System and method for controlling engagement of a clutch

• US 20060219509A1
• Filed: 03/31/2005
• Published: 10/05/2006
• Est. Priority Date: 03/31/2005
• Status: Abandoned Application

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Shah, Vaibhav Hasmukhlal, Kabrich, Todd Ryan, League, Richard Brookes, Sloan, Andrew William
• Application Number:
  US11/094,381
• Publication Number:
  US 20060219509A1
• Time in Patent Office: Days
• US Class Current: 192/3.630
• CPC Class Codes: F16D 2500/30406 Clutch slip
• CPC Class Codes: F16D 2500/50684 Torque resume after shifting
• CPC Class Codes: F16D 2500/70406 Pressure
• CPC Class Codes: F16H 2061/0209 with independent solenoid valves modulating the pressure individually for each clutch or brake
• CPC Class Codes: F16H 59/46 dependent on a comparison between speeds
• CPC Class Codes: F16H 61/061 using electric control means

Abstract

A method for controlling engagement of a clutch in a work machine includes determining a relative speed of the clutch of the work machine and selectively adjusting an actuation pressure applied to the clutch based at least in part on the clutch relative speed.

Claims

1. A method for controlling engagement of a clutch in a work machine, comprising:

determining a relative speed of the clutch of the work machine;

selectively adjusting an actuation pressure applied to the clutch based at least in part on the clutch relative speed.

2. The method of claim 1, wherein the determining the clutch relative speed includes measuring an input speed of the clutch and measuring an output speed of the clutch, and comparing the clutch output speed to the clutch input speed.

3. The method of claim 2, wherein the selectively adjusting the clutch actuation pressure includes determining a clutch actuation pressure as a function of the clutch relative speed and adjusting a signal to a clutch control valve based on the determined clutch actuation pressure.

4. The method of claim 3, wherein the clutch is a fluid actuated clutch, and the clutch control valve is a solenoid actuated control valve.

5. The method of claim 4, wherein the selectively adjusting the clutch actuation pressure includes selectively applying a plurality of signals to the solenoid actuated control valve to vary the clutch actuation pressure.

6. The method of claim 5, wherein the measuring the clutch input speed includes receiving a signal at a control unit from at least one clutch input speed sensor associated with the work machine.

7. The method of claim 6, wherein the measuring the clutch output speed includes receiving a signal at a control unit from at least one speed sensor associated with the work machine.

12. The method of claim 11, wherein the selectively adjusting the clutch actuation pressure includes selectively applying a plurality of signals to the solenoid actuated control valve to vary the clutch actuation pressure.

13. The method of claim 12, wherein the determining the transmission input speed includes receiving a signal at a control unit from at least one speed sensor associated with the work machine.

14. The method of claim 13, wherein the determining the transmission output speed includes receiving a signal at a control unit from at least one speed sensor-associated with the work machine.

8. A method for controlling engagement of a clutch in a work machine, comprising:

determining a transmission ratio of the work machine; and

selectively adjusting an actuation pressure applied to the clutch based at least in part on the transmission relative speed.

9. The method of claim 8, wherein the determining the transmission ratio includes determining at least one transmission input speed and determining at least one transmission output speed.

10. The method of claim 9, wherein the selectively adjusting the clutch actuation pressure includes determining a clutch actuation pressure as a function of the transmission ratio and adjusting a signal to a clutch control valve based on the determined clutch actuation pressure.

11. The method of claim 10, wherein the clutch is a fluid actuated clutch, and the clutch control valve is a solenoid actuated control valve.

15. A method for controlling engagement of a clutch in a work machine, comprising:

applying a first set of actuation pressures to the clutch for a majority of clutch engagement; and

applying a second set of actuation pressures to the clutch after the first set, the second set of clutch actuation pressures being less than a maximum clutch actuation pressure of the first set.

16. The method of claim 15, wherein the second set of clutch actuation pressures is applied when a clutch relative speed approaches a predetermined value.

17. The method of claim 16, wherein the clutch relative speed is determined by measuring an input speed of the clutch and measuring an output speed of the clutch, and comparing the clutch output speed to the clutch input speed.

18. The method of claim 17, wherein the applying the second set of clutch actuation pressures includes determining a clutch actuation pressure as a function of the clutch relative speed and selectively adjusting a signal to a clutch control valve based on the determined clutch actuation pressure.

19. The method of claim 18, wherein the clutch is a fluid actuated clutch, and the clutch control valve is a solenoid actuated control valve.

20. The method of claim 19, wherein the selectively adjusting the signal to a clutch control valve includes selectively applying a plurality of signals to the solenoid actuated control valve to vary the clutch actuation pressure.

21. The method of claim 20, wherein the measuring the clutch input speed includes receiving a signal at a control unit from at least one speed sensor associated with the work machine.

22. The method of claim 21, wherein the measuring the clutch output speed includes receiving a signal at a control unit from at least one speed sensor associated with the work machine.

23. The method of claim 22, wherein the second set of clutch actuation pressures is applied when a transmission ratio approaches a predetermined value.

24. The method of claim 23, wherein a transmission ratio is determined by determining at least one transmission input speed and determining at least one transmission output speed.

25. A system for controlling the engagement of at least one clutch in a transmission, the system comprising:

at least one electronic control unit configured to control engagement of the at least one clutch by;

determining a relative speed of the transmission; and

selectively adjusting an actuation pressure applied to the at least one clutch based at least in part on the transmission relative speed.

26. The system of claim 25, wherein the at least one electronic control unit is configured to receive a signal from at least one speed sensor and a signal from at least one speed sensor.

27. The system of claim 26, wherein the system further includes at least one clutch control valve responsive to signals from the at least one electronic control unit.

28. The system of claim 27, wherein the at least one clutch is a fluid actuated clutch.