Backpressure and rapid pressure-relieving control device for hydraulic cylinder

Abstract

The invention discloses a backpressure and rapid pressure-relieving control device for a hydraulic cylinder. The control device comprises an oil supply device, an overflow type cartridge valve, a main oil line directional control valve, a check valve and a pressure controlling module, wherein the LB port of the overflow type cartridge valve is conducted with the oil supply device; the LA port of the overflow type cartridge valve is conducted with a first work port of a hydraulic cylinder set; the return opening of the main oil line directional control valve is conducted with the oil supply device; the first work port of the mail oil line directional control valve is conducted with the connecting part of the LA port of the overflow type cartridge valve and the first work port of the hydraulic cylinder set; the second work port of the mail oil line directional control valve is connected with the second work port of the hydraulic cylinder set; the input end of the check valve is connected with the returning opening of the main oil line directional control valve; the output end of the check valve is connected with the second work port of the main oil line directional control valve; and the pressure controlling module is connected between the LX port of the cartridge valve and the oil supply device. In the invention, the backpressure of the hydraulic cylinder is controlled flexibly, and high-precision and large-flow control can be realized easily; and the control of the backpressure of the hydraulic cylinder is separated from safety protection function, and the device has excellent safety protection function at any time and has stronger adaptability.

Description

technical field [0001] The invention relates to the technical field of injection molding, in particular to a hydraulic cylinder back pressure and rapid pressure relief control device. Background technique [0002] Injection molding machinery is an automated production equipment that manufactures products through molding methods, and generally consists of mold clamping mechanisms, injection mechanisms, and hydraulic and electrical systems. For the mechanical design of the injection mechanism, most manufacturers at home and abroad adopt a coaxial and symmetrical arrangement, that is, the injection cylinders are symmetrically distributed on both sides of the screw, and the screw and the melting motor are coaxial and linked through a transmission device. In normal production, because the axial movement of the screw and the piston rod of the injection cylinder is carried out synchronously, the back pressure of the screw is realized by the oil return of the injection cylinder cont...

Images