Welding method of magnet thin-walled cylinder body in sealed housing assembly

Abstract

The invention provides a method for welding a thin-walled cylinder with a magnet sleeved inside in a seal housing component. The welding efficiency of the aluminum alloy thin-walled seal housing component can be obviously improved through the method, quality is stable, a connector is bright, fusion is even, and continuous and compact welding beads can be formed. According to the technical scheme, the method comprises the following steps that the butt joint positions of inner and outer housing welding joints are closely attached through a clamp, and annular welding joint pulse electron beam tack welding is carried out on the circumferential seam crossing of an assembled component; a deflection distance occurring to an electron beam caused by Lorentz force is compensated by an electron beam deflection angle; the total heat input amount of the electron beam is controlled with the impulse waveform of the pulse electron beam, the impulse waveform is steep in the front and gentle in the back, and welding is carried out through heat generated when beam flow ascends and descends; under the condition that small pulse power is set and steam pressure is reduced, a pulse back edge is prolonged by 3-5s, slow reduction is carried out, the focal position of the electron beam is adjusted to be within the range 0.55mm below the surface of a workpiece, the surface of a connector to be welded is melted and integrally welded, and the continuous welding beads are formed.

Description

technical field [0001] The invention relates to a welding method for a thin-walled cylindrical body with a magnet set inside a sealed shell assembly, and particularly requires a sealing product with high pressure resistance and low leakage rate, and a welding method for a sealed shell assembly with a magnet inside. Background technique [0002] The aluminum alloy thin-walled sealing shell is a typical high-pressure sealing product in the fuel measurement and control system, and its manufacturing accuracy directly affects the important characteristics of the fuel measurement and control system. Therefore, there are strict requirements for the connection of the housing components. Generally, there are two processing methods for the connection of sealed shell components: brazing and fusion welding. As the last process, there is no residual processing after welding, so the control of welding deformation is strictly required, and the weld seam is not allowed to penetrate the sea...

AI Technical Summary

Problems solved by technology

This kind of sealed shell assembly with a wall thickness of only 0.5mm adopts vacuum electron beam sealing welding. The vacuum electron beam welding equipment is not only expensive and complicated, but also the problem of air holes in welding is difficult to solve

The conventional welding method adopts brazing. The output heat of brazing is too large, the heat-affected zone is too wide, the welding deformation is serious, and the coaxiality cannot be controlled within 0.05mm. It is difficult to meet the use requirements and it is difficult to effectively control the welding quality from the process parameters Control, can not fundamentally avoid welding deformation, resulting in parts scrapped

Due to the magnets installed inside the sealed shell assembly, the conventional electron beam welding method is used, and the electron beam is easily affected by the Lorentz force in the magnetic field, causing displacement and deviation from the weld; in addition, the electron beam power density is too high and the penetration force is too strong 1. If the energy is too concentrated, the surface is likely to be not uniform enough, and the surface of the last 1 / 3 section of the weld has a concave defect. The main reason for this defect is that the shell is too thin, the heat capacity is relatively small, and the welding time is different during the welding process. The temperature rise of the section parts is very different, especially in the last 1 / 3 section of the welded girth weld. Due to the heating of the electron beam welding process and the heat conduction of the weld in the previous section, the temperature rise of the parts is already high, and the melting amount of the weld metal is relatively the first 2 The / 3 section is larger, and the welding seam is wider than the first 2 / 3 section and forms depressions of different depths, resulting in serious deformation of the parts after welding, and the coaxiality cannot be controlled within 0.05mm. When the welding depth exceeds the seam line It is very easy to have local burn-through and welding leakage, which will cause the parts to be scrapped.

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