Aluminum body self-piercing riveting quality control method based on force and displacement curve

Abstract

The invention discloses an aluminum body self-piercing riveting quality control method based on force and a displacement curve. A relationship standard curve of riveting force and punch displacement in the riveting process is built by experiments or simulation, and the variation trend of the riveting force corresponding to different riveting defects is acquired. Real-time detection is performed toobtain measured values of the punch displacement and the punch riveting force in the riveting process, and a current measured curve is drawn according to the measured values. The current measured curve is compared with the relationship standard curve, a riveting state is judged, and the punch riveting force of a riveting tool is controlled according to the riveting state. The force and displacement curve in the riveting process are monitored in real time, and riveting force values are controlled, so that the riveting force is kept within a reasonable range to ensure riveting quality.

Description

technical field [0001] The invention relates to a quality control method for self-piercing riveting of an aluminum body, in particular to a quality control method for self-piercing riveting of an aluminum body based on force and displacement curves. Background technique [0002] Self-piercing riveting refers to the connection process in which the rivet is pressed into the plate under the action of the punch to make it penetrate the upper plate, and under the joint action of the die and the lower plate, the rivet legs are opened to form a mechanical interlock. Riveting equipment includes blank holder, punch, hollow rivet, upper plate, lower plate and die; the riveting process is divided into four stages: [0003] The first is the clamping stage: the die is placed on the bottom of the lower plate, the blank holder is placed on the upper plate, and the upper plate and the lower plate to be riveted are pressed downward. At the same time, the rivet is vertically driven by the pun...

AI Technical Summary

Problems solved by technology

[0010] At present, the commonly used self-piercing riveting quality online detection methods mainly include: visual detection method, riveting point profile measurement method and mechanical testing method; the visual detection method is to use the camera to shoot the self-piercing riveting process, and after the grayscale processing of the captured image, read Among them, the luminance value of the key area is used to establish a luminance curve, and the algorithm is compared with the reference curve to judge whether the rivet is in the correct position. However, the visual inspection method can only identify the appearance defects of riveting, but cannot identify the internal quality defects of riveting; riveting point The profile measurement method is to cut the riveted joint along the radial direction of the joint, directly measure the parameter values ​​of LL, RL, R and H on the cutting surface, and evaluate the quality of the riveting based on this combined with the shape of the joint section. Obviously, this damage The property test cannot be applied to the real-time monitoring of riveting quality; the mechanical test method is to test the shear resistance of the joint through the tensile test, and to test the peeling resistance of the joint through the peel test; similarly, because the test process destroys the integrity of the riveted parts Cannot be used for real-time monitoring of riveting quality

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