The dynamic character of pillar of machining center of crankshaft end panel is analysed

Summary: In the light of trends of machining center of crankshaft end panel character asks tall and pillar shows different trends to answer the question such as character below different operating mode, contrary column structure had kinetic research. The kinetic analysis that is based on ANSYS is theoretical, undertook simplifying appropriately to model of machine tool pillar, the waits for parameter unit simulation to join a department contact that the osculatory character between interface uses 6 node is characteristic, built kinetic emulation model. The come to an agreement that undertook to the structure mode analysis and dynamic load fall answers an analysis, the oscillatory character that acquired machine tool structure and the trends that are out of shape distributinging rule; issues pillar to different operating mode answer a circumstance to undertake comparative, offerred the influence rule that different operating mode answers to pillar trends. Study the result makes clear, rise as height of main shaft box, structural natural frequency is changed somewhat, pillar trends answers even more apparent; the pillar below different operating mode all produced; of the biggest displacement to still make clear structural stiffness weak position around first-order natural frequency, provided academic basis to optimize structural stiffness further. Foreword crankshaft is one of core components of engine, demand of its treatment precision is higher, traditional horizontal turning and vertical milling cannot have satisfied the precision demand with higher and higher crankshaft. Current, the double pressure that domestic crankshaft manufacturing industry is facing cost and efficiency. In the light of conventional treatment the method is machining the inadequacy on precision, the author and collaboration of limited company of machine tool of Hangzhou engine numerical control develop structure of a kind of whole to be T machining center of crankshaft end panel. It uses integral type lathe bed to design, main shaft box is not drive of centre of gravity, avoid a few precision errors that cause as a result of objective reason. The treatment precision that bed of large scale computer can achieve and machine tool structure and its stability are direct and relevant [1] , because this reasonable construction designs the efficiency that can improve crankshaft machine and precision, the automation level that raises crankshaft treatment thereby [2] . The person such as Kang Fang, Fan Jinwei passes analytic pillar each rank the characteristic of mode, find be out of shape the largest area, choose in this area undertook humorous answers an analysis to be analysed more effectively with undertaking to its [3] . Undertake necessary structural motivation learn an analysis to machining center of crankshaft end panel it is thus clear that, can know the place with inadequate structure, improve for sequel raise structural intensity, stiffness to provide a basis, make its more rationalize. Because lathe bed volume is larger, integral stiffness is good, because this considers to will be based on ANSYS software originally, according to kinetic analysis academic key is aimed at pillar and main shaft box to undertake kinetic analysis, in order to study the trends that its issue in different operating mode is characteristic. These analysises can improve the academic basis with be offerred important to the structure of pillar of machining center of this crankshaft end panel. Pillar of 1, machine tool and model of structure of main shaft box are in the structural design of pillar, integral stiffness jumps over stability higher. This research considered the high accuracy of machining center and stiffness requirement, reduce spare parts amount as far as possible, use integral type pillar to design, whole pillar shows box of main shaft of cavity structure; to use drive of blame centre of gravity to design as one of important parts. Because machine centre of gravity place of the main shaft in the process,traditional main shaft form meets change and cause deflection of position of main shaft axes, and the main shaft in using the means that is not drive of centre of gravity to because machine a process,avoid well is changed as a result of centre of gravity place and arise " lower one's head " phenomenon. This research applies Solidworks to build the structural model of pillar and main shaft box, if the graph is shown 1 times,structure of machine tool pillar pursues. Graph Nextpage 1 of plan of structure of pillar of 1 machine tool, ; 2 of main shaft box, slideway; 3, when pillar machine tool is working, pillar and main shaft box can be come from inside, external stimulate brace up, these metropolises make its produce needless vibration, cause thereby be out of shape. If vibration has been out of shape big, will affect the treatment precision of machining center badly. Accordingly, very be necessary to undertake kinetic analysis to structure of machining center whole. 2, kinetic analysis considers to be based on ANSYS software to oppose column and main shaft box undertake originally theoretically finite yuan of analysis [4] . According to mode analytic theory and humorous answer an analysis to oppose column structure undertakes kinetic analysis theoretically [5] . 2. The inherent vibration that 1 mode analyses academic mode is rigid structure is characteristic, each mode has specific natural frequency, damp comparing and mode vibration shape. The oscillatory character that mode analysis basically uses at deciding the structure is mixed to reach its component (natural frequency and vibration shape) , it is the foundation of other kinetic analysis. The mode that uses small displacement theory analyses computational equation to be: 2. 2 humorous noise should analyse academic humorous to answer an analysis to be used at deciding linear structure is in to bear to press sine along with time (Jian Xie) a kind of technology that the stable state when regular change load answers. Its general motion equation is: NExtpage 3, build finite yuan of model that seek solution 3. 1 simplify finite yuan the model is in finite yuan before the analysis, can improve computational efficiency greatly through undertaking to complex rigid structure proper model simplifies. Because lathe bed volume is larger, this research is passed secure simply piece will make equivalent lathe bed, the trends that analyses pillar and main shaft case mainly is characteristic. The author undertakes simplifying appropriately to the pillar that builds in SolidWorks and model of main shaft box, after simplifying main by pillar, 4 slideway, main shaft box, and of equivalent lathe bed secure a composition. If pillar structure parameter expresses 1 to show. Next the author guides the model undertake material attribute setting and reseau differentiate in ANSYS Workbench. In analysing a model, the hypostatic part of general composition and slideway can use three-dimensional and hypostatic unit simulation, the waits for parameter unit simulation to join a department contact that the osculatory character between interface uses 6 node is characteristic [6] . If the graph is shown 2 times,machine tool pillar begs solution model sketch map. [7] express 1 pillar structure main parameter watch. 3. Condition of 2 models border installs dynamic and characteristic analysis to oppose column structure undertakes mode is analysed above all, get a structure each rank on the foundation that natural frequency and vibration shape; analyse in mode, through humorous analyse of noisy part of one's job gets pillar structure is analysing the trends inside frequency limits to answer character. Graph pillar of 2 machine tools begs Nextpage1 of solution model sketch map. 2. 3. At 4 o'clock, 4 tests nod; D, the distance basis between main shaft box and pillar bottom machines a circumstance actually, this research applies consolidate to be restrained surely on base, in treatment position of head of cutting tool knife brings to bear on through kinematic emulate gotten axial load (emulation process did not give out in article of space of be confined to) , box of analytic main shaft is located in pillar lowest respectively end, mid, top end the trends of the pillar when these 3 circumstances is characteristic. The to load circumstance of whole treatment operating mode also is shown 2 times like the graph, if attrib border condition expresses 2 to show. The watch is 2 different operating mode and 4 of watch of attrib border load, dynamic as a result the analysis passes character to undertake to 3 kinds of operating mode finite yuan of computation, this research got the natural frequency of pillar structure, and trends answers character, have trade off study to the result [8-11] . 4. 1 mode analysis passes mode analysis as a result, this research got the natural frequency of pillar structure. Knowable when stimulating Zhen Pin to lead the natural frequency that is close to pillar structure, can produce resonance phenomenon. In have relatively in the treatment process that high accuracy asks, the needless oscillatory and immediate effect that electric machinery place produces is on pillar, can serious effect machines precision. Accordingly, analytic structure natural frequency can reduce the effect that produces because of resonance place as far as possible. Before computation gets those who fall pillar structure machines a circumstance in 3 kinds 6 rank natural frequency, each operating mode each rank natural frequency watch is shown 3 times like the watch. Express 3 each operating mode each rank the oscillatory frequency that natural frequency expresses place of Nextpage electric machinery to arise is in 130 Hz of 0 ～ . By the watch 3 knowable, natural frequency increases as rank number and increase, and before two rank natural frequency (as it happens of 60 Hz = 3 600 R /min, 90 Hz = 5 400 R /min) is in this limits. Because this is in treatment process, electric machinery is used in high speed rotate speed when can be close to natural frequency quite, can cause resonance likely, need undertakes be analyticed further. Additional, make after comparing, discover through the natural frequency that falls to 3 kinds of operating mode, although be below the circumstance with changeless structure, natural frequency can produce a change likely also because of other factor, the pattern with exist definite. With the 1st rank natural frequency is exemple, when main shaft box is in lowest to carry, the static stiffness of pillar structure is tall, its natural frequency is taller also. A kind of approximate and linear proportional relation exists between natural frequency and static stiffness. Ever since a few rank second put in this kind of rule. This result can think follow-up structure optimizes the basis with be offerred certain. 4. 2 humorous answer an analysis to be as a result in treatment process, outside the vibration of the generation when running except electric machinery itself, the contact between cutting tool and workpiece can produce a dynamic load that has the law. Because this has the foundation that need analyses in mode to go up, analytic pillar falls in same frequency, the trends of 3 kinds of different operating mode answers a circumstance [12] . According to the graph 2 are shown, whole pillar structure is in Z up length is ambitious at X, Y up length, because the displacement of direction of this pillar Z is answered,want way of outclass X, Y. Graph 3 kinds of operating mode issue pillar of 3 machine tools the biggest displacement answers cutting tool graph basis pursues 3 knowable, below 3 kinds of operating mode, the trends of pillar answers a trend to basically agree. Lift as position of main shaft box, pillar displacement answers extent to increase; knowable as position of main shaft box rise, the stiffness decrescent of pillar structure, make trends is out of shape increase. Main shaft box is when top end, the biggest displacement gives cutting tool to be 55 Hz (in frequency now first-order natural frequency 56. Box of main shaft of 4 Hz) ; is in in when end, the biggest displacement gives cutting tool to be in frequency now 58. 3 Hz(first-order natural frequency 60. Box of main shaft of 2 Hz) ; is when lowermost end, the biggest displacement gives cutting tool to be in frequency now 61. 6 Hz(first-order natural frequency 62. 8 Hz) ; falls in 3 kinds of operating mode, the biggest displacement all gives cutting tool near respective now first-order natural frequency, this result and the mode before analyse result photograph be identical, on certain level also test and verify analytic effectiveness. Nextpage 3 is planted the include of choice limits as it happens of operating mode the journey of box of whole main shaft, because this is knowable, make cutting tool happening the biggest the frequency limits of displacement is 3 720 R /min) of ～ of 62 Hz(3 300 R /min of ～ of 55 Hz. Top end is the oldest displacement is 0. 022 Mm, the biggest displacement is carried in for 0. 013 Mm, lowest carries the biggest displacement for 0. 005 Mm, top end is the oldest 4 what displacement carries the biggest displacement for lowest about. 4 times. The trends below 3 kinds of operating mode is answered all accord with stiffness requirement, but the difference between its is bigger still. The trends in analysing 3 kinds of operating mode now is answered the biggest when (when frequency is 56 Hz) a kind of operating mode. Main shaft box is when top end, if the graph is shown 4 times,4 tests site answers a graph in the displacement below different frequency. Graph the biggest at 4 o'clock displacement answers 4 pillar the displacement that the graph nods 4 times answers the rule to agree basically. The test is shown to choose the place on numerical value taller, displacement answers bigger case, more apparent when be close to natural frequency. Distributinging cloud atlas of the stress when stimulating Zhen Pin to lead 56 Hz and meet an emergency is shown 5 times like the graph. Graph Nextpage of distributinging cloud atlas of 5 pillar stress and meet an emergency passes cloud atlas of stress meet an emergency to be able to see, pillar is out of shape main concentration combines below ministry and pillar half part in slideway. The result that combines 4 tests to nod displacement to answer graph and cloud atlas of stress meet an emergency is knowable, the vibration of pillar is with pillar coping vibration is given priority to. The author thinks, pillar should be used on the structure go up small big form will raise pillar Z to stiffness, raise below pillar half stiffness, this is worth to optimize the bring to sb's attention in the design in follow-up structure. 5, the vibration that last word author studied pillar and itself of structure of main shaft box to fall in 3 kinds of operating mode is characteristic, and in different stimulate trends of the displacement below Zhen Pin rate to answer a circumstance. The change and shows existing pattern change that the result indicates to because structural Jing Gang is spent,structural natural frequency is met, the trends of the biggest displacement below 3 kinds of operating mode answers cent not to appear around respective and first-order natural frequency, structural stiffness is lower, answer it is more apparent. When stimulating Zhen Pin clearly to lead limits to be inside 62 Hz of ～ of 55 Hz next, can produce bigger vibration to be out of shape, because this is in treatment process,should avoid this to stimulate Zhen Pin to lead limits as far as possible. Additional, analytic conclusion makes clear, although pillar structure stiffness satisfies a requirement, but the structure still is put in inadequacy, still remain to optimize improvement further. CNC Milling