Cushioning structure optimization of excavator arm cylinder

Severe impact and vibration may appear when a high-pressure cylinder is working. So in order to slow down the piston and prevent the damage to the cylinder, cushioning structures located in the end or head of a high-pressure cylinder should be optimized. In this work, the working principle of arm cylinder cushioning structures was analyzed, and multi-domain simulation models (especially cushioning model of the arm cylinder) of excavator were built on SimulationX platform. Finally, tests were carried out on a 6T excavator under typical working conditions to verify the model. Cushioning pressure and piston velocity were taken as the main evaluation indexes based on the model. The variable-controlling approach was adopted to test the sensitivity and to find out the optimal values of some key cushioning structure parameters individually. The results showed that the oblique planes on the outer surface of cushioning bush play the most important role in the cushioning of cylinder piston-side chamber, as for rod-side chamber, the throttling orifices on the cylinder cover affect the cushioning performance greatly. The angle of oblique planes of cushioning bush in piston-side chamber was set at 2.5°. Three oblique planes for piston-side cushioning bush have been recommended.