WO2018194033A1 - ガスセンサ - Google Patents

ガスセンサ Download PDF

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Publication number
WO2018194033A1
WO2018194033A1 PCT/JP2018/015746 JP2018015746W WO2018194033A1 WO 2018194033 A1 WO2018194033 A1 WO 2018194033A1 JP 2018015746 W JP2018015746 W JP 2018015746W WO 2018194033 A1 WO2018194033 A1 WO 2018194033A1
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WO
WIPO (PCT)
Prior art keywords
reference electrode
solid electrolyte
electrolyte body
detection
sensor element
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2018/015746
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English (en)
French (fr)
Japanese (ja)
Inventor
朗 齋藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Denso Corp
Original Assignee
Denso Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Denso Corp filed Critical Denso Corp
Priority to CN201880025844.8A priority Critical patent/CN110546492B/zh
Publication of WO2018194033A1 publication Critical patent/WO2018194033A1/ja
Priority to US16/601,859 priority patent/US11029277B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493—Details
    • F02D41/1494—Control of sensor heater
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4073—Composition or fabrication of the solid electrolyte
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
    • F02D41/1454—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an oxygen content or concentration or the air-fuel ratio
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • F02D41/1493—Details
    • F02D41/1495—Detection of abnormalities in the air/fuel ratio feedback system
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/4067—Means for heating or controlling the temperature of the solid electrolyte
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4077—Means for protecting the electrolyte or the electrodes

Definitions

  • the present disclosure relates to a gas sensor including a sensor element and a heater.
  • the gas sensor arranged in the exhaust pipe of the internal combustion engine uses the exhaust gas flowing in the exhaust pipe as a detection gas (measurement gas), and performs gas detection using the difference in oxygen concentration between this detection gas and a reference gas such as the atmosphere.
  • the gas sensor includes an application for detecting whether the air-fuel ratio of the internal combustion engine determined from the composition of the exhaust gas is on the fuel rich side or the fuel lean side with respect to the stoichiometric air-fuel ratio, and the air-fuel ratio of the internal combustion engine determined from the exhaust gas. There are uses for quantitative detection.
  • a bottomed cylindrical sensor element in which electrodes are arranged on the inner side surface and outer side surface of a bottomed cylindrical solid electrolyte body, or a plate-like sensor element in which electrodes are arranged on both sides of a plate-like solid electrolyte body Is used.
  • a heater for heating the solid electrolyte body and the electrode to the active temperature is disposed inside the solid electrolyte body.
  • the electrode provided on the inner surface of the solid electrolyte body is exposed to a reference gas such as the atmosphere as a reference electrode, and the electrode provided on the outer surface of the solid electrolyte body is: It is exposed to a detection gas as a detection electrode.
  • the detection electrode in the bottomed cylindrical sensor element is provided on a part of the outer surface of the solid electrolyte body in the circumferential direction to form a partial electrode.
  • the reference electrode in the bottomed cylindrical sensor element is generally provided on the entire circumference in the circumferential direction of the inner surface of the solid electrolyte body.
  • a technique for making a detection electrode a partial electrode is disclosed.
  • the circumferential formation range of the detection electrode provided on the outer surface of the solid electrolyte body is reduced as the distance from the heater at the tip of the solid electrolyte body increases.
  • the detection part by the detection electrode arranged on the outer surface of the solid electrolyte body is provided at the position on the tip side of the solid electrolyte body, and the heating part of the heater also has the effect of the detection part.
  • the heating part of the heater In order to heat up automatically, it is provided in the position of the front end side of a solid electrolyte body. Further, the position of the base end side of the detection part in the solid electrolyte body is held in the housing of the gas sensor. Therefore, when the solid electrolyte body is heated by the heater, the temperature at the position on the distal end side of the solid electrolyte body becomes higher than the temperature at the position on the proximal end side of the solid electrolyte body.
  • the performance required for the gas sensor includes heating the solid electrolyte body quickly and at a high temperature to achieve early activation with the solid electrolyte body and electrodes. In order to achieve this early activity, it is conceivable to reduce the amount of heat shrinkage to the housing by partializing not only the detection electrode but also the reference electrode. In the oxygen sensor of Patent Document 1, since the detection electrode is a partial electrode, it is possible to reduce the influence of heat shrinkage on the housing.
  • the present disclosure was obtained by providing a gas sensor that can adjust the shape of the inner lead portion and the circumferential width of the reference electrode to approximate the temperature distribution in the axial direction of the sensor element to the target temperature distribution. It is.
  • One aspect of the present disclosure includes a solid electrolyte body having ion conductivity in which a distal end portion of a cylindrical tube portion is blocked by a curved bottom portion, and a detection provided on an outer surface of the solid electrolyte body and exposed to a detection gas
  • a sensor element having an electrode and a reference electrode provided on an inner surface of the solid electrolyte body and exposed to a reference gas
  • a heater disposed at the inside of the solid electrolyte body in a state having a heat generating part for heating the solid electrolyte body at a tip part and a tip of the tip part contacting an inner surface of the bottom part.
  • the reference electrode is An inner side detection portion provided on the entire circumference in the circumferential direction centering on the central axis of the cylindrical portion at a position closest to the heat generating portion at the most distal end side position of the reference electrode;
  • An inner connection portion provided on the entire circumference or part of the circumferential direction at a position on the most proximal side of the reference electrode and connected to an inner terminal fitting;
  • An inner lead portion provided in a part of the circumferential direction at a position connecting the inner detection portion and the inner connection portion, and having a narrow formation range in the circumferential direction compared to the inner connection portion;
  • the formation range of the inner lead portion in the circumferential direction is a gas sensor that is gradually or taperedly reduced from the inner detection portion toward the inner connection portion.
  • the method of forming the reference electrode in the bottomed cylindrical sensor element is devised.
  • the reference electrode has an inner detection portion, an inner connection portion, and an inner lead portion, and the circumferential width of the inner lead portion decreases stepwise or in a tapered manner from the inner detection portion toward the inner connection portion. is doing.
  • the tip of the tip portion of the heater where the heat generating portion is provided is in contact with the inner side surface of the bottom portion of the solid electrolyte body.
  • the inner detection part of the reference electrode is appropriately heated by the heat generation part, and the sensor from the inner detection part via the inner lead part and the inner connection part Heat transfer to the base end side of the element can be appropriately suppressed.
  • the temperature around the inner detection unit is maintained as close as possible to a high temperature suitable for activation of the solid electrolyte body and each electrode. be able to. Further, by adjusting the shape of the inner lead portion and the circumferential width of the reference electrode, the temperature distribution in the axial direction of the sensor element can be brought close to the target temperature distribution.
  • the configuration of the inner lead portion of the reference electrode is such that the gas sensor is arranged between the detection electrode and the reference electrode according to the difference in oxygen concentration between the detection electrode in contact with the exhaust gas and the reference electrode in contact with the atmosphere. This is effective when used for detecting the electromotive force generated.
  • the air-fuel ratio of the internal combustion engine is in a weak rich region close to the stoichiometric air-fuel ratio due to the configuration of the inner lead portion, the air-fuel ratio and the electromotive force are The slope of the line indicating the above relationship becomes steep, and the detection accuracy of the air-fuel ratio in the weak rich region can be improved.
  • the side on which the bottom of the sensor element is provided is referred to as the distal end side, and the side opposite to the distal end side is referred to as the proximal end side.
  • a gas sensor that can adjust the temperature distribution in the axial direction of the sensor element to a target temperature distribution by adjusting the shape of the inner lead portion and the circumferential width of the reference electrode is provided. be able to.
  • each component is not limited only to the content of embodiment.
  • the gas sensor 1 of this embodiment includes a sensor element 2 and a heater 5.
  • the sensor element 2 includes a solid electrolyte body 3 having ion conductivity in which a distal end portion of a cylindrical tube portion 31 is closed by a curved bottom portion 32, and a solid electrolyte body 3. It has a detection electrode 4B provided on the outer side surface 301 and exposed to the detection gas (measurement gas) G, and a reference electrode 4A provided on the inner side surface 302 of the solid electrolyte body 3 and exposed to the reference gas A.
  • the heater 5 has a heat generating part 521 for heating the solid electrolyte body 3 at the tip, and the tip 501 of the tip is in contact with the inner surface 302 of the bottom 32. It is arranged inside the solid electrolyte body 3.
  • the reference electrode 4A has an inner detection part 41, an inner connection part 43, and an inner lead part 42 as shown in FIG.
  • the inner side detection part 41 is provided over the entire circumference in the circumferential direction C centering on the central axis O of the cylindrical part 31 at the position closest to the heat generating part 521 at the position of the most distal end L1 of the reference electrode 4A. ing.
  • the inner connection portion 43 is provided over the entire circumference in the circumferential direction C at the most proximal end L2 position of the reference electrode 4 ⁇ / b> A, and is connected to the inner terminal fitting 71. ing. As shown in FIGS.
  • the inner lead portion 42 is provided in a part of the circumferential direction C at a position connecting the inner detection portion 41 and the inner connection portion 43.
  • the formation range in the circumferential direction C of the inner lead portion 42 is gradually reduced as it goes from the inner detection portion 41 to the inner connection portion 43.
  • the direction along the central axis O of the sensor element 2 is referred to as an axial direction L, and the direction around the central axis O of the sensor element 2 is referred to as a circumferential direction C.
  • a direction extending radially from the center axis O of 2 is referred to as a radial direction R.
  • the side on which the bottom 32 of the sensor element 2 is provided is referred to as a distal end side L1
  • the side opposite to the distal end side L1 is referred to as a proximal end side L2.
  • the gas sensor 1 is disposed in an exhaust pipe through which exhaust gas exhausted from an internal combustion engine (engine) of a vehicle flows.
  • the gas sensor 1 detects gas using the exhaust gas flowing in the exhaust pipe as the detection gas G and the atmosphere as the reference gas A.
  • the gas sensor 1 of this embodiment detects an electromotive force generated between the detection electrode 4B and the reference electrode 4A via the solid electrolyte body 3, and the air-fuel ratio of the internal combustion engine determined from the composition of the exhaust gas is equal to the theoretical air-fuel ratio.
  • It is used as an oxygen sensor (also referred to as a ⁇ sensor) that determines whether it is on the fuel rich side where the ratio of fuel to air is higher or on the fuel lean side where the ratio of fuel to air is lower than the stoichiometric air-fuel ratio. .
  • the gas sensor 1 is used to bring the air-fuel ratio in the internal combustion engine close to the stoichiometric air-fuel ratio where the catalytic activity of the three-way catalyst disposed in the exhaust pipe is effectively maintained.
  • the gas sensor 1 can be arranged at either the upstream position or the downstream position of the exhaust gas flow with respect to the three-way catalyst arrangement position in the exhaust pipe.
  • the gas sensor 1 of the present embodiment can keep the temperature distribution in the axial direction L of the sensor element 2 appropriately, it can be used effectively even when the exhaust gas of the internal combustion engine becomes colder. Further, the temperature of the exhaust gas is lower at a position downstream of the three-way catalyst in the exhaust pipe than at a position upstream of the three-way catalyst.
  • the gas sensor 1 of this embodiment is preferably arranged at a position downstream of the arrangement position of the three-way catalyst where the temperature of the exhaust gas is lowered.
  • An air-fuel ratio sensor that detects the air-fuel ratio is disposed at a position upstream from the position where the three-way catalyst is disposed, and the air-fuel ratio sensor and the oxygen sensor can be used together in the combustion control of the internal combustion engine. .
  • the solid electrolyte body 3 of the sensor element 2 is mainly composed of zirconia, and is stabilized zirconia or a part in which a part of zirconia is substituted by a rare earth metal element or an alkaline earth metal element. Made of stabilized zirconia.
  • the solid electrolyte body 3 can be composed of yttria stabilized zirconia or yttria partially stabilized zirconia.
  • the solid electrolyte body 3 has ion conductivity that conducts oxide ions (O 2 ⁇ ) at a predetermined activation temperature.
  • the detection electrode 4 ⁇ / b> B and the reference electrode 4 ⁇ / b> A contain platinum that exhibits catalytic activity against oxygen and a material that constitutes the solid electrolyte body 3.
  • the bottom portion 32 of the solid electrolyte body 3 is formed in a hemispherical shape, and the cylindrical portion 31 of the solid electrolyte body 3 is formed in a cylindrical shape.
  • An opening 33 through which the reference gas A can flow into the solid electrolyte body 3 is formed at a position opposite to the bottom 32 in the axial direction L of the solid electrolyte body 3.
  • the outer diameter of each part in the axial direction L of the cylindrical part 31 is appropriately changed in consideration of attachment to the housing 61.
  • the detection electrode 4 ⁇ / b> B includes an outer detection portion 45, an outer connection portion 47, and an outer lead portion 46.
  • the outer side detection part 45 is the position of the most distal end L1 of the detection electrode 4B, and the position facing the inner side detection part 41 across the solid electrolyte body 3, and the circumferential direction C centering on the central axis O of the cylindrical part 31 Is provided over the entire circumference.
  • the outer connection portion 47 is provided over the entire circumference in the circumferential direction C at the most proximal end L2 position of the detection electrode 4B, and is connected to the outer terminal fitting 72.
  • the outer lead portion 46 is provided in a part of the circumferential direction C at a position connecting the outer detection portion 45 and the outer connection portion 47.
  • the inner side detection unit 41 of the reference electrode 4A is longer in the axial direction L than the outer side detection unit 45, and faces the entire inner side of the outer side detection unit 45 with the solid electrolyte body 3 interposed therebetween.
  • the outer connection portion 47 of the detection electrode 4B may be formed only on a part of the outer surface 301 of the cylindrical portion 31 in the circumferential direction C. In this case, the formation range of the outer lead portion 46 in the circumferential direction C is smaller than the formation range of the outer connection portion 47 in the circumferential direction C.
  • the inner lead portion 42 of the reference electrode 4 ⁇ / b> A of this embodiment changes so that the formation range in the circumferential direction C is reduced in three steps from the distal end side L ⁇ b> 1 in the axial direction L toward the proximal end side L ⁇ b> 2. Is formed.
  • the formation range in the circumferential direction C of the distal end side portion 421 located at the most distal end L 1 is the largest, and the intermediate portion 422 adjacent to the proximal end L 2 of the distal end side portion 421 is formed in the circumferential direction C.
  • the range is smaller than the formation range in the circumferential direction C of the distal portion 421, and the formation range in the circumferential direction C of the proximal portion 423 adjacent to the proximal side L2 of the intermediate portion 422 is the circumferential direction C of the intermediate portion 422. Is smaller than the formation range.
  • a step 424 is formed between the distal end portion 421 and the intermediate portion 422 and between the intermediate portion 422 and the proximal end portion 423.
  • the formation range of the inner lead portion 42 in the axial direction L is longer than the formation range of the inner detection portion 41 in the axial direction L and the formation range of the inner connection portion 43 in the axial direction L.
  • the distal end side portion 421, the intermediate portion 422, and the proximal end portion 423 are formed in parallel to the central axis O and the axial direction L of the cylindrical portion 31.
  • both side ends 420 in the circumferential direction C of the distal end side portion 421, the intermediate portion 422, and the proximal end side portion 423 are parallel to the axial direction L.
  • the step 424 between the distal end side portion 421, the intermediate portion 422, and the proximal end side portion 423 may be formed orthogonal to the axial direction L, or may be formed inclined with respect to the axial direction L. Good.
  • the inner lead portion 42 may be formed so that the formation range in the circumferential direction C is reduced in two steps from the distal end side L1 in the axial direction L toward the proximal end side L2. In this case, both end portions in the circumferential direction C of the distal end portion and the proximal end portion of the inner lead portion 42 that are reduced in two steps are formed in parallel to the axial direction L. Further, the inner lead portion 42 may be formed so that the formation range in the circumferential direction C is reduced in four or more steps from the distal end side L1 in the axial direction L toward the proximal end side L2.
  • the inner side detection part 41 of the reference electrode 4 ⁇ / b> A is provided continuously on the entire circumference of the position of the tip side L ⁇ b> 1 on the inner side surface 302 of the cylinder part 31 and the entire inner side surface 302 of the bottom part 32.
  • the front end 501 of the front end of the heater 5 is in contact with the inner side detection unit 41 on the inner side surface 302 of the bottom 32.
  • the outer side detection part 45 of the detection electrode 4 ⁇ / b> B is not provided on the outer side surface 301 of the bottom part 32.
  • the inner connection portion 43 of the reference electrode 4A may be formed only in a part of the inner side surface 302 of the cylindrical portion 31 in the circumferential direction C. In this case, the formation range in the circumferential direction C of the inner lead portion 42 is smaller than the formation range in the circumferential direction C of the inner connection portion 43.
  • the inner lead portion 42 and the outer lead portion 46 are formed in one place in the circumferential direction C in parallel with the central axis O and the axial direction L.
  • the imaginary line passing through the center in the circumferential direction C of the inner lead portion 42 is parallel to the axial direction L.
  • the relative positional relationship between the formation position in the circumferential direction C of the outer lead portion 46 in the detection electrode 4B and the formation position in the circumferential direction C of the inner lead portion 42 in the reference electrode 4A can be arbitrarily determined. 2 and 5, as an example, a state in which the inner lead portion 42 and the outer lead portion 46 are formed at positions shifted by 90 ° in the circumferential direction C is described.
  • the minimum cross-sectional area in the direction orthogonal to the axial direction L of the inner lead portion 42 of the reference electrode 4A and the minimum cross-sectional area in the direction orthogonal to the axial direction L of the outer lead portion 46 of the detection electrode 4B are the output voltage of the gas sensor 1. A resistance value that does not affect is ensured, and it is determined within a range that does not cause a problem from the viewpoint of heat resistance.
  • the inner lead portion 42 located in the vicinity of the inner detection portion 41 and the outer lead portion 46 located in the vicinity of the outer detection portion 45 also have a function of detecting gas in the same manner as the detection portions 41 and 45. To express.
  • a protective layer 21 made of a ceramic porous body is provided at the tip of the sensor element 2 so as to cover at least the entire outer detection portion 45 of the detection electrode 4B.
  • the protective layer 21 is for preventing the detection electrode 4B from being poisoned and wet.
  • the reference electrode 4A and the detection electrode 4B are formed by electroless plating. Since this electroless plating process is performed on a solid electrolyte body made of a material that is electrically inactive at room temperature, the electroless plating process is performed after the activation process is performed on the portion to be plated.
  • an active paste in which an organic platinum compound is dissolved in an organic solvent and the viscosity is adjusted with a binder or the like is applied to a porous carrier in which a porous rubber material, sponge material, felt material, or the like is formed in a predetermined shape. Impregnate. Then, this porous carrier is brought into contact with the solid electrolyte body 3 so as to draw a pattern shape of the reference electrode 4A and the detection electrode 4B, and the active paste is attached to the solid electrolyte body 3.
  • heat treatment is performed on the solid electrolyte body 3 provided with the active paste to remove organic substances in the active paste, and platinum atoms in the organic platinum compound in the active paste are fixed to the solid electrolyte body 3, and the reference electrode 4A and An electrode pattern of the detection electrode 4B is formed.
  • the heat treatment is performed after the active paste for forming the reference electrode 4A is attached to the solid electrolyte body 3 and after the active paste for forming the detection electrode 4B is attached to the solid electrolyte body 3. It can also be done separately.
  • the electrode pattern of the solid electrolyte body 3 is immersed in an electroless platinum plating solution containing a reducing agent to deposit platinum in the electrode pattern.
  • the reference electrode 4A and the detection electrode 4B are formed on the solid electrolyte body 3.
  • each electrode 4A, 4B can be formed by performing electroplating treatment in addition to performing electroless plating treatment, and can also be formed by using a paste containing platinum fine particles. .
  • the electrode reduction rate on the inner surface 302 of the solid electrolyte body 3 of the reference electrode 4A which is a partial electrode of this embodiment, is in the following range.
  • the surface area of the entire inner surface 302 of the solid electrolyte body 3 is S1
  • the surface area of the entire inner surface 302 of the solid electrolyte body 3 on which the reference electrode 4A is formed is S2.
  • the electrode reduction rate is represented by (S1-S2) / S1 as a ratio of the surface area where the reference electrode 4A is reduced in the entire inner surface 302 of the solid electrolyte body 3.
  • the electrode reduction rate has a relationship of 0.3 ⁇ (S1-S2) /S1 ⁇ 0.7. The critical significance indicated by this numerical range will be shown in confirmation test 1 described later.
  • the average film thickness of the reference electrode 4A is in the range of 0.4 to 1.6 ⁇ m. The critical significance indicated by this numerical range will be shown in confirmation test 2 described later.
  • the inner detection part 41, the inner lead part 42, and the inner connection part 43, which are parts of the reference electrode 4A, are formed to have a uniform thickness. However, a large number of pores are formed in the reference electrode 4A, and some of these many pores are continuously formed from the inside to the surface of the reference electrode 4A.
  • the average film thickness of the reference electrode 4A is obtained by measuring the film thickness at 10 locations in the plane direction of the reference electrode 4A and setting the average value of the film thickness at the 10 locations.
  • the inner lead portion 42 of the reference electrode 4A changes from the distal end side L1 in the axial direction L toward the proximal end side L2 so that the formation range in the circumferential direction C decreases in a tapered shape. It may be formed.
  • the formation range of the tapered inner lead portion 42 in the circumferential direction C continuously changes from the inner detection portion 41 to the inner connection portion 43.
  • the formation range of the inner lead portion 42 in the axial direction L is longer than the formation range of the inner detection portion 41 in the axial direction L and the formation range of the inner connection portion 43 in the axial direction L. Both side ends 420 are formed in a gentle taper shape.
  • the inclination angle between both ends in the circumferential direction C of the inner lead portion 42 is in the range of 2 to 10 °.
  • the heater 5 includes ceramic bases 51 ⁇ / b> A and 51 ⁇ / b> B and a heating element 52 made of a conductor provided on the base 51 ⁇ / b> B.
  • the heat generating portion 521 has a cross-sectional area that is the smallest in the heat generating body 52 and is a portion that generates heat due to Joule heat when the heat generating body 52 is energized.
  • the heat generating portion 521 is formed in a shape that meanders in the axial direction L at the distal end portion of the heat generating body 52.
  • the heater 5 is formed by winding a sheet-like base material 51B provided with a heating element 52 around a base material 51A serving as a mandrel.
  • the tip 501 of the base material 51A serving as a mandrel is in contact with the inner side surface 302 of the inner side detection unit 41 of the reference electrode 4A.
  • the gas sensor 1 includes a housing 61 that holds the sensor element 2, a distal end cover 62 that is attached to a distal end portion of the housing 61, and a proximal end side of the housing 61.
  • a proximal cover 63 attached to the part, an inner terminal fitting 71 attached to the inner side surface 302 of the proximal part of the sensor element 2, and an outer terminal attached to the outer surface 301 of the proximal part of the sensor element 2.
  • a metal fitting 72 and the like are provided.
  • the housing 61 is formed with an insertion hole 611 penetrating in the axial direction L in order to hold the sensor element 2.
  • the insertion hole 611 has a small diameter hole 612 located on the distal end side L1 in the axial direction L, and a large diameter hole 613 located on the proximal side L2 in the axial direction L and having a diameter larger than that of the small diameter hole 612. .
  • the sensor element 2 is inserted into the small-diameter hole portion 612 and the large-diameter hole portion 613 of the insertion hole 611, and a sealing material such as talc powder and a sleeve disposed in the gap between the sensor element 2 and the large-diameter hole portion 613. 64 is held.
  • the flange portion 34 which is the portion having the largest outer diameter in the sensor element 2 is locked to the end portion of the small-diameter hole portion 612, so that the sensor element 2 is prevented from coming out from the insertion hole 611 to the distal end side L1.
  • a caulking portion 615 that is bent toward the inner peripheral side is formed at a base end side portion in the axial direction L of the housing 61.
  • the sealing material 64 is compressed in the axial direction L between the caulking portion 615 and the flange portion 34, and the sensor element 2 is held by the housing 61.
  • a portion of the sensor element 2 on the tip side, in particular, the portion on which the inner side detection portion 41 and the outer side detection portion 45 are formed is disposed so as to protrude from the housing 61 to the tip side L1 in the axial direction L.
  • the distal end side cover 62 for protecting the sensor element 2 by covering the portion of the sensor element 2 protruding from the housing 61 to the distal end side L ⁇ b> 1 at the distal end portion in the axial direction L of the housing 61.
  • the front end side cover 62 is disposed in the exhaust pipe.
  • a gas passage hole 621 for allowing the detection gas G to pass therethrough is formed in the distal end side cover 62.
  • the front end side cover 62 can have a double structure or a single structure.
  • the exhaust gas as the detection gas G flowing into the tip side cover 62 from the gas passage hole 621 of the tip side cover 62 passes through the protective layer 21 of the sensor element 2 and is guided to the detection electrode 4B.
  • a proximal cover 63 is attached to the proximal end portion of the housing 61 in the axial direction L.
  • the proximal end side cover 63 is disposed outside the exhaust pipe.
  • An introduction hole 631 for introducing the atmosphere as the reference gas A into the proximal end side cover 63 is formed in a part of the proximal end side cover 63.
  • a filter 632 that does not allow liquid to pass while allowing gas to pass is disposed in the introduction hole 631.
  • the reference gas A introduced into the base end side cover 63 from the introduction hole 631 passes through the gap in the base end side cover 63 and is guided to the reference electrode 4A on the inner side surface 302 of the sensor element 2.
  • an inner terminal fitting 71 that is in contact with the inner connection portion 43 of the reference electrode 4A is mounted on the inner side surface 302 of the proximal end portion of the sensor element 2.
  • an outer terminal fitting 72 that contacts the outer connection portion 47 of the detection electrode 4B is attached to the outer surface 301 of the proximal end portion of the sensor element 2.
  • Lead wires 65 for electrically connecting the reference electrode 4A and the detection electrode 4B of the sensor element 2 to an external control device are attached to the inner terminal fitting 71 and the outer terminal fitting 72.
  • the lead wire 65 is held by a bush 66 disposed in the proximal end side cover 63.
  • the gas sensor 1 of the present embodiment can be used as a special air-fuel ratio sensor when the air-fuel ratio is in a weak rich region near the stoichiometric air-fuel ratio on the fuel rich side when used as an oxygen sensor.
  • this air-fuel ratio sensor When used as this air-fuel ratio sensor, a minute change in the output voltage of the gas sensor 1 is detected.
  • the gas sensor 1 of the present embodiment has an air value obtained by dividing the air mass supplied to the internal combustion engine by the minimum air mass theoretically necessary for complete combustion of the fuel when the theoretical air-fuel ratio is 14.5.
  • the excess air ratio ⁇ can be used to detect an air-fuel ratio within a range of 0.97 to 1.00 based on the electromotive force.
  • the reference electrode 4 ⁇ / b> A includes an inner detection part 41, an inner connection part 43, and an inner lead part 42, and the formation range of the inner lead part 42 in the circumferential direction C is from the inner detection part 41 toward the inner connection part 43. It is shrinking step by step.
  • the tip 501 of the tip of the heater 5 where the heat generating part 521 is provided is in contact with the inner side surface 302 of the bottom 32 of the solid electrolyte body 3.
  • the inner detection part 41 of the reference electrode 4A is appropriately heated by the heat generating part 521, and the inner detection part 41 to the inner lead part. Heat transfer to the base end side L2 of the sensor element 2 via the 42 and the inner connection portion 43 can be appropriately suppressed.
  • the temperature around the inner side detection unit 41 is set to a high temperature suitable for activation of the solid electrolyte body 3 and the electrodes 4A, 4B. It can be maintained in a state as uniform as possible. Further, by adjusting the shape of the inner lead portion 42 in the reference electrode 4A and the formation range in the circumferential direction C, the temperature distribution in the axial direction L of the sensor element 2 can be brought close to the target temperature distribution.
  • FIG. 7 shows the position (mm) from the distal end in the axial direction L on the outer surface 301 of the bottom 32 of the sensor element 2 to the proximal end L2 in the axial direction L, and the temperature (° C.) of the sensor element 2 at each position.
  • the relationship is shown.
  • the temperature distribution T2 in the axial direction L of the sensor element is shown.
  • the temperature in the range of 5 to 25 mm from the tip is higher than that of the sensor element 2 of the comparative embodiment.
  • the temperature in the range of 5 to 20 mm from the tip which is the range in the axial direction L in which the outer detector 45 and the inner detector 41 are disposed in the solid electrolyte body 3, The temperature is maintained close to the target temperature of 500 ° C.
  • the target temperature distribution of the sensor element 2 can be easily obtained by forming the reference electrode 4A as a partial electrode.
  • the portion on the tip side L1 of the sensor element 2 is It is heated more than the portion on the base end side L2. Further, since the portion on the base end side L2 of the sensor element 2 is held by the housing 61, heat shrinkage occurs from the portion on the base end side L2 to the housing 61.
  • the heat sink from the distal end side L1 to the proximal end side L2 of the sensor element 2 is reduced by reducing the formation range of the reference electrode 4A at the location where the inner lead portion 42 is formed. Is less likely to occur.
  • the formation range of the reference electrode 4A is reduced, so that the distal end L1 of the sensor element 2 is shifted from the proximal end L2.
  • the heat shrinkage is less likely to occur.
  • the effect of making it difficult for heat shrinkage to occur can also be obtained by reducing the number of detection electrodes 4B due to partial electrode formation.
  • the distance between the reference electrode 4A and the heater 5 is smaller than the distance between the detection electrode 4B and the heater 5, and the reference electrode 4A is close to the heater 5. Therefore, by reducing the inner lead portion 42 of the reference electrode 4A, an effect that the heat shrinkage from the distal end side L1 to the proximal end side L2 of the sensor element 2 hardly occurs becomes remarkable, and the temperature of the sensor element 2 is more appropriately set. Can be maintained.
  • the configuration of the inner lead portion 42 of the reference electrode 4A is effective when the gas sensor 1 is used as an oxygen sensor and is used as an air-fuel ratio sensor only when the air-fuel ratio is in a weak rich region near the stoichiometric air-fuel ratio on the fuel rich side. It is.
  • FIG. 8 shows the relationship between the excess air ratio ⁇ and the output voltage (V) of the gas sensor 1 for the sensor element 2 of this embodiment
  • FIG. 9 shows the reference electrode on the entire inner surface 302 of the solid electrolyte body 3. The relationship between the excess air ratio ⁇ and the output voltage (V) of the gas sensor 1 is shown for the sensor element of the comparative form having 4A.
  • the output voltage of the gas sensor 1 is output at about 0.1 V, while in the weak rich region where the excess air ratio ⁇ is in the range of 0.97 to 1.
  • the output voltage of the gas sensor 1 is about 0.7 to 0.83V.
  • the slope of the change in which the output voltage increases with respect to the change in the excess air ratio ⁇ in other words, the relationship indicating the relationship between the excess air ratio ⁇ (or air-fuel ratio) and the output voltage (or electromotive force).
  • the slope of the line is the rate of change of the output voltage.
  • the change rate of the output voltage in the weak rich region in the sensor element 2 of the present embodiment is compared with the change rate of the output voltage in the weak rich region of the sensor element of the comparative embodiment, as shown in FIG. You can see that it ’s big.
  • the relationship line of the weak rich region in the sensor element 2 of the present embodiment is steeper than the relationship line of the weak rich region in the sensor element of the comparative embodiment.
  • the air-fuel ratio detection accuracy in the weak rich region can be improved.
  • Such a characteristic that the rate of change of the output voltage in the weakly rich region is large is largely due to the configuration of the reference electrode 4A that is a partial electrode as described above.
  • an unburned gas such as HC (hydrocarbon) or CO (carbon monoxide) is adsorbed and a NOx (nitrogen oxide) is adsorbed according to the composition of the exhaust gas.
  • HC hydrogen
  • CO carbon monoxide
  • NOx nitrogen oxide
  • Pt platinum
  • Unburned gas is adsorbed.
  • the degree to which the base end side portion of the reference electrode 4A is colder than the tip end portion is strong. Therefore, it is difficult for HC, CO, etc. in the rich gas at the base end portion that is at a low temperature to leave, and the output voltage of the gas sensor 1 is easily maintained from the weak rich region to the vicinity of the theoretical air-fuel ratio, and the output voltage in the weak rich region The slope of is slow.
  • the temperature difference between the inner detection part 41 of the reference electrode 4A and the inner lead part 42 of the reference electrode 4A is reduced.
  • HC, CO, etc. in the rich gas adsorbed on the inner lead portion 42 are desorbed quickly, and the output voltage of the gas sensor 1 is hardly maintained from the weak rich region to the vicinity of the theoretical air-fuel ratio.
  • the slope of the output voltage in the region becomes steep.
  • the temperature of the outer side detection unit 45 and the inner side detection unit 41 in the sensor element 2 is maintained within a range of 400 to 600 ° C. As the temperature is lower, a difference between HC adsorption energy and CO adsorption energy, which will be described later, is more likely to occur, and the inclination of the output voltage of the gas sensor 1 in the weak rich region tends to be steep. However, when the temperature of the outer detection unit 45 and the inner detection unit 41 is less than 400 ° C., the catalytic activity of the detection electrode 4B and the reference electrode 4A becomes weak, and the output voltage of the gas sensor 1 may not be stable.
  • the temperature of the outer detection unit 45 and the inner detection unit 41 exceeds 600 ° C.
  • the difference between the adsorption energy of HC and the adsorption energy of CO becomes small, and the slope of the output voltage of the gas sensor 1 in the weak rich region becomes steep. Hard to become. Therefore, it is more preferable to maintain the temperatures of the outer detection unit 45 and the inner detection unit 41 within the range of 450 to 550 ° C. so as to be close to 500 ° C.
  • the formation range in the circumferential direction C of the inner lead portion 42 of the reference electrode 4A of this embodiment is gradually reduced as it goes from the inner detection portion 41 to the inner connection portion 43.
  • the inner lead portion 42 By forming the inner lead portion 42 in a stepwise manner, the change in the surface area of the reference electrode 4A in the axial direction L, that is, the change in the cross-sectional area of the reference electrode 4A in the direction orthogonal to the axial direction L can be moderated. Thereby, the area of the boundary part between the inner lead part 42 of the reference electrode 4A and the solid electrolyte body 3 is increased.
  • the difference in thermal expansion between the solid electrolyte body 3 and the reference electrode 4A that occurs during the temperature rise is moderated. Therefore, the thermal stress applied to the inner lead portion 42 is alleviated, and peeling or the like is less likely to occur in the inner lead portion 42.
  • the temperature distribution targeting the temperature distribution in the axial direction L of the sensor element 2 by adjusting the shape of the inner lead portion 42 in the reference electrode 4A and the formation range in the circumferential direction C. can be approached. Further, in the weakly rich region, it can be used not only as an oxygen sensor but also as an air-fuel ratio sensor that quantitatively detects changes in the air-fuel ratio. And the detection accuracy of the air-fuel ratio in this weak rich region can be improved.
  • ⁇ Confirmation test 1> As a performance test of the gas sensor 1, the rate of change of the output voltage of the gas sensor 1 in the weak rich region when the electrode reduction rate (S1-S2) / S1 ⁇ 100 (%) of the reference electrode 4A is changed ( The difference in inclination) and the temperature difference in each part of the sensor element 2 in the axial direction L were measured. Specifically, each of the gas sensors 1 in which the electrode reduction rate (S1 ⁇ S2) / S1 ⁇ 100 (%) of the sensor element 2 is changed in five stages of 25%, 30%, 50%, 70%, and 75%. Samples were designated as test samples 1 to 5, and the rate of change in output voltage for test samples 1 to 5 was determined.
  • the length in the axial direction L of the inner side detection portion 41 of the reference electrode 4A was 10 mm, and the length in the axial direction L of the inner side connection portion 43 of the reference electrode 4A was 5 mm.
  • the electrode reduction rate in this test is shown as a percentage.
  • the dimensions of the outer detection part 45, the outer lead part 46, and the outer connection part 47 of the detection electrode 4B in each sample were as follows. As shown in FIG. 3, the total length L1 of the sensor element 2 is 40 mm, the length L2 from the tip of the sensor element 2 to the tip of the outer detector 45 is 2 mm, the length L3 of the outer detector 45 is 5 mm, The length L4 from the tip of the sensor element 2 to the tip of the outer connecting portion 47 was 30 mm, and the length L5 of the outer connecting portion 47 was 35 mm. Both are shown as the length in the axial direction L.
  • each sample was heated by the heater 5 so that the tip of the sensor element 2 became 500 ° C., and the temperature of the tip of the sensor element 2 was measured. Further, after the temperature at the tip of the sensor element 2 of each sample is stabilized, a rich gas in which carbon monoxide, methane, propane and nitrogen are mixed so that the air-fuel ratio becomes 0.97 with respect to the gas sensor 1 of each sample.
  • the voltage detected between the reference electrode 4A and the detection electrode 4B was measured as an output voltage (sensor output).
  • the excess air ratio ⁇ is in the range of 0.97 to 1.00, which is a weak rich region, and the excess air ratio ⁇ is 0.97 to 0.98, 0.98 to 0.99, and 0.99 to 1. It was divided into three ranges of 00, and the change rate of the output voltage in these three ranges was obtained. The smallest value of the change rates of the output voltage in the three ranges was taken as the change rate of the output voltage.
  • the change rate of the output voltage in the three ranges is ⁇ 1, the change rate of the output voltage in the first range, ⁇ 2, the change rate of the output voltage in the second range, and ⁇ 3, the change rate of the output voltage in the third range.
  • ⁇ 1 (V 0.97 ⁇ V 0.98 ) /0.01
  • ⁇ 2 (V 0.98 ⁇ V 0.99 ) /0.01
  • ⁇ 3 (V 0.99 -V 1.00 ) /0.01
  • the output voltage when the excess air ratio ⁇ is 1.00 is V 1.00
  • the output voltage when the excess air ratio ⁇ is 0.99 is V 0.99
  • the output when the excess air ratio ⁇ is 0.98.
  • the output voltage when the voltage is V 0.98 and the excess air ratio ⁇ is 0.97 is V 0.97 .
  • the criterion for determining that the rate of change of the output voltage in the weakly rich region was large and the slope was steep was whether the rate of change of the output voltage was 10 or more. When the rate of change was 10 or more, it was marked as ⁇ as steep, and when the rate of change was less than 10, it was marked as x as slow.
  • the internal resistance of the sensor element 2 of each sample was also measured. This internal resistance was measured as the resistance between the reference electrode 4A and the detection electrode 4B.
  • the shape of the detection electrode 4B in each sample is the same, and the internal resistance increases as the electrode reduction rate (S1-S2) / S1 ⁇ 100 (%) of the reference electrode 4A in each sample increases.
  • the gas sensor 1 of each sample was placed in the exhaust pipe of the engine, and the engine was operated at 1000 rpm for 1000 hours so that the excess air ratio ⁇ was 0.95. Then, after the engine was operated, the internal resistance of the sensor element 2 in the gas sensor 1 of each sample was measured. In the determination of the internal resistance, the case where the internal resistance was 200 k ⁇ or less was rated as “ ⁇ ”, and the case where the internal resistance exceeded 200 k ⁇ was rated as “X”.
  • Table 1 shows the results of the change rate determination and the internal resistance determination.
  • the change rate of the output voltage was less than 10, so the judgment was x.
  • the determination was x.
  • both the determination of the change rate of the output voltage and the determination of the internal resistance were “good”.
  • the temperature in each part of the axial direction L of the sensor element 2 of each sample was measured.
  • the temperature was measured by using a thermocouple and bringing the temperature measuring contact of the thermocouple into contact with the location where the detection electrode 4B was formed.
  • the temperature in each part was measured at each position 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, and 40 mm away from the tip end of the sensor element 2 to the base end side L2.
  • the temperature of the sensor element 2 is maintained at 400 ° C. or higher at a position within the range of 5 to 20 mm from the distal end of the sensor element 2 to the base end side L2. However, at a position within a range of 25 to 40 mm from the distal end of the sensor element 2 to the proximal end side L2, the sensor element 2 decreases as the electrode reduction rate (S1-S2) / S1 ⁇ 100 (%) of the reference electrode 4A decreases. It can be seen that the decrease in temperature becomes significant. This shows that the temperature of the sensor element 2 can be kept high over a wide range in the axial direction L by increasing the electrode reduction rate of the reference electrode 4A.
  • ⁇ Confirmation test 2> the optimum range of the average film thickness ( ⁇ m) of the reference electrode 4A was confirmed. Specifically, the responsiveness of the gas sensor 1 and the internal resistance of the sensor element 2 when the average film thickness of the reference electrode 4A was changed were confirmed. Each sample of the gas sensor 1 using the sensor element 2 in which the average film thickness of the reference electrode 4A is changed in five stages of 0.33 ⁇ m, 0.40 ⁇ m, 1.12 ⁇ m, 1.60 ⁇ m, and 1.68 ⁇ m is a test product. The responsiveness and internal resistance of the test products 6 to 10 were obtained.
  • the length in the axial direction L of the inner side detection portion 41 of the reference electrode 4A is 10 mm
  • the length in the axial direction L of the inner connection portion 43 of the reference electrode 4A is 5 mm
  • the electrode reduction rate (S1- S2) / S1 ⁇ 100 (%) was 40%. Further, each sample was heated by the heater 5 so that the tip of the sensor element 2 became 500 ° C., and the temperature of the tip of the sensor element 2 was measured. Other conditions are the same as those in the confirmation test 1.
  • the average film thickness of the reference electrode 4A was determined by measuring the film thickness at any 10 locations of the reference electrode 4A using a fluorescent X-ray film thickness meter.
  • the responsiveness of the gas sensor 1 is that the gas sensor 1 using the sensor element 2 of each sample is arranged in the exhaust pipe of the engine, and the air-fuel ratio in the engine is changed from the fuel rich state where the excess air ratio ⁇ is 0.95 to the excess air ratio.
  • the determination is made based on the voltage drop time until the output voltage of the gas sensor 1 changes from 0.6V to 0.3V.
  • Table 3 shows the results of the determination of the responsiveness of the gas sensor 1 and the determination of the internal resistance of the sensor element.
  • the internal resistance of the sensor element 2 exceeded 200 k ⁇ , so the determination was x.
  • the determination was ⁇ because the responsiveness of the gas sensor 1 exceeded 200 ms.
  • the test products 7 to 9 in which the average film thickness of the reference electrode 4A is in the range of 0.4 to 1.6 ⁇ m both the determination of the responsiveness and the determination of the internal resistance are good. From this result, when the average film thickness of the reference electrode 4A is within the range of 0.4 to 1.6 ⁇ m, the responsiveness of the gas sensor 1 can be maintained high and the internal resistance of the sensor element 2 can be suppressed low. I understood.

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003322631A (ja) * 2002-04-30 2003-11-14 Ngk Spark Plug Co Ltd 酸素センサ
JP2014038061A (ja) * 2012-08-20 2014-02-27 Ngk Spark Plug Co Ltd ガスセンサ素子、ガスセンサ及びその製造方法
JP2015068698A (ja) * 2013-09-27 2015-04-13 株式会社デンソー ガスセンサ制御装置
JP2015166716A (ja) * 2014-03-04 2015-09-24 株式会社デンソー ガスセンサ素子とその製造方法並びにガスセンサ

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58127158A (ja) * 1982-01-25 1983-07-28 Mazda Motor Corp 酸素濃度検出素子
JPS61106941A (ja) * 1984-10-30 1986-05-24 Mazda Motor Corp エンジンの空燃比制御装置
JPH11153571A (ja) 1997-11-20 1999-06-08 Denso Corp 酸素センサ素子
JP2003083933A (ja) * 2001-09-11 2003-03-19 Ngk Spark Plug Co Ltd アンモニアガス濃度測定装置
JP5119131B2 (ja) * 2008-02-22 2013-01-16 日本特殊陶業株式会社 アンモニアガスセンサ
JP5182321B2 (ja) * 2010-05-13 2013-04-17 株式会社デンソー ガスセンサ素子、及び、これを内蔵したガスセンサ
JP5488289B2 (ja) * 2010-07-21 2014-05-14 株式会社デンソー 酸素センサ素子
GB2493690B (en) * 2011-05-20 2018-01-17 Univ Surrey Optical communication system
CA2870400A1 (en) * 2012-04-23 2013-10-31 Technical University Of Denmark Sensor employing internal reference electrode
JP2013238556A (ja) * 2012-05-17 2013-11-28 Denso Corp ガスセンサ
JP5770773B2 (ja) * 2012-05-24 2015-08-26 日本特殊陶業株式会社 ガスセンサ
JP6241123B2 (ja) * 2013-08-09 2017-12-06 株式会社デンソー ガスセンサ制御装置、及びガスセンサ制御方法
JP6558109B2 (ja) * 2014-07-25 2019-08-14 株式会社デンソー ガス濃度検出装置
JP6192689B2 (ja) * 2015-07-13 2017-09-06 日本特殊陶業株式会社 ガスセンサ素子、及び、ガスセンサ
JP6734733B2 (ja) * 2016-08-12 2020-08-05 日本特殊陶業株式会社 ガスセンサ用導電性酸化物焼結体、導電性酸化物焼結体、配線基板及びガスセンサ
US20190323986A1 (en) * 2018-04-18 2019-10-24 Delphi Technologies Ip Limited Gas sensor

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003322631A (ja) * 2002-04-30 2003-11-14 Ngk Spark Plug Co Ltd 酸素センサ
JP2014038061A (ja) * 2012-08-20 2014-02-27 Ngk Spark Plug Co Ltd ガスセンサ素子、ガスセンサ及びその製造方法
JP2015068698A (ja) * 2013-09-27 2015-04-13 株式会社デンソー ガスセンサ制御装置
JP2015166716A (ja) * 2014-03-04 2015-09-24 株式会社デンソー ガスセンサ素子とその製造方法並びにガスセンサ

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