Electronic control high-pressure common rail fuel injecting device

Abstract

The invention discloses an electronic control high-pressure common rail fuel injecting device comprising an electronic control high-pressure common rail fuel injector, a high-pressure common rail, an electronic control unit (ECU), a fuel selector switch, a differential pressure control valve and a high-pressure lubricating oil rail. By using the selector switch and selecting and starting various fuel subprograms stored in the ECU by switching a signal input circuit of the fuel programs, the device solves the problems of the switching of various fuels for the electronic control high-pressure common rail fuel injector to combust and the matching and lubrication of a slidably-matched circular hole surface of the electronic control high-pressure common rail fuel injector and a needle valve; and the ECU controls the frequency of an electronic control two-way valve to be higher than 1KHz. The invention avoids the wear and the failure of the needle valve, improves the work reliability, can combust various fuels with different components, not only can accurately control the optimal start fuel injection time and pulse width of various fuels, but also can control the speed of the fuel and allow a diesel engine to obtain the minimum fuel consumption rate and emission pollution.

Description

technical field [0001] The invention belongs to the technical field of internal combustion engines, and relates to a diesel engine fuel injection system, in particular to an electronically controlled high-pressure common rail fuel injection device. technical background [0002] Diesel engine has high thermal efficiency and has become a widely used engine. Diesel engines use diesel as fuel. As the world’s oil resources have decreased year by year in recent years, diesel prices have risen sharply. Countries around the world are looking for and promoting alternative fuels for diesel; national emission regulations and vehicle fuel consumption limits are becoming increasingly stringent, and countries around the world are constantly To improve diesel engines, it is necessary not only to reduce the fuel consumption rate and emissions of diesel engines, but also to make diesel engines suitable for burning different types of diesel alternative fuels in various regions. The world has...

AI Technical Summary

Problems solved by technology

At present, there are two general problems in the use of alternative fuels in diesel engines: one is that the pressure of fuel injection, the start of fuel injection, the fuel injection volume, and the fuel injection rate are important factors affecting the fuel consumption rate and emission pollution of diesel engines. The physical and chemical properties of the fuel are different, and the optimal fuel injection pressure, fuel injection timing (fuel injection advance angle), fuel injection quantity, and fuel injection rate are different when they are used in diesel engines. These parameters are different in the use of existing diesel engines It is difficult to adjust according to the replacement of fuel types, so the improved alternative fuel diesel engines are generally only suitable for burning one kind of fuel. Due to the different types of alternative fuels and the insufficient supply of alternative fuels in different regions due to different resources, the use of alternative fuels Diesel engines are difficult to popularize and apply; secondly, the viscosity of most of the alternative fuels is lower than that of diesel, while the plunger couplings of fuel injection pumps and needle valve couplings of fuel injection nozzles of diesel engines are lubricated and sealed by diesel oil, and low-viscosity alternative fuels are used. The fuel is prone to the problem of wear and failure of the plunger couple and the needle valve couple. At present, the method of adding viscosity-increasing additives to low-viscosity alternative fuels is used, but this also brings about increased fuel costs and the transformation of additives into diesel engines during combustion. New pollutants and additives in use gradually thicken the adhesion layer on the needle valve assembly of the injector, and the needle valve assembly sticks to death.

In order to solve the wear problem of the needle valve coupling, the utility model patent "Lubricating Device for Dimethyl Ether Engine Injector" (authorized announcement number CN1599266Y) provides a pressure regulating valve through the outlet of a high-pressure gas tank and a lubricating oil booster cylinder. The large oil cylinder is connected, and the lubricating oil in the pressurized small oil cylinder is pressed into the oil chamber on the needle valve mating surface through the pipeline to lubricate and seal. It is difficult to supply oil for a long time, especially the pressure difference between lubricating oil and fuel cannot be controlled. If the lubricating oil pressure is too high, it will flow into the fuel, and when it is too low, the low-viscosity dimethyl ether fuel will enter the fitting gap and cause the needle valve to wear and fail. Therefore, this device has no practical application examples so far; in order to solve the above problems, the invention patent "Double Fuel Pump Injection System for Diesel Engines" (authorized announcement number CN1312393C) invented a mechanical fuel injection system that uses two fuel pumps to inject two fuels, so that the diesel engine can burn two fuels. With two types of fuel, it is difficult for the mechanical fuel injection system to meet the National IV emission standard and the stricter fuel consumption limit in the future. There is also a problem that the needle valve of the fuel injector may be damaged when fuel with low viscosity (such as dimethyl ether) is used. The problem of easy wear and failure of parts

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