Patent ID: 7565898
Filing Date: 2009-07-28
Classification: F02D,F02M

Abstract:
1. A controller for a direct injection engine, the direct injection engine having a low-pressure pump pumping up fuel in a fuel tank and a high-pressure pump pressurizing a fuel which is directly injected into a cylinder through a fuel injector at a normal fuel pressure for engine idling, the controller comprising: a pressure detecting device for detecting a fuel pressure which is supplied to the fuel injector; a target fuel pressure establishing device for establishing a target fuel pressure according to a driving condition of the engine; a fuel pressure controlling device for controlling a discharge amount of the high-pressure pump in such a manner that the detected fuel pressure is consistent with the target fuel pressure, the fuel being introduced to the high-pressure pump by the low-pressure pump; a stop determining device for determining whether engine shut down is imminent; and a coolant temperature detecting device for detecting a temperature of an engine coolant; wherein the target fuel pressure establishing device establishes the target fuel pressure lower than the normal fuel pressure when the stop determining device determines that engine shut down is imminent and then the high-pressure pump is controlled so as to discharge the fuel at the target fuel pressure lower than the normal fuel pressure, and as the temperature of the engine coolant decreases, the target pressure establishing device increases the target pressure in a range where the target fuel pressure is lower than the normal fuel pressure.