NPN型接近开关在桥式起重机的应用

Application of NPN Proximity Switch in Bridge Crane

NPN型接近开关作为桥式起重机的安全限位开关,不仅可以改善机械式限位开关内部结构容易老化、回位弹簧因锈蚀或长期挤压而失去原有的弹性、触点接触不良或者无法复位等问题,还可以提高桥式起重机的整体安全性能。通过对接近开关工作原理、PLC选型以及桥式起重机控制方式进行分析,确定电气改造方案,采用NPN型接近开关作为桥式起重机起升机构、大车运行机构、小车运行机构的行程限位开关,实践表明NPN型接近开关的应用有利于提高桥式起重机的整体安全性能及其使用寿命。

As the safety limit switch of the bridge crane, NPN proximity switch can not only improve the internal structure of the mechanical limit switch easy to aging, the return spring lost its original elasticity due to corrosion or long-term extrusion, poor contact or unable to reset, etc., but also improve the overall safety performance of the bridge crane. Through the analysis of the working principle of proximity switch, PLC selection and bridge crane control mode, the electrical transformation scheme was determined. After the transformation, NPN proximity switch was used as the travel limit switch of the lifting mechanism, crane operation mechanism and trolley operation mechanism of the bridge crane. The practical application shows that NPN proximity switch is beneficial to improve the overall safety performance and service life of the bridge crane.