Processing method of tool radial runout of CNC milling machine
In the process of CNC milling machine cutting, there are many reasons for machining error. The error caused by tool radial runout is one of the important factors, which directly affects the minimum shape error and the geometric accuracy of the machined surface under ideal machining conditions. In the actual cutting, the tool radial runout affects the machining accuracy, surface roughness, tool wear non-uniformity and the cutting process characteristics of multi tooth tool. The larger the tool radial runout is, the more unstable the tool processing state is, and the more influence the processing effect is.
The radial runout of the tool is mainly caused by the radial cutting force. Therefore, reducing the cutting force in the direction of small diameter is an important principle to reduce the run out of the small path. The following methods can be used to reduce the minor run out:
1. Use sharp tools
The larger front angle of the tool is selected to make the tool sharper to reduce the cutting force and vibration. The larger tool back angle is selected to reduce the friction between the main and back tool surface and the elastic recovery layer of the transition surface of the workpiece, thus reducing the vibration. However, the front and rear angles of the tool cannot be too large, otherwise the strength and heat dissipation area of the tool will be insufficient. Therefore, different cutting tools’ front and back angles should be selected according to the specific conditions. When rough machining, smaller ones can be taken. However, in finishing, in order to reduce the radial run out of the tool, larger ones should be obtained to make the tool sharper.
2. Use tools with high strength
The strength of the tool can be increased in two ways. One is that the diameter of the tool rod can be increased by 20% when the same radial cutting force is applied, and the radial runout of the tool can be reduced by 50%. Second, the extension length of the tool can be reduced. The larger the tool extension length, the greater the deformation of the tool is during the process. In the process, the radial runout of the tool will change constantly, which will cause the workpiece surface to be uneven, the extension length of the tool will be reduced by 20%, and the radial runout of the tool will be reduced by 50%.
3. The front face of the tool should be smooth
In the process, the smooth front face can reduce the friction of the chip on the tool, and also reduce the cutting force of the tool, thus reducing the radial run out of the tool.
4. Spindle taper hole and collet cleaning
The spindle taper hole and collet shall be clean, and shall not be free of dust and debris generated during the processing of workpiece. When selecting the processing tool, when the tool with short extension length is used, the force shall be reasonable and even, and it shall not be too large or too small.
5. The selection of the cutting amount should be reasonable
If the tool is too small, the phenomenon of machining slip will appear, which will lead to the continuous change of the radial jumping momentum of the tool during machining. When the cutting force increases when the cutting amount of the machined surface is too large, the cutting force will increase, which will cause the tool to deform greatly, increase the radial jumping momentum of the tool during machining, and also make the machined surface not smooth.
6. Reverse milling is used in finishing
Because the clearance position between the screw and nut is changed during the milling, the feed of the workbench is uneven, which has impact and vibration, which affects the life of the machine tool and the tool and the roughness of the workpiece. When using the reverse milling, the cutting thickness changes from small to large, the load of the tool also changes from small to large, and the tool is more stable during processing. Note that this is only used in finishing, but also in rough machining, it is necessary to use the milling process. This is because the productivity of the milling is high and the service life of the tool can be guaranteed 7. the cutting fluid can be used reasonably.
7. Reasonable use of cutting fluid
The effect of water solution mainly on cutting force is very small. The cutting oil with lubrication can reduce the cutting force significantly. Because of its lubrication, it can reduce the friction between the front and chip of the tool and the transition surface between the rear and the workpiece, thus reducing the radial run out of the tool.
The practice shows that as long as the accuracy of manufacturing and assembly of each part of the machine tool is guaranteed, reasonable process and tooling are selected, the influence of radial runout of the tool on the machining accuracy of the workpiece can be minimized to the greatest extent.
Source: China Flange Manufacturer – Yaang Pipe Industry (www.epowermetals.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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