Method for determining the axial wear and the counterforce gradient in a multiple disk switching element
AssigneeZF Friedrichshafen AG
InventorsVolker Vogel, Rainer Denzler
Life of this patent
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Abstract
A method of detecting axial wear and a counterforce gradient of a multiple disc switching element (1) with position-controlled actuation with an electric motor (2), a spur gear stage (3) and a ball ramp (4) by one of a hydraulic pressure actuator and an electromagnetic actuator. The method comprises the step of determining, when a vehicle is at a standstill, the axial wear (J) and the counterforce gradient or the rigidity of the system by an overrun adaptation.
Claims4
A method of detecting both axial wear and one of a counterforce gradient and a rigidity of a system of a multiple disc switching element (1) with position-controlled actuation with an electric motor (2), a spur gear stage (3) and a ball ramp (4), by one of a hydraulic pressure actuator and an electromagnetic actuator, the method comprising the step of:
- determining, when a vehicle is at a standstill, the axial wear (J) and the counterforce gradient or the axial wear (J) and the rigidity of the system by an overrun adaptation;
- scanning an entire operating range (I) of discs of the switching element (1) with an ascending and a descending position-controlled ramp (C, D) when the vehicle is at a standstill;
- detecting the axial wear (J) of the discs and the counterforce gradient of the system by averaging corresponding measured values for the ascending and the descending ramp and
- maintaining a hysteresis (H) of the scanned ramp (C, D) to a minimum by varying motor torque (Mmotor).
A method of detecting axial wear and a counterforce gradient in a multiple disc switching element (1) which is actuated by an electric motor (2), a spur gear stage (3) and a ball ramp (4), the method comprising the steps of:
- measuring values of torque and angle of rotation of the electric motor (2) over an entire operating range (I) of discs of the switching element (1), when the vehicle is at a standstill, to determine an ascending and a descending position-controlled gradient (C, D) with a transition (E) occurring between the ascending position-controlled gradient (C) and the descending position-controlled gradient (D);
- varying the motor torque (Mmotor) to minimize a hysteresis (H) of the ascending and the descending position-controlled gradient (C, D);
- and
- detecting the axial wear (J) of the discs of the switching element (1) and the counterforce gradient of the system by averaging corresponding measured values for the ascending and the descending position-controlled gradient (C, D).
Dependencies are inferred from the claim text.