Virtual Prototype Design And Structure Optimization Of Rail Weld CNC Fine Milling Machine

Rail is a core part of railway track, and it is very important to traffic safety. Atpresent, domestic rail weld fine grinding equipment is adopted abroad and the foreignrailway design standard and its technical parameters can’t meet the higher demand ofChinese railway, especially the high-speed rail standard. Existing in the fine grinding,weld grinding does not reach the designated position, rising temperature in grindingcauses rail deformation and tissue damage, grinding accuracy can not meet and needsthe artificial correction, and serious grinding dust pollution seriously affected thequality of rail welding processing in our country. Specific to the railway standard andstatus quo of rail weld processing in China, Wuhan railway administration and WuhanLeaddo Measuring and Control co., LTD., jointly researched rail weld CNC finemilling machine and tried to replace the current rail weld fine grinding processingtechnology and equipment.Rail weld CNC fine milling machine motion performance is one of the importantperformances that reflect the machining accuracy and stability. Its coordination andrealizability are important factors of equipment design. To this end, this paperresearches mainly on the aspects:(1) Introduced the main structures and functions of fine milling machine,summarized the basic principle of fine milling, including the main technicalparameters and standards, milling and machining process. Expounded the essence offine milling machine control system, analyzed the detection and control object,described the scheme of milling machine measuring and control, and expounded theprocess of measuring and control in details.(2) With the aid of Solidworks and the idea of modular design, the author createdthe fine milling machine system CAD model of its main components: main shaft parts,lateral moving device, vertical moving device, the slider widgets, feeding system,measuring units and beam structure. The author also completed the creation of thewhole machine model on the basis of the designed parts assembly relationship. (3) This paper established the virtual prototype model of fine milling machine，and successfully completed the motion simulation of virtual prototype model of finemilling machine in the Adams software. Obtained the corresponding dynamicsimulation results and finished the related analysis and evaluation of the movementcharacteristic of the main moving parts.(4) By using the finite element analysis software Ansys Workbench, this papercompleted finite element analysis of the key parts in fine milling machine, and thedistribution regularity of stress and deformation of the main shaft, screw, beam body;However, the dynamic characteristics of these parts make great difference in thedynamic performance of a fine milling machine and machining accuracy. So wecompleted the dynamic analysis and got their inherent frequency and vibration model.The modal analysis results showed that the spindle and ball screw inherent frequencyis much higher, than the resonance region, and resonance would not occur, but theseventh-order inherent frequency of the beam body is close to the motor’s workingfrequency, which is likely to cause the resonance phenomenon.(5) Finally this paper made the parametric optimization design for the beamstructure, using orthogonal experiment design method. The analysis results show thatthe optimal solution, under the condition that ensures enough stiffness and strength,succeeded a considerable improvement of beam stiffness and a relatively smallweight loss.