Design And Key Technology Research Of Spiral Extrusion 3D Printing Device

3D printing technology integrates the professional knowledge of computer,material,machinery and control,and is especially suitable for small batch trial production and processing of single piece of solid and cavity structure products with complex curved surface.As one of the typical 3D printing technologies,extrusion 3D printing has the advantages of high material utilization,simple process and easy operation,among which the key to its application is the design of the feeding device.Based on the advantages of the existing extrusion 3D printer and screw pump,a new structure of spiral extrusion 3D printing device suitable for 3D printing of viscous materials is proposed,and the theoretical design and control strategy research of the new 3D printing device are carried out.The research of this paper mainly includes:1)A new structure of spiral extrusion 3D printing device is proposed.The mathematical model of spiral supply pump and 3D printing head is established.The calculation equations of printing efficiency and driving power are derived.The theoretical calculation formula of the internal flow field of the screw pump and the 3D printer is given,and the distribution law of the internal flow field of the 3D printer is studied.2)According to the 3D printing requirements of a cake,the specific structure of spiral extrusion 3D printing device is designed.The 3D solid model of spiral supply pump and 3D printing head is established by UG software.The model is imported into Fluent software for flow field and fluid structure coupling analysis,and the outlet pressure value close to the preset value is obtained,which reduces the shear force value by 25.7%.To ensure the smooth flow of materials in the pump,the speed gradient is small.The fluid structure coupling analysis of the screw feed pump and the 3D printhead is carried out,and the maximum deformation is 0.07% and 0.12% of the minimum size parameters.The parameters of rotating speed and inlet pressure of spiral sleeve with different parameters are simulated and optimized to get the best inlet pressure parameters and control method.Finite element static analysis of 3D printer frame and key connecting parts ensures the stability of the overall structure of the printer.3)The selection of the driving control elements and the design of the control circuit,the selection of the control elements and the definition of the key control parameters of the spiral extrusion 3D printing device are completed.The test platform of the spiral extrusion 3D printer is built,and the 3D printing process is preliminarily reproduced by the motor control.The efficient and high-precision printing control strategy is verified to ensure the stable control of the control elements.