Digital Sensor Thickness Measurement System And Applications

In the welding process of spot welding,the factor of influence on quality of welding spot is various,as to the definite welding material,the thickness of weldment is one of the key factors that affect quality of welding spot,also,when spot welding,the influence from various standard parameters is restrictive mutually.After the material,end surface shape and size of the electrode being designated,the welding current,the welding time and electrode force are mainly considered in choosing of welding standard according to the thickness of weldment.On the production line of automatic welding,if the thickness of weldment is uneven as a result of the limit of the existing technology of production and processing,which has a great influence on choosing of welding standard,so the unevenness of weldment becomes the bottleneck question which effects the quality and speed of welding,therefore,we must measure the thickness of weldment before the welding.Certainly,the manual measurement neither achieve the precision requirement,nor satisfy the demand of welding speed,specially on the existing automatic production line,automatic measurement and automatic selection of welding parameters appear especially important.Therefore,this paper has studied an automatic thickness measuring system based on the photoelectric encoder of E6B2-CWZ6C and the PLC high-speed counter of Siemens.The paper has first introduced the domestic and foreign present studying situation of thickness measuring system,then proposed this thickness measuring method of mechanical contact type in view of the actual work,also,the hardware compositions and software designing of the thickness measuring system have been specified,the parameter designing of the ball screw organization and connecting encoder with the PLC as well as the touching screen designing have been especially introduced.Finally,through the scene experiment,this paper has analyzed the measured results and their errors,proposed the methods of reducing errors and the improved measures of enhancing capacity of the thickness measuring system.This thickness measuring system can carry out thickness measuring to the transported weldment automatically,then transmit the measured data to the welding machine controller,and then choose the best welding parameters established in advance which correspond with the thickness of the weldment in order that the welding machine can weld the work piece automatically in sequence.This thickness measuring system has been applied to the automatic welding machine of shackle on the cobalt starting sheet successfully,which has indicated that the performance of this thickness measuring system is stable,the reliability is high,the precision of the measured results is high, also,this thickness measuring system can satisfy the welding machine controller to choose the best welding parameters well according to the different thickness of weldment,thus the automatic welding has been realized completely.The utilization of the thickness measuring system has not only enhanced the production efficiency,but also improved the welding quality greatly,has solved the problem of connecting cobalt starting sheet with shackle well,thus the productions of cobalt in the metallurgical enterprise have been enhanced,which has met the market demand.