diesel tachometer magnetic pickup

• 2022-05-07

Sensor mounted on flywheel housing of diesel engine Electromagnetic non-contact. It has nothing to do with the number of flywheel teeth, but pay attention to the installation distance. As long as the output signal is good and the tachometer display is consistent with the actual situation, it can be used. In addition, pay attention to whether the output voltage range is different from the original one. The sensor of diesel locomotive mainly has several functions: first, judge the top dead center of the engine and determine the timing of fuel injection; 2、 The output signal will display the engine speed. The sensor generally generates a pulse signal every time it scans a tooth. The specific number of teeth for one revolution is set in the ECU, so it will not be affected. However, pay attention to ensure that the output signal of the sensor is consistent with the original sensor signal. Otherwise, in addition to inaccurate speed, the operation of the fuel injection system may be affected. Usually, the domestic diesel engine is a magnetoelectric speed sensor. When the flywheel rotates, the magnetic signal is converted into electronic signal through the sensor.

The engine speed of diesel engine is mostly induced by magnetic pulse or magnetic winding. Magnetic pulse induction mode: the speed sensor collects the speed signal of the diesel engine so that the ECU can calculate the circulating fuel supply, and can also provide the crankshaft position signal so that the ECU can accurately control the fuel injection timing; The auxiliary speed sensor is used as the speed signal to calculate the signal of crankshaft angle and judge the cylinder. Magnetic winding mode: function of camshaft position sensor: each revolution of camshaft provides a signal to ECU, which determines that the piston of that cylinder is at the top dead center of compression stroke.

Mechanically, the flywheel speed is directly connected to the meter with a flexible shaft, and the pointer in the meter will swing according to the speed. The swing value can be read on the dial. The electronic type is a flywheel with an induction head, and a proximity switch is arranged next to it. The time interval of the induction signal is calculated by software to convert it into speed. Then it is reflected in the form of pointer or number.