LOW NOISE TYPE ELECTROMAGNET

PURPOSE:To reduce the sound produced by a movable body at the time of operation by a method wherein the movable body having a permanent magnet made to magnetize in the direction that the upper and lower leg pieces of first and second yokes oppose to each other is made to position between the leg pieces opposing to each other and the magnet is attracted or repulsed by the leg pieces and is made to displace in the direction intersecting orthogonally to the direction of magnetization. CONSTITUTION:A coil 2 is wound on a coil frame 3 and an iron core 1 is inserted in the frame 1. A first yoke 4 is formed into a U-shape by upper and lower leg pieces 4a and 4b and a coupling piece 4c and the pieces 4a and 4b are longer than the iron core 1 and are formed at positions separated from each other so that the piece 4a is not superposed on the piece 4b. A second yoke 5 is formed into a U-shape by upper and lower leg pieces 5a and 5b a coupling piece 5c and is made to position in such a way that the pieces 5a and 5b respectively oppose to the piece 4b and the piece 4a of the yoke 4. A movable body 6 consisting of a permanent magnet 7, which is made to magnetize in such a way that different polarities appear in the direction that the upper and lower leg pieces of the yokes 4 and 5 oppose to each other, and a movable frame 8 is arranged between the leg pieces, which oppose to each other, of the yokes 4 and 5. Accordingly, the magnet 7 is attracted or repulsed by the pieces 4a, 4b, 5a and 5b, is made to displace in the direction intersecting orthogonally to the direction of magnetization, does never collide with the leg pieces and the sound of the movable body 6 at the time of operation can be reduced.