各缸工作不均匀性的诊断研究

文中提出依据实测内燃机瞬时转速的变化，计算各缸的功值及最高燃烧压力值，藉以诊断各缸工作的不均匀性。研究表明这是一种简单，实用，可行的方法。     

Effect of obstacles on roads with different waviness values on the vehicle response

The effect of the increasing number of cosine-form obstacles, which are superposed on a standard homogeneous longitudinal road profile, is studied when the waviness of the basic road profile changes in the range from 1.5 to 3.5. First, the effect of the composed profile on the power spectral density (PSD) is analysed. It appears that the primary PSD in the form of a straight-line in the log-log plot breaks into two straight-line partial segments with quite different waviness values in the long and short wavelength bands. This seems to be a suitable model of a highly deteriorated road. Next, the effect on the response of two typical vehicles, viz. a personal car and a three-axle truck, is studied, and rather different results were obtained. In a summary valuation, it appears that the presence of additional obstacles causes independence of some of the vehicle response quantities of the primary waviness.     

Effect of obstacles on roads with different waviness values on the vehicle response

Abstract

The effect of the increasing number of cosine-form obstacles, which are superposed on a standard homogeneous longitudinal road profile, is studied when the waviness of the basic road profile changes in the range from 1.5 to 3.5. First, the effect of the composed profile on the power spectral density (PSD) is analysed. It appears that the primary PSD in the form of a straight-line in the log–log plot breaks into two straight-line partial segments with quite different waviness values in the long and short wavelength bands. This seems to be a suitable model of a highly deteriorated road. Next, the effect on the response of two typical vehicles, viz. a personal car and a three-axle truck, is studied, and rather different results were obtained. In a summary valuation, it appears that the presence of additional obstacles causes independence of some of the vehicle response quantities of the primary waviness.     

某轿车离合器不平整度引起的爬行抖动研究

某轿车采用双离合变速器,在起步爬行工况存在明显的整车抖动现象,并且导致变速器异响。本文通过试验分析手段发现整车抖动频率与发动机转速、输入轴转速以及转速差相关,结合离合器颤振的发生机理和发生条件,得出离合器执行过程中压力变化引起的颤振是整车爬行抖动的主要原因,离合器压力变化主要与本身结构参数—离合器不平整度(MGF)相关,通过整车试验方法和主观评价方法分析不同的离合器MGF值对整车抖动的影响,从而获得最优MGF值,有效解决该车抖动问题。