Abstract
This paper describes a cam-drive type proportional valve for water hydraulics and its dynamic characteristics. In the developed valve, the spool is driven by positive cam mechanism, m which a heart-like cam is placed between two cam-followers and the cam is driven by stepping motor. As for measurement of dynamic characteristics, the step and frequency response are measured using the constructed controller with micro computer. In addition, dynamic characteristics using an AC servo motor is also measured for improvement of dynamic characteristics of the developed valve. The 5% settling time of step response was 25 ms with the servo motor. Bandwidth of frequency response using the servo motor was about 30 Hz. Thus the response of the developed valve is better than conventional proportional valves is better than conventional proportional valves.
