| 摘要 |
PURPOSE:To substantially eliminate residual magnetism in demagnetization by employing the structure that the edge of leg material of each yoke is finished as internal and external magnetic pole surface, a magnetization/demagnetization coil and magnetization coil are wound respectively around the circumference of permanent magnet, namely, the permanent magnet is previously magnetized and the magnetization/demagnetization coil is wound only to the one permanent magnet. CONSTITUTION:In case of attracting an object 13, a current in a certain direction is applied, in view of increasing magnetization, to the magnetization/demagnetization coil 141 and magnetization coil 142 respectively wound to the circumferences of the permanent magnets 101 and 102. Thereby, the line of magnetic force indicated by arrow mark is generated substantially between the internal and external magnetic pole surfaces 11', 12' and an attracting object 13 through a gap and an attracting object 13 is attracted to the internal and external magnetic pole surfaces 12' and 11'. On the contrary, when a reverse current is applied to the magnetization/demagnetization coil 141 of the oner permanent magnet 101 and supply of current to the magnetization coil 142 of the other permanent magnet 102 is suspended, line of magnetic force of close loop is generated in the direction indicated by broken line. As a result, supply of line of magnetic force to the internal and external magnetic pole surfaces 12', 11' is suspended and residual magnetism disappears. |
