Patents by Inventor Toshihiro Sawa

Toshihiro Sawa 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).

  • Patent number: 7848832
    Abstract: To be able to restrain a height of a machine even when the machine is large-sized and smoothly move a table in XY? directions. An alignment apparatus includes two translational freedom degree guide portion (13), one rotational freedom degree guide portion (12), a translational drive/translational/rotational freedom degree mechanism module (6) including a linear motor provided at one of the translational freedom degree guide portion (13), a machine base portion (7), a reference generator portion (8), a two-dimensional position sensor (9), a calculating portion of compensation value (10). At least three of the translational drive/translational/rotational freedom degree mechanism modules (6) are uniformly arranged to a table (4).
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: December 7, 2010
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Takehiko Komiya, Toshiyuki Osuga, Toshihiro Sawa
  • Patent number: 7348749
    Abstract: A control device is provided for a synchronous motor, which drives the synchronous motor through a voltage operated PWM inverter and controls a torque and a speed of the motor, including a unit for causing a PWM carrier signal to have an arbitrary phase difference between two phases such UV, VW, or WU in three phases of U, V, and W, a unit for extracting a high frequency voltage and a high frequency current, which are thus generated from a detecting voltage or a command voltage and a detecting current, and a unit for estimating a position of a magnetic flux or position of a magnetic pole by using the high frequency voltage and the high frequency current which are excited.
    Type: Grant
    Filed: August 25, 2003
    Date of Patent: March 25, 2008
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Kozo Ide, Mitsujiro Sawamura, Toshihiro Sawa, Jun Oyama
  • Publication number: 20080019817
    Abstract: To be able to restrain a height of a machine even when the machine is large-sized and smoothly move a table in XY? directions. An alignment apparatus includes two translational freedom degree guide portion (13), one rotational freedom degree guide portion (12), a translational drive/translational/rotational freedom degree mechanism module (6) including a linear motor provided at one of the translational freedom degree guide portion (13), a machine base portion (7), a reference generator portion (8), a two-dimensional position sensor (9), a calculating portion of compensation value (10). At least three of the translational drive/translational/rotational freedom degree mechanism modules (6) are uniformly arranged to a table (4).
    Type: Application
    Filed: November 7, 2005
    Publication date: January 24, 2008
    Applicant: Kabushiki Kaisha Yaskawa Denki
    Inventors: Takehiko Komiya, Toshiyuki Osuga, Toshihiro Sawa
  • Publication number: 20070069682
    Abstract: It is an object of the invention to provide a control device for a synchronous motor which can detect the position of a magnetic pole from a zero speed without requiring a signal generator. The invention provides a control device for a synchronous motor which drives the synchronous motor through a voltage-operated PWM inverter and controls a torque and a speed of the motor, including means (6-3) for causing a PWM carrier signal to have an arbitrary phase difference between two phases such as UW, VW or WU in three phases of U, V and W, means (11) for extracting a high frequency voltage and a high frequency current which are thus generated from a detecting voltage or a command voltage and a detecting current, and means (12) for estimating a position of a magnetic flux or a position of a magnetic pole by using the high frequency voltage and the high frequency current which are extracted.
    Type: Application
    Filed: August 25, 2003
    Publication date: March 29, 2007
    Inventors: Kozo Ide, Mitsujiro Sawamura, Toshihiro Sawa, Jun Oyama
  • Patent number: 6351397
    Abstract: A protection apparatus and a protection method of a PWM cycloconverter wherein when the PWM cycloconverter is shut off, a surge voltage or an overcurrent is not produced on the output side are provided. A protection apparatus of a PWM cycloconverter is made up of fault detection means 30 for detecting a fault of the PWM cycloconverter, operation stop means 25 for turning off at least some of the uni-directional semiconductor switches 3 to 20 of the PWM cycloconverter if a fault signal occurs, continuous flow means for allowing a load current of the PWM cycloconverter to continuously flow if at least some output phases of the PWM cycloconverter become open, and protection switching means 50 for turning on and off the unidirectional semiconductor switches of the PWM cycloconverter based on the fault signal output from the fault detection means.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: February 26, 2002
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Toshihiro Sawa, Xiaorong Xia, Sadao Ishii, Eiji Yamamoto, Hidenori Hara
  • Patent number: 6058032
    Abstract: A multiple pulse-width modulation power conversion device for variable-speed drive of a three-phase AC motor comprises three units (11.sub.1, 11.sub.2, and 11.sub.3), each unit including n (n.gtoreq.2) batteries (12.sub.11, 12.sub.12, and 12.sub.13), each made up of a DC power supply or at least one battery cell, and n power converters (13.sub.11, 13.sub.12, and 13.sub.13) for converting the DC power of each of these batteries to single-phase AC power. Single-phase AC terminals within each unit are connected in series, and of the single-phase AC terminals within each unit, one of the single-phase AC terminals that is not connected to the single-phase AC terminal of another power converter is connected to a star connection, and the other is connected to a respective one of three input terminals of a three-phase AC motor. The power conversion device further comprises control circuits (14.sub.11, 14.sub.12, . . . , 14.sub.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: May 2, 2000
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Katsutoshi Yamanaka, Toshihiro Sawa, Eijiro Tajima
  • Patent number: 5969966
    Abstract: A power converting apparatus and a power converting method for driving a high voltage AC motor at a variable speed. Conventional invertor systems cannot solve technical subjects such as energy conservation, resource conservation, miniaturization, efficiency promotion and voltage and current waveform distortion suppression for improvement in environment needed by the market, and cannot solve another technical subject of improvement in redundancy such that, upon failure, operation is performed with a normal part.
    Type: Grant
    Filed: March 9, 1998
    Date of Patent: October 19, 1999
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Toshihiro Sawa, Tsuneo Kume, Koichi Hirano
  • Patent number: 5835371
    Abstract: A bridge-type power converter has, in each phase, a inductor (L.sub.1) connected between a connection point of said two switching elements (Q.sub.1, Q.sub.2) and an output terminal; capacitors (C.sub.1, C.sub.2) connected between the output terminal and a positive or negative side of a d.c. bus for changing an output voltage along a curve determined by a phenomenon of resonance with the reactor (L.sub.1) when the semiconductors switching elements (Q.sub.1, Q.sub.2) operate, causing abrupt changes of a voltage at the connection point; diodes (D.sub.3, D.sub.4) for changing a current path at a time when the resonance goes approximately one quarter of period to thereby stop the resonance; and constant voltage diodes (ZD.sub.1, ZD.sub.2) for absorbing the energy stored in the inductor (L.sub.1) during the resonance.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: November 10, 1998
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Tsuneo Kume, Toshihiro Sawa, Sumitoshi Sonoda, Kenji Yamada
  • Patent number: 5801509
    Abstract: An angular position detector for generating trains of A- and B-phase pulses which are 90.degree. out of phase with each other and a C-phase pulse per rotation are mounted on a permanent-magnet synchronous motor such that a magnetic pole origin of permanent magnets and a position where the C-phase pulse is generated agree with each other. After a power supply voltage is applied and in an initial stage before the permanent-magnet synchronous motor is operated normally, a motor control apparatus operates a current control loop with an alternating current command having a constant amplitude and a low frequency to supply an alternating current having a low frequency to the permanent-magnet synchronous motor for thereby rotating the rotor of the permanent-magnet synchronous motor from a stop at a low speed.
    Type: Grant
    Filed: September 27, 1996
    Date of Patent: September 1, 1998
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Toshihiro Sawa, Sumitoshi Sonoda, Syuuichi Fujii, Eiji Yamamoto
  • Patent number: 4916376
    Abstract: An inverter driving method for has an arrangement polyphase induction motor, for altering a plurality of winding connections of the motor and a storage arrangement for a plurality of motor control constant groups preset corresponding to the respective winding connections so as to perform optimal vector control. When the classification of the winding connection is selected, one set of motor control constant groups corresponding to the winding connection is read out of the storage arrangement and applied to a control unit of the induction motor as control constants.
    Type: Grant
    Filed: June 24, 1988
    Date of Patent: April 10, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Tuneo Kume, Toshihiro Sawa, Masanobu Miyazato, Mitsujiro Sawamura, Michihiko Zenke