Abstract: A spindle condition detection device for a machine tool includes: bearing load detecting means for detecting a load on a bearing that rotatably supports a spindle of a machine tool; and present usage ratio calculating means for calculating, based on the load detected by the bearing load detecting means, a present usage ratio that is a ratio of usage of the bearing with respect to a prescribed operating life of the bearing, which is achieved over a period until a present moment.

Abstract: A main spindle device includes: a main spindle; a rod accommodated in the main spindle, the rod being capable of moving to an unclamp position in a direction toward the first end, and when the main spindle is holding a tool, being capable of moving to a clamp position in a direction toward a second end; a biasing unit that biases the rod in the direction toward the second end with respect to the main spindle and that biases the rod to the clamp position when a collet is holding the tool; and a biasing force detector that detects a biasing force of the biasing unit which biases the rod in the direction toward the second end after the rod is moved in the direction toward the first end with respect to the main spindle to the unclamp position by force larger than the biasing force of the biasing unit.

Abstract: In a coolant system, the interior of a reservoir frame storing the coolant discharged from a machine tool is partitioned by a partition member into an outer peripheral coolant tub and a central coolant tub. The partition member is formed with a silt that extends in the depth direction to make the outer peripheral coolant tub communicate with the central coolant tub. A suction port of a pump that feeds the coolant in the central coolant tub to a filtering device is arranged in the central coolant tub. The coolant discharged from the machine tool is supplied to the central coolant tub without passing through the outer peripheral coolant tub. At least a part of the coolant filtered by the filtering device is supplied to the outer peripheral coolant tub without passing through the central coolant tub.

Abstract: A main spindle device includes: a main spindle; a rod accommodated in the main spindle, the rod being capable of moving to an unclamp position in a direction toward the first end, and when the main spindle is holding a tool, being capable of moving to a clamp position in a direction toward a second end; a biasing unit that biases the rod in the direction toward the second end with respect to the main spindle and that biases the rod to the clamp position when a collet is holding the tool; and a biasing force detector that detects a biasing force of the biasing unit which biases the rod in the direction toward the second end after the rod is moved in the direction toward the first end with respect to the main spindle to the unclamp position by force larger than the biasing force of the biasing unit.

Abstract: The damping property of a rear rolling bearing (133) is adjusted by controlling a damping force that is applied by damping application means (5, 134) based on, for example, the type of a tool (T). Thus, it is possible to provide the optimum damping properties for various tools that differ in natural vibration, and to suppress the generation of chattering of the various tools. As a result, it is possible to increase the cut amount per unit time to increase the productivity.

Abstract: In a coolant system, the interior of a reservoir frame storing the coolant discharged from a machine tool is partitioned by a partition member into an outer peripheral coolant tub and a central coolant tub. The partition member is formed with a silt that extends in the depth direction to make the outer peripheral coolant tub communicate with the central coolant tub. A suction port of a pump that feeds the coolant in the central coolant tub to a filtering device is arranged in the central coolant tub. The coolant discharged from the machine tool is supplied to the central coolant tub without passing through the outer peripheral coolant tub. At least a part of the coolant filtered by the filtering device is supplied to the outer peripheral coolant tub without passing through the central coolant tub.

Abstract: A spindle condition detection device for a machine tool includes: bearing load detecting means for detecting a load on a bearing that rotatably supports a spindle of a machine tool; and present usage ratio calculating means for calculating, based on the load detected by the bearing load detecting means, a present usage ratio that is a ratio of usage of the bearing with respect to a prescribed operating life of the bearing, which is achieved over a period until a present moment.

Abstract: The damping property of a rear rolling bearing (133) is adjusted by controlling a damping force that is applied by damping application means (5, 134) based on, for example, the type of a tool (T). Thus, it is possible to provide the optimum damping properties for various tools that differ in natural vibration, and to suppress the generation of chattering of the various tools. As a result, it is possible to increase the cut amount per unit time to increase the productivity.

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: 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 method of a crank pin that grinds an outer circumferential surface of the crank pin of a crankshaft having a crank journal and the crank pin eccentric to the crank journal by rotating a crankshaft around a central axis (a center of the journal) of the crank journal and moving a rotating grinding wheel in a diametric direction of the crankshaft according to rotation phase angle of the crankshaft, in which a rotation number of the crankshaft is changed in one revolution of the crankshaft to perform a grinding process.

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 cylindrical grinder includes a workpiece support section adapted to support a generally cylindrical workpiece and rotate the workpiece about a rotational axis, and a wheel head adapted to support and rotate a grinding wheel. The wheel head is moved relative to the workpiece support section, along a first direction parallel to a rotational axis of the workpiece and along a second direction perpendicular to the first direction in order to grind an outer surface of the workpiece. The wheel head is turnable relative to the workpiece so that a rotational axis of the grinding wheel can be tilted within a plane substantially passing through the rotational axis of the grinding wheel and the rotational axis of the workpiece, within a range extending across a reference plane perpendicular to the rotational axis of the workpiece. Further, link-type parallel link mechanisms for moving the grinding wheel are disclosed.

Abstract: A cylindrical grinder includes a workpiece support section adapted to support a generally cylindrical workpiece and rotate the workpiece about a rotational axis, and a wheel head adapted to support and rotate a grinding wheel. The wheel head is moved relative to the workpiece support section, along a first direction parallel to a rotational axis of the workpiece and along a second direction perpendicular to the first direction in order to grind an outer surface of the workpiece. The wheel head is turnable relative to the workpiece so that a rotational axis of the grinding wheel can be tilted within a plane substantially passing through the rotational axis of the grinding wheel and the rotational axis of the workpiece, within a range extending across a reference plane perpendicular to the rotational axis of the workpiece. Further, link-type parallel link mechanisms for moving the grinding wheel are disclosed.

Abstract: An apparatus for measuring a circularity deviation of a cylinder of an object intended to be integrally rotated about a rotation axis, the cylinder being eccentric as either intended or not with the rotation axis, the apparatus includes a measuring device, a motion controlling mechanism, and a circularity deviation calculating device. The measuring device is adapted to measure a circumferential surface of the cylinder at each measuring point “p” thereon in a three-point contact method. The motion controlling mechanism is configured to permit the measuring device to be moved along a circumference of the cylinder, which circumference lays on a cross section of the cylinder perpendicular to the rotation axis, in contact with the circumferential surface of the cylinder, during rotation of the cylinder about the rotation axis.

Abstract: A cylindrical grinder includes a workpiece support section adapted to support a generally cylindrical workpiece and rotate the workpiece about a rotational axis, and a wheel head adapted to support and rotate a grinding wheel. The wheel head is moved relative to the workpiece support section, along a first direction parallel to a rotational axis of the workpiece and along a second direction perpendicular to the first direction in order to grind an outer surface of the workpiece. The wheel head is turnable relative to the workpiece so that a rotational axis of the grinding wheel can be tilted within a plane substantially passing through the rotational axis of the grinding wheel and the rotational axis of the workpiece, within a range extending across a reference plane perpendicular to the rotational axis of the workpiece. Further, link-type parallel link mechanisms for moving the grinding wheel are disclosed.

Abstract: A bearing member for rotatably supporting a rotary shaft has an internal bore which forms a bearing surface. The bearing surface is formed with a plurality of rectangular fluid pockets in a circumferential direction thereof and a land portion around the fluid pockets. A plurality of protrusions extending in an axial direction of the rotary shaft are formed in each fluid pocket to be discontinued from the land portion. Further, a supply port is formed in each fluid pocket for supplying pressurized fluid therewith. Each of the supply ports is positioned at the upstream side in the rotational direction of the rotary shaft.

Abstract: An apparatus for machining a non-circular workpiece such as a piston wherein a tool is moved back and forth against the workpiece in accordance with profile data defining a desired final shape of the workpiece while the workpiece is rotated at a predetermined speed. The tool is moved by a composite movement of a linear motor driven in accordance with low frequency command values, and a piezoelectric actuator driven in accordance with high frequency command values. A numerical controller of the apparatus calculates the low frequency command values using a first Fourier series and the high frequency command values using a second Fourier series. Coefficients of the first and second Fourier series are determined using least square method in such a way that errors contained in the low and high frequency command values becomes within a predetermined limit.

Abstract: An apparatus for machining a non-circular workpiece, wherein the profile data of plural sections of the workpiece stored in the profile data storage means are transformed into the frequency functions of 1 to n degree which is a function of the rotary angular velocity of the workpiece. The calculation means finds the amplitudes and the phases of each degree of the frequency function of each of plural intermediate sections by means of the interpolation according to the position between selected two sections based on the frequency functions of the selected two sections so as to obtain high frequency functions and low frequency functions which are then converted to high frequency and low frequency profile data. The machining apparatus actuates a linear motor in accordance with the high frequency profile data and actuates a PZT actuator in accordance with the low frequency profile data.