用逼近法设计扫描用机构的近似轨迹

The Approximate Locus for Designing the Scanning Mechanism by Approximate Method

本文对曲柄摇块机构中导杆端点B的轨迹进行了分析研究,当导杆、机架和曲柄长度之间的比例满足9.05:2:1,曲柄转角在0～140°范围内转动时,导杆端点B的轨迹为一近似直线。当导杆、机架、曲柄长度分别为905,200,100mm时,偏离直线轨迹的最大误差仅为|ΔX_(max)|=0.7122mm,导杆端点B的行程可达486mm。

The locus of the extreme point B of the guard bar is studied in the crank and rocker panel mechanism. The conclusion reached shows that the ratio among the lengths of the guard bar, frame and crank is 9. 05 : 2 : 1 and the crank corner is within the range 0～140°, the locus of the extreme point B of the guard bar is an approximate straight line. Suppose the lengths of the guard bar, frame and crank is 905 mm, 200 mm and 100 mm, the biggest deviation from the locus is only |ΔX max|=0.7122mm and the travel of the extreme point B can reach to 486mm.