Safety has long become one of the important criteria for measuring car performance. The airbag system is currently one of the most widely used automotive passive safety systems. The system requires that the airbag harness should be able to supply power to its safety system within 100ms of the entire vehicle collision, and be able to transmit the signal from the sensor to the controller. The instructions of the controller are transmitted to the actuators. Due to the limitation of its special functions, the performance requirements of airbag wiring harnesses are much higher than other wiring harnesses in automobiles. At present, in addition to professional airbag manufacturers and large wiring harness joint ventures that produce airbag wiring harnesses, most domestic wiring harness companies lack knowledge of their technology and production requirements, and few manufacturers have set foot in them. To a certain extent, they have become domestic automotive wiring harness technology. The bottleneck of industry development.

1. Requirements for working life of automobile airbag harness

From the date of delivery of the product, under normal working conditions, the working life of the wiring harness assembly is designed to be less than 10 years or 160,000 km, and the performance will remain unchanged during the period.

2. Performance requirements of raw materials for airbag wiring harness

1) Performance requirements of connectors for airbag wiring harnesses

①In order to make it easier to distinguish the airbag system harness from other electrical system harnesses. At present, most automobile airbag system wiring harnesses and insurance mechanisms use yellow connectors, and some use dark blue or orange-red connectors.

②Design and select gold-plated terminals with good conductivity and durability to ensure the reliable operation of the airbag system.

③Design and choose a connector with a short-circuit plate mechanism (copper spring plate, also called short-circuit spring plate) to prevent accidental explosion of the airbag. When the connector is unplugged (the plug is unplugged or the plug and the socket are not fully integrated), the short-circuit strip will automatically short the two lead terminals near the plug or ring base on the side of the airbag igniter to prevent the airbag from being caused by static electricity or incorrect power-on Accidentally exploded.

④Design and select the connector of the terminal double lock mechanism. Each connector has a two-piece mechanism composed of a housing or a partition. This mechanism allows the terminal to be locked by two locking devices (the partition and the lock handle) to prevent the terminal from slipping out.

⑤Design and select the connector of the double lock mechanism of the sheath. The broadcast adapter (plug and socket) with this mechanism is locked by two locking devices, which increases the reliability of the connection. If the main lock is not locked, the 2 tabs will hinder and prevent the locking of the secondary lock.

Commonly used airbag harness connectors are generally products of AMP, FCI, MOLEX, JST and other companies.

2) Performance requirements of wires for airbag wiring harness

Most automobile companies have no special requirements for wires for airbag wiring harnesses (except for coil springs). For example, Japanese automobile companies mostly use AVSS wires for ordinary wiring harnesses. However, recently many wire manufacturers have begun to produce special wires for airbag harnesses. There is not much difference between the two, but they are slightly stronger in terms of flexibility and conductivity.

3) Requirements for outsourcing of airbag wiring harness

Airbag harnesses are generally wrapped and protected with yellow corrugated pipes or yellow PVC pipes. The performance of the pipes is slightly better than ordinary pipes in terms of flexibility and mechanical strength. The wiring harness is fixed on the vehicle body with a buckle or cable tie.

3. Mechanical performance requirements of airbag harness

All cable joints and connectors must be subjected to tensile tests under standard climatic conditions. The test load must be continuously increased and acted along the cable lead-out direction (180°), and the loading duration shall not be less than 10s. The applied load of the electric ignition plug (90° to the plug): 50 N; the applied load of the contact element lead: 80 N; the applied load of the wire and branch plug: 80 N; the applied load of the cable buckle: 100 N.

4. Electrical performance requirements for airbag wiring harness

While meeting the mechanical performance requirements, the airbag harness has high requirements for electrical performance. It is necessary to ensure that the airbag and seat belt pretensioner can be detonated normally, but also to prevent their accidental explosion. Therefore, the electrical performance of the airbag harness Requirements are as follows.

1) The current load capacity is loaded with 2A direct current for 10s, and no electrical and mechanical performance degradation is allowed.

2) Withstand voltage strength at room temperature, apply a DC voltage of 500V, and the insulation layer should be free from breakdown damage.

5. Separation and independence of airbag harness

The airbag harness system must be separated from other electrical systems. Both electrical signals and grounding must be completed independently. For safety reasons, the airbag system should adopt a double grounding method.

The airbag harness must have good adaptability to the environment.