Researches On Key Technologies Of A Multi-linkage High-speed Mechanical Press Machine

The multi-linkage high-speed precision mechanical press machine is one of the important branch of modern forging equipment.Its technological level can reflect the advanced level of forging machinery industry in some extent.Researches on multi-linkage high-speed me-chanical press machine started late in china,so some key technologies are still almost blank compared with foreign countries.Taking the high speed of multi-linkage press machine as object,key technologies,such as research on the configuration design of transmission mecha-nism,dimension synthesis,kinematic and dynamic modeling,and synthetic optimum dynamic balancing,are studied in this paper.The main research contents are as follows:On the basis of characteristics and design requirements of the existing transmission mecha-nism of high-speed mechanical press machine,a configuration of transmission mechanism is proposed,and the new unique characteristics are added to the mechanism.Compared with the traditional press machine,it has higher bearing capacity and lower crank load.The DOF(De-gree of freedom)and mobility of over-constraint mechanism is demonstrated by using the G-K formula and virtual prototype technology.Then,the over-constraint mechanism is sim-plified according to equivalent principle of kinematic characteristics,and the kinematics model of transmission mechanism is established.Based on the kinematic analysis,the design variables and constraint functions are deter-mined.Taking the weighted sum of the length of crank and the punching angle as objective function,the dimension synthesis math model of high-speed mechanical press machine is es-tablished,which take.The dimension parameters of multi-linkage transmission mechanism are determined by using optimization methodology,and a quantitative comparision with the crank high-speed press machine is given also.Then the kinematics characteristic of transmis-sion mechanism is simulated by Matlab software.The force/moment equilibrium equations are given by using the D Alembert principle on the basis of the kinematic analysis,but it cannot be solved.The mechanism is divided to re-solve the over-constraint problem of mechanism.The deformation compatibility equations for the over-constrained mechanism are obtained on the basis of the deformation compatibility analysis at each position of the mechanisms.The general resolution method of dynamic mod-eling of the over-constrained mechanism is presented and is used to establish the dynamic modeling of the over-constrained transmission mechanism of high-speed press machine.The constraint reaction forces of the kinematic pairs and driving torque are analyzed under the condition of punching,and the structural parameters of the components in the transmission mechanism are designed.The main source of vibration of frame,the limitation of existing complete balancing theory and the deficiency of synthetic dynamic balancing are discussed in this paper.Based on the dynamic analysis,the dynamic substitution of concentrated point-masses was introduced to represent the inertial properties of the links and to identify optimizing variables.First,we take the constraint reaction force of kinematical pair connected the frame as research object and remove the constant components that don't effect the vibration of the machine.Then,after a standardized processing,the weighting sum of the root-mean-squared constraint forces is de-fined as the objective function.The synthesis optimum dynamic balancing math model of high-speed mechanical press machine is established by using the methods of adding compo-nents,redistributing mass and counterweight.The constraint condition and the calculation method of weighted coefficient are given,and the inconsistent problem of dimention between all dynamic indexs is solved.The feasibility and effectiveness of the proposed methodology was illustrated by comparing it with the results of tradition optimization method.Based on the computation and analysis of kinematic,dynamic and synthetic optimum dy-namic balancing theory,combining with the pratical engineering need,the structure of all components of press machine is designed.The virtual prototype model is established,and the model is simulated by Solidworks software.Based on the above,product prototype of closed multi-linkage high-speed press machine is manufactured and the processing,assembling and debugging process are completed.Furthermore,the test schemes are designed.Then,the dy-namic performance of the press machine,such as the mechanical performance of components,vibration of reference point fixed on frame,dynamic performance of acceleration and decel-eration of press,dynamic accuracy of bottom dead center and the temperature of crankshaft position are tested on the test platform.The test results are compared with the corresponding theoretical results,which show that the design goal of press machine is reached,and the cor-rectness and effectiveness of proposed theory are validated.