Infrared thermal imaging in automotive electronics

With the rapid development of automotive electronics technology, the proportion of electrical and electronic components in vehicles is increasing, and its importance is increasingly drawing attention. Its quality directly affects the safety of vehicles. In the process of designing and assembling automobiles, the detection and diagnosis of partial electrical faults becomes more and more important. By using a thermal imager, the detection process can be simplified, the working efficiency can be improved, and the quality of the products can be greatly improved.

Automotive Electrical Appliances The main components of modern automotive appliances are:
1 Power system: including battery, generator, regulator. The generator is the main power source. When the generator is working normally, the generator supplies power to the electric equipment of the whole vehicle and charges the battery at the same time. The role of the regulator is to keep the output voltage of the generator constant.
2 start system: including series-excited DC motor, transmission mechanism, control device. Its role is to start the engine.
3 Ignition system: Including ignition switch, ignition coil, distributor assembly, spark plug and so on.
4 Lighting System: Including various types of lights inside and outside the car and their control devices. Used to ensure night driving safety.
5 signal system: including speakers, buzzer, flasher and various traffic signal lights.
6 Instrumentation system: including various electrical instrumentation (ampere meter, charge indicator or voltmeter, oil pressure gauge, thermometer, fuel gauge, speed and odometer,
Engine tachometer, etc.). Used to show the operating conditions of the device in the engine and car.
7 auxiliary electrical system: including electric wipers, air conditioners, low temperature starting preheating device, tape recorders, cigarette lighter, glass lifter and so on. In addition to automotive audio equipment, communications equipment and automotive TV and other service devices, such as electric wipers, electric window washers, electric window regulators, warm air ventilation devices, electric seat movement mechanism, engine cooling fan, electric Fuel pumps, electromagnetic clutches for air-conditioning compressors, etc.
8 electronic control system: including electronically controlled fuel injection device, electronic ignition device, anti-lock brake device, automatic transmission.
The above-mentioned electrical equipment is mainly based on low pressure (12V for gasoline vehicles and 24V for diesel vehicles) and DC electrical circuits, and the power consumption is also relatively small.
With the development of the modern automobile industry, hybrid electric systems have begun to be used in automobiles in order to achieve energy-saving and environmental protection requirements. A hybrid electric vehicle is a battery that uses a battery pack as a power source and is driven by electric motors and engine-driven wheels. In the electrical system, it not only needs the above electrical system, but also increases the hybrid drive electrical system. The hybrid power system mainly consists of three parts: the energy supply system, the electric drive system, and the mechanical transmission system.
(1) Energy supply system: It is composed of a power battery pack and an engine direct current generator set.
(2) Electric drive system: It is composed of inverter and motor.
(3) Mechanical transmission system: The mechanical output of the internal combustion engine and the electric motor is sent to the axle through the clutch and reducer.
The core of a hybrid electric vehicle is to replace its mechanical propulsion system with an inverter-controlled motor system and use battery instead of gasoline as on-board energy to meet the performance and price of the fuel vehicle on the premise of zero emissions or low emissions. The requirements of the indicator.
Automotive Electrical Testing With the rapid development of automotive electronics technology, the proportion of electrical and electronic components in vehicles is increasing, and its importance is increasingly drawing attention. Its quality directly affects the use of vehicles. Safety. In the process of designing and assembling automobiles, the detection and diagnosis of partial electrical faults becomes more and more important. By using a thermal imager, the detection process can be simplified, the working efficiency can be improved, and the quality of the products can be greatly improved.
Fluke Corporation thermal imaging camera is expected to reach, the problem that is immediately shot infrared thermal imager in the automotive circuit diagnosis is mainly applied in what areas?
Current through the medium, due to the existence of a certain resistance of the medium, according to the law of conservation of energy can be learned that the medium will consume a certain amount of energy, while generating a certain amount of heat, reflected in the temperature. The thermal imager can diagnose the presence or absence of design flaws in the circuit through the surface temperature characteristics of the automotive electrical appliances. Using the temperature information obtained, engineers can improve the design of the circuit principle, improve the stability of the entire automotive appliance, and ultimately improve the quality and safety of the vehicle.
The energy supply vehicle's electrical appliances are mainly based on DC voltage and current, and the power consumption is small, but the use of thermal imager can also be used to detect circuit components (
Such as power tube, ECU chip, etc.) temperature, circuit board temperature distribution, other system components (such as batteries, generators, DC motors, coils, fuses, etc.)
The temperature, the temperature of the electrical harness, and the temperature of each electrical contact, using the temperature information obtained, can diagnose whether the related system is faulty or abnormal.
Hybrid electric vehicles are relatively more complicated because electric drive system circuits are added compared to energy supply vehicles. Using a battery as an energy source, a system using an inverter-controlled motor replaces its mechanical propulsion system. This system requires the conversion between AC and DC, and the control of the inverter.
The analysis of the load capacity of the motor requires the use of larger values ​​of voltage, current, and greater power consumption. The performance of these functions has a certain relationship with the surface temperature. The thermal imager can analyze whether each function can work normally.
Typical customers include Lear Automotive, Shanghai Huapu, etc.
Why use an infrared camera to detect the temperature of automotive electrical appliances?
The design rationality, stability and service life of electrical appliances are closely related to temperature, so temperature is a very important parameter. At present, automotive engineers pay more attention to the electrical heating, but the detection method is not very effective and direct.
There are three types of existing temperature measurement methods:
1 Contact Thermocouple (Thermistor)
The contact thermocouple can not accurately test the temperature of the circuit components with smaller target, the reaction speed is slow, and it is inconvenient for the test operation of more points, and when the electrical voltage with relatively high voltage value is detected, such as the hybrid frequency conversion When operating, the operation is very unsafe. The contact thermocouple also cannot display the overall temperature distribution of the target electrical, and it is easy to cause the omission of the temperature anomaly.
2 infrared spot temperature meter infrared spot temperature meter reaction speed, but also non-contact temperature measurement, electrical detection for high voltage is also relatively safe, but the infrared spot temperature detector to detect smaller target circuit components, the display temperature is not accurate , And also does not have the function to display the temperature distribution of the panel as a whole temperature distribution of the target electrical, which easily leads to the omission of temperature abnormal points.
3 Infrared Thermal Imager The infrared thermal imager compensates for the shortcomings of contact thermometers and infrared spot thermometers. It has a fast response speed, safe non-contact temperature measurement, very low temperature detection of components and no problem, and can represent the target electrical temperature. Distribution is the ideal temperature detection tool.
What problems might you encounter while shooting?
1 There are some devices on the circuit board (such as the top surface of electrolytic capacitors, the back of power modules, and other chip-cleaning surfaces), and the emissivity is relatively low, so the detected temperature difference is large. When shooting such devices, the surface of the device should be painted black with black or black paint, and then perform temperature measurement and other operations.
2 When a small target cannot be resolved with a standard lens, the 10.5mm wide-angle lens can be replaced.
How can I do a good job in detecting the thermal image of automotive electrical appliances?
1 Select the thermal imager with high thermal sensitivity as much as possible;
2 first use the automatic mode to measure the temperature range; then manually set the level and span, set the temperature range to a minimum, and include the previously measured temperature range;
3 Switch each palette mode so that the thermal image display effect is the best (high contrast or iron red mode is recommended);