Since the electromagnetic proportional compound valve was recently developed, very little has been published on its characteristics.
This thesis is concerned with the study of the static and dynamic performance of a solenoid operated pressure relief valve with a pressure compensating mechanism similar to that of a hydraulic proportional compound valve.
The desired characteristics of a solenoid operated pressure relief valve with a pressure compensating mechanism are that the maximum pressure of the system should be proportional to input current of the solenoid and the load flow is always constant in spite of changes in load pressure or supply pressure.
The dynamic equations of the system are derived and analyzed applying the automatic control technique. From the analysis, parameters governing both static and dynamic performances are discussed. The dynamic equations were then solved by computer simulation for the nonlinear system and for the linearized approximation of the system.
The transient behavior of the valve system is presented and analyzed. It was found that the important parameters governing the dynamic characteristics are the pipe type orifice in pressure compensating spool, hydraulic feed back restrictor, damping length of the pressure compensating spool, and flow gain of the pressure compensating spool.
A typical solenoid operated pressure relief valve was designed and its performance in steady and transient state were tested by experiment. These experimental results show good agreement with predicted results of theoretical analysis and computer simulation.
It was found in the experiment that material property of the plunger and yoke of the solenoid has a significant influence on the performance of proportionality of this solenoid operated pressure relief valve.
