Patents by Inventor Takumi Uemura
Takumi Uemura 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).
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Patent number: 11901825Abstract: An isolated DC-DC converter includes a transformer, a full-bridge switching circuit, a protective circuit, a control unit, an inductor, and an output circuit. The isolated DC-DC converter includes a first voltage detection unit that detects a voltage value between a first conductive path and a second conductive path, and a first current detection unit that detects a current value of the inductor. The control unit determines at least one of a first dead time and a second dead time on the basis of the voltage value detected by the first voltage detection unit and the current value detected by the first current detection unit, using a method that increases the dead time as the voltage value increases and reduces the dead time as the current value increases.Type: GrantFiled: June 3, 2020Date of Patent: February 13, 2024Assignees: AutoNetworks Technologies, Ltd., Sumitomo Wiring Systems, Ltd., Sumitomo Electric Industries, Ltd.Inventors: Ibuki Kawamura, Takumi Uemura
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Patent number: 11512663Abstract: An engine is provided, which includes a combustion chamber defined by a piston crown surface, an inner wall surface of a cylinder, and a pentroof ceiling surface formed in a cylinder head, and an ignition part of a spark plug disposed at the ceiling surface to achieve flame propagation combustion inside the combustion chamber. A cavity recessed in a spherical cap shape is formed in a central area of the crown surface. An opening of an intake port is formed in the ceiling surface (intake side) and an opening of an exhaust port is formed in the ceiling surface (exhaust side). When seen in a cross-sectional view taken along a cylinder axis, the ignition part is located above the cavity to be offset toward the exhaust side with respect to a cylinder axial line whereas a cavity center point is located to be offset toward the intake side.Type: GrantFiled: January 31, 2022Date of Patent: November 29, 2022Assignee: Mazda Motor CorporationInventors: Satoshi Imamura, Masaki Fukuma, Naohiro Yamaguchi, Yoshitaka Wada, Takumi Uemura, Keisuke Yamamoto
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Patent number: 11502620Abstract: A voltage supply system and a power source that, in a voltage supply system in which a plurality of power sources (e.g., DC-DC converters) are connected in parallel, enable each power source to be set at a desired load ratio. The power source is used in a voltage supply system including a power source configured to output a voltage in a constant voltage mode on the basis of a first target voltage, and is connected in parallel to the constant voltage power source, the power source including a voltage generation unit configured to output a voltage switchably between a constant voltage mode based on a second target voltage greater than the first target voltage and a constant current mode based on a current limit value.Type: GrantFiled: May 31, 2019Date of Patent: November 15, 2022Assignee: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Tomoaki Ujimaru, Seiji Takahashi, Takaaki Sano, Takumi Uemura
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Publication number: 20220360180Abstract: An isolated DC-DC converter includes a transformer, a full-bridge switching circuit, a protective circuit, a control unit, an inductor, and an output circuit. The isolated DC-DC converter includes a first voltage detection unit that detects a voltage value between a first conductive path and a second conductive path, and a first current detection unit that detects a current value of the inductor. The control unit determines at least one of a first dead time and a second dead time on the basis of the voltage value detected by the first voltage detection unit and the current value detected by the first current detection unit, using a method that increases the dead time as the voltage value increases and reduces the dead time as the current value increases.Type: ApplicationFiled: June 3, 2020Publication date: November 10, 2022Inventors: Ibuki KAWAMURA, Takumi UEMURA
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Publication number: 20220282687Abstract: An engine is provided, which includes a combustion chamber defined by a piston crown surface, an inner wall surface of a cylinder, and a pentroof ceiling surface formed in a cylinder head, and an ignition part of a spark plug disposed at the ceiling surface to achieve flame propagation combustion inside the combustion chamber. A cavity recessed in a spherical cap shape is formed in a central area of the crown surface. An opening of an intake port is formed in the ceiling surface (intake side) and an opening of an exhaust port is formed in the ceiling surface (exhaust side). When seen in a cross-sectional view taken along a cylinder axis, the ignition part is located above the cavity to be offset toward the exhaust side with respect to a cylinder axial line whereas a cavity center point is located to be offset toward the intake side.Type: ApplicationFiled: January 31, 2022Publication date: September 8, 2022Inventors: Satoshi Imamura, Masaki Fukuma, Naohiro Yamaguchi, Yoshitaka Wada, Takumi Uemura, Keisuke Yamamoto
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Publication number: 20210399650Abstract: A voltage supply system and a power source that, in a voltage supply system in which a plurality of power sources (e.g., DC-DC converters) are connected in parallel, enable each power source to be set at a desired load ratio. The power source is used in a voltage supply system including a power source configured to output a voltage in a constant voltage mode on the basis of a first target voltage, and is connected in parallel to the constant voltage power source, the power source including a voltage generation unit configured to output a voltage switchably between a constant voltage mode based on a second target voltage greater than the first target voltage and a constant current mode based on a current limit value.Type: ApplicationFiled: May 31, 2019Publication date: December 23, 2021Applicant: SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Tomoaki UJIMARU, Seiji TAKAHASHI, Takaaki SANO, Takumi UEMURA
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Patent number: 10110117Abstract: A power converter has: switching elements connected in parallel to each of primary-side filter capacitors, freewheel diodes connected in parallel to the switching elements, and snubber resistances connected in parallel to the switching elements. The controller causes stoppage of the power converter by turning off each of the switching elements. After stoppage of the power converter, the controller causes a discharge circuit to operate by turning on a thyristor, thereby discharging the primary-side filter capacitors. By discharging of the primary-side filter capacitors, a secondary-side filter capacitor is discharged via the freewheel diodes.Type: GrantFiled: October 15, 2015Date of Patent: October 23, 2018Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Takumi Uemura, Kota Teramoto
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Publication number: 20180234010Abstract: A power converter has: switching elements connected in parallel to each of primary-side filter capacitors, freewheel diodes connected in parallel to the switching elements, and snubber resistances connected in parallel to the switching elements. The controller causes stoppage of the power converter by turning off each of the switching elements. After stoppage of the power converter, the controller causes a discharge circuit to operate by turning on a thyristor, thereby discharging the primary-side filter capacitors. By discharging of the primary-side filter capacitors, a secondary-side filter capacitor is discharged via the freewheel diodes.Type: ApplicationFiled: October 15, 2015Publication date: August 16, 2018Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Takumi UEMURA, Kota TERAMOTO
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Patent number: 9845013Abstract: A controller of an AC electric vehicle includes a first specific-frequency-current computation unit that extracts a current component corresponding to a first specific frequency set value from a main-transformer output current and outputs the current component as a first specific-frequency current, a subtractor that subtracts the first specific-frequency current from the main-transformer output current and outputs a subtraction result as a current deviation, a second specific-frequency-current computation unit that extracts a current component corresponding to a second specific frequency set value from the current deviation and outputs the current component as a second specific-frequency current, and a power-failure detection unit that compares the second specific-frequency current with a predetermined power-failure detection-current set value and outputs a power-failure detection signal when the second specific-frequency current is larger than the power-failure detection-current set value.Type: GrantFiled: June 29, 2012Date of Patent: December 19, 2017Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Tetsuo Sugahara, Takumi Uemura
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Publication number: 20150191086Abstract: A controller of an AC electric vehicle includes a first specific-frequency-current computation unit that extracts a current component corresponding to a first specific frequency set value from a main-transformer output current and outputs the current component as a first specific-frequency current, a subtractor that subtracts the first specific-frequency current from the main-transformer output current and outputs a subtraction result as a current deviation, a second specific-frequency-current computation unit that extracts a current component corresponding to a second specific frequency set value from the current deviation and outputs the current component as a second specific-frequency current, and a power-failure detection unit that compares the second specific-frequency current with a predetermined power-failure detection-current set value and outputs a power-failure detection signal when the second specific-frequency current is larger than the power-failure detection-current set value.Type: ApplicationFiled: June 29, 2012Publication date: July 9, 2015Applicant: Mitsubishi Electric CorporationInventors: Tetsuo Sugahara, Takumi Uemura