US 11,994,208 B2
Control method for calibrating an actuation of a converter lock-up clutch of a hydrodynamic torque converter
Sven Bieber, Markdorf (DE); Andreas Schwarz, Langenargen (DE); and Thomas Kurz, Langenargen (DE)
Assigned to ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed by ZF Friedrichshafen AG, Friedrichshafen (DE)
Filed on Jan. 13, 2023, as Appl. No. 18/154,346.
Claims priority of application No. 10 2022 200 531.7 (DE), filed on Jan. 18, 2022.
Prior Publication US 2023/0228326 A1, Jul. 20, 2023
Int. Cl. F16H 61/14 (2006.01)
CPC F16H 61/143 (2013.01) [F16H 2061/145 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A control method for calibrating an actuation of a converter lock-up clutch of a hydrodynamic torque converter with a pump wheel and a turbine wheel, which is connected to a power-split transmission, wherein the transmission comprises at least two clutches each associated with a respective power-split shaft assembly and configured to be actuated separately to close and open in order to apply a clutch torque (MK) to the turbine wheel and thereby change a rotation speed difference between the pump wheel and the turbine wheel, the control method comprising:
opening the converter lock-up clutch and the at least two clutches each associated with a respective power-split shaft assembly of the transmission, wherein the at least two clutches are configured to apply the clutch torque to the turbine wheel;
rotating the pump wheel at a specified rotation speed; and
applying the clutch torque (MK) to the turbine wheel as a function of the rotation speed difference between the pump wheel and the turbine wheel, in order to reach a specified set-point rotation speed difference; and
actuating the at least two clutches to close, each of the at least two clutches associated with the respective power-split shaft assembly of the transmission;
dividing, before applying the clutch torque to the turbine wheel, the specified set-point rotation speed difference into at least two ranges, wherein a number of ranges in the at least two ranges is smaller than or equal to a number of clutches of the at least two clutches that can be actuated separately in order to reach the specified set-point rotation speed difference;
actuating, in two of the at least two ranges, a different number of the at least two clutches in a closing direction in order to reach the specified set-point rotation speed difference;
increasing the rotation speed difference from a first to an nth range of the at least two ranges; and
limiting the rotation speed difference by the set-point rotation speed difference by correspondingly actuating in the closing direction an increasing number of the at least two clutches which can be actuated separately in order to reach the specified set-point rotation speed difference.