Multilayer Airbag Communication Portion Pressure Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air-bags face challenges in controlling pressure rise during deployment to efficiently absorb kinetic energy while maintaining high deployment speed and reducing injury criterion values, often requiring increased inflator gas capacity.

Innovation Solution

The air-bag features a multilayer structure in the communication portion between the main and sub-chambers, which restricts gas flow until the main chamber reaches a certain pressure, then allows gas to flow into the sub-chamber, reducing pressure rise and enhancing deployment speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If gas flows freely to the sub-chamber during deployment, then the deployment speed is improved, but the pressure rise in the main chamber is insufficient for occupant restraint

Engineering Contradiction:
Improvedeployment speedVSAvoidpressure rise in main chamber
Core Design Contradiction:
SpeedVSStress or pressure

Solution Approach 1:

The air-bag is divided into a main chamber and a sub-chamber that are separated but connected through a communication portion. This segmentation allows the main chamber to maintain high pressure for rapid deployment while the sub-chamber absorbs excess gas flow, resolving the contradiction between deployment speed and pressure maintenance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The communication portion acts as an intermediary between the main chamber and sub-chamber. It controls the timing and amount of gas flow from the main chamber to the sub-chamber, enabling the main chamber to achieve sufficient pressure rise while still allowing controlled gas transfer to improve overall deployment performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If the capacity of the inflator is increased to raise the pressure of the inflation portion, then the occupant restraint performance is improved, but the gas capacity requirement increases

Engineering Contradiction:
Improvepressure of inflation portionVSAvoidgas capacity of inflator
Core Design Contradiction:
Stress or pressureVSQuantity of substance

Solution Approach 1:

By segmenting the air-bag into main chamber and sub-chamber, the system can achieve the required pressure in the main chamber with a smaller inflator capacity. The sub-chamber serves as a gas reservoir that receives excess gas after the main chamber is pressurized, reducing the total gas capacity requirement while maintaining effective occupant restraint pressure.

Inventive Principle:
Principle #1Segmentation

3Strength

If the communication portion is formed by adhesion, welding, or suturing, then the structural integrity is improved, but the control of pressure variation upon opening becomes difficult

Engineering Contradiction:
Improvestructural integrity of communication portionVSAvoidcontrol of pressure variation
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The communication portion is designed to dynamically transition from a closed state (maintaining structural integrity through adhesion/welding/suturing) to an opened state in response to pressure differential. This dynamic behavior allows the system to maintain strong connections during normal conditions while automatically controlling pressure variation when the communication portion opens during deployment.

Inventive Principle:
Principle #15Dynamics

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 achieves rapid pressure rise in the main chamber during deployment, suppresses excessive pressure upon occupant contact, and decreases the required gas capacity of the inflator, thereby reducing injury to the occupant.

Implementation Method 1

the communication portion is made up of a multilayer structure portion having three or more layers... restricts gas flow until the main chamber reaches a certain pressure, then allows gas to flow into the sub-chamber

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3222474B1Air-bag
Publication Date: 2021.01.06 SUMISHO AIRBAG SYST CO LTD
  • EP3222474B1 patent drawingFigure 1~2A
  • EP3222474B1 patent drawingFigure 2B~2C
  • EP3222474B1 patent drawingFigure 3~4

AI summary

Provided is an air-bag capable of further reducing damage value to a passenger and limiting the amount of use of inflator gas by limiting an excessive increase in the internal pressure of the air-bag upon contacting the passenger while increasing the speed of deployment in a passenger protection area. The air-bag includes a main chamber and a sub-chamber that are connected via a communication portion, wherein the communication portion or a region adjacent to the communication portion is configured of a multilayer structure portion comprising three or more layers.