Research On Precision Design Of Key Components Of High Speed Precision Press

High speed precision press is widely used in electronic devices,rail transit,aerospace and other fields.The accuracy of slider bottom dead center is an important parameter to determine the product quality and die life,and it is also affected by many factors.It is of great significance to analyze and optimize the motion accuracy of key components of high-speed precision press.Taking the double slider six bar mechanism of high-speed precision press as the research object,this paper studied the influence of the wear of the rotary pair and the elastic deformation of the bar on the accuracy of the bottom dead center of the slider,comprehensively considered the analysis results of the two and the manufacturing error of the bar,carried out the synthesis and reliability evaluation of the length tolerance accuracy of the connecting rod,and designed the test experiment of the bottom dead center accuracy.The purpose of this paper is to put forward a reasonable and effective method to synthesize the tolerance accuracy of rod length.First of all,the wear of the rotating pair will enlarge the gap value,which is an important factor affecting the bottom dead center accuracy.Assuming that the journal is in continuous contact with the bushing,the wear position of each rotating pair and the relative motion between the journal bushing were determined by kinematics and dynamic statics analysis.Based on the Archard adhesive wear theory,the wear depth model of the rotary pair was established,and the relationship between the material properties,relative motion,contact stress and lubrication condition and the wear depth was established.The single cycle wear depth of each rotary pair was determined when the slider was located at the bottom dead center,and the influence of crankshaft speed on the wear depth was studied.Secondly,as another important factor affecting the accuracy of the bottom dead center,it is of great significance to study the elastic deformation of the bar.Based on the theory of elastodynamics,a mathematical model for elastic deformation analysis of multi bar mechanism was established,and a method for solving the motion accuracy of stamping mechanism considering elastic deformation was proposed.Taking the beam element as the equivalent element,considering the influence of transverse displacement,longitudinal displacement,angular displacement and curvature,the motion differential equation of the mechanism was established,and the real mode superposition method was used for decoupling solution to determine the elastic deformation of the component under different rotational speeds and the drift of the lower dead center.Finally,ADAMS software was used to simulate the rigid flexible coupling,which verifies the correctness of the calculation results.Then,based on the loop increment method,the error transfer model of the main motion mechanism of the high-speed precision press is established,which takes into account the research results of elastodynamics and the influence of component manufacturing error.According to the significance of error and the cost of rod process,the priority of precision comprehensive adjustment was determined.The distance between the center points of the rotating pair,that was,the length tolerance of the connecting rod,was designed and evaluated according to the Monte Carlo reliability simulation experiment.In addition,taking the design scheme as the object,combined with the results of wear depth analysis in this paper,the influence of wear on the accuracy retention of bottom dead center was studied,and the period of accuracy compensation measures and the allowable value of the maximum wear depth of the rotating pair were deduced under the consideration of this paper.Finally,the experiment platform of high-speed precision press was designed,including hardware,software and experiment scheme.The purpose of this experiment was to show the influence of elastic deformation and other factors on the accuracy of the bottom dead center by comparing the accuracy of the bottom dead center of the slider at different speeds.