Method and control apparatus for operating a vehicle drive train
AssigneeZF Friedrichshafen AG
InventorsTobias Brand, Markus Maurer
Life of this patent
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Abstract
A method for operating a vehicle drive train (1) comprising a prime mover (2), transmission (3), and comprising a driven end (4) may include limiting, during a demand for engaging a form-locking shift element (A, F) of the transmission (3) when a rotational speed of the driven end (4) is close to zero, a rate of change of a transmission input torque present at the form-locking shift element (A, F) to a value. Below the value, forces present at the form-locking shift element (A, F) during an engagement process are less than a load limit. Above the value, irreversible damage to the form-locking shift element (A, F) occurs.
Claims12
A method for operating a vehicle drive train (1) comprising a prime mover (2), a transmission (3), and comprising a driven end (4), the method comprising:
- limiting, during a demand for engaging a form-locking shift element (A, F) of the transmission (3) when a rotational speed of the driven end (4) is zero, a rate of change of a transmission input torque at the form-locking shift element (A, F) to a value,
- wherein below the value, one or more forces at the form-locking shift element (A, F) during an engagement process are less than a load limit, and
- wherein above the value, irreversible damage to the form-locking shift element (A, F) occurs.
A control unit for operating a vehicle drive train (1) that comprises a prime mover (2), a transmission (3), and a driven end (4), the transmission (3) comprising at least one form-locking shift element (A, F), the control unit configured for:
- limiting, during a demand for engaging the form-locking shift element (A, F) when a rotational speed of the driven end (4) is zero, a gradient of a progression of a transmission input torque at the form-locking shift element (A, F) to a value,
- wherein, below the value, one or more forces at the form-locking shift element (A, F) during an engagement process are less than a load limit, and
- wherein, above the value, irreversible damage to the form-locking shift element (A, F) occurs.
Dependencies are inferred from the claim text.