活塞裙部廓形的计算机辅助分析

在分析活塞裙部廓形的基础上，建立了其横向廓形的通用数学模型，并采用最小二乘法求解其廓形参数，使求解过程大大简化。此外，对椭圆－偏心圆规律的廓形，提出了改变拟合点数寻求最佳型线参数的方法。提出的方法不仅适用于标准椭圆型线及其１阶、２阶近似型线，而且对椭圆－偏心（正）圆等组合廓形参数的求解同样有效，克服了现有方法的缺陷，具有很好的通用性。实例计算表明，本文方法的通用性和精度均较好，具有较好的工程实用价值

On Computer Aided Analysis of Piston Skirt Contour

Based upon the analysis of piston skirt contour the shortcomings and limitation of the available model and its solution,a general mathematical model for complicated crosssection contour is presented and solved by general least square method (LSM).The process of solving contour parameters is thus greatly simplified.Furthermore,for compound contour composed of ellipse and circle (eccentric),a solution technique by changing the number of fitted points and searching optimal contour parameters is also put forward in this paper.The general mathematical model and its solution technique presented are suitable for not only first order but also second order approximation curve as well as compound contour composed of ellipse and circle (eccentric).Compared computation of the contour parameters and ellipse constructure parameters for the above contour curves shows that the general method and its solution technique are of good versatility and calculation accuracy,and thus applicable to manufacturing and measuring engineering.