Abstract: In a workpiece grinding method, a grinding allowance of a predetermined width (T) at at least an end surface portion 21 of a workpiece W is removed with a grinding wheel 10 (or 32) by rotating the workpiece W having a cylindrical portion 20 and the end surface portion 21 perpendicular thereto, by rotating the grinding wheel 10 (or 32) supported rotatably about an axis extending in parallel with the axis of the workpiece 10 (or 32), and by moving the grinding wheel 10 (or 32) relatively to the workpiece W.

Abstract: In a workpiece grinding method, a grinding allowance of a predetermined width (T) at at least an end surface portion 21 of a workpiece W is removed with a grinding wheel 10 (or 32) by rotating the workpiece W having a cylindrical portion 20 and the end surface portion 21 perpendicular thereto, by rotating the grinding wheel 10 (or 32) supported rotatably about an axis extending in parallel with the axis of the workpiece 10 (or 32), and by moving the grinding wheel 10 (or 32) relatively to the workpiece W.

Abstract: A grinding machine rotatably carrying a finish grinding wheel and a super-finish grinding wheel respectively on first and second wheel heads practices a method of grinding workpiece surfaces to super-finish surfaces with micro oil pockets. A surface of a workpiece rotatably carried on the machine is first ground with the finish grinding wheel to a predetermined diameter under the control of a sizing device. The workpiece surface is then ground with the super-finish grinding wheel to a target diameter under the control of a sizing device. The super-finish grinding is performed to the extent that peaks of a section curve representing the roughness of the workpiece surface attained by the finish grinding are removed but bottoms of the surface curve are left to a depth when the target diameter is reached, so that the bottoms so left of the roughness constitute the micro oil pockets.

Abstract: A cold-gas-blow-cooling type machining apparatus including a relative movement device which moves a workpiece and a machining tool relative to each other, and a cold-gas-blow supply device which supplies a cold gas blow to a machining point at which the workpiece is machined by the machining tool. The machining apparatus includes: a workpiece-temperature detecting device which detects a temperature of the workpiece; and a machining-condition control device which controls at least one of the relative movement device and the cold-gas-blow supply device, on the basis of the detected temperature of the workpiece. The machining-condition control device includes a cooling-condition control device which controls the cold-gas-blow supply device so as to control at least one of a temperature and a flow rate of the cold gas blow.

Abstract: A grinding machine rotatably carrying a finish grinding wheel and a super-finish grinding wheel respectively on first and second wheel heads practices a method of grinding workpiece surfaces to super-finish surfaces with micro oil pockets. A surface of a workpiece rotatably carried on the machine is first ground with the finish grinding wheel to a predetermined diameter under the control of a sizing device. The workpiece surface is then ground with the super-finish grinding wheel to a target diameter under the control of a sizing device. The super-finish grinding is performed to the extent that peaks of a section curve representing the roughness of the workpiece surface attained by the finish grinding are removed but bottoms of the surface curve are left to a depth when the target diameter is reached, so that the bottoms so left of the roughness constitute the micro oil pockets.

Abstract: A combination grinding machine grinds a plurality of axially arranged portions of a workpiece by use of a grinding wheel supported rotatably on a first wheel head and a superfinishing wheel supported rotatably on a second wheel head. A numerical control unit controls feed units for the first and second wheel heads in order to move the first and second wheel heads independently of each other in the axial direction of the workpiece and in the direction perpendicular to the axial direction, such that each of the axially arranged portions is ground by the grinding wheel, and simultaneously with this, another ground portion is superfinished by the superfinishing wheel.

Abstract: An apparatus capable of automatically determining grinding wheel dressing timing for dressing a grinding wheel. The apparatus estimates the abrasion of the grinding wheel in a grinding cycle on the basis of machining data and grinding conditions, and divides the grinding cycle into a plurality of stages according to the estimated abrasion to carry out grinding wheel dressing after the completion of every stage of the grinding cycle. In grinding a workpiece having a plurality of ground sections, the abrasion of the grinding wheel in grinding each ground section is estimated, and the abrasion is accumulated in accordance with grinding sequence. A ground section after grinding which grinding wheel dressing is to be carried out is determined on the basis of the cumulative abrasion. Similarly, the abrasions are accumulated for each of workpieces. A grinding wheel dressing is carried out after the completion of grinding a workpiece so that the cumulative abrasion may not exceed a predetermined value.