摘 要
随着科学技术的不断进步，整个国家自动化水平和信息化水平的长足发展，社会对这方面的要求越来越多。以前的工厂都是利用人工的方式进行生产加工，这样的工作的方式，不仅没有安全保障，而且没有很高的经济效益。
改革开放以来，国内的发展形式越来越好，竞争也越来越激烈，高科技设备逐渐代替了以前的手工操作方式，自动化设备也越来越多，自动控制系统用的越来越多。公司面对的压力也越来越大，不仅要考虑国内的对手，国外的竞争逐步加大，随着信息科技、市场经济的迅猛发展，国内、国际市场竞争日益激烈，产品更新更为迅速，尤其是随着高新科技的日新月异，产品的类型、工艺外形越来越复杂，再加上企业经营与发展必会面对劳工的短缺、人工成本要省力化、合理化与自动化的发展趋势，传统的手工送料已经不能满足要求，这时自动加料机就应运而生。在今天现代科学技术的许多领域中，什么是加料机呢？顾名思义，加料机就是专门用于粒料，粉料，片状料，带状等材料的自动化、数控化、精确化的输送机器，送料机是借助于机器运动的作用力加于材料，对材料进行运输的机器。
特别是近年来，各项技术的不断发展，如自动控制技术、电力电子技术、检测技术和信息技术，使得这些应用的领域越来越多。作为辅助装置的送料机构自动化水平也需要越来越高。
综上所述，在本着节约资金、降低成本、提高生产效率、保障人身安全、实现自动化运作的情况下对加料机构进行设计，研究出更加适合于工作环境的自动化加料机构。
本设计分析自动换水鱼缸实现的必要性和可行性，选用合适的PLC芯片和多种外围器件，完成硬件和软件的整体设计，最终实现了一个每天按时定量换水控制系统
关键词：自动换水加料系统；定时控制；实时显示
Abstract
With the continuous progress of science and technology, the level of automation and the level of information technology developed by leaps and bounds, the community on this request more and more. The former factories are using artificial methods of production and processing, such a way of working, not only without security, and there is no high economic efficiency.
Since the reform and opening up, the domestic form of development is getting better and better, more and more intense competition, high-tech equipment gradually replaced the previous manual mode of operation, more and more automated equipment, automatic control system with more and more. The pressure of the company is also growing, not only to consider the domestic rivals, foreign competition gradually increased, with the information technology, the rapid development of market economy, domestic and international market increasingly fierce competition, product updates more quickly, Especially with the ever-changing hi-tech, product type, process more and more complex shape, coupled with business development and development will face the shortage of labor, labor costs to save effort, rationalization and automation trends, the traditional Manual feeding has been unable to meet the requirements, then automatic feeding machine came into being. What is the feeder in many areas of modern science and technology today? As the name suggests, the feeder is dedicated to the automation of the material, powder, sheet, ribbon and so on. It is used to feed the material by means of the force of the machine. The machine that carries the transport.
Especially in recent years, the continuous development of various technologies, such as automatic control technology, power electronics technology, detection technology and information technology, making these applications more and more areas. The level of automation of the feed mechanism as an auxiliary device also needs to be higher and higher.
To sum up, in the conservation of capital, reduce costs, improve production efficiency, protect personal safety, to achieve the operation of the automation of the feeding mechanism to design, to develop a more suitable for the work environment of the automatic feeding agencies.
This design analyzes the necessity and feasibility of the automatic changing of the fish tank, selects the appropriate PLC chip and various peripheral devices, completes the overall design of the hardware and software, and finally realizes a daily quantitative water change control system
Key words: automatic water changing system; timing control; real-time display
一、设计的背景
在现代科学技术的许多领域中，自动控制技术起着越来越重要的作用，并且随着生产和科学技术的发展，自动化水平也越来越高。自动控制利用控制装置使被控对象的某个参数自动的按照预定的规律运行。本设计的自动加料机控制系统就是采用自动控制技术来实现功能的，这样就大大提高了工作的效率，整个过程又快又稳。
1.1 设计目的和意义
由于自动化在当今时代发展越来越快，自动化水平也不断的提高，所以PLC已成为了广泛的应用， PLC加料控制系统是工业流程中的一环，他通过PLC控制，接触器、传感器等配合。再辅以开关元件、热继电器等元件设备，以达到自动下料、称量、并将原料运走的全程自动运作。其中操作人员只需控制启动与停止按钮即可，并可在任何时候按下停车按钮，系统将在完成当前流程后再停车于初始状态，不用考虑因停车时间不对、原料滞留而引起的下次启动时过程错误，从而降低了对工作人员的操作要求及其劳动强度。
1.2 设计的要求
（1）按下启动按钮后，接通上输送带电动机（进料电动机）M3，上输送带运转，开始向秤斗进料。
（2）当称斗中的原料达到设定重量，料位开关S3动作，M3停止运行，停止进料，同时接通下输送带电动机（进料达到）M4（出料电动机）和开闸电动机M1，使下输送带运转，斗秤闸门打开，将料输出至下传送带。
（3）当闸门完全打开，碰撞闸门上限位开关S1，切断M1，M1停止运行。
（4）当称斗中原料下完，料位开关S4动作，接通关闸电动机M2，关闭闸门。
（5）当闸门完全关闭，碰撞闸门下限位开关S2，切断M2，M2停止运行，接通M3，料仓重新开始下料。
（6）按下停止按钮时，应等秤斗中的原料下完，再延时10S，待传送带上的原料输送完毕，自动切断电源，停止系统。
（7）如果出现故障，可直接切断电源，停止一切动作。
