Integrated Fuse Module With Pyrotechnic Interruption for HV Vehicles

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Solution Overview

Problem

Existing automotive electrical systems lack a compact, space-saving solution that integrates both passive and active circuit protection elements, particularly suited for high voltage applications and collision scenarios.

Innovation Solution

The active/passive automotive fuse module combines passive fuse elements with a pyrotechnic interrupter (PI) in a compact form factor. The module includes a base with fuse cavities, a fuse plate with fusible portions, a spacing cap, and a PI that uses a pyrotechnic initiator to forcibly drive a dielectric projectile through the fuse plate, interrupting electrical current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If passive fuse elements are used for overcurrent protection, then circuit protection is provided, but the system lacks active de-energization capability during collisions

Engineering Contradiction:
Improvecircuit protectionVSAvoidactive de-energization capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent combines passive fuse elements with an active pyrotechnic interrupter mechanism into a single integrated device. The fuse plate contains both fusible portions for passive overcurrent protection and a through-hole for the pyrotechnic interrupter to forcibly open the circuit during collisions, achieving both protection modes in one component.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fuse module serves multiple functions: it provides passive overcurrent protection through fusible portions that melt under excessive current, and active collision protection through a pyrotechnic interrupter that forcibly opens the circuit using a dielectric projectile. This multi-functional design eliminates the need for separate passive and active protection devices.

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

2Reliability

If separate passive and active protection devices are implemented, then both overcurrent and collision protection are provided, but the system occupies more space and is more complex

Engineering Contradiction:
Improveprotection coverageVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates separate passive fuse elements and active pyrotechnic interrupter mechanisms into a single unified fuse module. The fuse plate simultaneously contains fusible portions for passive protection and a through-hole for active interruption, reducing the number of components and simplifying the overall system architecture.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fuse module is divided into functional segments within a compact structure: the fuse plate with fusible portions, the pyrotechnic initiator chamber, the dielectric projectile, and the housing. This segmentation allows each function to be optimized independently while maintaining overall compactness and integration.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If traditional fuse designs are used, then manufacturing is simple, but the device lacks compact form factor for high voltage applications

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddevice size
Core Design Contradiction:
Ease of manufactureVSVolume of moving object

Solution Approach 1:

The patent employs a nested structure where the pyrotechnic initiator and dielectric projectile are contained within the fuse module housing, which also contains the fuse plate with fusible portions. This nesting arrangement maximizes space utilization and creates a compact form factor suitable for high voltage applications while maintaining manufacturability.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The fuse plate is designed with a three-dimensional structure that includes fusible portions extending into fuse cavities and a through-hole for the pyrotechnic interrupter. This dimensional design allows multiple protection functions to coexist in a compact volume, optimizing space utilization without compromising manufacturing simplicity.

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

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 effective overcurrent protection and ensures de-energization of electrical components during collisions, mitigating risks of fire and electrocution while being suitable for high voltage applications and compact installation.

Implementation Method 1

a pyrotechnic initiator within the PI to be detonated. A resultant increase in pressure within the PI rapidly forcibly drives a projectile through a conductor that extends through the PI.

Methodology Applied
Scientific EffectPyrotechnic detonation: Detonation

Implementation Method 2

the projectile, which is formed of a dielectric material, provides an electrically insulating barrier between separated portions of the conductor to prevent electrical arcing therebetween.

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

If current flowing through a fuse element exceeds the fuse element's rated current, the fuse element will melt, disintegrate, or otherwise separate, thereby arresting the current

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3736846B1Active/passive automotive fuse module
Publication Date: 2025.03.05 LITTELFUSE INC
  • EP3736846B1 patent drawingFigure 1
  • EP3736846B1 patent drawingFigure 2
  • EP3736846B1 patent drawingFigure 3

AI summary

An exemplary embodiment of active/passive automotive fuse module in accordance with the present disclosure may include an electrically insulating base, a fuse plate including a bus bar portion disposed on a top surface of the base above a projectile cavity formed in the base, the fuse plate further including a fusible portion electrically connected to the bus bar portion and adapted to open when an amount of current flowing through the fuse plate exceeds a current rating of the active/passive automotive fuse module, the active/passive automotive fuse module further including a pyrotechnic interrupter (PI) disposed atop the base and including a projectile positioned above the bus bar portion, the PI configured to drive the projectile through the bus bar portion upon actuation of the PI.