公开(公告)号：US20180059046A1

公开(公告)日：2018-03-01

申请号：US15686239

申请日：2017-08-25

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Noriko HIRATA ,  Yuki NAKAYAMA ,  Kosuke MONNA

IPC: G01N27/407 ,  G01N27/406

CPC classification number: G01N27/4077 ,  G01N27/4067 ,  G01N27/4074 ,  G01N27/4076

Abstract: A gas sensor in which an electrode is prevented from being poisoned is provided. A mixed-potential type gas sensor includes a sensor element composed a solid electrolyte. The sensor element includes: a measurement gas introduction space having an open end at a distal end and extending in a longitudinal direction; a sensing electrode provided on an inner side of the measurement gas introduction space; and a heater configured to heat the sensor element. The concentration of the gas component is determined based on a potential difference between the sensing electrode and a reference electrode, while the heater heats the sensor element so that a place having a temperature higher than the temperature of the sensing electrode and the melting point of a poisoning substance exists between the open end and the sensing electrode and the temperature decreases toward the sensing electrode.

公开(公告)号：US20180011051A1

公开(公告)日：2018-01-11

申请号：US15611053

申请日：2017-06-01

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Noriko HIRATA ,  Yuki NAKAYAMA ,  Kosuke MONNA

IPC: G01N27/407

CPC classification number: G01N27/4077 ,  G01N27/4074 ,  G01N27/4076

Abstract: A mixed-potential type gas sensor capable of preferably determining the concentration of THC including a kind of gas having a large C number is provided. A sensor element composed of an oxygen-ion conductive solid electrolyte is provided with, on its surface, a sensing electrode formed of a cermet of Pt, Au, and an oxygen-ion conductive solid electrolyte, and includes a reference electrode and a porous surface protective layer that covers at least said sensing electrode. An Au abundance ratio on a surface of noble metal particles forming the sensing electrode is 0.3 or more. The surface protective layer has a porosity of 28% to 40%, a thickness of 10 to 50 μm, and an area ratio of a coarse pore having a pore size of 1 μm or larger of 50% or more; or has a porosity of 28% to 40% and a thickness of 10 to 35 μm.

公开(公告)号：US20180010506A1

公开(公告)日：2018-01-11

申请号：US15640683

申请日：2017-07-03

Applicant: NGK INSULATORS, LTD.

Inventor： Kosuke MONNA ,  Taku OKAMOTO ,  Noriko HIRATA

IPC: F01N11/00 ,  F01N3/10

CPC classification number: F01N11/002 ,  F01N3/10 ,  F01N3/103 ,  F01N11/00 ,  F01N11/007 ,  F01N2550/02 ,  F01N2560/02 ,  F01N2560/026 ,  F01N2560/06 ,  F01N2900/0416 ,  Y02T10/47

Abstract: Provided is a method for diagnosing whether an oxidation catalyst has degraded, based on an output value from one diagnostic sensor with higher accuracy. When a ratio of nitrogen monoxide that is oxidized by a catalyst and discharged downstream of the catalyst as nitrogen dioxide, with respect to nitrogen monoxide contained in an exhaust gas supplied upstream of the catalyst in an exhaust path is defined as a NO conversion rate, a diagnostic sensor configured to output an electromotive force corresponding to the NO conversion rate as a diagnostic output is provided downstream of the catalyst in the exhaust path, and whether the catalyst has degraded beyond an acceptable limit is diagnosed by comparing the diagnostic output with a threshold value predetermined depending on a temperature of the catalyst.

公开(公告)号：US20140011113A1

公开(公告)日：2014-01-09

申请号：US13926120

申请日：2013-06-25

Applicant: NGK INSULATORS, LTD.

Inventor： Makoto OHMORI ,  Takashi RYU ,  Taku OKAMOTO

IPC: H01M8/02

CPC classification number: H01M8/0271 ,  H01M8/0258 ,  H01M8/1213 ,  H01M8/241 ,  H01M2008/1293

Abstract: The fuel cell includes a porous body including Ni particles, ceramic particles and pores; a power-generating section having an anode active layer formed on the porous body; and a dense interconnector formed on the porous body, and electrically connected with the anode active layer. When the porous body is exposed to a reducing atmosphere, the ceramic particles and the pores is greater than or equal to 14 volume % and less than or equal to 55 volume % in the contacting region, a volume ratio of the Ni particles to the total volume is greater than or equal to 15 volume % and less than or equal to 50 volume % in the contacting region, and a volume ratio of the Ni particles to a sum volume of a volume of the ceramic particles and a volume of the Ni particles is less than or equal to 82.5 volume % in the contacting region.

Abstract translation: 燃料电池包括包括Ni颗粒，陶瓷颗粒和孔的多孔体; 具有形成在所述多孔体上的阳极活性层的发电部; 以及形成在多孔体上并与阳极活性层电连接的致密互连器。 当多孔体暴露于还原气氛时，陶瓷颗粒和孔隙在接触区域中大于或等于14体积％且小于或等于55体积％，Ni颗粒与总体积的体积比 体积在接触区域中大于或等于15体积％且小于或等于50体积％，并且Ni颗粒与陶瓷颗粒的体积的总体积的体积比和Ni颗粒的体积 在接触区域中小于或等于82.5体积％。

公开(公告)号：US20220178869A1

公开(公告)日：2022-06-09

申请号：US17531870

申请日：2021-11-22

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Soichiro YOSHIDA ,  Ryo HASHIKAWA

IPC: G01N27/409 ,  G01N27/30 ,  G01N27/41 ,  G01N33/00 ,  G01N27/406 ,  G01N27/419

Abstract: A gas sensor includes a sensor element including an element body, a measurement pump cell being configured to pump out oxygen from surroundings of an inner measurement electrode to surroundings of an outer measurement electrode, and a measurement voltage detection sensor cell that detects a measurement voltage between a reference electrode and the inner measurement electrode, and a pump cell controller that executes a normal time measurement pump control process of pumping out oxygen in the measurement chamber during a normal operation time of the sensor element so that the measurement voltage reaches a normal time target value, and executes a start-up time measurement pump control process of pumping out oxygen in the measurement chamber at a start-up time of the sensor element earlier than the normal operation time so that the measurement voltage reaches a start-up time target value higher than the normal time target value.

公开(公告)号：US20220113280A1

公开(公告)日：2022-04-14

申请号：US17558775

申请日：2021-12-22

Applicant: NGK INSULATORS, LTD.

Inventor： Kunihiko NAKAGAKI ,  Taku OKAMOTO ,  Osamu NAKASONE ,  Nobukazu IKOMA

IPC: G01N27/41 ,  G01N27/407 ,  F01N11/00 ,  G01M15/10

Abstract: A gas sensor includes an element body, an adjustment pump cell, a preliminary pump cell, a measurement electrode, a reference electrode, a specific gas concentration detection device. The element body provides a measurement-object gas flow section to allow a measurement-object gas to be introduced into and flow through the measurement-object gas flow section. The adjustment pump cell adjusts an oxygen concentration of an oxygen concentration adjustment chamber in the measurement-object gas flow section. The preliminary pump cell pumps oxygen into a preliminary chamber to prevent the measurement-object gas in a low-oxygen atmosphere from reaching the oxygen concentration adjustment chamber, the preliminary chamber being provided upstream of the oxygen concentration adjustment chamber in the measurement-object gas flow section. The measurement electrode is disposed on an inner peripheral surface of a measurement chamber provided downstream of the oxygen concentration adjustment chamber in the measurement-object gas flow section.

公开(公告)号：US20200088666A1

公开(公告)日：2020-03-19

申请号：US16688101

申请日：2019-11-19

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Yuki NAKAYAMA ,  Kosuke MONNA ,  Osamu NAKASONE

IPC: G01N27/02 ,  G01N27/407 ,  G01N27/417

Abstract: Provided is a method of suitably judging necessity of a recovering process carried out on a mixed-potential gas sensor based on an extent of reversible deterioration occurring in a sensing electrode. The method includes the steps of: (a) performing impedance measurement between a sensing electrode exposed to a measurement gas and a reference electrode exposed to a reference atmosphere, which are provided in the gas sensor; and (b) judging necessity of a recovering process based on electrode reaction resistance or a diagnosis parameter correlating with the electrode reaction resistance wherein the electrode reaction resistance and the diagnosis parameter are obtained based on a result of the impedance measurement. The two steps are intermittently or periodically repeated during use of the gas sensor, and it is judged that a recovering process is necessary when the judge parameter satisfies a predetermined threshold condition in the step (b).

公开(公告)号：US20200080459A1

公开(公告)日：2020-03-12

申请号：US16555005

申请日：2019-08-29

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Osamu NAKASONE

IPC: F01N11/00 ,  B01D53/94 ,  G01M15/10 ,  F02D41/14 ,  F01N3/10

Abstract: A catalyst deterioration diagnosis method is a method for a system. The system includes a stepped transmission or a continuously variable transmission connected to an internal combustion engine, a catalyst into which an exhaust gas from the internal combustion engine is introduced, and a gas sensor having sensitivity to ammonia that outputs a detection value corresponding to a component of an exhaust gas that has passed through the catalyst. The catalyst deterioration diagnosis method includes the following steps. Monitoring of temporary increase of a detection value of the gas sensor is started, and thereby a temporarily increased amount of the detection value of the gas sensor is acquired. The monitoring is started when upshifting of the stepped transmission or pseudo-upshifting of the continuously variable transmission is performed. Whether or not the temporarily increased amount is larger than a threshold amount is determined.

公开(公告)号：US20200003724A1

公开(公告)日：2020-01-02

申请号：US16452714

申请日：2019-06-26

Applicant: NGK INSULATORS, LTD.

Inventor： Osamu NAKASONE ,  Taku OKAMOTO ,  Nobukazu IKOMA

IPC: G01N27/407 ,  G01N27/41

Abstract: A gas sensor detects the concentration of a specific gas on the basis of a pump current that flows when oxygen is pumped out from a measurement chamber, so that an oxygen concentration in the measurement chamber becomes a predetermined low concentration, the oxygen that is pumped out being oxygen that is generated when the specific gas is reduced in measurement chamber in a case where the specific gas is an oxide or being oxygen that is generated when a gas obtained as a result of conversion of the specific gas to an oxide is reduced in the measurement chamber in a case where the specific gas is a non-oxide. Further, the gas sensor corrects the pump current or the concentration of the specific gas on the basis of the oxygen concentration of the measurement-object gas when the measurement-object gas is in a rich atmosphere.

公开(公告)号：US20190383767A1

公开(公告)日：2019-12-19

申请号：US16438530

申请日：2019-06-12

Applicant: NGK INSULATORS, LTD.

Inventor： Kunihiko NAKAGAKI ,  Taku OKAMOTO ,  Nobukazu IKOMA

IPC: G01N27/41 ,  G01N27/407

Abstract: A gas sensor includes a structural body made up from a solid electrolyte that exhibits oxygen ion conductivity, a gas introduction port formed in the structural body, a preliminary chamber communicating with the gas introduction port and equipped with a preliminary pump electrode, a main chamber communicating with the preliminary chamber and equipped with a main pump electrode, and a measurement chamber communicating with the main chamber and equipped with a measurement electrode. In the gas sensor, at least a surface of the preliminary pump electrode is made of a material which exhibits a low activity with respect to a reaction between ammonia and oxygen.