Research On Automatic Welding Equipment Of Small-caliber Valve Inner Seam

Valve is a control component of pipeline transportation system, which can control the flow of pipeline and the equipment, and make the liquid, gas, or powder flow or be stop. No matter in our daily lives or industrial production, valve has played an extremely important role. This paper is based on how to automatically do the small-caliber valve inner face's seaming. However, it is difficult to deal with those welding issues when the small diameter valve's inner face needs to be welded in the production which due to lack of technical personnel and senior technical workers. Therefore, we often Arc weld manually, because the diameter is so small that leads to the restriction of operation, and also it needs repeatedly welding, what's more, the distance to the mouth of the valve is often too far (more than 100mm). While arc welding manually, sometimes people have to bend the welding rod, and it's very low efficiency.Meantime, it is difficult to ensure the welding quality under such a hard preheat environment. Therefore, a special automatic welding equipment is urgently needed to improve the efficiency and quality of small-caliber valve inner face's seaming, which meet the needs of the development of modern valves welding technology.PLC is a new product based on traditional relay control and computer control, and will gradually become a new automatic control device which has microprocessor core, and intergrate the automation technology, computer technology, and communication technology. It has many advantages such as excellent anti-interference ability, high reliability, small size, easy maintenance, as well as be modified online. Thus, it suits the control needs of small-caliber valve's inner seam welding.In this study, through the choice of the rack and positioner, provides a scaffold to support welding operations. Secondly, through the improve of gun's design to make sure the gun can reach into small-diameter pipeline. And lastly, by means of setting the PLC and touch screen, offer us two ways of small-caliber valve welding: automatic and manual welding, and at the same time, we can get the real-time control of welding parameters, such as tuning parameters of the swinging torch, welding current, and welding speed. That will give us a guarantee on the smooth progress of the welding, and fit for the trend of equipment automation. In addition, PLC eqiupped with a memory function that can store welding procedures of different sizes of small diameter valve , and when needing to change the welding sample size, we only to choose the relevant parameter on the touch screen.The welding method of this equipment is CO₂ welding. In this paper, we mainly dicuss some technology selection principles, besides, in order to face the possible interference, we also put forward some corresponding anti- interference measures.