Pyrotechnic Switch Residual Energy Dissipation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pyrotechnic switches primarily focus on disconnecting electrical connections but lack the capability to efficiently dissipate residual energies that may remain in a vehicle electrical system after a crash, due to capacitances.

Innovation Solution

A pyrotechnic switch design that includes an igniter, a separating element, and a busbar with a third connection line, where the second connection is electrically connected to the third connection upon activation, allowing for the disconnection of the first connection before establishing a new connection to ground, facilitating the dissipation of residual energies through a contact element, such as a nail-shaped contact element.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a pyrotechnic switch only disconnects electrical connections without providing a ground path, then the device complexity is reduced, but residual energies cannot be dissipated effectively

Engineering Contradiction:
Improvedissipation of residual energiesVSAvoidstructure of pyrotechnic switch
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The pyrotechnic switch is segmented into two independent pyrotechnic cartridges: a first cartridge for disconnecting the electrical connection (severing the busbar) and a second cartridge for establishing the ground connection (moving the contact element). This segmentation allows each cartridge to perform a specific function, enabling effective residual energy dissipation while keeping each individual cartridge relatively simple in structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The pyrotechnic switch system is designed to perform multiple functions: it can both disconnect electrical connections and establish ground connections for residual energy dissipation. The contact element serves dual purposes by being movable via the second pyrotechnic cartridge to create a ground path, while the busbar serves as both the electrical conductor to be severed and the structural component that the contact element moves toward.

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

2Reliability

If the busbar is severed before establishing ground connection, then safety is improved by preventing short circuits, but the time required for complete energy dissipation increases

Engineering Contradiction:
Improvesafety of electrical systemVSAvoidtime for residual energy dissipation
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The first pyrotechnic cartridge is designed to activate first, severing the busbar and disconnecting the electrical connection before the second cartridge establishes the ground connection. This preliminary action ensures that the main electrical path is broken first, preventing short circuits, while the subsequent ground connection provides a safe path for residual energy dissipation without causing harmful currents.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The contact element acts as an intermediary component that bridges the gap between the severed busbar and the ground connection. When moved by the second pyrotechnic cartridge, it creates a controlled electrical path from the isolated busbar section to ground, allowing residual energies to dissipate safely without creating dangerous short circuits across the main system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If a contact element is added to establish ground connection, then the capability to dissipate residual energies is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvecapability to establish ground connectionVSAvoidmanufacturing of pyrotechnic switch
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The ground connection functionality is extracted as a separate, independent function performed by the second pyrotechnic cartridge and contact element, rather than being integrated into the busbar or first cartridge. This extraction allows the ground connection system to be manufactured and tested independently, simplifying the overall manufacturing process despite the increased functionality.

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

Enables quick and reliable dissipation of residual energies in the vehicle electrical system by ensuring the connection to the voltage source is disconnected before establishing a ground connection, thereby preventing potential hazards.

Implementation Method 1

an igniter (3) which, in the activated state, triggers the separating element (4) to cut through the conductor rail (6)

Methodology Applied
Scientific EffectChemical energy transformation: Combustion

Implementation Method 2

a separating element (4) which, in the activated state, cuts through the conductor rail (6)

Methodology Applied
Scientific EffectMechanical cutting: Fracture Mechanics

Data Source

PatentEP3525223B1Pyrotechnic switch
Publication Date: 2020.10.07 VOLKSWAGEN AG
  • EP3525223B1 patent drawingFigure 1~3
  • EP3525223B1 patent drawingFigure 4~5

AI summary

The invention relates to a pyrotechnic switch (1) comprising a detonator (3), a separating element (4) and a busbar (6), wherein a first connection (7) and a second connection (8) are arranged on the busbar (6), wherein the pyrotechnic switch (1) is designed such that in the activated state the separating element (4) cuts the busbar (6), wherein the pyrotechnic switch (1) has at least a third connection (10) with a conductor (11), wherein the pyrotechnic switch (1) is designed such that in the activated state the second connection (8) is electrically connected to the third connection (10).