【作者】 黄建平；

【导师】 戴虹；

【作者基本信息】 西南交通大学 ， 材料加工工程， 2003， 硕士

【摘要】 钢轨焊接是高速铁路铺设工程中的关键环节。目前，我国铁路轨道工程中应用的多种合金钢轨，强度高，耐磨性好，但可焊性较差，而现有焊轨装备质量监控手段尚不完善，使线路存在安全隐患。因此，系统开展钢轨闪光焊质量在线诊断技术研究十分重要。 本文针对K190JIK钢轨焊机控制系统存在参数修改困难、焊接过程不够稳定、无焊接质量在线诊断功能等问题，采用日本三菱公司FX2N-64MR可编程序控制器、研华工控PCL—1800数据采集卡等为核心控制部件，对焊机的整机控制系统进行了全面升级。运用软件LabVIEW和VB开发了数据采集系统，完善了焊接稳压、调压、电流恒值控制与智能调节功能，利用VB建立了焊接质量在线诊断系统，并完成了系统组装调试与工艺试验研究工作。 结果表明：新型控制系统参数设置修改方便，控制柔性好，动态响应速度快，焊接过程稳定；焊接参数采集系统抗干扰能力强、数据可靠；以闪光时间百分比等焊接过程特征量为判据诊断焊接质量效果好，实用性强；当动立柱的前进、后退速度相同且为低速时，钢轨接头中灰斑缺陷数量最少。更多还原

【Abstract】 The welding of the steel rail is a key technology in express railway’s laying process. The alloy steel rail, which is used widely in the railway engineering in our country, has poor weldability although it has high intensity and excellent wearing capacity, and the means of quality control in rail welding equipment is still not perfect, which leads to the hidden safety trouble in railway. Therefore, it is very important to research on-line quality diagnosis technique in rail flash butt welding process systematically.Aiming at the problems of the K190JIK rail welding machine, that the parameter modification is difficult, the welding process is not enough stability and the welding machine has no on-line diagnosis function, In this paper, the control system of the welding machine was promoted completely adopting the FX2N-64MR programmable logic controller and the PCL-1800 data acquisition card, the DAS(Data Acquisition System) was set up by using LabVIEW and Visual Basic software, the functions of welding voltage stabilizing and adjusting, current controlling and intellectual modification was improved, welding quality diagnosis system was built up, and the assembling and debugging of the control system was completed, including the process experiments.The result shows that the new control system has convenient parameter modification, perfect controlling flexibility, rapid dynamic response speed, stable welding procedure; The DAS of welding parameters has strong ability of anti-disturbance and the data is reliable. The control effect and practicability of the diagnosis system judging the welding quality are both good by using the characteristic values of welding process such as the percentage of the flashing time. Gray-spots flaw in flash welding joints of rail is the least when the pole moves to and fro at the same velocity and the speed is slow.更多还原