A triangular circular arc convex rib friction welding drill pipe and its welding method

Abstract

The invention discloses a triangular arc-shaped ribbed friction-welded drill rod. The drill rod includes a triangular rod body, a friction-welded outer threaded connector and a friction-welded inner threaded connector. The drill rod is characterized in that each friction-welded connector includes a small stepped column and a large stepped column, the diameter of the large stepped column is identical to the diameter of the inscribed circle of the triangular contour of a triangular arc-shaped ribbed drill rod, and the diameter of the small stepped column of each connector is identical to the diameter of the inscribed circle of an inner triangular hole of the triangular arc-shaped ribbed drill rod. The invention has the advantages that relative rotations of the connectors and the rod body during friction welding is not affected, and the positioning function is achieved; moreover, the ends of the rod body reach a thermoplastic status due to a large amount of heat produced by mutual frictions, and embrace the small stepped columns during rapid upsetting due to extrusion deformation, so that the anti-torsion performance of the connectors and the rod body are improved.

Description

technical field [0001] The invention relates to a triangular circular arc convex rib friction welding drill pipe and a welding method thereof. Background technique [0002] At present, the structural types of domestic tunnel drill pipes mainly include smooth drill pipes, ribbed drill pipes, and triangular arc-convex drill pipes. The joints of the smooth drill pipe and the ribbed drill pipe are round steel, and the rod body is a steel pipe with the same outer diameter of the joint. The joint and the steel pipe of the rod body are connected by friction welding. Heat, when the heat accumulates to a certain range, it will be impacted, and the friction welding has high strength and high production efficiency. However, the section of the joint of the existing triangular arc-convex drill pipe is a triangular cross-section, and the rod body is a triangular pipe annulus. When friction welding is used, the joint cannot be effectively and continuously contacted with the cross-section ...

AI Technical Summary

Problems solved by technology

However, the section of the joint of the existing triangular arc-convex drill pipe is a triangular cross-section, and the rod body is a triangular pipe annulus. When friction welding is used, the joint cannot be effectively and continuously contacted with the cross-section rod body as a triangular pipe annulus during the rotation of the main shaft of the machine tool. Even if the heat reaches the requirements of the friction welding temperature, it is difficult to ensure that the three sides of the joint triangle are on the same plane as the three sides of the rod body during the upsetting impact process

Therefore, in the previous processing process, the triangular arc-convex drill pipe was generally processed into steps by joints at both ends. It is inserted into the triangular shape of the drill pipe body. At the same time, it is necessary to process three-sided grooves on the outside of the triangular drill pipe body, and form a fillet weld with manual arc welding of the joints at both ends. Since manual arc welding is prone to welding defects, in order to ensure the welding quality, the The small end is inserted into the drill pipe body to plug the welding hole, so there are many production processes, the welding quality is difficult to guarantee, and the production efficiency is low

Images