| 摘要 |
PURPOSE:To improve heating performance, by a method wherein, during use of a heater, when a water temperature sensor detects a value below a given temperature, a water pump for circulating engine-cooling water is forced into a stop and simultaneously a water pump for a heater is operated, and when the detected result exceeds the given temperature, a said water pump for circulation is operated. CONSTITUTION:An inlet side water flow passage 9, through which cooling water is supplied to a heater 12, is opened to a cylinder head cooling water passage 6, and an outlet side water flow passage 11 is also opened to the cooling water passage 6. A water pump 10 for a heater is mounted on a heater-cooling water circulating passage, and a cooling water temperature sensor 13 is attached on the cylinder head part-cooling water passage 6. When a water temperature sensor 13 detects temperature exceeding 85 deg.C, a water pump 4 for circulating cooling water is actuated, and the water pump 10 for a heater is brought to a stop. When the sensor detects any temperature of lower than 85 deg.C, the water pump 4 for circulating cooling water is brought to a stop, and the water pump 10 for a heater is operated. When cooling water is at a low temperature, cooling water for a heater is fed only through a cylinder head part in high temperature range, and high-temperature cooling water for heating up a heater is obtained. |
