Triple box and arc extinguish chamber connection structure and open-type circuit breaker

The invention relates to the technical field of high-voltage switch equipment, in particular to a triple box and arc extinguish chamber connection structure and an open-type circuit breaker. The connecting structure of the triple box and the arc extinguish chamber comprises a triple box butt joint flange and an arc extinguish chamber butt joint flange which are fixedly connected together, the arc extinguish chamber butt joint flange comprises a sleeve butt joint flange and a movable support butt joint flange, the outer diameter of the sleeve butt joint flange is larger than that of the triple box butt joint flange, and a step-shaped notch is formed in the butt joint position of the sleeve butt joint flange and the movable support butt joint flange. A shielding ring is fixedly installed on the step-shaped notch, the inner circumferential face of the shielding ring is matched with the surface of the step-shaped notch, the outer circumferential face of the shielding ring is in smooth butt joint with the outer ci