Laser welding is an efficient and precise welding method which uses laser beam with high energy density as heat source. Laser welding is one of the important applications of laser material processing technology. Welding process is heat conduction type, that is, laser radiation heats workpiece surface, surface heat conducts to the internal diffusion. By controling laser pulse width, energy, peak power and repetition frequency and other parameters, it can make the workpiece melting, the formation of a specific molten pool.
Laser welding is a non-contact welding method. The operation process does not need pressure, but inert gas to prevent oxidation of molten pool can be used some times. Filler metal is also occasionally used. Laser welding machine technology has been widely applied in high precision manufacturing fields such as automobiles, ships, airplanes, high-speed trains, etc., which has brought great improvement to people's quality of life and led the home appliance industry to enter the era of precise work.
Advantage analysis of Laser welding in the application of new energy vehicle motor stator:
One of the core components of new energy vehicles is the drive motor. In order to achieve the mass production of new energy vehicles, it is very necessary to improve the production efficiency and quality of the motor stator.
1. Traditional solutions
Motor stator is composed of silicon steel sheet by piled loading. Generally by welding method, several weld seams are welded on the overstew stator's outer cylindrical along the axial welding several weld, the silicon steel sheet can be firmly together. This is not only simple technology, but also increase insulation resistance between the stator silicon steel sheet, effective permeability section, thus improve the quality of the motor.
Traditional manual arc welding is rarely used because of the factors such as small arc heat but large heat-affected zone of weld, unsmooth weld, inability to realize automation and low efficiency. As to the tungsten argon arc welding, it is widely used because the arc has stability and good elasticity, no filling metal; it is easy to control welding parameters, has smooth and clean weld, no spatter and other factors. However, due to the high silicon content of silicon steel sheet, it is poor weldability, easy to crack after welding, and difficult to weld.
2. Laser welding solutions
Laser welding is to focus the laser beam of high power density output, make the spot small and energy concentrated, density high, so that the heating efficiency is fast and welding metal deformation is small. Because the silicon steel sheet is a kind of ferrosilicon alloy with higher silicon content and lower carbon content, its thermal conductivity is low, heat sensitivity is large, which is conducive to the rapid heating and melting with laser beam, so it can form a good joint weld.
The laser welding machine applied to the welding of the motor stator of new energy vehicles can realize the one-time welding of the whole motor stator. Compared with the traditional argon arc welding, the efficiency is 5-8 times higher, the weld quality is nearly perfect, and the heat affected zone is very small. The entire automatic laser welding unit can truly realize the stator assembly, compaction, laser welding and automatic blanking of the entire process of automatic completion. It greatly improves the production efficiency and quality of the motor stator of new energy vehicles, and finally provides a perfect solution for the realization of mass production and high-quality production of new energy vehicles.
