Patents by Inventor Kohei Hasegawa
Kohei Hasegawa 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: 10144996Abstract: A high strength cold rolled steel sheet with a low yield ratio has a chemical composition containing C: 0.05% to 0.10%, Si: 0.6% to 1.3%, Mn: 1.4% to 2.2%, P: 0.08% or less, S: 0.010% or less, Al: 0.01% to 0.08%, N: 0.010% or less, and the remainder being Fe and incidental impurities, on a percent by mass basis, and a microstructure in which the average grain size of ferrite is 15 ?m or less, the volume fraction of ferrite is 70% or more, the volume fraction of bainite is 3% or more, the volume fraction of retained austenite is 4% to 7%, the average grain size of martensite is 5 ?m or less, and the volume fraction of martensite is 1% to 6%, wherein the average C concentration (percent by mass) in the retained austenite is 0.30% to 0.70%, yield ratio is 64% or less, and the tensile strength is 590 MPa or more.Type: GrantFiled: December 4, 2013Date of Patent: December 4, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yuki Toji, Hideyuki Kimura, Kohei Hasegawa
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Patent number: 10094587Abstract: A heat-exchange ventilation device includes: a heater connection terminal to which an external connection heater is connected; a temperature sensor that measures a temperature of a supply air flow passing through an air supply passage; and a control unit that controls operations of an air supply fan and an air exhaust fan and turning-on and turning-off of the external connection heater based on a measurement result of the temperature sensor. The external connection heater is installed in an outdoor air-supply duct and heats a supply air flow flowing through the air supply passage into a heat exchanger. The air supply fan is operable at a plurality of intensities, and the control unit prohibits a state in which the air supply fan is operated at an intensity lower than an intensity set in advance and the external connection heater is turned on.Type: GrantFiled: October 10, 2014Date of Patent: October 9, 2018Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Kohei Hasegawa, Kohei Matsumoto, Masashi Ashino, Fumio Saito
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Patent number: 10090753Abstract: A power conversion device includes: a first power conversion circuit that converts power inputted from outside and outputs the converted power to a second power conversion circuit connected to the first power conversion circuit via a DC link, which outputs the converted power to a load; smoothing capacitors provided in an output part of the first power conversion circuit and an input part of the second power conversion circuit; a first and second common mode current extraction circuits provided in an input part of the first power conversion and second power conversion circuits; and a virtual neutral potential line that connects the first and second common mode current extraction circuits; a DC link filter circuit that includes a Y-shaped capacitor connected between the DC link part and the virtual neutral potential line.Type: GrantFiled: March 20, 2018Date of Patent: October 2, 2018Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kohei Hasegawa, Sari Maekawa, Takenori Yasuzumi, Atsuhiko Kuzumaki
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Publication number: 20180278141Abstract: A power conversion device includes: a first power conversion circuit that converts power inputted from outside and outputs the converted power to a second power conversion circuit connected to the first power conversion circuit via a DC link, which outputs the converted power to a load; smoothing capacitors provided in an output part of the first power conversion circuit and an input part of the second power conversion circuit; a first and second common mode current extraction circuits provided in an input part of the first power conversion and second power conversion circuits; and a virtual neutral potential line that connects the first and second common mode current extraction circuits; a DC link filter circuit that includes a Y-shaped capacitor connected between the DC link part and the virtual neutral potential line.Type: ApplicationFiled: March 20, 2018Publication date: September 27, 2018Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kohei Hasegawa, Sari Maekawa, Takenori Yasuzumi, Atsuhiko Kuzumaki
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Patent number: 10084442Abstract: A semiconductor device according to an embodiment includes a normally-off transistor having a first source, a first drain, and a first gate; a normally-on transistor having a second source electrically connected to the first drain, a second drain, and a second gate, a capacitor having a first end and a second end, the second end being electrically connected to the second gate, a first diode having a first anode electrically connected between the second end and the second gate and having a first cathode electrically connected to the second source, a first resistor provided between the first end and the first gate, and a second diode having a second anode electrically connected to the first end and having a second cathode electrically connected to the first gate, the second diode being provided in parallel with the first resistor.Type: GrantFiled: September 8, 2017Date of Patent: September 25, 2018Assignee: Kabushiki Kaisha ToshibaInventors: Kentaro Ikeda, Takenori Yasuzumi, Kohei Hasegawa
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Patent number: 10077486Abstract: A high-strength cold-rolled steel sheet has a composition and a microstructure. The microstructure comprises: ferrite having an average grain size of 5 ?m or less and a volume fraction of 3% to 20%, retained austenite having a volume fraction of 5% to 20%, and martensite having a volume fraction of 5% to 20%, the remainder being bainite and/or tempered martensite. The total number of retained austenite with a grain size of 2 ?m or less, martensite with a grain size of 2 ?m or less, or a mixed phase thereof is 150 or more per 2,000 ?m2 of a thickness cross section parallel to the rolling direction of the steel sheet.Type: GrantFiled: July 18, 2014Date of Patent: September 18, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yoshihiko Ono, Kohei Hasegawa
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Patent number: 10000090Abstract: The present invention provides a pneumatic radial tire for a passenger vehicle, having: a cross sectional width SW and an outer diameter OD controlled under an appropriate SW-OD relationship; and an optimized configuration of a crown portion thereof.Type: GrantFiled: November 2, 2012Date of Patent: June 19, 2018Assignee: BRIDGESTONE CORPORATIONInventors: Kohei Hasegawa, Isao Kuwayama
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Patent number: 9994941Abstract: A high strength cold rolled steel sheet has a chemical composition including, by mass %, C: 0.06 to 0.13%, Si: 1.2 to 2.3%, Mn: 0.6 to 1.6%, P: not more than 0.10%, S: not more than 0.010%, Al: 0.01 to 0.10% and N: not more than 0.010%, the balance comprising Fe and inevitable impurities. The steel sheet includes a microstructure containing not less than 90% in terms of volume fraction of ferrite with an average grain diameter of less than 20 ?m and 1.0 to 10% in terms of volume fraction of pearlite with an average grain diameter of less than 5 ?m. The ferrite has an average Vickers hardness of not less than 130. The steel sheet has a yield ratio of not less than 65% and a tensile strength of not less than 590 MPa.Type: GrantFiled: December 3, 2012Date of Patent: June 12, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yuki Toji, Kohei Hasegawa
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Patent number: 9941874Abstract: A switching unit of an embodiment includes a first switching element of normally-on type, a second switching element of normally-off type having a non-reference potential side conductive terminal connected to a reference potential side conductive terminal of the first switching element, a resistive element having one end connected to a conduction control terminal of the first switching element; a series capacitor connected between the other end of the resistive element and a conduction control terminal of the second switching element; and a diode having an anode connected to the other end of the resistive element and a cathode connected to a common junction of the first switching element and the second switching element.Type: GrantFiled: September 27, 2017Date of Patent: April 10, 2018Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kohei Hasegawa, Takenori Yasuzumi
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Patent number: 9920394Abstract: A bake-hardening galvanized steel sheet having a base steel sheet and a coating layer formed on the base steel sheet, the base steel sheet having a specified chemical composition and a metallographic structure including a ferrite phase and a cementite phase, in which an average ferrite grain diameter is controlled to be 10 ?m or more and 30 ?m or less, and in which the surface area of the interface between ferrite and cementite per unit volume is controlled to be 1.0/mm or more and 10.0/mm or less, a hydrogen concentration in steel of the base steel sheet is controlled to be less than 0.1 ppm, and a zinc coating weight per unit surface area of the steel sheet is controlled to be 40 g/m2 or more and 100 g/m2 or less.Type: GrantFiled: November 27, 2014Date of Patent: March 20, 2018Assignee: JFE STEEL CORPORATIONInventors: Kohei Hasegawa, Koichiro Fujita, Yusuke Kimata, Kozo Harada
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Patent number: 9923464Abstract: A switching device includes first and switching elements connected in series, a capacitor connected to a gate of the first switching element, a diode having an anode connected between the capacitor and the gate of the first switching element and a cathode connected to a source of the first switching element. A capacitance of the capacitor is equal to or greater than a value calculated by a predetermined expression.Type: GrantFiled: March 1, 2017Date of Patent: March 20, 2018Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kohei Hasegawa, Takenori Yasuzumi
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Publication number: 20180076712Abstract: A switching device includes first and switching elements connected in series, a capacitor connected to a gate of the first switching element, a diode having an anode connected between the capacitor and the gate of the first switching element and a cathode connected to a source of the first switching element. A capacitance of the capacitor is equal to or greater than a value calculated by a predetermined expression.Type: ApplicationFiled: March 1, 2017Publication date: March 15, 2018Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Kohei HASEGAWA, Takenori YASUZUMI
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Patent number: 9914988Abstract: Provided are a high-strength cold-rolled steel sheet having excellent formability, excellent ductility, excellent hole expansibility, and high yield ratio and a method for producing the same. The high-strength cold-rolled steel sheet contains 0.05% to 0.15% C, 0.10% to 0.90% Si, 1.0% to 2.0% Mn, 0.005% to 0.05% P, 0.0050% or less S, 0.01% to 0.10% Al, 0.0050% or less N, and 0.010% to 0.100% Nb, which are chemical components, on a mass basis, the balance being Fe and unavoidable impurities; has a microstructure which is a multi-phase structure containing 90% or more of a ferrite phase and 0.5% to less than 5.0% of a martensite phase on a volume fraction basis, the remainder being low-temperature transformation phases; and has a yield ratio of 70% or more.Type: GrantFiled: November 30, 2011Date of Patent: March 13, 2018Assignee: JFE Steel CorporationInventors: Katsutoshi Takashima, Yuki Toji, Kohei Hasegawa
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Publication number: 20180069434Abstract: A filter circuit includes: a first coil electromagnetically coupled to a current-carrying coil inserted into a current flow path; and a parallel circuit of a second coil and a capacitor, the parallel circuit being connecting across the first coil. The element constants of the second coil and the capacitor are set such that parallel resonance occurs at a frequency at which an impedance between the terminals of the current-carrying coil is equivalent to an impedance of the current-carrying coil alone.Type: ApplicationFiled: September 5, 2017Publication date: March 8, 2018Applicant: Kabushiki Kaisha ToshibaInventor: Kohei HASEGAWA
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Publication number: 20180037969Abstract: A steel sheet contains C: 0.15% to 0.22%, Si: 1.0% to 2.0%, Mn: 1.7% to 2.5%, P: 0.05% or less, S: 0.02% or less, Al: 0.01% to 0.05%, N: 0.005% or less, O: 0.01% or less, and the balance being iron and unavoidable impurities while satisfying [Si]/[Mn]?0.5 ([Si] and [Mn] represent Si and Mn contents, wherein the steel sheet has a structure including, in terms of area fraction, 60% to less than 100% of tempered martensite, 5% or less including 0% of untransformed austenite, and the balance being ferrite, and the ferrite has an average crystal grain size of less than 3.5 ?m, wherein less than 10 particles/100 ?m2 of Si—Mn compound oxide particles having a circle equivalent diameter of 5 ?m or less are present on a surface of the steel sheet, and the surface is covered with Si-based oxide at a coverage of 1% or less.Type: ApplicationFiled: February 16, 2016Publication date: February 8, 2018Inventors: Shimpei Yoshioka, Katsutoshi Takashima, Kohei Hasegawa, Yoshimasa Funakawa
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Publication number: 20180019743Abstract: A switching unit of an embodiment includes a first switching element of normally-on type, a second switching element of normally-off type having a non-reference potential side conductive terminal connected to a reference potential side conductive terminal of the first switching element, a resistive element having one end connected to a conduction control terminal of the first switching element; a series capacitor connected between the other end of the resistive element and a conduction control terminal of the second switching element; and a diode having an anode connected to the other end of the resistive element and a cathode connected to a common junction of the first switching element and the second switching element.Type: ApplicationFiled: September 27, 2017Publication date: January 18, 2018Applicant: Kabushiki Kaisha ToshibaInventors: Kohei HASEGAWA, Takenori Yasuzumi
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Publication number: 20180013415Abstract: A semiconductor device according to an embodiment includes a normally-off transistor having a first source, a first drain, and a first gate; a normally-on transistor having a second source electrically connected to the first drain, a second drain, and a second gate, a capacitor having a first end and a second end, the second end being electrically connected to the second gate, a first diode having a first anode electrically connected between the second end and the second gate and having a first cathode electrically connected to the second source, a first resistor provided between the first end and the first gate, and a second diode having a second anode electrically connected to the first end and having a second cathode electrically connected to the first gate, the second diode being provided in parallel with the first resistor.Type: ApplicationFiled: September 8, 2017Publication date: January 11, 2018Applicant: Kabushiki Kaisha ToshibaInventors: Kentaro IKEDA, Takenori YASUZUMI, Kohei HASEGAWA
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Publication number: 20170321297Abstract: A high-strength cold-rolled steel sheet having a specified chemical composition and a microstructure including ferrite having an average crystal grain diameter of 2 ?m or less in an amount of 10% to 25% in terms of volume fraction, retained austenite in an amount of 5% to 20% in terms of volume fraction, martensite having an average crystal grain diameter of 2 ?m or less in an amount of 5% to 15% in terms of volume fraction, and the balance being a multi-phase structure including bainite and tempered martensite having an average crystal grain diameter of 5 ?m or less, in which a relational expression, 0.35?V2/V1?0.75 (1), is satisfied, where V1 is a volume fraction of phases which are different from ferrite and V2 is a volume fraction of tempered martensite.Type: ApplicationFiled: October 27, 2015Publication date: November 9, 2017Applicant: JFE STEEL CORPORATIONInventors: Katsutoshi TAKASHIMA, Kohei HASEGAWA, Yoshimasa FUNAKAWA
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Patent number: 9806706Abstract: A switching unit of an embodiment includes a first switching element of normally-on type, a second switching element of normally-off type having a non-reference potential side conductive terminal connected to a reference potential side conductive terminal of the first switching element, a series capacitor connected between a conduction control terminal of the first switching element and a conduction control terminal of the second switching element, and a diode having an anode connected to the conduction control terminal of the first switching element and a cathode connected to a common junction of the first switching element and the second switching element.Type: GrantFiled: April 12, 2016Date of Patent: October 31, 2017Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Kohei Hasegawa, Takenori Yasuzumi
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Publication number: 20170219237Abstract: A heat-exchange ventilation device includes: a heater connection terminal to which an external connection heater is connected; a temperature sensor that measures a temperature of a supply air flow passing through an air supply passage; and a control unit that controls operations of an air supply fan and an air exhaust fan and turning-on and turning-off of the external connection heater based on a measurement result of the temperature sensor. The external connection heater is installed in an outdoor air-supply duct and heats a supply air flow flowing through the air supply passage into a heat exchanger. The air supply fan is operable at a plurality of intensities, and the control unit prohibits a state in which the air supply fan is operated at an intensity lower than an intensity set in advance and the external connection heater is turned on.Type: ApplicationFiled: October 10, 2014Publication date: August 3, 2017Applicant: Mitsubishi Electric CorporationInventors: Kohei HASEGAWA, Kohei MATSUMOTO, Masashi ASHINO, Fumio SAITO