This sub merged arc welding spiral pipe mill line, is used to uncoil the specified size steel coil, then roll into open tube, welding by submerged arc welder, cut by plasma cutting machine into fixed length, then processed and tested in finishing area,。The steel plate material is carbon steel/low carbon steel.In view of the variable specifications, large diameter and thin wall, and amplitude modulation up to 1600ram of this product, the external holding roller cantilever forming frame is selected.
1. Adjustment and quantity selection of forming roller
When the forming roller is uniformly distributed at a 45 ° angle according to the outer circle of the steel pipe, the adjustment tracks A, B and C of the pipe diameter change are a final straight line with an included angle of 30 ° with the horizontal line. However, considering the best stress surface, it should be 4.
If the base is divided into two parts and each part forms an angle of 30 ° with the corresponding bottom surface, the forming roller adjuster meeting the above two requirements will be formed. In order to minimize the output resistance of the forming roller to the welded pipe, the forming roller I should be rotated around the shaft on the small base with the change of the spiral angle. When the specification changes, the axial position of the helix will change, so the forming roller adjuster is required to be able to make lateral adjustment along the slide rail. In order to keep the bottom elevation unchanged and keep its position constant, when the pipe diameter changes, the upper and side forming rollers should be adjusted up, down, left and right. The above five adjustment factors are the basic elements of adjustable molding.
2 Design features of forming machine
(1) In order to make the outer roll adjustable, the cantilever molding machine can adapt to the 1600ram amplitude modulation requirements, and the rack extension arm is adjusted up and down along the square guide pillar by the transmission mechanism.
(2) In order to solve the problem of burning through during internal and external welding of thin-walled tubes, internal and external flux pads are provided.
(3) The inner welding point shall be close to the forming meshing point and the chassis rotation center as far as possible to prevent the strip steel springback from causing misalignment and facilitate the alignment and tracking of the inner welding head.