ignition coil introduce

With the development of gasoline engines in automobiles towards high speed, high compression ratio, high power, low fuel consumption, and low emissions, traditional ignition devices are no longer suitable for use. The core components of ignition devices are ignition coils and switch devices. By increasing the energy of the ignition coils, the spark plug can generate sufficient energy to produce sparks, This is the basic condition for the ignition device to adapt to the operation of modern engines. The ignition coil is divided into two types according to the magnetic circuit: open magnetic and closed magnetic. The traditional ignition coil is used with an open magnetic type, and its iron core is stacked with about 0.3 millimeters of silicon steel, with secondary and primary coils wound around the iron core. The closed magnetic type uses an iron core similar to III to wrap around the primary coil, and then wraps around the secondary coil outside. The magnetic field line is composed of an iron core to form a closed magnetic circuit. The advantage of the closed magnetic ignition coil is that it has less magnetic leakage, Due to its small energy loss and volume, electronic ignition systems generally use closed field ignition coils)

BMW 740Li introduce

The BMW 740Li is a high-end luxury sedan produced by BMW Germany. It belongs to the BMW 7 Series and is only produced locally in Germany. The new 740Li is equipped with a 4.0-liter V8 engine, which is an upgrade from the old 3.6-liter V8 engine. After a minor facelift, the new 7 Series has a more friendly appearance. In addition to using BMW's Double VANOS dual camshaft variable valve timing system, the new engine also uses a continuously adjustable Valvetronic electronic valve drive mechanism, significantly reducing fuel consumption and emissions. The maximum power of the engine is 225 kW, and the maximum torque is 390 Nm. The new i-drive system has also been upgraded to accelerate from stationary to 100 km/h in just 4.6 seconds, making operation faster and more convenient. However, it is still the most complex system among all BMW models