SD006welding torch

The basic concept and working principle of the welding gun

Basic concept: The gas shielded welding gun is a key component in the gas arc welding equipment, which is mainly used for MIG/MAG welding (such as carbon dioxide gas shielded welding, argon arc welding, etc.). During the welding process, it prevents the oxygen and nitrogen in the air from having an unbeneficial effect on the welding weld pool by sending out the welding wire and forming a protective gas atmosphere around it.

How it works: When welding starts, the power supply provides the electrical energy needed for the arc between the wire and the weldment. As the current passes through the wire, the ends of the wire are heated by resistance and melt to form molten droplets, while shielding gases are ejected from a specific channel of the torch around the wire and pool. The molten droplets transition into the weldment's molten pool under the action of the arc, and as the welding gun moves, the molten pool metal cools and solidifies to form a weld. The presence of shielding gas has an excellent effect on isolating the air and confirming the quality of the weld.

The structural composition of the gas shielded welding gun

Contact tip: The contact tip is a very important part of the gas shielded welding gun, it is in direct contact with the welding wire, and its main function is to conduct the welding current to the welding wire. The material of the contact tip usually has good conductivity and properties, such as copper alloys. The inner diameter size should be accurately matched to the diameter of the welding wire to confirm good conductivity and smooth feeding of the welding wire. If the contact tip is worn or the inner diameter is not suitable, it may lead to problems such as poor wire feeding and unstable arc.

Nozzle: The nozzle is located at the front end of the welding torch and its function is to spray the shielding gas evenly into the welding area. The shape and size of the nozzle will affect the coverage of the shielding gas. Common nozzle shapes are cylindrical and conical, and different nozzle shapes are suitable for different welding processes and requirements. For example, conical nozzles can provide more concentrated gas protection in some cases, facilitating welding in tight spaces or where gas protection is required.

Wire feeding mechanism: The wire feeding mechanism is one of the core components of the gas shielded welding gun. It includes parts such as wire feeding wheels, wire pressing wheels and wire feeding motors. The wire feed wheel transports the wire from the wire spool to the welding area through the friction between the wire and the wire, and the wire pressing wheel assists in wire feeding and adjusts the wire feeding pressure. The speed of the wire feeding motor can be adjusted according to the requirements of the welding parameters to control the feeding speed of the welding wire and confirm that the melting speed of the welding wire matches the feeding speed during the welding process.

Gun body and handle: The gun body is the main part of the whole welding gun, which contains various channels and lines, such as conductive lines, gas channels, etc. The handle is designed to be easy for the operator to hold, and its design performance stability principle can reduce the fatigue of the operator during the long-term welding process. There is also usually a control switch on the handle to start and stop the welding operation.

The type and function of the shielding gas of the gas shielded welding gun

Carbon dioxide (CO₂) gas: In CO2 gas shielded welding, carbon dioxide is used as a shielding gas. Its main function is to isolate the air and prevent oxygen and nitrogen from entering the welding pool. CO2 gas is relatively inexpensive, abundant in resources, and has a definite cooling effect on the weld pool during the welding process, helping to control the weld pool shape and weld formation. However, carbon dioxide gas also has some disadvantages, such as more spatter during welding, and a certain degree of oxidation of the weld seam.

Argon (Ar): In argon arc welding, argon is the main shielding gas. Argon is an inert gas that is chemically very stable and hardly reacts with any metal. As a result, it provides an extremely pure protective environment for the weld pool and is particularly suitable for welding non-ferrous metals such as aluminum, magnesium and their alloys, as well as stainless steel, which require high weld quality. The weld under argon protection is of good quality, the surface of the weld is smooth and beautiful, and the degree of oxidation is relatively low.

Gas mixtures: In addition to single gas protection, gas mixtures such as argon-carbon dioxide mixtures can also be used. This gas mixture combines the stability of argon with some of the advantages of carbon dioxide to reduce the spatter problem of pure carbon dioxide gas welding to a certain extent, while also reducing costs. The ratio of the gas mixture can be adjusted according to the specific welding material and process requirements.