Buckle Switch Magnetic Shielding for Hall Sensor Interference
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Solution Overview
Problem
Existing buckle devices with Hall element and magnet switches are prone to errors due to external magnetic field interference and require precise positioning, making them difficult to configure accurately.
Innovation Solution
A buckle device with a magnetic detector and magnet shielded by a frame and latch member, utilizing a shielding plate attached to the ejector that changes magnetic flux density, ensuring the switch operates reliably without external interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a Hall element and magnet are disposed adjacent to the buckle main body to detect latch state, then the latch state can be detected, but the Hall element is affected by external magnetic field interference
Solution Approach 1:
A shielding plate made of magnetic shielding material is introduced as an intermediary between the external magnetic field and the Hall element. The shielding plate selectively blocks external magnetic field lines while allowing the magnetic field from the detection magnet to reach the Hall element, thus protecting the sensor from interference without affecting the detection function
Solution Approach 2:
The magnetic shielding structure is designed to provide differential shielding: the shielding plate is positioned to block external magnetic fields from reaching the Hall element, while the detection magnet's field lines are routed to pass through to the Hall element. This creates localized magnetic field control where different regions have different shielding characteristics
2Measurement precision
If the magnet is positioned close to the Hall element to improve detection sensitivity, then detection accuracy improves, but the switch becomes sensitive to positional differences and difficult to configure
Solution Approach 1:
The shielding plate serves as a magnetic field mediator that shapes and directs the magnetic flux between the magnet and Hall element. By controlling the magnetic field distribution through the shielding plate's geometry and position, the system achieves stable detection characteristics that are less sensitive to small variations in component positioning
Solution Approach 2:
The shielding plate modifies the magnetic flux density distribution in the detection region. By adjusting the shielding plate's position, orientation, or geometric parameters, the magnetic field characteristics can be optimized to provide a broader acceptable range for component positioning while maintaining detection sensitivity
3Object-affected harmful factors
If a frame is added to surround the Hall element for magnetic shielding, then external magnetic field influence is reduced, but the device complexity increases
Solution Approach 1:
The shielding plate is integrated with the ejector mechanism, combining the magnetic shielding function with an existing mechanical component. This merging of functions eliminates the need for a separate shielding frame structure, reducing device complexity while maintaining magnetic field protection
Solution Approach 2:
Instead of a rigid frame structure, a thin shielding plate is used to provide magnetic shielding. This thin-film approach reduces structural complexity and material usage while effectively blocking external magnetic fields from reaching the Hall element
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 solution effectively restricts external magnetic field influence and simplifies configuration by minimizing positional sensitivity, ensuring accurate detection of the tongue plate's latch state without errors.
Implementation Method 1
A switch includes a magnetic detector which outputs a signal in accordance with a magnitude of magnetic flux density
Implementation Method 2
A magnet applies a magnetic field to the magnetic detector
Implementation Method 3
A shielding plate is attached to the ejector and interlocked with the ejector and which changes a magnitude of magnetic flux density applied from the magnet to the magnetic detector in accordance with a position of the ejector
Implementation Method 4
The magnetic detector and the magnet are magnetically shielded by at least the frame and the latch member which are made of a magnetic material
Data Source
AI summary
A buckle device includes a switch having a Hall element which outputs a signal in accordance with a magnitude of a magnetic flux density, a magnet which applies a magnetic field to the Hall element, and a shielding plate which is attached to an ejector so as to change the magnitude of the magnetic flux density transmitted from the magnet to the Hall element in accordance with a position of the ejector. The Hall element and the magnet are magnetically shielded by at least a frame and a latch member which are formed of a magnetic material.