| 摘要 |
PROBLEM TO BE SOLVED: To reduce a striking sound by a method wherein a smooth driving of a buffle is carried out even if icing occurs at the buffle and the buffle is driven in an opening direction by a small-sized low capacity stepping motor even if a biasing force is applied in a closing direction with a biasing means such as a leaf spring or the like. SOLUTION: This motor-driven type damper device is comprised of a buffle 4 for opening or closing an opening 3 through which fluid passes, a stepping motor for driving the buffle 4, and a means for transmitting the driving operation to the buffle 4. A pulse rate for driving the stepping motor at the time of starting the driving operation is set to be lower as compared with that applied during a driving operation of the buffle 4. In addition, there is provided a means for biasing the buffle 4 in its closing direction. As the buffle 4 is opened, the pulse rate for driving the stepping motor is set to be low. There is provided a member 8 abutted against the buffle 4 at either the closed position or the opened position of the buffle 4 to stop its motion. A pulse rate for driving the stepping motor is set to be lower just before abutment of the buffle against the member 8 as compared with that attained in the midway part of the driving operation of the buffle 4. |
