Method for controlling a hydraulic machine in a control system

• US 8,240,144 B2
• Filed: 01/16/2007
• Issued: 08/14/2012
• Est. Priority Date: 01/16/2006
• Status: Active Grant

• Current Assignee: Volvo Construction Equipment AB (Volvo AB)
• Original Assignee: Volvo Construction Equipment AB (Volvo AB)
• Inventors: Vigholm, Bo, Palo, Markku
• Primary Examiner(s): Lopez, Daniel
• Application Number:
  US12/097,922
• Publication Number:
  US 20080292474A1
• Time in Patent Office: 2,037 Days
• Field of Search: 603/27, 604/31
• US Class Current: 60/431
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22
• CPC Class Codes: E02F 9/2207 for reducing or compensating oscillations
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2289 Closed circuit
• CPC Class Codes: E02F 9/2292 Systems with two or more pumps
• CPC Class Codes: E02F 9/2296 Systems with a variable displacement pump
• CPC Class Codes: E02F 9/265 with follow-up actions (e.g. control signals sent to actuate the work tool)
• CPC Class Codes: F03C 1/00 Reciprocating-piston liquid engines
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F15B 11/0406 during starting or stopping F15B11/048 takes precedence
• CPC Class Codes: F15B 21/14 Energy-recuperation means
• CPC Class Codes: F15B 2211/20515 Electric motor
• CPC Class Codes: F15B 2211/20561 reversible
• CPC Class Codes: F15B 2211/20569 capable of working as pump and motor
• CPC Class Codes: F15B 2211/27 Directional control by means of the pressure source
• CPC Class Codes: F15B 2211/30515 Load holding valves
• CPC Class Codes: F15B 2211/3057 having two valves, one for each port of a double-acting output member
• CPC Class Codes: F15B 2211/50518 using pressure relief valves
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/6336 representing a state of the output member, e.g. position, speed or acceleration
• CPC Class Codes: F15B 2211/7053 : Double-acting output members
• CPC Class Codes: F15B 2211/851 : during starting
• CPC Class Codes: F15B 2211/88 : Control measures for saving energy
• CPC Class Codes: Y10T 137/8593 : Systems

Abstract

A method is provided for controlling a hydraulic machine in a control system when utilizing the hydraulic machine as a pump, in which an electric machine is connected in a driving manner to the hydraulic machine. The method includes detecting at least one operating parameter, determining, based on the detected operating parameter, whether a pressure supplied by the hydraulic machine is to be limited, and controlling the electric machine correspondingly.

Claims

1. A method for controlling a hydraulic machine in a control system when utilizing the hydraulic machine as a pump, in which an electric machine is connected in a driving manner to the hydraulic machine, comprising

detecting at least one operating parameter,

determining, based on the detected operating parameter, an allowed maximum pressure and whether a pressure supplied by the hydraulic machine is to be limited, and

controlling the electric machine to limit the pressure supplied by the hydraulic machine by controlling torque out from the electric machine and displacement of the hydraulic machine, wherein torque out from the electric machine is determined based on torque in to the electric machine.

2. The method as claimed in claim 1, comprising also controlling the electric machine in a way that corresponds to an efficiency of the hydraulic machine.

3. The method as claimed in claim 1, comprising utilizing various predetermined values of the torque into the electric machine.

4. The method as claimed in claim 1, wherein the hydraulic machine supplies a hydraulic actuator with pressurized hydraulic fluid.

5. A work machine for controlling an implement comprising

a hydraulic machine in a control system, the hydraulic machine being adapted to be used as a pump, and

an electric machine connected in a driving manner to the hydraulic machine, and

means for detecting at least one operating parameter,

wherein the control system is arranged to determine, based on the detected operating parameter, an allowed maximum pressure and whether a pressure supplied by the hydraulic machine is to be limited, and to control the electric machine to control the pressure supplied by the hydraulic machine by controlling torque out from the electric machine and displacement of the hydraulic machine, wherein torque out from the electric machine is determined based on torque in to the electric machine.

6. The work machine as claimed in claim 5, wherein the at least one operating parameter comprises a parameter that is indicative of the position of the implement.

7. The work machine as claimed in claim 5, wherein the at least one operating parameter comprises a parameter that is indicative of a different function than a function for which the hydraulic machine is arranged to supply a pressure.

8. The work machine as claimed in claim 5, wherein the at least one operating parameter comprises a speed of the work machine.

9. The work machine as claimed in claim 5, comprising controlling the electric machine corresponding to work currently being carried out by the work machine.

10. The work machine as claimed in claim 5, comprising controlling the electric machine corresponding to a type of implement that is arranged on the work machine.

11. The work machine as claimed in claim 5, wherein the at least one operating parameter comprises a mode selected by a driver.