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本科生毕业设计说明书（毕业论文）

题 目：基于

PLC的自动轧钢机控制

基于PLC的自动轧钢机控制

摘 要

随着社会的不断进步，钢材成为为社会建设的重要材料，其生产技术也发生了很大的变化。从原来的很多工人操作单轧机生产转变成了现在的钢材连轧生产线。

本文简单阐述了轧钢自动化的发展和现状及轧钢机的组成和分类，讲诉了轧钢原理和生产工艺流程，介绍了PLC的基本组成、特点以及工作原理，以及对基于西门子S7-200系列PLC控制的自动轧钢机系统进行了较为细致的设计，通过主回路，控制回路以及I/O分配的设计对PLC控制轧钢机的过程有了进一步认识，并对所用的设备进行了详细的选型，而且对该控制系统进行了软件编程。

关键词：可编程控制器；自动轧钢机；控制系统

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PLC-Based Control of Automatic Rolling Machine

Abstract

As society progresses, the steel became important materials of the social construction, production technology has undergone great changes. Many workers operate from the original single-mill production transformed into steel rolling production line now.

This paper briefly describes the development and current status rolling automation, complaint about the principles and rolling production process. Describes the basic components of PLC, characteristics and working principle. Through the main circuit, control circuit and I / O assignment design of the PLC control rolling mill process has been further understanding, the equipment used and a detailed selection, and the control system software programming.

Keywords: PLC; automatic rolling mill; control system

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目 录

摘 要 .............................................................................................................................I Abstract ......................................................................................................................... II 第一章 轧钢机 .............................................................................................................. 1 1.1 自动轧钢机的目的及实际意义 ......................................................................... 1 1.2 轧钢自动化发展的历史和现状 ......................................................................... 1 1.3 轧钢机的定义及组成 ......................................................................................... 3 1.3.1 定义 ............................................................................................................... 3 1.3.2 轧机的组成 ................................................................................................... 3 1.4 轧钢机的分类 ..................................................................................................... 3 1.5 轧钢原理及工艺流程 ......................................................................................... 4 1.5.1 轧钢原理 ....................................................................................................... 4 1.5.2 轧钢系统工艺流程 ....................................................................................... 4 1.6 轧钢工艺的发展前景 ......................................................................................... 5 第二章 可编程控制器 .................................................................................................. 8 2.1 PLC的由来和定义 .............................................................................................. 8 2.1.1 PLC的由来 ................................................................................................... 8 2.1.2 PLC的定义 ................................................................................................... 8 2.2 可编程序控制器的发展历程及问题和解决对策 ............................................. 8 2.2.1 可编程序控制器的发展历程 ....................................................................... 8 2.2.2 我国可编程序控制器发展中的问题及对策 ............................................. 10 2.3 可编程控制器的基本构成 ............................................................................... 11 2.3.1 可编程控制器的硬件组成 ......................................................................... 11 2.3.2 可编程控制器的软件组成 ......................................................................... 13 2.4 可编程控制器的工作原理 ............................................................................... 14 2.4.1 PLC的扫描工作方式 ................................................................................. 14 2.4.2 PLC的工作过程 ......................................................................................... 14 2.4.3 PLC对输入、输出的处理规则 ................................................................. 16

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2.5 可编程控制器系统与继电接触器系统工作原理的差别 ............................... 16 2.6 西门子S7-200系列可编程控制器 ................................................................. 18 2.6.1 S7—200系列的PLC的硬件资源 ............................................................. 18 2.6.2 S7—200的扩展模块 .................................................................................. 18 第三章 编程软件 ...................................................................................................... 24 3.1 STEP基本介绍 .................................................................................................. 24 3.2 STEP7基本功能及组成 .................................................................................... 25 3.2.1 基本功能 ..................................................................................................... 25 3.2.2 界面组成 ..................................................................................................... 25 3.3 编辑器简介 ....................................................................................................... 25 第四章 设计选型 ...................................................................................................... 26 4.1 电动机的选型 ................................................................................................... 26 4.1.1 轧钢机主传动电机的选择 ......................................................................... 26 4.1.2 辊道电机的选择 ......................................................................................... 26 4.1.3 压下电机的选择 ......................................................................................... 27 4.1.4 冷却泵的选择 ............................................................................................. 27 4.2 低压控制电器的选型 ....................................................................................... 27 4.2.1 控制按钮的选择 ......................................................................................... 27 4.2.2 刀开关的选择 ............................................................................................. 28 4.2.3 接触器的选择 ............................................................................................. 29 4.2.4 熔断器的选择 ............................................................................................. 30 4.2.5 热继电器的选择 ......................................................................................... 31 4.2.6 中间继电器的选择 ..................................................................................... 31 4.3 变频器选型 ....................................................................................................... 32 4.3.1 MM440变频器 ........................................................................................... 33 4.3.2 MM440变频器的特点 ............................................................................... 33 4.3.3 MM440变频器方框图和功能表 ............................................................... 34 4.3.4 MM440参数设定 ....................................................................................... 37 4.4 电抗器的选择 ................................................................................................... 37

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