JP4842870B2 - Sensor manufacturing jig and sensor manufacturing method - Google Patents

Description

  The present invention relates to a sensor manufacturing jig for protecting a ventilation filter and a method for manufacturing such a sensor in manufacturing a sensor for introducing outside air into the inside through a ventilation filter.

  Conventionally, a long detection element that detects a component to be measured, a metal shell that holds the detection element, and a rear end portion of the detection element that is disposed on the rear end side of the metal shell and inserted from the front end side opening There is known a sensor including an outer cylinder that accommodates the inside.

  Such a sensor includes a lead wire disposed inside the outer cylinder from the outside of the outer cylinder through the rear end opening of the outer cylinder and connected to the detection element, and a rear end opening of the outer cylinder. An elastic member (hereinafter, referred to as a grommet) that holds the lead wire in a state of covering the periphery of the lead wire in the radial direction is provided.

Among the sensors configured as described above, for example, an oxygen sensor, such as an oxygen sensor, introduces outside air into the sensor, and detects the physical quantity of the measurement object based on the introduced physical quantity of the outside air as a reference. A through hole for introducing outside air into the sensor is provided in the grommet. And the ventilation filter which has air permeability and waterproofness is arrange | positioned so that the rear-end side opening part in this through-hole may be covered. Thereby, ventilation | gas_flowing is ensured, without passing a water | moisture content inside a sensor (for example, refer patent document 1).
JP 2004-53425 A (FIG. 2)

  However, if the above-mentioned ventilation filter is disposed so as to be exposed on the rear end surface of the grommet, a manufacturing worker, a part of the machine, or the like may accidentally contact the ventilation filter during the sensor manufacturing process. was there. That is, there is a risk that scratches and dirt may adhere to the ventilation filter during sensor manufacture.

  The present invention has been made in view of these problems, and an object of the present invention is to provide a sensor manufacturing jig and a sensor manufacturing method that suppress damage and dirt from adhering to a ventilation filter during sensor manufacturing.

In order to achieve the above object, the invention according to claim 1 holds the detection element so that the tip of the detection element extending in the axial direction is exposed to the object to be measured, and the rear end in the axial direction of the detection element is open. A cylindrical casing that extends in the axial direction, and a plurality of lead wires that are disposed inside the casing from the outside of the casing through the opening on the rear end side of the casing and connected to the detection element, and a plurality of leads A first through hole penetrating along the axial direction to insert a plurality of lead wires in a state of covering the circumference of the lead wire in the radial direction, and a second through hole penetrating along the axial direction to introduce outside air And the first through holes are arranged in the circumferential direction in a cross section perpendicular to the axial direction of the elastic member. And The second through-hole is an elastic member formed radially inward of the first through-hole, and a ventilation filter that has air permeability and waterproofness and is disposed so as to cover the second through-hole of the elastic member. A columnar sensor manufacturing jig used when manufacturing a sensor comprising a sensor, wherein the sensor manufacturing jig is mounted on the elastic member rear end surface on the rear end side of the elastic member in which a plurality of lead wires and a ventilation filter are arranged. A main body that covers the second through-hole when placed, and a fitting part that protrudes from the main body and is fitted to the plurality of lead wires by contacting the periphery of the plurality of lead wires in the radial direction with its outer peripheral surface It is a jig for sensor manufacture characterized by having.

  The sensor manufacturing jig configured as described above has a fitting portion to be fitted to the lead wire. For this reason, the sensor manufacturing jig is arranged above the elastic member by fitting the portion of the lead wire extending from the elastic member to the outside of the outer cylinder and the fitting portion of the sensor manufacturing jig. Can be kept in a state.

  The second through hole is disposed so as to be inside the first through hole in a cross section perpendicular to the axial direction, and the sensor manufacturing jig has a main body portion and a fitting portion protruding from the main body portion. Therefore, by fitting the fitting portion with the lead wire, the portion of the ventilation filter that covers the second through hole (hereinafter referred to as the filter hole covering portion) is the main body portion of the sensor manufacturing jig. It can be held in a covered state. For this reason, even if the filter hole covering portion is exposed and arranged on the rear end side of the elastic member, this portion can be protected by the sensor manufacturing jig. As a result, in the state of being placed on the rear end surface of the elastic member, it is possible to prevent a manufacturing worker or a part of the machine from accidentally contacting the filter hole covering portion during the sensor manufacturing process. Scratches and dirt can be prevented from attaching.

  Further, in order to place the sensor manufacturing jig on the rear end surface of the elastic member, it is only necessary to fit the lead wire and the fitting portion, so the member for attaching the sensor manufacturing jig to the sensor Need not be prepared separately. Thereby, an increase in the manufacturing cost of the sensor can be suppressed.

  In addition, the sensor manufacturing jig can be attached by a simple operation of fitting the lead wire and the fitting portion, and the sensor manufacturing jig can be removed by a simple operation of removing the lead wire from the fitting portion. Therefore, the working efficiency of the sensor manufacturing work can be improved, and the sensor manufacturing jig can be easily held.

  Further, in the sensor manufacturing jig according to claim 1, as described in claim 2, the main body portion is for sensor manufacturing when the sensor manufacturing jig is placed on the elastic member rear end surface. It is preferable that the jig and the ventilation filter have a recess that is not in contact with the jig.

  According to the sensor manufacturing jig configured as described above, since the concave portion is disposed above the filter hole covering portion in the state of being placed on the elastic member, the filter hole covering portion is disposed on the sensor manufacturing jig ( Contact with the main body portion) can be suppressed. For this reason, it can suppress that a damage | wound and dirt adhere to a ventilation filter by a contact with the jig | tool for sensor manufacture, or a ventilation filter is damaged.

  By the way, when the surface of the sensor manufacturing jig that can be placed on the elastic member rear end surface is configured to cover substantially the entire elastic member rear end surface of the elastic member, the sensor When the manufacturing jig is placed on the elastic member, there is no portion to be pressed by the elastic member rear end surface when the elastic member is pushed into the rear end opening of the outer cylinder, so the elastic member is directly pressed. I can't. For this reason, it is necessary to push the elastic member through the sensor manufacturing jig, and when the sensor manufacturing jig is made of a soft material, there is a risk that the elastic member cannot be stably applied with force. There is.

  Further, when the sensor manufacturing jig and the elastic member have substantially the same diameter, and the sensor manufacturing jig and the elastic member are configured in the same color, the sensor manufacturing jig is mounted on the holding member. Since the boundary between the tool and the elastic member becomes unclear, it may be difficult to determine how far the elastic member is inserted when the elastic member is inserted.

  Therefore, in the sensor manufacturing jig according to claim 1 or 2, the area in the cross section perpendicular to the axial direction is smaller than that of the elastic member, as described in claim 3. It is good to be.

  According to the sensor manufacturing jig configured as described above, in a state where the sensor manufacturing jig is placed on the elastic member, a portion that is not in contact with the sensor manufacturing jig on the rear end surface of the elastic member ( Hereinafter, this will be referred to as a non-contact portion).

  For this reason, when the elastic member is pushed into the rear end side opening of the outer cylinder, it is possible to push the elastic member by directly pressing the non-contact portion. Thereby, force can be stably applied to the elastic member.

  In addition, since a step is formed at the portion where the sensor manufacturing jig and the elastic member are in contact with each other, the boundary between the sensor manufacturing jig and the elastic member becomes clear, and when the elastic member is pushed in, the elastic member is pushed to how far. Can be easily determined.

  In addition, a sensor is formed in which a groove extending from the outer peripheral portion of the elastic member to the rear end opening of the second through hole is formed on the rear end surface of the elastic member in order to discharge moisture and oil adhering to the ventilation filter to the outside. As a sensor manufacturing jig used for manufacturing the elastic member, as described in claim 4, the elastic member has an opening on the rear end side of the second through hole from the outer peripheral portion of the elastic member to the rear end surface of the elastic member. It is preferable that the sensor manufacturing jig has a convex portion that fits into the groove when placed on the rear end surface of the elastic member.

  According to the sensor manufacturing jig configured as described above, in a state where the jig is mounted on the elastic member, the path from the outside of the sensor to the ventilation filter through the groove is blocked by the convex portion. It is possible to prevent foreign matters from reaching the ventilation filter. Thereby, it can suppress that dirt adheres to a ventilation filter during the manufacturing process of a sensor.

  Furthermore, since the convex part of the sensor manufacturing jig is disposed in the groove of the elastic member in a state of being placed on the elastic member, the sensor manufacturing jig can be stably disposed on the rear end surface of the elastic member. it can.

  Further, in the sensor manufacturing jig according to any one of claims 1 to 4, as described in claim 5, the sensor manufacturing jig includes an elastic member rear end surface on a rear end side of the elastic member. Either one of the upper surface and the lower surface of the self-contacting surface may be brought into contact with the upper surface and the lower surface, and the upper surface and the lower surface may be formed in the same shape.

  According to the sensor manufacturing jig configured as described above, both the upper surface and the lower surface have a shape that can be placed on the elastic member rear end surface. For this reason, an operator who performs the work of placing the sensor manufacturing jig on the elastic member does not need to confirm which of the upper surface and the lower surface is placed on the elastic member rear end surface, The work efficiency can be improved.

Moreover, in the sensor manufacturing jig according to any one of claims 1 to 5, as described in claim 6, the sensor manufacturing jig may be configured in a color different from that of the elastic member.
According to the sensor manufacturing jig configured as described above, whether or not a member different from the elastic member is placed on the elastic member can be easily recognized by color. For this reason, it can suppress that the operator who performs the operation | work which manufactures a sensor forgets to attach or detach the sensor manufacturing jig.

  In addition, when placed on the elastic member, the boundary between the sensor manufacturing jig and the elastic member becomes clear, and it is possible to easily determine how far the elastic member is inserted when the elastic member is inserted. it can.

Next, in order to achieve the above-mentioned object, the invention according to claim 7 holds the detection element so that the tip of the detection element extending in the axial direction is exposed to the object to be measured, and the rear in the own axial direction. An axially extending casing formed with an open end, a plurality of lead wires disposed in the casing from the outside of the casing through the opening on the rear end side of the casing, and connected to the detection element; A first through hole penetrating along the axial direction in order to insert a plurality of lead wires in a state of covering the periphery of the lead wire in a radial direction, and a second through hole penetrating along the axial direction to introduce outside air Is formed, and the first through hole is disposed in the circumferential direction in a cross section perpendicular to the axial direction of the elastic member. With the second The through hole has an elastic member formed radially inward of the first through hole, and has air permeability and waterproofness, and is disposed so as to cover the rear end side opening in the second through hole of the elastic member. A lead wire insertion step of inserting a lead wire into the first through hole through an elastic member in which the air filter is disposed in the second through hole, and a method for manufacturing a sensor comprising: An attachment step of placing the sensor manufacturing jig according to claim 6 on the rear end surface of the elastic member on the rear end side of the elastic member, and pressing the elastic member into the rear end side opening of the casing. It is a sensor manufacturing method characterized by having a process and the process of removing the jig for sensor manufacture .

  According to the sensor manufacturing method configured as described above, it is possible to prevent a manufacturing operator, a part of the machine, or the like from accidentally contacting the filter hole covering portion after inserting the lead wire through the elastic member. It is possible to suppress the scratches and dirt from adhering to the ventilation filter.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view illustrating the entire configuration of an oxygen sensor 1 according to an embodiment to which the present invention is applied, FIG. 2 is a perspective view of a protective cap 100, and FIG. 3 is a cross-sectional perspective view of the upper end of the oxygen sensor 1 and the protective cap 100. FIG.

In the present embodiment, the lower end side of the oxygen sensor 1 in FIG. 1 corresponds to the “sensor front end side” in the present invention, and similarly, the upper end side of the oxygen sensor 1 corresponds to the “sensor rear end side”. .
As shown in FIG. 1, the oxygen sensor 1 is a shaft-shaped ceramic disposed in a detection element 2 and a detection element 2 formed in a hollow shaft shape whose end is closed by a solid electrolyte body mainly composed of ZrO _2. The heater 3 is configured by a casing 4 and the like for housing the internal structure of the oxygen sensor 1 and fixing the oxygen sensor 1 to a mounting portion such as an exhaust pipe.

  Among these, the casing 4 holds the detection element 2 and extends the detection part 25 into the inside of the exhaust pipe or the like, and extends between the upper part of the metal shell 5 and the reference element 2. It is comprised from the outer cylinder 6 which forms gas space.

  The metal shell 5 has a cylindrical main body and supports the detection element 2 from below, a filling member 52 made of talc powder filled in the upper part of the support member 51, and presses the filling member 52 from above. The sleeve 53 and the like to be stored are accommodated inside.

That is, an inwardly protruding step portion 54 is provided on the inner periphery on the lower end side of the metal shell 5, and the support member 51 is locked to the step portion 54 via the packing 55, thereby detecting the detection element. 2 is supported from below. A filling member 52 is disposed between the inner peripheral surface of the metal shell 5 on the upper side of the support member 51 and the outer peripheral surface of the detection element 2, and a cylindrical sleeve 53 and a packing 56 are disposed above the filling member 52. Are inserted into the metal shell 5 in a coaxial manner, and the upper end of the metal shell 5 is crimped inward (downward), so that the filling member 52 is pressurized and filled, whereby the detection element 2 is attached to the metal shell 5. It is firmly fixed against it. In addition, on the outer periphery on the lower end side of the metal shell 5, metal double protectors 57 and 58 having a plurality of holes are attached by welding while covering the protruding portion of the detection element 2.

  And after the lower end opening end part of the outer cylinder 6 is extrapolated to the said metal shell 5 so that the upper opening part of the metal shell 5 may be covered, welding is given to this lower end opening end part from the outside, and the outer cylinder 6 Is attached to the metal shell 5.

  Further, in the vicinity of the upper end opening 61 of the outer cylinder 6, an insulating separator 7 made of ceramic and formed in a cylindrical shape is inserted. The separator 7 has a flange portion 71 projecting outward on the outer peripheral surface near the center in the axial direction, and the lower end surface of the flange portion 71 is placed on the upper portion of the outer tube 6 when the outer tube 6 is crimped from the outside. It is held in the outer cylinder 6 in a locked manner.

  Further, the upper end opening 61 of the outer cylinder 6 has lead wires 21 and 22 connected to the electrodes of the detection element 2 and a pair of lead wires 23 and 24 connected to the ceramic heater 3 (not shown in FIG. 1). Refer to Fig. 3. Note that the lead wire 24 is not shown in Fig. 3 (hereinafter referred to as a heater lead wire), and a seal unit 10 is provided to prevent moisture and oil from entering the oxygen sensor 1. It has been.

  The seal unit 10 includes a cylindrical grommet 11 made of fluoro rubber, a cylindrical insertion member 30 that can be fitted into a through hole 14 that penetrates the center of the grommet 11 in the axial direction, and the cylindrical insertion member 30. From the sheet-like ventilation filter 40 that covers the upper end portion (atmosphere side end portion) and is sandwiched and fixed between the inner peripheral surface of the through hole 14 of the grommet 11 and the outer peripheral surface of the cylindrical insertion member 30. It is configured.

  The grommet 11 is formed with the through hole 14 and four insertion holes 15 (only two are shown in FIG. 1) through which the lead wires 21 and 22 and the heater lead wires 23 and 24 are inserted. Yes. The four insertion holes 15 are disposed so as to surround the through hole 14 disposed in the center.

  Further, four discharge grooves 19 extending in the radial direction from the opening of the through hole 14 are formed on the upper surface 18 of the grommet 11 (see FIG. 3, only two discharge grooves 19 are shown in FIG. 3). The discharge groove 19 is for discharging water and oil adhering to the ventilation filter 40 outward.

Further, the cylindrical insertion member 30 is folded toward the center in the axial direction at the atmospheric end 31 (see FIG. 3), and an atmospheric opening is formed by the folded portion.
The ventilation filter 40 is made of, for example, a porous fiber structure (for example, trade name: product name) obtained by stretching an unfired molded body of polytetrafluoroethylene (PTFE) in a uniaxial direction at a heating temperature higher than the melting point of PTFE. By Gore-Tex (Japan Gore-Tex Co., Ltd.), it is configured as a ventilation filter that blocks the permeation of liquid such as water droplets and allows the permeation of gas (air, water vapor, etc.). Further, an oil repellent coated porous fiber structure (trade name: Oleovent Filter (Japan Gore-Tex Co., Ltd.) (for example, black) can also be used. This can reduce the risk of entering the interior.

  When the grommet 11, the ventilation filter 40 and the cylindrical insertion member 30 are assembled, the cylindrical insertion member is arranged so that the ventilation filter 40 covers the atmospheric side end of the cylindrical insertion member 30 and the outer peripheral surface thereof. 30 and is inserted into the through hole 14 together with the cylindrical insertion member 30 in this state. In this way, the ventilation filter 40 is sandwiched between the outer peripheral surface of the cylindrical insertion member 30 and the inner peripheral surface of the through hole 14, and is fixed in a state where the ventilation path is closed. As a result, the air-side facing surface 41 of the ventilation filter 40 is disposed in a state of being exposed on the upper surface 18 of the grommet 11.

  The seal unit 10 thus formed is arranged inside the upper end opening 61 of the outer cylinder 6, and the grommet 11 is caulked in the radial direction via the outer cylinder 6. In this way, the outer cylinder 6 and the grommet 11 are brought into close contact with each other, and the sealing performance is further ensured. Then, air is introduced into the reference gas space from the atmosphere side through the ventilation path formed inside the cylindrical insertion member 30 while maintaining the air permeability and waterproofness by the ventilation filter 40.

  Next, as shown in FIG. 2, the protective cap 100 is formed in a cylindrical shape using a fluoro rubber having a color (for example, red) different from that of the grommet 11 as a material. The protective cap 100 protrudes from the main body portion 115 and the main body portion 115 to form the outer peripheral surface 101, and leads 21 and 22 (see FIG. 3, only the lead wire 21 is shown in FIG. 3) and heater leads. Four concave fitting portions 111 to be fitted with the wires 23 and 24 (see FIG. 3, only the heater lead wire 23 is shown) extend along the axial direction JH from the upper surface 102 to the lower surface 103. Is formed.

  As shown in FIG. 3, the protective cap 100 has a diameter smaller than the diameter of the grommet 11. A recess 112 is formed in the main body 115 on each of the upper surface 102 and the lower surface 103 of the protective cap 100. The recess 112 is formed such that the diameter of the opening 117 is larger than the diameter of the opening 17 of the through hole 14.

Next, a method for using the protective cap 100 in the manufacturing process of the oxygen sensor 1 will be described.
The protective cap 100 is used after the step of inserting the lead wires 21 and 22 and the heater lead wires 23 and 24 into the insertion hole 15 (hereinafter referred to as the lead wire insertion step) is completed during the manufacturing process of the oxygen sensor 1. The

  That is, after the lead wire insertion process is completed, the upper surface 102 or the lower surface 103 of the protective cap 100 is brought into contact with the upper surface 18 of the grommet 11 and the lead wires 21 and 22 and the heater lead wire are interposed between the four fitting portions 111. By fitting 23 and 24, the main body 115 of the protective cap 100 is placed on the upper surface 102 of the grommet 11 so as to cover the air-side facing surface 41 of the ventilation filter 40 (see FIG. 3). Thereby, the air-side facing surface 41 of the filter 40 is protected by the protective cap 100. In addition, the process of mounting the protective cap 100 on the upper surface 102 of the grommet 11 and attaching it to the oxygen sensor 1 in this way corresponds to the attaching process of the present invention.

  Thereafter, with the protective cap 100 placed on the upper surface 102 of the grommet 11, the grommet 11 is pushed into the inner side of the upper end opening 61 of the outer cylinder 6 and further caulked from the outer side of the outer cylinder 6, thereby 11 is joined to the outer cylinder 6.

Then, after the entire manufacturing process of the oxygen sensor 1 is completed, the protective cap 100 placed on the upper surface 102 of the grommet 11 is removed from the oxygen sensor 1.
In the protective cap 100 configured as described above, a fitting portion 111 that is fitted to the lead wires 21 and 22 and the heater lead wires 23 and 24 (hereinafter simply referred to as lead wires) is formed. For this reason, the part which extended from the grommet 11 in the lead wire to the exterior of the outer cylinder 6 and the fitting part 111 of the protective cap 100 are fitted, so that the protective cap 100 is disposed above the grommet 11. Can be held.

  Further, the protective cap 100 is formed such that at least one of the upper surface 102 and the lower surface 103 can be placed on the upper surface 18 of the grommet 11. For this reason, the lead wire and the fitting portion 111 are placed in a state where the surface (the upper surface 102 or the lower surface 103) that can be placed on the upper surface 18 of the grommet 11 is in contact with the upper surface 18 of the grommet 11. By fitting, the protective cap 100 can be held in a state where it is placed on the grommet 11 (hereinafter also referred to as a grommet-mounted state).

  And since the through-hole 14 is arrange | positioned so that it may become inside the insertion hole 15 in the cross section perpendicular | vertical to the axial direction JH, and the protective cap 100 has the main-body part 115 and the fitting part 111, outer periphery By fitting the fitting portion 111 formed on the surface 101 and the lead wire, the portion of the ventilation filter 40 covering the through hole 14 (hereinafter referred to as the filter hole covering portion) is covered with the protective cap 100. It can be kept in the state. For this reason, even if the filter hole covering portion is disposed on the upper surface 18 of the grommet 11, this portion can be protected by the protective cap 100. Thereby, in the state of being placed on the rear end face of the grommet, it is possible to prevent a manufacturing worker, a part of the machine, or the like from accidentally contacting the filter hole covering portion during the manufacturing process of the oxygen sensor 1. Scratches and dirt can be prevented from adhering to the filter 40.

  Further, in order to place the protective cap 100 on the rear end face of the grommet, the lead wire and the fitting portion 111 need only be fitted, so that a member for attaching the protective cap 100 to the oxygen sensor 1 is separately provided. There is no need to prepare. Thereby, the raise of the manufacturing cost of the oxygen sensor 1 can be suppressed, and the protective cap 100 can be hold | maintained easily.

  In addition, the protective cap 100 can be attached by a simple operation of fitting the lead wire and the fitting portion 111, and the protective cap 100 can be removed by a simple operation of removing the lead wire from the fitting portion 111. Therefore, the work efficiency of the manufacturing operation of the oxygen sensor 1 can be improved.

  Further, a recess 112 is formed in the main body 115 of the protective cap 100. For this reason, since the recessed part 112 is arrange | positioned above the filter hole coating | coated part in the state mounted in the grommet 11, it can suppress that a filter hole coating | coated part contacts the protective cap 100. FIG. For this reason, it can suppress that a damage | wound and dirt adhere to the ventilation filter 40 by contact with the protective cap 100, or the ventilation filter 40 is damaged.

  The protective cap 100 has a diameter smaller than that of the grommet 11. That is, the protective cap 100 is formed to have a smaller area in the cross section perpendicular to the axial direction JH than the grommet 11. Therefore, when the protective cap 100 is placed on the grommet 11, a portion that does not contact the protective cap 100 (hereinafter referred to as a non-contact portion) occurs on the upper surface 18 of the grommet 11. For this reason, when the grommet 11 is pushed into the upper end opening 61 of the outer cylinder 6, the grommet 11 can be pushed in by directly pressing the non-contact portion. Thereby, force can be stably applied to the grommet 11.

  Further, since there is a step at the portion where the protective cap 100 and the grommet 11 abut, the boundary between the protective cap 100 and the grommet 11 becomes clear, and it is easy to see how far the grommet 11 is pushed in when the grommet 11 is pushed in. Can be judged.

  Further, the upper surface 102 and the lower surface 103 of the protective cap 100 are formed in the same shape. Therefore, both the upper surface 102 and the lower surface 103 have a shape that can be placed on the upper surface 18 of the grommet 11. For this reason, an operator who carries out the work of placing the protective cap 100 on the grommet 11 does not need to confirm which of the upper surface 102 and the lower surface 103 has a shape that can be placed on the upper surface 18 of the grommet 11. , Work efficiency can be improved.

  The protective cap 100 is configured in a color different from that of the grommet 11. Therefore, whether or not a member different from the grommet 11 is placed on the grommet 11 can be easily recognized by the color. For this reason, it can suppress that the operator who performs the operation | work which manufactures the oxygen sensor 1 forgets to attach and detach the protective cap 100.

  Further, when the grommet 11 is placed, the boundary between the protective cap 100 and the grommet 11 becomes clear, and when the grommet 11 is pushed in, it can be easily determined how far the grommet 11 is pushed in.

  In the embodiment described above, the oxygen sensor 1 is the sensor according to the present invention, the insertion hole 15 is the first through hole according to the present invention, the through hole 14 is the second through hole according to the present invention, and the grommet 11 is the elastic member according to the present invention. The cap 100 is a jig for manufacturing a sensor according to the present invention, and the discharge groove 19 is a groove according to the present invention.

(Second Embodiment)
A second embodiment of the present invention will be described below with reference to the drawings. In the second embodiment, only parts different from the first embodiment will be described.

4 is a perspective view of the protective cap 200, and FIG. 5 is a cross-sectional perspective view of the upper end of the oxygen sensor 1 and the protective cap 200.
As shown in FIG. 4, the second embodiment is different from the first embodiment in that a convex portion 213 that can be fitted to the discharge groove 19 is formed on the upper surface 202 and the lower surface 203 of the protective cap 200. Is a point.

  Four convex portions 213 are provided on each of the upper surface 202 and the lower surface 203. As shown in FIG. 5, the four convex portions 213 formed on the lower surface 203 are in a state where the lower surface 203 of the protective cap 200 is in contact with the upper surface 18 of the grommet 11 (that is, the protective cap 200 is In a state where it can be fitted to the four discharge grooves 19 (only two discharge grooves 19 are shown in FIG. 5) formed on the upper surface 18 of the grommet 11. Is done. In the present embodiment, the convex portions 213 are arranged at substantially equal intervals along the circumferential direction SH as shown in FIG.

Further, the four convex portions 213 formed on the upper surface 202 are arranged to have the same shape as the lower surface 203.
In the protective cap 200 configured as described above, the path from the outside of the oxygen sensor 1 through the discharge groove 19 to the ventilation filter 40 is blocked by the convex portion 213 in a state of being placed on the grommet 11. For this reason, it is possible to prevent foreign matter from the outside of the oxygen sensor 1 (for example, soot generated during laser welding for joining the grommet 11 and the outer cylinder 6) from reaching the ventilation filter 40. Thereby, it is possible to prevent dirt from adhering to the ventilation filter 40 during the manufacturing process of the oxygen sensor 1.

  Furthermore, since the convex portion 213 of the protective cap 200 is disposed in the discharge groove 19 of the grommet 11 in a state of being placed on the grommet 11, the protective cap 200 can be stably disposed on the upper surface 18 of the grommet 11. .

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, As long as it belongs to the technical scope of this invention, a various form can be taken.
For example, in the present embodiment, the protective cap used in the manufacturing process of the oxygen sensor is shown. However, the present invention is not limited to the oxygen sensor, and may be a sensor that introduces outside air into the sensor through a ventilation filter. That's fine.

  In the present embodiment, the filter hole covering portion is exposed and arranged on the upper surface 18 of the grommet 11. However, the filter hole covering portion may be arranged inside the grommet 11.

Moreover, in this embodiment, although the casing was formed with the metal shell 5 and the outer cylinder 6, an integrally formed casing may be used.
Moreover, in this embodiment, although the attachment process was performed after the lead wire insertion process, and after that, the protective cap 100 was arrange | positioned to the grommet 11 until the whole manufacturing process was complete | finished, but before the whole manufacturing process is complete | finished after an attachment process. It may be removed.

  In the present embodiment, the convex portions 213 are arranged at equal intervals along the circumferential direction SH. However, the convex portions 213 may be fitted into the discharge groove 19 of the grommet 11 and may have a shape that matches the discharge groove of the grommet 11. That's fine. In the present embodiment, four protrusions 213 are formed. However, if the number corresponds to the number of discharge grooves 19 of the grommet 11 (for example, when there are three discharge grooves 19, the protrusions 213 are also three. Pieces) Good.

1 is a cross-sectional view illustrating an overall configuration of an oxygen sensor 1. FIG. It is a perspective view of protective cap 100 of a 1st embodiment. 1 is a cross-sectional perspective view of an upper end portion of an oxygen sensor 1 and a protective cap 100 according to a first embodiment. It is a perspective view of the protective cap 200 of 2nd Embodiment. It is a section perspective view of the upper end part of oxygen sensor 1 of a 2nd embodiment, and protective cap 200.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Oxygen sensor, 2 ... Detection element, 3 ... Ceramic heater, 4 ... Casing, 5 ... Main metal fitting, 6 ... Outer cylinder, 7 ... Separator, 10 ... Seal unit, 11 ... Grommet, 14 ... Through-hole, 15 ... Insertion Hole: 17 ... Opening part, 19 ... Discharge groove, 21,22 ... Lead wire, 23,24 ... Head lead wire, 30 ... Cylinder insertion member, 40 ... Ventilation filter, 100,200 ... Protective cap, 111 ... Fitting Joint part, 112 ... concave part, 213 ... convex part

Claims (7)

A cylindrical casing that extends in the axial direction and that holds the detection element so that the tip of the detection element extending in the axial direction is exposed to the object to be measured, and is formed by opening a rear end of the axial direction in the axial direction. ,
A plurality of lead wires disposed inside the casing from the outside of the casing through the rear end side opening of the casing and connected to the detection element;
A first through-hole penetrating along the axial direction to insert the plurality of lead wires in a state of covering the circumference in the radial direction of the plurality of lead wires, and penetrating along the axial direction to introduce outside air A columnar elastic member formed in the rear end side opening of the casing, wherein the first through hole is in a cross section perpendicular to the axial direction of the elastic member. The hole is arranged in the circumferential direction, and the second through hole is formed on an inner side in the radial direction with respect to the first through hole; and
A columnar sensor manufacturing jig for use in manufacturing a sensor having a breathability and a waterproof property, and comprising a ventilation filter disposed so as to cover the second through hole of the elastic member,
When the sensor manufacturing jig is placed on the elastic member rear end surface on the rear end side of the elastic member where the plurality of lead wires and the ventilation filter are arranged, a main body portion covering the second through hole; A jig for manufacturing a sensor, characterized by having a fitting portion that protrudes from the main body portion and has a plurality of lead wires in the radial direction and its outer peripheral surface being in contact with each other to be fitted into the lead wires. . The said main-body part has a recessed part from which the said sensor manufacture jig | tool and the said ventilation filter become non-contact, when the said sensor manufacture jig | tool is mounted in the said elastic member rear end surface. 1. A sensor manufacturing jig according to 1.   3. The sensor manufacturing jig according to claim 1, wherein an area in a cross section perpendicular to the axial direction is smaller than that of the elastic member. 4. The elastic member has a groove on the rear end surface of the elastic member from the outer peripheral portion of the elastic member to the rear end side opening of the second through hole,
The said sensor manufacturing jig | tool has a convex part fitted to the said groove | channel when mounted in the said elastic member rear end surface. The sensor manufacturing article in any one of Claims 1-3 characterized by the above-mentioned. jig. The sensor manufacturing jig abuts the elastic member rear end surface on the rear end side of the elastic member with any one of its upper surface and lower surface,
The sensor manufacturing jig according to claim 1, wherein the upper surface and the lower surface are formed in the same shape.   The sensor manufacturing jig according to claim 1, wherein the sensor manufacturing jig is configured in a color different from that of the elastic member. A casing extending in the axial direction formed by opening the rear end of the axial direction in the axial direction while holding the detection element so that the tip of the detection element extending in the axial direction is exposed to an object to be measured;
A plurality of lead wires disposed inside the casing from the outside of the casing through the rear end side opening of the casing and connected to the detection element;
A first through-hole penetrating along the axial direction to insert the plurality of lead wires in a state of covering the circumference in the radial direction of the plurality of lead wires, and penetrating along the axial direction to introduce outside air A columnar elastic member formed in the rear end side opening of the casing, wherein the first through hole is in a cross section perpendicular to the axial direction of the elastic member. The hole is arranged in the circumferential direction, and the second through hole is formed on an inner side in the radial direction with respect to the first through hole; and
A ventilation filter that is breathable and waterproof, and is disposed so as to cover a rear end side opening in the second through-hole of the elastic member.
The lead wire insertion step of inserting the lead wire into the first through hole, the elastic member in which the ventilation filter is disposed in the second through hole, and any one of claims 1 to 6. A mounting step of placing the sensor manufacturing jig on the rear end surface of the elastic member on the rear end side of the elastic member; a step of pressing the elastic member into the rear end side opening of the casing; and the sensor manufacturing And a step of removing the jig . A method for manufacturing a sensor.

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