Apparatus and method for monitoring resistance spot welding quality

Abstract

The invention belongs to a resistance spot welding quality monitoring device and a monitoring method in the field of metallic material resistance spot welding. The invention is characterized in that an independent displacement transducer, an independent electric pressure transducer, an independent current sensing device, an independent pressure transducer are arranged at different positions of a spot-welding equipment; the sensors are connected with a data acquisition analytic device. As the device adopts the method of diagnostic information extraction and the information integration during the course of spot welding, the quality of resistance spot welding can be monitored and determined on line; and the diagnostic information during the course of spot welding can be analyzed effectively. In addition, the diagnostic information abstracted has high signal to noise ratio, and distinct characteristics; and is stable. The resistance spot welding quality monitoring specimens abstracted have the advantages of expandability and so on, and can be widely used. The device is properly designed, and can be installed and maintained conveniently. Accordingly, the invention is highly practical; the implementation cost is low; and the invention can be promoted and applied easily.

Description

technical field [0001] The invention belongs to the field of resistance spot welding of metal materials, in particular to a resistance spot welding quality monitoring device and a monitoring method composed of multiple sensors and a data acquisition device. Background technique [0002] The resistance spot welding process is a highly nonlinear process with a large number of uncertain factors interacting with each other. Since the nucleation of resistance spot welding is in a closed state and cannot be directly observed, and the nucleation time is extremely short, short-term fluctuations in welding conditions will cause serious defects such as spattering, incomplete fusion or incomplete fusion. This is especially true for resistance spot welding of aluminum alloys. In actual production, due to the influence of many factors such as the change of the surface state of the workpiece, electrode wear, assembly clearance and disturbance of the mechanical structure, even if the prod...

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Problems solved by technology

However, this literature does not obtain universal characteristic information that can reflect the quality of resistance spot welding

[0006] (2) Constant heat or constant energy control method, which measures the electrode voltage and electrode current of resistance spot welding at the same time. Due to the high current of resistance spot welding, the electromagnetic induction noise is very large, although it can be realized by reducing the area covered by the twisted pair Noise reduction method, however, due to the limitations of the conditions of use in industrial applications, the area of ​​the twisted pair envelope cannot be reduced to a small size, resulting in serious signal distortion

As for how to use fewer sensors to obtain feature information that has a clear correspondence with spot welding quality to achieve spot welding quality monitoring, there is no good practical method in the prior art. At the same time, the stability and quality of resistance spot welding quality monitoring The scope of application cannot meet the practical requirements

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