Welding method at the door of bus side wall frame

Abstract

The invention relates to a welding method at the door of a bus side frame frame, which comprises the following steps: (1) a rectangular door frame is formed by four door posts and two door beams at the door of the bus side frame frame, and two of the four door posts are It is a group and arranged side by side on both sides of the door; (2) Two side-by-side door pillars are welded together by MIGA welding. The welding wire is H08Mn2SiA, the diameter of the welding wire is 1.2mm, the flux is HJ330, and the shielding gas is H08Mn2SiA. : 98% Ar+2% O2, welding bead length 500mm, spacing 100mm, welding current 140A, arc voltage 20V, gas flow 10L / min; The column is heated, the heating temperature is controlled at 300-350°C, the duration is 8-15 seconds, and then the two side-by-side door columns are heated with a spray gun at intervals of 4-8 seconds, 10-15 seconds, and 20-25 seconds. The method can avoid welding deformation and ensure the strength and installation of the car door.

Description

technical field [0001] The invention belongs to the technical field of welding, and in particular relates to a method for welding a door of a side frame of a bus. Background technique [0002] Metal welding refers to a connection method in which two separated metal objects are connected by atomic (molecular) bonding by appropriate means. At present, there are more than 40 kinds of metal welding methods, including fusion welding, pressure welding and brazing. [0003] Fusion welding is a method in which the workpiece interface is heated to a molten state during the welding process, and the welding is completed without pressure. During fusion welding, the heat source rapidly heats and melts the interface of the two workpieces to be welded to form a molten pool. The molten pool moves forward with the heat source, and after cooling, a continuous weld is formed to connect the two workpieces into one. In the fusion welding process, if the atmosphere is in direct contact with th...

AI Technical Summary

Problems solved by technology

However, due to many factors affecting welding quality, for example: different types of shielding gas and welding wire have different effects on arc state, electrical characteristics, thermal effect, metallurgical reaction and weld formation, etc., and the length of bead and welding parameters will also affect welding. The result has a great influence; therefore, welding may seem simple, but it is not. To ensure the quality of welding, many factors need to be considered comprehensively

[0005] The door of the side frame of the bus needs to be installed with a door, so the strength requirements for the door of the side frame of the bus are higher. The specifications of the existing rectangular tubes are small, and the strength of the door cannot be guaranteed after a single rectangular tube is welded.

In order to increase the strength of the door, either custom-made rectangular tubes with larger specifications, or use side-by-side rectangular tubes; however, the cost of customizing rectangular tubes is high, and the connection of two rectangular tubes after using side-by-side rectangular tubes is a big problem, because If the two rectangular tubes are not well welded, it will easily lead to welding deformation at the door. If the welding deformation cannot be controlled well, it will bring hidden dangers to the strength and installation of the door, and even affect driving safety.

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