Ultra-Precision Vertical Spindle Grinder for Ceramics

超精密陶瓷立式主轴磨床

基本信息

批准号：
59850028
负责人：
NAMBA Yoshiharu
金额：
$ 5.89万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1984
资助国家：
日本
起止时间：
1984 至 1985
项目状态：
已结题

项目摘要

Single crystals and glass ceramics of zero thermal expansion coefficient are expected to be machined ultra-precisely in near future. These materials have been lapped and polished because of their brittle mechanical properties. This research intends to develop a new ultra-precision vertical spindle grinder which can finish ceramic materials into flat mirror surfaces having sub-micron in dimensional accuracy. It is the most important to control the thermal expansion of materials to be ground, a grinding wheel and machine tool for getting the sub-micron accuracy in grinding process. This research tried to reduce such thermal expansion by two methods, that is, using of glass ceramics of zerothermal expansion coefficient as a material of a grinding wheel spindle and controlling the temperatures in room, grinding water and hydrostatic pressure oil for making the temperatures of a machine tool, grinding wheel and workpiece uniform. No body has developed a glass ceramic spindle because of brittleness and expensive cost for machining. By development of new casting ＆ heat treating processes and examination of grindability and polishability of the glass ceramics, the first grinding spindle made of glass ceramics having zero thermal expansion coefficient has been designed and manufactured. Depth of cut in grinding process is numerically controlled in the unit of 0.1 micron/pulse which is performed by the rigid spindles and bearings for a grinding wheel and table. Hydrostatic oil bearings are designed and manufactured having the features such as low thermal expansion, higher rigidity and higher revolutional accuracy. MnZn ferrite single crystal surfaces of 0.08micron in flatness and of 0.015 micron Rz in surface roughness were obtained by using this new grinder. By development of dressing and a grinding wheel, the smoother surface of less than 0.01 micron Rmax will be obtained by the machine.

零热膨胀系数的单晶和玻璃陶瓷有望在不久的将来进行超精密加工，因为这些材料具有脆性机械性能，因此本研究旨在开发一种新型超精密立式主轴磨床。可以将陶瓷材料加工成亚微米级的平面镜面，在磨削过程中控制被磨削材料的热膨胀，砂轮和机床是最重要的。研究尝试通过两种方法来减少这种热膨胀，即采用零热膨胀系数的玻璃陶瓷作为砂轮轴的材料，并控制室内温度、磨削水和静压油来调节机器的温度。由于玻璃陶瓷的脆性和加工成本昂贵，没有机构开发出均匀的刀具、砂轮和工件。通过开发新的铸造和热处理工艺以及对玻璃陶瓷的可磨削性和抛光性的检查，首次磨削。设计并制造了具有零热膨胀系数的玻璃陶瓷主轴，磨削过程中的切削深度以0.1微米/脉冲为单位进行数控，由静压砂轮和工作台的刚性主轴和轴承执行。含油轴承的设计和制造具有低热膨胀、更高刚性和更高革命精度的MnZn铁氧体单晶表面，平面度为0.08微米。通过使用这种新型磨床，可以获得0.015微米Rz的表面粗糙度。通过开发修整和砂轮，该机器将获得小于0.01微米Rmax的更光滑的表面。