Theoretical Optimization of Material for Repeatedly Operated Solenoid Valve with Numerical and Experimental Validation

Solenoids are electro mechanical actuators used in automotive industries as flow control valve. Solenoids replace the conventional mechanical valve since it is having a precise control and faster response. Solenoid is operated either in ON/OFF mode or Pulse Width Modulation mode (PWM). When operated in PWM at a given frequency, the solenoid undergoes finite number of repeated operations. A normally closed solenoid contains two critical parts, one is a plunger, which is a moving part and another is valve case, which is a static part. The plunger hits the valve case during repeated number of operations which undergo extreme wear. Since the functionality and performance of the solenoid mainly rely on the plunger and valve case, it is inevitable to have an optimum material selection in order to achieve higher durability.

This paper illustrates the study of material selection for an air control solenoid used for two wheeler application. Two different material combinations were selected and three dimensional model was developed with the help of modeling software. Theoretical and finite element analysis (FEA) was done to evaluate the structural behavior of different materials. The numerical analysis was done using a commercial software ANSYS. The solenoids with two different material combinations were developed. Durability test was carried out on these samples to evaluate the life and to understand the effect of material characteristics. Based on the comparison of the theoretical, numerical and experimental test results, the plunger with SUS631 material is superior to S45C material. Hence the optimum material for the solenoid plunger to have higher durability is SUS631.