Patent · US Expired

Controller for an automatic motor vehicle transmission

US5822708A · kind A · utility

16Cited by

12References

6Claims

0Family size

Assignee

Siemens Aktiengesellschaft · DE

Inventors

Thomas Wagner · Kerpen, DE
Michael Ulm · Alteglofsheim, DE
Friedrich Graf · Eggenfelden, DE

Key dates

Filing date	Nov 27, 1997
Grant date	Oct 13, 1998
Priority date	—
Expiry date	Nov 27, 2017

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF16H2061/0081
WIPO fieldMechanical elements
WIPO sectorMechanical engineering

Abstract

A control device for an automatic motor vehicle transmission reduces engine torque during a shifting operation, in particular a shifting operation in a traction mode, in order to increase smoothness of shifting. The engine torque reduction is begun at the earliest upon reaching a free-wheel point of the transmission and is ended shortly before a synchronizing point of the transmission is reached. The free-wheel point and the synchronizing point of the transmission are ascertained from rpm differences in the gearshift elements involved in the particular switching operation. Differential rpm thresholds used in the process and the intensity of the torque reduction are ascertained with fuzzy systems.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.