Magnetic Sensor Housing Wave Joint for Tamper Detection

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Solution Overview

Problem

Magnetic field sensors in motor vehicles lack sufficient security against manipulation and data corruption, as existing designs can be opened or tampered with, compromising the reliability of speed measurements.

Innovation Solution

The magnetic field sensor features a non-detachable housing with wave contours on both parts, forming a crown structure joining connection that is difficult to saw open without visible damage, and includes press-welded or ultrasonic welding for enhanced security, along with housing material weakenings and a pin-pocket connection to prevent unauthorized access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the housing parts are joined by a simple connection method, then the manufacturing process is easier and less complex, but the tamper resistance and security against manipulation are insufficient

Engineering Contradiction:
Improvetamper resistanceVSAvoidjoining connection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies wave contours (curved geometric features) on the housing edges that form an interlocking joining wave contour. These curved features make it difficult to separate the housing parts without visible damage, as any cutting or prying attempt would disrupt the wave pattern and leave permanent marks on the housing surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The wave contours create an asymmetric joining structure where the first and second housing parts have complementary but non-identical features. This asymmetric design prevents simple separation while maintaining a relatively simple manufacturing process through standard molding techniques.

Inventive Principle:
Principle #4Asymmetry

2Reliability

If the housing parts are made separable for maintenance access, then the ease of operation and maintenance is improved, but the protection against unauthorized access and data corruption is compromised

Engineering Contradiction:
Improvedata integrityVSAvoidmaintenance accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent incorporates visible damage indicators directly into the joining structure itself. The wave contours are designed so that any unauthorized separation attempt automatically creates visible damage, providing preliminary protection by making tampering evident before it can compromise the data or components inside.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent uses visible changes in the housing structure (damage indicators) to signal tampering. When the wave contours are disrupted by unauthorized separation, permanent visible changes occur on the housing surface, providing a clear visual indication that the device has been compromised and should not be used.

Inventive Principle:
Principle #32Color changes

3Reliability

If a non-removable joining connection is used, then the protection against manipulation is enhanced, but the ease of repair and component replacement becomes difficult

Engineering Contradiction:
Improveanti-manipulation securityVSAvoidhousing repairability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The wave contours provide a balanced solution by creating a secure yet repairable joint. The curved interlocking features maintain strong mechanical bonding for security while allowing controlled separation by authorized personnel using appropriate tools, enabling repair without complete destruction of the housing.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design significantly enhances security by making manipulation attempts recognizable through visible damage, ensuring the integrity of speed measurements and preventing unauthorized access to the sensor's internal components.

Implementation Method 1

press-welded or ultrasonic welding for enhanced security

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Implementation Method 2

press-welded or ultrasonic welding for enhanced security

Methodology Applied
Scientific EffectPressure welding: Welding

Data Source

PatentEP3865829B1Magnetic field sensor with a device housing
Publication Date: 2024.08.14 CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
  • EP3865829B1 patent drawingFigure 1
  • EP3865829B1 patent drawingFigure 2
  • EP3865829B1 patent drawingFigure 3

AI summary

The invention relates to a magnetic field sensor comprising a device housing (1) with at least a first housing part (2) and a second housing part (4) that closes the first housing part (2), wherein the first housing part (2) and the second housing part (4) are joined in the direction of a longitudinal axis (L) of the device housing (1) and connected by means of a non-removable joining connection (6). To increase the protection of the magnetic field sensor against possible tampering, it is proposed that the first housing part (2) and the second housing part (4) each have a corresponding wave contour (8, 10), wherein the wave contours (8, 10) are formed in the direction of the longitudinal axis (L) of the device housing (1) and on a housing edge (12) of the first housing part (2) and on a housing edge (14) of the second housing part (4), respectively, and form a joining wave contour (16) in the joining connection (6).