An electro-hydraulic proportional throttle valve and its control method

Abstract

The invention provides an electro-hydraulic proportional throttle valve and a control method thereof. The electro-hydraulic proportional throttle valve comprises a displacement sensor (1), a valve bush (6), a proportional directional valve (8), a main valve element (10), a valve body (12), an inlet pressure sensor (13), an outlet pressure sensor (17), a switching reversing valve (19), a main valvecover (20) and an operational amplifier module (21), wherein the valve bush (6) and the main valve element (10) are of a cylindrical structure; the valve bush (6) is mounted in an inner cavity of thevalve body (12); the main valve element (10) is sleeved by the valve bush (6); and the lower part of the displacement sensor (1) is mounted in the main valve element (10). The control method comprises the following steps: performing correlation among the main valve element (10) displacements, the inlet pressure and the outlet pressure of the throttle valve, and corresponding throttling coefficients of the corresponding valve element displacements through a fluid equation, and performing closed-loop control by an operational amplifier module (21). The control dead zones are small, and the control requirement on automation and intelligentization of a device is met.

Description

technical field [0001] The invention relates to a hydraulic system, more specifically to an electro-hydraulic proportional throttle valve and a control method thereof, belonging to the technical field of hydraulic control valves. Background technique [0002] As the control element of the hydraulic system, the hydraulic control valve usually requires its compact structure, simple operation, precise control, reliability and durability. [0003] The throttle valve in the hydraulic control valve is usually used to adjust the flow in the hydraulic system, and it often uses manual, hydraulic control, electric control or electro-hydraulic control to control the opening of the valve port to realize the adjustment function. The current manual and hydraulic control throttle valves are mainly based on open-loop control, the control accuracy is seriously affected by the load and system flow fluctuations, the control accuracy is low, it is difficult to realize remote control, and it is ...

AI Technical Summary

Problems solved by technology

The current manual and hydraulic control throttle valves are mainly based on open-loop control, the control accuracy is seriously affected by the load and system flow fluctuations, the control accuracy is low, it is difficult to realize remote control, and it is difficult to realize seamless connection with the electronic control system

However, the existing electro-hydraulic proportional throttle valve generally uses a standard two-way plug-in as the main valve stage, and the opening of the valve port controlled by the unit displacement of the valve core varies greatly. At the same time, due to the structural factors of the valve port, the hydraulic power and throttle coefficient The change is also very large, which makes the dead zone of the control large, the adjustment time of the dynamic response of the control is long, and it is difficult to use it in a fast and high-precision control system; The force mode is passive drive. Once the control stage fails, the entire valve port of the main valve stage will be fully opened, which will easily lead to damage to the host system; therefore, the existing electro-hydraulic proportional throttle valve has a certain limit in actual use.

It can be seen that as hydraulic equipment has higher and higher requirements for integration, there are more and more requirements for equipment automation and intelligent control, and the existing throttle valve is difficult to meet the demand. The need for safe and reliable throttle valves is becoming more and more urgent

Images