Patent ID: 9731693
Date: 2017-08-15
CPC Classifications: B60T

Claim:
1. A disk brake apparatus comprising: a caliper configured to be arranged adjacent to a disk integrally rotatable with a wheel of a vehicle, and comprising brake pads to be pressed against the disk for generating a braking force, a hydraulic cylinder, and a piston positioned in the hydraulic cylinder and configured to contact and press the brake pads to be pressed against the disk; an electric motor included with the caliper and configured to apply a parking brake; a piston thrust mechanism positioned in the caliper and including a thrust member configured to be driven by the electric motor to engage and thrust the piston without aid of a hydraulic pressure; a piston holding mechanism configured to hold the thrust member so as to hold a position of the piston which has been thrust; and a controller configured to control the electric motor, wherein the piston is configured to be thrust by at least any one of a hydraulic pressure supplied to the caliper according to an operation of a brake pedal, and a thrust force generated via the piston thrust mechanism by a rotation of the electric motor in a first rotational direction, wherein the controller acquires the hydraulic pressure supplied to the caliper when the holding of the piston at the thrust force generated by the electric motor is released by a rotation of the electric motor in a second rotational direction opposite to the first rotational direction, wherein the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor, when the hydraulic pressure acquired by the controller is lower than a predetermined value, and determines whether the thrust force generated by the electric motor is released based on a first predetermined time period elapsed from a start of driving of the electric motor, when the hydraulic pressure acquired by the controller is the predetermined value or higher, and wherein the controller sets the first predetermined time period based on a relationship between the hydraulic pressure acquired by the controller and a force by which the piston holding mechanism holds the piston, so as to reduce the first predetermined time period according to an increase in the hydraulic pressure acquired by the controller.