Abstract: In a vehicle brake apparatus for executing ABS control to prevent a wheel from locking in such a manner that braking force is controlled so as to keep a slip ratio of a wheel at a target slip ratio so that an excessive drop of a wheel speed from a vehicle body speed is adjusted, an output current for driving a braking actuator is set to a current on which oscillating waves are superimposed during ABS control so that the wheel speed changes to show oscillating waves. Even if the wheel speed once drops to an extent that the slip ratio exceeds the target slip ratio, further decrease of the wheel speed is restricted and the wheel speed turns to an increase soon and this cycle is repeated. Accordingly, there occurs no excessive drop of the wheel speed due to the response delay so that sufficient braking force is generated.

Abstract: In an electronic brake system, a brake pedal is operated by a driver according to a requisite braking force. Wheel cylinders equipped at respective vehicle wheels generate braking forces at the respective vehicle wheels. A master cylinder applies a brake fluid pressure to generate the respective wheel cylinder pressures. A pedal operation amount detection portion detects a stroke amount of the brake pedal. The brake pedal and the master cylinder are isolated from each other. The motor is driven based on the pedal operation amount detected by the pedal operation amount detection portion and then controls the brake fluid pressure.

Abstract: In a disk brake, a first surface of a wedge member is in line contact via a first roller bearing with a surface of the piston and a second surface of the wedge member is also in line contact via a second roller bearing with a surface of the guide member. Each of the first surface of the wedge member and the surface of the piston is perpendicular to a piston axis and each of the second surface of the wedge member and the surface of the guide member is inclined by a given angle to the piston axis. When a drive unit moves the wedge member substantially perpendicularly to the piston axis, the piston moves axially and presses a frictional material against a disk. Since force transmitted from the wedge member to the piston acts parallel to the piston axis with a less moment in a direction of pressing the piston against a wall surface of the cylindrical bore so that the piston moves smoothly.

Abstract: In a vehicle brake apparatus for executing ABS control to prevent a wheel from locking in such a manner that braking force is controlled so as to keep a slip ratio of a wheel at a target slip ratio so that an excessive drop of a wheel speed from a vehicle body speed is adjusted, an output current for driving a braking actuator is set to a current on which oscillating waves are superimposed during ABS control so that the wheel speed changes to show oscillating waves. Even if the wheel speed once drops to an extent that the slip ratio exceeds the target slip ratio, further decrease of the wheel speed is restricted and the wheel speed turns to an increase soon and this cycle is repeated. Accordingly, there occurs no excessive drop of the wheel speed due to the response delay so that sufficient braking force is generated.