| 摘要 |
PURPOSE:To prevent the mixture of dust or the like when the inside air is introduced, by detecting the difference in the existing condition of both black smoke or the like and dust or the like in the outside air, and by carrying out the inside/outside air changeover control of the air duct in accordance with the detected result. CONSTITUTION:A changeover means 1 is changed over so as to selectively introduce the outside air or the inside air into the air duct of a vehicle. And a control means 2 carries out changeover-control of the changeover means 1 between a plurality of introducing modes. In the above control system, a plurality of optical detecting means 3, 4 for detecting the fouling concentrations of the outside air respectively are provided. Further, a discriminating means 5 which discriminates whether or not respective detected fouling concentrations are together higher than a reference fouling concentration is provided. In addition, an output signal generating means 6 which, when the discriminated result is higher, generates an output signal for controlling the control means 2 into the inside air introducing mode; while, when the discriminated result is not higher, which generates an output signal for controlling the control means 2 into the outside air introducing mode is provided. |
