Buffing structure for rear end travel of hydraulic cylinder

Abstract

A buffing structure for rear end travel of hydraulic cylinder. The central portion of the bottom of the piston of the hydraulic cylinder is formed with an internal hole which axially extends through the piston and deeply extends into the piston stem. The internal hole has a large vent and a small vent which radially pass through the piston stem. The small vent is adjacent to the joint between the piston stem and an end face of the piston facing the rear end cap. The large vent is formed at a rear end of the internal hole deeply in the piston stem. The large vent is axially spaced from the small vent by a certain distance. When the piston moves to a position near the rear end cap of the hydraulic cylinder, the large vent is first sunk into the rear end cap and blocked. At this time, the oil can only flow through the small vent with smaller cross-sectional area so as to reduce oil flow and achieve a buffing effect.

What is claimed is:  
     
         1 . A buffing structure for rear end travel of hydraulic cylinder, a piston being disposed in the hydraulic cylinder and coupled with a piston stem passing through a rear end cap of the hydraulic cylinder, a central portion of the bottom of the piston being formed with an internal hole which axially extends through the piston and deeply extends into the piston stem, the internal hole having a large vent and a small vent which radially pass through the piston stem, the small vent being adjacent to the joint between the piston stem and an end face of the piston facing the rear end cap, the large vent being formed at a rear end of the internal hole deeply in the piston stem, the large vent being axially spaced from the small vent by a certain distance.