Arc extinguish chamber structure of high-voltage direct-current plastic shell type circuit breaker

The utility model discloses an arc extinguishing chamber structure of a high-voltage direct-current circuit breaker. The arc extinguishing device comprises a plurality of arc extinguishing grid sheetsarranged at intervals, flash barriers arranged at two sides of the arc extinguishing grid sheets and an arc extinguishing cover, the arc extinguishing grid sheets are provided with arc striking grooves. The arc extinguishing chamber comprises an arc inlet side and an air outlet side. The plurality of arc extinguishing grid sheets comprise a special main grid sheet, a main grid sheet and a secondary grid sheet. The plurality of arc extinguishing grid sheets are arranged from one side relatively close to the static contact; wherein the first to fourth sheets are special main grid sheets; wherein the fifth to fourteenth grid sheets are main grid sheets, the rest are secondary grid sheets, the thickness of the special main grid sheets is 1.2-2mm, narrowing extension ends are arranged on the special main grid sheets a