Arrangement And A Method For Controlling A Work Vehicle

• US 20080104953A1
• Filed: 02/17/2005
• Published: 05/08/2008
• Est. Priority Date: 02/17/2005
• Status: Active Grant

• Current Assignee: Volvo Construction Equipment AB (Volvo AB)
• Original Assignee: Volvo Construction Equipment Holding Sweden AB
• Inventors: Vigholm, Bo
• Granted Patent: US 7,712,309 B2
• Time in Patent Office: Days
• US Class Current: 60/413
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump

Abstract

An arrangement for controlling a work vehicle includes a power source, and a hydraulic circuit including a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream the actuator via a second conduit. The variable displacement hydraulic motor unit is arranged for controlling movement of the actuator.

Claims

1. An arrangement for controlling a work vehicle, comprising a power source, and a hydraulic circuit comprising a pump driven by the power source, at least one hydraulic actuator arranged in fluid connection with the pump via a first conduit, and a variable displacement hydraulic motor unit arranged in fluid connection with the actuator and downstream from the actuator via a second conduit wherein the variable displacement hydraulic motor unit is arranged for controlling movement of the actuator.

2. A control arrangement according to claim 1, wherein the arrangement comprises means for electrically controlling displacement of the variable displacement motor unit.

3. A control arrangement according to claim 1, wherein the motor unit is arranged for a rotation connection to the power source in order to transmit energy to the power source.

4. A control arrangement according claim 3, wherein the power source is connected to at least one further energy using component in the vehicle such that energy recovered by the motor unit may be transmitted to the at least one component.

5. A control arrangement according to claim 3, wherein the arrangement comprises at least one means for storing energy recovered by the motor unit.

6. A control arrangement according to claim 3, characterized in that wherein the arrangement comprises means for disconnecting a rotation connection between the power source and the motor unit.

7. A control arrangement according to claim 1, wherein the arrangement comprises a plurality of hydraulic circuits with a common pump driven by the power source.

8. A control arrangement according to claim 1, wherein the arrangement comprises a plurality of hydraulic actuators for performing a plurality of work functions, and that one variable displacement motor unit is arranged for controlling each work function.

9. A control arrangement according to claim 1, wherein at least one of the hydraulic actuators is formed by a hydraulic cylinder.

10. A control arrangement according to claim 1, wherein the arrangement comprises a set of on/off valves arranged on the first and second conduit for actuating the associated hydraulic actuator.

11. A control arrangement according to claim 10, wherein the arrangement comprises means for electrically controlling the on/off valves.

12. A control arrangement according to claim 1, wherein the arrangement comprises a means for sensing a rotational speed of the power source.

13. A control arrangement according to claim 12, wherein the arrangement comprises means for controlling an output pressure of the pump so that it exceeds the sensed load pressure existing in the actuator by a predetermined differential.

14. A control arrangement according to claim 1, wherein the arrangement comprises operator manouevrable means for generating a work function signal.

15. A control arrangement according to claim 1, wherein the power source is formed by an internal combustion engine arranged for propelling the work vehicle.

16. A control arrangement according to claim 1, wherein the second conduit is arranged for guiding substantially all fluid from the actuator to the associated motor unit.

17. A control arrangement according to claim 1, wherein the arrangement comprises means for sensing a load pressure subjected to the actuator during operation.

18. A control arrangement according to claim 1, wherein the pump and at least one of the motor units are coupled in such a way to the power source that they rotate at the same speed.

19. A work vehicle, wherein it comprises a control arrangement according to claim 1.

20. A method for controlling a work vehicle, comprising steps of

receiving a work function operator signal from an operator of the vehicle, and

depending on a requested work function in the operator signal, adjusting a displacement of a variable displacement hydraulic motor unit arranged downstream of a hydraulic actuator, which is arranged for performing the work function, for controlling movements of the actuator.

21. A method according to claim 20, further comprising the step of, at a same time as the step of adjusting the displacement of the motor unit is done, supplying a pressurized fluid in a non-throttled manner from a pump to the actuator so that the actuator performs the requested work function.

22. A method according to claim 21, further comprising the step of controlling movements of the actuator independent of which operation mode is currently in use, by adjusting the displacement of the variable displacement hydraulic motor unit.

23. A method according to claim 20, further comprising the step of recovering energy by transmitting energy from the motor unit to a power source.

24. A method according to claim 23, further comprising the step of operatively driving the pump by the power source.

25. A method according to claim 20, further comprising the step of sensing at least one vehicle operating parameter and adjusting the displacement of the motor unit also according to the sensed operating parameter.

26. A method according to claim 20, further comprising the step of sensing a speed of a power source driving the pump and adjusting the displacement of the motor unit according to the sensed speed.

27. A method according to claim 20, further comprising the step of actuating the actuator by controlling a plurality of on/off valves associated with the actuator.

28. A method according to claim 20, further comprising the step of sensing a load pressure subjected to the actuator during operation and controlling an output pressure of the pump so that it exceeds the sensed load pressure existing in the actuator by a predetermined differential.

29. A method according to claim 20, further comprising the step of sensing operation of an operator manoeuvrable control means and generating the work function signal accordingly.

31. A computer program product comprising computer program segments stored on a computer-readable medium for implementing the method as claimed in claim 20 when the program is run on a computer.

32. A computer program product comprising computer program segments stored on a computer-readable means for implementing the method as claimed in claim 20 when the program is run on a computer.