Patents Assigned to Okuma Corporation
  • Patent number: 12044594
    Abstract: A method for diagnosing an abnormality of rolling bearing includes: measuring a vibration of a rotator; performing a frequency analysis on the vibration to calculate a magnitude of a vibration at each frequency; calculating a characteristic frequency as a frequency of a vibration from a specification of the rolling bearing and a rotation speed of the rotator at a vibration measurement in the measuring; calculating a vibration value from which an effect of the rotation speed is removed by dividing a magnitude of a vibration at the characteristic frequency by a value including a base and an exponent, the base being a predetermined physical quantity in a proportional relation with an angular velocity of the rotator at the vibration measurement in the measuring, the exponent being a positive number; calculating an evaluation index based on the vibration value; and determining an existence of an abnormality based on the evaluation index.
    Type: Grant
    Filed: March 25, 2019
    Date of Patent: July 23, 2024
    Assignee: Okuma Corporation
    Inventors: Hiraku Sugiura, Issei Koike
  • Patent number: 12018933
    Abstract: An accuracy diagnostic device for a machine tool diagnoses an accuracy of the machine tool. The machine tool includes a change amount detection unit that measures a change amount. The change amount changes due to an installation environment and an operational motion. The accuracy diagnostic device includes a change-amount-reference-value recording unit that records a reference value of the change amount. The accuracy diagnostic device obtains the change amount measured by the change amount detection unit. The accuracy diagnostic device diagnoses a change of the accuracy of the machine tool based on a first change index derived from a magnitude of a change of the change amount per a predetermined period and a second change index derived from the current change amount and the reference value.
    Type: Grant
    Filed: June 7, 2021
    Date of Patent: June 25, 2024
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 12011793
    Abstract: A main spindle monitoring device determines an abnormality of a main spindle in a machine tool. The main spindle monitoring device includes a main spindle operation monitoring unit and a feed axis operation monitoring unit. The main spindle operation monitoring unit monitors a change of an operation condition of the main spindle based on a main spindle load. The feed axis operation monitoring unit monitors a change of an operation condition of a feed axis based on a feed axis load. The abnormality of the main spindle is determined when the main spindle operation monitoring unit detects the change of the operation condition of the main spindle and the feed axis operation monitoring unit does not detect the change of the operation condition of the feed axis in a state where a constant rotation speed is commanded to the main spindle while the feed axis is driving.
    Type: Grant
    Filed: September 15, 2020
    Date of Patent: June 18, 2024
    Assignee: Okuma Corporation
    Inventor: Takumi Hongo
  • Patent number: 12013233
    Abstract: An accuracy diagnostic device that diagnoses an influence on an accuracy of a machine tool due to a thermal deformation includes a temperature change rate calculation unit, an accuracy influence degree calculation unit, and an accuracy stabilization time period calculation unit. The temperature change rate calculation unit calculates a rate of a temperature change in a predetermined portion of the machine tool as a temperature change rate. The accuracy influence degree calculation unit calculates an influence degree on the machine tool accuracy due to the thermal deformation as an accuracy influence degree, based on the temperature change rate. The accuracy stabilization time period calculation unit calculates a time period until the machine tool accuracy is stabilized as an accuracy stabilization time period, based on the temperature change rate.
    Type: Grant
    Filed: June 7, 2021
    Date of Patent: June 18, 2024
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 11989002
    Abstract: An environmental temperature change prediction device includes an environmental temperature acquisition unit, an outside temperature acquisition unit, a plant environment pattern setting unit, a prediction model generating unit, and an environmental temperature change prediction unit. The environmental temperature acquisition unit measures a machine body temperature. The plant environment pattern setting unit defines in advance a classification rule for classifying change trends of the environmental temperature into a plurality of patterns based on data of the environmental temperature and the plant outside temperature and environmental temperature prediction models. The prediction model generating unit selects the applicable plant environment pattern and determines a parameter of the environmental temperature prediction model corresponding to the selected plant environment pattern.
    Type: Grant
    Filed: February 28, 2022
    Date of Patent: May 21, 2024
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 11988506
    Abstract: An error identification method includes: installing a calibrator including a sphere row A and a sphere row B in which a plurality of spheres are linearly aligned in a direction perpendicular to the sphere row A on a table such that the sphere row A and the sphere row B are approximately parallel to respective two of the translational axes and measuring positions of a plurality of spheres of the sphere row A and the sphere row B using a position measurement sensor tool; rotating the calibrator to a plurality of angles around a normal direction on the upper surface of the table to install on the table and measuring each position of the plurality of spheres of the sphere row A and the sphere row B; and identifying an error of the translational axis based on measured values in the installing and the rotating.
    Type: Grant
    Filed: July 6, 2022
    Date of Patent: May 21, 2024
    Assignee: Okuma Corporation
    Inventors: Tetsuya Matsushita, Takuya Kojima
  • Patent number: 11952815
    Abstract: A door open and close mechanism for opening and closing a plurality of doors in a machine tool including a cover. The door open and close mechanism includes a linkage mechanism and a slide mechanism. The linkage mechanism is disposed between an operation door and an intermediate door. The linkage mechanism associates the intermediate door with the opening and closing of the operation door. The slide mechanism is disposed between the operation door and the linkage mechanism. The slide mechanism enables the operation door alone to open and close by a predetermined moving distance. When the operation door is operated to open and close within the moving distance, the operation door alone opens and closes by the slide mechanism. When the operation door is operated to open and close beyond the moving distance, the intermediate door opens and closes in association through the linkage mechanism.
    Type: Grant
    Filed: May 20, 2022
    Date of Patent: April 9, 2024
    Assignee: Okuma Corporation
    Inventor: Tetsunobu Nishinaka
  • Patent number: 11953406
    Abstract: An accuracy diagnostic device includes a change amount detecting unit, a change amount recording unit, an accuracy change predictor, and an accuracy adjustment timing presenting unit. The change amount detecting unit detects a magnitude of a change in at least one of a state of a machine tool and a surrounding environment of the machine tool as a change amount. The change amount recording unit records the change amount. The accuracy change predictor predicts a future accuracy change of the machine tool using the change amount recorded in the change amount recording unit. The accuracy adjustment timing presenting unit presents a timing at which an accuracy adjustment is to be required for the machine tool based on the accuracy change predicted by the accuracy change predictor.
    Type: Grant
    Filed: April 20, 2022
    Date of Patent: April 9, 2024
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 11954566
    Abstract: A data collection system includes a classification model storing unit, a model delivery unit, a classification result storing unit, an optimum model recommendation unit, and a teacher data recording unit. The model delivery unit delivers a classification model to the user environment. The classification result storing unit classifies each of the classification models on the classification model storing unit using data with a label transmitted from the user environment as an input. The classification result storing unit stores a classification result including at least one of classification correctness or a percentage of correct answers for each input data. The optimum model recommendation unit presents an appropriate classification model for the input data based on the classification result for each of the classification models. The teacher data recording unit records the input data as teacher data or test data of the classification model.
    Type: Grant
    Filed: May 15, 2020
    Date of Patent: April 9, 2024
    Assignee: Okuma Corporation
    Inventor: Hiroshi Ueno
  • Patent number: 11892820
    Abstract: An error compensation method includes outputting at least one of a plurality of calibration-master conditions including a type of a calibration master that includes targets, obtaining measurement values of positions of the targets by detecting the positions of the plurality of targets under the calibration-master condition using a sensor mounted to the main spindle, and calculating an error value using the measurement value and a calibration value of the position of the target. The error compensation method further includes approximating a relation between the measurement values and the error values by a curve and a straight line, calculating a compensation parameter of a positioning error of a translational axis based on an approximate curve in a partial range of a stroke of the translational axis, and calculating the compensation parameter of the positioning error based on an approximate straight line in another range of the stroke of the translational axis.
    Type: Grant
    Filed: October 22, 2020
    Date of Patent: February 6, 2024
    Assignee: Okuma Corporation
    Inventors: Takuya Kojima, Tetsuya Matsushita, Yasunori Kondo
  • Patent number: 11868123
    Abstract: An abnormality diagnostic device for a feed axis mechanism diagnoses an abnormality occurrence and an abnormal portion of the feed axis mechanism. The feed axis mechanism transmits a rotation of a motor to a ball screw coupled by a coupling to rotate the ball screw. The abnormality diagnostic device includes a resonance frequency measuring unit and a diagnosis unit. The resonance frequency measuring unit measures a resonance frequency at a plurality of stroke positions within a stroke range of the feed axis mechanism. The diagnosis unit identifies the abnormal portion based on a relationship between the stroke positions and change amounts relative to a standard value of the measured respective resonance frequencies.
    Type: Grant
    Filed: April 20, 2022
    Date of Patent: January 9, 2024
    Assignee: Okuma Corporation
    Inventor: Takumi Hongo
  • Patent number: 11819924
    Abstract: A turning process method for processing a step-shaped workpiece includes: feeding a tool in a rotation axis direction and/or a radial direction of a workpiece while rotating the workpiece; using a tool that includes an insert with a main cutting edge having a straight portion and a machine tool having a pivot shaft of the tool in the machine side; processing a peripheral surface of the small diameter portion by turning the pivot shaft so as to have a cutting edge angle of less than 90°, the cutting edge angle having an angle between the straight portion of the main cutting edge and the rotation axis direction; and processing an end surface and a peripheral surface of the large diameter portion by turning the pivot shaft so as to have the cutting edge angle of 90° or more at a front of the large diameter portion.
    Type: Grant
    Filed: December 1, 2021
    Date of Patent: November 21, 2023
    Assignee: Okuma Corporation
    Inventor: Kazunori Fujise
  • Patent number: 11790700
    Abstract: A relearning necessity determination method is provided for determining a necessity of relearning of a learned diagnostic model in a machine tool including a machining abnormality diagnosing unit. The machining abnormality diagnosing unit determines normal or abnormality of machining using the diagnostic model generated through machine learning. The method includes storing a cumulative cutting time or a cumulative cutting distance of a tool mounted to the machine tool as a tool usage, storing the tool usage when the machining abnormality diagnosing unit diagnoses the machining as machining abnormality, and determining the necessity of the relearning of the diagnostic model based on a frequency distribution of the tool usage stored in the storing of the tool usage.
    Type: Grant
    Filed: July 13, 2020
    Date of Patent: October 17, 2023
    Assignee: Okuma Corporation
    Inventor: Hiroshi Ueno
  • Patent number: 11666999
    Abstract: A thermal displacement correction method is provided, including a first step of setting an initial tool temperature, a second step of estimating a temperature of a tool or a position measurement sensor based on the initial tool temperature and a temperature of a spindle, a third step of estimating an amount of thermal displacement of the tool or the position measurement sensor with a preliminarily set tool thermal displacement estimation formula based on the estimated temperature, and a fourth step of moving a feed shaft of the machine tool based on the estimated amount of thermal displacement to perform a correction. In the second step, the temperature of the spindle is measured, then a tool-mounted portion temperature of the spindle is estimated from the measured temperature.
    Type: Grant
    Filed: December 24, 2019
    Date of Patent: June 6, 2023
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 11662195
    Abstract: A correction value measurement method includes, measuring a position of a reference sphere, calculating a relative position of the reference sphere with respect to a sensing position from the position of the reference sphere, a length of the position measurement sensor, and a length of the reference tool. The method further includes acquiring a reference tool position as a distal end position of the reference tool using, calculating a length direction correction value of the position measurement sensor from the reference tool position, the position of the reference sphere, the relative position, and a length of the reference tool, and measuring the position of the reference sphere to calculate a radial direction correction value of the position measurement sensor.
    Type: Grant
    Filed: October 2, 2020
    Date of Patent: May 30, 2023
    Assignee: Okuma Corporation
    Inventor: Reiji Kanbe
  • Patent number: 11590622
    Abstract: A thermal displacement compensation apparatus includes a temperature measuring unit, a thermal displacement estimating unit, a thermal displacement compensation unit, a displacement measuring unit, a data recording unit, a thermal displacement compensation learning unit, and a displacement measurement timing diagnostic unit. The displacement measuring unit measures a displacement of a machine tool after compensating an axis command value. The thermal displacement compensation learning unit determines a thermal displacement estimation formula based on temperature information and the displacement recorded in the data recording unit. The displacement measurement timing diagnostic unit compares the temperature information at a past displacement measurement recorded in the data recording unit with current temperature information obtained from the temperature measuring unit, and determines whether to measure the displacement by the displacement measuring unit or not at a predetermined diagnosis timing.
    Type: Grant
    Filed: December 15, 2021
    Date of Patent: February 28, 2023
    Assignee: Okuma Corporation
    Inventor: Yuji Mizoguchi
  • Patent number: 11585725
    Abstract: A feed axis diagnostic device for a machine tool is provided. The machine tool machines a workpiece while driving a moving body with feed axes along a guide surface of a rolling guide mechanism. The feed axis diagnostic device includes a feed axis diagnostic unit configured to detect an abnormality in the rolling guide mechanism in the machine tool. The feed axis diagnostic unit is configured to acquire a feed speed during non-machining and a load applied to the feed axes at the feed speed. The abnormality is detected based on an approximate function calculated from relationships between a plurality of the feed speeds and a plurality of the loads acquired under a plurality of different feed speed conditions in a predetermined period.
    Type: Grant
    Filed: November 16, 2020
    Date of Patent: February 21, 2023
    Assignee: Okuma Corporation
    Inventor: Takumi Hongo
  • Patent number: 11433606
    Abstract: A three-dimensional shape processing method processes a workpiece into a predetermined three-dimensional shape by cutting work and additive manufacturing. The method includes forming a target surface for the additive manufacturing to be larger than a shape dimension of the three-dimensional shape, performing the additive manufacturing on the target surface that has been largely formed, and performing the cutting work on a region where the additive manufacturing has been performed to complete the three-dimensional shape.
    Type: Grant
    Filed: April 8, 2020
    Date of Patent: September 6, 2022
    Assignee: Okuma Corporation
    Inventor: Ryosuke Sasaki
  • Patent number: 11378379
    Abstract: A tool cutting edge measuring device that is mounted on a horizontal lathe and multitasking machine includes contact type sensors and an arm. The sensors are configured to measure cutting edge positions of tools in a machining chamber and the arm is movable between an advance position and a retracted position. The arm advances into the machining chamber at the advance position and retracts from the machining chamber at the retracted position. The arm has distal ends provided with two branching units branched into the X-axis direction and the Z-axis direction at the advance position and the sensors are mounted to the respective branching units.
    Type: Grant
    Filed: September 11, 2020
    Date of Patent: July 5, 2022
    Assignee: Okuma Corporation
    Inventor: Shinya Naruse
  • Patent number: 11376695
    Abstract: A work table includes a baseplate, a plurality of levers, a clamp plate, a lock mechanism, and an unlocking mechanism. The plurality of levers are disposed on a concentric circle on the baseplate. Guide bars protrude upward from the plurality of levers. The plurality of levers are each disposed to be movable in a radial direction of the circle. The clamp plate is placed on top surfaces of the levers. The clamp plate has elongated holes in the radial direction through which the guide bars penetrate. The lock mechanism urges the clamp plate downward such that the respective levers are fixed in a manner sandwiched between the baseplate and the clamp plate. The unlocking mechanism releases the fixing of the respective levers by the lock mechanism.
    Type: Grant
    Filed: April 9, 2020
    Date of Patent: July 5, 2022
    Assignee: Okuma Corporation
    Inventor: Koki Matsuura