Analysis of forces in an automobile ECV using in external variable displacement swash plate type compressor for air conditioning control system

To meet the demand of improved comfort for passengers, drive ability and standard in fuel economy; external variable displacement swash (wobble) plate type compressors are used in automobile air conditioning control system because of their low energy consumption and highly efficient characteristics. It controls the compressor displacement by increasing or reducing the swash plate angle. Solenoid operated electromagnetic control valve (ECV) in the compressor controls the air conditioning system by means of a pulse width modulation (PWM) input signal supplied from an external source (controller). The mechanism changes the swash plate angle by increasing or reducing the pressure of swash plate chamber using the ECV functions. The force (solenoid) for ECV operation is important as the force directly related to the movement of the internal feature i.e. mainly plunger of the ECV which is responsible for the amount of air/refrigerant flow that results the air conditioning control procedures with various pressure ports. The research paper highlights the improved theory and equation for calculating the working force (solenoid force) in ECV and experimental analysis of 3 (three) ECV samples followed by the comparison of theoretical and experimental force results.