High-Voltage Distribution Box Heat Sink to Prevent Bus Bar Arcing

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Solution Overview

Problem

Existing high voltage distribution boxes face issues with heat dissipation and electrical arcs due to loose connections between the bus bar and heat sink, which can occur during vehicle operation, posing a risk of electrical arcs.

Innovation Solution

A high voltage distribution box design that includes a thermally and electrically insulating sheet between the bus bar and heat sink, secured by a fastener with a tubular base and head portion to prevent electrical arcs, using a fastener with a thickness and height greater than the arc potential to secure the bus bar to a protrusion on the heat sink.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a sheet of material is secured by pinch fit engagement between the heat sink and bus bar, then heat dissipation is achieved, but the connection becomes loose due to vibrational loads causing electrical arcs

Engineering Contradiction:

Improveheat dissipationVSAvoidconnection stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The fastener is pre-installed in the bus bar before assembly, with its tubular base extending through the sheet material and heat sink. This preliminary positioning ensures that when the bolt is inserted, the components are already aligned and the fastener is ready to secure the connection, preventing loosening under vibration while maintaining thermal contact.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The fastener acts as an intermediary component between the bus bar and heat sink assembly. Its tubular base extends through the sheet material and heat sink, providing a mechanical intermediary structure that secures all components together while the sheet material maintains electrical insulation. This intermediary fastener prevents the loosening issues of direct pinch fit engagement.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a hole is present in the bus bar for bolt fastening, then secure connection is achieved, but an exposed electrically conductive surface is created where electrical arcs may occur

Engineering Contradiction:

Improveconnection securityVSAvoidelectrical arc risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The fastener's tubular base serves as an intermediary insulating element between the exposed hole in the bus bar and the bolt. The tubular base extends through the sheet material and heat sink, filling the aperture space and preventing direct exposure of the conductive hole. This intermediary structure maintains the necessary mechanical connection while eliminating the electrical arc hazard by insulating the exposed conductive surface.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Temperature

If the sheet material is made thermally conductive, then heat dissipation is improved, but electrical conductivity increases creating arc hazards

Engineering Contradiction:

Improveheat dissipationVSAvoidelectrical arc potential

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The sheet material is positioned locally between the heat sink and bus bar to provide thermal conduction where needed, while the fastener's tubular base provides local electrical insulation at the critical aperture region. This local differentiation of properties allows the sheet material to be thermally conductive for heat dissipation while the tubular base prevents electrical conduction and arc formation at the exposed surfaces.

Inventive Principle:

Principle #3Local quality

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

Effectively dissipates heat while preventing electrical arcs by ensuring secure insulation and spacing to prevent electrical arcs, enhancing safety and reliability.

Implementation Method 1

The operation of the electric components may generate heat. As such, the high voltage distribution box may include a heat sink for dissipating heat from the interior of the housing.

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

The sheet of material is both thermally conductive and electrically insulating

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

The tubular base has a thickness and a height greater than an arc potential so as to prevent an arc from occurring

Methodology Applied

Scientific EffectElectrical arc prevention: Electric Arc

Data Source

PatentUS20260024964A1High voltage distribution box with heat sink

Publication Date: 2026.01.22 SUMITOMO WIRING SYSTEMS LTD

AI summary

A high voltage distribution box includes a case housing a bus bar, a sheet of metal and a heat sink. The bus bar includes a first aperture. The sheet of material includes a second aperture registered to the first aperture. The heat sink is disposed in the case and includes a protrusion extending toward the bus bar. The protrusion includes a third aperture registered to the first aperture and the second aperture and the sheet of material is interposed between the protrusion and the bus bar. The high voltage distribution box further includes a fastener disposed within the first aperture, the second aperture and the third aperture. The fastener is configured to receive a bolt so as to secure the bus bar to the protrusion and has a thickness and a height greater than an arc potential so as to prevent an arc from occurring.