Method and system for diagnosing oil return failure of electronic control common rail oil sprayer

Abstract

The invention relates to a method and system for diagnosing an oil return failure of an electronic control common rail oil sprayer. The method comprises the following steps of: a, when the oil sprayer is in a non-spraying state and the rail pressure in a common rail pipe is more than a first preset threshold, diagnosing the oil return failure of the oil sprayer, otherwise, ending a diagnosis program; b, controlling a high-pressure oil pump to ensure that the rail pressure in the common rail pipe is a target pressure value PFin1, when the rail pressure in the common rail pipe is the target pressure value PFin1, stopping the working state of the high-pressure oil pump; c, calculating the variable required in the common rail pipe; d, comparing the variable with a preset reference value, judging whether the oil sprayer generates the oil return failure according to the relationship between the variable and the preset reference; and e, when the rail pressure in the common rail pipe is reduced to the preset pressure limit value, starting the high-pressure oil pump to ensure that the rail pressure in the common rail pipe is a target pressure value PFin2 under the current working condition. The method can be used for realizing online detection on the oil return failure of the oil sprayer and has the advantages of high automation degree and wide application range.

Description

technical field [0001] The invention relates to a fault diagnosis method and system, in particular to a fault diagnosis method and system for oil return faults of an electronically controlled common rail injector, and belongs to the technical field of fault diagnosis of diesel engine oil fuel injection systems. Background technique [0002] Most of the existing fuel injector fault diagnosis technologies focus on the fault diagnosis of the fuel injector's injection state. For example, the Chinese patent CN1773101A discloses a fault diagnosis method for a diesel engine injection system, which judges whether the fuel injector is faulty according to the transient speed difference of each cylinder of the engine and the pressure change rule of the common rail cavity before fuel injection of the fuel injection pump, but this method only It can judge the fuel injection failure caused by the stuck control piston of the fuel injector, but cannot diagnose the fuel return status of the ...

AI Technical Summary

Problems solved by technology

Although this method is capable of diagnosing the oil return fault of the injector, the method is primitive and crude, requiring disassembly of engine parts, and human operation is likely to lead to inaccurate measurement, large error in measurement results, and cannot diagnose online faults in real time, which is not conducive to timely The oil return failure of the injector was found

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