A Novel Precision Face Grinder for Advanced Optic Manufacture
- 物理技术－会议论文 
In this paper, a large-scale NC precision face grinding machine is developed. This grinding machine can be used to the precision machining of brittle materials. The base and the machine body are independent and the whole structure is configured as a "T" type. The vertical column is seat onto the machine body at the middle center part through a double of precision lead rails. The grinding wheel is driven with a hydraulic dynamic and static spindle. The worktable is supported with a novel split thin film throttle hydrostatic lead rails. Each of motion-axis of the grinding machine is equipped with a Heidenhain absolute linear encoder, and then a closed feedback control system is formed with the adopted Fanuc 0i-MD NC system. The machine is capable of machining extremely flat surfaces on workpiece up to 800mmx600mm. The maximums load bearing of the work table is 620Kg. Furthermore, the roughness of the machined surfaces should be smooth (Ra < 50nm-100nm), and the form accuracy less than 2 mu m (similar to 1 mu m)/200x200mm. After the assembly and debugging of the surface grinding machine, the worktable surface has been self-ground with 60# grinding wheel and the form accuracy is 3 mu m/600mmx800mm. Then the grinding experiment was conduct on a BK7 flat optic glass element (400mmx250mm) and a ceramic disc (Phi 100mm) with 60# grinding wheel, and the measuring results show the surface roughness and the form accuracy of the optic glass device are 0.07 mu m and 1.56 mu m/200x200mm, and these of the ceramic disc are 0.52 mu m and 1.28 mu m respectively.