diagram) position, and excess liquid through the valve of sequence 9, adjusted to a pressure of 1.0-1.5 MPa and dispenser 3 is fed to the drain.

At the end of the return stroke, all devices are set to their original position.

The increase in reliability is ensured by the complete filling of leaks in the working cavity 16 of the accelerator 7 and the guaranteed lowering of the movable piston 18.

The reduction in energy costs is due to a decrease in pressure in the hydraulic system during the fast downstroke and the stroke.

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Claims (1)

The claims A hydraulic press drive comprising working and return cylinders, a pump with a drain tank and a control system including an accelerator with a small and large control cavities and an injection cavity connected to the working cylinders, a distributor with a pilot pilot, a pressure valve with a non-return valve, united by 5 with a small input and an output with a large accelerator control cavity, an additional pressure spool with a check valve installed on the line between the distributor and the return cylinders, a suction valve and a relief valve connecting the large control cavity of the accelerator to tank, and a control pump associated with the pilot of the distributor and the cavity of the control valve 5 relief, characterized in that, in order to increase reliability and reduce energy costs when cutting parts from leather and artificial materials fishing, the pump control is associated with the cavity by means of return cylinders mages They were equipped with a non-return valve, and the pump sv — by means of a line with a valve, is energized with a delivery cavity of the accelerator of the kidney.