EP0246772A1
Expired / Lapsed
EP
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A suspension system for a motor vehicle
Assignee: MG Rover Group Ltd
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Filing: 1987-04-30
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Granted: —
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Expires: 2007-04-30
Abstract
Abstract The system comprises a spring between the vehicle body (13) and each wheel (15), a shock absorber (12) associated with each spring and which is switchable electromagnetically between soft and stiff settings, one or more accelerometers (16) sensing vertical acceleration of the vehicle body (13), an electronic filter (40, 41) for filtering the signals from the accelerometer (16) to select a band width of frequencies, either side of the primary ride frequency of the vehicle, and control means (18) for switching the shock absorbers between the soft and stiff settings whenever a pre-determined level of vertical motion within this band width is exceeded either in the bump or rebound directions.
Inventors
- 👤 Jonathan Andrew Fuller
- 👤 Philip Edward Mander
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 21:49
CPC Classifications
B; B60; B60G; B60G17/00; B60G17/015; B60G17/018; F; F16; F16F; F16F9/00; F16F9/06; F16F9/08; F16F9/088; B60G2400/00; B60G2400/10; B60G2400/102; B60G2400/106; B60G2400/20; B60G2400/204; B60G2400/206; B60G2400/30; B60G2400/33; B60G2400/40; B60G2401/00; B60G2401/10; B60G2500/00; B60G2500/10; B60G2500/102; B60G2600/00; B60G2600/02; B60G2600/14; B60G2600/22; B60G2600/26; B60G2600/60; B60G2600/602; B60G2600/604; B60G2800/00; B60G2800/01; B60G2800/012; B60G2800/014; B60G2800/22
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
177 words
A suspension system for a vehicle comprising: at least one resilient means 'connecting a sprung mass (13) and an unsprung mass (15); at least one damping means (12) switchable between a relatively soft setting and a relatively stiff setting for damping relative motion between the sprung mass (13) and the unsprung mass (15); a sensor means (16) for sensing motion of the sprung mass (13); filter means (40,41) for filtering a signal from the sensor (16) to select a pre-determined band width of frequencies of motion of the sprung mass (13); and control means (18) for switching the damping means (12) between the relatively soft and relatively stiff settings in response to a signal received from the sensor means (16) characterised in that each of the damping means (12) has a relatively stiff and soft setting in both the bump and rebound directions and that the damping means (12) are switched to the relatively stiff setting when the motion of the sprung mass (13) in either direction exceeds a pre-determined level set for that direction of motion.
Claim 2
Dependent Claim
177 words
A suspension system for a vehicle comprising: at least one resilient means 'connecting a sprung mass (13) and an unsprung mass (15); at least one damping means (12) switchable between a relatively soft setting and a relatively stiff setting for damping relative motion between the sprung mass (13) and the unsprung mass (15); a sensor means (16) for sensing motion of the sprung mass (13); filter means (40,41) for filtering a signal from the sensor (16) to select a pre-determined band width of frequencies of motion of the sprung mass (13); and control means (18) for switching the damping means (12) between the relatively soft and relatively stiff settings in response to a signal received from the sensor means (16) characterised in that each of the damping means (12) has a relatively stiff and soft setting in both the bump and rebound directions and that the damping means (12) are switched to the relatively stiff setting when the motion of the sprung mass (13) in either direction exceeds a pre-determined level set for that direction of motion.
Claim 3
Dependent Claim
21 words
A suspension system as claimed in claim 1 characterised in that the pre-determined band width is between 0.3Hz and 4.5 Hz.
Claim 4
Dependent Claim
35 words
A suspension system as claimed in claims 1 or 2 characterised in that the response time of the suspension system is substantially less than the period of one cycle of oscillation of the sprung mass.
Claim 5
Dependent Claim
72 words
A suspension system as claimed in any preceding claim characterised in that each of the damping means (12) has in addition to the relatively stiff and soft settings a further relatively harder setting and that the control means (18) is arranged to switch the damping means (12) between the relatively stiff and soft settings below a pre-determined vehicle speed and between the relatively stiff and harder settings above the pre-determined vehicle speed.
Claim 6
Dependent Claim
82 words
A suspension system as claimed in any of claims 1 tq 4 characterised in that the or each damping means (12) is a hydraulic shock absorber having a first solenoid valve (21) operable to change the damping effect in the bump direction from the relatively soft setting to the relatively stiff setting when actuated and a second solenoid valve (24) operable to change the damping effect in the rebound direction from the relatively soft setting to the relatively stiff setting when actuated.
Claim 7
Dependent Claim
40 words
A suspension system as claimed in any preceding claim characterised in that the sensor means (16) is a single accelerometer positioned on the sprung mass to effect switching of all of the damping means (12) of the vehicle substantially simultaneously.
Claim 8
Dependent Claim
65 words
A suspension system as claimed in any of claims 1 to 5 characterised in that the sensor means (16) is an accelerometer associated with each of the damping means (12) and that the control means (18) responds to the signals from each of the accelerometers to switch each of the damping means (12) independently in response to the signal received from the accelerometer associated therewith.
Claim 9
Dependent Claim
62 words
A suspension system as claimed in claim 7 characterised in that a displacement sensor is associated with each of the damping means (12) to measure relative movement between the sprung and unsprung masses and that switching between the relatively soft and relatively stiff settings is prevented when the sprung mass and unsprung mass are sensed to be moving in the same direction.
Claim 10
Dependent Claim
51 words
A suspension system as claimed in any preceding claim characterised in that further sensors associated with one or more of the braking system, throttle system and the steering system are arranged to supply the control means (18) with signals used thereby to modify the pre-determined levels during motion of the vehicle.
Claim 11
Dependent Claim
25 words
A suspension system as claimed in any preceding claim characterised in that the pre-determined level is a level of vertical acceleration of the sprung mass.
Claim 12
Dependent Claim
33 words
A suspension system as claimed in claim 10 characterised in that the pre-determined level of acceleration in the bump direction of motion is between 1.5 and 3.0 times that in the rebound direction.
Claim 13
Dependent Claim
34 words
A suspension system as claimed in claim 10 or in claim 11 characterised in that the pre-determined level of acceleration in each direction is reduced as the forward velocity of the vehicle is increased.
Claim 14
Dependent Claim
40 words
A suspension system as claimed in any of claims 10 to 12 characterised in that the damping settings are restored to the relatively soft setting as soon as the acceleration falls below the pre-determined level for that direction of motion.
Claim 15
Dependent Claim
43 words
1 4. A suspension system as claimed in any of claims 10 to 12 characterised in that the damping settings are switched to the relatively stiff setting at the first peak vertical acceleration of the sprung mass following the pre-determined level being exceeded.
Claim 16
Dependent Claim
41 words
A suspension system as claimed in claim 14 characterised in that the damping effect in each direction is restored to the relatively soft settings at the first; peak in acceleration of the sprung mass which does not exceed the pre-determined level.
Claim 17
Dependent Claim
39 words
A suspension system as claimed in claim 14 or in claim 15 characterised in that if no further peak acceleration is sensed within a pre-determined period of time then the damping settings are restored to the relatively soft setting.
Claim 18
Dependent Claim
28 words
A suspension system as claimed in any of claims 1 to 9 characterised in that the pre-determined level is a level of vertical velocity of the sprung mass.
Claim 19
Dependent Claim
39 words
A suspension system as claimed in claim 17 characterised in that the signal received from the sensor means (16) is integrated to convert the signal into one of vertical velocity before the signal is compared with the pre-determined level.
Claim 20
Dependent Claim
45 words
A suspension system as claimed in claim 17 or in claim 18 characterised in that the damper settings are switched to the relatively stiff setting on the first occasion that the direction of motion changes after a pre-determined level of vertical velocity has been exceeded.
Claim 21
Dependent Claim
51 words
A suspension system as claimed in any of claims 17 to 19 characterised in that the damping settings are restored to the relatively soft setting on the first occasion when the direction of motion of the sprung mass changes following a peak in velocity which does not exceed the pre-determined level.
References Cited (Backward Citations)
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GB2150258A
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EP0162818A1
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EP0162448B1
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EP0167159A2
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EP0205645A1
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