Control apparatus of internal combustion engine and control method of internal combustion engine

A control method of an internal combustion engine in which a plurality of cylinders is divided into a first cylinder group and a second cylinder group, the internal combustion engine being able to be selectively switched between operating in a partial cylinder operation mode in which only one of the first cylinder group and the second cylinder group is operated, and operating in a full cylinder operation mode in which both the first cylinder group and the second cylinder group are operated, and being provided with a supercharger formed of an exhaust driven supercharger having a turbine provided only in an exhaust passage of said first cylinder group, the control method comprising:

• selectively starting and stopping operation of the supercharger depending on a load on the internal combustion engine when the internal combustion engine is to be operated in the partial cylinder operation mode, only the first cylinder group being operated when the internal combustion engine is to be operated in the partial cylinder operation mode with supercharging and only the second cylinder group being operated when the internal combustion engine is to be operated in the partial cylinder operation mode with natural aspiration,
• wherein an air-fuel ratio of one of the first cylinder group and the second cylinder group is controlled according to the load on the internal combustion engine when the internal combustion engine is to be operated in the partial cylinder operation mode with supercharging.

A control apparatus of an internal combustion engine in which a plurality of cylinders is divided into a first cylinder group and a second cylinder group, comprising:

• a supercharger that is formed of an exhaust driven supercharger, and a turbine of the exhaust driven supercharger is provided only in an exhaust passage of the first cylinder group;
• a common intake passage for the first cylinder group and the second cylinder group;
• and
• a controller that selectively switches the internal combustion engine between operating in a partial cylinder operation mode in which only one of the first cylinder group and the second cylinder group is operated, and operating in a full cylinder operation mode in which both the first cylinder group and the second cylinder group are operated, as well as selectively starts and stops operation of the supercharger depending on a load on the internal combustion engine when the internal combustion engine is to be operated in the partial cylinder operation mode, wherein:
• the controller operates only the first cylinder group when the internal combustion engine is to be operated in the partial cylinder operation mode with supercharging;
• and
• the controller operates only the second cylinder group when the internal combustion engine is to be operated in the partial cylinder operation mode with natural aspiration.

A control apparatus of an internal combustion engine in which a plurality of cylinders is divided into a first cylinder group and a second cylinder group, comprising:

• a supercharger that is formed of an exhaust driven supercharger, and a turbine of the exhaust driven supercharger is provided only in an exhaust passage of the first cylinder group;
• and
• a controller that selectively switches the internal combustion engine between operating in a partial cylinder operation mode in which only one of the first cylinder group and the second cylinder group is operated, and operating in a full cylinder operation mode in which both the first cylinder group and the second cylinder group are operated, as well as selectively starts and stops operation of the supercharger depending on a load on the internal combustion engine when the internal combustion engine is to be operated in the partial cylinder operation mode, wherein:
• the controller operates only the first cylinder group when the internal combustion engine is to be operated in the partial cylinder operation mode with supercharging;
• and
• the controller operates only the second cylinder group when the internal combustion engine is to be operated in the partial cylinder operation mode with natural aspiration,
• wherein when the controller switches from operating the internal combustion engine in the partial cylinder operation mode with natural aspiration to operating the internal combustion engine in the partial cylinder operation mode with supercharging, the controller first switches to the full cylinder operation mode while starting the supercharger, and then switches to the partial cylinder operation mode with supercharging.