Abstract: Provided is a damper with which the energy efficiency for attenuating input vibration corresponding to the unsprung resonance frequency and the sprung resonance frequency can be improved. Also provided is a method for manufacturing this damper. In this damper the electrical resonance frequency, as specified by the inductance of an electromagnetic motor and the capacitance of a capacitor, is set within ±20% of the unsprung resonance frequency, thereby enabling the input vibration corresponding to the sprung resonance frequency as well as the input vibration corresponding to the unsprung resonance frequency to be reduced.

Abstract: Provided is a damper with which the energy efficiency for attenuating input vibration corresponding to the unsprung resonance frequency and the sprung resonance frequency can be improved. Also provided is a method for manufacturing this damper. In this damper the electrical resonance frequency, as specified by the inductance of an electromagnetic motor and the capacitance of a capacitor, is set within ±20% of the unsprung resonance frequency, thereby enabling the input vibration corresponding to the sprung resonance frequency as well as the input vibration corresponding to the unsprung resonance frequency to be reduced.

Abstract: A damper includes a polarized capacitor electrically connected to an electromagnetic motor. The surface area at a first fluid chamber side of a piston head is different from the surface area at a second fluid chamber side of the piston head in a cylinder. A positive electrode side of the polarized capacitor is connected to the electromagnetic motor at a side at which output voltage from the electromagnetic motor is positive when the piston head is displaced toward the first fluid chamber side.

Abstract: A damper includes a polarized capacitor electrically connected to an electromagnetic motor. The surface area at a first fluid chamber side of a piston head is different from the surface area at a second fluid chamber side of the piston head in a cylinder. A positive electrode side of the polarized capacitor is connected to the electromagnetic motor at a side at which output voltage from the electromagnetic motor is positive when the piston head is displaced toward the first fluid chamber side.

Abstract: An energy-regenerating damper including a piston provided with a housing fitted inside a cylinder so as to be able to slide against the inner surface of the cylinder, a stator contained in/fixed to the inside of the housing, a rotor supported so as to be able to rotate inside the stator, and damping valves provided at the top and bottom ends of the housing. The housing includes an upper half and a lower half fastened together by bolts, and a damper rod is fixed to the top end of the upper half. The upper half and the lower half each contain a bearing for supporting the rotor. A plurality of orifices through which a hydraulic oil circulates are drilled towards the outsides of the upper half and lower half, and circulation holes through which the hydraulic oil circulates are drilled towards the insides of the upper half and lower half.

Abstract: Disclosed is an energy-regenerating damper that ensures a compression stroke and has a simplified structure. A piston (16) is provided with: a housing (31) fitted inside a cylinder (12) so as to be able to slide against the inner surface of the cylinder; a stator (32) contained in/fixed to the inside of the housing (31); a rotor (33) supported so as to be able to rotate inside the stator (32); and damping valves (34, 35) provided at the top and bottom ends of the housing (31). The housing (31) comprises an upper half (31a) and a lower half (31b) fastened together by bolts (36), and a damper rod (13) is fixed to the top end of the upper half (31a). The upper half (31a) and the lower half (31b) each contain a bearing (39) for supporting the rotor (33).

Abstract: A damper of variable damping force adapted to be built into a vehicular suspension is disclosed. The damper has frictional force generating means for applying a frictional force to a rod. The frictional force generating means is disposed at one end of a cylinder and positioned externally of the latter.

Abstract: A device for driving a solenoid including a power supply, a switching element connected between the power supply and the solenoid in series therewith, a current circulating diode connected in parallel to the solenoid, a current detecting circuit for detecting an actual current flowing through the solenoid, and a PID computing unit for computing an on-duty value and an off-duty value according to a difference between a target current and the actual current detected and for outputting the on-duty value and the off-duty value. The device further includes a PWM duty driving unit for generating a PWM duty signal according to inputting of the on-duty value and supplying the PWM duty signal to the switching element to on/off control the switching element, and a reverse voltage applying circuit capable of applying a voltage of the power supply as a reverse voltage to the solenoid according to inputting of the off-duty value when the switching element is off.

Abstract: A device for driving a solenoid including a power supply, a switching element connected between the power supply and the solenoid in series therewith, a current circulating diode connected in parallel to the solenoid, a current detecting circuit for detecting an actual current flowing through the solenoid, and a PID computing unit for computing an on-duty value and an off-duty value according to a difference between a target current and the actual current detected and for outputting the on-duty value and the off-duty value.

Abstract: A cockpit is supported by a motion base in a state of being capable of making swinging movement. A host computer calculate vehicle motion information in accordance with operation of various operation equipments performed by a driver accommodated in the cockpit. A simulation image is formed, the cockpit is controlled for swinging movement, and various meters or the like in the cockpit are controlled on the basis of an obtained result of the calculation. Thus, the drive simulation is carried out in a state approximate to that of a real vehicle.

Abstract: A feed-forward control section controls, in a feed-forward manner, left and right hydraulic clutches C.sub.L and C.sub.R of a driving force distributing device by presuming such a driving force distribution amount .DELTA.T that a yaw rate corresponding to a turning state of a vehicle is obtained, based on an engine torque, an engine revolution-number, a vehicle speed, a steering angle and a lateral acceleration. On the other hand, a feedback control section calculates a deviation between a reference yaw rate calculated from the vehicle speed and the lateral acceleration and an actual yaw rate detected by a yaw rate sensor, and corrects the driving force distribution amount .DELTA.T calculating in the driving force distributing device in order to converge the deviation into zero.

Abstract: A small-sized damper is provided which enables to effectively vary the damping force of a damper even in a region in which the moving speed of a rod is small. On one of a damper main body and a rod which is inserted into the damper main body, there are mounted a magnet coil having a winding axial line which is coaxial with the damper, and magnetizable attracting members. By electric charging to the magnet coil, the magnetizable attracting members are attracted into contact with the other of the damper main body and the rod.

Abstract: An active engine mount system for supporting an engine on a vehicle body is used for controlling the vertical movement of the vehicle body produced by irregularities of the road surface. The engine mount system comprises an actuator interposed between the engine and the vehicle body for applying a vertical force to the vehicle body so that the vertical acceleration of the vehicle body for each given condition of the road surface may be minimized by adjusting a contribution of the mass of the engine to the mass of the vehicle body. The engine mount system may consist of a full active or semi active mount system. By detecting the road condition ahead of the vehicle, a particularly favorable result can be achieved.

Abstract: In a vehicle suspension system including a hydraulic actuator between a sprung mass consisting substantially of a vehicle body and an unsprung mass consisting substantially of a wheel, a force proportional to but opposite in phase to an inertia force acting on the unsprung mass is applied by the actuator to the unsprung mass so that the ability of the tire to maintain contact with the road surface may be improved. This produces very little effect on the behavior of the sprung mass, but the vehicle handling is significantly improved. Better contact with the road surface not only improves the vehicle handling but also reduces the consumption of energy by the hydraulic actuator. A particularly favorable result can be obtained when the hydraulic actuator further applies a damping force proportional to the absolute velocity of the sprung mass to the sprung mass.

Abstract: In an active vehicle suspension system employing a spring and a hydraulic actuator for supporting a wheel relative to a vehicle body, a control unit actuates the actuator so as to cancel the force applied by the spring force of the spring and a damping force applied by the hydraulic actuator. This damping force is typically produced by the flow resistance which the hydraulic oil encounters in the hydraulic circuit. This control action is carried out according to a signal obtained by processing an output of a displacement sensor between the wheel and the vehicle body with a first-order lead filter circuit. Thus, the control action is based on a readily available and highly responsive detection signal, an accurate and stable vibration control of the sprung mass of the vehicle or the vehicle body is made possible.

Abstract: In an active vehicle suspension system employing a double acting type single rod hydraulic linear actuator in which a piston is provided with two pressure receiving surfaces facing two different piston chambers defined by the piston received in a cylinder and having different areas, even when the line pressure of the hydraulic oil passage is lost, the height of the vehicle body can be maintained at a fixed level and a sudden change of the height of the vehicle body can be avoided by providing a hydraulic control device which appropriately controls the pressures of the upper and lower chambers so as to be inversely proportional to the areas of the corresponding pressure receiving surfaces as the pressure supplied to the hydraulic actuator is reduced.

Abstract: In an hydraulic active vehicle suspension system using a linear hydraulic cylinder as a primary actuator, controlled hydraulic pressure is supplied to an upper chamber of the hydraulic cylinder defined by a smaller pressure receiving surface of the piston and the cylinder while a reduced and fixed pressure is supplied to a lower chamber of the hydraulic cylinder defined by a larger pressure receiving surface of the piston and the cylinder, and an accumulator is connected to the lower chamber so that a desired hydraulic actuation can be accomplished by the controlled hydraulic pressure while sudden forces or inputs containing high frequency components applied to the lower chamber are absorbed by the accumulator.

Abstract: A hydraulic control device for an active suspension system employing a linear hydraulic cylinder including a piston connected in parallel with a spring between a wheel and a vehicle body, the piston having two pressure receiving surfaces of different areas facing two chambers separated by the piston in the cylinder, comprising a balancing valve for reducing the pressures of the two chambers to a level near the atmospheric pressure, a switch valve provided in a bypass passage between the two chambers for selectively communicating the two chambers with each other, a flow restricting orifice provided in the bypass passage; and an accumulator connected to the bypass passage capable of accommodating a change in the capacity of one of the chambers due to a piston rod extending from the piston out of the cylinder when the pressures of the two chambers are at the level near the atmospheric pressure.

Abstract: For better handling and improved riding comfort of a vehicle, there is provided a compound suspension system comprising a plurality of hydraulic shock absorbers each having a front chamber and a back chamber defined in front of and behind a piston member, respectively, received in a cylinder member, and a valve structure provided in each of the shock absorbers for selectively communicating the chambers to a conduit which is common to at least one other shock absorber, wherein: the valve structure comprises a valve element provided with a first part for varying a degree of communication between the front chamber and the common conduit and a second part for varying a degree of communication between the front chamber and the back chamber.