Mazda Motor Corporation

Shoichi Kamimura

Shin Takehara

Takeshi Edahiro

Toshiki Morita

Kenichi Watanabe

Akihiko Miyoshi

Hiroyoshi Kumada

A suspension system for an automotive vehicle has a cylinder interposed between a sprang weight and an unsprung weight for each of wheels so as to control the supply or discharge of operating liquid to the cylinder independently and separately, thereby controlling the posture of the vehicle body. This suspension system allows a slow control over the posture of the vehicle body, for example, by lowering a control gain for the posture control when the vehicle body is jacked up in order to exchange tires, inspection of the vehicle body, etc., to a greater degree than when the vehicle is running at ordinary conditions.

Suspension system for automotive vehicle

A suspension apparatus of a vehicle has a cylinder unit interposed between a sprang weight and an unsprung weight, which changes a ride height of the vehicle body by supplying or discharging an operating liquid through a supply/discharge control valve. The supply/discharge control value is controlled on the basis of a predetermined condition so as to control a posture of the vehicle body. There are further provided a bump detecting sensor for detecting a bump of each of the wheels, which occurs further from a state in which the wheel is bumped, and a pressure detecting sensor for detecting a pressure in the cylinder unit. When it is sensed by the bump detecting sensor that the bump occurs further from the bumping state, if the pressure detected by the pressure detecting sensor is continued in a lowering state for a given period of time, it is judged that the supply/discharge control valve is in trouble.

Suspension apparatus of a vehicle

A suspension apparatus of a vehicle has a cylinder unit interposed between a sprang weight and an unsprung weight, which changes a ride height of the vehicle body by supplying or discharging an operating liquid through a supply/discharge control valve. The supply/discharge control value is controlled on the basis of a predetermined condition so as to control a posture of the vehicle body. There are further provided a rebound detecting sensor for detecting a rebound of each of the wheels, which occurs further from a state in which the wheel is rebounded, and a pressure detecting sensor for detecting a pressure in the cylinder unit. When it is sensed by the rebound detecting sensor that the rebound occurs further from the rebounding state, if the pressure detected by the pressure detecting sensor is continued in an elevating state for a given period of time, it is judged that the supply/discharge control valve is in trouble.

A vehicle suspension system has fluid cylinders connected between the vehicle body and the respective wheels. A fluid control system controls feed and discharge of hydraulic fluid to and from the fluid cylinders and changes the suspension properties of the suspension system. A failure in the fluid control system is detected and when the control system fails, one of first to third measure modes is taken on the basis of the kind of the failure. Warning is just given and the control of feed and discharge of hydraulic fluid to and from the fluid cylinders being continued when the first measure mode is taken, the control of feed and discharge of hydraulic fluid to and from the fluid cylinders is interrupted with the chassis height fixed to the present height when the second measure mode is taken, and the fluid in the fluid cylinders is discharged and the chassis height is lowered when the third measure mode is taken.

Vehicle suspension system

An actuator for adjusting a height of the vehicle body is provided for each of the wheels and the height of the body is adjusted for each of the wheels by supplying and discharging an operating fluid to and from the actuator. A vehicle-height detecting sensor is also provided on each wheel for detecting the height of the vehicle body and for control over a posture of the body, namely, control over a supply or discharge of the operating liquid to or from the actuator is implemented with respect to bouncing, pitching or rolling of the body on the basis of output from the vehicle-height detecting sensor. Furthermore, a plurality of vertical G sensors for detecting acceleration in a vertical direction are provided to sense bouncing, pitching and rolling components of acceleration in the vertical direction, and the posture control utilizing the vehicle-height sensor is corrected so as not to make the vertical acceleration for the three components larger. Three vertical G sensors are provided so as to define a virtual plane representing the body, and that, for instance, two of the three vertical G sensors are disposed on the front portion of the body at positions bilaterally symmetrical to each other and one thereof is disposed on the rear portion thereof at a middle position, thereby allowing the three vertical G sensors to enable a detection of the acceleration in the vertical direction with respect to the bouncing, pitching and rolling components.

A friction detecting device comprising running condition detector for detecting a running condition of a vehicle including a lateral acceleration acting on a gravity center of the vehicle, steering angle detector for detecting steering angle of front and rear wheels of the vehicle, vehicle speed sensor, memory for storing stability factors of the vehicle including a vehicle weight, respective distances between the gravity center and front and rear axles, cornering powers acting on the front and rear wheels at a standard condition and a yawing moment of inertia, control unit for obtaining a frictional coefficient .mu. of a road surface on which the vehicle is running by employing a following formula;

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Hiroshima, Japan

Shoichi Kamimura