Internal combustion engine with regenerator

An internal combustion engine comprising:

• an engine body including a cylinder head and a cylinder block;
• a regenerator that accumulates heat;
• a circulation system that circulates a heat medium;
• a cylinder head part channel that circulates the heat medium in the cylinder head;
• a cylinder block part channel that circulates the heat medium in the cylinder block;
• a connecting channel that connects the cylinder head part channel with the cylinder block part channel;
• a heat supply device that supplies heat accumulated by the regenerator through the heat medium in the circulation system;
• and
• a restraining device that restrains circulation of the heat medium in the connecting channel when the heat is supplied by the heat supply device or the internal combustion engine is under cold conditions.