浅谈数控机床故障诊断与维护毕业论文

NANCHANG UNIVERSITY

学 士 学 位 论 文（设 计）

THESIS OF BACHELOR

（2009—2012年）

中文题目:

英文题目：

学 院： 系 别： 专业班级： 学生姓名： 学 号： 指导教师：

浅谈数控机床故障诊断与维护

Fault diagnosis and maintenance of CNC

machine

南昌大学高等职业技术学院

工程技术系

摘 要

电子技术的发展以及国内数控装置的发展使得数控装置的价格走低, 特别是经济型数控车系统的价格已经是到达了它的最低点。经济型数控车床在中国的机械加工行业中得到了迅速普及, 使得我国机械加工水平无论在加工质量方面还是在加工效率方面也得到了迅速提高。但是随着机床使用时间的延长, 数控机床会出现这样或那样的故障, 本文就以经济型数控机床的常见故障为例, 谈了一些解决的办法。

关键词：数控车床 霍尔开关 继电器 伺服驱

ABSTRACT

The development of electronic technology and domestic CNC device makes the development of numerical control device for lower prices, especially economic type NC system price is already reached its lowest point. Economic type NC lathe machining industry in China has been the rapid popularization, causes our country mechanical processing level both in quality or in processing efficiency is also improved rapidly. But with the extension of the time machine, CNC machine tools will appear such or in that way the fault, this paper focuses on the economic type CNC machine tools of the common faults as example, discussed some solutions. Key words: Holzer switch relay servo drive in CNC lathe

目 录

第1章 绪论

1.1 概述„„„„„„„„„„„„„„„„„„„„„„„„„„„（7）

1.1.1 一台四刀位数控车床, 发生一号刀位找不到, 其它刀位能正常换刀的故障现象„„„„„„„„„„„„„„„„„„„„„„„（7） 1.1.2 一台六刀位数控车床, 换刀时所有刀位都找不到, 刀架旋转数周后停止, 并且数控系统显示换刀报警, 换刀超时或没有信号输入„„（7） 1.1.3 一台配有FANUC-0imate 系统大连机床厂的六刀位车床, 选刀正常但是当所选刀位到位之后不能正常锁紧„„„„„„„„„„„„（8） 1.2 稳压电源故障„„„„„„„„„„„„„„„„„„„„„„（8） 1.3 系统程序锁故障„„„„„„„„„„„„„„„„„„„„„ （9） 1.4 结束语„„„„„„„„„„„„„„„„„„„„„„„„„ （9）

第二章 诊断

2.1数控机床的故障诊断技术„„„„„„„„„„„„„„„„„„„（9）

2.1.1数控系统自诊断„„„„„„„„„„„„„„„„„„„„（9） 2.1.2在线诊断和离线„„„„„„„„„„„„„„„„„„„（10） 2.2数控机床故障的实用诊断方法诊断„„„„„„„„„„„„„„（10）

2.2.1诊断常用的仪器、仪表及工具万用表-可测电阻、交、直流电压、电流„„„„„„„„„„„„„„„„„„„„„„„„„„„（11） 2.2.2诊断技术资料„„„„„„„„„„„„„„„„„„„„（11） 2.2.3故障处理„„„„„„„„„„„„„„„„„„„„„„（11） 2.2.4数控系统故障诊断方法„„„„„„„„„„„„„„„„（11） 2.2.5故障诊断应遵循的原则„„„„„„„„„„„„„„„„（11） 2.3数控机床故障的类型与特点„„„„„„„„„„„„„„„„„（12）

第三章 维护

3.1、主传动链的维护„„„„„„„„„„„„„„„„„„„„„ （13） 3.2刀库及换刀装置的维护„„„„„„„„„„„„„„„„„„„（13） 3.3液压系统的维护„„„„„„„„„„„„„„„„„„„„„„（14）

参考文献„„„„„„„„„„„„„„„„„„„„„„„„„„„„（14） 致谢„„„„„„„„„„„„„„„„„„„„„„„„„„„„„„„（14）

第1章 绪论

1.1 概述

数控车换刀一般的过程是:换刀电机接到换刀信号后, 通过蜗轮蜗杆减速带动刀架旋转, 由霍尔元件发出刀位信号, 数控系统再利用这个信号与目标值进行比较以判断刀具是否到位。刀换到位后, 电机反转缩紧刀架。在我维修数控车的过程中遇到了以下几个故障现象。

1.1.1一台四刀位数控车床, 发生一号刀位找不到, 其它刀位能正常换刀的故障现象

故障分析:由于只有一号刀找不到刀位, 可以排除机械传动方面的问题, 确定就是电气方面的故障。可能是该刀位的霍尔元件及其周围线路出现问题, 导致该刀

位信号不能输送给PLC 。对照电路图利用万用表检查后发现:1号刀位霍尔元件的24V 供电正常,GND 线路为正常,T1信号线正常。因此可以断定是霍尔元件损坏导致该刀位信号不能发出。

解决办法:更换新的霍尔元件后故障排除, 一号刀正常找到。

1.1.2一台六刀位数控车床, 换刀时所有刀位都找不到, 刀架旋转数周后停止, 并且数控系统显示换刀报警:换刀超时或没有信号输入

故障分析查找:对于该故障, 仍可以排除机械故障, 归咎于电气故障所致。产生该故障的电气原因有以下几种:1.磁性元件脱落;2. 六个霍尔元件同时全部损坏;3. 霍尔元件的供电和信号线路开路导致无电压信号输出。其中以第三种原因可能性最大。因此找来电路图, 利用万用表对霍尔元件的电气线路的供电线路进行检查。结果发现:刀架检测线路端子排上的24V 供电电压为0V, 其它线路均正常。以该线为线索沿线查找, 发现从电气柜引出的24V 线头脱落, 接上后仍无反应。由此判断应该是该线断线造成故障。

解决办法:利用同规格导线替代断线后, 故障排除。

1.1.3一台配有FANUC-0imate 系统大连机床厂的六刀位车床, 选刀正常但是当所选刀位到位之后不能正常锁紧。系统报警:换刀超时

故障分析查找:刀架选刀正常, 正转正常, 就是不能反向锁紧。说明蜗轮蜗杆传动正常, 初步定为电气线路问题。在机床刀架控制电气原理图上, 发现刀具反向锁紧到位信号是由一个位置开关来控制发出的, 是不是该开关即周围线路存在问题呢? 为了确认这个故障原因, 打开刀架的顶盖和侧盖, 利用万用表参照电路图检查线路, 发现线路未有开路和短路, 通过用手按动刀架反向锁紧位置开关, 观察梯形图显示有信号输入, 至此排除电气线路问题。推断可能是挡块运动不到位, 位置微动开关未动作。于是重新换刀一次来观察一下, 结果发现:果然挡块未运动到位。于是把挡块螺栓拧紧, 试换刀一次正常。再换一次刀, 原故障又出现了, 同时发现蜗杆端的轴套打滑并且爬升现象。难道是它造成了电机反转锁紧时位置开关的挡块不能到位? 于是把该轴套进行了轴向定位处理, 将刀架顶盖装好。结果刀架锁紧正常了。