Atsugi Unisia Corp.

Atsugi Motor Parts Company, Limited

Unisia Jecs Corporation

Junichi Emura

Shinobu Kakizaki

Fumiyuki Yamaoka

Mitsuo Sasaki

Hiroyuki Shimizu

Makoto Kimura

Issei Kanari

Shigeru Kikushima

Toru Takahashi

Takayuki Furuya

Hideaki Saito

A method of driving a stepping motor comprises dividing a drive signal for each drive step into a plurality of portions in the direction of a time axis, and controlling the drive signal in connection with the plurality of portions thereof in a way of PWM so as to obtain a pattern of a gradual change in a on-duty ratio of the drive signal.

Method of driving stepping motor

A suspension control system for an automotive vehicle is disclosed in which, in each shock absorber, interposed between the vehicular body and tire wheel, a damping coefficient varying adjuster is provided which changes a damping coefficient at either or both of piston stroke sides according to a control signal input thereto so that the damping coefficient is set to a target damping coefficient position, at lease one sprung mass acceleration sensor and at least one sprung mass speed sensor are provided, and the control unit is provided which outputs the control signal to the damping coefficient varying means according to a result of determination of whether the vertical sprung mass acceleration exceeds a predetermined threshold value and according to a direction and magnitude of the sprung mass speed so that the damping coefficient at either or both of the stroke sides is controlled to a target damping coefficient position.

Suspension control system for automotive vehicle including apparatus for

An apparatus for controlling the damping coefficient of shock absorbers which are associated with the road wheels of the vehicle, produces control signals using one or more of a bouncing rate, a pitching rate and a rolling rate value which is filtered out of a plurality of outputs provided by a plurality of acceleration sensors which are each located in proximity of a shock absorber. The control signal can be modified using the outputs of weight sensors which are used to derive the relative velocities of the road wheels with respect to the vehicle body.

Apparatus for controlling damping coefficient of vehicular shock absorber

A variable damping characteristics shock absorber includes a piston provided with first and second disc valves. Within a piston, an annular space is defined between the first and second disc valves. The annular space is selectively communicated with upper and lower fluid chambers defined in a shock absorber cylinder tube via a by-pass path. A variable orifice formed by means of a rotary valve is provided in the by-pass path.

Shock absorber with damping valve structure having wide range variable

A suspension control system for an automotive vehicle comprises a multi-stage variable damping force shock absorber which is variable of damping characteristics at a plurality of mutually different damping modes. The control system also comprises means for monitoring a vehicular driving parameter representing a suspension control parameter, a plurality of data maps set in a memory unit respectively containing a damping characteristics selection pattern for deriving damping characteristics, toward which the damping characteristics of the shock absorber is to be controlled, on the basis of the suspension control parameter. Means, responsive to the current damping characteristics of the shock absorber, are provided for selecting one of the data map, and means for performing suspension control with selected one of data map for deriving a suspension control signal by looking-up the selected one of data map in terms of the suspension control parameter for controlling damping characteristics of the shock absorber.

Automotive suspension system with enhanced response characteristics

A shock absorber has a cylinder tube coaxially arranged with a strut tube for defining therebetween an annular reservoir chamber and an upper reservoir chamber which is separated from the annular reservoir chamber. A first fluid path is defined for permitting fluid flow from a lower fluid chamber in the cylinder tube to an upper fluid chamber and the annular reservoir chamber in response to bounding stroke of vibration. A second fluid path is also defined for permitting fluid flow from the lower fluid chamber and the annular reservoir chamber to the upper fluid chamber and the upper reservoir chamber, in response to rebounding stroke of vibration. A first flow restriction means is disposed in the first path for generating damping force in response to bounding stroke of vibration, which damping force is variable depending upon the magnitude of the bounding stroke in essentially linear variation characteristics. A second flow restriction means is also disposed in the second path for generating damping force in response to bounding stroke of vibration, which damping force is variable depending upon the magnitude of the bounding stroke in essentially linear variation characteristics.

Reverse installation type variable damping force shock absorber variable

A shock absorber employs a seal structure which can sucessfully prevent a working fluid from causing leak flow for enhanced variation characteristics of damping force. The seal structure includes a seamless seal member applied on a piston and/or on an inner periphery of a piston rod guide member.

Hydraulic shock absorber with piston seal structure for enhancement of

A suspension control system is designed to adjust suspension characteristics between hard and soft for bounding and rebounding stroke independently of each other. The system has a sensor means for monitoring speed of a vehicular body as a sprung mass for producing a vehicle body speed indicative signal, which vehicle body speed indicative signal has a variable signal polarity depending upon the direction of vibration, and a sensor means for monitoring relative speed between the vehicular body and a vehicular wheel as an unsprung mass for producing a relative speed indicative signal which also has a variable signal polarity depending upon the direction of relative movement of the vehicular body and the vehicular wheel. A control unit detects a combination of signal polarities of the vehicle body speed indicative signal and the relative speed indicative signal for adjusting damping characteristics for bounding and rebounding vibration independently of each other and depending on the detected combination.

Semi-active suspension control system with reduced switching frequency

An automotive suspension system employs a pressure sensor means designed for monitoring fluid pressure in a fluid chamber of shock absorber to be compressed during piston bounding stroke. Variable suspension characteristics to vary suspension mode between HARD mode and SOFT mode so that suspension mode is normally set in SOFT mode and switched into HARD mode when variation rate of the output of the sensor means becomes greater than a predetermined rate and when the output of the sensor means represents a pressure higher than a predetermined level in the piston bounding stroke.

Automotive suspension system and shock absorber therefor

An automotive suspension system employs a pressure sensor means designed for monitoring fluid pressure in a fluid chamber of shock absorber to be compressed during piston bounding stroke. Variable suspension characteristics to vary suspension mode between HARD mode and SOFT mode so that suspension mode is normally set in SOFT mode and switched into HARD mode when the peak value of variation rate of the output of the sensor means is detected. The suspension system is provided a deadband for maintaining the suspension mode unchanged even when the peak of variation rate is detected.

Automotive suspension system with variable suspension characteristics

A hydraulic shock absorber is provided a capability of quick response in such an extent that harder damping characteristics is provided during bounding stroke in each vibration cycle and softer damping characteristics is provided during rebounding stoke in each vibration cycle. The hydraulic shock absorber is controlled the damping characteristics for damping road shock by switching damping characteristics between harder damping characteristics and softer damping characteristics during normal mode operation. On the other hand, in attitude change suppression mode, suspension characteristics for suppressing vehicular body attitude change irrespective of the vibration mode.

Damping characteristics variable hydraulic shock absorber for automotive

A variable-damping-force shock absorber such that the damping force determined through an orifice selected by an orifice adjuster according to the driver's preference can further automatically be increased during extension for improvement in road-holding ability and decreased during compression for improvement in riding comfort. The shock absorber according to the present invention comprises an annular member formed with an orifice and a disk valve disposed on top of the annular member. During extension, the disk valve is closed for allowing fluid to by-pass through an orifice of the annular member; during compression, the disk valve is opened for additionally allowing fluid to by-pass through the annular member. Further, since the various elements for adjusting the damping force are completely housed within the piston rod, it is possible to increase the stroke of the piston rod.

Variable-damping-force shock absorber

A variable-damping-force shock absorber in which the motor for rotating the orifice adjuster is housed within the cylinder and the orifice-adjuster position sensor for outputting binary coded sensor signals is incorporated. Therefore, it is possible to reduce noise generated from the motor while improving the lifetime of the motor because mud or rain water will not adhere onto the motor and to improve the precision and the response speed in rotating the orifice adjuster because the adjuster can be feedback controlled in digital fashion. Further, since the driven shaft of the motor or the reduction gear is loosely coupled with the orifice adjuster in the axial direction thereof, it is possible to reduce the torque or the size of the motor, because fluid pressure is not directly applied to the driven shaft via the orifice adjuster.

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Kanagawa, Japan

Junichi Emura