Control device

A control device comprising:

• a temperature estimation part that estimates a temperature of a piston of an internal combustion engine on the basis of at least any of a temperature of cooling oil for cooling the piston of the internal combustion engine of a vehicle, a temperature of cooling water for cooling the internal combustion engine, or an intake air temperature of the internal combustion engine;
• and
• a control part that i) reduces an upper limit value of a timing of fuel injection, at which a fuel injection part that injects fuel into the piston injects the fuel, when the temperature of the piston estimated by the temperature estimation part rises to a first threshold value corresponding to a heat-resistance temperature of the piston and ii) increases the upper limit value of the timing of fuel injection, at a temperature higher than the first threshold value, when the temperature of the piston stops rising.