Okuma Corporation | Date: 2016-07-14
A bearing diagnostic device senses a failure in a bearing of a machine tool including a rotation shaft device. The bearing diagnostic device includes a rotation counting unit, a temperature measuring unit, a frictional torque calculating unit, a rolling speed calculating unit, a bearing characteristic calculating unit, a storage unit, and a determination unit. The frictional torque calculating unit is configured to calculate a frictional torque of the rotation shaft device. The rolling speed calculating unit is configured to calculate a rolling speed of the bearing from the count of rotations. The bearing characteristic calculating unit is configured to calculate a bearing characteristic from the frictional torque and the rolling speed. The determination unit is configured to compare the bearing characteristic calculated by the bearing characteristic calculating unit with a reference bearing characteristic stored in the storage unit to determine a presence of a failure.
OKUMA Corporation | Date: 2016-09-09
A resolver for a rotation position detection device comprises a rotor portion having a resin gear having a hole formed at a center portion thereof through which a stationary shaft passes, and a rotor core connected to the resin gear; and a stator portion having the stationary shaft, an excitation wiring and a detection wiring, a back core, and a resin housing, wherein the excitation wiring and the detection wiring are arranged around the stationary shaft at a constant distance from the stationary shaft in a diameter direction, the back core is adjacent to or in contact with the stationary shaft, and the resin gear has a shape whose central portion projects in the shaft direction so as to be in contact with the back core.
Okuma Corporation | Date: 2016-06-22
An information acquisition device for machine tool includes a time series information recording unit, an event information recording unit, and an output unit. The time series information recording unit is configured to acquire machine information in time series at a predetermined timing. The event information recording unit is configured to record at least one of: a change content and time at which any one of step information related to a process step, tool information, control panel information related to a control panel of the machine tool, workpiece information, and operator information is changed; and an instruction and time at which the instruction related to a start or an end of machine control execution is issued. The output unit is configured to output time-series data of the machine information recorded in the time series information recording unit together with event data recorded in the event information recording unit.
Okuma Corporation | Date: 2016-06-15
A main spindle load monitoring device indicates a main spindle load in a machine tool that includes a tool with a plurality of edges on a main spindle and performs a process of a workpiece while the tool rotates with the main spindle. The main spindle load monitoring device includes a main spindle load detecting unit configured to detect a load on the main spindle, a main spindle load conversion unit, and a display control unit. The main spindle load conversion unit is configured to convert a time course of the main spindle load detected by the main spindle load detecting unit into a change of the main spindle load with respect to a main spindle rotation angle. The display control unit is configured to indicate a value of the main spindle load converted by the main spindle load conversion unit on a display screen in a polar coordinates system.
Okuma Corporation | Date: 2016-04-13
A vibration information display device includes a monitor, a vibration information acquisition unit, an operating information acquisition unit, a storage unit, and a display control unit. The monitor displays information on the chatter vibrations. The vibration information acquisition unit acquires vibration information when the chatter vibrations are detected. The operating information acquisition unit acquires operating information of the machine tool when the chatter vibrations are detected. The storage unit stores the acquired vibration information and operating information. The display control unit displays the vibration information and the operating information stored in the storage unit on the monitor. Alternatively, the display control unit displays the vibration information stored in the storage unit on the monitor together with trajectory information of a blade edge of the tool included in the operating information.
Okuma Corporation | Date: 2015-02-24
A method for controlling a machine tool in which a main spindle and a table are moved relative to each other by two or more translation axes and at least one rotation axis is provided. In the method, an error in a position of the tool with respect to the workpiece due to an error of the machine tool is corrected to calculate a translation axis command value and a rotation axis command value. The method includes a step of selecting an arbitrary axis configuration, a step of calculating a correction value for the translation axis for correcting the position error in a command value coordinate system of the translation axis included in the arbitrary axis configuration, and a step of calculating a correction value for the rotation axis for correcting the position error in a command value coordinate system of the rotation axis included in the arbitrary axis configuration.
OKUMA Corporation | Date: 2016-03-17
A position control device for driving one control target, using two drive shafts, has position control units provided to the respective drive shafts. Each position control unit includes a calculation unit for calculating a torque command value before compensation, a deflection vibration reduction torque compensator for calculating a deflection torque estimate and calculating a deflection vibration reduction torque compensation amount, based on the deflection torque estimate and a deflection vibration reduction compensation gain, and a compensator gain calculation unit for outputting, upon receipt of a tandem control command, to the deflection vibration reduction torque compensator, a signal for outputting the deflection vibration reduction torque compensation amount and calculating the deflection vibration reduction compensation gain, and the each of the position control units outputs a value obtained by adding the deflection vibration reduction torque compensation amount to the torque command value before compensation as the torque command value.
Okuma Corporation | Date: 2016-01-11
A thermal displacement correcting apparatus includes a correction amount estimating device and a parameter automatic selecting device that, in a machine tool having two different sets of specifications that differ due to the presence/absence of a scale and different methods of measuring the lengths of a bed and a table, estimate a thermal displacement correction amount of the machine tool of each set of specifications. The two devices store a collection of parameters for an estimated thermal displacement calculation corresponding to each of the bed, the scale, the table, and a workpiece, as a database, and select the parameters belonging to the set of specifications from the database based on machine information according to each set of specifications, calculate estimated thermal displacements of the bed, the table, and the workpiece, or also the scale, according to the selected parameters, and combine the estimated thermal displacements.
Okuma Corporation | Date: 2016-02-01
An error identification method of a machine tool includes an initial position measurement step of indexing a main spindle head rotation axis to an initial angle to measure an initial position of a measured jig, a table reference angle calculation step of calculating a reference angle of the table, a reference position measurement step of indexing the table rotation axis to the reference angle and indexing the main spindle head rotation axis to the initial angle, a relative position measurement step of respectively indexing the table rotation axis and the main spindle head rotation axis to a plurality of predetermined angles, an arc approximation step of approximating the plurality of measured position values into an arc, and an error calculation step of calculating an error of a center position of the rotation axis, a tilt error of the rotation axis, or a tilt error of the translational axis.
OKUMA Corporation | Date: 2016-05-19
A multi-turn detector is configured to detect an amount of multiple turns of an input shaft using a plurality of resolvers. Each resolver includes a rotor portion and a stator portion. The rotor portion has a rotor core composed of a magnetic flux modulating component. The rotor portion rotates in accordance with rotation of the input shaft at a reduction gear ratio that is different from that of a rotor portion of another resolver. The stator portion has an excitation winding that excites an ac magnetic flux in a direction of an axis of rotation of the rotor portion and two detection windings that output ac signals that are obtained by performing amplitude modulation in accordance with a rotation angle of the rotor portion. The excitation windings and the detection windings of the plurality of resolvers are formed by conductor traces in a common multi-layer printed circuit board.