Vehicle ride control system

• US 20060181034A1
• Filed: 02/17/2005
• Published: 08/17/2006
• Est. Priority Date: 02/17/2005
• Status: Active Grant

• Current Assignee: Spartan Motors Chassis, Inc. (The Shyft Group, Inc.)
• Original Assignee: Spartan Motors Chassis, Inc. (The Shyft Group, Inc.)
• Inventors: Kumar, Abhinav, Wilde, Michael D., Hart, John G.
• Granted Patent: US 7,416,189 B2
• Time in Patent Office: Days
• US Class Current: 280/5.515
• CPC Class Codes: B60G 15/12 and fluid damper
• CPC Class Codes: B60G 17/0152 characterised by the action on a particular type of suspension unit B60G17/01941 takes precedence
• CPC Class Codes: B60G 17/0165 to an external condition, e.g. rough road surface, side wind
• CPC Class Codes: B60G 17/08 Characteristics of fluid dampers adjusting fluid dampers in general F16F9/44 - F16F9/53
• CPC Class Codes: B60G 2202/154 with an accumulator
• CPC Class Codes: B60G 2202/24 Fluid damper
• CPC Class Codes: B60G 2400/102 vertical
• CPC Class Codes: B60G 2400/104 lateral or transversal with regard to vehicle
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B60G 2400/41 Steering angle
• CPC Class Codes: B60G 2500/10 Damping action or damper
• CPC Class Codes: B60G 2500/106 duty rate
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60G 2800/80 Detection or control after a system or component failure

Abstract

A ride control suspension control system having suspension control units with a damper and a single pressure regulator that controls dampening in both the compression and rebound chambers of the damper. The fluid control circuit may include a plurality of check valves that coordinate the flow of fluid to and from both chambers through the pressure regulator. In one embodiment, the system includes a central controller that receives input from a variety of sensors and directly controls operation the pressure regulators in each of the suspension control units without the need for any remote processors. The ride control suspension system may also include wheel position sensors that are external to the accumulator.

Claims

1. A ride control suspension control system for a vehicle comprising:

a plurality of sensors providing sensor signals indicative of a plurality of conditions;

a suspension control unit mounted between a sprung mass and an unsprung mass, said suspension control unit including a damper having a compression chamber and a rebound chamber, said suspension control unit further including a fluid control circuit selectively providing fluid communication between said compression chamber and said rebound chamber, said fluid control circuit including a single pressure regulator to selectively restrict flow of fluid from said compression chamber to said rebound chamber and from said rebound chamber to said compression chamber; and

a controller for controlling operation of said pressure regulator as a function of said sensor signals.

2. The system of claim 1 wherein said pressure regulator includes and inlet and an outlet;

said fluid control circuit including a first fluid path interconnecting said inlet and said compression chamber, said first fluid path including a first one-way component preventing fluid flow directly from said inlet to said compression chamber.

3. The system of claim 2 wherein said fluid control circuit includes a second fluid path interconnecting said outlet and said rebound chamber, said second fluid path including a second one-way component preventing fluid flow directly from said rebound chamber to said outlet.

4. The system of claim 3 wherein said fluid control circuit includes a third fluid path interconnecting said inlet and said rebound chamber, said third fluid path including a third one-way component preventing fluid flow directly from said inlet to said rebound chamber.

5. The system of claim 4 wherein said fluid control circuit includes a fourth fluid path interconnecting said outlet and said compression chamber, said fourth fluid path including a fourth one-way component preventing fluid flow directly from said compression chamber to said outlet.

6. The system of claim 5 wherein said fluid control circuit includes an accumulator in fluid communication with said second fluid path and said fourth fluid path.

7. The system of claim 5 wherein said fluid control circuit includes an accumulator in fluid communication with said compression chamber and said rebound chamber, said fourth one-way valve preventing fluid flow directly from said compression chamber to said accumulator, said second one-way valve preventing fluid flow directly from said rebound chamber to said accumulator.

8. The system of claim 7 wherein said first one-way valve, said second one-way valve, said third one-way valve and said fourth one-way valve are further defined as check valves.

9. The system of claim 8 wherein said pressure regulator includes an adjustable relief valve and a solenoid for selectively control said adjustable relief valve.

10. The system of claim 1 further comprising a second suspension control unit, a third suspension control unit and a fourth suspension control unit, each of said second, third and fourth suspension control units including a pressure regulator having a relief valve and a solenoid, said controller including means for providing first control signals directly to said solenoid of said first suspension unit, second control signals directly to said solenoid of said second suspension unit, third control signals directly to said solenoid of said third suspension unit and fourth control signals directly to said solenoid of said fourth suspension unit, whereby said controller provides direct control of each of said suspension control unit.

11. The system of claim 1 wherein said plurality of sensors includes a wheel position sensor mounted between a sprung mass and an unsprung mass of the vehicle.

12. The system of claim 1 wherein said fluid control circuit include a plurality of flow paths, each of said flow paths being internal to said suspension control unit, whereby said suspension control unit does not require any exposed external fluid lines.

13. A suspension control unit for use in damping forces between a sprung mass and an unsprung mass in a vehicle comprising:

a damper having a compression chamber and a rebound chamber, said damper being mountable between the sprung mass and the unsprung mass;

a fluid control circuit defining a flow path between said compression chamber and said rebound chamber, said fluid control circuit including a single pressure regulator selectively restricting fluid flow between said compression chamber and said rebound chamber; and

a controller receiving sensor signals from a plurality of sensors and controlling operation of said pressure regulator as a function of said sensor signals, said sensors signals being indicative of road and vehicle conditions.

14. The unit of claim 13 wherein said pressure regulator includes and inlet and an outlet;

said fluid control circuit including a first fluid path interconnecting said inlet and said compression chamber and a second fluid path interconnecting said outlet and said rebound chamber, said first fluid path including a first one-way component preventing fluid flow directly from said inlet to said compression chamber, said second fluid path including a second one-way component preventing fluid flow directly from said rebound chamber to said outlet.

15. The system of claim 14 wherein said fluid control circuit includes a third fluid path interconnecting said inlet and said-rebound chamber and a fourth fluid path interconnecting said outlet and said compression chamber, said third fluid path including a third one-way component preventing fluid flow directly from said inlet to said rebound chamber, said fourth fluid path including a fourth one-way component preventing fluid flow directly from said compression chamber to said outlet.

16. The system of claim 15 wherein said fluid control circuit includes an accumulator in fluid communication with said second fluid path and said fourth fluid path, said fourth one-way valve preventing fluid flow directly from said compression chamber to said accumulator, said second one-way valve preventing fluid flow directly from said rebound chamber to said accumulator.

17. The system of claim 16 further including a first cylinder containing said damper and a second cylinder containing said pressure regulator and said accumulator, said first cylinder and said second cylinder being adjoined at opposite longitudinal ends by a first end cap and a second end cap, said fluid control circuit being defined internal to said cylinders and said end caps.

18. A ride control suspension control system for a vehicle having a sprung mass and an unsprung mass comprising:

a plurality of sensors for providing sensor signals indicative of road and vehicle conditions;

a plurality of suspension control units mounted between the sprung mass and the unsprung mass, said suspension control units each including a damper having a compression chamber and a rebound chamber, said suspension control units each including a fluid control circuit defining at least one flow path between said compression chamber and said rebound chamber, each fluid control circuit including a single pressure regulator for variably controlling fluid flow in both directions between said compression chamber and said rebound chamber; and

a central controller electrically connected to each of said plurality of sensors and to said pressure regulators of each of said suspension control units, said central controller including a processor for processing said sensor signals in accordance with a plurality of predetermined algorithms to obtain separate control signals for each of said pressure regulators said central controller including an output circuitry to transmit each of said separate control signals to a corresponding one of said pressure regulators.

19. The system of claim 18 wherein said plurality of sensors includes a plurality of position sensors mounted between the sprung mass and the unsprung mass, said positions sensors providing sensor signals indicative of the relative position between the sprung mass and the unsprung mass.

20. The system of claim 18 wherein each of said pressure regulators includes an inlet and an outlet;

and

wherein each of said fluid control circuits includes a first one-way flow path permitting fluid flow from said compression chamber to said inlet, a second one-way flow path permitting fluid flow from said rebound chamber to said inlet, a third one-way flow path permitting fluid flow from said outlet to said compression chamber and a third one-way flow path permitting fluid flow from said outlet to said rebound chamber.

21. The system of claim 20 wherein said fluid flow circuit includes an accumulator, a fifth one-way flow path permitting fluid flow from said accumulator to said compression chamber, a sixth one-way flow path permitting fluid flow from said accumulator to said rebound chamber and a two-way flow path permitting fluid flow in both directions between said accumulator and said outlet.

22. The system of claim 21 further including a first cylinder containing said damper and a second cylinder containing said pressure regulator and said accumulator, said first cylinder and said second cylinder being adjoined at opposite longitudinal ends by a first end cap and a second end cap, said fluid control circuit being defined internal to said cylinders and said end caps.

23. A method for operating a vehicle ride control suspension system comprising the steps of:

providing a suspension control unit having a damper and a single pressure regulator for selectively controlling fluid flow between a compression chamber and a rebound chamber of the damper, collecting signals from a plurality of sensors indicative of conditions;

computing a compression signal based at least in part on one or more of the collected signals;

computing a rebound signal based at least in part on one or more of the collected signals, the rebound signal being computed separately from the compression signal;

applying one of the compression signal and the rebound signal to the single pressure regulator to selectively control fluid flow between the compression chamber and the rebound chamber as a function of the signals; and

repeating said collecting step, said compression signal computing step, said rebound signal computing step and said applying step.

24. The method of claim 23 wherein said applying step is further defined as applying the greater of the compression signal and the rebound signal to the single pressure regulator.

25. The method of claim 24 wherein said computing step and said applying step are performed by a single central controller.

26. A suspension control unit for use in damping forces between a sprung mass and an unsprung mass in a vehicle comprising:

a damper having a compression chamber and a rebound chamber, said damper being mountable between the sprung mass and the unsprung mass;

a fluid control circuit defining a flow path between said compression chamber and said rebound chamber, said fluid control circuit including a pressure regulator selectively restricting fluid flow between said compression chamber and said rebound chamber;

a control for selecting a ride control setting;

a controller receiving sensor signals from a plurality of sensors and controlling operation of said pressure regulator as a function of said sensor signals and said ride control setting, said sensors signals being indicative of road and vehicle conditions.