Abstract:

Focusing on tufting machine type of DHUN801D-400 and based on the problem of joint clearances in kinematic pairs, the joint clearances of coupling shafts system in needle mechanism are studied. Firstly, the structure of coupling shaft system in tufting machine is introduced and kinematic analysis is studied. Secondly, the three joints with clearance are considered in needle mechanism. And the displacement, velocity, acceleration and reaction force between kinematic pair in needle mechanism are obtained using the ADMAS software, then the impact on pile height is obtained according to the displacement of needle. Thirdly, regarding the coordinates of hinged points and length of bars as design variables, the reaction force and stroke of needle as objective function, the multi-objective optimization is carried out. Finally, the optimal hinge coordinates and the length of bars are got, and the influence of joints clearance on pile height is decreased to lowest.

Key words: tufting machine, coupling shaft system, joint clearance, multi-objective optimization