Kineto-elastodynamic Analysis Of Changeable Spatial Four-bar Linkage Weft Insertion Mechanism

Weft insertion mechanism is one of the most important components of loom, The weftweaving quality directly determines the quality of fabric and the loom grade. Currently, due todefects in the design and manufacture of weft insertion mechanism, the domestic high-speedlooms still have a large gap with the world’s most advanced loom. Therefore, studying theperformance of High Speed weft insertion mechanism is particularly important to improve thecompetitiveness of domestic looms and independent innovation capability.Based on the backward status of domestic high-grade rapier, the thesis uses the way ofvirtual prototype test and theoretical analysis to analysis the characteristics of kinematics, rigiddynamics and elastic dynamic of space four bar linkage mechanism, which can be included asfollows:1) Establish the mathematical models of the mechanism, by analysis and emulation,receive the kinematics curve by MATLAB software. Simultaneously, taking into account theimpact of the swing angle and spindle speed to movement of the sword, derive the optimalangle range and optimum speed, and list the intermediate variable expressions, as the inputvariables in the next chapter elastic dynamics.2) Establish the three-dimensional model of this mechanism with Pro/E software, whichis imported to ADAMS to add constraints. Then simulate after verifying the model. Finally, thecurves of movement are obtained, which can be compared with the motion characteristics of theprevious chapter.3) By considering the flexible member, generate the Neutral file in ANSYS, which isreplaced the previous rigid component, conduct a dynamic simulation on the model ofrigid-flexible coupling, and then analyze the impact to sword belt by changing the swingingfork’s material, spindle speed and considering the flexibility of swinging fork and spatial bear.4) Using the finite element method to analyze elastic dynamic for weft insertion space mechanism, found the motion differential equations of the beam element, by a combination ofeach unit of mass and stiffness matrices and the coordinate transformation, generate entiremechanism’s motion differential equations in global coordinate system. With the method ofQDA and Kinetic static analysis by the transferring the error to the end belt, get the error curves.Meanwhile, by changing the length of the crank and the fork angel, obtain the two impacts tothe end manipulator separately.