Patent ID: 8245684
Filing Date: 2012-08-21
Classification: F01M

Abstract:
1. A method for controlling oil pressure in a vehicle powertrain having an internal combustion engine with a start-stop function, the engine including a fluid lubrication and control system, an oil filter, and an oil pump driven by the engine to maintain fluid pressure to the lubrication and control system when the engine is running, the method comprising: accumulating engine oil via an accumulator when the engine is running; retaining the oil in the accumulator when the engine is shut-off; determining whether the engine is shut-off due to a start-stop event; determining whether engine shut-off time is greater than a minimum shut-off time; determining a temperature of the engine oil if the engine shut-off time is greater than the minimum shut-off time; determining an accumulator discharge time based on the determined temperature of the engine oil; and discharging the engine oil via the accumulator for the determined discharge time when the engine is not running to maintain engine oil pressure.