Current -limiting opening device

The utility model discloses a current -limiting opening device, including turning over the board assembly and turning over the fixed cover of board, wherein, turn over the fixed body that overlaps foroffering circular window on the lateral wall of board, turn over the board assembly including turning over board, torsional spring and cylindric lock, turn over the board and be a circular slab, seted up a through -hole on its face, and one side face middle part is equipped with the connecting piece that two parallel intervals set up and extended the circular slab, two pinholes that are used forinstalling the cylindric lock are seted up to the symmetry on two connecting pieces, and the torsional spring is worn the dress and just is located between two connecting pieces on the cylindric lock,it fixes in the window department of turning over the fixed cover of board through the cylindric lock to turn over the board assembly to it is turning over the fixed cover inboard of board to keep turning over board level sett