Damper position control device for automotive air conditioning system

Abstract

A damper position control device for use in an automotive air conditioning system. The damper position control device includes a motor actuator which rotates an air mix damper in forward and reverse directions, an electric power source, and an electric power source switch device. The motor actuator includes a motor, a gear which is operatively connected to the drive shaft of the motor and an air mix damper and which rotates the air mix damper in forward and reverse directions in accordance with the rotations thereof, and a rotation control device including a regulator which governs the upper and lower rotational limits of the drive shaft of motor and gear. The regulator includes at least three fixed contacts each of which is parallel to the others, but has the different length, and a movable contact which is in contact with at least two of the fixed contacts and which cycles along fixed contacts in accordance with the rotations of the drive shaft of motor and gear. The rotational angles of the drive shaft of motor and gear, i.e., the operating angles of air mix damper, are regulated by the interaction between the fixed contacts and a movable contact. One or more of the at least three fixed contacts are provided with at least one gap disposed at a fixed position therein. The at least one gap divides the fixed contacts into segments. A corresponding short-circuit switch device alternatively short-circuits or isolates the segments of the fixed contact on either side of each gap.