| 摘要 |
PURPOSE:To increase the generating heating value of an engine as well as to improve the heating performance, by operating a combustiveness drop-down device in time of a heater being in operation and a required heating value exceeding the specified value, in case of a vehicle provided with a circulation channel leading the cooling water in a heater core for heating use. CONSTITUTION:During cooler operation, when a blower switch 15 for a heating apparatus is turned to a range of LOW or Hi, a selector valve 20 is set to the closing position of a by-pass passage 19 by a control circuit 24, while each of on-off valves 21 and 22 is opened or closed. In addition, since thermostat valves 7 and 10 are set to come into a state of being closed, under this condition, cooling water of an engine E is heated by exhaust gases inside an exhaust passage 17 at a heat echanger 17 and then fed to a heater core 13 whereby a sufficient heat temperature can be secured there. Likewise, when the blower switch 15 is set to the Hi range, an EGR valve 28 is opened via an EGR control circuit 29, meaning that a heating value of the engine grows larger in conseguence so that a high heating temperature can be obtained. |
