AIRBAGThe only bag which can

carry a life to safety

BYD.MOHAN

11011A0314

CONTENTS

History of Airbag Operation Limitations Airbag fatality statistics Applications Conclusion

What are Airbags?

Supplementary Restraint System for driver and/or passenger safety in case of a crash.

HISTORY OF AIRBAG The airbag specified for automobile

use traces its origins as early as 1941

First invented by Walter Lind and John W. Hetrick

At the beginning compressed air was used

Types of Airbags Frontal Airbags Shaped airbag Side Airbag  Side Torso Airbag Curtain airbag  Knee Airbag Rear Curtain Airbag  Centre Airbag

WORKING OF AIR BAG

Basic MechanismA thin nylon bag in the steering wheel / above glove compartment inflates in the event of an impact and prevents the driver/passenger from hitting the steering wheel/dashboard.

Main Components:

1) Airbag module

2) Diagnostic Unit

3) Crash sensors

Airbag ModuleContains both inflator unit and light-weight fabric airbag and is located either inside: 1) Steering wheel hub 2) Above glove compartment 3) Near side compartment (as separate/combined head/side/window-curtain airbag)

Airbag: Thin nylon fabric bag folded neatly into steering wheel that inflates to the size of a large beach ball on impact.

Inflator unit: Contains a number of sodium azide pellets

which are electrically ignited to produce N2 that then fills the airbag. This is preferred to storing compressed gas in the unit (space, durability)

Diagnostic Unit:Enables inflator unit and sensors when vehicle is turned on, performs self check.Constantly monitors airbag readiness and indicates malfunctioning through an indicator on dashboardUsually stores electricity to activate airbag in the event that a crash damages the battery / link to battery

Sensors:•Several crash sensors located in the front of vehicle and in the passenger compartment.•Each senses the sudden deceleration or impact in the event of a crash and flips a mechanical switch to indicate a crash.

Ball tube crash sensor

Airbag Deployment

Frontal crash scenario: Car crashes into an obstacle (wall) at 20+ mphSensors detect the deceleration and inflator unit activated

Deployment sensitivity: To guard against accidental inflation on hard braking, sensors detect collisions into a solid barrier at speeds greater than 8-14 mph only as impacts

An electric current is used to heat a filament wire that ignites the NaN3 capsules, producing N2:

2NaN3 2Na + 3N2

10Na + 2KNO3 K2O + 5Na2O+ N2

K2O + Na2O SiO2 alkaline glass (safe, unignitable)

Limitations ?

Airbag fatality statistics

Applications:Airbag landing system

The Airbag Helmet

The unit is designed to shoot a protective, inflatable nylon hood around the user’s head

within one tenth of a second of impact.

The Airbag JacketThese jackets are designed to keep

motorcycle riders safe during a crash, and typically have anchoring cables and a CO2

cartridge.

The Avalanche Airbag

The Cell Phone Airbag• Honda teased tech aficionados with an idea of a

smartphone case that deploys an airbag when the phone is accidently dropped.

• The case uses six small airbags placed around the edges of the smartphone, which are deployed when the case takes a spill.

ConclusionAirbags are an effective secondary safety measure that reduces the risk of injury for vehicle occupants, in more severe collisions. RoSPA supports the fitment of airbags in vehicles if they are used in conjunction with - but not in place of - seat belts.