Magnetic Sensor Resin Cushioning Thermal Stress
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Solution Overview
Problem
Conventional rotation angle sensors face issues such as thermal deformation of resin spacers or molded components, making it difficult to maintain magnetic sensitive element characteristics, separate motor control circuits, increase terminal count, and lack sensitivity optimization and heat management, leading to potential corrosion and manufacturing challenges.
Innovation Solution
The solution involves using an elastic member around magnetic sensitive elements, integrating motor control circuits with magnetic sensitive elements, forming power and ground conductors into branches, optimizing arc-shaped magnets and yokes, exposing resin-molded components for ventilation, and insert-molding conductors to reduce terminal count and improve positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If resin spacers or molded components are used to install magnetic sensitive elements, then ease of manufacture is improved, but thermal deformation occurs causing deterioration of magnetic sensitive element characteristics
Solution Approach 1:
A resin layer is introduced as an intermediary substance between the magnetic sensitive element and the stator core. This resin layer serves as a stress-absorbing medium that prevents deformation stress from being transmitted to the magnetic sensitive element, thereby maintaining element characteristics while still using resin-based mounting methods for ease of manufacture.
Solution Approach 2:
The resin layer is applied beforehand to the stator core or mounting surface to create a cushioning layer that absorbs thermal expansion and contraction stresses. This pre-established protective layer prevents stress transmission to the magnetic sensitive element during temperature variations, ensuring characteristic stability.
2Ease of repair
If motor control circuits are formed as separate components, then ease of repair is improved, but inspection capability during manufacturing is reduced
Solution Approach 1:
The motor control circuit and magnetic sensitive element are integrated into a single functional unit or module. This merging allows for simultaneous inspection of both components during manufacturing while maintaining the ability to replace the entire module as a unit for ease of repair, eliminating the need for separate inspection processes.
3Device complexity
If commonality of terminals is implemented to reduce terminal count, then device complexity is reduced, but wiring arrangement flexibility is limited
Solution Approach 1:
Terminal structures are designed with multi-functionality to serve both power source and ground functions. The terminal design allows a single terminal structure to fulfill multiple electrical functions, reducing the overall terminal count while maintaining the necessary wiring flexibility through configurable connection arrangements.
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
This configuration enhances the stability of magnetic sensitive elements, improves detection accuracy, reduces terminal count, and prevents corrosion by managing thermal stress and heat, while maintaining efficient sensor operation.
Implementation Method 1
The Hall elements are mounted in the magnetic detecting (passing) gap of the stator... The Hall elements installed in the magnetic detecting gap are adapted to sense the magnetic flux which is varied by the rotation of the throttle shaft
Data Source
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AI summary
At the present invention, after the periphery of the magnetic sensitive element (33,34) is surrounded by an elastic member (32G), the magnetic sensitive element (33,34) is mold-formed with resin material. Soft epoxy or gel resin is employed as the elastic member (32G), poured in an element-mounting space and solidified. The magnetic sensitive element (33,34) is surrounded by silicone rubber. Such construction allows the magnetic sensitive element (33,34) not to be affected by vibration and allows the elastic member (32G) to absorb the stress which is created due to the thermal deformation of the molded resin (30).