PURPOSE: To enhance the reliability of braking by disposing a solenoid valve in a second brake system for rear wheels so as to control the brake pressure, and by controlling this solenoid valve in different patterns upon a tendency of rear wheel locking and upon occurrence of a failure in a first brake system, respectively.
CONSTITUTION: In a brake device comprising first and second brake systems for applying brake pressure to first and second groups of wheels of a vehicle, a rear wheel speed sensor A for detecting a rear wheel speed is provided, and a solenoid valve B is disposed in the second brake system so as to control the brake pressure of the second brake system. A determining means C determines a tendency of rear wheel locking in accordance with a detected rear wheel speed, and if a tendency of rear wheel locking is detected, a first control means D controls the solenoid valve B so as to prevent the locking. Further, there is provided a failure detecting means E for detecting a failure in a first brake pressure system. When this failure detecting means E detects a failure, a second control means F controls the solenoid valve B so that the latter is communication intermittently in a predetermined period, and thereafter is communication continuously.
FUJIMOTO SHIYUUSAKU
WATANABE TAKASHI
