Abstract: In a vitrified bonded grinding wheel having superabrasive grains 11 such as CBN, diamond or the like bonded with a vitrified bond 12, pores 16 of the vitrified bonded grinding wheel has impregnated thereinto a resin 17 consisting of any resin selected from, e.g., unsaturated polyester, vinyl ester and allyl ester which are in a liquid state at the normal temperature and which have a thermosetting property, and being capable of radical polymerization. Thus, any separation gas or the like is not generated when the impregnated resin is hardened, whereby the strength of the grinding wheel can be enhanced.

Abstract: In a wheel spindle device wherein a plurality of grinding wheels are attached in a juxtaposed relation to a wheel spindle rotatably carried on a wheel head of a grinding machine, a reference position for specifying a position in the circumferential direction of the grinding wheel is provided on a core member of each of the grinding wheels, and a plurality of inclined grooves at predetermined angular intervals are formed on a grinding surface of each grinding wheel to be inclined relative to the circumferential direction of each grinding wheel. In order that the fluctuations in the dynamic pressure and the grinding resistance between respective grinding wheels and workpiece portions ground therewith do not grow as a combined or synergy effect, the inclined grooves on each grinding wheel are shifted in angular phase from those on another grinding wheel, so that grinding efficiency and accuracy can be enhanced.

Abstract: In a grinding wheel in which abrasive tips for rough grinding and abrasive tips for finish grinding are alternately bonded to a periphery of a disk type base rotating about a rotation axis, each abrasive tip includes the abrasive layer for ed by bonding abrasive grains and a lower layer overlaid and integrally for led with the abrasive layer. The abrasive tip is attached to the periphery of the base at the lower layer. A Young's modulus of the lower layer of the abrasive tip for finish grinding relative to a load acting on the grinding surface of the abrasive tip in an inward direction of the grinding wheel is less than that of the abrasive tip for rough grinding.

Abstract: First and second end surface truing sections are formed by protruding cylindrical first and second base bodies from opposite end surfaces of a disc-like base of an opposite end surface truing tool in the axial direction thereof and by providing on the external surface of the first base body and the internal surface of the second base body first and second abrasive grain layers in which numerous diamond abrasive grains are adhered with bond material. The rotational axis of the opposite end surface truing tool is inclined relative to the rotational axis of the grinding wheel within almost the same plane at a predetermined inclination angle.

Abstract: First and second end surface truing sections are formed by protruding cylindrical first and second base bodies from opposite end surfaces of a disc-like base of an opposite end surface truing tool in the axial direction thereof and by providing on the external surface of the first base body and the internal surface of the second base body first and second abrasive grain layers in which numerous diamond abrasive grains are adhered with bond material. The rotational axis of the opposite end surface truing tool is inclined relative to the rotational axis of the grinding wheel within almost the same plane at a predetermined inclination angle.

Abstract: In a coolant supply method and apparatus for a grinding machine, when an end surface of a workpiece is ground with a grinding wheel end surface of a grinding wheel with coolant being supplied toward a grinding point, a first coolant flow is ejected toward a first position which is on the grinding wheel end surface on an upstream side of the grinding point, and intercepts an air layer rotating to follow the grinding wheel end surface. At the same time, a second coolant flow is ejected toward a second position which is on the grinding wheel end surface and which is closer to the grinding point than the first point, and clings onto the grinding wheel end surface at the second position where the follow air layer has been intercepted by the first coolant flow. Thus, the coolant of a sufficient volume can be supplied to the grinding point where the grinding wheel end surface grinds the end surface of the workpiece.

Abstract: In a coolant supply method and apparatus for a grinding machine, when an end surface of a workpiece is ground with a grinding wheel end surface of a grinding wheel with coolant being supplied toward a grinding point, a first coolant flow is ejected toward a first position which is on the grinding wheel end surface on an upstream side of the grinding point, and intercepts an air layer rotating to follow the grinding wheel end surface. At the same time, a second coolant flow is ejected toward a second position which is on the grinding wheel end surface and which is closer to the grinding point than the first point, and clings onto the grinding wheel end surface at the second position where the follow air layer has been intercepted by the first coolant flow. Thus, the coolant of a sufficient volume can be supplied to the grinding point where the grinding wheel end surface grinds the end surface of the workpiece.