Design And Research On The Automatic Tensioning Machine Of Prestressed Bars Of High-speed Railway Track Slab

With the rapid development of rail transit,high-speed railway technology has become more and more mature,which greatly improve the quality of life of the people,and promote the cultural and economic exchanges between regions.High-speed railway track slab plays an crucial role in the safe and stable operation of high-speed railway.The study shows that the arrangement of a certain number of steel bars in the high speed rail track slab,and make the steel bar subjected to a rated tension,which can obviously increase the service life of the track slab and reduce the crack degree of the slab.At present,the tensioning device in the production of the track slab is not only needs large manual workload,but also has the disadvantages of complex tensioning process,high-budget and inefficient.Therefore,this paper studies a new type of automatic tensioning machine of prestressed bars of high-speed railway track slab,so that only one tensioning process can meet the requirements of the specified tension,the main contents are as follows:(1)By consulting a large number of relevant literature and combined with the existing tensioning equipment,the expected function and composition of the tensioning machine are determined.It should be able to screwing and tensioning and locking the prestressed bar automatically.The tensioning platform should be able to automatic lifting and the machine capable of moving in the orbit to tensioning bars which have different positions.(2)This paper designs the hydraulic system of the tensioning machine and draws the hydraulic schematic diagram,introduces determination of the main parameters and components selection in the hydraulic system in detail.The electro-hydraulic proportional technology was used in hydraulic system,to make the tension grows linearly,so that the tensioning effect of the prestressed bars and the work efficiency have been improved and the service life of the track slab have been increased.(3)The mechanical structure of the tensioning machine was designed in this paper,including calculation and checking of gear drives,chain drives,shafts,bearings,joints.The finite element analysis of the key components was carried out and the strength requirement of the structure was checked.(4)The mathematical model of electro-hydraulic proportional system of hydraulic cylinder tension controlled by proportional relief valve was built,and the simulation diagram of the system was established by using MATLAB/Simulink.The parameters of the components were set up,and the simulation analysis was conducted.The PID controller was introduced,and its three parameters was set.Eventually,the perfect simulation results was obtained,which have satisfy the design demands.(5)The experimental platform of hydraulic cylinder controlled by proportional valve was set up,and examine the relevant experimental data.