公开(公告)号：US20220308010A1

公开(公告)日：2022-09-29

申请号：US17702005

申请日：2022-03-23

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA

IPC: G01N27/41 ,  G01N27/409 ,  G01N27/407 ,  G01N33/00

Abstract: A sensor element includes a base part including a plurality of oxygen-ion-conductive solid electrolyte layers stacked; a measurement-object gas flow part for introduction and flow of a measurement-object gas through one end part in a longitudinal direction of the base part; a main pump cell including an inner main pump electrode disposed on an inner surface of the measurement-object gas flow part, and an outer pump electrode; a target-gas-decomposing pump cell including a target-gas-decomposing pump electrode disposed at a position farther from the one end part than the inner main pump electrode, and an outer pump electrode; a residual-oxygen-measuring pump cell including a residual-oxygen-measuring electrode disposed at a position farther from the one end part than the inner main pump electrode, and an outer pump electrode; and a reference electrode. The target-gas-decomposing pump electrode comprises a metal material that has catalytic activity of decomposing a target gas to be measured.

公开(公告)号：US20220236211A1

公开(公告)日：2022-07-28

申请号：US17577425

申请日：2022-01-18

Applicant: NGK Insulators, Ltd.

Inventor： Takayuki SEKIYA ,  Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/409 ,  G01N27/41 ,  G01N33/00

Abstract: A sensor element includes: a base part containing an oxygen-ion conductive solid electrolyte as a constituent material; at least one internal space into which a measurement gas is introduced; and at least one pump cell including an internal electrode disposed to face the at least one internal space, an out-of-space pump electrode disposed at a location other than the at least one internal space, and a portion of the base part located between these electrodes, the internal electrode includes: an upper layer consisting of a noble metal, the solid electrolyte, and a pore; and a lower layer consisting of the noble metal and the solid electrolyte, and a volume ratio of the solid electrolyte in the lower layer is greater than a volume ratio of the solid electrolyte in the upper layer.

公开(公告)号：US20220113279A1

公开(公告)日：2022-04-14

申请号：US17497014

申请日：2021-10-08

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shotaro NIIZUMA ,  Toshihiro HIRAKAWA ,  Hayami AOTA

IPC: G01N27/41 ,  G01N27/407

Abstract: A gas sensor includes: a laminate including at least one layer made of a solid electrolyte; a measured gas flow path formed in the laminate; and a pump electrode exposed in the measured gas flow path. In a part of a rear end side region, the pump electrode is sandwiched between a first layer and a second layer or is covered with a covering layer formed on the inner surface of the measured gas flow path. The area of a portion exposed in the measured gas flow path, of the pump electrode is 4 mm2 or more. The area of a portion exposed in the measured gas flow path, of the front end side region is larger than the area of a portion exposed in the measured gas flow path, of the rear end side region.

公开(公告)号：US20200309729A1

公开(公告)日：2020-10-01

申请号：US16819925

申请日：2020-03-16

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/409 ,  G01N27/407 ,  G01N27/41 ,  G01N27/30 ,  G01N27/419

Abstract: A gas sensor includes a sensor element, a detection device, a reference gas regulating device. The sensor element includes an element body having disposed therein a measurement-object gas flow section, a measurement-object-gas-side electrode disposed in or out of the element body, a reference electrode disposed within the element body, and a reference gas introducing section that allows a reference gas to be introduced thereinto and to flow therethrough to the reference electrode. The reference gas regulating device allows an oxygen pump-in current to flow between the reference electrode and the measurement-object-gas-side electrode to pump oxygen into around the reference electrode from around the measurement-object-gas-side electrode. A ratio R1/R2 of a reaction resistance R1 of the reference electrode to a diffusion resistance R2 of the reference gas introducing section is greater than or equal to 0.1 and less than or equal to 2.0.

公开(公告)号：US20200309728A1

公开(公告)日：2020-10-01

申请号：US16819921

申请日：2020-03-16

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/409 ,  G01N27/406 ,  G01N27/419 ,  G01N27/41 ,  G01N27/30 ,  G01N27/407

Abstract: A sensor element includes an element body including an oxygen-ion-conductive solid electrolyte layer, the element body having a longitudinal direction, a measurement electrode disposed in the element body, a reference electrode disposed in the element body so as to come into contact with a reference gas, and a heater configured to heat the solid electrolyte layer. A center of gravity of the reference electrode overlaps the measurement electrode as viewed in a thickness direction of the solid electrolyte layer. A length of each of the reference electrode and the measurement electrode in a front-rear direction is less than or equal to 1.1 mm, the front-rear direction being a direction along the longitudinal direction of the element body. An area of the reference electrode as viewed in the thickness direction is greater than or equal to 1.0 mm2.

公开(公告)号：US20200072784A1

公开(公告)日：2020-03-05

申请号：US16551767

申请日：2019-08-27

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Mika KAI

IPC: G01N27/409 ,  G01N1/22

Abstract: A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having a gas inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet under predetermined diffusion resistance; an electrochemical pump cell including an electrode located on an outer surface of the ceramic body, an electrode facing the internal chamber, and a solid electrolyte located therebetween; and a heater buried in the ceramic body, and a leading-end protective layer being porous, and covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion. The leading-end protective layer has an extension extending into a widened portion included in the gas inlet, and fixed to an inner wall surface of the widened portion.

公开(公告)号：US20200041438A1

公开(公告)日：2020-02-06

申请号：US16522715

申请日：2019-07-26

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Mika KAI ,  Ryo ONISHI ,  Saki SUZUKI

IPC: G01N27/407 ,  G01N27/409 ,  G01N27/416 ,  G01N27/41 ,  G01N27/406

Abstract: A first leading-end protective layer surrounding a first range at least including a leading end surface of an element base is included on a side of one end portion. A single heat insulating space is interposed between the first layer and the element base in the first range. The element base further includes a second leading-end protective layer having a larger porosity than the first layer, and located on a whole side surface at least in the first range. An end portion of the first layer opposite the one end portion is a fixed portion to the second layer. A portion where the fixed portion is in contact with the second layer is 10% to 50%, in area, of the first range. The fixed portion and the second layer make an end portion angle of 5° to 15° in an end portion of the heat insulating space.

公开(公告)号：US20190285574A1

公开(公告)日：2019-09-19

申请号：US16351730

申请日：2019-03-13

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA ,  Yuki NAKAYAMA ,  Shota KAGEYAMA

IPC: G01N27/41 ,  G01N27/30 ,  G01N27/409 ,  G01N27/407

Abstract: A sensor element includes: a first inner space into which a measurement gas is introduced from outside; a second inner space communicated with the first inner space; a main pump cell constituted by an inner pump electrode facing the first inner space, an external pump electrode on a surface of the sensor element, and a solid electrolyte located therebetween; a measurement electrode facing the second inner space and functioning as a reduction catalyst for NOx; and a measurement pump cell constituted by the measurement electrode, the external pump electrode, and a solid electrolyte located therebetween. The inner pump electrode is a cermet made of an Au—Pt alloy containing Au ranging from 0.6 wt % to 1.4 wt % and ZrO2, and has a thickness ranging from 5 μm to 30 μm, a porosity ranging from 5% to 40%, and an area ranging from 5 mm2 to 20 mm2.

公开(公告)号：US20180284057A1

公开(公告)日：2018-10-04

申请号：US15938242

申请日：2018-03-28

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/41 ,  G01N27/407 ,  G01N27/30 ,  G01N27/406

Abstract: A sensor element includes a layered body that includes a measurement-object gas flowing portion which a measurement object gas is introduced and flowed in and a reference electrode that is formed inside of the layered body and a reference gas introducing layer made of a porous material that introduces a reference gas being used as a standard for detection of a specific gas concentration in the measurement-object gas and that flows the reference gas to the reference electrode, the reference gas introducing layer including an inlet portion serving as an inlet of the reference gas and one or more gas flowing spaces provided over a region from the inlet portion to the reference electrode in a direction in which the reference gas is flowed.

公开(公告)号：US20180284056A1

公开(公告)日：2018-10-04

申请号：US15938233

申请日：2018-03-28

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE

IPC: G01N27/41 ,  G01N27/407 ,  G01N27/30 ,  G01N27/406

Abstract: A sensor element includes a porous reference gas introduction layer for introducing a reference gas as a reference for detecting a specific gas concentration of a measurement-object gas from an entrance and allowing the reference gas to flow to a reference electrode disposed at the back, wherein the reference gas introduction layer is divided by a partition position defined to be in the range of 50 to 95% of the full length of the reference gas introduction layer from the entrance toward the inside, into a back side portion and an entrance side portion, the reference electrode is accommodated in the back side portion, and the diffusion resistance Rb of the entrance side portion is higher than the diffusion resistance Ra of the back side portion.