公开(公告)号：US20240337621A1

公开(公告)日：2024-10-10

申请号：US18744756

申请日：2024-06-17

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo HASHIKAWA ,  Yusuke WATANABE ,  Shingo TANAKA ,  Kazuki ITAMI

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

CPC classification number: G01N27/4072 ,  G01N27/301 ,  G01N27/41

Abstract: A sensor element includes an element body provided with a measurement-object gas flow section therein, a measurement electrode, a reference electrode, a reference-gas introduction section, and a heater that heats the element body. The reference-gas introduction section has a reference-gas introduction space that is open outward of the element body and that introduces a reference gas into the element body, and also has a porous reference-gas introduction layer that causes the reference gas to flow from the reference-gas introduction space to the reference electrode. The reference-gas introduction layer has a first porous region and a second porous region in a path segment serving as a reference-gas path between the reference-gas introduction space and the reference electrode. The second porous region has a low porosity region with a lower porosity than the first porous region and is disposed closer to the reference electrode relative to the first porous region.

公开(公告)号：US20230057032A1

公开(公告)日：2023-02-23

申请号：US17981528

申请日：2022-11-07

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shota KAGEYAMA ,  Yuki NAKAYAMA

IPC: G01N27/419 ,  G01N27/407

Abstract: A sensor element and fabrication method thereof, the sensor element includes: a main pump cell including an inner pump electrode facing a first inner space into which a measurement gas is introduced, an external pump electrode provided on an element surface, and a solid electrolyte therebetween; an auxiliary pump cell including an auxiliary pump electrode provided facing a second inner space, the external pump electrode, and the solid electrolyte therebetween; and a measurement pump cell including a measurement electrode, the external pump electrode, and the solid electrolyte therebetween. The inner pump electrode has a porosity of 10 - 25%, the auxiliary pump electrode has a porosity of 30 - 50%, a thickness ratio of both the electrodes is 1.0 - 4.0, and current flowing to the main pump cell has a current density of 0.05 - 0.5 mA/mm2 when the measurement gas has an oxygen concentration of 20.5%.

公开(公告)号：US20220268727A1

公开(公告)日：2022-08-25

申请号：US17740789

申请日：2022-05-10

Applicant: NGK INSULATORS, LTD.

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

IPC: G01N27/41 ,  G01N27/407

Abstract: A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having an inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the 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 porous leading-end protective layer surrounding a first range at least including a leading end surface and a region to be coped with water-induced cracking specified in advance. A single heat insulating space is interposed between the leading-end protective layer and a whole side surface of the element base at least in the above region.

公开(公告)号：US20220236210A1

公开(公告)日：2022-07-28

申请号：US17577423

申请日：2022-01-18

Applicant: NGK Insulators, Ltd.

Inventor： Takayuki SEKIYA ,  Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/409 ,  G01N27/41 ,  G01N27/417 ,  G01N27/407

Abstract: A sensor element includes a base part containing a 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 space electrode disposed to face the internal space, an out-of-space pump electrode disposed at a location other than the internal space, and a portion of the base part located between these electrodes, the internal space electrode includes a noble metal, the solid electrolyte, and a pore, and, in the internal space electrode, a ratio of a length of a boundary of a first region formed of the base part or the solid electrolyte contiguous with the base part and a second region occupied by the noble metal and the pore to a length of a boundary of the solid electrolyte and the internal space electrode is 1.1 or more.

公开(公告)号：US20220113277A1

公开(公告)日：2022-04-14

申请号：US17497012

申请日：2021-10-08

Applicant: NGK INSULATORS, LTD.

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

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

Abstract: A gas sensor includes: a laminate formed of a plurality of layers including at least one layer of a solid electrolyte; a reference gas chamber formed in the laminate and containing a reference gas; and a reference electrode partially exposed in the reference gas chamber. A portion which is not exposed in the reference gas chamber, of the reference electrode is sandwiched between, among the layers, a first layer and a second layer adjacent to the first layer. When an area of the portion sandwiched between the first layer and the second layer, of the reference electrode is defined as a first area, and an area of a portion exposed in the reference gas chamber, of the reference electrode is defined as a second area, a ratio of the first area to the second area is 0.3 or more.

公开(公告)号：US20220011261A1

公开(公告)日：2022-01-13

申请号：US17483657

申请日：2021-09-23

Applicant: NGK INSULATORS, LTD.

Inventor： Takayuki SEKIYA ,  Yusuke WATANABE

IPC: G01N27/41 ,  G01N33/00 ,  G01N27/407 ,  G01N27/30

Abstract: A gas sensor detects a specific gas concentration in a measurement-object gas and includes an element body and one or more pump cells. The element body includes an oxygen-ion-conductive solid electrolyte layer and is provided with a measurement-object gas flow section therein. The measurement-object gas flow section receives a measurement-object gas and allows the measurement-object gas to flow therethrough. The one or more pump cells each have an inner electrode and an outer pump electrode and pump out oxygen from around the inner electrode to around the outer pump electrode. The inner electrode is disposed in the measurement-object gas flow section and contains a catalytically-active noble metal. At least one pump cell of the one or more pump cells pumps out the oxygen by applying a repeatedly on-off controlled pump current between a measurement electrode and the outer pump electrode.

公开(公告)号：US20220011260A1

公开(公告)日：2022-01-13

申请号：US17482648

申请日：2021-09-23

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo ONISHI ,  Yasuhide KOJIMA ,  Yusuke WATANABE

IPC: G01N27/407 ,  G01M15/10

Abstract: A gas sensor element includes an element body including an oxygen-ion-conductive solid electrolyte layer; and a protective layer that covers at least part of the element body, and has a thermal conductivity ratio R of 1.6 or higher, the thermal conductivity ratio R (=λs/λt) being a surface direction thermal conductivity λs [W/m K] to a thickness direction thermal conductivity λt [W/m K].

公开(公告)号：US20210389268A1

公开(公告)日：2021-12-16

申请号：US17460752

申请日：2021-08-30

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo ONISHI ,  Yusuke WATANABE ,  Takashi HINO

IPC: G01N27/407

Abstract: A sensor element includes: an element base including a gas distribution part communicating from a gas inlet; and a leading-end protective layer including an inner layer covering an end portion and four side surfaces of the element base and an outer layer covering the inner layer and having a lower porosity than the inner layer, and a total thickness representative value, defined as an average of total thicknesses of the protective layer at a plurality of positions including a starting point, an intermediate position, and an innermost end of the gas distribution part, is 250 μm or more, and a film thickness variation degree, defined as a ratio of a difference between a maximum value and a minimum value of the total thicknesses with respect to the total thickness representative value when the value is based at 100, is 20 or less.

公开(公告)号：US20210310982A1

公开(公告)日：2021-10-07

申请号：US17353870

申请日：2021-06-22

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Tetsuya ISHIKAWA

IPC: G01N27/407 ,  G01N27/419

Abstract: A gas sensor according to the present application includes a detecting device that detects a specific gas concentration of a measurement-object gas based on an electromotive force generated between a reference electrode and a measurement electrode; and a reference gas regulating device that flows an oxygen pumping current between the reference electrode and a measurement-object gas side electrode and pumps oxygen from around the measurement-object gas side electrode to around the reference electrode, wherein when the average value of the oxygen pumping current is P and the limiting current value of a reference gas introduction layer when oxygen is pumped from around the reference electrode to around the measurement-object gas side electrode is Q, the ratio Q/P is from 0.8 to 10.

公开(公告)号：US20210080421A1

公开(公告)日：2021-03-18

申请号：US17022184

申请日：2020-09-16

Applicant: NGK INSULATORS, LTD.

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

IPC: G01N27/406 ,  G01N27/407

Abstract: A gas sensor includes: a sensor element; a plurality of element pads formed on a rear end portion of the sensor element; and a plurality of contact members holding the rear end portion of the sensor element and electrically connected respectively to the plurality of element pads. At least one contact member of the plurality of contact members has an end portion having a smaller width Wt than the other contact members.