Hydraulic braking pressure control system for an automotive vehicle

摘要

A hydraulic braking pressure control system for an automotive vehicle having a hydraulic pressure controlling circuit includes a hydraulic pressure generator that supplies hydraulic braking pressure to wheel brake cylinders of the vehicle through a hydraulic pressure controlling circuit, a pressure control device disposed in the hydraulic pressure controlling circuit between the hydraulic pressure generator and the wheel brake cylinders for controlling the hydraulic braking pressure in each of the wheel brake cylinders, and a reservoir disposed in the hydraulic pressure controlling circuit for storing brake fluid. A pump is disposed in the hydraulic pressure controlling circuit to pump brake fluid, and a motor is operatively connected to the pump to apply a driving force to the pump. A voltmeter is electrically connected to the motor to detect the output voltage of the motor and a calculating arrangement is provided to calculate the value of the decrease gradient of the output voltage of the motor. A condition check device detects that a malfunction has been caused in either the reservoir or the motor based on the calculation results of the calculation arrangement.