节点文献
基于直流数字调速方案的龙门刨床电控系统改造
【作者】 陈文菊；
【导师】 朱宏；
【作者基本信息】 电子科技大学 ， 模式识别与智能系统， 2009， 硕士
【摘要】 龙门刨床是机械加工行业中用途比较广泛的一种大型关键设备。目前我国许多厂家仍然在使用的老式龙门刨床中大多数都是上个世纪九十年代前制造的A系列大型龙门刨床。A系列龙门刨的主拖动系统采用的是交磁扩大机-发电机-电动机(K-F-D)调速系统,电控部分采用的是传统的继电器逻辑控制方式,因此存在着诸如能耗高、精度低、调速范围窄、控制线路复杂、稳定性差、故障率高等一系列问题。本课题正是在认真地分析和研究了龙门刨床原控制系统的基础上,针对原系统的缺陷和用户的要求,设计了以可编程控制器为核心,全数字式直流驱动器为调速单元的直流调速控制方案,对一台老式龙门刨床的电控系统进行了全面的大修和改造。具体方案是采用一台英国CT公司制造的M350R全数字式直流电机驱动器代替原来的K-F-D机组,实现对工作台拖动电机的驱动和调速;用一台三菱公司的FX2N-80MR型PLC与接触器和直流驱动器联机控制取代传统的继电器-接触器控制系统,从而省去了大量不必要的中间继电器、时间继电器和可调电阻;采用OMRON新型无触点接近开关代替了原来工作台老式的机械行程开关,增加了工作台换向的安全性和可靠性。此外新系统还增加了设备的磨削功能,扩大了该龙门刨床的加工用途。本论文详细地给出了整个系统电路(包括电机拖动电路、直流调速电路及逻辑控制电路)的工作原理和具体实现,并对龙门刨的各个动作的实现及系统调试作了详细说明,同时对相关的控制理论也进行了分析研究。通过改造后新系统克服了原控制系统的一系列缺点,系统的调速性能和稳定性得到了极大的改善,节能效果显著,且经济实用易于维护,为用户创造了良好的经济效益。
【Abstract】 Double-housing planer is common large-scale key equipment. It was widely used in mechanical processing industries. At present, most of the old planers which were still used in our country are A series of double-housing planer. The main drive of those planers utilize amplify-generator-motor drive system, the main shortcomings of the system are a serious waste of energy and limited speed range. In addition, because the logic control of old planer is based on the traditional relay control systems therefore a series of questions are existed. Such as circuit complexity, poor stability, and higher failure rate. After it was analyzed carefully that the original double-housing planer control system which aiming to overcome the drawbacks of the original system and to satisfy the user’s requirements, a new reformation program of the old double-housing planer’s electric control system has been designed this article, this program uses a programmable logic controller as the control core, as well as the DC digital drive as a speed control unit for the DC drive system.The specific reformation programs are as follows. First, instead of the original K-F-D generating units, the paper used the M350R DC digital drive to implement the speed control of the workbench drag motor. Second, instead of the traditional relay-contactor control system, a Mitsubishi FX2N-80MR PLC and contactors are used in performing logic control, thus a large number of unnecessary middle relays、time relay and adjustable resistor are eliminated. Meanwhile, OMRON proximity switches are adopted to replace the original old-fashioned mechanical trip switch, so the security and reliability are improvement when the workbench changes direction.In this paper, the interrelated control theories were introduced, and then it was illuminated, step by step, that the working principle and Electrical schematic diagram of the new system which include the Electric drag circuit, DC speed regulating circuit and Logic control circuit. At the same time, it was explained detailedly in this paper that the various actions realization and system debugging process of the new system.A series of shortcomings of the original system were overcomed by the new control system, while the performance and stability of the new control system has been greatly improved through those reformations. The most important is that the new system has advantages in energy-saving、economic and can be maintained easily.