초록 ▼

A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust p

A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, 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.

대표청구항 ▼

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 cylinde

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; anda 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, andwherein 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. 2. The disk brake apparatus according to claim 1, wherein the controller further sets the first predetermined time period to a shorter time as a voltage of the electric motor increases. 3. The disk brake apparatus according to claim 1, wherein the controller determines that the thrust force generated by the electric motor is released when a condition for the change status of the current for driving the electric motor that a value of the current for driving the electric motor decreases and a change rate of the value of the current for driving the electric motor also decreases is satisfied. 4. The disk brake apparatus according to claim 1, wherein the controller drives the electric motor for a second predetermined time period after determining that the thrust force generated by the electric motor is released. 5. 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 and configured to receive a hydraulic pressure from a master cylinder;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 piston; anda controller configured to control the electric motor,wherein the piston is configured to be thrust by at least any one of the 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, when the holding of the piston at the thrust force generated by the electric motor is released,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 a hydraulic pressure detected by a hydraulic pressure detector configured to detect the hydraulic pressure generated in the master cylinder is lower than a predetermined value, anddetermines 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 generated in the master cylinder is the predetermined value or higher, andwherein the controller sets the first predetermined time period based on a relationship between the hydraulic pressure detected by the hydraulic pressure detector 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 detected by the hydraulic pressure detector. 6. The disk brake apparatus according to claim 5, wherein the controller further sets the first predetermined time period to a shorter time as a voltage of the electric motor increases. 7. The disk brake apparatus according to claim 5, wherein the controller determines that the thrust force generated by the electric motor is released when a condition for the change status of the current for driving the electric motor that a value of the current for driving the electric motor decreases and a change rate of the value of the current for driving the electric motor also decreases is satisfied. 8. The disk brake apparatus according to claim 5, wherein the controller drives the electric motor for a second predetermined time period after determining that the thrust force generated by the electric motor is released. 9. 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 actuator included with the caliper and configured to apply a parking brake;a rotation/linear motion conversion mechanism configured to convert a rotation of the electric actuator into a linear motion to engage and thrust the piston, and hold the piston which has been thrust without aid of a hydraulic pressure; anda controller configured to control the electric actuator,wherein the piston is configured to be thrust by at least one any of a hydraulic pressure supplied to the caliper, and a thrust force generated via the rotation/linear motion conversion mechanism by a rotation of the electric actuator 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 actuator is released, and switches conditions for determining whether the thrust force generated by the electric actuator is released, based on a value of the hydraulic pressure acquired by the controller, andaccording to the conditions for determining whether the thrust force generated by the electric actuator is released, the controller makes a determination based on a change status of a current for driving the electric actuator, when the hydraulic pressure acquired by the controller is lower than a predetermined value, andthe controller makes a determination based on a first predetermined time period elapsed from a start of driving of the electric actuator, when the hydraulic pressure is the predetermined value or higher, andwherein the controller reduces the first predetermined time period according to an increase in the hydraulic pressure acquired by the controller. 10. The disk brake apparatus according to claim 9, wherein the controller further sets the first predetermined time period to a shorter time as a voltage of the electric actuator increases. 11. The disk brake apparatus according to claim 9, wherein the controller determines that the thrust force generated by the electric actuator is released when a condition for the change status of the current for driving the electric actuator that a value of the current for driving the electric actuator decreases and a change rate of the value of the current for driving the electric actuator also decreases is satisfied. 12. The disk brake apparatus according to claim 9, wherein the controller drives the electric actuator for a second predetermined time period after determining that the thrust force generated by the electric actuator is released.