Improvement Of The Warp Loosing Motion And The Control Of Warp Tension For An Air-jet Loom

As a kind of shuttleless loom, air-jet looms are one kind of the most promising looms. For the developing of textile industry, the air-jet loom develops towards the high-speed gradually in order to adapt to higher productivity. In high-speed conditions, the instance that vibration becomes more serious and work environment of warp ends gets worse are favorable to end breakage. So, it is very important to reduce vibration and control the fluctuation of warp tension.The back rest is the detecting and regulating element of warp tension, it is an important part of an air-jet loom. This dissertation makes the back rest system of type WG-2000 air-jet loom as the research object, analyzes the influence on warp deformation and warp tension by shedding motion, beating-up motion, warp loosing motion and back rest oscillating motion. Then, according to the condition that the resultant moment about the same axis is zero, the static and dynamic model of the back rest have been built up, and the influence on warp tension and the activities back rest swing by the change of the diametre of beam is obtained. Based on the original back rest system, the warp loosing motion for the air-jet loom is improved to reduce the affection of the change of beam's diametre.For the purpose of improving the warp loosing motion, this dissertation takes changing the parameters of the warp loosing motion that the lengths of the arms of the warp loosing motion into consideration. Specifically, the method that making stepper motor drive load to convert the rotary motion into linear motion is proposed. The origin arms of the warp loosing motion have been instead of screw nuts. So that, the lengths of the arms of the improved warp loosing motion can be changed in time when the diameter of the warp beam changes from the maximum to the minimum. A SDOF dynamic model is established by considering the swing of the activities back rest and analyzed, conclusions have been made that in the improved back rest system, the fluctuation of the warp tension and the varying of the back rest swing angle is more smoother than that of the origin one. Thus, it can control the warp tension better and the desired results are achieved.According to the improved design for the warp loosing motion of the WG-2000 air-jet loom, the datas and conclusions obtained by simulating and calculating can be benefit for the designing of the structure of this type of looms.