Controller for internal combustion engine, control method for internal combustion engine, and memory medium

A control method for controlling an internal combustion engine including cylinders, wherein

• the internal combustion engine includes an adjustment device, an exhaust passage, and an aftertreatment device for exhaust gas, the aftertreatment device being arranged in the exhaust passage,
• the control method comprises:
• adjusting, by the adjustment device, a fuel concentration in an intake port connected to a specified cylinder during a specified-cylinder deactivation period, the specified cylinder being one of the cylinders, the specified-cylinder deactivation period being a period during which supply of fuel by a fuel injection valve corresponding to the specified cylinder is deactivated;
• determining whether an execution request of a temperature-increasing process for the aftertreatment device has been issued;
• deactivating the supply of the fuel by the fuel injection valve corresponding to the specified cylinder and setting an air-fuel ratio of air-fuel mixture in a cylinder of the cylinders that differs from the specified cylinder to be richer than a stoichiometric air-fuel ratio when determining that the execution request has been issued;
• and
• operating the adjustment device so as to reduce the fuel concentration in the intake port connected to the specified cylinder when the temperature-increasing process is executed.

A non-transitory computer-readable memory medium that stores a program for causing a processor to execute a control process for controlling an internal combustion engine including cylinders, wherein

• the internal combustion engine includes an adjustment device, an exhaust passage, and an aftertreatment device for exhaust gas, the aftertreatment device being arranged in the exhaust passage,
• the control process comprises:
• adjusting, by the adjustment device, a fuel concentration in an intake port connected to a specified cylinder during a specified-cylinder deactivation period, the specified cylinder being one of the cylinders, the specified-cylinder deactivation period being a period during which supply of fuel by a fuel injection valve corresponding to the specified cylinder is deactivated;
• determining whether an execution request of a temperature-increasing process for the aftertreatment device has been issued;
• deactivating the supply of the fuel by the fuel injection valve corresponding to the specified cylinder and setting an air-fuel ratio of air-fuel mixture in a cylinder of the cylinders that differs from the specified cylinder to be richer than a stoichiometric air-fuel ratio when determining that the execution request has been issued;
• and
• operating the adjustment device so as to reduce the fuel concentration in the intake port connected to the specified cylinder when the temperature-increasing process is executed.