Engine turbocharger overspeed diagnosis method and system, and vehicle

Abstract

The invention relates to an engine turbocharger overspeed diagnosis method and system, and a vehicle. The engine turbocharger overspeed diagnosis method comprises the steps that a first threshold anda second threshold are set; operation parameters of an engine are obtained; obtained boost pressure and the obtained engine air flow are corrected into the boost pressure ratio and the air compressorflow under the standard atmosphere pressure and temperature condition correspondingly, then according to the corrected boost pressure ratio and the corrected air compressor flow, a performance pulse spectrogram of an air compressor of a turbocharger is inquired to obtain the predicted rotating speed of the turbocharger; according to the rotating speed of an engine and the opening degree of a throttle valve, a position pulse spectrogram of an air release valve actuator of the turbocharger is inquired to obtain the predicted opening degree of an air release valve, and the different value betweenthe predicted opening degree and the obtained opening degree of the air release valve of the turbocharger is calculated; and if the predicted rotating speed exceeds the first threshold, or the difference value exceeds the second threshold, it is judged that the turbocharger is subjected to overspeed, and if the predicted rotating speed does not exceeds the first threshold and the difference valuedoes not exceed the second threshold, it is judged that the turbocharger is not subjected to overspeed.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to an engine turbocharger overspeed diagnosis method, an engine turbocharger overspeed diagnosis system and a vehicle. Background technique [0002] At present, on gasoline engines used in vehicles, turbocharging technology has become one of the important technical means to meet future fuel consumption regulations. The turbocharger is the core component of the supercharged engine. It often works under the condition of high temperature, high load and high speed. Or supercharger overspeed, supercharger overspeed is very harmful, not only will cause supercharger impeller shaft damage failure, and when the situation is serious, debris and oil will enter the cylinder and destroy the entire engine. [0003] Although there are mature turbocharger speed measurement equipment, there is a problem of high cost. At present, it is used in the engine development stage, and the turbocharger ...

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Problems solved by technology

[0004] However, the above diagnostic method has problems such as insufficient reliability. In actual development or after-sales, supercharger overspeed failures often occur, and even cause the entire engine to be destroyed.

This is because neither the boost pressure nor the air flow is directly measured from the supercharger workload, and due to the complexity of the engine system, if there are abnormal conditions such as intake blockage or leakage of the booster line, it may cause booster damage. However, the supercharger speed calculated based on the boost pressure and air flow may still be within the normal range, which causes calculation and diagnosis distortion, which may lead to continuous failure of the supercharger due to misjudgment. Major problems such as overspeed damage or even destruction of the engine

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