1. Introduction
Airbag inflators—also known as gas generators—are the core components that enable airbag deployment.
When a collision occurs, the inflator rapidly produces gas to fill the airbag cushion within 20–40 milliseconds.
Although compact, an inflator contains precise engineering, chemical formulations, and safety mechanisms.
This article explains the internal structure, working process, and common classifications of airbag inflators used in modern vehicles.
2. Internal Structure of an Airbag Inflator
Most inflators share several essential components regardless of size or shape.
Key Internal Components
| Component |
Description |
Function |
| Initiator / Igniter |
Electrical device that receives signal from SRS ECU |
Starts the chemical reaction or gas release |
| Gas Generant (Propellant) |
Solid chemical pellets |
Burns rapidly to produce nitrogen gas |
| Filter / Cooling System |
Metal mesh & chambers |
Cools and cleans gas before entering airbag |
| Diffuser Housing |
Outer metal shell with outlet holes |
Directs gas into the airbag |
| Burst Disk / Seal |
Thin sealed membrane |
Breaks under pressure to release gas |
| Secondary Igniter (Dual-stage inflator) |
Additional igniter |
Controls second-stage inflation |
Inflators are designed to withstand extremely high temperature and pressure while maintaining safety during storage, transport, and operation.
3. How an Airbag Inflator Works
Step-by-Step Working Process
-
Collision Detected
Sensors send signal to the SRS control unit.
-
Igniter Activation
The igniter receives an electrical current and starts combustion.
-
Chemical Reaction
Gas generant burns rapidly, producing high-pressure nitrogen gas.
-
Gas Filtration & Cooling
The hot gas passes through filters to reduce temperature and remove particles.
-
Burst Disk Opens
Pressure breaks the internal seal, releasing gas.
-
Airbag Inflation
Gas flows into the airbag cushion, deploying it within milliseconds.
This precise process is synchronized with seat belt pretensioner activation for optimal occupant protection.
4. Classification of Airbag Inflators
Inflators are classified based on structure, deployment stages, and chemical composition.
4.1 By Deployment Stages
| Type |
Description |
Features |
| Single-Stage Inflator |
One igniter, one output stage |
Common in older or low-cost models |
| Dual-Stage Inflator |
Two igniters (independent or sequential) |
Used in advanced SRS systems |
| Adaptive Multi-Stage |
Multiple levels controlled by ECU |
High-end U.S. & European vehicles |
4.2 By Gas Production Method
| Type |
Mechanism |
Advantages |
| Pyrotechnic Inflator |
Solid propellant burns to create gas |
Compact, reliable, widely used |
| Stored Gas Inflator |
Pre-filled compressed gas |
Stable performance, no combustion |
| Hybrid Inflator |
Combination of combustion + stored gas |
Smooth inflation, used in curtain airbags |
4.3 By Airbag Application
| Application |
Typical Inflator |
Notes |
| Driver Airbag |
Small pyrotechnic / hybrid |
Usually 54–63 mm diameter |
| Passenger Airbag |
Large pyrotechnic or hybrid |
Higher gas volume |
| Side Airbag |
Compact stored-gas |
Fast deployment |
| Curtain Airbag |
Long tubular hybrid inflator |
Sustains inflation for rollover protection |
5. Performance Requirements
Airbag inflators must pass strict global standards:
-
FMVSS 208 / 214 (USA)
-
ECE R94 / R95 (Europe)
-
GB/T 19939 (China)
-
ISO 12097
Typical Technical Parameters
| Parameter |
Typical Value |
| Activation Time |
2–3 ms |
| Gas Output |
20–120 liters depending on airbag type |
| Operating Temperature |
−35°C to +90°C |
| Storage Life |
10–15 years |
| Pressure Range |
20–300 bar depending on type |
6. Why Inflator Quality Is Critical
-
Determines airbag deployment speed
-
Affects occupant protection level
-
Must remain stable for many years
-
Key to preventing over-inflation or under-inflation
-
Essential for compliance with global safety regulations
For manufacturers and repair markets, choosing a reliable inflator supplier ensures vehicle safety and reduces liability risks.
7. Conclusion
Airbag inflators may look simple but contain advanced engineering and strict safety requirements.
Understanding their internal structure and classification helps automakers, distributors, and repair shops select high-quality products that meet global standards.
Andaotong provides:
✔ Driver & passenger inflators
✔ Single-stage / dual-stage systems
✔ Sizes ∅54 / ∅60 / ∅62 / ∅59 mm
✔ For American, Asian, Middle Eastern, and Latin American vehicles
Il tuo messaggio deve contenere da 20 a 3000 caratteri!
