Device and method for controlling internal combustion engine

A method for controlling an internal combustion engine, wherein the internal combustion engine includes a fuel injection valve, a canister configured to collect fuel vapor generated in a fuel tank storing fuel supplied to the fuel injection valve, and an adjustment device configured to adjust a flow rate of fluid flowing from the canister to an intake passage, the method comprising:

• performing a base injection amount calculation process for calculating a base injection amount based on a charged air amount in a combustion chamber of the internal combustion engine;
• performing a feedback process for correcting the base injection amount based on an output value of an integral element obtained by using a difference between a detection value of an air-fuel ratio and a target value of the air-fuel ratio as an input value to adjust the detection value to the target value through feedback control;
• performing an injection valve operation process for operating the fuel injection valve based on the base injection amount corrected by the feedback process;
• performing a purge control process for operating the adjustment device to control the flow rate of the fluid flowing from the canister to the intake passage;
• and
• performing a correction limiting process for limiting the output value of the integral element so that a decreasing correction rate of the base injection amount has a decreasing tendency on condition that the charged air amount is decreased if the flow rate of the fluid is controlled to a value larger than zero by the purge control process.