Reliability Research Of Electro-Hydraulic Proportional Control For Walking Beam Furnace

At present, the walking beam furnace, which conveys and heats cold or hot billet in furnace step by step, is widely used in the hot production of sheet, rod and wire. As the hydraulic system for walking beam furnace makes movement of program cycle, with the requirements of short stepping cycle, high velocity, big inertia loads, heavy over-running loads, simultaneous multi-cylinder, continuous working, high reliability, and taking into account of process requirements of the step furnace, it requires a precise design of the hydraulic speed control system of the walking beam furnace.Considering the speed characteristics of walking beam furnace, referring to the domestic and oversea speed control mode of the walking beam furnace, analyzing and comparing the advantages and disadvantages of various methods, combining the actual production situation and the work requirements, This paper make the design of the derating reliability of components of the hydraulic system. According to process requirements, use constant pressure variable pump hydraulic pump, the main control valve proportional valve used to achieve variable speed control. Meanwhile, in order to ensure stable operation of lift cylinder in the system, superimposed on the inlet pressure compensator, timely adjustment of inlet pressure, thereby ensuring constant pressure on both sides of the cylinder so that cylinder in the load remains under different operating conditions and curve acceleration curve unchanged.The reliability model is established from the perspective of the whole system and the perspective of various subsystems on the basis of grasping fully information of the walking beam furnace hydraulic system, and the reliability prediction is made for the whole system and its subsystems. The reliability simulation model is established using Reliasoft Blocksim simulation software in order to identify system weaknesses. The fault tree simulation model is constructed for the hydraulic system according to the failure of furnace hydraulic system in the field, by using the discontinuous motion of lift cylinder as the top event of this failure to establish the fault tree and using Simulink software package provided by Matlab toolbox. A more intuitive display of system reliability is offered by Analysis of simulation. It has a good reference value for studying the reliability questions of hydraulic system of the walking beam furnace.