自适应广义S变换汽油机怠速振动分析

发布时间：2018-01-15 04:09

本文关键词：自适应广义S变换汽油机怠速振动分析　出处：《浙江大学学报(工学版)》2016年03期 　论文类型：期刊论文

【摘要】：为了获得某汽油机怠速时的振动特性,以便进行有针对性的NVH(振动、噪声、平顺性)改进优化,采用自适应广义S变换对发动机振动信号进行时频分析.与S变换结果的对比表明,自适应广义S变换具有更合适的时频分辨率.对某直列四缸汽油机进行怠速工况振动测试,并调整气门间隙及发动机热负荷.时频分布的对比表明,冷启动时主要振动源为配气机构及活塞敲击.冷机时,进、排气门落座激励频率分别为500~2 100 Hz及800~2200Hz,活塞敲击激励频率为400~6 000Hz.当热负荷增大后,发动机整体振幅锐减,喷油器激励凸显,燃烧激励始终微弱.热机时,进排气门落座激励频率分别为2 200~5 800Hz及3 800~6 000Hz,活塞敲击激励频率为2 500~3 000Hz以及4 500~5 000Hz,喷油器激励频率为3 800~5 700Hz.结果表明,不同热负荷状态下振动的频率特性区别较大,热机时低频成分减少.
[Abstract]:In order to obtain the vibration characteristics of a gasoline engine when idling, in order to carry out targeted NVH (noise, vibration and harshness) optimization of engine vibration signal time-frequency analysis using adaptive generalized S transform. Compared with the results of S transform, adaptive generalized S transform with time-frequency resolution is more appropriate. For idling vibration test on an inline four cylinder gasoline engine, and adjust the valve clearance and the heat load of the motor. By comparing the results of time-frequency distribution, the main vibration source for cold start valve and piston knocking. Cooler, into the exhaust valve, the excitation frequency was 500~2 100 Hz and 800~2200Hz, piston slap the excitation frequency is 400~6 000Hz. when the heat load increases, the amplitude of the whole engine dropped, injector incentive highlights, always weak. When the engine combustion excitation into the exhaust valve, the excitation frequency was 2 200~5 and 3 800Hz 800~6 0 00Hz, the piston excitation frequency is 2 500~3 000Hz and 4 500~5 000Hz, and the injector excitation frequency is 3 800~5 700Hz.. The results show that the frequency characteristics of vibration under different thermal loads are quite different, and the low frequency components of thermal engine decrease.

【作者单位】：浙江大学能源工程学院;浙江吉利动力总成研究院;
【分类号】：U464.171
【正文快照】： 怠速状态是发动机的一个主要运转工况,车辆在城市交通中时常会处在怠速工况[1].当怠速运转时,发动机几乎是仅有的噪声源[2],因此无论在商用车还是乘用车上,怠速噪声都是发动机重要的评价指标之一[3].降低发动机的怠速噪声同时也是社会的需求[4].振动与噪声具有紧密的联系,从振

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