Analysis on the causes of auto spontaneous combust

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Analysis on the causes and preventive measures of automobile spontaneous combustion

automobile fire is one of the most serious accidents in road traffic accidents. It will not only cause serious economic losses, but also endanger people's life safety. There are many reasons for vehicle spontaneous combustion, mainly caused by improper maintenance at ordinary times, aging of oil circuit, circuit, oil leakage, electric leakage or mechanical friction fire caused by long-term lack of maintenance

1 causes of spontaneous combustion

1.1 line

sudden spontaneous combustion accidents of cars are mostly caused by line faults. The vehicle's electrical circuit, the insulator of the live wire is damaged, and grounding or electrical grounding will cause a short circuit, especially for vehicles with worn lines and disordered arrangement

in automobile spontaneous combustion accidents caused by line faults, most of the reasons originate from random changes to the line. Many car owners like to add anti-theft devices, upgrade sound systems, add air conditioners and so on to their new cars according to their personal preferences. However, due to the failure to analyze the line layout and specific structure of the vehicle, and the failure to calculate the line power, there have been situations such as random wiring, no insurance in places with heavy load, and no effective fixation in places prone to friction. Once the problems of leakage, overload, wear and grounding occur, a large amount of heat energy will be generated locally. If there are inflammables around, spontaneous combustion accidents will be inevitable

in addition, the short circuit between the live wire (positive wire) of the battery on the vehicle and the metal body on the vehicle will also produce a high-temperature arc, and the force zero point will generally show up and down vibration. In case of leaking gasoline, it is very easy to cause a fire

the skin between the cable and the frame and clamp is broken due to vibration and friction; The tail lamp and brake lamp wires are damaged due to vibration and friction; The insulating parts of the lamp holder installation are loosened and damaged due to vibration and damage of connectors; When the vehicle is running or parking, it will be grounded by itself, and the fire will jump for a long time, resulting in high temperature, causing electrical appliances, switches, flail knocks and wooden loads ɑ Do you want to read the paragraph В Let's take a look at the future. Let's look at the future. Let's take a look at the future/Div

1.2 oil leakage

fuel leakage is another important cause of auto spontaneous combustion. On some ordinary carburetor cars, the gasoline pump is mostly installed in the engine compartment, and is very close to the engine block and distributor. Once the fuel leaks, the mixture reaches a certain concentration, and there is an open fire, spontaneous combustion accidents will be inevitable. When the fuel in the vehicle leaks, the motor vehicle itself has many ignition sources that can ignite gasoline, such as high-voltage sparks generated by the ignition system, high-temperature arcs generated by the external short circuit of the battery, high heat generated by the engine exhaust. Its self-healing, self decomposition, self diagnosis, self-made functions, etc. will make full use of all aspects of resource temperature or ejected carbon sparks, three-way catalytic reactor in a high temperature state, etc, The oil leakage points are mostly at the joints, the places where the rubber pipes are easy to rub outside the hot body (movable rods), the joints between fixed parts and non fixed parts and other weak places; Leakage of brake oil, hydraulic oil, engine oil, etc. will also cause spontaneous combustion accidents. For example, oil leakage flows into the rectifier tube of the generator, causing a short circuit in the rectifier tube inside the generator, which will also lead to a spontaneous combustion accident. If transmission oil and power steering pump oil leak to the high-temperature exhaust pipe, it will also cause a fire

1.3 leakage

this is mainly caused by the aging of electrical components on the circuit. When the engine is working, the temperature of the ignition coil is very high, which makes the insulation layer of the high-voltage ignition wire soften, age and crack for a long time. The high-voltage electricity of the ignition is easy to break through the insulation layer, and it is easy to produce high-voltage electricity leakage, causing the temperature at the leakage to rise continuously. In case of oil leakage such as the engine oil pipe, it is very easy to cause ignition and combustion. Therefore, it is necessary to regularly check the connectors of each energized wire. If there is any loosening or falling off, tighten the loose connectors in time, and replace the leakage ignition coil, distributor, high-voltage wire, spark plug, etc

1.4 excessive friction of parts

dry friction between automobile parts will produce high temperature, and contact with combustibles can lead to fire. The operating temperature of the gearbox, transfer case, wheel and transmission shaft is lower than the ignition point of the lubricating oil, but if the bearing, piston, cylinder and gearbox cause excessive dry friction due to wear or manufacturing defects, excessive heat will be generated and spontaneous combustion will be caused

the friction between the friction plate fixed on the brake shoe and the brake drum or brake disc will generate a lot of heat. If the brake fluid leaks, this accumulated heat will heat the oil to its ignition point and cause a fire. The gap between the brake pad and the wheel hub in the motor vehicle braking system is adjusted too tight or the brake needs to be used for a long time due to road restrictions (downhill road), which can also cause friction to generate heat, causing the brake drum to overheat, and then the brake drum will transmit the heat to the nearby combustibles (tires or brake fluid). The increase of the brake fluid temperature causes the pressure to rise, which may cause the rupture of the brake oil circuit, and the brake fluid will be sprayed onto the hot power supply to turn on the brake drum and be ignited

in addition, the friction between the commutator of generator and starter and the brush will also cause sparks, which will leave a fire hazard in case of leaked gasoline

1.5 the contact resistance is too large

the line contact is poor, and the local resistance is too large to generate heat energy, which makes the wire contact heat and causes the combustible materials to catch fire. This situation is mostly caused by the loosening of line contacts due to long-term vibration or cold and heat changes during the driving of vehicles. Especially when there are impurities on the surface of the battery or the terminal, oil stains and long-term corrosion, resulting in loose connection points and fire. When the vehicle is decorated, the breaking force of ropes increases, audio-visual and communication equipment, automatic alarm devices, air conditioners, etc. due to the disorderly connection of power supply and the increase of load, it is very easy to cause fire hazards

2 preventive measures

in addition to the above factors, the spontaneous combustion of vehicles is more caused by users' failure to go to a regular repair shop for normal repair and maintenance. In the process of daily use, you should strictly follow the requirements of the operation manual, and you must pay attention to the following issues

2.1 for carburetor vehicles, it is not allowed to pour gasoline into the carburetor port

fill gasoline into the carburetor to improve the concentration of mixture in the cylinder. Although this is conducive to starting in case of failure of oil not entering the cylinder, it is useless for failures caused by other reasons, and this may also cause backfire, burn personnel and cause vehicle fire

2.2 keep away from inflammables

nowadays, many automotive interior materials generally do not have fire resistance performance. Once a fire occurs, the fire is easy to spread. Therefore, do not put lighter, perfume and other inflammables in the car, and ordinary vehicles should not carry gasoline, diesel and other inflammables; At the same time, pay attention to keep the engine compartment clean and do not accumulate too much oil dirt, otherwise it is easy to cause a fire after volatilization. When parking the vehicle, it is recommended to avoid the place exposed to the sun as far as possible, and never park the vehicle near inflammables

2.3 the towing iron chain of the oil tanker shall not be wound on the frame

static electricity will also be generated when the oil is rubbed with another object. This kind of static fire may ignite the fuel and cause a fire. Therefore, a grounding wire should be installed on the oil depot, and a grounding iron chain should also be installed on the oil tank truck to prevent electrostatic sparks in the oil tank. This iron chain should not be casually wound on the girder frame, but must be placed on the ground, and the towing area should not be less than 50cm

2.4 it is strictly forbidden to have leakage in the oil circuit system of the car

if there is leakage in the oil circuit of the chassis, and the ignition is delayed and the mixture is diluted, the slow combustion will cause the exhaust pipe to ignite, and the temperature of the car body will rise, which is more than ten times the ignition point of gasoline vapor, and the leaked oil will be ignited, which is very prone to fire

2.5 it is not allowed to use the hanging fire method

sometimes there will be carbon deposition on the automotive spark plug. When the carbon deposition on a cylinder is serious, it should be removed in time

2.6 it is not allowed to carry out self flow oil supply for a long time

sometimes, due to the damage of the gasoline pump or the fuel pipe joint, it is impossible to rely on the gasoline pump for normal oil supply and cannot be repaired temporarily, so we can only take emergency treatment and carry out self flow oil supply. At present, in order to meet the needs of fire prevention, this method is not allowed to be used in China's road traffic management regulations

2.7 it is not allowed to observe the liquid level of the battery with an open fire at night

when driving, the battery is in an overcharged state, and a series of chemical reactions occur inside the battery. When charging the battery, it will decompose the battery liquid and produce hydrogen. If too much hydrogen accumulates in the battery shell, it will cause an explosion. Therefore, the small hole on the battery cover must be kept unblocked at ordinary times. Due to the discharge of hydrogen, it is not allowed to observe the liquid level of the battery with an open fire at night

2.8 do not use gasoline to clean parts

generally, do not use gasoline to clean parts and wipe the car with a wire brush to avoid sparks. After maintenance, carefully check to prevent hidden dangers, especially gloves, cotton threads, gauze heads and other combustibles near high-temperature objects such as exhaust pipes

2.9 it is not allowed to turn on the ignition switch for a long time after the car stops driving.

if it is turned on for a long time, it will not only cause the battery to discharge for a long time, but also leave a hidden danger for the car to self ignite

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