US 9,283,943 B2Granted

Brake apparatus

AssigneeHitachi Automotive Systems, Ltd.

InventorMasaru Sakuma

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Abstract

A brake apparatus, which is configured to generate a hydraulic pressure in a master cylinder, sets a control position of a primary piston. According to a movement of an input piston in response to an operation of a brake pedal, the brake apparatus generates a hydraulic pressure in a primary chamber of the master cylinder by driving the primary piston by an electric motor to supply brake fluid to a brake caliper, thereby exerting a brake effect. The brake apparatus sets a first control position where the primary chamber is out of communication with a reservoir, and a second control position where the primary chamber is in communication with the reservoir as a holding position of the primary piston when no brake is applied. Then, the brake apparatus appropriately switches the holding position of the piston between the first control position and the second control position.

Claims20

Dependent claims

A brake apparatus comprising:

a reservoir configured to reserve brake fluid;
a master cylinder in communication with the reservoir, the master cylinder being configured to generate a hydraulic pressure in a pressure chamber by cutting off communication between the pressure chamber and the reservoir according to a forward movement of a piston of the master cylinder;
a booster configured to operate the piston;
a hydraulic pressure detector configured to detect the hydraulic pressure generated in the pressure chamber;
and
a controller configured to control the booster,
wherein the booster includes an input member configured to be moved according to an operation of a brake pedal, an electric actuator configured to drive the piston, and a position detector configured to detect a position of the piston,
wherein the controller is configured to set at least two holding positions of the piston such that the piston is held at a first control original position and a second control original position based on a reference position by the electric actuator,
wherein the controller is configured to set the reference position from a position of the piston detected by the position detector in a state in which the controller causes the electric actuator to move the piston in a hydraulic pressure generation direction until the hydraulic pressure generated in the pressure chamber detected by the hydraulic pressure detector reaches a predetermined threshold value,
wherein the controller is configured to set the second control original position corresponding to a position of the piston in a state in which the piston is moved back from the reference position in a hydraulic pressure release direction by a first predetermined amount so as to establish the communication between the pressure chamber and the reservoir,
wherein the controller is configured to set the first control original position corresponding to a position of the piston in a state in which the piston is moved forward from the second control original position in the hydraulic pressure generation direction by a second predetermined amount, the second predetermined amount being different from the first predetermined amount, and
wherein the controller is configured to set the first control original position and the second control original position in a state in which the brake pedal is not operated.

9 more elements

A brake apparatus comprising:

a master cylinder in communication with a reservoir configured to reserve brake fluid, the master cylinder being configured to generate a hydraulic pressure in a pressure chamber by cutting off communication between the pressure chamber and the reservoir according a forward movement of a piston of the master cylinder;
a booster configured to operate the piston by an electric actuator according to a movement of an input member moved by an operation of a brake pedal;
a controller configured to control the electric actuator in response to the operation of the brake pedal;
a hydraulic pressure detector configured to detect the hydraulic pressure generated in the pressure chamber;
a position detector configured to detect a position of the piston,
wherein the controller is configured to control the electric actuator even independently of the operation of the brake pedal, and
wherein the controller is configured to set one of a first control original position and a second control original position as a holding position of the piston in a state in which the brake pedal is not operated, the first control original position being a position of the piston in which the communication between the pressure chamber and the reservoir is cut off, and the second control original position being a position of the piston in which the communication between the pressure chamber and the reservoir is established, and
wherein the controller is configured to change the holding position of the piston in a state in which the brake pedal is not operated, between the first control original position and the second control original position.

5 more elements

A brake apparatus comprising:

a master cylinder in communication with a reservoir configured to reserve brake fluid, the master cylinder being configured to generate a hydraulic pressure in a pressure chamber by cutting off communication between the pressure chamber and the reservoir according to a forward movement of a piston of the master cylinder;
a booster configured to operate the piston by an electric actuator according to a movement of an input member moved by an operation of a brake pedal;
a controller configured to control the electric actuator in response to the operation of the brake pedal;
wherein the controller is configured to receive detection signals from a hydraulic pressure detector configured to detect the hydraulic pressure generated in the pressure chamber and a position detector configured to detect a position of the piston,
wherein the controller is configured to control the electric actuator independently of the operation of the brake pedal,
wherein the controller is configured to set one of a hydraulic pressure generation position and a hydraulic pressure release position as a holding position of the piston in a state in which the brake pedal is not operated, the hydraulic pressure generation position being a position of the piston in which the communication between the pressure chamber and the reservoir is cut off, and the hydraulic pressure release position being a position of the piston in which the communication between the pressure chamber and the reservoir is established, and
wherein the controller is configured to set the holding position of the piston to the hydraulic pressure release position immediately after the operation of the brake pedal is finished, and the controller is configured to change the holding position of the piston to the hydraulic pressure generation position after a predetermined time has passed.

4 more elements

Dependencies are inferred from the claim text.