Patents by Inventor Tomio SAKASHITA

Tomio SAKASHITA 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: 11052841
    Abstract: Heat radiation base body 23 that is adjacent to electric motor unit EM and extends in direction of rotation shaft of electric motor is provided close to rotation shaft of electric motor. Board 24 of one electronic control unit of redundant system is fixed to heat radiation base body along direction in which heat radiation base body 23 extends with thermal conduction to heat radiation base body 23 allowed. Board 26 of the other electronic control unit of redundant system is fixed to heat radiation base body so as to face to board 24 of one electronic control unit of redundant system, with thermal conduction to heat radiation base body 23 allowed. Rotation position detection circuit board 22 to which neutral terminals 31 of electric motor for each phase are connected is provided between heat radiation base body 23 and motor housing 20.
    Type: Grant
    Filed: February 16, 2017
    Date of Patent: July 6, 2021
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Masao Fujimoto, Keiji Hamada, Tomio Sakashita
  • Patent number: 10532764
    Abstract: A motor driving device is operable with low current consumption at low cost and can be started up without delay. The motor driving device includes inverter circuits, relay circuits, power supply stabilizing capacitors, pre-charge circuits, and a control unit. The inverter circuits individually drive coil sets of a motor. Each relay circuit is provided between a power supply and a corresponding one of the inverter circuits. Each capacitor is provided between a corresponding one of the relay circuits and a corresponding one of the inverter circuits. The pre-charge circuits, which are provided corresponding individually to the capacitors, each charge a corresponding one of the capacitors before the relay circuits are driven. The control unit controls the pre-charge circuits so that the pre-charge circuits charge the capacitors at mutually different timings or alternately when failure diagnosis is performed on the relay circuits.
    Type: Grant
    Filed: February 6, 2017
    Date of Patent: January 14, 2020
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventor: Tomio Sakashita
  • Patent number: 10348237
    Abstract: Disclosed is a motor driving device for driving a motor having coil sets that includes energization systems each including a drive circuit, the drive circuits being one-to-one connected to the coil sets; first semiconductor switches disposed in the energization systems in a one-to-one correspondence, each first semiconductor switch lying between a power supply and the corresponding one of the drive circuits; and a second semiconductor switch which connects the power supply and each of the first semiconductor switches in series. Each of the first semiconductor switches includes a parasitic diode of which a forward direction is from the corresponding drive circuit to the second semiconductor switch, and the second semiconductor switch includes a parasitic diode of which a forward direction is from the power supply to the first semiconductor switches.
    Type: Grant
    Filed: February 3, 2017
    Date of Patent: July 9, 2019
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventor: Tomio Sakashita
  • Publication number: 20190077441
    Abstract: A motor driving device is operable with low current consumption at low cost and can be started up without delay. The motor driving device includes inverter circuits, relay circuits, power supply stabilizing capacitors, pre-charge circuits, and a control unit. The inverter circuits individually drive coil sets of a motor. Each relay circuit is provided between a power supply and a corresponding one of the inverter circuits. Each capacitor is provided between a corresponding one of the relay circuits and a corresponding one of the inverter circuits. The pre-charge circuits, which are provided corresponding individually to the capacitors, each charge a corresponding one of the capacitors before the relay circuits are driven. The control unit controls the pre-charge circuits so that the pre-charge circuits charge the capacitors at mutually different timings or alternately when failure diagnosis is performed on the relay circuits.
    Type: Application
    Filed: February 6, 2017
    Publication date: March 14, 2019
    Inventor: Tomio SAKASHITA
  • Publication number: 20190052218
    Abstract: Disclosed is a motor driving device for driving a motor having coil sets that includes energization systems each including a drive circuit, the drive circuits being one-to-one connected to the coil sets; first semiconductor switches disposed in the energization systems in a one-to-one correspondence, each first semiconductor switch lying between a power supply and the corresponding one of the drive circuits; and a second semiconductor switch which connects the power supply and each of the first semiconductor switches in series. Each of the first semiconductor switches includes a parasitic diode of which a forward direction is from the corresponding drive circuit to the second semiconductor switch, and the second semiconductor switch includes a parasitic diode of which a forward direction is from the power supply to the first semiconductor switches.
    Type: Application
    Filed: February 3, 2017
    Publication date: February 14, 2019
    Inventor: Tomio SAKASHITA
  • Publication number: 20180178739
    Abstract: Heat radiation base body 23 that is adjacent to electric motor unit EM and extends in direction of rotation shaft of electric motor is provided close to rotation shaft of electric motor. Board 24 of one electronic control unit of redundant system is fixed to heat radiation base body along direction in which heat radiation base body 23 extends with thermal conduction to heat radiation base body 23 allowed. Board 26 of the other electronic control unit of redundant system is fixed to heat radiation base body so as to face to board 24 of one electronic control unit of redundant system, with thermal conduction to heat radiation base body 23 allowed. Rotation position detection circuit board 22 to which neutral terminals 31 of electric motor for each phase are connected is provided between heat radiation base body 23 and motor housing 20.
    Type: Application
    Filed: February 16, 2017
    Publication date: June 28, 2018
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Masao FUJIMOTO, Keiji HAMADA, Tomio SAKASHITA
  • Patent number: 9831814
    Abstract: An electric motor drive control device includes: an inverter circuit that converts DC power inputted via a DC bus to multiphase AC power and outputs the multiphase AC power to an electric motor; a current detector that detects a DC current flowing in the DC bus; a PWM generator that generates PWM signals and outputs the PWM signals to the inverter circuit; a current calculator that calculates a current value for each of phases to be flowed to the electric motor based upon a value of the DC current and the PWM signals; and a current controller that generates a command signal based upon the current value, and outputs the command signal to the PWM generator, wherein: if one of the phases of the AC power has become missing, the current calculator determines which phase is one that has become missing and calculates current values for other phases.
    Type: Grant
    Filed: August 21, 2015
    Date of Patent: November 28, 2017
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Toshiyuki Ajima, Mitsuo Sasaki, Shigehisa Aoyagi, Tomonobu Koseki, Tomio Sakashita
  • Publication number: 20160094180
    Abstract: An electric motor drive control device includes: an inverter circuit that converts DC power inputted via a DC bus to multiphase AC power and outputs the multiphase AC power to an electric motor; a current detector that detects a DC current flowing in the DC bus; a PWM generator that generates PWM signals and outputs the PWM signals to the inverter circuit; a current calculator that calculates a current value for each of phases to be flowed to the electric motor based upon a value of the DC current and the PWM signals; and a current controller that generates a command signal based upon the current value, and outputs the command signal to the PWM generator, wherein: if one of the phases of the AC power has become missing, the current calculator determines which phase is one that has become missing and calculates current values for other phases.
    Type: Application
    Filed: August 21, 2015
    Publication date: March 31, 2016
    Inventors: Toshiyuki AJIMA, Mitsuo SASAKI, Shigehisa AOYAGI, Tomonobu KOSEKI, Tomio SAKASHITA
  • Patent number: 9143075
    Abstract: The present invention provides a motor drive control device provided with a shutoff circuit employing semiconductor relays and configured to drive a motor by a duty ratio control of an inverter, which stably drives the motor even in an operation state that drive duty ratio of phases are uneven. In the motor drive control device, output lines of three phases of the inverter circuit are connected to phases of the motor and further connected to a booster circuit, an output boosted by the booster circuit at a time of drive of the motor is distributed to semiconductor relays connected to respective phases of the motor, and furthermore, a switching circuit for stopping actuation of the booster circuit to shut off drive of the motor, is interposed in a line for supplying an electric power to the booster circuit.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: September 22, 2015
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Tomio Sakashita, Hiroshi Aoyagi
  • Publication number: 20140265965
    Abstract: The present invention provides a motor drive control device provided with a shutoff circuit employing semiconductor relays and configured to drive a motor by a duty ratio control of an inverter, which stably drives the motor even in an operation state that drive duty ratio of phases are uneven. In the motor drive control device, output lines of three phases of the inverter circuit are connected to phases of the motor and further connected to a booster circuit, an output boosted by the booster circuit at a time of drive of the motor is distributed to semiconductor relays connected to respective phases of the motor, and furthermore, a switching circuit for stopping actuation of the booster circuit to shut off drive of the motor, is interposed in a line for supplying an electric power to the booster circuit.
    Type: Application
    Filed: September 26, 2013
    Publication date: September 18, 2014
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Tomio SAKASHITA, Hiroshi Aoyagi
  • Publication number: 20130314013
    Abstract: In related art technique, an average neutral point voltage is detected via a low-pass filter. Time constant of the low-pass filter must be set to cover the entire output frequency band of an inverter and voltage fluctuation due to modulated signal must be separated from that due to a short circuit to ground. According to the present invention, whether abnormality such as a short circuit to ground or to supply occurs in output lines can be determined based on an actual neutral point voltage of a motor, which changes in a stepwise fashion in conformity to a PWM pulse pattern output by an inverter device, and a normal neutral point voltage which depends on a PWM pattern output by the inverter device. Highly reliable abnormality detection in accordance with the waveform of the neutral point voltage and stable abnormality detection not depending on the inverter output frequency are feasible.
    Type: Application
    Filed: May 23, 2013
    Publication date: November 28, 2013
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Toshiyuki AJIMA, Takuro KANAZAWA, Hiroshi AOYAGI, Yawara KATO, Tomio SAKASHITA, Atsushi YOSHITAKE