Pyrotechnic Initiator Nested Containers Laser Weld

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Solution Overview

Problem

Current high performance pyrotechnic initiators for automotive safety systems face challenges with complex and costly manufacturing processes, hermetic sealing issues, and limited performance enhancement due to moisture penetration and chemical interactions between primary and booster pyrotechnic materials, restricting the increase in energetic material loading.

Innovation Solution

A compact initiator design featuring a holder with reduced diameter for the inner container containing primary pyrotechnic material, sealed with a laser weld, and an outer container with a large volume for booster pyrotechnic material, both hermetically separated and integrated into a plastic body with laser weld connections, ensuring hermetic separation and protection from the environment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the amount of pyrotechnic materials is increased to improve ignition performance, then the ignition power is enhanced, but the initiator becomes voluminous and complex

Engineering Contradiction:
Improveignition powerVSAvoidinitiator structure complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent implements a nested container structure where an inner container holding primary pyrotechnic material is placed inside an outer container holding booster pyrotechnic material. This nesting approach allows high loading of both material types in a compact configuration, achieving high ignition power without increasing overall device complexity or volume.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Power

If the amount of pyrotechnic materials is increased to improve ignition performance, then the ignition power is enhanced, but the manufacturing process becomes complicated and costly

Engineering Contradiction:
Improveignition powerVSAvoidmanufacturing complexity
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The nested container design allows for modular assembly where the inner container with primary material is inserted into the outer container with booster material. This simplifies manufacturing compared to traditional multi-component designs, as it reduces the number of sealing interfaces and assembly steps while enabling high loading of pyrotechnic materials for enhanced ignition power.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the inner container is sealed to the holder with a laser weld, then hermetic separation is achieved, but the manufacturing precision requirement increases

Engineering Contradiction:
Improvehermetic sealingVSAvoidwelding precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces traditional mechanical sealing methods (such as threaded connections or snap-fits) with laser welding to join the inner container to the holder. This substitution provides superior hermetic sealing reliability, ensuring complete isolation between primary and booster pyrotechnic materials, though it does require precise positioning and surface preparation for the welding process.

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

4Reliability

If the outer container is sealed to the holder with a laser weld, then hermetic separation is achieved, but the manufacturing precision requirement increases

Engineering Contradiction:
Improvehermetic sealingVSAvoidwelding precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent employs laser welding to hermetically seal the outer container to the holder, replacing mechanical sealing approaches. This ensures reliable hermetic separation to prevent moisture and chemical interaction between pyrotechnic materials, while the welding process requires controlled precision in positioning and surface preparation.

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

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 design allows for a substantial increase in booster pyrotechnic material loading without degrading the sensitive primary material, providing a compact, high-performance ignition system with enhanced hermetic sealing and protection from moisture, suitable for automotive safety systems and other applications.

Implementation Method 1

the circumference connection of the inner container with the reduced diameter of the holder and/or circumference connection of the outer container with the holder of contacts is hermetic and is performed by first and/or the second laser weld

Methodology Applied
Scientific EffectLaser weld: Laser Beam Welding

Data Source

PatentEP2589920B1High performance initiator
Publication Date: 2016.12.14 INDET SAFETY SYST
  • EP2589920B1 patent drawingFigure 1

AI summary

The initiator consists of a plastic body (8), electrical contacts (9), a cover (7), an outer container (5) containing a booster pyrotechnic material (6), an inner container (3) which contains a primary pyrotechnic material (4) and a holder (1) of said contacts (9), which towards front the initiator has a reduced diameter (2), where the inner container (3) is sealed over the circumference of the reduced diameter (2) of holder, the inner container (3) being located within said outer container (5), the inner and outter container being hermetically sealed, preferably by laser welding (10a, 10b) to the holder (1) along their inner edges adjacent to the holder (1) of contacts where the adjacent outside edge of the outer container (5) is integrated into the plastic body (8) which carries also contacts (9) at the same time.