JP2005010156A - Gas sensor, gas sensor cap and gas sensor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a low-cost gas sensor of which terminal member can be formed easily, a gas sensor cap connected to the gas sensor, for transmitting an output signal to an external device, and a gas sensor unit capable of keeping a stable electrical connection state between the terminal member of the gas sensor and the gas sensor cap. <P>SOLUTION: This gas sensor 100 is equipped with a gas detection element 120 and the terminal member 150. The terminal member 150 comprises a plate having a prescribed bent shape, and has an output side terminal part 151 to be elastically enlarged when connected to a cap terminal 211, which is the cylindrical output side terminal part 151 electrically connected to the cap terminal 211, for outputting an output signal of the gas detection element 120, and an element side terminal part 153 to be inserted into the gas detection element 120, while being elastically contracted, which is the cylindrical element side terminal part 153 electrically connected to an inside electrode 112. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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

  Conventionally, various gas sensors having a gas detection element made of ceramic 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 include a bottomed cylindrical gas detection element made of ceramic and a cylindrical terminal member that outputs an output signal from the gas detection element to the outside. Among these, the terminal member is expensive because it is formed by processing a rod-shaped metal body (bar material or pipe material). In addition, since this terminal member has high rigidity, an electrically conductive packing having elasticity is interposed between the terminal member and the inner electrode formed on the inner peripheral surface of the gas detection element for good electrical connection. I was letting. For this reason, the gas sensors of Patent Document 1 and Patent Document 2 have become even more expensive.

  Further, although Patent Document 1 and Patent Document 2 do not describe a connection cord for electrically connecting a gas sensor and an external device (for example, ECU), it is connected to a terminal member of the gas sensor due to the influence of vibration or the like. There was a danger that the connection between the cord terminals was interrupted and noise was generated. For this reason, an electrical connection such as a gas sensor or a connection cord (gas sensor cap) that can maintain a stable electrical connection state between the terminal member of the gas sensor and an external terminal (cap terminal) provided on the connection cord (gas sensor cap). There has been a need for tools and gas sensor units containing them.

  The present invention has been made in view of the current situation, and is a low-cost gas sensor in which a terminal member can be easily formed, a gas sensor cap that is connected to the gas sensor and transmits an output signal to an external device, and a terminal of the gas sensor It is an object of the present invention to provide a gas sensor unit that can maintain a stable electrical connection state between a member and a gas sensor cap.

  The solution is a gas sensor comprising: a gas detection element; and a terminal member that is connected to an electrode formed on the gas detection element, and is connected to an external terminal and outputs an output signal from the gas detection element to the outside. The terminal member is an output-side terminal portion that is electrically connected and outputs the output signal while engaging with the external terminal, and the external terminal and the external terminal are connected when the external terminal is connected. An output including a plurality of contact points that elastically contact the external terminal and hold the external terminal along an orthogonal direction orthogonal to a moving direction that relatively moves at least one of the output side terminal portions. A gas sensor having a side terminal part and an element side terminal part electrically connected to the electrode.

In the gas sensor of the present invention, the output side terminal portion of the terminal member includes a plurality of contact points that elastically contact the external terminal along an orthogonal direction orthogonal to the moving direction.
Therefore, when the external terminal and the output side terminal portion of the terminal member are connected, the output side terminal portion contacts the external terminal at a plurality of contact points and elastically presses and electrically connects the external terminal. . That is, conduction between the gas sensor and the external terminal can be secured at a plurality of contact points, and each contact point is elastically pressed. For this reason, due to vibration or the like, the connection between the external terminal and the output side terminal portion is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced. In addition, since the output side terminal portion of the gas sensor is elastically connected to the external terminal along the orthogonal direction, when the external terminal is moved relative to the moving direction and attached to and detached from the output side terminal portion, Good detachability.

In addition, the output side terminal portion may be elastically contacted with the external terminal at a plurality of contact points along the orthogonal direction and hold the external terminal, and depending on the shape of the external terminal, a plurality of contact points are generated, What is necessary is just to select a form suitably so that it may arrange | position appropriately. As the form of the output side terminal portion, it should be different according to the shape (form) of the external terminal. For example, a plate material is wound in a cylindrical shape, and the cross section orthogonal to the axial direction is substantially C-shaped. Can be mentioned. Moreover, the form which wound the board | plate material so that a part might overlap and was made into the cylinder shape is also mentioned. In the output-side terminal portion of these forms, a form in which the outer peripheral surface of the external terminal is elastically wound from the outside, or a form in which the outer peripheral surface of the cylindrical external terminal is elastically pressed and expanded from the inner side in the radial direction Connect to the external terminal with. For this reason, the output-side terminal portion is in contact with the surface or the line according to the form of the external terminal with respect to the outer peripheral surface or the inner peripheral surface of the external terminal, and there are many contact points. . Or it has a some contact point by contacting the protrusion part formed in the outer peripheral surface or inner peripheral surface of an external terminal. In the output side terminal portion of these forms, the moving direction is a direction along the axis of the output side terminal portion, and the orthogonal direction is the radial direction of the output side terminal portion.
Furthermore, in the output terminal portion of the form in which the above-mentioned plate material is wound in a cylindrical shape and the cross section perpendicular to the axial direction is substantially C-shaped, or the plate material is wound in a tubular shape so as to partially overlap, It is good also as a form which provided the 1 or several protrusion part contacted with an external terminal. Further, the output-side terminal portion may have a substantially circular or substantially polygonal cross-sectional shape orthogonal to the axial direction.

  Furthermore, it is a portion sandwiched between two slits extending in the direction along the axial direction formed on the side surface of a cylindrical main body portion such as a cylindrical shape, and has an arc shape toward the radially outer side or the radially inner side. The slit type | mold protrusion part which protrudes and is formed in the form of this, and can move elastically in radial direction is disperse | distributed and arrange | positioned in the circumferential direction of a cylindrical main-body part, and the thing is mentioned. Furthermore, it is a tongue-like portion formed by a U-shaped slit on the side surface of a cylindrical body portion such as a cylindrical shape, and its tip protrudes obliquely toward the radially outer side or the radially inner side. In addition, there may be mentioned one in which a tongue-shaped protruding portion that is elastically movable in the radial direction is arranged at a plurality of locations in the circumferential direction of the cylindrical main body portion.

  Further, in the gas sensor described above, the output side terminal portion has the plurality of contact points arranged on a virtual cylinder passing through these, and when connected to the external terminal, the virtual cylinder expands or contracts. A gas sensor in which the plurality of contact points move so as to have a diameter may be used.

In the gas sensor of the present invention, the output side terminal portion of the terminal member has a plurality of contact points that are elastically in contact with the external terminal arranged on the virtual cylinder. A plurality of contact points move to reduce the diameter.
Therefore, when the external terminal and the output side terminal portion of the terminal member are connected, the output side terminal portion contacts the external terminal at a plurality of contact points, and the external terminal is placed radially outside or radially inside the virtual cylinder. Electrical connection while elastically pressing. That is, each contact point that conducts the gas sensor and the external terminal is elastically pressed from the radially outer side or the radially inner side. For this reason, instantaneous disconnection of the connection between the external terminal and the output side terminal due to vibration or the like can be prevented, and the detachability with respect to the external terminal is good, and in connecting the output side terminal with the external terminal, the virtual cylinder Since there is no dependency on the connection direction around the axis, and the output side terminal portion and the external terminal can be connected from any direction, the attachment is further facilitated.

The virtual cylinder is a form in which a virtual circle having a certain diameter is extended in the axial direction, and a plurality of contact points are arranged on the virtual cylinder. Even when a plurality of contact points are located on one virtual circle, the plurality of contact points are arranged on the virtual cylinder at the same position in the axial direction but at different positions in the circumferential direction. To do.
An output that has a plurality of contact points that elastically contact the external terminal, and these contact points move so that the virtual cylinder expands or contracts when connected to the external terminal. As the form of the side terminal portion, although it differs depending on the shape (form) of the external terminal, for example, as described above, the plate material is wound into a cylindrical shape, and the cross section perpendicular to the axial direction is substantially C-shaped, One example is one in which plate materials are wound so as to partially overlap to form a cylindrical shape. In the output side terminal portion of these forms, when the outer peripheral surface is connected to a cylindrical solid rod-shaped or hollow cylindrical external terminal, the output side is wrapped around the cylindrical outer peripheral surface of the external terminal. The terminal part contacts the external terminal. Therefore, in this case, since the outer peripheral surface of the external terminal contacts in a planar or linear manner, there are a large number of contact points. Moreover, these contact points are arranged on a virtual cylinder that coincides with the outer peripheral surface of the external terminal. On the other hand, when the output-side terminal portion of these forms is not connected to the external terminal and is in a free state, each contact point (part to be a contact point) is on a virtual cylinder having a smaller diameter than the above case. Placed in. That is, in these output side terminal portions, when connected to the external terminal, the contact point moves so that the diameter of the virtual cylinder increases. Even if the same output side terminal part is used, if it is connected to an external terminal provided with a plurality of protrusions protruding outward in the radial direction on the outer peripheral surface, it should be wrapped around the outer periphery of this external terminal. Thus, the output side terminal portion comes into contact with the external terminal, but a plurality of portions respectively in contact with the tops of the protrusions of the external terminal serve as contact points, and each contact point is arranged on a virtual cylinder. On the other hand, in the free state, each contact point is arranged on a virtual cylinder having a smaller diameter. Therefore, also in this case, in the output terminal portion of these forms, when connected to the external terminal, the contact point moves so that the virtual cylinder expands in diameter. In addition, the slit-type protrusions described above are dispersed at a plurality of locations in the circumferential direction of the cylindrical main body, and the tongue-type protrusions are dispersed at a plurality of locations in the circumferential direction of the cylindrical main body. The one arranged is also mentioned.

  Furthermore, it is a gas sensor of Claim 1 or Claim 2, Comprising: The said gas detection element consists of ceramics, it has a bottomed cylindrical shape where the axial direction front end side closed, and the said electrode is the said gas detection element. It is an inner electrode formed on the inner peripheral surface, the terminal member is made of a bent plate material having a predetermined shape, and the output terminal portion is cylindrical and elastic when connected to the external terminal. An output-side terminal portion that expands or contracts in diameter, and the element-side terminal portion has a cylindrical shape that is electrically connected to the inner electrode, and is inserted into the gas detection element while elastically reducing the diameter. The gas sensor is good.

  The gas sensor of the present invention has a cylindrical output-side terminal portion that elastically expands or contracts in diameter when connected to an external terminal. Accordingly, when the external terminal and the output side terminal portion are connected, the output side terminal portion is electrically connected while pressing the external terminal radially outward or radially inward. For this reason, due to vibration or the like, the connection between the external terminal and the output side terminal portion is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced. Moreover, since the output side terminal part of a gas sensor is the structure connected with an external terminal with the elastic force of itself (plate material), the attachment or detachment with respect to an external terminal becomes favorable.

  Furthermore, it has a cylindrical element-side terminal portion that is inserted into the gas detection element while being elastically reduced in diameter and is electrically connected to the inner electrode. Therefore, in this gas detection element, the element side terminal portion electrically connects the inner electrode while pressing the inner electrode from the inner side toward the outer side in the radial direction. For this reason, due to the influence of vibration or the like, the connection between the two is interrupted and the risk of generating noise can be reduced. Further, since the element side terminal portion is elastically reduced in diameter, it can be directly connected to the inner electrode. For this reason, as compared with the conventional case where the conductive packing having elasticity is interposed, the conductive packing is not required, so that the number of parts can be reduced and the cost can be reduced.

  Further, the terminal member having such an output side terminal part and an element side terminal part is made of a plate material having a predetermined shape which is bent. For this reason, the terminal member itself is easy to form, and the cost is low.

The terminal member of the present invention may be formed by connecting a plurality of members obtained by bending a plate material by welding or the like, but using a single metal plate, the output side terminal portion and the element side terminal portion are Each is preferably formed into a cylindrical shape.
Moreover, as a cylindrical form in an output side terminal part and an element side terminal part, what made the cross section orthogonal to an axial direction substantially C-shaped is mentioned, for example. Moreover, the form which rolled the board | plate material and was made into the cylinder shape so that a part may overlap may be sufficient. Further, the cross-sectional shape orthogonal to the axial direction is not limited to a substantially C shape, and may be a substantially circular shape, a substantially polygonal shape, or the like.

Furthermore, the gas sensor is preferably a gas sensor in which the inside of the gas detection element communicates with the outside of the gas sensor through the inside of the output side terminal portion and the element side terminal portion of the terminal member.
As described above, the terminal member of the present invention is made of a bent plate material, and has a cylindrical output-side terminal portion and element-side terminal portion. Therefore, the inside of the gas detection element (inside the cylinder) and the outside of the gas sensor communicate with each other through the inside of the output side terminal part and the element side terminal part (inside the cylinder). In other words, the terminal member constitutes a ventilation path for introducing the reference gas (outside air) into the gas detection element. For this reason, in the gas sensor of the present invention, it is not necessary to separately form a ventilation path for introducing the reference gas (outside air) to the inside of the gas detection element, and further, a work for forming a separate ventilation path for the terminal member. Since (for example, a perforation process) is not required, the cost is reduced.

  Further, in the gas sensor described above, it is preferable that the terminal member is a gas sensor in which the element side terminal portion is positioned on the distal end side in the axial direction with respect to the output side terminal portion. By setting the output-side terminal portion and the element-side terminal portion in such a positional relationship, the terminal member can be easily formed, and the gas sensor is inexpensive. Furthermore, since the ventilation path constituted by this terminal member has a shape extending in the axial direction, the reference gas (outside air) is easily introduced into the gas detection element.

  Furthermore, in any one of the above gas sensors, the output side terminal portion is an output side terminal portion that elastically contracts a diameter when inserted and connected to the inside of the external terminal. Of the side terminal portions, the rear end portion located on the rear end side in the axial direction is preferably a gas sensor having a shape bent inward.

  A terminal member made of a bent plate material tends to be less rigid than a member formed by processing a rod-shaped metal body. By the way, among the terminal members, in particular, the output side terminal portion connected to the external terminal is easily subjected to a load due to the influence of external vibration. On the other hand, in the gas sensor of the present invention, the rear end portion of the output side terminal portion has a shape bent inward, and the diameter of the rear end portion becomes smaller toward the rear end side. Yes. Thereby, rigidity can be made high, enabling the output side terminal part to elastically reduce the diameter.

  Another solution is the gas sensor according to claim 1 or 2, wherein the gas detection element is made of ceramic and has a bottomed cylindrical shape with a closed end in the axial direction. An inner electrode formed on the inner peripheral surface of the gas detection element, made of an insulating ceramic, and having a cylindrical envelope surrounding the gas detection element and the terminal member, and the terminal member is bent. The output-side terminal portion is cylindrical, and when the external terminal is inserted and connected to the inside thereof, the diameter of the output-side terminal portion is elastically expanded so that the outer peripheral surface and the surrounding surface are enclosed. An output side terminal portion in which a gap with the inner peripheral surface of the body is smaller than that before insertion, and the element side terminal portion is a cylindrical shape electrically connected to the inner electrode, and is elastically reduced in diameter as described above. It is a gas sensor inserted in a gas detection element.

The terminal member of the gas sensor of the present invention elastically expands the diameter when the external terminal is inserted and connected to the inside, so that the gap between the outer peripheral surface of the gas sensor and the inner peripheral surface of the enclosure is larger than before insertion. It has a smaller output side terminal portion. Therefore, when an external terminal is connected to the gas sensor of the present invention, the gap between the inner peripheral surface of the enclosure and the outer peripheral surface of the output side terminal portion is smaller than before connection. For this reason, in the gas sensor of the present invention, when used, the output side terminal portion surrounded by the enclosure is less likely to swing in the radial direction due to the influence of external vibrations. Fatigue failure (cracking, breakage, etc.) at a portion between the output side terminal portion and the element side terminal portion of the terminal member due to influence can be suppressed.
The terminal member of the gas sensor of the present invention is also made of a plate material having a predetermined shape that is bent. For this reason, the terminal member itself is easy to form, and the cost is low.

  Further, in the gas sensor described above, it is preferable that the terminal member is a gas sensor in which the element side terminal portion is positioned on the distal end side in the axial direction with respect to the output side terminal portion. By setting the output-side terminal portion and the element-side terminal portion in such a positional relationship, the terminal member can be easily formed, and the gas sensor is inexpensive. Furthermore, since the ventilation path constituted by this terminal member has a shape extending in the axial direction, the reference gas (outside air) is easily introduced into the gas detection element.

  Furthermore, in any of the above gas sensors, the terminal member may be a gas sensor formed integrally with a single plate material.

  The gas sensor of the present invention uses a terminal member formed integrally from a single plate material. Such a terminal member is low in cost because of easy molding.

  Furthermore, it is a gas sensor as described in any one of the above-mentioned, Comprising: It is good for the said output side terminal member to be a gas sensor whose cross section orthogonal to an own axis line is C shape among the said terminal members.

  In the gas sensor of the present invention, the output side terminal portion has a C-shaped cross section perpendicular to its own axis. Such an output-side terminal portion can be easily formed, has a large deformation range, and can easily realize an output-side terminal portion having elasticity with a relatively large elastic coefficient, so that the external terminal can be held strongly.

  Another solving means is a gas sensor that is connected to a gas sensor having a gas detection element and a terminal member having an output side terminal portion that outputs an output signal from the gas detection element to the outside, and transmits the output signal to an external device. A cap that is electrically connected to the output-side terminal portion while being engaged with the output-side terminal portion; a covering portion that is made of insulating rubber and covers the cap terminal; and is electrically connected to the cap terminal. A lead wire that transmits the output signal to an external device, and the cap terminal elastically contacts the cap terminal of the output side terminal portion when connected to the output side terminal portion. A gas sensor cap having a rigidity for moving a plurality of contact points arranged on a virtual cylinder passing through the plurality of contact points so that the virtual cylinder expands or contracts. A.

When the cap terminal of the gas sensor cap of the present invention is connected to the output side terminal portion of the terminal member of the gas sensor, a plurality of the output side terminal portions that are elastically contacted with the cap terminal and disposed on the virtual cylinder. The contact point has a rigidity to move the virtual cylinder so that the diameter of the virtual cylinder is increased or decreased. Therefore, when the output side terminal portion and the cap terminal are connected (engaged), the plurality of contact points of the output side terminal portion are electrically pressed while elastically pressing the cap terminal radially outward or radially inward. Connect to.
For this reason, due to the influence of vibration or the like, the connection between the output-side terminal portion and the cap terminal is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced.

  The cap terminal is configured to be engaged with the output side terminal portion of the terminal member of the gas sensor. When the cap terminal is engaged with the output side terminal portion, a plurality of contact points of the output side terminal portion are defined as contact points. What is necessary is just to have the rigidity which moves the virtual cylinder in which the point is arranged so as to expand or contract the diameter, and examples thereof include a columnar shape and a cylindrical shape. Also, those having an outer diameter changing in the axial direction, such as a taper shape, a reverse taper shape, or having a small diameter portion in the middle of the axial direction, a solid rod-like or hollow cylindrical cap Examples include terminals. Moreover, a cap terminal in the form of a bell with one end closed can also be used.

  The other solving means is the gas sensor cap according to claim 8, wherein the output side terminal portion of the terminal member is cylindrical and the output side terminal portion can be elastically expanded or reduced in diameter. The cap terminal is a gas sensor cap that has a cylindrical shape and has a rigidity for expanding or reducing the diameter of the output-side terminal portion without deforming itself when connected to the output-side terminal portion.

  The gas sensor cap of the present invention includes a cylindrical cap terminal having rigidity that elastically expands or contracts the output-side terminal portion of the terminal member without deforming itself when connected to the gas sensor. . Therefore, when the output side terminal portion and the cap terminal are connected (engaged), the output side terminal portion electrically connects the cap terminal while elastically pressing the cap terminal radially outward or radially inward. For this reason, due to the influence of vibration or the like, the connection between the output-side terminal portion and the cap terminal is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced. In addition, since the cap terminal and the output side terminal portion of the terminal member are connected by the elastic force of the output side terminal portion, the cap terminal can be easily attached to and detached from the output side terminal portion of the terminal member.

  Another solution is a gas sensor cap that is connected to the gas sensor according to any one of the above-described embodiments and transmits the output signal to an external device, and the external terminal is engaged with the output-side terminal portion. A cylindrical cap terminal that is electrically connected, made of insulating rubber, and a covering portion that covers the cap terminal, and a lead that is electrically connected to the cap terminal and transmits the output signal to an external device. And the cap terminal, when connected to the output-side terminal part, moves the plurality of contact points of the output-side terminal part so that the virtual cylinder expands or contracts the diameter. It is a gas sensor cap which has.

When the gas sensor cap of the present invention is also connected to the output side terminal portion of the connection terminal of the gas sensor, among the output side terminal portions, a plurality of contact points arranged on the virtual cylinder elastically contact with the cap terminal. Is rigid so that the virtual cylinder is expanded or contracted. Therefore, when the output side terminal part and the cap terminal are connected (engaged), the output side terminal part electrically connects the cap terminal while elastically pressing the cap terminal radially outward or radially inward.
For this reason, due to the influence of vibration or the like, the connection between the output-side terminal portion and the cap terminal is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced. In addition, since the cap terminal and the output side terminal portion of the terminal member are connected by the elastic force of the output side terminal portion, the cap terminal can be easily attached to and detached from the output side terminal portion of the terminal member.

  Another solution includes a gas detection element and a gas sensor having a terminal member that is connected to an electrode formed on the gas detection element, and is connected to an external terminal and outputs an output signal from the gas detection element to the outside. A gas sensor unit having a cap terminal connected to the terminal member of the gas sensor and transmitting the output signal to an external device, wherein the terminal member is engaged with the cap terminal. An output-side terminal portion that is electrically connected to output the output signal, the moving direction for relatively moving at least one of the cap terminal and the output-side terminal portion when connecting to the cap terminal. A gas sensor unit including an output side terminal portion having a plurality of contact points that elastically contact the cap terminal along an orthogonal direction orthogonal to the cap terminal. It is a door.

The gas sensor unit of the present invention has a gas sensor and a gas sensor cap. Among these, the output side terminal portion of the terminal member of the gas sensor has a plurality of contact points that elastically contact the cap terminal along the orthogonal direction when connected (engaged) with the cap terminal of the gas sensor cap.
Since the output side terminal portion has such a configuration, in the gas sensor unit of the present invention, the plurality of contact points of the output side terminal portion are electrically connected while elastically pressing the cap terminal. For this reason, due to the influence of vibration or the like, the connection between the output-side terminal portion and the cap terminal is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced.

  In addition, since the cap terminal and the output side terminal portion of the terminal member are connected by the elastic force of the output side terminal portion along the orthogonal direction, the cap terminal is relatively moved in the moving direction, and the output side When attaching to and detaching from the terminal portion, the detachability of the cap terminal with respect to the output side terminal portion of the terminal member becomes good, and as a result, the detachability of the gas sensor cap with respect to the gas sensor becomes good.

  Further, in the gas sensor unit described above, the output side terminal portion of the terminal member has the plurality of contact points arranged on a virtual cylinder passing through these and when the virtual cylinder is connected to the cap terminal, The gas sensor unit may be an output side terminal portion in which the plurality of contact points move so as to expand or contract the diameter.

In the gas sensor unit of the present invention, the output-side terminal portion of the terminal member has a plurality of contact points that elastically contact the cap terminal arranged on the virtual cylinder, and passes through the contact points when contacting the cap terminal. The virtual cylinder moves so as to expand or contract.
Since the output side terminal portion has such a configuration, in the gas sensor unit of the present invention, the plurality of contact points of the output side terminal portion elastically press the cap terminal radially outward or radially inward. While making electrical connections. For this reason, momentary disconnection of the connection between the output side terminal portion and the cap terminal due to vibration or the like can be prevented, the detachability of the cap terminal to the output side terminal portion of the terminal member is good, and the output side terminal portion is connected to the cap terminal. When connecting, there is no dependency of the connection direction around the axis of the virtual cylinder, and the output side terminal portion and the cap terminal can be connected from any direction. Therefore, in this gas sensor unit, the gas sensor and the gas sensor cap are connected. Installation is even easier.

  Furthermore, in the gas sensor unit described above, the output-side terminal portion of the terminal member is a cylindrical shape, and is an output-side terminal portion that elastically expands or contracts when connected to the cap terminal, The cap terminal may be a gas sensor unit that has a cylindrical shape and is engaged with the output side terminal portion by expanding or reducing the diameter of the output side terminal portion without deforming itself.

  The gas sensor unit of the present invention has a gas sensor and a gas sensor cap. Among these, the terminal member of the gas sensor has a cylindrical shape and has an output-side terminal portion that is elastically expanded or contracted when connected to the cap terminal of the gas sensor cap. The gas sensor cap engages with the output side terminal portion by expanding or reducing the diameter of the output side terminal portion without deforming itself. Therefore, in the gas sensor unit of the present invention, the output side terminal portion electrically connects the cap terminal while elastically pressing the cap terminal radially outward or radially inward. For this reason, due to the influence of vibration or the like, the connection between the output-side terminal portion and the cap terminal is momentarily interrupted, and the risk of generating noise or the like (the risk of a decrease in gas detection accuracy) can be reduced.

  In addition, since the cap terminal and the output side terminal portion of the terminal member are connected by the elastic force of the output side terminal portion, the cap terminal is easily attached to and detached from the output side terminal portion of the terminal member. The detachability of the gas sensor cap with respect to the gas sensor is good.

  Furthermore, it is a gas sensor unit of Claim 11 or Claim 12, Comprising: The said gas sensor consists of an insulating ceramic, and has the cylindrical enclosure surrounding the said gas detection element and the said terminal member, The output-side terminal portion of the terminal member is cylindrical, and is an output-side terminal portion that expands elastically when the cap terminal is inserted and connected to the inside of the terminal member. When inserted and connected to the inside of the side terminal part, it has the rigidity to expand the diameter of the output side terminal part without deformation, and the cap terminal is inserted and connected to the inside of the output side terminal part. By doing so, the output side terminal portion is elastically expanded in diameter, and the gas sensor unit is configured such that the gap between the outer peripheral surface of the output side terminal portion and the inner peripheral surface of the enclosure is made smaller than before insertion. good.

  In the gas sensor unit of the present invention, when the cap terminal is inserted inside the output side terminal part and connected to each other, the output side terminal part elastically expands in diameter, and the outer peripheral surface of the output side terminal part and the enclosure The gap with the inner peripheral surface is smaller than before insertion. For this reason, in the gas sensor unit according to the present invention, the output side terminal portion surrounded by the enclosure is less likely to swing in the radial direction due to the influence of external vibration. Fatigue failure (cracking, breakage, etc.) at a portion between the side terminal portion and the element side terminal portion can be suppressed.

  Also in the gas sensor unit of the present invention, since the cap terminal and the output side terminal portion of the terminal member are connected by the elastic force of the output side terminal portion, the cap terminal with respect to the output side terminal portion of the terminal member The detachability is good, and consequently the detachability of the gas sensor cap with respect to the gas sensor is good.

  Furthermore, in the gas sensor unit according to any one of the above, the gas detection element is made of ceramic and has a bottomed cylindrical shape with a closed end in the axial direction, and the electrode has an inner periphery of the gas detection element. An inner electrode formed on a surface, wherein the terminal member is made of a bent plate material having a predetermined shape, and is an element side terminal portion that is electrically connected to the inner electrode, and has a cylindrical shape and is elastically contracted. A gas sensor unit having an element-side terminal portion that is inserted into the gas detection element while having a diameter is preferable.

The gas sensor unit of the present invention has a cylindrical element-side terminal portion that is inserted into a bottomed cylindrical gas detection element while being elastically reduced in diameter and electrically connected to the inner electrode. Therefore, in this gas sensor unit, in the gas sensor element, the element-side terminal portion is electrically connected while pressing the inner electrode from the inner side toward the radially outer side. For this reason, due to the influence of vibration or the like, the connection between the two is interrupted and the risk of generating noise can be reduced. Further, since the element side terminal portion is elastically reduced in diameter, it can be directly connected to the inner electrode. For this reason, as compared with the conventional case where the conductive packing having elasticity is interposed, the conductive packing is not required, so that the number of parts can be reduced and the cost can be reduced.
Further, the terminal member of the gas sensor unit of the present invention is made of a bent plate material having a predetermined shape. For this reason, the terminal member itself is easy to form, and the cost is low.

  Furthermore, in the gas sensor unit described above, the internal space of the gas sensor cap communicates with the outside, and passes through the output side terminal portion and the element side terminal portion of the terminal member to the inside of the gas detection element. And a gas sensor unit in which the internal space of the gas sensor cap communicates.

  As described above, the terminal member of the present invention is made of a bent plate material, and has a cylindrical output-side terminal portion and element-side terminal portion. Therefore, the inside (in the cylinder) of the gas detection element and the internal space of the gas sensor cap communicate with each other through the inside (in the cylinder) of the output side terminal part and the element side terminal part. The internal space of the gas sensor cap communicates with the outside. Therefore, in the gas sensor unit of the present invention, the terminal member constitutes a ventilation path for introducing outside air into the gas detection element 120 as the reference gas through the internal space of the gas sensor cap. For this reason, in the gas sensor unit of the present invention, it is not necessary to separately form a ventilation path for introducing the reference gas (outside air) to the inside of the gas detection element. Further, a separate ventilation path is also formed for the terminal member. Since work (for example, a drilling process) is unnecessary, it becomes low-cost.

  Furthermore, in any one of the above gas sensor units, the terminal member may be a gas sensor unit integrally formed of a single plate material.

  The gas sensor unit of the present invention uses a terminal member formed integrally from a single plate material. Such a terminal member is low in cost because of easy molding.

  Furthermore, in any one of the gas sensor units described above, of the terminal members of the gas sensor, the output-side terminal member may be a gas sensor unit having a C-shaped cross section orthogonal to its own axis.

  In the gas sensor unit of the present invention, among the terminal members of the gas sensor, the output side terminal portion has a C-shaped cross section perpendicular to its own axis. Such an output-side terminal portion is easy to form, has a large deformation range, and can easily realize an output-side terminal portion having elasticity of a relatively large elastic coefficient. The gas sensor unit can be made.

  Furthermore, the gas sensor unit according to any one of the above, wherein the gas sensor is made of an insulating ceramic and has a cylindrical enclosure surrounding the gas detection element and the terminal member, and the gas sensor cap has an insulating property. A gas sensor comprising a covering portion that is made of rubber and covers the cap terminal, and the covering portion covers at least a part of the surrounding body in a state where the gas sensor cap and the gas sensor are connected. A unit.

The gas sensor constituting the gas sensor unit of the present invention has an enclosure made of insulating ceramic surrounding the gas detection element and the terminal member. For this reason, in the gas sensor unit in which the enclosure is exposed to the outside, the ceramic enclosure may be damaged when a foreign object collides from the outside.
On the other hand, in the gas sensor unit of the present invention, of the gas sensor cap, the covering portion made of insulating rubber includes an envelope covering portion that covers at least a part of the envelope when the gas sensor cap and the gas sensor are connected. Yes. For this reason, even when a foreign object flies from the outside toward the enclosure, the portion covered by the rubber enclosure covering portion of the enclosure can be prevented from being damaged.

  Further, in the gas sensor unit, the enclosure covering portion of the gas sensor cap has an annular close contact portion that is in close contact with a circumferential direction of an outer peripheral surface of the envelope, and the close contact portion is the gas sensor. When the cap and the gas sensor are connected, it is preferable that the gas sensor unit is formed in close contact with the outer peripheral surface of the rear end portion located on the rear end side in the axial direction of the enclosure.

  In the gas sensor unit of the present invention, the rubber envelope covering portion has an annular contact portion that is in close contact over the circumferential direction (360 degrees) of the outer peripheral surface of the envelope. Thereby, it is possible to prevent water from entering the gas sensor unit from between the gas sensor and the gas sensor cap.

  By the way, the gas sensor unit of the present invention is attached to an exhaust pipe of an internal combustion engine, for example, and can be used for detecting the oxygen concentration in the exhaust gas. In this case, since the gas detection element is exposed to high-temperature exhaust gas, the exhaust gas heat causes the gas detection element and the metal casing surrounding the circumference of the gas detection element to become high temperature, and this heat is applied to the enclosure covering portion. Is also transmitted. For this reason, there exists a danger that the rubber-made enclosure covering part (covering part) will deteriorate under the influence of this exhaust heat.

On the other hand, in the gas sensor unit of the present invention, when the gas sensor cap and the gas sensor are connected, the contact portion of the envelope covering portion is in close contact with the outer peripheral surface of the rear end portion located on the rear end side in the axial direction of the envelope body. To do. Accordingly, the close contact portion contacts (closely contacts) the enclosure at a position as far as possible from the gas detection element that becomes high temperature while covering and protecting the enclosure. For this reason, in the gas sensor unit of the present invention, it is possible to reduce the risk of deterioration of the rubber enclosure covering portion (covering portion) due to the influence of exhaust heat.
In addition, it is preferable to use fluorine-based rubber as the insulating rubber constituting the covering portion. By using the fluorinated rubber, the heat resistance can be improved and the adhesion to the enclosure can be improved.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a gas sensor 100 according to the first embodiment. The gas sensor 100 includes a gas detection element 120, an outer electrode 111, an inner electrode 112, an enclosure 130, a terminal member 150, and a casing 160.

  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 substantially cylindrical shape. The metal shell 161 includes an inner periphery receiving portion 161e for supporting a flange portion 120e of the gas detection element 120, which will be described later, and a tapered inner periphery receiving portion 161e whose diameter increases toward the rear end side. It is provided in a form that protrudes radially inward from the inner peripheral surface. Further, a screw portion 161b for attaching the gas sensor 100 to the exhaust pipe 10 (see FIG. 4) is formed outside the metal shell 161, and a screw portion 161b is provided on the rear end side of the screw portion 161b. A hexagonal portion 161d is provided around which an attachment tool for screwing into the exhaust pipe is engaged. The protector 162 is a metal, substantially cylindrical cylinder, and has a vent hole 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 bottom with a closed end portion 120b, and has a substantially cylindrical shape extending in the axis C direction. 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 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.
Further, in the present embodiment, the front end 120b side of the gas detection element 120 in the axis C direction is the front end side, the opposite side is the rear end side, and the same applies to other forms.

The outer electrode 111 is made of porous Pt or Pt alloy, and is provided so as to cover the outer surface 120 c of the tip 120 b of the gas detection element 120. The outer electrode 111 is provided up to the distal end surface of the flange portion 120e, and is electrically connected to the metal shell 161 via the packing 142. The inner electrode 112 is also formed by porous Pt or a Pt alloy, and is provided so as to cover the inner side surface 120d of the gas detection element 120.
The enclosure 130 is made of an insulating ceramic (specifically, alumina) and has a substantially cylindrical shape. The enclosure 130 includes a gas detection element 120, a metal shell 161, and a ceramic powder 141 formed of talc, with a distal end portion 131 of the surrounding body 131 surrounding the rear end portion of the gas detection element 120. It is hold | maintained so that it may interpose.

The terminal member 150 is made of, for example, SUS304, and has a substantially cylindrical shape as illustrated in FIG. 2, 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 substantially C-shaped cross section (see FIG. 2C) orthogonal to its own axis 151AX (terminal member axis 150AX) and is a cap of the cap terminal member 210. When the terminal 211 (see FIG. 3) is relatively moved in the direction along the axis 150AX (the vertical direction in FIG. 1) and inserted and connected to the inside thereof, the terminal 211 (see FIG. 3) is elastically expanded in diameter. ing. Further, convex portions 151b projecting radially inward are formed at three positions in the circumferential direction on the rear end side (upward in the drawing) of the output side terminal portion 151. Here, as shown in FIG. 2C, the inner vertices of the three convex portions 151b serve as contact points CP that elastically abut the cap terminals 211 described later along the radial direction thereof. A diameter E of a virtual circle and a virtual cylinder HC (indicated by a broken line in FIGS. 2B and 2C) in contact with the contact point CP of the three convex portions 151 b is defined as an inner diameter of the output side terminal portion 151.

  Further, in the output side terminal portion 151, at three locations in the circumferential direction corresponding to the convex portion 151b, an inner bent portion 151c punched out of the wall surface and bent radially inward, and an outer bent bent outward in the radial direction. A portion 151d is formed. Among these, the inner bent portion 151c is elastically bent outward in the radial direction when the cap terminal 211 (see FIG. 3) of the cap terminal member 210 is inserted and connected to the inner side of the output side terminal portion 151. Is formed. Further, as shown in FIG. 1, the outer bent portion 151 d comes into contact with the front end surface of the stepped portion 130 b of the enclosure 130 when the terminal member 150 is assembled to the gas sensor 100, and the output side terminal portion 151 ( It plays a role in preventing the terminal member 150) from coming off.

  The element-side terminal portion 153 has a cylindrical shape with a substantially C-shaped cross section orthogonal to its own axis 153AX (terminal member axis 150AX). As shown in FIG. 1, 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 112. Therefore, in the gas sensor 100, the element side terminal portion 153 is electrically connected while pressing the inner electrode 112 from the inner side toward the outer side in the radial direction. That is, the element side terminal portion 153 elastically contacts the inner electrode 112 at a number of contact points on the surface thereof. Even when vibration is applied to the gas sensor 100, one of the many contact points of the element side terminal portion 153 is in contact with the inner electrode 112. For this reason, due to the influence of vibration or the like, the connection between the two is interrupted and the risk of generating noise can be reduced.

In addition, since the element side terminal portion 153 is elastically reduced in diameter, the element side terminal portion 153 and the inner electrode 112 can be directly connected. For this reason, as compared with the conventional case where the conductive packing having elasticity is interposed, the conductive packing is not required, so that the number of parts can be reduced and the cost can be reduced.
Such a terminal member 150 can be integrally formed by pressing using a single metal plate having a predetermined shape. For this reason, formation is easy and the cost is low. Further, the metal plate is bent to form the terminal member 150, 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 150AX direction are formed into a cylindrical shape. Thus, a ventilation path T1 through which the reference gas (outside air) can be introduced to the inside of the gas detection element 120 is formed (see FIGS. 2 and 4). For this reason, after bending the terminal member 150, the operation | work (for example, drilling process) which forms a ventilation path separately is unnecessary, and it becomes low cost.

Such a gas sensor 100 is manufactured as follows.
First, as shown in FIG. 1, 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 111 and the inner electrode 112 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 terminal member 150 is inserted inside the enclosure 130 and the gas detection element 120. Specifically, the element side terminal portion 153 is inserted into the gas detection element 120 while elastically reducing the diameter, and is electrically connected to the inner electrode 112. At the same time, the terminal member 150 is prevented from coming off by placing the output side terminal portion 151 inside the enclosure 130 and bringing the outer bent portion 151d into contact with the front end surface of the stepped portion 130b of the enclosure 130. Can do. A gap S <b> 1 is provided between the inner peripheral surface 130 c of the enclosure 130 and the outer peripheral surface 151 e of the output-side terminal portion 151.
In this way, the gas sensor 100 is completed.

Next, the gas sensor cap 200 of the first embodiment will be described with reference to the drawings. FIG. 3 is a partial cross-sectional view of the gas sensor cap 200. The gas sensor cap 200 includes a cap terminal member 210, a covering portion 220 that covers the cap terminal member 210, and a lead wire 230.
The cap terminal member 210 is made of, for example, Inconel 718 (UK Inconel, trade name), and has a substantially cylindrical cap terminal 211 and a crimping portion 213 for crimping and connecting the lead wire 230. Among these, the cap terminal 211 has rigidity to expand the diameter of the output side terminal portion 151 without being deformed when inserted into the output side terminal portion 151 of the gas sensor 100 and connected thereto. The outer diameter of the cap terminal 211 is F.

One end of the lead wire 230 is crimped by a crimping portion 213 of the cap terminal member 210 and is electrically connected to the cap terminal 211. Therefore, an output signal from the gas detection element 120 of the gas sensor 100 can be transmitted to an external device (for example, an engine control unit (hereinafter also referred to as ECU)) through the lead wire 230.
The covering portion 220 is formed into a hollow shape using a fluorine-based rubber and has a substantially cylindrical enclosure covering portion 221. The rear end side of the enclosure covering portion 221 has a smaller inner diameter than the front end side, and this portion is referred to as a close contact portion 221c.

  In the gas sensor cap 200, the axis 210 </ b> AX of the cap terminal member 210 is arranged coaxially with the axis 220 </ b> AX of the enclosure covering part 221 in the covering part 220, and the lead wire 230 connected to the cap terminal member 210 is externally connected from the insertion port 223. It is comprised in the form extended to.

  Here, FIG. 4 shows a state when the gas sensor unit 300 including the gas sensor 100 and the gas sensor cap 200 according to the first embodiment is used. 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, the gas sensor 100 is screwed into the exhaust pipe 10 such that the front end side including the protector 162 is located in the exhaust pipe 10 and the rear end side portion of the metal shell 161 is exposed to the outside. To wear. At this time, the outer electrode 111 electrically connected to the metal shell 161 is grounded through the metal shell 161. Next, the cap terminal 211 of the gas sensor cap 200 is moved in the direction along the axis 210AX (vertical direction in FIG. 3) and inserted into the output side terminal portion 151 of the gas sensor 100 so that the gas sensor cap 200 is inserted. Is attached to the gas sensor 100.

At this time, since the inner diameter E (see FIG. 2) of the output side terminal portion 151 is smaller than the outer diameter F of the cap terminal 211 (F <E), the output side terminal portion 151 has a convex portion 151b (contact point). CP) receives a force radially outward from the cap terminal 211, and the output-side terminal portion 151 elastically expands in diameter.
Accordingly, the output-side terminal portion 151 is electrically connected while directly elastically pressing the cap terminal 211 radially inward at a plurality (three in this embodiment) of contact points CP. Thus, in the present embodiment, the output side terminal portion is in contact with the cap terminal 211 at the plurality of contact points CP. Further, since the contact point CP elastically presses the cap terminal 211, the connection between the output side terminal portion 151 and the cap terminal 211 is momentarily interrupted due to the influence of vibration of the vehicle or the like, and noise is generated. And the like (risk of gas detection accuracy degradation) can be reduced. As described above, the gas sensor unit 300 can be suitably used particularly for a two-wheeled vehicle because the risk of a decrease in gas detection accuracy due to the influence of vibration is small.

Further, since the diameter of the output side terminal portion 151 is increased, the gap S2 between the outer peripheral surface 151e of the output side terminal portion 151 and the inner peripheral surface 130c of the enclosure 130 is smaller than the gap S1 before insertion (S2 <S1). . Specifically, the gap S <b> 2 becomes almost zero, and the output side terminal portion 151 comes into contact with the inner peripheral surface 130 c of the enclosure 130. For this reason, the output-side terminal portion 151 surrounded by the enclosure 130 is less likely to swing in the radial direction due to the influence of vibration of the vehicle or the like. Fatigue fracture (cracks, breakage, etc.) can be suppressed. More specifically, the output-side terminal 151 has a dimensional relationship between the inner diameter E of the output-side terminal portion, the outer diameter of the cap terminal 211, and the inner diameter of the enclosure 130 so as to be in pressure contact with the inner peripheral surface 130c of the enclosure 130. Has been selected. For this reason, since the cap terminal 211 and the enclosure 130 are strongly integrated via the output side terminal portion 151 of the terminal member 150, the gas sensor cap 200 is firmly held by the gas sensor 100.
On the other hand, the output-side terminal portion 151 is elastically connected to the cap terminal 211 along the radial direction (the left-right direction in FIG. 4) perpendicular to the axis 151AX (see FIG. 2). When the cap terminal 211 is moved in the direction along the axis 210AX of the cap terminal member 210 (vertical direction in FIG. 3) and is attached to and detached from the output side terminal portion 151, the cap terminal 211 can be easily attached and detached, and the detachability is also good.

  In addition, since the output side terminal portion 151 and the cap terminal 211 are in contact with each other at a contact point CP disposed on the virtual cylinder HC, the output side terminal portion 151 is connected when the output side terminal portion 151 and the cap terminal 211 are connected. The axis 151AX (gas sensor axis C, see FIG. 2) and the axis 210AX (see FIG. 3) of the cap terminal member 210 are coaxial, and the cap terminal 211 is inserted into the output terminal portion 151. That is, the cap terminal 211 of the gas sensor cap 200 can be connected to the output side terminal portion 151 of the gas sensor 100 (see FIG. 4) attached to the exhaust pipe 10 from any direction around the axis C.

  Furthermore, by attaching the gas sensor cap 200 to the gas sensor 100, the enclosure 130 can be covered by the enclosure covering portion 221 of the gas sensor cap 200. For this reason, for example, even when a foreign object such as a pebbles flies toward the enclosure 130 while the vehicle is running, the portion of the enclosure 130 covered by the rubber enclosure cover 221 is damaged. Can be prevented. In particular, in the first embodiment, since almost the entire enclosure 130 is covered, there is little risk that foreign matter directly hits the enclosure 130 from the outside, and damage to the enclosure 130 can be prevented.

  Furthermore, the ring-shaped close contact portion 221c of the rubber envelope covering portion 221 can be in close contact over the circumferential direction (360 degrees) of the outer peripheral surface 130d of the envelope 130. Thereby, it is possible to prevent water from entering between the gas sensor 100 and the gas sensor cap 200 into the gas sensor unit 130.

  Incidentally, as shown in FIG. 4, since the front end side of the gas sensor 100 is exposed to high-temperature exhaust, the gas detection element 120 and the metal shell 161 become high temperature due to exhaust heat, and the exhaust heat passes through them to the covering portion 220 of the gas sensor cap 200. Is also transmitted. For this reason, there exists a danger that the rubber-made enclosure covering part 221 (covering part 220) will deteriorate by the influence of this exhaust heat.

On the other hand, in the gas sensor unit 300, the contact portion 221c of the enclosure covering portion 221 is in close contact with the rear end portion 131 located on the rear end side of the enclosure 130. Accordingly, the close contact portion 221c covers (protects) the enclosure 130 at a position as far as possible from the front end side (the gas detection element 120 or the like) of the gas sensor 100 that becomes high temperature while covering and protecting the enclosure 130. For this reason, it is possible to reduce the risk that the rubber envelope covering portion 221 (covering portion 220) will deteriorate due to the influence of exhaust heat.
In the gas sensor unit 300, since the covering part 220 is formed of fluorine-based rubber, the heat resistance of the covering part 220 is good, and the adhesion to the enclosure 130 is also good.

  In addition, the lead wire 230 has a large number of conductor wires, and can communicate with the gaps between the conductor wires in the length direction. In such a gas sensor unit 300, a reference gas (outside air) is taken from the outside into the covering portion 220 via the lead wire 230 of the gas sensor cap 200, and further, this reference gas is passed through the terminal member 150 (air passage T1). Thus, the gas can be taken into the gas detection element 120 (inside the cylinder).

(Deformation)
Next, a modification of the first embodiment will be described with reference to FIG. As shown in FIG. 5, the first modification is the same in the gas sensor, the gas sensor cap, and the gas sensor unit except that the shape of the terminal member 750 used is different from the terminal member 150 of the first embodiment. Therefore, only the form of the terminal member 750 will be described.

  The terminal member 750 (see FIG. 5) used in the gas sensor according to the present modified embodiment can be easily understood when compared with the terminal member 150 (see FIG. 2) used in the gas sensor of the embodiment. 153 and the connecting portion 152 are the same as those of the terminal member 150. On the other hand, the output side terminal portion 751 is different from the output side terminal portion 151 only in having an inner bent tongue portion 751b instead of the convex portion 151b of the output side terminal portion 151. That is, the output side terminal portion 751 of the terminal member 750 has inner bent tongue portions 751b instead of the convex portions 151b at three locations in the circumferential direction.

  The inner bent tongue portion 751b is a tongue-like portion formed by a U-shaped slit provided in the output side terminal portion 751, like the inner bent portion 151c, and the tip thereof is the diameter of the output side terminal portion. It is formed to project obliquely toward the inner side in the direction, and can be moved elastically in the radial direction. Therefore, in the output side terminal portion 751, as shown in FIG. 5C, the tips of the three inner bent tongue portions 751b are connected to the cap terminal 211 instead of the convex portion 151b in the first embodiment. The contact point CP comes into contact. In this modification, the diameter K of the virtual cylinder HC (indicated by a broken line in FIGS. 5B and 5C) that is in contact with the contact point CP of the three inner bent tongues 751b is set to the output side terminal 751. The inner diameter.

The output-side terminal portion 751 has a substantially C-shaped cylindrical section (see FIG. 5C) orthogonal to its own axis 751AX (terminal member axis 750AX), and the cap terminal 211 ( 3) is inserted and connected to the inside thereof, the three inner bent tongues 751b elastically move radially outward, and the inner diameter K thereof elastically expands.
Therefore, the output terminal portion 751 is also electrically connected while elastically pressing the cap terminal 211 radially inward at a plurality (three in this modification) of contact points CP. Thus, also in this modification, the output-side terminal portion 751 is in contact with the cap terminal 211 at a plurality of contact points CP. Further, since the contact point CP elastically presses the cap terminal 211, the connection between the output side terminal portion 151 and the cap terminal 211 is momentarily cut off due to the influence of vibration of the vehicle or the like, and noise is generated. And the like (risk of gas detection accuracy degradation) can be reduced.

(Embodiment 2)
Next, a second embodiment of the present invention will be described with reference to the drawings.
FIG. 6 is a cross-sectional view of the gas sensor 400 of the second embodiment. The gas sensor 400 according to the second embodiment is different from the gas sensor 100 according to the first embodiment in the shapes of the terminal member and the enclosure, and the other parts are the same.

The gas sensor 400 includes the same gas detection element 120, outer electrode 111, inner electrode 112, and casing 160 as the gas sensor 100 of the first embodiment, and an enclosure 430 and a terminal member 450 that are different from the gas sensor 100 of the first embodiment.
Among these, the enclosure 430 is made of an insulating ceramic and has a substantially cylindrical shape, similar to the enclosure 130 of the first embodiment. However, as compared to the enclosure 130 of the first embodiment, the enclosure 430 has an axial direction. The length is shortened.

As shown in FIG. 7, the terminal member 450 has a substantially cylindrical shape, and includes an output-side terminal portion 451, an element-side terminal portion 453, and a connecting portion 452 that connects the two.
Among these, the output-side terminal portion 451 has a cylindrical shape (see FIG. 7D) having a substantially C-shaped cross section perpendicular to its own axis 451AX (terminal member axis 450AX). The terminal 511 (see FIG. 8) is relatively moved in the direction along the axis 450AX (the vertical direction in FIG. 6), and inserted into the cap terminal 511 (see FIG. 8) of the cap terminal member 510 and connected thereto. When it does, it is comprised so that it may reduce in diameter elastically.

Furthermore, convex portions 451b protruding outward in the radial direction are formed at three places in the circumferential direction of the central portion in the axial direction. The convex portion 451b abuts on the rear end surface 430f of the enclosure 430 and plays a role of preventing the output side terminal portion 451 from entering the enclosure 430 (see FIG. 6).
Further, an outer bent portion 451d that is punched and bent radially outward is formed on the distal end side of the output side terminal portion 451. The outer bent portion 451d abuts on the front end surface 430d of the step portion 430b of the enclosure 430 and plays a role in preventing the output side terminal portion 451 from coming off (see FIG. 6).

The element-side terminal portion 453 has a cylindrical shape having a substantially C-shaped cross section perpendicular to its own axis 453AX (terminal member axis 450AX). As shown in FIG. 6, 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 112. Therefore, in the gas sensor 400, the element side terminal portion 453 is electrically connected while pressing the inner electrode 112 from the inner side toward the outer side in the radial direction. For this reason, due to the influence of vibration or the like, the connection between the two is interrupted and the risk of generating noise can be reduced.
In addition, since the element side terminal portion 153 is elastically reduced in diameter, the element side terminal portion 153 and the inner electrode 112 can be directly connected. For this reason, as compared with the conventional case where the conductive packing having elasticity is interposed, the conductive packing is not required, so that the number of parts can be reduced and the cost can be reduced.

  Such a terminal member 450 can be integrally formed by pressing using a single metal plate having a predetermined shape. For this reason, formation is easy and the cost is low. Further, the metal plate is bent to form the terminal member 450, and the output side terminal portion 451 and the element side terminal portion 453 are formed into a cylindrical shape, thereby introducing the reference gas (outside air) to the inside of the gas detection element 120. A possible ventilation path T2 is formed (see FIGS. 7 and 9). For this reason, after bending the terminal member 450, the operation | work (for example, drilling process) which forms a ventilation path separately is unnecessary, and it becomes low cost.

By the way, the terminal member 450 made of a bent plate material tends to have lower rigidity than that formed by processing a rod-shaped metal body. In particular, the output-side terminal portion 451 connected to the cap terminal 511 is likely to be loaded under the influence of external vibration, and therefore it is not preferable that the rigidity is lowered. On the other hand, the terminal member 450 of the present embodiment has a shape in which the rear end portion 451f of the output side terminal portion 451 is bent radially inward as shown in the partial sectional view of FIG. ing. Thereby, rigidity can be made high, enabling the diameter of the output side terminal part 451 to be elastically reduced.
Here, as shown in FIGS. 7B and 7D, a virtual cylinder (virtual circle) HC passing through a contact point CP in contact with the convex portion 511b of the cap terminal 511 described below in the output side terminal portion 451. Is the inner diameter of the output-side terminal portion 451.

Next, the gas sensor cap 500 of the second embodiment will be described with reference to the drawings. FIG. 8 is a partial cross-sectional view of the gas sensor cap 500. The gas sensor cap 500 includes a cap terminal member 510, a covering portion 520 that covers the cap terminal member 510, and a lead wire 230.
The cap terminal member 510 includes a bottomed cylindrical cap terminal 511 having a substantially U-shaped cross section, and a crimped portion 513 for crimping and connecting the lead wire 230.

  Among these, the cap terminal 511 has rigidity to reduce the diameter of the output side terminal portion 451 without deforming itself when the output side terminal portion 451 of the gas sensor 400 is inserted and connected to the inside. Yes. The cap terminal 511 has convex portions 511b protruding radially inward at three locations in the circumferential direction of the central portion of the axis 510AX. Here, the diameter H of the virtual circle in contact with the three convex portions 511b is defined as the inner diameter of the cap terminal 511 (see FIG. 8).

As in the first embodiment, one end of the lead wire 230 is crimped by a crimping portion 513 of the cap terminal member 510 and is electrically connected to the cap terminal 511. Therefore, an output signal from the gas detection element 120 of the gas sensor 400 can be transmitted to an external device (for example, ECU) through the lead wire 230.
The covering portion 520 is formed into a hollow shape using a fluorine-based rubber and has a substantially cylindrical enclosure covering portion 521. In addition, let the cyclic | annular inner side part of the enclosure cover part 221 be the contact part 521c.

Here, FIG. 9 shows a state when the gas sensor unit 600 including the gas sensor 400 and the gas sensor cap 500 of the second embodiment is used. The gas sensor unit 600 can be used to detect the oxygen concentration in the exhaust gas of the internal combustion engine, for example, as in the first embodiment.
Specifically, the gas sensor 400 is attached to the exhaust pipe 10 as in the first embodiment. Next, the cap terminal 511 is moved in the direction along the axis 510AX (vertical direction in FIG. 8) so that the output side terminal portion 451 of the gas sensor 400 is inserted inside the cap terminal 511 of the gas sensor cap 500, The gas sensor cap 500 is attached to the gas sensor 400.

At this time, since the outer diameter G (see FIG. 7) of the output side terminal portion 451 is larger than the inner diameter H (see FIG. 8) of the cap terminal 511 (G> H), the output side terminal portion 451 is a cap terminal. As shown in FIG. 9B, a virtual cylinder (virtual circle) HC in the cross section of the portion of the output side terminal portion 4521 that contacts the convex portion 511b is received from the convex portion 511b of 511 inward in the radial direction. The output-side terminal portion 451 is elastically reduced in diameter so that the diameter thereof becomes H.
Accordingly, the output-side terminal portion 451 is electrically elastic while elastically pressing the convex portion 511b of the cap terminal 511 radially outward at a plurality of contact points CP (three points in the second embodiment) due to its own elasticity. Connect to. Thus, also in the second embodiment, the output side terminal portion is in contact with the cap terminal 511 at the plurality of contact points CP. Further, since the contact point CP elastically presses the cap terminal 511, the connection between the output side terminal portion 451 and the cap terminal 511 is momentarily cut off due to the influence of vibration of the vehicle or the like, and noise is generated. And the like (risk of gas detection accuracy degradation) can be reduced. As described above, the gas sensor unit 600 can be suitably used particularly for a two-wheeled vehicle because the risk of a decrease in gas detection accuracy due to the influence of vibration is small.

Further, the output side terminal portion 451 is elastically connected to the cap terminal 511 along the radial direction (left and right direction in FIG. 9) orthogonal to the axis 451AX (see FIG. 7). When the cap terminal 511 is moved in the direction along the axis 510AX of the cap terminal member 510 (vertical direction in FIG. 8) and is attached to and detached from the output side terminal portion 451, it can be easily attached and detached, and the detachability is also good.
Moreover, since the output side terminal portion 451 and the cap terminal 411 are in contact with each other at a contact point CP disposed on the virtual cylinder HC, the axis 451AX (see FIG. 7) of the output side terminal portion 451 and the axis of the cap terminal member 510 It is sufficient that the output terminal portion 451 is covered with the cap terminal 511 so that 510AX (see FIG. 8) is coaxial. That is, the cap terminal 511 of the gas sensor cap 500 can be connected to the output side terminal portion 451 of the gas sensor 100 (see FIG. 9) attached to the exhaust pipe 10 from any direction around the axis C.

Furthermore, by attaching the gas sensor cap 500 to the gas sensor 400, the enclosure 430 can be covered by the enclosure covering portion 521 of the gas sensor cap 500. For this reason, for example, even when a foreign object such as a pebbles flies toward the enclosure 430 while the vehicle is running, the portion of the enclosure 430 covered by the rubber enclosure cover 521 is damaged. Can be prevented.
Further, the annular close contact portion 521c of the rubber envelope covering portion 521 can be closely attached over the circumferential direction (360 degrees) of the outer peripheral surface 130d of the envelope 430. Thereby, it is possible to prevent water from entering between the gas sensor 400 and the gas sensor cap 500 into the gas sensor unit 130.

  Also in such a gas sensor unit 600, similarly to the gas sensor unit 300 of the first embodiment, a reference gas (outside air) is taken into the covering portion 520 from the outside through the lead wire 230 of the gas sensor cap 500, and further, this reference gas Can be taken into the inside (cylinder) of the gas detection element 120 through the terminal member 450 (air passage T2).

In the above, the present invention has been described according to the first and second embodiments and the modified embodiments. However, the present invention is not limited to the above-described embodiments and the like, and can be appropriately modified and applied without departing from the gist thereof. Needless to say, it can be done.
For example, in the gas sensors 100 and 400 of the first and second embodiments, a heater may be provided to heat the gas detection element 120.

In the gas sensors 100 and 400 of the first and second embodiments, the terminal members 150 and 450 having the output-side terminal portions 151 and 451 and the element-side terminal portions 153 and 453 are integrally formed of a single plate material. The terminal part and the element side terminal part may be separately formed and joined by welding or the like to form the terminal member.
Further, in the gas sensors 100 and 400 of the first and second embodiments, the output side terminal portions 151 and 451 and the element side terminal portions 153 and 453 are formed in a cylindrical shape having a substantially C-shaped cross section orthogonal to the axial direction. However, it is not limited to such a shape, for example, it is good also as a cylindrical shape by winding a board | plate material so that a part may overlap. Further, the cross-sectional shape orthogonal to the axial direction is not limited to a substantially C shape, and may be a substantially circular shape, a substantially polygonal shape, or the like.

  Moreover, as a form of the contact part with an external terminal (cap terminal) in the output side terminal part, the convex part 511b was illustrated in Embodiment 1, and the inner side bent tongue part 751b was illustrated in the deformation | transformation form. Moreover, in Embodiment 2, the cross-sectional substantially C-shaped output side terminal part 451 illustrated that the outer peripheral surface becomes a contact part. However, other forms are also conceivable. For example, in the terminal member 850 shown in FIG. 10, a portion of the output-side terminal portion 851 sandwiched between two slits extending in the direction along the axis 851AX is directed outward in the radial direction. The slit-shaped protrusions 851e are arranged in a distributed manner in the circumferential direction so as to protrude in an arc shape and be elastically movable in the radial direction. In the output side terminal portion 851, the top of the slit-type protruding portion 851e serves as a contact point CP with the external terminal (cap terminal), and the diameter L of the virtual cylinder passing through the plurality of contact points CP is connected to the external terminal. Sometimes it becomes elastically small, that is, its diameter is reduced.

1 is a partial cross-sectional view of a gas sensor 100 according to Embodiment 1. FIG. It is a figure which shows the terminal member 150 concerning Embodiment 1, (a) is the front view, (b) is the side view, (c) is DD sectional drawing. 3 is a partial cross-sectional view of a gas sensor cap 200 according to Embodiment 1. FIG. It is explanatory drawing which shows a mode when the gas sensor unit 300 concerning Embodiment 1 and this are used. It is a figure which shows the terminal member 750 concerning a deformation | transformation form, (a) is the front view, (b) is the side view, (c) is JJ sectional drawing. It is a fragmentary sectional view of gas sensor 400 concerning Embodiment 2. FIG. It is a figure which shows the terminal member 450 concerning Embodiment 2, (a) is the top view, (b) is the front view, (c) is the side view, and sectional drawing of the rear-end part 455, (d). FIG. 5 is an end view of a cross section of the output side terminal portion. It is a fragmentary sectional view of gas sensor cap 500 concerning Embodiment 2. FIG. (A) is explanatory drawing which shows a mode when the gas sensor unit 600 concerning Embodiment 2 and this are used, (b) is an end elevation of the cross section of the output side terminal part 451 of the terminal member 450. FIG. It is a figure which shows the terminal member 850 concerning another example of a form, (a) is the front view, (b) is the side view.

Explanation of symbols

100,400 Gas sensor 112 Inner electrode 120 Gas detection element 130,430 Enclosure 150,450,750,850 Terminal member 151,451,751,851 Output side terminal part 153,453 Element side terminal part 200,500 Gas sensor cap 210, 510 Cap terminal members 211 and 511 Cap terminals (external terminals)
220, 520 Covering part 221, 521 Enclosure covering part 221c, 521 Adhering part 230 Lead wire 300, 600 Gas sensor unit

Claims (20)

A gas detection element;
A gas sensor comprising: a terminal member connected to an electrode formed on the gas detection element, and connected to an external terminal to output an output signal from the gas detection element to the outside,
The terminal member is
An output side terminal portion that electrically connects and outputs the output signal while engaging with the external terminal,
When connecting with the external terminal, elastically contacts the external terminal along an orthogonal direction orthogonal to a moving direction in which at least one of the external terminal and the output side terminal portion is relatively moved, An output side terminal portion including a plurality of contact points for holding the external terminal;
A gas sensor comprising: an element side terminal portion electrically connected to the electrode. The gas sensor according to claim 1,
The output side terminal portion is
The plurality of contact points are disposed on a virtual cylinder passing through them;
A gas sensor in which the plurality of contact points move so that the virtual cylinder expands or contracts when connected to the external terminal. The gas sensor according to claim 1 or 2, wherein
The gas detection element is made of ceramic and has a bottomed cylindrical shape with a closed end in the axial direction.
The electrode is an inner electrode formed on the inner peripheral surface of the gas detection element,
The terminal member is made of a bent plate material having a predetermined shape,
The output side terminal portion is a cylindrical shape, and when connected to the external terminal, is an output side terminal portion that elastically expands or contracts in diameter,
The element-side terminal portion is a gas sensor that has a cylindrical shape that is electrically connected to the inner electrode, and is inserted into the gas detection element while being elastically reduced in diameter. The gas sensor according to claim 3,
The output-side terminal portion is an output-side terminal portion that elastically reduces the diameter when inserted and connected to the inside of the external terminal,
The gas sensor which the back end part located in the said axial direction rear end side among the said output side terminal parts has the shape bent inside. The gas sensor according to claim 1 or 2, wherein
The gas detection element is made of ceramic and has a bottomed cylindrical shape with a closed end in the axial direction.
The electrode is an inner electrode formed on the inner peripheral surface of the gas detection element,
Made of insulating ceramic, comprising a cylindrical enclosure surrounding the gas detection element and the terminal member,
The terminal member is made of a bent plate material having a predetermined shape,
The output-side terminal portion is cylindrical, and elastically expands when the external terminal is inserted and connected to the inside of the output-side terminal portion, so that a gap between the outer peripheral surface of the output-side terminal portion and the inner peripheral surface of the envelope body Is the output side terminal that becomes smaller than before insertion,
The element-side terminal portion is a gas sensor that has a cylindrical shape that is electrically connected to the inner electrode, and is inserted into the gas detection element while being elastically reduced in diameter. The gas sensor according to any one of claims 3 to 5,
The terminal member is a gas sensor formed integrally with a single plate material. It is a gas sensor as described in any one of Claims 1-6, Comprising:
Among the terminal members, the output-side terminal member is a gas sensor having a C-shaped cross section orthogonal to its own axis. A gas sensor cap that is connected to a gas sensor having a gas detection element and a terminal member having an output side terminal portion that outputs an output signal from the gas detection element to the outside, and transmits the output signal to an external device;
A cap terminal that is electrically connected while engaging with the output terminal portion;
A covering portion that is made of insulating rubber and covers the cap terminal;
A lead wire electrically connected to the cap terminal and transmitting the output signal to an external device;
The cap terminal is a plurality of contact points that elastically contact with the cap terminal among the output side terminal portions when connected to the output side terminal portion, and is arranged on a virtual cylinder passing through them. A gas sensor cap having rigidity for moving a plurality of contact points so that the virtual cylinder is expanded or contracted. The gas sensor cap according to claim 8,
The gas sensor is an output side terminal portion whose output side terminal portion of the terminal member is cylindrical and can be elastically expanded or reduced in diameter,
The said cap terminal is a gas sensor cap which is a cylinder shape and has the rigidity which expands or reduces the diameter of the said output side terminal part, without deform | transforming itself, when connecting with the said output side terminal part. A gas sensor cap that is connected to the gas sensor according to any one of claims 1 to 6 and transmits the output signal to an external device,
The external terminal is a cylindrical cap terminal that is electrically connected while being engaged with the output side terminal portion,
A covering portion that is made of insulating rubber and covers the cap terminal;
A lead wire electrically connected to the cap terminal and transmitting the output signal to an external device;
When the cap terminal is connected to the output-side terminal portion, the gas sensor cap has rigidity that moves the plurality of contact points of the output-side terminal portion so that the virtual cylinder is expanded or contracted. A gas detection element, and a gas sensor having a terminal member connected to an external terminal and outputting an output signal from the gas detection element to the outside while being connected to an electrode formed on the gas detection element;
A gas sensor cap having a cap terminal connected to the terminal member of the gas sensor and transmitting the output signal to an external device;
A gas sensor unit comprising:
The terminal member is
An output side terminal portion that is electrically connected to output the output signal while engaging with the cap terminal,
A plurality of elastically contacting the cap terminal along an orthogonal direction orthogonal to a moving direction for relatively moving at least one of the cap terminal and the output-side terminal portion when connecting to the cap terminal. A gas sensor unit including an output side terminal portion having a contact point. The gas sensor unit according to claim 11,
The output side terminal portion of the terminal member is:
The plurality of contact points are arranged on a virtual cylinder passing through them, and when connected to the cap terminal, the plurality of contact points move such that the diameter of the virtual cylinder is increased or reduced. Gas sensor unit that is. The gas sensor unit according to claim 11 or 12,
The output terminal portion of the terminal member is
An output side terminal portion that is cylindrical and elastically expands or contracts when connected to the cap terminal,
The cap terminal is a gas sensor unit which is cylindrical and is formed by expanding or reducing the diameter of the output side terminal portion and engaging the output side terminal portion without deforming itself. The gas sensor unit according to claim 11 or 12,
The gas sensor is made of an insulating ceramic and has a cylindrical envelope surrounding the gas detection element and the terminal member.
The output side terminal portion of the terminal member is:
When the cylindrical cap is inserted and connected to the inside of the cap terminal, it is an output side terminal portion that expands elastically,
The cap terminal, when inserted and connected to the inside of the output side terminal portion, has a rigidity to expand the diameter of the output side terminal portion without deforming itself,
By inserting and connecting the cap terminal inside the output side terminal portion, the output side terminal portion elastically expands in diameter, and the outer peripheral surface of the output side terminal portion and the inner periphery of the enclosure A gas sensor unit in which the gap with the surface is made smaller than before insertion. The gas sensor unit according to any one of claims 11 to 14,
The gas detection element is made of ceramic and has a bottomed cylindrical shape with a closed end in the axial direction.
The electrode is an inner electrode formed on the inner peripheral surface of the gas detection element,
The terminal member is
It consists of a bent plate material of a predetermined shape,
An element side terminal portion electrically connected to the inner electrode,
A gas sensor unit having an element-side terminal portion that is cylindrical and is inserted into the gas detection element while being elastically reduced in diameter. The gas sensor unit according to claim 15,
The internal space of the gas sensor cap communicates with the outside,
A gas sensor unit in which an inner side of the gas detection element and an inner space of the gas sensor cap communicate with each other through the output side terminal portion and the element side terminal portion of the terminal member. The gas sensor unit according to claim 15 or 16,
The terminal member is a gas sensor unit formed integrally with a single plate material. The gas sensor unit according to any one of claims 11 to 17,
Among the terminal members of the gas sensor, the output-side terminal member is a gas sensor unit having a C-shaped cross section orthogonal to its own axis. The gas sensor unit according to any one of claims 11 to 18,
The gas sensor is made of an insulating ceramic and has a cylindrical envelope surrounding the gas detection element and the terminal member.
The gas sensor cap is made of insulating rubber, and has a covering portion that covers the cap terminal,
The said covering part is a gas sensor unit containing the enclosure covering part which covers at least one part of the said enclosure in the state which connected the said gas sensor cap and the said gas sensor. The gas sensor unit according to claim 19,
The envelope covering portion of the gas sensor cap has an annular contact portion that is in close contact with the circumferential direction of the outer peripheral surface of the envelope,
The close contact portion is a gas sensor unit formed in close contact with an outer peripheral surface of a rear end portion located on the rear end side in the axial direction of the enclosure when the gas sensor cap and the gas sensor are connected.

Images