Relationship between coupler curve properties of a 4-bar linkage and its dimensional types

Three types of 4-bar linkages can trace the same coupler curve according to the cognate mechanism law. Based on the investigation of the relationship between dimensions of a linkage and the harmonic component characteristic parameters of the coupler curve of the linkage, it was found that six types of linkages are related to the same coupler curve, and they belong to two groups of cognate mechanisms, in which the coupler curves have the same shape and are symmetric. The relationships among the dimensional types of these six mechanisms are presented. The corresponding examples have also proved these conclusions. This work enriches the cognate mechanism law, and can result in more candidate mechanisms for mechanism dimensional synthesis.

平面四杆机构轨迹近似综合的全方案优选

本文将连续法与优化理论相结合，首次解决了平面四杆机构轨迹近似综合的全方案优选问题。文中首先将四杆机构拆分成主、从两支并分别建立各支优化的目标函数；然后用连续法依次求出主、从支优化目标函数对应梯度方程组的全部解，进而得到每个目标函数的全部极小值点（即优化问题的全部解），排除没有物理意义的解，得到主、从两支的全部方案；最后将主、从支进行组合便得到能近似实现给定轨迹点的全部机构方案。

平面机构轨迹再现的计算机图谱综合法

作者用连杆平面固结的极坐标代替以往的直角坐标并绘制轨迹图形,以显示各轨迹图形之间的内在关系,从而给代数法综合四杆机构提供了新的逼近目标函数。以轨迹图形的特征参数为依据,将图形存入计算机,使计算机能按图谱进行综合。两工个程实例证明,本方法具有应用的现实性。