Patents Assigned to Okúma Corporation
  • Patent number: 11602811
    Abstract: A machine tool includes a headstock that holds a workpiece, a tool post that is movable in a first axis direction parallel to a workpiece rotation axis and in a second axis direction orthogonal to the first axis and holds a tool, an in-machine robot, an opening for communicating the inside and the outside of a working chamber, and a door that opens and closes the opening. The robot includes a root joint fixed in the working chamber and a link unit positioned on a distal end side of the root joint. The root joint is a linear-motion joint extendable in a direction orthogonal to the workpiece rotation axis, and is a linear-motion joint extendable between the length for causing the entire link unit to be positioned inside the working chamber and the length for causing the entire link unit to be positioned outside the working chamber.
    Type: Grant
    Filed: January 21, 2021
    Date of Patent: March 14, 2023
    Assignee: OKUMA CORPORATION
    Inventor: Shoichi Morimura
  • Publication number: 20230076585
    Abstract: An accuracy analysis system for a machine tool includes: a control unit, a data server, a data communication unit, a data analyzer, a corrected machine accuracy calculation unit, and a data display unit. The control unit stores preliminarily obtained accuracy data regarding a machine accuracy, compensation data for compensating for an error, and machine information. The data communication unit transmits the accuracy data, the compensation data, and the machine information to the data server. The data analyzer uses the accuracy data and the compensation data in the data server to obtain a compensation data correction value as a correction value of the compensation data and expected accuracy data when the compensation data correction value is applied. The corrected machine accuracy calculation unit calculates a post-correction machine accuracy from the expected accuracy data. The data display unit displays the post-correction machine accuracy calculated by the corrected machine accuracy calculation unit.
    Type: Application
    Filed: August 24, 2022
    Publication date: March 9, 2023
    Applicant: OKUMA CORPORATION
    Inventor: Reiji KANBE
  • Publication number: 20230069773
    Abstract: A method includes: installing a square calibration master on a table, and measuring each of measurement surfaces A, B, and C of the square calibration master by a position measurement sensor attached to a main spindle; calculating a first squareness between the measurement surfaces A and B; calculating a second squareness between the measurement surfaces A and C; calculating a difference between the first squareness and the second squareness; comparing the difference with a preliminarily set difference threshold value; calculating an average value of the first squareness and the second squareness when the difference is equal to or less than the difference threshold value, and calculating a corrected squareness based on an angular deviation and the first squareness or the second squareness when the difference exceeds the difference threshold value; and setting the compensation parameter based on the average value or the corrected squareness.
    Type: Application
    Filed: August 24, 2022
    Publication date: March 2, 2023
    Applicant: OKUMA CORPORATION
    Inventors: Yasunori KONDO, Tetsuya MATSUSHITA, Takuya KOJIMA
  • 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
  • Publication number: 20230056310
    Abstract: A method for calibrating a positional relation between a main spindle and a contact tool sensor attached to a table in a machine tool. The method includes: mounting a reference tool on the main spindle and obtaining measurement position coordinates as respective tool sensor measurement values, the measurement position coordinates being of a distal end of the reference tool in at least two different measurement regions on an upper surface of the contact tool sensor; outputting predetermined difference values based on the respective tool sensor measurement values; determining an abnormality when the difference values are compared with preliminarily set acceptable values and at least one of the difference values are out of the acceptable values; and calibrating a positional relation between the main spindle and the contact tool sensor based on the respective tool sensor measurement values when the abnormality is not determined at the determining of abnormality.
    Type: Application
    Filed: August 19, 2022
    Publication date: February 23, 2023
    Applicant: OKUMA CORPORATION
    Inventor: Daichi KAWAUCHI
  • 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: 11579198
    Abstract: An inverter system includes a converter, an inverter, a first switch SW1 that connects between the converter and an AC power source, a capacitor that smooths a DC power in a DC bus, a resistor Rr connected from a positive voltage side of the DC bus to ground, a second switch SW2 that connects between the resistor Rr and ground, and a controller that controls drive of the inverter system. The controller is configured to: after charging the capacitor, while the first switch SW1 is in an OFF state, turn on the second switch SW2 and obtain a first across voltage ER1 of the resistor Rx; turn on an element, among semiconductor elements of the inverter, that is connected to the negative voltage side of the DC bus, and then obtain a second across voltage ER2 of the resistor Rx; and inspect insulation resistance of a motor based on the across voltages ER1, ER2.
    Type: Grant
    Filed: November 2, 2021
    Date of Patent: February 14, 2023
    Assignee: OKUMA CORPORATION
    Inventor: Motozumi Yura
  • Patent number: 11571775
    Abstract: A machine tool is disclosed. The machine tool includes a robot which is compact and which enables easy use of different end effectors for respective purposes. An internal robot includes a plurality of joints that are composed of a base joint and parallel joints, and a plurality of links. The distal end is split into two or more branches, each having a tool changer. An end effector is detachably attachable to each of the tool changers. Rotation of the base joint causes a change between a first tool-following position and a second tool-following position, so that different end effectors are used for respective purposes by using an end effector attached to a tool changer in the first tool-following position and using an end effector attached to another tool changer in the second tool-following position.
    Type: Grant
    Filed: August 6, 2020
    Date of Patent: February 7, 2023
    Assignee: OKUMA CORPORATION
    Inventor: Shoichi Morimura
  • Publication number: 20230010557
    Abstract: An error identification method for identifying an error includes: securing a calibrator having three or more spheres on the table; measuring an initial position of the calibrator with a position measurement sensor tool; calculating a reference angle of each of the rotation axes for positioning the calibrator to a predetermined reference position using a measured value in the measuring; indexing each of the rotation axes individually to a plurality of indexed angles with respect to the reference angle and measuring a center position of a sphere of the calibrator secured on the table at each of the indexed angles with the position measurement sensor tool; and identifying a positioning error and a straightness error of the linear axis, a squareness error between the respective linear axes, and a position error and an inclination error of each of the rotation axes based on a measured value in the indexing.
    Type: Application
    Filed: July 6, 2022
    Publication date: January 12, 2023
    Applicant: OKUMA CORPORATION
    Inventors: Tetsuya MATSUSHITA, Takuya KOJIMA
  • Publication number: 20230010236
    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: Application
    Filed: July 6, 2022
    Publication date: January 12, 2023
    Applicant: OKUMA CORPORATION
    Inventors: Tetsuya MATSUSHITA, Takuya KOJIMA
  • Patent number: 11526144
    Abstract: A numerical control device of a machine tool recognizes a failure of a vibration detection unit in a relatively short time to minimize damage to functions achieved using the vibration detection unit. A program interpreting unit interprets an automatic tool exchange operation, and a storage unit is instructed to store vibration information V(x) from the vibration detection unit. After the automatic tool exchange operation is finished, the storage unit is instructed to stop storage. When none of the vibration information V(x) stored in the storage unit exceeds a prescribed vibration level, a vibration information analysis unit determines abnormality of the vibration detection unit.
    Type: Grant
    Filed: June 28, 2019
    Date of Patent: December 13, 2022
    Assignee: OKUMA CORPORATION
    Inventor: Noriyuki Fukui
  • Publication number: 20220381076
    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: Application
    Filed: May 20, 2022
    Publication date: December 1, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Tetsunobu NISHINAKA
  • Patent number: 11507062
    Abstract: A numerical control apparatus of a machine tool that performs tapping, includes a numerical control, an acceleration learning block, an acceleration/deceleration processing unit that applies an acceleration/deceleration process to the command acceleration and the position command value to calculate a post-acceleration/deceleration position command value, a position control unit that calculates a speed command value based on the post-acceleration/deceleration position command value, a speed/torque control unit that calculates a motor torque command value from the speed command value, and a current control unit that calculates a motor current value of a spindle motor from the motor torque command value. The acceleration learning block outputs, as the command acceleration A, an initial command acceleration A[0] which is smaller than the calculated command acceleration, in accordance with a state quantity of the spindle motor, to the acceleration/deceleration processing unit.
    Type: Grant
    Filed: November 25, 2019
    Date of Patent: November 22, 2022
    Assignee: OKUMA CORPORATION
    Inventor: Yuji Uchida
  • Publication number: 20220350322
    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: Application
    Filed: April 20, 2022
    Publication date: November 3, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Takumi HONGO
  • Publication number: 20220341820
    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: Application
    Filed: April 20, 2022
    Publication date: October 27, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Yuji MIZOGUCHI
  • Publication number: 20220314385
    Abstract: Provided is a cutting fluid tank for a machine tool, with which the operator's time and effort for cleaning are reduced and the maintainability is enhanced, without entailing an increase in size. In a tank body, a cutting fluid flow channel having a spiral shape and extending from a tank center region to a tank outer peripheral region is formed by a flow channel forming plate. An inflow port into which a cutting fluid from inside a machining chamber flows is provided at an outer peripheral region of the lid, whereas an outflow port to take out the cutting fluid in the tank body to an outside is provided at a center region of the lid. A pump to pump up and supply the cutting fluid to the machining chamber is provided at the outflow port.
    Type: Application
    Filed: March 18, 2022
    Publication date: October 6, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Hiroaki Naramoto
  • Publication number: 20220291656
    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: Application
    Filed: February 28, 2022
    Publication date: September 15, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Yuji MIZOGUCHI
  • Publication number: 20220288735
    Abstract: Provided is a tool pot overcoming a problem that dirt adhered to the tool pot is transferred to a contact face of a tool. A pull stud holder includes a pusher that moves in a direction orthogonal to an axis of the tool whereby a tapered face provided at a distal end of the pusher pushes a tapered face of a pull stud in an axial direction of the tool. A base member includes a pull stud receiver that receives an end face of the pull stud. The pusher and the pull stud receiver prevent rotation of the pull stud and movement thereof in the axial direction of the tool. A flange holder includes a key that fits into a keyway of a flange, thereby preventing rotation of the flange.
    Type: Application
    Filed: March 11, 2022
    Publication date: September 15, 2022
    Applicant: OKUMA CORPORATION
    Inventor: Makoto Yoshida
  • 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: 11426831
    Abstract: A cooling liquid feeder for feeding a cooling liquid into a cooling liquid hole defined in a tool includes a first connector disposed on a turret which retains the tool, a first flow channel for directing the cooling liquid from the first connector to the cooling liquid hole, a robot installed in a machining chamber and equipped with an end effector, a second connector disposed on the end effector and configured to be detachably attached to the first connector in a liquid tight manner, and a second flow channel for directing the cooling liquid from a source of the cooling liquid to the second connector, in which the robot is actuated to attach the second connector to the first connector for feeding the cooling liquid into the cooling liquid hole.
    Type: Grant
    Filed: October 15, 2019
    Date of Patent: August 30, 2022
    Assignee: OKUMA CORPORATION
    Inventors: Tomoki Hayashi, Shoichi Morimura