Welding device

The invention discloses a welding device and belongs to the technical field of welding. The welding device comprises a pneumatic mechanism, a welding connection part, a movable welding part and a fixed welding part which are mutually connected. The welding connection part, the movable welding part and the fixed welding part are connected with one another, so that a welding loop is formed. Closing or opening of the welding loop is achieved by controlling connection or disconnection between the movable welding part and the fixed welding part through the pneumatic mechanism. A welded plate is placed between the movable welding part and the fixed welding part. A welding gun makes contact with the welding connection part when the movable welding part is communicated with the fixed welding part, so that currents sequentially pass through the movable welding part, the welded plate and the fixed welding part and then flow to the welding connection part, and accordingly welding of the welded plate is achieved. According to the welding device, a welding copper plate is installed in the position where operation is relatively easy, and the welding process of an oil filling port box and a side body is achieved through electric conduction of the copper plate.