JPH0633411Y2 - Ceramic base terminal mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a terminal mounting structure for a cylindrical ceramic substrate such as an oxygen sensor.

[Prior Art] Conventionally, as a terminal mounting structure of a cylindrical ceramic base having a conductive contact portion on its surface like an oxygen detection element, a metal fitting for a terminal having an elastic arm conforming to the shape of the ceramic base has been used. Some are fitted to the conductive contact on the surface.

As shown in the partially cutaway view of FIG. 6, using such a terminal connection structure, a pair of porous electrodes 12 are formed on the front and back surfaces of a bag-shaped oxygen ion conductive solid electrolyte 10 such as ZrO _2. There is an oxygen sensor using a detection element 16 provided with the sensors 14 and 14 (Japanese Patent Application No. 61-146210 and Japanese Patent Application Laid-Open No. 63-3251).

This oxygen sensor includes a metallic shell 18, the above-mentioned detection element 16 held via the insulating ceramic spacer 20, the talc powder 22 filled in the metallic shell 18, and the ceramic sleeve 24,
A protective tube 26 for the detection element 16, an outer electrode terminal fitting 28 connected to the outer electrode 12 of the detection element 16, an inner electrode terminal fitting 32 connected to the inner electrode 14 of the detection element 16, and a built-in The outer electrode terminal fitting 33 of the ceramic heater 30, the electrode terminal fittings 28, 32, 33 and the lead wires 34, 36, 38, 39 respectively connected to the ceramic heater 30, the terminal fittings 28, 32, etc. It has protective housings 40, 42.

As shown in FIG. 7, the detection element 16 includes a cylindrical portion 50, a flange portion 52 that engages with the ceramic spacer 20, and a detection portion 54 that is exposed to the ambient atmosphere. In the vicinity of the opening of the cylindrical portion 50,
The conductive contact portion 56 of the outer porous electrode 12 is provided, and the conductive contact portion 56 and the detection portion 54 side of the porous electrode 12 are connected by a lead 58. The electrode 12 on the detection section 54 side is covered with the porous protective layer and is not visible.

Also, the outer electrode terminal fitting 28, as shown in FIG.
Two curved arms 60 and 62, a grip portion 64 that grips the lead wire 34, and a lead portion 6 that connects the arms 60 and 62 and the grip portion 64.
With 6 and.

The outer electrode terminal fitting 28 is attached to the detection element 16 by gripping the conductive contact portion 56 of the detection element 16 by the elastic force of the two arms 60 and 62.

The oxygen sensor having the terminal connection structure as described above is easy to manufacture, and the oxygen gas partial pressure signal generated between the porous manufacturing 12 and 14 of the detection element 16 is connected to the outer electrode terminal fitting 28 and the inner side. An oxygen sensor for grounding the outer porous electrode of the detection element to the exhaust gas system via the metal shell for outputting from the lead wires 34, 36 via the electrode terminal metal fitting 32 (for example, Japanese Examined Patent Publication 59).
-41952 etc.), there is no influence of noise due to the spark plug, noise due to the potential difference of the ground, etc., and it is possible to detect the oxygen gas partial pressure signal accurately.

[Problems to be Solved by the Invention] However, in the above-described terminal connection structure, the connection terminal 28 and the detection element 16 are connected only by the elastic force of the arms 60 and 62, so that the internal connection of an internal combustion engine or the like may be improved during use. It may come off due to vibration.

Alternatively, the connecting terminal 28 may come off due to an excessive force applied to the lead wire 34 at the time of assembling the oxygen sensor.

[Means for Solving Problems] The present invention adopts the following means in order to solve the above problems.

That is, the gist of the present invention is to provide a terminal metal fitting having a curved arm and a lead portion on a columnar ceramic substrate having a conductive contact portion exposed on the surface, and to mount the conductive contact portion of the ceramic substrate on the elastic force of the arm. In a terminal mounting structure for a ceramic base to be mounted by gripping, the surface of the ceramic base has a concave or convex engagement receiving portion, and the terminal fitting is formed of a metal plate, and is composed of the metal plate. A terminal mounting structure of a ceramic base is characterized in that the arm has a convex or concave engaging portion that engages with the engaging receiving portion.

Here, at least one or more annular grooves, or at least one or more protrusions or recesses can be used as the engagement receiving portions provided on the surface of the ceramic base.

Also, as the engaging portion provided on the arm of the terminal fitting,
It is possible to use at least one tooth provided on the distal end of the arm in the circumferential direction and which engages with the engagement receiving portion, or at least one claw along the axial direction of the arm.

[Operation] In the present invention, since the arm is made of a metal plate, the contact in the conductive contact portion can be made substantially planar. Therefore, since the area of the contact is increased, noise is not generated at the contact and stability is increased. Further, for the same reason, the contact resistance is reduced and the reliability of the processing of the electric signal is increased. Furthermore, durability is also improved. Moreover, even if the elastic force of the metal plate is increased, the ceramic is not damaged, so that the elastic force can be increased and the connection can be performed firmly.

Particularly, in the present invention, the fact that the elastic force can be increased and the functions of the engagement receiving portion and the engagement portion act synergistically, that is, the arm firmly grips the ceramic substrate. At the same time, since the engaging portion provided on the arm is securely engaged with the engaging receiving portion of the ceramic base, even if an excessive force is applied to the lead wire during assembly, the terminal will not come off. Moreover, for the same reason, the terminal will not come off even if a large vibration is applied during use.

Further, in the present invention, the part of the engaging part of the terminal fitting that engages with the ceramic base and the part of the terminal fitting that keeps electrical continuity by contacting the conductive contact part of the ceramic base are separate parts. be able to. Therefore, the engagement force at the engagement portion and the contact pressure at the conductive contact portion can be set independently. As a result, unlike the conventional case, the engaging force is too strong so as to prevent the terminal from coming off, and the conductive contact portion is damaged, thus causing no contact failure.

[Embodiment] A first embodiment of the present invention will be described with reference to the perspective view of FIG.

In the present embodiment, the present invention is applied to an oxygen sensor using a bag-shaped detection element 70. The configuration other than the detection element 70 and the outer electrode terminal fitting 72 is similar to that of the conventional oxygen sensor shown in FIG.

As shown in FIG. 1, the detecting element 70 of this embodiment has a cylindrical portion 7
4. A collar portion 76 that engages with the ceramic spacer, and a detection portion 78 that is exposed to the ambient atmosphere. In the vicinity of the opening of the cylindrical portion 74, a plurality of annular grooves 80 and a conductive contact portion 82 that covers a part of the plurality of annular grooves 80 are provided. The conductive contact portion 82 is connected by the lead 84 to the detection portion 78 side of the outer porous electrode of the detection element 70. The outer porous electrode on the side of the detector 78 is
It is invisible because it is covered with the porous protective layer 86.

In addition, the outer electrode terminal fitting 72 includes two curved arms.
88, 90, a grip portion 92 for gripping a lead wire (not shown), and a lead portion 94 for connecting the arms 88, 90 to the grip portion 92. Teeth 96 and 98 that engage with the annular groove 80 provided in the detection element 70 are provided at the circumferential ends of the arms 88 and 90 of the terminal fitting 72.

Then, the cylindrical portion 74 of the detection element 70 is inserted into the space formed by the two arms 88, 90 of the outer electrode terminal fitting 72 from the lower side of the drawing to attach the outer electrode terminal fitting 72 to the detection element 70. .

Electrode terminal fittings 72 installed as described above
Since the teeth 96 and 98 are firmly engaged with the annular groove 80 of the detection element 70 by the elastic force of the two arms 88 and 90, does not move due to vibration or the like.

In this embodiment, the case where a plurality of annular grooves 80 are provided has been described, but only one annular groove may be provided.

A second embodiment of the present invention will be described with reference to the perspective view of FIG.

In the present embodiment, the present invention is applied to an oxygen sensor using a bag-shaped detection element 170. The configuration other than the detection element 170 is similar to that of the oxygen sensor of the first embodiment shown in FIG.

As shown in FIG. 2, the detecting element 170 of the present embodiment is different from the detecting element 70 of the first embodiment in that notches 181 are provided in the lower part of a plurality of annular grooves 180.

In the detection element 170 of the present embodiment, the conductive contact portion 182 that covers a part of the annular groove 180 and the detection portion 17 of the outer porous electrode of the detection element 170.
The lead 184 connecting to the 8 side passes through the inside of the notch 181. Therefore, in addition to the effects of the first embodiment, there is an effect that when the terminal fitting for the outer electrode (not shown) is attached, there is no risk of accidentally scraping off the lead 184 with the teeth of the terminal fitting.

In the present embodiment, the case where a plurality of annular grooves 180 are provided has been described, but only one annular groove has the same effect. Further, although the notch 181 is provided only in the lower part of the plurality of annular grooves 180 in this embodiment, it may be provided in the entire length of the annular groove 180 or the entire cylindrical portion of the detection element 170.

A third embodiment of the present invention will be described with reference to the perspective view of FIG.

In the present embodiment, the present invention is applied to an oxygen sensor using a bag-shaped detection element 270. Since the configuration other than the detection element 270 and the outer electrode terminal fitting 272 is the same as that of the conventional oxygen sensor shown in FIG. 6, its explanation is omitted.

As shown in FIG. 3, the detecting element 270 of this embodiment has a cylindrical portion 2
74, a collar portion 276 engaging with the ceramic spacer, and a detection portion 278 exposed to the ambient atmosphere. In the vicinity of the opening of the cylindrical portion 274, the annular groove 280 and the cylindrical portion 274 adjacent to the annular groove 280.
A conductive contact portion 282 that covers the outer circumference is provided. This conductive contact portion 282 is the sensing portion 27 of the outer porous electrode of the sensing element 270.
It is connected to the 8 side with lead 284. The outer porous electrode on the detection section 278 side is covered with the porous protective layer 286 and is not visible.

The outer electrode terminal fitting 272 includes two curved arms 288 and 290 and a grip portion 29 that grips a lead wire (not shown).
2, the lead portion 294 that connects the arms 288, 290 and the grip portion 292
With. At the upper ends of the arms 288 and 290 of the terminal fitting 272, teeth 29 that engage with the annular groove 280 provided in the detection element 270 are provided.
6, 298 are provided, and electrode contact parts 300, 302 are provided below the tips of the arms 288, 290.

Then, the two arms 288 and 290 of the terminal fitting 272 for the outer electrode.
In the space formed by
The outer electrode terminal fitting 272 is attached to the detection element 270 by inserting the cylindrical portion 274 of the.

Electrode terminal fittings 272 attached as described above
The teeth 296,298 due to the elastic force of the two arms 288,290.
Is firmly engaged with the annular groove 280 of the detection element 270, and therefore is not displaced by vibration or the like. Further, since the electrode contact portions 300 and 302 of the outer electrode terminal fitting 272 are not provided with teeth, the conductive contact portion 282 and the lead 284 are not accidentally scraped off during mounting.

A fourth embodiment of the present invention will be described with reference to the perspective view of FIG.

In the present embodiment, the present invention is applied to an oxygen sensor using a bag-shaped detection element 470. The configuration other than the detection element 470 and the outer electrode terminal fitting 472 is the same as that of the conventional oxygen sensor shown in FIG.

As shown in FIG. 4, the detection element 470 of this embodiment has a cylindrical portion 4
74, a collar portion 476 engaging with the ceramic spacer, and a detection portion 478 exposed to the ambient atmosphere. In the vicinity of the opening of the cylindrical portion 474, a thickness of 50 to 10 formed by screen printing is used.
A large number of 0 μm square convex portions 480 are provided, and a conductive contact portion 482 is provided so as to cover the outer periphery of the cylindrical portion 474 adjacent to the large number of convex portions 480. The conductive contact portion 482 is connected to the detection portion 478 side of the outer porous electrode of the detection element 470 by the lead 484. The outer porous electrode on the detection unit 478 side is covered with the porous protective layer 486 and is not visible.

The outer electrode terminal fitting 472 includes two curved arms 488 and 490, and a gripping portion 49 that grips a lead wire (not shown).
2, the lead portion 494 that connects the arms 488 and 490 and the grip portion 492
With. Above the arms 488 and 490 of the terminal fitting 472,
A plurality of claws 496 that engage with a large number of convex portions 480 provided on the detection element 470 are provided, and electrode contact portions 498 are provided below the tips of the arms 488 and 490 in the circumferential direction.

Then, the two arms 488 and 490 of the terminal fitting 472 for the outer electrode
In the space formed by
The outer electrode terminal fitting 472 is attached to the detection element 470 by inserting the cylindrical portion 474 of.

Electrode terminal fittings 472 mounted as described above
The elastic force of the two arms 488 and 490 causes the multiple claws 4
Since 96 firmly engages with the large number of convex portions 480 provided on the surface of the detection element 470, it does not deviate due to vibration or the like.

A fifth embodiment of the present invention will be described with reference to the perspective view of FIG.

In the present embodiment, the present invention is applied to an oxygen sensor using a bag-shaped detection element 500. The configuration other than the detection element 500 and the outer electrode terminal fitting 510 is similar to that of the conventional oxygen sensor shown in FIG.

As shown in FIG. 5, the detection element 500 of this embodiment has a cylindrical portion 5
20, a collar 530 that engages with the ceramic spacer, and a detector 540 that is exposed to the ambient atmosphere. A plurality of protrusions 550 and a conductive contact portion 555 are provided near the opening of the cylindrical portion 520. The conductive contact portion 555 is connected to the detection portion 540 side of the outer porous electrode of the detection element 500 by the lead 557. The outer porous electrode on the detection unit 540 side is the porous protective layer 560.
It is covered with the and can not be seen.

The outer electrode terminal fitting 510 includes two curved arms 570 and 575 and a grip portion 57 that grips a lead wire (not shown).
7, lead portion 580 connecting the arms 570, 575 and the grip portion 577
With. The arms 570 and 575 of the terminal fitting 510 have a plurality of holes that engage with a plurality of protrusions 550 provided on the detection element 500.
585 is provided, and the entire arms 570 and 575 serve as electrode contact portions.

Then, the two arms 570 and 575 of the terminal fitting 510 for the outer electrode
In the space formed by
The outer electrode terminal fitting 510 is attached to the detection element 500 by inserting the cylindrical portion 520 of.

The electrode terminal fitting 510 attached as described above.
The plurality of holes 585 are firmly engaged with the plurality of protrusions 550 provided on the surface of the detection element 500 by the elastic force of the two arms 570 and 575, and thus are not displaced by vibration or the like.

The present invention is not limited to the above embodiments unless the gist thereof is changed.

Although the terminal mounting structure of the detection element of the oxygen sensor has been described in the present embodiment, it may be used as a terminal mounting structure of a glow plug, another sensor, or the like.

[Advantages of the Invention] In the present invention, since the arm is made of a metal plate, the contact in the conductive contact portion can be substantially planar. Therefore, since the area of the contact is increased, noise is not generated at the contact and stability is increased. Further, for the same reason, the contact resistance is reduced and the reliability of the processing of the electric signal is increased. Furthermore, durability is also improved. Moreover, even if the elastic force of the metal plate is increased, the ceramic is not damaged, so that the elastic force can be increased and the connection can be performed firmly.

Particularly, in the present invention, the fact that the elastic force can be increased and the functions of the engagement receiving portion and the engagement portion act synergistically, that is, the arm firmly grips the ceramic substrate. At the same time, the engaging portion provided on the arm is securely engaged with the engaging receiving portion of the ceramic base. Therefore,
There is a remarkable effect that the terminal does not come off even if an excessive force is applied to the lead wire at the time of assembly, and the terminal does not come off even if a large vibration is applied at the time of use.

Further, in the present invention, the part of the engaging part of the terminal fitting that engages with the ceramic base and the part of the terminal fitting that keeps electrical continuity by contacting the conductive contact part of the ceramic base are separate parts. be able to. Therefore, the engagement force at the engagement portion and the contact pressure at the conductive contact portion can be set independently. As a result, unlike the conventional case, the engaging force is too strong so as to prevent the terminal from coming off, and the conductive contact portion is damaged, thus causing no contact failure.

[Brief description of drawings]

1 is a perspective view illustrating a first embodiment of the present invention, FIG. 2 is a perspective view illustrating a second embodiment of the present invention, and FIG. 3 is a perspective view illustrating a third embodiment of the present invention. 4 is a perspective view illustrating a fourth embodiment of the present invention, FIG. 5 is a perspective view illustrating a fifth embodiment of the present invention, FIG. 6 is a partially cutaway view of a conventional oxygen sensor, and FIG. FIG. 1 is a perspective view illustrating a conventional terminal mounting structure. 16,70,170,270,470,500 …… Detecting element, 28,72,172,272,472,510 …… Outer electrode terminal fitting (terminal fitting) 56,82,182,282,482,555 …… Conductive contact 60,62,88,90,188,190,288,290,498,570,575 …… Arm 80,180,280 …… Annular groove 96,98,196,198,296,298… … Tooth 480 …… Convex section, 496 …… Claw 550 …… Projection section, 585 …… Hole

Claims (4)

[Scope of utility model registration request] 1. A terminal metal fitting having a curved arm and a lead portion is attached to a columnar ceramic base having a conductive contact portion exposed on the surface, and the conductive contact portion of the ceramic base is held by the elastic force of the arm. In the terminal mounting structure of the ceramic base body, the surface of the ceramic base body has a concave or convex engagement receiving portion, the metal fitting for the terminal is made of a metal plate, and the arm made of the metal plate is A ceramic base terminal mounting structure having a convex or concave engaging portion that engages with an engaging receiving portion. 2. The terminal mounting structure for a ceramic base according to claim 1, wherein the engagement receiving portion is at least one annular groove. 3. The utility model registration claim according to claim 1, wherein the engaging portion is at least one tooth provided on the distal end in the circumferential direction of the arm and engaging with the engaging receiving portion. The structure for mounting a terminal on a ceramic base according to any one of paragraphs 2. 4. The structure for mounting a terminal on a ceramic base according to claim 1, wherein the engaging portion is at least one pawl along the axial direction of the arm. .