Noise measuring system for engine accessory system in hemi-anechoic room

Abstract

The invention relates to a noise measuring system for an engine accessory system in a hemi-anechoic room. A load is respectively applied to a power steering pump, an electric generator and an air compressor in an accessory system, thus each accessory is enabled to work under the load, and a measuring result is enabled to be closer to life. The accessory system (3) is arranged on a testing motor (2), the testing motor (2) is arranged on a bench in the semi-anechoic room, the testing motor (2) is connected with a power measurement machine (1) through a transmission shaft, a crankshaft of the testing motor (2) is driven to rotate by the power measurement machine (1), and the accessory system (3) is driven to work by the testing motor (2); and a microphone (10) is arranged around the testing motor (2) , the noise of the accessory system (3) at work is collected by the microphone (10), and the noise is provided to a processing unit for processing and collection. By adopting the noise measuring system, interference brought by combustion noise of the testing motor, noise of induction and exhaust, and mechanical noise of a motor body and the like are eliminated, and the noise of the engine system is measured more accurately.

Description

technical field [0001] The invention relates to the technical field of noise testing of an automobile engine accessory system, in particular to a system for testing the noise of an engine accessory system in a semi-anechoic chamber. Background technique [0002] The engine accessory system generally includes air compressor, generator, power steering pump, water pump, etc. The accessories are driven by the crankshaft pulley through the accessory belt. At present, the noise of the accessory system is also a major contributor to the engine noise, especially when the engine is idling, the noise of the accessory system is relatively prominent, and it needs to be controlled. In the NVH test, the noise level of the accessory gear train can be approximately calculated by the partial operation method, that is, under a certain working condition, first test the sound pressure level SPL1 when the engine is working with the accessory belt, and then remove the accessory belt, so that If ...

AI Technical Summary

Problems solved by technology

[0005] The present invention designs a noise test system for the engine accessory system in a semi-anechoic chamber. The technical problem it solves is that the noise test results of the accessory system calculated by the existing divisional operation method contain the interference of other noises, and at the same time, it is built separately The noise test bench of the accessory system has defects such as high cost and long period

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