Application of infrared thermal imager in the automotive industry


The application of infrared thermal imaging technology in the automotive field has been around for a long time. In addition to routine thermal imaging inspections of electrical equipment in automotive production plants, the use of a wide range of thermal imaging cameras in automotive development allows for more efficient, faster and more accurate diagnosis of automobiles. Related defects in design, structure, etc. Here are a few pictures and text descriptions for typical diagnostic applications:

1. Engine fault diagnosis:

In general, the engine is subjected to vibration and noise tests for overall structural evaluation. However, for some minor defects of the engine (for example, tiny cracks, subtle structural design differences, etc.), it is difficult to accurately diagnose the first two methods. Infrared thermal imaging technology can reflect the subtle structural defects into subtle temperature differences, so that it can achieve the diagnostic results that cannot be achieved by other methods. By taking the heat map of the internal engine of the car, we can see the temperature distribution inside the engine car at a glance. . The temperature at each component location accurately reflects the performance of the engine in actual operation.

2. Brake system fault diagnosis:

The brake diagnosis of a vehicle depends on many factors. The front brake system is responsible for a large proportion of braking depending on the weight distribution, vehicle size, and vehicle height. Using a thermal imaging camera to compare the temperature of the front and rear wheels of the vehicle is simple and feasible. In general, the temperature of the front wheels should be higher than the temperature of the rear wheels. If the temperature of the two front wheels (or the rear wheels) is also different, it can be judged that there is a lack of smoothness in the brake system, which may be due to air. The figure above shows the front wheel temperature distribution of the actual shot.

3, **body air tightness test:

The quality of the car’s air conditioning system is critical to the use of the car, and the overall air tightness of the car body will directly affect the efficiency of the air conditioning system. When conducting a car test, turn on the air conditioning system inside the car (run for a period of time), and then use the infrared camera to take a picture of the whole car. If the airtight leak occurs in the door of the car, the glass joint, etc., it can be seen that the temperature here is not the same as the ambient temperature. Thereby an accurate analysis and evaluation of the overall air-tightness of the vehicle body can be provided.

4, the detection of the window heating wire:

The heating wire is located in the rear glass of the car, and its normal operation will directly affect the safe driving of the car in the foggy situation. The use of thermal imaging cameras allows for a comprehensive and rapid diagnosis of the distribution of the entire heating wire.

5, the detection of automobile exhaust pipe:

Excessive temperature of the exhaust pipe can reflect insufficient combustion, which provides an indirect assessment of the operating conditions of the engine system. If the temperature distribution of the pipeline is not uniform, it can reflect the structural defects of the pipeline itself. Others, the bearing system of the chassis of the car, the electrical equipment, the comfort of the vehicle body, etc., can all be detected and diagnosed by the thermal imager.

6. Motor detection

The most common motor fault is bearing damage and stator-rotor friction. The common feature of the two is that in the event of a fault, the temperature inside the motor and the casing will increase significantly. The thermal imaging camera is based on this feature. Infrared detection works.

Bearing failure:

Under normal conditions, after a certain period of operation, the bearing will gradually wear out and eventually cannot be used. This is a normal phenomenon. However, the foundation of the motor is not stable, the mechanical transmission is not stable, the excessive vibration, the intrusion of dirt and impurities, the excessive or too little lubricating oil, and the unreasonable method of installing and disassembling the bearing cause the bearing to be damaged quickly. The obvious signs of bearing damage are: the bearing and the bearing cover are overheated, the vibration of the motor is intensified, and an abnormal sound is emitted, which increases the load torque of the motor, causing the motor to overheat, and often causes the motor to rotate.

Fixed rotor failure:

The reason why the stator and rotor of the motor are rubbed in addition to the bearing damage, the bending of the rotating shaft, the deformation of the core, the crack of the base and the end cap, the end of the end cover are not tight, and the internal friction of the motor will cause the rotor to rub. The stator and rotor phase rubbing will cause strong sound and vibration of the motor, causing high temperature on the surface of the phase rubbing. In severe cases, it will also generate smoke and sparks. The insulating material on the surface of the tank becomes brittle at high temperature and even burns the coil.

How to do infrared thermal image detection of motor

The infrared camera can also directly display the highest temperature or the lowest temperature value of the subject while obtaining the infrared image. When the above two types of faults occur, the temperature of the faulty part will be abnormally high. The infrared camera can accurately detect the highest temperature, so that the exact location of the fault can be directly found, which is quick and convenient, and can greatly reduce the fault check of the staff. time.

7. Car tire testing

Tires, shouldering the important responsibility of vehicle safety, its quality and performance are related to the overall performance of the car. The performance of the tire material is closely related to the temperature. The overall working condition of the tire can be understood by observing the surface temperature of the tire.

Excessively high temperature on the surface of the tire can lead to severe degradation of the material properties of the tire, resulting in rapid damage to the tire; if the temperature is too low, the grip provided is not sufficient to withstand the power of the car, and the car can be difficult to handle and slip.

Using a thermal imaging camera system to monitor and analyze the temperature of running tires can help tire design engineers to test tire performance more intuitively. It can also help improve tire design, select better tire materials, and improve tire product quality. Overall performance of the car.

8. Automotive air conditioning testing

  a dust clogged

The automobile air conditioner evaporator is exposed to a dusty environment for a long time, and if it is not cleaned in time, the heat exchanger fins are excessively thick or dirty. If the evaporator fins or the outer filter are clogged, the indoor air volume is insufficient and the cooling efficiency is low. If the condenser fins are clogged, the flow resistance of the inlet and outlet airflows will increase, the air volume will decrease, and the condensing pressure and condensation temperature will increase. When the ambient temperature is high in summer, the compressor will frequently open and stop, even Burn the compressor and drag the motor.

The infrared camera can be used to see the difference between the normal position and the dust position displayed during the operation of the evaporator, so that the dust collection position can be quickly found and the maintenance personnel can be processed in time.

b fin damage deformation

The evaporator and condenser fins (also known as ribs) are tightly sleeved over the outer wall of the copper tube, and the sheet spacing is evenly aligned. For example, if the fins are accidentally knocked down during handling and installation, the light will affect the amount of air in and out, reduce the heat exchange efficiency, and reduce the cooling capacity or heat (heat pump type); the heavy one will make the compressor not work. .

c pipeline rupture leak

The evaporator and the condenser coil or U-tube are welded. When the welding head leaks, oil traces generally occur. This failure may result in low evaporation temperature and pressure or low condensation temperature and pressure.

The evaporator is monitored. If the leak is serious, it can be directly seen through the monitored infrared picture. If it is only a suspect, the temperature trend generated by monitoring for a period of time can be used to analyze whether there is a real leak.

d evaporator frosting ice

Whether it is an integral air conditioner or a split air conditioner, when the cooling is normal in the summer, the indoor evaporator condensation is normal, and the frost is not correct. The frosting (ice) of the evaporator is generally not caused by the evaporator itself. The causes of frosting are: (1) the temperature controller fails or the temperature is set too low; (2) the air volume is too small; (3) the refrigerant bias More or insufficient; (4) the evaporator pressure is too low; (5) the evaporator surface is dirty.


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