Ka Group Ag

Jimmy Engman

Ole Jonny Waerp

Jimmy Chau

The present invention is directed to a method for determining a force transmission contact point of an actuating element () of an electric clutch actuator which comprises a linear drive assembly configured to linearly move the actuating element () towards a preload plunger () which is linked by a pushrod () to a clutch lever () and to move the pushrod () to turn the clutch lever, characterized by including the steps: monitoring an oscillation of the pushrod () by monitoring the position of the pushrod () and determining in consecutive time periods at least one of a maximum, minimum and centre value of the pushrod position, deriving a measure of non-oscillatory movement of the pushrod () based on a difference between at least one of the respective maximum, minimum and centre values of the pushrod position in a current and at least one of the preceding time periods or based on a difference between a combination of the respective positions in the current and at least one of the preceding time periods; and determining that the actuating element () has reached the force transmission contact point if the measure of non-oscillatory movement of the pushrod exceeds a predetermined threshold value.

Method for determining a force transmission contact point of an electric clutch actuator

The invention relates to an electrically driven clutch actuators () for actuating the clutch of a transmission of a vehicle. An actuator comprises a spindle nut () on a spindle () and a pressure piece () displaceable relative to the spindle nut () and coupled to the spindle nut by a biasing spring (). By rotation of the threaded spindle under a driving force of an electric motor (), the spindle nut () compresses the biasing spring () and displaces the pressure piece () to disengage the clutch. A latching mechanism () is configured to limit displacement of the spindle nut away from the pressure piece under the force of the expanding biasing spring when the driving force is reduced below a predetermined level. Further, a control unit is described that reduces the driving force in response to a trigger condition to reduce power consumption in the clutch disengaged state.

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Kongsberg, Norway

Jimmy Engman