| 摘要 |
PURPOSE:To improve the responsive properties by intensifying a resistance to an eddy current by surrounding a movable body consisting of a cylindrical ferromagnetic material and which can move freely in a direction of shaft line and providing a coil for magnetizing said movable body in the shaft direction. CONSTITUTION:An electromagnet 1 comprises a cylindrical movable body 2 and a fixed body 3 which is arranged so as to surround said body 2 as the basic components. The movable body 2 is composed of a straight cylinder 2a, end plates 2b and 2c for supporting said cylinder 2a, and a shaft 2d penetrating through the center of said end plates and having a common shaft with the straight cylinder 2a. Also the shaft 2d and the part designated by 2e-2g of the movable body 2 are formed of non-magnetic material and other parts are formed of ferromagnetic material. The ferromagnetic material part of the straight cylinder 2a becomes a part of the magnetic circuit formed by excitation of coils 10, 11, 12 and 13. In order to reduce the generation of eddy currents, the straight cylinder 2a is made of a thin-film structure. |
