| 摘要 |
PURPOSE:To enhance the efficiency of a heater by making the hunting of water temperature slowly during the cold season and also the rise of water temperature during the startup of engine easier by controlling the opening and closing conditions of a shutter according to the temperature of cooling water in the radiator. CONSTITUTION:When the temperature of cooling water in a radiator 7 reaches a set temperature T1, 92 deg.C for example, as the first stage control, a water temperature switch 18a is opened, supply of voltage to a solenoid valve 17a is interrupted, and negative pressure terminal is closed. Since negative pressure of engine does not act on a diaphragm actuator 11a and atmospheric pressure is introduced from the open terminal of the valve 17a, a connecting bar 12a is not attracted by the actuator 11a, and a shutter 10a connected to the bar 12a is opened. When the temperature of cooling water reaches a set temperature T2, 100 deg.C for example, as the second stage control, the water temperature switch 18b is opened, the diaphragm actuator 11b becomes inoperative, and the shutter 10b is opened. |
