Tool and spindle parts of the manufacturing error, clamping error caused by the NC tool axis and the ideal rotation axis between the axis of rotation and eccentricity, and the specific processing technology, tooling and so may produce CNC milling machine tool in the radial runout.
1. The effect of the spindle itself on the radial beating
The main causes of the radial runout error of the spindle are the coaxiality error of each journal of the spindle, the various errors of the bearing itself, the coaxiality error between the bearings, the deflection of the spindle and so on. Their influence on the radial rotation accuracy of the spindle With the different ways of processing and different. These factors are in the machine tool manufacturing and assembly process, such as the formation of the machine as the operator is difficult to avoid their impact.
2. The effect of the inconsistency between the tool center and the spindle rotation center
When the tool is installed in the spindle, if the center of the tool and the rotation center of the spindle are not consistent, it will also bring the tool's radial runout. The specific influencing factors are: tool and chuck with the knife on the method is correct and the quality of the tool itself.
3. The impact of specific processing technology
The radial runout of the tool during machining is mainly due to the radial cutting force exerting radial runout. The radial cutting force is the total cutting force in the radial component. It will make the workpiece bending deformation and produce vibration when processing, is the main component of the workpiece processing quality. It is mainly affected by the amount of cutting, tool and work a material, tool geometry, lubrication and processing methods and other factors.
The Reason and Solution of Tool Beating
Third, reduce the radial beating method
The radial runout of the tool during machining is mainly due to the radial cutting force exerting radial runout. Therefore, reducing the radial cutting force is an important principle to reduce the radial runout. There are several ways to reduce radial runout:
1. Use sharp tools
Choose a larger tool front angle, so that the knife tool more sharp, to reduce the cutting force and vibration. The larger the angle of the milling cutter is used to reduce the friction between the main tool face of the tool and the elastic recovery layer of the workpiece transition surface, so that the vibration can be reduced. However, the front and rear corners of the tool can not be selected too large, otherwise it will lead to the strength of the tool and the cooling area is insufficient. Therefore, in order to combine the specific situation of different tool front angle and rear angle, roughing can take a small number, but in the finishing, out of the tool to reduce the radial runaway considerations, you should get some larger, so that the tool More sharp.
2. Use a high-strength tool
Mainly through two ways to increase the strength of the tool. First, you can increase the diameter of the arbor When subjected to the same radial cutting force, the diameter of the arbor increases by 20% and the tool's radial runout can be reduced by 50%. Second, you can reduce the length of the tool extension, the greater the length of the tool extension, the greater the deformation of the tool when processing, processing in constant changes, the tool will run the radial beating constantly changing, resulting in the workpiece The machining surface is not smooth. Similarly, the tool extension length is reduced by 20% and the tool's radial runout is reduced by 50%.
3. The nose of the tool should be smooth
In the processing, the smooth rake face can reduce the chip on the NC tool friction, but also can reduce the cutting force of the tool, thereby reducing the tool radial runout.
4. Spindle taper hole and chuck cleaning
Spindle taper holes and chucks are clean and can not have dust and debris generated when the workpiece is machined. Selection of processing tools, try to use a shorter length of the knife on the knife, the intensity should be reasonable and uniform, not too large or too small.
5. Choose the amount of knife to choose a reasonable
When the amount of knife is too small, there will be the phenomenon of processing slippage, resulting in the tool in the radial direction of the movement of the ever-changing, so that the processing of the surface is not smooth when the knife is too large, the cutting force will increase, thus Resulting in tool deformation, increase the tool in the radial radial runout, but also make the processing of the surface is not smooth.
6. Use reverse milling during finishing
As the milling distance between the screw and the nut is changed, the feed of the table is uneven, so that there is impact and vibration, affecting the machine tool, the life of the tool and the surface roughness of the workpiece. Reverse milling, the cutting thickness from small to large, the load of the tool from small to large, the tool in the processing more stable. Note that this is only used during finishing, or to use rough milling during roughing because of the high productivity of the milling and the endurance of the tool end mill
7. Use cutting fluid reasonably
Reasonable use of cutting fluid to cool the main effect of the aqueous solution on the cutting force is very small. The cutting oil, which is mainly lubricated, can significantly reduce the cutting force. Due to its lubrication, it is possible to reduce the friction between the tool nose and the chip and between the flank and the workpiece transition surface, thereby reducing the tool radial runout.
