12V190燃气内燃机曲轴平衡块极限轮廓设计

Design of the limit profile of crankshaft balancer for 12V190 gas engine

为解决12V190燃气内燃机增大行程时曲轴平衡块需增大质径积造成的平衡块形状设计困难问题,通过推导活塞相对平衡块的位移公式,绘制活塞裙底部运动包络线,确定平衡块的极限轮廓。使用三维软件进行运动模拟,验证平衡块极限轮廓的正确性。结果表明,活塞裙底和平衡块不干涉且紧密贴合。根据12V190燃气内燃机的结构和平衡块的加工工艺,将平衡块的极限外轮廓由椭圆修正为圆弧,并在活塞底部设计避让弧,使平衡块的重心外移,获得较大的质径积。

To solve the difficulty in designing the shape of the balance block caused by the need to increase the mass-semidiameter of the crankshaft balance block when increasing the stroke of a 12V190 gas internal combustion engine,the displacement formula of the piston relative to the balance block is derived,and the motion envelope of the piston skirt bottom is drawn to determine the limit contour of the balance block.Use 3D software for motion simulation to verify the correctness of the limit contour of the balance block.The results indicate that the bottom of the piston group and the balance block do not interfere and are tightly fitted.According to the structure of the 12V190 gas internal combustion engine and the processing technology of the balance block,the limit outer contour of the balance block is modified from an ellipse to a circular arc,and an avoidance arc is designed at the bottom of the piston to shift the center of gravity of the balance block outward and obtain a larger mass diameter product.