Magnetic Shield for Position Sensor Foreign Substance Adsorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position detecting devices for seat sliding systems are prone to erroneous detection due to foreign substances being attracted by the magnetic force and adhering to the housing, leading to contact sounds or abrasion, and increased manufacturing costs from using cover members to prevent such issues.
Innovation Solution
A position detecting device with a magnet, magnetic sensor, and a magnetic shield having a magnetic gap between the magnet and the shield, where the magnetic shield is disposed on the second magnetic pole side, effectively shielding the magnetic flux and preventing foreign substance adsorption, while maintaining high detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cover member is provided to prevent foreign substance adsorption, then reliability is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The harmful magnetic flux is extracted and redirected through the magnetic shield to a specific path, separating it from the detection area. The magnetic shield takes out the problematic magnetic field lines and guides them through a designated route that does not interfere with foreign substances or detection accuracy.
Solution Approach 2:
The magnetic shield acts as an intermediary element between the magnet and the external environment. It mediates the magnetic flux by providing a controlled path for magnetic field lines, preventing them from attracting foreign substances while maintaining detection functionality.
2Reliability
If a cover member is provided to prevent foreign substance adsorption, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The magnetic shield performs multiple functions simultaneously: it directs magnetic flux, prevents foreign substance adsorption, and maintains detection accuracy. This multi-functionality eliminates the need for separate cover members, reducing part count and manufacturing cost while improving reliability.
Solution Approach 2:
The magnetic shield combines the functions of magnetic flux management and foreign substance prevention into a single component. By merging these functions, the design eliminates the need for additional cover members, thereby reducing manufacturing complexity and cost.
3Ease of operation
If the detection target pushes and opens the cover member, then detection function is achieved, but contact sound and abrasion occur
Solution Approach 1:
The mechanical interaction between the detection target and cover member is replaced by a magnetic field-based detection system. The magnetic shield directs magnetic flux to detect the presence and position of the target without requiring physical contact, thereby eliminating contact sounds and abrasion.
Solution Approach 2:
The magnetic shield serves as an intermediary that enables detection through magnetic flux redirection rather than mechanical contact. The detection target interacts with the magnetic field through the shield, eliminating the need for direct mechanical contact that produces harmful sounds and wear.
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 prevents foreign substance adsorption, enhances detection accuracy, and reduces manufacturing costs by minimizing the influence of disturbing magnetic fields and misalignment, thereby improving the reliability and efficiency of the position detection system.
Implementation Method 1
a magnetic shield that has a magnetic gap between the magnet and the magnetic shield, and that includes a magnetic material which is disposed on the second magnetic pole side of the magnet
Data Source
AI summary
A position detecting device includes: a magnet that has a first magnetic pole and a second magnetic pole; a magnetic sensor that detects a change in magnetic flux generated by a detection target which enters between the magnet and the magnetic sensor on the first magnetic pole side of the magnet; and a magnetic shield that has a magnetic gap between the magnet and the magnetic shield, and that includes a magnetic material which is disposed on the second magnetic pole side of the magnet.