DIRECT DIGITAL CONTROL FOR 2D PRESSURE CONTROL VALVE

抄録

The 2D pressure control valve is a piloted pressure control valve designed with two motions of a single spool. The rotary motion combining a hydraulic bridge forms the pilot stage of the valve to control the pressure of a spool chamber, while another spool chamber is directly connected to the load pressure. The hydraulic bridge (pilot stage) is developed with the concept of pressure linear distribution along a damping pipe under small Reynolds Number and has a significant effect on both static and dynamic characteristics of the valve. The rotary motion of the spool is actuated by a digital electrical-to-mechanical interface. The interface mainly composed of a stepper motor connected to the valve as an actuator though a proper coupling and a digital valve controller which is basically a one-chip computer system. The core part of the controller for the stepper motor is an algorithm which will keep stepper motor under continuous control. In this way the quantitative accuracy and the response of the valve are simultaneously sustained. In this paper the structural parameter affecting the characteristics are analyzed and discussed. And the dynamic properties of the valve under the actuation of the stepper motor are tested.