Denso Corporation

Yoichi Abe

Mamoru Sawada

Shuichi Yonemura

Takahiro Yamaguchi

Toshiya Morikawa

Takashi Sato

Takeshi Fuchida

Hideshi Mori

In the brake apparatus having a rotary pump, outer and inner rotors of the rotary pump are made of bearing steel and inner and outer teeth portions of the rotors are respectively processed by nitriding hardening or carbo-nitriding hardening. Accordingly, outer circumferential region of the outer teeth portion and inner circumferential region of the inner teeth are constituted by nitrided layer containing 15 to 40 percents retained austenite so that teeth faces of the outer and inner teeth portions in mesh may have higher wear resistance.

Hydraulic circuit having a rotary type pump and brake apparatus for a vehicle provided with the same

A characteristic changing device is adopted in the inventive brake control system for the vehicle. The characteristic changing device sets a differential pressure between a first brake hydraulic pressure which is applied to wheel cylinders and a second brake hydraulic pressure which is generated by a master cylinder so that the first brake hydraulic pressure is higher than the second hydraulic pressure when the second brake hydraulic pressure is reduced. Due to the differential pressure set as described above, the first brake hydraulic pressure enough to exhibit effective braking force is kept even if the second brake hydraulic pressure is reduced.

Brake control apparatus for vehicle

An operated quantity of a brake pedal is detected based on a signal from a stroke sensor. A starting criterion to start brake assisting is determined with respect to an operational speed of the brake pedal in response to the operated quantity of the brake pedal. An operated-quantity change is calculated by differentiating the operated quantity of the brake pedal. It is determined whether the operated-quantity change exceeds the starting criterion. If the operated-quantity change exceeds the starting criterion, brake assisting is started by driving a pump to increase wheel cylinder pressure.

Brake control apparatus for a vehicle

A hydraulic circuit has a rotary type pump comprising a rotor rotating with a driving shaft and a casing which holds the rotor and the driving shaft. The casing further comprises an inlet port through which fluid is introduced to spaces formed by the rotor, an outlet port through which fluid is discharged from the spaces, and a hydraulic path for leading fluid from clearance around said driving shaft to the outside of the casing. A reservoir is provided to store fluid coming through the hydraulic path. A return conduit is disposed between the reservoir and an upstream side conduit connected to the inlet port in order that fluid stored in the reservoir is returned to the upstream side conduit. In the return conduit, a check valve is disposed to prevent the reverse flow of fluid from the upstream side conduit to the reservoir.

Hydraulic circuit having a rotary type pump and brake apparatus for a

A brake control apparatus for a vehicle employs a pressure-amplifying device which reduces a quantity of brake fluid generating a first brake-fluid pressure in a first conduit connected to a master cylinder, and increases second brake-fluid pressure in a second conduit, applied to a wheel cylinder simultaneously with the reduction in brake-fluid quantity in the first conduit. As a result, increase in the first brake-fluid pressure is suppressed even when a driver depress a brake pedal and load to generate the first brake-fluid pressure is alleviated. Additionally, the pressure-amplifying device applies the increased second brake-fluid pressure to the wheel cylinder. Therefore, it is possible to ensure sufficient braking force.

Growing community of inventors

Kariya, Japan

Yoichi Abe