SPR Joint CT Inspection for Non-Destructive Quality Control
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Solution Overview
Problem
Existing methods for inspecting self-piercing rivet (SPR) joints in automotive components require destructive processes, leading to increased costs and scrap, and lack efficient, non-destructive quality control techniques.
Innovation Solution
A non-destructive computerized tomography (CT) scanning method and system are employed to inspect SPR joints, capturing high-resolution images without altering the assembly, allowing for precise measurement of dimensions and features like interlock, minimum thickness, and button height.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If destructive inspection methods (cutting, polishing) are used to inspect SPR joints, then measurement precision is improved, but productivity is worsened due to increased time and scrap
Solution Approach 1:
The patent replaces mechanical destructive inspection methods (cutting, polishing) with non-destructive electromagnetic radiation-based CT scanning. The CT system uses X-rays to capture three-dimensional images of the SPR joint internally, eliminating the need for physical destruction while maintaining inspection accuracy and significantly improving productivity by inspecting complete assemblies.
Solution Approach 2:
The patent creates a digital copy (three-dimensional image) of the SPR joint's internal structure through CT scanning. This virtual model allows for complete quality assessment without physically altering the actual joint, enabling repeated inspections of the same assembly and eliminating scrap generation.
2Measurement precision
If destructive inspection methods are used, then measurement precision is improved, but loss of substance is worsened due to increased scrap
Solution Approach 1:
The patent replaces mechanical destructive inspection with non-destructive CT scanning using electromagnetic radiation. This substitution preserves the complete assembly during inspection, eliminating the material waste associated with cutting and polishing operations while maintaining the ability to accurately assess joint quality.
Solution Approach 2:
The patent creates a digital replica of the joint's internal structure through CT imaging. This virtual copy enables thorough quality inspection without touching or altering the physical assembly, completely preventing scrap generation from destructive sampling.
3Measurement precision
If destructive inspection methods are used, then measurement precision is improved, but use of energy is worsened due to additional processing steps
Solution Approach 1:
The patent replaces energy-intensive mechanical processes (cutting, polishing, multiple imaging steps) with a single CT scanning operation. The CT system captures three-dimensional data in one process, eliminating the cumulative energy consumption of sequential mechanical preparation and multiple two-dimensional imaging operations.
Solution Approach 2:
The patent merges multiple inspection functions (cross-sectional viewing, dimensional measurement, defect detection) into a single CT scanning operation. This consolidation eliminates the need for separate cutting, polishing, and imaging steps, reducing total energy consumption while maintaining comprehensive quality assessment capabilities.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method provides accurate quality control with reduced scrap and cost, enabling efficient inspection of SPR joints without destruction, thus saving energy and resources.
Implementation Method 1
perform a computerized tomography (CT) scan of the joint
Data Source
Figure 1~1A
Figure 2
Figure 3~4
AI summary
A system and method for inspecting an assembly including components joined by self-piercing rivets by a computerized tomography (CT) scan of the joint is provided. The system includes a source of x-rays, a mounting unit for an assembly including the joint which is subject to the x-rays, and an x-ray detector disposed opposite the source for detecting the x-rays. The x-rays are provided at a high energy level of at least 200 kV to generate images having a resolution of at least 200 micrometers (μm). A computer stitches the images together to form reconstructive images which show details of the joint. The assembly to be inspected is not destroyed or modified prior to the inspection process. The resolution of the images generated by the x-rays is high enough to determine the presence of cracks, if any, the interlock (SH), minimum thickness (Tmin), and overall structure of the unmodified assembly.