Because the car uses flammable liquids and gases as fuel, all parts of the car are filled with a lot of flammable lubricating oil, and a lot of flammable decorative materials are used in the interior. There are various transmission parts and power lines on the car. If there is a mechanical or electrical failure, it is easy to cause a fire. Many drivers don't have the corresponding fire-fighting knowledge, or there is no fire-fighting equipment in their cars, so they often don't rescue them in time at the early stage of the car fire, which makes small fires cause great disasters and many tragedies. In recent years, with the rapid improvement of the national economic level, China's automobile industry has developed rapidly, the number of cars has increased rapidly, and automobile fire accidents have become increasingly frequent, which has attracted the attention of the majority of car owners and all walks of life.

First, several reasons for car fire

(1) Fire caused by car collision.

The fuels used by cars are generally gasoline and diesel. The capacity of the fuel tank varies from 20 liters to 200 liters. When a car collides, the oil pipe and fuel tank will rupture and fuel will overflow. After the collision, the short-circuit spark of power supply, the collision spark of metal friction and the high-temperature hot surface of the engine will all cause fire. For example, on May 2, 2007/KLOC-0, a van in a construction site in Jinyang New District, Guiyang City was mishandled, causing the vehicle to hit a rock, causing oil leakage, causing a fire and burning the whole vehicle.

(2) Fire caused by vehicle failure

1. Oil circuit fault

(1) Fuel leakage

In the fuel injection system, the damage of the oil supply pipe and the oil return pipe, the looseness of the interface between the oil circuit and various components, and the rupture of the oil tank are all easy to cause fuel leakage, and the leaked fuel will catch fire when it meets the ignition source (high-voltage electric spark, high-temperature arc and high-temperature exhaust pipe).

(2) Oil leakage

Oil pipe rupture, oil filter oil leakage and chassis damage may cause oil leakage. Although it is not as dangerous as fuel leakage, oil leakage will reduce the lubricating ability of the engine, make mechanical friction generate heat for a long time, cause local high temperature and make combustible substances catch fire. Although engine oil is not a flammable liquid, its flash point will decrease after long-term heating and aging. When the oil temperature is close to its flash point during driving, once it leaks, it will be easily ignited when it meets a fire source. In addition, the leaked engine oil adheres to the surface of engine parts, forming oil stains. If the engine is overheated for a long time, it may also burn and catch fire.

2. Wire failure

(1) leakage

The parts that are easy to leak electricity in automobiles mainly include spark plugs, ignition heads and batteries. The spark plug is installed on the cylinder, which has two main functions: one is to generate sparks in the fuel chamber to ignite the mixture and generate power; The second is to seal the spark plug hole and maintain the pressure in the cylinder. The high voltage supplied by the ignition coil to the spark plug through the distributor and wire is between 20000 and 30000 volts. In addition, the spark plug electrode is in a high-temperature and high-pressure combustion chamber (about 45 times atmospheric pressure), and it is also necessary to maintain extremely high air tightness. Due to the harsh working environment, the insulator of spark plug is easy to be broken down. If there is oil dirt and stolen goods, it is easy to produce high-voltage electric leakage and fire. The ignition head is located on the distributor, which is used to supply current to each spark plug, and it is also easy to leak electricity. Relatively speaking, the risk of battery leakage is small, but the frequency is also high.

(2) Grounding

Grounding is mainly to guide the phenomenon of flashover between damaged wires and metals. The harm of grounding is that grounding will lead to high temperature of conductor due to long-term flashover, accelerate insulation damage and aging, thus expanding the ignition range, which may lead to conductor skin burning or ignition of paint and flammable materials. The main reasons for grounding are line aging damage, line overload, loose wire connection and so on. The parts of the car that are easy to ground mainly include: battery, electronic regulator, rotor winding, starter armature winding, etc.

(3) Poor contact

The circuit of the car is numerous and complicated, which connects all the parts of the car. Because the vehicle is inevitably in a state of vibration for a long time during driving, it is easy to loosen the connection part of the wire, resulting in poor contact. When the contact resistance is too large, the contact point of the conductor will heat up, and the heat will accumulate to a certain extent, and the skin of the conductor will be burnt or even caught fire.

(4) Short circuit

The starter switch of the engine was welded to death due to the burnt contact, which caused the starter electromagnetic switch to fail to release, causing the starter to heat up and catch fire (the safe starting time of the starter is 5 seconds). In addition, the contact of the engine reverse current circuit breaker is closed due to adhesion, which will cause the battery current to flow back into the generator and its wires, resulting in overheating and fire of the coil.

(5) electrolyte

The electrolyte contained in the battery is in danger of discharge and explosion, so once the battery cover plug is not tightly sealed, or impurities are mixed in the electrolyte, it may cause the electrolyte to spray out, and the electrolyte will evaporate or overheat and explode at high temperature.

3. Mechanical failure

(1) mechanical friction

① The engine lubrication system is short of oil, and the piston, cylinder and gearbox are excessively rubbed due to wear or manufacturing defects, resulting in high temperature, which is easy to cause fire.

(2) The gap of vehicle brake pads is adjusted too tightly, which leads to fire. If the brake pads are adjusted too tightly, it will hinder heat dissipation and lead to overheating of the brake drum. Once the heat is transferred to the combustible, if the temperature is too high and exceeds the self-ignition point of the combustible, it will cause an open flame.

(3) Tire friction overheating. Under normal circumstances, tire friction will not cause danger. However, when the tire is under-inflated or the vehicle is overloaded, the tire sidewall is bent and deformed, which leads to the failure of bonding between the fiber or metal on the tire sidewall and the rubber material, which intensifies the friction between them. The heat generated in the tire is difficult to dissipate, and the accumulation of heat leads to the heating of rubber, which will cause the tire to burn if it exceeds its self-ignition point.

(4) The friction between the rectifier rotor of the generator and the starter and the brush will also produce sparks, and it will also cause a fire when it encounters flammable substances such as oil.

(2) Other mechanical failures

(1) carburetor backfire. Because the throat and oil measuring hole of carburetor can't work normally, the proportion of combustible mixture is out of balance, which leads to the tempering of carburetor (low concentration of combustible mixture) or the explosion of exhaust pipe or even the discharge of sparks (high concentration of combustible mixture).

② The deflagration limiter fails. The deflagration limiter is used to control the ignition time. When it fails, it will cause deflagration in the cylinder, which will easily cause the exhaust pipe to release sparks and become a dangerous fire source.

Vehicle failures caused fires, mostly on some old models. With the increase of vehicle service life, the parts on the vehicle are aging and worn, especially some rubber oil pipes are aging and oil leakage, and the insulation layer of power cord is aging and oil leakage. Due to neglect or neglect of maintenance, vehicles working with diseases are not only easy to cause traffic accidents, but also easy to cause vehicle fires. However, some car owners or repair shops use some sub-factories or even fake and inferior parts to maintain their vehicles for cheap prices. These parts can not meet the design conditions of the original car, and it is easy to cause vehicle failure.

In addition, the owner's unauthorized modification of the vehicle is also a factor that cannot be ignored in the fire caused by vehicle failure. At present, in order to meet different personalized use needs, people install vehicle remote control, burglar alarm, reversing radar, car stereo, and even turbocharging system. Due to the immaturity of China's automobile refitting industry, many refitting workshops refit without the technical data of the original vehicle, which leads to the mismatch between the power cord and power of the refitted parts and the design of the original vehicle, resulting in man-made fire hazards. For example, in May 2006, the author participated in the investigation of a car fire. A car owner in Guiyang installed a reversing radar after buying a certain type of car. Less than a week after buying a car, the rear of the car caught fire when the car was driving normally due to the fault of the reversing radar line. Because there was no license plate and no fire extinguisher, the whole car was burned.

(3) Improper operation and maintenance may cause fire.

1. Improper operation

For example, some so-called "old" drivers like to supply fuel directly to the carburetor when the fuel pipeline of the carburetor vehicle is blocked and other reasons lead to poor fuel supply, which can easily lead to fuel imbalance and exhaust pipe shooting. For another example, some new drivers forget to release the parking brake (hand brake) when the vehicle starts running, which causes the parking brake to rub against the wheel hub for a long time to generate high temperature and cause a fire. Most vehicle oil pumps are installed at the bottom of the fuel tank, and they rely on fuel for cold calibration. When the fuel runs out of oil level, some drivers fail to refuel in time, which makes the oil pump lose its oil level cooling, which leads to the oil pump heating and burning out, which easily leads to short circuit and fire.

2. Improper maintenance

The oil pollution of automobile fuel system was not wiped in time. Oil pollution itself is a combustible substance. When there are a large number of ignition sources in the engine compartment, it is easy to cause combustion. Secondly, the long-term accumulation of oil pollution is not conducive to timely detection of oil leakage.

Careless, in the process of maintaining the vehicle, flammable items such as cloth balls are randomly discarded in the hood, which may cause a fire. In addition, putting the wrench on the battery will cause the battery to short-circuit and heat up, release hydrogen and cause an explosion.

(4) Other human factors.

1. Smoking

The surface temperature of cigarette butts is generally 300-400℃, and the center temperature can reach 700-800℃. Inadvertently throwing cigarette butts on flammable materials in the car or throwing them into the box may cause a fire.

2. Vehicles carrying inflammable and explosive chemical dangerous goods shake, vibrate or collide during loading and driving, resulting in damaged packaging, container dumping or untidy sealing, exposure of inflammable and explosive goods, encountering fire source or chemical reaction, causing fire, which develops rapidly and is difficult to put out. For example, there have been many fire accidents of yellow phosphorus transport vehicles on Guizhou Expressway. Most of these accidents are caused by the rupture and leakage of yellow phosphorus barrels during the transportation of yellow phosphorus. Once the sealed water in the yellow phosphorus bucket is exposed to the air, it will react with oxygen in the air and cause spontaneous combustion.

In addition, putting some daily chemicals in the car is also easy to cause fire. For example, some car owners put disposable gas lighters on the dashboard, which was blown by the sun and caused a fire. Some car owners put cylinders of organic combustible gases, such as wax and essence, on the car, which were not handled properly and buried fire hazards. The author once personally found a bottle of watch wax placed by the driver in the engine compartment of a Santana official car of an institution, and the driver drove the car for more than a month without knowing it!

3. Incorrect parking position

Park your car near flammable materials. Once the combustible material catches fire, it will ignite the oil stain on the tire, chassis or bumper (plastic) of the vehicle, which will cause the vehicle to burn. The fire source (such as the spark in the exhaust pipe) and heat source in the car are also easy to ignite these combustibles, but will spread to the car. At present, the exhaust pipes at the bottom of many cars are equipped with three-way catalytic devices, which are low in position and high in surface temperature, and are easy to ignite ground combustibles, such as waste paper, dried weeds and leaves.

4. Artificial arson or fire

For example, setting off fireworks and firecrackers to ignite vehicles.

(5) Other uncertain factors

If some vehicles are not used for a long time, sometimes animals such as cats, mice and snakes will nest in them. These animals will bite off the oil pipeline and electrical circuit of the vehicle, which will easily lead to oil leakage, short circuit and fire when the vehicle restarts.

Second, the car fire prevention

(a) to do a good job of daily inspection of vehicles.

Regularly check whether the plugs (or connectors) of electrical appliances, switches, lamp holders and brake light switches are loose or fall off. Pay special attention to check whether the terminals and insulation of high-current electrical appliances such as ignition switch, battery, starting relay and motor are reliable, and correct the unreliable situation in time to prevent electrical circuit failure or poor contact; Always check whether the paint parts, oil leakage parts, flammable wires, plugs, switches and clamps around moving parts, frames, fuel tanks, carburetors and cushions are "skinned". , and promptly correct the bad situation that may be grounded; Always check the engine and chassis for oil leakage. Pay special attention to the tightness of the fuel pipe, brake fluid pipe and power steering pipe, especially the fuel pipe and power steering pipe, and deal with any leakage in time. Power steering oil is easy to burn. If the oil touches the high temperature part of the engine, it may cause a fire under the hood. In fact, the power steering control valve and pipeline are generally arranged under the front panel and close to the engine, so it is very important to pay attention to its oil pipe sealing. If the driver does not have certain electrical and oil knowledge, he should go to a regular and qualified repair shop for maintenance according to the condition of the car. In addition, there are phenomena such as mucilage smell, smoking, and abnormal temperature displayed by the temperature sensor of the three-way catalytic reactor, which cannot be ignored.

(B) to prevent wire short circuit

It is necessary to maintain and repair the vehicle regularly. When a vehicle breaks down, it should be repaired in a special repair shop. You can't connect the power cord indiscriminately, especially you can't use fake fuses, and it's even convenient to replace standard fuses with refractory metals such as copper wires. Once it is found that the ammeter indicates a large discharge current, the electrical work is suddenly interrupted (such as heavy-duty electrical equipment such as headlights and air-conditioning motors), rubber smells, or smoke is seen near the side gap of the hood and the dashboard, you should quickly pull over and turn off the engine, turn off the main power switch of the whole vehicle, find out the reason and troubleshoot.

(3) Prevent the engine from backfiring

Tempering is a common phenomenon in carburetor cars, and it is a kind of slapping sound produced when the mixture combustion continues until the beginning of the intake stroke, which makes the flame spread to the intake manifold and even the carburetor throat through the intake valve. Check the oil circuit and electric circuit when tempering is found. The oil circuit may be caused by too thin mixture and too late ignition time, which needs to be adjusted. It may also be caused by the breakdown of cylinder gasket and air leakage of intake manifold gasket.

(four) no illegal operation

Don't connect the lines randomly, so as not to cause excessive local load and heat the lines. At present, because there are many new drivers, most of them don't know mechanical knowledge, and the fire caused by illegal vehicle operation is on the rise. In particular, renting a car or hiring a driver temporarily only cares about Dora running fast and making more money, failing to maintain the minor faults of the vehicle in time, and even operating illegally. If there is a problem during driving, you should try to pull over and wait for professional rescue. Don't do it yourself.

(five) do not illegally store dangerous goods.

Don't put lighters, perfumes, mousse and other dangerous goods in the car. If these items are placed in the parts of the car that are easily focused by the sun's rays, there are also certain fire hazards. So check the inside of the car when you lock it, and don't leave these dangerous goods. In addition, ordinary vehicles are not allowed to carry dangerous goods such as gasoline and diesel.

(6) Keep the engine compartment clean and tidy, and don't accumulate too much dirt.

The accumulation of oil dirt and grease in the engine cylinder will accelerate the leakage of ignition coil wires or spark plugs. Moreover, at high temperature, oil dirt and grease are easy to volatilize fuel vapor, which will cause fire in case of electric spark caused by grounding.

(seven) the car should always have a portable fire extinguisher, and learn to use it.

Vehicle fire extinguishers mainly include dry powder fire extinguishers, carbon dioxide fire extinguishers and water-based fire extinguishers. It is essential for vehicles to be equipped with fire extinguishing equipment, and the fire extinguishing agent should be replaced regularly to ensure that the fire extinguishers are complete and effective. Every driver should be familiar with the use of fire extinguishers to avoid being helpless in the event of an accident.

Third, the car fire self-help measures

Car fires often occur on the road, and they spread and burn rapidly. Even if the fire brigade calls the police, the fire will be very strong when the fire truck arrives at the scene, and most vehicles will be destroyed by the fire. If the driver can master some common sense of self-help in car fire and use the car fire extinguisher to put out the fire in the early stage, it will not cause the tragedy of car crash and death.

Once a fire breaks out in a vehicle, you should call the police as soon as possible, and try your best to use the on-board fire extinguisher or other fire extinguishing conditions for initial fighting. It is particularly important to note that if there are abnormal phenomena such as engine smoking or fire during driving, drivers and passengers should keep a clear head after confirming that the car is on fire, do not panic, stay away from flammable and explosive places and densely populated areas such as automobile gas stations and liquefied gas stations, park the car on the side of the road and tighten the parking brake. If the engine compartment is on fire, when preparing to put out the fire, remember not to open the engine compartment cover at this time, because there is insufficient air in the engine compartment at this time, and the fire burns slowly, which is beneficial to put out the fire. If the hatch cover is opened, a lot of fresh air will help the flame spread and burn quickly. At this time, the fire extinguisher can be used in the car. By opening a gap on the hood or opening a gap on the hood, the fire can be quickly extinguished.

In short, a car is a combination of inflammable and explosive dangerous goods, high-temperature fire sources and high-voltage and low-voltage wires. The oil circuit and wires are complex, so it can be said that it is a mobile matchbox. In order to prevent automobile fire, it is necessary to carry out regular maintenance on vehicles, regularly check whether there is leakage of electrical appliances, switches and wires, strengthen the inspection of fuel leakage, promptly eliminate such faults as "leakage", "oil leakage" and "air leakage", replace bad accessories, ensure the safety of vehicle circuits and oil circuits, keep vehicles in good working condition at any time, stay away from "fire source" or "spontaneous combustion environment", and equip with on-board fire extinguishing equipment.

I hope I can help you.