双α结打结器关键传动机构设计

Design of Key Transmission Mechanism of Double-α-knot Knotter

摘要:

提出了一种利用两组打结嘴同时绞扭出两个α结的方法，并采用一套具有对称的不完整齿面和凸轮槽的驱动齿盘，实现两打结嘴的等速、相向、间歇转动与拢推切装置规律摆动。依据压捆作业要求，确定了用凸轮-摆臂运动转换形式顺序实现拢绳、切断、推扣和回位的传动方案；利用反转法建立驱动凸轮的轮廓曲线方程，用Matlab编程得到凸轮轮廓曲线并分析动力传递特性。在打结试验台上对压捆过程进行了模拟，结果表明利用驱动齿盘严格同步和对应的动力传递，可满足同时成双α结过程对结构、位置和运动匹配的要求。

Abstract:

A method to simultaneously tie double-α-knots by using two bill hooks was put forward. Driven by a toothed disk with a symmetric intermittent gearing and a cam groove, the two bill hooks of the double-α-knot knotter rotated intermittently in the opposite direction at an identical speed and the arm swung in accordance with the regularity of holding the strand, pushing the loop and cutting the strand. The transmission scheme to implement sequentially the holding of the strand, the cutting of the strand, the pushing of the loop and the return of the knotter by transforming the rotation of the cam to that of the oscillating of the arm was determined according to the demands of the baling. The curve equation of the cam profile was established by means of the kinematic inversion. A detailed curve of the cam profile was obtained by programming in Matlab and the force transfer characteristic was analyzed. A knotting test rig was developed. The results of simulating the baling process on the test rig indicated that rigorous synchronization of motion of the two α-knot knotters driven by the toothed disk and their corresponding force transfer met the requirements of the matching of the structure, the position and the motion of double-α-knot knotter.