Compositive Control Of Power Position Pose And Speed On Virtual Axis Polishing Process

1 IntroductionWith the development of automobile industry, electric industry and some newhigh-tech industries ,the larger is the proportion of NC machining parts withfree-form surface in all, the higher and higher requirements are made for qualityand efficiency of machining on free-form surfaces. After the roughing method isused, precision machining, such as polishing and polishing, is necessary to obtainrequired part's surfaces. Near for over ten years, With the development at a highspeed in relevant science and technology, such as the technology of the computerand modern control theory, etc., flexibility machining become more perfect. Theautomatic machining of free-form surfaces come to true basically. However, thesesubsequent processes of precision machining still depend mainly on the handworkof skilled mechanists. Productivity effect of handwork is very low and its quality isunstable. As to the machining of free-form surfaces, low cost and short period andhigh quality were its main aim. As a result of that, the research of a kind ofincreasingly automated polishing equipment is imperative. Series-parallel virtualaxis machine tools for polishing free-form surfaces meets the requirement.However, if we want to the mashine exert the must function, the parameter's choiceis very importance. This dissertation carefully study on parameter' choice ofpower position pose and speed on JDYP51 model virtual axis polishing machinetool by manufacture in jilin university, and finally has determined the bestparameter.2 The structure theory of parallel part and pose analysis of series-parallel virtualaxis machine tools for polishing free-form surfacesOur machine tool adopts the structure of Figure 1 . And during the study ,we often use thepredigested model given by Figure 2. Pose analysis of series-parallel is axes position ofpolishing tools is related to inseries mechanism but not parallel mechanism. It wasproved by Euler angles. Axes position of polishing tools by inferential reasoning is:η = arccos( ?cosθ1 sinθ2)β = arccos( ?sinθ1 sinθ2)γ = arccos( ?cosθ2)R ail2R ail1R ail3P o lishto o lFigure 1. the structure of the parallel kinematics machine toolFigure 2. the predigested model of the machine tool动平台并联机构串联机构RailSlidingblockpoleHukejointIn serialsaxis 2polishi-ng toolsParallelmechanismMoveplatformSerialmechanismIn serialsaxis 13 System's demarcates and the choice of polishing toolsIn order to accurately adjusts the actual machining condition, we needs tocarry on to the system's demarcates, in this article then mainly ground to thesystem polishing power and the speed has carried on accurate demarcating. In thechoice of polishing tool aspect, we study on two kinds of polishing wheel withdifferent combine preparation, they are ceramics wheel and resin wheel of 180 # ,240 # . Think over surface roughness and remove quantity of workpiece bypolishing, analyse the polishing effect. And study on polishing with wheel ofdifferent radii, finally we selected appropriately polishing tool. Figure 3 is thepolishing effect influence by wheel's characteristic, figure 4 is the polishing effectinfluence by wheel's radii.Figure 3. the polishing effect influence by wheel's characteristicFigure 4. the polishing effect influence by wheel's radii4 Study on experimentation of machining parameterHave many factors influence machining effect after workpiece processing,Face to JDYP51 model virtual axis machine tool for polishing by manufacture injilin university, it's factors mainly includes power speed pose and position. In thearticle I have carried on the single factor influence experiment in view of themachine's special details, and take the above influence factor as the processingparameter. And finally the definite parameter are: F=30N n=800r/minV f=400mm/min η =90° β =60° γ =30°。 Figure 5 is the situation by nomachining workpiece and machining workpiece contrast.(a) beginning Ra=1.5μm (b) after polishing Ra=0.339μmFigure 5 The situation by no machining workpiece and machining workpiece contrast.5 ConclusionIn the dissertation I demarcates to system's power and speed on JDYP51model virtual axis machine tool for polishing, and selected appropriately polishingtool, analyse the machining mechanism of virtual axis machine tool for polishing.Elaborated many factors that influence machine tool machining effect. Accordingto the special details, take the polishing power motorial speed rotational speed ofmain axis and wheel's pose and position as machining parameter conducted thesingle factor influence experimental, determined the most superior parameter.Explained that the polishing workpiece's surface roughness can reach 0.3um by selectthe machining parameter suitably.