Engine ignition system

When the engine is running, various signals are continuously input into ECU. Besides signals from throttle position sensor, air flow sensor, water temperature sensor, etc. There are also important G signals and Ne signals. G signal is the reference position signal of top dead center. Toyota divides G signal into Gl signal and G2 signal, separated by 180 (crankshaft angle 360). G 1 signal reflects the compression top dead center reference position of the sixth cylinder, and G2 signal reflects the compression top dead center reference position signal of the first cylinder. Ne signal is the engine crankshaft speed signal. G signal and Ne signal are generated by crankshaft position sensor. G signal is generated by two flange timing rotors synchronized with the distributor shaft and G 1 G2 induction coils installed on both sides of the timing rotors; The Ne signal is geNerated by a 24-tooth rotor and an ne induction coil. Every time the distributor rotates, it generates a G 1 signal, a G2 signal and 24 Ne signals. The period of Ne signal is 15 distributor angle, that is, 30 crankshaft angle. G 1 and G2 signals are located at 10 before the top dead center of the sixth cylinder and the first cylinder respectively. According to G(G 1, G2) signal, ECU can accurately calculate the time and engine speed of each revolution of 1 crankshaft. Based on the rotational speed and other sensor input parameters, ECU can look up the table to get the ignition advance angle and the energization time of the ignition coil, then calculate the energization and deenergization time of the igniter after the G signal, and finally output the ignition control signal IGt to the ignition controller. Because IGt signal controls three ignition coils at the same time, ECU also needs to output cylinder judgment signal. At the same time, ECU also generates cylinder judgment signals IGdA and IGdB according to the signals of G 1, G2 and Ne. The ignition controller identifies the cylinder to be ignited according to the level combination of the cylinder judgment signals IGdA and IGdB, and controls the ignition time according to the ignition timing signal IGt. Figure 8- 13 shows the time series waveform of the cylinder judgment signal, and Table 8- 1 shows the state table of the cylinder judgment signal. For example, when IGDA = 1 and IGDB = 0, cylinders 3 and 4 need to be ignited. The cylinder discrimination circuit in the ignition controller turns off the power transistor VT3 and cuts off the primary winding current of the ignition coils of cylinders 3 and 4, so that the secondary of the ignition coils generates high voltage, and cylinders 3 and 4 ignite at the same time.