| During the working of roadway temporary support stents,column cylinders and pushing cylinders might sustain large eccentric loads with low-precision in synchronization.The hydraulic synchronous system based on synchronous valve with large pressure loss and low efficiency can’t control the speed and meet the big change of flow range.Based on the above status and the background of dividing condition of double-cylinder synchronization,the principle of open-loop control of synchronization with speed-control and high-precision in the condition of large eccentric loads was put forward in the paper.The system combines with load-sensing system,compensation of LUDV,speed-control synchronous valve.Based on the principle of adptive flow and pressure,the load-sensing system and synchronous valve control the flow with high-precision and high-efficiency,and the pressure compensated valve makes the outlet pressure of control valves equal to chosen biggest load pressure in the condition of large eccentric loads,and speed-control synchronous valve controls flow with regulating opening degree of two-step throttle which meets large change of flow range.The paper analysed the principle and built the mathematical model of load-sensing system,pressure compensated technology,flow adaptive valve and hydraulic cylinder.Based on the software AMESim,the paper built the AMESim models of the hydraulic system and the comparative system with verification,compared the synchronous precision between the hydraulic system and comparative system in the condition of large eccentric loads and time-varying loads to prove the correctness of the principle.The paper carried on the simulation in condition of different eccentric loads to verify the inclined loading proof capability.Based on the software Pro/E,the paper built the speed-control synchronous valve model,observed the velocity vector of inner flow field with FLUENT,and carried on the simulation combined with AMESim and ADAMS to prove the correctness and accuracy of speed-control synchronous valve. |
