Mechanism Optimization And Accuracy Analysis Of Tuck-in Selvedge Device

Tuck-in selvedge device is one kind of attachments installed on the looms, Its function isweaving the yarn into the weaving opening to forming a neat cloth Eaves with a small crochet,and it is one of attachments with demanding stability installed on the looms. However, In actualoperation, for the reason of parts difficult process and deviation control, joint gap is inevitablyexisted. In the condition of high-speed operation and speed weaving, position repeat accuracy ofcrochet is not desirable, it is easy to make a hook-yarn failure. Wherefore, this paper will analysethe flaw of the mechanism, make a new better form mechanism and kinematic analysis oforiginal mechanism and DOF comparative analysis and verification between the originalmechanism and the new mechanism, in the condition of having the same crochet rule, and finishthe parts design of the bew mechanism and accuracy analysis of this two mechanisms in order toget a better tuck-in selvedge device. The research and analysis of this paper is very important andmeaningful to the development of textile machinery.According to the practical flaw of tuck-in selvedge device, This paper will be based on acommon tuck-in selvedge device, studying the crochet driving mechanism of a right tuck-inselvedge device, making a study of the following aspects detailedly:1) Drawing the motion sketch of the crochet driving mechanism of tuck-in selvedge device,getting crochet rule by theoretical calculations, and anylizing the working principle3D model ofthe mechanism with Pro/E, and getting crochet rule by simulation analysis of Pro/E, thencomparing the results of simulation analysis and theoretical calculations.2) According to the result of actual measurement of tuck-in selvedge device, presenting abetter form of crochet driving mechanism, finishing the DOF comparative analysis between theoriginal mechanism and the new mechanism using a space more closed-shaped mechanism DOFcalculation method. The result indicates: the new mechanism has a same DOF with the theoriginal mechanism, and meet the operational requirements of tuck-in selvedge device. 3) In the condition of having the same crochet rule, getting the contour of conjugate camwith heoretical calculations, then presenting a method of getting the contour of conjugate cambased on Pro/E, compared the contour of this two methods. The result indicates: After comparing,two methods get the same contour of conjugate cam, and the contour has a medium size andsmooth curves, it is suitable to produce; On the other hand, according to the the characteristic ofmechanism designing the related parts and mapping of2D drawings of the parts, and making thesimulation analysis process, after making a3D model of the new mechanism, the resultindicates:There is no interference, in line with the realistic requirements.4) Presenting logical hypotheses, making joint force analysis and kinematic analysis of theoriginal mechanism and the new mechanism, then finishing the accuracy analysis of this twomechanisms form two parts which are the size deviation of the basic member and the jointclearance. The result indicates: compared with the original mechanism, the new form ofmechanism has less number of joints, lower difficulty of parts processing, and better accuracyand stability.