US 2012/0073286 A1 · BOOSTER

Abstract

An electric booster including a plunger movable by operation of a brake pedal, an electric motor controlled based on a relative displacement between the plunger and the linear motion member, which is detected by a relative displacement sensor, and a ball and screw mechanism. The linear motion member pushes a piston of a master cylinder through a reaction member, thereby generating a brake force. Part of a reaction force from the master cylinder is fed back to the brake pedal through the reaction member. When a reference position sensor detects that a relative position of the plunger to the linear motion member coincides with a predetermined reference position, a detection value of the relative displacement sensor is stored as a relative displacement reference value, and relative displacement between the plunger and the linear motion member is determined.

Claims20

Dependent claims

A booster comprising:

an input member configured to be moved forward or backward according to an operation of a brake pedal;
a boosting member disposed so as to be movable relative to the input member;
an actuator configured to drive the boosting member;
a thrust force transmission mechanism configured to transmit a thrust force of the input member and the boosting member to a master cylinder, and transmit a reaction force from the master cylinder to the input member and the boosting member at a predetermined ratio;
a relative displacement detector configured to detect a relative displacement between the input member and the boosting member;
a controller configured to control an operation of the actuator based on the relative displacement detected by the relative displacement detector;
and
a reference position detector configured to detect that a relative position of the input member to the boosting member coincides with a predetermined reference position.

5 more elements

A booster comprising:

an input member configured to be moved forward or backward according to an operation of a brake pedal;
a boosting member configured to be moved according to a forward or backward movement of the input member to generate a hydraulic pressure in a master cylinder;
an actuator configured to drive the boosting member;
a thrust force transmission mechanism configured to transmit a part of a reaction force of the hydraulic pressure generated in the master cylinder to the input member;
a relative displacement detector configured to detect a relative displacement between the input member and the boosting member;
a controller configured to control an operation of the actuator;
and
a reference position detector configured to detect that a relative position of the input member to the boosting member coincides with a predetermined reference position,
wherein the controller calculates the relative displacement between the input member and the boosting member based on a detection value of the relative displacement detector when the reference position detector detects that the relative position of the input member to the boosting member coincides with the predetermined reference position, and the controller controls the operation of the actuator based on the calculated relative displacement.

6 more elements

A booster comprising:

a boosting member configured to be moved by an actuator according to a forward or backward movement of an input member configured to be moved forward or backward according to an operation of a brake pedal, to generate a hydraulic pressure in a master cylinder;
a thrust force transmission mechanism configured to transmit a part of a reaction force from the master cylinder to the input member;
a relative displacement detector configured to detect a relative displacement between the input member and the boosting member;
a controller configured to control an operation of the actuator;
and
a reference position detector configured to detect that a relative position of the input member to the boosting member coincides with a predetermined reference position,
wherein the controller stores a detection value of the relative displacement detector as a relative displacement reference value when the reference position detector detects that the relative position of the input member to the boosting member coincides with the predetermined reference position, calculates the relative displacement between the input member and the boosting member based on the relative displacement reference value, and controls the operation of the actuator based on the calculated relative displacement.

4 more elements

Dependencies are inferred from the claim text.

Booster

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Booster

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Abstract

Claims20