Application of the hottest Proengineer in cam mach

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The application of pro/engineer in cam processing

in banknote printing and coinage machinery, there are many cams, including plane cams and spatial cams. The processing of spatial cams has always been a difficulty in mechanical processing. The traditional processing method is milling with dividing head or machining with profiling method, which is difficult to process, long cycle, low processing accuracy and high requirements for the level of operators. Since our factory purchased CNC machine tools, the use of CNC milling machines equipped with CNC dividing heads to process spatial cams has replaced the traditional processing methods, which has greatly improved the processing accuracy and efficiency of cams. However, the NC processing program of spatial cams has always been manually programmed, and manual programming has many shortcomings, mainly as follows:

1. Programming is complex and heavy workload

in the working diagram of spatial cams, The theoretical outline or working outline dimension of the cam is given in rectangular coordinate form or tabular form on the expanded drawing of its outer cylinder. If the contour dimension of the cam is divided equally at 360 ° by 1 °, 360 coordinate points will be input in the program, which is a heavy workload and easy to make mistakes. However, sometimes the cam contour coordinates on the drawing will be given in the form of averaging every 5 ° or 10 °. Due to the large interval, the data cannot be used directly, and programmers are required to interpolate and refine the cam contour, which is very difficult or even impossible in manual programming

2. Inconvenient program modification

after the program is compiled, if errors are found or need to be modified during the first piece test cutting, such as the reverse milling is changed to the forward milling, the program needs to be readjusted, and the adjustment process is very complicated

3. Low machining accuracy of cam contour

in manual programming, the two coordinate points in the program are connected by a straight line, that is, linear interpolation. Due to the limitations of manual programming, enough coordinate points cannot be obtained, which makes the working contour of the processed spatial cam have errors with the actual contour, and the surface has edges, is not smooth, and the accuracy is low

in view of the shortcomings of traditional machining and manual programming, now we make full use of the existing cad/cam software pro/engineer wildfire version 3.0 to solve the machining problem of spatial cam

I. original data of cam

an existing cam is disassembled from the printing equipment, and the cam surface has certain wear. After three-dimensional mapping, the actual contour data of the cam surface is obtained. The results are shown in figure 1:

Figure 1: cam expansion diagram

if the model is directly modeled according to the data given by three-dimensional coordinates, it can be seen from three-dimensional figure 2 that the cam surface is not smooth and uneven, In particular, there are obvious edges at the junction of the transition section and the arc. If the cam is processed in this way, it must not be used. At this time, the programming technician manually programs according to the data given by the three coordinates. It is not only difficult to manually refine the interpolation, but also complex to program, heavy workload, and difficult to proofread the data. If you can obtain the recognizable files of the NC milling machine through software, the programming process will be greatly simplified

Figure 2: original three-dimensional modeling figure

II. Using the data given by pro/engineer wildfire version 3.0

for three coordinates, we decided to use pro/engineer wildfire version 3.0 software to complete the improvement of CAM data, simulate processing and automatically generate the recognizable data table of CNC milling machine

1. Use pro/engineer wildfire version 3.0 for data analysis and correction

after entering the software, click file, new, select new sketch, enter curve in the name, and then enter the sketch mode. In the sketch environment, first establish the coordinate system, and draw a spline at will, select the spline, and right-click to enter the curve attribute interface, expand the file menu as shown in Figure 3, then select the arrow to select the established coordinate system, and finally click the Save button, You can save the coordinate values of several feature points of the spline as curve_ S file

figure 3

open curve using Notepad program_ S file, you can see the file format used by splines in PR o/engineer, as shown in Figure 4

Figure 4: file format used by spline curve

paste the data coordinate points given by three coordinates into curve in the format of figure_ S file and save it. Then return to the interface of the figure again, select the open file to open the curve just saved_ S file, and "there are different points in the file, do you want to continue?" Prompt, select Yes. At this time, the cam data is transferred into pro/engineer, as shown in Figure 5

figure 5

in order to make the curve smooth and make the overall curvature change smoothly, the more regular the curvature diagram is, the better the smoothness of the cam is. We select the smoothing in fitting, and set the value of sporadic points to 30. We find that the modified curve is close to the ideal, save and exit the sketch

2. 3D modeling

create a new part from the file. The name is set to be mainly used for the movement of the beam of the experimental machine as T. first stretch a cylinder, select the model benchmark from the insertion menu to enter the graph, enter spline to confirm, select the data from the sketch menu to come from the file, select the curve file just created from the system file, set the scale and rotation to 1 and 0 respectively after entering, save and exit. Select the variable section scanning tool, enter the sketch, draw the section, select the relationship from the tool, and enter the formula "3.9+evalgraph (" spline ", trajpar*360)", as shown in Figure 6. The final generated three-dimensional model is shown in Figure 7, which shows that the smoothness of the cam surface is relatively ideal

Figure 7: modified 3D figure

3. 3D simulation processing

in pro/engineer, create a new manufacturing from the file, enter the manufacturing mode, and set the manufacturing mode, as shown in Figure 8. Select the 3D model just built. After the reference model is built, we need to create a workpiece based on the high-density silicon column and sensor. Here we select the built workpiece for assembly, as shown in Figure 9. Change the automatic option to default and confirm to exit. In the manufacturing setting, the machine tool selects 4 axes and selects a processing zero point, which is set at the center of the cylinder end face and sets the cylinder tool withdrawal plane. Then set the machining settings, select the track, as shown in Figure 10, select the tool, parameters, and four axis plane for corresponding settings, and finally customize the settings, as shown in Figure 11, and generate the track, as shown in Figure 12. Enter NC detection, that is, 3D simulation processing, as shown in Figure 14

Figure 12: tool path

modify the parameters in the parameter tree, and set the tool walking times and rough and fine machining allowance according to the actual situation, which can quickly generate the tool path and realize rough and fine machining. Refer to figure 13 for parameter setting, in which 0.2mm finishing allowance is reserved

Figure 13: parameter tree this investment and production expansion enables us to meet the growing product demand

Figure 14: simulation processing results

from the above simulation results, the smoothness of the cam surface is very good, reaching the expected effect. Finally, the post-processing automatically generates the G code file that can be recognized by the NC milling machine, as shown in Figure 15. After Haas machining of horizontal NC milling machine, three coordinate re inspection and installation test, it is found that the improvement effect is obvious, and the roller follower moves smoothly on the cam surface, achieving the expected effect

Figure 15: machining program

III. conclusion

the importance of cad/cam software in NC machining is fully reflected through the solution of spatial cam machining problems. By using pro/engineer software, we have also solved the machining problems of various spatial cams and planar cams. At present, we have accumulated rich experience in processing cams. The software also greatly improves the ability of data analysis and correction, reduces the difficulty of manual programming, and ensures the machining accuracy of parts, thus improving the production efficiency and reducing the technical level requirements for operators. Therefore, only when the technicians engaged in NC machining deeply understand and master one or more cad/cam software, and make reasonable use of it in practice, can they deeply tap the processing potential of NC machine tools, continuously improve the process ability of machining workshops, and improve product quality. (end)

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