Study On The Weft Insertion Principle Of A Combination Of Airflow And Gripper

The jet loom has the advantages of high speed,wide width and high quality in the course of decades of development.But because of the working medium,the air-jet loom is easy to untwisting when weaving high twist yarn and lack of drag force when weaving heavy fabric.In order to optimize the weft insertion effect of the airflow,an improved weft insertion method of weft yarns with a gripper at the tail end of the yarn was proposed according to the influence of the protrusion of the yarn surface on the drag force.In this article an improved weft insertion system is simply proposed based on the predecessors,and selected a clamping device suitable for the improved weft insertion system through experiments and theories.Then through the combination of experiments and simulation to verify the reasonableness and superiority of this method.The specific work is as follows:(1)the magnetic buckle type ball gripper is selected on the basis of the experiment and the theoretical analysis,and the appropriate gripper size is selected to ensure that the drag force is large enough to ensure and meanwhile the yarn does not break because of the excessive traction.The drag force of different size gripper is obtained through experiments,and the diameter of gripper is determined to be 5mm.(2)the finite element model of the yarn with gripper in the latitudinal flow field is established by using Hypermesh.In order to prevent the influence of the reed clearance on the simulation,the required pressure reduction correction is determined by the air flow experiment.In Fluent,the dynamic grid technique is used to simulate the flight state of the yarn with gripper in the latitudinal flow field under the pressure of 0.3MPa-0.5MPa,and the result is concluded that this kind of weft insertion is feasible and can reduce the gas consumption.(3)the movement of the gripper in the guide tube with changing diameter is simulated by simulation,and the improved result is compared with the unchanged.It is found that the change of the diameter of the guide tube can further optimize the effect of the weft insertion.(4)An high-speed camera is used to capture the flying state of the yarn with gripper,the speed of the clamp and yarn is compared with the simulation speed to verify the rationality of the simulation and the practical feasibility of the new method of weft insertion.In this paper,the gripper,selected by experiment and numerical calculation,can complete the weft insertion in the improved weft insertion system under the reasonable gas supply pressure,and achieves the goal of increasing yarn traction,increasing variety adaptability and energy saving and reducing consumption.