Controller and control method for fuel injection timing of internal combustion engine

A control method for controlling a fuel injection timing of an internal combustion engine, wherein the internal combustion engine includes a direct injection valve that injects fuel into a combustion chamber and a lubrication device that discharges lubricant toward a rear surface of a piston,

• the control method comprising:
• setting, through at least one of two processes, an injection start timing of fuel by the direct injection valve, wherein one of the two processes is a process for setting the injection start timing to be more advanced when a rotation speed of a crankshaft of the internal combustion engine is high than when the rotation speed is low, and the other one of the two processes is a process for setting the injection start timing to be more advanced when a load on the internal combustion engine is large than when the load is small;
• and
• operating the direct injection valve in order to start injecting fuel from the direct injection valve at the injection start timing,
• the control method further comprising:
• advancing the injection start timing to a larger extent when a coolant temperature that is a temperature of coolant in the internal combustion engine is greater than or equal to a preset temperature than when the coolant temperature is lower than the preset temperature;
• and
• setting, in a case in which the coolant temperature is greater than or equal to the preset temperature, a smaller advancement amount at the injection start timing when a lubricant temperature that is a temperature of the lubricant is lower than a predetermined temperature than when the lubricant temperature is greater than or equal to the predetermined temperature.

A non-transitory computer-readable storage medium that stores a program causing a processor to execute a control process for controlling a fuel injection timing of an internal combustion engine, wherein the internal combustion engine includes a direct injection valve that injects fuel into a combustion chamber and a lubrication device that discharges lubricant toward a rear surface of a piston,

• the control process comprising:
• setting, through at least one of two processes, an injection start timing of fuel by the direct injection valve, wherein one of the two processes is a process for setting the injection start timing to be more advanced when a rotation speed of a crankshaft of the internal combustion engine is high than when the rotation speed is low, and the other one of the two processes is a process for setting the injection start timing to be more advanced when a load on the internal combustion engine is large than when the load is small;
• and
• operating the direct injection valve in order to start injecting fuel from the direct injection valve at the injection start timing;
• the control process further comprising:
• advancing the injection start timing to a larger extent when a coolant temperature that is a temperature of coolant in the internal combustion engine is greater than or equal to a preset temperature than when the coolant temperature is lower than the preset temperature;
• and
• setting, in a case in which the coolant temperature is greater than or equal to the preset temperature, a smaller advancement amount at the injection start timing when a lubricant temperature that is a temperature of the lubricant is lower than a predetermined temperature than when the lubricant temperature is greater than or equal to the predetermined temperature.