Onboard oil injection quantity control self-learning method for common rail oil injector

Abstract

The invention discloses an onboard oil injection quantity control self-learning method for a common rail oil injector. The conventional self-learning process is relatively convenient to implement, but cannot cover all working rail pressure of an engine, and has certain limitation on learning effect. The method comprises the following steps of: under the condition that the whole vehicle urgently throttles down the engine, implementing a small pulse width injection to a specific cylinder of the engine, monitoring and calculating the ratio of the angular acceleration of the specific cylinder to the angular acceleration mean of other cylinders without fuel injection, and querying a previously calibrated MAP chart of the angular acceleration ratio and the oil injection quantity to realize onboard self-learning of the injection property of the oil injector; and performing self-learning correction on the actual oil injection quantity of the oil injector according to the onboard self-learning result of the injection property of the common rail oil injector. By the method, the actual oil injection quantity of the oil injector is accurately controlled, and the problems of poor injection effect for multi-times and even serious discharge and noise and the like caused by mechanical aging in the using process of the common rail oil injector are solved.

Description

technical field

[0001] The invention belongs to the technical field of electric control of internal combustion engines, and in particular relates to a self-learning method for controlling the fuel injection volume of a common rail fuel injector. Background technique

[0002] The high-pressure common rail fuel injection system can not only achieve higher injection pressure, but also independently and flexibly control the fuel injection timing, fuel injection rate and fuel injection pressure to achieve the ideal fuel injection law, while reducing emissions and ensuring excellent fuel efficiency. power and fuel economy. For diesel engines that adopt a particle filter DPF exhaust aftertreatment system, in order to meet the ideal fuel injection law, 5-stage injection is often used. Such as figure 1 The function description of the five-stage injection is shown: the first and second stages are pre-injection, which can improve cold start performance, shorten the ignition delay per...

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