Stir friction welding method for hollow aluminum extruded section splicing arc plate

Abstract

The invention discloses a stir friction welding method for a hollow aluminum extruded section splicing arc plate, and belongs to the field of welding method of a large arc roof plate component of an aluminum alloy car body of a railway passenger car. For stir friction welding of the aluminum alloy car body roof arc plate component of the railway passenger car, and a welding sequence of one-step reversed assembling and two-step forward assembling and a control method for weldment assembly interval values are proposed; a thickened protrusion is arranged on the position, adjacent to a weld seam,of the outer surface of the aluminum alloy hollow extruded section, the protrusion width and the diameter of the root of a stirring needle are maintained at a ratio of 95% to 105%, in order to ensurethe size of a post-weld workpiece, during the two-step forward assembling, when pre-fabrication reverse deformation friction stir welding is conducted, a thickened raised metal is filled in the gap generated at the weld seam of the outer surface of the pre-fabrication deformed curved section aluminum alloy hollow extruded section by the rotary extrusion of a stirring head, and the friction stir welding does not require additional raised metal grinding removal work; the method ensures the structural size requirement of aluminum alloy product components of the curved section hollow extruded section.

Description

technical field [0001] The invention belongs to the field of welding methods for large-scale arc roof plate parts of aluminum alloy car bodies of rail passenger cars, and in particular relates to a friction stir welding method for assembling arc plates of hollow aluminum profiles. Background technique [0002] Such as figure 1 and figure 2 As shown, the roof arc plate 1 of the aluminum alloy car body of a rail passenger car is usually formed by symmetrical splicing and welding of two outer plates 1-1, two double-side connecting plates 1-2 and one middle plate 1-3. The splicing position of any two adjacent plate parts of the large arched integral part forms two upper and lower weld seams that need to be welded. A total of five arc panels used are hollow aluminum alloy extruded profiles. This type of profile has an upper arc panel a, a lower arc panel b, and a sandwich cavity c separated by multiple sets of ribs. When the roof arc plate 1 is manufactured, all the upper arc...

AI Technical Summary

Problems solved by technology

[0008] For the friction stir welding of the long parts of the aluminum alloy car body hollow aluminum profile roof arc plate of the arc-shaped section rail passenger car, the gap between the workpieces is increased due to the dual effects of the vertical pressure of the friction stir head and the welding deformation of the curved surface. Large or even exceed the allowable requirements of the process, thereby reducing the welding quality and even leading to the technical problem that the friction stir welding cannot be implemented, and in order to solve the existing friction stir welding compensation method that increases the raised filler, the width L of the raised structure must be greater than the shaft shoulder radius R, so that additional follow-up grinding process is required to remove residual protrusions. This grinding process is not only time-consuming and labor-intensive, but also has the risk of grinding damage to weld seams and components. The invention provides a hollow aluminum profile spliced ​​circular arc plate friction stir welding

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