Spring-Clip Housing Joint for EMC Shielding and Gap Tolerance

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Solution Overview

Problem

Existing solutions for electromagnetic compatibility (EMC) and electrostatic discharge (ESD) protection between die cast housing parts of electronic control units (ECUs) are complicated and costly, and struggle to accommodate manufacturing tolerance variations.

Innovation Solution

A resilient spring-clip joining element with pairs of jaws that self-position and engage housing parts, increasing gripping force to secure them together, thereby providing EMC/ESD protection while allowing for variations in gap sizes between parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complicated EMC/ESD protection solutions such as gaskets with embedded metal elements and screw fasteners are used, then electromagnetic compatibility and electrostatic discharge protection are improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
ImproveEMC/ESD protectionVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions (EMC protection, ESD protection, mechanical joining, and gap compensation) into a single spring-clip joining element. The resilient engagement elements simultaneously provide electrical contact for EMC/ESD protection and mechanical securing of housing parts, eliminating the need for separate gaskets and fasteners.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The joining element serves multiple purposes: it provides mechanical fastening through resilient engagement, maintains electrical continuity for EMC protection, offers ESD mitigation through conductive pathways, and compensates for manufacturing gaps through its spring mechanism. This multi-functional design replaces several specialized components with one universal element.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If gaskets with embedded metal elements and screw fasteners are used, then electromagnetic compatibility and electrostatic discharge protection are improved, but manufacturing cost increases

Engineering Contradiction:
ImproveEMC/ESD protectionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent combines multiple functions (EMC protection, ESD protection, mechanical joining, and gap compensation) into a single spring-clip joining element. The resilient engagement elements simultaneously provide electrical contact for EMC/ESD protection and mechanical securing of housing parts, eliminating the need for separate gaskets and fasteners.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring-clip joining element appears to be a cost-effective alternative to expensive gaskets with embedded metal elements. By using a simpler resilient mechanism with integrated conductive features, the solution reduces material costs while maintaining protective functions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If rigid joining methods are used, then structural stability is improved, but adaptability to manufacturing tolerance variations deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidgap compensation
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent employs resilient engagement elements that can dynamically adjust to varying gap sizes between housing parts. The spring mechanism allows the joining element to flex and adapt to manufacturing tolerances while maintaining secure engagement and electrical contact, unlike rigid fasteners that require precise alignment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The resilient nature of the engagement elements allows the joining system to change its physical parameters (engagement force, position) in response to varying gap conditions. This enables the same joining element to effectively accommodate different manufacturing tolerances without compromising structural stability.

Inventive Principle:
Principle #35Parameter changes

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 simplifies the assembly process, reduces material costs, and ensures effective EMC/ESD protection by aligning and securing housing parts with a self-adapting M-shaped configuration that maintains closure and resistance to environmental factors.

Implementation Method 1

a resiliently biased joining element, or spring-clip... the first pair of engagement elements receives and engages with the first part of the housing by a first engagement force, and the second pair of engagement elements receives and engages with the second part of the housing by a second engagement force

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4478847A1Joining element for a housing
Publication Date: 2024.12.18 APTIV TECHNOLOGIES AG
  • EP4478847A1 patent drawingFigure 1~2
  • EP4478847A1 patent drawingFigure 3~4
  • EP4478847A1 patent drawing

AI summary

A joining element (21), such as to provide electromagnetic shielding of assembled halves (11, 12) of an electronic control unit (10). The element (21), e.g. formed as one elongate and continuous piece from spring steel, comprises a first pair of resilient elements (22) for receiving a first half (12) of the housing, and a second pair of resilient elements (24) for receiving a second half of the housing. The elements act as jaws to position and secure the parts in aligned configuration and bridge any gap/variations in the respective adjoining edges.