Vacuum solenoid is solenoid valve. It controls the vacuum or pressure inside EGR valve chamber by ECU to supply the driving force for EGR valve.

• Principle of vacuum solenoid

ECU controls the vacuum solenoid valve through comprehensive analysis and calculation according to the signal of clutch sensor, water temperature sensor, throttle sensor, engine speed sensor etc. if the vacuum solenoid valve is not energized, the movable iron core of the coil blocks the vacuum passage to cut off the way to EGR valve; if the vacuum solenoid is energized, the movable core of the coil open the vacuum passage to connect the way to EGR valve.
The comprehensive processing to the signals from all sensors will provide different pulse signal to EGR solenoid, which makes the opening and closing time of the valve differently to ?control the vacuum degree of EGR valve that needs for relative opening and EGR ratio for different engine running condition, and also change the exhaust gas volume involved in recirculation.

Core advantage: The pressure output diagram of the product below shows that the output pressure curve of RICHLEO vacuum solenoid is smooth. It works stable and is not appreciably affected by surrounding factors with higher performance comparing to the similar products from home and abroad.
See below pressure output diagram.