Test evaluation method for engine super knock safety margin

Abstract

The invention discloses a test evaluation method for an engine super knock safety margin. The test evaluation method for the engine super knock safety margin comprises the following steps that (1) detonation pressure data are collected by monitoring super knock in an engine bench test to determine a probability curve of the distribution of the super knock detonation pressure of an engine; (2) By monitoring the occurrence of super knock in an endurance test of a whole vehicle, the occurrence frequency of super knock is counted so as to determine the occurrence frequency of the super knock undera certain endurance mileage of the whole vehicle; and (3) the failure probability of parts due to over-explosion under the certain mileage of the whole vehicle is determined through detonation pressure prevention strength values of parts and the probability curve of the distribution of the over-explosion detonation pressure of a bench. Design evaluation is provided for part design by scientific methods, and part failures caused by the super knock can be greatly reduced.

Description

technical field [0001] The invention relates to the technical field of engine testing, in particular to a test evaluation method for engine super knock safety margin design. Background technique [0002] In order to meet the increasingly stringent fuel consumption requirements of automobile engines and to improve engine efficiency, supercharging technology for traditional internal combustion engines and gasoline engines combined with in-cylinder direct injection technology are considered to be the main ways to improve fuel economy and reduce emissions. As the boost ratio and load continue to increase, the gasoline engine will produce an occasional abnormal combustion phenomenon - super knocking under the condition of low speed and heavy load. The intensity of super knock and the damage to the engine are much greater than that of ordinary knock, and the peak pressure in the cylinder can even exceed 30Mpa, resulting in the failure of engine components, which will immediately l...

AI Technical Summary

Problems solved by technology

The intensity of super knock and the damage to the engine are much greater than that of ordinary knock, and the peak pressure in the cylinder can even exceed 30Mpa, resulting in the failure of engine components, which will immediately lead to the failure of other related components and systems, and finally lead to the failure of the engine. Parts and engines not only bring about the rise of after-sales costs, customer complaints, but even cause unpredictable dangers to drivers

[0003] The occurrence and explosion pressure of super-knock are random. Based on the scientific design method of engine parts without anti-knock pressure safety margin at this stage, it is impossible to accurately judge whether the safety margin design of parts meets the definition, and whether it can meet the requirements of super-knock The definition of aftermarket failure target value caused by knocking, therefore, it is very necessary to provide a scientific and effective test evaluation method for engine super knock safety margin design

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