公开(公告)号：US20180284058A1

公开(公告)日：2018-10-04

申请号：US15938279

申请日：2018-03-28

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe ,  Takayuki Sekiya

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

Abstract: A gas sensor includes a reference gas regulating device that applies a control voltage that is repetitively set to on state and off state between the reference electrode and the measurement-object gas side electrode to pump in oxygen to the periphery of the reference 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.

公开(公告)号：US12265054B2

公开(公告)日：2025-04-01

申请号：US17702005

申请日：2022-03-23

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe ,  Takayuki Sekiya

IPC: G01N27/41 ,  G01N27/407 ,  G01N27/409 ,  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：US12222314B2

公开(公告)日：2025-02-11

申请号：US17577426

申请日：2022-01-18

Applicant: NGK Insulators, Ltd.

Inventor： Takayuki Sekiya ,  Yusuke Watanabe ,  Shiho Iwai

IPC: G01N27/41 ,  G01N27/406 ,  G01N27/407 ,  G01N27/409 ,  G01N27/417 ,  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 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：US12222313B2

公开(公告)日：2025-02-11

申请号：US17577423

申请日：2022-01-18

Applicant: NGK Insulators, Ltd.

Inventor： Takayuki Sekiya ,  Yusuke Watanabe ,  Shiho Iwai

IPC: G01N27/41 ,  G01N27/406 ,  G01N27/407 ,  G01N27/409 ,  G01N27/417 ,  G01N33/00

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：US12140579B2

公开(公告)日：2024-11-12

申请号：US17989745

申请日：2022-11-18

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe ,  Takayuki Sekiya ,  Daichi Ichikawa

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

Abstract: A controller of the gas sensor can perform diagnostic processing of diagnosing a situation of control to the gas sensor in a case that the gas sensor in an operation state is determined to satisfy a predetermined diagnostic condition and adjustment processing of adjusting a condition for controlling the gas sensor in accordance with a result of diagnosis. In the diagnostic processing, a main pump voltage and a diagnostic threshold as a value of a voltage not causing decomposition of NOx in the main pump cell are compared. In the adjustment processing, temperature adjustment processing to cause, in a case that the main pump voltage is diagnosed to be equal to the threshold or more, the main pump voltage to be less than the threshold, at least in a way that the heater part increases the element driving temperature in the operation state by a predetermined increase amount is performed.

公开(公告)号：US12135307B2

公开(公告)日：2024-11-05

申请号：US17460752

申请日：2021-08-30

Applicant: NGK INSULATORS, LTD.

Inventor： Ryo Onishi ,  Yusuke Watanabe ,  Takashi Hino

IPC: G01N27/407 ,  G01N27/41

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：US12066397B2

公开(公告)日：2024-08-20

申请号：US17205199

申请日：2021-03-18

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe

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

CPC classification number: G01N27/41 ,  G01M15/102 ,  G01N27/4072 ,  G01N27/4075

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：US11940406B2

公开(公告)日：2024-03-26

申请号：US17205617

申请日：2021-03-18

Applicant: NGK INSULATORS, LTD.

Inventor： Takayuki Sekiya ,  Yusuke Watanabe

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

CPC classification number: G01N27/409 ,  G01N27/4072 ,  G01N27/41 ,  G01N27/419 ,  G01N33/0037

Abstract: A sensor element includes an element body having a measurement-object gas flow section being provided therein, a first measurement pump cell that includes a first measurement electrode being disposed in a first measurement chamber and a first outer measurement electrode and that pumps out oxygen produced in a first measurement chamber, and a second measurement pump cell that includes a second measurement electrode being disposed in a second measurement chamber and a second outer measurement electrode and that pumps out oxygen produced in a second measurement chamber. The measurement-object gas flow section is configured such that a measurement-object gas passes through an oxygen concentration adjustment chamber and a first measurement-electrode diffusion-rate-controlling section in this order and reaches the first measurement chamber and that the measurement-object gas passes through the first measurement chamber and a second measurement-electrode diffusion-rate-controlling section in this order and reaches the second measurement chamber.

公开(公告)号：US11885765B2

公开(公告)日：2024-01-30

申请号：US17207996

申请日：2021-03-22

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe ,  Mika Kai ,  Ryo Onishi ,  Saki Suzuki ,  Takashi Hino

IPC: G01N27/407 ,  C04B38/00 ,  G01N27/41 ,  G01N27/419

CPC classification number: G01N27/4077 ,  C04B38/00 ,  G01N27/4071 ,  G01N27/4078 ,  G01N27/41 ,  G01N27/419

Abstract: A sensor element includes: an inner protective layer having a porosity of 30% to 65% on two main surfaces; an intermediate protective layer having a porosity of 25% to 80%, which is equal to or smaller than the porosity of the inner layer; and an outer protective layer surrounding an element base on an outermost periphery on the one end portion of the element, and having a porosity of 15% to 30%, which is smaller than the porosity of the intermediate layer, wherein these layers are laminated in this order at least in a range in which the at least one inner chamber is provided in the element base, the outer is in contact with the inner layer in a range in which the at least one inner chamber is not provided, and a difference of porosity between the inner layer and the outer layer is 10% to 50%.

公开(公告)号：US11885764B2

公开(公告)日：2024-01-30

申请号：US17353870

申请日：2021-06-22

Applicant: NGK INSULATORS, LTD.

Inventor： Yusuke Watanabe ,  Tetsuya Ishikawa

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

CPC classification number: G01N27/4071 ,  G01N27/4072 ,  G01N27/41 ,  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.