PURPOSE: To constantly supply a grinding fluid efficiently to a grinding area and enable a difficultly grindable material such as a brittle material to be easily provided with a specular-finished curved surface over the entire surface thereof, by controlling the direction of a nozzle according to the location of grinding.
CONSTITUTION: An optical glass, which is generally said to be difficult to grind, is ground to form a spherical lens. Five optical glasses differing in hardness are selected as works 2. A grinding wheel 1 used here is a #3000 diamond impregnated grinding wheel with a diameter of 150mm. Grinding is carried out with a depth of cut of 2μm, a revolution speed of the grinding wheel of 10000rpm, and a supply rate of the grinding fluid of 10l/min. When the wheel 1 is located at an apex of the work 2, a nozzle 4 is so set that the jetting direction of the grinding fluid is inclined by 3° counterclockwise from the tangential direction for the grindstone 1. Then, as the position of the wheel 1 is deviated from the apex of the work 2, the direction of the nozzle 4 is gradually changed so that a large quantity of the grinding fluid 5 is constantly supplied efficiently to the surface being ground. In this manner, a specular surface is obtained over the entire ground surface.
ARIMOTO AKIRA
MORIYAMA SHIGEO
HITACHI KOKI KK