平面五杆仿图仪机构

Planar 5-Bar Pantograph Mechanism

经典的仿图仪有西尔维斯特仿图仪和谢伊涅尔仿图仪,西尔维斯特仿图仪有一个输入点和一个输出点,且输入和输出相互旋转一定角度;谢伊涅尔仿图仪存在一个输入点和两个输出点,虽然谢伊涅尔仿图仪比西尔维斯特仿图仪多出一个输出点,但是输入和输出必须在一条直线上,相互转角始终为0或180°。它们都是平面五杆的平行四边形机构。基于平面五杆机构的拓扑结构,结合仿图仪可以对任意的图形进行成比例放缩的特点,设计一些特殊的输入图形,以此导出仿图仪构成的必要条件。基于此提出一种新型的平面五杆仿图仪机构,并给出构件尺寸的确定方法,推广并统一了两种经典的平面仿图仪。

There are two different kinds of classical pantograph mechanisms called Sylvester pantograph mechanism and Shay Nel pantograph mechanism.The first one has one input point and one output point,and the two points don＇t need to lay on a same line.The second one,the Shay Nel pantograph mechanism has one input point and two output points,but they have to stay in the same line.Both mechanisms are planar 5-bar parallelogram mechanisms.Based on the topologies of planar 5-bar mechanism and the fact that pantograph can scale any graphs,necessary condition is set up for the pantograph by giving some particular input curves.And then a new type of planar 5-bar pantograph mechanism is proposed,which unifies the two classical pantograph mechanisms.