| As one of the important parts of the axial flow impeller,the complex curved blade has attracted the attention of the manufacturing industry and the academic circle with the wide application of turbine,steam turbine and aeroengine.The machining quality of complex curved blade directly influences the main performance of turbine,steam turbine and aeroengine.The blade has the characteristics of complex design process,complex surface of space,poor working environment and high precision.So the blade design,material,mechanical processing,heat treatment and surface spray coating process need high requirements,any tiny defects in designing and manufacturing will affect the work efficiency,even damage of the whole unit.With the development of information technology and automation technology,surface processing is becoming more and more stable and efficient.More and more new technology and new method applied to surface machining.In this paper,the rapid prototyping technology is used to complete the manufacture of large curved surface structure in the big project of "new principle and new technology for the integrated manufacturing of blade complex surface".Free-form surface machining 3D printer based on double parallel rod mechanism is the combination of the advantages of parallel mechanism and the current fused deposition3 D printers,which can not only make full use of advantages such as high precision,flexibility,and the flexible parallel mechanism,but also solve the problem of small motion space in parallel mechanism through the linkage of upper and lower double parallel mechanism.Structure throughthe stepper motor control completes nozzle3-SPS parallel mechanism's X,Y,Z direction linear motion and the working platform 3-SPS parallel mechanism's X,Y overturn,which completes manufacturing blades of large surface and supported to cantilever,hollow structure to reduce or even remove support purpose.Free-form surface machining 3D printer based on double parallel is proposed for the first time,and two patents are applied for the invention patent.The process of development and test research in double parallel rod mechanism based on free-form surface machining 3D printers includes the required degree of freedom structure,distribution of degree of freedom,kinematics analysis,movement space kinematics simulation calculation,structure static simulation,structure and test set up and the subsequent experiment.The absolute DOF of the nozzle 3-SPS parallel mechanism and the working platform 3–SPS parallel mechanism are established,and the kinematics acceleration dynamic analysis are completed.The models of location,velocity and established which are between the absolute DOF and drive.The model is established by Lagrange.Considering the structure design and the kinematic analysis of the 3-RPS parallel mechanism,the work space is solved with different locations and poses.The finite element model of 3-SPS parallel mechanism and the whole machine are established,and the static and dynamic performance of the parallel mechanism and the whole machine are analyzed by using the finite element analysis software ANSYS.The parallel structure and the static performance of the whole machine are better.Through kinematics ADAMS simulation,the reliability of structure kinematics is verified and the stability of structural kinematics is improved.Setting up print prototype,developing control strategy,writing control program.The experimental verification of the cantilever structure,the test verification of the hollow structure,and the Angle of the work platform to be flipped and the Angle test of the part structure and normal line of the test piece were completed.Validation can be directly printed with normal by controlling the working platform flip into 80 °Angle of structure,and reduce the more than 80 ° angle of the support structure of the specimens,and by controlling the working platform flip directly print large anglehollow structure,and to reduce excessive size hollow structure of the support material. |
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