Air Bag: Description and Operation

The driver and passenger air bag modules consist of the following components which cannot be disassembled:
- Inflator
- Bag
- Container
- Cover

The inflator is screwed into a metal cup shaped container. The bag is then folded on top of the inflator and the whole subassembly is closed by the cover.

The driver air bag module is attached to the steering wheel, the cover forming the outer surface of the steering wheel boss. The cover has invisible 'split lines' moulded in its surface allowing the air bag to easily exit though the cover when the system deploys.

The passenger air bag module is located above the glove compartment and is integrated into the instrument panel to provide an unobtrusive appearance. The cover is a one piece moulding which is attached to the instrument panel along the windshield edge, and by two plastic shear bolts along its front edge. As the air bag deploys, the cover is forced free of the plastic shear bolts, but remains attached to the instrument panel.

Driver And Passenger Air Bag Module Inflator:

The purpose of the inflator is to generate the gas needed to fill the air bag. It consists of a high strength steel casing filled with a solid propellant charge and an electrically activated igniter. The igniter is activated by an electrical current which in turn ignites the propellant charge. The very rapid burning of the propellant produces sufficient gas to fill the air bag(s). As the gases expand they cool, preventing heat damage to the bag. The driver air bag module has one inflator and bag, with a filled volume of 30 litres. The passenger air bag module has one inflator and bag, with a filled volume of 60 litres.

The air bag(s) are a one - piece woven item with a silicon coating to provide flame and heat protection in the vicinity of the inflator. The shape of the passenger air bag is tailored to suit the vehicle proportions.