US 5,634,869 AGranted

Shift control system for automatic transmission

AssigneeToyota Jidosha Kabushiki Kaisha

InventorsTsuyoshi Mikami, Hidehiro Oba, Nobuaki Takahashi

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Abstract

A shift control system can perform clutch-to-clutch shifts without occurrence of delay in shifting operation and aggravation of shift shock, by decreasing an engaging force of a first frictional engagement device and increasing an engaging force of a second frictional engagement device, and comprises a low pressure retention instructer for maintaining the second frictional engagement device at a predetermined low level until a revolution speed of a rotary member reaches a predetermined value upon the shift, an engagement instructer for increasing the engaging force of the second frictional engagement device after the revolution speed of the rotary member has reached said predetermined value, and a pressure rise instructer for increasing the engaging force of the first frictional engagement device after increasing the engaging force of the second frictional engagement device.

Claims8

Dependent claims

A shift control system for an automatic transmission which has a first frictional engagement means and a second frictional engagement means, in which a shift of the automatic transmission is carried out by decreasing an engaging force of said first frictional engagement means and increasing an engaging force of said second frictional engagement means, comprising:

a low pressure retention instructing means for maintaining the engaging force of said second frictional engagement means at a predetermined low level until a revolution speed of a rotary member reaches a predetermined value upon the shift;
an engagement instructing means for increasing the engaging force of said second frictional engagement means after the revolution speed of said rotary member reaches said predetermined value;
and
a pressure rise instructing means for increasing the engaging force of said first frictional engagement means after increasing the engaging force of said second frictional engagement means.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 08/606,857Filed 26 Feb 1996
Priority: JP 7-0706723 Mar 1995
Granted: 3 Jun 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

B60W 30/18
Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of…:…
B60W 10/04
Conjoint control of vehicle sub-units of different type or different function: including control of propulsion units
B60W 10/11
Including control of change-speed gearings: stepped gearings
B60W 30/1819
Propelling the vehicle: propulsion control with control means using analogue circuits, relays or mechanical links