Crankshaft position sensor works - Solutions - Huaqiang

How does the engine electronic control system know which cylinder to ignite? In fact, it is calculated from the signals output by the crankshaft position sensor and the camshaft position sensor. The camshaft position sensor can measure which cylinder piston is in the compression stroke state, and the crankshaft position sensor can measure which cylinder piston is on. At the end, so the two generally work together.
The crankshaft position sensor is used to determine the position of the crankshaft. It is typically mounted in a distributor that detects the position of the top dead center of the piston and also detects the speed of the engine. It is mainly divided into three types: photoelectric, Hall effect and magnetoelectric induction.
The photoelectric crank position sensor consists of a signal plate with a light hole and a signal generator, usually installed in a distributor, and the signal plate and the distributor shaft rotate together. The outer ring of the signal disc will form a signal with a crank angle of one degree; the six optical holes slightly inside will form a signal with a crank angle of one hundred and twenty degrees. The signal generator consists of two light-emitting diodes and photodiodes and circuits mounted on the distributor housing; the photodiode and LED are directly opposite each other. The signal plate is installed between the photodiode and the light-emitting diode, and the light hole on the upper surface forms a phenomenon in which the light shielding and the light transmission are alternately changed. If the light of the LED is blocked, the photodiode has no voltage to form; if the light of the LED is incident on the photodiode, the photodiode forms a voltage. The voltage signal is amplified by the shaping of the circuit, and then the signals of the crank angles of one degree and one hundred and twenty degrees are input to the electronic control unit. At this time, the electronic control unit calculates the engine based on the signals. The speed also has the position of the crankshaft.
Both the crankshaft position sensor and the Hall effect speed sensor operate with Hall effect signals. The Hall signal generator is mounted in the distributor and is coaxial with the sub-fire head. The permanent magnet and the packaged Hall chip are fixed to the distributor disc as a whole. The number of engine cylinders is the same as the number of notches on the trigger impeller. When the blade above the impeller is triggered to enter between the Hall element and the permanent magnet, the magnetic field of the Hall trigger is bypassed by the blade. The voltage is zero, so the sensor has no signal output; when the gap on the impeller is triggered between the Hall element and the permanent magnet, the magnetic line enters the Hall element. At this time, the Hall voltage will increase and the sensor will There will be a voltage signal output.
The magnetoelectric induction speed sensor and the crank position sensor are respectively located on the upper and lower layers of the distributor. The sensor consists of a rotor and a permanent magnet induction detection coil, wherein the rotor rotates as the distributor shaft rotates. There are many forms of timing rotors. The rotor of the speed has twenty-four teeth, and the permanent magnet induction detection coil should be fixed to the distributor. If you know the signal of the crankshaft position sensor and the signal of the speed sensor, as well as the working sequence of each cylinder, you can identify the position of the crankshaft of each cylinder. Both of their rotor signal plates can be mounted on a camshaft or a crankshaft.