Nitrogen spring over-travel protection structure

The utility model relates to the technical field of stamping die nitrogen springs, and discloses a nitrogen spring overtravel protection structure which comprises a cylinder barrel and a plunger rod installed in the cylinder barrel, a limiting sleeve is arranged between the plunger rod and the cylinder barrel, the top of the limiting sleeve is higher than the top of the cylinder barrel, a containing groove is formed in the outer wall of the limiting sleeve, and a sealing O-shaped ring is arranged in the containing groove. The sealing O-shaped ring abuts against the inner wall of the cylinder barrel and the bottom of the containing groove, an annular air leakage groove is formed in the inner wall of the cylinder barrel and located below the sealing O-shaped ring, and the distance between the air leakage groove and the sealing O-shaped ring is smaller than the distance between the top of the limiting sleeve and the top of the cylinder barrel. The over-travel protection structure for the nitrogen spring prevents