tailieunhanh - Machinability and Surface Integrity Part 9

Tham khảo tài liệu 'machinability and surface integrity part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Machinability and Surface Integrity 349 a Rotating Cutting-force Dynamometer RCD mounted on a CNC milling machine. .see .300 .108 E e se .e - Drilling d 25 mm VC 75 mm min f mm rev. 0 a 45 .B 0 b Typical cutting data from the RCD - the drilling signal has been magnified cutting forces for a single cutting edge are illustrated. E 4 __ .900 FF N1 .700 cnm Figure 180. A Rotating Cutting-force Dynamometer RCD utilising piezoelectric sensor systems. Courtesy of Kistler Instrumente AG 350 Chapter 7 bration certificate to ensure that the results obtained are both valid and sound. A cautionary note if the dynamometer has been inadvertently dropped or it has possibly collided with an obstruction when in use on the machine tool it should be sent back to the manufacturer for servicing and recalibration otherwise spurious cutting force data may be the result. Machining Modelling and Simulation Introduction Previously it was been widely accepted that most cutting tool modelling technqiues are somewhat incomplete in both their analysis of the process and their accompanying derived mathematics. Early but worthy attempts at analysing the chip formation mechanics of the orthogonal cutting process were undertaken initially by Ernst and Merchant 1941 - shown schematically depicted in Fig. 181 followed by further work concerning the analytical graphical interpretation of the orthogonal cutting action which was presented by Merchant and Zlatin 1945 and later work by Lee and Shaffer 1951 - not shown. This earlier work was then followed by Zorev s 1963 interpretation of an idealised cutting model Fig. 182 . In all of these above modelling cases and others not mentioned - for brevity s sake the very complex nature of the cutting process is a vast subject straddling many engineering and physical disciplines. Such modelling involves aspects of the tool s geometry chip tool contact lengths and pressures chip formation cutting forces frictional and .