Is the fuel injector used to realize intermittent injection?

To understand this problem, let's first look at the working principle of the nozzle: the nozzle is an electromagnetic valve, with an electromagnetic coil, a needle valve, a nozzle and a return spring. When the ECU sends a signal to the fuel injector, the electromagnetic coil is turned on, the needle valve is sucked up, and the fuel is ejected through the gap between the needle valve and the nozzle and enters the intake manifold. The fuel injection quantity is determined by the ECU's decision on the length of time to open the fuel injection needle valve according to various information. The basic fuel injection quantity is pre-stored in the memory (ROM) of ECU, and is pre-set by the working state of the engine (i.e. the rotational speed signal from the crank angle sensor and the air flow signal from the air flow meter). When preheating, starting, accelerating, increasing oil supply and reducing oil supply during deceleration, it is necessary to modify the preset oil supply. Timing control of fuel injection: There are generally two injection methods. The first mode is simultaneous injection: in each engine working cycle, it is injected into the cylinder twice at the same time, that is, in each cylinder engine working cycle, pulse signals with equal pulse width are sent from ECU to each injector twice at the same time. The second type is sequential injection: in a working cycle of the engine, it is injected into each cylinder in turn according to the order of ignition, but when the engine is started, in order to supply more fuel, it is injected into each cylinder twice at the same time in a working cycle of the engine. During deceleration or high-speed operation, the oil supply to each cylinder is cut off. Control of fuel injection quantity: The fuel pump pressure of the same type of EFI vehicle is constant, and the fuel nozzle pressure is always constant as long as it is adjusted by the fuel pressure regulator, regardless of the throttle opening. The fuel nozzle is strictly matched with the fuel pump and fuel pressure regulator, and only the designed pressure can achieve the best atomization effect. The pressure is lower than the design pressure, and the sprayed oil is not foggy or columnar, and should not be mixed with air. When the pressure is too high, the sprayed oil is conical and difficult to mix. Moreover, the injection force is too large, and a lot of fuel is directly sprayed on the pipe wall, which directly affects the mixing ratio parameters. The pressure should be constant regardless of acceleration or idling. Different models have different pressures. (The selection of several gears of the cleaning machine mentioned by a friend is actually the pressure selection for different models, not the different acceleration idle pressure, the wrong selection of injection pressure and the poor atomization of the nozzle. ) The injection quantity depends on the injection time. According to the different control methods of electromagnetic coil, fuel injectors are divided into voltage-driven type and current-driven type. Voltage formulas can also be divided into low resistance and high resistance. High resistance can be connected to 12V, and low resistance can only be connected to low voltage. If you connect 12V by mistake for a long time, the coil will be burnt out. When the fuel is injected, the voltage provided by the computer is constant, such as 12V, which immediately becomes 0V when the fuel is cut off. This change is instantaneous, just like 0 and 65438+ in computer language. Alternating current is called alternating current. It seems that there is basically no alternating current in the car except in front of the generator rectifier.