| 摘要 |
A cooling water circulation system (100) is configured so that cooling water is delivered from a water pump (113) toward a cylinder head (111) via a pump delivery pipe (114). Further, the system (100) is configured so that an engine block cooling switching section (170) changes the supply of the cooling water from the cylinder head (111) to a cylinder block (112) in accordance with a cooling water temperature. An EGR cooler branch pipe (151), which branches off from the pump delivery pipe (114) is connected to an EGR cooler (150). The EGR cooler branch pipe (151) is provided with an EGR cooler cooling switching valve (153) that opens or closes in accordance with an operating state. |
