桥式起重机控制系统 毕业论文.doc

摘要 桥式起重机作为物料搬运系统中一种典型设备，在企业生产活动中应用广泛作用显著，因此对于提高桥式起重机的运行效率，确保运行的安全可靠性，降低物料搬运成本是十分重要。传统的桥式起重控制系统主要采用继电器接触器进行控制，采用交流绕线串电阻的方法进行启动和调速，这种控制系统存在可靠性差，操作复杂，故障率高。电能浪费大，效率低等缺点。因此对桥式起重机控制系统进行研究具有现实意义，也是国内外相关行业专家学者的一个研究课题。 本文针对桥式起重机控制系统中存在的上述问题，把可编程序控制器和变频器应用于桥式起重机控制系统上，并进行了较深入的研究。 PLC系统采用SEIMENS公司产品，能控制起重机大车、小车的运行方向和速度换档;吊钩的升、降方向及速度换档，同时能检测各个电机故障现象并送往工业触摸屏进行显示，减小了传统继电一接触式控制系统的中间环节，减少了硬件和控制线，极大提高了系统的稳定性，可靠性；为了更加有效的防止重物下滑，在桥式起重机起升机构各加上一套由旋转编码器、PG数模转换和PLC相结合的闭环系统，使主副吊钩拖动更加稳定、可靠。 关键词:可编程序控制器； 桥式起重机； 变频调速 ABSTRACT The bridge crane carries a kind of typical equipment in the supplies system ,so it have extensive function in the activity of producing enterprise , so it is important to improve the bridge crane operational efficiency,guarantee the safe reliability to be operated,reduce the cost of the supplies carrying. But the traditional bridge crane control system mainly adopts relay and contactor to control bridge crane,adopt the methods of wire winding bunch of resistance to start and adjust speed of motor,the control system have many disadvantages,for example:dependability is bad,it is complicated to operate，fault rate is high.the electric energy is wasted greatly,efficiency is low.carrying on the research to the bridge crane control system has realistic meanings,it is a subject for research of relevant experts and scholars both at home and abroad too. To the question that exist in the bridge crane control system ,the paper apply Programmable controller and frequency converter on control system of bridge crane,have carried on deeper research in relevant respects. PLC system adopts the SIEMENS Company products,can control the crane cart,car operation direction and change speed;to rise,lower cliver direction and change speed,can measure each motor trouble phenomenon and send this to touch-sensitive screen of industry to show at the same time,have reduced traditional electric