In hydraulic control system, servo valve, as a high-precision and high-response control element, is widely used in aerospace, mechanical automation, industrial robots and other fields. Among them, the spring pair Chinese servo valve is a common type, and its structural design ensures that the valve core can automatically return to the neutral position when there is no control signal input, thus realizing the safety protection and stable control of the system. This paper will focus on the principle and operation method of spring resetting Chinese servo valve.
First, the basic structure and working principle of spring-aligned Chinese servo valve.
Spring-centered Chinese servo valve is mainly composed of valve body, valve core, electromagnetic coil, feedback mechanism and centering spring. During normal operation, the electric signal output by the controller is converted into magnetic force through the electromagnetic coil, which drives the valve core to move left or right, thus changing the flow direction of hydraulic oil and controlling the movement direction and speed of the actuator (such as hydraulic cylinder or hydraulic motor).
When the control signal is zero, the electromagnetic force disappears. At this time, the centering springs installed at both ends of the valve core work to push the valve core back to the mechanical neutral position. This structural design ensures that the hydraulic actuator can stop moving or return to a safe position in the case of power failure or signal loss of the system, so as to avoid equipment damage or safety accidents.
Second, the principle of spring resetting the Chinese servo valve
The resetting process of the spring to the Chinese servo valve mainly depends on the elastic force of the spring:
1. Spring-driven reset: When there is no control signal, the electromagnetic coil is not energized, and the spring force becomes the only driving force. Two symmetrically arranged springs act on both sides of the valve core respectively to make it return to the central position under the balance of force.
2. Mechanical limit protection: In order to prevent the spool from deviating too much from the neutral position, a mechanical limit device is usually provided to ensure that the spool can be limited within a reasonable range even under abnormal conditions, which is convenient for the spring to reset smoothly.
Third, the realization way of servo valve reset
1. Automatic reset: In the normal operation of the control system, when the electric signal returns to zero, the servo valve automatically resets by the spring. This is the most common and reliable way.
2. Manual reset: In some special occasions, such as system maintenance or debugging, it may be necessary to manually reset the spool to the neutral position. This is usually achieved by external mechanical devices or manual adjustment screws.
3. Forced reset: In case of failure (such as jamming and solenoid failure), forced reset may be required by external force or auxiliary means of hydraulic system, but this requires professional operation and attention to avoid damaging components.
Fourth, the factors affecting the reset performance
-Spring fatigue or damage: After long-term use, the spring may lose its elasticity or break, which will affect the reset effect.
-Worn or stuck valve core: impurities entering the valve body or long-term wear will cause the valve core to be stuck, and the spring cannot drive it to reset.
-Electromagnetic system failure: Although it does not affect the spring reset function, if the electromagnetic system is abnormal, it may lead to misoperation and affect the overall control effect.
tag
The reset mechanism of spring to Chinese servo valve is an important guarantee for its safety and reliability. In practical application, the spring state, the cleanliness of the valve core and the working condition of the electromagnetic system should be checked regularly to ensure the normal play of the reset function. Only by paying attention to all aspects of system design, installation and maintenance, can we give full play to the role of servo valve in high-precision hydraulic control system and ensure the stability and safety of equipment operation.