Patents by Inventor Hajime Urai
Hajime Urai 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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Publication number: 20230056704Abstract: Provided is a power conversion system that can suppress a fault in a short-circuiting switch that bypasses a fault unit and enhance the reliability and redundancy of the system. The power conversion system is provided with a plurality of power converter units that are formed by using semiconductor switch elements and are connected in series, and comprises: switch elements that are provided to input terminals and/or output terminals of the power converter units and bypass the power converter units; and overvoltage suppressing elements which are connected in parallel with the switch elements and in which conducting states are changed by an application of a prescribed voltage.Type: ApplicationFiled: February 25, 2021Publication date: February 23, 2023Inventors: Hajime URAI, Hiroshi KAMIZUMA, Kimihisa FURUKAWA, Noriya NAKAO, Kinya NAKATSU
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Publication number: 20210082644Abstract: A movable main contact; a movable arc contact; a puffer cylinder including the movable main contact; a hollow rod that is arranged inside the puffer cylinder, includes the movable arc contact, and has an inner space through which an insulating gas flows; a thermal puffer chamber surrounded by the puffer cylinder and the hollow rod; an insulating cover that is provided to the hollow rod, and covers the movable arc contact; an insulating nozzle provided to the puffer cylinder; and a cylindrical flow guide extending in the axial direction are included. The flow guide is installed in the thermal puffer chamber, positioned on the outer circumference side of the hollow rod, and connected to the insulating nozzle. The space between the flow guide and the hollow rod is connected to the space between the insulating nozzle and the insulating cover, and serves as a flow path of the insulating gas.Type: ApplicationFiled: July 30, 2020Publication date: March 18, 2021Inventors: Hideyuki KOTSUJI, Hajime URAI, Masanao TERADA, Takahiro NISHIMURA, Yuichiro YAMANE
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Patent number: 10916394Abstract: A gas circuit breaker includes a gas suppresser composed of a protruded portion which is formed on a horizontal surface facing an exhaust cylinder of a shaft guide and which forms a gap between itself and the exhaust cylinder and an enlarged portion which is adjacent to the protruded portion and where a gap to the exhaust cylinder is enlarged so that the shaft guide, which operates along an inner circumferential surface of the exhaust cylinder, which is provided to an inner circumferential portion of a movable side main conductor and is provided to outer circumferences of an exhaust shaft and an operation rod, and couples the operation rod with the exhaust shaft, is axially adjacent to a sliding member that slides along the exhaust cylinder with no space to the exhaust cylinder and suppresses discharge of heated and pressurized insulating gas.Type: GrantFiled: July 30, 2018Date of Patent: February 9, 2021Assignee: Hitachi, Ltd.Inventors: Toshiaki Sakuyama, Hajime Urai, Masanao Terada, Ryoichi Shiobara, Takahiro Nishimura, Makoto Hirose, Yuichiro Yamane
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Publication number: 20200279705Abstract: While lowering sliding resistance of an exhaust cylinder and reducing effects on a circuit breaking operation, an amount of high temperature and high pressure gas discharged into an insulating support cylinder is reduced, and both ground insulation performance and circuit breaking performance are improved.Type: ApplicationFiled: July 30, 2018Publication date: September 3, 2020Inventors: Toshiaki SAKUYAMA, Hajime URAI, Masanao TERADA, Ryoichi SHIOBARA, Takahiro NISHIMURA, Makoto HIROSE, Yuichiro YAMANE
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Patent number: 10699863Abstract: In order to solve the above-described problems, a gas circuit breaker of the present invention has an insulating nozzle disposed so as to cover an inner surface of a coupling member such that an end surface of the coupling member and an end surface of the insulating nozzle form one surface (the end surface of the coupling member is flush with the end surface of the insulating nozzle), in order to suppress contact between a high-temperature and high-pressure gas generated by an arc and the coupling member coupling the insulating nozzle and a driving rod.Type: GrantFiled: February 14, 2019Date of Patent: June 30, 2020Assignee: Hitachi, Ltd.Inventors: Toshiaki Sakuyama, Masanao Terada, Hajime Urai, Yuichiro Yamane, Takahiro Nishimura
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Publication number: 20190287746Abstract: In order to solve the above-described problems, a gas circuit breaker of the present invention has an insulating nozzle disposed so as to cover an inner surface of a coupling member such that an end surface of the coupling member and an end surface of the insulating nozzle form one surface (the end surface of the coupling member is flush with the end surface of the insulating nozzle), in order to suppress contact between a high-temperature and high-pressure gas generated by an arc and the coupling member coupling the insulating nozzle and a driving rod.Type: ApplicationFiled: February 14, 2019Publication date: September 19, 2019Inventors: Toshiaki SAKUYAMA, Masanao TERADA, Hajime URAI, Yuichiro YAMANE, Takahiro NISHIMURA
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Patent number: 10354821Abstract: To provide a gas circuit breaker designed to achieve further improvement in interruption performance for a small to medium current. The gas circuit breaker according to the present invention includes: an operation mechanism 1; a heat puffer chamber 19; a machine puffer chamber 32; a release valve 34; a movable main contact 5 and movable arc contact 11; a stationary main contact 6 and stationary arc contact 12; a movable-side leading conductor 14; and a stationary-side leading conductor 15, and features: a separation cylinder 21 for radially partitioning the heat puffer chamber 19; an inner circumferential flow path 24 formed on an inner circumferential side of the separation cylinder 21; and a check valve 22 for opening or closing a communication hole 23.Type: GrantFiled: February 21, 2018Date of Patent: July 16, 2019Assignee: Hitachi, Ltd.Inventors: Toshiaki Sakuyama, Ryoichi Shiobara, Hajime Urai, Makoto Hirose, Masanao Terada, Takahiro Nishimura
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Patent number: 10256060Abstract: Realized is a shape of a grooved cam that maximizes break performance by appropriately setting an electrode operation, with a minimum weight increase.Type: GrantFiled: December 19, 2017Date of Patent: April 9, 2019Assignee: Hitachi, Ltd.Inventors: Masanao Terada, Taichiro Yamashita, Hiroaki Hashimoto, Hajime Urai, Makoto Hirose
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Patent number: 10199188Abstract: A bidirectional driving mechanism 10 has a drive-side linkage rod 11, a driven-side linkage rod 13, two levers 12 that link the drive-side linkage rod with the driven-side linkage rod, and a guide 14 that regulates the operation of the drive-side linkage rod 11 and the driven-side linkage rod 13. A moveable pin 18 is passed through a first groove cam 16 of the drive-side linkage rod 11, a second groove cam 17 of the guide 14, and third groove cams 19 of the levers 12, and by operation of the drive-side rod 13, the moveable pin 18 moves within the respective groove cams 16, 17, 19, causing the levers 12 to rotate, the driven-side linkage rod 13 to be driven in a direction opposite to the drive-side linkage rod 11, and a driven-side arc electrode 5 to be driven in a direction opposite to a drive-side arc electrode 4.Type: GrantFiled: January 12, 2016Date of Patent: February 5, 2019Assignee: Hitachi, Ltd.Inventors: Masanao Terada, Yuki Nakai, Yoichi Oshita, Hiroaki Hashimoto, Hajime Urai, Katsuhiko Shiraishi
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Patent number: 10157719Abstract: A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.Type: GrantFiled: May 30, 2017Date of Patent: December 18, 2018Assignee: HITACHI, LTD.Inventors: Yuki Nakai, Masanao Terada, Hajime Urai, Takashi Iida, Noriyuki Yaginuma
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Publication number: 20180277323Abstract: To provide a gas circuit breaker designed to achieve further improvement in interruption performance for a small to medium current. The gas circuit breaker according to the present invention includes: an operation mechanism 1; a heat puffer chamber 19; a machine puffer chamber 32; a release valve 34; a movable main contact 5 and movable arc contact 11; a stationary main contact 6 and stationary arc contact 12; a movable-side leading conductor 14; and a stationary-side leading conductor 15, and features: a separation cylinder 21 for radially partitioning the heat puffer chamber 19; an inner circumferential flow path 24 formed on an inner circumferential side of the separation cylinder 21; and a check valve 22 for opening or closing a communication hole 23.Type: ApplicationFiled: February 21, 2018Publication date: September 27, 2018Inventors: Toshiaki SAKUYAMA, Ryoichi SHIOBARA, Hajime URAI, Makoto HIROSE, Masanao TERADA, Takahiro NISHIMURA
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Publication number: 20180226214Abstract: There is provided a gas circuit breaker that includes: a puffer shaft connected to one of a pair of arcing contacts, a puffer cylinder that is coaxially provided on an outer circumference of the puffer shaft, an insulating nozzle that is fixed to the puffer cylinder on a breaker side, an insulating rod that connects the puffer shaft and an operating device to each other, a shaft guide that is provided on an outer circumference of the puffer shaft and the insulating rod, and an exhaust guide that is provided on an outer circumference of the shaft guide, in which hot gas is discharged into a gas tank through a shaft exhaust hole of the puffer shaft, between the puffer shaft and the shaft guide, and a conductor exhaust hole of a movable side exhaust conductor in the middle of interrupting operation, the shaft exhaust hole of the puffer shaft communicates with a shaft guide exhaust hole of the shaft guide in a region near a current zero point before the termination of the interrupting operation, and thus an exhauType: ApplicationFiled: December 27, 2017Publication date: August 9, 2018Inventors: Hideyuki KOTSUJI, Hajime URAI, Masanao TERADA, Makoto HIROSE
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Publication number: 20180182578Abstract: Realized is a shape of a grooved cam that maximizes break performance by appropriately setting an electrode operation, with a minimum weight increase.Type: ApplicationFiled: December 19, 2017Publication date: June 28, 2018Inventors: Masanao TERADA, Taichiro YAMASHITA, Hiroaki HASHIMOTO, Hajime URAI, Makoto HIROSE
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Patent number: 9959999Abstract: A method for controlling a power switching apparatus to solve problems including: setting a target time reaching a predetermined position immediately before a target phase by a time calculator during an opening and closing operation of a movable arc contact with respect to a fixed arc contact in a target phase at a predetermined average switching speed; and controlling an electric motor at a speed equal to or less than an average switching speed immediately before the target phase from an operation start time to the target time by a motor controller.Type: GrantFiled: June 8, 2016Date of Patent: May 1, 2018Assignee: Hitachi, Ltd.Inventors: Koichiro Adachi, Hajime Urai, Katsuhiko Shiraishi, Masataka Sasaki
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Patent number: 9899172Abstract: The invention is intended to provide a circuit breaker or a circuit breaker operating method enabling a current interruption action to be performed efficiently. A circuit breaker is characterized in that includes a fixed contact and a movable contact that comes in and goes out of contact with the fixed contact; a main circuit conductor that is electrically connected to the fixed contact and the movable contact; an operating mechanism including a mover configured by concatenating permanent magnets or magnetic materials alternately having opposite N and S magnetic polarities along the direction of motion axis of the movable contact and magnetic poles disposed to face the N and S magnetic polarities of the mover and wound with windings; a current detector that detects a current flowing through the main circuit conductor; and a control device that varies the amount of a current to be supplied to the windings of the magnetic poles, depending on a current value detected by the current detector.Type: GrantFiled: March 27, 2013Date of Patent: February 20, 2018Assignee: Hitachi, Ltd.Inventors: Hajime Urai, Yasuaki Aoyama, Hiroaki Hashimoto, Katsuhiko Shiraishi, Tatsuro Kato, Ayumu Morita, Toshiaki Rokunohe, Yoichi Oshita
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Publication number: 20180025868Abstract: A bidirectional driving mechanism 10 has a drive-side linkage rod 11, a driven-side linkage rod 13, two levers 12 that link the drive-side linkage rod with the driven-side linkage rod, and a guide 14 that regulates the operation of the drive-side linkage rod 11 and the driven-side linkage rod 13. A moveable pin 18 is passed through a first groove cam 16 of the drive-side linkage rod 11, a second groove cam 17 of the guide 14, and third groove cams 19 of the levers 12, and by operation of the drive-side rod 13, the moveable pin 18 moves within the respective groove cams 16, 17, 19, causing the levers 12 to rotate, the driven-side linkage rod 13 to be driven in a direction opposite to the drive-side linkage rod 11, and a driven-side arc electrode 5 to be driven in a direction opposite to a drive-side arc electrode 4.Type: ApplicationFiled: January 12, 2016Publication date: January 25, 2018Applicant: HITACHI, LTD.Inventors: Masanao TERADA, Yuki NAKAI, Yoichi OSHITA, Hiroaki HASHIMOTO, Hajime URAI, Katsuhiko SHIRAISHI
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Patent number: 9870884Abstract: To provide a gas circuit breaker having a space-saving and highly reliable double motion mechanism with high design freedom. In a double motion mechanism of the gas circuit breaker, a driven side movable pin is communicated with a lever driven side hole cut in the opposite side with respect to a rotation axis of a lever. A round hole through which a driving side movable pin is inserted and an elongate hole through which the driven side movable pin is inserted are cut in the outside of the lever. A position retaining member to suppress rotation of the driving side movable pin about two axes vertical to a pin axis is provided. The driving side movable pin is moved in respective grooved cams with an operation of the driving side rod, to rotate the lever, drive the driven side connecting rod in an opposite direction to the driving side connecting rod, and drive the driven side arcing contact in an opposite direction to the driving side arcing contact.Type: GrantFiled: March 23, 2017Date of Patent: January 16, 2018Assignee: Hitachi, Ltd.Inventors: Masanao Terada, Hajime Urai, Daisuke Ebisawa, Hiroaki Hashimoto, Riichi Nagao
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Publication number: 20170345593Abstract: A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.Type: ApplicationFiled: May 30, 2017Publication date: November 30, 2017Applicant: HITACHI, LTD.Inventors: Yuki NAKAI, Masanao TERADA, Hajime URAI, Takashi IIDA, Noriyuki YAGINUMA
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Publication number: 20170278654Abstract: To provide a gas circuit breaker having a space-saving and highly reliable double motion mechanism with high design freedom. In a double motion mechanism of the gas circuit breaker, a driven side movable pin is communicated with a lever driven side hole cut in the opposite side with respect to a rotation axis of a lever. A round hole through which a driving side movable pin is inserted and an elongate hole through which the driven side movable pin is inserted are cut in the outside of the lever. A position retaining member to suppress rotation of the driving side movable pin about two axes vertical to a pin axis is provided. The driving side movable pin is moved in respective grooved cams with an operation of the driving side rod, to rotate the lever, drive the driven side connecting rod in an opposite direction to the driving side connecting rod, and drive the driven side arcing contact in an opposite direction to the driving side arcing contact.Type: ApplicationFiled: March 23, 2017Publication date: September 28, 2017Inventors: Masanao TERADA, Hajime URAI, Daisuke EBISAWA, Hiroaki HASHIMOTO, Riichi NAGAO
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Patent number: 9620315Abstract: Provided is a gas circuit breaker that can reduce control energy smaller than that in previous double motion systems and an excessive force applied to a moveable pin to achieve a highly reliable double motion system. A gas circuit breaker has a double motion mechanism unit including a driving-side connecting rod, a driven-side connecting rod, a lever to connect the rods, and a guide to define the motion of the driving-side and driven-side connecting rods. A moveable pin extends through a first grooved cam of the driving-side conencting rod, a second grooved cam of the guide, and a third grooved cam of the lever. The driving-side connecting rod operates to move the moveable pin inside the grooved cams. Thus, the lever is rotated, the driven-side connecting rod is driven opposite to the driving-side connecting rod, and the driven-side arcing contact is driven opposite to the driving-side arcing contact.Type: GrantFiled: May 26, 2014Date of Patent: April 11, 2017Assignee: Hitachi, Ltd.Inventors: Masanao Terada, Hajime Urai, Katsuhiko Shiraishi, Yoichi Oshita, Hiroaki Hashimoto, Noriyuki Yaginuma