Patents by Inventor Narutoshi Yokokawa

Narutoshi Yokokawa 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: 20150357822
    Abstract: An inverter electric generator system is comprised of: master and at least one slave inverter generators, each inverter generator including a communication section, a controller section generating a PWM carrier and an inverter circuit switched by the PWM carrier to generate an alternative current with a controlled voltage and a controlled frequency, the communication sections being mutually connected to exchange a communication data, and the inverter circuits being connected in parallel so as to collect and output the alternative currents as an electric power output, wherein each of the controller sections is configured to synchronize any point of the PWM carrier with any bit of the communication data received by the communication section. The PWM carriers of the master and the slave inverter generators thereby mutually get synchronized.
    Type: Application
    Filed: June 3, 2015
    Publication date: December 10, 2015
    Inventors: Narutoshi YOKOKAWA, Kazumi MURATA, Junichi KANAI, Naoyuki MASHIMA
  • Patent number: 9054622
    Abstract: The present invention is a control device of a motor, for drawing out a capacity of the motor as much as possible so as to achieve a high-speed high-output performance thereof while securing a stability, including: a converter unit configured to rectify and smooth an AC voltage, and to output a DC main circuit voltage; an inverter unit configured to pass a current for driving the motor, with the use of the main circuit voltage; a current detector configured to detect an armature current passing through the motor; a position detector disposed on the motor, the position detector being configured to detect a motor speed; and a current control unit configured to control, upon reception of a q-axis current command (Iqr), the armature current passing through the motor, by outputting a signal for driving the inverter unit, with the use of data from the current detector and data from the position detector.
    Type: Grant
    Filed: November 9, 2010
    Date of Patent: June 9, 2015
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Narutoshi Yokokawa
  • Patent number: 8916982
    Abstract: An inverter generator used in combination with a motor and an ECU generating a pulse at each predetermined rotation angle of the motor is comprised of: an electric generator driven by the motor configured to generate alternating current electric power; estimating means for estimating an electrical angle of alternating voltage of the alternating current electric power from the pulse, the estimating means being electrically connected with the ECU; a converter configured to convert the alternating current electric power into direct current electric power, the converter electrically connected with the electric generator and the estimating means; and an inverter configured to convert the direct current electric power into alternating current output electric power, the inverter electrically connected with the converter.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: December 23, 2014
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Junichi Kanai, Naoyuki Mashima
  • Publication number: 20140328092
    Abstract: An inverter device includes a voltage command value output unit that outputs a voltage command value, voltage sensors that detect output voltage from a switching circuit, a Fourier transform unit that performs frequency analysis on the output voltage detected by the respective voltage sensors, and a voltage correction value calculation unit that obtains harmonics with respect to a drive frequency of the switching circuit subjected to the frequency analysis by the Fourier transform unit and obtains a voltage correction coefficients for correcting the voltage command value so as to cancel the harmonics. The voltage correction value calculation unit calculates coefficients each for each degree of the harmonics and determines whether the coefficients converges when calculating the coefficients so as to obtain the voltage correction coefficients based on the coefficients which are determined to converge.
    Type: Application
    Filed: April 28, 2014
    Publication date: November 6, 2014
    Applicant: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi YOKOKAWA, Tomoyuki HOSHIKAWA, Kazumi MURATA, Masayuki WATANABE, Junichi KANAI, Naoyuki MASHIMA
  • Patent number: 8803345
    Abstract: An inverter generator includes a motor, an electric generator and an ECU generating a pulse at each predetermined rotation angle of the motor. Estimating means estimates an initial electrical angle of alternating voltage produced by the generator from the pulse and calculates a phase shift angle to estimate continuous electrical angle of the alternating voltage. A converter converts the alternating current electric power into direct current electric power under d-q control based on the phase shift angle. An inverter converts the direct current electric power into alternating current output electric power.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: August 12, 2014
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Junichi Kanai, Naoyuki Mashima
  • Patent number: 8786225
    Abstract: An inverter power generator includes a current controller 14a setting a current limit ratio according to a rotation speed of a synchronous motor 13 and controls a converter current according to the current limit ratio. The current controller sets the current limit ratio to 70% if the synchronous motor is at a rotational speed equal to an idle speed of an engine 11. Until the rotational speed of the synchronous motor reaches a rated speed, the output current limiter linearly increases the current limit ratio up to 100%. With this, the rotational speed of the engine becomes reasonably increasable even if a sudden load increase occurs when the engine is operating at low speed.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: July 22, 2014
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Tomoyuki Hoshikawa, Kazumi Murata, Junichi Kanai, Naoyuki Mashima
  • Patent number: 8624533
    Abstract: An inverter includes a voltage command generator generating a voltage command value according to an externally specified voltage value, a PWM signal generator generating a PWM signal according to the voltage command value and frequency command value, and a switching unit generating a three-phase AC power according to the PWM signal. The voltage command generator decreases the voltage command value if the output current increases, to prevent the rotation speed of a prime move from suddenly changing. If the output current exceeds a preset upper current threshold, the voltage command value is clamped at a preset minimum output voltage, thereby securing the minimum output voltage for an increase in the output current.
    Type: Grant
    Filed: March 9, 2012
    Date of Patent: January 7, 2014
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Tomoyuki Hoshikawa, Kazumi Murata, Junichi Kanai, Naoyuki Mashima
  • Publication number: 20130221879
    Abstract: The present invention is a control device of a motor, for drawing out a capacity of the motor as much as possible so as to achieve a high-speed high-output performance thereof while securing a stability, including: a converter unit configured to rectify and smooth an AC voltage, and to output a DC main circuit voltage; an inverter unit configured to pass a current for driving the motor, with the use of the main circuit voltage; a current detector configured to detect an armature current passing through the motor; a position detector disposed on the motor, the position detector being configured to detect a motor speed; and a current control unit configured to control, upon reception of a q-axis current command (Iqr), the armature current passing through the motor, by outputting a signal for driving the inverter unit, with the use of data from the current detector and data from the position detector.
    Type: Application
    Filed: November 9, 2010
    Publication date: August 29, 2013
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventor: Narutoshi Yokokawa
  • Patent number: 8468187
    Abstract: A digital filter device capable of removing the effect of noise such as chattering from a zero crossing signal is provided. A digital filter device 4 filtering a binary digital signal DIN and outputting a binary digital signal DOUT is provided with a toggle flip-flop 12 which switches a signal level of the digital signal DOUT each time a trigger signal is input; an XOR circuit 13 which outputs a first enable signal EN1 while a signal level of the digital signal DIN does not match with the signal level of the output digital signal DOUT; and a charge counter 14 which counts in synchronization with a clock signal CLK while the first enable signal EN1 is input and resets the count to an initial value and outputs a carry on signal ON_RCO as the trigger signal to the toggle flip-flop 12 when the count has reached an upper limit value.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: June 18, 2013
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Shouichi Sato
  • Publication number: 20120229065
    Abstract: An inverter includes a voltage command generator generating a voltage command value according to an externally specified voltage value, a PWM signal generator generating a PWM signal according to the voltage command value and frequency command value, and a switching unit generating a three-phase AC power according to the PWM signal. The voltage command generator decreases the voltage command value if the output current increases, to prevent the rotation speed of a prime move from suddenly changing. If the output current exceeds a preset upper current threshold, the voltage command value is clamped at a preset minimum output voltage, thereby securing the minimum output voltage for an increase in the output current.
    Type: Application
    Filed: March 9, 2012
    Publication date: September 13, 2012
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventors: Narutoshi YOKOKAWA, Tomoyuki Hoshikawa, Kazumi Murata, Junichi Kanai, Naoyuki Mashima
  • Publication number: 20120229063
    Abstract: An inverter power generator includes a current controller 14a setting a current limit ratio according to a rotation speed of a synchronous motor 13 and controls a converter current according to the current limit ratio. The current controller sets the current limit ratio to 70% if the synchronous motor is at a rotational speed equal to an idle speed of an engine 11. Until the rotational speed of the synchronous motor reaches a rated speed, the output current limiter linearly increases the current limit ratio up to 100%. With this, the rotational speed of the engine becomes reasonably increasable even if a sudden load increase occurs when the engine is operating at low speed.
    Type: Application
    Filed: March 9, 2012
    Publication date: September 13, 2012
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventors: Narutoshi Yokokawa, Tomoyuki Hoshikawa, Kazumi Murata, Junichi Kanai, Naoyuki Mashima
  • Publication number: 20120139239
    Abstract: An inverter generator includes a motor, an electric generator and an ECU generating a pulse at each predetermined rotation angle of the motor. Estimating means estimates an initial electrical angle of alternating voltage produced by the generator from the pulse and calculates a phase shift angle to estimate continuous electrical angle of the alternating voltage. A converter converts the alternating current electric power into direct current electric power under d-q control based on the phase shift angle. An inverter converts the direct current electric power into alternating current output electric power.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 7, 2012
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventors: Narutoshi YOKOKAWA, Junichi Kanai, Naoyuki Mashima
  • Publication number: 20120139265
    Abstract: An inverter generator used in combination with a motor and an ECU generating a pulse at each predetermined rotation angle of the motor is comprised of: an electric generator driven by the motor configured to generate alternating current electric power; estimating means for estimating an electrical angle of alternating voltage of the alternating current electric power from the pulse, the estimating means being electrically connected with the ECU; a converter configured to convert the alternating current electric power into direct current electric power, the converter electrically connected with the electric generator and the estimating means; and an inverter configured to convert the direct current electric power into alternating current output electric power, the inverter electrically connected with the converter.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 7, 2012
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventors: Narutoshi YOKOKAWA, Junichi Kanai, Naoyuki Mashima
  • Patent number: 8091589
    Abstract: A loom (1) has feed motor (27) rotating a warp beam (3) in a direction to feeding warps (V) from the warp beam (3), a heddles (10) opening and closing the warps (V) fed off from the warp beam (3), a reed (13) beating wefts (H) inserted into the openings of the warps (V) by a weft inserting device (11), a surface motor (61) rotating a surface roller (17) to pull in the woven fabric (W), which has been beaten by the reed (13) and formed of the warps (V) and the wefts (H), in the pulling direction, a position detector (35) detecting the tension of the warps (V), and a control device 25 having an adaptive filter unit (83) filtering the tension detected by the position detector (35), and controlling the feed motor (27) and the surface motor (61) on the basis of the tension filtered by that adaptive filter unit (83) so that the tension of the warps (V) to a predetermined target tension.
    Type: Grant
    Filed: September 1, 2008
    Date of Patent: January 10, 2012
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Narutoshi Yokokawa
  • Patent number: 7895010
    Abstract: A resolver apparatus having a high detection precision detecting angle signals from signals detected at a resolver (7) and detecting a velocity signal from the detected angle signals. Utilizing the fact that an error waveform of a resolver is comprised of predetermined n-th order components inherent to the resolver and has reproducibility, an angle error estimator (13) applies a frequency transform, for example, a Fourier transform, to high frequency components of velocity signal including error generated from detected angle signals including error to calculate a magnitude of error for each of a plurality of divided components and combining the calculated errors to reproduce the detected error and generate an error waveform signal. An angle signal correction circuit (14) uses this error waveform signal to correct an angle signal including error detected at the resolver.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: February 22, 2011
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Narutoshi Yokokawa
  • Publication number: 20110000576
    Abstract: A loom (1) has feed motor (27) rotating a warp beam (3) in a direction to feeding warps (V) from the warp beam (3), a heddles (10) opening and closing the warps (V) fed off from the warp beam (3), a reed (13) beating wefts (H) inserted into the openings of the warps (V) by a weft inserting device (11), a surface motor (61) rotating a surface roller (17) to pull in the woven fabric (W), which has been beaten by the reed (13) and formed of the warps (V) and the wefts (H), in the pulling direction, a position detector (35) detecting the tension of the warps (V), and a control device 25 having an adaptive filter unit (83) filtering the tension detected by the position detector (35), and controlling the feed motor (27) and the surface motor (61) on the basis of the tension filtered by that adaptive filter unit (83) so that the tension of the warps (V) to a predetermined target tension.
    Type: Application
    Filed: September 1, 2008
    Publication date: January 6, 2011
    Applicant: TOSHIBA KIKAI KABUSHIKI KAISHA
    Inventor: Narutoshi Yokokawa
  • Publication number: 20090313313
    Abstract: A digital filter device capable of removing the effect of noise such as chattering from a zero crossing signal is provided. A digital filter device 4 filtering a binary digital signal DIN and outputting a binary digital signal DOUT is provided with a toggle flip-flop 12 which switches a signal level of the digital signal DOUT each time a trigger signal is input; an XOR circuit 13 which outputs a first enable signal EN1 while a signal level of the digital signal DIN does not match with the signal level of the output digital signal DOUT; and a charge counter 14 which counts in synchronization with a clock signal CLK while the first enable signal EN1 is input and resets the count to an initial value and outputs a carry on signal ON_RCO as the trigger signal to the toggle flip-flop 12 when the count has reached an upper limit value.
    Type: Application
    Filed: June 14, 2007
    Publication date: December 17, 2009
    Applicant: Toshiba Kikai Kabushiki Kaisha
    Inventors: Narutoshi Yokokawa, Shouichi Sato
  • Publication number: 20090167296
    Abstract: A resolver apparatus having a high detection precision detecting angle signals from signals detected at a resolver (7) and detecting a velocity signal from the detected angle signals. Utilizing the fact that an error waveform of a resolver is comprised of predetermined n-th order components inherent to the resolver and has reproducibility, an angle error estimator (13) applies a frequency transform, for example, a Fourier transform, to high frequency components of velocity signal including error generated from detected angle signals including error to calculate a magnitude of error for each of a plurality of divided components and combining the calculated errors to reproduce the detected error and generate an error waveform signal. An angle signal correction circuit (14) uses this error waveform signal to correct an angle signal including error detected at the resolver.
    Type: Application
    Filed: December 22, 2008
    Publication date: July 2, 2009
    Inventor: NARUTOSHI YOKOKAWA