Patents by Inventor Tadashi Okita

Tadashi Okita has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20170315533
    Abstract: A machine tool control device according to the present invention includes a feedback counter for obtaining A- and B-phase signals of rectangular waves or sine waves and a one-rotation signal, which are outputted from a sensor for detecting the position or speed of a driven axis or a motor, to calculate a feedback count value that is a count value of the number of feedback pulses generated from the A- and B-phase signals; a feedback count value storage unit for storing an inter-one-rotation-signal feedback count value that is the feedback count value counted between the two sequential one-rotation signals; a reference value storage unit for storing an anomaly determination reference value corresponding to the inter-one-rotation-signal feedback count value; and an anomaly cause determination unit for determining the cause of an anomaly by comparison between the inter-one-rotation-signal feedback count value and the anomaly determination reference value.
    Type: Application
    Filed: April 25, 2017
    Publication date: November 2, 2017
    Applicant: FANUC CORPORATION
    Inventors: Tadashi Okita, Yuuki Morita, Geng Li
  • Publication number: 20170300033
    Abstract: To provide a motor control device, motor control method, and non-transitory computer readable medium recording a motor control program, which add a backlash correction amount to a position command for a motor at the appropriate timing. Included are a first position detection part that detects a first position which is a position of a movable part; a second position detection part that detects a second position which is a position of a driven part; a positional error calculation part that calculates positional error, which is deviation between a converted first position detected value and a second position detected value; and a backlash correction part that adds a backlash correction amount when the absolute value for the variation of the positional error since reversal of a position command was detected exceeds the predetermined reference value.
    Type: Application
    Filed: April 10, 2017
    Publication date: October 19, 2017
    Inventors: Shoutarou HASHIMOTO, Tadashi OKITA, Yuuki MORITA
  • Publication number: 20170277160
    Abstract: A controller for controlling a synchronized operation of spindle and feed axes.
    Type: Application
    Filed: March 24, 2017
    Publication date: September 28, 2017
    Inventors: Yuuki MORITA, Daisuke TAJIMA, Tadashi OKITA
  • Patent number: 9755566
    Abstract: A controller and a method for a machine tool, capable of discriminating the factors in overheating, and taking appropriate measures depending on each factor. A first amplifier of the controller has an acceleration/deceleration judging part which judges as to whether the spindle motor is accelerated or decelerated; a first temperature estimating part which estimates a first amount of change in temperature of the spindle motor when the spindle motor is in the acceleration/deceleration state; a second temperature estimating part which estimates a second amount of change in temperature of the spindle motor when the spindle motor is in the steady state; a comparing part which compares the first and second estimated values. A numerical controlling part of the controller transmits an operation command for changing the operation of at least one of the spindle motor and a feed shaft motor, when the spindle motor is overheated.
    Type: Grant
    Filed: October 9, 2014
    Date of Patent: September 5, 2017
    Assignee: Fanuc Corporation
    Inventor: Tadashi Okita
  • Patent number: 9753452
    Abstract: A machine tool controller including a numerical control section, a spindle-axis control section and a feed-axis control section. The spindle-axis control section includes a section for making the spindle axis perform an accelerated rotation at maximum capacity from a process start position toward a target thread depth, with a maximum rotation speed set as a target value; a section for detecting a maximum acceleration during the accelerated rotation based on a rotational position; a section for detecting a residual rotation amount from a current position to the target thread depth, based on a total rotation amount and the rotational position; a section for detecting a current speed based on the rotational position; and a section for making the spindle axis perform a decelerated rotation at maximum capacity to reach the target thread depth after the accelerated rotation, based on the maximum acceleration, the residual rotation amount and the current speed.
    Type: Grant
    Filed: October 16, 2015
    Date of Patent: September 5, 2017
    Assignee: FANUC CORPORATION
    Inventors: Yuuki Morita, Tadashi Okita
  • Publication number: 20170185067
    Abstract: A machine tool controller according to an embodiment of the present invention, for controlling a spindle and a feed axis, includes a motor temperature obtaining unit for obtaining and outputting the winding temperature of a spindle motor as a motor temperature; an inverter temperature obtaining unit for obtaining and outputting the temperature of an inverter that drives the spindle motor as an inverter temperature; a motor temperature comparator for comparing the outputted motor temperature with an overheat temperature for the motor; an inverter temperature comparator for comparing the outputted inverter temperature with an overheat temperature for the inverter; and an overheating assessment unit for imposing a restriction on the output of the spindle motor according to the smaller one of the differences between the motor temperature and the overheat temperature for the motor and between the inverter temperature and the overheat temperature for the inverter.
    Type: Application
    Filed: December 13, 2016
    Publication date: June 29, 2017
    Applicant: FANUC CORPORATION
    Inventors: Daisuke Tajima, Tadashi Okita
  • Patent number: 9692348
    Abstract: A motor control device includes a load torque estimation unit configured to estimate a load torque applied to a motor, a torque comparison unit configured to compare the load torque with a reference torque, a time measurement unit configured to measure a time span during which the load torque is higher than the reference torque, a time comparison unit configured to compare the time span with a reference time, and a decision unit configured to decide that the motor is subjected to an excessive load when the time span exceeds the reference time.
    Type: Grant
    Filed: November 4, 2015
    Date of Patent: June 27, 2017
    Assignee: FANUC CORPORATION
    Inventors: Shoutarou Hashimoto, Tadashi Okita
  • Patent number: 9581989
    Abstract: A control device of a machine tool which filters possible continued machining time data estimated from a value of current of a motor to thereby enable an accurate grasp of the time regardless of fluctuation of the load, that is, a control device of a machine tool which has a motor which drives a spindle, which control device of a machine tool can use a value of current of the motor, an overheat temperature of the motor, and a temperature of the motor to estimate the time until reaching the overheat temperature when the current operating current continues to be run through the motor, filter the estimated value of time by a filter to display a possible continued processing time, change a filter time constant based on either of a value of current and current command value, and accurately display the possible continued processing time even if the load fluctuates.
    Type: Grant
    Filed: June 29, 2015
    Date of Patent: February 28, 2017
    Assignee: Fanuc Corporation
    Inventors: Geng Li, Tadashi Okita
  • Publication number: 20170028490
    Abstract: A controller for controlling a synchronized operation of spindle and feed axes. A spindle-axis control section includes an initial-motion control section for making a spindle axis perform an accelerated rotation at maximum capacity from a process start position; a maximum-acceleration detecting section for detecting a maximum acceleration of the spindle axis; a residual rotation-amount detecting section for detecting a residual rotation amount of the spindle axis; a current-speed detecting section for detecting a current speed of the spindle axis; a positioning-motion control section for making the spindle axis perform a decelerated rotation so as to reach the target thread depth after the accelerated rotation; and an overshoot detecting section for detecting an overshoot of the spindle axis during the decelerated rotation.
    Type: Application
    Filed: July 22, 2016
    Publication date: February 2, 2017
    Inventors: Yuuki MORITA, Tadashi OKITA, Daisuke TAJIMA
  • Patent number: 9557731
    Abstract: A control device (1) of a gear processing machine has a bus (51) that communicates by directly connecting between a tool axis controller (22) and a workpiece axis controller (12), and, in this control device, the position of a tool axis (40) that is detected by a tool axis position detection sensor (25) is supplied to a workpiece axis controller via a bus, an upper controller (10) supplies a predetermined synchronization ratio and a superimposition command for applying a twisting operation to a workpiece axis controller, and the workpiece axis controller adds a value that is generated by multiplying the position of the tool axis that is supplied via the bus, by the synchronization ratio, and the superimposition command, and generates a motion command for a workpiece axis (30).
    Type: Grant
    Filed: August 10, 2012
    Date of Patent: January 31, 2017
    Assignee: FANUC CORPORATION
    Inventors: Tadashi Okita, Yasusuke Iwashita
  • Publication number: 20160357171
    Abstract: A controller for controlling a synchronized operation of spindle and feed axes. A spindle-axis control section includes an initial-motion control section for making a spindle axis perform an accelerated rotation at maximum capacity from a process start position; a maximum-acceleration detecting section for detecting a maximum acceleration of the spindle axis; a residual rotation-amount detecting section for detecting a residual rotation amount of the spindle axis; a current-speed detecting section for detecting a current speed of the spindle axis; a decelerating-motion control section for making the spindle axis perform a decelerated rotation at a gradually increasing deceleration so as to reach an intermediate rotation speed after the accelerated rotation; and a positioning-motion control section for making the spindle axis perform a decelerated rotation at maximum capacity so as to reach the target thread depth after reaching the intermediate rotation speed.
    Type: Application
    Filed: June 3, 2016
    Publication date: December 8, 2016
    Inventors: Yuuki MORITA, Daisuke TAJIMA, Tadashi OKITA
  • Publication number: 20160315575
    Abstract: A motor control device includes a converter that converts AC power into DC power, a smoothing capacitor provided in a DC link, an inverter that converts the DC power in the DC link into AC power for a motor, a capacitor capacity measurement unit that measures a capacity of the smoothing capacitor, a data record unit that records a plurality of pieces of data composed of a measurement value of the capacity of the smoothing capacitor and a date or both a date and time when the measurement has been performed, a deterioration characteristic calculation unit that calculates a deterioration characteristic line indicating a change of the capacity of the smoothing capacitor with respect to elapsed time, on the basis of the recorded data, and a life prediction unit that predicts a period when a life of the smoothing capacitor ends, on the basis of the deterioration characteristic line.
    Type: Application
    Filed: March 23, 2016
    Publication date: October 27, 2016
    Applicant: FANUC CORPORATION
    Inventors: Kenta Yamamoto, Tadashi Okita
  • Publication number: 20160291580
    Abstract: A controller for controlling a synchronized operation of spindle and feed axes. A spindle-axis control section includes a section for making a spindle axis perform an accelerated rotation at maximum capacity from a process start position; sections for respectively detecting a maximum acceleration, a residual rotation amount and a current speed of the spindle axis; a section for making the spindle axis perform a decelerated rotation at maximum capacity to reach a target thread depth after the accelerated rotation; and a section for executing a torque-limiting during the accelerated rotation of the spindle axis, in such a manner that a torque command lower than a maximum torque command is given to the spindle axis at a start of acceleration, and thereafter the torque command is gradually increased so that the maximum torque command is given to the spindle axis when a predetermined time has elapsed.
    Type: Application
    Filed: March 29, 2016
    Publication date: October 6, 2016
    Applicant: FANUC CORPORATION
    Inventors: Yuuki Morita, Tadashi Okita
  • Patent number: 9377773
    Abstract: A motor controller is configured to judge whether or not the amount of displacement of a driven body after the direction of movement of the driven body is reversed, exceeds a predetermined threshold value, and whether or not the amount of displacement of a motor after the direction of movement of the motor is reversed, exceeds another predetermined threshold value. When the amount of displacement of the driven body exceeds the threshold value, or the amount of displacement of the motor exceeds a second threshold value, the correction of the commands to the motor is terminated.
    Type: Grant
    Filed: April 22, 2015
    Date of Patent: June 28, 2016
    Assignee: FANUC CORPORATION
    Inventors: Shoutarou Hashimoto, Tadashi Okita
  • Patent number: 9356550
    Abstract: A motor controller includes: a motor rotation angle acquisition unit acquiring the rotation angle of the motor; a main shaft rotation angle acquisition unit acquiring the rotation angle of the main shaft; a one-rotation signal acquisition unit acquiring a one-rotation signal output every time the main shaft rotates once; a motor rotation speed calculation unit calculating the rotation speed of the motor from the rotation angle of the motor; a main shaft speed calculation unit calculating the rotation speed of the main shaft from the rotation angle of the main shaft; and an abnormality determination unit in which, when a change amount of the rotation angle of the motor or when the difference between the rotation speed of the motor and the rotation speed of the main shaft deviates from a second range, it is determined that an abnormality has occurred in the power transmission unit.
    Type: Grant
    Filed: November 21, 2014
    Date of Patent: May 31, 2016
    Assignee: FANUC CORPORATION
    Inventors: Daisuke Tajima, Tadashi Okita
  • Publication number: 20160134227
    Abstract: A motor control device includes a load torque estimation unit configured to estimate a load torque applied to a motor, a torque comparison unit configured to compare the load torque with a reference torque, a time measurement unit configured to measure a time span during which the load torque is higher than the reference torque, a time comparison unit configured to compare the time span with a reference time, and a decision unit configured to decide that the motor is subjected to an excessive load when the time span exceeds the reference time.
    Type: Application
    Filed: November 4, 2015
    Publication date: May 12, 2016
    Inventors: Shoutarou Hashimoto, Tadashi Okita
  • Publication number: 20160116909
    Abstract: A machine tool controller including a numerical control section, a spindle-axis control section and a feed-axis control section. The spindle-axis control section includes a section for making the spindle axis perform an accelerated rotation at maximum capacity from a process start position toward a target thread depth, with a maximum rotation speed set as a target value; a section for detecting a maximum acceleration during the accelerated rotation based on a rotational position; a section for detecting a residual rotation amount from a current position to the target thread depth, based on a total rotation amount and the rotational position; a section for detecting a current speed based on the rotational position; and a section for making the spindle axis perform a decelerated rotation at maximum capacity to reach the target thread depth after the accelerated rotation, based on the maximum acceleration, the residual rotation amount and the current speed.
    Type: Application
    Filed: October 16, 2015
    Publication date: April 28, 2016
    Inventors: Yuuki MORITA, Tadashi OKITA
  • Publication number: 20160028331
    Abstract: A motor control device of the present invention is a control device for a motor for driving a feed shaft of a machine tool, and includes: a power outage detector for detecting a power outage of a power source for supplying power to drive the motor; a forcible decelerator for forcibly decelerating the motor in response to a torque command when a power outage is detected; a DC link voltage monitor for monitoring a DC link voltage applied to an amplifier for driving the motor; a determination unit for determining whether the value of the DC link voltage is greater than a first threshold, or whether the change ratio of the DC link voltage is greater than a second threshold; and, a torque command limiter for limiting the torque command to a predetermined torque command limiting value, in accordance with the result of determination at the determination unit.
    Type: Application
    Filed: July 20, 2015
    Publication date: January 28, 2016
    Inventors: Shoutarou Hashimoto, Tadashi Okita
  • Publication number: 20160008938
    Abstract: A control device of a machine tool which filters possible continued machining time data estimated from a value of current of a motor to thereby enable an accurate grasp of the time regardless of fluctuation of the load, that is, a control device of a machine tool which has a motor which drives a spindle, which control device of a machine tool can use a value of current of the motor, an overheat temperature of the motor, and a temperature of the motor to estimate the time until reaching the overheat temperature when the current operating current continues to be run through the motor, filter the estimated value of time by a filter to display a possible continued processing time, change a filter time constant based on either of a value of current and current command value, and accurately display the possible continued processing time even if the load fluctuates.
    Type: Application
    Filed: June 29, 2015
    Publication date: January 14, 2016
    Inventors: Geng Li, Tadashi Okita
  • Publication number: 20150355627
    Abstract: A motor control system which makes a tool motor and a workpiece motor rotate in synchronization in a machine tool equipped with a tool motor, a workpiece motor, and a tool shaft movement motor which drives a linear shaft to change an intershaft distance between the tool shaft and the workpiece shaft, wherein when the power outage detector detects a power outage of the power supply during synchronous rotation of the tool motor and the workpiece motor, the operation of the forced deceleration circuit for causing forced deceleration of either one of the tool motor and workpiece motor is made to be delayed by a predetermined time and during that time the tool shaft movement motor is used to drive the linear shaft and separate the tool and workpiece as a retraction operation to thereby prevent damage to the tool and the workpiece at the time of a power outage.
    Type: Application
    Filed: June 9, 2015
    Publication date: December 10, 2015
    Inventors: Shoutarou HASHIMOTO, Tadashi OKITA