The braking vacuum system of BMW X 1 electric vacuum pump F49PHEV consists of the components shown in the following figure. F49PHEV braking system 1- motor electronic equipment; 2- Primary domain controller; 3— Dynamic stability control system DS C；; ; 4- Brake vacuum pressure sensor; 5— Brake pedal; 6- Brake booster; 7— Digital motor electronic equipment DME；; 8— Electric vacuum pump; 9- Mechanical Real Empty Pump
In order to ensure that the brake servo device can assist the driver when braking, it is necessary to equip with sufficient vacuum source. B38 engine generates necessary vacuum through mechanical vacuum pump, as shown in the following figure. Because the B38 engine still needs to ensure the vacuum supply during the shutdown phase, the vacuum system is enhanced by the electric vacuum pump. When the vacuum value in the vacuum system drops below a predetermined threshold, the electric vacuum pump is activated. The actual no-load data is recorded by the brake actual no-load sensor in the brake servo device. Schematic diagram of vacuum source F49PHEV driven by internal combustion engine; B- electric drive; 1- mechanical vacuum pump; 2- check valve; 3- electric vacuum pump; 4- Brake booster
The motor device is the central control unit for controlling the electric vacuum pump. The device supplies power to the brake vacuum sensor and reads the pressure signal. If necessary, EME can start the electric vacuum pump. When the specified vacuum degree is reached, the start of the electric vacuum pump is cancelled.
If the real air pressure provided by the electric vacuum pump is insufficient, the D SC hydraulic control unit is used to store pressure to help provide braking force. If the electric vacuum source fails, pure electric driving is prohibited. If this happens, EME will send a request signal to start the internal combustion engine after pressing the brake pedal. After the engine is started, the mechanical vacuum pump ensures the vacuum state. Notify the driver of the fault information through the central data display. The signal transmission of the brake vacuum source is shown in the following figure. F49PHEVA- signal transmission of brake vacuum source in information input; B- information output; C- voltage output; D- engine start request signal; 1- brake vacuum pressure sensor; 2- Electrical and electronic equipment; 3— Dynamic stability control system DSC；; 4- electric vacuum pump; 5- Criminal Investigation Bureau; Central data display screen; 6- Brake pedal travel sensor; 7— Digital motor electronic equipment DME；; 8- gasoline engine; 9- Mechanical Real Empty Pump
Mercedes-Benz S5 00PHEV electric vacuum pump The electric vacuum pump is started by the control unit of the stable driving system of the electric vehicle as required, and its function is to establish a vacuum in the brake booster BAS and keep the vacuum during electric operation. The entity and interface of the electric air pump are shown in the following figure. Mercedes-Benz electric vacuum pump 1- electric plug-in type; 2- vacuum interface; M6 —— Vacuum air pump Vacuum air pump generates vacuum air and delivers it to the brake booster BAS through the corresponding vacuum air pipeline. When the internal combustion engine is running, the vacuum degree is guaranteed by the mechanical vacuum pump. @20 19