Development And Experimental Research Of TIG Automatic Welding Machine For Water Supply Copper Pipe

The water supply copper pipe in the factory is produced by the artificial flame brazing welding process.The welding process of the copper pipe joint involved the use of 45%silver filler metal which require high skill from workers/operators as well as high labour intensity.In order to reduce the cost of raw materials and labour during the process,the factory proposed the task of developing and designing a set of automatic welding machine for copper pipes.The design of developing the TIG automatic welding machine was carried out based on the different types of copper pipes joints.The developed machine also consists of six(6)different parts;a)the frame,b)the rotary driving mechanism of copper pipe(each at upper and lower sets),c)the copper pipe clamping and adjusting equipment,d)the welding clamping and adjusting mechanism,e)the welding power supply and f)computer interfaceThe automatic welding machine used tungsten inert gas(TIG)welding process to achieve precise control of welding heat input,user-friendly and conveniently operable.For different copper pipe weldments,the location welding and preheating can be done automatically under the condition of fillet without filling.In order to avoid the heat accumulation of the circumferential welding of copper pipes during welding,the preheating and welding parameters can be segmented.With the developed TIG automatic welding machine,an investigation is carried out on the filling and non-filling welding process for the 30 mm pipe and pipe sleeve.Suitable preheating and welding parameters were found,the welding joints with firm and reliable quality were achieved.Macroscopic and metallographic observations,as well as penetration examination of the welded joints,showed absent of defects such as pores,non-fusion and cracks.In addition,a set of air tightness detection device has been designed.According to the technical requirements of the company,gas tightness has also been carried out,the weldments were found to have no gas leakage.The TIG automatic welding machine developed for copper pipe has since been completed.The commissioning and welding process test on the enterprise site was conducted and passed the acceptance of the company successfully.