Piston structure for hydraulic pile hammer

The piston structure comprises a cylinder body and a piston assembly, the piston assembly is arranged in the cylinder body, the cylinder body is divided into an upper cavity and a lower cavity by the piston assembly, and the piston assembly comprises a hammer core, a limiting ring, a front sleeve, a rear sleeve, a screw plug, a sliding block, a pressure ring, a piston ring, a speed reduction ring and a sealing assembly. The whole piston assembly is compact in structure, no fastener is arranged, and the problems that threads of the fastener loosen and fall off in the violent vibration environment are solved; a reasonable sealing system divides a cylinder body into an upper air cavity and a lower liquid cavity, air and liquid are prevented from mutually flowing, a cavity c and an oil hole leading to the cavity c are formed, the internal pressure of the cavity c can be released by detaching a screw plug, and convenience and safety are guaranteed when a piston assembly is detached; the piston ...