公开(公告)号：US20220236212A1

公开(公告)日：2022-07-28

申请号：US17577426

申请日：2022-01-18

Applicant: NGK Insulators, Ltd.

Inventor： Takayuki SEKIYA ,  Yusuke WATANABE ,  Shiho IWAI

IPC: G01N27/409 ,  G01N33/00 ,  G01N27/41 ,  G01N27/417 ,  G01N27/407

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 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 electrode includes a noble metal, the solid electrolyte, and a pore, and, in the internal electrode, a degree of variation 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 in a thickness direction of the element is 0.5 μm or more and 6.5 μm or less.

公开(公告)号：US20220011258A1

公开(公告)日：2022-01-13

申请号：US17487027

申请日：2021-09-28

Applicant: NGK INSULATORS, LTD.

Inventor： Takayuki SEKIYA ,  Yusuke WATANABE

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

Abstract: Provided are a gas sensor and a method for controlling the gas sensor, wherein the gas sensor comprises: a heater unit which performs a temperature adjustment of heating and keeping a sensor element warm; a pump drive control unit which controls pump driving for at least a gas-to-be measured flow unit; a measurement pump cell which detects a concentration of a specific gas in the gas to be measured, on the basis of an electromotive force generated between a reference electrode and a measurement electrode; a heater control unit which controls the heater unit; and a pump stop unit which stops the pump driving by the pump drive control unit after the heater control unit stops energizing the heater unit.

公开(公告)号：US20210389269A1

公开(公告)日：2021-12-16

申请号：US17460763

申请日：2021-08-30

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo ONISHI ,  Yusuke WATANABE ,  Takashi HINO

IPC: G01N27/407

Abstract: A leading-end protective layer of a sensor element includes: an inner layer covering a leading end surface and four side surfaces of an element base; and an outer layer covering the inner layer and having a lower porosity than the inner layer, and a film thickness variation degree, defined as a ratio of a difference between a maximum and a minimum value of total thicknesses of the leading-end protective layer at following positions with respect to an average value of the total thicknesses when the value is based at 100, is 20 or less: two positions to intersect with the protective layer, on planes passing through line intersections of an imaginary plane containing the end surface and imaginary planes containing main surfaces of the element base, and forming an angle of 45° with the former imaginary plane, and an intermediate position in an element thickness direction on the end surface.

公开(公告)号：US20210302400A1

公开(公告)日：2021-09-30

申请号：US17208060

申请日：2021-03-22

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA

IPC: G01N33/00 ,  G01N27/419 ,  G01N27/409 ,  G01N27/407 ,  G01N27/41

Abstract: A limiting-current type gas sensor including a sensor element including a base part made of an oxygen-ion conductive solid electrolyte and measuring concentration of NOx in a measurement gas includes: a pump cell including a first electrode disposed to be capable of being in contact with a gas introduced into the element and a second electrode disposed so that a part made of the solid electrolyte is located between the first electrode and the second electrode; and a pumping diagnostic part to determine whether an inter-electrode electric field produced in the part made of the solid electrolyte through application of a predetermined pump voltage between the electrodes exceeds a first threshold, and, when the inter-electrode electric field exceeds the first threshold, the predetermined pump voltage is reduced so that the inter-electrode electric field falls below the first threshold.

公开(公告)号：US20210302363A1

公开(公告)日：2021-09-30

申请号：US17205199

申请日：2021-03-18

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE

IPC: G01N27/41 ,  G01M15/10

Abstract: A sensor element includes an element body provided with a measurement-object gas flow section therein; a measurement electrode disposed in the measurement-object gas flow section; a measurement-object-gas side electrode disposed on the element body; a reference electrode disposed inside the element body; and a reference-gas introduction section having a reference-gas introduction space and a porous reference-gas introduction layer, the reference-gas introduction space introducing a reference gas into the element body, the porous reference-gas introduction layer causing the reference gas to flow from the reference-gas introduction space to the reference electrode. Limiting current A as a limiting current when oxygen is pumped out from a periphery of the reference electrode to a periphery of the measurement-object-gas side electrode is 30 μA or lower, A×Ra as a product of a diffusion resistance Ra [/mm] of the reference-gas introduction space and the limiting current A is 50,000 or smaller.

公开(公告)号：US20210302354A1

公开(公告)日：2021-09-30

申请号：US17192070

申请日：2021-03-04

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Takayuki SEKIYA

IPC: G01N27/409 ,  G01N27/407

Abstract: A sensor element for detecting a specific gas concentration in a measurement-object gas includes: an element body including an oxygen-ion-conductive solid electrolyte layer, and having inside a measurement-object gas flow portion that introduces and flows a measurement-object gas and a reference gas chamber used to store a reference gas that is a reference for detecting a specific gas concentration; a reference electrode disposed in the reference gas chamber; and an electrically conductive portion which includes a reference electrode terminal and a reference electrode lead portion that provides electrical continuity between the reference electrode terminal and the reference electrode. The reference gas chamber is provided inside the sensor element in an isolated form, and at least part of the electrically conductive portion is densely formed so as to block movement of oxygen between the reference gas chamber and the outside of the sensor element via the electrically conductive portion.

公开(公告)号：US20210172902A1

公开(公告)日：2021-06-10

申请号：US17113432

申请日：2020-12-07

Applicant: NGK INSULATORS, LTD.

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

IPC: G01N27/406 ,  H01R11/11 ,  G01N27/409 ,  H01R4/18 ,  H01R13/20

Abstract: A metal terminal includes an element contacting portion which is disposed at one end of the metal terminal and is placed in contact with a sensor element, a lead wire retaining member which is disposed at another end of the metal terminal, and crimps and retains lead wires, a positioning member disposed between the one end and the other end and extending in a direction intersecting one direction, the positioning member positioning the metal terminal on a ceramic housing, and a guide member provided integrally with the positioning member at a site between the positioning member and the lead wire retaining member.

公开(公告)号：US20210080424A1

公开(公告)日：2021-03-18

申请号：US17022194

申请日：2020-09-16

Applicant: NGK INSULATORS, LTD.

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

IPC: 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. The plurality of contact members include contact members that each have an outer end surface protruding out from a corresponding one of end surfaces of the sensor element.

公开(公告)号：US20210063343A1

公开(公告)日：2021-03-04

申请号：US16991082

申请日：2020-08-12

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke WATANABE ,  Shotaro NIIZUMA

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

Abstract: A sensor element includes: a sensor electrode disposed on one main surface of a solid electrolyte layer to face a measurement gas introduction space, and having an oxygen decomposition ability and a NOx decomposition ability; a monitor electrode disposed on the one main surface of the solid electrolyte layer to face the measurement gas introduction space, and having the oxygen decomposition ability; and a reference electrode disposed on the other main surface of the solid electrolyte layer to face a reference gas introduction space, wherein a heater element of a heater part overlaps 50% or more of an area of each of the sensor electrode and the monitor electrode in plan view.

公开(公告)号：US20200064302A1

公开(公告)日：2020-02-27

申请号：US16669558

申请日：2019-10-31

Applicant: NGK INSULATORS, LTD.

Inventor： Takayuki SEKIYA ,  Shota KAGEYAMA ,  Yusuke WATANABE

IPC: G01N27/407 ,  G01N27/417

Abstract: A gas sensor element in which oxidation of electrodes and a heater occurring with continued use is suppressed is provided. The gas sensor element includes a plurality of solid electrolyte layers stacked one over another, and includes an electrochemical cell including a pair of electrodes and a portion of the plurality of solid electrolyte layers existing between the pair of electrodes; a heater part capable of heating the gas sensor element; and a gettering layer located between the plurality of solid electrolyte layers and between the plurality of solid electrolyte layers and each of the pair of electrodes, and gettering impurities in a metal component of the electrodes and the heater part during driving of the gas sensor element.