Experiment Research On Modal Analysis Of CNC Machine Tool For Active Spindle Movement Excitation

With the rapid development of manufacturing industry and the rapid excellentimprovement of national industrial process, the requirement of performance ofthe manufacturing equipment is increasingly stringent, and it is mainly reflected in twoaspects of machine tool performance that high speed and high precision. However, thedynamic characteristics have a negative impact on the machining accuracy of machinetool under the condition of the high speed and distinct variable load, even cause thevibration of the machine tool and weaken the machining accuracy, what is more, thefrequencies and modal shape happen to change. the pool dynamic characteristics ofmachine tool seriously restricted the machining capability, so it is important to improvethe dynamic characteristics of machine tool structure, and it has also become an importantresearch topic of machine tool improvement. In view of this, based the973Program "Instability mechanism of multi-axis machining super deformed parts and optimization ofcontrolling quality " project, the paper presents a new and more effective methods activespindle movement excitation technique to analysis the dynamic characteristics ofmachine tool spindle structure, and provide an effective complement of activeexcitation techniques. In this paper, the main study contents are as follows:this paper puts forward an active spindle movement excitation method, and realizesit by means of numerical control G code. The effectiveness of the new technique isvalidated by the active spindle movement excitation experiment and experiment blowingthe spindle by a hammer；Analysis the influence on excitation effect the factors involvedin design process have. It mainly focus on the effect different excitation rules, thedesigned speed and tools have on energy and frequency band of excitation；To study thechange of dynamic characteristics of machine tool structure when the spindle is static orworking by comparing the results of hammer test and active spindle movement excitationtest；By comparing the experiment results of the active spindle movement excitation testand the test of active excitation in feed direction with no machining, it has proved that thenew excitation method is more effective than other excitation methods to excite thespindle structure. and it is an excellent complement of active excitation techniques withoutmachining.