Nippondenso Co., Ltd.

Masuhiro Kondo

Kazutoshi Yogo

Hideo Wakata

Masahiko Kamiya

Yuzo Imoto

Nobuyoshi Onogi

Takahiro Goshima

Vibration observed in a tire wheel portion exhibits a resonant vibration phenomenon in which vibration fluctuates between a wheel and a surface of a tire. This phenomenon shows different characteristics depending upon how the surface of the tire is in contact with a road surface. Here, a detector derives a parameter corresponding to a gradient of a coefficient of friction based on these characteristics and detects a brake condition. Also, a controller executes ABS control based on such parameter.

Brake condition detector and vehicle controller using the same

A brake control system for a motor vehicle which is equipped with a running state detector for detecting a running state of the motor vehicle so as to adjust a braking pressure in a wheel-braking cylinder of the motor vehicle in accordance with the detected vehicle running state. The brake control system has a first restriction adjusting valve provided between a hydraulic pressure generating source and the wheel-braking cylinder for adjusting the braking pressure to be supplied from the hydraulic pressure generating source to the wheel-braking cylinder, and a second restriction adjusting valve provided between the wheel-braking cylinder and a reservoir for adjusting a braking liquid to be discharged from the wheel-braking cylinder to the reservoir. Also included in the system is a control unit for outputting control signals to the first and second restriction adjusting valves so as to control the braking pressure in the wheel-braking cylinder in accordance with the detected vehicle running state. This arrangement allows setting of the braking hydraulic pressure increasing and decreasing speeds so as to permit a smooth brake control operation.

Brake control system and restriction adjusting valve for vehicles

A pressure control valve for use in an automobile braking system includes a spool slidably movable for providing selective fluid communication between a pressure fluid source, a wheel cylinder, and a reservoir. The spool has, or is associated with, a pressure-bearing member responsive to a fluid pressure from the wheel cylinder, for applying a first biasing force to the slidable member to urge the slidable member to a position in which the wheel cylinder and the reservoir communicates with each other. An electromagnetic coil responds to an electric signal for generating an electromagnetic force to urge the slidable member to the above position. The slidable member is normally biased by a spring under a second biasing force, greater than the first biasing force, to urge the slidable member to a position in which the pressure fluid source and the wheel cylinder communicate with each other. The fluid pressure in the wheel cylinder is regulated to cause the sum of the fluid pressure in the wheel cylinder and the electromagnetic force from the electromagnetic coil to counterbalance the second biasing force.

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Chiryu, Japan

Masuhiro Kondo