公开(公告)号：US20210063344A1

公开(公告)日：2021-03-04

申请号：US16996032

申请日：2020-08-18

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shiho IWAI

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

Abstract: In a sensor element for a limiting-current type gas sensor measuring concentration of NOx in a measurement gas, an inner pump electrode located to face a first internal space communicating, under predetermined diffusion resistance, with a gas inlet through which a measurement gas is introduced from an external space is made of a cermet of a Pt—Au alloy and zirconia, and includes a first portion located on a surface farther from a heater part and a second portion located on a surface closer to the heater part from among surfaces opposing each other in the first internal space, an Au content with respect to the Pt—Au alloy as a whole of the second portion is 0.3 wt % or more smaller than that of the first portion, and a total area of the first portion and the second portion is 10 mm2 to 25 mm2.

公开(公告)号：US20200284752A1

公开(公告)日：2020-09-10

申请号：US16879163

申请日：2020-05-20

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takao MURASE ,  Masashi YASUI ,  Rui SAKAGUCHI

IPC: G01N27/406 ,  H05B1/02 ,  H05B3/26

Abstract: The heater 72 of the heater portion includes the linear portions 78 and the bend portions 77. A resistance value per unit length of the bend portions 77 at least at a temperature within a temperature range of no less than 700° C. and no more than 900° C. is lower than a resistance value per unit length of the linear portions 78.

公开(公告)号：US20200271618A1

公开(公告)日：2020-08-27

申请号：US16795806

申请日：2020-02-20

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo ONISHI ,  Yusuke WATANABE

IPC: G01N27/407

Abstract: A sensor element is used to detect the concentration of a predetermined component in a gas. The sensor element includes a sensor element body including a solid-state-electrolyte layer having oxygen-ion conductivity, an outer pump electrode that is disposed on an upper surface, which is one of the surfaces, of the sensor element body, and a porous protective layer that is provided so as to cover at least the outer pump electrode. A spatial layer is provided between the porous protective layer and the sensor element body. The spatial layer includes a first spatial layer between the porous protective layer and the outer pump electrode. The maximum-height roughness Rz of a region of the inner surface of the porous protective layer, the region facing the outer pump electrode, is 50 μm or smaller.

公开(公告)号：US20200041441A1

公开(公告)日：2020-02-06

申请号：US16522720

申请日：2019-07-26

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：US20200041440A1

公开(公告)日：2020-02-06

申请号：US16522718

申请日：2019-07-26

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 a gas inlet at one end portion thereof; at least two internal chambers 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 chambers, and solid electrolytes 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 part from a leading end surface to two internal chambers close to the gas inlet of the element base. A single heat insulating space is interposed between the leading-end protective layer and a portion of the element base in which the two internal chambers are located.

公开(公告)号：US20190293585A1

公开(公告)日：2019-09-26

申请号：US16434594

申请日：2019-06-07

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takao MURASE ,  Masashi YASUI

IPC: G01N27/02 ,  G01N33/00 ,  G01N27/407

Abstract: A gas sensor 10 includes a tubular protective cover 30 having an element chamber 37 therein and configured to allow a measured gas to flow from the outside into the element chamber 37; and a long sensor element 20 including a detecting portion 23 located in the element chamber 37 and configured to detect a specified gas concentration in the measured gas. An inclination angle θt of an axial direction of the sensor element 20 (i.e., a direction parallel to an element axis A1) in the element chamber 37 with respect to an axial direction of the protective cover 30 (i.e., a direction parallel to a cover axis A2) is 1° or greater.

公开(公告)号：US20190285573A1

公开(公告)日：2019-09-19

申请号：US16351565

申请日：2019-03-13

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA

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

Abstract: A sensor element includes: a main pump cell constituted by an inner pump electrode facing a first inner space into which a measurement gas is introduced, an external pump electrode provided on a surface of the sensor element, and a solid electrolyte located therebetween; and a measurement pump cell constituted by a measurement electrode facing a second inner space communicated with the first inner space and functioning as a reduction catalyst for NOx; and a solid electrolyte located therebetween. The inner pump electrode is a cermet made of Pt and ZrO2, the inner pump electrode has a porosity ranging from 1-5% and a thickness ranging from 5-20 μm, a resistance of the main pump cell is equal to or smaller than 150Ω, and a diffusion resistance from the gas inlet to the inner pump electrode is ranging from 200-1000 cm−1.

公开(公告)号：US20180284052A1

公开(公告)日：2018-10-04

申请号：US15938118

申请日：2018-03-28

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA

IPC: G01N27/407

Abstract: A gas sensor includes reference gas regulating device that applies a control voltage that is set between the reference electrode and the measurement-object gas side electrode; and a detecting device that detects the specific gas concentration in the measurement-object gas on the basis of a voltage between the reference electrode and the measurement electrode during a second period, from among a first period that is started upon setting of the control voltage to on state, during which a potential difference between the reference electrode and the measurement-object gas side electrode is large, and the second period that is started upon setting of the control voltage to off state after the potential difference falls from the first period. Tf, a fall time of the potential difference between the first period and the second period, and T2, a second time that is a length of the second period, satisfies Tf≤T2.

公开(公告)号：US20170089852A1

公开(公告)日：2017-03-30

申请号：US15248160

申请日：2016-08-26

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takao MURASE ,  Masashi YASUI

IPC: G01N27/02 ,  G01N33/00

Abstract: A gas sensor 10 includes a tubular protective cover 30 having an element chamber 37 therein and configured to allow a measured gas to flow from the outside into the element chamber 37; and a long sensor element 20 including a detecting portion 23 located in the element chamber 37 and configured to detect a specified gas concentration in the measured gas. An inclination angle θt of an axial direction of the sensor element 20 (i.e., a direction parallel to an element axis A1) in the element chamber 37 with respect to an axial direction of the protective cover 30 (i.e., a direction parallel to a cover axis A2) is 1° or greater.