共查询到19条相似文献,搜索用时 187 毫秒
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轿车异响越来越成为用户关注的重点,发动机是轿车噪声的主要激励源之一。文章介绍了发动机常见噪声,并通过CAE分析,确定了噪声源。结合生产中的问题,借助CAE分析手段,排除了设计影响因素。通过测量分析发动机噪声的声谱特点,快速识别了发动机异响声部位,并结合发动机凸轮轴表面加工工艺偏差,找到了引起发动机异响的根本原因,指出该方法可以在产品开发和批量生产中,对发动机机械噪声进行快速测试识别,并指导发动机凸轮轴加工。 相似文献
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汽车在行驶过程中,无论发动机或底盘均有噪声发出,正确判定噪声发出部位、确定出噪声和异响的有关机件,有助于迅速排除故障,使车辆恢复良好的状态。但由于驱动桥离驾驶室较远,有时在异响和噪声辨别时则要采取以下四招。一招:发动机异响与驱动桥噪声的辨别首先使汽车在较平坦的路面上行驶一定里程,使后桥的工作温度升至正常。然后,在行驶中记下汽车发出异响和噪声时的车速以及发动机转速;停车后,放变速杆在空挡位置,缓加速,直至 相似文献
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汽车在行驶过程中,无论发动机或底盘均有噪声发出,正确判定噪声发出的部位、确定引起噪声和异响有关机件,有助于迅速排除故障,使车辆恢复良好的状态。但由于驱动桥距驾驶室较远,有时异响和噪声需按比较分辨法进行确定。1.发动机与驱动桥噪声的分辨首先使汽车在较平坦的路面上行驶一定里程,使 相似文献
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汽车异响为整车常见的抱怨,排气歧管异响一般较少见,但在某排气歧管开发过程中,某1.5L AT整车在加速过程中出现一种很清脆的"沙沙"声,属于高频范围。经过噪声排查测试,该异响是由于歧管的流道过短、设计不合理而产生。通过对比四种不同结构的排气岐管的噪声测试结果,发现歧管设计中应该避免歧管出口流道设计过短,各流道长至少在150mm以上,并应达到完全隔离的状态,避免各缸之间气流的相互干涉而产生异响噪声。 相似文献
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汽车工作时各系统振动发出的声音统称为汽车的响声,有些书籍上又称之为噪声。而这些响声又可分为正常响声和非正常响声(异响)两大类。汽车的很多故障都是通过异响表现出来的,异响是现象,故障才是本质。如不及时排除故障极易造成重大机械事故。 相似文献
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商用汽车在行驶过程中,无论发动机或底盘均有噪声发出,正确判定噪声发出的部位,确定噪声和异响有关机件,有助于迅速排除故障,使车辆恢复良好的状态.但由于驱动桥离驾驶室较远,有时异响和噪声需按比较分辨法进行确定. 相似文献
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F. Payri A. J. Torregrosa A. Broatch L. Monelletta 《International Journal of Automotive Technology》2009,10(6):761-769
Combustion noise in passenger cars powered with direct injection (DI) diesel engines is frequently the main reason why end-users
are reluctant to drive this type of vehicle. Thus, the great potential of diesel engines for environment preservation — due
to their lower CO2 emissions — could be missed. This situation worsens with the current design trends (engine downsizing) and the emerging new
diesel combustion concepts (Homogeneous Charge Compression Ignition-HCCI, Premixed Charge Compression Ignition-PCCI, etc.),
which are intrinsically noisy. This negative feature can be even more critical in transient operation due to the contribution
of the temporal changes of both source and transmission path on engine noise. Therefore, combustion noise must be considered
as an additional essential factor in engine development, together with performance, emissions and driveability. Thus, suitable
evaluation procedures that can be integrated into the global engine development process in a timely and cost-effective manner
are imperative. Regarding the evaluation procedures, most of the work available in the literature addressed combustion noise
at steady operation. To surpass this limitation, two possible approaches — adapted from the classical and multiple regression
methods — for the overall level assessment of combustion noise in transient conditions are evaluated in this paper. 相似文献
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阐述了绿色设计理念在当今汽车设计中必要性,总结了绿色设计在汽车材料、减少汽车尾气排放、汽车外观造型、降低噪声污染、汽车材料回收等方面的应用,分析了绿色设计给汽车企业带来的效益,并对其美好的发展前景进行了展望。 相似文献
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This paper focuses on the mechanisms of combustion noise during the accelerating operation of multi-cylinder diesel engines
using testing technology for the transient conditions of IC engines. Based on impact factors, such as the gas dynamic load
and cylinder pressure oscillations, tests and analysis of the combustion noise during transient and steady-state conditions
for different loads are made on four-cylinder naturally aspirated engines, turbocharged engines, EGR-introduced engines, and
high pressure common rail engines. The laws of combustion noise difference for the same engine speed and load are researched
during transient and steady-state conditions. It is found that during transient conditions, the maximum pressure rise rate
and the high frequency oscillation amplitude of the cylinder pressure are all higher than those observed during steadystate
conditions for the same engine speed and load. With their joint action, the combustion noise during transient conditions is
greater than that during steady-state conditions. Turbocharging is useful in reducing the combustion noise during transient
conditions. Turbocharging has a better effect on the control over the combustion noise during transient conditions with a
constant engine speed and an increasing torque than in conditions with a constant torque and an increasing engine speed. One
of the main reasons for different control effects on the combustion noise is that turbocharging causes different wall temperatures
inside combustion chambers. The introduction of the appropriate EGR is helpful in the reduction of the combustion noise during
transient conditions. The key to the control of combustion noise with EGR during transient conditions is whether a real-time
adjustment to the EGR rate can be made to achieve the optimization of the EGR rates for different transient conditions. By
means of analyzing the differences in the combustion noise between the transient and steady-state conditions for different
pilot injection controls, we obtain a strategy for controlling the combustion noise during transient conditions with a pilot
injection. Compared with the steady-state conditions, a larger pilot injection quantity and a longer interval between the
main injection and pilot injection should be selected for transient conditions, and this is verified through tests. 相似文献
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为了在设计阶段保证整车的NVH性能,通过搭建虚拟路面仿真平台探究轮胎关键物理参数对于整车路面振动噪声的影响规律。结合实车采集的试验场NVH路面PSD、高精度物理轮胎CDTire模型以及整车声固耦合模型,建立完整的整车路噪仿真环境。通过某款SUV的仿真结果表明,不同款轮胎及同款轮胎不同批次对整车路面振动噪声有直接的影响。虚拟路面方法可以在整车开发早期甄别出在车辆噪声中起主导作用的频率段,从而排查明显的NVH设计缺陷,同时,可以为车型NVH正向开发提供轮胎选型依据。 相似文献
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在渗流计算理论与极限平衡方法的基础上,对库水位升降作用下路基边坡的瞬态渗流场与稳定性进行数值模拟与研究。研究结果表明:1)在库水位上升过程中,浸润线位置几乎与库水位的变化“同步”,只存在短时间的“滞后”效应;而在库水位下降过程中,滑坡体内浸润线位置严重滞后于库水位的变化。2)库水位上升期间,路基边坡孔隙水压力增加,安全系数增加,最高库水位(175m)持续期,路基边坡孔隙水压力增加,安全系数缓慢降低;库水位下降期间,路基边坡孔隙水压力降低,安全系数迅速降低,最低库水位(145m)持续期,路基边坡孔隙水压力降低。安全系数缓慢增加。 相似文献
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对进气噪声的产生原理进行分析和研究,利用赫姆霍兹谐振消声器的设计原理,设计了适合某车型的谐振腔,降低了进气噪声的声压级。消声降噪效果明显。 相似文献