GB2270048A - A vehicle suspension system - Google Patents

A vehicle suspension system Download PDF

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Publication number
GB2270048A
GB2270048A GB9218445A GB9218445A GB2270048A GB 2270048 A GB2270048 A GB 2270048A GB 9218445 A GB9218445 A GB 9218445A GB 9218445 A GB9218445 A GB 9218445A GB 2270048 A GB2270048 A GB 2270048A
Authority
GB
United Kingdom
Prior art keywords
vehicle
suspension system
control unit
vehicle suspension
foregoing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB9218445A
Other versions
GB2270048B (en
GB9218445D0 (en
Inventor
Adam Ruddle
Julian Buckingham
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MG Rover Group Ltd
Original Assignee
MG Rover Group Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MG Rover Group Ltd filed Critical MG Rover Group Ltd
Priority to GB9602845A priority Critical patent/GB2295361B/en
Priority to GB9218445A priority patent/GB2270048B/en
Publication of GB9218445D0 publication Critical patent/GB9218445D0/en
Publication of GB2270048A publication Critical patent/GB2270048A/en
Application granted granted Critical
Publication of GB2270048B publication Critical patent/GB2270048B/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/016—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/016—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input
    • B60G17/0162—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input mainly during a motion involving steering operation, e.g. cornering, overtaking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/015—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements
    • B60G17/016—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input
    • B60G17/0164—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load the regulating means comprising electric or electronic elements characterised by their responsiveness, when the vehicle is travelling, to specific motion, a specific condition, or driver input mainly during accelerating or braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G17/00—Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a supporting surface and a sprung part of vehicle or for locking suspension during use to meet varying vehicular or surface conditions, e.g. due to speed or load
    • B60G17/02—Spring characteristics, e.g. mechanical springs and mechanical adjusting means
    • B60G17/033—Spring characteristics, e.g. mechanical springs and mechanical adjusting means characterised by regulating means acting on more than one spring
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G21/00—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces
    • B60G21/10—Interconnection systems for two or more resiliently-suspended wheels, e.g. for stabilising a vehicle body with respect to acceleration, deceleration or centrifugal forces not permanently interconnected, e.g. operative only on acceleration, only on deceleration or only at off-straight position of steering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2202/00—Indexing codes relating to the type of spring, damper or actuator
    • B60G2202/40—Type of actuator
    • B60G2202/41—Fluid actuator
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2204/00—Indexing codes related to suspensions per se or to auxiliary parts
    • B60G2204/80—Interactive suspensions; arrangement affecting more than one suspension unit
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/10—Acceleration; Deceleration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/10—Acceleration; Deceleration
    • B60G2400/106—Acceleration; Deceleration longitudinal with regard to vehicle, e.g. braking
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/20—Speed
    • B60G2400/204—Vehicle speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/25—Stroke; Height; Displacement
    • B60G2400/252—Stroke; Height; Displacement vertical
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/30—Propulsion unit conditions
    • B60G2400/33—Throttle position
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2400/00—Indexing codes relating to detected, measured or calculated conditions or factors
    • B60G2400/40—Steering conditions
    • B60G2400/41—Steering angle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2500/00—Indexing codes relating to the regulated action or device
    • B60G2500/30—Height or ground clearance
    • B60G2500/32—Height or ground clearance of only one vehicle part or side
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
    • B60G2800/01—Attitude or posture control
    • B60G2800/012—Rolling condition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60G—VEHICLE SUSPENSION ARRANGEMENTS
    • B60G2800/00—Indexing codes relating to the type of movement or to the condition of the vehicle and to the end result to be achieved by the control action
    • B60G2800/01—Attitude or posture control
    • B60G2800/014—Pitch; Nose dive

Abstract

A suspension system comprises four suspension units 10, 12, 14, 16 each associated with a respective vehicle wheel and each having first and second hydraulic chambers 18, 20 communicating through a fluid flow damper 22, 24, 26 and a gas chamber 32. Electrically controlled valves 46, 48, 50, 52 are provided in hydraulic lines 42, 44 connecting the hydraulic chambers of the units together. The valves are controlled by a control unit 54 operating in response to sensors of vehicle acceleration 56, braking 58 steering 60 and suspension 62. <IMAGE>

Description

A Vehicle Suspension System The present invention relates to a vehicle suspension system having at least two suspension units, each suspension unit having first and second hydraulic chambers interconnected by a fluid flow damping means, the first hydraulic chamber being connected to a piston associated with a vehicle wheel such that movement of the piston varies the volume of the first hydraulic chamber, and the second hydraulic chamber having a movable wall connected to a resilient reaction means such as a gas spring.
Such a system is disclosed, for example in GB1177848.
There is a problem with such systems that if the hydraulic chambers of the individual units are interconnected to improve the ride characteristics of the system, the vehicle becomes susceptible to pitch and roll.
The present invention provides a suspension system as described above wherein the suspension units are hydraulically inter-connected, and electrically controlled valve means are provided for controlling fluid flow between the units.
The valve means can be controlled so as the restrict fluid flow between suspension units when the vehicle is cornering, accelerating or braking.
This can be achieve by a control unit operating in response to signals from, for example, accelerometers, or sensors for sensing the condition of the suspension system steering mechanism or braking system, or vehicle speed.
Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a diagram of a vehicle suspension system according to the invention.
Referring to Figure 1 the suspension system comprises four hydropneumatic suspension units 10,12,14,16 each associated with a respective wheel of a vehicle.
Each unit has a first hydraulic chamber 18 and a second hydraulic chamber 20 separated by a fluid flow damper in the form of a dividing wall 22 having two holes 24 26 through it. Each of the holes 24 has a leaf spring 28,30 which covers it, the leaf springs being on opposite sides of the dividing wall to allow hydraulic fluid through in opposite directions. Each unit 10,12,14,16 also has a gas chamber 32 separated from the second hydraulic chamber 20 by a movable wall in the form of a diaphragm 34. The first hydraulic chamber 18 of each unit 10,12,14,16 has a flexible lower wall 36 acted on by a piston 38 which moves vertically with the respective wheel of the vehicle.
Movement of each wheel causes a flow of fluid between the first and second chambers of the respective unit which is damped by the damper 22,24,26, and compression of the respective gas chamber which acts as a resilient reaction means to absorb the wheel movement.
The first hydraulic chamber 18 of each unit 10,12,14,16 has a communicating port 40 through which it is connected via a hydraulic line 42 to the unit on the same side of the vehicle. Further hydraulic lines 44 connect each unit to that at the same end of the vehicle. In each of the hydraulic lines 42, 44 is a valve 46, 48, 50, 52. The valves 46, 48, 50, 52 are electrically operated and are controlled by a control unit 54.
The control unit 54 is connected to an accelerometer 56 which measures the acceleration of the vehicle, a speed sensor 57 for measuring vehicle speed, a braking sensor 58 for sensing the condition of the vehicle braking system, a throttle sensor 59 for sensing the position of the throttle, a steering sensor 60 for sensing the steering angle of the vehicle steering system and four suspension sensors 62, 64, 66, 68 for sensing the position of the four pistons 38 associated with the vehicle wheels thereby measuring the vertical position of each of the vehicle wheels and a drive mode switch.
In operation the control unit 54 is arranged to determine when the vehicle is in a roll or pitch situation, such as cornering, accelerating or braking, and to operate the valves 46, 48, 50, 52 to restrict the roll or pitch which occurs.
If the vehicle is travelling in a straight line without accelerating or braking the valves 46, 48, 50, 52 are open. If one wheel, eg that associated with suspension unit 10, moves up or down, hydraulic fluid flows not only through the damper 26 compressing or expanding the gas spring 32 in that unit, but also via the hydraulic lines 42, 44 through the dampers in the other units 12, 14, 16 compressing or expanding the gas springs in those units.
If the piston 38 in suspension unit 10 moves upwards beyona a set position the control unit 54 is arranged to close progressively the valves 48, 50 in the hydraulic lines 42, 44 connected directly to that suspension unit as the piston travels further upwards. This increases progresively the reistance to movement of the wheel as it moves upwards beyond a set position, thus improving the ability of the system to absorb large upward forces applied to the wheel.
If the vehicle starts to corner, so the steering sensor 60 sends a signal to the control unit 54 indicating that the vehicle is turning, and the suspension sensors 62, 64, 66, 68 send signals to the control unit 54 indicating that the vehicle is starting to roll to one side, a roll situation is detected and the valve 50, between the two front suspension units 10,12 and the valve 52 between the two rear suspension units 14, 16 are closed. This prevents further flow of hydraulic fluid from one side of the vehicle to the other and hence restricts further roll.
Similarly, if the brakes are applied while the vehicle is moving the braking sensor 58 sends a signal to the control unit 54 indicating that the brakes have been applied, the accelerometer sends a signal indicating that the vehicle is slowing down and the suspension sensors 62,64,66,68 send a signal indicating that the vehicle is starting to pitch. The control unit 54 then closes the valve 46 between the two right hand suspension units 12, 16 and the valve 48 between the two left hand suspension units 10,14 and further pitch is restricted.
When the vehicle is accelerating from rest or low speeds the system can increase traction by reducing front roll stiffness. When the throttle sensor 59 senses that the throttle is open more than a set amount and the vehicle speed is below a set value the control unit identifies an accleration condition in which the driven wheels, in this case the front wheels, need good traction. In order for this to occur the valve 50 between the two front suspension units 10, 12 is opened. The valve 52 between the two rear suspension units 14, 16 is closed to maintain overall roll stiffness for the vehicle.
As with other known suspension systems a driver operated switch could also be included in the sytem of the present invention for example allowing the driver to choose between an ordinary mode and a sports mode in which roll stiffness is increased by controlling the valves 50, 52 between the opposite sides of the vehicle to allow less fluid flow when the vehicle is cornering.

Claims (10)

1. A vehicle suspension system comprising at least two suspension units each associated with a respective wheel of a vehicle and each having first and second hydraulic chambers interconnected by a fluid flow damping means the first hydraulic chamber being connected to a piston associated with a vehicle wheel such that movement of the piston varies the volume of the first hydraulic chamber, and the second hydraulic chamber having a movable wall connected to a resilient reaction means, wherein the suspension units are hydraulically inter-connected, and electrically controlled valve means are provided for controlling fluid flow between the units.
2. A vehicle suspension system according to claim 1 wherein the first hydraulic chambers of the suspension units are inter-connected.
3. A vehicle suspension system according to Claim 1 or claim 2 further comprising accelerometers mounted on the vehicle for sending signals to the control unit to control the valve means.
4. A vehicle suspension system according to any foregoing claim further comprising suspension sensor means for sensing the condition of the vehicle suspension and sending signals to the control unit to control the valve means.
5. A vehicle suspension system according to any foregoing claim further comprising steering sensor means for sensing the condition of the steering means of the vehicle and sending signals to the control unit to control the valve means.
6. A vehicle suspension system according to any foregoing claim further comprising braking sensor means for sensing the condition of the braking means of the vehicle and sending signals to the control unit to control the valve means.
7. A vehicle suspension system according to any foregoing claim further comprising speed sensor means for sensing the speed of the vehicle and sending signals to the control unit to control the valve means.
8. A vehicle suspension system according to any foregoing claim wherein the control unit is arrange to restrict fluid flow between suspension units when the vehicle is cornering, accelerating or braking.
9. A vehicle suspension system according to any foregoing claim wherein the control unit is arranged to differentiate on the basis of signals sent to it between vehicle pitch or roll and wheel movement caused by the surface over which the vehicle is travelling.
10. A vehicle suspension system substantially as hereinbefore described with reference to the accompanying drawings.
GB9218445A 1992-08-29 1992-08-29 A vehicle suspension system Expired - Lifetime GB2270048B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB9602845A GB2295361B (en) 1992-08-29 1992-08-29 A vehicle suspension system
GB9218445A GB2270048B (en) 1992-08-29 1992-08-29 A vehicle suspension system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9218445A GB2270048B (en) 1992-08-29 1992-08-29 A vehicle suspension system

Publications (3)

Publication Number Publication Date
GB9218445D0 GB9218445D0 (en) 1992-10-14
GB2270048A true GB2270048A (en) 1994-03-02
GB2270048B GB2270048B (en) 1996-07-31

Family

ID=10721190

Family Applications (2)

Application Number Title Priority Date Filing Date
GB9602845A Expired - Lifetime GB2295361B (en) 1992-08-29 1992-08-29 A vehicle suspension system
GB9218445A Expired - Lifetime GB2270048B (en) 1992-08-29 1992-08-29 A vehicle suspension system

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB9602845A Expired - Lifetime GB2295361B (en) 1992-08-29 1992-08-29 A vehicle suspension system

Country Status (1)

Country Link
GB (2) GB2295361B (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1338322A (en) * 1972-08-31 1973-11-21 Wheeler J J Suspension system for vehicles
GB1378787A (en) * 1971-05-12 1974-12-27 Honda Motor Co Ltd Vehicle suspension systems
GB1396890A (en) * 1971-07-09 1975-06-11 Rover Co Ltd Vehicle suspension systems
GB2155409A (en) * 1984-01-24 1985-09-25 Mitsubishi Motors Corp Vehicle suspension apparatus

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1378787A (en) * 1971-05-12 1974-12-27 Honda Motor Co Ltd Vehicle suspension systems
GB1396890A (en) * 1971-07-09 1975-06-11 Rover Co Ltd Vehicle suspension systems
GB1338322A (en) * 1972-08-31 1973-11-21 Wheeler J J Suspension system for vehicles
GB2155409A (en) * 1984-01-24 1985-09-25 Mitsubishi Motors Corp Vehicle suspension apparatus

Also Published As

Publication number Publication date
GB2295361A (en) 1996-05-29
GB2270048B (en) 1996-07-31
GB2295361B (en) 1996-07-31
GB9602845D0 (en) 1996-04-10
GB9218445D0 (en) 1992-10-14

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732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)