摘要
机构的尺度综合问题是机构学中的经典问题,为了建立起一套相对系统完整的、设计透明度高、应用简便的空间连杆机构尺度综合的几何流程,从空间连杆机构的运动几何学原理出发,以连杆机构中的浮动构件作为研究对象,将其简化为构件上的一条定直线,并将该条直线假想为导向构件,研究其在有限分离位置情况下的运动几何学特征,建立相应的空间运动几何学模型,实现空间运动学问题向空间几何学问题的转化。在此基础上,根据直线所占据的空间位置数不同,将直线多位置数问题拆解为多个少位置数问题的组合,进一步研究所提取几何特征之间的几何关联性,结合二平面投影系统,在明确了投影变换主投影方向的前提下,将几何学问题由空间向平面转化,并在平面系统中构建出相应的线导引模型。最后,根据机构的传动任务,结合运动反转理论,将空间机构的传动任务转化为线导引模型的求解问题,拟定出一套行之有效的空间连杆机构尺度综合方法。最终,以空间RSSR传动机构5位置函数综合问题为例,利用空间连杆机构尺度综合的几何流程,得到了满足精确5位置函数传递关系的RSSR机构的解。综合算例的结果进一步验证了该综合理论体系的有效性及实用性。同时,该方法不局限于输入、输出运动规律为转动–转动传动机构的尺度综合,也可对转动–移动、转动–平面运动、转动–空间运动的传动机构进行机构尺度求解。
A classic problem in mechanism design is the dimensional synthesis of mechanisms,and established here is a relatively systematic,transparent,and simple geometric process for the dimensional synthesis of spatial linkages.Starting with the rules governing the kinematic geometry of a spatial linkage,the research object is the floating link in the linkage,simplified as a fixed line on the link.This straight line is a guiding component,and its kinematic geometric characteristics are studied under the condition of finite separation positions.On this basis,the spatial kinematic geometry model of a line in the case of finite separation positions is established,which transforms the problem of space kinematics into that of spatial geometry.Next,based on the different number of spatial positions occupied by the straight line,its multi-position problem is decomposed into several combinations of multiple few-position problems.Furthermore,the geometric correlation between the extracted geometric characteristics is studied.By combining the two-plane projection system and clarifying the main projection direction of the projection transformation,the corresponding line guidance model is constructed in the plane system,which transforms geometric problems from space to plane.Finally,according to the motion task of the mechanism,the function generation task of the spatial mechanism is transformed into the problem of finding a solution for the line guidance model by using the principles of kinematic inversion,and an effective method is proposed for the dimensional synthesis of spatial linkages.Finally,the function generation synthesis problem involving a five-position RSSR mechanism is taken as an example,and by using the geometric synthesis process for spatial linkage mechanisms,a solution is obtained whereby the RSSR mechanism can realize five sets of precise function relations.Numerical results confirm the effectiveness and practicality of the synthesis method,and not limited to the dimensional synthesis of mechanisms with rotation input and rotation output,this method is also applicable to mechanisms with rotation input and slide output,rotation input and planar motion output,and rotation input and spatial motion output.
作者
王瀚超
郭颖颖
林松
江竞宇
WANG Hanchao;GUO Yingying;LIN Song;JIANG Jingyu(School of Physics and Electromechanical Engineering,Longyan University,Longyan 364030,China;School of Mechanical Engineering,Tongji University,Shanghai 201804,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2024年第6期314-324,共11页
Advanced Engineering Sciences
基金
福建省自然科学基金项目(2022J05246)
龙岩学院博士科研启动项目(LB2021014)。
关键词
空间连杆机构
尺度综合
几何法
二平面投影系统
线导引模型
spatial linkages
dimensional synthesis
geometric method
two-plane projection system
line-guidance model
作者简介
王瀚超(1989-),男,讲师,博士.研究方向:机构非线性运动分析与综合.E-mail:whc120005@126.com。
