| 摘要 |
PURPOSE:To prevent the thermal shock at the end of warming-up, by opening a constricted passage, which connects a water jacket and a radiator to each other, at the temperature of cooling water lower than that at the end of warming- up, to heighten the temperature of the cooling water in the radiator. CONSTITUTION:A first flow return line comprising a passage 17, a radiator 18 and a passage 21 and a second flow return line having a passage 24 are connected to a first water jacket 4 provided in a cylinder head 2 and to second water jacket 5 provided in a cylinder block 3. When the temperature of cooling water is lower than a first level (e.g. 80 deg.C), a control valve 14 is closed and another control valve 15 is open. When the temperature is not lower than the first level, the control valve 14 is open and the other 15 is closed. When the temperature is not lower than a second level (e.g. 95 deg.C), the control valves 14, 15 are both open. Desired temperature control is thus effected. When the temperature of the cooling water has reached a third level (e.g. 70 deg.C) lower than the first level, before reaching the first level, a control valve 30 is opened to connect a constricted passage 29 to the radiator 18 to cause a small qauntity of warm water to flow through the radiator. |
