公开(公告)号：US20220283114A1

公开(公告)日：2022-09-08

申请号：US17825062

申请日：2022-05-26

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Soichiro YOSHIDA ,  Ryo HASHIKAWA

IPC: G01N27/407

Abstract: A gas sensor includes a sensor element and a pump cell controller. The pump cell controller performs a normal time control process after a heater control process is started, the normal time control process including a main pump control process, an auxiliary pump control process of controlling an auxiliary pump cell so that a voltage for auxiliary pump reaches a target value, and a normal time measurement pump control process of pumping out oxygen in a measurement chamber by controlling the measurement pump cell so that a measurement voltage reaches a normal time target value. In an early stage of the normal time control process, the pump cell controller performs a correction process of correcting the target value of the voltage for auxiliary pump to a value higher than a target value in a period after the early stage.

公开(公告)号：US20220299464A1

公开(公告)日：2022-09-22

申请号：US17825080

申请日：2022-05-26

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Soichiro YOSHIDA ,  Ryo HASHIKAWA

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

Abstract: A gas sensor includes a sensor element and a pump cell controller. During a normal operation time of the sensor element, the pump cell controller executes a normal time measurement pump control process of pumping out the oxygen in a measurement chamber by controlling a measurement pump cell so that voltage for measurement reaches a normal time target value. At the start-up time of the sensor element, the pump cell controller executes a start-up time measurement pump control process of pumping out the oxygen in the measurement chamber by controlling the measurement pump cell so that the voltage for measurement reaches a start-up time target value higher than the normal time target value. When determining that the oxygen concentration in the measurement chamber is stabilized, the pump cell controller makes switching from the start-up time measurement pump control process to the normal time measurement pump control process.

公开(公告)号：US20210302356A1

公开(公告)日：2021-09-30

申请号：US17213775

申请日：2021-03-26

Applicant: NGK INSULATORS, LTD.

Inventor： Soichiro YOSHIDA ,  Kunihiko NAKAGAKI

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

Abstract: A gas sensor includes a laminated body constituted by at least two ceramic layers laminated thereon, and having at least one gas introduction port, and at least one internal vacancy, and an outer side electrode formed on the laminated body, and provided in order to discharge oxygen from the internal vacancy, wherein a slit portion connected to an external space, and which is formed in the laminated body in covering relation to the outer side electrode, is interposed between the ceramic layers and the outer side electrode.

公开(公告)号：US20220178869A1

公开(公告)日：2022-06-09

申请号：US17531870

申请日：2021-11-22

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Soichiro YOSHIDA ,  Ryo HASHIKAWA

IPC: G01N27/409 ,  G01N27/30 ,  G01N27/41 ,  G01N33/00 ,  G01N27/406 ,  G01N27/419

Abstract: A gas sensor includes a sensor element including an element body, a measurement pump cell being configured to pump out oxygen from surroundings of an inner measurement electrode to surroundings of an outer measurement electrode, and a measurement voltage detection sensor cell that detects a measurement voltage between a reference electrode and the inner measurement electrode, and a pump cell controller that executes a normal time measurement pump control process of pumping out oxygen in the measurement chamber during a normal operation time of the sensor element so that the measurement voltage reaches a normal time target value, and executes a start-up time measurement pump control process of pumping out oxygen in the measurement chamber at a start-up time of the sensor element earlier than the normal operation time so that the measurement voltage reaches a start-up time target value higher than the normal time target value.

公开(公告)号：US20180356364A1

公开(公告)日：2018-12-13

申请号：US15996560

申请日：2018-06-04

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Yuki NAKAYAMA ,  Soichiro YOSHIDA

IPC: G01N27/416 ,  G01N27/04

Abstract: A method of inspecting an electrode provided in a gas sensor element includes the steps of: producing, in advance, a calibration curve representing a relation between an Au maldistribution degree defined based on a ratio of an area of a portion at which Au is exposed on a noble metal particle surface and calculated from a result of XPS or AES analysis on an inspection target electrode, and a predetermined alternative maldistribution degree index correlated with the Au maldistribution degree and acquired in a non-destructive manner from the gas sensor element heated to a predetermined temperature; acquiring a value of the alternative maldistribution degree index for the inspection target electrode of the gas sensor element while the gas sensor element is heated to the predetermined temperature; and determining whether the Au maldistribution degree satisfies a predetermined standard based on the calibration curve and the acquired inspection value.

公开(公告)号：US20220107288A1

公开(公告)日：2022-04-07

申请号：US17487009

申请日：2021-09-28

Applicant: NGK Insulators, Ltd.

Inventor： Soichiro YOSHIDA ,  Kosuke UJIHARA

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

Abstract: The gas sensor is configured to measure a concentration of a predetermined gas component. The gas sensor includes a sensor element. An internal cavity configured to introduce the measurement target gas from an external space is formed inside the sensor element. The sensor element has a long side and a short side in a plan view. In the sensor element, a proportion of a length in the short side direction of a portion that is shortest in the short side direction, out of portions in which the internal cavity is not formed, to the length of the short side is 0.22 or more. The sensor element has an upper face and a lower face. A proportion of a length from the end portion of the internal cavity near the lower face to the lower face, to a thickness of the sensor element, is 0.50 or more and 0.65 or less.

公开(公告)号：US20190025244A1

公开(公告)日：2019-01-24

申请号：US16035750

申请日：2018-07-16

Applicant: NGK INSULATORS, LTD.

Inventor： Taku OKAMOTO ,  Yuki NAKAYAMA ,  Soichiro YOSHIDA

IPC: G01N27/407 ,  G01N27/417 ,  G01N27/30 ,  G01N27/406

CPC classification number: G01N27/4071 ,  G01N27/301 ,  G01N27/4067 ,  G01N27/4076 ,  G01N27/4077 ,  G01N27/4175

Abstract: A gas sensor includes a sensor element made of an oxygen-ion conductive solid electrolyte and is configured to determine a concentration of a measurement target gas component based on a sensitivity characteristic as a predetermined functional relation held between a sensor output and the concentration of the gas component. The sensor output is a potential difference generated between a sensing electrode of the sensor element heated to a predetermined sensor drive temperature and a reference electrode. At the reference electrode, Au is concentrated at a predetermined maldistribution degree on the surface of a noble metal particle. In the present invention, the sensitivity characteristic is calibrated so as to suit the maldistribution degree at the reference electrode, based on the value of a predetermined alternative maldistribution degree index acquired in a non-destructive manner by performing predetermined measurement while the sensor element is heated to the predetermined temperature.