Patents by Inventor Tomokazu Sakashita

Tomokazu 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).

  • Publication number: 20210143680
    Abstract: A first converter performs power conversion and outputs AC power. The AC power outputted from the first converter is supplied to a first coil. The first coil is magnetically coupled with a second coil, and the AC power is transmitted from the first coil to the second coil. A second converter is connected to the second coil, and converts the AC power transmitted to the second coil to DC power and supplies the DC power to a load. A first control unit controls the first converter so as to alternately switch between a first state of outputting rectangular wave voltage which cyclically changes and a second state of outputting constant reference voltage, on the basis of required power of the load.
    Type: Application
    Filed: July 5, 2019
    Publication date: May 13, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takuya NAKANISHI, Tomokazu SAKASHITA
  • Patent number: 10907606
    Abstract: An ignition device according to the present invention includes: an ignition plug, which includes a first electrode, a second electrode, and a dielectric body arranged between the electrodes; an AC power supply configured to generate an AC voltage to be applied between the electrodes; a thermal plasma detection portion configured to output a thermal plasma occurrence signal when thermal plasma has occurred between the electrodes; and an application time period determination portion configured to determine an application time period for the AC voltage during one cycle of the internal combustion engine in advance before the application, and when the thermal plasma occurrence signal is received while the AC voltage is being applied based on the application time period, change the application time period so as to shorten the application time period.
    Type: Grant
    Filed: May 24, 2018
    Date of Patent: February 2, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takahiro Inoue, Taichiro Tamida, Ryota Asakura, Tomokazu Sakashita, Takashi Hashimoto
  • Publication number: 20200280184
    Abstract: A power controller includes: a plurality of switching elements provided in one-to-one correspondence with a plurality of power supplies, and each of which switches on or off to switch between supplying and stopping supplying a load with electric power from a corresponding one of the plurality of power supplies; a processing unit which computes an operation amount for adjusting an amount of the electric power supplied to the load; and a signal generator which determines, for each control, a switching-element count indicating a total number of switching elements to be turned on among the plurality of switching elements, and a duty ratio of the switching-element count, based on the operation amount, and generates a drive signal for driving the plurality of switching elements successively, based on the switching-element count and the duty ratio.
    Type: Application
    Filed: February 26, 2016
    Publication date: September 3, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Satoshi OJIKA, Tomokazu SAKASHITA, Toshio OKAMURA, Shinichiro OIKAWA
  • Publication number: 20200271084
    Abstract: An ignition device according to the present invention includes: an ignition plug, which includes a first electrode, a second electrode, and a dielectric body arranged between the electrodes; an AC power supply configured to generate an AC voltage to be applied between the electrodes; a thermal plasma detection portion configured to output a thermal plasma occurrence signal when thermal plasma has occurred between the electrodes; and an application time period determination portion configured to determine an application time period for the AC voltage during one cycle of the internal combustion engine in advance before the application, and when the thermal plasma occurrence signal is received while the AC voltage is being applied based on the application time period, change the application time period so as to shorten the application time period.
    Type: Application
    Filed: May 24, 2018
    Publication date: August 27, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takahiro INOUE, Taichiro TAMIDA, Ryota ASAKURA, Tomokazu SAKASHITA, Takashi HASHIMOTO
  • Publication number: 20200274440
    Abstract: In order to provide a power conversion device capable of estimating a load voltage with high accuracy without directly detecting the load voltage to be applied to a load, a control circuit is provided, which includes a means for estimating the load voltage to be applied to the load based on an electric current of a resonant circuit, an AC frequency of an inverter and an electrostatic capacitance of the load, or a means for estimating the load voltage based on the electric current of the resonant circuit, the AC frequency of the inverter, an inductance of a resonant coil and a correction coefficient previously set from a relationship between a voltage of the resonant coil and the load voltage, and which controls an output to a target load voltage based on the estimated load voltage.
    Type: Application
    Filed: April 2, 2018
    Publication date: August 27, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota ASAKURA, Tomokazu SAKASHITA, Takahiro INOUE
  • Publication number: 20200274399
    Abstract: A power conversion device comprises an inner coil which can transmit power between an external coil by coupling magnetically with the external coil, an inverter whose AC side is connected to the inner coil and power conversion can be performed between the AC side and a DC side and a bidirectional DC/DC converter which comprises an intermediate capacitor, is connected to the DC side of the inverter and can perform power conversion bidirectionally between a DC power source, which is connected to a side which is opposite to the side of the inverter, and the inverter, wherein in switching operation from power reception to power transmission where power reception operation is switched to power transmission operation, after control of discharging charges which are accumulated in the intermediate capacitor is performed, the power transmission operation is started.
    Type: Application
    Filed: December 15, 2017
    Publication date: August 27, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takuya YABUMOTO, Tomokazu SAKASHITA
  • Patent number: 10622906
    Abstract: A power conversion apparatus (10) includes a plurality of power conversion units (12) each having a function of converting an input direct current voltage to a different direct current voltage, and a control unit (15) that controls the plurality of power conversion units (12) in accordance with a target value Vaim for the sum of voltages output from the plurality of power conversion units (12). When making one or more of the power conversion units (12) output a first voltage which is fixed and making a different one of the power conversion units (12) output a second voltage which is adjusted in accordance with the target value Vaim, the control unit (15) repeatedly switches a power conversion unit (12) to output the second voltage at least between two of the power conversion units (12).
    Type: Grant
    Filed: December 19, 2016
    Date of Patent: April 14, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hiroyuki Osuga, Takayuki Hidaka, Takashi Miyamoto, Tomokazu Sakashita, Satoshi Ojika
  • Patent number: 10522978
    Abstract: In an ignition plug, since a ground electrode is formed in a thin-rod-shape or a mesh-like shape, sufficiently strong radicals are locally generated by a barrier discharge, an anti-inflammation effect by the electrode is small, and the growth of a flame is hardly hindered. Furthermore, by making the thickness dimension of a second dielectric facing a discharge region uniform, the barrier discharge is spread over the surface of the second dielectric, the generation of the radicals is maintained, and combustibility after ignition is promoted. Furthermore, because an end portion of a high voltage electrode and a ground electrode are disposed to face each other within a combustion chamber, a fuel gas introduced into the combustion chamber is liable to flow into the discharge region, and is easily ignited by the radicals generated due to the discharge.
    Type: Grant
    Filed: October 7, 2016
    Date of Patent: December 31, 2019
    Assignees: Mitsubishi Electric Corporation, NGK SPARK PLUG CO., LTD.
    Inventors: Taichiro Tamida, Takahiro Inoue, Takashi Hashimoto, Akira Nakagawa, Tomokazu Sakashita, Takayoshi Nagai, Kimihiko Tanaya, Hiroyuki Kameda, Yuichi Yamada, Kenji Ban
  • Patent number: 10516337
    Abstract: A DC voltage conversion circuit in which the miniaturization of the inductor is attained and the frequency of control band can be widened, by suppressing the ripple current which flows into the inductor using a general magnetic core without using a special multi-leg magnetic core. A DC voltage conversion circuit is provided with two sets of magnetic flux cancellation conversion circuits each of which is provided with two sets of series circuits of two semiconductor circuits, a first magnetic flux cancellation type transformer, and a inductor; a second magnetic flux cancellation type transformer connected to the two sets of magnetic flux cancellation conversion circuits; and a control circuit which controls switching devices of semiconductor circuits.
    Type: Grant
    Filed: April 13, 2017
    Date of Patent: December 24, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Satoshi Ojika, Tomokazu Sakashita, Satoshi Shintaku
  • Publication number: 20190348918
    Abstract: A DC voltage conversion circuit in which the miniaturization of the inductor is attained and the frequency of control band can be widened, by suppressing the ripple current which flows into the inductor using a general magnetic core without using a special multi-leg magnetic core. A DC voltage conversion circuit is provided with two sets of magnetic flux cancellation conversion circuits each of which is provided with two sets of series circuits of two semiconductor circuits, a first magnetic flux cancellation type transformer, and a inductor; a second magnetic flux cancellation type transformer connected to the two sets of magnetic flux cancellation conversion circuits; and a control circuit which controls switching devices of semiconductor circuits.
    Type: Application
    Filed: April 13, 2017
    Publication date: November 14, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Satoshi OJIKA, Tomokazu SAKASHITA, Satoshi SHINTAKU
  • Patent number: 10436127
    Abstract: A change amount per unit time of an engine output command for controlling engine output of an internal combustion engine is calculated as an engine output increasing rate, and a power supply device is controlled so that power corresponding to the calculated engine output increasing rate is supplied to a combustion promoter generation device. The combustion promoter generation device generates a combustion promoter through the power supplied from the power supply device to supply the combustion promoter to a combustion chamber of the internal combustion engine, and a generation amount of the combustion promoter increases as the supplied power increases. In this manner, the generation amount of the combustion promoter is adjusted.
    Type: Grant
    Filed: December 3, 2015
    Date of Patent: October 8, 2019
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takahiro Inoue, Taichiro Tamida, Takashi Hashimoto, Noboru Wada, Akira Nakagawa, Tomokazu Sakashita, Tetsuya Honda
  • Publication number: 20190288605
    Abstract: A power conversion apparatus (10) includes a plurality of power conversion units (12) each having a function of converting an input direct current voltage to a different direct current voltage, and a control unit (15) that controls the plurality of power conversion units (12) in accordance with a target value Vaim for the sum of voltages output from the plurality of power conversion units (12). When making one or more of the power conversion units (12) output a first voltage which is fixed and making a different one of the power conversion units (12) output a second voltage which is adjusted in accordance with the target value Vaim, the control unit (15) repeatedly switches a power conversion unit (12) to output the second voltage at least between two of the power conversion units (12).
    Type: Application
    Filed: December 19, 2016
    Publication date: September 19, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hiroyuki OSUGA, Takayuki HIDAKA, Takashi MIYAMOTO, Tomokazu SAKASHITA, Satoshi OJIKA
  • Publication number: 20190186454
    Abstract: A barrier-discharge-type ignition apparatus that can accurately determine the application voltage, of a barrier ignition plug, that causes a non-ignition discharge to occur. In the barrier-discharge-type ignition apparatus, in a combustion assist control, the voltage difference between the one-period-prior application voltage and the present-period application voltage in the AC period is calculated based on an application voltage detected by a voltage detection circuit; then, it is determined whether or not a discharge exists in the barrier ignition plug, based on the comparison between the voltage difference and a preliminarily set discharge determination threshold value.
    Type: Application
    Filed: February 28, 2017
    Publication date: June 20, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryota ASAKURA, Tomokazu SAKASHITA, Takahiro INOUE
  • Publication number: 20190078520
    Abstract: A change amount per unit time of an engine output command for controlling engine output of an internal combustion engine is calculated as an engine output increasing rate, and a power supply device is controlled so that power corresponding to the calculated engine output increasing rate is supplied to a combustion promoter generation device. The combustion promoter generation device generates a combustion promoter through the power supplied from the power supply device to supply the combustion promoter to a combustion chamber of the internal combustion engine, and a generation amount of the combustion promoter increases as the supplied power increases. In this manner, the generation amount of the combustion promoter is adjusted.
    Type: Application
    Filed: December 3, 2015
    Publication date: March 14, 2019
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Takahiro INOUE, Taichiro TAMIDA, Takashi HASHIMOTO, Noboru WADA, Akira NAKAGAWA, Tomokazu SAKASHITA, Tetsuya HONDA
  • Publication number: 20180301877
    Abstract: In an ignition plug, since a ground electrode is formed in a thin-rod-shape or a mesh-like shape, sufficiently strong radicals are locally generated by a barrier discharge, an anti-inflammation effect by the electrode is small, and the growth of a flame is hardly hindered. Furthermore, by making the thickness dimension of a second dielectric facing a discharge region uniform, the barrier discharge is spread over the surface of the second dielectric, the generation of the radicals is maintained, and combustibility after ignition is promoted. Furthermore, because an end portion of a high voltage electrode and a ground electrode are disposed to face each other within a combustion chamber, a fuel gas introduced into the combustion chamber is liable to flow into the discharge region, and is easily ignited by the radicals generated due to the discharge.
    Type: Application
    Filed: October 7, 2016
    Publication date: October 18, 2018
    Applicants: Mitsubishi Electric Corporation, NGK SPARK PLUG CO., LTD.
    Inventors: Taichiro TAMIDA, Takahiro INOUE, Takashi HASHIMOTO, Akira NAKAGAWA, Tomokazu SAKASHITA, Takayoshi NAGAI, Kimihiko TANAYA, Hiroyuki KAMEDA, Yuichi YAMADA, Kenji BAN
  • Patent number: 9709017
    Abstract: In an ignition device of a spark-ignition internal combustion engine that performs ignition with high energy efficiency while reducing power to be input to a spark plug, after a DC-voltage-pulse generation circuit that generates a DC voltage pulse between electrodes of a spark plug is operated by a control circuit, an AC-pulse generation circuit that generates an AC pulse between the electrodes of the spark plug is operated. Furthermore, the control circuit controls the AC-pulse generation circuit with a plurality of group pulses and quiescent periods between the group pulses are provided.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: July 18, 2017
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Hashimoto, Tomokazu Sakashita, Takayoshi Nagai
  • Patent number: 9516714
    Abstract: A control circuit performs ON/OFF control for a switching element so that LED current flowing in an LED unit is within a rated current range. In the case where the LED unit is lit, a voltage applied between both ends of series connection of a reactor and the LED unit becomes a first bus voltage, when the switching element is ON, and becomes a voltage lower than the first bus voltage, that is determined based on the first bus voltage and a second bus voltage, when a switching element is OFF.
    Type: Grant
    Filed: January 9, 2013
    Date of Patent: December 6, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hirohisa Kuwano, Takayoshi Nagai, Tomokazu Sakashita
  • Publication number: 20160102647
    Abstract: In an ignition device of a spark-ignition internal combustion engine that performs ignition with high energy efficiency while reducing power to be input to a spark plug, after a DC-voltage-pulse generation circuit that generates a DC voltage pulse between electrodes of a spark plug is operated by a control circuit, an AC-pulse generation circuit that generates an AC pulse between the electrodes of the spark plug is operated. Furthermore, the control circuit controls the AC-pulse generation circuit with a plurality of group pulses and quiescent periods between the group pulses are provided.
    Type: Application
    Filed: May 30, 2013
    Publication date: April 14, 2016
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takashi HASHIMOTO, Tomokazu SAKASHITA, Takayoshi NAGAI
  • Publication number: 20150035444
    Abstract: A control circuit performs ON/OFF control for a switching element so that LED current flowing in an LED unit is within a rated current range. In the case where the LED unit is lit, a voltage applied between both ends of series connection of a reactor and the LED unit becomes a first bus voltage, when the switching element is ON, and becomes a voltage lower than the first bus voltage, that is determined based on the first bus voltage and a second bus voltage, when a switching element is OFF.
    Type: Application
    Filed: January 9, 2013
    Publication date: February 5, 2015
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hirohisa Kuwano, Takayoshi Nagai, Tomokazu Sakashita