Be based on finite the structure of beam of spot milling machine of yuan of analysis is optimized

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  • source:NEHMER CNC Machining
Summary: In the light of the situation that produces trace of moire shape knife in workpiece surface is not worth as a result of crossbeam component stiffness in treatment, use three-dimensional software SolidWorks and finite yuan of analysis that CosmosWorks of analytic plug-in unit undertakes building model and static, dynamic property to spot milling machine, basis beam vibration is mixed relative to metabolic vibration shape amplitude, and the working environment of the machine tool and the structure that the machine tool designs are mechanical and academic, put forward to improve a proposal to a few of horizontal fine grain, through finite yuan of analysis its function has bigger rise, undertake test and verify through mode experiment, actual measurement value and theoretical value contrast knowable, the beam after improving has better static, dynamic performance, prove structure of horizontal fine grain optimizing a design is feasible. Foreword spot milling machine is the spot treatment facilities that converts plant with Yu Shi. To get used to the treatment environment of the spot, requirement spot milling machine is below the condition such as contented function, precision, its quality and bulk as far as possible the smallest. Milling machine is not worth surface of the workpiece in be being machined to produce trace of moire shape knife as a result of crossbeam component stiffness, affected treatment precision and exterior quality. CosmosWorks of article have the aid of is finite yuan of software, build milling machine finite yuan of model, to main shift the component undertakes static, dynamic function is analysed, put forward reasonable to milling machine structure improvement method. Graph the 1 structural sketch map that is spot milling machine. 1 finite of yuan of model build collect plain the gravity of the case of main shaft of three-dimensional and hypostatic model that SolidWorks software builds spot milling machine and the torque M that cantilever produces are direct action at crossbeam, make crossbeam seizes change form (2) seeing a picture, so crossbeam is the crucial part of spot milling machine, its stiffness affects treatment precision directly, because this regards the object of main analysis as crossbeam. Graph the 3 hypostatic models that are beam of spot milling machine. Graph the 2 beam of hypostatic model 　 of beam of 3 milling machine of original structure finite yuan of analysis 　 2. 1 model simplifies crossbeam solders for armor plate structure, show each this solder dots to all serve as the rigid node of the model, main shaft box brief melt into is mixed actual structure is basic the box shape structure with consistent weight, the contact that considers main shaft box and slide is out of shape far be less than crossbeam be out of shape, so the interface definition of slide and main shaft box is rigid contact. Graph the 4 model 　 after applying to load to carry on one's shoulder or back 2. 2 differentiate reseau guides to the hypostatic model of crossbeam person CosmosWorks is finite yuan of software is medium, build finite yuan of computation model, use hypostatic unit to differentiate reseau, unit amount is 17256, node amount is 9352, eye of number of degrees of freedom is 97659. 2. 3 definitions are restrained and use beam of to load carry on one's shoulder two end are secured through bolt go up in slide carriage, be in finite yuan of model is medium, the freedom of each direction that the border horizontal fine grain restrains brief melt into and the node that answer relatively with calm bolt position is spent, namely Zhou Ding and bolt position are relative should each freedom of node spend the tie that will realize pair of beam, crossbeam suffers force to give priority to the gravity of axle box and milling force, the biggest deflection of crossbeam happens in main shaft box to run crossbeam when the position intermediate: Graph the 4 models after to differentiate reseau hind applies to load carry on one's shoulder to restrain to crossbeam and slide pursue, through seeking solution, the biggest deflection of crossbeam is 0. 1547mm, when actual measurement is machined, be (0. 15-0. 20 Mm) left and right sides, analytic result and the error that process actually agree basically, ambitious at workpiece 0. The flatness of 06mm asks. Graph 5 for cloud atlas of original structure displacement. Undertake to the machine tool mode is analysed, can show character of machine tool trends to be a graph apparently 6, of 7 the first, 2 rank vibration shape graph. Before watch L is 5 rank natural frequency and vibration shape: Through the analysis knowable middle cross beam of first-order vibration shape arises below outer force drive relatively substantially be out of shape, make in machining a process the fixed position precision of milling cutter becomes poor, affected the treatment precision of workpiece badly. Because this wants,undertake improvement to the structure of crossbeam. 3 beam structure is improved and analyse 　 3. The improvement of 1 beam structure is analysed from above knowable, the stiffness inadequacy of crossbeam is influence metabolic main reason. The design is improved in crossbeam in, wait for respect element considering the working environment of the machine tool, when improving, basic to crossbeam structure is not made change greatly, twisted stiffness to use diagonal to raise crossbeam to fight muscle board is fought twist theory, the muscle crossbeam interior board instead X; To develop fore-and-aft muscle adequately board fight seize property, muscle board decorates angle to should be become with horizontal as far as possible 45. With 135. direction, improvement plan is as follows: (1) general muscle board amount by turn into 3 pieces formerly 5, ply increases 15mm by 10mm; (2) increases a fore-and-aft level in crossbeam interior muscle board S. Ply is 15mm; (D of horn of 3) general echelon by 16. Increase for 20. ; (4) beam interior adds X muscle newly board, ply is 15mm, wide for 30mm. The structure after improving sees a picture 8. 3. 2 finite yuan of crossbeam model after the analysis will be improved guide finite yuan of analysis software is medium, after be being calculated through the analysis, reach of crossbeam be out of shape (the vibration shape result of 9) seeing a picture and beam, crossbeam is in the biggest deflection in machining a process 0. 056mm, the biggest deflection compares the beam after improving before improving, reduce apparently. 3. 3 computation result and experimental test and verify are test and verify the rationality that afore-mentioned improvement, had mode test to milling machine. With the vibrator of all alone suspension with one small stiffness, sine sweep drive has to the machine tool on 3 heading that carry a department in main shaft respectively, 14 are decorated to measure a place on milling machine, the oscillatory signal of the system of collect of 8 acceleration sensor that carries upside of front, beam and slide to go up in main shaft through installation, undertake to its mode is analysed. From the watch 2 in can see, the computational result of the article and test test result compare be identical, dynamic function had crossbeam to rise apparently. Among them, first-order frequency deviation is opposite bigger, because when stiffness is being calculated, the contact of box of machine tool main shaft and slide does not have a consideration,this is, bring about first-order mode result to slant small. 4 last words are passed finite yuan of way is right former beam and the dynamic analysis after improving and contrast, discuss crossbeam interior the layout of muscle board is dynamic to its the influence of function, the measurement that uses mode to be measured relative to displacement with horizontal Liang Zhen is the referenced basis of the design, put forward to suggest to the improvement of crossbeam, pass experimental test and verify, of crossbeam structure optimizing a design is feasible, to reducing its deflection, raise treatment precision to have favorable effect. CNC Milling CNC Machining