Structural Design And Research Of 3D Printer Based On Decoupled Parallel Mechanism

As an emerging technology in the rapid prototyping field, 3D printing technology colligates computer technology, precision machinery, materials science and other advanced technologies, which greatly shortens the processing cycle of products, and has been widely used in medicines, automobiles, aerospace and other fields. However, the 3D printing equipment widely uses serial mechanism as the actuator, so there are some problems such as poor printing precision, and low speed, making it difficult for the promotion of the 3D printer. The actuator which is the main body of 3D printer is one of the key factors that affect the quality of 3D printing. Therefore, this paper regards 3D printer actuator as a departure point to undertake research, aiming at solving the existing problems of the 3D printing equipment.Through the analysis of the working mechanism of the FDM process 3D printer, the motion principle of the 3D printer is described, the deficiencies of the 3D printer actuator in the structure and function are pointed out, the factors that affect the 3D printing speed and accuracy are summarized, and finally, the design method of decoupling parallel 3D printing robot is proposed. Comparing the advantages and disadvantages of coupling and decoupling parallel mechanism, the 3D printer selects 3-CUR decoupling parallel mechanism as the actuator.By the kinematics analysis of actuator, mapping relationship between input and output is obtained. Based on the input and output differential relation of the mechanism, the error model of the mechanism is established to analyze the positioning accuracy of the mechanism. The kinematic accuracy of the mechanism is optimized with the dexterity as the target. Taking print space as the goal, the mechanism parameters are optimized based on the performance atlas of the mechanism parameters and Genetic Algorithm.The dynamic model of mechanism is established by Newton Euler method, which is verified on the basis of the given trajectory with the use of Adams software and MATLAB software. Without considering the mass of the bars, the dynamic model is translated into static model and the whole solution of the mechanism is obtained by maple software. Under the given condition, the change curves of constrained forces and torque are drawing by using MATLAB software to analyze the stress characteristics of mechanism. By setting the rotation pair, establish the mapping relation between the moving platform deformation and the six dimensional loads.Based on theoretical analysis, the bars are designed. The stiffness characteristics of the virtual prototype are verified by finite element analysis software. Finally, the prototype is manufactured and the control principle is analyzed.