JP2006162597A - Gas sensor unit and sensor cap - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas sensor unit capable of making an inner space gas-permeable and watertight with respect to an outside, and a sensor cap, in the gas sensor unit which has a gas sensor and which has the sensor cap, having a cap terminal for connecting a sensor terminal of the gas sensor and having an envelope member for surrounding the inner space, in cooperative manner with the gas sensor. <P>SOLUTION: This gas sensor unit 300 is provided with the gas sensor 100 having a gas detecting element 120 and the sensor terminal 150, and the sensor cap 200 having the cap terminal 210 connected to the sensor terminal 150 and having a coating member 220 comprising rubber. The sensor cap 200 is a filter member 240, having gas permeability and water repellency and closes a communication hole 223d to make an outside space SPO gas-permeable and watertight with respect to the inner space SPI. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a gas sensor unit that combines a gas sensor having a gas detection element and a sensor cap that is attached to the gas sensor and transmits the output of the gas sensor to the outside, and a sensor cap.

  Conventionally, various gas sensors having gas detection elements have been proposed. Examples of these gas sensors include those having a gas detection element made of oxygen ion conductive zirconia ceramic and attached to an exhaust pipe of an internal combustion engine to detect the oxygen concentration in the exhaust (for example, patents). Reference 1 and Patent Reference 2).

Japanese Utility Model Publication No. 53-95884 Japanese Utility Model Publication No. 53-95886

  The gas sensors of Patent Literature 1 and Patent Literature 2 have a bottomed cylindrical gas detection element made of ceramic, and a cylindrical sensor terminal that outputs an output signal from the gas detection element to the outside. In these gas sensors, an output signal is transmitted to the outside (for example, ECU) through a connection terminal connected to the sensor terminal, and a reference gas (outside air) is introduced inside the gas detection element through the cylinder of the sensor terminal. The sensor terminal is ventilated and the inside of the gas detection element is ventilated.

In such a gas sensor that sends a signal output by connecting a sensor terminal to a connection terminal, a cap that covers the connection terminal (cap terminal) and the sensor terminal in order to protect the sensor terminal or connect to the sensor terminal. There is a case where a sensor cap having a surrounding member is required.
In such sensor caps, in addition to the introduction of reference gas from the outside, abnormal changes in the reference gas concentration due to gas generation from the gas sensor or foreign matter that has entered the sensor cap, corrosion of the sensor terminal and cap terminal, etc. In order to prevent this, it is sometimes required to provide a communication hole with the external space in order to quickly ventilate the internal space composed of the gas sensor and the sensor cap.
On the other hand, there is a case where it is required to make this internal space watertight in order to prevent a short circuit or corrosion of the sensor terminal and the cap terminal due to water droplets or the like entering the internal space from the outside.

  The present invention has been made in view of such a situation, and includes a sensor cap having a gas sensor, a cap terminal connected to the sensor terminal of the gas sensor, and an enclosing member surrounding the internal space with the gas sensor. It is an object of the present invention to provide a gas sensor unit and a sensor cap that can be ventilated between the internal space and the outside and are watertight.

  The solution is a gas sensor having a gas detection element and a sensor terminal connected to an electrode formed on the gas detection element and transmitting an output signal from the gas detection element, and a sensor cap coupled to the gas sensor. And a cap terminal that is electrically connected to the sensor terminal, and an enclosure member that is coupled to the gas sensor and forms an internal space with the gas sensor, and transmits the output signal to an external device. A gas sensor unit including a cap, wherein the surrounding member includes a communication hole that communicates the outside and the internal space, and the sensor cap is a filter member having air permeability and water repellency, And a gas sensor unit having a filter member that can ventilate between the internal space and the water tightly.

In the gas sensor unit of the present invention, the sensor cap includes an enclosure member having a communication hole and a filter member that closes the communication hole, and the internal space and the outside can be ventilated and watertightly closed.
For this reason, it is easy to ventilate the internal space while preventing water droplets from entering the internal space. Therefore, when the air in the internal space is used as the reference gas for the gas detection element, the outside air can be easily introduced into the internal space. In addition, because the internal space can be quickly ventilated, the output accompanying abnormal changes in the reference gas concentration due to gas generation from foreign matter adhering to the inside of the gas detection element, sensor terminal, cap terminal, or surrounding member Abnormality and corrosion of sensor terminals and cap terminals can be prevented.

In addition, as a form of a gas detection element, a plate-like thing can also be used besides a bottomed cylindrical thing. An appropriate material can be used according to the gas to be detected. For example, in the oxygen sensor, a fixed electrolyte body mainly made of zirconia ceramic can be used.
In addition to the gas detection element and the sensor terminal, the gas sensor may have a cylindrical envelope made of an insulating material and surrounding the sensor terminal.

  The surrounding member is coupled to the gas sensor and forms an internal space with the gas sensor. For example, the inner space is configured in close contact with the outer peripheral surface of the gas detection element or the outer peripheral surface of the sensor terminal. In addition, for example, as described above, the internal space may be configured in close contact with another member constituting the gas sensor, such as an enclosure surrounding the sensor terminal.

The filter member may have any form as long as it has air permeability and water repellency, can ventilate between the outside and the internal space, and closes the communication hole in a watertight manner. The filter member can be positioned at least one of the outside, the inside, and the inside of the communication hole than the communication hole of the surrounding member.
Moreover, as a filter member, according to the form at the time of closing a communicating hole, things, such as a sheet form, tube shape, cup shape, or a rod shape, can be used suitably. For example, Gore-Tex (trade name) and the like can be cited as sheet-like, tube-like, and cup-like ones. In addition, as a rod-shaped material, a polytetrafluoroethylene (PTFE) powder is compression-molded while leaving a void, and is heated to integrate the powders, and the continuous porous material in which fine pores are continuous three-dimensionally What has a structure can be used.
Specifically, a filter member made of a water-repellent material that is sheet-like and has air permeability in the thickness direction, covers the communication hole from the outside of the surrounding member, and fixes the sheet-like filter member to the outer peripheral surface of the surrounding member Is mentioned.
Moreover, the form which packed and fixed the rod-shaped filter member which consists of a water-repellent material which has air permeability at least in the axial direction of a communicating hole in the communicating hole is mentioned. Or the form which inserted and fixed the filter member which extended | stretched the filter film which has air permeability and water repellency in the thickness direction in the direction which cross | intersects the axial direction of a communicating hole is mentioned.
Further, the filter member is made of a water-repellent material that is sheet-like and breathable in the thickness direction, covers the communication hole from the inside of the surrounding member, that is, from the inner space side, and the sheet-like filter member is placed on the inner peripheral surface of the surrounding member. The form to fix is mentioned. Alternatively, a rod-shaped filter member made of a water-repellent material having air permeability at least in the axial direction of the communication hole may be brought into contact with the periphery of the communication hole so as to cover the communication hole from the inner space side.
Furthermore, the filter member is made of a water-repellent material that is sheet-like and has air permeability in the thickness direction. The filter member is pushed together with the metal pipe into the communication hole so as to block one opening of the metal pipe that is open at both ends. The filter member is deformed into a cup shape while being supported by a metal pipe, and the filter member is held between the outer peripheral surface of the metal pipe and the inner peripheral surface of the communication hole.

  Further, in the gas sensor unit, at least one of the surrounding member and the filter member is made of an elastic material, and the inner wall surface of the communication hole of the surrounding member and the outer surface of the filter member are elastic. And a gas sensor unit in close contact with water.

  In the gas sensor unit of the present invention, due to the elasticity of at least one of the surrounding member and the filter member, the inner wall surface of the communication hole of the surrounding member and the outer surface of the filter member are in elastic and watertight contact. Thereby, watertightness can be improved also between the inner wall surface of a communicating hole, and the outer surface of a filter member.

An example of the elastic material forming the surrounding member is a polymer material having elasticity. However, it is preferable to select an appropriate material in consideration of the heat resistance and elasticity of the surrounding member. Further, in consideration of ease of deformation, it is preferable to use a polymer material having rubber elasticity. Specifically, materials such as neoprene rubber, chloroprene rubber, silicon rubber, and fluorine rubber can be used. When heat resistance is required, it is preferable to use fluorine rubber.
An example of the elastic material forming the filter member is a sponge such as urethane foam.

  Further, in the gas sensor unit according to claim 1, the filter member is made of a water-repellent material having air permeability in at least the axial direction of the communication hole, and has an outer peripheral contact portion that forms a column shape extending in the axial direction. The surrounding member is made of a polymer material having elasticity, and by its own elasticity, the inner wall surface of the communication hole is brought into close contact with the outer peripheral contact portion of the filter member to hold the filter member watertight. A unit.

  When holding the filter member in the communication hole, a caulking member made of metal is externally fitted from the outer peripheral surface of the surrounding member in the radial direction of the communication hole, and the enclosure member is caulked, and the filter member is inserted into the communication hole. It can also be set as the structure which hold | maintains. However, with this configuration, the filter member and the surrounding member generally have a higher coefficient of thermal expansion than the caulking member made of metal. Therefore, when the temperature rises, the filter member and the surrounding member expand according to the coefficient of thermal expansion. Therefore, the filter member is plastically deformed, and the outer diameter of the outer peripheral contact portion is slightly reduced. On the other hand, when the temperature is low, the filter member is greatly contracted, so that the outer diameter is reduced by plastic deformation, and there is a possibility that the water tightness may be reduced between the outer peripheral surface of the outer peripheral contact portion and the inner wall surface of the communication hole of the surrounding member. is there.

On the other hand, in the gas sensor unit of the present invention, even if it is exposed to a high temperature, it is not limited by thermal expansion by the caulking member, so that the outer diameter is hardly reduced due to plastic deformation, and deterioration of water tightness is prevented. The
In addition, in this gas sensor unit, ventilation (ventilation) can be ensured by the air permeability of the filter member in the axial direction, and the filter member is closely contacted with the surrounding member at the outer peripheral contact portion of the filter member. Water-tightness can be maintained even at the interface. Further, the surrounding member holds the filter member by the elasticity of the surrounding member. For this reason, only the filter member is sufficient as the filter member, which is preferable because the number of parts is reduced.

  The surrounding member is made of a polymer material having elasticity, and an appropriate material may be selected in consideration of the heat resistance and elasticity of the surrounding member. In view of ease of deformation, it is preferable to use a polymer material having rubber elasticity. Specifically, materials such as neoprene rubber, chloroprene rubber, silicon rubber, and fluorine rubber can be used. When heat resistance is required, it is preferable to use fluorine rubber.

  The gas sensor unit according to claim 3, wherein the surrounding member is an annular protruding portion that protrudes inwardly at a portion forming the inner wall surface of the communication hole, and is included in the filter member. The gas sensor unit may include a protruding portion that is in close contact with a part of the outer peripheral surface of the outer peripheral contact portion.

  In the gas sensor unit of the present invention, the surrounding member is an annular projecting portion projecting inwardly at a portion forming the inner wall surface of the communication hole, and is in close contact with a part of the outer peripheral surface of the outer peripheral contact portion of the filter member. Protrusions are provided. That is, the inner wall surface forming the communication hole of the surrounding member is not closely attached to the entire outer peripheral surface of the outer peripheral contact portion of the filter member, but the annular protrusion of the inner wall surface is closely attached to the outer peripheral surface of the outer peripheral contact portion. The outer peripheral contact portion is in close contact with a part of the outer peripheral surface. Thereby, the adhesive force of the inner wall surface which makes the communicating hole of the surrounding member with respect to the outer peripheral surface of an outer periphery contact | adherence part can be improved, and the watertightness between both can be improved.

  Further, in the gas sensor unit according to claim 3 or 4, the filter member includes a smoothing treatment performed on an outer peripheral surface of the outer peripheral contact portion that is in contact with an inner wall surface of the communication hole of the surrounding member. It is preferable to use a gas sensor unit.

  In the gas sensor unit of the present invention, the outer peripheral surface of the outer peripheral contact portion of the filter member is smoothed. For this reason, compared with the case where it is not smooth | blunted, it becomes easy to closely_contact | adhere to the inner wall face of a communicating hole, and the water-tightness in this part can be improved more.

In addition, as the smoothing process, it is only necessary that the outer peripheral surface of the outer peripheral contact portion is smooth with a lower surface roughness than before the processing, and specifically, the outer peripheral contact portion of the outer peripheral surface of the filter member. It is only necessary that the surface roughness is lower than that of a porous outer peripheral surface other than the above or an axial end surface.
As a specific method of the smoothing process, there is a method of smoothing the outer peripheral surface by heating the outer peripheral surface of the outer peripheral contact portion of the filter member to melt the outer peripheral surface and its vicinity in the radial direction.
More specifically, a method of smoothing the outer peripheral surface by bringing the outer peripheral surface of the outer peripheral contact portion of the filter member into contact with the heated surface and melting the outer peripheral surface and its vicinity in the radial direction can be mentioned.

  Further, in the sensor cap, in order to prevent the filter member from being removed from the surrounding member, the communication hole is formed outside the inner wall surface holding the filter member and is smaller in diameter than the outer peripheral contact portion of the filter member. It is more preferable that the outer portion is formed and has an outer projecting portion that projects toward the axis of the communication hole. This is because the risk of the filter member coming off from the communication hole and falling off can be prevented by the outer projecting portion.

  Furthermore, if the above-mentioned form is made a superordinate concept, the gas sensor unit according to any one of claims 2 to 5, wherein the surrounding member is configured such that the filter member is detached outside through the communication hole. The gas sensor unit may be provided with a detachment preventing portion for preventing the above.

  In the gas sensor unit of the present invention, the surrounding member includes a separation preventing unit that prevents the filter member from separating through the communication hole. For this reason, there is no possibility that the filter member is detached outside through the vent hole.

  Furthermore, it is a gas sensor unit as described in any one of Claims 2-6, Comprising: The said sensor cap is connected with the said cap terminal, The lead wire which sends out the said output signal to the exterior is provided, The said filter The member may include a lead insertion hole that penetrates along the axis of the communication hole and passes through the lead wire, and the lead wire may be a gas sensor unit that is watertightly held by the filter member.

In the gas sensor unit of the present invention, the filter member includes a lead insertion hole, and the lead wire is watertightly held by the filter member. By adopting such a configuration, ventilation between the outside and the internal space is possible through the communication hole of the surrounding member, and the lead wire can be taken out to the outside through the communication hole.
For this reason, an insertion hole for leading the lead wire to the outside is separately provided in the surrounding member, and the lead wire is inserted into the insertion hole and held, and further, the water tightness between the lead wire and the surrounding member in this portion is maintained. Therefore, it is not necessary to provide a separate structure. Therefore, the gas sensor unit can be constructed with a simple structure and at a low cost.

In addition, as a method of holding the lead wire with the filter member, among the columnar filter member, the lead insertion hole is surrounded, and the caulking member is placed in a portion (lead caulking portion) that is different from the outer peripheral contact portion in the axial direction. Can be externally fitted and crimped to reduce the diameter of the lead crimping portion and the lead insertion hole in the lead crimping portion, and hold the lead wire at the lead crimping portion. In this case, in order to further hold the lead wire in the filter member in a water-tight manner, for example, when the caulking member is externally fitted to the lead caulking portion and caulked, a method of caulking strongly enough to be water-tight or a separate lead There is a technique of sealing between the wire and the outer surface of the filter member or the inner wall surface of the lead insertion hole with a sealing material such as an adhesive.
In addition, as a method of holding the lead wire, a method of fixing the lead wire to the inner wall surface of the lead insertion hole using an adhesive or fixing the lead wire to the outer surface of the filter member can also be mentioned. In this case, in order to hold the lead wire in a watertight manner on the filter member, it is preferable to consider the application amount and location of the adhesive so as to have watertightness.

However, as described above, when the lead crimping portion is crimped with a crimping member and the lead wire is held in the lead insertion hole, depending on the degree of diameter reduction of the lead crimping portion due to crimping, There is a case where the air permeability in the axial direction at the lead crimping portion is insufficient or the air permeability is lost.
Therefore, when holding the lead wire in the lead insertion hole by crimping the lead crimping portion with a crimping member, it is possible to ventilate between the outside and the internal space without going through the lead crimping portion. It is preferable to consider the form of the filter member or the direction in which ventilation is possible so that the ventilation path is formed.
For example, with respect to a filter member having air permeability in the axial direction of the communication hole, in addition to the outer peripheral close contact portion having a relatively large columnar shape, the outer peripheral close contact portion is different in diameter from the outer peripheral close contact portion in the axial direction. A shape with a small diameter portion is preferable. In the filter member of this form, even if a small diameter portion or a position farther from the outer peripheral contact portion than the small diameter portion is crimped as the lead crimping portion, the diameter is between the outer peripheral contact portion and the small diameter portion. Ventilation is possible between the surface caused by the difference (specifically, an annular surface orthogonal to the axis, a tapered surface, etc.) and the surface on the opposite side of the outer diameter close contact portion from the small diameter portion. is there. Therefore, if the filter member is arranged in the communication hole of the surrounding member so that one of these surfaces faces the outside and the other faces the internal space, the air permeability of the lead crimping portion is increased or decreased. Sex can be secured.
Alternatively, the filter member has air permeability in the axial direction of the communication hole, and is provided with an intermediate ventilation portion positioned between the columnar outer peripheral contact portion and the lead crimping portion, and at least in the intermediate ventilation portion, A filter member that allows ventilation through the outer peripheral surface can also be used. In this filter member, even if the lead crimping portion is crimped, the outside of the outer peripheral surface of the intermediate ventilation portion and the inside of the outer peripheral contact portion can be ventilated. Ventilation is possible between the fastening part (intermediate ventilation part) and the opposite surface. Therefore, if the filter member is arranged in the communication hole of the surrounding member so that one of these surfaces faces the outside and the other faces the internal space, the air permeability of the lead crimping portion is increased or decreased. Sex can be secured.

  8. The gas sensor unit according to claim 7, wherein the sensor cap includes a caulking member, and the filter member includes a columnar outer peripheral contact portion extending in the axial direction and the outer peripheral contact portion. A lead crimping portion that is located in a different part in the axial direction and is smaller in diameter than the outer peripheral contact portion, and the lead crimping portion is externally fitted and crimped into the lead insertion hole, A gas sensor unit in which the lead wire is held watertight may be used.

In the gas sensor unit of the present invention, the filter member includes a lead crimping portion. Then, a caulking member is fitted onto the lead caulking portion and caulked to hold the lead wire in a lead insertion hole in a watertight manner. For this reason, in addition to being able to send an output signal to the outside through the lead wire, it is possible to prevent water from entering the internal space between the outer peripheral surface of the lead wire and the inner peripheral surface of the lead insertion hole of the filter member. Can do.
Furthermore, this filter member has air permeability at least in the axial direction of the communication hole, and has an outer peripheral contact portion and a lead crimping portion having a smaller diameter. For this reason, since the lead caulking portion with a small diameter is caulked with a caulking member, even if the air permeability decreases or disappears at this lead caulking portion, at least the large diameter outer periphery contact portion and the small diameter lead caulking portion The air permeability between the surface caused by the difference in diameter with the tightening portion and the surface on the opposite side of the lead crimping portion of the outer peripheral contact portion is maintained.
Thus, in the gas sensor unit of the present invention, while the lead wire is inserted through the filter member, while ensuring ventilation through the communication hole, the filter member and the surrounding member, and between the filter member and the lead wire are watertight, It is possible to prevent water from entering the internal space.

  Furthermore, it is a gas sensor unit as described in any one of Claims 1-8, Comprising: The said surrounding member is good to be a gas sensor unit which consists of fluororubber.

In general, a gas detection element such as an oxygen sensor has a characteristic of operating in a high-temperature environment (for example, 300 ° C. or higher). Therefore, the gas detection element is inserted into an exhaust pipe and heated by exhaust gas or heated by a heater. Many things are designed to work. Therefore, it is desirable to use a material that has heat resistance and is unlikely to be thermally deteriorated as the surrounding member.
On the other hand, in the gas sensor unit of the present invention, the fluorocarbon rubber is used for the surrounding member, so that the heat resistance is high, the thermal deterioration is difficult, and the internal space can be kept watertight for a long time.

  Furthermore, it is a gas sensor unit as described in any one of Claims 1-9, Comprising: The said communicating hole contains multiple opening opened to the exterior, The said filter member is either of these opening from said outside. It is preferable that the gas sensor unit is disposed at a position where it cannot be visually recognized.

  2. Description of the Related Art In recent years, high-pressure washing machines that spray water pressurized to high pressure from nozzles at high speed have become widespread as apparatuses for washing automobiles and the like. For this reason, when the gas sensor unit arranged at a position where the filter member can be visually recognized from the outside through the opening of the communication hole is mounted on the vehicle and washed with a high-pressure washing machine, the high-speed water directly flows into the filter member. As a result, water pressure exceeding the water pressure resistance of the filter member is applied to the filter member, and there is a possibility that water drops may pass through the filter member.

  On the other hand, in the gas sensor unit of the present invention, the filter member is disposed at a position where it cannot be visually recognized through any opening from the outside. For this reason, even if water enters at high speed through the opening from the outside, it is difficult for the high speed water to reach the filter member directly. That is, water entering at high speed from the outside through the opening can collide with the wall surface forming the communication hole of the surrounding member before reaching the filter member, and the momentum (speed) can be reduced. Therefore, even when water enters at high speed through the opening of the communication hole from the outside, the water can be prevented from passing through the filter member.

  By the way, even if the filter member is arranged at a position where it cannot be visually recognized from the outside through the opening, when only one opening is provided, if the water continues to enter from the opening at a high speed, the inside of the communication hole will eventually be filled with water. It will be satisfied. In this state, when water enters at high speed from the opening, water pressure equivalent to that when high-speed water directly reaches the filter member is applied to the filter member, and there is a possibility that water droplets may permeate the filter member. It was.

On the other hand, in the gas sensor unit of the present invention, a plurality of communication hole openings are provided. Thereby, even if water enters at a high speed from one opening, the water can be discharged to the outside from the other opening, so there is no possibility that high water pressure is applied to the filter member, and the above-described problems can be prevented.
As described above, in the gas sensor unit of the present invention, even when water enters at high speed through the opening of the communication hole from the outside, the water can be prevented from passing through the filter member.

  Furthermore, it is a gas sensor unit as described in any one of Claims 1-10, Comprising: The said gas detection element is a gas detection element using the reference gas introduce | transduced into the said interior space through the said communicating hole from the exterior. In addition, a gas sensor unit may be provided in which a ventilation path that guides the reference gas introduced from the outside to the gas detection element is formed between the filter member and the gas detection element.

  In the gas sensor unit of the present invention, a gas detection element that uses a reference gas introduced from the outside through a communication hole is used as a gas detection element, and an air passage that guides the reference gas introduced from the outside from the filter member to the gas detection element. Provided. For this reason, in the gas sensor unit of the present invention, the gas to be detected can be appropriately detected using the reference gas introduced from the outside.

  Furthermore, in the gas sensor unit according to claim 11, when the relative movement direction of the gas sensor when the sensor cap and the gas sensor are combined is a first movement direction, the cap terminal is A cylindrical portion having a cylindrical shape extending in the first movement direction, the first cylindrical portion having a cylindrical portion constituting a part of the air passage, and located on the first movement direction side of the cylindrical portion. The moving direction side portion includes an inner surface of the surrounding member, an abutting portion that abuts in the first moving direction, and a separating portion that is separated from the inner surface of the surrounding member, and the sensor cap includes the separating of the cap terminal. It is preferable that the gas sensor unit is configured to introduce the reference gas into the cylindrical portion through a portion and an inner surface of the surrounding member.

  In the gas sensor unit of the present invention, the first movement direction side portion located on the first movement direction side of the cylindrical portion of the cap terminal includes a contact portion that contacts the inner surface of the surrounding member in the first movement direction. . Thereby, in the gas sensor unit of this invention, even when a vibration etc. apply, it can prevent reliably that the cap terminal connected with the sensor terminal moves to a 1st movement direction.

Moreover, the first movement direction side portion of the cylindrical portion of the cap terminal also includes a separation portion that is separated from the inner surface of the surrounding member. As a result, the sensor cap can introduce the reference gas taken in from the communication hole into the cylindrical portion through the gap between the cap terminal and the inner surface of the surrounding member. Therefore, in the gas sensor unit of the present invention, the reference gas can be appropriately guided to the gas detection element via the inside of the cylindrical portion.
Examples of the cylindrical portion include a cylindrical cylindrical portion, and a cylindrical portion in which an annular annular portion is integrally connected to the first moving direction side end of the cylindrical portion. Can do. In the latter cylindrical portion, a portion of the annular annular portion that contacts the inner surface of the surrounding member is a contact portion, and a portion that is separated from the inner surface of the surrounding member is a separation portion.

  The other solution is coupled to a gas sensor having a gas detection element and a sensor terminal connected to an electrode formed on the gas detection element to transmit an output signal from the gas detection element. A sensor cap that is transmitted to the apparatus, wherein the cap terminal is electrically connected to the sensor terminal; and the cap terminal is received between the gas sensor and the gas sensor when the sensor cap is coupled to the gas sensor. An enclosing member that forms a cap terminal accommodating space that forms an internal space, the enclosing member including a communication hole that communicates the outside and the cap terminal accommodating space, and has air permeability and water repellency. A sensor cap having a filter member capable of ventilating between the cap terminal housing space and water-tightly closing the communication hole.

The sensor cap of the present invention has an enclosing member having a communication hole and a filter member that closes the communication hole, and allows the cap terminal accommodating space and the outside to be ventilated to close the communication hole in a watertight manner.
For this reason, when this sensor cap is combined with the gas sensor, it is easy to ventilate the internal space while preventing water droplets from entering the internal space. Therefore, when the air in the internal space is used as the reference gas for the gas detection element, the outside air can be easily introduced into the internal space. In addition, because the internal space can be quickly ventilated, the output accompanying abnormal changes in the reference gas concentration due to gas generation from foreign matter adhering to the inside of the gas detection element, sensor terminal, cap terminal, or surrounding member Abnormality and corrosion of sensor terminals and cap terminals can be prevented.

  14. The sensor cap according to claim 13, wherein at least one of the surrounding member and the filter member is made of a material having elasticity, and an inner wall surface of the communication hole of the surrounding member and an outer surface of the filter member. Is preferably a sensor cap that is elastically and in watertight contact.

  In the sensor cap of the present invention, due to the elasticity of at least one of the surrounding member and the filter member, the inner wall surface of the communication hole of the surrounding member and the outer surface of the filter member are in elastic and watertight contact. Thereby, watertightness can be improved also between the inner wall surface of a communicating hole, and the outer surface of a filter member.

  14. The sensor cap according to claim 13, wherein the filter member is made of a water-repellent material having air permeability in at least the axial direction of the communication hole and has a columnar outer peripheral contact portion extending in the axial direction. The surrounding member is made of a polymer material having elasticity, and by its own elasticity, the inner wall surface of the communication hole is brought into close contact with the outer peripheral contact portion of the filter member to hold the filter member watertight. A sensor cap is preferable.

  When holding the filter member in the communication hole, a caulking member made of metal is externally fitted from the outer peripheral surface of the surrounding member in the radial direction of the communication hole, and the enclosure member is caulked, and the filter member is inserted into the communication hole. It can also be set as the structure which hold | maintains. However, with this configuration, due to the difference in thermal expansion coefficient between the caulking member, the filter member and the surrounding member, plastic deformation of the outer peripheral contact portion of the filter member occurs, and the outer peripheral surface of the outer peripheral contact portion and the communication hole of the surrounding member There is a risk that the watertightness between the wall surface and the wall surface may decrease.

On the other hand, the sensor cap of the present invention is not limited by thermal expansion by the crimping member even when exposed to high temperatures, and therefore, the outer diameter is hardly reduced due to plastic deformation, and the water tightness is prevented from being lowered. The
In addition, in this sensor cap, ventilation (ventilation) can be ensured by the air permeability of the filter member in the axial direction, and the outer peripheral contact portion of the filter member is in close contact with the surrounding member without any gap. Watertightness can be maintained even at the interface with the member. Further, the surrounding member holds the filter member by the elasticity of the surrounding member. For this reason, only the filter member is sufficient as the filter member, and the number of parts of the sensor cap is preferably reduced.

  Furthermore, it is a sensor cap of Claim 15, Comprising: The said surrounding member is a cyclic | annular protrusion part which protrudes toward the inner side in the site | part which makes the said inner wall face of the said communicating hole, Comprising: Among the said filter members It is preferable that the sensor cap includes a protruding portion that is in close contact with a part of the outer peripheral surface of the outer peripheral contact portion.

  In the sensor cap of the present invention, the surrounding member is an annular projecting portion projecting inwardly at a portion forming the inner wall surface of the communication hole, and is closely adhered to a part of the outer peripheral surface of the outer peripheral contact portion of the filter member. Protrusions are provided. That is, the inner wall surface forming the communication hole of the surrounding member is not closely attached to the entire outer peripheral surface of the outer peripheral contact portion of the filter member, but the annular protrusion of the inner wall surface is closely attached to the outer peripheral surface of the outer peripheral contact portion. The outer peripheral contact portion is in close contact with a part of the outer peripheral surface. Thereby, the adhesive force of the inner wall surface which makes the communicating hole of the surrounding member with respect to the outer peripheral surface of an outer periphery contact | adherence part can be improved, and the watertightness between both can be improved.

  Furthermore, it is a sensor cap of Claim 15 or Claim 16, Comprising: As for the said filter member, the outer peripheral surface contact | abutted to the inner wall surface of the said communicating hole of the said surrounding member among the said outer periphery close_contact | adherence parts is a smoothing process. It is preferable to use a sensor cap.

  In the sensor cap of the present invention, the outer peripheral surface of the outer peripheral contact portion of the filter member is smoothed. For this reason, compared with the case where it is not smooth | blunted, it becomes easy to closely_contact | adhere to the inner wall face of a communicating hole, and the water-tightness in this part can be improved more.

  Furthermore, it is a sensor cap as described in any one of Claims 14-17, Comprising: The said surrounding member is a sensor provided with the removal prevention part which prevents that the said filter member separates outside through the said communicating hole. A cap is recommended.

In the sensor cap of the present invention, the surrounding member includes a separation preventing portion that prevents the filter member from separating through the communication hole. For this reason, there is no possibility that the filter member is detached outside through the vent hole.
Here, examples of the detachment preventing portion include a portion located on the outer end side of the communication hole from the filter member among the portions forming the communication hole of the surrounding member. Specifically, the inner diameter smaller than the inner diameter of the inner wall surface of the communication hole that is located on the outer end side of the communication hole than the filter member and is in close contact with the outer peripheral contact portion of the filter member, in the portion forming the communication hole of the surrounding member The site | part which has can be illustrated.

  Furthermore, it is a sensor cap as described in any one of Claims 14-18, Comprising: The lead wire which connects to the said cap terminal and sends out the said output signal to the exterior is provided, The said filter member is the said communication It is preferable to include a lead insertion hole penetrating along the axis of the hole and penetrating the lead wire, and the lead wire is a sensor cap that is watertightly held by the filter member.

In the sensor cap of the present invention, the filter member includes a lead insertion hole, and the lead wire is held in a watertight manner on the filter member. By adopting such a configuration, ventilation between the outside and the internal space is possible through the communication hole of the surrounding member, and the lead wire can be taken out to the outside through the communication hole.
For this reason, an insertion hole for leading the lead wire to the outside is separately provided in the surrounding member, and the lead wire is inserted into the insertion hole and held, and further, the water tightness between the lead wire and the surrounding member in this portion is maintained. Therefore, it is not necessary to provide a separate structure. Therefore, the sensor cap is simple and inexpensive.

  Furthermore, it is a sensor cap of Claim 19, Comprising: A crimping member is provided, The said filter member is a site | part which differs in the said axial direction from the outer periphery contact part which makes the column shape extended in the said axial direction, and the said outer periphery contact part A lead caulking portion having a diameter smaller than that of the outer peripheral contact portion, and the lead caulking member is externally fitted and caulked to the lead caulking portion so that the lead wire is watertight in the lead insertion hole. It is preferable to use a sensor cap that is held on the surface.

In the sensor cap of the present invention, the filter member includes a lead crimping portion. Then, a caulking member is fitted onto the lead caulking portion and caulked to hold the lead wire in a lead insertion hole in a watertight manner. For this reason, in addition to being able to send an output signal to the outside through the lead wire, it is possible to prevent water from entering the internal space between the outer peripheral surface of the lead wire and the inner peripheral surface of the lead insertion hole of the filter member. Can do.
Furthermore, this filter member has air permeability at least in the axial direction of the communication hole, and has an outer peripheral contact portion and a lead crimping portion having a smaller diameter. For this reason, since the lead caulking portion with a small diameter is caulked with a caulking member, even if the air permeability decreases or disappears at this lead caulking portion, at least the large diameter outer periphery contact portion and the small diameter lead caulking portion The air permeability between the surface caused by the difference in diameter with the tightening portion and the surface on the opposite side of the lead crimping portion of the outer peripheral contact portion is maintained.
Thus, in the sensor cap of the present invention, while the lead wire is inserted through the filter member, while ensuring ventilation through the communication hole, the filter member and the surrounding member, and between the filter member and the lead wire are watertight, It is possible to prevent water from entering the internal space.

  Furthermore, it is a sensor cap as described in any one of Claims 13-20, Comprising: The said surrounding member is good to be a sensor cap which consists of fluororubber.

  Since the sensor cap of the present invention uses fluoro rubber for the surrounding member, even if the gas detection element is coupled to a gas sensor that is exposed to a high temperature, it is less likely to be thermally deteriorated and the internal space can be kept watertight for a long period of time. .

  Furthermore, it is a sensor cap as described in any one of Claim 13-21, Comprising: The said communicating hole contains multiple opening opened to the exterior, The said filter member is either of these opening from the outside. It is preferable that the sensor cap is disposed at a position where it cannot be visually recognized through the sensor cap.

  In the sensor cap of the present invention, the filter member is arranged at a position where it cannot be visually recognized through any opening from the outside. For this reason, even when water enters from the outside through the opening at high speed, the high-speed water hardly reaches the filter member directly. That is, water entering at high speed from the outside through the opening can collide with the wall surface forming the communication hole of the surrounding member before reaching the filter member, and the momentum (speed) can be reduced. Therefore, even when water enters at high speed through the opening of the communication hole from the outside, the water can be prevented from passing through the filter member.

Moreover, since the gas sensor unit of the present invention has a plurality of openings for the communication holes, even if water enters at a high speed from one opening, the water can be discharged to the outside from the other opening. For this reason, since there is no possibility that high water pressure will be applied in the communicating hole, there is no possibility that high water pressure will be applied to the filter member.
As described above, in the gas sensor unit of the present invention, even when water enters at high speed through the opening of the communication hole from the outside, the water can be prevented from passing through the filter member.

  The sensor cap according to any one of claims 13 to 22, wherein the gas detection element of the gas sensor coupled to the sensor cap is introduced into the internal space from the outside through the communication hole. A gas detection element using a reference gas, wherein the sensor cap is a ventilation path that guides the reference gas introduced from the outside from the filter member to the gas detection element when the sensor cap and the gas sensor are combined. It is preferable that the sensor cap is configured to be configured as follows.

  When the sensor cap of the present invention is used and is combined with a gas sensor to form a gas sensor unit, an air passage that guides a reference gas introduced from the outside to the gas detection element is provided between the filter member and the gas detection element. Can be provided. Therefore, by using the sensor cap of the present invention, it is possible to form a gas sensor unit that can appropriately detect the gas to be detected using the reference gas introduced from the outside.

  24. The sensor cap according to claim 23, wherein when the relative movement direction of the gas sensor when the sensor cap and the gas sensor are combined is a first movement direction, the cap terminal is A cylindrical portion having a cylindrical shape extending in the first movement direction, the first cylindrical portion having a cylindrical portion constituting a part of the air passage, and located on the first movement direction side of the cylindrical portion. The moving direction side portion includes an inner surface of the surrounding member, an abutting portion that abuts in the first moving direction, and a separating portion that is separated from the inner surface of the surrounding member, and the sensor cap includes the separation of the cap terminal. It is preferable that the sensor cap is configured to introduce the reference gas into the cylindrical portion through the portion and the inner surface of the surrounding member.

  In the sensor cap of the present invention, the first moving direction side portion located on the first moving direction side of the cylindrical portion of the cap terminal includes a contact portion that contacts the inner surface of the surrounding member in the first moving direction. . For this reason, in the gas sensor unit formed by coupling the sensor cap of the present invention to the gas sensor, the cap terminal connected to the sensor terminal of the gas sensor can be restricted from moving in the first movement direction.

  Moreover, the first movement direction side portion of the cylindrical portion of the cap terminal also includes a separation portion that is separated from the inner surface of the surrounding member. As a result, the sensor cap can introduce the reference gas taken in from the communication hole into the cylindrical portion through the gap between the cap terminal and the inner surface of the surrounding member. Therefore, in the gas sensor unit using the sensor cap of the present invention, the reference gas can be appropriately guided to the gas detection element via the inside of the cylindrical portion.

In addition, as a cylindrical part of a cap terminal, for example, a cylindrical part having a cylindrical shape, a cylindrical part in which an annular annular part is integrally connected to a first movement direction side end of a cylindrical part, etc. Can be mentioned. In the latter cylindrical portion, a portion of the annular annular portion that contacts the inner surface of the surrounding member is a contact portion, and a portion that is separated from the inner surface of the surrounding member is a separation portion.
Moreover, the contact part of a cap terminal should just be a site | part which contact | abuts the inner surface of an enclosure member at least, when a sensor cap and a gas sensor are couple | bonded. That is, the contact portion of the cap terminal is not in contact with the inner surface of the surrounding member already before the sensor cap and the gas sensor are coupled, but also when the sensor cap and the gas sensor are coupled with each other. Including those that abut.

Embodiments of the present invention will be described with reference to the drawings.
Example 1
FIG. 1 is an explanatory diagram illustrating a gas sensor unit 300 according to the first embodiment and a state when the gas sensor unit 300 is used. As can be understood from FIG. 1, the gas sensor unit 300 according to the first embodiment includes a gas sensor 100 and a sensor cap 200 disposed on the rear end side (upward in FIG. 1) in the axis AX direction of the gas sensor 100. . This gas sensor unit 300 is an oxygen sensor that is fastened to an exhaust pipe 10 of a vehicle in a form in which a tip portion of the gas sensor 100 protrudes into the exhaust pipe and measures an oxygen concentration in the exhaust gas.

Among these, as shown in FIG. 2, the gas sensor 100 includes a gas detection element 120, an enclosure 130, a sensor terminal 150, and a casing 160.
In the following description, the direction where the sensor cap is attached in the direction along the axis AX will be described as the rear end side, and the opposite side will be described as the front end side.

  The casing 160 has a metal shell 161 and a protector 162. The metal shell 161 is made of SUS430 and is formed in a cylindrical shape. The metal shell 161 is an inner peripheral receiving portion 161e for supporting a flange portion 120e of the gas detecting element 120 described later, and has a tapered inner diameter that decreases in diameter toward the tip side (downward in FIG. 2). The circumferential receiving portion 161e is provided in a circumferential manner so as to protrude radially inward from the inner circumferential surface. Further, a screw portion 161b for attaching the gas sensor 100 to the exhaust pipe 10 (see FIG. 1) is formed outside the metal shell 161, and a rear end side (upward in FIG. 2) of the screw portion 161b. Is provided with a hexagonal portion 161d that engages an attachment tool for screwing the screw portion 161b into the exhaust pipe 10. The protector 162 is a metal, cylindrical bottomed cylindrical body, and has a plurality of ventilation holes 162 b for introducing exhaust gas in the exhaust pipe 10 into the gas sensor 100.

  The gas detection element 120 is made of a solid electrolyte having oxygen ion conductivity, has a bottomed shape with a closed end portion 120b, and has a cylindrical shape extending in the direction of the axis AX. On the outer periphery of the gas detection element 120, a flange portion 120e protruding outward in the radial direction is provided, and a metal is formed between the front end side surface of the flange portion 120e and the surface of the inner periphery receiving portion 161e of the metal shell 161. The gas detection element 120 is disposed in the metal shell 161 with the made packing 142 interposed. A typical example of the solid electrolyte constituting the gas detection element 120 is ZrO2 in which Y2O3 or CaO is dissolved, but other alkaline earth metal or rare earth metal oxides and ZrO2 A solid solution may be used. Further, this may contain HfO2.

An outer electrode 121 is formed on the distal end portion 120b of the gas detection element 120 so as to cover the outer peripheral surface 120c. The outer electrode 121 is made of porous Pt or Pt alloy. The outer electrode 121 is provided up to the tip side surface of the flange portion 120e, and is electrically connected to the metal shell 161 via a metal packing 142. Therefore, the potential of the outer electrode 121 can be taken out from the metal shell 161.
On the other hand, an inner electrode 122 is also formed on the inner peripheral surface 120d of the gas detection element 120 so as to cover it. The inner electrode 122 is also formed by forming Pt or a Pt alloy in a porous manner.

  The enclosure 130 is made of an insulating ceramic (specifically, alumina) and has a cylindrical shape. The envelope 130 is a ceramic powder formed of talc in such a form that the front end portion 131 of which the thickness is thick surrounds the portion of the gas detection element 120 on the rear end side of the flange portion 120e. 141 and 141 are held so as to be interposed between the gas detection element 120 and the metal shell 161.

The sensor terminal 150 is made of, for example, SUS304, has a cylindrical shape, and includes an output-side terminal portion 151, an element-side terminal portion 153, and a connecting portion 152 that connects the two.
Among these, the output side terminal portion 151 has a cylindrical shape having a substantially C-shaped cross section orthogonal to the axis AX. The output side terminal portion 151 moves the sensor connecting portion 211 (see FIGS. 1 and 4) of the cap terminal 210 relative to each other in the direction along the axis AX (in the vertical direction in FIGS. It is configured to elastically expand its diameter when inserted into the. Further, convex portions 151b projecting radially inward are formed at three positions in the circumferential direction on the rear end side (upward in FIG. 2) of the output side terminal portion 151.

  Further, in the output side terminal portion 151, a part of the output side terminal portion 151 is punched out radially inward at three corresponding circumferential directions on the tip side (downward in FIG. 2) from the convex portion 151 b. A bent inner bent portion 151c and an outer bent portion 151d bent outward in the radial direction are formed. Among these, as will be described later, the inner bent portion 151c elastically extends radially outward when the insertion portion 216 (see FIG. 4) of the cap terminal 210 is inserted and connected to the inner side of the output side terminal portion 151. When the insertion portion 216 is bent and inserted to a predetermined position, the bending is returned to cause a click feeling. Further, as shown in FIG. 2, the outer bent portion 151d abuts on the front end surface (step surface) of the step portion 130b of the enclosure 130 when the sensor terminal 150 is assembled to the gas sensor 100, so that the output side It plays the role of preventing the terminal portion 151 (sensor terminal 150) from coming off.

  On the other hand, among the sensor terminals 150, the element-side terminal portion 153 also has a cylindrical shape having a substantially C-shaped cross section orthogonal to the axis AX. As shown in FIG. 2, the element side terminal portion 153 is inserted into the gas detection element 120 while being elastically reduced in diameter, and is electrically connected to the inner electrode 122. Therefore, in the gas sensor 100 of the first embodiment, the element side terminal portion 153 is electrically connected while pressing the inner electrode 122 from the inner side toward the outer side in the radial direction.

  Such a sensor terminal 150 is formed by press molding using a single metal plate having a predetermined shape. For this reason, it is easy to form and low cost. Further, in the sensor terminal 150 of the first embodiment, the metal plate is bent, and the output-side terminal portion 151 and the element-side terminal portion 153 located on the distal end side (downward in FIG. 2) in the axis AX direction are cylindrical. Since the reference gas (outside air) taken into the sensor cap 200 is introduced to the inside (inner electrode 122) of the gas detection element 120, a ventilation path P (shown by a broken arrow in FIG. 1) is formed. Can be secured.

Such a gas sensor 100 is manufactured as follows.
First, as shown in FIG. 2, a casing 160 in which a metal shell 161 and a protector 162 are integrated is prepared. Next, the gas detection element 120 provided with the outer electrode 121 and the inner electrode 122 is inserted into the casing 160 together with the packing 142. Next, a ring packing 143 is disposed on the rear end side of the flange 120e of the gas detection element 120, and a predetermined amount of ceramic powder 141 is filled in the gap between the metal shell 161 and the gas detection element 120. Next, the enclosure 130 is inserted so that the distal end portion 131 is interposed between the gas detection element 120 and the metal shell 161, and is brought into contact with the ceramic powder 141. Next, the envelope body 130 is pressurized toward the distal end side, and the crimped portion 161c is interposed between the crimped portion 161c of the metal shell 161 and the envelope body 130 with the crimped ring 144 interposed therebetween. The above components are fixed together by caulking.

Finally, the sensor terminal 150 is inserted inside the enclosure 130 and the gas detection element 120. Specifically, the element side terminal portion 153 of the sensor terminal 150 is inserted into the gas detection element 120 while being elastically reduced in diameter, and is electrically connected to the inner electrode 122. At the same time, the output side terminal portion 151 is pushed toward the front end side, and the stop portion 151f formed in the shape of a petal that is orthogonal to the axis line AX and goes radially outward from the rear end of the output side terminal portion 151 is enclosed. 130 is brought into contact with the rear end face 130e. In this way, the output side terminal portion 151 is disposed inside the enclosure 130.
In addition, by pushing the output side terminal portion 151 until the stop portion 151f contacts the rear end surface 130e of the enclosure 130, the outer bent portion 151d bent radially inward is released and returned, and the envelope 130 Since it comes to engage with the front end surface (step surface) of the stepped portion 130b, it is possible to prevent the sensor terminal 150 from coming off.
In this way, the gas sensor 100 is completed.

  In the state where the insertion portion 216 of the cap terminal 210 is not inserted into the output side terminal portion 151 shown in FIG. 2, the output side terminal portion 151 has a diameter slightly larger than the inner diameter of the rear end portion 132 of the enclosure 130. It is in a small state. For this reason, a gap S <b> 1 is generated between the inner peripheral surface 132 c of the rear end portion 132 of the enclosure 130 and the outer peripheral surface 151 e of the output-side terminal portion 151.

  Next, the sensor cap 200 of the first embodiment will be described with reference to the drawings. FIG. 3 is a partially broken sectional view of the sensor cap 200. The sensor cap 200 includes a cap terminal 210, a covering member 220 that covers and holds the cap terminal 210, a lead wire 230, and a filter member 240.

  Among these, the covering member 220 is formed into a hollow shape using insulating fluorine-based rubber, and constitutes a cap terminal accommodating space SPS for accommodating the cap terminal 210. The covering member 220 surrounds the terminal rear end portion 221 located on the rear end side (upward in the drawing) of the cap terminal 210 and the circumference of the cap terminal 210 in the radial direction. An outer peripheral covering portion 222 for surrounding the outer peripheral surface and a lead surrounding portion 223 for surrounding the lead wire 230 or the filter member 240 are provided. The lead wire 230 is drawn into the inside of the covering member 220 through a communication hole 223d including a small-diameter vent hole 223b and a filter holding hole 223c.

  Of the outer periphery covering portion 222, the gripping portion surrounding portion 222 b on the rear end side (upward in the drawing) has a relatively large diameter and is positioned around the outer peripheral surface gripping portion 215 of the cap terminal 210. On the front end side (downward in the figure) adjacent to the gripper peripheral part 222b, the inner diameter is smaller than that of the gripper peripheral part 222b, and the outer peripheral surface 130d (rear end) of the envelope 130 of the gas sensor 100 A close contact portion 222c that is dimensioned to be in close contact with the outer peripheral surface 132d) of the portion 132. Further, on the distal end side (downward in the drawing) of the contact portion 222c, the contact portion 222c extends from the contact portion 222c to the distal end side, and has an inner diameter larger than that of the contact portion 222c. An extended surrounding portion 222d that surrounds the surface 130d while being spaced apart from the surface 130d is provided.

  The cap terminal 210 (see FIG. 3 and FIG. 4) is made of, for example, Inconel 718 (Inconel, UK), and is formed by drawing a plate material. The cap terminal 210 is electrically connected by caulking a double-substantially cylindrical sensor connecting portion 211 (corresponding to a cylindrical portion) and a core wire 231 of the lead wire 230 formed integrally with the sensor connecting portion 211. And a core caulking portion 212 to be used. Further, as will be described later, the filter member 240 having the lead wire 230 inserted therein is caulked to have a filter caulking portion 213 for gripping and fixing the lead wire 230 and the filter member 240.

  Among these, the sensor connecting portion 211 is concentric and plate-like annular portion 214 with respect to the axis CX, and protrudes to one side (downward in FIG. 4A) along the axis CX connected to the outer peripheral edge of the annular portion 214. An outer peripheral surface gripping portion 215 and a cylindrical insertion portion 216 that is continuous with the inner peripheral edge of the annular portion 214 and protrudes to the same side as the outer peripheral surface gripping portion 215. The annular portion 214, the outer peripheral surface grip portion 215, and the insertion portion 216 are integrally molded with each other.

Of these, the outer peripheral surface gripping part 215 is connected to the outer peripheral edge of the annular part 214, and is divided into three parts extending from the base end part 215a by slits SL1 and SL2 extending from the base end part 215a. It has a gripping part 215b (215ba, 215bb, 215bc). Further, a third slit SL3 exists between both ends in the circumferential direction of the C-shaped base end portion 215a. The slits SL1, SL2, and SL3 have a shape extending from the distal end side end 215d of the outer peripheral surface gripping portion 215 to the proximal end portion 215a side.
Projections 215c (215ca, 215cb, 215cc) projecting inward are formed on the above-mentioned divided grips 215ba, 215bb, 215bc, respectively. Specifically, the three protrusions 215ca, 215cb, and 215cc are arranged in the circumferential direction at an angle of 120 degrees from each other.
As will be described later, three projecting portions 215c are brought into contact with the outer peripheral surface 130d of the envelope 130 of the gas sensor 100 (the outer peripheral surface 132d of the rear end portion 132), respectively, and the outer peripheral surface gripping portion 215 of the sensor connecting portion 211 is surrounded by the envelope. The rear end 132 of 130 is fitted into this part so as to surround it. In this case (see FIG. 1), the three divided grip portions 215b are elastically bent outward in the radial direction due to the presence of the divided slits SL1, SL2, and SL3. The cap terminal 210 elastically holds the enclosure 130 by this reaction force.

On the other hand, as described above, the insertion portion 216 has a cylindrical shape with the axis CX as the center, and has a rigidity that prevents deformation such as a reduced diameter and an increased diameter. Therefore, as will be described later, when the gas sensor 100 is inserted into the output side terminal portion 151 and brought into contact with the output side terminal portion 151, the output side terminal portion 151 can be expanded without deforming itself.
The insertion portion 216 includes, from the annular portion 214 side, a cylindrical portion having a relatively large diameter and a relatively long conducting portion 216a in the axis CX direction, a small-diameter portion 216b having a smaller diameter than the conducting portion 216a, and the small-diameter portion 216b. The insertion tip portion 216c having a larger diameter is provided in this order.

When the outer peripheral surface gripping part 215 of the sensor connection part 211 is fitted into the enclosure 130 of the gas sensor 100 (see FIG. 1), the insertion part 216 is inside the enclosure 130 and the output side terminal part of the sensor terminal 150 151 is inserted inside 151. At this time, the conducting portion 216 a contacts the convex portion 151 b of the output side terminal portion 151 and is electrically connected to the output side terminal portion 151. Further, an inner bent portion 151c of the output side terminal portion 151 is located on the outer side in the radial direction of the small diameter portion 216b. When the cap terminal 210 is detached from the sensor terminal 150, the inner bent portion 151c is inserted. It is engaged with the portion 216c so that it cannot be easily removed. Further, when the insertion portion 216 of the cap terminal 210 is completely inserted into the output-side terminal portion 151 of the sensor terminal 150, the inner bent portion 151c is released from the state of being in contact with the insertion tip portion 216c, and a click feeling is generated. .
As shown in FIG. 1, the annular portion 214 is an output side terminal portion located on the rear end surface 130 e of the enclosure 130 in a state where the insertion portion 216 is inserted into the output side terminal portion 151 of the sensor terminal 150. By abutting against the stop portion 151f of 151, the insertion portion 216 of the cap terminal 210 is further prevented from being inserted into the distal end side.

  Next, the lead surrounding portion 223 will be described (see FIG. 3). The lead surrounding portion 223 surrounds the lead wire 230 and the filter member 240, and includes a filter holding portion 223e for holding the filter member 240 therein and an overhang portion 223g. The communication hole 223d includes a filter holding hole 223c constituted by the inner wall surface 223f of the filter holding portion 223e and a small-diameter ventilation hole 223b constituted by the inner wall surface of the overhanging portion 223g. The communication hole 223d communicates the external space SPO with the internal space SPI (see FIG. 1) formed by the gas sensor 100 and the sensor cap 200, and as described above, draws the lead wire 230 from the outside. It is out.

  In addition to the core wire 231, the lead wire 230 has a double coating of a first coating material 232 and a second coating material 233. As described above, the lead wire 230 is electrically connected to the sensor connecting portion 211 by crimping the tip end of the core wire with the core wire crimping portion 212 of the cap terminal 210. Therefore, an output signal from the inner electrode 122 of the gas detection element 120 of the gas sensor 100 can be transmitted to an external device (for example, an engine control unit (ECU)) through the lead wire 230.

  The filter member 240 has a lead insertion hole 241 in the center, and a convex portion in which a lead crimping portion 242 having a relatively small diameter and an outer peripheral contact portion 243 having a larger diameter than the lead crimping portion 242 are connected in a stepped manner. It has a letter shape. The filter member 240 is made of PTFE having a continuous porous structure in which fine pores are continuous, and is made of a material that can be three-dimensionally ventilated in addition to the axis LX (left and right direction in FIG. 3) of the lead insertion hole 241.

  The core wire 231 and the first covering material 232 of the lead wire 230 are inserted into the lead insertion hole 241. Then, as described above, the lead crimping portion 242 of the filter member 240 is crimped by the filter crimping portion 213 of the cap terminal 210, so that the first covering material 232 of the filter member 240 and the lead wire 230 is connected to the cap terminal 210. It is integrated. Further, the lead caulking portion 242 of the filter member 240 is strongly caulked by the filter caulking portion 213 so as to be watertight, thereby preventing water droplets from entering through the lead insertion holes 241.

  The outer peripheral contact portion 243 of the filter member 240 has a columnar shape extending in the direction of the axis LX, and a body portion 243c positioned around the lead insertion hole 241 and a smoothing process surrounding the periphery of the body portion 243c in an annular shape. Part 243d. The main body portion 243c is porous and can be ventilated three-dimensionally, whereas the smoothing processing portion 243d is not porous and is dense without air permeability. Therefore, the outer peripheral surface of the smoothing processing unit 243d (the outer peripheral surface of the outer peripheral contact portion 243) 243b has a surface roughness higher than that of the other outer surface (for example, the ventilation surface 243e) of the filter member 240. It is low.

The filter member 240 is held at a predetermined position by the outer peripheral contact portion 243 having a large diameter being sandwiched between the filter holding portion 223e of the lead surrounding portion 223 and the elasticity of the lead surrounding portion 223. Since the filter member 240 (its outer peripheral contact portion 243) is held only by the elasticity of the lead surrounding portion 223 as described above, the filter member 240 can be freely thermally expanded even when this portion is at a high temperature. There is no plastic deformation such that the diameter of the (outer peripheral contact portion 243) becomes small. For this reason, there is no fear that the watertightness caused by such plastic deformation will occur, and the reliability with respect to the watertightness is high.
As described above, since the outer peripheral surface 243b of the outer peripheral contact portion 243 is smooth, the inner wall surface 223f of the filter holding portion 223e holding the filter member 240 and the outer peripheral surface 243b are smooth. Compared to the case of using a filter member that has not been subjected to the conversion treatment, the filter member is more closely attached, so that the entry of water from this portion can be more reliably prevented.

  Further, as described above, since the filter member 240 is made of PTFE having a continuous porous structure, water does not pass through the outer peripheral contact portion 243 but air can pass therethrough. Therefore, in the sensor cap 200 according to the first embodiment, as shown by the dashed arrows in FIGS. 1 and 3, the ventilation surface 243e facing the external space SPO in the outer peripheral contact portion 243 of the filter member 240, and the gas sensor Ventilation can be performed between the diameter difference surface 243f facing the internal space SPI constituted by the sensor cap 100 and the sensor cap 200. Therefore, the internal space SPI can be quickly ventilated. Further, outside air (reference gas) can be supplied to the inside of the gas detection element 120 of the gas sensor 100 through the inside of the covering member 220 and the sensor terminal 150.

  Further, the lead surrounding portion 223 includes an overhanging portion 223g having a diameter smaller than that of the filter holding portion 223e at a position adjacent to the filter holding portion 223e (right adjacent in the drawing). The projecting portion 223g is configured to project toward the inner side (axis LX side) than the filter holding portion 223e. The presence of the projecting portion 223g projecting toward the axis LX prevents the filter member 240 from coming out of the communication hole 223d (small-diameter vent hole 223b) outward (right side in the figure). In the first embodiment, the overhang portion 223g corresponds to the separation preventing portion.

The filter member 240 is charged with PTFE powder in a mold having a predetermined shape and hardened with a compressive force that generates a gap between the powders, and then heated at a temperature lower than the melting point of PTFE. As a result, the powders are fused together to form an unprocessed filter member 250 having a predetermined shape which is microscopically and has a continuous porous structure in which fine pores are three-dimensionally continuous and can be three-dimensionally ventilated ( (See FIG. 5).
In this unprocessed filter member 250, the unprocessed large diameter portion 253 that will later become the outer periphery contact portion 243 has a larger size than the outer periphery contact portion 243.

  Next, the filter 240 of the first embodiment is formed by using the smoothing device J shown in FIG. The smoothing device J includes a smoothing cylinder member JG and a heater HT. Among these, the smoothing cylindrical member JG has a large-diameter cylindrical portion JG1 having a cylindrical shape larger than the diameter of the raw large-diameter portion 253 of the raw filter member 250. Further, the small diameter cylindrical portion JG3 having the same diameter as the outer peripheral contact portion 243 of the processed filter member 240 and a small diameter compared to the large diameter cylindrical portion JG1, and a smooth inner peripheral surface, and a diameter It consists of a tapered cylindrical portion JG2 connecting the large cylindrical portion JG1 and the small diameter cylindrical portion JG3. Of these, a heater HT is wound around the tapered cylindrical portion JG2 and the small-diameter cylindrical portion JG3 so that these portions can be heated.

Specifically, the tapered tube portion JG2 and the small diameter tube portion JG3 are previously maintained at a temperature slightly higher than the melting point of PTFE using the heater HT. After that, the raw filter member 250 is put into the large diameter cylindrical portion JG1 and pushed toward the tapered cylindrical portion JG2 and the small diameter cylindrical portion JG3. Then, as the process proceeds, the unprocessed large diameter portion 253 of the unprocessed filter member 250 comes into contact with the tapered tube portion JG2 and is pressed inward. At the same time, the outer peripheral portion of the unprocessed large diameter portion 253 is melted by the heat from the tapered cylindrical portion JG2, and the fine pores are crushed. Eventually, at the time of removal from the small diameter cylindrical portion JG3, the outer diameter of the outer peripheral contact portion 243 coincides with the inner diameter of the small diameter cylindrical portion JG3, and the smoothing processing portion 243d located on the outer periphery of the outer peripheral contact portion 243 is once melted. It is a dense material made of PTFE and does not have air permeability. Further, the outer peripheral surface 243b of the smoothing processing portion 243d is smoothed by the inner peripheral surface of the small diameter cylindrical portion JG3.
Thus, the filter member 240 used in Example 1 could be formed.

  Thereafter, the lead wire 230 is inserted into the lead insertion hole 241 of the filter member 240, the core wire 231 is crimped by the core wire crimping portion 212 of the cap terminal 210, and the lead of the filter member 240 is crimped by the filter crimping portion 213. The fastening portion 242 is crimped. As a result, the first covering material 232 of the lead wire 230 is crimped by the lead crimping portion 242 of the filter member 240 and integrated in a watertight manner. Next, the lead wire 230 is pulled out through the communication hole 223d (the small-diameter vent hole 223b and the filter holding hole 223c) of the covering member 220, and the cap terminal 230 is pushed into the covering member 220 to hold the filter member 240 in the filter. The sensor cap 200 is completed by being positioned inside the hole 223c and held by the filter holding portion 223e.

A state when the gas sensor unit 300 including the gas sensor 100 and the gas sensor cap 200 of the first embodiment is used is shown in FIG. This gas sensor unit 300 can be used, for example, to detect the oxygen concentration in the exhaust gas of an internal combustion engine.
Specifically, first, in the gas sensor 100, the front end side including the protector 162 is positioned in the exhaust pipe 10, and the exhaust pipe 10 is exposed to the outside from the threaded portion 161 b of the metal shell 161. Screw on. At this time, the outer electrode 111 electrically connected to the metal shell 161 is grounded through the metal shell 161. Next, the sensor cap 200 is moved in a direction along the axes AX and CX (vertical direction in FIG. 1) so that the axis CX of the cap terminal 210 coincides with the axis AX of the gas sensor 100. The sensor cap 200 is attached to the gas sensor 100 such that the insertion portion 216 is inserted inside the output-side terminal portion 151 of the gas sensor 100 to form the gas sensor unit 300. In the first embodiment, the direction (upward direction in FIG. 1) from the gas sensor 100 toward the gas sensor cap 200 among the directions along the axes AX and CX (vertical direction in FIG. 1) is the first movement direction. Equivalent to.

  By the way, as shown in FIG. 3, among the sensor connection portions 211 (corresponding to the cylindrical portion) of the cap terminal 210, an annular portion 214 (first movement direction) located on the first movement direction side (upper side in FIG. 3). (Corresponding to the side portion) has an abutting portion 214 b that abuts against the inner surface 228 of the covering member 220. That is, the cap terminal 210 is in contact with the inner surface 228 of the covering member 220 in the first movement direction (upward in FIG. 3). Therefore, as described above, when the sensor cap 200 is coupled to the gas sensor 100, the cap terminal 210 can be connected to the sensor terminal 150 in a state where movement of the cap terminal 210 in the first movement direction is restricted.

  Therefore, in the first embodiment, even when the annular portion 214 of the cap terminal 210 is brought into contact with the stopper 151f of the gas sensor 100 when the sensor cap 200 and the gas sensor 100 are coupled, the cap terminal 210 is positioned in the first movement direction. There is no risk of shifting. For this reason, when the annular portion 214 of the cap terminal 210 is brought into contact with the stopper 151f of the gas sensor 100 and the sensor cap terminal 200 and the gas sensor 100 are coupled, the cap terminal 210 and the sensor terminal 150 are placed at a predetermined position. It can be connected properly.

  Moreover, the annular portion 214 of the cap terminal 210 has a separation portion 214 c that is separated from the inner surface 228 of the covering member 220. That is, in the first embodiment, the annular portion 214 of the cap terminal 210 is expanded by expanding the cap terminal accommodating space SPS (internal space SPI) between the annular portion 214 of the cap terminal 210 and the inner surface 228 of the covering member 220. And a part of a reference gas vent P (indicated by broken-line arrows in FIG. 3) introduced from the outside is formed between the cover member 220 and the inner surface 228 of the covering member 220. For this reason, the outside air (reference gas) introduced from the external space SPO through the communication hole 223d passes between the separation portion 214c of the cap terminal 210 and the inner surface 228 of the covering member 220 into the cylinder of the insertion portion 216 of the cap terminal 210. Can lead. Therefore, outside air (reference gas) can be introduced inside the gas detection element 120 of the gas sensor 100.

Further, when the sensor cap 200 and the gas sensor 100 are coupled, as shown in FIG. 1, the outer peripheral surface gripping portion 215 of the cap terminal 210 is used to provide a rear end portion (rear end) of the outer peripheral surface 130d of the enclosure 130 of the gas sensor 100. The outer peripheral surface 132d) of the portion 132 is surrounded and directly gripped. Thereby, the cap terminal 210 is fixed to the enclosure 130. Accordingly, the sensor cap 200 is attached and fixed to the gas sensor 100. In the first embodiment, since the envelope body 130 is gripped from the radially outer side by the outer peripheral surface gripping portion 215 of the cap terminal 210, the envelope body 130 can be securely fixed and is not affected by the dimensional relationship or the like inside the envelope body 130. In addition, since the shape and dimensions of the outer peripheral surface gripping part 215 can be determined, the form and dimensions of the outer peripheral surface gripping part 215 can be easily designed so that the enclosure can be gripped with an appropriate holding force.
In addition, since the cap terminal 210 is fixed to the enclosure 130 by the outer peripheral surface gripping part 215, other portions, that is, the insertion part 216 (conducting part 216a and the like) are also fixed to the enclosure 130.

  On the other hand, with respect to the insertion part 216 of the cap terminal 210, the conduction part 216a abuts on the convex part 151b of the output side terminal part 151. Therefore, the output-side terminal portion 151 is electrically connected while elastically pressing the conduction portion 216a of the cap terminal 210 radially inward at a plurality of contact portions (three points in the first embodiment). As described above, in the first embodiment, the output-side terminal portion 215 is in contact with the cap terminal 210 with a plurality of contact portions (convex-shaped portions 215b). The connection between the terminal portion 151 and the cap terminal 210 is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced.

  Furthermore, the output side terminal portion 151 receives a force radially outward from the conducting portion 216a at the convex portion 151b, and the output side terminal portion 151 is elastically expanded. As the output-side terminal portion 151 expands in this way, the gap S2 between the outer peripheral surface 151e of the output-side terminal portion 151 and the inner peripheral surface 132c of the rear end portion 132 of the enclosure 130 is larger than the gap S1 before insertion. It is made smaller (S2 <S1).

  However, in consideration of the dimensional tolerances of the enclosure 130, the output side terminal portion 151, and the conducting portion 216a, when the enclosure 130, the output side terminal portion 151, and the conducting portion 216a having dimensions within the tolerance are used, Also in this case, the gap S2 is preferably set to a value larger than zero (S2> 0). In this case, the convex portion 151b and the conductive portion 216a have the dimensions and dimensional tolerances of the output-side terminal portion 151 and the conductive portion 216a so that an appropriate insertion resistance is obtained and an appropriate pressure contact force is obtained for conduction. Can be set as appropriate.

Even if the distance S2> 0, the cap terminal 210 (conducting portion 216a) is fixed to the enclosure 130 by the outer peripheral surface gripping portion 215, so that even if the gas sensor unit 300 receives vibrations of the vehicle or the like. The output-side terminal portion 151 surrounded by the enclosure 130 does not swing in the radial direction. For this reason, it is possible to prevent fatigue failure (cracking, breakage, etc.) from occurring in the connecting portion 152 of the sensor terminal 150 due to the influence of vibration.
As described above, the gas sensor unit 300 according to the first embodiment has a low risk of gas detection accuracy due to the influence of vibration and damage to the sensor terminal 150, and has good vibration resistance. Therefore, it can also be suitably used for a motorcycle with strong vibration.

  Further, the cap terminal 210 has a protruding portion 215c of the outer peripheral surface gripping portion 215 that is radially outward from the outer peripheral surface 130d of the enclosure 130 and is radially connected to the convex portion 151b of the output side terminal portion 151 at the conductive portion 216a. It is elastically connected from the inside. Therefore, when the cap terminal 210 is moved in the direction along the axis CX (AX) (vertical direction in FIG. 1) and the sensor cap 200 is attached to and detached from the gas sensor 100, the cap terminal 210 can be easily attached and detached, and the attachment / detachment property is also good. is there.

  Further, in the gas sensor unit 300 of the first embodiment, as described above, the communication hole 223d is provided in the lead surrounding portion 223 of the sensor cap 200, and this is closed by the filter member 240 having air permeability and water repellency. For this reason, as shown by a broken line arrow in FIG. 1, ventilation between the external space SPO and the internal space SPI formed by the gas sensor 100 and the sensor cap 200 can be performed through the filter member 240. Therefore, the internal space SPI can be quickly ventilated. Further, outside air (reference gas) can be supplied to the inside of the gas detection element 120 of the gas sensor 100 through the inside of the covering member 220 forming the ventilation path P and the inside of the sensor terminal 150.

  Moreover, the filter member 240 has a lead insertion hole 241 in the center, and the lead wire 230 is inserted in a watertight manner. Therefore, the lead wire 230 can be guided to the outside through the communication hole 223d while preventing water from entering the internal space SPI.

(Modification 1)
Next, a sensor cap 400 according to a first modification of the first embodiment will be described with reference to FIG. The sensor cap 400 according to the first modification is different from the sensor cap 200 according to the first embodiment in the form of the lead surrounding portion 423, particularly the shape of the filter member 440. Therefore, description of similar parts will be omitted or simplified, and different parts will be mainly described.

  The sensor cap 200 of Example 1 described above has a convex section in cross section, and has a relatively large outer peripheral contact portion 243 and a lead crimping portion 242 having a smaller diameter, and a stepped portion is formed between them. The filter member 240 having the diameter difference surface 243f orthogonal to the axis LX was used (see FIG. 3).

On the other hand, the sensor cap 400 according to the first modification similarly has a relatively large-diameter outer peripheral contact portion 443 and a lead crimping portion 442 having a smaller diameter. A tapered portion 444 having a diameter difference surface 444b that gradually decreases in diameter toward the tightening portion 442 is provided.
Therefore, when the lead crimping portion 442 is crimped by the filter crimping portion 413 of the cap terminal 410, the filter member 440 and the cap terminal 410 are integrated as well as the lead insertion hole 441 as in the first embodiment. The existing lead wire 230 can be integrated with the filter member 440 in a watertight manner. However, the air permeability in the lead crimping portion 442 may be reduced or lost.

  However, the filter member 440 of the first modification has a taper portion 444, and a diameter difference surface 444b (outer peripheral surface of the taper portion 444) generated by a diameter difference between the outer peripheral contact portion 443 and the lead crimping portion 442. The inside and outside can be ventilated. For this reason, as shown by a broken line in FIG. 6A, the space between the external space SPO and the cap terminal accommodating space SPS, specifically, the ventilation surface 443e of the outer peripheral contact portion 443 facing the external space SPO, Ventilation is possible between the taper portion 444 and the diameter difference surface 444b facing the cap terminal accommodating space SPS. Thus, also in the sensor cap 400 of the first modification, the internal space SPI can be quickly ventilated, and the outside air (reference gas) can be supplied to the inside of the gas detection element 120 of the gas sensor 100.

In addition, the outer peripheral part of the outer periphery contact | adherence part 443 is made into the smoothing process part 443d similarly to the above-mentioned Example 1. FIG. Therefore, the lead enclosure portion 423 can be in close contact with the filter holding portion 423e without any gap, and the filter member 440 can be more securely held watertight.
Similarly to the first embodiment, the lead surrounding portion 423 includes a protruding portion 423g that protrudes inward from the filter holding portion 423e and forms a small-diameter vent hole 423b. Yes. Due to the presence of the overhanging portion 423g, the filter member 440 is prevented from coming out from the communication hole 423d (small-diameter vent hole 423b) to the outside (right side in the figure). In the first modification, the overhang portion 423g corresponds to the separation preventing portion.

(Modification 2)
Next, a sensor cap 500 according to a second modification of the first embodiment will be described with reference to FIG. The sensor cap 500 according to the second modification also differs from the sensor cap 200 according to the first embodiment in the form of the lead surrounding portion 523, particularly the shape of the filter member 540. Therefore, description of similar parts will be omitted or simplified, and different parts will be mainly described.

In the sensor cap 500 of the second modification, as in the first embodiment, the outer peripheral contact portion 543 having a relatively large diameter and the lead crimping portion 542 having a smaller diameter are provided. A small-diameter intermediate diameter portion 544 is provided.
Accordingly, when the lead crimping portion 542 is crimped by the filter crimping portion 513 of the cap terminal 510, the filter member 540 and the cap terminal 510 are integrated, and the lead wire 230 that is inserted through the lead insertion hole 541 is It can be integrated with the filter member 540 in a watertight manner. However, the air permeability in the lead crimping portion 542 may be lowered or lost.

However, the filter member 540 according to the second modification has a small intermediate diameter portion 544, and internal and external ventilation is generated on the diameter difference surface 543 f generated by the difference in diameter between the outer peripheral contact portion 543 and the small intermediate diameter portion 544. Is possible. For this reason, as shown by a broken line in FIG. 6B, the space between the external space SPO and the cap terminal accommodating space SPS, specifically, the ventilation surface 543e of the outer peripheral contact portion 543 facing the external space SPO, The space between the diameter difference surface 543f facing the cap terminal accommodating space SPS can be ventilated.
In the second modification, the outer peripheral surface of the small-diameter intermediate portion 544 is not subjected to a smoothing process and is a breathable outer peripheral surface 544b having air permeability. For this reason, it is possible to ventilate the cap terminal accommodating space SPS through the breathable outer peripheral surface 544b.
Thus, also in the sensor cap 500 of the second modification example, it is possible to quickly ventilate the internal space SPI and supply the reference gas into the gas detection element 120.

In addition, the outer peripheral part of the outer periphery contact | adherence part 543 is made into the smoothing process part 543d similarly to the above-mentioned Example 1. FIG. Therefore, the lead enclosure portion 523 can be in close contact with the filter holding portion 523e without any gap, and the filter member 540 can be more securely held in a watertight manner.
Similarly to the first embodiment, the lead surrounding portion 523 includes an overhanging portion 523g that protrudes inward from the filter holding portion 523e and forms a small diameter small diameter air hole 523b. Yes. Due to the presence of the protruding portion 523g, the filter member 540 is prevented from slipping out from the communication hole 523d (small-diameter vent hole 523b) to the outside (right side in the figure). In addition, a thin-walled portion 523h is formed in the lead surrounding portion 523 at a position corresponding to the lead crimping portion 542 to facilitate ventilation. In the second modification, the overhang portion 523g corresponds to the separation preventing portion.

(Modification 3)
Next, a sensor cap 600 according to a third modification of the first embodiment will be described with reference to FIG. The sensor cap 600 according to the third modification also differs from the sensor cap 200 according to the first embodiment in the form of the lead surrounding portion 623, particularly the shape of the filter member 640. Therefore, description of similar parts will be omitted or simplified, and different parts will be mainly described.

  In the sensor cap 600 of the third modification example, the filter member 640 is provided in the lead surrounding portion 623 of the covering member 620 as in the first embodiment. However, the filter member 640 has a substantially cylindrical shape, and its outer periphery. The contact portion 643 and the lead crimping portion 642 have substantially the same diameter at least before crimping. In addition, an intermediate ventilation portion 644 having the same diameter is provided between them. Further, in Example 1 and the like, the filter crimping portion 213 is provided integrally with the cap terminal 210. However, in the third modification, the lead crimping is performed by the C-shaped crimping member 613 separately from the cap terminal 610. The part 642 is caulked. Thereby, the lead wire 230 inserted through the lead insertion hole 641 can be integrated with the filter member 640 in a watertight manner. However, the air permeability in the lead crimping portion 642 may be reduced or eliminated.

However, the filter member 640 of the third modification has an intermediate ventilation portion 644 between the outer peripheral contact portion 643 and the lead crimping portion 642, and the outer peripheral surface has a breathable outer peripheral surface 644b. Therefore, the inside and outside can be ventilated through this surface. For this reason, as shown by a broken line in FIG. 6C, the space between the external space SPO and the cap terminal accommodating space SPS, specifically, the ventilation surface 643e of the outer peripheral contact portion 643 facing the external space SPO, Ventilation is possible between the intermediate ventilation portion 644 facing the cap terminal accommodating space SPS and the breathable outer peripheral surface 644b.
In the third modification, the air-permeable outer peripheral surface 644b of the intermediate ventilation portion 644 is not smoothed.
Thus, also in the sensor cap 600 of the third modification, the internal space SPI can be quickly ventilated and the reference gas can be supplied into the gas detection element 120.

In addition, although the outer peripheral part of the outer periphery contact | adherence part 643 is not shown in FIG.6 (c), the smoothing process may be carried out similarly to the above-mentioned Example 1. FIG. By performing the smoothing process, it is possible to further improve the adhesion between the lead surrounding portion 623 and the filter holding portion 623e, thereby improving the water tightness.
Similarly to the first embodiment, the lead surrounding portion 623 includes a protruding portion 623g that protrudes inward from a position adjacent to the filter holding portion 623e and forms a small-diameter vent hole 623b. The filter member 640 is prevented from coming out from the communication hole 623d (small-diameter vent hole 623b) to the outside (right side in the figure). Further, a thin wall portion 623h is formed at a position corresponding to the lead crimping portion 642 and the intermediate ventilation portion 644 in the lead surrounding portion 623, so that ventilation is easy. In the third modification, the overhang portion 623g corresponds to the separation preventing portion.

(Modification 4)
Next, a sensor cap 700 according to a fourth modification of the first embodiment will be described with reference to FIG. In Example 1 and Modifications 1 to 3 described above, the lead wire 230 is integrated with the filter member 240 and the like in a watertight manner by caulking the filter member 240 and the like. On the other hand, the sensor cap 700 according to the fourth modification differs in that the lead wire is fixed to the filter member without depending on the caulking of the filter member, and the others are the same. Therefore, description of similar parts will be omitted or simplified, and different parts will be mainly described.

  In the above-described first embodiment, the filter member 240 includes the outer peripheral contact portion 243 and the lead crimping portion 242. On the other hand, in the sensor cap 700 of the fourth modification, the filter member 740 includes only the outer peripheral contact portion 743 corresponding to the outer peripheral contact portion 243 in the first embodiment. Further, the filter member 740 of this modification 4 has a lead insertion hole 741 having a diameter larger than the outer diameter of the lead wire 230 (the outer diameter of the first covering material 232), and the lead wire 230 is loosely inserted. It becomes. The lead wire 230 (first covering material 232) is fixed in a watertight manner using an adhesive seal material 750 made of resin filled in the lead insertion hole 741.

  By this filter member 740, between the external space SPO and the cap terminal accommodating space SPS, specifically, the outer ventilation surface 743e of the outer peripheral contact portion 743 facing the external space SPO and the cap terminal accommodating space SPS are faced. Ventilation between the inner ventilation surface 743f is possible. Thus, also in the sensor cap 700 of the fourth modification, the internal space SPI can be quickly ventilated, and the outside air (reference gas) can be supplied to the inside of the gas detection element 120 of the gas sensor 100.

The outer peripheral portion of the filter member 740 (outer peripheral contact portion 743) is a smoothing processing portion 743d as in the first embodiment. Accordingly, the lead enclosure portion 723 can be in close contact with the filter holding portion 723e without any gap, and the filter member 740 can be held watertight.
Further, as in the first embodiment and the first to third modifications, the lead encircling portion 723 has a small diameter vent hole 723b that protrudes inward from the position surrounding the filter holding portion 723e. An overhang portion 723g is formed, and the filter member 740 is prevented from slipping out from the communication hole 723d (small diameter vent hole 723b) to the outside (right side in the figure). In the fourth modification, the overhang portion 723g corresponds to the separation preventing portion.

(Modification 5)
Further, a sensor cap 800 according to a fifth modification of the first embodiment will be described with reference to FIG. In the sensor cap 700 according to the above-described modified example 4, the lead wire is fixed to the filter member without depending on the caulking of the filter member. However, in the sensor cap 700 of the modified example, the loosely inserted lead wire 230 was fixed and sealed with an adhesive sealant 750 filled in the lead insertion hole 741. On the other hand, the sensor cap 800 according to the fifth modification is different in that the sensor cap 800 is fixed and sealed outside the lead insertion hole 741, and the others are the same. Therefore, description of the same parts as those in the first embodiment and the fourth modification will be omitted or simplified, and different parts will be mainly described.

  Also in the sensor cap 800 of the fifth modification, the filter member 840 includes only the outer peripheral contact portion 843 corresponding to the outer peripheral contact portion 243 in the first embodiment. However, unlike the filter member 740 of the fourth modified example, the lead insertion hole 841 has substantially the same diameter as the outer diameter of the lead wire 230 (the outer diameter of the first covering material 232). The lead wire 230 is a resin laid on the corner between the lead wire 230 (first covering material 232) and the outer ventilation surface 843e of the outer peripheral contact portion 843 or the inner ventilation surface 843f. It is fixed in a watertight manner using an adhesive sealing material 850 made of

  Even in this case, the filter member 840 faces between the external space SPO and the cap terminal accommodating space SPS, specifically, the outer ventilation surface 843e facing the external space SPO and the cap terminal accommodating space SPS. Ventilation is possible between the inner ventilation surface 843f. Thus, also in the sensor cap 800 of the fifth modification, the internal space SPI can be quickly ventilated, and the outside air (reference gas) can be supplied to the inside of the gas detection element 120 of the gas sensor 100.

The outer peripheral portion of the filter member 840 (outer peripheral contact portion 843) is the smoothing processing portion 843d, as in the first embodiment and the fourth modification, and is in close contact with the filter holding portion 823e of the lead enclosure 823 without any gap. However, the filter member 840 is kept watertight.
Further, as in the first embodiment and the first to third modifications, the filter member 840 projects to the inner side at a position adjacent to the filter holding portion 823e so as to form a small diameter small vent hole 823b. A portion 823g is provided, and the filter member 840 is prevented from coming out of the communication hole 823d (small-diameter vent hole 823b) outward (right side in the figure). In the fifth modification, the overhang portion 823g corresponds to the separation preventing portion.

(Modification 6)
Next, a sensor cap 900 according to a sixth modification of the first embodiment will be described with reference to FIGS. The sensor cap 900 according to the sixth modification is different from the sensor cap 200 according to the first embodiment in the form of the lead surrounding portion of the covering member, and the other is the same. Accordingly, the description of the same parts as those in the first embodiment will be omitted or simplified, and different parts will be mainly described.

  In the sensor cap 200 according to the first embodiment, as shown in FIG. 3, the inner diameter of the small vent hole 223 b that leads the lead wire 230 out of the lead surrounding portion 223 is set to the lead wire 230 (first covering material 232). ) Was larger than the outer diameter. Thus, an annular space is provided between the lead wire 230 (first covering material 232) and the small-diameter vent hole 223b, and an annular opening 223k that opens in the direction along the axis LX is provided, through the opening 223k. The ventilation between the external space SPO and the cap terminal accommodating space SPS (internal space SPI) can be performed.

  However, in recent years, high-pressure washing machines that spray water pressurized at high pressure from nozzles at high speed have become widespread as apparatuses for washing automobiles and the like. For this reason, when the gas sensor unit 300 provided with the sensor cap 200 having the above-described structure is mounted on a vehicle and washed with a high-pressure washing machine, for example, as shown in FIG. There is a possibility that the filter member 240 may reach directly from the opening 223k of the surrounding portion 223. At this time, when the water pressure exceeding the water pressure resistance of the filter member 240 is applied to the filter member 240, there is a possibility that water droplets may pass through the filter member 240.

  On the other hand, in the sensor cap 900 according to the sixth modified example, as shown in FIG. 8, the lead surrounding portion 923 includes a contact surrounding portion 923 j that is in close contact with the outer periphery of the first covering material 232 of the lead wire 230. . For this reason, even when a car is washed using a high-pressure washer, water can enter the sensor cap 900 at a high speed between the lead wire 230 (first covering member 232) and the lead enclosure 923 (adhesion enclosure 923j). There is no risk of entering.

  Further, in the sensor cap 900 of the sixth modification example, the projecting portion 923g (corresponding to the separation preventing portion) of the lead surrounding portion 923 is penetrated in a direction perpendicular to the axis LX (direction perpendicular to the paper surface in FIG. 8), Through holes 923h and 923i communicating with the small-diameter vent hole 923b are provided. As a result, as shown by the broken-line arrows in FIG. 9, the ventilation between the external space SPO and the cap terminal accommodating space SPS (internal space SPI) is appropriately performed through the through holes 923h and 923i and the small-diameter ventilation hole 923b. It can be carried out. As shown in FIG. 9, the through holes 923h and 923i are arranged at positions facing each other with the lead wire 230 interposed therebetween.

  Moreover, in the sensor cap 900 of the sixth modification, as shown by the two-dot chain lines arrows KS1 and KS2 in FIG. 9, the filter member 240 is not visible through the openings 923kh and 923ki of the through holes 923h and 923i. Holes 923h and 923i are arranged. In other words, the filter member 240 is disposed at a position where it cannot be seen through any of the openings 923kh and 923ki of the through holes 923h and 923i.

  For this reason, even if water enters from the outside through the openings 923 kh and 923 ki at high speed, the high speed water does not reach the filter member 240 directly. That is, the water that has entered from the outside through the openings 923 kh and 923 ki at high speed is made to collide with the inner wall surface that forms the through holes 923 h and 923 i and the small-diameter vent hole 923 b before reaching the filter member 240. The momentum (speed) can be reduced. Therefore, even when water enters at high speed through the openings 923 kh and 923 ki from the outside, the water can be prevented from passing through the filter member 240.

  By the way, even if the filter member 240 is disposed at a position where it cannot be visually recognized through the opening from the outside, when only one opening (for example, only the opening 923 khh) is provided, water can be quickly discharged from the opening (for example, the opening 923 khh). If the air continues to enter, the inside of the communication hole 923d (for example, the inside of the through hole 923h and the small diameter vent hole 923b) will be filled with water. In this state, when water enters at a high speed from an opening (for example, the opening 923 khh), the water pressure equivalent to that when the high-speed water directly reaches the filter member 240 is applied to the filter member 240, and the water droplets are filtered. There is a risk of passing through 240.

  On the other hand, in the sensor cap 900 of the sixth modification, two openings (opening 923kh and opening 923ki) are provided for the communication hole 923d that opens to the outside. Thereby, even if water continues to enter at a high speed from one opening (for example, opening 923 kh), the water can be discharged to the outside from the other opening (for example, opening 923 ki). There is no risk of water pressure being applied, and there is no risk of the above problems.

(Example 2)
Next, a gas sensor unit 1200 and a sensor cap 1000 according to the second embodiment will be described with reference to FIGS. The gas sensor unit 1200 of the second embodiment is different from the gas sensor unit 300 of the first embodiment only in the sensor cap, and the gas sensor is the same. Specifically, as shown in FIG. 10, the gas sensor 100 is the same as that of the first embodiment, and the sensor cap 1000 is different from that of the first embodiment.

  The sensor cap 1000 according to the second embodiment is different from the sensor cap 200 according to the first embodiment in the form of the covering member, the form of the filter member, and the arrangement position thereof. Therefore, in the following, the sensor cap 1000 according to the second embodiment will be described with a focus on differences from the sensor cap 200 according to the first embodiment.

  In the sensor cap 200 of the first embodiment, as shown in FIG. 3, the filter member 240 having the lead insertion hole 241 is used, and the lead wire 230 (first covering material 232) is inserted into the lead insertion hole 241. Thus, the filter member 240 is disposed in the lead enclosure 223 together with the lead wire 230.

On the other hand, in the sensor cap 1000 of the second embodiment, as shown in FIG. 11, a filter member 1040 having no lead insertion hole is used, and the filter member 1040 is provided in a filter enclosure provided separately from the lead enclosure portion 1027. It is arranged in the part 1023.
Specifically, the filter member 1040 is a filter member including a cylindrical main body portion 1041 and a smoothing processing portion 1042 surrounding the main body portion 243c in an annular shape. Further, unlike the first embodiment, the covering member 1020 is provided with communication holes 1023d (small-diameter vent holes 1023b and filter holding holes 1023c) on the side opposite to the lead surrounding portion 1027 when viewed from the axis CX. Accordingly, the filter member 1040 is disposed in the filter holding hole 1023 c separately from the lead wire 230.

  Further, in the second embodiment, the filter holding portion 1023e forming the filter holding hole 1023c is provided with annular protruding portions 1023m and 1023n protruding toward the inner side (the axis FX side of the filter member 1040), and the protruding portions 1023m, 1023n is brought into close contact with the outer peripheral surface 1040b of the filter member 1040 to hold the filter member 1040. That is, unlike Example 1, the inner wall surface of the filter holding portion 1023e is not brought into close contact with the entire outer peripheral surface 1040b of the filter member 1040 (smoothing processing portion 1042), but the annular protrusions 1023m and 1023n are connected to the filter member 1040. The outer peripheral surface 1040b is in close contact with the outer peripheral surface 1040b. Thereby, the contact | adhesion power of the inner wall face of the filter holding | maintenance part 1023e with respect to the outer peripheral surface 1040b of the filter member 1040 can be heightened, and the watertightness between the filter member 1040 and the filter holding | maintenance part 1023e can be improved.

  In addition, the filter surrounding portion 1023 forming the communication hole 1023d includes an overhanging portion 1023g having a diameter smaller than that of the filter holding portion 1023e at a position adjacent to the filter holding portion 1023e (left adjacent in FIG. 11). . The projecting portion 1023g is configured to project toward the inner side (axis FX side) than the filter holding portion 1023e. The presence of the projecting portion 1023g projecting toward the axis line FX prevents the filter member 1040 from coming out of the communication hole 1023d (small-diameter vent hole 1023b) outward (left side in FIG. 11). In the second embodiment, the overhanging portion 1023g corresponds to the separation preventing portion.

  The filter member 1040 is elastically deformed so as to increase the inner diameter of the overhanging portion 1023g, and the filter member 1040 is moved inwardly of the communication hole 1023d (rightward in FIG. 11) from the opening 1023k of the filter surrounding portion 1023. By pushing, it can be placed in the filter holding hole 1023c.

  12, an annular portion 1014 (first movement direction) located on the first movement direction side (upper side in FIG. 12) of the sensor connection portion 1011 (corresponding to the cylindrical portion) of the cap terminal 1010. (Corresponding to the side portion) has an abutting portion 1014 b that abuts against the inner surface 1028 of the covering member 1020. That is, the cap terminal 1010 is in contact with the inner surface 1028 of the covering member 1020 in the first movement direction (upward in FIG. 12). Therefore, as in the first embodiment, when the sensor cap 1000 is coupled to the gas sensor 100, the cap terminal 1010 can be connected to the sensor terminal 150 in a state where the movement of the cap terminal 1010 in the first movement direction is restricted.

  Therefore, in the second embodiment, when the sensor cap 1000 and the gas sensor 100 are coupled, the cap terminal 1010 is moved in the first movement direction (see FIG. 5) even if the annular portion 1014 of the cap terminal 1010 is brought into contact with the stopper 151f of the gas sensor 100. 12, there is no risk of displacement in the upward direction along the axis CX. Therefore, if the annular portion 1014 of the cap terminal 1010 is brought into contact with the stopper 151f of the gas sensor 100 and the sensor cap 1000 and the gas sensor 100 are coupled, as shown in FIG. However, the gas sensor unit 1200 appropriately connected at a predetermined position can be formed.

  Moreover, as shown in FIG. 12, the annular portion 1014 of the cap terminal 1010 has a separating portion 1014 c that is separated from the inner surface 1028 of the covering member 1020. That is, by expanding the cap terminal accommodating space SPS (internal space SPI) between the annular portion 1014 of the cap terminal 1010 and the inner surface 1028 of the covering member 1020, the annular portion 1014 of the cap terminal 1010 and the inner surface 1028 of the covering member 1020 are expanded. A part of a reference gas ventilation path P (indicated by a broken arrow in FIG. 10) formed from the outside is formed. For this reason, the outside air (reference gas) introduced from the external space SPO through the communication hole 1023d passes through the gap 1014c of the cap terminal 1010 and the inner surface 1028 of the covering member 1020 into the cylinder of the insertion portion 1016 of the cap terminal 1010. Can lead. Accordingly, it is possible to introduce the outside air (reference gas) into the gas detection element 120 of the gas sensor 100 as indicated by the dashed arrow in FIG.

(Modification 7)
Next, a sensor cap 1100 according to a modification of the second embodiment will be described with reference to FIGS. The sensor cap 1100 of the present modification 7 differs from the sensor cap 1000 of the second embodiment in the form of the filter surrounding portion (specifically, the communication hole), and is otherwise substantially the same. Therefore, the description of the same part as that of the second embodiment is omitted or simplified, and the different part will be mainly described.

  In the sensor cap 1000 of Example 2, as shown in FIG. 11, the communication hole 1023d is a through hole coaxial with the axis FX of the filter member 1040. For this reason, the filter member 1040 can be visually recognized from the opening 1023k of the communication hole 1023d. However, when the gas sensor unit with the sensor cap 1000 attached to the gas sensor 100 is attached to a vehicle, for example, as shown in FIG. 1 and washed with a high pressure washer, high-speed water enters from the opening 1023k, The possibility of reaching the filter member 1040 directly is considerable. In this case, a water pressure exceeding the water pressure resistance of the filter member 1040 is applied to the filter member 1040, and there is a possibility that water droplets may pass through the filter member 1040.

  On the other hand, in the sensor cap 1100 of the present modified example 7, as shown in FIG. 13, a protruding portion 1123g (corresponding to a detachment preventing portion) that forms a small-diameter vent hole 1123b in the filter surrounding portion 1123 is provided. It is made into the shape and it is set as the form which does not open in the outer direction (left direction in FIG. 13) along the axis line FX. Then, a through hole 1123h (see FIG. 14) and a through hole 1123i are provided which penetrate the projecting portion 1123g in a direction orthogonal to the axis FX (a direction orthogonal to the paper surface in FIG. 13) and communicate with the small diameter vent hole 1123b. Yes. As a result, as shown by the broken-line arrows in FIG. 13, the ventilation between the external space SPO and the cap terminal accommodating space SPS (internal space SPI) is appropriately performed through the through holes 1123h and 1123i and the small-diameter ventilation holes 1123b. It can be carried out.

  In addition, in the sensor cap 1100 of the seventh modification, as shown by the two-dot chain lines arrows KS1 and KS2 in FIG. 14, the filter member 1040 cannot be seen through the openings 1123kh and 1123ki of the through holes 1123h and 1123i. Holes 1123h and 1123i are arranged. In other words, the filter member 1040 is arranged at a position where it cannot be seen through any of the openings 1123kh and 1123ki of the through holes 1123h and 1123i.

  For this reason, even if water enters from the outside through the openings 1123 kh and 1123 ki at high speed, the high speed water does not reach the filter member 1040 directly. That is, before reaching the filter member 1040, the water that has entered from the outside through the openings 1123kh and 1123ki collides with the inner wall surface that forms the through-holes 1123h and 1123i and the small-diameter vent hole 1123b, and reaches the filter member 1040. Momentum (speed) can be reduced. Therefore, even when water enters at high speed through the openings 1123 kh and 1123 ki from the outside, the water can be prevented from passing through the filter member 1040.

Furthermore, in the sensor cap 1100 of the seventh modification, two openings (opening 1123 kh and opening 1123 ki) are provided for the communication hole 1123 d that opens to the outside. Thereby, even if water continues to enter from one opening (for example, opening 1123 kh) at high speed, the water can be discharged to the outside from the other opening (for example, opening 1123 ki).
In particular, in Modification 7, as shown in FIG. 14, the through holes 1123h and 1123i are arranged at positions facing each other with the small-diameter vent hole 1123b interposed therebetween. For this reason, the water which entered at high speed from one opening (for example, opening 1123 kh) is smoothly discharged to the outside from the other opening (for example, opening 1123 ki). Therefore, there is no possibility that a high water pressure is applied to the filter member 1040, and there is no possibility that the above-described problems occur.

  Further, as shown in FIG. 13, also in the seventh modification, similarly to the second embodiment, the filter holding portion 1123e is provided with annular projecting portions 1123m and 1123n that project toward the inner side (axis FX side), The protrusions 1123m and 1123n are brought into close contact with the outer peripheral surface 1040b of the filter member 1040 to hold the filter member 1040. Thereby, the adhesive force of the inner wall surface of the filter holding | maintenance part 1123e with respect to the outer peripheral surface 1040b of the filter member 1040 can be heightened, and the watertightness between the filter member 1040 and the filter holding | maintenance part 1123e can be improved.

  As shown in FIG. 12, also in the present modified example 7, in the same manner as in the second example, among the sensor connection parts 1011 (corresponding to the cylindrical part) of the cap terminal 1010, the first movement direction side (FIG. 12). The annular portion 1014 (corresponding to the first moving direction side portion) located on the upper side in FIG. 1 has an abutting portion 1014b that abuts against the inner surface 1128 of the covering member 1120. That is, the cap terminal 1010 is in contact with the inner surface 1128 of the covering member 1120 in the first movement direction (upward in FIG. 12). Therefore, as in the first embodiment, when the sensor cap 1100 is coupled to the gas sensor 100, the cap terminal 1010 can be connected to the sensor terminal 150 in a state where movement of the cap terminal 1010 in the first movement direction is restricted.

  Therefore, in the seventh modification as well, as in the second embodiment, even when the annular portion 1014 of the cap terminal 1010 is brought into contact with the stop portion 151f of the gas sensor 100 when the sensor cap 1100 and the gas sensor 100 are coupled, the cap terminal 1010 There is no risk of displacement in the first movement direction. For this reason, if the annular portion 1014 of the cap terminal 1010 is brought into contact with the stop portion 151f of the gas sensor 100 and the sensor cap 1100 and the gas sensor 100 are coupled, the cap terminal 1010 and the sensor terminal 150 are properly connected at predetermined positions. Can be connected to.

  Furthermore, as in the second embodiment, as shown in FIG. 12, the annular portion 1014 of the cap terminal 1010 has a separation portion 1014 c that is separated from the inner surface 1128 of the covering member 1120. That is, by expanding the cap terminal accommodating space SPS (internal space SPI) between the annular portion 1014 of the cap terminal 1010 and the inner surface 1128 of the covering member 1120, the annular portion 1014 of the cap terminal 1010 and the inner surface 1128 of the covering member 1120. A part of a reference gas ventilation path P (indicated by a dashed arrow in FIG. 13) introduced from the outside is formed. For this reason, outside air (reference gas) introduced from the external space SPO through the communication hole 1123d passes through the space 1014c of the cap terminal 1010 and the inner surface 1128 of the covering member 1120 into the cylinder of the insertion portion 1016 of the cap terminal 1010. Can lead. Therefore, even if the sensor cap 1100 of the present modification 7 is used, outside air (reference gas) is placed inside the gas detection element 120 of the gas sensor 100 as shown by the dashed arrows in FIG. It becomes possible to introduce.

As mentioned above, although this invention was demonstrated according to Example 1, 2, and the modifications 1-7, this invention is not limited to the said Example etc., In the range which does not deviate from the summary, it changes suitably. Needless to say, this is applicable.
For example, in the above-described first embodiment, the lead insertion hole 241 is provided in the filter member 240 and the like, and the lead wire 230 is passed through the lead device and the subsequent 241. However, the lead wire may be separately taken out from the other part of the covering member, and the filter member may be ventilated.

In Example 1 and Modifications 1 and 2, the lead crimping portion 242 and the like of the filter member 240 are crimped by the filter crimping portion 213 and the like that are part of the cap terminal 210. However, it is not necessary to use a part of the cap terminal 210 or the like for crimping the lead crimping part 242 or the like, and the lead crimping part may be crimped using a crimping member prepared separately from the cap terminal. Anyway.
Furthermore, in Example 1 and Modifications 1 to 3, the filter member 240 and the like are connected to the inner side (cap terminal housing space SPS side, cap terminal sensor connection side, left side in FIG. 3) from the outer peripheral contact portion 243. The caulking portion 242 is arranged. However, it is also possible to arrange the lead crimping portion on the outer side (outer space side, small-diameter vent hole side, right side in FIG. 3) from the outer peripheral contact portion, and crimp it with a crimping member. Furthermore, the lead caulking portion may be disposed so as to be positioned in the small-diameter vent hole.

In addition, in any of the embodiments, the filter member 240 or the like is not disposed in the small-diameter vent hole 223c or the like as the filter member 240 or the like.
However, as shown by a broken line in FIG. 3, for example, a small-diameter-large-diameter-small three-stage shape is further provided in the small-diameter vent hole 223c and further provided with an outer projecting portion 245 projecting from the overhang portion 223g. These filter members can also be used. When the outer protrusion 245 is thus provided to eliminate the depression due to the small diameter vent 223c, for example, the axis LX coincides with the vertical line, and in the sensor cap 200, the sensor connecting portion 211 is located below the filter member 240. When this gas sensor unit is used in the form located at the position, water can be accumulated in the small-diameter vent hole 223c, and the problem that it is difficult to vent through the filter member can be prevented.
As described above, even if the lead caulking portion is provided in the small-diameter vent hole, the depression due to the small-diameter vent hole 223c can be eliminated. Therefore, it is only necessary that the depression due to the small diameter vent hole 223c can be eliminated by the filter member.

It is explanatory drawing which shows a mode when the gas sensor unit 300 concerning Example 1 and this are used. 1 is a partial cross-sectional view of a gas sensor 100 according to Example 1. FIG. 1 is a partial cross-sectional view of a sensor cap 200 according to Example 1. FIG. It is a figure which shows the cap terminal used for the sensor cap concerning Example 1, (a) is a front view, (b) is a bottom view. In the filter member used for the sensor cap concerning Example 1, it is explanatory drawing which shows the smoothing process of an outer periphery contact | adherence part. It is a fragmentary sectional view showing an important section of a sensor cap concerning modification 1, 2, and 3. (a) is modification 1, (b) is modification 2, and (c) is a fragmentary sectional view concerning modification 3. It is. FIG. 10 is a partial cross-sectional view showing a main part of a sensor cap according to modified examples 4 and 5, and FIG. 9A is a partial cross-sectional view according to modified example 4 and FIG. 14 is a partial cross-sectional view of a sensor cap 900 according to Modification 6. FIG. It is an AA arrow fragmentary sectional view of FIG. It is explanatory drawing which shows a mode when the gas sensor unit 1200 concerning Example 2 and this are used. It is a fragmentary sectional view of the sensor cap 1000 concerning Example 2. FIG. It is the BB arrow partial sectional view of FIG. 11, and DD arrow partial sectional drawing of FIG. 10 is a partial cross-sectional view of a sensor cap 1100 according to Modification 7. FIG. It is CC sectional view taken on the line of FIG.

Explanation of symbols

AX (gas sensor) axis 100 gas sensor 120 gas detection element 130 enclosure 130d outer peripheral surface 150 sensor terminal 151 output side terminal part 153 element side terminal part 161 metal shell 200, 400, 500, 600, 700, 800, 900, 1000, 1100 Sensor cap 210, 410, 510, 610, 710, 810, 1010 Cap terminal 211, 1011 Sensor connection part (tubular part)
213, 413, 513, filter caulking part (caulking member)
613 Caulking member 214, 1014 annular portion (first movement direction side portion)
215 Gripping part (holding part)
215b, 215ba, 215bb, 215bc Split gripping part 215c, 215ca, 215cb, 215cc Protruding part 215d (Surface gripping part) tip side end SL1, SL2 Split slit SL3 Split slit 216 Insertion part 216a Conducting parts 220, 420, 520, 620, 720, 820, 1020, 1120 Cover member (enclosure member)
222 Outer periphery covering portion 222b Holding portion surrounding portion 222c Adhering portion 223d, 423d, 523d, 623d, 723d, 823d, 923d, 1023d, 1123d Communication hole 230 Lead wire 240, 440, 540, 640, 740, 840, 1040 Filter member ( Filter member)
241, 441, 541, 641, 741, 841 Lead insertion hole LX (lead insertion hole) axis 242, 442, 542, 642 Lead crimping portion 242 b (inside lead crimping portion) inner wall surface 243, 443, 543, 643 , 743, 843, 1042 Outer peripheral contact portion 243 b (outer peripheral contact portion) outer peripheral surface 243 c (outer peripheral contact portion) main body 243 d, 443 d, 543 d, 743 d, 843 d (outer peripheral contact portion) smoothing processing unit 245 outer protrusion 250 Unprocessed filter member 253 Unprocessed large diameter portion 750, 850 Adhesive sealant 300, 1200 Gas sensor unit SPI Internal space SPO External space (external)
SPS cap terminal accommodating space 1023m, 1023n, 1123m, 1123n Protruding part 223g, 423g, 523g, 623g, 723g, 823g, 923g, 1023g, 1123g Overhanging part (detachment preventing part)
223k, 923kh, 923ki, 1023k, 1123kh, 1123ki Opening 214b, 1014b Abutting part 214c, 1014c Separating part

Claims (24)

A gas detection element, and
A gas sensor having a sensor terminal connected to an electrode formed on the gas detection element and transmitting an output signal from the gas detection element;
A sensor cap coupled to the gas sensor,
A cap terminal electrically connected to the sensor terminal; and
An enclosing member coupled to the gas sensor and forming an internal space with the gas sensor;
A gas sensor unit comprising: a sensor cap that transmits the output signal to an external device;
The surrounding member includes a communication hole that communicates the outside and the internal space,
The sensor cap is a gas sensor unit having a filter member having air permeability and water repellency, the filter member being capable of ventilating between the outside and the internal space and closing the communication hole in a watertight manner. The gas sensor unit according to claim 1,
At least one of the surrounding member and the filter member is made of an elastic material,
A gas sensor unit in which an inner wall surface of the communication hole of the surrounding member and an outer surface of the filter member are in elastic and watertight contact. The gas sensor unit according to claim 1,
The filter member is
It is made of a water-repellent material having air permeability at least in the axial direction of the communication hole,
It has a peripheral contact portion that forms a column shape extending in the axial direction,
The surrounding member is made of a polymer material having elasticity, and by its own elasticity, the inner wall surface of the communication hole is brought into close contact with the outer peripheral contact portion of the filter member to hold the filter member watertight. unit. The gas sensor unit according to claim 3,
The surrounding member is
A gas sensor unit comprising an annular projecting portion projecting inward at a portion forming the inner wall surface of the communication hole, the projecting portion being in close contact with a part of the outer peripheral surface of the outer peripheral contact portion of the filter member. . The gas sensor unit according to claim 3 or 4,
The filter member is
The gas sensor unit in which the outer peripheral surface which contact | abuts the inner wall surface of the said communicating hole of the said surrounding member among the said outer periphery contact | adherence parts is smoothed. The gas sensor unit according to any one of claims 2 to 5,
The surrounding member is
A gas sensor unit comprising a separation preventing unit that prevents the filter member from separating through the communication hole. The gas sensor unit according to any one of claims 2 to 6,
The sensor cap is
A lead wire connected to the cap terminal and sending the output signal to the outside,
The filter member is
Penetrating along the axis of the communication hole, including a lead insertion hole formed by inserting the lead wire,
The gas sensor unit, wherein the lead wire is watertightly held by the filter member. The gas sensor unit according to claim 7,
The sensor cap is
With a caulking member,
The filter member is
An outer periphery contact portion having a column shape extending in the axial direction;
The outer peripheral contact portion is located at a different part in the axial direction, and includes a lead crimping portion having a diameter smaller than that of the outer peripheral contact portion,
A gas sensor unit comprising: the lead caulking portion fitted on the lead caulking portion and caulked to hold the lead wire in a watertight manner in the lead insertion hole. The gas sensor unit according to any one of claims 1 to 8,
The surrounding member is a gas sensor unit made of fluororubber. The gas sensor unit according to any one of claims 1 to 9,
The communication hole includes a plurality of openings that open to the outside,
The gas sensor unit, wherein the filter member is disposed at a position where it cannot be visually recognized through any of the plurality of openings from the outside. The gas sensor unit according to any one of claims 1 to 10,
The gas detection element is a gas detection element that utilizes a reference gas introduced from the outside into the internal space through the communication hole,
A gas sensor unit in which an air passage for guiding the reference gas introduced from the outside to the gas detection element is formed between the filter member and the gas detection element. The gas sensor unit according to claim 11,
When the relative movement direction of the gas sensor when combining the sensor cap and the gas sensor is the first movement direction,
The cap terminal is a cylindrical portion that extends in the first movement direction, and has a cylindrical portion that constitutes a part of the air passage.
The first movement direction side portion located on the first movement direction side in the cylindrical portion is:
An abutting portion that abuts the inner surface of the surrounding member and the first moving direction;
A separating portion that is spaced apart from the inner surface of the surrounding member,
The sensor cap is configured to introduce the reference gas into the cylindrical portion through the space between the cap terminal and the inner surface of the surrounding member. A sensor cap that is coupled to a gas sensor having a gas detection element and a sensor terminal that is connected to an electrode formed on the gas detection element and transmits an output signal from the gas detection element, and transmits the output signal to an external device Because
A cap terminal electrically connected to the sensor terminal;
An enclosing member that constitutes a cap terminal accommodating space that forms an internal space with the gas sensor when the cap cap is accommodated and the sensor cap is coupled to the gas sensor,
An enclosing member including a communication hole communicating the outside and the cap terminal housing space;
A sensor cap having a breathability and water repellency, and a filter member capable of ventilating between the outside and the cap terminal housing space and closing the communication hole in a watertight manner. The sensor cap according to claim 13,
At least one of the surrounding member and the filter member is made of an elastic material,
A sensor cap in which an inner wall surface of the communication hole of the surrounding member and an outer surface of the filter member are in elastic and watertight contact. The sensor cap according to claim 13,
The filter member is
It is made of a water-repellent material having air permeability at least in the axial direction of the communication hole,
It has a peripheral contact portion that forms a column shape extending in the axial direction,
The surrounding member is made of a polymer material having elasticity, and the inner wall surface of the communication hole is brought into close contact with the outer peripheral contact portion of the filter member by its own elasticity, thereby holding the filter member watertight. cap. The sensor cap according to claim 15, wherein
The surrounding member is
A sensor cap comprising an annular projecting portion projecting inward at a portion forming the inner wall surface of the communication hole, the projecting portion being in close contact with a part of the outer peripheral surface of the outer peripheral contact portion of the filter member . A sensor cap according to claim 15 or claim 16, wherein
The filter member is
The sensor cap formed by smoothing the outer peripheral surface which contact | abuts the inner wall surface of the said communicating hole of the said surrounding member among the said outer periphery contact | adherence parts. The sensor cap according to any one of claims 14 to 17,
The surrounding member is
A sensor cap comprising a separation preventing portion for preventing the filter member from separating through the communication hole. The sensor cap according to any one of claims 14 to 18, comprising:
A lead wire connected to the cap terminal and sending the output signal to the outside,
The filter member is
Penetrating along the axis of the communication hole, including a lead insertion hole formed by inserting the lead wire,
The lead wire is a sensor cap that is watertightly held by the filter member. The sensor cap according to claim 19, wherein
With a caulking member,
The filter member is
An outer periphery contact portion having a column shape extending in the axial direction;
The outer peripheral contact portion is located at a different part in the axial direction, and includes a lead crimping portion having a diameter smaller than that of the outer peripheral contact portion,
A sensor cap formed by fitting the caulking member to the lead caulking portion and caulking, and holding the lead wire in the lead insertion hole in a watertight manner. The sensor cap according to any one of claims 13 to 20,
The surrounding member is a sensor cap made of fluororubber. The sensor cap according to any one of claims 13 to 21,
The communication hole includes a plurality of openings that open to the outside,
The said filter member is a sensor cap arrange | positioned in the position which cannot be visually recognized through any of said some opening from the outside. The sensor cap according to any one of claims 13 to 22,
The gas detection element of the gas sensor coupled to the sensor cap is a gas detection element that uses a reference gas introduced into the internal space from the outside through the communication hole,
The sensor cap is
A sensor cap comprising a vent path configured to guide the reference gas introduced from the outside from the filter member to the gas detection element when the sensor cap and the gas sensor are combined. A sensor cap according to claim 23, wherein
When the relative movement direction of the gas sensor when combining the sensor cap and the gas sensor is the first movement direction,
The cap terminal is a cylindrical portion that extends in the first movement direction, and has a cylindrical portion that constitutes a part of the air passage.
The first movement direction side portion located on the first movement direction side in the cylindrical portion is:
An abutting portion that abuts the inner surface of the surrounding member and the first moving direction;
A separating portion that is spaced apart from the inner surface of the surrounding member,
The sensor cap is configured to introduce the reference gas into the cylindrical portion through the gap portion of the cap terminal and the inner surface of the surrounding member.

Images