Study Of Planar Nine-bar Linkage For Transmission Characteristics And Simulation Analysis

In order to meet the requirements of rapid clamping, slow blanking and fast return,mechanical fine blanking press often adopts the2-DOF Double-Knuckle transmissionmechanism. It is the mechanism which adopted by GKP-F Series of fine blanking pressmade by Switzerland Feintool Company, and it was designed in the form of biaxialnine-bar linkage. As a multi-linkage of two degrees of freedom, the mechanism itself hasa good regulatory. However, the biaxial nine-bar linkage mechanism itself was originallydriven by a single normal motor via gear engagement. Considering that the servo press hasadvantages of high flexibility, high precision, high efficiency which can better fulfill thebasic requirements of the fine blanking press, this thesis transformed the biaxial nine-barlinkage into a full servo mechanism driven by two servo motors. Meanwhile, design a20KN servo press for experiment and further experimental study of the transmissioncharacteristics of the mechanism will be researched. The contents and research results areas follows：Build the mathematical model of the nine-bar linkage with two degrees of freedomwhich is driven by two servo motors. And, list the closed loop vector equation of themechanism. Then, solve the angular displacement, angular velocity, angular accelerationof the linkage, and the displacement, velocity; acceleration of the slider, in thetransmission system, thus the kinematic analysis is completed. Accordingly, further studyof the characteristics of transmission and the impact of the linkage’s size on the slidemotion curve can be researched.The virtual prototype of the mechanism has been established by using ofMSC.ADMAS software. Study the torque distribution of the double crank under the wholetrip load conditions of the slider. After analyzing the role of triangle in mechanism’s amplification characteristics, improve the mechanism’s amplification performance bychanging the size of the triangle and make the maximum torque of the double crank innominal stroke be balanced. In this way, solve the problem which single motor power istoo big because of the large required torque on single crank.Determine the transmission mechanism’s layout scheme of the prototype，design thestructure of the transmission mechanism, slider, guide and press body, and construct thethree-dimensional digitalization model. Due to the complex loading conditions of thecrank, do the strength and stiffness checking to the crank with the finite element method;do the static analysis of the body and find the weak area, and improve its structure.Complete the assembly of the servo press and the interference checking. Do thekinematics simulation of machine in UG NX kinematic analysis module Motion. Theinfluence of the initial phase difference between the two cranks, i.e., the phase leading orlagging, on the output curve of the slide in synchronous mode was simulated using thepowerful post-processing features of the software ADAMS, thus providing a reference forfuture completion of the prototype synchronous control experiment.