| 摘要 |
PURPOSE:To eliminate the reverse current, strengthen the magnetic field of a main electrode, flatten the distribution of the magnetic field, and improve the breaking performance by setting the inner diameter and outer diameter of a cup-shaped coil electrode and the diameter of a bottom plate to the preset relationship. CONSTITUTION:The diameter D3 of the bottom plate 9 of a coil electrode is set to the inner diameter D2 or above of the coil electrode 2 and the outer diameter or below only at the lower sections of circular arc sections 7a and 7b. No reverse current flows from a holder 3 to the circular arc sections 7a and 7b, the magnetic field generated by the current flowing through the circular arc sections 7a and 7b can be effectively utilized, the magnetic field distribution is flattened, the breaking performance is improved. |
