Partial prefill of clutch for coast downshift conditions in a vehicle

Patent metadata

Field	Value
Publication number	US-8965653-B2
Application number	US-201313949295-A
Country	US
Kind code	B2
Filing date	Jul 24, 2013
Priority date	Jul 24, 2013
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

A vehicle transmission includes a plurality of oncoming clutches that are hydraulically-actuated. A controller is operatively connected to the plurality of oncoming clutches. An algorithm stored on and executable by the controller causes the controller to determine if at least one predefined coast condition is met and identify the plurality of oncoming clutches configured to be engageable during a downshift event from an initial gear ratio to respective other gear ratios. The initial gear ratio is greater than each of the respective other gear ratios. The algorithm causes the controller to generate a first pressure command to at least partially pressurize a first one of the oncoming clutches to a first staging pressure (P S1 ) if the at least one predefined coast condition is met prior to the downshift event. The first staging pressure (PS 1 ) is defined as a first return spring pressure (P R1 ) minus a first variable correction factor (CF 1 ).

First claim

The invention claimed is:

1. A transmission comprising:
a plurality of oncoming clutches, each of the plurality of oncoming clutches being hydraulically-actuated;
a controller operatively connected to the plurality of oncoming clutches;
an algorithm stored on and executable by the controller to cause the controller to:
determine if at least one predefined coast condition is met;
identify the plurality of oncoming clutches configured to be engageable during a downshift event…

Assignees

• Gm Global Tech Operations Inc

Inventors

• Kokko Kristopher J
• Monajemi Dara
• Webert David C
• Igel Amanda P

Classifications

• F16D48/06 Primary

  Mechanical Engineering · mapped topic

• B60W10/02

  Operations & Transport · mapped topic

• B60W10/10

  Operations & Transport · mapped topic

• F16D48/062 Primary

  Mechanical Engineering · mapped topic

• F16D2500/70282

  Mechanical Engineering · mapped topic