Design And Optimization Research On Automatic Fabric Cutter

This dissertation has researched and designed automatic fabric cutter, including mechanical system, electrical control system, vibration modal analysis and optimization on key part. The mechanical system has discussed total scheme, transmission, sustentation, slider-crank mechanism, cutting head and auxiliary system. Electrical control system has studied motion control and pneumatic and vacuum system. Then vibration modal analysis on moving beam of the cutter is performed, intrinsic rule of natural frequency of the beam is found out and a corresponding optimization design is given.The dissertation firstly discusses total scheme of mechanical system, introduces a method of cutting based on high speed movement of blade. Work flow of cutting is made according to technical requirements. Based on comparison of methods of transmission and sustentation, low cost, precision and maintainability, timing belt driving and gear-rack driving are adopted as transmission scheme and linear bushing rail is adopted as sustentation scheme for the cutting system. Then a key mechanism—cutting head is researched, which is composed of blade-vibration cutting and automatic rotating mechanism, grinding mechanism and blade-feeding mechanism. Kinematics analysis and simulation on slider-crank mechanism are finished. Finally selection of driving devices and structure of auxiliary system are described.A frame of motion control composed of PC, I/O module, motion control card, servo motor and stepping motor based on CAN bus is established in electrical control system, the principle of pneumatic and vacuum system are studied and given, as a result, this integrated control system realizes mechanical, electric and pneumatic harmony.Moving beam is a very important part of the cutting system, which is a bridge linking X axis and Y axis movement of workbench and a frame foundation for cutting head, its performance influences pointing precision of cutting, quick response of the system, stability of movement. Based on theory of vibration, this dissertation analyses modal of the beam using ANSYS. According to the result of calculating on ten sets of natural frequency and modal vibration, transformation figures and data table are showed. Then analysis on sensitivity relationship between structure parameters and natural frequency of beam is performed, and an optimization model is established, in which the objective is natural frequency of beam and design variable is structure parameters of beam. This dissertation gives a program of the optimization process in ANSYS. Data from solving the program show that optimization reaches the anticipative aim for improvement on structure.