Abstract:

In order to optimize the nozzle position of the pneumatic weft yarn tucking device for shuttleless weaving machines, aiming at low stability of weft yarn head during pneumatic tucking, a two-dimensional fluid-structure interaction model was established using finite element analysis software to study the motion of weft yarn head under different working conditions. A high-speed camera was used to capture the yarn motion in the pure pneumatic tucking device under different working conditions and the results were analyzed in conjunction with the two-dimensional fluid-structure interaction simulation results. During the simulation, the fixed end of the yarn was located at the origin, and its initial position was in the positive direction of the X-axis. The free end of the yarn moved around the origin in the negative direction of the Y-axis under the action of the oblique airflow; When the yarn moved close to be parallel to the Y-axis, the oblique airflow was closed, and the tucking airflow was opened and acted on the yarn to continue to move until the tucking was completed. The results show that the weft yarn can be tucked in 3.98 ms under the airflow angle of 90°, 60°, 45° and 30°. The oblique airflow at different incident angles has a significant effect on yarn tucking stability, by comparing the movement of the yarns with the angle of oblique airflow, it is obtained that the oblique airflow with an incident angle of 45° is the most excellent, which greatly improves the yarn tucking stability.

Key words: pneumatic tucking device, oblique airflow, tucking airflow, fluid-structure interaction, yarn tucking, shuttleless weaving