叉车柴油机加速工况声品质改进试验研究

汪会斌，余磊，樊士贡，谢俊杰

安徽全柴动力股份有限公司技术中心，安徽 滁州  239500

摘要：为降低某叉车柴油机加速过程中的噪声，试验分析柴油机加速异响产生的原因，研究喷油规律对加速噪声的影响，分析声品质参数，并提出改进方案。试验结果表明：柴油机急加速“嘎嘎”声是由燃烧过程缸内压力升高率过大导致，增加预喷量可以在一定程度上降低噪声水平，但对加速异响几乎没有影响；减小喷油提前角可以轻微降低加速异响；降低轨压上升率可以明显降低加速异响，轨压上升率由150 MPa/s降低至100 MPa/s，柴油机加速时异响消失，响度的变化趋势与声压级基本一致，尖锐度和粗糙度降低，声品质明显提升。

关键词：柴油机；轨压上升率；预喷油量；喷油提前角；声品质

Experimental study on sound quality improvement of a diesel engine for forklift trucks under acceleration conditions

WANG Huibin, YU Lei, FAN Shigong, XIE Junjie

Technology Center, Anhui Quanchai Group Power Co., Ltd., Chuzhou 239500, China

Abstract: In order to reduce the noise in the acceleration process of a forklift diesel engine, the causes of the abnormal sound of the diesel engine and the influence of the fuel injection regularity on the acceleration noise are studied experimentally. The sound quality parameters are analyzed and the improvement scheme is proposed. The test results show that the "rattling" sound during rapid acceleration of the diesel engine is caused by the excessive pressure rise rate in the cylinder during the combustion process. Increasing the pre-injection fuel quantity can reduce the noise level to a certain extent, but it has little effect on the accelerating abnormal noise. Reducing the fuel injection advance angle can slightly reduce the acceleration abnormal noise. Reducing the rail pressure rise rate can significantly reduce the acceleration abnormal noise. The rail pressure rise rate is reduced from 150 MPa/s to 100 MPa/s. The abnormal noise disappears when the diesel engine is accelerating. The change trend of loudness is basically consistent with the sound pressure level. The sharpness and roughness are reduced, and the sound quality is significantly improved.

Keywords: diesel engine; rising rate of rail pressure; pre-injection fuel quantity; fuel injection advance angle; sound quality