Abstract: In a rough grinding step the large quantity of coolant supplied to cool the grinding point enables the flow to pass through a wheel-following air layer and reach the grinding point while the supply of an air jet is stopped during this step. At a fine grinding step, the grinding point can be cooled with a small quantity of coolant in so far it is reliably supplied to the grinding point. This is realized by supplying an air jet to intercept the wheel-following air layer which rotates to follow the grinding wheel, while supplying the coolant in small quantity. Consequently, the coolant is prevented from being scattered by the air jet and suspended in form of mist when supplied in large quantity at the rough grinding step, and the coolant quantity used can be reduced at fine grinding step and minute grinding step.

Abstract: In a rough grinding step the large quantity of coolant supplied to cool the grinding point enables the flow to pass through a wheel-following air layer and reach the grinding point while the supply of an air jet is stopped during this step. At a fine grinding step, the grinding point can be cooled with a small quantity of coolant in so far it is reliably supplied to the grinding point. This is realized by supplying an air jet to intercept the wheel-following air layer which rotates to follow the grinding wheel, while supplying the coolant in small quantity. Consequently, the coolant is prevented from being scattered by the air jet and suspended in form of mist when supplied in large quantity at the rough grinding step, and the coolant quantity used can be reduced at fine grinding step and minute grinding step.

Abstract: The present invention supplies coolant to a grinding wheel surface and reliably guides the coolant to a grinding point on the grinding wheel surface, thereby significantly reducing the amount of coolant to be used. In a grinding method and device for supplying coolant while grinding a workpiece W with a rotating grinding wheel 1, a fluid nozzle 2 is disposed upstream from a grinding point 11 on the circumferential surface 10 of the grinding wheel 1. The fluid nozzle 2 blows a jet of fluid across an air layer 12, which is a layer of flowing air dragged along the circumferential surface 10 of the grinding wheel 1, from one lateral side of the air layer 12 to the other lateral side thereof. A grinding fluid nozzle 3 supplies coolant to a region between the grinding point 11 and a cutoff position 13 at which the fluid jet from the fluid nozzle 2 has deflected the air flow from the air layer 12. The coolant supplied from the grinding fluid nozzle 3 contacts the grinding point 11 on the grinding surface 10.

Abstract: The present invention supplies coolant to a grinding wheel surface and reliably guides the coolant to a grinding point on the grinding wheel surface, thereby significantly reducing the amount of coolant to be used.

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 circular or non-circular workpiece is ground in a plurality of grinding steps, including a final finish grinding step. A grinding wheel is caused to effect profile generation movement in synchronism with rotation of the workpiece and in accordance with profile data derived from the target shape of the workpiece. In each grinding step, the grinding wheel is advanced in such a manner that the grinding wheel causes cut-in movement within a predetermined cut-in angle defined on the workpiece. After completion of the final finish grinding step, the grinding wheel is retracted over a predetermined back-off angle defined on the workpiece. The retraction is effected in accordance with composite data obtained through combining the profile data and back-off data. The back-off angle is greater than the cut-in angle employed during the final finish grinding step.

Abstract: A circular or non-circular workpiece is ground in a plurality of grinding steps, including a final finish grinding step. A grinding wheel is caused to effect profile generation movement in synchronism with rotation of the workpiece and in accordance with profile data derived from the target shape of the workpiece. In each grinding step, the grinding wheel is advanced in such a manner that the grinding wheel causes cut-in movement within a predetermined cut-in angle defined on the workpiece. After completion of the final finish grinding step, the grinding wheel is retracted over a predetermined back-off angle defined on the workpiece. The retraction is effected in accordance with composite data obtained through combining the profile data and back-off data. The back-off angle is greater than the cut-in angle employed during the final finish grinding step.

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: A cold-gas-blow-cooling type machining apparatus in which a cold gas blow is provided to cool a machining tool and a workpiece while the workpiece is machined by the machining tool. The machining apparatus includes: a rectifying device which rectifies the machining tool; a workpiece-temperature detecting device which detects a temperature of the workpiece; and a rectifying-device control device which controls an operation of the rectifying device on the basis of the temperature of the workpiece which is detected by the workpiece-temperature detecting device.

Abstract: A cooling apparatus includes a lubricating fluid tank, a lubricating fluid nozzle, a lubricating fluid regulating device, a cooling fluid tank, a cooling fluid nozzle and a cooling fluid regulating device. The cooling fluid nozzle supplies cooling fluid to the workpiece to enhance cooling effect of the cooling fluid. The lubricating fluid nozzle feeds lubricating fluid to the machining zone to prevent frictional heat generated in the machining zone from raising temperature of the workpiece. Since an appropriate amount of the lubricating fluid within the range helps the cooling effect of the cooling fluid, a quantity of the cooling fluid is reduced within the minimum range of the cooling fluid. A consumption of the lubricating fluid is much smaller than that of the cooling fluid. Therefore, a total amount of the fluids is extremely reduced. The range of flow rates of the lubricating fluid has an upper limit that is preferably approximately 100.0 cm3/h or smaller in 1.

Abstract: A grinding wheel comprising abrasive grains, a bonding material for bonding the abrasive grains, and grain clusters of accumulated filler grains having a size smaller than the abrasive grains. The grinding wheel may be a vitrified grinding wheel, and in this case, chromium oxide having good affinity with the vitrified bonding material may be used as the filler grains.

Abstract: A workpiece and a grinding wheel are rotated and the grinding wheel is moved in a direction parallel to the rotational axis of the workplace so as to grind a cylindrical surface of the workpiece. After a part of the cylindrical surface is ground, a rest device is advanced towards the workpiece so as to support the part of the cylindrical surface of the workpiece which has been ground. Under the condition, the remaining portion of the cylindrical surface of the workpiece is ground.

Abstract: A grinding wheel for grinding a workpiece has a first grinding surface and a second grinding surface successive thereto. The first and second grinding surfaces are parallel to and inclined with respect to the rotational axis of the workpiece, respectively. A diameter of the workpiece to be ground in a next grinding operation is measured in advance. An angle to be formed between the second grinding surface and the rotational axis of the workpiece is selected based upon the measured diameter of the workpiece. The selected angle is established between the second grinding surface and the rotational axis of the workpiece. The grinding wheel is moved relative to the workpiece in a direction of the rotational axis of the workpiece, whereby the cylindrical surface of the workpiece is firstly ground by the second grinding surface and subsequently ground by the first grinding surface of the grinding wheel.

Abstract: A method and apparatus for grinding a cylindrical surface of a workpiece by a traverse movement of a grinding wheel having a relatively narrow grinding surface. To improve the cylindricity of cylindrical surface, the traverse grinding is divided into a rough traverse grinding and a finish traverse grinding. In the rough traverse grinding, a traverse girding is carried out with a large depth of cut which would causes a deterioration of the cylindricity at one end of the cylindrical surface. In the finish traverse grinding, a traverse girding is carried out with a small depth of cut to improve the cylindricity. In another embodiment, one of grinding conditions such as the traverse speed of the grinding wheel, the rotational speed of the workpiece and the peripheral speed of the grinding wheel is changed when the grinding wheel approaches an end of the cylindrical surface at which the traverse grinding ends so as to make the grinding force constant, thereby improving the cylindricity of the cylindrical surface.