An Investigation on The Cutting Force Model for Ball End Mill

• Main Authors: Ming-Liang Lin, 林明良
• Other Authors: 蔡志成
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/12956881574279088867

碩士 === 國立中興大學 === 機械工程學系 === 90 === The variation of cutting force in metal cutting reflects characteristics, such as the surface quality and tool life, of the cutting process; and therefore plays an important role in the cutting process. As the application of ball end mill on the machining of mold and die, in particular at high spindle rotation, becomes common, cutting forces of ball end mills deserve to be investigated. The force model of a ball end mill, however, differs from that of a regular end mill due to the difference on geometry. This thesis investigates the cutting forces of ball end mills, including the development of theoretical model, experiment design and excusion, and verification of theoretical model. The theoretical cutting force model is based on the assumption that tangential cutting force is a function of instant cross-section of the chip, but not chip thickness used in most previous work. The instant cross-section, however, is computed via the path of tool. The second part is planning experiments of ball cutting .planning experiments of high rotational speed ball cutting of NAK80 and Al6061 individually .According to this planning ,we can confer the influence of ball cutting parameters and cutting force .The third part is analyzing the measuring data of the cutting force in the second part .According to the data to calculate Kt、Kr and Ku .And then to simulate cutting force .The result is that the percentage error of cutting force Fx is between 10.3% to37.9%.The maximum of simulation error is between 0.1 to 3.6 N ,and the minimum of simulation error is between 0.1 to 13.3 N; the percentage error of cutting force Fy is between 4.8% to15.8%.The maximum of simulation error is between 0 to 12.9 N ,and the minimum of simulation error is between 0.1 to 16.6 N; the percentage error of cutting force Fz is between 1.2% to16.7%.The maximum of simulation error is between 2.8 to 7.0 N ,and the minimum of simulation error is between 1.3 to 12.5 N .The most part of the error is in the standard error zone .of the experiment measuring .It means that the model of ball cutting force theory is reasonable.