1. Crankshaft and camshaft position sensors
Crankshaft position sensor? Location? Sensor (CPS), also known as engine speed and crank angle sensor, is used to collect crank angle and engine speed signals and input them to electronic control unit (ECu) to determine ignition time and fuel injection time.
2. Photoelectric crankshaft and camshaft position sensors
design feature
The photoelectric crankshaft camshaft position sensor produced by Nissan Company is improved from the distributor, which is mainly composed of signal panel (i.e. signal rotor), signal generator, distributor, sensor housing and wire harness plug.
3. Magnetic induction crankshaft and camshaft position sensors
The working principle of the magnetic induction sensor is that the path through which the magnetic lines of force pass is the air gap between the stator and rotor of the permanent magnet N-pole, and the air gap between the rotor's convex teeth and the stator's magnetic head, magnetic head, magnetic conductive plate and permanent magnet S-pole. When the signal rotor rotates, the air gap in the magnetic circuit will change periodically, and the reluctance of the magnetic circuit and the magnetic flux passing through the signal coil head will also change periodically. According to the principle of electromagnetic induction, alternating electromotive force will be induced in the induction coil.
Magnetic induction crankshaft position sensor for Jetta and Santana cars
1) Structural features of crankshaft position sensor: The magnetic induction crankshaft position sensor of Jetta AT, GTX and Santana 2000GSi cars is installed on the cylinder block near the clutch side in the crankcase, and is mainly composed of a signal generator and a signal rotor, as shown in Figure 2-25.
The signal generator is fixed on the engine block by screws and consists of permanent magnets, induction coils and wire harness plugs. Induction coil is also called signal coil. The permanent magnet has a magnetic head, which is opposite to the toothed signal rotor installed on the crankshaft. The magnetic head is connected with the yoke (magnetic plate) to form a magnetic conduction loop.
Jetta AT, GTx, Santana 2000GSi car magnetic induction crankshaft position sensor signal as reference signal, ECU controls fuel injection time and ignition time according to the signal generated by large backlash. When ECu receives the signal generated by large backlash, it controls the ignition time, fuel injection time and primary current conduction time (i.e. conduction angle) of the ignition coil according to the signal of small backlash.
3) Toyota TCCS magnetic induction crankshaft and camshaft position sensor.
The magnetic induction crankshaft camshaft position sensor used in Toyota Computer Control System (1FCCS) is improved from the distributor and consists of upper and lower parts. The upper part is a generator for detecting crankshaft position reference signal (i.e. cylinder identification and top dead center signal, called G signal); The lower part is divided into the crankshaft speed and angle signal of the generator (called Ne signal).
4. Hall crankshaft and camshaft position sensor
Structure and working principle of Hall sensor
Hall-type crankshaft and camshaft position sensors and other types of Hall-type sensors are based on Hall effect.
Hall effect: Hall effect (Hall? Is it John from America? Dr. E.H.Hall, a physicist at Hopkins University, first discovered it in 1879. He found that when a rectangular platinum conductor with a current of I is placed in a magnetic field perpendicular to the magnetic field lines with a magnetic induction of B (see Figure 2-27), a voltage UH perpendicular to the current direction and the magnetic field direction will be generated on the two lateral sides of the platinum conductor, and it will disappear immediately when the magnetic field is cancelled. This voltage is later called Hall voltage, and UH is directly proportional to the current I passing through the platinum conductor and the magnetic induction B, that is (see next page).
Components made of Hall effect are called Hall elements, and sensors made of Hall elements are called Hall sensors. Using the Hall effect, not only the voltage but also the current flowing through the wire can be detected by switching the magnetic field, because the magnetic field around the wire is proportional to the current flowing through the wire. Since 1980s, the number of Hall sensors used in automobiles has increased dramatically, mainly because Hall sensors have two outstanding advantages: first, the output voltage signal is similar to a square wave signal; Second, the output voltage has nothing to do with the rotational speed of the measured object. Hall sensor is different from magnetic induction sensor, which needs external power supply.
(2) Hall camshaft position sensor of Jetta and Santana cars.
Differential Hall Crankshaft Position Sensor
Cherokee jeep and Hongqi CA7220E cars adopt differential Hall crankshaft position sensors, and their camshaft position sensors are all ordinary Hall sensors.
5. Structural characteristics of differential Hall sensor
The differential Hall sensor, also known as the dual Hall sensor, is similar to the magnetic induction sensor in structure, as shown in Figure 2-30a. It consists of a signal rotor with convex teeth and a Hall signal generator. The working principle of differential Hall sensor is the same as that of ordinary Hall sensor. According to the working principle of Hall sensor. When the missing teeth and protruding teeth on the engine flywheel rotate the two probes of the differential Hall circuit, the air gap between the missing teeth or protruding teeth and the Hall probe will change, and the magnetic flux will also change accordingly, and an alternating voltage signal will be generated in the Hall element of the sensor, as shown in Figure 2-30b. Its output voltage is formed by the superposition of two Hall signal voltages. Because the output signal is a superimposed signal, the air gap between the rotor teeth and the signal generator can be increased to (10.5) mm (only 0.2 ~ 0.4 mm for a common Hall sensor), so the signal rotor can be made into a toothed disk structure like the rotor of a magnetic induction sensor, and its outstanding advantage is that the signal rotor is easy to install. In automobiles, the toothed rotor is usually installed on the crankshaft of the engine, or the flywheel of the engine is used as a sensor.
Signal conversion of equipment
(2) The differential Hall crankshaft position sensor of Cherokee Jeep.
1) Structural features: The 2.5L (four-cylinder) and 4.0L (six-cylinder) electronically controlled fuel injection engines of Cherokee Jeep adopt Hall crankshaft position sensors with differential Hall circuits. It is installed on the transmission housing. Sensors provide ECu with signals of engine speed and crankshaft position (angle) as one of the important basis for calculating fuel injection time and ignition time.
(3) Hall camshaft position sensor of Cherokee Jeep.
Structural features: The cylinder discrimination signal of Cherokee Jeep engine control system is provided by Hall camshaft position sensor, also known as synchronous signal sensor. It is installed in the distributor and mainly consists of pulse ring (signal rotor) and Hall signal generator.
There are convex blades on the pulse ring, accounting for 180. Distributor shaft angle (equivalent to 360. Crankshaft angle). The part without blades also accounts for 180. Distributor shaft angle (360. Crankshaft angle). The pulse ring is installed on the distributor shaft and rotates with the distributor shaft.
(4) Hall crankshaft position sensor of differential of Hongqi CA7720E car.
The differential Hall crankshaft position sensor used in SIMOS4S3 electronic fuel injection system equipped on CA488.3 engine of Hongqi CA7220E car consists of a signal rotor and a signal generator. The signal rotor is a toothed disc, which is installed at the front end of the transmission housing. It is similar to the rotor of the magnetic induction crankshaft position sensor used on Jetta AT and GTX cars, with 58 convex teeth evenly distributed on its circumference. There are 57 small teeth missing and one big tooth missing. Output reference signal with large backlash, corresponding to a certain angle before compression top dead center of engine 1 cylinder or cylinder 4. The radian occupied by a large backlash is equivalent to that occupied by two convex teeth and three small backlash. Because the signal rotor rotates with the crankshaft, the crankshaft rotates once (360. ), the signal rotor also rotates once (360. ), so the crank angle of the convex teeth and backlash on the circumference of the signal rotor is? 360。 The crank angle of each convex tooth and small backlash is 3. (58×3。 +57×3。 =345。 ), the crankshaft angle occupied by large backlash is 15. (2×3。 +3×3。 =? 15。 ),
The application and application principle of the position sensor have been explained clearly above. I hope Tutu's explanation is what you want. With the gradual improvement of living standards, position sensors are gradually proposed and applied to intelligent transportation, fuel efficiency detection, ground buildings and other fields. Although most of these are still under consideration, the application of position sensors will certainly expand slowly. The above is the application of position sensor introduced by Bunny. I hope it helps you.