Denso Corporation

Youichi Abe

Mamoru Sawada

Shuichi Yonemura

Syuichi Yonemura

A first fluid line couples first and second wheel cylinders. A second fluid line couples third and fourth wheel cylinders. A first pressure increasing unit increases pressure applied to the first and second wheel cylinders to a second pressure level which is greater than a first pressure generated by a master cylinder. When the first pressure increasing unit is in operation, a pressure difference setting unit sets a difference between pressure applied to the first and second wheel cylinders and pressure applied to the third and fourth wheel cylinders.

Vehicular brake system for performing effective brake operations

A vehicle braking system can, for example when the performance of a booster has deteriorated, reduce a brake pedal depressing force required to obtain a sufficient braking force and thereby lighten the burden on the driver. A booster and a master cylinder generate a brake fluid pressure in correspondence with an operation of a brake pedal. Wheel cylinders connected to the master cylinder generate wheel braking forces in wheels of the vehicle. It is determined if a vehicle braking state corresponds to a state of operation of the brake pedal, and when it is determined that the vehicle braking state does not correspond to the brake pedal operation brake fluid pressure in the wheel cylinders is increased with a pump. In this way, it is possible to obtain a predetermined braking force corresponding to the brake pedal operation at all times.

Braking system for a vehicle

When a vacuum booster fails, an pressure amplifying mechanism increases a wheel brake pressure. After that, even when it is detected that the vehicle is brought into a stopped state, the state in which an increased brake fluid pressure is applied to wheel cylinders is held. If a condition for terminating control to maintain a stationary state of the vehicle is satisfied, that is, if a predetermined time period has elapsed since when the vehicle stops, the operation of the pressure amplifying mechanism is stopped to reduce the wheel cylinder pressure.

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Kariya, Japan

Youichi Abe