Automatic level control system for automotive vehicle with fail-safe system therefor
First Claim
1. A height control system for an automotive vehicle comprising:
- an actuator means, disposed between a vehicle body and a vehicular wheel axle, for adjusting the vertical separation between said vehicle body and said wheel axle by controlling an actuator so as to adjust vehicle height to a given height;
a damper control means, cooperative with said actuator means, for adjusting damping characteristics of a vehicular suspension system, which damper control means adjusts the damping characteristics by adjusting a damper pressure relative to said actuator pressure;
a vehicle height sensor for monitoring vehicle height and producing a vehicle height indicative signal;
a detector responsive to said vehicle height indicative signal for detecting when the vehile height lies outside of a predetermined height range; and
a controller responsive to said detector detecting vehicle height outside of said predetermined height range for operating said actuator means to adjust said actuator pressure so as to adjust the vehicle height to within said predetermined height range, said controller also operating said damper control means so as to hold said damper pressure substantially equal to said actuator pressure during height adjustment.
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Accused Products
Abstract
An automotive height control system for an automotive vehicle includes an actuator disposed within a vehicle suspension system for adjusting the vertical dimension between a vehicle body and a wheel axle. The actuator is connected to a controller to receive a control signal which orders adjustment of the vehicle height. The height control system further includes a damping characteristics controller cooperative with the actuator for adjusting damping characteristics of the suspension system according to the vehicle height. In addition, the system is provided with a vehicle height sensor which monitors the height of the vehicle from the road surface and provides a vehicle height indicative signal. A fail-safe system detects abnormal height conditions as indicated by the vehicle height indicative signal to produce a fail-safe signal. The actuator and the damping characteristics controller respond to the fail-safe signal by equalizing their internal pressures.
129 Citations
19 Claims
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1. A height control system for an automotive vehicle comprising:
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an actuator means, disposed between a vehicle body and a vehicular wheel axle, for adjusting the vertical separation between said vehicle body and said wheel axle by controlling an actuator so as to adjust vehicle height to a given height; a damper control means, cooperative with said actuator means, for adjusting damping characteristics of a vehicular suspension system, which damper control means adjusts the damping characteristics by adjusting a damper pressure relative to said actuator pressure; a vehicle height sensor for monitoring vehicle height and producing a vehicle height indicative signal; a detector responsive to said vehicle height indicative signal for detecting when the vehile height lies outside of a predetermined height range; and a controller responsive to said detector detecting vehicle height outside of said predetermined height range for operating said actuator means to adjust said actuator pressure so as to adjust the vehicle height to within said predetermined height range, said controller also operating said damper control means so as to hold said damper pressure substantially equal to said actuator pressure during height adjustment. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A height control system for an automotive vehicle comprising:
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a suspension strut disposed between a vehicle body and a vehicular wheel axle; a first pneumatic chamber associated with said suspension strut and adapted to adjust the vertical separation between said vehicle body and said wheel axle by controlling a pressure therein so as to hold vehicle height at a given height; a second pneumatic chamber connected to said first pneumatic chamber through a communication passage; a pneumatic pressure supply circuit connected to said first pneumatic chamber for introducing and exhausting the pneumatic pressure into and from said first pneumatic chamber for adjusting the pneumatic pressure within the latter; a pressure control valve means disposed within said pneumatic pressure supply circuit, for controlling introduction and exhausting of the pneumatic pressure in said first pneumatic chamber; a damper control valve means disposed within said communication passage for establishing and blocking communication between said first and second pneumatic chambers for adjusting the effective volume of the first pneumatic chamber; a vehicle height sensor for monitoring vehicle height and producing a vehicle height indicative signal; a detector responsive to said vehicle height indicative signal for detecting when the vehicle height lies outside of a predetermined height range; and a controller responsive to said detector detecting said vehicle height outside of said predetermined height range for operating said pressure control valve means so as to adjust vehicle height to within said predetermined height range, said controller also operating said damper control valve means so as to hold said damper control valve means open during vehicle height adjustment. - View Dependent Claims (14, 15)
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16. In a height control system for an automotive vehicle comprising:
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a suspension strut disposed between a vehicle body and a vehicular wheel axle; a first pneumatic chamber associated with said suspension strut and adapted to adjust the vertical separation between said vehicle body and said wheel axle by controlling a pressure therein so as to hold vehicle height at a given height; a second pneumatic chamber connected to said first pneumatic chamber through a communication passage; a pneumatic pressure supply circuit connected to said first pneumatic chamber for introducing and exhausting the pneumatic pressure into and from said first pneumatic chamber for adjusting the pneumatic pressure within the latter; a pressure control valve means disposed within said pneumatic pressure supply circuit, for controlling introduction and exhausting of the pneumatic pressure in said first pneumatic chamber; a damper control valve means disposed within said communication passage for establishing and blocking communication between said first and second pneumatic chambers for adjusting the effective volume of the first pneumatic chamber; a vehicle height sensor for monitoring vehicle height and producing a vehicle height indicative signal; a detector responsive to said vehicle height indicative signal for detecting when the vehicle height lies outside of a predetermined height range, and a controller for controlling operation of said pressure control valve means and said damper control valve means, a process for performing vehicle height control comprising the steps of; monitoring varition of said vehicle height indicative signal value and detecting when vehicle height lies outside of a predetermined range; opening said damper control valve in response to a vehicle height indicative signal value indicative of a vehicle height outside of said predetermined range; measuring elapsed time starting from detection of said vehicle height indicative signal value indicative of vehicle height outside of said predetermined range and continuing for as long as the vehicle height remains outside of said predetermined range; when said elapsed time exceeds a predetermined period, operating said pressure control valve so as to adjust pnuematic pressure in said first pneumatic chamber in order to return the vehicle height within said predetermined range; and holding said damper control valve open during said pressure control valve operation step. - View Dependent Claims (17, 18, 19)
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Specification