Angle Sensor Blind Hole Hermetic Seal Moisture Protection
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Solution Overview
Problem
Existing angle sensors used in vehicle chassis control systems are prone to errors and have a short service life due to moisture ingress, which damages the evaluation circuit and renders them inoperable, especially when exposed to dirt and moisture from the road.
Innovation Solution
The angle sensor is designed with two sensor elements, where one has a blind hole for rotatable mounting of the other, creating a hermetic seal that protects the evaluation circuit from moisture, and includes a magnetic field transmission system with materials like plastic and metal for durability and low friction, using additives like Teflon to reduce wear and friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the angle sensor is exposed to the road environment to detect wheel position, then measurement functionality is achieved, but moisture and dirt ingress damage the evaluation circuit and reduce service life
Solution Approach 1:
The angle sensor is divided into two separate sensor elements: a first sensor element containing the evaluation circuit and a second sensor element containing the transmitter magnet. This segmentation allows the first sensor element to be hermetically sealed and protected from moisture while the second sensor element can rotate freely to detect wheel position, thus resolving the contradiction between reliability and environmental exposure
Solution Approach 2:
The second sensor element is rotatably mounted within a blind hole of the first sensor element, creating a nested structure. The blind hole acts as a hermetic seal that protects the evaluation circuit in the first sensor element from moisture ingress while allowing the nested second sensor element to rotate and perform measurements, thereby protecting sensitive components while maintaining functionality
2Measurement precision
If the evaluation circuit is directly exposed to the magnetic field for measurement, then measurement accuracy is improved, but moisture damage to the circuit reduces reliability
Solution Approach 1:
By separating the evaluation circuit into its own hermetically sealed first sensor element, the circuit can maintain close proximity to the magnetic field for accurate measurement while being protected from moisture damage, thus simultaneously achieving measurement precision and reliability
Solution Approach 2:
The blind hole structure acts as an intermediary that allows magnetic field transmission while providing hermetic protection. The magnetic field can pass through the blind hole to reach the evaluation circuit, but the blind hole wall prevents moisture from reaching the circuit, thus mediating between measurement requirements and protection needs
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 design significantly extends the service life of the angle sensor by preventing moisture damage and improving measurement accuracy through a protected evaluation circuit and reduced wear, while allowing for cost-effective manufacturing.
Implementation Method 1
This physical field is preferably a magnetic field because it can pass through common housing materials such as plastic or metal and can thus be received in the first sensor element
Implementation Method 2
The blind hole itself insulates an interior of the corresponding sensor element in which the blind hole is formed from the moisture, so that the moisture cannot penetrate into the interior
Implementation Method 3
using additives like Teflon to reduce wear and friction
Data Source
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AI summary
The invention relates to a method for manufacturing an angle sensor (16) for detecting a rotation angle (18) based on a relative angular position of a physical field (32), comprising a first sensor element (26) and a second sensor element (36) between which the physical field (32) is transmissible, wherein the first sensor element (26) comprises a blind hole (34) in which the second sensor element (36) is rotatably mounted, comprising the process steps of providing the second sensor element (36) and overmolding the second sensor element (36) with a material for forming a housing (26) for the first sensor element (26).