| 摘要 |
PURPOSE:To simplify construction by combining a single vacuum switch with a single three-port solenoid valve to enable switch-over in at least three modes of air conditioning by varying the combination of the opening and closing conditions, of plural blow-off ports. CONSTITUTION:A ventilation damper 6, a defroster damper 7, and a heat damper 8 are opened and closed by means of negative-pressure operated diaphragms 1 and 2, while a water valve 35 is opened and closed by means of a negative- pressure operated diaphragm 3. And, a vacuum switch B has a negative-pressure connecting port 13, an atmospheric pressure connecting port 14 which can be switchedly connected to a negative-pressure source and the atmosphere, and an all-time atmospheric-pressure connected port 15. The operation of the switch B is controlled by a power servo-diaphragm 10 in accordance with a negative pressure which is fed through a valve box C which is controlled based on the command of a car-room control amplifier 12. And, a three-port solenoid valve 16 which is shifted being interlocked with a refrigerant compressor E, is connected to the port 14. |
