Design Of Unilateral Stitching Device For Carbon Fiber Preform Based On Improved Technology And Research On Stitching Behavior

Carbon/carbon(C/C)composite material is a structural composite material developed in the past two decades.Its three-dimensional fabric has a good overall structure and a high fiber volume content.The structural properties of structural components made after CVD composite treatment are superior.Is an excellent substrate for the production of high-performance structural materials and thermal protection materials,which significantly improves the mechanical properties of composite materials in many aspects,especially the fundamental shortcomings of structural composite materials such as low interlayer strength and easy delamination.It is used in new technological fields such as aviation,aerospace,automotive,and medical.This paper introduces a single-side stitching technology for C/C composites.Based on the analysis of the research status of carbon fiber three-dimensional fabric forming equipment at home and abroad,this paper studies and analyzes the existing single-sided double-needle stitching process,pointing out the existing The defects existing in the process of stitching,that is,the existing stitching process only relies on the cooperation of the hook thread and the lead needle,and the hooking and the wrong hook phenomenon may occur during the stitching process,and the process is improved for the defect.From the improved stitching process,it is determined that the stitching device includes a lead mechanism,a hooking mechanism,a thread take-up mechanism,a dialing mechanism and a feeding workbench,and the design and comparison analysis of each part of the mechanism is performed to select the best.The scheme and detailed structural design of each part,using Pro/E 3D modeling software to build a virtual prototype.In order to determine the size of each mechanism and enable each mechanism to accurately match the completion of the suturing action,the kinematics analysis of each mechanism during the design process,in order to achieve a unilateral suturing action and stable operation of the suture stitches,avoiding only the lead pin and the stitching process The poor cooperation of the hook needle causes the hook needle to be hooked and mis-hooked,which causes problems such as lost loops and broken stitches.The principle of unilateral stitching and the principle of the action of the hook needle and the lead pin are analyzed.Based on the improvement of the original stitching process,the trajectory superposition idea was put forward,and a three-dimensional prefabricated single-side stitching device for C/C composite material was designed.The dialing mechanism of the dialing mechanism was analyzed to establish the dialing mechanism.The mathematical model of the line principle,and the trajectory simulation analysis using MATLAB,verified the rationality of the dialing principle.According to the improved single-sided double-needle stitching process and the mechanism motion relationship of the C/C composite prefabricated single-side stitching device,the control system design,electrical circuit planning,PLC programming and debugging of the sewing system are performed.The suture experiment was carried out with the debugging suture device,the suturing behavior was studied,the yarn consumption during the suturing process was calculated,and the corresponding thread take-up mechanism was designed according to the balance of supply and demand,the thread quantity and the thread tension required for the yarn.The analysis is carried out to adjust the stitch length and the thickness of the seam to optimize the stitching effect,thereby verifying the rationality of the improved process,the accuracy of the movement of the threading mechanism,and finally the stitching of the fabric.