JP2018009958A - Gas sensor and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas sensor that can hold a terminal metal fitting reliably in a separator and connect an electrode pad of a sensor element to the terminal metal fitting safely, and a manufacturing method of the same.SOLUTION: The gas sensor comprises: a sensor element including an electrode pad; a terminal metal fitting 20 connected to the electrode pad; separators 90, 95; and a lead wire 146 connected to a rear end of the terminal metal fitting. The terminal metal fitting includes, at its tip side and rear end side, a tip side locking part 29 and a rear end side locking part 45e, respectively. The separator is composed of a tip side separator 90 and a rear end side separator 95 connected to each other, the tip side separator including a first locking part 90 s1 having a rear end facing surface, and the rear end side separator including a second locking part 95s having a tip end facing surface. The terminal metal fitting includes, between the tip side separator and the rear end side separator, the tip side locking part locked on the rear end facing surface and the rear end side locking part locked on the tip end facing surface.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a gas sensor including a sensor element that detects the concentration of a gas to be detected and a method for manufacturing the gas sensor.

As a gas sensor for detecting the concentration of oxygen or NOx in exhaust gas of an automobile or the like, one having a plate-like sensor element using a solid electrolyte is known.
As this type of gas sensor, a plurality of electrode pads are provided on the outer surface on the rear end side of the plate-like sensor element, and a terminal metal fitting is electrically contacted to each of the electrode pads to output a sensor output signal from the sensor element to the outside. What takes out or supplies electric power to the heater laminated | stacked on the sensor element is widely used (patent document 1).

As shown in FIG. 14, the terminal fitting 200 is formed in, for example, a strip shape obtained by cutting and raising a metal plate, and its distal end is folded back toward a sensor element (not shown) to be elastically connected to an electrode pad of the sensor element. And a crimping portion 204 for crimping the tip of the lead wire 146.
Further, on the side opposite to the folded portion 202 of the terminal metal fitting 200, an engaging portion 206 having an L-shaped cross section protrudes, and this engaging portion 206 is formed in an L shape formed on the tip side of the separator hole 300h of the separator 300. The terminal fitting 200 is held in the separator 300 by being received in the groove portion 300g and the engaging portion 206 engaging with the tip-facing surface 300s of the groove portion 300g.
In the example of FIG. 14, the terminal fitting 200 is rotated about 90 degrees counterclockwise, and the locking portion 206 is inserted into the upper right groove portion 300g. In addition, a total of four terminal fittings 200 are respectively accommodated in separate groove portions 300g.

Here, the connection (caulking) of the lead wire 146 to the terminal fitting 200 is performed as follows. First, the lead wire 146 is pulled out from the rear end side of the separator 300 to the front end F side of the separator 300 through the separator hole 300h. Next, the leading end of the lead wire 146 is crimped by the crimping portion 204 of the terminal fitting 200 disposed on the leading end side of the separator 300, and the lead wire 146 is connected to the terminal fitting 200.
When the lead wire 146 is pulled to the rear end R side and pulled out to the rear end side of the separator 300, the terminal fitting 200 connected to the lead wire 146 is also pulled to the rear end R side, and the locking portion 206 is formed in the groove portion 300g. While being accommodated, the groove portion 300g is engaged with the leading end facing surface 300s to prevent the groove portion 300g from coming off to the rear end side. In this way, the terminal fitting 200 can be assembled to the separator 300.

JP 2012-230076 (FIGS. 3 and 4)

However, since the conventional terminal fitting 200 merely prevents the rear end side from coming off by the locking portion 206, the terminal fitting 200 is displaced to the front end side when an external force or the like is applied, and the electrical connection with the electrode pad is performed. May become unstable. Further, if the clearance between the locking portion 206 and the groove portion 300g is reduced to increase the retaining force, the frictional force between the locking portion 206 and the groove portion 300g is increased when the terminal fitting 200 is assembled to the separator 300. Thus, the pulling load to the rear end side R of the lead wire 146 is increased, and the efficiency of the assembling work is lowered.
Therefore, an object of the present invention is to provide a gas sensor that can securely hold a terminal fitting inside a separator and stably connect an electrode pad of the sensor element and the terminal fitting, and a method for manufacturing the same. .

  In order to solve the above problems, the gas sensor of the present invention has a plate shape extending in the axial direction, and has a sensor element having an electrode pad on the outer surface on the rear end side, and extends in the axial direction, and is electrically connected to the electrode pad. A terminal fitting to be connected, a cylindrical separator that holds the terminal fitting and surrounds the rear end side of the sensor element, and is connected to the rear end side of the terminal fitting and pulled out to the rear end side of the separator. The terminal fitting has a front end side locking portion and a rear end side locking portion on the front end side and the rear end side, respectively, and the separator is arranged in the axial direction. Each of the front end side separator includes a front end side separator and a rear end side separator disposed on the front end side and the rear end side and connected to each other, and the front end side separator has a first locking portion having a rear end facing surface. End separator is at the tip The terminal fitting has a front-end-side engagement portion engaged with the rear-end-facing surface between the front-end-side separator and the rear-end-side separator. The rear end side latching portion is latched and held by the tip-facing surface.

According to this gas sensor, the front end side locking portion and the rear end side locking portion of the terminal fitting to which the lead wire is connected are respectively the rear end facing surface of the front end side separator and the front end facing surface of the rear end side separator. Therefore, it is possible to prevent the terminal fitting from coming out to the front end side and the rear end side inside the front end side separator and the rear end side separator.
As a result, the terminal metal fitting is securely held inside the front end side separator and the rear end side separator, and for example, when an external force is applied, the terminal metal fitting is prevented from being displaced in the axial direction. The metal fitting can be stably electrically connected.
In addition, in order to hold the terminal metal fitting inside the front end side separator and the rear end side separator, it is not necessary to make the clearance between the insertion hole of the separator and the terminal metal fitting excessively small, so that the frictional force between them increases. Therefore, it is possible to suppress an increase in the drawing load to the rear end side of the lead wire, and to prevent a decrease in the efficiency of the assembly work.

In the gas sensor of the present invention, the contact point between the terminal fitting and the electrode pad may be located between the rear end facing surface and the front end facing surface.
According to this gas sensor, since the terminal fitting straddles the contact and is locked to the front end side separator and the rear end side separator at two positions on the front end side and the rear end side, for example, when an external force or the like is applied, It is possible to further suppress the axial displacement of the terminal fitting that is in contact with the contact, and the electrical connection with the electrode pad is further stabilized.

In the gas sensor of the present invention, the terminal fitting includes a distal end terminal fitting and a rear end terminal fitting disposed on the distal end side and the rear end side, respectively, and the distal end side fitting is connected to the distal end side member. The rear end side metal fitting has the rear end side latching portion, and the rear end side metal fitting is connected to the lead wire and is connected to the rear end side separator. At least a portion may be accommodated, the distal end side metal fitting may be in contact with the electrode pad, and at least a portion of itself may be accommodated in the distal end side separator.
According to this gas sensor, a complicatedly shaped front end side terminal fitting having an elastic portion to be connected to the electrode pad is separated from a rear end side terminal fitting that is connected to a lead wire that requires complicated work such as a caulking process. In the caulking step, productivity can be improved because it is sufficient to handle the rear end side metal fittings with a simple shape.

In the gas sensor of the present invention, the tip end of the rear end side terminal fitting forms at least a part of a column or a cylinder, and the rear end side of the tip end side terminal fitting has a connection part that forms at least a part of a cylinder, The tip portion may be inserted into the connection portion.
According to this gas sensor, since the connecting portion and the tip end portion are rotationally symmetric about the axis line, even if the positions of the rear end side terminal fitting and the tip end terminal fitting around the axis line are slightly misaligned, The front end portion can be fitted and the rear end side terminal fitting and the front end side terminal fitting can be easily and reliably connected to each other.

  The gas sensor manufacturing method of the present invention has a plate shape extending in the axial direction, a sensor element having an electrode pad on the outer surface on the rear end side, and a terminal extending in the axial direction and electrically connected to the electrode pad. A metal separator, a cylindrical separator that holds the terminal metal fitting and surrounds the rear end side of the sensor element, and a lead wire connected to the rear end side of the terminal metal fitting and drawn to the rear end side of the separator, The terminal fitting has a front end side locking portion and a rear end side locking portion on the front end side and the rear end side, respectively, and the separator is each in the axial direction. A front end side separator and a rear end side separator arranged on the front end side and the rear end side and connected to each other, and the front end side separator has a first locking portion having a rear end facing surface, and the rear end Side separator facing the tip The front end side separator and the rear end side separator are disposed on the front end side and the rear end side of the terminal fitting, respectively, and the front end side separator and the rear end side separator are disposed. Between the front end side separator and the rear end side separator so that the front end side locking portion is locked to the rear end facing surface, and the rear end side locking portion is locked to the front end facing surface. And holding the terminal fitting in between.

  Also by this gas sensor manufacturing method, it is possible to prevent the terminal fitting from being pulled out to the front end side and the rear end side inside the front end side separator and the rear end side separator. As a result, the terminal metal fitting is securely held inside the front end side separator and the rear end side separator, and for example, when an external force is applied, the terminal metal fitting is prevented from being displaced in the axial direction. The metal fitting can be stably electrically connected. In addition, in order to hold the terminal metal fitting inside the front end side separator and the rear end side separator, it is not necessary to make the clearance between the insertion hole of the separator and the terminal metal fitting excessively small, so that the frictional force between them increases. Therefore, it is possible to suppress an increase in the drawing load to the rear end side of the lead wire, and to prevent a decrease in the efficiency of the assembly work.

  According to the present invention, it is possible to obtain a gas sensor that can securely hold the terminal fitting inside the separator and can stably electrically connect the electrode pad of the sensor element and the terminal fitting.

It is sectional drawing which follows the axial direction of the gas sensor which concerns on embodiment of this invention. It is a perspective view of a front end side terminal metal fitting. It is a perspective view of another tip side terminal metal fitting. It is a perspective view of a rear-end side terminal metal fitting. It is a perspective view of a front end side separator. It is process drawing which hold | maintains the front end side terminal metal fitting in the front end side separator. It is sectional drawing which shows the state which hold | maintained the front end side metal fitting to the front end side separator. It is process drawing which hold | maintains a rear-end side terminal metal fitting in a rear-end side separator. It is sectional drawing containing the penetration hole of a front end side separator. It is sectional drawing containing the penetration hole of a rear-end side separator. It is process drawing which shows the assembly | attachment of the front end side separator and rear end side separator in the predetermined cross section of FIG. 9, FIG. It is process drawing which shows the assembly | attachment of the front end side separator and rear end side separator in another cross section of FIG. 9, FIG. It is a perspective view which shows the modification of a terminal metal fitting. It is a perspective view of the conventional terminal metal fitting.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is an overall cross-sectional view of the gas sensor (NOx sensor) 1 according to an embodiment of the present invention along the direction of the axis O, FIGS. 2 and 3 are perspective views of the front end side terminal fittings 20 and 30, and FIG. FIG. 5 is a perspective view of the distal end side separator 90, FIG. 6 is a process diagram for holding the distal end side terminal brackets 20 and 30 on the distal end side separator 90, and FIG. FIG. 8 is a sectional view showing a state of being held by the side separator 90, and FIG. 8 is a process drawing of holding the rear end side terminal fitting 40 by the rear end side separator 95. FIG. 7 shows a cross section perpendicular to the direction of the axis O along the line AA in FIG.
The gas sensor 1 is a NOx sensor that detects the oxygen concentration in the exhaust gas of automobiles and various internal combustion engines.

In FIG. 1, the gas sensor 1 includes a cylindrical metal shell 138 having a screw portion 139 for fixing to an exhaust pipe formed on the outer surface, and an axis O direction (longitudinal direction of the gas sensor 1: vertical direction in the figure). A sensor element 10 having an extending plate shape, a cylindrical ceramic sleeve 106 disposed so as to surround the periphery of the sensor element 10 in the radial direction, and an inner space on the front end side of the sensor element 10 are provided at a rear end portion of the sensor element 10. The front end side separator 90 made of ceramic and disposed in a state of surrounding the periphery, and the six front end sides inserted and held through the insertion holes 90h (90h1, 90h2) penetrating the front end side separator 90 in the direction of the axis O Terminal fittings 20 and 30 (only four are shown in FIG. 1), a ceramic cylindrical rear end side separator 95, and six rear end side terminal fittings 40 held by the rear end side separator 95. In Figure 1, includes a shows only two), the.
Further, as will be described later, the rear end side separator 95 is disposed in contact with the rear end side of the front end side separator 90 and is connected to each other.
The front end side terminal fittings 20 and 30 and the rear end side terminal fitting 40 are disposed on the front end side and the rear end side, respectively, and are connected to each other. The connection body of the front end side terminal fittings 20 and 30 and the rear end side terminal fitting 40 corresponds to “terminal fitting” in the claims.

As will be described in detail later, as shown in FIG. 5, the insertion holes 90h1 and 90h2 of the front end side separator 90 communicate with the internal space 90v on the front end F side of the front end side separator 90, and the insertion holes 90h1 and 90h2 Each of the front end side metal fittings 20 and 30 held on the opposite side faces the outer surface on the rear end side of the sensor element 10 and is electrically connected to the electrode pad 11a formed on the outer surface.
In addition, three electrode pads 11 a are arranged in the width direction on both surfaces of the rear end side of the sensor element 10. Each electrode pad 11a can be formed as a sintered body mainly composed of Pt, for example.
On the other hand, the gas detector 11 at the tip of the sensor element 10 is covered with a porous protective layer 14 such as alumina.

  The metal shell 138 is made of stainless steel, has a through-hole 154 that penetrates in the axial direction, and has a substantially cylindrical shape that has a shelf 152 that protrudes radially inward of the through-hole 154. The sensor element 10 is disposed in the through hole 154 so that the tip of the sensor element 10 protrudes from the tip of the sensor element 10. Further, the shelf portion 152 is formed as an inwardly tapered surface having an inclination with respect to a plane perpendicular to the axial direction.

In addition, inside the through hole 154 of the metal shell 138, a substantially annular shaped ceramic holder 151 made of alumina surrounding the radial periphery of the sensor element 10, a powder filling layer 153 (hereinafter also referred to as a talc ring 153), And the above-mentioned ceramic sleeve 106 is laminated | stacked from the front end side to the rear end side in this order.
Further, a caulking packing 157 is disposed between the ceramic sleeve 106 and the rear end portion 140 of the metal shell 138. Note that the rear end portion 140 of the metal shell 138 is crimped so as to press the ceramic sleeve 106 toward the distal end side via the crimping packing 157.

  On the other hand, as shown in FIG. 1, a metal (for example, stainless steel) 2 having a plurality of holes and covering the protruding portion of the sensor element 10 on the outer periphery of the front end side (lower side in FIG. 1) of the metal shell 138. An external protector 142 and an internal protector 143, which are heavy protectors, are attached by welding or the like.

An outer cylinder 144 is fixed to the outer periphery on the rear end side of the metal shell 138. Further, a lead wire 146 is connected to the rear end side of the rear end side terminal fitting 40, and the lead wire 146 is drawn out to the rear end side of the rear end side separator 95.
Then, six lead wires 146 (only two are shown in FIG. 1) drawn from the rear end side separator 95 are inserted into the opening on the rear end side (upper side in FIG. 1) of the outer cylinder 144. A rubber grommet 170 in which a lead wire insertion hole 170h is formed is disposed.

In addition, on the rear end side (upper side in FIG. 1) of the sensor element 10 that protrudes from the rear end portion 140 of the metal shell 138, a front end side separator 90 is disposed, and a flange portion 90p that protrudes radially outward from the outer surface. Is provided. The front end side separator 90 is held inside the outer cylinder 144 by the flange portion 90p coming into contact with the outer cylinder 144 via the holding member 169.
Further, a rear end side separator 95 is disposed between the grommet 170 and the front end side separator 90, and the rear end side separator 95 presses the front end side separator 90 toward the front end side by the elastic force of the grommet 170. As a result, the flange 90p is pressed against the holding member 169 side, and the front end side separator 90 and the rear end side separator 95 are connected to each other inside the outer cylinder 144 (that is, without being separated in the direction of the axis O). ) Is retained.

2 and 3 are perspective views of the distal end side metal fittings 20 and 30, respectively. In this embodiment, two types of tip-side terminal fittings 20 and 30 are used.
As shown in FIG. 7, the four tip side terminal fittings 30 are all symmetrical with each other in the tip end side separator 90 because the tip end side terminal fittings 30 adjacent to each other in the tip side separator 90 have a line-symmetric shape. This will be described using the side terminal fitting 30 (position I at the upper left in FIG. 7).
Here, the lower left tip metal fitting 30 at the position II in FIG. 7 is symmetrical with respect to the tip terminal fitting 30 at the position I with the line along the surface direction of the sensor element 10 as an axis. The tip-side terminal fitting 30 at the lower right position III in FIG. 7 is line-symmetric with respect to the tip-side terminal fitting 30 at the position II with a line perpendicular to the surface direction of the sensor element 10 as an axis. The tip terminal fitting 30 at the position IV in the upper right of FIG. 7 is axisymmetric with respect to the tip terminal fitting 30 at the position I with a line perpendicular to the surface direction of the sensor element 10 as an axis.

In addition, since the two distal end side terminal fittings 20 are both symmetrical with respect to each other in the distal end side separator 90, one of the distal end side terminal fittings 20 (FIG. 7). The position will be described using
Here, the lower end side terminal fitting 20 in FIG. 7 is axisymmetric with respect to the upper end side terminal fitting 20 with the line along the surface direction of the sensor element 10 as an axis. Note that the tip-side terminal fitting 20 is positioned between the two tip-side terminal fittings 30 along the width direction of the sensor element 10.

As shown in FIG. 2, the front end side terminal fitting 20 extends in the direction of the axis O as a whole, and has a connection portion 23 connected to the rear end side terminal fitting 40 and a substantially plate-shaped main body connected to the front end side of the connection portion 23. 21 and an elastic portion 22 that is folded back toward the sensor element 10 on the distal end side of the main body portion 21 are integrally provided.
The distal end side terminal fitting 20 can be manufactured, for example, by punching out one metal plate (Inconel (registered trademark), etc.) and then bending it into a predetermined shape, but is not limited thereto.

  The connecting portion 23 has a cylindrical shape with a C-shaped cross section, and a cylindrical rear end side terminal fitting 40 having a C-shaped cross section at the front end is inserted into and connected to the cylinder. In this case, the front end side terminal fitting 20 is indirectly connected to the lead wire 146 via the rear end side terminal fitting 40.

The outer sides of both sides in the width direction at the center of the axis O direction of the main body 21 are folded back 90 degrees toward the sensor element 10 to form a U-shaped holding portion 27. The connecting portion 23 is integrally connected to the rear end side of the main body portion 21. The main body 21 secures the strength of the tip-side terminal fitting 20 as a base portion of the tip-side terminal fitting 20. The pair of holding portions 27 are spaced apart in a C shape toward the rear end side.
On the other hand, a pair of rectangular piece-shaped rear end side holding portions 25, 25 that are flush with the main body portion 21 extend outward from both sides in the width direction on the rear end side in the axis O direction of the main body portion 21. Similarly, a pair of rectangular piece-shaped tip side holding portions 29 and 29 that are flush with the body portion 21 extend outward from both sides in the width direction on the tip side in the axis O direction of the body portion 21.
The pair of tip side holding portions 29 and 29 correspond to a “tip side locking portion” in the claims.

  The elastic part 22 is folded back toward the sensor element 10 from the front end of the main body part 21 and is elastically connected to the electrode pad 11a (see FIG. 1) at the contact P1. The elastic part 22 is elastically bent in the radial direction with respect to the main body part 21.

Further, as shown in FIG. 3, the front end side terminal fitting 30 extends in the direction of the axis O as a whole, and has a substantially plate-like shape connected to the connection portion 33 connected to the rear end side terminal fitting 40 and the front end side of the connection portion 23. The main body 31 and the elastic portion 32 that is folded back toward the sensor element 10 on the distal end side of the main body 31 are integrally provided.
The distal end side terminal fitting 30 can be manufactured, for example, by punching out one metal plate (Inconel (registered trademark) or the like) and then bending it into a predetermined shape, but is not limited thereto.
The connecting portion 33 has a cylindrical shape similar to that of the connecting portion 23, and, like the connecting portion 23, the rear end side terminal fitting 40 is inserted and connected in its own cylinder.

The main body 31 has an L-shaped cross section, and the outer side in one width direction of the main body 31 is folded back 90 degrees toward the sensor element 10 to form a position holding portion 35. The connecting portion 33 is integrally connected to the rear end side of the main body portion 31. The main body 31 secures the strength of the tip-side terminal fitting 30 as a base portion of the tip-side terminal fitting 30. Further, a portion of the position holding portion 35 at the tip slightly from the center in the direction of the axis O is recessed stepwise toward the main body portion 31, and the tip-facing surface forms a tip portion 35f.
The front end portion 35f corresponds to a “front end side locking portion” in the claims.

  The elastic part 32 is folded back toward the sensor element 10 from the front end of the main body part 31 and is elastically connected to the electrode pad 11a (see FIG. 1) at the contact P2. The elastic part 32 is elastically bent in the radial direction with respect to the main body part 31.

On the other hand, as shown in FIG. 4, the rear end side terminal fitting 40 extends in the direction of the axis O as a whole, and has a substantially terminal shape connected to the lead terminal 146 and a crimp terminal portion 47 connected to the lead wire 146. Neck portion 41, cylindrical large-diameter portion 45 in which a connecting plate is bent in a C-shaped cross section on the distal end side of neck portion 41, and a cylinder in which a connecting plate is folded in a C-shaped cross section on the distal end side of large-diameter portion 45 And a tip portion 43 having a shape.
The rear end side terminal fitting 40 can be manufactured, for example, by punching out a single metal plate (SUS304 or the like) and then bending it into a predetermined shape, but is not limited thereto.

The crimp terminal portion 47 holds the conducting wire 146w in a tubular shape by sandwiching and crimping the exposed conducting wire 146w by stripping the coating on the tip of the lead wire 146.
The tip portion 43 has a cylindrical shape and is pointed toward the tip. And the front-end | tip part 43 is inserted in the cylinder of the connection parts 23 and 33, and the rear-end side terminal metal fitting 40 is electrically connected with the front-end | tip terminal metal fittings 20 and 30. As shown in FIG.
The large diameter portion 45 is larger in diameter than the crimp terminal portion 47 and the tip portion 43, and the rear end facing surface 45 e of the large diameter portion 45 is exposed to the outside in the radial direction from the crimp terminal portion 47.
The rear end facing surface 45e corresponds to a “rear end side locking portion” in the claims.

As shown in FIG. 5, the front end side separator 90 has insertion holes 90 h 1 and 90 h 2, and each insertion hole 90 h 1 and 90 h 2 communicates with the internal space 90 v on the front end F side of the front end side separator 90.
The insertion holes 90h2 are arranged at the four corners of the front end side separator 90, and the insertion holes 90h1 are located between the two insertion holes 90h2 along the width direction of the sensor element 10.
A rear end facing surface 90s1 is formed on the front end side of the insertion hole 90h1, and a rear end facing surface 90s2 is formed on the front end side of the insertion hole 90h2.
The rear end-facing surfaces 90s1 and 90s2 correspond to “first locking portions” in the claims.
A recess 90r that is recessed along the width direction of the sensor element and straddling the internal space 90v is formed on the surface facing the rear end of the front end separator 90. As will be described in detail later, the concave portion 90r is engaged with the convex portion 95p of the rear end side separator 95.

As shown in FIG. 6, when the distal end side terminal fitting 20 is inserted into the insertion hole 90h1 from the rear end side (FIG. 6 (a)), the distal end side holding portion 29 of the distal end side terminal fitting 20 faces the rear end. The front end side metal fitting 20 is prevented from coming off to the front end side by coming into contact with the surface 90s1, and the front end side metal fitting 20 is held in the front end side separator 90 (FIG. 6B).
Similarly, when the distal end side terminal fitting 30 is inserted into the insertion hole 90h2 from the rear end side (FIG. 6A), the distal end portion 35f of the distal end side terminal fitting 30 comes into contact with the rear end facing surface 90s2 and the distal end side. The terminal metal fitting 30 is prevented from coming off to the front end side, and the front end side terminal metal fitting 30 is held in the front end side separator 90 (FIG. 6B).
In addition, the connection parts 23 and 33 protrude toward the rear end side of the front end side separator 90 in a state where the front end side terminal fittings 20 and 30 are held in the front end side separator 90 (FIG. 6B).

On the other hand, as shown in FIG. 8, the rear end side separator 95 has six insertion holes 95h arranged in the circumferential direction. The insertion hole 95h has a large diameter on the tip F side and is reduced in a step shape near the center in the axis O direction, and this step portion forms a tip-facing surface 95s (FIG. 8A).
The tip facing surface 95s corresponds to a “second locking portion” in the claims.
Further, on the outer peripheral side of the front end facing surface of the rear end side separator 95, two convex portions 95p that protrude along the width direction of the sensor element are formed. The convex portion 95p is adapted to engage with the concave portion 90r of the front end side separator 90.

Then, the lead wire 146 is passed through the front end side of the insertion hole 95 h in advance, and the lead wire 146 is connected to the rear end side terminal fitting 40 on the front end side of the rear end side separator 95. Next, when a part of the lead wire 146 side of the rear end side terminal fitting 40 is inserted into the insertion hole 95h from the front end F side and the lead wire 146 is pulled out to the rear end side, the large diameter portion of the rear end side terminal fitting 40 is obtained. The rear end facing surface 45e (see FIG. 4) 45 abuts the front end facing surface 95s to prevent the rear end side terminal fitting 40 from coming off to the rear end side, and the rear end side terminal fitting 40 is connected to the rear end side separator 95. (FIG. 8B).
At this time, the distal end side of the distal end portion 43 of the rear end side terminal fitting 40 (the distal end side from the center of the distal end portion 43 in the axis O direction) protrudes from the front end facing surface of the rear end side separator 95.
Further, the outer diameter of the large diameter portion 45 is slightly smaller than the inner diameter of the insertion hole 95h, and the large diameter portion 45 engages with the insertion hole 95h to hold the rear end side terminal fitting 40 in the rear end side separator 95.

Next, referring to FIG. 9 to FIG. 12, a mode in which the front end side metal fittings 20 and 30 and the rear end side metal terminal 40 are held by the front end side separator 90 and the rear end side separator 95 so as to be sandwiched in the direction of the axis O. explain.
First, since the positions of the insertion holes of the separators 90 and 95 differ depending on the front end side metal fittings 20 and 30 and the rear end side metal fittings 40 corresponding thereto, the cross section including the insertion holes of the separators 90 and 95. Are shown in FIGS.
As shown in FIG. 9, a cross section of the front separator 90 that is perpendicular to the plate surface of the sensor element 10, passes through the opposing insertion hole 90 h 1, and extends along the axis O direction is indicated by a line X 1 -X 1. Further, a cross section of the front end side separator 90 that is perpendicular to the plate surface of the sensor element 10, passes through the opposing insertion hole 90 h 2, and extends along the axis O direction is represented by X 2 -X 2 line.
Similarly, as shown in FIG. 10, a cross section of the rear end side separator 95 along the X1-X1 line is represented by a Y1-Y1 line, and a cross section of the rear end side separator 95 along the X2-X2 line is represented by a Y2-Y2 line.

11 shows a front end side separator 90 and a rear end side separator as viewed from a cross section taken along line X1-X1 of the front end side separator 90 of FIG. 9 and a cross section taken along line Y1-Y1 of the rear end side separator 95 of FIG. It is process drawing which shows 95 assembly | attachment.
In FIG. 11, the front end side holding portion (front end side locking portion) 29 of the front end side terminal fitting 20 is locked to the rear end facing surface (first locking portion) 90s1. Further, the rear end facing surface (front end side locking portion) 45e of the corresponding rear end side terminal fitting 40 is locked to the front end facing surface (second locking portion) 95s (FIG. 11A).
In this state, the convex portion 95p of the rear end side separator 95 is engaged with the concave portion 90r of the front end side separator 90 in the direction of the axis O, and the front end side separator 90 and the grommet 170 are not shown between the holding member 169 and the grommet 170 (not shown). By holding the rear end side separator 95 in between, the front end side separator 90 and the rear end side separator 95 are connected to each other (FIG. 11B).

At this time, the front end portion 43 of the rear end side terminal fitting 40 protruding to the front end side of the rear end side separator 95 is fitted into the connection portion 23 of the front end side metal fitting 20 protruding to the rear end side of the front end side separator 90. Both terminal fittings are connected.
Then, in a state where both terminal fittings are connected, the leading end side holding portion 29 is locked to the rear end facing surface 90s1, thereby preventing the leading end side terminal fitting 20 from coming off to the leading end side. Similarly, the rear end facing surface 45e is locked to the front end facing surface 95s, thereby preventing the rear end side terminal fitting 40 from coming off to the rear end side. Since the front end side terminal fitting 20 and the rear end side terminal fitting 40 are connected in the direction of the axis O to form an integral “separator”, the front end side terminal fitting 20 and the rear end side terminal fitting 40 are connected to the front end side separator 90 and It is possible to prevent the rear end side separator 95 from coming out to the front end side and the rear end side.

On the other hand, FIG. 12 shows the front end side separator 90 and the rear end as viewed from the cross section along the line X2-X2 of the front end side separator 90 of FIG. 9 and the cross section along the line Y2-Y2 of the rear end side separator 95 of FIG. FIG. 10 is a process diagram showing assembly of the side separator 95.
In FIG. 12, the front end portion (front end side locking portion) 35f of the front end side terminal fitting 30 is locked to the rear end facing surface (first locking portion) 90s2. Further, the rear end facing surface (front end side locking portion) 45e of the corresponding rear end side terminal fitting 40 is locked to the front end facing surface (second locking portion) 95s (FIG. 12A).
In this state, the convex portion 95p of the rear end side separator 95 is engaged with the concave portion 90r of the front end side separator 90 in the direction of the axis O, and the front end side separator 90 and the grommet 170 are not shown between the holding member 169 and the grommet 170 (not shown). By holding the rear end side separator 95 in between, the front end side separator 90 and the rear end side separator 95 are connected to each other (FIG. 12B).

At this time, the front end portion 43 of the rear end side terminal fitting 40 protruding to the front end side of the rear end side separator 95 is inserted into the connecting portion 33 of the front end side metal fitting 30 protruding to the rear end side of the front end side separator 90. Both terminal fittings are connected.
Then, in a state where both terminal fittings are connected, the distal end portion 35f is locked to the rear end facing surface 90s2, thereby preventing the distal end side terminal fitting 30 from coming off to the distal end side. Similarly, the rear end facing surface 45e is locked to the front end facing surface 95s, thereby preventing the rear end side terminal fitting 40 from coming off to the rear end side. Since the front end side terminal fitting 30 and the rear end side terminal fitting 40 are connected in the direction of the axis O to form an integral “separator”, the front end side terminal fitting 30 and the rear end side terminal fitting 40 are connected to the front end side separator 90 and It is possible to prevent the rear end side separator 95 from coming out to the front end side and the rear end side.
11 and 12, for easy understanding, terminal fittings (tip-side terminal fittings 20 and 30 and rear-end-side terminals) facing each other in the separator (tip-side separator 90 and rear-end-side separator 95) are used. One of the metal fittings 40) is not shown.

As described above, when the terminal fittings (front end side metal fittings 20 and 30 and the rear end side metal fitting 40) are securely held inside the separator (front end side separator 90 and rear end side separator 95), for example, when an external force or the like is applied. Therefore, it is possible to suppress the displacement of the terminal fittings 20 and 30 in the direction of the axis O, and to stably electrically connect the electrode pad 11a of the sensor element 10 and the terminal fitting.
Also, the clearance between the insertion holes 90h1, 90h2, and 95h of the separators (the front end side separator 90 and the rear end side separator 95) and the terminal fittings (the front end side terminal fittings 20, 30 and the rear end side terminal fitting 40) is excessively reduced. Since it is not necessary to hold the terminal fitting, it is possible to prevent the frictional force between them from increasing and the pulling load to the rear end side of the lead wire 146 from increasing, thereby preventing the efficiency of the assembly work from being lowered.

In the present embodiment, as shown in FIG. 11, the contact point P1 between the distal end side terminal fitting 20 and the electrode pad 11a is formed along the axis O direction with a rear end facing surface 90s1 (first locking portion) and a front end facing surface ( (Second locking portion) 95s. Similarly, as shown in FIG. 12, the contact point P2 between the distal end side terminal fitting 30 and the electrode pad 11a has a rear end facing surface 90s2 (first locking portion) and a front end facing surface (second engagement) along the direction of the axis O. Stopping part) is located between 95s.
As a result, the terminal fittings (front end side metal fittings 20 and 30 and rear end side terminal fitting 40) straddle the contacts P1 and P2, and the separators (the front end side separator 90 and the rear end side separator) at two positions on the front end side and the rear end side. 95), for example, when an external force or the like is applied, the terminal metal fittings 20 and 30 that contact the electrode pad 11a at the contacts P1 and P2 are further prevented from being displaced in the direction of the axis O. The electrical connection is further stabilized.

In the present embodiment, as described above, there are two terminal fittings, that is, the front-end-side terminal fitting 20 connected to the electrode pad 11a of the sensor element 10 and the rear-end-side terminal fitting 40 connected to the lead wire 146. Is connected.
Accordingly, the tip end side metal fittings 20 and 30 having complicated shapes having elastic portions connected to the electrode pads 11a from the rear end side metal fittings 40 that are connected to the lead wires 146 that require complicated operations such as a caulking process. Since the rear end side terminal fitting 40 having a simple shape may be handled in the caulking process, productivity is improved.

In the present embodiment, as shown in FIGS. 2 to 4, the distal end portion 43 of the rear end side terminal fitting 40 has a cylindrical shape, and the rear end side of the distal end side terminal fittings 20 and 30 has a cylindrical connection portion. 23, 33.
Thus, since the connection parts 23 and 33 and the front-end | tip part 43 are rotationally symmetrical around the axis line O, respectively, the position of the rear-end side terminal metal fitting 40 and the front-end | tip side terminal metal fittings 20 and 30 around the axis line O is somewhat. Even if they are misaligned, the front end portion 43 can be fitted into the connection portions 23 and 33, and the rear end side terminal fitting 40 and the front end side terminal fittings 20 and 30 can be easily and reliably connected to each other.

  It goes without saying that the present invention is not limited to the above-described embodiment, but extends to various modifications and equivalents included in the spirit and scope of the present invention.

For example, as shown in FIG. 13, the terminal fitting 50 may be integrated with the front end side and the rear end side without being separated. In this case, the distal end portion of the terminal fitting 50 has the same shape as that obtained by removing the connection portion 23 from the terminal fitting 20, and the main body portion 21, the elastic portion 22, the rear end side holding portion 25, the holding portion 27, and the tip end, respectively. The main body 51 has the same shape as the side holding part 29, the elastic part 52, the rear end side holding part 55, the holding part 57, and the front end side holding part 59.
Similarly, the rear end portion of the terminal fitting 50 has the same shape as that obtained by removing the distal end portion 43 from the terminal fitting 40, and the crimp terminal portion 53 and the diameter same as those of the crimp terminal portion 47 and the large diameter portion 45, respectively. It has a large part 58. The distal end side of the large diameter portion 58 is integrally connected to the main body portion 51.
In the terminal fitting 50, the front end holding portion 59 corresponds to the “front end side locking portion”, and the rear end facing surface 58e of the large diameter portion 58 corresponds to the “rear end side locking portion”.

The shape of the terminal fitting and the separator is not limited to the above embodiment.
The connection (connection) structure between the rear end side terminal fitting and the front end side terminal fitting is not limited to the above. For example, the rear end side of the front end side terminal fitting has a male pin shape, and this male pin is the front end of the rear end side terminal fitting. You may make it insert in the cylindrical part of a side.
In the case where the rear end side of the front end side terminal fitting or the front end side of the rear end side terminal fitting is formed into a cylindrical shape, it is not limited to a cylinder but may be a square tube such as a square tube. Further, the cylinder may be at least part of the cylinder (for example, C-shaped) without being completely closed. Moreover, it is good also as a form which makes one cylinder of one cylinder of a front end side terminal metal fitting or a rear end side terminal metal fitting or a part thereof.

  Examples of the gas sensor include an NOx sensor, an oxygen sensor, and a full range gas sensor.

DESCRIPTION OF SYMBOLS 1 Gas sensor 10 Sensor element 11a Electrode pad 20, 30, 40, 50 Terminal metal fitting 20, 30 Front end side terminal metal fitting 23, 33 Connection part 29, 35f, 59 Front end side latching part 40 Rear end side terminal metal fitting 43 Rear end side terminal Metal fitting tip 45e, 58e Rear end locking part 90 Separator (front end separator)
90s1, 90s2 first locking part (rear face)
95 Separator (rear end separator)
95s 2nd locking part (tip facing surface)
146 Lead wire O Axis P1, P2 Contact

Claims (5)

A sensor element having a plate shape extending in the axial direction and having an electrode pad on the outer surface on the rear end side;
A terminal fitting extending in the axial direction and electrically connected to the electrode pad;
A cylindrical separator that holds the terminal fitting and surrounds the rear end side of the sensor element;
A lead wire connected to the rear end side of the terminal fitting and drawn out to the rear end side of the separator,
The terminal fitting has a front end side locking portion and a rear end side locking portion on the front end side and the rear end side, respectively.
The separator includes a front end side separator and a rear end side separator that are disposed on the front end side and the rear end side in the axial direction and connected to each other, and the front end side separator has a first end facing surface. The rear end side separator has a second locking portion having a tip-facing surface;
In the terminal fitting, between the front end side separator and the rear end side separator, the front end side engaging portion is engaged with the rear end facing surface, and the rear end side engaging portion is engaged with the front end facing surface. A gas sensor that is stopped and held.   2. The gas sensor according to claim 1, wherein a contact point between the terminal fitting and the electrode pad is positioned between the rear end facing surface and the front end facing surface. The terminal fitting is composed of a distal end terminal fitting and a rear end terminal fitting arranged on the distal end side and the rear end side, respectively, and the distal end side metal fitting has the distal end side locking portion, The rear end side metal fitting has the rear end side locking portion;
The rear end side metal fitting is connected to the lead wire, and at least a part of itself is accommodated in the rear end side separator,
3. The gas sensor according to claim 1, wherein the tip-side terminal fitting is in contact with the electrode pad, and at least a part of the tip-side terminal fitting is accommodated in the tip-side separator.   The distal end portion of the rear end side terminal fitting forms at least a part of a column or a cylinder, and the rear end side of the distal end side terminal fitting has a connection portion that forms at least a part of a cylinder, and the distal end portion The gas sensor according to claim 3 in which is inserted. A sensor element having a plate shape extending in the axial direction and having an electrode pad on the outer surface on the rear end side;
A terminal fitting extending in the axial direction and electrically connected to the electrode pad;
A cylindrical separator that holds the terminal fitting and surrounds the rear end side of the sensor element;
A lead wire connected to the rear end side of the terminal fitting and drawn out to the rear end side of the separator, and a method of manufacturing a gas sensor comprising:
The terminal fitting has a front end side locking portion and a rear end side locking portion on the front end side and the rear end side, respectively.
The separator includes a front end side separator and a rear end side separator that are disposed on the front end side and the rear end side in the axial direction and connected to each other, and the front end side separator has a first end facing surface. The rear end side separator has a second locking portion having a tip-facing surface;
The front end side separator and the rear end side separator are disposed on the front end side and the rear end side of the terminal fitting, respectively, and the front end side locking portion is located between the front end side separator and the rear end side separator. A step of holding the terminal fitting between the leading end side separator and the trailing end side separator so as to be locked to the end facing surface and the trailing end side locking portion to be locked to the leading end facing surface; The manufacturing method of a gas sensor.

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