Patent ID: 8494735
Filing Date: 2013-07-23
Classification: B60W,E02F,F16H,Y10T

Abstract:
1. A method of operating a hydrodynamic torque converter lock-up clutch in a power transmission of a working machine comprising a lifting hydraulic mechanism of at least one hydraulically actuated lifting device, and the torque converter having an input and an output, the method comprising the steps of: using a position sensor, coupled to transmission electronics, for determining a position of the lifting hydraulic mechanism; comparing, via the transmission electronics, the determined position of the lifting hydraulic mechanism to a predefined limit value for the position of the lifting hydraulic mechanism; using a speed sensor, coupled to the transmission electronics, for determining a rotational speed of a turbine of the torque converter; comparing, via the transmission electronics, the rotational speed of the turbine to a predefined threshold value; disengaging, via the transmission electronics, the hydrodynamic torque converter lock-up clutch on condition that the predefined limit value for the position of the lifting hydraulic mechanism for the at least one hydraulically actuated lifting device is exceeded so as to provide a drive connection, between the input and the output, which experiences hydraulic power loss, engaging, via the transmission electronics, the hydrodynamic torque converter lock-up clutch, on condition that both the turbine rotational speed exceeds the predefined threshold value and the position of the lifting hydraulic mechanism falls below the predefined limit value, to achieve a loss free drive connection between the input and the output; and when driving downhill with the hydrodynamic 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 hydrodynamic torque converter lock-up clutch on condition that one of a speed of the vehicle falls below a threshold value and a transmission input torque exceeds a predefined threshold value.