Development of a Tiny Impact Device for Hammering Inspection

This paper presents a development of a tiny impact device which can be mounted on a small robot for hammering inspection in a narrow place. The developed device utilizes magnetic forces of permanent magnets. The main part of the device consists of three permanent magnets. When a movable magnet is placed between two magnets fixed so as to attract each other, the movable magnet is rapidly drawn to one of the fixed magnets. The device makes the movable magnet to be adsorbed by changing the magnetic force balance and takes out an impact force generated at the moment of adsorption as a hammering force. The size and weight of the device are 20(depth)×17(width)×30(height)mm and 25.6g. Also, the device can generate continuous impact with low-power consumption. First, the basic principle of generating an impact with permanent magnets is explained. Then, the structure and operation flow of the developed device are described in detail. Performance of the device estimated theoretically is discussed. The availability of the device is verified by a hammering test.