Balasubramaniyan, S., Ramachandran, S., Bashyam, S., and Kumar, S., "Theoretical Wear Rate Prediction and Experimental Validation of Repeatedly Operated Solenoid Valve," SAE Technical Paper 2017-28-1973, 2017.
Solenoids are type of inductive actuators extensively used in mobility industries as flow control valves. Now a day, the conventional mechanical actuators are replaced by solenoids, because the solenoids have high precision control and faster response within a controlled magnetic field. Solenoids are classified into two types based on the mode of operation. Solenoid is operated either in ON/OFF mode for switching applications or in Pulse Width Modulation (PWM) for high frequency applications. A solenoid consists of two critical parts, one is the reciprocating plunger and another is the static valve case. During higher number of repeated operations, the solenoid plunger hits the valve case and induces wear on the seating surface. The solenoids are also exposed to the corrosive environment in some applications. Since the functionality and performance of the solenoid mainly depends on the plunger and valve case, it is necessary to have an optimum material, heat treatment and surface coatings selection for plunger and valve case in order to achieve higher durability, wear protection and corrosion resistance.This paper emphasizes the study of material optimization for an Air control solenoid used in two wheeler application. The Air control solenoid is directly integrated into the fuel management system and hence it is highly exposed to the fuel vapour environment. In order to optimize the material for solenoid, various different material combinations with multiple surface coatings and heat treatment of plunger and valve case were selected and wear rate was predicted theoretically using wear prediction models. Also, the solenoids with different material, heat and surface treatment combinations of plunger and valve case were developed and operational durability test was carried out on these samples for higher number of cycles to understand the effect of material characteristics. Based on the comparison of the theoretical and experimental test results, the SUS304 valve case and the plunger made of SUM22 with heat treatment is having higher durability, wear protection and corrosion resistance as compared to other combinations.