The oxygen sensor is a measuring element that uses ceramic sensing elements to measure the oxygen potential in various heating furnaces or exhaust pipes, calculates the corresponding oxygen concentration based on the principle of chemical equilibrium, so as to monitor and control the air-fuel ratio of combustion in the furnace, and ensure that the product quality and exhaust emissions meet the standards. It is widely used in the atmosphere control of various coal combustion, oil combustion, gas combustion and other furnaces. Sensors require metal encapsulation welding, and the quality of welding has a significant impact on the application of sensors. Let's take a look at the technical application of laser welding machine in welding oxygen sensors.
The wall thickness of the oxygen sensor base is 5-12mm, and the shell thickness of the catalytic converter body is generally 1mm - 2mm. There is a large difference between the two thicknesses. The existing welding process uses arc welding welding to form the shell. In the production process, too much current is likely to cause leakage welding of the catalytic converter shell, and too little current causes insufficient connection strength of the oxygen sensor. Therefore, laser welding technology can be selected. The laser welding machine uses fiber laser, and the laser adopts an integrated structure, It has the functions of safety protection and environmental protection, combined with a fully enclosed welding cabinet, with a compact structure and high integration. The gantry welding module is equipped with a multi-dimensional adjustable laser welding head, a two-dimensional horizontal CNC high-precision workbench, and specialized fixtures to complete the precision welding requirements.
Laser welding machine application in welding oxygen sensors
1.The laser welding machine should minimize welding spatter as much as possible.
The oxygen sensor base is welded to the catalytic converter body, where the weld seam is very sensitive to welding spatter. On the one hand, the welding slag generated by welding adheres to the oxygen sensor base and surrounding areas, which may affect the accuracy of sensor signal transmission. On the other hand, the catalytic converter body is a closed cylindrical structure. If there is welding slag splashing inside the catalytic converter shell, it cannot be automatically discharged, and manual cleaning is also difficult to operate, The residual welding slag poses a hidden danger to the service life and NVH performance of the catalyst.
2.The welding seam should ensure the connection strength and high air tightness requirements.
The catalytic converter assembly becomes a gas processing device, and the overall connection strength and airtightness requirements of the assembly are high. The welding seam between the oxygen sensor base and the catalytic converter body also has connection strength and airtightness requirements. The thickness of the oxygen sensor base is generally 6-12mm, and the thickness of the catalytic converter body shell is generally 1.5mm-2mm. There is a significant difference in thickness between the two, so the welding process window selection is very narrow. Current fluctuations, differences in welding surface conditions, and fluctuations in welding gaps can all cause defects such as welding leakage in the catalytic converter shell.
The above is the technical application of laser welding machine in welding oxygen sensors. Automatic laser welding equipment is suitable for welding and processing automotive sensors, which not only ensures the quality of sensor welding but also improves processing efficiency. The oxygen sensor catalytic converter body is the most important component for achieving the performance of the catalytic converter assembly. The quality requirements of the parts are high, and the cost of individual parts is high. Enterprises pay high attention to the quality and qualification rate of the parts.
