Abstract: The suspension system has a cylinder unit disposed at each wheel for displacing a vehicle height of the vehicle body by a supply or a discharge of operating liquid and a vehicle height sensor disposed at each wheel for sensing the vehicle height of the body. An actual status amount of the posture of the body, such as a pitch amount or a roll amount, is determined on the basis of output from the vehicle height sensor, thereby controlling the supply or discharge of the operating liquid to or from the cylinder unit in order to allow the actual posture amount to reach a given target value. When the running status is detected to such an extent that changes the status amount, the target value can be corrected in anticipation prior to a change in the posture status amount, thereby preventing the change in the posture status amount.

Abstract: A vehicle suspension system includes a liquid piston-cylinder device connected between the vehicle body and a wheel. A liquid pump is provided in a liquid passage which connects the liquid piston-cylinder device to a reservoir in which hydraulic liquid is reserved, and feeds under pressure the hydraulic liquid in the reservoir through the liquid passage. A control valve controls the flow of the hydraulic liquid through the liquid passage, thereby controlling feed and discharge of the hydraulic liquid to and from the liquid piston-cylinder device in order to control the properties of the suspension. An accumulator is connected to the liquid passage between the liquid pump and the control valve and accumulates the hydraulic liquid under pressure. A return passage connects the reservoir to the liquid passage between the liquid pump and the control valve and is provided with an on-off valve which opens and closes the return passage.

Abstract: 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.

Abstract: A vehicle suspension system including a hydraulic cylinder and a gas spring having a gas chamber and a hydraulic chamber which is connected with the hydraulic cylinder. The hydraulic cylinder is located between the vehicle body and the wheel to support the body on the wheels. A control valve is provided for controlling the supply of hydraulic pressure to the cylidner in accordance with a signal from a control unit. The control unit receives a detection signal from a detector which detects the pressure in the cylinder and produces a control signal in accordance with a transfer function H(s)=R.times.S/(1+R.times.S).

Abstract: The suspension system of the present invention comprises support means installed between a wheel and the vehicle body exerting suspension force which can be changed irrespective of relative displacement between the wheel and the vehicle body. According to low frequency components of a parameter which respresents changing condition of the relative displacement, the support means is controlled to exert a suspension force in such a way that the relative displacement can be suppressed. Such parameters include the relative displacement and the rate of the change thereof.According to the present invention, suspension characteristics can be maintained to maintain riding qualities and rolling and pitching properties in a preferable condition throughout all running conditions.

Abstract: The method comprises determining a first resonant frequency of a system comprising a vibratory body, a supporting body and a vibration damping device disposed therebetween. Vibrations at the first resonant frequency are dampened by defining first and second chambers in the device which are separate from each other and communicate with each other through a passage configured to impart a second resonant frequency to fluid received within the passage which substantially equals the first resonant frequency.

Abstract: A damper of a vibration damping system is installed to connect a power unit and a vehicle body and disposed independent from power unit mount devices. The damper is positioned in the direction of a tangent line of the direction of roll of the power unit. The damper consists of an elastomeric wall member defining a first fluid chamber and connected to the power unit, and an elastomeric diaphragm member defining a second fluid chamber which is communicated through a communication passage with the first fluid chamber. A liquid is filled in the first and second fluid chambers and the communication passage. The volume of the communication passage is changed in response to engine speed of the power unit, thereby effectively damping vibrations of the power unit in roll direction.

Abstract: A suspension system consists of a suspension rod interposed between a vehicle body side member and a wheel side member to elastically connect them. The suspension rod includes a first elastomeric member connected to the vehicle body side member and defining a first fluid chamber. A second elastomeric member is provided in the suspension rod structure to be connected to the wheel side member, defining a second fluid chamber. The first and second fluid chambers are communicated with each other through a fluid communication passage. An incompressive fluid is filled in the first and second fluid chambers and in the fluid communication passage, thereby constituting a fluid dynamic damper for suppressing resonance vibration of the suspension system.

Abstract: An improved power unit mounting device capable of dumping in a wide range of frequency of vibration. The device having an inner liquid chamber comprises an auxiliary chamber provided on a chassis separately from the mounting device proper. The mounting device proper is formed with the inner chamber communicating with the auxiliary chamber through a plurality of fluid channels.

Abstract: A fluid-containing power unit mount device in which an elastic member is secured between a power unit side base plate and a vehicle body side base plate to form an inner space. A fluid is enclosed in the inner space, forming a fluid chamber. An aperture is provided in one of the base plates, and this aperture is blocked by an elastic member on which is mounted a mass body.

Abstract: A mounting apparatus for a power unit comprises a first elastic member comprising a rubber-like elastic member and a second elastic member comprising rubber-like elastic members and a mass member therebetween. The first and second elastic members are disposed in parallel, wherein the weight of mass member can be changed or the second elastic member can be functionally engaged and disengaged with the first elastic member so that the reduction of the spring constant or oscillation transmitting rate is obtained just above the resonant frequency of the second elastic member while the degrading of the oscillation transmitting can be prevented below the resonant frequency.

Abstract: A structure for supporting a power unit for a vehicle wherein the power unit comprises an engine proper and a transmission housing. The transmission housing is connected with the engine proper in a direction transversely of the vehicle body. The engine proper is supported on one of two longitudinally extending side members on or near a principal axis of inertia of the power unit and the transmission housing is supported on the other of the side members at two points in opposed relation to each other with respect to the axis.