Internal circulation oil cylinder having built in logic valve

Abstract

An internal circulation hydro-cylinder is composed of piston, hydro-cylinder, piston rod and logic valve. The piston has axial channel for two oil cavities isolated by piston rod in hydro-cylinder of guide channel, the logic valve is set on one side of the piston and closely fixed on the piston rod to make high-pressure oil go into oil control chamber of the logic valve separately through channels set on the piston rod so valve bush is pushed to move the block or open of axial channel of the piston rod as oil in two oil cavities flows forward and back ward within internal circulation. It is not necessary to set external channel for oil circulation.

Description

Technical field [0001] The invention relates to a hydraulic device, in particular to a hydraulic oil cylinder used for injection molding machines, plastic molding machines, die-casting machines and hydraulic presses. Background technique [0002] Existing fully hydraulic injection molding machines use multiple oil cylinders to move, close, lock and open the mold. The logic valve of the hydraulic system controls the reciprocating movement of the cylinders. The two oil cylinders separated by the piston The oil in the cavity needs to flow back and forth into and out of the two oil cavities through the outer channel composed of oil ports, joints, pipes, etc., to complete the opening and closing of the mold. For injection molding machines with high precision and high speed requirements, in order to ensure the high-speed locking of the mold The mold clamping cylinder must be in a high-speed operating state, and the oil in its two oil chambers must flow back and forth at high speed...

AI Technical Summary

Problems solved by technology

[0002] Existing fully hydraulic injection molding machines use multiple oil cylinders to move, close, lock, and open the mold. The logic valve of the hydraulic system controls the reciprocating movement of the oil cylinder. The two oil cylinders separated by the piston The oil in the cavity needs to flow back and forth into and out of the two oil cavities through the outer channel composed of oil ports, joints, pipes, etc. to complete the opening and closing of the mold. For injection molding machines with high precision and high speed requirements, in order to ensure the high speed locking of the mold The mold clamping cylinder must be in a high-speed operating state, and the oil in its two oil chambers must flow back and forth at high speed through the outer channel, which will increase the oil temperature, consume pressure oil energy, and even reduce oil quality, affecting the normal operation of the hydraulic system. The outer channel of the oil is prone to leakage, so higher requirements are required for the material quality, sealing performance, and flow rate of the outer channel.

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