Roll control system for a motor vehicle

Details Roll control system for a motor vehicle Roll control system for a motor vehicle

1999-11-12

2001-08-21

Rice, Kenneth R. (Department: 2167)

Land vehicles

Suspension modification enacted during travel

Including condition or parameter adjustment occurring at...

C280S005505, C280S124106

Reexamination Certificate

active

06276693

ABSTRACT:

TECHNICAL FIELD
The present invention relates to a roll control system for a motor vehicle, and in particular to a semi-active roll control system.
BACKGROUND OF THE INVENTION
In order to prevent excessive rolling (which has an impact on vehicle attitude and handling) of a motor vehicle, especially during cornering, it is known to provide a torsion bar between the front wheels of a motor vehicle, and, in some cases, a second torsion bar between the rear wheels. However, during straight line motion of a vehicle and when the vehicle is off-road, the torsion bar can have a detrimental effect on comfort and wheel articulation. Semi-active roll control systems have been proposed which monitor various vehicle conditions. Such roll control systems include a locking device associated with the torsion bar and the wheels. When the sensed vehicle conditions indicate roll control is not required, the locking device is unlatched to effectively disconnect the effect of the torsion bar between the wheels. When the sensed vehicle conditions indicate that roll control is required, the locking device is latched to connect the wheels by way of the torsion bar. The latch position of the locking device determines the overall effect of the torsion bar on the wheels, and hence determines the level of roll control on the vehicle. In certain circumstances, it is possible to latch the torsion bar in the wrong position.
SUMMARY OF THE INVENTION
The object of the present invention is to lessen the risk and problems of potential incorrect latching.
A roll control system in accordance with the present invention for installation between axially aligned wheels of a motor vehicle comprises a torsion bar; a first hydraulic actuator attached to one end of the torsion bar and attachable to one of the wheels; a second hydraulic actuator attached to the other end of the torsion bar and attachable to the other wheel; and an electronic control unit monitoring one or more predetermined vehicle operating conditions; wherein the first and second hydraulic actuators are substantially identical, each comprising a compression chamber containing hydraulic fluid, a rebound chamber containing hydraulic fluid, a movable piston between and fluidly isolating the compression chamber and the rebound chamber, a piston rod connected to the piston and extending through the rebound chamber, a gas chamber containing pressurised gas acting on the hydraulic fluid in the rebound chamber, and an electrically operated valve between the compression chamber and the rebound chamber and actuated by the control unit dependent on the monitored conditions, the valve being actuable between a two-way position in which the valve allows hydraulic fluid to flow between the compression chamber and the rebound chamber and a one-way position in which the valve allows hydraulic fluid to flow from the rebound chamber into the compression chamber but not from the compression chamber into the rebound chamber.
In the present invention, the net force within each hydraulic actuator is such as to tend to move the piston in each hydraulic actuator to a full rebound position in which the volume of the associated rebound chamber is at a minimum. If the control unit actuates the valve of one of the hydraulic actuators for roll control, when the associated piston is not in the full rebound position, the net force will gradually move the piston towards full rebound. As a consequence, the roll control system of the present invention reduces the problem of latching the torsion bar in an incorrect position.


REFERENCES:
patent: 3417985 (1968-12-01), Hannan
patent: 4930807 (1990-06-01), Lachaize
patent: 5040823 (1991-08-01), Lund
patent: 5231583 (1993-07-01), Lizell
patent: 5505780 (1996-04-01), Pascarella
patent: 5547211 (1996-08-01), Runkel
patent: 0 607 516 (1994-07-01), None
patent: 0 829 383 (1998-03-01), None
patent: 2006131 (1979-05-01), None
patent: 2 006 131 (1979-05-01), None

Affiliated with

Also associated with

Rating

Roll control system for a motor vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Roll control system for a motor vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Roll control system for a motor vehicle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2503469