METHOD FOR OPERATING THE TORQUE CONVERTER LOCK-UP CLUTCH IN A POWER TRANSMISSION OF A MOBILE MACHINE COMPRISING AT LEAST ONE HYDRAULICALLY ACTUATED LIFTING DEVICE

• US 20110202244A1
• Filed: 09/30/2009
• Published: 08/18/2011
• Est. Priority Date: 10/23/2008
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Kurz, Thomas, Hofler, Hans
• Granted Patent: US 8,494,735 B2
• Time in Patent Office: Days
• US Class Current: 701/60
• CPC Class Codes: B60W 2710/024 of torque converter lock-up clutch
• CPC Class Codes: E02F 9/202 Mechanical transmission, e.g. clutches, gears clutches per se F16D, gears per se F16H
• CPC Class Codes: E02F 9/2253 Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission
• CPC Class Codes: F16H 2059/385 Turbine speed
• CPC Class Codes: F16H 59/50 Inputs being a function of the status of the machine, e.g. position of doors or safety belts
• CPC Class Codes: F16H 61/143 using electric control means
• CPC Class Codes: Y10T 74/20018 Transmission control

Abstract

A method of operating the torque converter lock-up clutch in a power transmission of a working machine comprising at least one hydraulically actuated lifting device. The torque converter lock-up clutch is actuated for disengagement when a predefined limit value for the position of the lifting hydraulic mechanism of the at least one lifting device is exceeded. When the position of the lifting hydraulic mechanism falls below a predefined limit value and when the turbine rotational speed exceeds a predefined threshold value, the torque converter lock-up clutch is reengaged.

Claims

1-4. -4. (canceled)

5. A method of operating a torque converter lock-up clutch in a power transmission of a working machine comprising at least one hydraulically actuated lifting device, the method comprising the steps of:

disengaging the torque converter lock-up clutch when a predefined limit value for a position of the lifting hydraulic mechanism for the at least one hydraulically actuated lifting device is exceeded, and

engaging the torque converter lock-up clutch, when the turbine rotational speed exceeds a predefined threshold value and if the position of the lifting hydraulic mechanism falls below the predefined limit value.

6. The method of operating the torque converter lock-up clutch in the power transmission according to claim 5, further comprising the step of when the position of the at least one hydraulically actuated lifting device falls below the predefined limit value, engaging the torque converter lock-up clutch when the turbine rotational speed exceeds the predefined threshold value where the turbine torque is the same for both an engaged and a disengaged torque converter lock-up clutch.

7. The method of operating the torque converter lock-up clutch in the power transmission according to claim 5, further comprising the step of, when driving downhill with the torque converter lock-up clutch engaged and in an event of exceeding the predefined limit value for the position of the lifting hydraulic mechanism, only disengaging the torque converter lock-up clutch when one of a speed of the vehicle falls below a threshold value and a transmission input torque exceeds a predefined threshold value.

8. The method of operating the torque converter lock-up clutch in the power transmission according to claim 5, further comprising the step of controlling engagement and disengagement of the torque converter lock-up clutch via transmission electronics which evaluates at least one input signal indicating the position of the lifting hydraulic mechanism, the turbine rotational speed and a motor rotational speed and a motor torque.

9. A method of operating a torque converter lock-up clutch in a power transmission of a working machine comprising at least one hydraulically actuated lifting device, the method comprising the steps of:

disengaging the torque converter lock-up clutch when a predefined limit value for a position of the lifting hydraulic mechanism for the at least one hydraulically actuated lifting device is exceeded, and

engaging the torque converter lock-up clutch, when the turbine rotational speed exceeds a predefined threshold value and if the position of the lifting hydraulic mechanism falls below the predefined limit value

when the position of the at least one hydraulically actuated lifting device falls below the predefined limit value, engaging the torque converter lock-up clutch when the turbine rotational speed exceeds the predefined threshold.

10. The method of operating the torque converter lock-up clutch in the power transmission according to claim 9, further comprising the step of, when driving downhill with the torque converter lock-up clutch engaged and in an event of exceeding the predefined limit value for the position of the lifting hydraulic mechanism, only disengaging the torque converter lock-up clutch when one of a speed of the vehicle falls below a threshold value and a transmission input torque exceeds a predefined threshold value.

11. The method of operating the torque converter lock-up clutch in the power transmission according to claim 10, further comprising the step of controlling engagement and disengagement of the torque converter lock-up clutch via transmission electronics which evaluates at least one input signal indicating the position of the lifting hydraulic mechanism, the turbine rotational speed and a motor rotational speed and a motor torque.