tachometer for single cylinder engine

• 2022-10-24

Ours tachometer can be used on single cylinder engine. Single cylinder engine is the simplest of all engines. It has only one cylinder and is the basic form of engine. When a single cylinder engine is working, the mixture in the cylinder ignites once every one revolution (two-stroke) or two revolutions (four stroke) of the crankshaft. From the sound and vibration, it can be clearly felt that the engine is working intermittently, and the exhaust is also "jerky" intermittent sound. From the point of view of working continuity, the single cylinder engine is unstable, with large speed fluctuation and easy to shut down.

Because the multiple of the calculation formula is different, the motorcycle is loaded with a gasoline engine. Take a car loaded with a gasoline engine as an example. Motorcycles are generally single cylinder engines, and cars are multi cylinder engines. The tachometer signals of gasoline engines are all primary signals from the ignition coils. For four stroke engines, the crankshaft completes work every two revolutions, that is, an ignition signal is generated every two revolutions of the crankshaft. Then the crankshaft speed of a single cylinder engine is: 2 × Number of ignition signals generated within 1 minute; For a multi cylinder engine, every cylinder has to do work once every two revolutions of the crankshaft. For a four cylinder gasoline engine, for example, every two revolutions of the crankshaft will generate four ignition signals. Therefore, its tachometer's speed calculation multiple is different from that of a single cylinder gasoline engine's tachometer, so it cannot be used universally.

The speed signals of diesel vehicles are output by special speed sensors. There are many types. Some take voltage signals, and some take frequency signals generated by sensors. Generally, the flywheel is used as the target pulley, and some phase signals are taken from a certain phase of the generator. During the calculation, the number of generator magnetic poles and the ratio of the generator pulley to the crankshaft pulley should also be calculated.

When you look at the dashboard of diesel vehicles, you feel that there is a big difference between diesel vehicles and gasoline vehicles. The biggest difference lies in the tachometer: the maximum tachometer reading of gasoline vehicles can be as high as 7000~8000 revolutions, individual models can be as high as more than 10000 revolutions, and the maximum speed of single cylinder motorcycles can be as high as more than 15000 revolutions. However, the maximum speed of the diesel vehicle's tachometer is generally about 4000 rpm. The truck's tachometer has a maximum speed of only 2800 rpm, and the most economical speed range is generally about 1500 rpm. It is not recommended to use the high speed range.