COOLING ACTION OF GRINDING FLUID IN SHALLOW GRINDING

A new method is proposed for measuring the heat transfer coefficient in the vicinity of the wheel-workpiece contact zone. The accuracy of measurement is estimated by using a finite element method and the factor for correcting the measured results is derived. The experiments are performed in a number of conditions where grinding fluid is supplied and the following measures are consequently recommended for increasing the cooling efficiency: (1) set the velocity of coolant to more than the critical value to penetrate the air flow layer formed around the wheel periphery; (2) use a nozzle with a thin throat, about 1 mm in height, and attach a scraper plate above the nozzle outlet; (3) choose a wheel of large grain size and dress roughly, or form shallow grooves on the wheel periphery; and (4) set a higher wheel speed.