Oil injector suction inflection point detection circuit, turn-on time calculation method and system

Abstract

The invention discloses an oil injector suction inflection point detection circuit, a turn-on time calculation method and a system. The oil injector suction inflection point detection circuit comprises a sampling circuit, a DA converter and a comparer, wherein the sampling circuit is used for collecting the driving circuit of an oil injector in real time, and the DA converter is controlled by a digital signal to adjust the analog output; one input end of the comparer is connected with the output end of the DA converter, and another input end of the comparer is connected with the sampling circuit; the analog output of the DA converter is controlled to change according to a certain step size to trigger the output switching activity of the comparer; and the output switching pulse of the comparer is related to the generation time of the suction inflection point of the oil injector. The oil injector suction inflection point detection circuit, the oil injector turn-on time calculation methodand the system can accurately detect the generation time of the suction inflection point of the oil injector and accurately calculate the turn-on time of the oil injector without the influence of thechange of solenoid valve parameters.

Description

technical field [0001] The invention relates to the technical field of fuel injectors, relates to a fuel injector pull-in inflection point detection circuit, and also relates to a fuel injector opening time calculation method and system. Background technique [0002] Gasoline engine fuel injector (hereinafter referred to as "fuel injector") is an executive element in the engine electronic injection system, which is used to spray high-pressure fuel regularly and quantitatively. Usually, the fuel injector is a solenoid valve. There is an electromagnetic coil inside the fuel injector, and the outside is connected to the fuel injector control device through a socket. The needle valve at the head of the fuel injector is connected with the armature. Suction is generated, the armature and the needle valve are sucked up, the fuel injection hole is opened, and the fuel is sprayed out at high speed through the annular gap between the pintle of the needle valve head and the injection h...

AI Technical Summary

Problems solved by technology

[0003] The injector will generate a current inflection point when the armature starts to move and the armature is fully seated. The opening time of the injector is related to the generation time of the injector’s suction inflection point (that is, the armature is fully seated). In order to correctly calculate the opening of the injector Time needs to detect the inflection point of the injector. At present, most of the differential circuits are used to detect the inflection point of the injector. The differential circuit needs to use high-precision resistors and capacitors to build detection circuits. High-precision resistors and capacitors are expensive. , and the differential circuit is sensitive to the rate of change of the current, if the inductance parameter of the solenoid valve changes due to aging, it will cause the differential circuit to fail to detect the inflection point of pull-in

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