Feb 16, 2020
Laser welding equipment is mainly composed of laser welding room, laser generator (including cooling system), light guide system, welding machine and control system.
1. Laser welding room
The laser power applied to body welding is relatively large, and it will inevitably produce scattering, refraction and other phenomena during work, and even equipment failure, which is harmful to human bodies. Therefore, the general factory will build a closed welding room at the laser welding station, and the protection level must reach the US FDA laser safety standard Class 4 to prevent laser leakage from causing harm to the human body. When the laser beam is working, no one is allowed in the welding chamber.
2. Laser generator
There are two types of lasers used for laser welding: CO2 gas lasers and YAG solid-state laser generators.
The most important properties of a laser generator are output power and beam quality. From these two considerations, CO2 lasers have greater advantages than YAG lasers, and are currently the main lasers used in deep-melt welding. Most applications of CO2 lasers in production are still in the range of 1.5 to 6kW, but now the world's largest CO2 laser has reached 50kW. In the past, YAG lasers have had difficulty raising power for quite a long time. Generally, the power is less than 1kW, which can be used for micro-connection of thin and small parts. However, in recent years, foreign countries have made breakthrough progress in the development and production of high-power YAG lasers, the maximum power has reached 5kW, and has been put on the market. Due to its short wavelength, which is only 1/10 of the CO2 laser, it is beneficial for metal surface absorption, and can be transmitted by optical fiber, which greatly simplifies the light guide system. It can be expected that the high-power YAG laser welding technology will develop rapidly in the future and become a strong competitor of CO2 laser welding.
3. Light guide and focusing system
The light guide focusing system consists of circular polarizers, beam expanders, reflectors or optical fibers, focusing lenses, etc., to achieve the function of changing the polarization state and direction of the beam, transmitting the beam and focusing. The condition of these optical parts is extremely important to the quality of laser welding Impact. Under the action of high-power lasers, the performance of optical components, especially lenses, will deteriorate, reducing transmittance; thermal lens effects (shortening of the focal length of the lens due to thermal expansion); surface contamination will also increase transmission loss. Therefore, the quality, maintenance and working condition monitoring of optical components are very important to ensure the quality of welding.
4. Laser welding machine
Its role is to realize the relative movement between the beam and the workpiece, to complete the laser welding, divided into two special welding machines and general welding machines. The latter often uses numerical control systems, which have two-dimensional or three-dimensional welding machines with rectangular coordinates or articulated laser welding robots.