Dual- differential circuit of hydraulic press

Abstract

The invention relates to a dual-differential circuit of a hydraulic press. The dual-differential circuit comprises an oil cylinder, an oil pump and an oil tank, wherein the oil cylinder is vertically arranged, a lower cavity of the oil cylinder is connected with the oil pump through an oil pipe, and the oil pump is connected with the oil tank through the oil pipe. The dual-differential circuit of the hydraulic press is characterized by further comprising an electromagnetic valve and a differential valve, wherein a first oil outlet of the differential valve is connected with an upper cavity of the oil cylinder through the oil pipe; a second oil outlet of the differential valve is connected with the lower cavity of the oil cylinder through the oil pipe; a control port of the differential valve is connected with an oil outlet of the electromagnetic valve through the oil pipe; an oil inlet of the electromagnetic valve is connected with the oil pump through the oil pipe; an oil return opening of the electromagnetic valve is connected with an oil tank through the oil pipe; and the oil inlet of the electromagnetic valve is connected with the lower cavity of the oil cylinder through the oil pipe. With the adoption of the dual-differential circuit of the hydraulic press, rapid oil compensation for the upper cavity of the oil cylinder can be performed without a prefill valve during quick descending; and oil mass required by rapid oil compensation for the upper cavity of the oil cylinder during quick return stroke further can be realized when oil in the oil tank is less and the oil discharge quantity of the oil pump is smaller.

Description

technical field

[0001] The invention relates to a hydraulic press circuit, in particular to a double differential circuit of a hydraulic press for controlling the rapid downstroke and rapid return of a piston in a vertically installed oil cylinder of the hydraulic press. Background technique

[0002] As we all know, due to certain functional requirements, the piston in the vertically installed cylinder of the hydraulic machine needs fast downward and fast return strokes, which usually requires speeding up the circuit of the hydraulic machine.

[0003] At present, the speed-increasing circuit of hydraulic presses used in the industry includes oil cylinders, full displacement oil pumps, oil tanks, and filling valves. When the piston in the cylinder of the speed-increasing circuit of this hydraulic press descends rapidly, the upper chamber of the oil cylinder quickly replenishes oil and the lower chamber of the oil cylinder quickly discharges oil. When the piston in the oil c...

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