Abstract:
During the pushing and pulling operations of the push cylinder of the hydraulic support in the working face, the instantaneous pressure surge at startup is severe, which can lead to cylinder bulging, expansion, seal failure, or even the fracture of connecting pins. To address this issue, the causes of pressure surges at the startup of the push cylinder are analyzed, and an electro-hydraulic buffer control valve is proposed to mitigate these surges. A theoretical analysis was conducted on key parameters such as valve opening, hydraulic resistance, and pressure-flow characteristics, and the key structural parameters of the electro-hydraulic buffer control valve were designed. A simulation model was developed in AMESim to verify its feasibility in buffering push pressure. Based on theoretical analysis and simulation results, a prototype of the electro-hydraulic buffer control valve was developed, and a simulation test platform was established to evaluate its performance by simulating push cylinder loads. The results showed that after using the electro-hydraulic buffer control valve, the pressure surge of the push cylinder was reduced from 17 MPa to 9.6 MPa, with a slight decrease in pushing speed. Field tests in an underground working face further confirmed the buffering effect of the electro-hydraulic buffer control valve on the push cylinder. The results showed that after installing the electro-hydraulic buffer control valve, the impact pressure of the push cylinder decreased from 22.3 MPa to 16.2 MPa, reducing the instantaneous pressure surge at startup by 27.3%. The findings verify that the electro-hydraulic buffer control valve can effectively reduce pressure surges during the pushing operations, providing a new solution for pressure buffering in push cylinders of hydraulic supports.