Metal Sheet Joint Structure for Reliable Electrical Contact

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Solution Overview

Problem

Existing structures using screws to fasten metal sheets for electrical connectivity risk losing connection if the screw loosens, leading to potential electrical disconnection.

Innovation Solution

A structure with protrusions and elastically deformable portions on adjacent metal sheets that ensure electrical contact through elastic deformation, eliminating the need for special fastening members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a screw is used to fasten the metal sheets together to ensure electrical connection, then the electrical connectivity between base materials is improved, but the reliability deteriorates if the screw loosens undesirably

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidfastening structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention divides the contact interface into multiple protrusions and corresponding recesses on different metal sheets. This segmentation creates multiple contact points that ensure electrical connectivity even if one contact point fails or loosens, thereby improving reliability without requiring complex fastening mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The protrusions and recesses are designed to automatically maintain contact through elastic deformation of the metal sheets. When sheets are stacked, the elastic properties cause the protrusions to naturally press against the recesses, creating self-maintaining electrical contact without requiring additional fasteners or complex assembly procedures.

Inventive Principle:
Principle #25Self-service

2Reliability

If multiple protrusions and elastically deformable portions are added to ensure electrical connection, then the electrical connectivity is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoidmetal sheet fabrication difficulty
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the physical parameters of the metal sheets by adding localized protrusions and elastically deformable portions. These structural modifications alter the mechanical and electrical contact properties, enabling reliable electrical connection through controlled elastic deformation and enhanced contact pressure at specific interfaces.

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

Maintains electrical connection between metal sheets even when fastening members loosen, preventing noise and leakage currents without requiring additional fasteners.

Implementation Method 1

a first elastically deformable portion provided on the first metal sheet in such a manner that the first elastically deformable portion surrounds a periphery of the first protrusion, the first elastically deformable portion being elastically deformable at the time of the fastening with the fastening member

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4730930A1structure
Publication Date: 2026.04.22 MITSUBISHI ELECTRIC CORP
  • EP4730930A1 patent drawingFigure 1A~1C
  • EP4730930A1 patent drawingFigure 2A~2B
  • EP4730930A1 patent drawingFigure 3A~3B

AI summary

A structure formed by placing a plurality of metal sheets (10, 20) one on another in a sheet-thickness direction, the plurality of metal sheets (10, 20) each having an electrically conductive base material covered with an insulating coating, the structure including: a protrusion (11) provided on a first metal sheet (10) of the plurality of metal sheets (10, 20) that are adjacent to each other and are fastened together with a screw (51), the protrusion protruding toward a second metal sheet (20); an elastically deformable portion (12) provided on the metal sheet (10) in such a manner that the elastically deformable portion (12) surrounds the protrusion (11), the elastically deformable portion (12) being elastically deformable at the time of the fastening with the screw (51); a protrusion (21) disposed on the metal sheet (20) in such a manner that the protrusion (21) protrudes toward the metal sheet (10), and crosses the protrusion (11); and an elastically deformable portion (22) provided on the metal sheet (20) in such a manner that the elastically deformable portion (22) surrounds the protrusion (21), the elastically deformable portion (22) being elastically deformable at the time of the fastening with the screw (51). The end of the first protrusion (11) and the end of the second protrusion (21) contact each other at the time of the fastening with the screw (51).