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US 6,186,923 B1Granted
Increased automatic gear box spontaneity
AssigneeZF Friedrichshafen AG
InventorsChristian Popp, Friedrich Tenbrock, Hansjörg Rosi
Life of this patent
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Abstract
The invention relates to a method for increasing the spontaneity of automatic gear boxes with overlapping gear shifts. The overlapping gear shifts consist of three phases. Upshifting from a first gear ratio to a second gear ratio is aborted and downshifting to a first gear ratio occurs if an abort criterion is detected. The abort criterion is validated if a request for downshifting is made by the driver and detected before the third overlapping shift phase begins.
Claims6
A method for carrying out an overlapping gear shift in an automatic transmission comprising the steps of:
- opening a first clutch (K1);
- closing a second clutch (K2);
- determining in a first phase of the overlapping gear shift a pressure curve of the first clutch (K1) by a transmission input rotational speed (nT);
- taking over a load of the first clutch (K1) by the second clutch (K2) in a second phase of the overlapping gear shift;
- closing completely the second clutch (K2) in a third phase of the overlapping gear shift;
- triggering an upshift from a first gear ratio (i1) to a second gear ratio (i2) without a time delay;
- detecting an abort criterion, said criterion corresponding to a down shift request presettable by a driver;
- interrupting the upshift without delay;
- and
- returning to the first gear ratio (i1) when the abort criterion is present prior to a beginning of the third phase of the overlapping gear shift;
- wherein a spontaneity of the automatic transmission is increased.
8 more elements
Dependencies are inferred from the claim text.