Dual-common-rail injection-rate-variable diesel oil injection system used for diesel engine

Abstract

The invention discloses a dual-common-rail injection-rate-variable diesel oil injection system used for a diesel engine, and belongs to the technical field of diesel oil injection systems used for diesel engines. By adoption of the dual-common-rail injection-rate-variable diesel oil injection system used for the diesel engine, the problems that in the prior art, the injection pressure of a conventional common-rail injection system is constant in each injection process, the main injection rate shape of an electric-control injector is only rectangular, and consequentially, the combustion and fuel economical efficiency and the combustion noise of an engine are directly affected, and the optimal requirement of the engine for overall working conditions cannot be met are solved. According to thedual-common-rail injection-rate-variable diesel oil injection system used for the diesel engine, the injection pressure can be decreased and increased in each injection process through two oil rails,one cylinder and two electric-control injectors while the injection pressure is independent of the rotating speed of the engine, so that an ideal injection rate which can be changed continuously andflexibly is finally obtained, and the injection rate shape meets the requirement of the engine for the overall working conditions.

Description

technical field [0001] The invention belongs to the technical field of diesel injection systems for diesel engines, in particular to a dual common rail variable injection rate diesel injection system for diesel engines. Background technique [0002] With the increasingly stringent emission regulations, the limit value of exhaust pollutants is getting lower and lower, especially in recent years, the limit value of diesel engine exhaust pollutants (mainly particles and nitrogen oxides) has reached the level of China V or China VI. In order to reduce the above two exhaust pollutants at the same time and make engine emissions meet the requirements of emission regulations, electronically controlled high-pressure common rail injection technology has become one of the implementation strategies to meet emission regulations. [0003] Electronically controlled high-pressure common rail injection technology refers to a closed-loop system composed of high-pressure oil pump, high-pressur...

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Problems solved by technology

[0005] During a single fuel injection process, the fuel injection pressure of the conventional common rail fuel injection system is constant, so that the shape of the main injection fuel injection rate of the electronically controlled fuel injector is only a rectangle. This characteristic is very important for engine combustion, fuel economy and combustion noise. It has a direct impact and cannot meet the best requirements of the engine under all operating conditions

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