Fault Diagnosis Method of Blockage of Engine Air Intake Pressure Relief Valve

Abstract

The invention relates to a fault diagnosis system and method for engine air inlet relief valve blockage. The fault diagnosis system is mainly composed of a supercharge pressure sensor arranged at an outlet of an engine compressor, an electronic control unit used for algorithm execution and a control algorithm routine. The method using the system for fault diagnosis comprises the steps that the demand load or actual load of an engine are collected during throttle closure or gear shifting, and when the demand load or actual load of the engine meets a certain diagnosis condition, fault diagnosis is started; and whether a blockage fault occurs to an air inlet relief valve or not is determined according to positive gradient and negative gradient alternation conditions of signals by collecting supercharge pressure values in real time. The two failure modes of mechanical part faults and ice blockage of the air inlet relief valve are completely covered, and fault diagnosis is achieved through a simple method under the condition that a vehicle runs normally without intervention. A user is prompted to maintain the vehicle actively through the fault reporting, and a maintainer is helped to achieve rapid positioning, so that the phenomenon that performance of a supercharger is lowered due to the fact that the supercharger surges for a long time is avoided.

Description

technical field [0001] The invention belongs to the technical field of engine control, and in particular relates to a fault diagnosis system and a diagnosis method for blockage of an engine intake pressure relief valve. Background technique [0002] For a supercharged engine with a throttle, when there is a negative gradient load change such as closing the throttle, the instantaneous opening of the throttle will become smaller. In order to avoid supercharger surge, the intake pressure relief valve should be opened quickly to keep the supercharger running at a higher speed and ensure the effective acceleration of the engine. However, if the intake pressure relief valve fails to open normally due to mechanical component failure or ice blockage, it will not be able to protect the supercharger. If this failure state lasts for a period of time, the performance of the supercharger will be seriously reduced, resulting in insufficient vehicle power and increased fuel consumption. ...

AI Technical Summary

Problems solved by technology

However, if the intake pressure relief valve fails to open normally due to mechanical component failure or ice blockage, it will not be able to protect the supercharger

If this failure state lasts for a period of time, the performance of the supercharger will be severely reduced, resulting in insufficient vehicle power and increased fuel consumption.

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