Electro-hydraulic control system capable of achieving ultralow-speed stable running of hydraulic machine

Abstract

The invention discloses an electro-hydraulic control system capable of achieving ultralow-speed stable running of a hydraulic machine. The electro-hydraulic control system mainly comprises a hydraulic pump, an overflow valve, a check valve, a three-way flow control valve, a first two-way ball valve, an adjustable fluidic resistor, a second two-way ball valve, a third two-way ball valve, a supporting valve, a main hydraulic cylinder and a return cylinder. At the ultralow-speed feeding stage of the hydraulic machine, the electro-hydraulic control system has a route of hydraulic oil entering the return cylinder through the hydraulic pump, the check valve, the adjustable fluidic resistor and the second two-way ball valve all the time, and therefore a certain opening can still be kept at the ultralow-speed feeding stage of the hydraulic machine, the unstable phenomenon that the hydraulic oil is intermittent when the flow is too small is avoided, and stability of the ultralow-speed running of the hydraulic machine is ensured. The three-way flow control valve is arranged on an oil inlet route of the main hydraulic cylinder, and therefore the oil inlet flow of the main hydraulic cylinder can be effectively controlled at the ultralow-speed feeding stage, and it is ensured that the hydraulic machine can run according to a preset displacement-speed curve or a displacement-pressing force curve.

Description

technical field [0001] The invention relates to an electro-hydraulic control system for realizing ultra-low-speed stable operation of a hydraulic press, in particular to an electro-hydraulic control system for ultra-low-speed operation of an isothermal forging hydraulic press. Background technique [0002] Hydraulic presses, especially isothermal forging hydraulic presses, usually require ultra-low speed operation due to their specific working conditions. Due to the ultra-low-speed working stage (up to 0.001mm / s), the discharge flow rate of the return cylinder is very small, which is not enough to maintain a certain opening of the support valve, which leads to the unstable state of the support valve being open and closed. This makes the running speed of the main hydraulic cylinder and the slider unstable under this working condition, which destroys the grain flow law inside the workpiece and affects the molding quality of the workpiece. How to make the hydraulic press still...

AI Technical Summary

Problems solved by technology

Due to the ultra-low-speed working stage (up to 0.001mm / s), the discharge flow rate of the return cylinder is very small, which is not enough to maintain a certain opening of the support valve, which leads to the unstable state of the support valve being open and closed. This makes the running speed of the main hydraulic cylinder and slider unstable under this working condition, which destroys the grain flow law inside the workpiece and affects the molding quality of the workpiece.

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