Reinforced Flexible Connector Ends for Flake-Free Battery Pack Joining

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Solution Overview

Problem

Existing connectors for battery packs, particularly those used in electric vehicles, face challenges in achieving flexibility and sufficient strength due to the thin material thickness of multilayer metallic strips, leading to issues with connection reliability and the risk of metal flakes causing short circuits.

Innovation Solution

The use of reinforcing elements, such as sheets or flat conductors, at the ends of the metallic band to create a welding knot with the band's layers, enhancing the connection strength and preventing metal flakes by optimizing material usage and avoiding direct contact with joining tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If thermal joining processes are used to bond connecting elements to the metallic strip, then connection strength is improved, but metal flakes are created that can detach and cause short circuits

Engineering Contradiction:
Improveconnection strengthVSAvoidmetal flake detachment
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent replaces thermal joining processes with mechanical joining processes. Specifically, it uses cold pressing, crimping, or riveting methods to attach connecting elements to the metallic strip, thereby avoiding the thermal energy input that causes metal flake detachment while still achieving sufficient connection strength.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediate layer or interface structure between the connecting element and the metallic strip. This intermediate structure acts as a mediator that distributes mechanical stress evenly, preventing direct stress concentration that would cause metal flake detachment, while still ensuring reliable electrical and mechanical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If connection eyelets are inserted directly into the metallic strip material, then connection is achieved, but sufficient strength is not provided due to the extremely thin layers

Engineering Contradiction:
Improveconnection simplicityVSAvoidconnection strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent creates a composite structure consisting of the metallic strip, the connecting element (eyelet), and an intermediate reinforcement layer. This composite construction combines the electrical conductivity of the metallic strip with the mechanical strength of the eyelet and reinforcement layer, achieving both ease of manufacture and sufficient connection strength.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent adds a third dimension to the connection by introducing a reinforcement layer that extends beyond the plane of the thin metallic strip. This dimensional addition provides structural support and distributes loads across a larger volume, compensating for the insufficient thickness of the original strip material.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If cohesive joining processes are used to connect all layers together, then reliable connection is achieved, but considerable welding energy is introduced causing outer layers to tear off or burn

Engineering Contradiction:
Improvelayer connection reliabilityVSAvoidlayer damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the joining process into separate stages: first, the individual layers are connected to each other using low-energy mechanical joining methods; second, the connecting element is attached to the assembled layers. This segmentation avoids concentrating excessive energy in a single step, preventing layer damage while ensuring reliable connections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies joining force selectively only to the regions where connection is needed, rather than uniformly across all layers. The connecting element and reinforcement layer are positioned to distribute the joining action across multiple contact points, reducing the energy intensity at any single point and preventing localized overheating or damage.

Inventive Principle:
Principle #16Partial or excessive action

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 solution provides a flexible connector with increased pull-out force and secure, long-term stable contacting, preventing metal flakes and ensuring reliable connections without damaging the joining partners.

Implementation Method 1

The reinforcing element is thus arranged between the surface of the band and a sonotrode. This leads to the desired protection of the belt while at the same time optimizing the use of materials.

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Data Source

PatentEP3631898B1Flexible connector
Publication Date: 2023.12.27 AUTO KABEL MANAGEMENT GMBH
  • EP3631898B1 patent drawingFigure 1a~2c
  • EP3631898B1 patent drawingFigure 3a~3b
  • EP3631898B1 patent drawingFigure 3c~4

AI summary

The invention relates to a flexible connector comprising a multilayer metal strip (4) and at least one connection element which is arranged at at least one strip end (2), wherein the layers of the metal strip are bonded together in the region of the strip end, and a reinforcement element (6) is arranged at the strip end (2), said reinforcement element being bonded to the strip.