IC Tag Displacement Detector for Fastener Loosening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting loosening of fasteners, such as bolts and nuts, are inefficient due to reliance on visual inspection, operator proficiency, or costly equipment like strain gauges and ultrasonic sound waves, which face challenges with accessibility, environmental durability, and accuracy.
Innovation Solution
A displacement detection system utilizing IC tags for non-contact communication, where a first member and a second member with IC tags and blocking members detect relative movement or rotation, allowing for easy and stable detection of loosening without the need for direct contact or complex calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If visual inspection with paint markings is used to detect loosening, then the detection method is simple, but it is extremely difficult to perform inspection when the bolt is located where it is difficult to access visually and the paint may come off due to weather or temperature changes
Solution Approach 1:
The patent replaces the mechanical/visual marking system with a magnetic field-based detection system. A magnet is attached to the bolt head and a magnetic sensor detects the magnet's position and orientation. This substitution eliminates the need for paint markings that can come off, enabling reliable detection even in hard-to-reach locations while maintaining operational simplicity through automated sensing.
2Ease of manufacture
If hammering method is used to detect loosening, then the detection can be performed without special equipment, but the determination depends on operator proficiency and experienced operators may still make errors
Solution Approach 1:
The patent replaces the manual hammering method with an automated magnetic field detection system. The magnetic sensor objectively measures the magnet's position and orientation on the bolt head, eliminating subjective human judgment. This provides precise, repeatable measurements of loosening without requiring operator expertise or physical contact with the fastener.
3Reliability
If strain gauge is attached to fastener for detection, then stable detection of loosening is achieved, but calibration by tensile tester is required after attachment which consumes much time and effort
Solution Approach 1:
The patent replaces the strain gauge method with a magnetic field-based detection system. Instead of requiring mechanical calibration with a tensile tester, the system uses a magnet attached to the bolt head and a magnetic sensor to detect position and orientation changes. This eliminates the time-consuming calibration process while maintaining reliable detection of loosening through objective magnetic field measurements.
4Reliability
If ultrasonic sound wave method is used to measure axial force, then loosening can be detected stably, but the end surfaces of bolt head and opposite surface must be precisely flat and contact of predetermined period is required which increases inspection time and device cost
Solution Approach 1:
The patent replaces the ultrasonic sound wave method with a magnetic field-based detection system. Instead of requiring precisely flat end surfaces and contact-based ultrasonic probes, the system uses a magnet attached to the bolt head and a non-contact magnetic sensor. This eliminates the need for complex ultrasonic equipment and tedious surface preparation while achieving stable detection of loosening through magnetic field measurements.
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 reliable, non-contact detection of loosening in fasteners, reducing the risk of human error and environmental impact, while simplifying installation and operation, and providing cost-effective maintenance.
Implementation Method 1
Either one of the first member and the second member includes an IC tag for detection (35) performing non-contact communication with a peripheral device
Implementation Method 2
the other includes a blocking member (23, 26, 28) composed of an electrical conductor that blocks the communication performed by the IC tag
Data Source
AI summary
The present invention provides a displacement detector for a relative displacement of a fixed member and a movable member, which includes a first member and a second member. The first member is secured to the fixed member and composed of an insulator. The second member moves relative to the fixed member, integrally with the movable member. The second member is disposed opposite to the first member. The second member is composed of an insulator. Either of the first member and the second member includes an IC tag for detection performing non-contact communication, and the other includes a blocking member composed of a conductor blocking the communication performed by the IC tag. When the second member moves a predetermined amount relative to the first member, starting from an initial state, the IC tag for detection moves from inside to outside a region of the blocking member or vice versa.