6.2.1 Experimental Equipment
Equipment used in the grinding experiment is shown in Fig. 1, where experimental platform is K-P36 NC surface grinder produced by German Schleifring. Built-in grinding program and grinding wheel dressing program are used in the grinding experiment. Main parameters include: maximum power output by spindle is 4.5 kW, range of spindle speed is 45~4800 r/min, transverse feed speed of workbench is 30~30000 mm/min, longitudinal feed speed of workbench is 4~4000 mm/min and workbench size is 1000×950 mm. Grinding wheel used in the experiment is 80# white corundum ceramic bond grinding wheel, grinding wheel model is WA80MV12P and its dimensions are 300×20×76.2 mm.
Figure 1. The experimental equipment in surface grinding process: 1-NC surface grinder, 2-grinding wheel, 3-operation panel, 4-MQL supply system, 5-workpiece, 6-three-way dynamometer, 7-nozzle, 8-thermal IR imager, 9-data acquisition unit, 10-data amplifier, 11-computer
Liquid supply forms used in the grinding experiment include flood grinding and MQL as shown in Fig. 1 (a) and Fig. 1 (b). MQL liquid supply device in this experiment is Bluebe MQL liquid supply system produced by Fuji company. An impulse is used to convey grinding fluid, regulate air pressure, control flow quantities of conveyed oil fluid and compressed air and regulating ratio of gas to liquid sprayed from the nozzle for the sake cooling and lubricating. As a general rule, air pressure is set as 4 bar~6.5 bar, compressed air and MQL grinding fluid are sprayed out of nozzle and enter machining area through high-pressure air after being mixed and atomized, and quantity of grinding fluid consumed is 30-100 ml/h per unit width of grinding wheel(HEISEL, LUTZ, WASSMER, & WALTER, 1998).