| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cylinder head cooling structure efficiently cooling a cylinder head by supplying the optimum amount of cooling water according to cooling water temperature and exhaust gas temperature to the cylinder head. Ž<P>SOLUTION: A solenoid valve 24 is provided for varying the opening area of a main communication hole 18 allowing an upper main water jacket 15 to communicate with a lower main water jacket 16. The solenoid valve 24 is controlled based on the cooling water temperature and exhaust gas temperature, thereby varying the opening area of the main communication hole 18. Especially, during cold time, when the exhaust gas temperature is below a target exhaust gas temperature, the opening area of the main communication hole 18 is reduced. When such a condition that the exhaust gas temperature is not less than the target exhaust gas temperature and below a limit exhaust gas temperature and also the cooling water temperature is below a target cooling water temperature is satisfied, the solenoid valve 24 is controlled in a direction closing the main communication hole 18. Thereby, the opening area of the main communication hole 18 is reduced. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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