Modeling and simulation analysis of a novel proportional water flow valve with a digital pilot stage

The position straightness of the hydraulic supports is the key factor to the intelligent fully mechanized mining, and the adjacent cylinder is the actuator used to pull the hydraulic support. However, the control component of the adjacent cylinder is electromagnetic on/off valve that cannot control the movement of adjacent cylinder proportionally. Therefore, a novel proportional water flow valve with a digital pilot stage is proposed to control the trajectory of adjacent cylinder precisely. The novel valve consists of a dual active cartridge main valve and a digital pilot valve that includes a high speed on/off valve A (HSV-A) and a throttle valve piloted by the high speed on/off valve B (HV-B). A coupling dynamic mathematical model of the flow valve is formulated and the dynamic characteristics of the valve is analyzed theoretically. The fluctuation of the throttle valve and main spool motion is also analytically calculated. In addition, the influences of the control parameters and key structural parameters on the throttle valve and the main valve's motion are analyzed on the basis of AMESim simulation respectively. The simulation results have demonstrated that the displacement fluctuation of the valve can be reduced by increasing the control frequency. The throttle valve closed-loop displacement fluctuation is about 0.2 mm and 0.1 mm when the control frequency is 100 Hz and 200 Hz. What's more, decreasing the main valve orifice diameter can also effectively lower the main valve displacement fluctuation, while it will diminish the main valve response speed at the same time.