组合式带平段避碰函数凸轮及最优设计

本文构造了一种新型组合式带平段避碰函数凸轮型线,同时具有较大的时面值和较好的动力性能,可以应用于具有苛刻避碰要求的配气系统设计中.给出了型线的设计方法;采用较复杂精确的多自由度动力分析模型,对配气系统进行分析;在此基础上,建立了凸轮型线的动态优化设计模型.算例表明,该型线在着重满足避碰要求的同时,使机构具有大的时面值和较好的动力性能,有利于减小余隙容积,提高内燃机综合性能.优化型线应用于某新机型中,取得了良好的实际效果.

CONSTRUCTION AND OPTIMIZATION OF COMBINED FUNCTION CAM PROFILE FOR AVOIDING COLLISION

A new type of combined function cam profile for avoiding collision was presented. It can be used in a valve train when restricted by the requirement of avoiding collision. This type of cam profile has a large value of valve-opening time-area beside having good dynamic characteristics. Design method for the cam profile was given. A complicated multi-freedom analysis model was established to understand the dynamic characteristics of the valve train clearly. Based on these, an optimization design model was established. The example given shows that the effect of avoiding collision in this cam profile is well accomplished and that the valve train has accepted general properties simultaneously. Consequently, it is good for use in diesel engines to increase its performance in general and the time-area of cam profile. Outer characteristic of a diesel engine adopting the optimized cam profile was also shown.