According to the embodiment of the present disclosure, it provides an inspection valve installed at a flow path connecting a reservoir to a chamber of a master cylinder, comprising: a housing at which a bore is formed and having one side at which an inlet hole is formed; a plunger provided to be movable along the bore of the housing; a seat member configured to close one side of the bore and through which an outlet hole passes; and an elastic member having one side supported by the plunger and the other side supported by the seat member, wherein the plunger is provided to block the outlet hole when a hydraulic pressure flowing in through the inlet hole is greater than an elastic force of the elastic member.

Also, according to the embodiment of the present disclosure, it provides an inspection valve installed at a bypass flow path connecting a front side of a check valve to a rear side thereof at a reservoir flow path connecting a reservoir to a master cylinder, comprising: a housing at which a bore is formed and having one side at which an inlet hole communicating with the master cylinder is formed; a plunger provided to be movable along the bore of the housing; a seat member configured to close one side of the bore and through which an outlet hole communicating with the reservoir passes; and an elastic member having one side supported by the plunger and the other side supported by the seat member, wherein the check valve is provided at the reservoir flow path and enables fluid to flow in a direction from the reservoir to the master cylinder, and the plunger is provided to block the outlet hole when a hydraulic pressure flowing in through the inlet hole is greater than an elastic force of the elastic member.

In an electric automobile traveling by driving a rear wheel with an electric motor mounted on a vehicle body rear part, a load distributed to the rear wheel is larger than a load distributed to a front wheel by an amount corresponding to a weight of the electric motor. Therefore, it is desirable that a braking force distribution amount to the rear wheel be larger than that to the front wheel. Without providing a proportional pressure reducing valve changing a ratio of braking force distributed between the front and rear wheels, it is possible, by supplying a same brake fluid pressure from a master cylinder to front and rear wheel brake calipers and carrying out regenerative braking in the rear wheel, to make the braking force distribution amount to the rear wheel larger than that to the front wheel.

A method for operating a brake system, which brake system includes a master brake cylinder, which is actuated by the driver with the aid of a brake force booster, a driver-independent pressure source, and at least one wheel brake to which a wheel speed sensor is assigned. During a braking operation initiated by the driver, which is identified in particular by a brake lamp switch, the present vehicle deceleration is determined and compared with a predefined threshold value, and the at least one driver-independent pressure source is activated if the determined vehicle deceleration reaches or falls below the predefined threshold value. A brake system for a motor vehicle, which brake system has a control unit in which the method is carried out is also disclosed.

A hydraulic motor vehicle brake system comprises a vehicle dynamic control system which comprises a first brake circuit which acts on at least one first wheel brake, and a second brake circuit which acts on at least one second wheel brake, the first brake circuit comprising a first hydraulic pressure generator and the second brake circuit comprising a second hydraulic pressure generator, which can be actuated electrically for control interventions. Furthermore, the hydraulic motor vehicle brake system comprises an electrically actuable third hydraulic pressure generator, and a controller which is configured to detect failure of at least one of the two brake circuits and a requirement of a control intervention on the at least one brake circuit, to actuate at least the third hydraulic pressure generator for assisting the control intervention.

A method for operating a hydraulic brake system of a motor vehicle having a brake booster and a hydraulic brake boost wherein a brake pressure is detected and an underpressure, prevailing in an underpressure chamber of the brake booster is estimated on the basis of the detected brake pressure. The hydraulic brake boost controlled based on the estimated underpressure, with the estimated underpressure taking into account an actuation of the hydraulic brake boost.

A vehicle brake system and method for increasing the brake pressure in a first wheel brake cylinder and for limiting the brake pressure in a second wheel brake cylinder of a vehicle brake system. The method includes increasing a first brake pressure in the first wheel brake cylinder by controlling/holding a wheel inlet valve in its open state and controlling/holding a first wheel outlet valve in its closed state, and limiting an increase of a second brake pressure in the second wheel brake cylinder during the transfer of brake fluid into the first wheel brake cylinder by controlling/holding a second wheel inlet valve in its closed state and controlling a second wheel outlet valve into its open state. The second wheel outlet valve is controlled with a pulse width-modulated signal so that during the transfer of brake fluid, the second wheel outlet valve is permanently in its open state.

A method and a system for verifying normal operation of a negative pressure sensor of a brake booster is provided. The method and system verify whether the negative pressure sensor of the brake booster is in normal operation and the normal operation of the booster negative pressure sensor is detected by mutually verifying values measured by the booster negative pressure sensor and values measured by sensors that indirectly sense the booster negative pressure.

A method for boosting a braking force in an electronically slip-controllable vehicle brake system, as well as an electronically slip-controllable vehicle brake system. Vehicle brake systems of this kind are at least equipped with a power brake unit and electronic slip-controllable vehicle brake system. In the case of a malfunction of the power brake unit, the traction-slip control device (92) takes over the boosting. A method for determining a composite signal which is adjusted by controlling a drive of a pressure generator of the slip-controllable vehicle brake system accordingly. To this end, an electronic control unit records two mutually independent input quantities, converts these input quantities into evaluation signals and sums the evaluation signals mathematically to yield a composite signal. The latter represents a setpoint brake pressure that the slip-controllable vehicle brake system supplies by controlling a pressure generator accordingly.

The method relates to a method for boosting the braking force in an electromotor operated slip-controllable vehicle brake system having electromechanical brake boosting. The vehicle brake system includes a braking-intention detection device, an electromechanically actuatable brake booster, and an electronically actuatable brake-pressure control device. In the event of a malfunction of the brake booster, the boosting of the brake pressure is alternatively assumed by the brake-pressure control device. In the event of a malfunction of the brake boosting, it is checked whether a generation and a transmission of a trigger signal representing the actuation of the braking-intention detection device from the first electronic control device of the brake booster to a second electronic control device of the brake-pressure control device is possible, and if this is so, the trigger signal is transmitted via an existing communications link between the control devices.

A hydraulic motor vehicle brake system comprises a vehicle dynamic control system which comprises a first brake circuit which acts on at least one first wheel brake, and a second brake circuit which acts on at least one second wheel brake, the first brake circuit comprising a first hydraulic pressure generator and the second brake circuit comprising a second hydraulic pressure generator, which can be actuated electrically for control interventions. Furthermore, the hydraulic motor vehicle brake system comprises an electrically actuable third hydraulic pressure generator, and a controller which is configured to detect failure of at least one of the two brake circuits and a requirement of a control intervention on the at least one brake circuit, to actuate at least the third hydraulic pressure generator for assisting the control intervention.