Vehicle Power Connector with Copper Insert for Aluminum Conductor

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Solution Overview

Problem

In vehicle electrical systems, existing power connectors face challenges with weight savings due to high intrinsic weight of cables, particularly with aluminum materials that tend to cold flow and form oxidation layers, leading to increased contact resistance and connection instability over time.

Innovation Solution

A power connector design featuring a strip-shaped current conductor with a through-opening and a contact insert made of a mechanically stronger material, such as copper, which forms a material-bonded connection to prevent cold flow and oxidation, ensuring high fatigue strength and electrical conductivity through a screw or bolt connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If aluminum material is used for weight savings in vehicle electrical systems, then weight is reduced, but the material tends to cold flow and form oxidation layers, leading to increased contact resistance and connection instability

Engineering Contradiction:
Improveweight of cableVSAvoidconnection stability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The invention uses a composite structure consisting of an aluminum current conductor (for weight savings) and a copper contact insert (for reliable electrical connection). The copper insert is mechanically pressed into the aluminum conductor, creating a bimetallic composite that combines the advantages of both materials: aluminum provides lightweight construction while copper ensures low contact resistance and high connection stability.

Inventive Principle:
Principle #40Composite materials

2Reliability

If copper material is used for high mechanical strength and low oxidation, then connection reliability is improved, but weight increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidweight of cable
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention applies local quality by using copper specifically at the contact insert location where electrical connection reliability is critical, while the rest of the current conductor remains aluminum to maintain lightweight construction. This localized use of copper optimizes the connection interface without unnecessarily increasing the overall weight of the cable assembly.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If screw connection is used for simple assembly, then ease of manufacture is improved, but aluminum cold flow causes loosening over time

Engineering Contradiction:
Improveassembly simplicityVSAvoidconnection stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The copper contact insert acts as an intermediary between the screw connection and the aluminum current conductor. The screw connects to the copper insert, which has high mechanical strength and does not cold flow, while the aluminum conductor remains unaffected by the mechanical fastening forces. This intermediary prevents the cold flow problem that would otherwise occur with direct screw connection to aluminum.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Weight of moving object

If oxidation layer forms on aluminum surface, then weight is unchanged, but contact resistance increases

Engineering Contradiction:
Improveweight of cableVSAvoidelectrical conductivity
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The invention extracts the contact surface from the aluminum material and places it on the copper material. The copper contact insert is exposed at the connection interface, providing an oxidation-resistant surface for electrical contact. This separates the electrical contact function from the aluminum conductor, eliminating the oxidation layer problem that would otherwise increase contact resistance.

Inventive Principle:
Principle #2Taking out (Extraction)

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 provides a durable, lightweight, and low-maintenance electrical connection with reduced contact resistance and increased mechanical strength, effectively addressing weight and reliability issues in vehicle electrical systems.

Implementation Method 1

aluminum tends to cold flow and thus only ensures a comparatively unfavorable fatigue strength of the screw connection

Methodology Applied
Scientific EffectCold flow: Creep

Implementation Method 2

aluminum tends to form an oxidation layer in reaction with atmospheric oxygen, which, among other things, can undesirably increase the contact resistance

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3719932B1Power connector, method of manufacturing the same, and electrical connection assembly
Publication Date: 2022.10.05 INTERCABLE AUTOMOTIVE SOLUTIONS GMBH
  • EP3719932B1 patent drawingFigure 1~2
  • EP3719932B1 patent drawingFigure 3~4
  • EP3719932B1 patent drawingFigure 5~6

AI summary

A current connector (1), in particular a busbar, for the electrical system of a vehicle is proposed. The current connector (1) has a ribbon-shaped conductor (2) made of a first metallic material and having at least one through-hole (5) penetrating the conductor (2) in its thickness direction. Furthermore, the current connector (1) has at least one contact insert (6) which is arranged in the through-hole (5) of the conductor (2) to make electrical contact with it, extends at least partially over the thickness of the conductor (2), and is made of a second metallic material that is mechanically stronger than the first metallic material.