Internal-combustion engines – Charge forming device – Fuel injection system
Reexamination Certificate
2000-07-19
2001-11-13
Solis, Erick (Department: 3747)
Internal-combustion engines
Charge forming device
Fuel injection system
C123S00100A, C073S035020, C073S117020
Reexamination Certificate
active
06314944
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a fuel property determination method and apparatus for determining property of fuel supplied to internal combustion engines.
In gasoline engines mounted on vehicles, gasoline fuel is injected in intake ports of the engine by fuel injectors mounted on an intake pipe of the engine. Most of the injected fuel is directly sucked into cylinders of the engine. However, a part of the injected fuel remains on the inner peripheral walls of the intake port or on the surface of intake valves for a moment, and then gradually evaporates and enters the cylinders. Thus, the amount of fuel sucked into each cylinder varies with the amount of evaporation of fuel remaining on the inner peripheral wall or the like as the fuel wet.
The amount of evaporation, that is, speed of evaporation, depends on fuel property. The fuel property varies even among the same type of fuel and among fuel producers. It is also varied in dependence on season and sales area, even if the fuel is of the same producer's. It is therefore necessary to accurately determine the fuel property so that the air-fuel ratio of air-fuel mixture supplied to the engine may be accurately controlled in consideration of the amount of evaporation of fuel.
It is proposed to detect the fuel property by a fuel property sensor provided in a fuel tank. The fuel property sensor, however, adds cost.
It is also proposed in JP-A-5-65838 to measure a period required to complete engine cranking by increasing the amount of fuel at the time of engine starting, and to determine the fuel property based on the measured engine starting period. However, the engine starting period varies with engine coolant temperature and other factors other than the fuel property, thus disabling accurate determination of the fuel property from the measured engine starting period.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a fuel property determination method and apparatus which is capable of accurately determining property of fuel supplied to engines.
According to a first aspect of the present invention, the amount of fuel supplied to the engine immediately after starting the engine is corrected based on property of fuel which is determined immediately after engine starting. The fuel property is determined based on the amount of fuel injected, but remaining upstream the cylinder and not burned in a cylinder. The fuel property is determined from an accumulated intake air amount and an accumulated fuel injection amount. If the calculated value indicates that the fuel is a heavy type, the amount of fuel injected in the next engine starting operation is increased to compensate for the amount of fuel which will remain upstream the cylinder.
According to a second aspect of the present invention, the fuel property is determined based on an increase of pressure in a fuel tank detected while the fuel tank is in a fully closed condition. Preferably, the detected increase in the pressure is corrected with a decrease of pressure in the fuel tank which results from supply of fuel from the fuel tank to the engine.
REFERENCES:
patent: 5111796 (1992-05-01), Ogita
patent: 5345908 (1994-09-01), Nishimura et al.
patent: 5711272 (1998-01-01), Maegawa et al.
patent: 6109225 (2000-08-01), Ogita et al.
patent: 5-65838 (1993-03-01), None
Denso Corporation
Nixon & Vanderhye P.C.
Solis Erick
LandOfFree
Fuel property determination from accumulated intake air... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fuel property determination from accumulated intake air..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel property determination from accumulated intake air... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2593657