Abstract: There is here disclosed a nozzle type ELID grinding apparatus comprising a conductive grindstone 12 having a contact surface with a workpiece 1; and an ion supply nozzle 16 that supplies an electrolytic medium 2 containing hydroxyl ions (OH?) onto a surface of the conductive grindstone, the workpiece being ground while the surface of the grindstone is dressed by electrolysis or chemical reaction. Furthermore, the apparatus comprises a grindstone power source 14 for setting the conductive grindstone to be a positive potential (+).

Abstract: There is a workpiece clamp device 10 for horizontally holding a thin section long workpiece 1 having a constant section shape or having the same section shape in spaced positions in a longitudinal direction in two positions of the same section shape. The workpiece clamp device 10 is constituted of a driving clamp device 10A and a driven clamp device 10B comprising the same holding device 12. The driving clamp device 10A rotates the workpiece 1 centering on a horizontal axis O extending in a longitudinal direction of the workpiece, and the driven clamp device 10B follows movement of the workpiece and idles centering on the horizontal axis. An arbitrary portion to be machined of the workpiece can be directed in a direction in which the portion is easily machined by the rotation (e.g., upward direction).

Abstract: A voltage is applied between a cylindrical cutting grindstone 2 that rotates about a vertical axis Y and a cylindrical truing grindstone 6 that rotates about a horizontal axis X. The vertical outer surface 2a and the horizontal lower surface 2b of the cutting grindstone are trued by a plasma discharge. Then without applying the voltage, the cutting grindstone 2 is trued mechanically by the truing grindstone 6, and while the outer periphery and lower surface of the cutting grindstone are dressed electrolytically, the outer periphery and lower surface are made to contact a workpiece 1 and process a micro-V groove. This method makes it possible to produce an immersion grating with a high resolution using hard, brittle materials such as germanium, gallium arsenide and lithium niobate.

Abstract: A method for glass substrate chamfering using a metal-bonded outer-surface grindstone 12 for simultaneously processing the end surface and the oblique surfaces of the outer periphery of a doughnut-like glass substrate 1 with a circular hole 1a at the center thereof, and a metal-bonded inner-surface grindstone 14 for simultaneously processing the end surface and the oblique surfaces of the inner periphery are provided; the outer-surface grindstone and the inner-surface grindstone simultaneously grind end surfaces and oblique surfaces of the outer and inner peripheries of the glass substrate, and during grinding, the outer-surface grindstone is sharpened by dressing it electrolytically, and the inner-surface grindstone is sharpened by an electrolytic dressing when not processing as the glass substrate is being replaced.