郑显良, 张华阳, 李灵敏, 郑永强

 (1．南车戚墅堰机车车辆工艺研究所有限公司，江苏 常州 213011；2．北京理工大学机械与车辆工程学院，北京 100081；3．南车戚墅堰机车有限公司，江苏 常州 213011）

    摘要：本文通过确定活塞关键部位的换热系数和温度边界条件，计算得出250型柴油机活塞的温度场，活塞的最高温度为384℃在钢顶喉口部位，并与活塞实测平均温度比较，温度相吻合。并计算和分析了在该温度负荷下的活塞热应力和热变形情况，最大热应力为246MPa在钢顶拱顶部位，径向最大热变形在钢顶顶面边缘部位，变形量为0.49mm。

    关键词：活塞、温度场、热负荷

Abstract： The paper determined the heat transfer coefficient and the temperature boundary conditions for  key sites of pistons and obtained piston temperature field 250 diesel engine by calculation.  The maximum temperature at the piston throat  up to 384℃ in consistent with the measured temperature. And then the thermal stress and thermal deformation of pistons were calculated at the simulation temperature field.  The maximum thermal stress reach 246MPa at the piston dome, and the maximum radial thermal deformation occurred at the edges of the piston top surface, causing a deformation of 0.49mm.

Key words: Piston；Temperature Field；Thermal Load