Method and system for limiting torque load associated with an implement

• US 7,546,729 B2
• Filed: 12/18/2006
• Issued: 06/16/2009
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Palmer, Marvin Kent, Kamisetty, SriVidya Lavanya, Budde, Steven Conrad
• Primary Examiner(s): LESLIE, MICHAEL S
• Application Number:
  US11/640,184
• Publication Number:
  US 20080142232A1
• Time in Patent Office: 911 Days
• Field of Search: 603/28, 604/33, 604/34, 604/46, 604/49, 604/63
• US Class Current: 60/449
• CPC Class Codes: E02F 9/2214 for reducing the shock generated at the stroke end
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump

Abstract

A method for reducing a torque load associated with an implement includes determining a speed associated with a power source, wherein the power source is configured to provide power to a hydraulic pump, determining a position associated with an implement system, and limiting a flow associated with the hydraulic pump based on the speed associated with the power source and the position associated with the implement system.

Claims

1. A method for reducing a torque load associated with an implement, the method comprising:

determining a speed associated with a power source, wherein the power source is configured to provide power to a hydraulic pump;

determining a position associated with an implement system; and

limiting a flow associated with the hydraulic pump based on the speed associated with the power source and the position associated with the implement system,

wherein the limiting occurs when the speed associated with the power source falls below a predetermined threshold speed and the position associated with the implement system falls within a predetermined positional proximity of a stop point associated with the implement system.

2. The method of claim 1, wherein the determining the position associated with the implement system further includes determining a velocity associated with the implement system.

3. The method of claim 1, wherein the limiting includes reducing a command value to a hydraulic actuator associated with the implement system and the hydraulic pump.

4. The method of claim 1, wherein the limiting includes reducing a maximum potential flow from the hydraulic pump.

5. The method of claim 1, wherein the limiting ceases when the speed associated with the power source exceeds the predetermined threshold.

6. The method of claim 1, wherein the limiting may be terminated based on input from an operator.

7. A machine, comprising:

a frame;

a traction device;

a power source operatively connected to a hydraulic pump and configured to provide power to the hydraulic pump; and

a controller configured to execute the method according to claim 1.

8. A system for reducing a torque load associated with an implement, the system comprising:

a controller communicatively connected to a power source, a first sensor configured to sense a speed associated with the power source, and a second sensor configured to sense a position of an implement system, wherein the power source is operatively connected to a hydraulic pump and configured to provide power to the hydraulic pump, and wherein the controller is configured to

determine the speed associated with the power source based on input from the first sensor,

determine the position associated with the implement system based on input from the second sensor,

generate a signal based on the speed associated with the power source and the position associated with the implement system, wherein the signal affects a flow of fluid associated with the hydraulic pump; and

affect the flow of fluid when the speed associated with the power source falls below a predetermined threshold speed and the position associated with the implement system falls within a predetermined positional proximity of a stop point.

9. The system of claim 8, wherein the signal is provided to an electro-hydraulic actuator fluidly connected to the implement system and the hydraulic pump.

10. The system of claim 8, wherein the signal is provided to an actuator operatively linked to a swash plate associated with the hydraulic pump, wherein the swash plate is configured to vary a maximum potential flow output from the hydraulic pump.

11. The system of claim 8, further including at least one sensor configured to sense a velocity of the implement system, wherein the at least one sensor is communicatively connected to the controller.

12. The system of claim 8, wherein the predetermined threshold speed is between about 600 RPM and about 850 RPM.

13. The system of claim 8, wherein the controller is further configured to cease affecting the flow of fluid when the speed associated with the power source rises above a predetermined threshold speed.

14. The system of claim 8, wherein the controller is further configured to cease affecting the flow of fluid upon receiving a predetermined command sequence from an operator.

15. A method of limiting the motion of a hydraulic cylinder on a machine, the method comprising:

sensing a speed associated with a power source, wherein the power source is related to a machine and configured to drive a hydraulic pump associated with the machine;

sensing a position associated with an implement system, wherein the implement system is associated with the machine, a hydraulic cylinder, and the hydraulic pump;

receiving a command to provide a flow of fluid from the hydraulic pump to the implement system to impart motion to the implement system; and

reducing the flow of fluid from the hydraulic pump, resulting in a reduced velocity of the implement system, when the speed associated with the power source falls below a power source speed threshold and the position associated with the system falls within a predetermined positional proximity of a stop point associated with the implement system.

16. The method of claim 15, wherein the reducing includes limiting the flow through an electro-hydraulic actuator fluidly connected to the implement system and the hydraulic pump.

17. The method of claim 15, wherein the reducing is further affected based on a velocity of the implement system.

18. The method of claim 15, wherein the reducing ceases upon receiving a predetermined command sequence from an operator.