Patent ID: 6711486
Filing Date: 2004-03-23
Classification: B60W,F16D,Y10T

Abstract:
Drive unit for a motor vehicle, comprising:a driving motor (1) with an output shaft (2), a gearbox (10) with an input shaft (9), a friction clutch (3) with a first friction element (4) joined to the output shaft, and a second friction element (8) joined to the input shaft, a clutch actuator (12) for engagement and disengagement of the clutch, an electronic control unit (20) for controlling the actuator dependent on signals fed into the control unit from a first sensor (21), which first sensor senses the rotational speed of the output shaft, a second sensor (22) which senses the rotational speed of the input shaft, a third sensor (23) which senses the position of the clutch actuator, and a fourth sensor (24) which senses the position of a gear selector (25) for shifting between the various gear speeds of the gearbox, wherein, reference values of torque transmitted by the clutch (3) as a function of the position of the actuator (12) are stored in the control unit (20), and the control unit is set firstly, when the gear selector (25) is moved from a neutral position to a gear-selected position, to calibrate the actuator to a reference position which provides a predetermined desired value of the torque, and secondly, at regular intervals in the neutral position of the gearbox (10), to check the actual value of the torque at said reference position of the actuator and, if there is torque deviation from the desired value, to adjust the reference position, so that the actual value of the torque is moved towards the desired value.