US 6,626,786 B2 · Speed shift control apparatus of automatic transmission

Abstract

At the time of the 6→3 speed shift, an automatic transmission achieves a 6→4→3 speed shift by controlling the servo pressures of four engageable elements. A control apparatus controls the servo pressure of one engageable element in accordance with the servo pressures of other engageable elements. The engagement and release timings are adjusted by determining and controlling the oil pressures of the hydraulic servos, taking into consideration the 6→4 shift state (torque sharing) during a shift transitional period. Therefore, engine blow and prolongation are prevented during the 6→3 shift control.

Claims32

Dependent claims

A speed shift control apparatus of an automatic transmission wherein a speed shift from a first gear speed to a second gear speed requires operation of four engageable elements, the first gear speed being achieved by an engagement of a first engageable element and an engagement of a second engageable element, the second gear speed being achieved by an engagement of a third engageable element and an engagement of a fourth engageable element,

the speed shift control apparatus comprising speed shift control means for controlling a state of the second engageable element in accordance with a state of the first engageable element.

the speed shift control apparatus comprising speed shift control means for controlling a state of the second engageable element in accordance with a state of the third engageable element;
and
the second engageable element starts to be released after the first engageable element starts to be released.

A speed shift control apparatus of an automatic transmission wherein a speed shift from a first gear speed to a second gear speed needs operation of four engageable elements, and the first gear speed is achieved by an engagement of a first engageable element and an engagement of a second engageable element, and the second gear speed is achieved by an engagement of a third engageable element and an engagement of a fourth engageable element,

the speed shift control apparatus comprising speed shift control means for controlling a state of the second engageable element in accordance with a state of the first engageable element and a state of the third engageable element.

Dependencies are inferred from the claim text.

Facts

Application

09/995,664Filed 29 Nov 2001

Priority

JP 2000-39986228 Dec 2000

Published

US 2002/0086761 A14 Jul 2002

Granted

30 Sep 2003

Term ends

Not estimatedThe source records don’t support an estimate.

Classification6 codes

F16H 61/0437
Smoothing ratio shift: by using electrical signals
F16H 61/08
Smoothing ratio shift: timing control
F16H 2061/0444
Smoothing ratio shift: during fast shifting over two gearsteps, e.g. jumping from fourth to second gear
F16H 2061/0451
Smoothing ratio shift: during swap-shifts, i.e. gear shifts between different planetary units, e.g. with double transitions shift involving three…

Speed shift control apparatus of automatic transmission

Life of this patent

Speed shift control apparatus of automatic transmission

Life of this patent

Abstract

Claims32