Airbag Actuator Pre-Mounting Method Using Plastic Mounting Element

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Solution Overview

Problem

Conventional explosive bolts used in airbag modules for activating tensile means are over-dimensioned and expensive, requiring complex and time-consuming constructional changes for mounting, which increases costs and assembly time.

Innovation Solution

A method of pre-mounting a tensile means with an actuator assembly and a mounting element inside the module casing, eliminating the need for threading through slits or apertures, and using a synthetic material for the mounting element to enable quick, easy, and cost-effective mounting, with the tensile means often integrated into the airbag during manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If conventional explosive bolts are used to activate tensile means, then high force absorption capability is achieved, but cost and device complexity increase

Engineering Contradiction:

Improveforce absorption capabilityVSAvoidmounting complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The system is divided into separate functional components: a plastic actuator assembly containing the explosive charge and a separate mounting element with aperture. This segmentation allows the actuator to be designed for optimal force absorption while the mounting element handles the fastening function, reducing overall complexity

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The mounting element acts as an intermediary component between the actuator assembly and the module casing. It provides a simplified interface through its aperture design, eliminating the need for complex threading operations and reducing mounting complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If conventional explosive bolts are used, then robust fastening is achieved, but assembly time increases

Engineering Contradiction:

Improvefastening reliabilityVSAvoidassembly time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The mounting element is pre-formed with an aperture that accepts the actuator assembly in a simple insertion motion. This preliminary preparation of the mounting interface eliminates time-consuming threading operations during assembly, reducing assembly time while maintaining fastening reliability through the designed aperture-actuator fit

Inventive Principle:

Principle #10Preliminary action

3Reliability

If complex constructional changes are made for mounting, then secure fastening is achieved, but manufacturing cost increases

Engineering Contradiction:

Improvefastening securityVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The mounting element is designed as a simple, inexpensive plastic component with an aperture that can be easily manufactured and disposed of after use. This approach prioritizes low manufacturing cost and ease of production over reusability, allowing secure fastening to be achieved through simple design rather than complex constructional changes

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

4Reliability

If tensile means are threaded through slits or apertures in module casing, then secure mounting is achieved, but assembly complexity increases

Engineering Contradiction:

Improvemounting securityVSAvoidmounting procedure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of threading the tensile means through apertures in the module casing, the invention inverts the approach by having the actuator assembly itself engage with the mounting element's aperture. This reversal eliminates the need for complex threading procedures through the casing, reducing mounting procedure complexity while maintaining mounting security through the actuator-m mounting interface

Inventive Principle:

Principle #13The other way round (Inversion)

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 an inexpensive, compact, and easy-to-manufacture airbag module with simplified mounting, ensuring reliable fastening and restraint of fragments, reducing assembly time and costs while maintaining safety standards.

Implementation Method 1

the mounting element forms a restraint cage for the at least one separated fragment

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS11214218B2Method for assembling an actuator assembly and air bag module comprising an assembled actuator assembly

Publication Date: 2022.01.04 ZF AUTOMOTIVE GERMANY GMBH

AI summary

The invention relates to an airbag module (16) of a vehicle safety system as well as to a method of mounting an actuator assembly (10) for activating a tensile means (12) on a module casing (14) of the airbag module (16), comprising the following steps:a) the tensile means (12) is connected to the actuator assembly (10) and is fixed to a mounting element (18) together with the actuator assembly (10) so that the tensile means (12), the actuator assembly (10) and the mounting element (18) constitute a pre-mounted unit (20);the pre-mounted unit (20) is arranged inside the module casing (14) and is fastened to the module casing (14) by means of the mounting element (18).