Method for detecting laser welding quality in real time

Abstract

The invention discloses a method for detecting laser welding quality in real time, The method comprises the following steps of acquiring a laser welding sound signal in real time by using a sound signal acquiring system and storing the laser welding sound signal; carrying out analytical calculation on the laser welding sound signal and a noise source signal by using a computer, separating a laser welding characteristic sound signal from a noise source, and acquiring a distribution diagram of sound pressure level strength of a space radiation sound field; filtering the interference from a light signal by using a weld pool pinhole monitoring system, shooting and storing a weld pool pinhole image; and overlaying the distribution diagram of the sound pressure level strength of the space radiation sound field into the weld pool pinhole image by using the computer, acquiring the sound pressure level strength and a weld pool pinhole state at a certain moment, comparing the sound pressure level strength and the weld pool pinhole state at the certain moment with preset sound pressure level strength and weld pool pinhole state under a normal welding condition so as to determine the laser welding quality. By using the method, the state of a pinhole is observed in real time, and the laser welding quality is improved.

Description

technical field [0001] The invention relates to the detection of laser welding quality, in particular to a method for real-time detection of laser welding quality. Background technique [0002] As an advanced connection technology, laser welding has the advantages of fast welding speed and good weld shape, and is widely used in various fields. However, the laser welding process is a very complex process of physical and chemical reactions, such as: the generation of small holes in the molten pool and laser plasma and its refraction, emission and absorption of laser light, etc. Changes in these factors have a great impact on the quality of welding. Moreover, after a long period of continuous welding, the deformation of the weldment caused by heat will lead to changes in the weld gap; under the influence of the thermal lens effect, the focus lens will also cause the focal length to change after being heated and deformed. Changes in these factors will affect the stability of la...

AI Technical Summary

Problems solved by technology

However, the acoustic signal generated by the laser is mainly due to the formation of small holes in the molten pool. Only the microphone array can be used to detect its quality problems to a certain extent, but the state of the small holes cannot be observed in real time, and after analysis, it is observed that The result is not intuitive, which has an impact on the detection of laser welding quality, and cannot guarantee the quality of laser welding

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