1种满足控制计划要求的凸轮型面设计方法

针对液压机械控制装置要求按给定的稳态控制计划设计杠杆、凸轮、弹簧等结构性能参数的问题,采用了考虑离心飞重块工作在燃油中的浮力效应和液体离心力效应对离心飞重换算轴向离心力的修正方法,精确地计算了转速摆动活门的转速-弹簧位移关系的输入输出特性；利用转速给定装置凸轮杠杆机构的叠加特性解决了油门杆角度和发动机进口温度同时变化时相关的控制计划反映在指令弹簧上的位移计算问题；同时从刚架的运动特性规律中抽象出几何不变性,提出了1种按控制计划的不同要求对转速指令凸轮、慢车温度修正凸轮和大车温度修正凸轮进行设计的方法.设计的凸轮按其内在的输入输出特性关系通过各模块之间的信息传递关系以液压机械的控制方式实现了发动机所要求的复杂转速控制计划,对这一设计方法进行了对比验证,可满足设计要求,具有通用性.

A Design Method of Cam Surface Based on Requirement of Control Schedule

In Hydro-Mechanical control Unit (HMU), structural and performance parameters such as parameters of lever, cam, and spring need to be designed according to given steady state control schedule. Using correction method for correcting axial centrifugal force of flyweights which takes buoyancy and centrifugal effects into consideration, input/output characteristics of the relationship between rational speed and displacement of spring were calculated accurately. Calculation problem for displacement imposed on command spring by related control schedule when power lever angle and engine inlet temperature changed simultaneously was solved using superposition of cam-lever mechanism in speed given unit. Meanwhile, geometrical invariability can be abstracted from motion characteristic of frame. A method of designing speed command cam, idle temperature correction cam and max temperature correction cam according to different requirements of control schedule was proposed. The designed cam implemented complex speed control schedule required by engine in hydro-mechanical ways via data link between modules, according to its inner input/output character relationship. The design method was compared and verified, which meet design requirements and provide universality.