To provide cushion structure for hydraulic cylinders allowing a plurality of hydraulic cylinders to absorb the inertia force of one working tool almost equally.
This cushion structure has boom cylinders 1, 1a for driving a boom provided in a hydraulic shovel, and forms cushion chambers comprising rod side chambers 4b, 24b for relaxing impact caused by pistons 5, 25 moving following the elongating action of the boom cylinders 1, 1a, near the respective stroke ends of the boom cylinders 1, 1a when elongated. A communicating means is provided for communicating the respective cushion chambers of the boom cylinders 1, 1a. The communicating means comprises oil ducts 50, 51 respectively provided at the boom cylinders 1, 1a and communicated at one ends with the respective cushion chambers of the boom cylinders 1, 1a while being opened at the other ends to the outside of the boom cylinders 1, 1a, and a communicating line 52 for communicating these oil ducts 50, 51.
YASUOKA TOMOHIKO
RO AKINORI
