Fire protection design of automobile wiring harness
In recent years, automobile fire accidents have occurred frequently. According to statistics, about 70% of fire problems are related to wiring harnesses. Therefore, it is necessary to introduce the fire protection design of automobile wiring harness.
Principle of wiring harness ignition:
There must be three conditions for the wiring harness to catch fire: Heat source, burning material, gas, all three are indispensable.
I. Principle of wiring harness ignition:
The key to combustibles is diesel oil, automotive gasoline, automotive engine oil, lubricating oil and other grease compounds. Everyone should properly understand the definition of combustion: Generally, the temperature of the exhaust pipe can reach more than 800 °, and the short-circuit failure of the wire can cause 1100 °. The above high temperature has been able to melt the copper wire. The ignition point of most substances has already been reached, so the only difference is the burning speed.
II. Fire protection design standards
Keep the standards in mind:
1. Take precautions and prevent fires from the root cause;
2. Minimize the burning speed;
3. There must be no vicious incidents of personal safety, casualties.
Here is a brief introduction to the above points:
1. Preventing problems before they happen is to take into account the elimination of combustion safety hazards from the wiring harness design.
2. The key to reducing the burning rate is the application of fireproof materials.
3. Equipment related to safety escape can be opened normally at any time. For example, car doors, panoramic sunroofs, etc., to prevent people from being unable to escape after a fire.
III. Automotive wiring harness fire protection design
The key to the fire protection design of automobile wiring harness is two points:
One is the wiring harness layout design plan. The second is the design scheme of cable diameter and insurance matching.
1. Layout design plan of automobile wiring harness:
The automobile wiring harness must bypass the high-temperature heat source by more than 150 mm, and the high-temperature heat source must be increased by insulating aluminum tiles.
The layout of automobile wiring harness should bypass sharp edges and moving components to avoid damage to the wiring harness and short circuit failure.
The automobile wire harness is prevented from passing directly under the oil pipeline to avoid dripping on the wire harness after oil leakage.
2. Design scheme of wire and insurance matching
The maximum temperature resistance of the insulation layer of the Japanese marking line is only 120 °, and Japanese manufacturers are fully implementing lean production management, and the diameter of the wire is too small. However, fire accidents on Japanese cars are rare. The author thinks that there are two key points: First, the parts suppliers of Japanese manufacturers are relatively single, and they are basically Japanese companies. Coupled with the popularity of Japanese quality culture, the consistency of the products is very high. The second is that Japanese manufacturers have done a good job in product certification, with detailed design scheme certification steps.
