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US 4,796,911 AGranted
Automotive suspension system with roll-stabilizer having road condition-dependent torsion modulus, and control of torsional modules
AssigneeNissan Motor Co., Ltd.
InventorsJunsuke Kuroki, Tohru Takahashi, Ken Ito
Life of this patent
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Abstract
An automotive suspension system has a roll stablizer with an adjustable torsion modulus. The torsion modulus of the stabilizer is adjusted depending upon road surface conditions and other parameters. A controller is associated with the stabilizer to adjust its torsion modulus. When the vehicle is moving on a relatively smooth road surface, the torsion modulus of the stabilizer is adjusted toward to a relatively high value. On the other hand, when the vehicle travels along a rough road, the torsion modulus is adjusted toward a lower value.
Claims23
An automotive vehicle suspension system comprising:
- first means for rotatably supporting a pair of vehicle wheels and for supporting a vehicle body;
- a roll stabilizer connected to said first means and extending perpendicular to the longtudinal axis of the vehicle, said stabilizer producing a damping force against rolling moment applied to said first means, said stabilizer including second means for adjusting torsion modulus of the stabilizer to adjust the damping force produced;
- an actuator associated with said second means for operating said second means to adjust the torsion modulus of the stabilizer;
- a detector adapted to detect a preselected vehicle driving condition-indicative parameter and produce a detector signal indicative thereof;
- and
- a controller including means responsive to the detector signals for deriving a smooth or rough road condition indicative signal on the bases of the detector signals relative to a predetermined road roughness, and means responsive to the road condition indicative signal for providing a control signal indicative of the road condition to said actuator to activate the latter so as to adjust the torsion modulus of said stabilizer and the damping force produced thereby at least between a higher and a lower value responsive to the smooth or rough road condition indicative signal, respectively;
- said stabilizer comprising a first torsion bar segment associated with a first portion of said first means near one of said vehicle wheels and a second torsion bar segment associated with a second portion of said first means near a second vehicle wheel, and said second means comprising a connector tube to which the proximal ends of said first and second segments are connected, said connector tube being filled with a magnetic fluid in which the concentration of ferromagnetic material included therein is subject to adjustable spacial gradients according to external magnetic fields, which in turn influences the torsion modulus of the stabilizer, and said actuator comprising third means for producing a magnetic field with an adjustable field strength around said connector tube, which field strength is determined by said control signal.
4 more elements
An automotive vehicle suspension system comprising:
- first means for rotatably supporting a pair of vehicle wheels and for supporting a vehicle body;
- a roll stabilizer connected to said first means and extending perpendicular to the longitudinal axis of the vehicle, said stabilizer producing a damping force against rolling moment applied to said first means, said stabilizer including second means for adjusting the torsion modulus of the stabilizer to adjust the damping force produced;
- an actuator associated with said second means for operating said second means to adjust the torsion modulus of the stabilizer;
- road condition detecting means including a road sensor utilizing ultrasonic waves to measure the distance between the road surface and the vehicle body for detecting road surface conditions and for producing signals indicative of the measured distance;
- a controller including means:
- for periodically sampling the detector signals indicative of the measured distance between vehicle body and road surface and producing sampled distance values;
- for averaging the sampled distance values to derive an average value;
- for comparing the average value with each of said sampled distance values to derive difference therebetween;
- for counting the number of differences greater than a given reference value;
- for comparing the counted number with a given threshold and providing a road condition indicative signal representing that the vehicle is on a relatively smooth road surface when the counted number is less than said threshold;
- and
- responsive to the road condition indicative signal for deriving a desired value of the torsion modulus to be produced by said stabilizer and feeding a control signal indicative of the derived value of the torsion modulus to said actuator to activate the latter so as to adjust the damping force to be produced by the stabilizer.
9 more elements
An automotive vehicle system comprising:
- a suspension system interposed between road wheels and a vehicle body and having variable characteristics at least between a softer suspensin mode and a harder suspension mode;
- road condition detecting means including a road sensor to measure the distance between the road surface and the vehicle body for detecting road surface conditions and for producing signals indicative of the measured distance;
- and
- controller means associated with said suspension system for controlling suspension characteristics thereof, depending upon roughness of the road surface, at least between said softer suspension mode and said harder suspension mode, said controller means including means for periodically sampling the detector signals indicative of the measured distance between vehicle body and road surface and producing sampled distance values, means for averaging the sampled distance values to derive an average value, means for comparing the average value with each of said sampled distance values to derive a difference therebetween, means for counting the number of differences greater than a given reference value, means for comparing the counter number with a given threshold and providing a road roughness indicative signal representing that the vehicle is on a relatively smooth road surface when the counted number is less than said threshold;
- said controller means being responsive to the roughness indicative signal for operating said suspension system in the harder suspension mode.
2 more elements
An automotive vehicle suspension system comprising:
- a suspension system interposed between road wheels and a vehicle body and having variable suspension characteristics;
- road condition detecting means including a road sensor to measure the distance between the road surface and the vehicle body for detecting road surface conditions and for producing signals indicative of the measured distance;
- and
- a controller means associated with said suspension system for controling suspension characteristics thereof, depending upon the roughness of the road surface, at least between a softer suspension mode and a harder suspension mode, said controller means including means for periodically sampling the detector signals indicative of the measured distance between vehicle body and road surface and producing sampled distance values, means for averaging the sampled distance values to derive an average value, means for comparing the average value with each of said sampled distance values to derive a difference therebetween, means for counting the number of differences greater than a given reference value, means for comparing the counter number with a given threshold and providing a road roughness indicative signal representing that the vehicle is on a relatively rough road surface when the counted number is greater than said threshold;
- said controller means being responsive to the roughness indicative signal for operating said suspension system in the softer suspension mode.
2 more elements
Dependencies are inferred from the claim text.