Patent ID: 6481805
Filing Date: 2002-11-19
Classification: B60T

Abstract:
A braking apparatus comprising:a first contact unit including a brake rotor arranged on a rotary shaft side of a wheel; a second contact unit including at least a brake pad; an actuator arranged to press the second contact unit against the first contact unit; a control unit for controlling the operation of the actuator and performing a position control operation for moving the second contact unit in such a manner that an interval between the first contact unit and the second contact unit is smaller than a preset clearance, and a force control operation for pressing the second contact unit against the first contact unit in accordance with a required braking force, said control unit comprising a pad clearance setting unit for maintaining a preset clearance between the brake pad and the brake rotor; a pad position control unit for moving the brake pad to a position substantially in contact with the brake rotor; a brake force control unit for controlling the pressure to press the brake pad against the brake rotor; and a switching unit for switching between the brake force control unit, the pad position control unit and the pad clearance setting unit; a brake fluid source for supplying the brake fluid, a brake pad driving unit for driving the brake pad under the pressure of said brake fluid, and a pump for supplying the brake fluid to said brake pad driving unit or reducing the pressure of the brake fluid of said brake pad driving unit midway of the fluid path connecting said brake fluid source and said brake pad driving unit, wherein said pad clearance setting unit maintains the preset clearance between the brake pad and the brake rotor by specifying a volume of the brake fluid corresponding to the pad clearance to be returned to the brake fluid source from said brake pad driving unit based on the state in which the brake pad is in contact with the brake rotor, and wherein said pad position control unit supplies the volume of the brake fluid corresponding to the pad clearance to said brake pad driving unit.