Submerged arc welding is a welding method in which the arc burns under the flux layer. It has the advantages of stable welding quality, high welding production efficiency, no arc light and less smoke and dust. In the process of submerged arc welding, the traditional welding torch uses the contact tip to introduce the energy of the welding power supply to the welding wire, and through the arc, the energy of the welding line is input into the molten pool of the welding seam of steel pipes. However, in actual production, the contact tip of the traditional welding torch is prone to wear, which can lead to jamming or high temperatures of welding wire. A new submerged arc welding torch is introduced in this article; the working principle of the new submerged arc welding torch is analyzed, and its application is compared with the traditional submerged arc welding torch in test production.
The spiral submerged arc welded pipe requires good welding continuity and a stable molten pool shape, otherwise, it is easy to cause welding defects and affect the performance of the welding seam. Therefore, the conductive tip on the welding torch is responsible for stably inputting the energy of the welding line into the molten pool. The role of the welding torch is crucial. However, the contact tip on the traditional welding torch is easy to wear in actual production, resulting in jamming or high temperature of welding wires. The structure of the traditional welding torch is shown in Figure 1.
1. Welding head No. 1 2. Joint 3. Conductive rods 4. Connecting bolts 5. Nuts 6. Conductive tips
Figure 1 The structure of the traditional welding torch
1. Base 2. Core rod 3. Axial channel 4. Connecting plate 5. Conductive connecting plate 6. Cooling air duct 7. Conductive nozzle 8. Pressure cap 9. Conductive connecting rod 10. Screw 11. Tile seat 12. Pin shaft 13. Adjustment handle 14. Vertical plate 15. Rectangular round springs 16. Adjusting bolt
Figure 2 The structure of the new submerged arc welding torch
2. The new structural design of the submerged arc welding torch
To solve the problems encountered in the welding process of traditional welding torches in the actual production of spiral seam submerged arc welded pipes, the welding torch structure is designed to ensure the quality of welding seams in the process of spiral seam submerged arc welded steel pipes.
The structure of the newly designed submerged arc welding torch is shown in Figure 2. Its characteristics are that the top of the core rod is fixed on the base, and the core rod is provided with an axial channel for the welding wire to pass through; the top of the base has a hole for the welding wire to pass through, and the hole at the top of the base connects with the axial channel of the core rod, including the electrical connection plate. The adjustment connection plate is fixed on the conductive connection plate by screws, and the conductive connection plate and the adjustment connection plate are provided with holes for the core rod to pass through. A vertical plate is fixed on the adjusting connecting plate; the front end of the adjusting bolt with a shoulder is fixed on the base, and the rear end of the adjusting bolt protrudes from the vertical plate. The protruding part is equipped with an adjusting handle, and the adjusting bolt is covered with a circular spring. The front end of the circular spring rests on the shoulder of the adjusting bolt; the rear end of the circular spring rests on the vertical plate. The base is provided with a pin shaft, and the adjusting connecting plate is provided with a pin shaft matching the base. The bottom of the conductive connecting plate is fixed with a hollow conductive connecting rod; the conductive tip is installed on the pressure cap, and the pressing cap is screwed to the bottom of the conductive connecting rod. The core rod enters the conductive connecting rod through the adjustment connecting plate and the conductive connecting plate. The length of the left half of the core rod is less than that of the right half. The bottom of the left half of the core rod is in the conductive connecting rod, and the right half of the core rod enters the conductive tip. At the same time, a cooling air duct connected with the hollow part in the middle is provided on the conductive connecting rod.
3. The working principle of the newly designed submerged arc welding torch
When the gap between the welding wire and the through hole of the contact tip is big, turn the adjustment handle to make the adjustment connecting plate and the conductive connecting plate swings around the pin shaft on the base, and the core rod supports the welding wire to ensure unchanged direction when leaving the contact tip. The output center of the welding wire does not change at all, and there will be no welding deviation and jamming of welding wires caused by deviation of welding wires, ensuring the stable conduction of the contact tip, stable welding penetration and good welding effect. Since the cooling air duct is provided on the conductive connecting rod, the temperature of the conductive connecting rod and the contact tip can be cooled, thereby reducing the temperature of the welding wire, achieving maximum penetration under the same welding specification, and reducing power consumption.
