Design Of Novel 3D Printer Mechanism Based On Planar Four-Bar And Five-Bar Composite With Variable Bar Length

The planar parallel five-bar mechanism has the advantages of high stiffness,low inertia,stable structure and high precision,as well as the characteristics of simple kinematics and dynamics solution.Planar four-bar mechanism is a single-degree-of-freedom mechanism.The connecting rod curve is smooth and rich in variety.Add the function of the planar four-bar linkage to the planar five-bar parallel mechanism,to generate a new mechanism,improve the performance of the 3 d printer mechanism to improve the serrated trajectory surface phenomena and molding parts internal organization performance problems,at the same time,the agency to change institutions,length and increased the flexible body,improve the planar four-bar linkage path synthesis ability of different curve.For the above mechanism,this paper adopts the form of theoretical analysis,simulation analysis and experimental comparison for the design,and its contents mainly include:(1)give the overall mechanism design scheme according to the design index of 3D printer,establish the mechanism model,and complete the kinematics theoretical analysis of the mechanism.(2)firstly,the workspace of planar parallel five-bar mechanism was analyzed from the geometric position,and then the parameters of planar parallel five-bar mechanism were optimized and solved based on the global motion performance index.Finally,the motion flexibility of the mechanism was evaluated according to the solved parameters.(3)the derivative mechanism of planar parallel five-bar mechanism is designed,and genetic algorithm+fminsearch function is proposed to jointly solve the planar four-bar mechanism,and the involute curve is taken as an example to verify the effectiveness of this method and the track synthesis ability of planar four-bar mechanism.(4)kinematics simulation of 3D printer mechanism is carried out.Through kinematics simulation of circular trajectory,simulation curve and theoretical curve are compared to verify the correctness of position equation and jacobian matrix theory derivation of planar parallel five-bar mechanism.After that,the motion of the mechanism when the four-bar and five-bar joint closed curve is drawn is simulated and analyzed,and the whole movement period of the mechanism is obtained.(5)a new type of planar four-bar and five-bar compound mechanism based on variable bar length is constructed and tested.Firstly,the experimental platform of the mechanism was built to control the motor motion of the driving motor to make the expected trajectory of the end running.The four-bar trajectory and five-bar trajectory were compared and finally compared with the simulation situation.