Evaluation method for low-temperature cold-start oil injection test of direct-injection gasoline engine stand

Abstract

The invention relates to an evaluation method for a low-temperature cold-start oil injection test of a direct-injection gasoline engine stand, which comprises the following steps of: constructing a test stand, preparing the test at the early stage, performing the low-temperature cold-start oil injection test, comparing the wall wetting conditions of a cylinder barrel under different oil injection parameters after the test, and by combining the different oil injection parameters, obtaining optimal oil injection control parameters. According to the evaluation method for the low-temperature cold start oil injection test of the direct injection gasoline engine pedestal, whether oil injection control parameters adopted by the developed direct injection gasoline engine are reasonable in cold start and warm-up stages in a low-temperature environment or not, whether the risk that fuel oil collides with the wall exists or not, and whether engine oil dilution can be caused or not can be judged; through examination of the test, whether the design of the engine fuel injector and related fuel injection parameter control are reasonable or not can be reflected in time; and the method can effectively judge the wall wetting condition of the cylinder barrel, the design scheme of parts and control parameters under the limiting condition after cold start of the engine in the low-temperature environment, ensures the development quality of engine products, and improves the reliability of the engine.

Description

technical field [0001] The invention belongs to the technical field of automobile engine testing, and in particular relates to a verification method for a special test of an engine bench, in particular to a method for evaluating a direct-injection gasoline engine bench low-temperature cold-start fuel injection test. Background technique [0002] From July 1, 2020, all light vehicles sold and registered should meet the National 6a limit value requirements, and the test cycle has also been changed from the NEDC cycle of the National V stage to the WLTC cycle. The new emission standards have stricter requirements on the limit values ​​of HC, CO, NOx and other pollutants, which are about 50% lower than those of the National V. Test requirements. Studies have shown that, compared with the steady-state operating conditions of a warm engine, CO, HC, and PN pollutant emissions are concentrated in the cold start and warm-up stages. [0003] In order to meet the requirements of the ...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a low-temperature cold-start fuel injection test evaluation method of a direct-injection gasoline engine bench to solve the problem of verifying whether there is a wet wall of the fuel injection cylinder during the warm-up operation stage after the low-temperature cold start of the engine

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