Design Of Welding Machine For The Elbow Girth

With the continuous development of the pipeline industry and large-scale application of pipelines, the demand for pipe welding is increasing. Pressure pipes, commonly as transmission media of oil, gas and other high pressure gas, play an important role in the national economy. Considering its safety and reliability, the welding requirements must be guaranteed. At present, various generic pipelines welding equipment has emerged at home and abroad, however, for the welding of some special pipes, their main welding method is manual welding in many cases and their welding quality and efficiency can not be guaranteed. So the development of the appropriate special welding machine has become an important issue.This paper designs a kind of elbow girth welding machine, using submerged arc welding as its welding mode to realize the welding of the long straight pipe and the elbow. In the mechanical structure, the welding machine is mainly composed of positioner, mobile trolley, adjustable stand, welded baffles, welder mount. Positioner, with its unique clamping and a relatively novel transmission structure, using motor reducer as its power source, achieves rotation displacement of the workpiece. Mobile trolley uses sprocket chain as its drive mode to run on a long track and achieve remote transport of the workpiece. Simultaneously, it is possible for its clamping and lifting cylinder to clamp and lift the workpiece. Adjustable stand plays a role in the positioning of the workpiece before the workpiece is clamped. For the welding method is the submerged arc, the design of welded baffle blocks is stacking order for the flux and ensure that there is no interference between the tube elbow and welded baffles during the rotation. Welder mount’s major role is to support, and it is mounted a wire feeder and cylinders and other devices. Under the action of the cylinder, the nose section of welding machine can advance and retreat. Meanwhile, the cross board of the nose section can achieve manual adjustment of the torch.In the welding control system, using Siemens S7-200 series PLC as its core control, Siemens touch screen SMART-700 IE as its man-machine interface. Use PLC to realize the control of the positioner’s rotation speed and angle, the welding speed, the torch swing, the mobile trolley speed, etc. And touch screen enables the input and display of welding parameters. The entire device is equipped with a flux automatic recycling machines and water-cooled torch and other devices.The numerous field welding experiments show that the elbow girth welding machine runs smoothly and it is with high degree of automation and good welding effect. It meets the requirements of production quality and efficiency and is ideal professional equipment for pipeline welding.