JP2005091289A - Sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor capable of reducing the complicatedness in the assembling work of a detection element and a lead frame and hard to peel the electrode terminal part of a detection element even if external force is applied to the lead frame. <P>SOLUTION: The total region air-fuel ratio sensor 2 is equipped with an insulating contact member 82 having a locking hole part 415 and a second locking hole part 425 on the contact surface with the lead frame and the lead frame 10 having a locking protruded part 18 and a narrow locking protruded part 218. It becomes unnecessary to hold the lead frame 10 for preventing the falling-off of the lead frame 10 from the insulating contact member 82 in work for integrally assembling the detection element 4 and the lead frame 10 with the insulating contact member 82 by locking the locking protruded part 18 and the narrow locking protruded part 218 with the locking hole part 415 and the second locking hole part 425 and the complicatedness of the assembling work can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention has a plate-like shape extending in the axial direction, a detection element having an electrode terminal portion formed on the rear end side, and a metal terminal member that is electrically connected to the electrode terminal portion of the detection element to form a current path And two insulations that are arranged so as to sandwich the rear end side of the detection element on which the electrode terminal portion is formed and the metal terminal member, and at least a part of the metal terminal member abuts itself. The present invention relates to a sensor including a contact member and a holding and fixing member that holds two insulating contact members.

  2. Description of the Related Art Conventionally, there has been known a sensor having a plate-like shape extending in the axial direction and a detection element (sensor element) in which a detection unit is formed on the tip side directed toward a measurement object. Examples of such sensors include gas sensors such as λ sensors, full-range air-fuel ratio sensors, oxygen sensors, and NOx sensors, and temperature sensors that perform temperature detection.

  The plate-shaped detection element is generally configured to include a detection unit on the front end side in the axial direction (longitudinal direction) and an electrode terminal unit on the rear end side. As a sensor having such a detection element, a lead frame (metal terminal member) made of a conductive material is electrically connected to the electrode terminal portion, so that a current flowing between the detection element and an external device can be reduced. There is a structure in which a part of the current path is formed by a lead frame. In addition, in the current path that electrically connects the detection element and the external device, for example, a detection current (detection signal) corresponding to the detection result by the detection element, or when the detection element includes a heater, Current for power supply flows.

  As an insulating contact member for connecting the lead frame and the detection element, an insulating contact member made of two members and arranged so as to sandwich the rear end side of the detection element and the metal terminal member is known. (Patent Document 1).

Thus, the lead frame can be brought into contact with the electrode terminal portion of the detection element by sandwiching the detection element and the lead frame using the two insulating contact members.
JP 2001-343356 A (FIGS. 1 and 4)

  However, when the above-described two insulating contact members are used, in assembling the detection element and the lead frame, there is a possibility that the lead frame may drop off from the insulating contact member, and the detection element and the lead frame may be moved by moving the lead frame. The relative position of the lead frame becomes inappropriate, and the electrical connection between the lead frame and the electrode terminal portion may be poor. In order to prevent such dropping and connection failure, it is necessary to hold the lead frame for the purpose of preventing movement of the lead frame, and the number of work steps increases, so that the assembly workability is poor.

  In addition, a sensor having a structure in which the lead frame is simply sandwiched between the detection element and the insulating contact member is subjected to an external force applied to the lead frame, for example, from a lead wire after completion. In some cases, the position of the lead frame moves and the electrode terminal portion (metallized portion) of the detection element is scraped off by the lead frame. When such peeling of the electrode terminal portion occurs, the electrical contact state between the electrode terminal portion and the lead frame becomes poor, causing a problem that normal operation of the sensor cannot be continued.

  Accordingly, the present invention has been made in view of these problems, and can reduce the complexity of the assembly work of the detection element and the lead frame, and the electrode terminal portion of the detection element is peeled even when an external force is applied to the lead frame. It is an object to provide a sensor that is difficult to perform.

  The invention according to claim 1, which has been made to achieve the above object, has a plate-like shape extending in the axial direction, the front end side is directed to the measurement object, and the electrode terminal portion is formed on the rear end side. A metal terminal member that is electrically connected to the electrode terminal portion of the detection element to form a current path, a rear end side of the detection element that is formed of an insulating material and has the electrode terminal portion, and a metal terminal member A sensor comprising two insulating contact members arranged so as to be sandwiched and having at least a part of the metal terminal member in contact with itself, and a clamping fixing member holding the two insulating contact members. The member includes an engagement hole formed on a contact surface with the metal terminal member, and the metal terminal member protrudes toward the insulating contact member and is disposed inside the engagement hole. Together It has a protrusion, and the engagement protrusion is elastically held in the engagement hole in a state of being elastically deformed so as to generate a biasing force against the inner surface of the engagement hole. It is a sensor.

  The protrusion for engagement of the metal terminal member provided in the sensor is disposed inside the engagement hole of the insulating contact member and elastically deforms to generate a biasing force against the inner surface of the engagement hole. It is configured.

  That is, when the engagement protrusion is disposed in the engagement hole, pressure is generated between the engagement protrusion and the engagement hole by the biasing force generated by the engagement protrusion, and the engagement protrusion is It will be in the state elastically held by the inner surface of a hole, and will not fall out from the hole for engagement. Thereby, a metal terminal member can be assembled | attached to an insulated contact member, and it can prevent that a metal terminal member falls off from an insulated contact member.

  In order to prevent the metal terminal member from falling off from the insulating contact member in the operation of assembling the detection element, the metal terminal member, and the insulating contact member by engaging the engaging protrusion with the engaging hole in this way, The work of holding the metal terminal member is not necessary, and the complexity of the assembling work can be reduced.

  Further, by engaging and holding the engaging protrusion in the engaging hole, even when an external force is applied to the metal terminal member, the relative position between the metal terminal member and the insulating contact member is difficult to change, The movement of the metal terminal member can be suppressed. Thereby, it can prevent that the relative position of a metal terminal member and a detection element changes, and it can prevent that the electrode terminal part of a detection element is scraped off by the movement of a metal terminal member.

  Therefore, according to the present invention, it is possible to reduce the complexity of the assembly operation of the detection element and the metal terminal member, and to realize a sensor in which the electrode terminal portion of the detection element is difficult to peel even when an external force is applied to the metal terminal member. .

  Next, in the above-described sensor, as described in claim 2, the engaging protrusion has a substantially U-shaped cross-section in a plane parallel to the protruding direction, and the apex portion of the substantially U-shaped It is preferable to generate an urging force against the inner surface of the engagement hole by elastic deformation.

That is, when the apex portion of the engaging protrusion formed in a substantially U shape is elastically deformed, the opening interval dimension at the opening end portion of the substantially U shape changes.
When such a U-shaped engaging protrusion is inserted and arranged in the engaging hole in a state of being elastically deformed so that the opening interval size of the opening side end portion is reduced, the U-shaped protrusion is restored to return to the original shape. Due to the force, the opening interval dimension at the opening side end portion is expanded and deformed. Then, pressure is generated between the engaging protrusion and the inner surface of the engaging hole due to the biasing force (restoring force) generated by the engaging protrusion. The engagement protrusion is held in the engagement hole by this pressure, so that the metal terminal member can be assembled to the insulating contact member.

  Therefore, according to the present invention, it is possible to reduce the complexity of the assembly operation of the detection element and the metal terminal member, and to realize a sensor in which the electrode terminal portion of the detection element is difficult to peel even when an external force is applied to the metal terminal member. .

  In order to form a substantially U-shaped protrusion for engagement on the metal terminal member, for example, a long portion extending from the front end side to the rear end side of the metal terminal member is deformed into a substantially U shape by bending. A substantially U-shaped engagement protrusion can be formed.

  Further, as the shape of the metal terminal member provided with the substantially U-shaped protrusion for engagement, for example, the U-shaped opening side end portion is disposed on the insulating contact member side facing the insulating contact member, and the U-shaped apex portion is made of metal. The aspect arrange | positioned at the side (detection element side) connected with the main-body part of a terminal member is mentioned. On the other hand, as the shape of the metal terminal member, there is also an aspect in which the U-shaped opening side end is disposed on the detection element side and the U-shaped apex portion is disposed on the insulating contact member side. Since the latter metal terminal member is inserted into the engaging hole from the apex portion having a small opening interval dimension among the engaging protrusions, the metal terminal member is inserted into the engaging hole from the open side end portion having a large opening interval dimension. In comparison, there is an advantage that the operation of inserting the engaging protrusion into the engaging hole is facilitated.

  Next, in the above-described sensor, as described in claim 3, the engaging protrusion includes a plurality of extending portions protruding toward the insulating contact member, and the extending portions are elastically deformed to form a plurality. It is preferable to generate a biasing force against the inner surface of the engagement hole by changing the distance between the extended portions.

That is, the plurality of extending portions are elastically deformed, and the distance between the extending portions in the cross section perpendicular to the projecting direction changes.
When the protrusions for engagement having such a shape are inserted and arranged in the engagement holes in a state of being elastically deformed so that the distance between the extended parts is reduced, the distance between the extended parts is restored by the restoring force. Try to enlarge. Then, pressure is generated between the engaging protrusion and the inner surface of the engaging hole due to the biasing force (restoring force) generated by the engaging protrusion. With this pressure, the engaging protrusion is held in the engaging hole, so that the metal terminal member can be assembled to the insulating contact member.

  Therefore, according to the present invention, it is possible to reduce the complexity of the assembly operation of the detection element and the metal terminal member, and to realize a sensor in which the electrode terminal portion of the detection element is difficult to peel even when an external force is applied to the metal terminal member. .

  Next, in the above-described sensor, as described in claim 4, the metal terminal member has an elongated frame main body extending in the axial direction, and extends from the front end of the frame main body, and at least one of itself. An element abutting portion extending in the axial direction so as to be disposed between the frame main body portion and the detection element, and abutting against an electrode terminal portion of the detection element. At least a part of the connecting side end portion that is connected to the front end of the main body portion and bends inward in the radial direction to change direction is configured to be elastically deformed by applying an external force, and the metal terminal member is In its own free state, the open end located on the rear end side in the axial direction of the element abutting portion does not abut against the frame main body, and is sandwiched between the detection element and the insulating contact member and connected to the connecting end. If the part is elastically deformed Element may open end portion of the contact portion in a state in contact with the frame main body.

  In this sensor, in the free state of the metal terminal member, the element contact portion does not contact the frame main body portion with the open end portion of the element contact portion located on the rear end side in the axial direction. It is supported by the frame main body at one place (the connecting side end connected to the tip of the frame main body). For this reason, in the state where the open end of the element contact portion does not contact the frame main body, the metal terminal member causes the element contact portion to be detected by the stress generated by the elastic deformation of the connection end. It is comprised so that it may press against a terminal part.

  In addition, when the connection side end (at least a part of the connection side end) is elastically deformed and the open end of the element contact portion contacts the frame main body, the metal terminal member is connected to the element contact portion. It is configured to be supported by the frame main body at two locations, a side end and an open end. When the element contact portion is supported at two locations in this way, the metal terminal member is not only elastically deformed at the end on the connection side, but also between the detection element and the frame main body portion in the element contact portion. The element contact portion is pressed against the electrode terminal portion of the detection element by the stress generated by the elastic deformation of the portion located in the region.

  That is, the metal terminal member has different pressures for pressing the element contact portion against the detection element depending on whether the open end of the element contact portion is in contact with the frame main body portion or not. It is comprised so that it may become. More specifically, in the metal terminal member, the pressure of pressing the element contact portion against the electrode terminal portion of the detection element is such that the open end of the element contact portion does not contact the frame main body ( Compared to the one-point support state, the state in which the open end of the element contact portion abuts the frame main body (two-point support state) is configured to be larger.

  As described above, the element contact portion that is in the two-point support state at the time of completion of the sensor has a larger stress generated by elastic deformation than that in the one-point support state. In other words, the metal terminal member can press the element contact portion against the electrode terminal portion of the detection element with greater stress, and the electrical connection state between the metal terminal member and the electrode terminal portion of the detection element is improved. Can do.

  This metal terminal member has a width larger than that of a metal terminal member having a structure in which the element contact portion is always in the one-point support state because the stress increases when the element contact portion is in the two-point support state. There is no need to increase the size and thickness, the expansion of the arrangement space can be suppressed, and the sensor can be used for a sensor that is required to be downsized.

  Therefore, according to the present invention, in the initial stage during assembly work, the element contact portion is set to a one-point support state, and the pressure generated between the metal terminal member and the detection element is suppressed to a small level. The detection element is hardly damaged during the assembly work with the terminal member. Thus, since it becomes difficult to cause breakage of the detection element during the assembly work, it is not necessary to pay attention so that the detection element is not damaged, so that the complexity of the assembly work can be reduced.

  In addition, at the time of completion of the sensor, by setting the element contact portion in a two-point support state, a large pressure can be secured between the metal terminal member and the detection element. The connection state of is improved.

  Next, in the above-described sensor, as described in claim 5, the insulating contact member includes an element sandwiching portion facing a plate surface on which the electrode terminal portion is formed, and a surface of the detection element. It is preferable to include an element guide portion facing a side surface located on the side of the plate surface.

  The insulating contact member is configured to include portions (element clamping portion and element guide portion) that face at least two different surfaces (plate surface and side surface) of the surface of the detection element. When sandwiching the detection element and the metal terminal member using the two insulating contact members, the two element clamping portions sandwich the detection element and the metal terminal member, so that the electrode terminal portion and the metal terminal of the detection element By connecting the members and holding the detection element from the side surfaces by the two element guide portions, the arrangement position of the detection element can be set between the two element holding portions.

  That is, when assembling each member by sandwiching the detection element and the metal terminal member using two insulating contact members, the two element guide portions can prevent the detection element from moving to an inappropriate position in the width direction. The detection element can be securely held between the element holding portions. For this reason, in the work of assembling the detection element and the metal terminal member, it is not necessary to hold the detection element in order to prevent displacement of the detection element with respect to the insulating contact member.

  Further, since the element guide portion abuts against the side surface of the detection element, it is possible to prevent the detection element from moving in the width direction in the completed sensor, and thus it is possible to prevent the detection element from moving due to application of external force. Thereby, it can prevent that the relative position of a detection element and a metal terminal member changes, and even when an external force is applied to a detection element, the electrode terminal part of a detection element becomes difficult to peel.

  Therefore, according to the present invention, in the assembly work of the detection element and the metal terminal member, the work of pressing the detection element in order to prevent misalignment can be omitted, thereby reducing the complexity of the assembly work in the sensor manufacturing process. be able to. In addition, even when an external force acting on the sensor reaches a component (detection element) inside the sensor, it is possible to prevent the electrode terminal portion of the detection element from peeling off.

  Two element guide portions may be provided in one insulating contact member. In this case, the two element guide portions are arranged so that the two element guide portions respectively face two different side surfaces of the detection element. The interval dimension may be set according to the width dimension of the detection element.

  When an insulating contact member having an element guide portion is used, for example, as described in claim 6, one element guide portion is provided in one insulating contact member, and two insulating contact members are provided. It is preferable that the two element guide portions are arranged so as to sandwich the detection element from the side surface by arranging so as to sandwich the detection element.

  Such an insulating contact member can be used for various types of detection elements having different width dimensions because the distance between the two element guide portions can be changed by changing the relative position of the two insulating contact members. Can do. In other words, since this insulating contact member can be applied to various types of detection elements, it becomes a common component (general-purpose component) that can be widely used for different types of sensors. A sensor equipped with this insulating contact member is a common component. The cost can be reduced by the conversion.

  Therefore, the sensor of the present invention includes an insulating contact member that is shared so that other types of sensors can be used. Therefore, there is an advantage that costs can be reduced by sharing components.

  Next, in the above-described sensor, as described in claim 7, the insulating sleeve is provided on the front end side of the insulating contact member and supports the detection element, and the insulating sleeve is provided on the rear end surface of the metal terminal member. It is good to provide the terminal arrangement | positioning part for arrange | positioning a front-end | tip part.

  In this sensor, the insulating sleeve having the terminal arrangement portion is disposed on the distal end side of the insulating contact member, and the distal end portion of the metal terminal member is disposed on the terminal arrangement portion of the insulating sleeve, so that the distal end of the metal terminal member is disposed. The moving range of the part can be limited within a certain range. Thereby, even when an external force is applied to the metal terminal member, the movement of the metal terminal member can be restricted, and the relative position between the detection element and the metal terminal member can be prevented from changing.

  Therefore, according to the present invention, the relative position between the detection element and the metal terminal member can be prevented from changing, and the electrode terminal portion of the detection element can be prevented from peeling even when an external force is applied to the metal terminal member. .

  Next, in the above-described sensor, as described in claim 8, the insulating contact member includes a flange portion that protrudes radially outward from the outer peripheral side surface, and the sandwich fixing member contacts the flange portion. Good.

  As described above, the insulating contact member is provided with the flange portion, and the relative position between the insulating contact member and the sandwich fixing member can be easily determined at a fixed position by bringing the sandwich fixing member into contact with the flange portion.

  Then, by setting in advance the formation position of the flange portion in the insulating contact member so that the relative position between the insulating contact member and the holding and fixing member is an appropriate position, the arrangement position of the holding and fixing member with respect to the insulating contact member is easy. Can be set to an appropriate position. The appropriate relative position means a position where the holding and fixing member can reliably hold the two insulating contact members.

  As a result, the clamping and fixing member can be easily arranged at an appropriate position of the insulating contact member. As a result, the two insulating contact members sandwiched between the clamping and fixing members can properly sandwich the detection element and the metal terminal member, thereby detecting The connection state between the element and the metal terminal member becomes good.

  Therefore, according to the present invention, when the detection element and the metal terminal member are assembled using the clamping and fixing member and the insulating contact member, the positioning operation of the clamping and fixing member with respect to the insulating contact member is easy. Can be reduced.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
In this embodiment, a detection element (gas sensor element) for detecting a specific gas in exhaust gas to be measured is assembled to be used for air-fuel ratio feedback control in automobiles and various internal combustion engines. The full-range air-fuel ratio sensor 2 (hereinafter also referred to as the air-fuel ratio sensor 2) mounted on the exhaust pipe of the internal combustion engine will be described.

FIG. 1 is a cross-sectional view showing an overall configuration of an air-fuel ratio sensor 2 of an embodiment to which the present invention is applied.
The air-fuel ratio sensor 2 includes a cylindrical metal shell 102 having a screw portion 103 formed on the outer surface for fixing to an exhaust pipe, and a detection element 4 having a plate shape extending in the axial direction (vertical direction in the figure). The cylindrical ceramic sleeve 6 arranged so as to surround the circumference of the detection element 4 and the electrode terminal portions 30, 31, 32, 34, 36 of the detection element 4 are electrically connected to form a current path. 5 lead frames 10 and two insulating contact members 82 made of alumina arranged with the lead frame 10 and the rear end of the detection element 4 sandwiched therebetween.

  The detection element 4 has a plate-like shape extending in the axial direction, and a detection portion 8 covered with a protective layer is formed on the front end side (downward in the figure) directed to the gas to be measured, and the rear end side (in the figure) Electrode terminal portions 30, 31, 32, 34, and 36 are formed on the first plate surface 21 and the second plate surface 23, which are in a positional relationship between the front and back surfaces of the upper outer surface. The lead frame 10 is electrically connected to the electrode terminal portions 30, 31, 32, 34, and 36 of the detection element 4 by being disposed between the detection element 4 and the insulating contact member 82. The lead frame 10 is also electrically connected to a lead wire 46 disposed inside the sensor from the outside, and an external device to which the lead wire 46 is connected and the electrode terminal portions 30, 31, 32, 34. , 36 is formed.

  The metal shell 102 has a substantially cylindrical shape having a through hole 109 penetrating in the axial direction, and having a shelf 107 protruding radially inward of the through hole 109 and facing the rear end side. In addition, the metal shell 102 has the detection portion 8 arranged outside the front end side of the through hole 109 and the electrode terminal portions 30, 31, 32, 34, 36 arranged outside the rear end side of the through hole 109. The detection element 4 inserted through 109 is held. Furthermore, the shelf 107 has a tapered surface with a diameter increasing toward the rear end side that is inclined with respect to a plane perpendicular to the axial direction.

  In addition, inside the through hole 109 of the metal shell 102, an annular ceramic holder 106, a powder-filled layer 108 (hereinafter also referred to as a talc ring 108), and an auxiliary sleeve 110, surrounding the detection element 4 in the radial direction. The second powder filling layer 111 and the ceramic sleeve 6 are laminated in this order from the front end side to the rear end side.

  A substantially cylindrical contact support member 112 having a stepped portion 113 is disposed between the ceramic sleeve 6 and the rear end portion 104 of the metal shell 102, and the shelf 107 of the ceramic holder 106 and the metal shell 102. A protective cover 129 functioning as a packing for maintaining airtightness is disposed between the two.

  The protective cover 129 is made of a metal material (for example, stainless steel) and has a bottom surface portion that covers the side surfaces of the ceramic holder 106, the talc ring 108, and the auxiliary sleeve 110 and covers the peripheral edge portion of the ceramic holder 106. It is formed in a cylindrical shape. The bottom surface portion of the protective cover 129 has a central opening having a size that allows the detection element 4 to be inserted into the central portion.

  Further, the contact support member 112 is disposed so that the stepped portion 113 is sandwiched between the ceramic sleeve 6 and the rear end portion 104 of the metal shell 102. The rear end portion 104 of the metal shell 102 is crimped so as to press the ceramic sleeve 6 against the front end side via the contact support member 112.

Here, a perspective view showing a schematic structure of the detection element 4 is shown in FIG. In FIG. 2, the detection element 4 is shown by omitting an intermediate portion in the axial direction.
The detection element 4 has a rectangular shape in which an element portion 20 formed in a plate shape extending in the axial direction (left-right direction in FIG. 2) and a heater 22 formed in a plate shape extending in the axial direction are stacked. It is formed in a plate shape having an axial cross section. Since the detection element 4 used as the air-fuel ratio sensor 2 is a conventionally known element, a detailed description of its internal structure and the like is omitted, but the schematic configuration is as follows.

  First, the element unit 20 includes an oxygen concentration cell element in which a porous electrode is formed on both sides of a solid electrolyte substrate, an oxygen pump element in which a porous electrode is formed on both sides of the solid electrolyte substrate, and a gap between these elements. The spacers are stacked to form a hollow measurement gas chamber. This solid electrolyte substrate is made of zirconia in which yttria is dissolved as a stabilizer, and the porous electrode is mainly made of Pt. The spacer forming the measurement gas chamber is mainly composed of alumina, and inside the hollow measurement gas chamber is one porous electrode of the oxygen concentration cell element and one porous electrode of the oxygen pump element. It arrange | positions so that an electrode may be exposed. The measurement gas chamber is formed so as to be positioned on the distal end side of the element portion 20, and a diffusion rate controlling portion made of porous ceramic for communicating the measurement gas chamber and the outside is provided on the distal end side of the spacer. The portion where the measurement gas chamber is formed corresponds to the detection unit 8.

Next, the heater 22 is formed by sandwiching a heating resistor pattern mainly composed of Pt between insulating substrates mainly composed of alumina.
The element unit 20 and the heater 22 are joined to each other via a ceramic layer (for example, zirconia ceramic or alumina ceramic). The detection element 4 has a porous ceramic for preventing poisoning (for example, an alumina-based ceramic, etc.) on at least the surface of the electrode exposed to the measurement object (exhaust gas in this embodiment) on the tip side. ) Is formed. In the present embodiment, the entire front end side of the detection element 4 including the surface of the electrode exposed to the exhaust gas is covered with a protective layer.

  In such a detection element 4, as shown in FIG. 2, three electrode terminal portions 30, 31, 32 are formed on the rear end side (right side in FIG. 2) of the first plate surface 21, and the second plate surface. Two electrode terminal portions 34, 36 are formed on the rear end side of 23. The electrode terminal portions 30, 31, and 32 are formed in the element portion 20. One electrode terminal portion is one porous electrode and oxygen pump element of the oxygen concentration cell element exposed inside the measurement gas chamber. Are electrically connected in common with one of the porous electrodes. The remaining two electrode terminal portions of the electrode terminal portions 30, 31, and 32 are electrically connected to the other porous electrode of the oxygen concentration cell element and the other porous electrode of the oxygen pump element, respectively. . The electrode terminal portions 34 and 36 are formed in the heater 22 and are respectively connected to both ends of the heating resistor pattern via vias (not shown) that cross in the thickness direction of the heater.

  As shown in FIG. 1, the detection element 4 configured in this way protrudes from the front end of the metal shell 102 on the front end side (downward in FIG. 1) fixed to the exhaust pipe, and also on the rear end side. The electrode terminal portions 30, 31, 32, 34, and 36 are fixed to the inside of the metal shell 102 in a state of protruding from the rear end of the metal shell 102.

  On the other hand, as shown in FIG. 1, a metal (for example, stainless steel) having a plurality of holes and covering the protruding portion of the detection element 4 on the outer periphery of the front end side (downward in FIG. 1) of the metal shell 102. A double external protector 42 and an internal protector 43 are attached by welding or the like.

  An outer cylinder 44 is fixed to the outer periphery of the rear end side of the metal shell 102. Further, in the opening on the rear end side (upper side in FIG. 1) of the outer cylinder 44, five leads electrically connected to the electrode terminal portions 30, 31, 32, 34, and 36 of the detection element 4, respectively. A ceramic separator 48 and a grommet 50 each having a lead wire insertion hole 61 through which the wire 46 is inserted are disposed.

Two insulating contact members 82 are arranged on the rear end side (upper side in FIG. 1) of the detection element 4 protruding from the rear end portion 104 of the metal shell 102.
Next, the insulating contact member 82 will be described.

The insulating contact members 82 are made of an insulating material (ceramic or the like), and two insulating contact members 82 are provided so as to sandwich the rear end portion of the detection element 4 and the lead frame 10.
The air-fuel ratio sensor 2 is opposed to the first insulating contact member 401 disposed opposite to the first plate surface 21 of the detection element 4 and the second plate surface 23 of the detection element 4 as the insulating contact member 82. And a second insulating contact member 402 disposed.

  FIG. 4 is a perspective view of two insulating contact members 82 (first insulating contact member 401 and second insulating contact member 402). FIG. 4 shows the insulating contact member 82 in a single state before sandwiching the detection element 4 and the lead frame 10.

  First, as shown in FIG. 4, the first insulating contact member 401 includes an element clamping portion 411 facing the first plate surface 21 on which the electrode terminal portions 30, 31, and 32 are formed on the surface of the detection element 4, An element guide portion 413 facing a side surface of the surface of the detection element 4 located on the side of the first plate surface 21.

  The first insulating contact member 401 includes three engagement hole portions 415 on the contact surface of the element sandwiching portion 411 with the lead frame 10. The engagement hole 415 is formed as a through hole penetrating in the direction perpendicular to the first plate surface 21 of the detection element 4 in the element clamping part 411.

  Furthermore, the first insulating contact member 401 includes two first rib portions 87 that protrude toward the detection element 4 on the inner surface of the element sandwiching portion 411 that serves as a contact surface with the lead frame 10. The first rib portion 87 is provided as a lead frame boundary portion that forms a boundary between the three first frame arrangement grooves 86 for individually arranging the three lead frames 10 in an electrically insulated state. The three first frame arrangement grooves 86 are formed at positions corresponding to the electrode terminal portions 30, 31, 32 on the first plate surface 21 of the detection element 4.

The first insulating contact member 401 includes a flange 83 that protrudes radially outward from the outer peripheral side surface that does not face the detection element 4.
Next, as shown in FIG. 4, the second insulating contact member 402 includes a second element sandwiching portion 421 facing the second plate surface 23 on which the electrode terminal portions 34 and 36 are formed on the surface of the detection element 4. And a second element guide portion 423 facing the side surface orthogonal to the second plate surface 23 of the surface of the detection element 4.

  The second insulating contact member 402 includes two second engagement holes 425 on the contact surface of the second element holding portion 421 with the lead frame 10. The second engagement hole 425 is formed as a through hole penetrating in the direction perpendicular to the second plate surface 23 of the detection element 4 in the second element clamping portion 421.

  Further, the second insulating contact member 402 includes a second rib portion 89 that protrudes toward the detection element 4 on the inner surface of the second element sandwiching portion 421 that serves as a contact surface with the lead frame 10. The second rib portion 89 is provided as a lead frame boundary portion that forms a boundary between two second frame placement grooves 88 for individually placing the two lead frames 10 in an electrically insulated state. The two second frame arrangement grooves 88 are formed at positions corresponding to the electrode terminal portions 34 and 36 on the second plate surface 23 of the detection element 4.

Further, the second insulating contact member 402 is formed with a flange 83 that protrudes radially outward from an outer peripheral side surface that does not face the detection element 4.
Next, the lead frame 10 will be described. A perspective view showing the appearance of the lead frame 10 is shown in FIG.

  Note that the air-fuel ratio sensor 2 of this embodiment has two types of lead frames 10 (the first lead frame 11 shown on the left side in FIG. The second lead frame 211) shown in FIG. The lead frame 10 is formed of a well-known material (for example, Inconel, stainless steel, etc.) that can maintain elasticity (spring elasticity) even when repeatedly exposed to high temperatures.

First, the first lead frame 11 will be described.
The first lead frame 11 extends from the front end of the frame main body 12, which is a long plate-like member extending in the axial direction, and a part of the first lead frame 11 includes the frame main body 12 and the detection element 4. An element abutting portion 16 extending in the axial direction so as to be disposed between and an engaging projection 18 projecting in a direction perpendicular to the axial direction from the frame main body portion 12, and one of the element abutting portions 16. The portion is configured to contact the electrode terminal portion of the detection element 4.

  The projecting portion 18 for engagement is formed by bending a part of the frame main body portion 12 so that a cross-sectional shape in a plane parallel to the projecting direction is formed in a substantially U shape, and the vertex portion of the substantially U shape is elastically deformed. It is configured to

  When the engagement protrusion 18 is not elastically deformed, the opening interval dimension at the substantially U-shaped opening side end is set to the engagement hole of the insulation contact member 82 (specifically, the second insulation contact member 402). The second engagement hole 425) is formed to be larger than the inner diameter. In addition, the engagement protrusion 18 can be inserted into the engagement hole of the insulating contact member 82 and can be disposed inside the engagement hole by reducing the size of the opening interval due to elastic deformation.

  The frame main body 12 has a width dimension changing portion 13 at a substantially intermediate position in the axial direction, and a front end portion located at the front end of the width dimension changing portion 13 and a rear end of the width dimension changing portion 13. The rear end portion located is configured to have a different width dimension. In addition, a curved portion 19 is formed in a portion of the frame main body 12 that is slightly on the distal end side from the engagement protrusion 18, and the frame main body 12 is curved with a portion at the distal end rather than the curved portion 19. The rear end portion of the portion 19 is configured so that the position in the thickness direction of the plate surface is different.

Further, the frame main body 12 is formed such that the width dimension W1 of the plate surface at the front end side portion relative to the width dimension changing part 13 is 1.2 [mm] and the thickness is 0.2 [mm].
Here, the width dimension is a dimension in a direction perpendicular to the axial direction and perpendicular to the gap interval direction between the element contact portion 16 and the frame main body portion 12. Further, the lead frame 10 (the first lead frame 11 and the second lead frame 211) is formed to have a narrower width and a smaller thickness compared to a conventional lead frame.

  The element contact portion 16 includes a connection side end portion 14 that is connected to the distal end of the frame main body portion 12 and bends inward in the radial direction to change the direction. In the free state of the first lead frame 11 itself, the element contact portion 16 is provided. An open side end 15 located on the rear end side in the axial direction of the portion 16 is formed so as to be separated from the frame main body portion 12. The element abutting portion 16 is curved in an arc shape so that the gap dimension from the axial intermediate portion to the frame main body portion 12 is longer than the gap dimension from the open side end portion 15 to the frame main body portion 12. The convex surface of the arcuate shape is in contact with the detection element 4.

  The connection-side end 14 of the element abutting portion 16 is configured to be elastically deformed by applying an external force, and the first lead frame 11 is configured such that the connection-side end 14 is elastically deformed. The gap between the frame main body 12 and the element contact portion 16 is configured to change. In addition, when the first lead frame 11 is assembled to the insulating contact member 82, the tip portion of the first lead frame 11 (in this embodiment, the connecting side end portion 14) is more distal than the tip of the insulating contact member 82. The size is arranged on the side.

  Further, the element contact portion 16 is configured such that the open side end portion 15 comes into contact with the frame main body portion 12 when the connection side end portion 14 is elastically deformed and the open side end portion 15 approaches the frame main body portion 12. Has been.

  Further, the first lead frame 11 has a gap dimension (axial direction) between the open end 15 of the element contact portion 16 and the frame body 12 when no external force is applied and the connecting end 14 is not elastically deformed. The dimension in the direction orthogonal to the first frame arrangement groove 86 of the insulating contact member 82 is smaller than the depth dimension of the first frame arrangement groove 86.

  When the first lead frame 11 is sandwiched between the detection element 4 and the insulating contact member 82 and the connecting end 14 is elastically deformed, the open end 15 of the element contact portion 16 is the frame. While being in contact with the main body portion 12, at least a part of the element contact portion 16 is arranged outside the first frame arrangement groove 86 and is in contact with the electrode terminal portion of the detection element 4.

  Further, the first lead frame 11 is integrally provided with a lead wire connecting portion 17 formed wider than the frame main body portion 12 at the rear end portion (upper end portion in the drawing) of the frame main body portion 12. The lead wire connecting portion 17 is formed into a substantially cylindrical shape by bending, and then crimped radially inward with the core wire of the lead wire 46 (not shown) inserted thereinto. Connected to line 46.

  Next, the second lead frame 211 includes a second frame body 212 having a width dimension narrower than the width dimension changing unit 13 in comparison with the frame body 12 of the first lead frame 11; A second element abutting portion 216 having a width dimension narrower than that of the element abutting portion 16 of the first lead frame 11 and a narrowness having a width dimension narrower than that of the connection side end portion 14 of the first lead frame 11. The connection-side end portion 214, the narrow engagement protrusion 218 formed to be narrower than the engagement protrusion 18 of the first lead frame 11, and the width dimension narrower than the curved portion 19 of the first lead frame 11. And a narrow bend portion 219 formed. The narrow connection side end 214 is configured to connect the distal end of the second frame main body 212 and the distal end of the second element contact portion 216.

  The second frame main body 212 is formed such that the width W2 of the plate surface at the tip side portion relative to the narrow curved portion 219 is 0.8 [mm] and the thickness is 0.2 [mm]. Although the width dimension of the plate surface of the frame 11 is different from that of the frame main body portion 12, the cross-sectional shape in a plane parallel to the axial direction and perpendicular to the plate surface is substantially the same as that of the frame main body portion 12.

  The second element abutting portion 216 has a plate surface having a width dimension different from that of the element abutting portion 16 of the first lead frame 11, but the cross-sectional shape in a plane parallel to the axial direction and perpendicular to the plate surface is It is formed in an arc shape substantially the same as the contact portion 16, and includes a second open side end 215 corresponding to the open side end 15. The narrow connection side end 214 has a plate surface width dimension different from that of the connection side end 14 of the first lead frame 11, but the cross-sectional shape in a plane parallel to the axial direction and perpendicular to the plate surface is the connection side end. It is formed in an arc shape substantially similar to the portion 14. The narrow engagement protrusion 218 is different in the width of the plate surface from the engagement protrusion 18 of the first lead frame 11, but the cross-sectional shape in a plane parallel to the axial direction and perpendicular to the plate surface is the engagement protrusion. It is formed in an arc shape substantially the same as the portion 18.

  Further, the second lead frame 211 includes a second lead wire connecting portion 217 formed in a shape substantially the same as the lead wire connecting portion 17 of the first lead frame 11 at the rear end portion of the second frame main body portion 212. ing.

  Next, a partial cross-sectional perspective view of the insulating contact member 82 (second insulating contact member 402 and first insulating contact member 401) in a state where the lead frame 10 (first lead frame 11 and second lead frame 211) is assembled. Is shown in FIG.

  As shown in FIG. 5, the first lead frame 11 of the lead frame 10 is arranged in the second frame arrangement groove 88 of the insulating contact member 82 (second insulating contact member 402), and the engaging protrusion 18 is provided. The insulating contact member 82 is assembled by being fitted into the second engagement hole 425. The two first lead frames 11 assembled to the second insulating contact member 402 are arranged in the second frame arrangement groove 88 while being insulated from each other by the second rib portion 89. At this time, the two first lead frames 11 are arranged at positions corresponding to the electrode terminal portions 34 and 36 of the detection element 4.

  The second lead frame 211 of the lead frame 10 is disposed in the first frame disposition groove 86 of the insulating contact member 82 (first insulating contact member 401), and the narrow engagement protrusion 218 has an engagement hole. By being fitted to 415, the insulating contact member 82 is assembled. Note that the three second lead frames 211 assembled to the first insulating contact member 401 are disposed in the first frame disposition groove 86 in a state of being insulated from each other by the first rib portion 87. At this time, the three second lead frames 211 are arranged at positions corresponding to the electrode terminal portions 30, 31, and 32 of the detection element 4.

  By arranging the two insulating contact members 82 (the first insulating contact member 401 and the second insulating contact member 402) with the lead frame 10 assembled in this manner so as to sandwich the rear end portion of the detection element 4, the lead The element contact portion 16 (second element contact portion 216) of the frame 10 and the electrode terminal portions 30, 31, 32, 34, and 36 of the detection element 4 can be electrically connected while being in contact with each other.

Next, the ceramic sleeve 6 will be described.
In FIG. 6, the perspective view showing the external appearance of the ceramic sleeve 6 is shown.
As shown in FIG. 6, the ceramic sleeve 6 is formed in a substantially cylindrical shape having an element insertion hole 71 penetrating in the axial direction, and the leading end portion of the lead frame 10 is disposed on the rear end surface (upper side surface in the drawing). The terminal arrangement | positioning part 73 for this is provided.

  The element insertion hole 71 is formed in a size that allows the detection element 4 to be inserted. The terminal arrangement portion 73 is formed by being drilled from the rear end surface of the ceramic sleeve 6 toward the front end side, and on the side where the first plate surface 21 of the detection element 4 is disposed in the element insertion hole 71. Three of the element insertion holes 71 are formed on the side where the second plate surface 23 of the detection element 4 is disposed.

  Further, the ceramic sleeve 6 is formed with a reduced diameter portion having a small diameter dimension in a cross section perpendicular to the axial direction on the rear end side, and a boundary portion where the diameter dimension changes is opposed to the rear end side. A step engaging portion 75 is formed. The ceramic sleeve 6 is configured such that the step engaging portion 75 is engaged with the rear end portion 104 of the metal shell 102 via the contact support member 112.

  Next, after the two insulating contact members 82 (the first insulating contact member 401 and the second insulating contact member 402) to which the lead frame 10 is assembled are assembled to the rear end portion of the detection element 4, the ceramic separator 48 and the outer An operation for assembling the air-fuel ratio sensor 2 by assembling the cylinder 44 will be described.

  FIG. 7 is an explanatory diagram showing each step of the assembly work of the air-fuel ratio sensor 2. FIG. 7 shows a work process after the detection element 4 is assembled to the metal shell 102 via the contact support member 112, the ceramic sleeve 6 or the like.

  First, in a first stage in FIG. 7, two insulating contact members 82 (first insulating contact member 401 and second insulating contact member 402) assembled with the lead frame 10 (first lead frame 11 and second lead frame 211) are assembled. ) Is arranged so as to sandwich the detection element 4. As a result, the lead frame 10 is in contact with and electrically connected to the electrode terminal portions 30, 31, 32, 34, 36 of the detection element 4.

  At this time, the front end surface of the flange portion 83 of the insulating contact member 82 is brought into contact with the rear end of the contact support member 112, and the front end portion of the insulating contact member 82 is disposed inside the contact support member 112.

  In the first stage, the first insulating contact member 401 assembled with the three second lead frames 211 is disposed on the side facing the first plate surface 21 of the detection element 4, and the second lead frame 211. The operation of arranging the tip portion of the terminal on the terminal arrangement portion 73 of the ceramic sleeve 6 is performed. Similarly, the second insulating contact member 402 assembled with the two first lead frames 11 is arranged on the side facing the second plate surface 23 of the detection element 4, and the tip portion of the first lead frame 11 is arranged. The operation of arranging the terminals on the terminal arrangement portion 73 of the ceramic sleeve 6 is performed.

  At this time, the number of formed terminal arrangement portions 73 adjacent to the two plate surfaces of the detection element 4 is confirmed by visual recognition or the like, and the first plate surface 21 and the first number of the detection element 4 are determined based on the number of formed terminal arrangement portions 73. By identifying the two plate surfaces 23, it is possible to prevent the first insulating contact member 401 and the second insulating contact member 402 from being placed in the wrong positions.

  In the element holding work (work for holding the detection element 4 by the ceramic sleeve 6) performed at an earlier stage than the first stage, the first plate is sufficiently confirmed after the plate surface direction of the detection element 4 is sufficiently confirmed. The detection element 4 with respect to the ceramic sleeve 6 is arranged such that the surface 21 faces the side where the three terminal arrangement portions 73 are formed and the second plate surface 23 faces the side where the two terminal arrangement portions 73 are formed. The direction is determined.

  In the next second stage, an operation of caulking and deforming the contact support member 112 inward in the circumferential direction is performed. As a result, the contact support member 112 holds the two insulating contact members 82 arranged so as to sandwich the detection element 4 and the lead frame 10, and the first insulating contact member 401 and the second insulating contact member 402 The gap distance of is shortened.

  In the subsequent third stage, an operation of placing the ceramic separator 48 at the rear end portion of the insulating contact member 82 is performed. At this time, the cylindrical member 49 is integrally assembled on the tip side of the ceramic separator 48.

  In the next fourth stage, the outer cylinder 44 is disposed so as to cover the insulating contact member 82 and the ceramic separator 48, the outer cylinder 44 is fixed to the metal shell 102, and the grommet 50 is formed in the rear end side opening of the outer cylinder 44. Work to fix.

  At this time, the outer cylinder 44 is fixed to the metal shell 102 by caulking work inward in the radial direction and laser welding. In addition, the ceramic separator 48, the cylindrical member 49, and the grommet 50 are fixed to the outer cylinder 44 by caulking portions corresponding to the ceramic separator 48, the cylindrical member 49, and the grommet 50 inward in the radial direction. .

  In this way, after the lead frame 10, the insulating contact member 82 and the detection element 4 are assembled together, the outer tube 44 and the like are joined to the metal shell 102 by laser welding and the grommet 50 is crimped. Thus, the air-fuel ratio sensor 2 is completed by performing a fixing operation for fixing to the outer cylinder 44, and the manufacturing process of the air-fuel ratio sensor 2 is completed.

  Here, FIG. 8 is an explanatory diagram showing a deformed state of the lead frame 10 when the contact support member 112 is crimped and the two insulating contact members 82 are assembled to the detection element 4. In FIG. 8, one lead frame 10 and the detection element 4 are illustrated, and the insulating contact member 82 is not illustrated.

  First, in the first step in which the lead frame 10 itself is in a free state, no external force is applied to the lead frame 10 and the connecting side end 14 is not elastically deformed. The open end 15 does not contact the frame body 12.

  In the next second step, the two insulating contact members 82 are arranged inside the contact support member 112 and the detection element 4 is sandwiched between the two insulating contact members 82, so that the element abutting portion 16 of the lead frame 10 is sandwiched. By applying an external force, the connection-side end portion 14 is elastically deformed, and the open-side end portion 15 of the element contact portion 16 contacts the frame main body portion 12. As a result, the element contact portion 16 is supported by the frame main body portion 12 at two locations of the connection side end portion 14 and the open side end portion 15.

  In the subsequent third step, the contact support member 112 is crimped to shorten the gap between the two insulating contact members 82, thereby further applying an external force to the element contact portion 16 of the lead frame 10. At this time, the element contact portion 16 is elastically deformed in the axial direction along the plate surface of the detection element 4, and is in contact with the electrode terminal portion of the detection element 4 in a wide area and has two points. Since it is in the support state, it comes into contact with the detection element 4 while exerting a large pressure.

  By performing the assembling work in this manner, the detection element 4, the lead frame 10, and the insulating contact member 82 can be assembled together. Here, the elastic deformation state of the first lead frame 11 during the assembly work has been described, but the second lead frame 211 also shows a deformation state similar to that of the first lead frame 11.

  In this embodiment, the lead frame 10 corresponds to the metal terminal member described in the claims, the contact support member 112 corresponds to the clamping member, and the ceramic sleeve 6 corresponds to the insulating sleeve.

  As described above, the air-fuel ratio sensor 2 of this embodiment has the insulating contact member 82 (first insulating contact) having the engaging hole portion 415 and the second engaging hole portion 425 on the contact surface with the lead frame 10. Member 401, second insulating contact member 402), and lead frame 10 (first lead frame 11 and second lead frame 211) having a protrusion 18 for engagement and a protrusion 218 for narrow engagement. Yes.

  The engagement protrusion 18 and the narrow engagement protrusion 218 are formed in a substantially U shape, and the vertex portion of the approximately U shape is elastically deformed. When the engagement protrusion 18 and the narrow engagement protrusion 218 are not elastically deformed, the opening interval dimension at the substantially U-shaped opening side end portion is the engagement hole 415, the second engagement hole 425. It is formed to be larger than the inner diameter dimension, and is configured to be able to be inserted into the engagement hole part 415 and the second engagement hole part 425 by reducing the opening interval dimension by elastic deformation.

  The engagement protrusion 18 and the narrow engagement protrusion 218 of the lead frame 10 provided in the sensor are disposed in the engagement hole 415 and the second engagement hole 425 of the insulating contact member 82 and elastically deformed. When the opening interval size is reduced, a restoring force is generated to return to the original shape.

  That is, when the engagement protrusion 18 and the narrow engagement protrusion 218 are arranged in the engagement hole 415 and the second engagement hole 425, the urging force (restoration) generated by the engagement protrusion 18 and the narrow engagement protrusion 218 is generated. Force) generates a pressure between the engagement protrusion 18 and the narrow engagement protrusion 218 and the engagement hole 415 and the second engagement hole 425, and the engagement protrusion 18 and the narrow engagement protrusion 218. Is held on the inner surface of the engagement hole 415 and the second engagement hole 425. As a result, the lead frame 10 and the insulating contact member 82 can be assembled, and the lead frame 10 can be prevented from falling off the insulating contact member 82.

  As described above, the engagement protrusion 18 and the narrow engagement protrusion 218 are engaged with the engagement hole 415 and the second engagement hole 425, thereby assembling the detection element 4, the lead frame 10, and the insulating contact member 82. In the work, it is not necessary to hold the lead frame 10 in order to prevent the lead frame 10 from falling off from the insulating contact member 82, and the complexity of the assembling work can be reduced.

  In the completed full-range air-fuel ratio sensor 2, the engagement protrusion 18 and the narrow engagement protrusion 218 are engaged with and held in the engagement hole 415 and the second engagement hole 425. Even when an external force is applied to the frame 10, the relative position between the lead frame 10 and the insulating contact member 82 is difficult to change, and the lead frame 10 can be prevented from moving. As a result, the relative position between the lead frame 10 and the detection element 4 can be prevented from changing, and the electrode terminal portions 30, 31, 32, 34, and 36 of the detection element 4 can be prevented from being scraped off due to the movement of the lead frame 10. it can.

  In addition, since the movement of the lead frames 10 can be suppressed and the adjacent lead frames 10 can be prevented from coming into contact with each other, the entire region air-fuel ratio sensor 2 causes a failure in the current path due to the contact between the adjacent lead frames 10. Can be prevented.

  Therefore, the full-range air-fuel ratio sensor 2 of the present embodiment can reduce the complexity of the assembly work of the detection element 4 and the lead frame 10, and the electrode terminal portion of the detection element 4 even when an external force is applied to the lead frame 10. 30, 31, 32, 34, and 36 are sensors that are difficult to peel off.

  In the air-fuel ratio sensor 2, the lead frame 10 is configured so that the open end 15 located on the rear end side in the axial direction of the element contact portion 16 contacts the frame main body 12 in the free state of the lead frame 10 itself. Without contact, the element contact portion 16 is supported by the frame main body portion at one location. For this reason, in the state where the open side end 15 of the element contact portion 16 does not contact the frame main body portion 12, the lead frame 10 has the element contact portion 16 due to the stress generated by the elastic deformation of the connection side end portion 14. Is pressed against the electrode terminal portion of the detection element 4.

  Further, when the connecting side end 14 is elastically deformed and the open side end 15 of the element abutting portion 16 abuts the frame main body portion 12 of the lead frame 10, the element abutting portion 16 is connected to the connecting side end 14 and It is configured to be supported by the frame body 12 at two locations on the open end 15. Thus, when the element contact portion 16 is supported at two locations, the lead frame 10 is not only elastically deformed at the connection side end portion 14 but also elastically deformed at the intermediate portion in the axial direction of the element contact portion 16. Due to the generated stress, the element contact portion 16 is pressed against the electrode terminal portion of the detection element 4.

  That is, the lead frame 10 presses the element contact portion 16 against the detection element 4 depending on whether the open end 15 of the element contact portion 16 is in contact with the frame main body portion 12 or not. It is comprised so that a pressure may become a different magnitude | size. More specifically, the lead frame 10 has a pressure that presses the element contact portion 16 against the electrode terminal portion of the detection element 4, and the open end 15 of the element contact portion 16 is applied to the frame main body portion 12. The state in which the open end 15 of the element contact portion 16 contacts the frame main body 12 (two-point support state) is larger than the state in which the element contact portion 16 does not contact (one-point support state). .

  As described above, the element contact portion 16 that is in the two-point support state at the time of completion of the sensor has a larger stress generated by elastic deformation than that in the one-point support state. That is, the lead frame 10 can press the element contact portion 16 against the electrode terminal portion of the detection element 4 with a greater stress, and the electrical connection state between the lead frame 10 and the electrode terminal portion of the detection element 4 is good. Can be.

  The lead frame 10 has a stress that increases when the element abutting portion 16 is in a two-point support state, so that the lead frame 10 has a structure in which the element abutting portion 16 is always in a one-point support state. Therefore, it is not necessary to increase the width dimension and the thickness dimension, the expansion of the arrangement space can be suppressed, and the entire area air-fuel ratio sensor 2 can be reduced in size.

  Therefore, according to the full-range air-fuel ratio sensor 2 of the present embodiment, the element abutting portion 16 is set to the one-point support state in the initial stage during the assembly work, and the space between the lead frame 10 and the detection element 4 is set. By suppressing the pressure generated at the time, the detection element 4 is hardly damaged during the assembly work with the lead frame 10. Thus, since it becomes difficult to cause the detection element 4 to be damaged during the assembly work, it is not necessary to pay attention so that the detection element 4 is not damaged, so that the complexity of the assembly work can be reduced.

  In addition, when the sensor is completed, since the element contact portion 16 is set in a two-point support state, a large pressure can be secured between the lead frame 10 and the detection element 4, so that the lead frame 10 and the electrode terminal The connection state with the parts 30, 31, 32, 34, and 36 becomes good.

  Next, in the full-range air-fuel ratio sensor 2, the first insulating contact member 401 faces the surface (plate surface) on which the electrode terminal portions 30, 31, 32, 34, and 36 are formed, of the surface of the detection element 4. And a device guide portion 413 facing the surface (side surface) located on the side of the plate surface of the surface of the detection device 4. That is, the first insulating contact member 401 is configured to include portions (an element clamping part 411 and an element guide part 413) respectively facing at least two different surfaces (plate surface and side surface) of the surface of the detection element 4. .

  Similarly, the second insulating contact member 402 includes portions (second element sandwiching portion 421 and second element guide portion 423) respectively facing at least two different surfaces (plate surface and side surface) of the surface of the detection element 4. Configured.

  When the detection element 4 and the lead frame 10 are clamped using the first insulating contact member 401 and the second insulating contact member 402, the element clamping unit 411 and the second element clamping unit 421 By sandwiching the lead frame 10, the electrode terminal part of the detection element 4 and the lead frame 10 are connected, and the element guide part 413 and the second element guide part 423 hold the detection element 4 from the side surface. The arrangement position of the detection element 4 can be set between the element clamping unit 411 and the second element clamping unit 421.

  That is, when the detection element 4 and the lead frame 10 are sandwiched using the first insulation contact member 401 and the second insulation contact member 402 and the respective members are assembled, the detection element 4 is detected by the element guide portion 413 and the second element guide portion 423. Can be prevented from moving to an inappropriate position in the width direction, and the detection element 4 can be securely clamped between the element clamping part 411 and the second element clamping part 421.

  For this reason, when the detection element 4 and the lead frame 10 are assembled, it is not necessary to hold the detection element 4 in order to prevent displacement of the detection element 4 with respect to the insulating contact member 82.

  Moreover, since the element guide part 413 and the 2nd element guide part 423 contact | abut to the side surface of the detection element 4, since it can suppress that the detection element 4 moves to the width direction in the air-fuel ratio sensor 2 after completion, external force It is possible to prevent the detection element 4 from moving due to the application of. Thereby, it is possible to prevent the relative position between the detection element 4 and the lead frame 10 from changing, and even when an external force is applied to the detection element 4, the electrode terminal portion of the detection element 4 is difficult to peel off.

  Therefore, according to the full-range air-fuel ratio sensor 2, in the assembly work of the detection element 4 and the lead frame 10, the work of pressing the detection element 4 in order to prevent displacement can be omitted. Can be reduced. In addition, even when an external force acting on the full-range air-fuel ratio sensor 2 reaches parts (such as the detection element 4 and the lead frame 10) inside the sensor, it is possible to prevent the electrode terminal portion of the detection element 4 from peeling off.

  Note that each of the first insulating contact member 401 and the second insulating contact member 402 is provided with one element guide portion (element guide portion 413 and second element guide portion 423) so as to sandwich the detection element 4 therebetween. By being arranged, each element guide part (element guide part 413 and second element guide part 423) is arranged so as to sandwich the detection element 4 from the side surface.

  Since the first insulating contact member 401 and the second insulating contact member 402 can change the distance between the two element guide portions (the element guide portion 413 and the second element guide portion 423) by changing the relative position of each other, It can be used for various types of detection elements having different width dimensions.

  That is, since the first insulating contact member 401 and the second insulating contact member 402 can be applied to various types of detection elements having different width dimensions, common components (general-purpose components) that can be widely used for different types of sensors. Become. In general, since common parts (general-purpose parts) can be manufactured at low cost, the full-range air-fuel ratio sensor 2 of the present embodiment can achieve cost reduction by sharing parts.

  The full-range air-fuel ratio sensor 2 includes a ceramic sleeve 6 that is disposed on the distal end side of the insulating contact member 82 and supports the detection element 4. The rear end surface of the ceramic sleeve 6 has a distal end portion of the lead frame 10. The terminal arrangement | positioning part 73 for arrange | positioning is formed.

  For this reason, in the full-range air-fuel ratio sensor 2, the tip portion of the lead frame 10 (in the present embodiment, the connecting side end portion 14) is arranged in the terminal arrangement portion 73 of the ceramic sleeve 6. The moving range of the tip portion can be limited within a certain range. Thereby, even when some external force is applied to the lead frame 10, the movement of the lead frame 10 can be restricted, and the relative position between the detection element 4 and the lead frame 10 can be prevented from changing.

  Therefore, according to the full-range air-fuel ratio sensor 2, it is possible to prevent the relative position between the detection element 4 and the lead frame 10 from changing, and even when an external force is applied to the lead frame 10, the electrode terminal portion 30 of the detection element 4. , 31, 32, 34, 36 can be prevented from peeling off.

  In the air-fuel ratio sensor 2, the insulating contact member 82 includes a flange portion 83 that protrudes radially outward from the outer peripheral side surface, and the contact support member 112 is in contact with the flange portion 83 of the insulating contact member 82. It is configured.

  In this way, by bringing the contact support member 112 into contact with the flange 83 of the insulating contact member 82, the relative position between the insulating contact member 82 and the contact support member 112 can be easily set at a fixed position.

  And the contact support member with respect to the insulation contact member 82 is set in advance by setting the formation position of the flange 83 in the insulation contact member 82 so that the relative position between the insulation contact member 82 and the contact support member 112 is an appropriate position. 112 can be easily set to an appropriate position. The appropriate relative position means a position where the contact support member 112 can reliably hold the two insulating contact members 82.

  As a result, the contact support member 112 can be easily disposed at an appropriate position of the insulating contact member 82. As a result, the two insulating contact members 82 sandwiched between the contact support members 112 properly connect the detection element 4 and the lead frame 10 to each other. Since it can be clamped, the connection state between the detection element 4 and the lead frame 10 becomes good.

  Therefore, according to the full-range air-fuel ratio sensor 2, when the detection element 4 and the lead frame are assembled using the contact support member 112 and the insulating contact member 82, the positioning operation of the contact support member 112 with respect to the insulating contact member 82 is easy. Therefore, the complexity of the assembling work can be reduced.

  In the full-range air-fuel ratio sensor 2, the contact support member 112 is fixed to the metal shell 102, and the insulating contact member 82 is supported by the contact support member 112. For this reason, even if some impact force is applied to the full-range air-fuel ratio sensor 2, the relative position between the insulating contact member 82 and the metal shell 102 is difficult to change. The detection element 4 is fixed to the metal shell 102 by a ceramic sleeve 6 or the like.

  For these reasons, the entire area air-fuel ratio sensor 2 is unlikely to change the relative position between the detection element 4 and the insulating contact member 82 even when an external force (impact) is applied. It is possible to prevent the detection element 4 from being broken due to the swinging of.

  Furthermore, since the air-fuel ratio sensor 2 is provided with a gap between the contact support member 112 and the outer cylinder 44, even when the outer cylinder 44 is deformed by some external force, the deformation amount is larger than the gap dimension. If it is small, the influence does not reach the contact support member 112. For this reason, even when the outer cylinder 44 is deformed, it is possible to avoid the influence of the influence on the insulating contact member 82 via the contact support member 112. Thus, the detection element 4 can be prevented from being damaged.

As mentioned above, although the Example of this invention was described, this invention is not limited to the said Example (henceforth 1st Example), It can take a various aspect.
For example, the lead frame is not limited to one having a substantially U-shaped engagement protrusion, and a third engagement protrusion 318 including a plurality of extending portions 321 as shown in FIG. A lead frame 311 can also be used.

FIG. 9 is a perspective view of the third lead frame 311.
The third lead frame 311 extends from the tip of the third frame main body 312 and the third frame main body 312 made of a long plate-like member extending in the axial direction, and part of the third lead frame 311 is the third frame main body. A third element abutting portion 316 extending in the axial direction so as to be disposed between 312 and the detection element 4, and a third engaging protruding portion 318 protruding from the third frame main body portion 312 in a direction perpendicular to the axial direction. , And a part of the third element contact part 316 is configured to contact the electrode terminal part of the detection element 4.

  The third element contact portion 316 includes a third connection side end 314 that is connected to the tip of the third frame main body 312 and bends radially inward to change the direction. The third lead frame 311 is configured to be elastically deformed when an external force is applied, and the third connection side end 314 is elastically deformed, so that the third frame main body 312 and the third element abut on each other. The gap interval with the portion 316 is configured to change.

  The third engaging protrusion 318 includes two extending portions 321 extending from a substantially central position in the axial direction of the third frame main body 312, and the two extending portions 321 include the third frame main body 312. And projecting in a direction perpendicular to the axial direction from each other and being substantially parallel to each other with a predetermined interval. The third engaging protrusion 318 is configured such that the extension portion 321 is elastically deformed and the distance between the two extension portions 321 changes.

  When the extended portion 321 is not elastically deformed, the third engaging protrusion 318 has an interval between the extended portions 321 so that the engagement hole of the insulating contact member 82 (specifically, the second insulating portion The contact member 402 is formed larger than the inner diameter of the second engagement hole 425). In addition, the third engagement protrusion 318 can be inserted into the engagement hole of the insulating contact member 82 and can be disposed inside the engagement hole by reducing the distance dimension by elastic deformation.

  When the third engaging protrusions 318 are inserted and arranged in the engagement holes in a state of being elastically deformed so that the distance between the extending portions 321 is reduced, the third engaging protrusions 318 are restored by the restoring force. Try to increase the spacing dimension. Then, pressure is generated between the third engagement protrusion 318 and the inner surface of the engagement hole due to the urging force (restoring force) generated by the third engagement protrusion 318. By this pressure, the third engaging protrusion 318 is held in the engaging hole, whereby the third lead frame 311 and the insulating contact member 82 can be assembled.

  Therefore, when the third lead frame 311 is used, it is possible to reduce the complexity of the assembling work of the detection element and the lead frame, and the electrode terminal portion of the detection element is difficult to peel off even when an external force is applied to the lead frame. Can be realized.

  The third lead frame 311 has a width W3 of 1.2 [mm] and a thickness of 0.2 [mm], and can be used as a substitute part for the first lead frame 11. The third width dimension changing unit 313 of the third lead frame 311 corresponds to the width dimension changing unit 13 of the first lead frame 11, and the third open-side end 315 of the third lead frame 311 is the first lead frame 311. The first lead frame 11 corresponds to the open end 15, and the third lead wire connection portion 317 of the third lead frame 311 corresponds to the lead wire connection portion 17 of the first lead frame 11, and the third lead frame 311. Among these, the third bending portion 319 corresponds to the bending portion 19 of the first lead frame 11.

  A lead frame having substantially the same shape as the third lead frame 311 and having a width dimension of 0.8 [mm] and a thickness of 0.2 [mm] is an alternative to the second lead frame 211. Can be used as a part.

  In addition, the protrusion part for an engagement provided with an extending part is not restricted to the form provided with two extending parts, If it is the structure from which the space | interval dimension of extending parts changes, it will be three or more extending parts It may be a mode provided with. For example, an aspect including three extending portions arranged so that the cross-sectional shape of the engaging protrusion is a triangle, or four extending portions arranged so that the cross-sectional shape of the engaging protrusion is a quadrangle The aspect provided is mentioned.

  In the above embodiment, the engagement hole as a through hole penetrating the insulation contact member has been described as the engagement hole of the insulation contact member. However, the engagement hole formed in the insulation contact member is penetrated. It is not restricted to a hole, and if it has the area | region for arrange | positioning the protrusion part for engagement, you may form in the aspect from which a depth dimension becomes finite.

  Furthermore, in the above embodiment, the insulating contact member in which one element guide portion is provided in one insulating contact member has been described, but two element guide portions may be formed in one insulating contact member. In this case, the distance dimension between the two element guide portions may be set according to the width dimension of the detection element so that the two element guide portions respectively face two different side surfaces of the detection element.

  In addition, by providing a plating layer with a conductive metal on the surface of the lead frame, it is possible to suppress oxidation on the contact surface with the electrode terminal portion of the detection element, and the contact resistance value increases due to oxidation and the like. Can be prevented. Note that the plating layer is not necessarily formed on the entire surface of the lead frame, and is preferably formed so as to include at least a portion in contact with the electrode terminal portion of the detection element.

  Furthermore, in the said Example, although the detection element provided with three electrode terminal parts on the 1st board surface and two electrode terminal parts on the 2nd board surface was demonstrated, the number of electrode terminal parts is the said aspect. However, the detection element having an arbitrary number of electrode terminal portions can be used. In that case, as the insulating contact member, an insulating contact member to which a number of lead frames corresponding to the electrode terminal portions on the corresponding plate surface can be assembled is used.

  For example, for a detection element in which three electrode terminal portions are formed on each of the first plate surface and the second plate surface, two first insulating contact members 401 may be used, and the first plate surface and the second plate surface may be used. For the detection element in which two electrode terminal portions are formed on the plate surface, two second insulating contact members 402 may be used.

  In the sensor configured to assemble the detection element and the lead frame using two insulating contact members, the form of the insulating contact member disposed on the first plate surface and the second plate surface is set according to the number of electrode terminal portions, respectively. Thus, there is an advantage that it is possible to cope with various kinds of detection elements having different numbers of electrode terminal portions. In addition, since the insulating contact member can be used as a common component in different types of sensors, the manufacturing cost can be reduced.

It is sectional drawing which shows the whole structure of an air fuel ratio sensor. It is a perspective view showing the schematic structure of a detection element. It is a perspective view showing the appearance of a lead frame. It is a perspective view of an insulation contact member (a 1st insulation contact member, a 2nd insulation contact member). It is a partial cross section perspective view of the insulation contact member in the state where a lead frame was assembled. It is a perspective view showing the external appearance of a ceramic sleeve. It is explanatory drawing showing each process of the assembly operation | work of a full area air fuel ratio sensor. It is explanatory drawing showing the deformation | transformation state of a lead frame at the time of crimping a contact support member and attaching two insulation contact members to a detection element. It is a perspective view of a 3rd lead frame.

Explanation of symbols

  2 ... All-range air-fuel ratio sensor, 4 ... detection element, 6 ... ceramic sleeve, 10 ... lead frame, 11 ... first lead frame, 18 ... projection for engagement, 21 ... first plate surface, 23 ... second plate surface , 30, 31, 32, 34, 36 ... electrode terminal part, 44 ... outer cylinder, 73 ... terminal arrangement part, 82 ... insulating contact member, 83 ... collar part, 112 ... contact support member, 211 ... second lead frame, 218 ... Narrow engagement protrusion, 311 ... third lead frame, 318 ... third engagement protrusion, 321 ... extension, 401 ... first insulation contact member, 402 ... second insulation contact member, 411 ... element clamping 413 ... element guide part, 415 ... engagement hole part, 421 ... second element clamping part, 423 ... second element guide part, 425 ... second engagement hole part.

Claims (8)

A plate-like shape extending in the axial direction, a detection element in which the front end side is directed to the measurement object and the electrode terminal portion is formed on the rear end side;
A metal terminal member that is electrically connected to the electrode terminal portion of the detection element to form a current path;
2 formed of an insulating material and disposed so as to sandwich the rear end side of the detection element on which the electrode terminal portion is formed and the metal terminal member, and at least a part of the metal terminal member abuts against itself 2 Two insulated contact members;
A clamping and fixing member that holds the two insulating contact members;
A sensor comprising:
The insulating contact member includes an engagement hole formed on a contact surface with the metal terminal member,
The metal terminal member protrudes toward the insulating contact member and includes an engagement protrusion disposed inside the engagement hole,
The engagement protrusion is elastically held in the engagement hole in a state of being elastically deformed so as to generate a biasing force against the inner surface of the engagement hole;
Sensor characterized by. The engaging protrusion has a substantially U-shaped cross-section in a plane parallel to the protruding direction, and the substantially U-shaped apex portion is elastically deformed, so that the engaging protrusion protrudes from the inner surface of the engaging hole. Creating a biasing force,
The sensor according to claim 1. The engaging protrusion includes a plurality of extending portions that protrude toward the insulating contact member, and the extension portion is elastically deformed to change a distance between the extending portions. Generating an urging force against the inner surface of the engaging hole,
The sensor according to claim 1. The metal terminal member is
An elongated frame main body extending in the axial direction;
An element that extends from the front end of the frame main body and extends in the axial direction so that at least a part of the frame main body is disposed between the frame main body and the detection element, and is in contact with the electrode terminal portion of the detection element A contact portion, and
Of the element abutting portions, at least a part of the connecting side end portion that is connected to the tip of the frame main body portion and bends inward in the radial direction to change the direction is elastically deformed by applying an external force. Configured,
In the free state of the metal terminal member, the open side end located on the rear end side in the axial direction of the element contact part does not contact the frame body part,
A state where the open side end of the element abutting portion abuts on the frame main body when the connecting side end is elastically deformed by being sandwiched between the detecting element and the insulating contact member; To become a,
The sensor according to any one of claims 1 to 3, wherein: The insulating contact member is
An element clamping part facing the plate surface on which the electrode terminal part is formed, of the surface of the detection element;
An element guide portion facing a side surface located on a side of the plate surface of the surface of the detection element,
The sensor according to any one of claims 1 to 4, wherein: One of the element guide portions is provided in one of the insulating contact members,
The two insulating contact members are arranged so as to sandwich the detection element, so that the two element guide portions are arranged so as to sandwich the detection element from the side surface;
The sensor according to claim 5. An insulating sleeve that is disposed on the distal end side of the insulating contact member and supports the detection element;
The insulating sleeve includes a terminal arrangement portion for arranging a tip portion of the metal terminal member on a rear end surface;
The sensor according to any one of claims 1 to 6, wherein: The insulating contact member includes a flange that protrudes radially outward from the outer peripheral side surface,
The clamping member is in contact with the flange,
The sensor according to claim 1, wherein: