一、概述活塞,作为内燃机的一个零件,正从原来的圆柱形、偏心圆锥形、多段圆锥形、单椭圆形等简单外圆型面,发展到目前广泛采用的中凸变椭圆形状。中凸变椭圆活塞的形状如图1所示。活塞裙部的形状从母线方向是中凸形,而在横截面上呈椭圆形状或近似椭圆形状而且各横截面的椭圆度在轴线方向上是变化的。 First, an overview of the piston, as a part of the internal combustion engine, is from the original cylindrical, eccentric conical, multi-stage conical, single oval and other simple cylindrical surface, developed to the currently widely used convex convex oval shape. In the convex oval piston shape shown in Figure 1. The shape of the piston skirt is convex in the direction of the generatrices and elliptical or nearly elliptical in cross section and the ovality of each cross section varies in the axial direction.