Electric closed-loop control flow control valve

Abstract

The invention discloses an electric closed-loop flow control adjusting valve. A displacement sensor is coaxially arranged on a main valve core to detect the main valve core displacement; output signals of the displacement sensor are input to a measuring amplifier, and are transformed and amplified by the measuring amplifier to generate feedback signals; the feedback signals are input to a subtracter, the subtracter receives command signals and the feedback signals of control valve opening, the command signals and the feedback signals are subtracted to obtain a deviation signal which is input to closed-loop control equipment; the deviation signal is corrected by the closed-loop control equipment and is input to an adding device; a feedforward controller receives the command signal and corrects the deviation signal, the deviation signal is input to the adding device; and the adding device performs adding operation on output signals which are output by the closed-loop control equipment and the feedforward controller, and the added signals are input to a proportional amplifier to control output force of an electromechanical transducer. An electric closed loop channel is superimposed on an inner mechanical feedback path; when the displacement sensor or the displacement measuring amplifier is abnormal, the valve opening quantity is still can be controlled successively; and the normal operation of the valve system is guaranteed, the reliability of the system is improved, and the control precision and response speed are improved obviously.

Description

technical field [0001] The invention relates to an electro-hydraulic proportional flow control valve in a hydraulic control element, in particular to a flow regulating valve which adopts an electric closed-loop principle to continuously control the flow entering a hydraulic actuator. Background technique [0002] The two-way proportional throttle valve is an important flow control element in the electro-hydraulic system. In the application requiring large flow, the pilot control type structure is often used. Early pilot-controlled proportional throttle valves used the principle of internal mechanical feedback to control the opening of the main valve. core displacement—pilot valve displacement follow-up principle, etc., but due to the internal mechanical feedback principle, the control precision of the valve is low and the dynamic response is slow. Proportional throttle valve controlled by electric closed loop. The existing electrical closed-loop control proportional thrott...

AI Technical Summary

Problems solved by technology

The existing electrical closed-loop control proportional throttle valve removes the internal mechanical feedback link of the original proportional throttle valve, and there is only one electrical feedback channel between the displacement of the main spool and the set value. When the amplifier fails, the valve is in an open-loop control state, and the valve port is fully opened, losing continuous control function and may lead to accidents

In addition, the existing proportional throttle valves all use proportional electromagnets as electro-mechanical converters, so the cost is very high

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