石材立式磨機(jī)設(shè)計(jì),石材立式磨機(jī)設(shè)計(jì),石材,立式,設(shè)計(jì) Oil V : cutting speed, m/s; f : feed rate per revolution, (m); c : volumetric specific heat of the work material: J/mm 3 C, in this example, the grinding wheel; k t : thermal diffusivity of the wheel, m 2 /s. In this analysis of TSDC and WC tools, the cutting speed, feed rate and volumetric specific heat of the wheel were kept constant. Therefore any difference in the mean temperature rise at the cutting interface would mostly likely arise from the difference of specific energy of cutting. The specific energies for TSDC and WC are shown in Fig 6. It can be seem that in the initial stages, the specific energy Fig 4 Wear coefficients of TSDC and WC 900 800 700 600 500 400 300 200 100 0 1000500 1500 2000 2500 3000 3500 400045000 W ear coefficient x10 -6 (mm 3 /Nm) Cumulative cutting distance (m) 242.9 404.6 606.0 852.5 1.7 1.8 1.6 2.0 2.6 2.4 1.3 TSDC WC Fig 5 The thrust forces of TSDC and WC 1000 900 800 700 600 500 400 300 200 100 0 -100 20015010050 250 300 350 400 450 5000 Thrust force (N) Time (s) 1000 900 800 700 600 500 400 300 200 100 0 -100 400200 600 800 1000 1200 1400 16000 Thrust force (N) Time (s) Fig 3 Set up of rock cutting test Cutter drum Rock Hydraulic motor INDUSTRIAL DIAMOND REVIEW 1/0852 Oil it increases as the wear flat area increases. It is observed that the rate of increase in the thrust force is different for different tool materials depending on the rate of increase in the wear flat area. 3 The rock cutting performance of TSDC picks was much better than that of WC picks. Under the same cutting conditions, WC picks showed severe tool wear, while no obvious wear was identified on TSDC picks. The thrust force on the cutter drum laced with WC picks was significantly higher than that observed when laced with TSDC picks. 4 The tool wear affects the cutting force in two contrasting mechanisms. As the tool wear increases, the preset depth of cut is reduced which causes the cutting force to drop. However, as the tools wear, the frictional forces increase with a corresponding increase in the cutting force. Therefore the cutting force may either increase or decrease depending on which mechanism is dominant. 800 700 600 500 400 300 200 100 0 -100 500 1000 1500 20000 T o r que (Nm) Displacement (mm) 800 700 600 500 400 300 200 100 0 -100 500 1000 1500 20000 T o r que (Nm) Displacement (mm) 40 35 30 25 20 15 10 5 0 500 1000 1500 20000 Thrust force (kN) Displacement (mm) 40 35 30 25 20 15 10 5 0 500 1000 1500 20000 Thrust force (kN) Displacement (mm) Fig 12 Torques of TSDC and WC picks during the rock cutting Fig 13 Thrust forces of TSDC and WC picks during the rock cutting Authors: X. S. Li, J. N. Boland and H. Guo work for CSIRO Exploration and Mining, PO Box 883, Kenmore QLD 4069, Australia. Acknowledgments The authors would like to thank Peter Clark for his effort in the design and construction of the wear test rig and technical support in carrying out the wear tests. Thanks also go to Craig Harbers and Michael Cunnington for their assistance in carrying out the rock cutting tests. This article is based on a paper presented at the 2nd International Industrial Diamond Conference held in Rome, Italy on April 19-20 2007 and is printed with kind permission of Diamond At Work Ltd. References 1 J. A. Martin and R. J. Fowell, Factors Governing the Onset of Severe Drag Tool Wear in Rock Cutting, Int J Rock Mech Min Sci, 1997, 34, p 59-69. 2 J. N. Boland, X. S. Li, H. Alehossein, et al, Abrasive Wear Behaviour of Diamond Composite Cutting Elements, Intertech 2003, July 28 - August 1, Vancouver, Canada, 2003, Proceedings CD. 3 P. Larsson, N. Axen, T. Ekstrom, et al, Wear of a New Type of Diamond Composite, Int J Refractory Metals & Hard Materials, 1999, 17, p 453-460. 4 I. M. Hutchings, Tribology: Friction and Wear of Engineering Materials, Oxford: Butterworth-Heinemann Publ., 2001, p 273. 5 J. A. Williams, Wear Modelling: Analytical, Computational and Mapping: a Continuum Mechanics Approach, Wear, 1999, 225-229, p 1-17. 6 N. Cook, Tool Wear and Tool Life, ASME Transactions, J Eng Ind, 1973, 95(11), p 931-938. 7 L. J. Yang, Determination of the Wear Coefficient of Tungsten Carbide by a Turning Operation, Wear, 2001, 250, p 366-375. 8 G. S. Upadhyaya, Cemented Tungsten Carbides, New Jersey: Noyes Publications, 1998, p 196-197. 9 X. S. Li and I. M. Low, Cutting Forces of Ceramic Cutting Tools, Key Engineering Materials, 1994, 96, p 81-136. 10 L. Gould, Sensing Tool and Drive Element Conditions in Machine Tools, Sensor 1988, p 5-13. 11 E. Dimla and Snr Dimla, Sensor Signals for Tool-Wear Monitoring in Metal Cutting Operations - a Review of Methods, Int J of Mach Tools and Manu, 2000, 40 (8), p 125-138. INDUSTRIAL DIAMOND REVIEW 1/0854 Oil & gas