Pile up elevating system based on invariable pulling force of cylinder

The utility model discloses a pile up elevating system based on invariable pulling force of cylinder, including a left side, two supports that right side symmetry set up, be equipped with between twosupports and follow the crane that piles up that it reciprocated, two supports are realized taut chain and pile up the crane being connected with taut cylinder through take -up sprocket, two taut cylinders all lead to an air through tube and an electromagnetic on -off valve, pressure regulating overflow valve, an unidirectional valve, the 2nd electromagnetic on -off valve connects, all overlap ontwo supports to be equipped with and mesh driving sprocket with the lifting rack ring, all mesh with a lifting chain wheel bottom of two lifting rack ring, the cover is established on the roller bearing on is fixed in two supports between two lifting chain wheel, the roller bearing makes its rolling driving source be connected with one. Two cylinders of this establishment of institution combine unidirectional rotating's sp