Patent ID: 8746814

Claim:
A vehicle brake fluid pressure control apparatus including: a fluid pressure adjusting unit capable of performing adjustment of individually increasing and decreasing brake fluid pressures acting respectively on wheel brakes for front wheels and wheel brakes for rear wheels so as to prevent the front wheels and the rear wheels from being locked during braking; and allowable differential pressure setting means for setting allowable differential pressures allowable between the brake fluid pressures of the wheel brakes for the left and right coaxial front wheels and between the brake fluid pressures of the wheel brakes for the left and right coaxial rear wheels, the operation of the fluid pressure adjusting unit being controlled in such a way that each of the differential pressures between the brake fluid pressures of the wheel brakes for the left and right coaxial front wheels and between the brake fluid pressures of the wheel brakes for the left and right coaxial rear wheels is equal to or lower than a corresponding one of the allowable differential pressures set by the allowable differential pressure setting means, wherein the vehicle brake fluid pressure control apparatus comprises lock fluid pressure acquiring means for acquiring a lock fluid pressure of a wheel brake of a secondary wheel coaxial with and other than a wheel which is selected as a primary control target, the lock fluid pressure being a fluid pressure at which pressure decrease by an anti-lock brake control is started, the lock fluid pressure acquiring means calculating the lock fluid pressure on the basis of an output fluid pressure of a master cylinder common to the wheel brakes and drive electric currents of electromagnetic valves forming part of the fluid pressure adjusting unit, and wherein the allowable differential pressure setting means sets the allowable differential pressures to correspond to an estimated road surface friction coefficient which is calculated on the basis of at least the lock fluid pressure obtained by the lock fluid pressure acquiring means.