Engine overrun prevention system for automatic transmission
AssigneeIsuzu Motors Limited
InventorNobuyuki Nishimura
Life of this patent
Estimating the term…
Abstract
A controller (9) estimates (calculates) an engine revolution speed of after shifting to a target gear position, based on vehicle speed and a gear ratio of an automatic transmission (3) at the target gear position. Then, the controller (9) changes the target gear position to a higher one when the calculated engine revolution speed is not less than a preset value. The controller changes the target gear position by one or more gears. Since the target gear position is raised, an engine does not overrun upon shifting down. If the target gear position is lower than a current gear position by one gear, and an engine overrun is expected, no shifting down is admitted.
Claims20
An engine overrun prevention apparatus suitable for an automatic transmission comprising:
- a first controller for calculating an engine revolution speed of after shifting to a target gear position, based on vehicle speed and a gear ratio of an automatic transmission at the target gear position;
- and
- a second controller for changing the target gear position to a higher gear position when the calculated engine revolution speed is not less than a preset value.
An apparatus comprising:
- calculation means for calculating an engine revolution speed of after shifting to a target gear position, based on vehicle speed and a gear ratio of an automatic transmission at the target gear position;
- and
- gear position change means for changing the target gear position to a higher gear position when the calculated engine revolution speed is not less than a preset value.
A method comprising the steps of:
- A) determining whether an engine revolution speed at a target gear position is greater than a preset value;
- and
- B) changing the target gear position to a higher gear position.
Dependencies are inferred from the claim text.