An electric brake device is provided which is capable of early detecting presence/absence of abnormality in the brake device during the traveling of a vehicle in the absence of the operation of a brake application device. A controller includes an abnormality detecting operation controller which operates the electric motor according to a predetermined condition during the traveling of the vehicle in the absence of the operation of the brake application device. The device further includes an abnormality detector which obtains a measured value of a predetermined item related to the vehicle when the electric motor is operated by the abnormality detecting operation controller, and compares the measured value with an estimated value or a set value to detect presence/absence of abnormality in the brake device.

An electric brake device is provided which is capable of early detecting presence/absence of abnormality in the brake device during the traveling of a vehicle in the absence of the operation of a brake application device. A controller includes an abnormality detecting operation controller which operates the electric motor according to a predetermined condition during the traveling of the vehicle in the absence of the operation of the brake application device. The device further includes an abnormality detector which obtains a measured value of a predetermined item related to the vehicle when the electric motor is operated by the abnormality detecting operation controller, and compares the measured value with an estimated value or a set value to detect presence/absence of abnormality in the brake device.

Disclosed is an electric brake system. The electric brake system includes a master cylinder including first and second chambers, and first and second pistons disposed at the first and second chambers, respectively; a simulation device connected to the master cylinder and configured to provide a reaction force according to pedal effort of a brake pedal; a hydraulic pressure supply device configured to generate a hydraulic pressure by a hydraulic piston which is operated by an electrical signal that is output to correspond to displacement of the brake pedal; a hydraulic pressure control unit configured to deliver the hydraulic pressure discharged from the hydraulic pressure supply device to a wheel cylinder provided at each of wheels; a first backup flow path and a second backup flow path configured to connect the master cylinder and the hydraulic pressure control unit; a first cut valve and a second cut valve configured to control delivery of a hydraulic pressure of the first and second backup flow paths; an electronic control unit (ECU); a first pressure sensor installed between the first chamber of the master cylinder and the first cut valve; and a second pressure sensor installed at the first hydraulic flow path, the second hydraulic flow path, or the hydraulic pressure control unit, wherein, in a state in which the second cut valve is closed and the outlet valve, which is connected to the second backup flow path, is opened, to discharge the hydraulic pressure in the hydraulic pressure control unit connected to the second hydraulic flow path, the ECU operates the hydraulic pressure supply device to generate a pressure in the first chamber, and when a measured value of the second pressure sensor is less than an expected value, the ECU determines that the second piston of the master cylinder is stuck.

A leakage inspecting method of an electric brake system, which includes a master cylinder connected to a reservoir, a simulation device having one side connected to the master cylinder to provide a reaction force according to the pedal effort of the brake pedal, a simulation valve provided at a flow path connected to the master cylinder or a flow path connected to the reservoir, a hydraulic pressure supply device operated by an electrical signal of a pedal displacement sensor sensing a displacement of the brake pedal and configured to generate hydraulic pressure, and a hydraulic pressure control unit, comprising: executing an inspection mode for inspecting for a leak of the simulation valve and a sealing member provided inside a chamber of the master cylinder by providing an inspection valve at a flow path connecting the master cylinder to the reservoir, wherein the inspection mode includes: (a1) closing a cut valve provided at a flow path connecting the master cylinder to the hydraulic pressure control unit when the inspection valve is open; (b1) pressurizing a piston disposed inside the master cylinder according to the pedal effort of the brake pedal and detecting whether pressure is formed through a pressure sensor; and (c1) determining that a leak does not exist when pressure detected through the pressure sensor satisfies a preset criterion.

A method for diagnosing an electric brake system is disclosed. The method for diagnosing an electric brake system, which includes a reservoir, a master cylinder, a first backup flow path, a second backup flow path, a first cut valve, a second cut, a simulation device, a hydraulic pressure supply device, a first hydraulic flow path, a second hydraulic flow path, a hydraulic control unit, and an electronic control unit configured to control the hydraulic pressure supply device and the valves on the basis of hydraulic pressure information and displacement information of the brake pedal, comprising a first diagnosis mode of: closing the first cut valve and the second cut valve when the pedal effort is not provided to the brake pedal; operating the hydraulic pressure supply device to generate hydraulic pressure at the hydraulic control unit; measuring the hydraulic pressure in the first or second hydraulic circuit; and comparing the measured hydraulic pressure with a first reference pressure to diagnose abnormality of the valves.

It is an object of the invention to provide a brake device capable of detecting a failure in each of components, by which booster control is performed, at an early stage even during vehicle running. The brake device is configured to discharge brake fluid into a communicating fluid path that connects a fluid path of a primary system and a fluid path of a secondary system, and to control a first communicating valve for restricting a flow of brake fluid from the communicating fluid path to the fluid path of the primary system and a second communicating valve for restricting a flow of brake fluid from the communicating fluid path to the fluid path of the secondary system in respective valve-closing directions, so as to check at least a state of the pump.

A brake system includes a reservoir and a master cylinder operable to provide a brake signal responsive to actuation of a brake pedal connected thereto. A power transmission unit is configured for selectively providing pressurized hydraulic fluid for actuating at least one of the pair of front wheel brakes and the pair of rear wheel brakes in a normal non-failure braking mode. A plurality of iso/dump valve arrangements are each hydraulically interposed between the power transmission unit and a corresponding one of the wheel brakes. A plurality of two-position three-way valves are each hydraulically connected with the master cylinder, the power transmission unit, and at least a selected wheel brake of the pair of front wheel brakes. The three-way valves selectively control hydraulic fluid flow from a chosen one of the master cylinder and the power transmission unit to the corresponding one of the front wheel brakes.

A brake system includes a reservoir and a master cylinder operable to provide a brake signal responsive to actuation of a brake pedal connected thereto. A power transmission unit is configured for selectively providing pressurized hydraulic fluid for actuating at least one of the pair of front wheel brakes and the pair of rear wheel brakes in a normal non-failure braking mode. A plurality of iso/dump valve arrangements are each hydraulically interposed between the power transmission unit and a corresponding one of the wheel brakes. A plurality of two-position three-way valves are each hydraulically connected with the master cylinder, the power transmission unit, and at least a selected wheel brake of the pair of front wheel brakes. The three-way valves selectively control hydraulic fluid flow from a chosen one of the master cylinder and the power transmission unit to the corresponding one of the front wheel brakes.

For testing the functional capability of a hydraulic power vehicle braking system, a power brake pressure generator is switched on. The power brake pressure generator displaces brake fluid through the non-actuated master brake cylinder into a brake fluid reservoir, which is why no brake pressure is built up. A brake pressure build-up allows a hidden defect to be inferred, which has no impact during normal operation and is therefore not noticed.