JP2018084483A - Manufacturing method of solid electrolytic sensor and solid electrolytic sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a solid electrolytic sensor for inhibiting mixture of gas into two spaces sandwiching a solid electrolytic sensor element.SOLUTION: At least one portion of a cylindrical part 10s of a solid electrolytic sensor element 10 formed in a bottomed cylindrical shape is positioned inside a cylindrical holder 20. A glass ring 30 is inserted between an inner peripheral surface of the holder and an outer peripheral surface of the cylindrical part while being held between two outer rings 40 formed from a material that does not soften/melt at a softening point of the glass. The two outer rings are pressed by push rod members 60a, 60b from both end sides of the holder, respectively, while the glass rings are softened by heating. The glass ring is deformed by pressing force operating via the two pressed outer rings so as to adhere to both of the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical part to form a glass sealing layer 31. At least one portion of the two respective outer rings is buried or adhered to both the sides of the sealing layer.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a manufacturing method of a solid electrolyte sensor that detects a gas concentration using a solid electrolyte as a sensor element, and a solid electrolyte sensor manufactured by the manufacturing method.

  Various solid electrolyte sensors that detect gas concentrations such as hydrogen gas, oxygen gas, carbon dioxide gas, and water vapor using solid electrolytes (ion conductive ceramics) as sensor elements have been proposed. Is going. The solid electrolyte sensor uses the principle of a concentration cell that generates a potential difference due to the difference in concentration of the same ions, and the electromotive force generated in the solid electrolyte when the concentration of the gas to be detected is different in the two spaces that sandwich the solid electrolyte. Measure. If the gas concentration in one space is known, the gas concentration in the other space can be known from the measured electromotive force and the temperature of the sensor element by the Nernst equation.

  Therefore, in the solid electrolyte sensor, the two spaces need to be partitioned by the solid electrolyte. In a conventional solid electrolyte sensor, a sensor element is fixed to one end of a cylindrical support member (holder), and the whole of the holder and the sensor element has a bottomed cylindrical shape, thereby partitioning two spaces (for example, , See Patent Document 1).

  However, in addition to this, it is difficult to completely and hermetically seal the sensor element and the holder, and it is a fact that a very small gap tends to remain. If there is even a slight gap between the sensor element and the holder, the gas (reference gas) in the space where the concentration of the gas to be detected is known and the measurement gas (gas in the measurement atmosphere) are mixed, resulting in an accurate Measurement is not possible. In particular, when the concentration difference between the measurement gas and the reference gas is large, the influence of the gas mixture on the detection result is large. In addition, when the detection target gas is hydrogen, the size of the molecule is small. Therefore, even if the size of the void is extremely small, the gas easily passes through, and the influence of the gas mixing on the detection result is large.

JP 2011-174832 A

  Accordingly, in view of the above circumstances, the present invention provides a method for manufacturing a solid electrolyte sensor in which mixing of gas in two spaces sandwiching a solid electrolyte sensor element is suppressed, and a solid electrolyte sensor manufactured by the manufacturing method. Is the issue.

In order to solve the above problems, a method for manufacturing a solid electrolyte sensor according to the present invention (hereinafter, simply referred to as “manufacturing method”)
“At least part of the cylindrical portion of the sensor element of the solid electrolyte formed in the bottomed cylindrical shape is positioned inside the cylindrical holder,
In a state where the glass ring is sandwiched between two outer rings formed of a material that does not soften or melt at the glass softening point of the glass ring, the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion Inserted between
While softening the glass ring by heating, the two outer rings are pressed by the push rod members from both ends of the holder, respectively, and the glass made by the pressing force acting via the two pressed outer rings The ring is deformed so as to be in close contact with both the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion, thereby forming a glass sealing layer, and two outer rings on both sides of the sealing layer. At least a portion is embedded or adhered.

  In this manufacturing method, the glass ring is softened and deformed by heating, and is brought into close contact with both the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion of the bottomed cylindrical sensor element. A glass sealing layer that seals the voids in an annular shape is formed. Since the glass softened by heating has high adhesiveness, it adheres well to the inner peripheral surface of the holder and the outer peripheral surface of the sensor element.

  In particular, in this manufacturing method, a pressing force is applied to the glass softened by heating from both ends of the holder through the pressing rod members. Therefore, the glass deformed by the pressing force is in good contact with both the inner peripheral surface of the holder and the outer peripheral surface of the sensor element (hereinafter sometimes referred to as “inner and outer peripheral surface”), and the inner peripheral surface of the holder and the sensor A glass sealing layer is formed that hermetically seals a gap between the outer peripheral surfaces of the elements (hereinafter sometimes referred to as “a gap between the inner and outer peripheral surfaces”). Thereby, since two space which pinched | interposed the sensor element is divided by the airtight sealing layer, mixing of the gas of two space is suppressed effectively.

  Here, if the push rod member for applying a pressing force to the glass ring from both sides is directly pressed against the glass ring, the push rod member sticks to the glass. That is, if the push rod member is pulled out of the holder during heating, the softened glass is pulled out while adhering to the push rod member. On the other hand, when the push rod member is pulled out after the glass is cooled, the glass is cured in a state where the push rod member is bonded to the softened glass, and therefore the push rod member cannot be pulled away from the glass.

  In contrast, in this manufacturing method, the glass ring is sandwiched between the outer rings, and the pressing force from the push rod member is applied to the glass ring via the outer ring. Since this outer ring is formed of a material that does not soften or melt at the glass softening point of the glass ring, the push rod member does not adhere to the outer ring. Therefore, the push rod member can be pulled out of the holder without any problem during heating or after cooling. Here, examples of the “material that does not soften or melt at the glass softening point of the glass ring” include ceramics, stainless steel, and glass having a softening point higher than that of the glass ring glass.

  On the other hand, since the outer ring is pushed toward the glass ring by the push rod member, at least part of the outer ring is embedded or bonded to the glass softened by heating, and the glass is cured to be integrated with the glass sealing layer. . That is, the outer ring remains together with the glass sealing layer in the solid electrolyte sensor manufactured by the present manufacturing method.

Next, the solid electrolyte sensor according to the present invention is:
“The cylindrical holder,
A solid electrolyte sensor element which is formed in a bottomed cylindrical shape, and at least a part of the cylindrical part is located inside the holder;
A glass sealing layer that is annular and is in close contact with both the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion;
Two outer rings formed of a material that is partially embedded or bonded to both sides of the sealing layer and that does not soften or melt at the softening point of the glass of the sealing layer;
Is provided. "

  This is a solid electrolyte sensor manufactured by the above manufacturing method. The glass sealing layer formed by softening and deforming the glass ring tightly contacts the inner and outer peripheral surfaces and hermetically seals the gap between the inner and outer peripheral surfaces. Two spaces are partitioned by an airtight sealing layer, and mixing of gases in the two spaces is effectively suppressed.

  Further, in this configuration, when the glass sealing layer is formed, the outer ring that is necessary for applying the pressing force to the glass ring remains in an integrated state with the sealing layer. ing.

  As described above, as an effect of the present invention, a method for manufacturing a solid electrolyte sensor in which mixing of gases in two spaces sandwiching a sensor element of solid electrolyte is suppressed, and a solid electrolyte sensor manufactured by the manufacturing method are provided. Can be offered.

(A), (b) It is a figure explaining the manufacturing method which is one Embodiment of this invention. (C), (d) It is a figure explaining a manufacturing method following FIG. (A) It is an enlarged view of A range in Drawing 1 (b), and (b) is an enlarged view of B range in Drawing 2 (c). It is sectional drawing which cut | disconnected the solid electrolyte sensor manufactured by the manufacturing method of FIGS. (A) It is a figure explaining the manufacturing method of a modification, (b) It is sectional drawing which cut | disconnected the solid electrolyte sensor manufactured by the manufacturing method of Fig.5 (a) at the center in the vertical direction. (A)-(d) It is a figure which illustrates the positional relationship of the sensor element and holder in a solid electrolyte sensor.

  Hereinafter, a method for manufacturing a solid electrolyte sensor 1 according to an embodiment of the present invention will be described with reference to FIGS. Here, the case where this invention is applied to the manufacturing method of the solid electrolyte sensor which measures the gas concentration in a gaseous phase is illustrated.

  The manufacturing method of this embodiment softens and deforms the glass ring 30 with respect to the holder 20 by setting the solid electrolyte sensor element 10, the glass ring 30, and the outer ring 40, and heating. It comprises a softening / deformation step and a cooling step for hardening the softened glass.

  More specifically, the holder 20 has a cylindrical shape and is made of ceramics such as alumina. The sensor element 10 has a bottomed cylindrical shape, and its cylindrical portion 10s has a cylindrical shape. At the bottom 10b (closed end) of the sensor element 10, an inner electrode 11 is provided on the surface on the inner space side, and an outer electrode 12 is provided on the surface on the outer space side.

  In the setting step, positioning is performed so that at least a part of the cylindrical portion 10 s of the sensor element 10 is positioned inside the holder 20. The holder 20 is installed with the axial direction as the vertical direction, and the sensor element 10 is placed on the support rod 50 and supported from below. The support bar 50 is a columnar member or a cylindrical member having an outer diameter substantially equal to the outer diameter of the cylindrical portion 10 s of the sensor element 10. Here, the sensor element 10 is placed on the support rod 50 with the open end 10e of the sensor element 10 facing downward, and a part of the cylindrical portion 10s and the open end 10e are located inside the holder 20, and the bottom portion The case where the positional relationship of the holder 20 and the sensor element 10 is adjusted so that 10b protrudes outside from the upper end of the holder 20 is illustrated.

  Then, a gap S between the inner peripheral surface of the holder 20 and the outer peripheral surface of the cylindrical portion 10 s of the sensor element 10 (a gap S between the inner and outer peripheral surfaces) from the lower side of the pair of push rod members 60 a and 60 b. A push rod member 60a for applying a pressing force is installed. The push rod members 60 a and 60 b are cylindrical members whose inner diameter is larger than the outer diameter of the cylindrical portion 10 s and whose outer diameter is smaller than the inner diameter of the holder 20.

  The glass ring 30 sandwiched between the two outer rings 40 is placed on the upper end of the push rod member 60a. Both the glass ring 30 and the outer ring 40 have an annular shape whose inner diameter is larger than the outer diameter of the cylindrical portion 10 s and whose outer diameter is smaller than the inner diameter of the holder 20. Depending on the thickness desired for the glass sealing layer 31 to be formed, a plurality of the glass rings 30 may be used in an overlapping manner. As a result, the sensor element 10, the glass ring 30, and the outer ring 40 are set on the holder 20 (see FIG. 1A).

  In the present embodiment, the outer ring 40 is made of ceramics. Since ceramics do not soften or melt at the softening point of glass, ceramics exemplified by alumina, mullite, zirconia, and cordierite can be used without particular limitation.

  In the softening / deformation step, with the glass ring 30 softened by heating, the other push rod member 60b is inserted into the gap S between the inner and outer peripheral surfaces from above and pushed down (see FIG. 1B). As a result, a pressing force acts on the softened glass ring 30 from the push rod member 60b via the outer ring 40. Here, the case where the holder 20, the support rod 50, and the push rod member 60a are placed on the same surface is illustrated by way of illustration, but in this case, the outer ring 40 is also moved from the lower push rod member 60a by reaction. A pressing force acts on the glass ring 30 via the. The holder 20 and the support bar 50 may be held by another member so that a space is provided below the holder 20 and the lower push bar member 60a may be moved upward. The state in which the pressing force is applied by the push rod members 60a and 60b while the glass ring 30 is heated is held for a predetermined time.

  When a pressing force acts on the softened glass ring 30 from above and below via the outer ring 40, the glass ring 30 is deformed so as to be spread outward, and the inner peripheral surface and the cylindrical portion of the holder 20. It closely adheres to both of the outer peripheral surfaces of 10s (see FIG. 2C and FIG. 3B). At the same time, a part of the two outer rings 40 respectively pressed toward the glass ring 30 by the push rod members 60 a and 60 b are embedded from above and below on both sides of the softened glass ring 30. In the figure, the deformation of the softened glass ring 30 is schematically shown. Further, although only the end portion of the outer ring 40 is illustrated as being embedded in the glass, depending on the degree of softening of the glass ring 30, the two outer rings 40 come into contact with the glass. In some cases, the outer ring 40 may be in a state of being bonded to the glass without being buried.

  Since the glass ring 30 and the outer ring 40 are inserted into the gap S between the inner and outer peripheral surfaces, the clearance between the inner and outer peripheral surfaces is unavoidable, but the clearance between the outer ring 40 and the inner and outer peripheral surfaces is It is desirable to set the outer ring 40 so that it can slide in the gap S without resistance when pressed by the push rod members 60a and 60b. On the other hand, the clearance between the glass ring 30 and the inner and outer peripheral surfaces is set to such a size that the glass ring 30 pressed in a softened state can sufficiently adhere to the inner and outer peripheral surfaces by deformation.

  In the cooling step, cooling is performed by removing the pressing force by pulling out the push rod member 60b from the holder 20 or by pulling out both of the push rod members 60a and 60b from the holder 20. As a result, the softened and deformed glass ring 30 is cured while being in close contact with both the inner and outer peripheral surfaces, and a glass sealing layer 31 is formed. After cooling, the support rod 50 is removed (see FIG. 2 (d)).

  Through the above steps, the solid electrolyte sensor 1 having the configuration shown in FIG. 4 is manufactured. In other words, the cylindrical holder 20 is formed in a bottomed cylindrical shape, and at least a part of the cylindrical portion 10 s is located inside the holder 20, and is annular, and the holder The glass sealing layer 31 is in close contact with both the inner peripheral surface 20 and the outer peripheral surface of the cylindrical portion 10 s, and a part is embedded or bonded to both sides of the sealing layer 31. The solid electrolyte sensor 1 includes two outer rings 40 formed of a material that does not soften or melt at the softening point of the glass.

  Since the outer ring 40 is not deformed even when heated and pressed at a temperature at which the glass of the glass ring 30 is softened, the outer ring 40 is interposed between the outer ring 40 embedded or bonded on both sides of the sealing layer 31 and the inner and outer peripheral surfaces. In this case, the initially set clearance remains as it is. Therefore, when the outer ring 40 is pushed straight in the softening / deformation process, in the manufactured solid electrolyte sensor 1, the outer ring 40 is in contact with the inner peripheral surface of the holder 20 and the outer peripheral surface of the cylindrical portion 10s. Absent.

  As described above, according to the manufacturing method of the present embodiment, in a state where the glass ring 30 is softened by heating, the pressing force is applied and deformed from both end surface sides to be brought into close contact with both the inner and outer peripheral surfaces. The glass sealing layer 31 that hermetically seals the gap S between the inner and outer peripheral surfaces can be formed. Thereby, since the two spaces sandwiching the sensor element 10 are partitioned by the airtight sealing layer 31, mixing of the gas in the two spaces is effectively suppressed, and the gas concentration can be accurately measured. Can be manufactured.

  Since the pressing force from the push rod members 60a and 60b is applied to the glass ring 30 through the outer ring 40 that is not softened / deformed, the pressing force is removed without adhering to the softened glass. The push rod members 60a and 60b can be pulled out.

  The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the above-described embodiments, and various improvements can be made without departing from the scope of the present invention as described below. And design changes are possible.

  For example, in the above embodiment, the solid electrolyte sensor 1 in which a part of the cylindrical portion 10s of the sensor element 10 and the open end 10e are located inside the holder 20 and the bottom portion 10b is located outside the holder 20, and The manufacturing method was illustrated. Without being limited thereto, as shown in FIGS. 5A and 5B, the entire sensor element 10, that is, the cylindrical portion 10s, the open end 10e, and the bottom portion 10b are located inside the holder 20. It can be set as the sensor 1b and its manufacturing method. FIG. 5A shows a case where the sensor element 10 is placed on the support bar 50 with the bottom 10b facing downward, but the sensor element 10 with the open end facing downward is illustrated as a support bar. 50 may be placed. Further, a spacer 55 can be used as shown in the figure for adjusting the position of the holder 20 and the sensor element 10.

  FIG. 6 shows the positional relationship between the sensor element 10 and the holder 20 in the solid electrolyte sensor. FIG. 6A shows the sensor element 10 in which a part of the cylindrical portion 10 s and the open end 10 e are located inside the holder 20, as in the solid electrolyte sensor 1 described with reference to FIGS. 1 to 4. FIG. 6B shows a case where the entire sensor element 10 including the open end 10e and the bottom portion 10b is the holder, as in the solid electrolyte sensor 1b described with reference to FIG. This is a case where it is located inside 20. In addition, as shown in FIG. 6C, a mode in which a part of the cylindrical portion 10s and the bottom portion 10b are located inside the holder 20 and the open end 10e is located outside the holder 20, or FIG. As shown in the figure, only a part of the cylindrical portion 10 s is positioned inside the holder 20, and both the bottom portion 10 b and the open end 10 e can be positioned outside the holder 20.

  In any of these configurations, the two spaces Sp <b> 1 and Sp <b> 2 sandwiching the sensor element 10 can be airtightly partitioned by the sealing layer 31. Here, FIGS. 6A to 6D show that the space Sp2 is a measurement atmosphere, the holder 20 is inserted into the measurement opening 90, and one of the outer peripheral surface and the inner peripheral surface of the sensor element 10 is measured. And the reference gas is introduced into the space Sp1.

  In the examples of FIGS. 6A and 6D, the bottom 10 b where the inner electrode 11 and the outer electrode 12 are provided in the sensor element 10 protrudes from the holder 20, so that highly responsive detection is possible. On the other hand, in the example of FIG. 6B, there is an advantage that the entire sensor element 10 is protected by the holder 20. Further, in the example of FIG. 6C, there is an advantage that the measurement gas in the internal space of the sensor element 10 is not easily affected by the airflow in the measurement atmosphere (space Sp2).

DESCRIPTION OF SYMBOLS 1,1b Solid electrolyte sensor 10 Sensor element 10e Open end 10s Cylindrical part 20 Holder 30 Glass ring 31 Sealing layer 40 Outer ring 60a, 60b Push rod member

Claims (2)

Positioning at least part of the cylindrical portion of the solid electrolyte sensor element formed in the bottomed cylindrical shape inside the cylindrical holder,
In a state where the glass ring is sandwiched between two outer rings formed of a material that does not soften or melt at the glass softening point of the glass ring, the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion Inserted between
While softening the glass ring by heating, the two outer rings are pressed by the push rod members from both ends of the holder, respectively, and the glass made by the pressing force acting via the two pressed outer rings The ring is deformed so as to be in close contact with both the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion, thereby forming a glass sealing layer, and two outer rings on both sides of the sealing layer. A method for producing a solid electrolyte sensor, wherein at least a part of the solid electrolyte sensor is embedded or adhered. A cylindrical holder;
A solid electrolyte sensor element which is formed in a bottomed cylindrical shape, and at least a part of the cylindrical part is located inside the holder;
A glass sealing layer that is annular and is in close contact with both the inner peripheral surface of the holder and the outer peripheral surface of the cylindrical portion;
Two outer rings formed of a material that is partially embedded or bonded to both sides of the sealing layer and that does not soften or melt at the softening point of the glass of the sealing layer;
A solid electrolyte sensor comprising:

Images