Locking suspension system

• US 7,051,851 B2
• Filed: 11/04/2002
• Issued: 05/30/2006
• Est. Priority Date: 11/04/2002
• Status: Expired due to Fees

• Current Assignee: Volvo Trucks North America Incorporated (AB Volvo)
• Original Assignee: Volvo Trucks North America Incorporated (AB Volvo)
• Inventors: White, Darris, Svartz, Bjorn O.
• Primary Examiner(s): RODRIGUEZ, PAMELA
• Application Number:
  US10/287,291
• Publication Number:
  US 20040084266A1
• Time in Patent Office: 1,303 Days
• Field of Search: 188/300, 188/266.1, 188/266.5, 180 8913- 8915, 280/5.5, 280/5.504, 280/5.507, 280/5.512, 280/5.514, 280/5.515, 280/6.15, 280/6.157, 280/6.159, 280/6.16, 700/44, 702/181, 702/179, 701/48, 701/36, 701/70
• US Class Current: 188/300
• CPC Class Codes: B60G 17/005 Suspension locking arrangements for retractable wheels B62D61/12
• CPC Class Codes: B60G 17/0155 pneumatic unit
• CPC Class Codes: B60G 17/0164 mainly during accelerating or braking
• CPC Class Codes: B60G 17/052 Pneumatic spring characteristics B60G17/048 takes precedence ; valves per se F16K
• CPC Class Codes: B60G 2200/30 Rigid axle suspensions
• CPC Class Codes: B60G 2202/152 Pneumatic spring
• CPC Class Codes: B60G 2204/4605 hydraulically, e.g. interrupting communication between the chambers of a hydraulic cylinder
• CPC Class Codes: B60G 2300/026 Heavy duty trucks
• CPC Class Codes: B60G 2400/204 Vehicle speed
• CPC Class Codes: B60G 2400/252 vertical
• CPC Class Codes: B60G 2400/32 Torque on propulsion shaft
• CPC Class Codes: B60G 2400/33 Throttle position
• CPC Class Codes: B60G 2400/38 Speed of engine rotation
• CPC Class Codes: B60G 2400/39 Brake pedal position
• CPC Class Codes: B60G 2400/412 of steering wheel or column
• CPC Class Codes: B60G 2600/00 Indexing codes relating to particular elements, systems or processes used on suspension systems or suspension control systems
• CPC Class Codes: B60G 2800/182 Traction
• CPC Class Codes: B60G 2800/21 Traction, slip, skid or slide control
• CPC Class Codes: B60G 2800/22 Braking, stopping
• CPC Class Codes: B60G 2800/702 Improving accuracy of a sensor signal
• CPC Class Codes: B60G 2800/95 : Automatic Traction or Slip Control [ATC]
• CPC Class Codes: B60G 9/00 : Resilient suspensions of a rigid axle or axle housing for two or more wheels the axle being a part of a set of tandem axles B60G5/00-B60G5/065; with leaf springs B60G11/02-B60G11/08

Abstract

A method and apparatus for controlling frame rise on a heavy duty truck having a frame, a drive axle connected to the frame, and a selectively lockable suspension component disposed therebetween for maintaining the relative position therebetween. Signals indicative of at least one of the following vehicle operating parameters: engine speed, brake pressure, vehicle speed, air bag pressure, steering wheel angle, vehicle height, or throttle position are monitored and a predicted thrust is calculated that will be applied to the drive axle based on the monitored signals. The selectively lockable suspension component is locked if the predicted thrust exceeds a predetermined threshold and is also controlled with respect to other operating parameters such as whether vehicle brakes are applied, any instantaneous change in torque, vehicle operating speed, and the length of time the selectively lockable suspension component has been locked.

Claims

1. A method for controlling frame rise on a heavy duty truck having a frame, a drive axle connected to the frame, and a selectively lockable suspension component disposed between the frame and drive axle for maintaining a relative position between the frame and drive axle, the method comprising:

monitoring signals indicative of vehicle operating parameters;

calculating a predicted torque that will be applied to the drive axle based on the monitored signals;

locking the selectively lockable suspension component if the predicted torque exceeds a predetermined threshold.

2. The method of claim 1, wherein the monitored signals comprise signals indicative of at least one of the following vehicle operating parameters:

engine speed, engine torque, brake pressure, vehicle speed, air bag pressure, steering wheel angle, vehicle height, or throttle position.

3. The method of claim 1 comprising determining whether the vehicle brakes are engaged and unlocking the selectively lockable suspension component when the brakes are engaged.

4. The method of claim 1 comprising calculating an instantaneous change in predicted torque and unlocking the selectively lockable suspension component if the instantaneous change in predicted torque exceeds a predetermined threshold.

5. The method of claim 1 comprising monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is higher than a predetermined nominal operating speed and the selectively lockable suspension component has been locked for more than a first time limit.

6. The method of claim 5, wherein the predetermined nominal operating speed is 40 miles per hour.

7. The method of claim 5 wherein the first time limit is 2 seconds.

8. The method of claim 1 comprising monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is lower than a predetermined nominal operating speed, the predicted torque is lower than a lower torque threshold and the selectively lockable suspension component has been locked for more than a second time limit.

9. The method of claim 8, wherein the predetermined nominal operating speed is 40 miles per hour.

10. The method of claim 8 wherein the second time limit is 2 seconds.

11. The method of claim 8 where the lower torque threshold is 500 foot-pounds.

12. The method of claim 1 comprising monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is lower than a predetermined operating speed, the predicted torque is greater than a lower torque threshold and the selectively lockable suspension component has been locked for more than a third time limit.

13. The method of claim 12 wherein the predetermined nominal operating speed is 40 miles per hour.

14. The method of claim 12 wherein the lower torque limit is 500 foot-pounds.

15. The method of claim 12 wherein the third time limit is two minutes.

16. A device for controlling frame rise on a heavy-duty truck having a frame, a drive axle connected to the frame that drives truck wheels, and a selectively lockable suspension component disposed therebetween for maintaining the relative position therebetween, the device comprising a controller having a microprocessor storing a set of instructions, the instructions comprising:

monitoring signals indicative of vehicle operating parameters;

calculating a predicted thrust that will be applied at the truck wheels based on the monitored signals; and

locking the selectively lockable suspension component if the predicted thrust exceeds a predetermined threshold.

17. The device of claim 16 wherein the monitored signals comprise signals indicative of at least one of the following vehicle operating parameters:

engine speed, engine torque, brake pressure, vehicle speed, air bag pressure, steering wheel angle, vehicle height, or throttle position.

18. The device computer of claim 16 wherein the instructions comprise determining whether the vehicle brakes are engaged and unlocking the selectively lockable suspension component when the brakes are engaged.

19. The device of claim 16 wherein the instructions comprise calculating an instantaneous change in predicted thrust and unlocking the selectively lockable suspension component if the instantaneous change in predicted thrust exceeds a predetermined threshold.

20. The device of claim 16 wherein the instructions comprise monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is higher than a predetermined nominal operating speed and the selectively lockable suspension component has been locked for more that a first time limit.

21. The device of claim 16 wherein the instructions comprise monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is lower than a predetermined nominal operating speed, the predicted thrust is lower than a lower thrust threshold and the selectively lockable suspension component has been locked for more than a second time limit.

22. The device of claim 16 wherein the instructions comprise monitoring vehicle speed and the length of time the selectively lockable suspension component has been locked and unlocking the selectively lockable suspension component if the vehicle speed is lower than a predetermined operating speed, the predicted torque is greater than a lower torque threshold and the selectively lockable suspension component has been locked for more than a third time limit.