Internal combustion engine control device and internal combustion engine control system

An internal combustion engine control device applied to an internal combustion engine having a cylinder, an air-intake passage through which air is supplied to the cylinder and an exhaust gas passage through which exhaust gases are emitted from the cylinder, the internal combustion engine control device comprising:

• an external EGR regulating device connected between the air-intake passage and the exhaust gas passage for regulating an external EGR amount of exhaust gases partially recirculated from the exhaust passage to the air-intake passage;
• an internal EGR regulating device for regulating an internal EGR amount of combusted gases partially remaining in the cylinder,
• external and internal EGR ratio control means for controlling operations of the external EGR regulating device and the internal EGR regulating device for thereby controlling a ratio between the external EGR amount and the internal EGR amount;
• and
• surrounding atmospheric pressure acquiring means for acquiring a surrounding atmospheric pressure around the internal combustion engine;
• wherein the external and internal EGR ratio control means variably controls the ratio depending on the acquired surrounding atmospheric pressure such that the lower the surrounding atmospheric pressure, the greater will be the internal EGR amount.

An internal combustion engine control device applied to an internal combustion engine having a cylinder, an air-intake passage through which air is supplied to the cylinder and an exhaust gas passage through which exhaust gases are emitted from the cylinder, the internal combustion engine control device comprising:

• an external EGR regulating device connected between the air-intake passage and the exhaust gas passage for regulating an external EGR amount of exhaust gases partially recirculated from the exhaust passage to the air-intake passage;
• an internal EGR regulating device for regulating an internal EGR amount of combusted gases partially remaining in the cylinder,
• external and internal EGR ratio control means for controlling operations of the external EGR regulating device and the internal EGR regulating device for thereby controlling a ratio between the external EGR amount and the internal EGR amount;
• and
• surrounding atmospheric pressure acquiring means for acquiring a surrounding atmospheric pressure around the internal combustion engine;
• wherein the external and internal EGR ratio control means is responsive to an engine rotation speed, an engine load and the surrounding atmospheric pressure, the external and internal EGR ratio control means including means for determining a target EGR amount in response to the surrounding atmospheric pressure such that the lower the engine rotation speed and the engine load, the larger will be the total EGR amount, and means for variably controlling the ratio between the external EGR amount and the internal EGR amount in the target EGR amount depending on the surrounding atmospheric pressure such that the lower the surrounding atmospheric pressure, the greater will be the internal EGR amount.