Laser welding robot is a kind of welding equipment that heats the workpiece surface in a narrow area when focusing the laser beam on the workpiece surface, and connects two workpieces by melting the workpiece and slightly solidifying. The robot is equipped with laser welding head, which can realize high-precision welding in three-dimensional space environment.
The welding process of laser welding robot roughly includes the following steps:
1. Preparation work: Conduct pre-treatment such as deburring, polishing, and cleaning on the workpiece, and set welding procedures and parameters.
2. Establish welding position: Use the robot's coordinate system to determine the accurate position of the parts to be welded.
3. Positioning welding head: The robot accurately positions the welding head to the position to be welded according to the set welding program.
4. Welding: The robot focuses a laser beam on the weld seam, heats the surface of the workpiece to melt, and acts on the metal to metal connection. During the welding process, robots use lasers to monitor and track the weld seam, in order to achieve accurate welding.
5. Cooling: The robot stops laser irradiation and cools down to quickly cool the welding area to achieve a stable connection state.
6. Complete relevant work: After the welding is completed, the robot removes the welding head and carries out subsequent related work, such as cleaning the welding head and recording welding data.
In a word, laser welding robot can realize high-precision and high-efficiency welding by carrying laser welding joints. The main principle of this equipment is to use a laser beam to heat the weld seam, heating the metal to the melting point temperature in a short period of time, and achieving welding.
Principle and technology of Laser beam welding
Laser welding of metal materials is essentially a process of interaction between laser and non transparent substances. This process is extremely complex, and at the micro level it is a quantum process, while at the macro level it manifests as phenomena such as reflection, absorption, melting, and vaporization. Laser welding can be realized by continuous or pulsed laser beam. The principle of laser welding can be divided into heat conduction welding and laser deep penetration welding. When the power density is less than 104-105 W/cm2, it is heat conduction welding, where the melting depth is shallow and the welding speed is slow; When the power density is greater than 105-107 W/cm2, the metal surface is heated and concave into "holes", forming deep penetration welding, which has the characteristics of fast welding speed and large aspect ratio.
During the interaction between laser and workpiece, there will be self oscillation effects, with periodic changes in the molten pool, small holes in the molten pool, and metal flow phenomena. The frequency of this oscillation is related to the parameters of the laser beam, the thermophysical properties of the metal, and the dynamic characteristics of the metal vapor. The periodic changes in the molten pool can result in two unique phenomena in the weld seam: one is a gas hole filled with metal vapor. Due to the periodic changes, the metal in the molten pool flows from front to back around it, and the disturbance caused by metal evaporation may cut off the waist of the small hole, causing the vapor to remain in the weld seam and form gas holes after solidification. The other is a periodic change in the depth of penetration at the root of the weld seam, This is related to the periodic changes of small pores.