| 摘要 |
PURPOSE:To perform optimum room heating, by constituting a preheater such that it is stopped, when a temperature of engine cooling water increases to a predetermined value or more, while operated when the temperature decreases to a predetermined value or less. CONSTITUTION:If a main switch in a vehicle side and a main switch of a preheater 21 are turned on, a pump 23 feeds cooling water of an engine 11 to the preheater 21 because a thermostat valve 18 is closed. Simultaneously, combustion is started in the preheater 21, and the cooling water is heated. The heated cooling water of the engine circulates in flow paths 26, 15 performing room heating through a defroster heater 27 and heaters 28, 29, 31 in a car room. And if a temperature of the water increases to a predetermined value, the engine, in which its cooling water is prevented from circulating in a side of the preheater 21 by opening the thermostat valve 18, forms a circulating circuit through a radiator 12 while stops the combustion in the preheater 21. By this constitution, the optimum room heating can be performed. |
