Method and arrangement for determining the wear condition of a shifting clutch
AssigneeZF Friedrichshafen AG
InventorFranz Bitzer
Life of this patent
Estimating the term…
Abstract
A method of determining the wear condition of a shifting clutch (1) of a motor vehicle which is provided either for interrupting the force flow or equalizing the rotation speed between a drive output shaft (2) of an internal combustion engine (3) and a drivetrain (4). The wear condition of the clutch (1) is determined from the parameters of clutch release path (sausrück) the and release force (Fausrück), at a release bearing (5) of the clutch (1) and, for this purpose, a difference between the clutch release path (sausrück), at a first increase-point (11; 12) of the release force (Fausrück) and at a reference point (13) represented by a second increase of the release force (Fausrück), is measured when the clutch is actuated.
Claims11
A method for determining a wear condition of a shifting clutch of a motor vehicle in which the clutch is provided for one of interrupting a force flow and equalizing a rotational speed between a drive output shaft of an internal combustion engine and a drivetrain of the motor vehicle, the method comprising the steps of:
- moving the clutch along a clutch release path during a single clutch actuation,
- detecting a first location of the clutch along the clutch release path where, at a start of the clutch actuation, an initial increase of a release force in a release bearing occurs,
- detecting a second location of the clutch along the clutch release path where, during the single clutch actuation, and after both the initial increase of release force and a decrease in the release force on the release bearing, a subsequent increase of the release force in the release bearing occurs,
- defining the second location as a reference point value,
- defining a distance between the first location and the second location along the release path as a path difference, and
- comparing the path difference to a first predefined limit to determine the wear condition of the clutch.
An arrangement for determining a wear condition of a shifting clutch that is located in a motor vehicle for one of interrupting a force flow and equalizing a rotational speed between a drive output shaft of an internal combustion engine and a drivetrain of the motor vehicle,
- a first sensor for detecting release forces in a release bearing of the clutch, when the clutch is actuated during a single actuation, a second sensor for determining a release path of the clutch in relation the release force in the release bearing of the clutch, a control unit for defining, a first location of the clutch along the release path where, at a start of the single clutch actuation, a first initial increase of a release force in the release bearing occurs,
- the control unit defining a second location of the clutch along the release path where, during the single clutch actuation, and after both the initial increase of release force and a span of a decrease in the release force on the release bearing, a subsequent increase of the release force in the release bearing occurs,
- the control unit defining the second location as a reference point value,
- the control unit defining a distance between the first location and the second location along the release path as a path difference and determining the wear condition of the clutch by comparing the path difference to a first predefined limit, and
- the sensor for detecting release forces, in an area of the release bearing of the clutch, is connected to the control unit for evaluating a parameter determined by the sensor.
A method of determining an absolute value of wear of a shifting clutch of a motor vehicle, in which the clutch is provided for one of interrupting a flow of force and equalizing a rotation speed between a drive output shaft of an internal combustion engine and a drivetrain of the motor vehicle, the method comprising the steps of:
- monitoring, via a force sensor, a release force at a release bearing of the clutch;
- monitoring a clutch release path of the clutch as the clutch is released;
- measuring a difference in the clutch release path between a first location of the clutch when, at the initiation of disengagement, an initial increase in the release force on the release bearing is detected, and a second location of the clutch when, during the same disengagement, and after both the initial increase of release force and a span of a decrease in the release force on the release bearing, a subsequent increase of the release force in the release bearing occurs, and
- determining the wear of the clutch from a difference between the first location and the second location of the clutch compared to a predefined limit of difference.
Dependencies are inferred from the claim text.