The Research And Design Of Automatic Welding Machine For Pin Tube

Pin tube which is made by welding pin to outer surface of tube is one type of heat-transfer components. It is used to fix in the section of convection chamber of heating-furnace in petrochemical and chemical industry, in order to meet the heat transfer of two different fluids between shells and tubes. The traditional manufacturing method of pin tube, which pin is loaded by manual and welt by ordinary weld gun, with heavy labor intensity, low productivity, high energy consumption and instable welding quality, can not adapt to the requirement of modern manufacturing. Automatic welding machine for pin tube, which is designed by the author and made by theory of quick manufacture, can make pin tube machined automatically, has higher productivity and stabile machining quality.Advantages and disadvantages of current machine methods of pin tube are analyzed sufficiently, specific welding objects—pin and tube are taken into account, short-cycle stud welding is chose as welding method of pin tube. According to automatic machining procedure and needs of pin tube, and with the consideration of realistic manufacturing technology of factory, an automatic welding machine for pin tube is designed. Research content of this paper is arranged as followed:1. By doing much research on necessary movements of machine and key technique of welding procedure, a newly mechanical structure is confirmed and three-dimensional model is built by Pro/ENGINEER. The structure is simple, reliable, easy to make, can make indexing, feeding, positioning and welding operated automatically.2. Meeting all kinds of working conditions and forms of pneumatic actuators in the machine, a simple and reliable pneumatic circuit is put forward. Parameters and specifications of pneumatic components are calculated based on different load and needed velocity.3. According to characteristic and control mode of controlled objects, control strategy for machine is designed based on PLC. Hardware and software system are introduced in detail; some circuit diagrams related to specific hardware structure are provided; lad programs related to main program are also provided.4. The reliability of movements of drawn-arc and return is key factor to the success of the project. Models of two movements and its load are set up using...