Spring Stress Inspection Under Load Using X-Ray Diffraction
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Solution Overview
Problem
Existing methods fail to accurately evaluate stress distribution in springs under load, particularly due to insufficient consideration of shape changes and residual stress, which is crucial for weight reduction in automotive parts.
Innovation Solution
A method involving applying a load to the spring, measuring stress using X-ray diffraction with the cos α method, and determining if the measured stress meets predefined criteria to ensure accurate stress distribution under load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the finite element method is used to simulate stress distribution under assumed load, then the stress caused by spring shape can be inspected, but the residual stress from shot peening and actual stress under load cannot be accurately evaluated
Solution Approach 1:
The patent replaces the mechanical simulation approach (finite element method with assumed loads) with a non-destructive inspection method using X-ray diffraction to directly measure residual stress on the spring surface. This substitution allows actual stress measurement under various load conditions without requiring complex simulations or destructive testing, thereby improving both measurement precision and product evaluation reliability.
Solution Approach 2:
The patent introduces an intermediary measurement system (X-ray diffraction inspection apparatus) that acts as a mediator between the spring product and the evaluation process. This intermediary enables indirect measurement of stress distribution under load by measuring lattice plane inclination changes, allowing accurate stress evaluation without directly interfering with the spring's functionality or requiring destructive sampling.
2Measurement precision
If destructive inspection is used to measure residual stress after shot peening, then residual stress can be inspected, but the spring cannot be used and stress under load cannot be evaluated
Solution Approach 1:
The patent replaces destructive mechanical inspection methods with non-destructive X-ray diffraction measurement. This substitution allows residual stress to be measured accurately while preserving the spring for actual use, thereby maintaining production efficiency and enabling subsequent load-based stress evaluation that was impossible with destructive testing.
Solution Approach 2:
The inspection method enables the spring to essentially inspect itself for stress distribution issues without requiring external destructive sampling. The X-ray diffraction technique measures the spring's own lattice structure changes under load, allowing the product to be evaluated in its actual service condition without being removed from the production flow or sacrificed for testing.
3Weight of moving object
If the spring shape is changed to reduce weight, then weight reduction is achieved, but stress distribution becomes complex and difficult to inspect
Solution Approach 1:
The patent replaces complex mechanical stress analysis methods with X-ray diffraction measurement, which directly measures lattice plane inclination changes caused by stress. This substitution works regardless of spring shape complexity, enabling accurate stress distribution measurement on weight-reduced springs with optimized geometries that would be difficult to analyze using traditional finite element simulation or mechanical testing methods.
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
Enables the production of springs with verified stress distribution under load, facilitating stable weight reduction and quality assurance.
Implementation Method 1
measuring the stress on a surface of an active part of the spring using X-ray diffraction with cos α method
Implementation Method 2
measuring the stress on a surface of an active part of the spring using X-ray diffraction with cos α method
Data Source
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AI summary
Provided is a method of manufacturing a spring for inspecting the stress distribution of the spring under load. The method for manufacturing a spring (1) includes the steps of applying a load to the spring (1), measuring the stress of the spring (1) under the load, and releasing the load applied to the spring (1), the measuring the stress of the spring (1) being made by measuring the stress on the surface of the active part of the spring (1) using X-ray diffraction with the cosα method, and the method further including the step of determining whether the magnitude of the stress of the spring (1) meets a criterion.