Gas supply apparatus for internal combustion engine

A gas supply apparatus for an internal combustion engine, which includes a fuel injection valve that is adapted to directly inject fuel into a combustion chamber of the internal combustion engine through at least one fuel injection hole of the fuel injection valve, the gas supply apparatus comprising:

• a supply arrangement that is adapted to supply high-oxygen-concentration gas, which has an oxygen concentration that is higher than an oxygen concentration of fresh air, and low-oxygen-concentration gas, which has an oxygen concentration that is lower than the oxygen concentration of the fresh air, into the combustion chamber such that at a time of injecting fuel mist from the at least one fuel injection hole of the fuel injection valve into the combustion chamber, high-level-oxygen-concentration gas, which has an oxygen concentration that is equal to or lower than the oxygen concentration of the high-oxygen concentration gas, and low-level-oxygen-concentration gas, which has an oxygen concentration that is lower than the oxygen concentration of the high-level-oxygen-concentration gas and is equal to or higher than the oxygen concentration of the low-oxygen-concentration gas, are formed from the high-oxygen-concentration gas and the low-oxygen-concentration gas in an adjacent region of the combustion chamber, which is adjacent to the fuel mist, wherein:
• the high-level-oxygen-concentration gas is located in a corresponding area of the adjacent region, which is generally opposite from the at least one fuel injection hole of the fuel injection valve, while the fuel mist being held between the corresponding area of the adjacent region and the at least one fuel injection hole of the fuel injection valve, and the low-level-oxygen-concentration gas is located in a remaining area of the adjacent region, which is other than the corresponding area of the adjacent region, in which the high-level-oxygen-concentration gas is located;
• the supply arrangement includes a first intake port and a second intake port, which are adapted to supply the low-oxygen-concentration gas and the high-oxygen-concentration gas, respectively, into the combustion chamber;
• the first intake port is adapted to supply the low-oxygen-concentration gas into a center region of the combustion chamber, in which a central axis of the combustion chamber is located and which extends in a direction of the central axis;
• the second intake port is adapted to supply the high-oxygen-concentration gas into an outer peripheral region of the combustion chamber, which is located on an outer side of the center region and is other than the center region;
• the gas supply apparatus further comprises an interrupt-supply device that is adapted to supply the high-oxygen-concentration gas into the first intake port to supply the high-oxygen-concentration gas into the combustion chamber through the first intake port before a time of supplying the low-oxygen-concentration gas into the combustion chamber through the first intake port.