Control of lock-up clutch in torque converter of motor vehicle automatic gearbox

摘要

The lock-up clutch (16) between the impeller (13) and turbine (12) of a torque converter is used in two modes, one to provide a mechanical connection between these two elements, and one to provide a hydrodynamic connection. Its control unit uses a solenoid (24) with a variable work cycle to adjust the oil pressure feeding the clutch. A sensor (31) measures the oil temperature and generates a corresponding signal. Other sensors (32 to 34) measure the engine load and degree of slip between turbine and impeller, again generating signals. These three input signals are used by the control unit to adjust the start of the solenoid's working cycle when the demand for a clutch mode change is received.