Laser welding multifunctional negative pressure gas protection device and method

Abstract

The invention discloses a laser welding multifunctional negative pressure gas protection device and method. During small-batch multi-variety laser welding, the problems that production efficiency is seriously affected since tools are repeatedly replaced, air holes are likely to be produced, forming is not uniform, and fusion depth loss is serious in the welding process are prominent. The device comprises a negative pressure fence (1), an isolation separation bin (2) is installed in the negative pressure fence, the rear side of the isolation separation bin is provided with a tail drag cover (3), two air inlet pipes (4) are installed above the tail drag cover, one side of the negative pressure fence is provided with a direct protection channel air inlet pipe (15), the isolation separation bin is of a square cylindrical solid structure in the appearance and forms an angle of 20-50 degrees with the vertical direction, a compressed air injection air chamber (8), a gradual transition structure (9) and a straight air outlet (10) are sequentially arranged above the interior of the isolation separation bin, and a direct conveying type gas protection channel (11) is arranged below the interior of the isolation separation bin and communicates with a separation bin air inlet hole (12). The device is used for laser welding multifunctional negative pressure gas protection.

Description

Technical field: [0001] The invention relates to the technical field of welding equipment, in particular to a laser welding multifunctional negative pressure gas protection device and a protection method. Background technique: [0002] At present, when small-batch multi-variety laser welding production is carried out in the industry, a prominent problem is that the production efficiency is seriously affected by repeated tooling changes. The welding process is extremely unstable, and it is prone to porosity, uneven forming, and serious loss of penetration. When laser welding titanium alloy, aluminum alloy, stainless steel, carbon steel, high-strength steel and other materials, in order to avoid the performance degradation of the weld due to high temperature oxidation, it is necessary to take certain protective measures. At present, it is most common to apply the front gas protection of the weld. , Effective protection methods; [0003] Because when welding different plate thickness...

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Problems solved by technology

[0003] Because for laser welding of different plate thicknesses, there are generally large differences in the gas protection methods at the front of the weld. For example, when welding 3~8mm medium and thick plates, due to the large energy output, large weld width, and slow cooling speed , generally adopt the dragging hood gas shielding form with a large protection range and uniform air flow, but when welding thin plates below 2mm, due to the large shielding gas flow in the dragging hood gas shielding form, the cooling speed of the melting zone is too fast and the fluidity becomes poor , it is easy to cause burn-through or uneven welding leakage during the welding process, so only straight-tube gas shielding can be used; in addition, when the thickness of the weldment is more than 8mm, high-power or even 10,000-watt-level ultra-high-power laser welding is used. Due to the excessive thermal energy conversion effect and the strong interference of plasma plume and metal vapor, the welding process is extremely unstable, and welding problems such as porosity, uneven forming, and serious loss of penetration depth are easily to be solved.

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