A brief introduction to the function of automobile sensor
Vehicle sensor is an input device of vehicle computer system. It transfers all kinds of operation information of vehicle, such as speed, temperature of various mediums, and operation condition of engine, and so on, and transfers it into electrical signal to lose to computer, so that the engine is in the best working state.
Common types of automobile sensors
1, throttle position sensor
Principle: the throttle position sensor is installed on the throttle to detect the opening of the throttle. It interacts with the throttle through the lever mechanism, and then reflects the different working conditions of the engine. The sensor can check the different operating conditions of the engine and enter the electronic control unit (ECU) to control the different fuel injection.
It has three types: type switch contact type solar term door position sensor (Santana 2000 and Tianjin three peak bus), linear variable resistance type solar term door position sensor (Beijing Cherokee), integrated solar term door position sensor (domestic Audi 100 V6 engine).
2, inlet pressure sensor
Principle: the intake pressure sensor can measure absolute pressure in the intake manifold according to the load state of the engine, and convert it into electrical signal and rotational speed signal, and send it to the computer as a basis for deciding the basic fuel injection quantity of the injector.
Application: the Audi type 100 car (V6 engine), Santana 2000 car, Beijing Cherokee (25L engine), TOYOTA crown 3 car and so on are all used this pressure sensor. At present, the semiconductor pressure sensitive resistance type intake pressure sensor is widely used.
3, crankshaft position sensor
Principle: also known as the crank angle sensor, the sensor is the most important in computer controlled ignition system, its function is to detect the TDC signal, the crank angle signal and the engine speed signal, and the input to the computer so that the computer can send instructions according to the optimal ignition time of the cylinder ignition sequence.
Applications: there are three types of crankshaft position sensors: electromagnetic pulse type crankshaft position sensor, Holzer effect crankshaft position sensor (Santana 2000 car and Beijing Cherokee), photoelectric effect crankshaft position sensor. The type of the crankshaft position sensor is different, and its control mode and control precision are also different. The crankshaft position sensor is usually installed on the side of the crankshaft pulley or sprocket, some installed on the front end of the camshaft, and some installed on distributor (Santana 2000).
4. Air flow sensor
Principle: air flow sensor is to transfer the air into an electrical signal unit (ECU) as an electrical signal, as one of the basic signals to determine the injection.
Application: according to the principle of measurement is different, can be divided into rotary vane type air flow sensor (TOYOTA pVIA wagon), Carmen vortex air flow sensor (TOYOTA Lexus LS400), hot wire air flow sensor (Volvo B230F engine Nissan Trinidad carriage with VG30E engine and the domestic Tianjin three peaks with TJ6481AQ4 bus) and hot film air flow sensor of four types. The former two are volume flow type, and the latter two are mass flow type. At present, the hotline air flow sensor and hot film air flow sensor are mainly used in two kinds.
5. Detonation sensor
The detonation sensor is installed on the cylinder body of the engine to monitor the detonation of the engine at any time. At present, there are two categories of resonance and non resonance type.
Many sensors are used to judge the fault of the sensor. It should not only consider the sensor itself, but the whole circuit of the fault should be considered. Therefore, in addition to the inspection of the sensor, the wiring harness, the connector and the related circuit between the sensor and the ECU are also checked.