| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit breaker that can prevent stagnation on a grid of arc drawn from an arc entrance of an arc extinguishing device, and move the arc to a gas exit side of the arc extinguishing device in short time, thereby surely performing arc parting and arc cooling by the grid.SOLUTION: An arc extinguishing device 11 for extinguishing arc occurring between a fixed contact and a movable contact comprises plural grids 13 which are located at an arc entrance 15 side at one ends of the grids and at a gas exit 16 side at the other ends of the grids and arranged in a layer form so as to be spaced from one another through gaps. The grid has a pair of arc driving plates 17, 18 formed of magnetic material, and a resin plate 19 laminated between the pair of arc driving plates. An arc cut-out groove 20 is formed at the end portion of the arc entrance side. A gas blow-out unit 21 for blowing out vaporized gas occurring due to melting of the resin plate as ablation gas directing from the arc entrance side to the gas exit side is formed in the pair of arc driving plates.SELECTED DRAWING: Figure 2 |
