Abstract: In order to solve the problem of yam breakage when using Tufting stitching process to stitch hard sandwich composite preforms, the stitching process was improved, and the stitching head was designed parametrically based on the improved Tufting stitching process. Firstly, the suturing mechanism of the suturing head is graphically simplified and analyzed, and the parameters are designed through the given working conditions of the process to obtain the structure of the suturing mechanism, the initial values of the parameters are calculated by the analytical method, and the boundary values of the parameters are calculated. The theoretical simulation analysis of the parameters is performed using Matlab. The results show that the relevant parameters calculated by the analytical method do not meet the design requirements. Based on the problems in the calculation of the parameters by the analytical method, a parametric virtual prototype is established using ADAMS, and the parametric modeling is performed to obtain a better value. Finally, the simulation analysis and verification of the obtained parameter values are carried out, and a virtual prototype and a processing entity prototype are established. The experimental results prove that the parametric design of the suture head runs stably, reduces the yarn breakage of the suture thread, meets the requirements of the work design, and lays a theoretical foundation for the development of subsequent engineering prototypes.

Key words: hard sandwich structure preform; improved Tufting stitching process stitch head; offset crank slider mechanism; ADAMS parameterized design; composites