WO2019150767A1 - Gas sensor element and gas sensor - Google Patents

Gas sensor element and gas sensor Download PDF

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Publication number
WO2019150767A1
WO2019150767A1 PCT/JP2018/045175 JP2018045175W WO2019150767A1 WO 2019150767 A1 WO2019150767 A1 WO 2019150767A1 JP 2018045175 W JP2018045175 W JP 2018045175W WO 2019150767 A1 WO2019150767 A1 WO 2019150767A1
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WO
WIPO (PCT)
Prior art keywords
gas sensor
lead portion
external electrode
heel
flange
Prior art date
Application number
PCT/JP2018/045175
Other languages
French (fr)
Japanese (ja)
Inventor
恵介 中川
正剛 上野
清家　晃
遊 山川
茂弘 大塚
Original Assignee
日本特殊陶業株式会社
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 日本特殊陶業株式会社 filed Critical 日本特殊陶業株式会社
Priority to CN201880087977.8A priority Critical patent/CN111656176B/en
Priority to JP2019513459A priority patent/JP6875505B2/en
Publication of WO2019150767A1 publication Critical patent/WO2019150767A1/en

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    • 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
    • G01N27/409—Oxygen concentration cells

Definitions

  • the present disclosure relates to a gas sensor element and a gas sensor including an element body formed in a bottomed cylindrical shape.
  • the element body is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and has a flange that protrudes radially outward.
  • a gas sensor element comprising:
  • a saddle lead part is formed on the collar part in order to be electrically connected to a metal shell that holds the gas sensor element.
  • the saddle lead portion is made of a noble metal such as platinum.
  • the lead part needs to be formed in a wide range in order to ensure electrical connection with the metal shell. For this reason, when an expensive noble metal is used for the lead part, there is a problem that the manufacturing cost of the gas sensor element is significantly increased.
  • This disclosure reduces the manufacturing cost of the gas sensor element.
  • the element body is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and is formed to have a flange portion protruding radially outward.
  • the external electrode includes a noble metal, and is formed on the outer surface of the element body so as to extend from the distal end side toward the collar part from the collar part.
  • the heel lead portion overlaps the external electrode and is formed along the circumferential direction of the element body on at least the heel portion facing the distal end side along the circumferential direction of the element body.
  • a heel lead part has a conductive oxide as a main component.
  • the “main component” refers to a component exceeding 50% by mass with respect to all components constituting the target site.
  • the gas sensor element of the present disclosure configured as described above has a conductive oxide that is less expensive than a noble metal as a main component of the heel lead portion, thereby reducing the amount of noble metal used in the heel lead portion and the manufacturing cost of the gas sensor element. Can be reduced.
  • the heel lead portion and the external electrode are formed to extend to the rear end side outer peripheral surface that is the outer peripheral surface on the rear end side with respect to the front end facing surface of the heel portion.
  • the electrodes may contact each other on the outer peripheral surface on the rear end side.
  • the gas sensor element and the holding member that holds the gas sensor element are formed on the tip-facing surface because a load is applied to the tip-facing surface during the manufacturing process. Even when the heel lead portion peeled off from the heel portion, the heel lead portion and the external electrode are in contact with each other on the outer peripheral surface on the rear end side. Thereby, the gas sensor element of this indication can improve the reliability of conduction with a heel lead part and an external electrode at the time of the above-mentioned manufacturing process.
  • Another aspect of the present disclosure is a gas sensor including the gas sensor element of one aspect of the present disclosure and a holding member that holds the gas sensor element.
  • the gas sensor of the present disclosure configured as described above is a gas sensor including the gas sensor element of one embodiment of the present disclosure, and can obtain the same effects as the gas sensor element of the present disclosure. That is, the gas sensor of the present disclosure can reduce the manufacturing cost of the gas sensor by reducing the manufacturing cost of the gas sensor element.
  • the heel lead portion and the holding member are in direct contact with each other, or are electrically connected to each other through a conductive member between the heel lead portion and the holding member. It may be.
  • the gas sensor of the present disclosure between the first contact surface where the heel lead portion or the external electrode and the holding member are in contact, and the tip-facing surface, A part of the lead part and a part of the external electrode may be arranged.
  • the conductive member when the conductive member is interposed between the heel lead portion and the holding member, the second contact surface where the heel lead portion or the external electrode and the conductive member are in contact with each other, and the tip-facing surface A part of the heel lead part and a part of the external electrode may be disposed between the two.
  • the gas sensor of the present disclosure configured as described above is configured so that the first and second contact portions are separated even when the heel lead portion is peeled off at the front end side of the first and second contact surfaces in the manufacturing process. It is possible to maintain a state in which a part of the heel lead part and a part of the external electrode are in contact with each other on the rear end side with respect to the front end side end part of the contact surface.
  • the leading end side of the first and second contact surfaces is separated from the distal end side of the first and second contact surfaces as compared to the rear end side of the first and second contact surfaces. Is likely to occur. Thereby, the gas sensor of this indication can improve the reliability of conduction with a heel lead part and an external electrode in the above-mentioned manufacturing process.
  • the gas sensor 1 of this embodiment is attached to an exhaust pipe of a vehicle such as an automobile or a motorcycle, for example, and detects an oxygen concentration contained in the exhaust gas in the exhaust pipe.
  • the gas sensor 1 includes a gas sensor element 3, a separator 5, a closing member 7, a terminal fitting 9 and a lead wire 11. Furthermore, the gas sensor 1 includes a metal shell 13, a protector 15, and an outer cylinder 16. The metal shell 13, the protector 15, and the outer cylinder 16 are arranged so as to cover the periphery of the gas sensor element 3, the separator 5, and the closing member 7.
  • the outer cylinder 16 includes an inner outer cylinder 17 and an outer outer cylinder 19.
  • the gas sensor 1 does not include a heater for heating the gas sensor element 3. That is, the gas sensor 1 detects the oxygen concentration by activating the gas sensor element 3 using the heat of the exhaust gas.
  • the gas sensor element 3 is formed using a solid electrolyte body having oxygen ion conductivity. As shown in FIG. 2, the gas sensor element 3 has a bottomed cylindrical shape with a closed end portion 25 and has a cylindrical element body 21 that extends in the direction of the axis O (hereinafter referred to as the axial direction). On the outer periphery of the element body 21, an element flange 23 is formed that protrudes radially outward along the circumferential direction.
  • the solid electrolyte body constituting the element body 21 is a partially stabilized zirconia sintered body obtained by adding yttria (Y 2 O 3 ) or calcia (CaO) as a stabilizer to zirconia (ZrO 2 ). It is configured.
  • the solid electrolyte constituting the element body 21 is not limited to these, and includes “solid solution of alkaline earth metal oxide and ZrO 2 ”, “solid solution of rare earth metal oxide and ZrO 2 ”, and the like. It may be used.
  • a solid electrolyte body containing HfO 2 therein may be used as the solid electrolyte body constituting the element body 21.
  • An outer electrode 27 is formed on the outer peripheral surface of the element main body 21 at the distal end portion 25 of the gas sensor element 3.
  • the outer electrode 27 is an electrode in which Pt or a Pt alloy is formed to be porous.
  • the surface of the element flange 23 is formed by a top surface 23a, a front end facing surface 23b, and a rear end facing surface 23c.
  • the top surface 23a is located on the outermost side in the radial direction in the element flange 23 and is a surface parallel to the axial direction.
  • the tip-facing surface 23b is a surface that is inclined so as to approach the axis O as the distance from the top surface 23a increases from the tip of the top surface 23a toward the tip of the element body 21.
  • the rear-facing surface 23c is a surface that is inclined so as to approach the axis O as the distance from the top surface 23a increases from the rear end of the top surface 23a toward the rear end of the element body 21.
  • An annular lead portion 28 is formed on the top surface 23a and the tip-facing surface 23b of the element flange 23.
  • the annular lead portion 28 contains, as a main component, a conductive oxide containing a crystal phase having a perovskite oxide crystal structure that satisfies the following composition formula (1) (that is, a perovskite phase).
  • La a Mb Ni c O x (1)
  • the coefficients a, b, and c satisfy the following relational expressions (2a), (2b), and (2c), respectively.
  • a vertical lead portion 29 made of Pt or the like is formed between the outer electrode 27 and the annular lead portion 28 on the outer peripheral surface of the element body 21 so as to extend in the axial direction.
  • the vertical lead portion 29 extends to the top surface 23 a of the element flange portion 23.
  • the vertical lead portion 29 electrically connects the outer electrode 27 and the annular lead portion 28.
  • a rectangular overlapping area RO indicated by a broken line in FIG. 2 is an area where the vertical lead portion 29 and the annular lead portion 28 overlap.
  • an inner electrode 30 is formed on the inner peripheral surface of the gas sensor element 3.
  • the inner electrode 30 is an electrode in which Pt, a Pt alloy, or an oxide conductor is formed to be porous.
  • the outer electrode 27 is exposed to the exhaust gas, and the inner electrode 30 is exposed to the reference gas, so that the gas sensor element 3 detects the oxygen concentration in the exhaust gas.
  • the reference gas is the atmosphere.
  • the separator 5 is a cylindrical member formed of an electrically insulating material (for example, alumina).
  • the separator 5 has a through-hole 35 into which the lead wire 11 is inserted at the axial center.
  • the separator 5 is disposed so that a gap 18 is provided between the separator 5 and the inner outer cylinder 17 covering the outer peripheral side.
  • the closing member 7 is a cylindrical sealing member made of an electrically insulating material (for example, fluoro rubber).
  • the closing member 7 includes a protruding portion 36 that protrudes radially outward at the rear end thereof.
  • the closing member 7 includes a lead wire insertion hole 37 into which the lead wire 11 is inserted at the center of the shaft.
  • the front end surface 95 of the closing member 7 is in close contact with the rear end surface 97 of the separator 5, and the side outer peripheral surface 98 on the front end side of the protruding portion 36 of the closing member 7 is in close contact with the inner surface of the inner outer cylinder 17. . That is, the closing member 7 closes the rear end side of the outer cylinder 16.
  • the reduced diameter portion 19 g extends radially inward on the rear end side of the closing member 7, and the distal-facing surface 19 a of the reduced diameter portion 19 g is formed as a surface facing the distal end side of the gas sensor 1. ing.
  • a lead wire insertion portion 19c for inserting the lead wire 11 and the lead wire protection member 89 is formed in the central region of the reduced diameter portion 19g.
  • the lead wire protection member 89 is a cylindrical member having an inner diameter that can accommodate the lead wire 11, and is made of a material having flexibility, heat resistance, and insulation (for example, a glass tube and a resin tube). Yes.
  • the lead wire protection member 89 is attached in order to protect the lead wire 11 from flying objects (for example, stone or water) from the outside.
  • the lead wire protection member 89 includes a plate-like flange portion 89b that protrudes outward in the vertical direction in the axial direction at the tip end portion 89a.
  • the collar portion 89b is formed not over a part of the lead wire protection member 89 in the circumferential direction but over the entire circumference.
  • the flange portion 89 b of the lead wire protection member 89 is sandwiched between the front end facing surface 19 a of the reduced diameter portion 19 g of the outer outer cylinder 19 and the rear end facing surface 99 of the closing member 7.
  • the terminal fitting 9 is a cylindrical member formed of a conductive material in order to extract the sensor output to the outside.
  • the terminal fitting 9 is electrically connected to the lead wire 11 and is disposed so as to be in electrical contact with the inner electrode 30 of the gas sensor element 3.
  • the terminal fitting 9 includes a flange portion 77 protruding outward in the radial direction (that is, the direction perpendicular to the axial direction) on the rear end side.
  • the flange portion 77 includes three plate-like flange pieces 75.
  • the lead wire 11 includes a core wire 65 and a covering portion 67 that covers the outer periphery of the core wire 65.
  • the metal shell 13 is a cylindrical member formed of a metal material (for example, iron or SUS430).
  • the metal shell 13 is formed with a step portion 39 projecting radially inward on the inner peripheral surface.
  • the step 39 is formed to support the element flange 23 of the gas sensor element 3.
  • a threaded portion 41 for attaching the gas sensor 1 to the exhaust pipe is formed on the outer peripheral surface on the tip side of the metal shell 13.
  • a hexagonal portion 43 is formed on the rear end side of the threaded portion 41 of the metal shell 13 to engage the attachment tool when the gas sensor 1 is attached to or detached from the exhaust pipe. Further, a cylindrical portion 45 is provided on the rear end side of the hexagonal portion 43 in the metal shell 13.
  • the protector 15 is formed of a metal material (for example, SUS310S), and is a protective member that covers the distal end side of the gas sensor element 3, and introduces exhaust gas to the gas sensor element 3 through a plurality of formed gas flow holes. To do.
  • the protector 15 is fixed so that the rear edge thereof is sandwiched between the element flange portion 23 of the gas sensor element 3 and the step portion 39 of the metal shell 13 via a packing 88 formed of a conductive material. Yes.
  • the ceramic powder 47 made of talc and the alumina are formed between the metal shell 13 and the gas sensor element 3 from the front end side to the rear end side.
  • a ceramic sleeve 49 is disposed.
  • a distal end portion 55 is disposed.
  • the distal end portion 55 of the inner outer cylinder 17 is formed in a shape that extends radially outward. That is, the rear end portion 51 of the tubular portion 45 is crimped, so that the front end portion 55 of the inner outer tube 17 is interposed between the rear end portion 51 of the tubular portion 45 and the ceramic sleeve 49 via the metal ring 53.
  • the inner outer cylinder 17 is fixed to the metal shell 13.
  • a cylindrical filter 57 formed of a resin material (for example, PTFE) is disposed on the outer periphery of the inner outer cylinder 17, and an outer outer cylinder 19 formed of, for example, SUS304L is disposed on the outer periphery of the filter 57.
  • the filter 57 can be ventilated but can suppress the intrusion of moisture.
  • the caulking portion 19b of the outer outer cylinder 19 is caulked inward in the radial direction from the outer peripheral side, whereby the inner outer cylinder 17, the filter 57, and the outer outer cylinder 19 are fixed integrally.
  • the caulking portion 19 h of the outer outer cylinder 19 is caulked inward in the radial direction from the outer peripheral side, whereby the inner outer cylinder 17 and the outer outer cylinder 19 are integrally fixed, and the lateral outer peripheral surface of the closing member 7. 98 comes into close contact with the inner surface of the inner outer cylinder 17.
  • the inner outer cylinder 17 and the outer outer cylinder 19 are provided with a vent hole 59 and a vent hole 61, respectively. That is, the inside and outside of the gas sensor 1 can be ventilated through the vent holes 59 and 61 and the filter 57.
  • the outer electrode 27 and the inner electrode 30 are arranged so as to sandwich the element body 21 at the distal end portion 25 of the gas sensor element 3.
  • the element body 21 and the pair of electrodes constitute an oxygen concentration cell and generate an electromotive force according to the oxygen concentration in the exhaust gas. That is, the gas sensor element 3 detects the oxygen concentration in the exhaust gas by exposing the outer electrode 27 to the exhaust gas and the inner electrode 30 to the reference gas at the distal end portion 25 of the gas sensor element 3.
  • the outer electrode 27 is electrically connected to the annular lead portion 28 via the vertical lead portion 29 as described above.
  • the annular lead portion 28 is electrically connected to the metal shell 13 via a packing 88 made of a conductive material and the protector 15. Note that the shape and arrangement of the outer electrode 27 are merely examples, and various other shapes and arrangements can be employed.
  • an inner electrode 30 is formed on the inner peripheral surface of the element body 21 of the gas sensor element 3.
  • the inner electrode 30 includes an inner detection electrode portion 30a and an inner lead portion 30b.
  • the inner detection electrode part 30 a is formed so as to cover the inner surface of the tip part 25 of the element body 21.
  • the inner lead portion 30 b contacts the inner detection electrode portion 30 a and is electrically connected to the terminal fitting 9.
  • the inner detection electrode part 30a and the inner lead part 30b are formed so as to cover the entire inner surface of the element body 21 as a whole.
  • the outer electrode 27 and the inner detection electrode part 30a are formed in the front end side region F1, and the inner lead part 30b is formed in the rear end side region F2.
  • the tip end region F1 of the element body 21 corresponds to the tip portion 25 of the element body 21.
  • a part of the annular lead part 28 and a part of the vertical lead part 29 are arranged between the contact surface PC1 where the annular lead part 28 and the packing 88 are in contact with the front end facing surface 23b.
  • “A portion of the annular lead portion 28 and a portion of the vertical lead portion 29 are disposed between the contact surface PC1 and the tip-facing surface 23b” means that the contact surface PC1 extends from the contact surface PC1 toward the tip-facing surface 23b.
  • a straight line that is, a normal line of the contact surface PC ⁇ b> 1) corresponding to passing through the annular lead portion 28 and the vertical lead portion 29.
  • a green compact is produced. Specifically, first, as a powder of a solid electrolyte body that is a material of the element body 21, a powder obtained by adding 5 mol% of yttria (Y 2 O 3 ) as a stabilizer to zirconia (ZrO 2 ) (hereinafter also referred to as 5YSZ). In contrast, a powder to which alumina powder is further added is prepared. When the total material powder of the element body 21 is 100% by mass, the content of 5YSZ is 99.6% by mass, and the content of alumina powder is 0.4% by mass. After this powder is pressed, an unsintered compact is obtained by carrying out cutting so as to form a cylinder.
  • Y 2 O 3 yttria
  • ZrO 2 stabilizer to zirconia
  • a slurry containing platinum (Pt) and zirconia is applied to each of the formation positions of the outer electrode 27, the vertical lead portion 29, and the inner electrode 30.
  • the slurry for forming the outer electrode 27 and the vertical lead portion 29 is a slurry in which 15% by mass of monoclinic zirconia is added to platinum.
  • the slurry for forming the inner electrode 30 is added with 15% by mass of “99.6% by mass of 5YSZ / 0.4% by mass alumina mixed powder” (that is, the same composition as the element body 21) with respect to platinum.
  • the resulting slurry is used.
  • a slurry of the annular lead portion 28 is produced.
  • the raw material powder of the conductive oxide is weighed, then wet mixed and dried to prepare the raw material powder mixture, and 700 to 1300 ° C. for 1 to 5 hours. Calcination is performed to prepare a calcination powder. Then, the calcined powder is pulverized by a wet ball mill or the like to adjust to a predetermined particle size.
  • La (OH) 3 or La 2 O 3 , Co 3 O 4 , Fe 2 O 3 , and NiO can be used as the raw powder for the perovskite phase.
  • the calcined powder adjusted to a predetermined particle size is mixed by a wet ball mill or the like, and dissolved in a solvent such as terpineol or butyl carbitol together with a binder such as ethyl cellulose to produce a slurry.
  • a solvent such as terpineol or butyl carbitol
  • a binder such as ethyl cellulose
  • the slurry of the annular lead portion 28 is applied to the position where the annular lead portion 28 is formed.
  • the green compact coated with each slurry is dried and then fired at a predetermined firing temperature.
  • the firing temperature is, for example, 1250 ° C. or higher and 1450 ° C. or lower, and preferably 1350 ⁇ 50 ° C.
  • the gas sensor element 3 can be manufactured by performing the above steps.
  • the gas sensor element 3 configured in this manner includes an element body 21, an outer electrode 27, a vertical lead portion 29, and an annular lead portion 28.
  • the element body 21 is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and is formed to have an element flange 23 protruding outward in the radial direction.
  • the vertical lead portion 29 includes a noble metal and is formed on the outer surface of the element main body 21 so as to extend from the tip side to the element flange portion 23 with respect to the element flange portion 23.
  • the annular lead portion 28 overlaps with the vertical lead portion 29 and is formed along the circumferential direction of the element body 21 on at least the tip-facing surface 23 b facing the tip side in the element collar portion 23.
  • the annular lead portion 28 has a length along the circumferential direction of the element main body 21 on the tip-facing surface 23 b in the circumferential direction of the longitudinal lead portion 29 in the overlapping region RO where the longitudinal lead portion 29 and the annular lead portion 28 overlap. It is formed to be longer than the length along.
  • the annular lead portion 28 contains a conductive oxide as a main component.
  • the “main component” refers to a component exceeding 50% by mass with respect to all components constituting the target portion (that is, the annular lead portion 28).
  • the gas sensor element 3 uses a conductive oxide cheaper than a noble metal as a main component of the annular lead portion 28, thereby reducing the amount of noble metal used in the annular lead portion 28 and reducing the manufacturing cost of the gas sensor element 3. can do.
  • annular lead portion 28 and the vertical lead portion 29 are formed so as to extend to the top surface 23a on the rear end side with respect to the front end facing surface 23b of the element collar portion 23, and the annular lead portion 28 and the vertical lead portion 29 are mutually connected. Contact is made at the top surface 23a.
  • the gas sensor element 3 a load is applied to the tip-facing surface 23b during a manufacturing process (hereinafter referred to as an assembly process) in which the gas sensor element 3, the metal shell 13 that holds the gas sensor element 3, and the protector 15 are assembled.
  • an assembly process a manufacturing process in which the gas sensor element 3, the metal shell 13 that holds the gas sensor element 3, and the protector 15 are assembled.
  • the annular lead portion 28 formed on the tip-facing surface 23b is peeled off from the element flange 23
  • the annular lead portion 28 and the vertical lead portion 29 are in contact with each other on the top surface 23a.
  • the gas sensor element 3 can improve the reliability of conduction between the annular lead portion 28 and the vertical lead portion 29 during the above assembly process.
  • the annular lead portion 28 is peeled off from the element flange 23 because the conductive oxide that is the main component of the annular lead portion 28 has ductility, unlike noble metals such as platinum. Because it is not.
  • the gas sensor 1 includes a gas sensor element 3, a metal shell 13 that holds the gas sensor element 3, and a protector 15.
  • the gas sensor 1 since the gas sensor 1 includes the gas sensor element 3, the same effect as the gas sensor element 3 can be obtained. That is, the gas sensor 1 can reduce the manufacturing cost of the gas sensor 1 by reducing the manufacturing cost of the gas sensor element 3.
  • the annular lead portion 28, the metal shell 13, and the protector 15 are electrically connected to each other through a packing 88 between the annular lead portion 28, the metal shell 13, and the protector 15.
  • a part of the annular lead part 28 and a part of the vertical lead part 29 are disposed between the contact surface PC1 where the annular lead part 28 and the packing 88 are in contact with the front end facing surface 23b.
  • the gas sensor 1 configured in this manner is in contact even when the annular lead portion 28 is peeled off at the distal end side (that is, radially inward) from the distal end side end portion of the contact surface PC1 during the assembly process. It is possible to maintain a state in which a part of the annular lead portion 28 and a part of the vertical lead portion 29 are in contact with each other on the rear end side (that is, radially outside) of the front end portion of the surface PC1. In the above assembly process, peeling of the annular lead portion 28 is more likely to occur on the front end side than the front end side end portion of the contact surface PC1 compared to the rear end side than the front end side end portion of the contact surface PC1. .
  • FIG 5 is a view of the annular lead portion 28 as viewed from the front end side.
  • a crack CR is generated radially inward from the radially inner end portion EF of the region RC in contact with the packing 88. It shows the state.
  • the gas sensor 1 can improve the reliability of conduction between the annular lead portion 28 and the vertical lead portion 29 during the above assembly process.
  • the element collar 23 corresponds to the collar
  • the outer electrode 27 and the longitudinal lead 29 correspond to the external electrode
  • the annular lead 28 corresponds to the collar lead
  • the top surface 23a is the rear surface. It corresponds to the end side outer peripheral surface.
  • the metal shell 13 and the protector 15 correspond to a holding member, the packing 88 corresponds to a conductive member, and the contact surface PC1 corresponds to a second contact surface.
  • this indication is not limited to the above-mentioned embodiment, and can carry out various modifications.
  • the annular lead portion 28 is disposed on the longitudinal lead portion 29
  • the longitudinal lead portion 29 may be disposed on the annular lead portion 28.
  • the vertical lead portion 29 is thin, if the vertical lead portion 29 is disposed on the annular lead portion 28, disconnection is likely to occur in the vertical lead portion 29. For this reason, it is desirable that the annular lead portion 28 be disposed on the vertical lead portion 29.
  • the annular lead portion 28 has a conductive oxide as a main component.
  • a component other than the conductive oxide for example, rare earth-added ceria may be included.
  • the lead part (namely, collar lead part) formed in the element collar part 23 showed the form which is cyclic
  • the annular lead portion 28 is formed on the entire tip-facing surface 23b. However, the annular lead portion 28 may be formed on a part of the tip-facing surface 23b.
  • the packing 88 is interposed between the annular lead portion 28 and the protector 15 so as to be electrically connected to each other.
  • the annular lead portion 28 and the protector 15 may be in direct contact with each other.
  • a part of the annular lead part 28 and a part of the vertical lead part 29 are arranged between the contact surface PC2 where the annular lead part 28 and the protector 15 are in contact with the tip-facing face 23b.
  • “A portion of the annular lead portion 28 and a portion of the vertical lead portion 29 are disposed between the contact surface PC2 and the tip-facing surface 23b” means that the contact surface PC2 extends from the contact surface PC2 toward the tip-facing surface 23b.
  • a straight line that is, a normal line of the contact surface PC ⁇ b> 2 that corresponds to passing through the annular lead portion 28 and the vertical lead portion 29.
  • the contact surface PC2 corresponds to the first contact surface.
  • the element collar 23 may be curved at the outermost point PO located on the outermost side in the radial direction.
  • the rear end side end portion of the front end facing surface 23b is the outermost point PO.
  • the angle ⁇ between the normal vector VN of the tip-facing surface 23b and the axis O gradually approaches 90 ° as it moves from the tip-side end of the tip-facing surface 23b toward the rear end. And the location where this angle (theta) changed from less than 90 degrees to 90 degrees turns into the rear end side edge part of the front end direction surface 23b.
  • the angle ⁇ between the normal vector VN1 and the axis O at the outermost point PO is 90 °.
  • each of the above embodiments may be shared by a plurality of components, or the functions of a plurality of components may be exhibited by one component. Moreover, you may abbreviate
  • at least a part of the configuration of each of the above embodiments may be added to or replaced with the configuration of the other above embodiments.
  • all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure.

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Abstract

This gas sensor element comprises an element body, external electrode, and flange lead part. The element body primarily consists of a solid electrolyte body, is formed in a bottomed cylinder shape that extends in the axial direction and has a closed distal end, and has a flange part that protrudes outwardly in the radial direction. The external electrode includes a noble metal and is formed on the outer surface of the element body so as to extend toward the flange part from the side further to the distal end than the flange part. The flange lead part overlaps with the external electrode and is formed along the circumferential direction of the element body on a distal-end-facing surface that faces the distal end side at least at the flange part. The flange lead part is formed so as to have a length along the circumferential direction of the element body on the distal-end-facing surface that is longer than the length along the circumferential direction of the external electrode of an overlapping portion where the external electrode and flange lead part overlap. The flange lead part primarily consists of a conductive oxide.

Description

ガスセンサ素子およびガスセンサGas sensor element and gas sensor 関連出願の相互参照Cross-reference of related applications
　本国際出願は、２０１８年１月３１日に日本国特許庁に出願された日本国特許出願第２０１８－１５５７３号に基づく優先権を主張するものであり、日本国特許出願第２０１８－１５５７３号の全内容を参照により本国際出願に援用する。 This international application claims priority based on Japanese Patent Application No. 2018-15573 filed with the Japan Patent Office on January 31, 2018, and is based on Japanese Patent Application No. 2018-15573. The entire contents are incorporated herein by reference.
　本開示は、有底筒状に形成された素子本体を備えるガスセンサ素子およびガスセンサに関する。 The present disclosure relates to a gas sensor element and a gas sensor including an element body formed in a bottomed cylindrical shape.
　特許文献１のように、固体電解質体を主体として、軸線方向に延びて先端が閉じた有底筒状に形成されるとともに、径方向外側に突出する鍔部を有するように形成された素子本体を備えるガスセンサ素子が知られている。 As in Patent Document 1, the element body is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and has a flange that protrudes radially outward. There is known a gas sensor element comprising:
　このようなガスセンサ素子では、ガスセンサ素子を保持する主体金具と電気的に接続するために、鍔部に鍔リード部が形成されている。この鍔リード部は、白金等の貴金属で形成されている。 In such a gas sensor element, a saddle lead part is formed on the collar part in order to be electrically connected to a metal shell that holds the gas sensor element. The saddle lead portion is made of a noble metal such as platinum.
特開２０１７－２０９２８号公報JP 2017-20928 A
　鍔リード部は、主体金具との電気的接続を確保するために、広範囲に形成する必要がある。このため、鍔リード部に高価な貴金属を用いると、ガスセンサ素子の製造コストが大幅に上昇してしまうという問題があった。 鍔 The lead part needs to be formed in a wide range in order to ensure electrical connection with the metal shell. For this reason, when an expensive noble metal is used for the lead part, there is a problem that the manufacturing cost of the gas sensor element is significantly increased.
　本開示は、ガスセンサ素子の製造コストを低減する。 This disclosure reduces the manufacturing cost of the gas sensor element.
　本開示の一態様は、素子本体と、外部電極と、鍔リード部とを備えるガスセンサ素子である。素子本体は、固体電解質体を主体として、軸線方向に延びて先端が閉じた有底筒状に形成されるとともに、径方向外側に突出する鍔部を有するように形成される。外部電極は、貴金属を含み、鍔部よりも先端側から鍔部へ向かって延びるようにして素子本体の外表面に形成される。鍔リード部は、外部電極と重なり、少なくとも鍔部において先端側に面する先端向き面上に、素子本体の周方向に沿って形成され、先端向き面上における素子本体の周方向に沿った長さが、外部電極と鍔リード部とが重なる重なり部における外部電極の周方向に沿った長さより長くなるように形成される。そして、本開示のガスセンサ素子では、鍔リード部は、導電性酸化物を主成分とする。なお、「主成分」とは、対象となる部位を構成する全成分に対し、５０質量％を超える成分をいう。 One aspect of the present disclosure is a gas sensor element including an element body, an external electrode, and a heel lead portion. The element body is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and is formed to have a flange portion protruding radially outward. The external electrode includes a noble metal, and is formed on the outer surface of the element body so as to extend from the distal end side toward the collar part from the collar part. The heel lead portion overlaps the external electrode and is formed along the circumferential direction of the element body on at least the heel portion facing the distal end side along the circumferential direction of the element body. Is formed so as to be longer than the length along the circumferential direction of the external electrode in the overlapping portion where the external electrode and the heel lead portion overlap. And in the gas sensor element of this indication, a heel lead part has a conductive oxide as a main component. The “main component” refers to a component exceeding 50% by mass with respect to all components constituting the target site.
　このように構成された本開示のガスセンサ素子は、貴金属より安価な導電性酸化物を鍔リード部の主成分とすることにより、鍔リード部における貴金属の使用量を削減し、ガスセンサ素子の製造コストを低減することができる。 The gas sensor element of the present disclosure configured as described above has a conductive oxide that is less expensive than a noble metal as a main component of the heel lead portion, thereby reducing the amount of noble metal used in the heel lead portion and the manufacturing cost of the gas sensor element. Can be reduced.
　また、本開示の一態様では、鍔リード部および外部電極は、鍔部における先端向き面よりも後端側の外周面である後端側外周面まで延びるように形成され、鍔リード部および外部電極は互いに、後端側外周面で接触するようにしてもよい。 Further, in one aspect of the present disclosure, the heel lead portion and the external electrode are formed to extend to the rear end side outer peripheral surface that is the outer peripheral surface on the rear end side with respect to the front end facing surface of the heel portion. The electrodes may contact each other on the outer peripheral surface on the rear end side.
　このように構成された本開示のガスセンサ素子では、ガスセンサ素子と、ガスセンサ素子を保持する保持部材とを組み付ける製造工程時において先端向き面に荷重が掛かることに起因して、先端向き面に形成されている鍔リード部が鍔部から剥がれた場合であっても、後端側外周面で鍔リード部および外部電極が互いに接触している。これにより、本開示のガスセンサ素子は、上記の製造工程時において、鍔リード部と外部電極との導通の信頼性を向上させることができる。 In the gas sensor element of the present disclosure configured as described above, the gas sensor element and the holding member that holds the gas sensor element are formed on the tip-facing surface because a load is applied to the tip-facing surface during the manufacturing process. Even when the heel lead portion peeled off from the heel portion, the heel lead portion and the external electrode are in contact with each other on the outer peripheral surface on the rear end side. Thereby, the gas sensor element of this indication can improve the reliability of conduction with a heel lead part and an external electrode at the time of the above-mentioned manufacturing process.
　本開示の別の態様は、本開示の一態様のガスセンサ素子と、このガスセンサ素子を保持する保持部材とを備えるガスセンサである。 Another aspect of the present disclosure is a gas sensor including the gas sensor element of one aspect of the present disclosure and a holding member that holds the gas sensor element.
　このように構成された本開示のガスセンサは、本開示の一態様のガスセンサ素子を備えたガスセンサであり、本開示のガスセンサ素子と同様の効果を得ることができる。すなわち、本開示のガスセンサは、ガスセンサ素子の製造コストの低減により、ガスセンサの製造コストを低減することができる。 The gas sensor of the present disclosure configured as described above is a gas sensor including the gas sensor element of one embodiment of the present disclosure, and can obtain the same effects as the gas sensor element of the present disclosure. That is, the gas sensor of the present disclosure can reduce the manufacturing cost of the gas sensor by reducing the manufacturing cost of the gas sensor element.
　また、本開示の別の態様では、鍔リード部と保持部材とは、直接接触するか、鍔リード部と保持部材との間に導電部材を介することにより、互いに電気的に接続されているようにしてもよい。そして、本開示のガスセンサは、鍔リード部と保持部材とが直接接触する場合には、鍔リード部または外部電極と保持部材とが接触する第１接触面と、先端向き面との間に、鍔リード部の一部分および外部電極の一部分が配置されるようにしてもよい。また、本開示のガスセンサは、鍔リード部と保持部材との間に導電部材を介している場合には、鍔リード部または外部電極と導電部材とが接触する第２接触面と、先端向き面との間に、鍔リード部の一部分および外部電極の一部分が配置されるようにしてもよい。 In another aspect of the present disclosure, the heel lead portion and the holding member are in direct contact with each other, or are electrically connected to each other through a conductive member between the heel lead portion and the holding member. It may be. When the heel lead portion and the holding member are in direct contact with each other, the gas sensor of the present disclosure, between the first contact surface where the heel lead portion or the external electrode and the holding member are in contact, and the tip-facing surface, A part of the lead part and a part of the external electrode may be arranged. Further, in the gas sensor according to the present disclosure, when the conductive member is interposed between the heel lead portion and the holding member, the second contact surface where the heel lead portion or the external electrode and the conductive member are in contact with each other, and the tip-facing surface A part of the heel lead part and a part of the external electrode may be disposed between the two.
　このように構成された本開示のガスセンサは、上記の製造工程時において第１，２接触面の先端側端部よりも先端側で鍔リード部が剥がれた場合であっても、第１，２接触面の先端側端部よりも後端側において鍔リード部の一部分と外部電極の一部分とが接触した状態を維持することができる。なお、上記の製造工程時において、第１，２接触面の先端側端部より先端側は、第１，２接触面の先端側端部より後端側と比較して、鍔リード部の剥離が発生し易い。これにより、本開示のガスセンサは、上記の製造工程時において、鍔リード部と外部電極との導通の信頼性を向上させることができる。 The gas sensor of the present disclosure configured as described above is configured so that the first and second contact portions are separated even when the heel lead portion is peeled off at the front end side of the first and second contact surfaces in the manufacturing process. It is possible to maintain a state in which a part of the heel lead part and a part of the external electrode are in contact with each other on the rear end side with respect to the front end side end part of the contact surface. In addition, in the manufacturing process described above, the leading end side of the first and second contact surfaces is separated from the distal end side of the first and second contact surfaces as compared to the rear end side of the first and second contact surfaces. Is likely to occur. Thereby, the gas sensor of this indication can improve the reliability of conduction with a heel lead part and an external electrode in the above-mentioned manufacturing process.
ガスセンサを軸線方向に切断した状態を示す図である。It is a figure which shows the state which cut | disconnected the gas sensor to the axial direction. ガスセンサ素子の正面図である。It is a front view of a gas sensor element. ガスセンサ素子の断面図である。It is sectional drawing of a gas sensor element. 素子鍔部の周辺における環状リード部、縦リード部およびパッキンの断面図である。It is sectional drawing of the cyclic | annular lead part in the periphery of an element collar part, a vertical lead part, and packing. 環状リード部におけるクラック発生箇所を示す図である。It is a figure which shows the crack generation location in a cyclic | annular lead part. 素子鍔部の周辺における環状リード部、縦リード部およびプロテクタの断面図である。It is sectional drawing of the cyclic | annular lead part in the periphery of an element collar part, a vertical lead part, and a protector. 別の実施形態の素子鍔部の断面図である。It is sectional drawing of the element collar part of another embodiment.
　３…ガスセンサ素子、２１…素子本体、２３…素子鍔部、２３ｂ…先端向き面、２７…外側電極、２８…環状リード部、２９…縦リード部 3 ... gas sensor element, 21 ... element body, 23 ... element collar, 23b ... tip end surface, 27 ... outer electrode, 28 ... annular lead part, 29 ... vertical lead part
　以下に本開示の実施形態を図面とともに説明する。 Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
　本実施形態のガスセンサ１は、例えば自動車およびオートバイ等の車両の排気管に取り付けられ、排気管内の排気ガスに含まれる酸素濃度を検出する。 The gas sensor 1 of this embodiment is attached to an exhaust pipe of a vehicle such as an automobile or a motorcycle, for example, and detects an oxygen concentration contained in the exhaust gas in the exhaust pipe.
　ガスセンサ１は、図１に示すように、ガスセンサ素子３、セパレータ５、閉塞部材７、端子金具９およびリード線１１を備える。さらにガスセンサ１は、主体金具１３と、プロテクタ１５と、外筒１６とを備えている。主体金具１３、プロテクタ１５および外筒１６は、ガスセンサ素子３、セパレータ５および閉塞部材７の周囲を覆うように配置される。なお、外筒１６は、内側外筒１７および外側外筒１９を備えている。 As shown in FIG. 1, the gas sensor 1 includes a gas sensor element 3, a separator 5, a closing member 7, a terminal fitting 9 and a lead wire 11. Furthermore, the gas sensor 1 includes a metal shell 13, a protector 15, and an outer cylinder 16. The metal shell 13, the protector 15, and the outer cylinder 16 are arranged so as to cover the periphery of the gas sensor element 3, the separator 5, and the closing member 7. The outer cylinder 16 includes an inner outer cylinder 17 and an outer outer cylinder 19.
　ガスセンサ１は、ガスセンサ素子３を加熱するためのヒータを備えていない。すなわち、ガスセンサ１は、排気ガスの熱を利用してガスセンサ素子３を活性化して酸素濃度を検出する。 The gas sensor 1 does not include a heater for heating the gas sensor element 3. That is, the gas sensor 1 detects the oxygen concentration by activating the gas sensor element 3 using the heat of the exhaust gas.
　ガスセンサ素子３は、酸素イオン伝導性を有する固体電解質体を用いて形成されている。ガスセンサ素子３は、図２に示すように、先端部２５が閉塞された有底筒形状であり、軸線Ｏの方向（以下、軸線方向）に延びる円筒状の素子本体２１を有している。この素子本体２１の外周には、周方向に沿って径方向外向きに突出した素子鍔部２３が形成されている。 The gas sensor element 3 is formed using a solid electrolyte body having oxygen ion conductivity. As shown in FIG. 2, the gas sensor element 3 has a bottomed cylindrical shape with a closed end portion 25 and has a cylindrical element body 21 that extends in the direction of the axis O (hereinafter referred to as the axial direction). On the outer periphery of the element body 21, an element flange 23 is formed that protrudes radially outward along the circumferential direction.
　なお、素子本体２１を構成する固体電解質体は、ジルコニア（ＺｒＯ２）に安定化剤としてイットリア（Ｙ２Ｏ３）またはカルシア（ＣａＯ）を添加してなる部分安定化ジルコニア焼結体を用いて構成されている。素子本体２１を構成する固体電解質体は、これらに限られることはなく、「アルカリ土類金属の酸化物とＺｒＯ２との固溶体」、「希土類金属の酸化物とＺｒＯ２との固溶体」などを用いてもよい。さらには、これらにＨｆＯ２が含有された固体電解質体を、素子本体２１を構成する固体電解質体として用いてもよい。 The solid electrolyte body constituting the element body 21 is a partially stabilized zirconia sintered body obtained by adding yttria (Y 2 O 3 ) or calcia (CaO) as a stabilizer to zirconia (ZrO 2 ). It is configured. The solid electrolyte constituting the element body 21 is not limited to these, and includes “solid solution of alkaline earth metal oxide and ZrO 2 ”, “solid solution of rare earth metal oxide and ZrO 2 ”, and the like. It may be used. Furthermore, a solid electrolyte body containing HfO 2 therein may be used as the solid electrolyte body constituting the element body 21.
　ガスセンサ素子３の先端部２５には、素子本体２１の外周面に外側電極２７が形成されている。外側電極２７は、ＰｔあるいはＰｔ合金を多孔質に形成した電極である。 An outer electrode 27 is formed on the outer peripheral surface of the element main body 21 at the distal end portion 25 of the gas sensor element 3. The outer electrode 27 is an electrode in which Pt or a Pt alloy is formed to be porous.
　素子鍔部２３の表面は、頂面２３ａと、先端向き面２３ｂと、後端向き面２３ｃとにより形成されている。 The surface of the element flange 23 is formed by a top surface 23a, a front end facing surface 23b, and a rear end facing surface 23c.
　頂面２３ａは、素子鍔部２３において径方向の最も外側に位置し、軸線方向に対して平行な面である。先端向き面２３ｂは、頂面２３ａの先端を起点として素子本体２１の先端に向かって頂面２３ａから遠ざかるにつれて軸線Ｏに近付くように傾斜した面である。後端向き面２３ｃは、頂面２３ａの後端を起点として素子本体２１の後端に向かって頂面２３ａから遠ざかるにつれて軸線Ｏに近付くように傾斜した面である。 The top surface 23a is located on the outermost side in the radial direction in the element flange 23 and is a surface parallel to the axial direction. The tip-facing surface 23b is a surface that is inclined so as to approach the axis O as the distance from the top surface 23a increases from the tip of the top surface 23a toward the tip of the element body 21. The rear-facing surface 23c is a surface that is inclined so as to approach the axis O as the distance from the top surface 23a increases from the rear end of the top surface 23a toward the rear end of the element body 21.
　そして、素子鍔部２３の頂面２３ａと先端向き面２３ｂには、環状の環状リード部２８が形成されている。 An annular lead portion 28 is formed on the top surface 23a and the tip-facing surface 23b of the element flange 23.
　環状リード部２８は、以下の組成式（１）を満たすペロブスカイト型酸化物結晶構造を有する結晶相（すなわち、ペロブスカイト相）を含有する導電性酸化物を主成分として含んでいる。 The annular lead portion 28 contains, as a main component, a conductive oxide containing a crystal phase having a perovskite oxide crystal structure that satisfies the following composition formula (1) (that is, a perovskite phase).
　　ＬａａＭｂＮｉｃＯｘ　　・・・（１）
　ここで、元素ＭはＣｏとＦｅとＣｕのうちの一種以上を表し、ａ＋ｂ＋ｃ＝１であり、１．２５≦ｘ≦１．７５である。係数ａ，ｂ，ｃはそれぞれ、以下の関係式（２ａ），（２ｂ），（２ｃ）を満たす。 La a Mb Ni c O x (1)
Here, the element M represents one or more of Co, Fe, and Cu, a + b + c = 1, and 1.25 ≦ x ≦ 1.75. The coefficients a, b, and c satisfy the following relational expressions (2a), (2b), and (2c), respectively.
　　　０．４５９≦ａ≦０．５３５　　・・・（２ａ）
　　　０．２００≦ｂ≦０．４７５　　・・・（２ｂ）
　　　０．０２５≦ｃ≦０．３５０　　・・・（２ｃ）
　素子本体２１の外周面のうち外側電極２７と環状リード部２８との間には、Ｐｔ等で形成された縦リード部２９が軸線方向に延びるように形成されている。縦リード部２９は、素子鍔部２３の頂面２３ａまで延びる。縦リード部２９は、外側電極２７と環状リード部２８とを電気的に接続している。図２において破線で示す矩形の重複領域ＲＯは、縦リード部２９と環状リード部２８とが重なる領域である。 0.459 ≦ a ≦ 0.535 (2a)
0.200 ≦ b ≦ 0.475 (2b)
0.025 ≦ c ≦ 0.350 (2c)
A vertical lead portion 29 made of Pt or the like is formed between the outer electrode 27 and the annular lead portion 28 on the outer peripheral surface of the element body 21 so as to extend in the axial direction. The vertical lead portion 29 extends to the top surface 23 a of the element flange portion 23. The vertical lead portion 29 electrically connects the outer electrode 27 and the annular lead portion 28. A rectangular overlapping area RO indicated by a broken line in FIG. 2 is an area where the vertical lead portion 29 and the annular lead portion 28 overlap.
　また、図１に示すように、ガスセンサ素子３の内周面には、内側電極３０が形成されている。内側電極３０は、Ｐｔ、Ｐｔ合金あるいは酸化物導電体を多孔質に形成した電極である。ガスセンサ素子３の先端部２５において、外側電極２７が排気ガスに晒され、内側電極３０が基準ガスに晒されることで、ガスセンサ素子３は、排気ガス中の酸素濃度を検出している。本実施形態では、基準ガスは大気である。 Further, as shown in FIG. 1, an inner electrode 30 is formed on the inner peripheral surface of the gas sensor element 3. The inner electrode 30 is an electrode in which Pt, a Pt alloy, or an oxide conductor is formed to be porous. At the front end portion 25 of the gas sensor element 3, the outer electrode 27 is exposed to the exhaust gas, and the inner electrode 30 is exposed to the reference gas, so that the gas sensor element 3 detects the oxygen concentration in the exhaust gas. In this embodiment, the reference gas is the atmosphere.
　セパレータ５は、電気絶縁性を有する材料（例えばアルミナ）で形成された円筒形状の部材である。セパレータ５は、その軸中心に、リード線１１が挿入される貫通孔３５が形成されている。セパレータ５は、その外周側を覆う内側外筒１７との間に空隙１８が設けられるように配置されている。 The separator 5 is a cylindrical member formed of an electrically insulating material (for example, alumina). The separator 5 has a through-hole 35 into which the lead wire 11 is inserted at the axial center. The separator 5 is disposed so that a gap 18 is provided between the separator 5 and the inner outer cylinder 17 covering the outer peripheral side.
　閉塞部材７は、電気絶縁性を有する材料（例えばフッ素ゴム）で形成された円筒形状のシール部材である。閉塞部材７は、その後端に径方向外向きに突出する突出部３６を備える。閉塞部材７は、その軸中心にリード線１１が挿入されるリード線挿入孔３７を備えている。閉塞部材７の先端面９５は、セパレータ５の後端面９７に密着し、閉塞部材７のうち突出部３６よりも先端側の側方外周面９８は、内側外筒１７の内面に密着している。すなわち、閉塞部材７は、外筒１６の後端側を閉塞している。 The closing member 7 is a cylindrical sealing member made of an electrically insulating material (for example, fluoro rubber). The closing member 7 includes a protruding portion 36 that protrudes radially outward at the rear end thereof. The closing member 7 includes a lead wire insertion hole 37 into which the lead wire 11 is inserted at the center of the shaft. The front end surface 95 of the closing member 7 is in close contact with the rear end surface 97 of the separator 5, and the side outer peripheral surface 98 on the front end side of the protruding portion 36 of the closing member 7 is in close contact with the inner surface of the inner outer cylinder 17. . That is, the closing member 7 closes the rear end side of the outer cylinder 16.
　閉塞部材７の後端向き面９９と、外側外筒１９の縮径部１９ｇの先端向き面１９ａとの間で、リード線保護部材８９の鍔部８９ｂが挟まれた状態で、リード線保護部材８９が支持される。 In a state where the flange portion 89b of the lead wire protection member 89 is sandwiched between the rear end facing surface 99 of the closing member 7 and the front end facing surface 19a of the reduced diameter portion 19g of the outer outer cylinder 19, 89 is supported.
　このうち、縮径部１９ｇは、閉塞部材７よりも後端側にて、径方向内側に延びており、縮径部１９ｇの先端向き面１９ａは、ガスセンサ１の先端側に向く面として形成されている。縮径部１９ｇの中央領域には、リード線１１およびリード線保護部材８９を挿入するためのリード線挿入部１９ｃが形成されている。 Among these, the reduced diameter portion 19 g extends radially inward on the rear end side of the closing member 7, and the distal-facing surface 19 a of the reduced diameter portion 19 g is formed as a surface facing the distal end side of the gas sensor 1. ing. A lead wire insertion portion 19c for inserting the lead wire 11 and the lead wire protection member 89 is formed in the central region of the reduced diameter portion 19g.
　リード線保護部材８９は、リード線１１を収容可能な内径寸法を有する筒状部材であり、可撓性、耐熱性および絶縁性を有する材料（例えば、ガラスチューブおよび樹脂チューブなど）で構成されている。リード線保護部材８９は、リード線１１を外部からの飛来物（例えば、石や水など）から保護するために取り付けられる。 The lead wire protection member 89 is a cylindrical member having an inner diameter that can accommodate the lead wire 11, and is made of a material having flexibility, heat resistance, and insulation (for example, a glass tube and a resin tube). Yes. The lead wire protection member 89 is attached in order to protect the lead wire 11 from flying objects (for example, stone or water) from the outside.
　リード線保護部材８９は、先端側端部８９ａにおいて、軸線方向の垂直方向における外向きに突出する板状の鍔部８９ｂを備える。鍔部８９ｂは、リード線保護部材８９の周方向の一部ではなく、全周にわたり形成されている。 The lead wire protection member 89 includes a plate-like flange portion 89b that protrudes outward in the vertical direction in the axial direction at the tip end portion 89a. The collar portion 89b is formed not over a part of the lead wire protection member 89 in the circumferential direction but over the entire circumference.
　リード線保護部材８９の鍔部８９ｂは、外側外筒１９の縮径部１９ｇの先端向き面１９ａと閉塞部材７の後端向き面９９との間に挟まれている。 The flange portion 89 b of the lead wire protection member 89 is sandwiched between the front end facing surface 19 a of the reduced diameter portion 19 g of the outer outer cylinder 19 and the rear end facing surface 99 of the closing member 7.
　端子金具９は、センサ出力を外部に取り出すために、導電性材料で形成される筒状部材である。端子金具９は、リード線１１に電気的に接続されるとともに、ガスセンサ素子３の内側電極３０に電気的に接触するように配置されている。端子金具９は、その後端側に径方向（すなわち、軸線方向に対して垂直の方向）の外向きに突出するフランジ部７７を備えている。フランジ部７７は、３枚の板状のフランジ片７５を備えている。 The terminal fitting 9 is a cylindrical member formed of a conductive material in order to extract the sensor output to the outside. The terminal fitting 9 is electrically connected to the lead wire 11 and is disposed so as to be in electrical contact with the inner electrode 30 of the gas sensor element 3. The terminal fitting 9 includes a flange portion 77 protruding outward in the radial direction (that is, the direction perpendicular to the axial direction) on the rear end side. The flange portion 77 includes three plate-like flange pieces 75.
　リード線１１は、芯線６５と、芯線６５の外周を覆う被覆部６７とを備えている。 The lead wire 11 includes a core wire 65 and a covering portion 67 that covers the outer periphery of the core wire 65.
　主体金具１３は、金属材料（例えば鉄またはＳＵＳ４３０）で形成された円筒状の部材である。主体金具１３には、内周面において径方向内側に向かって張り出した段部３９が形成されている。段部３９は、ガスセンサ素子３の素子鍔部２３を支持するために形成されている。 The metal shell 13 is a cylindrical member formed of a metal material (for example, iron or SUS430). The metal shell 13 is formed with a step portion 39 projecting radially inward on the inner peripheral surface. The step 39 is formed to support the element flange 23 of the gas sensor element 3.
　主体金具１３のうち先端側の外周面には、ガスセンサ１を排気管に取付けるためのネジ部４１が形成されている。主体金具１３のうちネジ部４１の後端側には、ガスセンサ１を排気管に着脱する際に取付工具を係合させる六角部４３が形成されている。さらに、主体金具１３のうち六角部４３の後端側には、筒状部４５が設けられている。 A threaded portion 41 for attaching the gas sensor 1 to the exhaust pipe is formed on the outer peripheral surface on the tip side of the metal shell 13. A hexagonal portion 43 is formed on the rear end side of the threaded portion 41 of the metal shell 13 to engage the attachment tool when the gas sensor 1 is attached to or detached from the exhaust pipe. Further, a cylindrical portion 45 is provided on the rear end side of the hexagonal portion 43 in the metal shell 13.
　プロテクタ１５は、金属材料（例えばＳＵＳ３１０Ｓ）で形成されており、ガスセンサ素子３の先端側を覆う保護部材であり、複数個形成されたガス流通孔を介して排気ガスをガスセンサ素子３に対して導入する。プロテクタ１５は、その後端縁が、導電性材料で形成されたパッキン８８を介して、ガスセンサ素子３の素子鍔部２３と主体金具１３の段部３９との間に挟まれるようにして固定されている。 The protector 15 is formed of a metal material (for example, SUS310S), and is a protective member that covers the distal end side of the gas sensor element 3, and introduces exhaust gas to the gas sensor element 3 through a plurality of formed gas flow holes. To do. The protector 15 is fixed so that the rear edge thereof is sandwiched between the element flange portion 23 of the gas sensor element 3 and the step portion 39 of the metal shell 13 via a packing 88 formed of a conductive material. Yes.
　ガスセンサ素子３のうち素子鍔部２３の後端側領域においては、主体金具１３とガスセンサ素子３との間に、先端側から後端側にかけて、滑石で形成されたセラミック粉末４７と、アルミナで形成されたセラミックスリーブ４９とが配置されている。 In the rear end region of the element flange 23 of the gas sensor element 3, the ceramic powder 47 made of talc and the alumina are formed between the metal shell 13 and the gas sensor element 3 from the front end side to the rear end side. A ceramic sleeve 49 is disposed.
　さらに、主体金具１３の筒状部４５の後端部５１の内側には、金属材料（例えばＳＵＳ４３０）で形成された金属リング５３と、金属材料（例えばＳＵＳ３０４Ｌ）で形成された内側外筒１７の先端部５５とが配置されている。内側外筒１７の先端部５５は、径方向外向きに広がる形状に形成されている。つまり、筒状部４５の後端部５１が加締められることで、内側外筒１７の先端部５５が、金属リング５３を介して筒状部４５の後端部５１とセラミックスリーブ４９との間に挟まれて、内側外筒１７が主体金具１３に固定される。 Further, on the inner side of the rear end portion 51 of the cylindrical portion 45 of the metal shell 13, there are a metal ring 53 formed of a metal material (for example, SUS430) and an inner outer tube 17 formed of a metal material (for example, SUS304L). A distal end portion 55 is disposed. The distal end portion 55 of the inner outer cylinder 17 is formed in a shape that extends radially outward. That is, the rear end portion 51 of the tubular portion 45 is crimped, so that the front end portion 55 of the inner outer tube 17 is interposed between the rear end portion 51 of the tubular portion 45 and the ceramic sleeve 49 via the metal ring 53. The inner outer cylinder 17 is fixed to the metal shell 13.
　また、内側外筒１７の外周には、樹脂材料（例えばＰＴＦＥ）で形成された筒状のフィルタ５７が配置されるとともに、フィルタ５７の外周には、例えばＳＵＳ３０４Ｌで形成された外側外筒１９が配置されている。フィルタ５７は、通気は可能であるが水分の侵入は抑制できる。 A cylindrical filter 57 formed of a resin material (for example, PTFE) is disposed on the outer periphery of the inner outer cylinder 17, and an outer outer cylinder 19 formed of, for example, SUS304L is disposed on the outer periphery of the filter 57. Has been placed. The filter 57 can be ventilated but can suppress the intrusion of moisture.
　そして、外側外筒１９の加締め部１９ｂが外周側から径方向内向きに加締められることにより、内側外筒１７とフィルタ５７と外側外筒１９とが一体に固定される。また、外側外筒１９の加締め部１９ｈが外周側から径方向内向きに加締められることにより、内側外筒１７と外側外筒１９とが一体に固定され、閉塞部材７の側方外周面９８が、内側外筒１７の内面に密着することとなる。 Then, the caulking portion 19b of the outer outer cylinder 19 is caulked inward in the radial direction from the outer peripheral side, whereby the inner outer cylinder 17, the filter 57, and the outer outer cylinder 19 are fixed integrally. Further, the caulking portion 19 h of the outer outer cylinder 19 is caulked inward in the radial direction from the outer peripheral side, whereby the inner outer cylinder 17 and the outer outer cylinder 19 are integrally fixed, and the lateral outer peripheral surface of the closing member 7. 98 comes into close contact with the inner surface of the inner outer cylinder 17.
　なお、内側外筒１７および外側外筒１９は、それぞれ通気孔５９および通気孔６１を備えている。すなわち、通気孔５９，６１とフィルタ５７を介して、ガスセンサ１の内部と外部との通気が可能である。 The inner outer cylinder 17 and the outer outer cylinder 19 are provided with a vent hole 59 and a vent hole 61, respectively. That is, the inside and outside of the gas sensor 1 can be ventilated through the vent holes 59 and 61 and the filter 57.
　図３に示すように、外側電極２７と内側電極３０は、ガスセンサ素子３の先端部２５において、素子本体２１を挟み込むように配置されている。素子本体２１および一対の電極（すなわち、外側電極２７および内側電極３０）は、酸素濃淡電池を構成して、排気ガス中の酸素濃度に応じた起電力を発生させる。つまり、ガスセンサ素子３の先端部２５において、外側電極２７が排気ガスに晒され、内側電極３０が基準ガスに晒されることで、ガスセンサ素子３は、排気ガス中の酸素濃度を検出する。 As shown in FIG. 3, the outer electrode 27 and the inner electrode 30 are arranged so as to sandwich the element body 21 at the distal end portion 25 of the gas sensor element 3. The element body 21 and the pair of electrodes (that is, the outer electrode 27 and the inner electrode 30) constitute an oxygen concentration cell and generate an electromotive force according to the oxygen concentration in the exhaust gas. That is, the gas sensor element 3 detects the oxygen concentration in the exhaust gas by exposing the outer electrode 27 to the exhaust gas and the inner electrode 30 to the reference gas at the distal end portion 25 of the gas sensor element 3.
　外側電極２７は、上述の通り、縦リード部２９を介して環状リード部２８に電気的に接続されている。環状リード部２８は、導電性材料で形成されたパッキン８８およびプロテクタ１５を介して、主体金具１３に電気的に接続されている。なお、外側電極２７の形状および配置は単なる一例であり、これ以外の種々の形状および配置を採用可能である。 The outer electrode 27 is electrically connected to the annular lead portion 28 via the vertical lead portion 29 as described above. The annular lead portion 28 is electrically connected to the metal shell 13 via a packing 88 made of a conductive material and the protector 15. Note that the shape and arrangement of the outer electrode 27 are merely examples, and various other shapes and arrangements can be employed.
　また、ガスセンサ素子３の素子本体２１の内周面には、内側電極３０が形成されている。内側電極３０は、内側検知電極部３０ａと、内側リード部３０ｂとを備える。 Also, an inner electrode 30 is formed on the inner peripheral surface of the element body 21 of the gas sensor element 3. The inner electrode 30 includes an inner detection electrode portion 30a and an inner lead portion 30b.
　内側検知電極部３０ａは、素子本体２１の先端部２５の内表面を覆うように形成されている。内側リード部３０ｂは、内側検知電極部３０ａ上に接触し、端子金具９と電気的に接続される。内側検知電極部３０ａおよび内側リード部３０ｂは、全体として素子本体２１の内面の全面を覆うように形成されている。 The inner detection electrode part 30 a is formed so as to cover the inner surface of the tip part 25 of the element body 21. The inner lead portion 30 b contacts the inner detection electrode portion 30 a and is electrically connected to the terminal fitting 9. The inner detection electrode part 30a and the inner lead part 30b are formed so as to cover the entire inner surface of the element body 21 as a whole.
　つまり、ガスセンサ素子３の素子本体２１は、先端側領域Ｆ１に外側電極２７および内側検知電極部３０ａが形成され、後端側領域Ｆ２に内側リード部３０ｂが形成されている。素子本体２１の先端側領域Ｆ１は、素子本体２１の先端部２５に相当する。 That is, in the element body 21 of the gas sensor element 3, the outer electrode 27 and the inner detection electrode part 30a are formed in the front end side region F1, and the inner lead part 30b is formed in the rear end side region F2. The tip end region F1 of the element body 21 corresponds to the tip portion 25 of the element body 21.
　図４に示すように、環状リード部２８とパッキン８８とが接触する接触面ＰＣ１と、先端向き面２３ｂとの間に環状リード部２８の一部分および縦リード部２９の一部分が配置される。「接触面ＰＣ１と先端向き面２３ｂとの間に環状リード部２８の一部分および縦リード部２９の一部分が配置される」とは、接触面ＰＣ１から先端向き面２３ｂに向かって延びるとともに接触面ＰＣ１に対して垂直な直線（すなわち、接触面ＰＣ１の法線）が環状リード部２８および縦リード部２９を通過することに相当する。 As shown in FIG. 4, a part of the annular lead part 28 and a part of the vertical lead part 29 are arranged between the contact surface PC1 where the annular lead part 28 and the packing 88 are in contact with the front end facing surface 23b. “A portion of the annular lead portion 28 and a portion of the vertical lead portion 29 are disposed between the contact surface PC1 and the tip-facing surface 23b” means that the contact surface PC1 extends from the contact surface PC1 toward the tip-facing surface 23b. A straight line (that is, a normal line of the contact surface PC <b> 1) corresponding to passing through the annular lead portion 28 and the vertical lead portion 29.
　次に、ガスセンサ素子３の製造方法を説明する。 Next, a method for manufacturing the gas sensor element 3 will be described.
　第１工程では、未焼結成形体を作製する。具体的には、まず、素子本体２１の材料である固体電解質体の粉末として、ジルコニア（ＺｒＯ２）に安定剤としてイットリア（Ｙ２Ｏ３）を５ｍｏｌ％添加した粉末（以下、５ＹＳＺともいう）に対して、さらにアルミナ粉末を添加した粉末を用意する。素子本体２１の材料粉末全体を１００質量％としたとき、５ＹＳＺの含有量は９９．６質量％であり、アルミナ粉末の含有量は０．４質量％である。この粉末をプレス加工した後に、筒形となるように切削加工を実施することで、未焼結成形体を得る。 In the first step, a green compact is produced. Specifically, first, as a powder of a solid electrolyte body that is a material of the element body 21, a powder obtained by adding 5 mol% of yttria (Y 2 O 3 ) as a stabilizer to zirconia (ZrO 2 ) (hereinafter also referred to as 5YSZ). In contrast, a powder to which alumina powder is further added is prepared. When the total material powder of the element body 21 is 100% by mass, the content of 5YSZ is 99.6% by mass, and the content of alumina powder is 0.4% by mass. After this powder is pressed, an unsintered compact is obtained by carrying out cutting so as to form a cylinder.
　次に、第２工程では、外側電極２７、縦リード部２９および内側電極３０のそれぞれの形成位置に対して、白金（Ｐｔ）およびジルコニアを含有するスラリーを塗布する。このとき、外側電極２７、縦リード部２９を形成するためのスラリーは、白金に対して１５質量％の単斜晶ジルコニアを添加したスラリーを用いる。内側電極３０を形成するためのスラリーは、白金に対して、「９９．６質量％の５ＹＳＺ／０．４質量％アルミナの混合粉末」（すなわち、素子本体２１と同じ組成）を１５質量％添加したスラリーを用いる。 Next, in the second step, a slurry containing platinum (Pt) and zirconia is applied to each of the formation positions of the outer electrode 27, the vertical lead portion 29, and the inner electrode 30. At this time, the slurry for forming the outer electrode 27 and the vertical lead portion 29 is a slurry in which 15% by mass of monoclinic zirconia is added to platinum. The slurry for forming the inner electrode 30 is added with 15% by mass of “99.6% by mass of 5YSZ / 0.4% by mass alumina mixed powder” (that is, the same composition as the element body 21) with respect to platinum. The resulting slurry is used.
　次に、第３工程では、環状リード部２８のスラリーを作製する。環状リード部２８のスラリーの作製においては、まず、導電性酸化物の原料粉末を秤量した後、湿式混合して乾燥することにより、原料粉末混合物を調整し、７００～１３００℃で１～５時間仮焼して仮焼粉末を作製する。そして、この仮焼粉末を、湿式ボールミル等による粉砕を行い所定の粒度に調整する。このとき、ペロブスカイト相の原料粉末としては、例えば、Ｌａ（ＯＨ）３又はＬａ２Ｏ３、並びに、Ｃｏ３Ｏ４、Ｆｅ２Ｏ３、及びＮｉＯを用いることができる。そして、所定の粒子サイズに調整された仮焼粉末を、湿式ボールミル等により混合し、ターピネオールやブチルカルビトール等の溶媒に、エチルセルロース等のバインダとともに溶解することにより、スラリーを作製する。 Next, in the third step, a slurry of the annular lead portion 28 is produced. In the production of the slurry for the annular lead portion 28, first, the raw material powder of the conductive oxide is weighed, then wet mixed and dried to prepare the raw material powder mixture, and 700 to 1300 ° C. for 1 to 5 hours. Calcination is performed to prepare a calcination powder. Then, the calcined powder is pulverized by a wet ball mill or the like to adjust to a predetermined particle size. At this time, for example, La (OH) 3 or La 2 O 3 , Co 3 O 4 , Fe 2 O 3 , and NiO can be used as the raw powder for the perovskite phase. Then, the calcined powder adjusted to a predetermined particle size is mixed by a wet ball mill or the like, and dissolved in a solvent such as terpineol or butyl carbitol together with a binder such as ethyl cellulose to produce a slurry.
　次に、第４工程では、環状リード部２８の形成位置に対して、環状リード部２８のスラリーを塗布する。 Next, in the fourth step, the slurry of the annular lead portion 28 is applied to the position where the annular lead portion 28 is formed.
　次の第５工程では、各スラリーが塗布された未焼結成形体について、乾燥を行った後、所定の焼成温度で焼成する。この焼成温度は、例えば、１２５０℃以上であり且つ１４５０℃以下であり、１３５０±５０℃が好ましい。 In the next fifth step, the green compact coated with each slurry is dried and then fired at a predetermined firing temperature. The firing temperature is, for example, 1250 ° C. or higher and 1450 ° C. or lower, and preferably 1350 ± 50 ° C.
　上記の各工程を実施することで、ガスセンサ素子３を製造することができる。 The gas sensor element 3 can be manufactured by performing the above steps.
　このように構成されたガスセンサ素子３は、素子本体２１と、外側電極２７および縦リード部２９と、環状リード部２８とを備える。 The gas sensor element 3 configured in this manner includes an element body 21, an outer electrode 27, a vertical lead portion 29, and an annular lead portion 28.
　素子本体２１は、固体電解質体を主体として、軸線方向に延びて先端が閉じた有底筒状に形成されるとともに、径方向外側に突出する素子鍔部２３を有するように形成される。縦リード部２９は、貴金属を含み、素子鍔部２３よりも先端側から素子鍔部２３へ向かって延びるようにして素子本体２１の外表面に形成される。環状リード部２８は、縦リード部２９と重なり、少なくとも素子鍔部２３において先端側に面する先端向き面２３ｂ上に、素子本体２１の周方向に沿って形成される。また環状リード部２８は、先端向き面２３ｂ上における素子本体２１の周方向に沿った長さが、縦リード部２９と環状リード部２８とが重なる重複領域ＲＯにおける縦リード部２９の周方向に沿った長さより長くなるように形成される。そしてガスセンサ素子３では、環状リード部２８は、導電性酸化物を主成分とする。なお、「主成分」とは、対象となる部位（すなわち、環状リード部２８）を構成する全成分に対し、５０質量％を超える成分をいう。 The element body 21 is mainly formed of a solid electrolyte body, is formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and is formed to have an element flange 23 protruding outward in the radial direction. The vertical lead portion 29 includes a noble metal and is formed on the outer surface of the element main body 21 so as to extend from the tip side to the element flange portion 23 with respect to the element flange portion 23. The annular lead portion 28 overlaps with the vertical lead portion 29 and is formed along the circumferential direction of the element body 21 on at least the tip-facing surface 23 b facing the tip side in the element collar portion 23. Further, the annular lead portion 28 has a length along the circumferential direction of the element main body 21 on the tip-facing surface 23 b in the circumferential direction of the longitudinal lead portion 29 in the overlapping region RO where the longitudinal lead portion 29 and the annular lead portion 28 overlap. It is formed to be longer than the length along. In the gas sensor element 3, the annular lead portion 28 contains a conductive oxide as a main component. The “main component” refers to a component exceeding 50% by mass with respect to all components constituting the target portion (that is, the annular lead portion 28).
　このようにガスセンサ素子３は、貴金属より安価な導電性酸化物を環状リード部２８の主成分とすることにより、環状リード部２８における貴金属の使用量を削減し、ガスセンサ素子３の製造コストを低減することができる。 As described above, the gas sensor element 3 uses a conductive oxide cheaper than a noble metal as a main component of the annular lead portion 28, thereby reducing the amount of noble metal used in the annular lead portion 28 and reducing the manufacturing cost of the gas sensor element 3. can do.
　また、環状リード部２８および縦リード部２９は、素子鍔部２３における先端向き面２３ｂよりも後端側の頂面２３ａまで延びるように形成され、環状リード部２８および縦リード部２９は互いに、頂面２３ａで接触する。 Further, the annular lead portion 28 and the vertical lead portion 29 are formed so as to extend to the top surface 23a on the rear end side with respect to the front end facing surface 23b of the element collar portion 23, and the annular lead portion 28 and the vertical lead portion 29 are mutually connected. Contact is made at the top surface 23a.
　これにより、ガスセンサ素子３では、ガスセンサ素子３と、ガスセンサ素子３を保持する主体金具１３およびプロテクタ１５とを組み付ける製造工程（以下、組付工程）時において先端向き面２３ｂに荷重が掛かることに起因して、先端向き面２３ｂに形成されている環状リード部２８が素子鍔部２３から剥がれた場合であっても、頂面２３ａで環状リード部２８および縦リード部２９が互いに接触している。このため、ガスセンサ素子３は、上記の組付工程時において、環状リード部２８と縦リード部２９との導通の信頼性を向上させることができる。なお、上記の組付工程時において、環状リード部２８が素子鍔部２３から剥がれるのは、環状リード部２８の主成分である導電性酸化物が、白金等の貴金属と異なり、延性を有していないためである。 As a result, in the gas sensor element 3, a load is applied to the tip-facing surface 23b during a manufacturing process (hereinafter referred to as an assembly process) in which the gas sensor element 3, the metal shell 13 that holds the gas sensor element 3, and the protector 15 are assembled. Even when the annular lead portion 28 formed on the tip-facing surface 23b is peeled off from the element flange 23, the annular lead portion 28 and the vertical lead portion 29 are in contact with each other on the top surface 23a. For this reason, the gas sensor element 3 can improve the reliability of conduction between the annular lead portion 28 and the vertical lead portion 29 during the above assembly process. In the above assembly process, the annular lead portion 28 is peeled off from the element flange 23 because the conductive oxide that is the main component of the annular lead portion 28 has ductility, unlike noble metals such as platinum. Because it is not.
　またガスセンサ１は、ガスセンサ素子３と、このガスセンサ素子３を保持する主体金具１３およびプロテクタ１５とを備える。このようにガスセンサ１は、ガスセンサ素子３を備えているため、ガスセンサ素子３と同様の効果を得ることができる。すなわち、ガスセンサ１は、ガスセンサ素子３の製造コストの低減により、ガスセンサ１の製造コストを低減することができる。 The gas sensor 1 includes a gas sensor element 3, a metal shell 13 that holds the gas sensor element 3, and a protector 15. Thus, since the gas sensor 1 includes the gas sensor element 3, the same effect as the gas sensor element 3 can be obtained. That is, the gas sensor 1 can reduce the manufacturing cost of the gas sensor 1 by reducing the manufacturing cost of the gas sensor element 3.
　またガスセンサ１では、環状リード部２８と主体金具１３およびプロテクタ１５とは、環状リード部２８と主体金具１３およびプロテクタ１５との間にパッキン８８を介することにより、互いに電気的に接続されている。そしてガスセンサ１は、環状リード部２８とパッキン８８とが接触する接触面ＰＣ１と、先端向き面２３ｂとの間に、環状リード部２８の一部分および縦リード部２９の一部分が配置される。 In the gas sensor 1, the annular lead portion 28, the metal shell 13, and the protector 15 are electrically connected to each other through a packing 88 between the annular lead portion 28, the metal shell 13, and the protector 15. In the gas sensor 1, a part of the annular lead part 28 and a part of the vertical lead part 29 are disposed between the contact surface PC1 where the annular lead part 28 and the packing 88 are in contact with the front end facing surface 23b.
　このように構成されたガスセンサ１は、上記の組付工程時において接触面ＰＣ１の先端側端部よりも先端側（すなわち径方向内側）で環状リード部２８が剥がれた場合であっても、接触面ＰＣ１の先端側端部よりも後端側（すなわち径方向外側）において環状リード部２８の一部分と縦リード部２９の一部分とが接触した状態を維持することができる。なお、上記の組付工程時において、接触面ＰＣ１の先端側端部より先端側は、接触面ＰＣ１の先端側端部より後端側と比較して、環状リード部２８の剥離が発生し易い。図５は、環状リード部２８を先端側から見た図であって、環状リード部２８において、パッキン８８が接触した領域ＲＣの径方向内側端部ＥＦより径方向内側にクラックＣＲが発生している状態を示している。これにより、ガスセンサ１は、上記の組付工程時において、環状リード部２８と縦リード部２９との導通の信頼性を向上させることができる。 The gas sensor 1 configured in this manner is in contact even when the annular lead portion 28 is peeled off at the distal end side (that is, radially inward) from the distal end side end portion of the contact surface PC1 during the assembly process. It is possible to maintain a state in which a part of the annular lead portion 28 and a part of the vertical lead portion 29 are in contact with each other on the rear end side (that is, radially outside) of the front end portion of the surface PC1. In the above assembly process, peeling of the annular lead portion 28 is more likely to occur on the front end side than the front end side end portion of the contact surface PC1 compared to the rear end side than the front end side end portion of the contact surface PC1. . FIG. 5 is a view of the annular lead portion 28 as viewed from the front end side. In the annular lead portion 28, a crack CR is generated radially inward from the radially inner end portion EF of the region RC in contact with the packing 88. It shows the state. Thereby, the gas sensor 1 can improve the reliability of conduction between the annular lead portion 28 and the vertical lead portion 29 during the above assembly process.
　以上説明した実施形態において、素子鍔部２３は鍔部に相当し、外側電極２７および縦リード部２９は外部電極に相当し、環状リード部２８は鍔リード部に相当し、頂面２３ａは後端側外周面に相当する。 In the embodiment described above, the element collar 23 corresponds to the collar, the outer electrode 27 and the longitudinal lead 29 correspond to the external electrode, the annular lead 28 corresponds to the collar lead, and the top surface 23a is the rear surface. It corresponds to the end side outer peripheral surface.
　また、主体金具１３およびプロテクタ１５は保持部材に相当し、パッキン８８は導電部材に相当し、接触面ＰＣ１は第２接触面に相当する。 The metal shell 13 and the protector 15 correspond to a holding member, the packing 88 corresponds to a conductive member, and the contact surface PC1 corresponds to a second contact surface.
　以上、本開示の一実施形態について説明したが、本開示は上記実施形態に限定されるものではなく、種々変形して実施することができる。 As mentioned above, although one embodiment of this indication was explained, this indication is not limited to the above-mentioned embodiment, and can carry out various modifications.
　例えば上記実施形態では、縦リード部２９の上に環状リード部２８が配置されている形態を示したが、環状リード部２８の上に縦リード部２９が配置されるようにしてもよい。但し、縦リード部２９は薄いため、環状リード部２８の上に縦リード部２９が配置されていると、縦リード部２９において断線が発生し易くなる。このため、縦リード部２９の上に環状リード部２８が配置されるのが望ましい。 For example, in the above-described embodiment, the form in which the annular lead portion 28 is disposed on the longitudinal lead portion 29 is shown, but the longitudinal lead portion 29 may be disposed on the annular lead portion 28. However, since the vertical lead portion 29 is thin, if the vertical lead portion 29 is disposed on the annular lead portion 28, disconnection is likely to occur in the vertical lead portion 29. For this reason, it is desirable that the annular lead portion 28 be disposed on the vertical lead portion 29.
　また上記実施形態では、環状リード部２８が導電性酸化物を主成分として含んでいる形態を示したが、導電性酸化物以外の成分（例えば、希土類添加セリア）を含むようにしてもよい。 In the above embodiment, the annular lead portion 28 has a conductive oxide as a main component. However, a component other than the conductive oxide (for example, rare earth-added ceria) may be included.
　また上記実施形態では、素子鍔部２３に形成されるリード部（すなわち、鍔リード部）が環状である形態を示したが、縦リード部２９と環状リード部２８とが重なる領域において素子本体２１の周方向に沿った長さが縦リード部２９より長い有端環状または円弧状であってもよい。また、上記の組付工程時において、鍔リード部とパッキン８８との接触を確保するために、鍔リード部における軸線方向の長さを、パッキン８８における軸線方向の長さより長くすることが望ましい。 Moreover, in the said embodiment, although the lead part (namely, collar lead part) formed in the element collar part 23 showed the form which is cyclic | annular, the element main body 21 in the area | region where the vertical lead part 29 and the cyclic | annular lead part 28 overlap. It may be an end-like annular shape or a circular arc shape whose length along the circumferential direction is longer than that of the vertical lead portion 29. Further, in the above assembling process, in order to ensure the contact between the heel lead portion and the packing 88, it is desirable that the axial length of the heel lead portion is longer than the axial length of the packing 88.
　また上記実施形態では、環状リード部２８が先端向き面２３ｂ上の全体に形成されている形態を示したが、先端向き面２３ｂの一部の上に形成されるようにしてもよい。 In the above embodiment, the annular lead portion 28 is formed on the entire tip-facing surface 23b. However, the annular lead portion 28 may be formed on a part of the tip-facing surface 23b.
　また上記実施形態では、環状リード部２８とプロテクタ１５との間にパッキン８８を介することにより、互いに電気的に接続される形態を示したが、図６に示すように、パッキン８８を介することなく、環状リード部２８とプロテクタ１５とが直接接触するようにしてもよい。この場合には、環状リード部２８とプロテクタ１５とが接触する接触面ＰＣ２と、先端向き面２３ｂとの間に環状リード部２８の一部分および縦リード部２９の一部分が配置される。「接触面ＰＣ２と先端向き面２３ｂとの間に環状リード部２８の一部分および縦リード部２９の一部分が配置される」とは、接触面ＰＣ２から先端向き面２３ｂに向かって延びるとともに接触面ＰＣ２に対して垂直な直線（すなわち、接触面ＰＣ２の法線）が環状リード部２８および縦リード部２９を通過することに相当する。なお、接触面ＰＣ２は第１接触面に相当する。 In the above embodiment, the packing 88 is interposed between the annular lead portion 28 and the protector 15 so as to be electrically connected to each other. However, as shown in FIG. The annular lead portion 28 and the protector 15 may be in direct contact with each other. In this case, a part of the annular lead part 28 and a part of the vertical lead part 29 are arranged between the contact surface PC2 where the annular lead part 28 and the protector 15 are in contact with the tip-facing face 23b. “A portion of the annular lead portion 28 and a portion of the vertical lead portion 29 are disposed between the contact surface PC2 and the tip-facing surface 23b” means that the contact surface PC2 extends from the contact surface PC2 toward the tip-facing surface 23b. A straight line (that is, a normal line of the contact surface PC <b> 2) that corresponds to passing through the annular lead portion 28 and the vertical lead portion 29. The contact surface PC2 corresponds to the first contact surface.
　また上記実施形態では、素子鍔部２３の表面が頂面２３ａと先端向き面２３ｂとの境界で屈曲している形態を示した。しかし、図７に示すように、素子鍔部２３において径方向の最も外側に位置する最外点ＰＯで湾曲しているようにしてもよい。この場合には、先端向き面２３ｂの後端側端部は最外点ＰＯである。なお、先端向き面２３ｂの先端側端部から後端側へ向かうにつれて、先端向き面２３ｂの法線ベクトルＶＮと軸線Ｏとの成す角度θは徐々に９０°に近付いていく。そして、この角度θが９０°未満から９０°に変化した箇所が先端向き面２３ｂの後端側端部となる。最外点ＰＯにおける法線ベクトルＶＮ１と軸線Ｏとの成す角θは９０°である。 Moreover, in the said embodiment, the form where the surface of the element collar part 23 was bent in the boundary of the top surface 23a and the front end surface 23b was shown. However, as shown in FIG. 7, the element collar 23 may be curved at the outermost point PO located on the outermost side in the radial direction. In this case, the rear end side end portion of the front end facing surface 23b is the outermost point PO. Note that the angle θ between the normal vector VN of the tip-facing surface 23b and the axis O gradually approaches 90 ° as it moves from the tip-side end of the tip-facing surface 23b toward the rear end. And the location where this angle (theta) changed from less than 90 degrees to 90 degrees turns into the rear end side edge part of the front end direction surface 23b. The angle θ between the normal vector VN1 and the axis O at the outermost point PO is 90 °.
　上記各実施形態における１つの構成要素が有する機能を複数の構成要素に分担させたり、複数の構成要素が有する機能を１つの構成要素に発揮させたりしてもよい。また、上記各実施形態の構成の一部を、省略してもよい。また、上記各実施形態の構成の少なくとも一部を、他の上記実施形態の構成に対して付加、置換等してもよい。なお、特許請求の範囲に記載の文言から特定される技術思想に含まれるあらゆる態様が本開示の実施形態である。 The functions of one component in each of the above embodiments may be shared by a plurality of components, or the functions of a plurality of components may be exhibited by one component. Moreover, you may abbreviate | omit a part of structure of each said embodiment. In addition, at least a part of the configuration of each of the above embodiments may be added to or replaced with the configuration of the other above embodiments. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of the present disclosure.

Claims (4)

  1. 　固体電解質体を主体として、軸線方向に延びて先端が閉じた有底筒状に形成されるとともに、径方向外側に突出する鍔部を有するように形成された素子本体と、
    　貴金属を含み、前記鍔部よりも先端側から前記鍔部へ向かって延びるようにして前記素子本体の外表面に形成される外部電極と、
    　前記外部電極と重なり、少なくとも前記鍔部において先端側に面する先端向き面上に、前記素子本体の周方向に沿って形成される鍔リード部であって、前記先端向き面上における前記素子本体の前記周方向に沿った長さが、前記外部電極と前記鍔リード部とが重なる重なり部における前記外部電極の前記周方向に沿った長さより長くなるように形成される鍔リード部と
    　を備えるガスセンサ素子であって、
    　前記鍔リード部は、導電性酸化物を主成分とするガスセンサ素子。     Mainly a solid electrolyte body, an element body formed in a bottomed cylindrical shape extending in the axial direction and closed at the tip, and having a flange protruding radially outward;
    An external electrode that includes a noble metal and is formed on the outer surface of the element body so as to extend from the distal end side toward the collar than the collar;
    A heel lead portion that is formed along a circumferential direction of the element body on a tip-facing surface that overlaps the external electrode and faces the tip side at least in the heel portion, and the element body on the tip-facing surface A heel lead portion formed so that a length along the circumferential direction of the external electrode is longer than a length along the circumferential direction of the external electrode in an overlapping portion where the external electrode and the heel lead portion overlap. A gas sensor element,
    The said lead | read | reed part is a gas sensor element which has a conductive oxide as a main component.
  2. 　請求項１に記載のガスセンサ素子であって、
    　前記鍔リード部および前記外部電極は、前記鍔部における前記先端向き面よりも後端側の外周面である後端側外周面まで延びるように形成され、
    　前記鍔リード部および前記外部電極は互いに、前記後端側外周面で接触するガスセンサ素子。     The gas sensor element according to claim 1,
    The flange lead portion and the external electrode are formed to extend to a rear end side outer peripheral surface which is an outer peripheral surface on the rear end side with respect to the front end facing surface in the flange portion,
    The saddle lead portion and the external electrode are in contact with each other on the rear end side outer peripheral surface.
  3. 　請求項１または請求項２に記載のガスセンサ素子と、前記鍔リード部と電気的に接続された状態で前記ガスセンサ素子を保持する保持部材とを備えるガスセンサ。 A gas sensor comprising: the gas sensor element according to claim 1 or 2; and a holding member that holds the gas sensor element in a state of being electrically connected to the saddle lead portion.
  4. 　請求項３に記載のガスセンサであって、
    　前記鍔リード部と前記保持部材とは、直接接触するか、前記鍔リード部と前記保持部材との間に導電部材を介することにより、互いに電気的に接続されており、
    　前記鍔リード部と前記保持部材とが直接接触する場合には、前記鍔リード部または前記外部電極と前記保持部材とが接触する第１接触面と、前記先端向き面との間に、前記鍔リード部の一部分および前記外部電極の一部分が配置され、
    　前記鍔リード部と前記保持部材との間に前記導電部材を介している場合には、前記鍔リード部または前記外部電極と前記導電部材とが接触する第２接触面と、前記先端向き面との間に、前記鍔リード部の一部分および前記外部電極の一部分が配置されるガスセンサ。     The gas sensor according to claim 3,
    The heel lead portion and the holding member are in direct contact with each other, or are electrically connected to each other through a conductive member between the heel lead portion and the holding member,
    When the heel lead portion and the holding member are in direct contact, the heel lead portion or the external electrode and the first contact surface where the holding member is in contact with the tip facing surface A portion of the lead portion and a portion of the external electrode are disposed;
    When the conductive member is interposed between the flange lead portion and the holding member, the second contact surface where the flange lead portion or the external electrode and the conductive member are in contact with each other, and the tip-facing surface A gas sensor in which a part of the heel lead part and a part of the external electrode are arranged between the two.
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