A study on characteristics of vacuum solenoid valves

Abstract

Vacuum solenoid valves have been widely used in internal combustion engine engines. They are used to regulate various processes in the car’s systems by controlling actuators – for example, variable geometry of the turbocharger, exhaust gas recirculation (EGR) valves, various bypass or throttle valves. The vacuum solenoid valves are controlled by the electronic control unit (ECU) by means of a constant frequency and pulse width modulation of the controlling signal. In operation, these valves change their characteristics over time, which leads to a change in the control of the actuators, and hence to the overall operation of the engine and systems related to the environmental performance of the vehicle. Often there is no feedback on the actual value compared to the demand and their correct diagnosis is difficult. In this work an experimental study was performed, which shows dependence of pressure characteristics from possible deviations of some parameters (vacuum system, power supply) in operation of the vehicle.