Patent ID: 7431407

Claim:
A vehicle brake device comprising: a master cylinder for generating a fluid pressure depending on the stepping state of a brake pedal; a pedal stroke sensor for detecting a pedal stroke of the brake pedal; a differential pressure control valve constituted by a solenoid valve including two ports and configured to vary the differential pressure between the two ports, when the brake pedal is depressed, in dependence on the pedal stroke detected by the pedal stroke sensor, and connected at one of the two ports thereof directly to an outlet port of the master cylinder; control means for controlling the energization of the differential pressure control valve to generate a controlled differential pressure between the two ports of the differential pressure control valve, the control means including controlled differential pressure deriving means for deriving the controlled differential pressure corresponding to the pedal stroke detected by the pedal stroke sensor; a stroke simulator connected directly to the other port of the differential pressure control valve for absorbing the pressurized fluid supplied from the outlet port of the master cylinder through the differential pressure control valve; and a one-way valve arranged in parallel relation with the differential pressure control valve for permitting the flow only from the stroke simulator to the master cylinder; wherein the controlled differential pressure deriving means is configured to derive the controlled differential pressure from an operation expression or a map representing the correlation between the pedal stroke detected by the pedal operation state detection means and the controlled differential pressure; and wherein the control means further includes: applied current deriving means for deriving an applied current value corresponding to the controlled differential pressure derived by the control differential pressure deriving means, from an operation expression or a map representing the correlation between the controlled differential pressure and the applied current value to the differential pressure control valve; and differential pressure control valve control means for controlling the differential pressure control valve based on the applied current value derived by the applied current deriving means.