| 摘要 |
PROBLEM TO BE SOLVED: To provide a suction device which has an attracting mechanism, that suppresses the influences of magnetic lines of force generated from permanent magnets of a minimum, and prevents the demagnetization of the permanent magnets with time and utilizes the magnetic forces of the magnets. SOLUTION: In the switch box of a room illuminating lamp, applying the attracting mechanism using permanent magnets, paired two permanent magnets 1a and 1b are attached to a steel sheet 3 fitted to the rear surface of a cover 2, with their directions of magnetization being directed in the opposite directions. Consequently, an annular magnetic field is formed from the magnet 1a to the magnet 1a, through a plate 23 made of a steel sheet, the magnet 1b, and the steel sheet 3 and the leakage of magnetic lines of force to a room side is reduced significantly. At the same time, the suction forces of the magnets 1a and 1b and the plate 23 are increased. In addition, the demagnetization of the magnets 1a and 1b with time is also reduced.
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