Denso Corporation

Denso Corpora Tion

Kabushiki Kaisha Toyota Chuo Kenkyusho

Takashi Araki

Keigo Mizutani

Masato Katsuno

Mitsunobu Nakato

Mitsunobu Nakatou

Go Miyagawa

Masahiro Yamamoto

Masayuki Tamura

Manabu Yoshidome

Toshihiro Sakawa

Keisuke Mizutani

Takehito Kimata

Yusuke Todo

Yuusuke Toudou

Hirofumi Noda

Yuto Tamei

Tadashi Nakamura

Hiroki Ichikawa

Shota Hagino

Koichi Yoshida

Yuusuke Kawamoto

Kumi Sawaguchi

Yuusuke Endo

Masato Minato

Tatsuya Yoshikawa

Yuji Kawasaki

A gas sensor includes a sensor element including a solid electrolyte, a gas chamber, a pump electrode, a sensor electrode, and a reference electrode. The pump electrode and sensor electrode are provided in the solid electrolyte in a state in which the pump electrode and the sensor electrode are housed in the gas chamber. The reference electrode is provided in the solid electrolyte. The pump electrode and the sensor electrode contain Au. Au content in a surface layer is equal to or greater than 1 mass % and higher than Au content in a reference layer. The surface layer is an area from a surface of the sensor electrode to a depth of 0.3 nanometers. The reference layer is an area located at depths ranging from 2 or more to 3 or less nanometers beneath the surface of the sensor electrode.

Gas sensor

A gas sensor is equipped with a housing, an insulator retained by an inner periphery of the housing, a sensing device having a front end portion protruding from a front end surface of the insulator, and a protective cover which covers a front end portion of the sensing device. A pump electrode and a sensor electrode are disposed in a front end portion of the solid electrolyte body. The pump electrode is exposed to a measurement gas and regulates the concentration of oxygen in the measurement gas. The sensor electrode is exposed to the measurement gas and measures the concentration of a given gas component in the measurement gas after being regulated in concentration of oxygen by the pump electrode. A base end portion of the sensor electrode in a lengthwise direction is located closer to a base end side of the gas sensor than a front end surface of the housing is. This minimizes a variation in temperature of the sensor electrode and enhances the accuracy in measuring the concentration of the given gas component.

An exhaust gas sensor includes an element cover, a heater, a heater control section, and a cover state diagnosing section. The element cover accommodates a sensor element including a detection section and includes one or more gas flow holes. The heater heats the sensor element. The heater control section controls how the heater heats the sensor element. The cover state diagnosing section diagnoses a state of the element cover using heater information obtained when the heater is operated by the heater control section. The cover state diagnosing section includes a diagnosability determining section, which determines whether the state of the element cover is diagnosable based on an accuracy of the heater information obtained from an operating state of the heater and a surrounding environmental state of the element cover.

Exhaust gas sensor

On a cross sectional surface Xof a pump electrodein a gas sensor element forming a gas sensor, a noble metal areahaving Pt&#x2014;Au aggregations, a solid electrolyte areahaving solid electrolyte aggregations, a mixture area in which Pt&#x2014;Au alloy and solid electrolyte are distributed, and pores. The mixture areais formed within a range of 30 to 90% in an overall area of the cross sectional surface X, excepting the pores. The pores are formed adjacent to the mixture area

Pump electrode and reference electrode for gas sensor

A particulate matter detecting apparatus (S) comprises a sensor body (S) which has a sensor device () which is retained in a housing (H) secured to an exhaust pipe () of an internal combustion engine (ENG) and detects particulate matter contained in exhaust gas, a sensor temperature determining unit () which works to determine a temperature of the sensor device, and a mounted condition diagnosis unit () which diagnoses a mounted condition where the sensor body is mounted in the exhaust pipe. The mounted condition diagnosis unit includes a diagnosis threshold setting unit () and a mount error determining unit (). The diagnosis threshold setting unit determines a diagnosis threshold (Tth), as used in a diagnosis of the mounted condition, as a function of an operating condition of the internal combustion engine to have a temperature value lower than a temperature of the sensor device when the sensor body is normally mounted in the exhaust pipe. When a sensor temperature (T), as determined by the sensor temperature determining unit, is lower than the diagnosis threshold, the mount error determining unit determines that an error in the mounted condition is occurring.

Particulate matter detecting apparatus capable of mounted condition diagnosis

An exhaust gas sensor that detects a specific component included in an exhaust gas includes a sensor element including a detector, an element cover that accommodates the sensor element and has a gas ventilation hole, a heater that heats the sensor element, a heater control section, and an installation state diagnosis section that diagnoses a state of an element cover based on a sensor temperature detected by a sensor temperature detection section. The installation state diagnosis section includes a temperature variation amount calculation section that calculates a sensor temperature variation amount, a temperature variation amount integration section that sums the sensor temperature variation amounts, and an abnormality determination section that determines presence or absence of an abnormal installation based on a comparison result between variation amount integration information of the sensor temperature and a diagnosis threshold value.

A sensor device is equipped with a housing having an element cover retaining a sensor element such that a detection section of the sensor element is positioned at the tip end of the sensor element. The element cover includes an inner cover provided with inner side holes and an inner tip face hole respectively provided therein, and an outer cover provided with outer side holes in a side thereof, with the tip position of the outer side holes located closer to the tip end than is the tip position of the inner cover. Between the outer surface of the inner cover and the inner surface of the outer cover there is a large clearance section at the tip end and a small clearance section at the base end, providing a flow path that is shaped for connecting the large clearance section and the small clearance section without a step.

Sensor device detecting specific component in gas

A sensor device includes an element cover at the tip end of a housing, retaining a sensor element. An outer cover is provided with outer side holes, with the tip position of the outer side holes being farther toward the tip end than is the tip position of an inner cover, and a first flow passage having a gas flow direction that is at right angles to the axial direction is formed at the inner side of the outer cover. An inner side hole in the inner cover is open to a second flow passage provided between the side surfaces of the inner cover and the outer cover, and a detection surface of the sensor element is located on an extension line in an extension direction of a guide member which extends obliquely into the interior of the inner cover from the tip-position edge of the inner side hole.

Sensor device

The present invention provides a gas sensor capable of suppressing a variation of a sensor output by a sensor cell to be small. A sensor element of a gas sensor comprises a first solid electrolyte body and a second solid electrolyte body having oxygen ion conductivity, a measured gas chamber into which the measured gas is introduced, a first reference gas chamber and a second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. A value obtained by dividing a first average cross-sectional area of the first reference gas chamber by the first length is larger than the value obtained by dividing the second average cross-sectional area of the second reference gas chamber by the second length.

A PM detection sensor has a sensor body part made of an insulating member and a positive electrode and a negative electrode. The positive electrode is composed of a plurality of positive electrode segments. The negative electrode is composed of a plurality of negative electrode segments. A deposition surface is formed on the sensor body part. These electrode segments are formed on the deposition surface to be exposed to exhaust gas introduced into the inside of the PM detection sensor. The positive electrode segments and the negative electrode segments are arranged adjacently to and separately from each other, on the deposition surface, along a short width direction and a long width direction of each electrode segment. The short width direction and the long width direction are orthogonal to a normal direction of the deposition surface.

Particulate matter detection sensor

Provided is a gas sensor achieving improvement in detection accuracy for a specific gas component and responsiveness for detecting the specific gas component. A guide body is provided at a base end section of a first inner circulation hole in an inner cover of the gas sensor. The base end section is located between a base end position P2 mm away from a tip end of a sensor element in an axial direction L towards a base end side Land a tip end position P2 mm away from the tip end towards a tip end side L. The tip end is on the base end side Lrelative to an imaginary line K passing through a base end and a tip end on a surface on the tip end side of the guide body.

A gas sensor is equipped with a sensor element which detects a specific gas concentration within a gas that is being measured, a housing having the sensor element disposed in the interior thereof and retained therein, and an element cover disposed at an axial-direction tip end of the housing. The tip of the sensor element is provided with a gas introduction part. The element cover has an inner cover and an outer cover, with a space opened between the inner cover and outer cover. Inner side flow holes provided in the inner cover are disposed closer to an axial-direction base end than is a tapered-diameter step part. The distance between the tip of the sensor element and the inner-side flow holes of the inner cover, with respect to an axial direction, is less than or equal to 1.6 mm.

A gas sensor includes a solid electrolyte, a gas chamber, a reference gas chamber, a pump cell, a monitor cell, and a sensor cell. The gas chamber has a spatial width Wconstant in a width direction W orthogonal to the direction of flow of a gas in a position where the pump electrode, the monitor electrode, and the sensor electrode are provided on the solid electrolyte. An amount of shift &#x394;Xof a central position Oof a gap S in the width direction W between the monitor electrode and the sensor electrode from a central position Oin the width direction of the pump electrode has relationship of &#x394;X&#x2264;&#xbc; Wwhere the pump electrode has a width W. In addition, positions &#x394;Yof a of a side surface of the monitor electrode and of a side surface of the sensor electrode from the central position Oin the width direction W of the pump electrode have relationship of &#x394;Y&#x2264;&#xbd; W

Gas sensor for detecting concentration of specific gas component

Provided is a gas sensor improving accuracy of detection of specific gas in measurement gas, while maintaining high responsiveness in detection of the specific gas. A sensor element of a gas sensor includes a first solid electrolyte and second solid electrolyte having oxygen ionic conductivity, a measurement gas chamber into which measurement gas is introduced, a first reference gas chamber and second reference gas chamber into which reference gas is introduced, a first pump cell, a second pump cell, a sensor cell, and a heater. The sensor cell detects a specific gas component in the measurement gas having an oxygen concentration adjusted by the pump cells. The heater is located opposite to a second principal surface of the second solid electrolyte on which the sensor cell is formed.

A gas sensor includes a pump cell unit that regulates the oxygen concentration of a measured gas using a pump electrode, a monitor cell unit that detects the residual oxygen concentration of the measured gas using a monitor electrode, and a sensor cell unit that detects the concentration of a specific gas component in the measured gas using a sensor electrode. Between a pump electrode lead part and the sensor electrode, there is arranged the monitor electrode. Between an upstream portion of the pump electrode lead part and a monitor electrode lead part, there is provided an interval wof 0.5 mm or more.

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Kariya, Japan

Takashi Araki