Fuel supply apparatus for internal combustion engine

A fuel supply apparatus for an internal combustion engine having a plurality of cylinders, which supplies fuel through fuel injection valves provided corresponding to the plurality of cylinders, said fuel supply apparatus comprising:

• fuel injection control means for controlling an amount of fuel supplied to said engine by changing a fuel injection period of said fuel injection valve, and performing a fuel injection with a plurality of injection modes including a reference injection mode;
• and
• fuel pressure parameter calculating means for calculating a fuel pressure parameter indicative of a pressure of the fuel supplied to said fuel injection valve,
• wherein said fuel injection control means includes:
• fuel injection amount parameter setting means for setting a fuel injection amount parameter for controlling a valve opening period of said fuel injection valve in the reference injection mode according to an operating condition of said engine;
• injection mode determining means for determining whether or not an injection mode of the fuel injection to be performed is the reference injection mode;
• and
• correcting means for correcting the fuel injection amount parameter according to a ratio of the fuel pressure parameter value corresponding to another injection mode which differs from the reference injection mode, and the fuel pressure parameter value corresponding to the reference injection mode, when the injection mode is determined to be the other injection mode.

A fuel supply apparatus for an internal combustion engine having a plurality of cylinders, which supplies fuel through fuel injection valves provided corresponding to the plurality of cylinders, said fuel supply apparatus comprising:

• fuel injection control means for controlling an amount of fuel supplied to said engine by changing a fuel injection period of said fuel injection valve, and performing a fuel injection with a plurality of injection modes including a reference injection mode,
• wherein the reference injection mode is a single injection mode in which fuel injection periods of said fuel injection valves corresponding to the plurality of cylinders do not overlap, and another injection mode is an overlapped injection mode in which the fuel injection periods corresponding to a part or all of the plurality of cylinders overlap with each other,
• wherein said fuel injection control means includes:
• fuel injection amount parameter setting means for setting a fuel injection amount parameter for controlling a valve opening period of said fuel injection valve in the reference injection mode according to an operating condition of said engine;
• average fuel pressure calculating means for calculating an average fuel pressure which is an average value of a pressure of fuel supplied to said fuel injection valve during a main fuel injection, said average fuel pressure calculating means performing the calculation immediately after completion of the main fuel injection performed according to the fuel injection amount parameter;
• and
• additional correction amount calculating means for calculating an additional correction amount according to a ratio of the average fuel pressure calculated by said average fuel pressure calculating means and a reference average fuel pressure corresponding to the reference injection mode,
• wherein an additional fuel injection for injecting fuel of the additional correction amount is performed immediately after execution of the main fuel injection.

A fuel supply method for an internal combustion engine having a plurality of cylinders, for supplying fuel through fuel injection valves provided corresponding to the plurality of cylinders,

• wherein an amount of fuel supplied to said engine is controlled by changing a fuel injection period of said fuel injection valve, and a fuel injection is performed with a plurality of injection modes including a reference injection mode,
• said fuel supply method comprising the steps of:
• a) setting a fuel injection amount parameter for controlling a valve opening period of said fuel injection valve in the reference injection mode, according to an operating condition of said engine;
• b) determining whether or not an injection mode of the fuel injection to be performed is the reference injection mode;
• and
• c) correcting the fuel injection amount parameter so as to compensate shortage or oversupply of the fuel injection amount according to a correction parameter when the injection mode is determined to be another injection mode which differs from the reference injection mode, the correction parameter indicating a time period which affects a pressure change of the fuel supplied to said fuel injection valve caused by employing the other injection mode.

A fuel supply method for an internal combustion engine having a plurality of cylinders, for supplying fuel through fuel injection valves provided corresponding to the plurality of cylinders,

• wherein an amount of fuel supplied to said engine is controlled by changing a fuel injection period of said fuel injection valve, and a fuel injection is performed with a plurality of injection modes including a reference injection mode,
• said fuel supply method comprising the steps of:
• a) setting a fuel injection amount parameter for controlling a valve opening period of said fuel injection valve in the reference injection mode according to an operating condition of said engine;
• b) determining whether or not an injection mode of the fuel injection to be performed is the reference injection mode;
• c) calculating a fuel pressure parameter indicative of a pressure of the fuel supplied to said fuel injection valve;
• and
• d) correcting the fuel injection amount parameter according to a ratio of the fuel pressure parameter value corresponding to another injection mode which differs from the reference injection mode, and the fuel pressure parameter value corresponding to the reference injection mode, when the injection mode is determined to be the other injection mode.

A fuel supply method for an internal combustion engine having a plurality of cylinders, for supplying fuel through fuel injection valves provided corresponding to the plurality of cylinders,

• wherein an amount of fuel supplied to said engine is controlled by changing a fuel injection period of said fuel injection valve, and a fuel injection is performed with a plurality of injection modes including a reference injection mode,
• wherein the reference injection mode is a single injection mode in which fuel injection periods of said fuel injection valves corresponding to the plurality of cylinders do not overlap, and another injection mode is an overlapped injection mode in which the fuel injection periods corresponding to a part or all of the plurality of cylinders overlap with each other,
• said fuel supply method comprising the steps of:
• a) setting a fuel injection amount parameter for controlling a valve opening period of said fuel injection valve in the reference injection mode according to an operating condition of said engine;
• b) calculating an average fuel pressure which is an average value of a pressure of fuel supplied to said fuel injection valve during a main fuel injection, the calculation being performed immediately after completion of the main fuel injection performed according to the fuel injection amount parameter;
• c) calculating an additional correction amount according to a ratio of the average fuel pressure calculated in said step b) and a reference average fuel pressure corresponding to the reference injection mode;
• and
• d) performing an additional fuel injection for injecting fuel of the additional correction amount immediately after execution of the main fuel injection.