Patent attributes
A warm-up device is provided in a cooling-water circuit, through which cooling water is circulated so as to pass through an engine. The warm-up device has a heat accumulating passage, in which a heat accumulating device is provided, and an accumulating-device bypassing passage bypassing the heat accumulating device. A waste-heat collecting device is provided in the cooling-water circuit so that heat is collected from exhaust gas from the engine and such collected heat is accumulated in the heat accumulating device. The cooling water is circulated through the heat accumulating device during a start-up operation of the engine in order to heat the cooling water flowing into the engine so as to quickly warm up the engine.