Dynamic Characteristic Research Of The Alien Stone Machining Center (HTM50200)

With the development of numerical control machine under the direction of high speed, highaccuracy and high efficiency, just considering the good static stiffness is far from meeting thedesign requirements of the machine tool. The dynamic characteristic has become an importantindex of the performance evaluation of them. By using the method of dynamic design to replacestatic design has also become the inevitable trend in the development of modern machine toolsdesign. Due to the dynamic characteristic of machine tools seriously affect the machiningaccuracy, machining efficiency and service life etc, so it has become a necessary part in theperformance evaluation and machine tools design.This paper uses the machining center called HTM50200type which our school andShenyang machine group jointly developed as a research object, establish the finite elementmodel of the structure of this machine tool by using software named ANSYS, and to achievemodal analysis and the dynamic response analysis. Through these above analysis to calculate thestructure modal frequencies and modal shape, find out the weak links of the machine tool, andput forward the reasonable improvement plan. In the process of dynamic response analysis,extract the response characteristic of the cutter tip between its displacement and accelerationwith frequency. Considering the spindle-cutting tool system is the direct factors in effectingmachining accuracy and efficiency, especially analyse about the static and dynamiccharacteristics of this spindle component, mainly includes the static analysis and modal analysisand critical speed analysis, the dynamic response analysis, and the machining precision analysison the basis of them, etc.In the condition of different speed, different cutting depth and different feed rate, do emptyoperation and cutting test, at the same time collect vibration signal of X, Y and Z axis offront-end of electric spindle by using vibration test system. Through the spectrum analysis,synthetically evaluate the operation performance of machine tool, determine the range of flutterfrequency and the parameters of the best cutting process. Based on the experimental modaltheory, achieve the experimental modal analysis of the machine and key components by themethod of hammer which single point vibration and more response. After that we obtained thekinds of modal parameters including modal frequency, model shapes and damping coefficient.Contrasting calculation result of the finite element and test data, shows the rationality andaccuracy of these above finite element modeling, and discusses the reasonable reasons forproducing deviations. Besides, combining the local modal analysis of turning head and sculpturehead, and the testing about dynamic stiffness, we find out the weak structure of the machine tool.These above research content of this paper provide reference for the research of the machine structure improvement and advance the whol e dynami c performance in the next step.