|EFI system of injector|
EFI gasoline injector device is a key component, which controls the ultimate jet fuel, if a problem, the engine work will be normal or not immediately stop working.
Jet carburetor installed in the original position, combined with the throttle, this form is called the single-point electronic-controlled fuel injection, it has the advantages of low cost and simple maintenance, and is due to shortcomings with the cylinder injection point ranging from the result of uneven distribution of fuel, cold-starter, easily fuel in the intake pipe wall adhesion.
Jet installed in each cylinder intake manifold, this form is called multi-point fuel injection control device, and is currently the most gasoline engines used in the form of EFI. It has the advantages of each cylinder has its own jet, the jet intake valve as close as possible to avoid a single point of Electronic Fuel Injection flaws and shortcomings is the high cost of maintenance complex.
At present the majority of automotive engines have adopted multi-point EFI form, but also a small number of types of vehicles using single-point EFI form. If the old carburetor engine will be converted into a single-EFI EFI point form.
General Automotive Electronic Fuel Injection Device has three components: supply of gas supply and control of some parts. Some of them oil from tanks, gas pumps, fuel filter, pressure regulator and fuel injector components, gas pumps gasoline from the tank filter out impurities in the fuel filter, pressure regulator, the pressure to a high pressure gasoline Intake manifold in the negative pressure, then sent to the pipeline by the spray tanks. Jet equivalent of a switch, control switch components is ECU (electronic control unit).
Jet from electromagnetic coil control, and the electromagnetic coil currents on and off is controlled by the ECU. According to ECU sensor feedback signal processing, signal sent to the jet, the signals identified jet injection petrol and open time, and this time interval known as the jet's "pulse width." Jet electromagnetic coil electricity generated from the magnetic field, in the role of the magnetic field of the spring plunger overcome by suction, leaving with a valve seat, under the pressure of gasoline in the mouth emitted from the nozzle when electromagnetic coil magnetic field when electricity disappeared , in the spring plunger under downward force, the valve seat withstand the nozzle mouth closed, the gasoline it from leaving. Valve to construct a ball valve and the valve division two. In order to ensure the precision of the injection, the needle and ball valve or valve seat are required to have a high machining accuracy, and the valve lift small, only about 0.1 mm. The pressure regulator, in front of the injector is a high-pressure Circuit, the rear intake manifold is a low pressure formed a pressure differential negative pressure to ensure that the fuel spray mist formed near the intake valve.
Although more electronically controlled fuel injection system each cylinder has a jet, the jet injector of the pulse width is determined by the amount that is depends on the jet injector open time. However, specific to different injection form, but not all, of the more general Fuel Injection System (MPI) and sequential fuel injection (SFI) points.
In MPI system, the jet was divided into several groups, the same group of the jet at the same time has been opened. For example, a 4-cylinder machine jet divided into two groups, each of the two jet, which the two groups take turns jet injection, the engine crankshaft every lap to a group of jet injector. Such a system is the jet parallel, ECU only to the same group all the same signal injector, the injector in the same amount of time opening and closing, programming simple, streamlined electronic circuits, but it's different for the engine The lack of random changes in the status of the function will produce oil and gas in the inlet manifold stranded phenomenon.
SFI system in a jet connect directly with the ECU, respectively control, it can be precise injector opened just before the intake valve is opened, injector fuel injection period between the two can do instantaneous adjustment of the gas mixture features to adapt to different conditions change. Therefore SFI is electronically controlled multi-point fuel injection system in the most accurate and the best way, many car engines have adopted this approach.