DOOR OF AIR-CONDITIONING DEVICE FOR VEHICLE

PROBLEM TO BE SOLVED: To selectively open and close doors respectively having a different opening area without lowering the air blowing efficiency by providing an auxilia ry door, which can be freely slid, in a door body, giving the energizing force to the auxiliary door in the direction to be projected from the door body, and providing a tip of the auxiliary door with a rail guide for regulating the project ed variable. SOLUTION: An auxiliary door 17, which can be slid for protruding and receding, is provided in a door body 15 fitted to a unit case freely to be rotated. A spring 20 as an energizing member for giving the energizing force to the auxiliary door 17 in a direction to be projected from the door body is provided, and while a tip of the auxiliary door 17 is provided with a rail guide 22 for abutting on the rail surface of the slide door for correction so as to regulate the projected variable of the auxiliary door 17. With this structure, area of a bent foot door 9 can be changed in response to position thereof by the auxiliary door 17, and a dedicated structure for adjusting the projected variable of the auxiliary door 17 is unnecessary. Consequently, area of the door to be opened and closed can be changed without providing a member for increasing the ventilation resistance.