JP2017203632A - Gas sensor and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas sensor with improved sealability (pressurized water resistance) even if the gas sensor may be hit by high-pressure water.SOLUTION: A gas sensor includes: a cylindrical internal cylinder having a first vent hole 51; a cylindrical external cylinder 70 having a second vent hole; and a water-impermeable ventilation filter 30 held between the internal cylinder and the external cylinder in a radial direction. The external cylinder includes: a first tightening part 71 positioned closer to a leading end side in an axial direction than the second vent hole 74; a second tightening part 72 positioned closer to a rear end side in the axial direction than the second vent hole; and a convex projection part 75 including the second vent hole and projecting closer to an outside in a radial direction than the first tightening part and the second tightening part. An external surface of the ventilation filter has a shape being curved outward in the radial direction while being in contact along an inner surface of the convex projection part.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a gas sensor and a method for manufacturing the gas sensor.

  Conventionally, a gas sensor has been used to measure the concentration of a specific gas component of exhaust gas from an internal combustion engine. Patent Document 1 discloses a waterproof structure for an oxygen sensor, which is a type of gas sensor. In this prior art, a water-impermeable member is disposed between the inner cylinder and the outer cylinder, and pressure is applied from the outside of the outer cylinder to the inside in the radial direction, thereby improving the sealing performance of the water-impermeable member.

Japanese Patent Laid-Open No. 08-145939

  However, when a water-impermeable member having air permeability is disposed between the inner cylinder and the outer cylinder, the sealability of the water-impermeable member is sufficient only by applying pressure from the outside of the outer cylinder to the inside in the radial direction. It may not be. For example, when there is a possibility that high-pressure water is applied to the gas sensor as in the case where the gas sensor is installed in an exhaust gas pipe of a motorcycle, there is a possibility that the sealing performance (water pressure resistance) is insufficient in the related art. .

  The present invention has been made to solve the above-described problems, and can be realized as the following forms.

(1) According to one aspect of the present invention, the detection element extending in the axial direction, the cylindrical metal shell that surrounds the periphery of the detection element in the radial direction and holds the detection element, and attached to the metal shell A cylindrical inner cylinder that extends to the rear end side in the axial direction from the metal shell and has a first vent hole, and a cylindrical shape that is disposed so as to surround the radial circumference of the inner cylinder and has a second vent hole There is provided a gas sensor having an outer cylinder, and a non-permeable air-permeable filter sandwiched between the inner cylinder and the outer cylinder in the radial direction. In this gas sensor, the outer cylinder has a first crimping portion that is closer to the distal end side in the axial direction than the second vent hole, and a second caulking portion that is closer to the rear end side in the axial direction than the second vent hole. A tightening portion, and a convex protrusion that includes the second ventilation hole and protrudes radially outward from the first and second crimping portions, and the outer surface of the ventilation filter is It has a shape curved radially outward while contacting along the inner surface of the convex protrusion.
According to this gas sensor, the outer surface of the ventilation filter has a shape that is curved radially outward while being in contact with the inner surface of the convex protrusion of the outer cylinder. Since there is no gap into which water from the water can enter, the sealing property is high and the water pressure resistance is sufficient. That is, even when high-pressure water hits the second vent hole of the outer cylinder, the possibility of high-pressure water entering the gas sensor can be reduced.

(2) According to another aspect of the present invention, a detection element extending in the axial direction, a cylindrical metal shell surrounding the detection element in the radial direction and holding the detection element, and attached to the metal shell And a cylindrical inner cylinder having a first ventilation hole extending from the metal shell to the rear end side in the axial direction, and a cylinder having a second ventilation hole arranged so as to surround the circumference of the inner cylinder in the radial direction There is provided a method for manufacturing a gas sensor having a cylindrical outer cylinder and a non-permeable air-permeable filter sandwiched between the inner cylinder and the outer cylinder in the radial direction. The gas sensor manufacturing method includes: a clamping step of clamping the ventilation filter between the inner cylinder and the outer cylinder; and the outer cylinder is added radially inward while compressing the ventilation filter along the axial direction. By tightening, the outer cylinder is provided with a first crimping portion located on the distal end side in the axial direction with respect to the second vent hole, and a second caulking portion located on the rear end side in the axial direction with respect to the second vent hole. Forming a tightening portion and a convex protrusion including the second ventilation hole and projecting radially outward from the first crimping portion and the second crimping portion; and an outer surface of the ventilation filter A caulking step of deforming the ventilation filter so as to have a shape curved radially outward while contacting along the inner surface of the convex protrusion.
According to this manufacturing method, in the caulking step, the outer surface of the air filter is crimped inward in the radial direction while compressing the air filter along the axial direction so that the outer surface of the air filter is the inner surface of the convex protrusion of the outer tube. The ventilation filter is deformed so as to have a shape curved radially outward while being in contact with each other, so that there is no gap through which water from the outside can enter, the sealing performance is improved, and the water pressure resistance is sufficient. Become. That is, even when high-pressure water hits the second vent hole of the outer cylinder, the possibility of high-pressure water entering the gas sensor can be reduced.

(3) According to still another embodiment of the present invention, a detection element extending in the axial direction, a cylindrical metal shell that surrounds the periphery of the detection element in the radial direction and holds the detection element, and attached to the metal shell And extending to the rear end side in the axial direction with respect to the metal shell, and is disposed so as to surround the inner periphery of the inner cylinder in the radial direction, and has a second ventilation hole. There is provided a method of manufacturing a gas sensor having a cylindrical outer cylinder and a non-permeable air-permeable filter sandwiched between the inner cylinder and the outer cylinder in the radial direction. The gas sensor manufacturing method includes: a clamping step of clamping the ventilation filter between the inner cylinder and the outer cylinder; and caulking the outer cylinder radially inward to allow the second cylinder to pass through the second cylinder. A first caulking portion located on the front end side in the axial direction from the air hole; a second caulking portion located on the rear end side in the axial direction from the second air vent; and the second air vent. A caulking step that forms a first caulking portion and a convex projecting portion that projects radially outward from the second caulking portion; simultaneously with the caulking step or after the caulking step, The convex projecting portion is configured to bring the outer surface of the vent filter into contact with the inner surface of the convex projecting portion by pushing the peripheral portion of the second vent hole of the convex projecting portion of the outer cylinder from the outside. And a shaping step for shaping.
According to this manufacturing method, at the same time as or after the caulking step, the peripheral portion of the second vent hole of the convex protrusion of the outer cylinder is pushed in from the outside, so that the ventilation filter is formed along the inner surface of the convex protrusion. Since the convex protrusion is shaped so as to contact the outer surface, there is no gap where water from the outside can enter between the ventilation filter and the peripheral portion of the second ventilation hole of the outer cylinder, and the sealing performance is improved. It has sufficient water pressure resistance. That is, even when high-pressure water hits the second vent hole of the outer cylinder, the possibility of high-pressure water entering the gas sensor can be reduced.

(4) In the gas sensor manufacturing method, the caulking step may be performed while compressing the ventilation filter along the axial direction.
According to this configuration, since the outer surface of the ventilation filter is easily deformed along the inner surface of the convex protrusion in the caulking step, the sealing performance can be further improved.

  The present invention can be realized in various forms, for example, in the form of a gas sensor ventilation structure or the like.

The external view of the gas sensor as one Embodiment of this invention. Sectional drawing of a gas sensor. Explanatory drawing which shows the one part process of the manufacturing method of the gas sensor of 1st Embodiment. The figure which shows the external appearance of the gas sensor before and behind the caulking process of the outer cylinder of 1st Embodiment. Sectional drawing of the ventilation structure of the gas sensor after the caulking process of the outer cylinder of 1st Embodiment. The figure which shows the external appearance of the gas sensor before and behind the caulking process of the outer cylinder of 2nd Embodiment. Sectional drawing of the ventilation structure before and behind the shaping process of the convex protrusion part of 2nd Embodiment.

A. Gas sensor structure:
FIG. 1 is an external view of a gas sensor as one embodiment of the present invention. In the following description, the downward direction on the paper surface along the axis O of the gas sensor 100 in FIG. 1 will be described as the front end side, and the upward direction on the paper surface will be described as the rear end side. The gas sensor 100 is an oxygen sensor that measures the oxygen concentration in the exhaust gas of a vehicle such as a motorcycle. The gas sensor 100 is fixed to the vehicle in such a manner that its tip portion protrudes into the exhaust pipe of the vehicle.

  FIG. 2 is a cross-sectional view of the gas sensor 100 along the axis O. FIG. The gas sensor 100 as a whole has a substantially cylindrical shape extending along the axis O. The gas sensor 100 includes a detection element 10, a metal shell 20, a protector 60, an inner cylinder 50, and an outer cylinder 70. The detection element 10 is also referred to as “sensor element 10”.

  The detection element 10 constitutes an oxygen concentration cell in which a pair of electrodes are laminated on both surfaces of an oxygen ion conductive solid electrolyte body. The detection element 10 is a known oxygen sensor element that outputs a detection value corresponding to the oxygen partial pressure. The detection element 10 includes a bottomed cylindrical solid electrolyte body 11 whose outer diameter is tapered toward the tip, an inner electrode (reference electrode) 10a formed on the inner surface of the solid electrolyte body 11, a solid An outer electrode (detection electrode) 10 d formed on the outer surface of the electrolyte body 11. A flange 12 is provided near the center of the detection element 10 in the axial direction. The detection element 10 detects the gas by making the internal space of the detection element 10 a reference gas atmosphere and bringing the detection target gas into contact with the outer surface of the detection element 10. A lead wire 62 for taking out a detection signal from the inner electrode 10 a protrudes from the rear end of the gas sensor 100. A glass braided tube 61 for protecting the lead wire 62 is provided on the outer periphery of the lead wire 62. This glass braided tube 61 can be omitted.

  The metal shell 20 is a cylindrical member that surrounds the periphery of the detection element 10 in the radial direction and holds the detection element 10, and is formed of metal (for example, stainless steel or carbon steel). On the inner surface of the metal shell 20, a step portion 20b whose inner diameter is reduced toward the distal end is provided. Further, in the vicinity of the center of the metal shell 20 in the axial direction, a polygonal flange portion 20c protruding outward in the radial direction is provided in order to engage the attachment tool. Furthermore, a male screw portion 20d is formed on the outer surface on the tip side of the flange portion 20c. The male screw portion 20d of the metal shell 20 is attached to, for example, a screw hole of an exhaust pipe of a motorcycle (motorcycle), and the tip of the detection element 10 is disposed in the exhaust pipe. ) Can be detected. In the gas sensor 100, a gasket 29 that prevents gas from being released when the gas sensor 100 is attached to the exhaust pipe is further fitted into the step portion between the front end surface of the flange portion 20c and the rear end of the male screw portion 20d. It is.

  A powder filling portion 31 that is compressed and filled with talc powder is disposed in a space between the portion on the rear end side of the flange portion 12 of the detection element 10 and the metal shell 20. The gap between the detection element 10 and the metal shell 20 is sealed by the powder filling unit 31. A cylindrical insulating member (ceramic sleeve) 32 is disposed on the rear end side of the powder filling unit 31.

  The protector 60 is a bottomed cylindrical metal member and covers the distal end portion of the detection element 10 protruding from the metal shell 20 toward the distal end side. The protector 60 is formed with a plurality of holes 64 for taking the exhaust gas into the protector 60. The exhaust gas that has flowed into the protector 60 from the plurality of holes 64 is supplied to the outer electrode 10d as a gas to be detected.

  The inner cylinder 50 is a cylindrical member that is attached to the metal shell 20 and extends further to the rear end side in the axial direction than the metal shell 20. The inner cylinder 50 is fixed to the rear end portion of the metal shell 20 and covers the rear end portion of the detection element 10. The inner cylinder 50 can be made of, for example, stainless steel such as SUS430, SUS304, SUS304L, SUS310S, SUS316, SUS316L, or a metal such as carbon steel. A metal ring 33 formed of, for example, stainless steel or carbon steel is disposed between the inner surface of the rear end portion of the metal shell 20 and the outer surface of the front end portion of the inner cylinder 50. The distal end portion of the inner cylinder 50 is fixed by a crimping portion 22 provided at the rear end portion of the metal shell 20 while being sandwiched between the metal ring 33 and the insulating member 32. In other words, the front end portion of the inner cylinder 50 is fixed between the metal ring 33 and the insulating member 32 by forming the caulking portion 22 by caulking the rear end portion of the metal shell 20. Further, by this caulking, the insulating member 32 is pressed against the distal end side and the powder filling part 31 is crushed, and the insulating member 32 and the powder filling part 31 are caulked and fixed. The gap of the metal shell 20 is sealed.

  A substantially cylindrical and insulating separator 34 is disposed inside the inner cylinder 50. The separator 34 is formed with an insertion hole 35 that penetrates in the direction of the axis O and through which the lead wire 62 is inserted. The outer surface of the separator 34 is separated from the inner surface of the inner cylinder 50 so that the outside air can flow.

  A connection terminal 65 is electrically connected to the distal end side of the lead wire 62. The connection terminal 65 is a member for taking out the sensor output to the outside, and protrudes to the tip side from the separator 34. The connection terminal 65 is inserted into the detection element 10 so as to be electrically connected to the inner electrode 10a.

  Inside the inner cylinder 50, a substantially cylindrical grommet 40 as a sealing member is disposed in contact with the rear end of the separator 34. The grommet 40 has an insertion hole 42 that penetrates in the direction of the axis O and through which the lead wire 62 is inserted. The grommet 40 can be formed of, for example, a rubber material such as silicon rubber or fluorine rubber. The grommet 40 has a cylindrical body portion 43 on the front end side, and has a flange portion 44 having a diameter larger than that of the body portion 43 at the rear end of the body portion. The collar portion 44 is press-fitted into the inner rear end of the outer cylinder 70. The body 43 is crimped by the outer cylinder 70 via the rear end portion of the inner cylinder 50.

  In the side surface of the inner cylinder 50, a plurality of first vent holes 51 are opened side by side in the circumferential direction at a position closer to the tip side than a position where the grommet 40 is disposed. A cylindrical ventilation filter 30 is disposed outside the inner cylinder 50 so as to cover the first ventilation holes 51. A metal cylindrical outer cylinder 70 is further arranged outside the inner cylinder 50 and the ventilation filter 30.

  The outer cylinder 70 is a cylindrical member disposed so as to surround the circumference of the inner cylinder 50 in the radial direction. The outer cylinder 70 can be formed with metals, such as stainless steel and carbon steel, such as SUS430, SUS304, SUS304L, SUS310S, SUS316, SUS316L, for example. On the side surface of the outer cylinder 70, a plurality of second ventilation holes 74 are opened side by side in the circumferential direction. As a result, the inside of the inner cylinder 50 and further to the inner electrode 10a of the detection element 10 through the second ventilation hole 74 of the outer cylinder 70, the ventilation filter 30, and the first ventilation hole 51 of the inner cylinder 50. The outside air can be introduced. The rear end portion of the outer cylinder 70 is bent radially inward, and the rear end surface of the flange portion 44 of the grommet 40 is in contact with the rear end portion. In addition, an opening through which the lead wire 62 is inserted is provided at the radial center of the rear end portion of the outer cylinder 70.

  The outer cylinder 70 is fixed to the outer periphery of the inner cylinder 50 by being crimped together with the inner cylinder 50 in the radial direction. In the present embodiment, the concave three caulking portions 71 to 73 are formed in order from the distal end side on the outer cylinder 70 by this caulking. The first caulking portion 71 is formed on the tip side of the second ventilation hole 74. The second caulking portion 72 is formed on the rear end side with respect to the second ventilation hole 74. A portion between the first caulking part 71 and the second caulking part 72 is formed as a convex projecting part 75 projecting radially outward from the first caulking part 71 and the second caulking part 72. . The convex protrusion 75 includes a plurality of second ventilation holes 74. The third caulking portion 73 is formed around the trunk portion 43 of the grommet 40 so as to include the rear end of the inner cylinder 50.

  The ventilation filter 30 is sandwiched between the inner cylinder 50 and the outer cylinder 70 in the radial direction, and the caulking portion 71 of the outer cylinder 70 provided at the position of the front end side and the rear end side of the second ventilation hole 74. , 72. The ventilation filter 30 is a non-water-permeable and air-permeable hollow cylindrical member, and can be constituted by a porous structure of a water-repellent resin such as a fluorine resin. Since the ventilation filter 30 has water repellency, the reference gas (atmosphere) can be introduced into the internal space of the detection element 10 without passing external water.

B. First Embodiment of Gas Sensor Manufacturing Method:
Drawing 3 is an explanatory view showing a part of process of the manufacturing method of the gas sensor in a 1st embodiment. In FIG. 3, for convenience of illustration, the top and bottom (the front end and the rear end) are drawn upside down from FIGS.

  FIG. 3A shows an assembling process of the separator assembly 81 and the detection element assembly 82. The separator assembly 81 is an assembly in which the separator 34, the grommet 40, and the outer cylinder 70 are sequentially inserted from the rear ends of the connection terminal 65 and the lead wire 62. In a state before the outer cylinder 70 is caulked, the outer cylinder 70 has a small diameter portion 76 on the rear end side, a large diameter portion 78 on the front end side, and a stepped portion 77 therebetween. Each of the small diameter portion 76 and the large diameter portion 78 has a hollow straight cylindrical shape. A plurality of second ventilation holes 74 described in FIG. 2 are provided near the center of the large diameter portion 78 in the axial direction, but the illustration is omitted in FIG.

  In the detection element assembly 82, the metal shell 20, the detection element 10, the inner cylinder 50, the protector 60, the ventilation filter 30, the insulating member 32, the powder filling unit 31, and the metal ring 33 are assembled. Assembly. A crimping portion 22 is provided at the rear end portion of the metal shell 20, and the inner cylinder 50 is fixed to the metal shell 20 by the crimping portion 22. The ventilation filter 30 is installed on the outer periphery of the inner cylinder 50 with its tip in contact with the crimping portion 22 of the metal shell 20. In this state, the ventilation filter 30 has a hollow right cylindrical shape.

  The assembly of the separator assembly 81 and the detection element assembly 82 is performed by inserting the rear end of the inner cylinder 50 included in the detection element assembly 82 into the space 90 formed in the separator assembly 81, and connecting the connection terminal 65 of the separator assembly 81, This is done by inserting the detector 10 into the interior. By this assembly, the lead wire 62 and the detection element 10 are electrically connected. In addition, the separator 34 and the body 43 of the grommet 40 are disposed in the inner cylinder 50, and the outer cylinder 70 is disposed on the outer periphery of the inner cylinder 50, and the rear end portion of the outer cylinder 70 and the rear end surface of the inner cylinder 50 In this state, the collar portion 44 of the grommet 40 is disposed between the two. The ventilation filter 30 is held between the caulking portion 22 of the metal shell 20 and the stepped portion 77 of the outer cylinder 70 in a state where the ventilation filter 30 is inserted into the space between the inner cylinder 50 and the outer cylinder 70. This step corresponds to a clamping step of clamping the ventilation filter 30 between the inner cylinder 50 and the outer cylinder 70.

  When the assembly of the separator assembly 81 and the detection element assembly 82 is completed, as shown in FIG. 3B, a caulking step for caulking the outer cylinder 70 radially inward is performed. The caulking of the outer cylinder 70 is performed at three positions indicated by broken lines in FIG. 3B, and the three caulking portions 71 to 73 and the convex protruding portion 75 described in FIG. 2 are formed. Each of these crimping portions 71 to 73 can be formed by using, for example, a split ring-shaped crimping jig divided into a plurality (for example, four) in the circumferential direction. In the first embodiment, this caulking is performed by the first jig 210 disposed on the front end side of the flange 20c of the metal shell 20 and the second jig 220 disposed on the rear end side of the outer cylinder 70. Thus, the outer cylinder 70 is pressed against the metal shell 20 side. This pressing is for compressing the ventilation filter 30 in the axial direction.

  FIG. 4 is a view showing the appearance of the gas sensor before and after the caulking process of the outer cylinder 70. When caulking of the outer cylinder 70 is executed, three caulking portions 71 to 73 and a convex protrusion 75 are formed on the outer periphery of the outer cylinder 70. A plurality of second ventilation holes 74 are provided in the vicinity of the center of the convex protrusion 75 in the axial direction along the circumferential direction of the convex protrusion 75. In this example, four second air holes 74 are provided every 90 degrees.

  FIG. 5 is a longitudinal cross-sectional view of the gas sensor ventilation structure after the outer cylinder 70 is crimped. FIG. 5A shows a part of the longitudinal section of the rear end portion of the gas sensor, and FIG. 5B shows an enlarged portion B in the vicinity of the second vent hole 74. As shown in FIGS. 5A and 5B, the ventilation filter 30 has a shape in which the outer surface is curved outward while contacting the inner surface of the convex protrusion 75. As described with reference to FIG. 3B, such a shape of the ventilation filter 30 is obtained by crimping the outer cylinder 70 while compressing the ventilation filter 30 along the axial direction, It can be obtained by forming the part 71, the second crimping part 72, and the convex protrusion 75 between them. That is, since the ventilation filter 30 is compressed along the axial direction when the outer cylinder 70 is caulked, when the convex protrusion 75 is formed on the outer cylinder 70, the outer surface of the ventilation filter 30 is the convex protrusion. It deform | transforms in contact with the inner surface of 75, and becomes a shape curved outward. By so doing, it is difficult for water to enter the inside from the second vent hole 74 of the outer cylinder 70, so that it is possible to obtain good water pressure resistance. Note that, from the viewpoint of water pressure resistance, it is preferable that the outer surface of the ventilation filter 30 is in contact or in close contact with the inner surface of the peripheral portion of the second ventilation hole 74 among the protruding protrusions 75.

  FIG. 5C shows a state of the projecting protrusion 75 of the outer cylinder 70 and the ventilation filter 30 in the comparative example. In this comparative example, the outer surface of the ventilation filter 30 is not in contact with the inner surface of the convex protrusion 75, and a gap G is formed between them. Therefore, for example, when high-pressure water hits the second vent hole 74 of the outer cylinder 70, there is a problem that the high-pressure water is likely to enter the gas sensor.

  On the other hand, in the gas sensor of the first embodiment shown in FIGS. 5A and 5B, there is no gap through which water can pass between the protruding protrusion 75 of the outer cylinder 70 and the ventilation filter 30, so that the sealing performance is high. High and has sufficient water pressure resistance. That is, even when high-pressure water hits the second vent hole 74 of the outer cylinder 70, the possibility of high-pressure water entering the gas sensor can be reduced.

C. Second Embodiment of Gas Sensor Manufacturing Method:
FIG. 6 is a diagram illustrating an appearance of the gas sensor before and after the caulking process of the outer cylinder 70 in the second embodiment. 6A and 6B show the caulking process of the outer cylinder 70 which is substantially the same as that in FIGS. 4A and 4B in the first embodiment, but the caulking process shown in FIG. The point that the outer cylinder 70 is not pressed in the axial direction at the time of fastening is different from the first embodiment. That is, in the second embodiment, when the outer cylinder 70 is caulked, the ventilation filter 30 is not compressed along the axial direction of the gas sensor.

  FIG. 6C shows a shaping process performed after the caulking process shown in FIGS. In this shaping step, the convex protrusion 75 is shaped by pushing the peripheral edge portion of the second vent hole 74 of the convex protrusion 75 from the outside using the jig 230.

  FIG. 7 is a longitudinal sectional view of the gas sensor ventilation structure before and after the shaping process of the convex protrusion 75, and corresponds to FIG. 5B of the first embodiment. As shown in FIG. 7A, before the shaping process of the convex protrusion 75, the outer surface of the ventilation filter 30 comes into contact with the inner surface of the convex protrusion 75 (the inner surface of the peripheral portion of the second vent hole 74). However, a gap G is formed between them. Therefore, the gap G can be eliminated by performing a shaping process in which the peripheral portion of the second vent hole 74 of the convex protrusion 75 is pushed from the outside using the jig 230. As a result, as shown in FIG. 7B, the outer surface of the ventilation filter 30 comes into contact with the inner surface of the convex protrusion 75. In other words, also in the second embodiment, as in the first embodiment, the outer surface of the ventilation filter 30 has a shape curved outward while contacting along the inner surface of the convex protrusion 75. .

  As described above, also in the second embodiment, a structure without a gap through which water from the outside can enter is obtained between the convex protrusion 75 of the outer cylinder 70 and the ventilation filter 30, so that the sealing performance is high. A gas sensor having sufficient water pressure resistance can be provided. That is, even when high-pressure water hits the second vent hole 74 of the outer cylinder 70, the possibility of high-pressure water entering the gas sensor can be reduced.

  In FIG. 6, the shaping process of FIG. 6C is executed after the caulking process of the outer cylinder 70 of FIGS. 6A and 6B, but the shaping process is performed simultaneously with the caulking process. You may do it. In the example of FIG. 6, the ventilation filter 30 is not compressed in the axial direction when the outer cylinder 70 is caulked. However, as in the first embodiment, the outer cylinder is compressed while the ventilation filter 30 is compressed in the axial direction. 70 may be caulked. Also in this case, by performing the shaping process shown in FIG. 6C, a structure having an outer curved shape while the outer surface of the ventilation filter 30 is in contact with the inner surface of the convex protrusion 75, It is possible to obtain more reliably.

D. Variations:
In addition, this invention is not restricted to said Example and embodiment, In the range which does not deviate from the summary, it is possible to implement in various aspects.

・ Modification 1:
The configuration of the gas sensor of the above-described embodiment is an exemplification, and the present invention is applicable to gas sensors having various configurations other than this.

DESCRIPTION OF SYMBOLS 10 ... Detection element 10a ... Inner electrode 10d ... Outer electrode 11 ... Solid electrolyte body 12 ... Gutter part 20 ... Metal | metal fitting 20b ... Step part 20c ... Gutter part 20d ... Male screw part 22 ... Clamping part 29 ... Gasket 30 ... Ventilation filter 31 ... Powder filling part 32 ... Insulating member 33 ... Metal ring 34 ... Separator 35 ... Insertion hole 40 ... Grommet 42 ... Insertion hole 43 ... Body part 44 ... Girder part 50 ... Inner cylinder 51 ... First vent hole 60 ... Protector 61 ... Glass braided tube 62 ... Lead wire 64 ... Hole 65 ... Connection terminal 70 ... Outer cylinder 71 ... First caulking part 72 ... Second caulking part 73 ... Third caulking part 74 ... Second vent hole 75 ... Convex shape Projection part 76 ... Small diameter part 77 ... Step part 78 ... Large diameter part 81 ... Separator assembly 82 ... Detection element assembly 90 ... Space 100 ... Gas sensor 210 ... First jig 220 ... Second treatment 230 ... jig

Claims (4)

A detection element extending in the axial direction, a cylindrical metal shell that surrounds the periphery of the detection element in the radial direction and holds the detection element, and a rear end side in the axial direction with respect to the metal shell that is attached to the metal shell A cylindrical inner cylinder having a first ventilation hole, a cylindrical outer cylinder having a second ventilation hole disposed so as to surround the radial circumference of the inner cylinder, and the inner cylinder in the radial direction. A gas sensor having a water impermeable ventilation filter sandwiched between the outer cylinder,
The outer cylinder includes a first crimping portion located on the distal end side in the axial direction with respect to the second vent hole, and a second crimping portion located on the rear end side in the axial direction with respect to the second vent hole; A convex projecting portion including the second vent hole and projecting radially outward from the first caulking portion and the second caulking portion,
The gas sensor according to claim 1, wherein an outer surface of the ventilation filter has a shape curved radially outward while contacting along an inner surface of the convex protrusion. A detection element extending in the axial direction, a cylindrical metal shell that surrounds the periphery of the detection element in the radial direction and holds the detection element, and a rear end side in the axial direction with respect to the metal shell that is attached to the metal shell A cylindrical inner cylinder having a first ventilation hole, a cylindrical outer cylinder having a second ventilation hole disposed so as to surround the radial circumference of the inner cylinder, and the inner cylinder in the radial direction. A non-water-permeable ventilation filter sandwiched between the outer cylinder and a gas sensor manufacturing method comprising:
A clamping step of clamping the ventilation filter between the inner cylinder and the outer cylinder;
The outer cylinder is crimped inward in the radial direction while compressing the ventilation filter along the axial direction, whereby the first crimping is located on the outer cylinder on the distal end side in the axial direction with respect to the second ventilation hole. Part, a second crimping portion located on the rear end side in the axial direction with respect to the second vent hole, and a radial direction with respect to the first crimping portion and the second crimping portion including the second vent hole A convex protrusion that protrudes outward, and the outer surface of the vent filter has a shape that is curved radially outward while contacting the inner surface of the convex protrusion. A caulking step to deform,
A method of manufacturing a gas sensor, comprising: A detection element extending in the axial direction, a cylindrical metal shell that surrounds the periphery of the detection element in the radial direction and holds the detection element, and a rear end side in the axial direction with respect to the metal shell that is attached to the metal shell A cylindrical inner cylinder having a first ventilation hole, a cylindrical outer cylinder having a second ventilation hole disposed so as to surround the radial circumference of the inner cylinder, and the inner cylinder in the radial direction. A non-water-permeable ventilation filter sandwiched between the outer cylinder and a gas sensor manufacturing method comprising:
A clamping step of clamping the ventilation filter between the inner cylinder and the outer cylinder;
By caulking the outer cylinder inward in the radial direction, the outer cylinder is provided with a first crimping portion located on the distal end side in the axial direction with respect to the second ventilation hole, and the axial direction with respect to the second ventilation hole. A second caulking portion on the rear end side, and a convex projecting portion including the second ventilation hole and projecting radially outward from the first caulking portion and the second caulking portion. Caulking process;
Simultaneously with the caulking step or after the caulking step, by pushing the peripheral edge portion of the second vent hole of the convex protrusion of the outer cylinder from the outside, along the inner surface of the convex protrusion A shaping step of shaping the convex protrusion so as to contact the outer surface of the ventilation filter;
A method of manufacturing a gas sensor, comprising: It is a manufacturing method of the gas sensor according to claim 3,
The method of manufacturing a gas sensor, wherein the caulking step is performed while compressing the ventilation filter along the axial direction.

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