学海网

毕业设计 C620数控化改造 共31页、10184字 附组装图、零件图
摘　要
这次毕业设计主要是将一台C620型普通车床进行经济型数控改造设计，由于定位精度高，所以纵、横向导轨均采用贴塑导轨，传动系统采用滚珠丝杠，同时，为提高传动刚度和消除间隙，对丝杠进行预拉伸，传动齿轮采用双片错齿消隙齿轮，驱动元件采用步进电机。为了保证加工螺纹时，主轴转一转，刀架移动一个被加工螺纹的螺距或导程，主轴用脉冲发生器通过波纹管联接，并将纵向和横向进给系统用单片机控制，是其成为一个能独立运动的开环进给伺服系统。
数控系统采用MCS—51系列的8031单片机扩展系统。因为MCS—51系列的单片机具有集成度高、可靠性高、功能强、速度快、抗干扰能力强等优点。控制系统由微机部分、键盘及显示器I/O接口及光电隔离电路、步进电机功率放大电路组成。系统的加工程序和控制命令通过键盘操作实现，显示器采用数码管，以显示加工数据及机床状态等信息。为了达到机床要求的分辨率，传动系统采用步进电机齿轮减速后，带动丝杠。
设计改造后的经济型数控机床具有定位、直线插补、顺逆圆弧插补、暂停、循环加工、公英制螺纹加工等功能，且加工质量稳定可靠。零件加工的适应性强，自动化程度高。
关键词：车床，数控，改造，滚珠丝杠
Abstract
This design mainly is transforming an ordinary C620 lathe into an economy numerical control, because the accuracy is high, the lead rail uses plastic lead rail; the transmission system uses the ball screw. At the same time, we can carry on the pre-stretch to the guide screw and use double gears in the transmission gear to enhance the transmission rigidity and the elimination gap. The driving parts use ball screw. When processing thread, the main axle transfers a revolution, the tool holder must moves a pitch or lead of the thread, the main axle and the pulse generator link together through a corrugated pipe. A Single Chip Microcomputer controls the longitudinal and crosswise feeding system, so it will because an open-loop servo system which can move independently.
The numerical control system uses the MCS-51 series 8031 Single Chip Microcomputer to expand the system. Because the MCS-51 series Single Chip Microcomputer have high integration rate, high reliability, strong function, quick speed, and strong anti-jamming ability and so on .The control system is made up of the microcomputer part, the keyboard and the monitor, the I/O interfaces and the light electricity isolation electric circuit. The system processing procedure and control orders are controlled by keyboard, the monitor realized process data and the information of machine tools with figures tube. In order to realize the resolving power, transmission system use stepper motor to drive the ball screw after being decreased.
After the transformation design , the economy numerical control machine has the localization , the straight line inserts , inserts along the counter circular arc , function suspension ,circulation processing , male inch thread processing and so on .The processing quality is stable and reliable . Components processing compatibility and the automation are strengthened.
Keyword: lathe， numerical control ， alteration ， ball screw
目录
引言 3
1 概述 4
1.1 毕业设计的目的 4
1.2 设计任务 4
1.3 设计的必要性 4
1.3.1 数控改造目的 4
1.3.2 数控改造的优点 5
2总体方案设计 5
2.1 系统的运动方式与伺服系统的选择 5
2.2 计算机系统 5
2.3 机械传动方式 5
2.3.1纵向滚珠丝杠 6
2.3.2横向滚珠丝杠 6
2.3.3总体方案 7
3进给伺服系统设计 7
3.1纵向进给伺服系统 8
3.1.1 计算进给牵引力Fm(N) 8
3.1.2 计算最大动载荷C 9
3.1.3 滚珠丝杠螺母副的传动效率计算 10
3.1.4 刚度验算 10
3.1.5 稳定性校核 11
3.2横向进给伺服系统 11
3.2.1 计算进给牵引力 11
3.2.2 计算最大动负载C 12
3.2.3选择滚动丝杠螺母副 12
3.2.4传动效率计算 13
3.2.5 刚度验算 13
3.2.6稳定性校核 15
3.3齿轮传动比计算 16
3.3.1 纵向进给齿轮箱传动比计算 16
3.3.2横向进给齿轮箱传动比计算 16
3.4步进电机的选型 17
3.4.1纵向进给步进电机 17
3.4.2横向步进电机 21
3.4.3 计算步进电机空载启动频率和工作时的频率 24
4 数控系统硬件电路设置 24
4.1 数控系统基本硬件组成 24
4.2 选择 CPU 的类型 25
4.3 74LS138 CPU 和存储器 26
4.4 I/O接口电路 26
4.5 软件环行分配器 27
4.6 控制系统 27
4.7 其它辅助电路 28
参考书目 29
致 谢 30
外文翻译 31