Cushion Member Segmentation for Gas Generator Placement

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Solution Overview

Problem

Conventional gas generators face difficulties in effectively using cushion members to absorb vibrations and impacts within the combustion chamber, especially when the cushion member is larger than the opening, leading to complications in placement and potential manufacturing issues.

Innovation Solution

A gas generator design featuring a cushion member with a circular portion and protrusions, where the outer diameter of the circular portion is smaller than the inner diameter of the opening, allowing for easier placement and maintaining shape retention and elasticity to facilitate positioning within a cup-shaped combustion chamber with a smaller opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the cushion member is made larger to cover the bottom portion of the combustion chamber, then the vibration absorption effectiveness is improved, but the difficulty of placing the cushion member through the opening increases

Engineering Contradiction:

Improvevibration absorption effectivenessVSAvoidease of placing cushion member

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The cushion member is divided into a circular base portion and multiple protrusions extending from the periphery. This segmentation allows the base portion to pass through the opening while the protrusions extend outward to cover the bottom portion, resolving the contradiction between size and placeability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The cushion member transitions from a two-dimensional disk shape to a three-dimensional structure with protrusions extending in the radial direction. This dimensional change enables the cushion member to achieve both small insertion profile and large coverage area simultaneously.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the cushion member is folded to fit through the small opening, then the placeability is improved, but the shape retention property deteriorates

Engineering Contradiction:

Improveplaceability through openingVSAvoidshape retention property

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

By segmenting the cushion member into a rigid circular base and flexible protrusions, the design allows the base to maintain its shape while the protrusions can deform during insertion and then return to their original configuration, preserving shape retention.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circular base portion provides a stable, curved structure that naturally resists deformation during insertion, while the protrusions can flex and then recover, maintaining the overall shape integrity of the cushion member.

Inventive Principle:

Principle #14Spheroidality (Curvature)

3Manufacturing precision

If the cushion member is made with higher shape retention, then the positioning accuracy is improved, but the ease of insertion through small opening deteriorates

Engineering Contradiction:

Improvepositioning accuracyVSAvoidease of insertion

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The cushion member is segmented into a rigid circular base for precise positioning and protrusions that can flex during insertion. This segmentation allows the base to maintain its shape for accurate positioning while the protrusions accommodate the insertion process.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different parts of the cushion member have different mechanical properties: the circular base has high rigidity for positioning accuracy, while the protrusions have higher flexibility for ease of insertion, achieving both requirements through local quality differentiation.

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

The design enhances workability and positioning of the cushion member, effectively alleviating the influence of external vibrations and impacts on the gas generating agents, while minimizing manufacturing complications.

Implementation Method 1

a cushion member being disposed on a bottom portion of the combustion chamber... to absorb vibrations and alleviate impact on the gas generating agents

Methodology Applied

Scientific EffectVibration absorption: Damping

Implementation Method 2

to absorb vibrations and alleviate impact on the gas generating agents

Methodology Applied

Scientific EffectImpact absorption: Damping

Data Source

PatentEP2552754B1Gas generator having combustion chamber including cushion member

Publication Date: 2014.12.03 DAICEL CORP

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Figure 2(a)~2(b)
Figure 3(a)~3(b)

AI summary

The present invention provides a gas generator for a restraining apparatus of a vehicle, including a combustion chamber, a tabular cushion member being disposed on a bottom portion of the combustion chamber, the solid gas generating agent as a gas generating source, being charged in the combustion chamber inside the gas generator together with the cushion member, the combustion chamber being substantially in a cup shape in which an inner diameter (D1) of an opening is smaller than an inner diameter (D2) of the bottom portion, the cushion member including a circular portion serving as a base part and a plurality of protrusions protruding from a peripheral edge of the circular portion, an outer diameter (d1) of the circular portion and the inner diameter (D1) of the opening satisfying a relationship of d1 1, and an outer diameter (d2) including the protrusions satisfying relationships of d2 > D1 and d2 = D2.