The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 2004
Filed:
Mar. 28, 2002
Martin Vohmann, Esslingen, DE;
Ralf Dreibholz, Meckenbeuren, DE;
ZF Friedrichshafen AG, Friedrichshafen, DE;
Abstract
A process for controlling and regulating a clutch in a stepped load switchable automatic transmission for a motor vehicle where an electronic control device determines the behavior of the clutch during three operating conditions by way of a first or a second control circuit, and that a shift from a first into a second gear ratio stage takes place. In accordance with the invention, the first control circuit is used for controlling and regulating the clutch during the first operating condition, whose controlled variable is equivalent to the actual value of the engine speed (n_MOT_IST). During the second driving condition, a second control circuit is used, whose controlled variable is equivalent to the actual value of a differential rotational speed (dnK_IST) of the clutch, and during the third operating condition, the clutch is impinged with a controlled pressure value dependent upon various influence magnitudes.