Design Of Single-side Stitching Device For Carbon/carbon Composite Preform And Research On Its Motion Trajector

As a carbon fiber and fabric reinforced carbon matrix composite material,carbon/carbon composite material has the characteristics of high specific strength,high specific modulus,high dimensional stability and excellent thermal shock resistance.It is mainly used in aerospace and defense industries,has also been widely used in the fields of automobiles,ships,bridge construction,medicine and so on.In order to give full play to the overall performance of the three-dimensional fabric,the composite material one sided stitching technology,as one of the effective methods to improve the delamination resistance of the preform,played an important role in the reinforcement of the carbon/carbon composite preforms.In order to realize the Z-direction stitching of carbon/carbon composite material preforms,this paper analyzes the current domestic and foreign stitching technology of composite material preforms based on the research on one-sided and double needle single thread stitching technology,and analyzes the current domestic unilateral,There are problems in the stitching process,a one-sided and double needle single-thread stitching equipment prototype was designed,the stitching experiment was carried out to verify the feasibility of the prototype.The stitch forming principle of the one-sided and double needle single-thread stitching process is studied,and the one sided and double needle single-thread stitching process is improved in view of the loss of loops and wrong hooks in the stitching process of the one-sided and double needle single thread.The stitching device is divided into four parts: lead mechanism,thread hook mechanism,thread pulling mechanism and thread take-up mechanism.Compare and analyze each mechanism plan,determine the optimal mechanism transmission plan,and determine the specific parameters of each mechanism according to the process requirements,and complete the establishment of the three-dimensional model.In order to ensure that the various mechanisms cooperate accurately during the movement process,the time and position relationship of the prototype is analyzed,and it is determined that each mechanism does not interfere during the movement process.Analyze the mechanism of stitch stable loop formation of the suture thread under the cooperation of the thread needle and the crochet needle in the one-sided and double needle single thread process,and add a slider lever threading mechanism with a variable fulcrum to ensure that the crochet needle is smoothly taken from the hooked thread pass through the loop to form an interlock of stitches.Analyze the principle of the routing mechanism,establish a mathematical model of the routing mechanism,and conduct a trajectory simulation analysis to determine the rationality of the routing mechanism.Analyze the thread needles and crochet needles at the key working parts of the suture process,determine the appropriate parameters and shapes of the thread needles and crochet needles,and analyze the static failure of the thread needles and crochet needles based on the finite element analysis software;The shape of the suture loop during the suture process determines the position of the thread pulling hook of the thread pulling mechanism.Complete the actual processing and installation of the suture device,and carry out the control system design,circuit planning,PLC programming,operation and debugging of the stitching device.A one-sided stitching prototype was used to conduct stitching experiments to verify the stability of the one-sided and double needle single-thread suture equipment,and analyze the factors affecting the suture stitches during the experiment.