Development Of The Prediction Software And Experimental Investigation On High Speed Milling Force

1. IntroductionHigh speed milling processing is one of world advanced techniques of manufacture today. With the development of industry, the high-speed cutting already has been the promoted application in the production. From 1990s, the high speed processing in domestic and foreign raises the application upsurge. Some domestic enterprises, especially, some mold manufacture company imported large quantities of high speed numerical control lathes and processing center.Because of lacking of the reasonable cutting parameter choice plan and the end mill choice method, the high-speed cutting processing still could not spread in the production. The cutting force is one of most important physical parameters in the process of milling. The cutting force decides the power of consuming and the distortion of the craft system in the cutting process, simultaneously, the cutting force also direct influence the hot production in the cutting, and further affects the attrition, the breakage, the abrasive resistance of the end mill and so on. For the precision and the processing quality in the process also has the direct influence. Established the model of the cutting force, especially through the prediction of the high speed processing process, can enhance the accuracy of the choice of cutting parameter and provide the theory basis for the formulation of the reasonable high-speed cutting technological process. Therefore, the milling force prediction is very necessary.2. Selection of the milling force modelIn order to facilitate the milling force prediction, this article develops high speed milling force prediction software in the platform Visual C++ that used commonly. Based on the multitudinous milling force model analysis, the cutting force model of the flat head knife milling sidewall inferred by Professor Zhang Lei, Jilin University is my choice.da -the axial depth of cut,dr -the radial depth of cut,nt -the spindle speed of the end mill,N- the number of teeth of the end mill,R- the radius of the end mill ,Vf -the feed rate of the end mill,α-the inclination angle of end mill,bh -the geometry parameter of end mill,Rw -the radius of curved part surface before peripheral milling, Fx -the total cutting force of X direction , Fy -the total cutting force of Y direction, Fz- the total cutting force of Z direction, Kr -the constant of cutting pressure , KT -the constant of cutting pressure, t c-the average thickness of cuttingThe parameter of material in the model is a factor which other models few considers.3.The development of prediction softwareThrough the analysis of the formula (1), we can summarize the factors of influencing the high speed milling force :the depth of axial cuts, the depth of radial direction, the rotational speed of the axle, the feed rate, the end mill's number of teeth, the work piece material, the end mill's radius, the end mill's angle of spiral, the work piece radius and so on. All these factors are changed unceasingly in the actual production, therefore, to design the connection between user and the software is necessary.All these factors can be summarized up three types. Three different dialog boxes are constructed to accept the input. Respectively they are the end mill dialog box (Figure 1), material dialog box (Figure 2) and craft dialog box (Figure 3).From the formula (1), in the high speed milling process, the milling force including x direction, y direction and z direction milling forces. In order to make the user facilitate to analyze the milling force of three directions, this software uses the technology of window lattice division in Visual C++ and divides the software interface into three different views. In each view the milling force of one direction was demonstrated, as shown in Figure 4. Figure 4 Software interfaceThe software interface is developed to reach the aim of understanding simply and making the user facilitate to change the parameter of the milling force quickly. Using the toolbar can quickly assigns out the end mill dialog box, the craft dialog box, and the material dialog box to revise the parameters.Two combination frames controls in the end mill dialog box and the material dialog box can be found. This is database connection of the software. For different enterprises, the components material ordinary processed and the end mill used all respectively has theirself commonly several groups. In order to avoid inputing multitudinous milling parameter trouble that each time only duplicates, this software uses the database and the combination frame union control to finish this function. Clicking the combination frame controls, you can see the under pulls options, these items are the pre-edition in the database file. If necessary the user can change database file to match their own situation, the data can be increased automatically to the under pulls option. There is no need to change the internal structure and the code of the software.Clicking some value in the Pulls option, the data of the edits in the frame will be able to fill automatically that decrease the user's repetition work. The individual change also can be changed directly in edits in the frame quickly.When the prediction window which has the prediction curve is covered by other window, the curve will disappear. Solving the problem must study the window redraws. This dissertation draws in the message handling function which corresponds to the window redrew to avoid the danger that the window redrawing the prediction curve erased.Based on the milling force prediction analysis to the different parameter which different values carry on, we can see the prediction of this software consistent with the high speed milling general rule completely. The software has achieved the goal of simulating high speed milling force.When this software develop completely, it can be used separating from Visual C ++ development environment and can be used on any personal computer. This software will give some advices when the designer of the lathe designs the structural element and the numerical control forms personnel Compiled NC code. It has positive significance to obtain good processing efficiency and processing quality and derease material wasting.4. The prediction and experiment on milling forceThe article analyzes the rule of milling force when the speed of axis,the spindle speed of the end,the feed rate of the end mill,the axial depth of cut,the radial depth of cut and the number of teeth of the end mill change using the milling force prediction software. The prediction results show that along with the spindle speed and the cutter teeth increasing, the milling force of X,Y direction decrease:along with the the axial depth of cut,the radial depth of cut and the feed rate of the end mill increasing,the milling force of X,Y direction also increase.