AIR-CONDITIONING DEVICE FOR VEHICLE

PURPOSE:To effectively prevent entrance of exhaust gas to the interior of a car room by expediting a timing of switching to an internal air introduction mode when a blower output exceeds a given reference value during switching of an open air introduction mode to an internal air introduction mode when gas concentration of the open air exceeds a given threshold. CONSTITUTION:Through automatic control of air-conditioning by means of a control unit 30 for an air-conditioning device 1, switching of the opening of an air mix damper 15 and a fan output, switching of introduction ports 12 and 13 and discharge ports 9-11 for air-conditioned air, and ON/OFF of a compressor 23 are decided based on detecting outputs from temperature sensors 42-45 and a solar radiation sensor 46. Actuators 20-22 are respectively driven and temperature is automatically controlled to the target set value of a temperature set volume 36. In this case, a gas sensor 41 to detect gas concentration of the open air is located, and when a detecting value is increased to a value higher than a given threshold, an open air introduction mode is switched to an internal air introduction mode. When a blower output is three stages or more, a given threshold is narrowly varied and a timing of switching to an internal air introduction mode is accelerated.