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Control Process of Electric Vacuum-Assisted Braking System

Pulished on Aug. 09, 2019

As a Power Brake Booster Factory, let's talk about the control of the electric vacuum assisted braking system.

1. Turn on the car 12V power supply, the pressure delay switch is closed, the vacuum pump is about 30s after the switch is turned off, then the vacuum inside the vacuum tank is about 80kPa.

2. When the vacuum in the vacuum tank drops to 55 kPa, the pressure delay switch closes again.

3. The pressure alarm signals when the vacuum in the vacuum tank drops to approximately 34 kPa. If the EV Vacuum Pump control switch has a significant short turn on and off, a leak has occurred. According to this control strategy, an intermittent vacuum generation system is designed. The basic working principle of the intermittent vacuum generation system is that when the driver starts the car, the 12V power supply is turned on, and the pressure delay switch and the pressure alarm start the pressure self-test. If the vacuum in the vacuum tank is less than 55 kPa, the pressure diaphragm will squeeze the contacts, thereby turning on the power, and the vacuum pump starts to work;

Vacuum Brake Booster System

Vacuum Brake Booster System

When the vacuum increases to 55 kPa, the pressure delay switch is turned off, and then the vacuum pump continues to work for about 30 seconds after the delay relay; the pressure delay switch will self-test each time the driver has a braking action, thereby judging whether the electric vacuum pump should work; if the vacuum inside the vacuum tank is lower than 34kPa, the Vacuum Brake Booster System can not provide effective vacuum boost, then the pressure alarm will send a signal to remind the driver to pay attention to the driving speed. The electric vacuum pump control can also be controlled by an electronic control unit. As long as the pressure switch is replaced by an absolute pressure sensor, the electric vacuum pump can be controlled by the control unit to control the relay.