Patents by Inventor Mitsunobu NAKATO
Mitsunobu NAKATO 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: 11209388Abstract: The present invention provides a gas sensor capable of suppressing a variation of a sensor output by a sensor cell to be small. A sensor element of a gas sensor comprises a first solid electrolyte body and a second solid electrolyte body having oxygen ion conductivity, a measured gas chamber into which the measured gas is introduced, a first reference gas chamber and a second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. A value obtained by dividing a first average cross-sectional area of the first reference gas chamber by the first length is larger than the value obtained by dividing the second average cross-sectional area of the second reference gas chamber by the second length.Type: GrantFiled: May 15, 2017Date of Patent: December 28, 2021Assignee: DENSO CORPORATIONInventors: Keisuke Mizutani, Keigo Mizutani, Shota Hagino, Mitsunobu Nakato, Takashi Araki
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Patent number: 11209387Abstract: A gas sensor element including a solid electrolyte body, a sensor electrode, and a reference electrode is provided. The solid electrolyte body has oxygen ion conductivity and includes a measurement gas surface to be exposed to a measurement gas introduced from the exterior and a reference gas surface to be exposed to a reference gas introduced from the exterior. The sensor electrode is provided on the measurement gas surface of the solid electrolyte body. The reference electrode is provided on the reference gas surface of the solid electrolyte body. The sensor electrode includes a porous body containing a solid electrolyte having oxygen ion conductivity and a precious metal, the peak pore size of the sensor electrode being 0.03 ?m to 0.3 ?m.Type: GrantFiled: December 9, 2016Date of Patent: December 28, 2021Assignee: DENSO CORPORATIONInventors: Yusuke Todo, Mitsunobu Nakato, Hiroki Ichikawa
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Publication number: 20210255137Abstract: A gas sensor includes a sensor element including a solid electrolyte, a gas chamber, a pump electrode, a sensor electrode, and a reference electrode. The pump electrode and sensor electrode are provided in the solid electrolyte in a state in which the pump electrode and the sensor electrode are housed in the gas chamber. The reference electrode is provided in the solid electrolyte. The pump electrode and the sensor electrode contain Au. Au content in a surface layer is equal to or greater than 1 mass % and higher than Au content in a reference layer. The surface layer is an area from a surface of the sensor electrode to a depth of 0.3 nanometers. The reference layer is an area extending to a depth of 2 or more to 3 or less nanometers from the surface of the sensor electrode.Type: ApplicationFiled: May 6, 2021Publication date: August 19, 2021Inventors: Tatsuya YOSHIKAWA, Yusuke TODO, Mitsunobu NAKATO, Takashi ARAKI, Yuji KAWASAKI
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Patent number: 11009481Abstract: Provided is a gas sensor achieving improvement in detection accuracy for a specific gas component and responsiveness for detecting the specific gas component. A guide body is provided at a base end section of a first inner circulation hole in an inner cover of the gas sensor. The base end section is located between a base end position P1 2 mm away from a tip end of a sensor element in an axial direction L towards a base end side L1 and a tip end position P2 2 mm away from the tip end towards a tip end side L2. The tip end is on the base end side L1 relative to an imaginary line K passing through a base end and a tip end on a surface on the tip end side of the guide body.Type: GrantFiled: April 7, 2017Date of Patent: May 18, 2021Assignee: DENSO CORPORATIONInventors: Takashi Araki, Mitsunobu Nakato
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Publication number: 20210088472Abstract: A gas sensor, an oxygen concentration measuring unit, and a computation unit are included. The gas sensor measures a concentration CNOX of specific gas contained in measured gas. The oxygen concentration measuring unit measures a concentration CO2 of oxygen in the measured gas outside the gas sensor. The gas sensor has a measured gas chamber, a reference gas chamber, a diffusion resistance unit, a pump cell, and a sensor cell. The computation unit computes a concentration CNOX of the specific gas by using the concentration CO2 of oxygen measured by using the oxygen concentration measurement unit and the sensor current.Type: ApplicationFiled: December 3, 2020Publication date: March 25, 2021Inventors: Yusuke KAWAMOTO, Yusuke TODO, Hiroo IMAMURA, Mitsunobu NAKATO
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Patent number: 10935517Abstract: A gas sensor element of the present disclosure includes a measurement gas chamber, a solid electrolyte body, and a sensor electrode. The sensor electrode has a noble metal region which contains at least Rh and Pt, an electrolyte region which is formed by a solid electrolyte, and a mixed region in which the noble metal and the solid electrolyte are mixed. With respect to a correlation curve which represents a correlation between a mass percentage concentration c of Rh and a thickness d of the mixed region, when a reaction resistance to a measured gas in the sensor electrode is 40 k?, the concentration c of Rh and the thickness d are set so that at coordinates (c, d), the concentration c has a positive coordinate point and the thickness d has a positive coordinate point.Type: GrantFiled: December 20, 2017Date of Patent: March 2, 2021Assignee: DENSO CORPORATIONInventors: Yusuke Todo, Mitsunobu Nakato, Hiroaki Yoto
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Patent number: 10895553Abstract: Provided is a gas sensor improving accuracy of detection of specific gas in measurement gas, while maintaining high responsiveness in detection of the specific gas. A sensor element of a gas sensor includes a first solid electrolyte and second solid electrolyte having oxygen ionic conductivity, a measurement gas chamber into which measurement gas is introduced, a first reference gas chamber and second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. The sensor cell detects a specific gas component in the measurement gas having an oxygen concentration adjusted by the pump cells. The heater is located opposite to a second principal surface of the second solid electrolyte on which the sensor cell is formed.Type: GrantFiled: April 19, 2017Date of Patent: January 19, 2021Assignee: DENSO CORPORATIONInventors: Keisuke Mizutani, Keigo Mizutani, Mitsunobu Nakato, Takashi Araki
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Patent number: 10890552Abstract: A gas sensor includes a pump cell unit that regulates the oxygen concentration of a measured gas using a pump electrode, a monitor cell unit that detects the residual oxygen concentration of the measured gas using a monitor electrode, and a sensor cell unit that detects the concentration of a specific gas component in the measured gas using a sensor electrode. Between a pump electrode lead part and the sensor electrode, there is arranged the monitor electrode. Between an upstream portion of the pump electrode lead part and a monitor electrode lead part, there is provided an interval w1 of 0.5 mm or more.Type: GrantFiled: December 7, 2016Date of Patent: January 12, 2021Assignee: DENSO CORPORATIONInventors: Keigo Mizutani, Keisuke Mizutani, Mitsunobu Nakato, Takashi Araki
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Patent number: 10788448Abstract: A gas sensor which can improve an accuracy in detecting a specific gas component by properly correcting for the influence of residual oxygen is provided. The gas sensor includes a solid electrolyte plate, a measured gas chamber into which a measured gas flows, a pump cell which adjusts an oxygen concentration of the measured gas using a pump electrode, a monitor cell which detects a residual oxygen concentration of the measured gas using a monitor electrode, and a sensor cell which detects a specific gas component concentration of the measured gas using a sensor electrode. The maximum thickness of the sensor electrode is greater than the maximum thickness of the monitor electrode, and the difference between the maximum thickness of the sensor electrode and the maximum thickness of the monitor electrode is between 4 ?m and 30 ?m, inclusive.Type: GrantFiled: November 3, 2016Date of Patent: September 29, 2020Assignee: DENSO CORPORATIONInventors: Keigo Mizutani, Keisuke Mizutani, Mitsunobu Nakato, Takashi Araki
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Publication number: 20190383768Abstract: Provided is a gas sensor improving accuracy of detection of specific gas in measurement gas, while maintaining high responsiveness in detection of the specific gas. A sensor element of a gas sensor includes a first solid electrolyte and second solid electrolyte having oxygen ionic conductivity, a measurement gas chamber into which measurement gas is introduced, a first reference gas chamber and second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. The sensor cell detects a specific gas component in the measurement gas having an oxygen concentration adjusted by the pump cells. The heater is located opposite to a second principal surface of the second solid electrolyte on which the sensor cell is formed.Type: ApplicationFiled: April 19, 2017Publication date: December 19, 2019Inventors: Keisuke MIZUTANI, Keigo MIZUTANI, Mitsunobu NAKATO, Takashi ARAKI
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Patent number: 10393696Abstract: A gas sensor includes a sensor element. The sensor element includes; a solid electrolyte body that has oxygen ion conductivity and includes a first main surface exposed to a gas to be measured and a second main surface exposed to a reference gas; a sensor electrode that is provided on the first main surface and detects a specific gas component in the gas to be measured; and a reference electrode that is provided on the second main surface. The sensor electrode is made of a Pt—Rh alloy that contains 30 mass % to 70 mass % Pt and 70 mass % to 30 mass % Rh, when an overall noble metal component is 100 mass %. A variation amount of the Rh content of the Pt—Rh alloy from an outermost surface to a depth of 350 nm in a thickness direction of the sensor electrode is within a range of up to 10 mass %.Type: GrantFiled: July 14, 2017Date of Patent: August 27, 2019Assignee: DENSO CORPORATIONInventors: Yusuke Todo, Mitsunobu Nakato, Hiroaki Yoto, Hiroki Ichikawa
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Publication number: 20190227027Abstract: The present invention provides a gas sensor capable of suppressing a variation of a sensor output by a sensor cell to be small. A sensor element of a gas sensor comprises a first solid electrolyte body and a second solid electrolyte body having oxygen ion conductivity, a measured gas chamber into which the measured gas is introduced, a first reference gas chamber and a second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. A value obtained by dividing a first average cross-sectional area of the first reference gas chamber by the first length is larger than the value obtained by dividing the second average cross-sectional area of the second reference gas chamber by the second length.Type: ApplicationFiled: May 15, 2017Publication date: July 25, 2019Inventors: Keisuke MIZUTANI, Keigo MIZUTANI, Shota HAGINO, Mitsunobu NAKATO, Takashi ARAKI
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Publication number: 20190094172Abstract: Provided is a gas sensor achieving improvement in detection accuracy for a specific gas component and responsiveness for detecting the specific gas component. A guide body is provided at a base end section of a first inner circulation hole in an inner cover of the gas sensor. The base end section is located between a base end position P1 2 mm away from a tip end of a sensor element in an axial direction L towards a base end side L1 and a tip end position P2 2 mm away from the tip end towards a tip end side L2. The tip end is on the base end side L1 relative to an imaginary line K passing through a base end and a tip end on a surface on the tip end side of the guide body.Type: ApplicationFiled: April 7, 2017Publication date: March 28, 2019Inventors: Takashi ARAKI, Mitsunobu NAKATO
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Publication number: 20190025248Abstract: A gas sensor which can improve an accuracy in detecting a specific gas component by properly correcting for the influence of residual oxygen is provided. The gas sensor includes a solid electrolyte plate, a measured gas chamber into which a measured gas flows, a pump cell which adjusts an oxygen concentration of the measured gas using a pump electrode, a monitor cell which detects a residual oxygen concentration of the measured gas using a monitor electrode, and a sensor cell which detects a specific gas component concentration of the measured gas using a sensor electrode. The maximum thickness of the sensor electrode is greater than the maximum thickness of the monitor electrode, and the difference between the maximum thickness of the sensor electrode and the maximum thickness of the monitor electrode is between 4 ?m and 30 ?m, inclusive.Type: ApplicationFiled: November 3, 2016Publication date: January 24, 2019Inventors: Keigo MIZUTANI, Keisuke MIZUTANI, Mitsunobu NAKATO, Takashi ARAKI
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Publication number: 20190004008Abstract: A gas sensor element including a solid electrolyte body, a sensor electrode, and a reference electrode is provided. The solid electrolyte body has oxygen ion conductivity and includes a measurement gas surface to be exposed to a measurement gas introduced from the exterior and a reference gas surface to be exposed to a reference gas introduced from the exterior. The sensor electrode is provided on the measurement gas surface of the solid electrolyte body. The reference electrode is provided on the reference gas surface of the solid electrolyte body. The sensor electrode includes a porous body containing a solid electrolyte having oxygen ion conductivity and a precious metal, the peak pore size of the sensor electrode being 0.03 ?m to 0.3 ?m.Type: ApplicationFiled: December 9, 2016Publication date: January 3, 2019Applicant: DENSO CORPORATIONInventors: Yusuke TODO, Mitsunobu NAKATO, Hiroki ICHIKAWA
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Publication number: 20180364193Abstract: A gas sensor includes a pump cell unit that regulates the oxygen concentration of a measured gas using a pump electrode, a monitor cell unit that detects the residual oxygen concentration of the measured gas using a monitor electrode, and a sensor cell unit that detects the concentration of a specific gas component in the measured gas using a sensor electrode. Between a pump electrode lead part and the sensor electrode, there is arranged the monitor electrode. Between an upstream portion of the pump electrode lead part and a monitor electrode lead part, there is provided an interval w1 of 0.5 mm or more.Type: ApplicationFiled: December 7, 2016Publication date: December 20, 2018Inventors: Keigo MIZUTANI, Keisuke MIZUTANI, Mitsunobu NAKATO, Takashi ARAKI
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Publication number: 20180172626Abstract: A gas sensor element of the present disclosure includes a measurement gas chamber, a solid electrolyte body, and a sensor electrode. The sensor electrode has a noble metal region which contains at least Rh and Pt, an electrolyte region which is formed by a solid electrolyte, and a mixed region in which the noble metal and the solid electrolyte are mixed. With respect to a correlation curve which represents a correlation between a mass percentage concentration c of Rh and a thickness d of the mixed region, when a reaction resistance to a measured gas in the sensor electrode is 40 k?, the concentration c of Rh and the thickness d are set so that at coordinates (c, d), the concentration c has a positive coordinate point and the thickness d has a positive coordinate point.Type: ApplicationFiled: December 20, 2017Publication date: June 21, 2018Inventors: Yusuke TODO, Mitsunobu NAKATO, Hiroaki YOTO
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Publication number: 20180017520Abstract: A gas sensor includes a sensor element. The sensor element includes; a solid electrolyte body that has oxygen ion conductivity and includes a first main surface exposed to a gas to be measured and a second main surface exposed to a reference gas; a sensor electrode that is provided on the first main surface and detects a specific gas component in the gas to be measured; and a reference electrode that is provided on the second main surface. The sensor electrode is made of a Pt—Rh alloy that contains 30 mass % to 70 mass % Pt and 70 mass % to 30 mass % Rh, when an overall noble metal component is 100 mass %. A variation amount of the Rh content of the Pt—Rh alloy from an outermost surface to a depth of 350 nm in a thickness direction of the sensor electrode is within a range of up to 10 mass %.Type: ApplicationFiled: July 14, 2017Publication date: January 18, 2018Inventors: Yusuke TODO, Mitsunobu NAKATO, Hiroaki YOTO, Hiroki ICHIKAWA