JP2011215093A - Method for manufacturing gas sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a gas sensor, preventing a holding part or a covering part from coming into contact with a filter member when arranging an arm part in the groove part of a plug member.SOLUTION: An outer cylinder 3 is held to an attaching jig in the holding process. Since a holding part is arranged on the front side in an attaching direction from the arm part 33 of the outer cylinder 3 at this time, the attaching jig is brought into contact with a grommet 9 before the outer cylinder 3 comes into contact with the base 94 of the groove part 93 in the arranging process. When the arm part 33 is arranged in the groove part 93 of the grommet 9 in the shifting process, a protection part 34 and the filter member 87 are separatedly arranged to suppress the damage of the filter member 87.

Description

  The present invention relates to a method of manufacturing a gas sensor having a ventilation structure for ensuring the air permeability between the inside and outside of an outer cylinder while holding a detection element for measuring a gas to be measured inside the metal shell or the outer cylinder. Is.

  2. Description of the Related Art Conventionally, a gas sensor that uses a solid electrolyte body made of ceramics such as zirconia and includes a detection element that detects the concentration of a specific gas component (for example, oxygen) in exhaust gas discharged from an internal combustion engine is known. For example, the detection element of the oxygen sensor that detects the oxygen concentration has a pair of a detection electrode that is exposed to exhaust gas and a reference electrode that is exposed to a reference gas (usually air) sandwiching the solid electrolyte body It is formed on the surface. This detection element detects the oxygen concentration in the exhaust gas according to the difference in oxygen partial pressure between two atmospheres separated by the solid electrolyte body, that is, between the exhaust gas and the reference gas.

  Such an oxygen sensor has a metal shell for holding the detection element and an outer cylinder that covers the periphery of the detection element, and further, on the rear end side of the outer cylinder, for closing the inside of the outer cylinder. A plug member (grommet) is assembled. In addition to the lead wire insertion hole through which the lead wires (sensor output lead wire and heater lead wire) are inserted, this plug member ensures air permeability between the inside and the outside of the outer cylinder, and the detection element. An air communication hole (through hole) for introducing a reference gas is provided on the reference electrode side. Further, the air communication hole of the plug member is provided with a filter member for introducing air into the outer cylinder (air permeability) and preventing water droplets or the like from entering (waterproof).

  Further, as in Patent Document 1 and Patent Document 2, gas sensors are also known in which a protective member is provided that covers the air communication hole of the plug member from the rear side (external side) of the outer cylinder and protects the filter member. By providing a protective member, the filter member can be prevented from being directly exposed to the outside, and the filter member can be prevented from being damaged by contact with the vegetation or impact from the outside due to collision with flying stones, etc. is doing. This protective member is a ventilation part (protection part) having an opening smaller than the air communication hole, or a covering part that covers the filter member so that the filter member cannot be seen, and vents the air communication hole from the gap with the plug member However, it has the structure couple | bonded with the outer cylinder through the arm part.

JP 2008-292459 A JP 2008-292460 A

  In recent years, a gas sensor in which a protective part, a covering part, and an arm part are directly provided on an outer cylinder without using a protective member as in Patent Documents 1 and 2 has been studied. Specifically, an arm portion is connected to the rear end side of the outer cylinder, and a protective portion and a covering portion are provided so as to connect to the arm portion. Thus, there exists an advantage that a number of parts reduces by forming an outer cylinder, a protection part, a coating | coated part, and an arm part by one member.

  By the way, when assembling the outer cylinder composed of one member with the protective part, the covering part, and the arm part to the plug member, the arm part of the outer cylinder is disposed in the groove provided in the plug member. This groove is originally provided to assist water drainage when the plug member is flooded from the outside, and does not deteriorate the ventilation performance of the air communication hole, but by disposing the arm in this groove, The outer cylinder can be prevented from rotating in the circumferential direction with respect to the plug member. Therefore, when the outer cylinder and the plug member are assembled, the lead wire taken out from the lead wire insertion hole of the plug member can be prevented from coming into contact with the outer cylinder and being damaged.

  However, when the arm portion of the outer cylinder is disposed in the groove portion of the plug member, the protective portion or the covering portion comes into contact with the filter member assembled to the plug member, and the filter member may be damaged. This is because the filter member is arranged in the air communication hole to prevent water from collecting in the depression formed by the air communication hole and the filter member and thereby reducing the ventilation performance of the air communication hole. This is because, when the filter member is assembled to the plug member, the filter member may be arranged in a form exposed on the rear side of the groove portion of the plug member.

  On the other hand, it is possible to prevent the filter member from being damaged by disposing the arm portion of the outer cylinder in the groove portion of the plug member while separating the protective portion and the covering portion from the filter member. In the assembling method of the plug member and the stopper member, it is difficult to dispose the protective portion or the protective portion and the filter member apart from each other.

  The conventional method of assembling the outer cylinder and the plug member is to join a plurality of connecting terminals and a plurality of lead wires connecting a lead wire and an electrode (detection electrode or reference electrode) etc. The lead wire is inserted into the lead wire insertion hole of the separator and the plug member. The separator is disposed closer to the distal end side of the gas sensor than the plug member, and is for preventing contact between the plurality of connection terminals.

  Then, the lead wire is inserted into the outer cylinder in a non-contact state with the arm part, the protection part, and the covering part provided on the rear end side of the outer cylinder, and then the outer cylinder covers the periphery of the separator and the plug member. The plug member is fitted from the rear end side. At this time, since the separator, the plug member, and the outer cylinder are independently arranged (because movement in the axial direction is not restricted with respect to other members), first, the arm portion of the outer cylinder is the plug member. It will move until it contacts the bottom surface of the groove. That is, when the arm part of the outer cylinder comes into contact with the bottom surface of the groove part of the plug member, the movement of the outer cylinder toward the distal end side of the plug member is restricted. Therefore, in this method, it is difficult to dispose the arm portion of the outer cylinder in the groove portion of the plug member while separating the ventilation portion and the protection portion from the filter member.

  Therefore, the present invention has been made to solve the above-described problem, and can prevent the holding portion or the covering portion from coming into contact with the filter member when the arm portion is disposed in the groove portion of the plug member. It aims at providing the manufacturing method of a gas sensor.

The method of manufacturing a gas sensor according to the present invention includes a detection element that extends in the axial direction and has a detection unit for detecting a gas to be detected on the tip side of the gas sensor, and the detection unit projects from the tip of the detection unit. A metal shell that surrounds the periphery of the element in the radial direction, a cylindrical outer tube that is disposed on the rear end side of the metal shell, and whose tip is fixed to the metal shell, and is disposed inside the outer tube. A plug member, wherein a lead wire insertion hole through which a lead wire for taking out a detection signal of the detection element is inserted, and a filter member having air permeability and waterproof properties are interposed between the inside and the outside of the outer cylinder In the method of manufacturing a gas sensor, the air communication holes that enable the atmospheric communication of the plug members formed so as to extend in the axial direction, respectively,
The plug member extends toward the outside in the radial direction avoiding the lead wire insertion hole starting from the atmosphere communication hole on the rear end facing surface side of the plug member, and is notched toward the distal end side of the plug member, A protective portion that has a groove portion having a bottom surface and a side surface and protects the filter member by covering the air communication hole of the plug member from the rear end side in the axial direction, and is smaller than the opening of the air communication hole The filter member is covered by covering the atmospheric communication hole of the plug member from the rear end side in the axial direction so that the filter member cannot be visually recognized when viewed from the axial direction of the protective part having the opening or the gas sensor. A covering part to be protected, which is connected to the protection part or the covering part, and allows radial passage between the inside and the outside of the atmosphere communication hole through a gap between itself and the plug member; Extend to An arm portion at least partially disposed in said groove of said plug member, but it is formed by the outer tube and the first member,
When the outer cylinder is engaged with the outer cylinder from the rear side in the attaching direction to the plug member, the outer cylinder is arranged on the front side in the attaching direction with respect to the arm portion of the outer cylinder. Preparing a mounting jig having a possible holding portion and a lead wire holding portion for positioning the lead wire with respect to the outer cylinder while holding the lead wire slidably in the extending direction,
A holding step of holding the outer cylinder on the mounting jig, a lead wire holding step of holding the lead wire on the lead wire holding portion of the mounting jig, and the outer direction along the extending direction of the lead wire The arm part of the outer cylinder is arranged on the rear side of the plug member while sliding the mounting jig integrated with the cylinder so that the holding part of the mounting jig and the plug member are in contact with each other. And placing the arm part of the outer cylinder into the groove part of the plug member while pressing the outer cylinder in the mounting direction of the plug member and separating the protective part or the covering part from the filter member. And a shifting step of arranging.

  Thus, the attachment jig which has a holding | maintenance part and a lead wire holding | maintenance part is prepared, and an outer cylinder is hold | maintained at an attachment jig | tool at a holding process. At this time, since the holding portion is arranged on the front side in the mounting direction with respect to the arm portion of the outer cylinder, when the outer cylinder is externally fitted to the plug member in the subsequent arrangement step, first, the mounting jig When the holding portion is in contact with the plug member, movement of the outer cylinder and the attachment jig toward the distal end side of the plug member can be restricted. Thereby, it does not move until the arm part of an outer cylinder contact | abuts to the bottom face of the groove part of a plug member. Then, in the shifting step, the outer cylinder is pressed so that the arm portion of the outer cylinder is disposed in the groove of the plug member while separating the protective portion or the covering portion and the filter member. As a result, when the filter member is assembled to the plug member, the filter member is exposed to the rear side of the groove portion, and even when the outer tube is externally fitted to the plug member, It can suppress that a protection part or a covering part contacts a filter member, and can control that a filter member is damaged.

In addition, the gas sensor manufacturing method of the present invention includes a cylindrical separator that is disposed on the tip side of the plug member and encloses a connection terminal connected to the lead wire, and the separator has a radially outer side. It is preferable that a projecting flange portion is provided, and in the shifting step, the outer tube is brought into contact with the flange portion after the stopper member is brought into contact with the separator. Thereby, the restriction | limiting of the movement to the axial direction front end side of an outer cylinder and a plug member can be achieved by a separator. Specifically, the restriction of the movement of the plug member toward the distal end side in the axial direction can be achieved by contacting the separator, and the restriction of the movement of the outer cylinder toward the distal end side in the axial direction can be achieved by contacting the flange portion. Therefore, when assembling the outer cylinder to the plug member during the shifting process, the outer cylinder arm part is in the groove part of the plug member only by the shape of the separator without the protective part or covering part of the outer cylinder contacting the filter member. Can be securely arranged.
The shape of the separator is the axial distance between the flange part and the arm part of the outer cylinder (specifically, the axial distance from the contact position between the flange part and the outer cylinder to the arm part of the outer cylinder), The axial distance between the rear end surface of the separator and the bottom surface of the groove portion of the plug member ensures that the arm portion of the outer tube is in the groove portion of the plug member without the protective portion or covering portion of the outer tube being in contact with the filter member. What is necessary is just to set suitably so that it can arrange | position.

  Further, in the gas sensor manufacturing method according to the present invention, the holding portion holds the arm portion so that the mounting jig is engaged with the outer cylinder from the rear side in the mounting direction of the outer cylinder to the plug member. It is preferable to combine them. As a result, the outer cylinder can be easily held by the mounting jig, and when the mounting jig is engaged with the outer cylinder, it is easy to arrange the holding part on the front side in the mounting direction rather than the arm part of the outer cylinder. Can be achieved.

  Furthermore, in the gas sensor manufacturing method of the present invention, it is preferable that the plug member has a convex portion protruding from the bottom surface of the groove portion toward the rear end side, and the arm portion is in contact with the convex portion. . Thus, by providing the plug member with the convex portion, contact between the arm portion and the bottom surface of the groove portion can be further prevented.

It is a longitudinal cross-sectional view which shows the structure of the gas sensor 1 of 1st Embodiment. It is a perspective view of the grommet 9 before an assembly | attachment. It is the figure which looked at the gas sensor 1 from the axis line O direction rear end side (upper side in FIG. 1). It is a perspective view of the outer cylinder 3 before an assembly | attachment. 6 is a perspective view of a mounting jig 400. FIG. It is the figure which looked at the attachment jig | tool 400 from the front of the attachment direction (in the arrow C direction in FIG. 5). It is the figure which looked at the attachment jig | tool 400 from the back of the attachment direction (in the arrow D direction in FIG. 5). FIG. 7 is a bending cross-sectional view of the mounting jig 400 as viewed from the direction of the arrow along a bending line EE indicated by a two-dot chain line in FIG. 5 (or FIG. 6). It is a figure which shows a holding process. It is a figure which shows a lead wire holding process. It is a figure which shows an arrangement | positioning process. It is a figure which shows the shift process. It is a principal part longitudinal cross-sectional view of the gas sensor 201 as a modification. It is the figure which looked at the gas sensor 201 from the axis line O direction rear end side (upper side in FIG. 13). It is a longitudinal cross-sectional view which shows the structure of the gas sensor 700 as a modification. It is a perspective view which shows the shape of the rear-end part of the outer cylinder 510 as a modification. It is a perspective view which shows the shape of the rear-end part of the outer cylinder 520 as a modification.

  Hereinafter, an embodiment of a gas sensor embodying the present invention will be described with reference to the drawings. First, as a first embodiment, the structure of a gas sensor 1 will be described with reference to FIGS. 1 is used by being attached to an exhaust pipe (not shown) of exhaust gas discharged from an engine of an internal combustion engine such as an automobile. In the following, in the direction of the axis O of the gas sensor 1, the side toward the tip of the detection element 6 inserted into the exhaust pipe (the closed side and the lower side in the figure) is the tip side, and the side in the opposite direction ( The upper side in the figure will be described as the rear end side.

  The gas sensor 1 shown in FIG. 1 is a sensor for detecting the concentration of oxygen in the exhaust gas flowing through the exhaust pipe, and the elongated and closed cylindrical detection element 6 is connected to the metal shell 5 and the outer cylinder 3. And a structure held in the protector 4. A lead wire 18 is drawn out from the gas sensor 1 for taking out a signal output from the detection element 6 and energizing the heater 7 provided in the detection element 6. Each lead wire 18 is electrically connected to a sensor control device (not shown) provided at a position away from the gas sensor 1 or an electronic control device (ECU) of an automobile.

  The detection element 6 of the gas sensor 1 is formed by forming a solid electrolyte body 61 made of zirconia into a bottomed cylindrical shape, and a reference electrode 62 made of Pt or a Pt alloy covers almost the entire surface of the solid electrolyte body 61. It is formed in a porous shape so as to cover it. Similarly to the reference electrode 62, the detection electrode 63 made of Pt or a Pt alloy is formed on the outer surface of the solid electrolyte body 61 in a porous shape. The front end side (closed side) of the detection element 6 is configured as a detection unit 64, and the detection electrode 63 on the outer surface is exposed to the exhaust gas flowing in the exhaust pipe (not shown). Although not shown, the detection electrode 63 is covered with a porous electrode protection layer made of heat-resistant ceramic, and is protected from poisoning by exhaust gas. In addition, a flange-like flange portion 65 protruding outward in the radial direction is provided at a substantially intermediate position in the axis O direction of the detection element 6. A rod-shaped heater 7 for heating and activating the solid electrolyte body 61 is inserted into the cylindrical hole of the detection element 6.

  The detection element 6 is held in the cylindrical hole 55 of the metal shell 5 in a state where the circumference of the detection element 6 is surrounded by the cylindrical metal shell 5. The metal shell 5 is a cylindrical member made of stainless steel such as SUS430, and a male threaded portion 52 that is screwed into a mounting portion (not shown) of the exhaust pipe is formed on the distal end side. A distal end engaging portion 56 is formed on the outer periphery of the male screw portion 52 to engage a protector 4 described later on the outer periphery thereof. The detection part 64 of the detection element 6 protrudes further to the tip side than the tip engagement part 56.

  A tool engaging portion 53 having a radially increased diameter is formed on the rear end side of the male screw portion 52 of the metal shell 5 and is used when the gas sensor 1 is attached to an attachment portion (not shown) of the exhaust pipe. An installation tool is engaged. An annular gasket 11 is inserted into a portion between the tool engaging portion 53 and the male screw portion 52 to prevent gas from being released through the attachment portion of the exhaust pipe. A caulking portion 57 for caulking and fixing the detection element 6 held in its cylindrical hole 55 is provided on the rear end side of the metal shell 5. The rear end portion 66 of the detection element 6 protrudes further toward the rear end side than the caulking portion 57. And between the tool engaging part 53 and the crimping part 57, the rear-end engaging part 58 with which the front-end | tip part 31 of the outer cylinder 3 mentioned later is engaged is formed in the outer periphery.

  Next, a step portion 59 is provided on the front end side in the cylindrical hole 55 of the metal shell 5 so that the inner periphery thereof protrudes radially inward, and the metal packing 12 is attached to the step portion 59. A cylindrical support member 13 made of alumina is engaged therewith. The inner periphery of the support member 13 is also formed in a step shape, and the flange portion 65 of the detection element 6 is supported by the support member 13 through a metal packing 14 disposed in the stepped portion. Further, the cylindrical hole 55 is filled with a filler member 15 made of talc powder on the rear end side of the support member 13, and the rear end side of the filler member 15 is sandwiched between the filler member 15 and the support member 13. A tubular sleeve 16 made of alumina is disposed on the surface.

  An annular ring 17 is disposed on the rear end side of the sleeve 16, and the sleeve 16 is connected to the filling member 15 via the ring 17 by caulking the caulking portion 57 of the metal shell 5 inward in the radial direction. It is pressed. Through the caulking of the caulking portion 57, the filling member 15 presses the flange portion 65 of the detecting element 6 toward the support member 13 locked to the stepped portion 59 of the metal shell 5, so that the cylindrical hole of the metal shell 5 is pressed. In addition to being compressed and filled in 55, the gap between the inner peripheral surface of the cylindrical hole 55 and the outer peripheral surface of the detection element 6 is filled in an airtight manner. As described above, the detection element 6 is held in the cylindrical hole 55 of the metal shell 5 through the members sandwiched between the crimping portion 57 and the step portion 59 of the metal shell 5.

  Next, the protector 4 that covers the detection portion 64 of the detection element 6 protruding from the front end engagement portion 56 toward the front end side in the axis O direction is assembled to the front end engagement portion 56 of the metal shell 5 by welding. ing. The protector 4 protects the detection portion 64 of the detection element 6 that protrudes into the exhaust pipe when the gas sensor 1 is attached to the exhaust pipe (not shown) from collision of water droplets or foreign matters contained in the exhaust gas. It is. The protector 4 has a bottomed cylindrical shape, an outer protector 41 whose peripheral edge on the opened side is joined to the tip engaging portion 56, and a bottomed cylindrical inner protector fixed inside the outer protector 41. 45 to form a double structure. On the outer peripheral walls of the outer protector 41 and the inner protector 45, there are respectively introduced inlets 42 for introducing exhaust gas into the interior and leading them to the detection part 64 of the detection element 6 (the gas inlets of the inner protector 45 are Not shown). Further, on the bottom walls of the outer protector 41 and the inner protector 45, outlets 43 and 48 for discharging water droplets and exhaust gas entering the inside are opened, respectively.

  Further, a tubular separator 8 made of insulating ceramics is disposed on the rear end side in the axis O direction from the rear end portion 66 of the detection element 6. The separator 8 has an accommodating portion 82 that independently accommodates four connection terminals 19 (three of which are shown in FIG. 1). The accommodating portion 82 penetrates the separator 8 in the direction of the axis O, and is configured to allow ventilation between the front end side and the rear end side of the separator 8. Each connection terminal 19 has a pair of electrodes 71 (one of which is shown in FIG. 1) exposed on the rear end side to energize the reference electrode 62, the detection electrode 63, and the heating resistor of the heater 7. Electrode 71 is shown)) and is electrically connected to each other. The separator 8 accommodates the connection terminals 19 in a separated state to prevent contact between the connection terminals 19. Core wires of four lead wires 18 are caulked and joined to each connection terminal 19 (two lead wires 18 are shown in FIG. 1), and each lead wire 18 is a grommet described later. 9 is pulled out to the outside of the gas sensor 1. Further, a flange portion 81 protruding radially outward is provided on the outer peripheral surface of the separator 8, and a substantially cylindrical holding metal fitting 85 is fitted on the outer peripheral surface on the tip side of the flange portion 81. Yes.

  A grommet 9 made of fluorine rubber is disposed on the rear end side of the separator 8. As shown in FIG. 2, the grommet 9 is a member formed in a substantially cylindrical shape with the axis O direction as the height direction, and includes an air communication hole 91 and four lead wire insertion holes 92 penetrating in the axis O direction. Have. The air communication hole 91 is formed at the center in the radial direction of the grommet 9, and the lead wire insertion holes 92 are equally spaced in the circumferential direction so as to surround the air communication hole 91 on the outer peripheral side of the air communication hole 91. Are formed respectively. As shown in FIG. 1, the atmosphere communication hole 91 is provided for introducing the atmosphere into the gas sensor 1 (in an outer cylinder 3 described later) via the accommodating portion 82 of the separator 8. In the outer cylinder 3, the detection element 6 is held by the metal shell 5 in a form in which the rear end portion 66 is projected, but the reference electrode 62 formed in the bottomed cylinder of the detection element 6 is in the atmosphere. It is configured to be exposed. As shown in FIG. 3, the four lead wires 18 described above are inserted into the four lead wire insertion holes 92 independently of each other. The grommet 9 corresponds to a “plug member” in the claims.

  As shown in FIGS. 2 and 3, the rear end facing surface 99 facing the rear end when the grommet 9 is assembled to the gas sensor 1 starts from the position where the air communication hole 91 is formed, and moves to the outer peripheral side. Four groove portions 93 extending in a groove shape along the radial direction are formed. The groove 93 is notched toward the front end side of the grommet 9 and is formed by the bottom surface 94 and two side surfaces 95 connecting the bottom surface 94 and the rear end facing surface 99. Each groove portion 93 is disposed between two adjacent lead wire insertion holes 92 so as to avoid the positions of the four lead wire insertion holes 92 opened on the rear end facing surface 99. Therefore, the rear end facing surface 99 is divided into four sections by the groove 93.

  As shown in FIG. 1, a filter member 87 and a fastener 88 are inserted into the atmosphere communication hole 91 of the grommet 9. The filter member 87 is a thin-film filter having a micron-sized network structure made of a fluororesin such as PTFE (polytetrafluoroethylene), and is configured to allow air to communicate without passing water droplets. is there. The clasp 88 is a member formed in a cylindrical shape, and a filter member 87 is sandwiched between the outer periphery of itself and the inner periphery of the air communication hole 91 and fixed to the grommet 9. The groove part 93 of the grommet 9 described above forms a flow path that leads to the outer peripheral side so that water droplets or the like that could not pass through the filter member 87 do not accumulate on the filter member 87. Therefore, it is preferable that the rear end of the filter member 87 is disposed on the rear end side with respect to the bottom surface 94 of the groove portion 93. In addition, the groove part 93 may have an inclination which goes to the rear end side from the front end side in the axis O direction as it goes from the radially outer side to the central side.

  Next, a cylindrical outer cylinder 3 extending in the direction of the axis O is assembled to the rear end side of the metal shell 5. As shown in FIG. 4, the outer cylinder 3 is formed of stainless steel such as SUS304 in a cylindrical shape extending along the direction of the axis O, and further, a distal end portion 31 positioned on the distal end side (lower side in FIG. 4) from the approximate center. Is formed in a large diameter. The inner diameter of the distal end portion 31 is formed larger than the outer diameter of the rear end engaging portion 58 in order to engage the distal end portion 31 with the rear end engaging portion 58 (see FIG. 1) of the metal shell 5. As shown in FIGS. 3 and 4, the rear end of the rear end portion 38 located on the rear end side of the outer cylinder 3 is bent inward in the radial direction to form a connecting portion 32. Four arm portions 33 having a plate shape extending toward the axis O are projected from four circumferential directions.

  Each arm portion 33 is connected to the outer periphery of a circular plate-shaped protection portion 34. The protective part 34 has an outer diameter that is almost the same size as the atmosphere communication hole 91 of the grommet 9 shown in FIG. 2, and the thickness direction is aligned with the axis O direction as shown in FIGS. The arm portion 33 supports the hole 91 so that the hole 91 is covered. Further, as shown in FIG. 4, the protection portion 34 is provided with a protruding portion 35 that protrudes toward the rear end side. The opening provided in the projecting portion 35 is formed smaller than the opening (size) of the air communication hole 91 (see FIG. 1), and the entry of flying stones or the like into the air communication hole 91 is prevented. . The ventilation between the outside and the atmosphere communication hole 91 (that is, the ventilation between the inside and the outside of the outer cylinder 3) is ensured through the opening of the protruding portion 35. By providing the protection part 34 in this way, the filter member 87 disposed in the air communication hole 91 can be protected from external impacts such as contact with plants and collision with flying stones, and damage can be prevented. it can. In addition, the protrusion part 35 is arrange | positioned ahead of the rear-end facing surface 99 of the grommet 9 (that is, the protrusion part 35 is arrange | positioned in the grommet 9). Thereby, it can prevent that the lead wire 18 contacts the protrusion part 35 and is damaged.

  As shown in FIG. 1, the outer cylinder 3 having such a structure surrounds each side surface of the rear end portion 66 of the detection element 6, the separator 8, and the grommet 9 arranged in the direction of the axis O in the circumferential direction. In this state, it is arranged on the rear end side of the metal shell 5. The front end portion 31 of the outer cylinder 3 is fitted on the outer periphery of the rear end engaging portion 58 of the metal shell 5 and is crimped radially inward from the outer peripheral side. Further, the outer tube 3 is fixed to the metal shell 5 by performing laser welding around the outer periphery of the tip 31.

  Further, the side surface of the outer cylinder 3 corresponding to the position of the front end side of the flange portion 81 of the separator 8 is crimped radially inward around the outer periphery. A holding metal fitting 85 is disposed at this position, and the holding metal fitting 85 is caulked and held in the outer cylinder 3 in a state where the separator 8 is held inside itself. The side surface of the outer cylinder 3 corresponding to the position of the rear end side of the flange portion 81 of the separator 8 is also crimped radially inward at a plurality of locations in the circumferential direction. The caulking of this portion is performed at a position in contact with the rear end of the flange portion 81. The flange portion 81 is sandwiched between the caulking portion and the holding metal fitting 85, and movement of the separator 8 in the direction of the axis O is restricted. Yes.

  Further, as shown in FIG. 1, the grommet 9 disposed on the rear end side of the separator 8 is disposed in the rear end portion 38 of the outer cylinder 3 and faces the rear end of the grommet 9 divided into four sections. The surface 99 passes between the four arm portions 33 and protrudes from the outer cylinder 3 to the rear end side, and the arm portion 33 is disposed in the groove portion 93 as shown in FIG. At this time, as shown in FIG. 1, the arm portion 33 is disposed with a bottom surface 94 of the groove portion 93 and a gap T <b> 1. Thereby, even if the grommet 9 is thermally expanded by heat received from the exhaust pipe, the exhaust gas, or the like and is expanded to the rear end side of the gas sensor 1, the groove 93 of the grommet 9 is not caught by the arm portion 33. As a result, a difference in the expansion ratio between the groove 93 in the grommet 9 and other parts (for example, four parts forming the rear end facing surface 99) hardly occurs, and a crack (crack) occurs in the groove 93 of the grommet 9. This can be suppressed.

Next, an example of the manufacturing method of the gas sensor 1 will be described in the following procedure.
First, the structure of the mounting jig 400 used when manufacturing the gas sensor 1 will be described with reference to FIGS. FIG. 5 is a perspective view of the mounting jig 400. 6 is a view of the mounting jig 400 as viewed from the front in the mounting direction (in the direction of arrow C in FIG. 5). FIG. 7 is a view of the mounting jig 400 as viewed from the rear in the mounting direction (in the direction of arrow D in FIG. 5). FIG. 8 is a bending cross-sectional view of the mounting jig 400 as viewed from the direction of the arrow along a bending line EE indicated by a two-dot chain line in FIG. 5 (or FIG. 6).

  A mounting jig 400 shown in FIG. 5 is a jig for placing the outer cylinder 3 when assembling the gas sensor 1 (see FIG. 1), and is made of, for example, nitrile rubber (NBR) along the mounting direction. It has a cylindrical shape having a central axis P (indicated by a one-dot chain line in the figure). As shown in FIGS. 5 to 8, the mounting jig 400 has a base 420 that has a stepped shape with a diameter increased on the rear side in the mounting direction, and projects from the base 420 toward the front in the mounting direction. In addition, a holding portion 410 is formed. The holding part 410 is a part for holding the outer cylinder 3 integrally with the mounting jig 400 itself, and is specifically surrounded by the protection part 34, the arm part 33, and the rear end part 38 of the outer cylinder 3. The four protrusions 411 that can be inserted into the gap (see FIG. 4) are arranged side by side in the circumferential direction. When holding the outer cylinder 3, the arm portions 33 are respectively inserted between the side surfaces 412 of the two protruding portions 411 adjacent in the circumferential direction of the central axis P.

  Further, the inner surface 413 of each protruding portion 411 facing the central axis P side forms a passage that surrounds the central axis P and into which the protective portion 34 is inserted. At this time, the inner diameter of the passage is formed to be slightly smaller than the size of the outer periphery of the protection part 34 so that the protection part 34 receives a load. As shown in FIG. 8, the passage formed by the inner surface 413 is enlarged in the vicinity of the base on the base 420 side of the holding portion 410, and when the protection portion 34 moves to this position, the protection portion 34 is moved to each inner surface. The load received from 413 is released. At this time, in order to prevent contact between the protection part 34 and the base part 420, the base part 420 is formed with a recess-shaped accommodation part 421 that is continuous with the passage formed by the inner surface 413 of the protruding part 411. Further, the outer surface 414 of the protruding portion 411 is formed at a position having a gap with the rear end portion 38 of the outer cylinder 3. By the way, although the protrusion part 411 of the holding | maintenance part 410 is a form which protrudes from the base part 420, respectively, in the manufacture process of the gas sensor 1 mentioned later, the front end surface 415 of the attachment direction of the outer cylinder holding | maintenance part 410 is a rear-end facing surface of the grommet 9. The protruding length of the protruding portion 411 from the base portion 420 is adjusted so that the outer cylinder 3 does not contact the bottom surface 94 of the groove portion 93 of the grommet 9 when it contacts with 99. That is, when the outer cylinder 3 is held by the mounting jig 400, the tip end surface 415 of the protruding portion 411 is disposed at least in front of the mounting direction with respect to the position of the arm portion 33.

  As shown in FIGS. 5 to 8, the outer peripheral surface of the mounting jig 400 has a groove shape extending along the central axis P from the front end surface of the holding portion 410 in the mounting direction to the rear end surface of the base portion 420 in the mounting direction. Four lead wire holding portions 430 are formed. The lead wire holding portion 430 includes a bottom wall surface 431 having a circular cross section provided at a central position in the cross section of each protrusion 411 with respect to the central axis P of the holding portion 410, and an inner diameter (cross section diameter) of the bottom wall surface 431. ) And the side wall surface 432 opposed at a narrower width. The inner diameter of the bottom wall surface 431 is formed to be substantially the same as the outer diameter of the lead wire 18 (see FIG. 1) of the gas sensor 1. When the lead wire 18 is inserted into the lead wire holding portion 430, the lead wire 18 is disposed in the bottom wall surface 431, but the side wall surface 432 is narrower than the outer diameter of the lead wire 18 and leads It functions to prevent the line 18 from coming off. Further, when the front end surface 415 in the mounting direction of the outer cylinder holding portion 410 contacts the rear end facing surface 99 of the grommet 9, the lead wire insertion hole 92 of the grommet 9 and the bottom wall surface 431 of the mounting jig 400 are connected. As shown, the arrangement relationship of the four bottom wall surfaces 431 in the cross section orthogonal to the central axis P with respect to the central axis P is the arrangement relationship of the four lead wire insertion holes 92 in relation to the axis O in the cross section orthogonal to the axis O of the grommet 9. It is comprised so that it may correspond substantially. Further, the outer diameter of the base portion 420 is formed larger than the outer diameter of the outer surface 414 of each protruding portion 411. For this reason, the depth of the groove of the lead wire holding portion 430 in the base portion 420 is deeper than the depth of the groove in the holding portion 410, and the side wall surface 432 prevents the lead wire 18 from coming off more securely on the base portion 420 side. Made.

  Next, a method for manufacturing the gas sensor 1 using the mounting jig 400 will be described with reference to FIGS. FIG. 9 is a diagram illustrating a holding process. FIG. 10 is a diagram showing a lead wire holding process. FIG. 11 is a diagram illustrating an arrangement process. FIG. 12 is a diagram illustrating a shifting process. The sectional views of the gas sensor 1 and the mounting jig 400 of FIGS. 9 to 12 are shown by way of example when viewed from the direction of the arrow along the bending line Z shown by the dotted line in FIG. In the following, the process of attaching the outer cylinder 3 to the grommet 9 will be mainly described, but the manufacturing process of other parts of the gas sensor 1 is well known and will be omitted or simplified.

  The metal shell 5 of the gas sensor 1 shown in FIG. 1 is obtained by forging a rod-shaped steel material made of stainless steel such as SUS430 and then performing a cutting process to obtain a tool engaging portion 53, a rear end engaging portion 58, a male screw. After forming the shape of the part 52, the cylindrical hole 55, etc., it is produced by rolling a screw thread on the male screw part 52. The detection element 6 has a reference electrode 62 and a detection electrode 63 formed on the surface of the solid electrolyte body 61 formed in a bottomed cylindrical shape by, for example, plating, and further covers the surface of the detection electrode 63 so as to cover the electrode protective layer. It is produced by baking after forming. Then, the protector 4 manufactured in a separate process is joined to the metal shell 5 by welding, and the detection element 6 is caulked and held in the cylindrical hole 55 of the metal shell 5, so that the assembly intermediate on the front end side of the gas sensor 1 is obtained. Produced.

  On the other hand, the core wire of the lead wire 18 is caulked and joined to each of the four connection terminals 19 produced from the conductive plate material, and two of the connection terminals 19 are connected to the electrode 71 of the heater 7. The connection terminal 19 and the heater 7 are accommodated in the separator 8, and the lead wire 18 is inserted into the separator 8 and the grommet 9.

[Holding process]
Next, as shown in FIG. 9, the four lead wires 18 drawn out from the lead wire insertion holes 92 of the grommet 9 are surrounded by the protection portion 34, the arm portion 33, and the rear end portion 38 of the outer cylinder 3. Each of the gaps (see FIG. 4) is inserted so as not to contact the arm portion 33 and the protection portion 34. In this state, the front side of the mounting jig 400 in the mounting direction is directed to the outer cylinder 3, the center axis P is aligned with the axis O of the outer cylinder 3, and the outer cylinder is surrounded by the protection portion 34, the arm portion 33, and the rear end portion 38. Each protrusion 411 of the holding portion 410 is inserted into each of the gaps. In other words, the arm 34 is passed between the side surfaces 412 of the protrusions 411 adjacent to each other in the circumferential direction with respect to the central axis P, and the protection part 34 is provided between the inner surfaces 413 facing the central axis P of the four protrusions 411. Arrange. Thereby, the attachment jig 400 and the outer cylinder 3 are positioned with respect to each other. Then, when the mounting jig 400 is moved in the mounting direction along the axis O as it is and the protective part 34 of the outer cylinder 3 is stored in the storage part 421 of the mounting jig 400, the inner surface 413 prevents the protective part 34 from coming off. It functions (see FIG. 10), and the outer cylinder 3 is integrally held by the mounting jig 400.

[Lead wire holding process]
Next, as shown in FIG. 10, the side portions of the lead wire holding portion 430 provided on the protruding portion 411 of the mounting jig 400 inserted into the gap where the four lead wires 18 are respectively arranged. It is inserted between the wall surfaces 432 and arranged on the bottom wall surface 431. Each of the lead wires 18 functions to prevent the side wall surface 432 narrower than the outer diameter of the lead wire 18 from coming off, and is held in the bottom wall surface 431 on which each is disposed. Accordingly, the lead wire 18 is surrounded by the protruding portion 411 and is protected from contact with the protection portion 34, the arm portion 33, and the rear end portion 38 of the outer cylinder 3.

[Arrangement process]
As described above, since the mounting jig 400 is made of NBR, the mounting jig 400 is slippery with respect to the lead wire 18 while holding the lead wire 18 on the bottom wall surface 431 of the lead wire holding portion 430. As shown in FIG. 11, when the outer cylinder 3 held integrally with the mounting jig 400 is slid in the extending direction of the lead wire 18, the mounting jig 400 and the outer cylinder 3 are guided by the lead wire 18, It reaches the rear end side of the grommet 9. Since the positional relationship between the outer cylinder 3 and the lead wire 18 is determined by the mounting jig 400 so that the outer cylinder 3 and the lead wire 18 do not come into contact with each other, there is a possibility that the outer cylinder 3 rubs or damages the lead wire 18 during this sliding movement. Absent.

  When the mounting jig 400 and the outer cylinder 3 reach the rear end side of the grommet 9, the arm portion 33 of the outer cylinder 3 is the bottom surface of the groove 93 of the grommet 9 in accordance with the definition of the protruding length of the protruding portion 411 from the base 420. Prior to contacting 94, the front end surface 415 of the mounting jig 400 contacts the rear end facing surface 99 of the grommet 9. At this time, the bottom wall surface 431 of the lead wire holding portion 430 of the mounting jig 400 is guided by the lead wire 18 and connected to the lead wire insertion hole 92 of the grommet 9. Thereby, since the mounting jig 400 is positioned with respect to the grommet 9, the side surfaces 412 of the protrusions 411 are arranged to be connected to the grooves 93 of the grommet 9, and the passage formed by the inner surface 413 is formed on the grommet 9. It is arranged to be connected to the air communication hole 91.

[Shifting process]
Then, as shown in FIG. 12, the outer cylinder 3 is pressed along the axis O in the mounting direction. The protection part 34 of the outer cylinder 3 is guided by the inner surface 413 of the projecting part 411 of the mounting jig 400 toward the atmospheric communication hole 91 of the grommet 9, and the arm part 33 is guided between the side surfaces 412 of each projecting part 411. Then, it goes to each groove 93 of the grommet 9. The arm portions 33 are respectively accommodated in the grooves 93 of the grommet 9, and the protection portion 34 is disposed in a region where the inner periphery of the air communication hole 91 extends in the direction of the axis O on the rear end side of the filter member 87. Then, the air communication hole 91 is closed. At this time, the grommet 9 abuts on the separator 8, and the outer cylinder 3 abuts on the flange portion 81 of the separator 8, so that the arm portion 33 does not abut against the bottom surface 94 of the groove portion 93. The bottom surface 94 of 93 and the gap S are provided. The gap S has a larger distance than the gap T1. This takes into account that the grommet 9 in the subsequent process is swollen and fixed by the outer cylinder 3 so that the grommet 9 swells to the rear end side.

  In the subsequent manufacturing process, the mounting jig 400 is removed, the holding metal fitting 85 is inserted between the outer cylinder 3 and the separator 8, and the outer cylinder 3 is crimped to hold the separator 8 in the outer cylinder 3. Further, the rear end portion 38 of the outer cylinder 3 is caulked to fix the grommet 9 to the outer cylinder 3, and the front end portion 31 of the outer cylinder 3 is engaged with the rear end engaging portion 58 of the metal shell 5, The gas sensor 1 is completed by caulking the periphery of 31 and laser welding.

  As described above, when the outer cylinder 3 is held by the mounting jig 400 in the holding step, the holding portion 410 is disposed on the front side in the mounting direction with respect to the arm portion 33 of the outer cylinder 3, and thereafter The mounting jig 400 can be brought into contact with the grommet 9 before the outer cylinder 3 comes into contact with the bottom surface 94 of the groove portion 93 in the arranging step. And after forming the path | route which guides the arm part 33 and the protection part 34 to the groove part 93 and the air | atmosphere communicating hole 91, respectively, the outer cylinder 3 is engaged with the grommet 9 at a shift process. At this time, the outer cylinder 3 is pressed so that the arm part 33 of the outer cylinder 3 is disposed in the groove 93 of the grommet 9 while separating the protection part 34 and the filter member 87. Thereby, when the filter member 87 is assembled to the grommet 9, the filter member 87 is exposed to the rear side of the groove portion 93 even when the outer cylinder 3 is externally fitted to the grommet 9. Moreover, it can suppress that the protection part 34 of the outer cylinder 3 contacts the grommet 9, and can suppress that the filter member 87 is damaged.

  Further, since the arm portion 33 does not assemble the separator 8, the grommet 9, and the outer cylinder 3 while pressing the bottom surface 94 of the groove portion 93, the groove portion 93 of the grommet 9 contracts by the arm portion 33, and the groove portion 93 in the grommet 9. It is possible to suppress the occurrence of a crack in the groove portion 93 of the grommet 9 due to a difference in shrinkage ratio between the other portion (for example, four portions forming the rear end facing surface 99).

  Further, after the grommet 9 is brought into contact with the separator 8 in the shifting step, the outer cylinder 3 is brought into contact with the flange portion 81 of the separator 8, so that the movement of the outer cylinder 3 and the grommet 9 toward the distal end in the axial direction is performed. Regulation can be achieved by the separator 8. Therefore, when assembling the outer cylinder 3 to the grommet 9 during the shifting process, the arm part 33 of the outer cylinder 3 is formed with only the shape of the separator 8, and the protective part 34 of the outer cylinder 3 does not contact the filter member 87. 9 can be reliably disposed in the groove 93.

  Furthermore, when the holding portion 410 holds the arm portion 33, the outer cylinder 3 can be easily held by the mounting jig 400, and when the outer cylinder 3 is held by the mounting jig 400, It can be easily achieved that the holding portion 410 is arranged more forward than 33 in the mounting direction.

In addition, it cannot be overemphasized that the structure shown by the said embodiment is an illustration, and various changes are possible.
For example, in the first embodiment, the protective portion 34 is provided on the outer cylinder 3, but the present invention is not limited thereto. For example, a modification in which the covering portion 234 is provided on the outer cylinder 203 as described in FIGS. The gas sensor 201 of Example 1 may be used. Of the components constituting the gas sensor 201 of the first modification, the same components as those of the gas sensor 1 are used except for the outer cylinder 203. Therefore, the form of the outer cylinder 203 will be described here, and description of other parts will be omitted or simplified.

  As shown in FIG. 13, the outer cylinder 203 of the gas sensor 201 is formed of stainless steel such as SUS304 in the shape of a bottomed cylinder as in the first embodiment, the bottom portion is cut out, and the arm portion 233 and the covering portion 234 are formed. Formed. As shown in FIGS. 17 and 18, the covering portion 234 has a circular plate shape having an outer diameter substantially the same size as the air communication hole 91 of the grommet 9, and is an opening of the rear end portion 238 that surrounds the outer periphery of the grommet 9. It is supported by two arms 233 extending radially inward from the end 232. The covering portion 234 is not provided with an opening.

  In the gas sensor 201 having such a configuration, the covering portion 234 is disposed so as to cover the atmospheric communication hole 91. For this reason, as shown in FIG. 14, when the gas sensor 201 is viewed from the rear end side along the axis O, it is blocked by the covering portion 234, and the filter member 87 cannot be visually recognized. As a result, the filter member 87 is protected from contact with plants, collision with flying stones, and the like, and damage due to external impact is prevented.

  The two arm portions 233 are disposed in the two groove portions 93 among the four groove portions 93 of the grommet 9. As shown in FIG. 13 and FIG. 14, in the groove portion 93 on the side where the arm portion 233 is not disposed (here, referred to as the groove portion 293 for convenience), the groove portion 93 is provided between the covering portion 234 and the groove portion 293. A gap communicating with the air communication hole 91 is generated. Through this gap, ventilation between the outside and the atmosphere communication hole 91 (that is, ventilation between the inside and outside of the outer cylinder 203) is secured. Of course, the groove portion 93 on the side where the arm portion 233 is disposed also has a gap T3 between the groove portion 93 and the covering portion 234, so that the outside and the air communication hole 91 can be ventilated through this gap. .

  Furthermore, a gap T3 is provided between the arm portion 233 and the bottom surface 94 of the groove portion 93. Thereby, even if the grommet 9 is thermally expanded by heat received from the exhaust pipe, the exhaust gas, or the like and is expanded to the rear end side of the gas sensor 201, the groove portion 93 of the grommet 0 is not caught by the arm portion 233. As a result, a difference in the expansion ratio between the groove 93 in the grommet 9 and other parts is unlikely to occur, and the occurrence of cracks in the groove 93 of the grommet 9 can be suppressed.

  Also in the gas sensor 201 of the first modification, the same manufacturing method (holding process, lead wire holding process, arrangement process, shifting process) as in the first embodiment is performed, which is the same as in the first embodiment. The effect of can be obtained. That is, when the outer cylinder 203 is held by the mounting jig 400 in the holding process, the holding part 410 is arranged on the front side in the mounting direction with respect to the arm part 233 of the outer cylinder 203. The mounting jig 400 can be brought into contact with the grommet 9 before the outer cylinder 203 comes into contact with the bottom surface 94 of the groove portion 93. And after forming the path | route which guides the arm part 233 and the coating | coated part 234 to the groove part 93 and the air | atmosphere communicating hole 91, respectively, the outer cylinder 203 is engaged with the grommet 9 at a shift process. At this time, the outer cylinder 203 is pressed so that the arm portion 233 of the outer cylinder 203 is disposed in the groove 93 of the grommet 9 while separating the covering portion 234 and the filter member 87. Thereby, when the filter member 87 is assembled to the grommet 9, even when the filter member 87 is exposed to the rear side of the groove portion 93 and disposed, the outer cylinder 203 is fitted to the grommet 9. Moreover, it can suppress that the coating | coated part 234 of the outer cylinder 203 contacts the grommet 9, and can suppress that a filter member 87 breaks.

  In the first embodiment and the first modification, the number of the arm portions 33 and 233 supporting the protection portion 34 and the covering portion 234 is four or two, but the protection portion or the covering portion is formed by one arm portion. May be supported. Of course, the number of arms may be three, five, or more. Further, the number of the groove portions 93 of the grommet 9 may be increased or decreased according to the number of the arm portions, or the number of the groove portions 93 may be larger than the number of the arm portions.

Further, in the gas sensor 1 of the first embodiment and 201 of the first modification, the following convex portion 96 may be provided in the groove portion 93 of the grommet 9. The following description will be given as a modification of the gas sensor 1 of the first embodiment, but the same applies to the gas sensor 201 of the modification 1.
Specifically, as shown in FIG. 15, one convex portion 96 is provided from the bottom surface 94 of the groove portion 93 of the grommet 9 toward the rear end side. The convex portion 96 abuts on the arm portion 33 of the outer cylinder 3, and the arm portion 33 and the bottom surface 94 of the groove portion 93 are provided so as to maintain a distance in the axial direction length of the convex portion 96. Thus, by providing the convex part 96 in the grommet 9, the contact between the arm part 33 and the bottom face 94 of the groove part 93 can be further prevented.

In the first embodiment, the protrusions 35 are provided on the protection part 34, but various changes can be made to the shape of the holes.
For example, like the outer cylinder 510 shown in FIG. 16, a large opening 513 may be provided in the protection portion 511, and a mesh member 512 formed by assembling a wire material in a mesh shape may be attached to the opening 513. While the filter member 87 is protected from breakage by the mesh member 512, ventilation through the opening 513 can be ensured.
Moreover, you may provide the some hole 522 in the protection part 521 like the outer cylinder 520 shown in FIG. If the inner diameter of the hole 522 is appropriately set while ensuring ventilation through the hole 522, the filter member 87 is sufficiently large enough to prevent impact from the outside due to contact with plants or collision of flying stones. Can be protected from breakage. Of course, the number of the holes 522 can be changed as appropriate, and if the total opening area is increased by increasing the number of holes, sufficient ventilation can be ensured in the ventilation portion 521.

  Moreover, in the gas sensor 1 of 1st Embodiment and the gas sensor 201 of the modification 1, although the detection element 6 was comprised by the bottomed cylindrical shape, even if it is a plate-shaped detection element, it is not restricted to this. good.

1, 201 ······················································· Lead wire 3, 203 ·············· ... Protection part 35 ... Projection part 4 ... Protector 5 ... Metal fitting 6 ... Detection element 8 ... Separator 81 ... Flange 9 ...・ ・ Grommet 91 ... Air communication hole 92 ... Lead wire insertion hole 93 ... Groove 94 ... ..... Bottom face 95 ..... Side surface 234 ..... Covering part 400 ..... Mounting member

Claims (4)

A detection element that extends in the axial direction and has a detection unit for detecting a gas to be detected on its tip side;
A metallic shell that surrounds the periphery of the detection element in the radial direction while projecting the detection unit from its tip,
A cylindrical outer cylinder that is disposed on the rear end side of the metal shell and whose front end is fixed to the metal shell;
A plug member disposed inside the outer cylinder, with a lead wire insertion hole through which a lead wire for taking out a detection signal of the detection element is inserted, and a filter member having air permeability and waterproofness interposed therebetween A plug member formed so that atmospheric communication holes that enable atmospheric communication between the inside and the outside of the outer cylinder are respectively extended in the axial direction;
In the manufacturing method of the gas sensor provided with
The plug member extends toward the outside in the radial direction avoiding the lead wire insertion hole starting from the atmosphere communication hole on the rear end facing surface side of the plug member, and is notched toward the distal end side of the plug member, A groove having a bottom surface and a side surface;
A protective part that protects the filter member by covering the atmospheric communication hole of the plug member from the rear end side in the axial direction, the protective part having an opening smaller than the opening of the atmospheric communication hole, or the gas sensor A covering portion that protects the filter member by covering the air communication hole of the plug member from the rear end side in the axial direction so that the filter member cannot be visually recognized when viewed from the axial direction, A covering portion that allows ventilation between the inside and the outside of the atmosphere communication hole through a gap with the plug member, and is connected to the protective portion or the cover portion and extends in the radial direction, at least a part of which is the plug member The arm portion disposed in the groove portion is formed of one member with the outer cylinder,
When the outer cylinder is engaged with the outer cylinder from the rear side in the attaching direction to the plug member, the outer cylinder is arranged on the front side in the attaching direction with respect to the arm portion of the outer cylinder. Preparing a mounting jig having a possible holding portion and a lead wire holding portion for positioning the lead wire with respect to the outer cylinder while holding the lead wire slidably in the extending direction,
A holding step of holding the outer cylinder on the mounting jig;
A lead wire holding step of holding the lead wire in the lead wire holding portion of the mounting jig;
The mounting jig integrated with the outer cylinder is slid along the extending direction of the lead wire, and the holding portion of the mounting jig and the plug member are brought into contact with each other. An arrangement step of arranging an arm portion on the rear side of the plug member;
A shifting step of placing the arm portion of the outer cylinder in the groove portion of the plug member while pressing the outer tube in the direction in which the plug member is attached and separating the protective portion or the covering portion from the filter member. When,
A method for producing a gas sensor, comprising: The gas sensor has a cylindrical separator that is disposed on the tip side of the plug member and encloses a connection terminal connected to the lead wire, and the separator includes a flange portion that protrudes radially outward,
2. The method of manufacturing a gas sensor according to claim 1, wherein, in the shifting step, the outer cylinder is brought into contact with the flange portion after being brought into contact with the plug member and the separator.   The said holding | maintenance part engages the said attachment jig | tool with the said outer cylinder from the back side of the attachment direction to the said plug member of the said outer cylinder by clamping the said arm part. The manufacturing method of the gas sensor of Claim 2.   The said plug member has a convex part which protrudes toward the rear end side from the said bottom face of the said groove part, The said arm part contact | abuts to the said convex part. The manufacturing method of the gas sensor of claim | item.