Patents Assigned to Okuma Corporation
  • Publication number: 20180259951
    Abstract: A state diagnostic device collects a usage state and diagnostic data of components, and selects, from the collected diagnostic data, at least one of diagnostic data obtained in a state where the usage state of the components is a truly normal state and diagnostic data obtained in a state where the usage state of the components is a truly abnormal state. The selected diagnostic data is defined as master data. A diagnosis result obtained by diagnosing the master data based on a current diagnostic model is compared with a diagnosis result obtained by diagnosing the master data based on a new diagnostic model, and whether the current diagnostic model is consistent with the new diagnostic model is determined. When the consistency is satisfied, the diagnostic model is updated from the current diagnostic model to the new diagnostic model.
    Type: Application
    Filed: February 21, 2018
    Publication date: September 13, 2018
    Applicant: Okuma Corporation
    Inventors: Takahiro TAMAKOSHI, Hiroshi Ueno, Tomoharu Ando
  • Patent number: 10073436
    Abstract: A fully-closed loop position controller with a velocity control system based on a velocity feedback of mixed velocities of a motor velocity and a load velocity. The fully-closed loop position controller identifies a ratio of load moment of inertia in real time to select an optimum mix gain in accordance with a changing ratio of load moment of inertia such that a position loop gain and a speed loop gain can be varied accordingly. The fully-closed loop position controller controls the load position based on the mix gain, the position loop gain, and the velocity loop gain.
    Type: Grant
    Filed: November 29, 2016
    Date of Patent: September 11, 2018
    Assignee: OKUMA CORPORATION
    Inventor: Satoshi Eguchi
  • Publication number: 20180243833
    Abstract: An operational control method is provided for a machine tool that includes a plurality of tool holders with a cutting-tool. The machine tool relatively moves the tool holders with respect to a workpiece to process the workpiece. The operational control method includes determining whether an abnormality has occurred in the cutting-tool during a processing or not, determining whether a simultaneous processing in which at least two or more of the tool holders perform the processings to an identical workpiece is being performed or not and whether the cutting-tool having the detected abnormality is the cutting-tool that is performing the simultaneous processing or not when the abnormality is detected, and causing the tool holder with the cutting-tool having the detected abnormality to take an abnormality avoidance operation and another of the tool holders to take a response operation based on a determination result at the determining of the simultaneous processing.
    Type: Application
    Filed: January 29, 2018
    Publication date: August 30, 2018
    Applicant: Okuma Corporation
    Inventors: Takaaki TANAKA, Ryosuke Sasaki
  • Publication number: 20180218255
    Abstract: A diagnostic device diagnoses a state of a test object. The diagnostic device includes a physical model base diagnosis unit, a mathematical model base diagnosis unit, a model update necessity determination unit, and an update notification unit. The physical model base diagnosis unit is configured to perform the diagnosis using a feature quantity. The mathematical model base diagnosis unit is configured to perform the diagnosis using a machine learning model. The model update necessity determination unit is configured such that if diagnostic results by the physical model base diagnosis unit and the mathematical model base diagnosis unit differ, the model update necessity determination unit determines that at least one of a physical model or a mathematical model is necessary to be updated. The update notification unit is configured such that if the model update necessity determination unit determines that the update is necessary, the update notification unit notifies it.
    Type: Application
    Filed: December 20, 2017
    Publication date: August 2, 2018
    Applicant: Okuma Corporation
    Inventors: Hiroshi UENO, Tomoharu ANDO, Takashi NORIHISA, Takumi HONGO
  • Publication number: 20180181103
    Abstract: A temperature of a portion of which the temperature is difficult to directly measure is accurately estimated in a simple method. In S1, information about a coolant discharging/stopping state is obtained. As the information about the coolant discharging/stopping state, a flag is used such that the flag represents 1 for the discharging state and the flag represents 0 for the stopping state. Next, in S2, temperature data is obtained from temperature sensors provided in components of a machine tool, a machining space, and a coolant tank. Next, in S3, lag process is performed for the coolant discharging/stopping state flag, and coefficients for measured temperatures of the coolant and the structure are calculated. Next, in S4, the measured temperatures are multiplied by the coefficients, and an estimated temperature of a portion to which the temperature sensor is not attached is calculated.
    Type: Application
    Filed: November 3, 2017
    Publication date: June 28, 2018
    Applicant: Okuma Corporation
    Inventor: Yuji MIZOGUCHI
  • Patent number: 10008963
    Abstract: A compensation function constituting device calculates a correlation coefficient based on a moving distance required for reversing a moving direction of a movable unit and a sliding resistance acting on the movable unit, and a compensation amount output device calculates a moving distance on a position command value required until the movable unit starts to move according to the correlation coefficient and a feedback torque when the moving direction is reversed and increases a torque compensation amount in accordance with the moving distance after reversing the moving direction until the moving distance after the moving direction is reversed reaches the moving distance required until the movement is started.
    Type: Grant
    Filed: April 14, 2015
    Date of Patent: June 26, 2018
    Assignee: OKUMA CORPORATION
    Inventors: Takeshi Sakai, Masashi Miyaji
  • Patent number: 9993904
    Abstract: A position controller includes a position detector, a speed command operator, a first adder, a torque command operator, a second adder, a drive unit, a runout amount correcting device, and a third adder. The runout amount correcting device is configured to employ a value related to deviation between a command value and a detection value in physical quantity of a movable part as a reference signal. The runout amount correcting device is configured to calculate a position correction amount from rotation angle information of the main spindle and the reference signal. The runout amount correcting device is configured to estimate a runout amount of a cutting edge of the tool from the reference signal. The runout amount correcting device is configured to calculate the position correction amount such that influences of the respective cutting edges appearing in the reference signal are leveled.
    Type: Grant
    Filed: December 4, 2015
    Date of Patent: June 12, 2018
    Assignee: Okuma Corporation
    Inventor: Masashi Miyaji
  • Patent number: 9983563
    Abstract: A method for controlling a machine tool in which a main spindle on which a tool is mounted and a table holding a workpiece are moved relative to each other by two or more translation axes that are not perpendicular to each other and at least one rotation axis. In the method, an error in a position of the tool with respect to the workpiece due to a geometric error is corrected to calculate a command value for controlling the translation axis. The method includes a conversion step of converting the error and a correction value for correcting the error by performing a homogeneous coordinate transformation from a workpiece coordinate system to the imaginary Cartesian coordinate system, and a correction value calculation step of calculating a correction value in a command value coordinate system of the translation axis by performing a homogeneous coordinate transformation of the correction value.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: May 29, 2018
    Assignee: Okuma Corporation
    Inventors: Yasunori Kondo, Tetsuya Matsushita
  • Patent number: 9984452
    Abstract: In an NC device having a function as a monitoring apparatus for a machine tool, a monitoring parameter and a retracting parameter which are set and inputted through an input unit by an operator, can be stored in a storage unit. When, for example, monitoring is performed by using a load on a main spindle as machine information, a machining monitoring unit displays a monitored state on a monitor, and compares a threshold value, of the load on the main spindle, according to which occurrence of abnormality is determined, and which is set in the monitoring parameter, and an instruction load generated by a machine operation instruction unit with each other, to determine whether or not abnormality has occurred. When abnormality is determined as having occurred, a retracting instruction is transmitted to a retracting instruction unit according to the retracting parameter, and display is performed on the monitor.
    Type: Grant
    Filed: October 3, 2016
    Date of Patent: May 29, 2018
    Assignee: Okuma Corporation
    Inventors: Tomoharu Ando, Takaaki Tanaka
  • Patent number: 9983564
    Abstract: 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.
    Type: Grant
    Filed: January 11, 2016
    Date of Patent: May 29, 2018
    Assignee: Okuma Corporation
    Inventors: Toshihiko Murahashi, Hironori Funaguchi
  • Publication number: 20180133807
    Abstract: A processing apparatus includes a cutting tool that processes a clamped workpiece, a quenching unit capable of emitting a laser beam, and a vibration cutting unit capable of vibrating a distal end with a vibration cutting tool mounted thereon. The cutting tool, the quenching unit, and the vibration cutting unit are movable relative to the workpiece. The cutting tool cuts the workpiece before being quenched. The quenching unit applies laser quenching as a surface hardening treatment to the workpiece. The vibration cutting unit finishes the quenched workpiece by applying the vibration cutting tool to the workpiece while vibrating the vibration cutting tool.
    Type: Application
    Filed: October 23, 2017
    Publication date: May 17, 2018
    Applicant: Okuma Corporation
    Inventors: Eiji SHAMOTO, Takashi Ueda, Seiei Yamamoto
  • Publication number: 20180120827
    Abstract: A diagnostic result display method in a diagnostic device calculates a diagnostic result by a determination of a predetermined state and a certainty factor of the determination. The diagnostic result display method includes setting preset predetermined colors to predetermined states, setting a preset area of a geometric shape according to certainty factors, and displaying the area of the geometric shape in at least one of the predetermined colors.
    Type: Application
    Filed: September 12, 2017
    Publication date: May 3, 2018
    Applicant: Okuma Corporation
    Inventors: Takumi HONGO, Hitoshi SUMI
  • Publication number: 20180111238
    Abstract: A machine tool includes a base, a table, a main spindle, and a trunnion unit. The table is installed on the base. A tool is mounted to the main spindle. The main spindle is caused to approach a workpiece on the table along an up-down direction. The trunnion unit is configured to rotatably hold the table on which the workpiece is placed using a rotation axis along a front-rear direction as a center. The trunnion unit is disposed movable in a right-left direction.
    Type: Application
    Filed: September 12, 2017
    Publication date: April 26, 2018
    Applicant: Okuma Corporation
    Inventor: Koji Tsuchida
  • Patent number: 9952249
    Abstract: A torque command value and an acceleration detection value are accumulated when a driven portion is subjected to acceleration/deceleration driving, and, from a ratio between the two, inertia of a movable portion is calculated. By executing the acceleration/deceleration driving about a position where influence of gravity torque is zero, the influence of the gravity torque included in the torque command value before and after the center position is offset, whereby inertia can be estimated correctly even with a machine structure in which the influence of gravity differs depending on the position of the motor.
    Type: Grant
    Filed: April 25, 2014
    Date of Patent: April 24, 2018
    Assignee: OKUMA CORPORATION
    Inventor: Masashi Miyaji
  • Patent number: 9952582
    Abstract: Maximum values of actual machining allowances of a workpiece in respective cutting flutes are averaged by control amounts of respective cutting flutes calculated by an arithmetic unit. The arithmetic unit converts the calculated control amounts into an amount in each axis direction and subtracts the value from a feed axis command value in an NC program stored in a storage unit. Then, a numeral value control unit performs machining by controlling respective feed axes based on the subtracted feed axis command value.
    Type: Grant
    Filed: September 1, 2015
    Date of Patent: April 24, 2018
    Assignee: Okuma Corporation
    Inventor: Hiroshi Inagaki
  • Patent number: 9932979
    Abstract: An oil pressure control device for supplying oil pressure by rotating a hydraulic pump, by means of a motor, comprises an oil pressure sensor; a speed instruction operation unit for outputting a speed instruction value, based on a difference between an oil pressure determination value from the oil pressure sensor and an oil pressure instruction value; a torque instruction value operation unit for calculating a torque instruction value, based on a difference between a speed determination value and the speed instruction value; and a current control unit for controlling a current of the motor, based on the torque instruction value, and adds the load variation compensation speed outputted from the load variation compensation unit and the speed instruction value.
    Type: Grant
    Filed: November 14, 2014
    Date of Patent: April 3, 2018
    Assignee: OKUMA CORPORATION
    Inventor: Tomohiro Shibata
  • Patent number: 9933333
    Abstract: 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.
    Type: Grant
    Filed: July 14, 2016
    Date of Patent: April 3, 2018
    Assignee: Okuma Corporation
    Inventors: Naoki Kawada, Issei Koike
  • Publication number: 20180071876
    Abstract: In a machine tool, when machining is in a steady zone, a rotation phase of a main spindle at the time of measurement in the N-th sampling is calculated, and the calculated rotation phase and the measurement value are recorded in a recording section so as to be associated with each other. The measurement and calculation of the rotation phase of the main spindle at the time of each measurement are continued for plural times of rotations of the main spindle, and thus the measurement values are obtained at various rotation phases, whereby change in drive force during one rotation of the main spindle is finally calculated.
    Type: Application
    Filed: August 9, 2017
    Publication date: March 15, 2018
    Applicant: Okuma Corporation
    Inventor: Takaaki TANAKA
  • Patent number: 9910422
    Abstract: 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.
    Type: Grant
    Filed: February 1, 2016
    Date of Patent: March 6, 2018
    Assignee: Okuma Corporation
    Inventor: Tetsuya Matsushita
  • Patent number: 9906184
    Abstract: A temperature detection element that detects a temperature of a detector is provided in a detector that detects a rotational position and/or a rotational speed of a rotor of a motor. An estimated value of a change of a wiring temperature is calculated based on a current supplied to the wiring of the motor. An estimated value of a change of the detector temperature is calculated based on the estimated value of the change of the wiring temperature. A difference between the detector temperature detected by the temperature detection element and the estimated value of the change of the detector temperature is set as an environmental temperature. The environmental temperature is added to the estimated value of the change of the wiring temperature, to estimate an absolute value of the wiring temperature. The wiring temperature is monitored based on the estimated absolute value of the wiring temperature.
    Type: Grant
    Filed: December 2, 2015
    Date of Patent: February 27, 2018
    Assignee: OKUMA CORPORATION
    Inventor: Takahiko Yato