JP2016017895A - Sensor and manufacturing method of sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor and a manufacturing method of the sensor capable of appropriately maintaining a fitting depth of a sensor element into a connection terminal thereby preventing an electrode extraction part of the sensor element from wearing and capable of excellently maintaining an electrical contact between the connection terminal and the electrode extraction part.SOLUTION: In a sensor including: a sensor element 3 formed with an electrode extraction part 3CP on a rear end side; and a connection terminal 91 having a terminal part 93 and a main body part 94 of the rear end side of a terminal part, while the terminal part being fitted into the sensor element, the sensor element is provided with a housing part 3R which is recessed from the inner peripheral surface. The terminal part is provided with a terminal side protrusion 93P accommodated into the housing part and a contact part 93C formed on the tip end side nearer than the terminal side protrusion and brought into contact with the electrode extraction part. One or more places are arranged for a folding part 96a which is folded at a curved line in the direction orthogonal to the direction of the axis O between the terminal part of the connection terminal and the main body part, and a spring part 96 elastically bent in an axial direction is provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sensor in which a connection terminal for taking out an output of a sensor element for detecting a detected object is fitted on the rear end side of the sensor element, and a method for manufacturing the sensor.

  2. Description of the Related Art Conventionally, an oxygen sensor that detects the concentration of oxygen contained in automobile exhaust gas is known as an example of a sensor that includes a sensor element that detects an object to be detected. As shown in FIG. 8, as the sensor element 300 of this oxygen sensor, a detection unit formed by sandwiching a solid electrolyte body from the inside and the outside from a pair of electrodes on the tip side of the solid electrolyte body formed in a bottomed cylindrical shape. What has 300CS is known (patent document 1). On the surface of the outer peripheral surface 300S on the rear end side of such a sensor element 300, an electrode extraction portion 300CP for extracting a detection signal from the detection portion 300CS is formed via a lead portion 300CL. Then, the connection terminal 910 is connected to the lead wire for outputting the detection signal from the detection unit 300CS to the external circuit via the connector unit 950. The connection terminal 910 is attached to the rear end side of the sensor element 300, and the connection terminal 910 and the electrode extraction part 300CL are electrically connected by contact.

Here, in the sensor described in Patent Document 1, the sensor element (oxygen sensor element) 300 has a cylindrical shape, so that the contact between the electrode extraction portion 300CP provided on the rear end side and the connection terminal 910 can be reliably performed. The connection terminal 910 is provided with a cylindrical terminal portion (gripping portion) 930. In addition, a plate-like main body 940 is connected to the rear end side of the terminal portion 930 via a neck portion 960, and the connector portion 950 is connected to the rear end side of the main body portion 940 to form a connection terminal 910. Yes. Further, a separator 1210 is disposed on the rear end side of the connection terminal 910, holds the main body portion 940 in an insertion hole (not shown) of the separator 1210, and the front end surface 1210f of the separator contacts the rear end edge 930e of the terminal portion 930. It touches.
And, when assembling the sensor, by pressing the terminal portion 930 of the connection terminal 910 to the tip end side in the axis O direction via the separator 1210, the sensor element 300 pushes the terminal portion 930 outward in the radial direction, The sensor element 300 is fitted on the rear end side. After the fitting, the sensor element 300 is held by the elastic force of the terminal portion 930 so as to be wrapped by the inner peripheral surface of the terminal portion 930, so that the contact between the connection terminal 910 and the electrode extraction portion 300CP is maintained well. can do.

  Further, a receiving portion 300R that is recessed from the outer peripheral surface is provided on the rear end side of the electrode extraction portion 300CP of the sensor element 300, and a protruding portion 930P that is received in the receiving portion 300R is provided in the terminal portion 930. For this reason, when the terminal portion 930 is fitted to the rear end side of the sensor element 300, the protruding portion 930P pushes the terminal portion 930 away from the outer peripheral surface 300S of the sensor element 300, and the terminal portion 930 is fitted. After the insertion, the protrusion 930P is accommodated in the accommodating portion 300R when the predetermined insertion depth is reached, and the connection terminal 910 and the electrode extraction portion 300CP can be brought into contact with each other. Thus, when the terminal portion 930 is fitted, the electrode extraction portion 300CP provided on the outer peripheral surface 300S of the sensor element 300 is scraped at the tip of the terminal portion 930, or the terminal portion 930 on the tip side of the protrusion portion 930P. It is possible to prevent the provided contact portion 930C and the electrode extraction portion 300CP from rubbing and wearing.

JP 2008-298535 A

However, if the pressing force of the connection terminal 910 by the separator 1210 becomes too large, the terminal portion 930 is deeply fitted to the distal end side beyond a predetermined position, and the electrode extraction portion provided on the distal end side of the housing portion 300R of the sensor element 300 There is a risk of scraping or wearing 300 CP. In addition, when the terminal portion 930 is pushed deep enough so that the protruding portion 930P of the terminal portion 930 gets over the housing portion 300R, the terminal portion 930 is expanded again, and the contact portion 930C provided in the terminal portion 930 and the electrode extraction portion There is a problem that the electrical connection becomes unstable due to separation from 300 CP.
Therefore, the present invention appropriately maintains the fitting depth of the connection terminal to the sensor element, makes it difficult for the connection terminal to come out of the sensor element, and further prevents wear of the electrode extraction portion of the sensor element due to the fitting of the connection terminal, It is an object of the present invention to provide a sensor and a method for manufacturing the sensor that can satisfactorily maintain electrical contact between a connection terminal and an electrode lead-out portion.

  In order to solve the above-described problem, the sensor of the present invention is a sensor element having a bottomed cylindrical shape extending in the axial direction and closed at the tip side, and a detection unit for detecting a detection target at the tip side A sensor element having an electrode extraction part for extracting the output of the detection unit on the outer peripheral surface on the rear end side, and covering the circumferential direction on the rear end side of the sensor element, and the electrode extraction part A terminal part that is electrically connected; and a plate-like main body part connected to a rear end side of the terminal part, and a connection terminal that outputs a detection signal from the detection part to an external circuit, In the sensor in which the terminal portion is fitted into the sensor element and the terminal portion and the electrode extraction portion are in contact with each other, the sensor element has a rear end side in the axial direction with respect to the electrode extraction portion, from an outer peripheral surface. A recessed housing is provided and the connection The terminal portion of the child is formed in a terminal side protruding portion that is protruded inward from an inner peripheral surface and is accommodated in the accommodating portion, and is formed on a tip side of the terminal side protruding portion, and is in contact with the electrode extraction portion An element-side protrusion that protrudes outward from the outer surface of the electrode extraction portion in a direction perpendicular to the axial direction, on the rear end side of the electrode extraction portion of the sensor element. Part is provided in at least a part of the circumferential direction, and the rear end edge of the terminal part is located on the front end side with respect to the front end edge of the element-side convex part, Between them, there is provided a spring portion that has one or more folded portions that are folded back in a direction perpendicular to the axial direction and elastically bends in the axial direction.

According to this sensor, when the terminal portion is fitted to the rear end side of the sensor element and brought into contact with the electrode extraction portion, even if the pressing force to the main body portion on the rear end side from the spring portion of the connection terminal becomes too large, Since the pressing force is absorbed by the elastic force of the spring part and the excessive pressing force is applied to the terminal part on the tip side from the spring part, the fitting depth of the connection terminal to the sensor element is kept appropriately, and the terminal part Can be prevented from being pushed further into the tip side and scraping or wearing the electrode lead-out portion. In addition, when a terminal-side protruding part is provided on the connection terminal, the terminal part is expanded due to excessive pressing force on the terminal part and the terminal part is deeply fitted, so that the contact part and the electrode take-out part are separated. It is possible to suppress separation and electrical connection from becoming unstable.
Moreover, since the terminal side protrusion is provided in the terminal part or the element side convex part is provided in the sensor element, the terminal side protruding part or the element side convex part spreads the terminal part and away from the outer peripheral surface of the sensor element. As a result, the terminal portion can be fitted in such a manner that the terminal portion is not brought into contact with the electrode extraction portion provided on the outer peripheral surface. Furthermore, the terminal-side protruding portion or the element-side convex portion also acts as a retaining portion that prevents the connection terminal from coming off the sensor element.

The sensor of the present invention includes a separator that holds at least a part of the main body portion of the connection terminal and is disposed on the rear end side of the terminal portion so as to be separated from the terminal portion, and the connection via the separator. The terminal portion may be fitted into the sensor element by pressing the terminal toward the distal end side in the axial direction.
According to this sensor, since the connection terminal is pressed by the separator included in the sensor, other members that press the connection terminal are not required, and productivity is improved.

In the sensor of the present invention, the main body portion is provided with a locking portion that protrudes from the main body portion in a direction orthogonal to the axial direction and is locked to the insertion hole of the separator, and the spring portion is the locking portion. You may be located in the front end side rather than a part.
According to this sensor, the separator can be reliably separated to the rear end side of the terminal portion, the pressing force of the separator is reliably absorbed by the elastic force of the spring portion, and the terminal portion is pushed further to the front end side. Can be further suppressed.

  The sensor manufacturing method of the present invention is a sensor element having a bottomed cylindrical shape extending in the axial direction and closed at the distal end side, and has a detection unit for detecting the detected object at the distal end side, A sensor element having an electrode take-out portion for taking out the output of the detection portion on the outer peripheral surface on the rear end side, covers the circumferential direction on the rear end side of the sensor element, and is electrically connected to the electrode. A terminal part and a plate-like main body part connected to the rear end side of the terminal part; a connection terminal for outputting a detection signal from the detection part to an external circuit; and a main body part of the connection terminal. In a method for manufacturing a sensor, comprising: a separator that holds at least a part and is disposed on the rear end side of the terminal portion and spaced apart from the terminal portion. A receiving part that is recessed from the outer peripheral surface is provided on the rear end side in the axial direction. In addition, the terminal portion of the connection terminal is formed on the tip side of the terminal-side protruding portion, the terminal-side protruding portion that is accommodated in the accommodating portion while protruding inward from the inner peripheral surface, A contact portion that comes into contact with the electrode extraction portion, or on the rear end side of the electrode extraction portion of the sensor element, on the outer side in the direction orthogonal to the axial direction from the outer surface of the electrode extraction portion. A protruding element-side convex portion is provided in at least a part of the circumferential direction, and a folding portion that is folded back in a direction perpendicular to the axial direction is provided between the terminal portion of the connection terminal and the main body portion. The spring part which has the above and is elastically bent in the axial direction is provided, the separator holding the connection terminal is pressed to the distal end side in the axial direction, and the terminal side protruding part is accommodated in the accommodating part. Or the end The terminal portion as a rear end edge of the part is positioned at the front end side from the distal end edge of the element-side convex portion fitted into the rear end side of the sensor element, for connecting said contact portion electrically with the electrode.

  According to the present invention, the fitting depth of the connection terminal to the sensor element is appropriately maintained, the connection terminal is difficult to be removed from the sensor element, and further, the wear of the electrode extraction portion of the sensor element due to the fitting of the connection terminal is prevented. The electrical contact between the connection terminal and the electrode lead-out portion can be maintained well.

It is sectional drawing which cut | disconnected the sensor which concerns on the 1st Embodiment of this invention in the surface which follows an axial direction. It is a perspective view which shows the structure of a sensor element and a connection terminal. It is a perspective view which shows the holding state to the separator of a connection terminal. It is a figure which shows the mechanism which absorbs the pressing force of a separator, reducing the clearance gap G by the elastic force of a spring part. It is a figure which shows the aspect which manufactures a sensor. It is process drawing which shows the process of inserting a terminal part in a sensor element. It is a perspective view which shows the structure of the sensor element and connection terminal of a sensor which concern on the 2nd Embodiment of this invention. It is a perspective view which shows the structure of the conventional sensor element and a connecting terminal.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 shows a cross-sectional structure of the sensor 100 according to the first embodiment of the present invention cut along a plane along the axial direction (direction from the distal end toward the proximal end). FIG. 2 is a perspective view showing the structure of the sensor element and the connection terminal.
In this embodiment, the sensor 100 is an oxygen sensor that is inserted into the exhaust pipe of an automobile and the tip (arrow F side in FIG. 1) is exposed to the exhaust gas to detect the oxygen concentration in the exhaust gas. The sensor element 3 is a known oxygen sensor element that constitutes an oxygen concentration cell in which a pair of electrodes are laminated on an oxygen ion conductive solid electrolyte body and outputs a detection value corresponding to the amount of oxygen. FIG. 3 is a perspective view showing a state in which the connection terminal 91 is held on the separator 121. FIG. 4 is a view showing a mechanism for absorbing the pressing force of the separator 121 while reducing the gap G by the elastic force of the spring portion 96.
Note that the lower side (arrow F side) in FIG. 1 is the distal end side of the sensor 100, and the upper side in FIG. 1 is the proximal end side of the sensor 100.

The sensor 100 is assembled so that a substantially cylindrical (hollow shaft-shaped) sensor element 3 (in this example, an oxygen sensor element) 3 having a closed end is inserted and held inside a cylindrical metal fitting body (main metal fitting) 20. It has been. The sensor element 3 includes a cylindrical solid electrolyte body that is tapered toward the tip, and an inner electrode 3B and an outer electrode 3C that are respectively formed on the inner and outer peripheral surfaces of the solid electrolyte body. The internal space of the sensor element 3 is set as a reference gas atmosphere, and the gas to be detected is brought into contact with the outer surface of the sensor element 3 to detect the gas. A round bar heater 15 is inserted into the hollow portion of the sensor element 3 so as to raise the temperature of the solid electrolyte body to the activation temperature. Furthermore, although mentioned later in detail, the accommodating part 3R is formed in the rear end side of the sensor element 3, and the terminal side protrusion part 93P accommodated in the accommodating part 3R is formed in the outer side terminal 91. FIG.
A cylindrical outer tube 40 that holds lead wires and terminals (described later) provided on the proximal end side of the sensor element 3 and covers the proximal end portion of the sensor element 3 is joined to the proximal end portion of the metal fitting body 20. ing. Further, an insulating and cylindrical separator 121 is caulked and fixed inside the outer cylinder 40 on the proximal end side of the sensor element 3. On the other hand, the detection part at the tip of the sensor element 3 is covered with a protector 7. Then, by attaching the male screw portion 20d of the metal fitting body 20 of the sensor 100 manufactured in this way to a screw hole such as an exhaust pipe, the detection part at the tip of the sensor element 3 is exposed in the exhaust pipe, and the detected gas (exhaust gas) Gas). A polygonal flange 20c for engaging a hexagon wrench or the like is provided near the center of the metal fitting body 20, and the step between the flange 20c and the male thread 20d is attached to the exhaust pipe. A gasket 14 is inserted to prevent the gas from leaking when it is blown.

A flange portion 3 a is provided on the center side of the sensor element 3, and a step portion that is reduced in diameter is provided on the inner peripheral surface near the tip of the metal fitting body 20. In addition, a cylindrical ceramic holder 5 is disposed on a surface facing the base end of the step portion via a washer 12. The sensor element 3 is inserted inside the metal fitting body 20 and the ceramic holder 5, and the flange 3 a of the sensor element 3 is in contact with the ceramic holder 5 from the base end side.
Further, the cylindrical talc powder 6 and the cylindrical ceramic sleeve 10 are arranged in a gap in the radial direction (direction orthogonal to the axial direction) between the sensor element 3 and the metal fitting body 20 on the proximal end side of the flange portion 3a. ing. Then, the metal ring 30 is disposed on the proximal end side of the ceramic sleeve 10, and the base end portion of the metal fitting body 20 is bent inward to form the crimped portion 20a, whereby the ceramic sleeve 10 is pressed against the distal end side. As a result, the talc ring 6 is crushed and the ceramic sleeve 10 and the talc powder 6 are fixed by caulking, and the gap between the sensor element 3 and the metal fitting body 20 is sealed.

A separator 121 is disposed on the rear end side of the gas sensor element 3, and a holding metal fitting 80 is disposed in the gap between the separator 121 and the outer cylinder 40. The separator 121 is held inside the holding metal fitting 80.
The separator 121 is provided with insertion holes (four in this example), and the plate-like base portions 74 and 94 of the inner terminal 71 and the outer terminal 91 are inserted and fixed to two of the insertion holes, respectively. Connector portions 75 and 95 are formed at the rear ends of the plate-like base portions 74 and 94, respectively, and lead wires 41 and 41 are crimped to the connector portions 75 and 95, respectively. Further, a heater lead wire 43 (only one is shown in FIG. 1) drawn from the heater 15 is inserted into two insertion holes (heater lead holes) (not shown) of the separator 121.
A cylindrical grommet 131 is caulked and fixed inside the outer cylinder 40 on the rear end side of the separator 121, and two lead wires 41 and two heater lead wires 43 are respectively inserted from the four insertion holes of the grommet 131. Has been pulled out.
A through hole 131 a is formed at the center of the grommet 131 and communicates with the internal space of the gas sensor element 3. A water-repellent ventilation filter 140 is interposed in the through-hole 131a of the grommet 131 so that the reference gas (atmosphere) is introduced into the internal space of the gas sensor element 3 without passing outside water.
The outer terminal 91 corresponds to a “connection terminal” in the claims, and the plate-like base portion 94 corresponds to a “main body” in the claims.

  On the other hand, a cylindrical protector 7 is fitted on the front end side of the metal fitting body 20, and the front end side of the sensor element 3 protruding from the metal fitting body 20 is covered with the protector 7. The protector 7 is configured by attaching a bottomed cylindrical metal (for example, stainless steel, etc.) double outer protector 7b and an inner protector 7a having a plurality of holes (not shown) by welding or the like.

As shown in FIG. 2, the outer electrode (detection electrode) 3C is formed on the distal end side of the outer circumferential surface 3S of the gas sensor element 3, and the outer electrode 3C is provided over the entire circumference on the distal end side of the outer circumferential surface 3S. Portion 3CS, a linear lead portion 3CL extending from the detection portion 3CS to the rear end, and a portion extending in the circumferential direction on the rear end side of the outer peripheral surface 3S and connected to the lead portion 3CL (detection portion 3CS) Electrode extraction portion 3CP. The electrode extraction portion 3CP is formed to be wider than the lead portion 3CL in the circumferential direction, and the electrode extraction portion 3CP and the lead portion 3CL have a T shape. Further, the inner electrode 3B (see FIG. 1) is provided on the surface of the inner hole 3d in the rear end portion 3e from the front end portion of the outer peripheral surface 3S. The rear end 3e is a chamfered corner.
Further, a receiving portion 3R that is recessed radially inward from the outer peripheral surface 3S is provided on the rear end side with respect to the electrode extraction portion 3CP of the sensor element 3 and on the front end side with respect to the rear end portion 3e. The accommodating portion 3R can be formed by, for example, press-molding and firing the sensor element 3 having the general shape of the accommodating portion 3R from a powder containing a solid electrolyte body, and then finishing by cutting.

On the other hand, the outer terminal (connection terminal) 91 is elongated from the front end to the rear end, and is integrally formed by bending a thin metal plate (corrosion resistant heat resistant superalloy plate) punched into a predetermined shape. A plate-like base portion 94 is formed on the rear end side of the outer terminal 91, and a connection end portion 95 that is caulked and connected to the core wire of the lead wire 41 is disposed on the rear end side of the plate-like base portion 94. A cylindrical terminal portion 93 is connected to the distal end side of the plate-like base portion 94 via a spring portion 96 that is narrower than the plate-like base portion 94.
The spring portion 96 extends to the rear end side flush with the outer surface of the terminal portion 93, then bends radially outward, and further has a folded portion 96 a that is folded back in a radial direction on the rear end side. The bent portion is bent in the axial direction on the rear end side and connected to the plate-like base portion 94. The spring portion 96 is elastically bent in the axial direction at the folded portion 96a.
Further, a wide portion 94w that is wider than other portions is formed on the center side in the axial direction of the plate-like base portion 94, and the central portion of the wide portion 94w is punched into a U-shape with the rear end side fixed, and the wide portion 94w A cut-and-raised portion 94Y cut and raised on the back side (the surface opposite to the front side) is provided.

As shown in FIG. 3, when the connection terminal 91 is inserted from the front end side of the insertion hole 121 h of the separator 121, the shoulder portion 94 s on the rear end side of the wide portion 94 w is a tapered portion 121 t that faces the front end side in the insertion hole 121. The connection terminal 91 is positioned in the separator 121. The cut and raised portion 94Y is in contact with the outer end wall of the insertion hole 121h, and the plate-like base portion 94 is held in the insertion hole 121h by the spring force. In addition, the connection terminal 91 is held by the separator 121 such that the separator 121 is separated from the rear end side of the terminal portion 93 by providing a gap G.
Therefore, as shown in FIG. 4, even when the separator 121 is pushed to the tip side with an excessive pressing force, the pressing force of the separator 121 is absorbed while the gap G is reduced by the elastic force of the spring portion 96, and the terminal portion 93. Is prevented from being pushed further toward the tip side.
In the present embodiment, the spring portion 96 is accommodated in the insertion hole 121 h of the separator 121. The shoulder portion 94s corresponds to a “locking portion” in the claims.

Further, the terminal portion 93 has a cylindrical shape centered on the axis O, and has a C-shaped cross section having a slit M along the generatrix on the opposite side to the plate-like base portion 94. The inner diameter of the terminal portion 93 is smaller than the outer diameter of the rear end portion of the gas sensor element 3 (outer peripheral surface 3S), and when the terminal portion 93 is externally fitted to the gas sensor element 3 and expanded, the terminal portion 93 is caused by a spring force. Is shrunk and pressed by the outer electrode 3C (electrode extraction part 3CP) of the gas sensor element 3.
In addition, the terminal portion 93 is provided with a total of four hemispherical terminal side protruding portions 93P (only three are shown in FIG. 2) that are accommodated in the accommodating portion 300R while protruding inward from the inner peripheral surface. The inner surface of the terminal portion 93 on the tip side of the terminal side protruding portion 93P constitutes a contact portion 93C that comes into contact with the electrode extraction portion 3CP.
Further, on the distal end side of the terminal portion 93, there are a total of eight piece-like guide pieces 98 in which the terminal portion 93 is folded back radially outward at the distal edge 93f intermittently and radially in the circumferential direction (FIG. 2). (Only three are shown). The guide piece 98 extends radially outward while extending from the tip edge 93f toward the tip, and serves as a guide when the terminal portion 93 is externally fitted to the sensor element 3.

This sensor 100 is manufactured as shown in FIG. First, the sensor element assembly B is assembled while holding the sensor element 3 inside the metal shell 20. Specifically, the sensor element 3 is disposed on the ceramic holder 5 disposed in the metal shell 20. Thereafter, the talc 6 is filled in the gap between the metal shell 20 and the sensor element 3, the ceramic sleeve 10 and the metal packing 30 are sequentially disposed on the talc 6, and the rear end side of the metal shell 20 is swaged. The element assembly B is assembled.
On the other hand, the outer cylinder 40 is disposed together with the grommet 131 on the separator 121 assembled with the inner terminal 71 and the outer terminal 91 on the outer cylinder 40, and the separator assembly A is assembled. Specifically, the inner terminal 71 and the outer terminal 91 connected to the lead wire 41 are inserted into the separator 121, and then the separator 121 is brought into contact with the stepped portion 40 d of the outer cylinder 40.
Thereafter, the holding metal fitting 80 is inserted into the gap between the separator 121 and the outer cylinder 40, the grommet 131 is disposed on the rear end side of the outer cylinder 40, and the separator assembly A is assembled. The heater 15 is already attached to the inner terminal 71.

Then, when the axis lines of the separator assembly A and the element assembly B are aligned and the separator assembly A is put on the rear end of the sensor element assembly B, the heater 15 is inserted into the sensor element 3 and the inner electrode 3B of the sensor element 3 is inserted. The outer electrode 3C is electrically connected to the inner terminal 71 and the outer terminal 91, respectively. After that, among the outer cylinder 40, the outer peripheral part of the holding metal fitting 80, the outer peripheral part of the grommet 131, and the overlapping part with the metal shell 20 are respectively crimped, and the overlapping part between the outer cylinder 40 and the metal shell 20 is laser welded or the like. The outer cylinder 40 is connected to the rear end of the metal shell 20 to manufacture the sensor 100.
When pushing the separator assembly A into the sensor element assembly B, a pressurizing device (not shown) is used to push the separator 121 with a predetermined stroke. At this time, the separator 121 and the terminal portion 93 are separated from each other. As described with reference to FIG. 4, the terminal portion 93 has a constant force while absorbing the pressing force of the separator 121 by the elastic force of the spring portion 96. It is pushed to the side. Thereby, the tip end side of the terminal portion 93 gets over the housing portion 3R of the sensor element 3 and expands the diameter by its own elastic force, and thus close to the rear end portion of the sensor element 3 (the electrode extraction portion of the outer electrode 3C). 3CP forming part).
In this manner, the terminal portion 93 of the outer terminal 91 is externally fitted to the outer peripheral surface on the rear end side of the sensor element 3, and the electrode extraction portion 3CP and the terminal portion 93 are electrically connected. Thereby, the detection signal of the outer electrode 3C (detector 3CS) is taken out from the outer terminal 91 via the lead wire 41.

Next, a process of fitting the terminal portion 93 into the sensor element 3 during manufacturing will be described with reference to FIG.
First, as shown in FIG. 6A, when the terminal portion 93 is externally fitted from the front end side to the rear end side of the sensor element 3, the inner surface of the guide piece 98 comes into contact with the rear end portion 3e of the sensor element 3, and the guide piece The terminal portion 93 is fitted into the distal end side of the sensor element 3 while expanding the diameter with 98 as a guide.
When the terminal portion 93 is further externally fitted to the front end side of the sensor element 3 (FIG. 6B), the inner surface of the terminal portion 93 gets over the rear end portion 3e and pushes the terminal portion 93 into a letter C shape. Here, when the terminal portion 93 is further fitted on the distal end side of the sensor element 3 (FIG. 6C), the distal end edge 93f of the terminal portion 93 is the electrode extraction portion 3CP provided on the outer peripheral surface 3S of the sensor element 3. Proximity to.
Further, when the terminal portion 93 is externally fitted to the front end side of the sensor element 3 (FIG. 6D), the terminal side protruding portion 93P of the terminal portion 93 gets over the rear end portion 3e. At this time, the terminal-side protruding portion 93P further pushes the terminal portion 93 into a cross-section and moves the terminal portion 93 away from the outer peripheral surface 3S of the sensor element 3, so that the tip edge 93f of the terminal portion 93 contacts the electrode extraction portion 3CP. The terminal portion 93 can be fitted more deeply while preventing this.
When the terminal portion 93 is further externally fitted to the front end side of the sensor element 3 (FIG. 6 (e)), the terminal side protruding portion 93P of the terminal portion 93 gets over the rear end portion 3e and is accommodated in the small diameter accommodating portion 3R. Accordingly, the diameter of the entire terminal portion 93 is reduced by its own elastic force, and the terminal portion 93 and the electrode extraction portion 3CP are in electrical contact.

Here, as described with reference to FIG. 5, when the separator assembly A is pushed into the sensor element assembly B, the separator 121 is pushed in by a predetermined stroke using a pressurizing device (not shown).
At this time, as shown in FIG. 6E, the terminal portion 93 is already fitted to a predetermined depth, and the separator 121 is connected to the terminal even though the terminal portion 93 and the electrode extraction portion 3CP are in electrical contact. The part 93 may be further pressed toward the tip side.
Even in such a case, as described with reference to FIG. 4, the pressing force of the separator 121 is pushed so as not to exceed a certain force (a force equal to the elastic force of the spring portion 96) by the elastic force of the spring portion 96. Since pressure is absorbed, it can suppress that the terminal part 93 is pushed into the front end side any more. As a result, as shown in FIG. 6 (f), the fitting depth of the connection terminal 91 to the sensor element 3 is kept constant, and the terminal portion 93 is deeply fitted to the distal end side beyond a predetermined position, so that the electrode extraction portion It is possible to suppress the 3CP from being scraped or worn. Further, since the terminal side protruding portion 93P of the terminal portion 93 gets over and deeply fits over the housing portion 3R, the terminal portion 93 is expanded in diameter, and the contact portion 93C and the electrode extraction portion 3CP are separated from each other, and electrical connection is not achieved. It can also be suppressed that it becomes stable.

Moreover, since the terminal side protrusion part 93P is provided in the terminal part 93, the terminal side protrusion part 93P spreads the terminal part 93, and keeps it away from the outer peripheral surface 3S of the sensor element 3, As a result, the terminal part 93 is made into the sensor element 3. The terminal portion 93 can be fitted so as not to contact the electrode extraction portion 3CP provided on the outer peripheral surface 3S.
Furthermore, the terminal side protruding portion 93P also functions as a retaining portion that prevents the outer terminal 91 (terminal portion 93) from coming off the sensor element 3.
When the outer terminal 91 is fitted into the sensor element 3, a load (pressing force) is applied to the spring portion 96 in the direction of the axis O, but in the completed sensor 100 in which the outer terminal 91 is fitted into the sensor element 3. The load (pressing force) may be applied to the spring portion 96 in the direction of the axis O or may not be applied.

  As shown in FIG. 8, in the conventional connection terminal 910, the neck portion 960 that connects the terminal portion 930 and the main body portion 940 extends straight from the terminal portion 930 toward the rear end side in the axial direction, and then in the radial direction. It is bent inward and connected to the main body 940, and does not have a folded portion that folds in a radial direction. For this reason, when the separator 1210 excessively presses the connection terminal 910 toward the distal end, the neck 960 does not necessarily bend at the position of the neck 860, so that the neck 960 cannot sufficiently absorb the pressing force of the separator 121. It is. In addition, since the separator 1210 and the terminal portion 930 are not separated from each other, the pressing force of the separator 1210 is directly applied to the terminal portion 930, and the pressing force of the separator 121 is not absorbed halfway.

  In the present embodiment, the connection terminal 91 is held in the separator 121 via the shoulder portion 94s on the rear end side of the wide width portion 94w. For this reason, the separator 121 can be reliably separated to the rear end side of the terminal portion 93, the pressing force of the separator 121 is reliably absorbed by the elastic force of the spring portion 96, and the terminal portion 93 is pushed further to the front end side. Can be further suppressed.

Next, a sensor according to a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a perspective view showing structures of the sensor element 3Z and the connection terminal 91Z of the sensor 100Z according to the second embodiment of the present invention. The sensor 100Z according to the second embodiment has the same configuration as the first embodiment except for the sensor element 3Z and the outer terminal 91Z. Therefore, the same components as the sensor 1 according to the first embodiment are used. These are omitted from the illustration or are given the same reference numerals, and the description thereof is omitted.
The connection terminal 91Z does not have an element-side convex portion, and a connection terminal having a general shape can be used as it is.
On the other hand, the sensor element 3Z has an element-side convex portion 3P that protrudes radially outward from the outer peripheral surface 3S and the outer surface of the electrode extraction portion 3CP on the rear end side of the electrode extraction portion 3CP. In the example of FIG. 7, the element-side convex portion 3 </ b> P includes a diameter-enlarged portion 3 </ b> P <b> 1 that increases in a taper shape from the rear end edge of the sensor element 3 toward the front end side, and a straight portion 3 </ b> P <b> 2 that extends from the enlarged diameter portion 3 </ b> P < And have. Further, the tip edge 3Pf of the convex portion 3P (straight portion 3P2) forms a step portion and is connected to the outer peripheral surface 3S.

  Also in the second embodiment, when the outer terminal 91Z is fitted into the sensor element 3, the pressing force is absorbed by the elastic force of the spring portion 96, so that the terminal portion 93 is prevented from being pushed further toward the distal end side. Can do. As a result, the fitting depth of the outer terminal 91Z into the sensor element 3Z is kept constant, and the terminal portion 93 is prevented from being deeply fitted to the distal end side beyond a predetermined position to scrape or wear the electrode extraction portion 3CP. be able to.

Further, since the element-side convex portion 3P is provided in the sensor element 3Z, the element-side convex portion 3P spreads the terminal portion 93 and moves away from the outer peripheral surface 3S of the sensor element 3Z. As a result, the terminal portion 93 is moved to the sensor element 3Z. The terminal portion 93 can be fitted so as not to contact the electrode extraction portion 3CP provided on the outer peripheral surface 3S.
Furthermore, the element-side convex portion 3P also functions as a retaining portion that prevents the outer terminal 91Z (terminal portion 93) from coming out of the sensor element 3Z.

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, in the above embodiment, the outer terminal 91 is held in the separator 121 in advance, and the outer terminal 91 is fitted into the sensor element 3 via the separator, but the main body 94 of the outer terminal 91 is different from the separator 121. It may be held by a member and fitted into the sensor element 3.
Moreover, in the said embodiment, although the spring part 96 owned one folding | returning part 96a, you may have several folding | turning part. In addition, when it has a several folding | turning part, each folding | returning part will respectively be located in a line with an axial direction. The shapes of the folded portion and the spring portion are not limited to the above embodiment.
The shape, position, and number of terminal side protrusions 93P provided in the terminal portion 93 are not limited to the above embodiment. Further, the shape of the accommodating portion 3R of the sensor element 3 is not limited to the above embodiment. In the above-described embodiment, the length in the axial direction of the accommodating portion 3R is made longer than the length in the axial direction of the terminal side protruding portion 93P. This is because the terminal side protruding portion 93P is reliably accommodated in the accommodating portion 3R in consideration of the dimensional variation (tolerance) of the accommodating portion 3R in the manufacture of the sensor element 3.

Further, the shape of the element-side convex portion 3P of the sensor element 3Z is not limited to the above embodiment. In the above-described embodiment, a part of the element side convex portion 3P in the circumferential direction is notched to form the notched portion 3X, and the outer surface of the notched portion 3X is flush with the outer circumferential surface 3S in the axial direction. Yes. And the convex part which protruded from the outer surface 3S and the outer surface of electrode extraction part 3CP by fitting the terminal part 93 in the sensor element 3Z so that the neck part 96 is located inside the notch part 3X in the circumferential direction This prevents the neck 96 from interfering with 3P. However, the invention is not limited thereto, and the element-side convex portion 3P may be formed over the entire circumference.
Furthermore, the terminal portion 93 has a cylindrical shape that covers the rear end side of the sensor element 3, and may have a shape that can be spread outward in the radial direction. One slit is provided in the axial direction of the terminal portion 93 described above. The cross section perpendicular to the entering axial direction may be a C-shaped cross section, or a shape having a plurality of slits in the axial direction.

3, 3Z sensor element 3CS detection part 3CP electrode extraction part 3R accommodating part 3S outer peripheral surface of sensor element 3P element side convex part 91, 91Z connection terminal 93 terminal part 93C contact part 93P terminal side protrusion 94 body part 94s locking part 96 Spring part 96a Folded part 100, 100Z Sensor 121 Separator O Axis G Gap between terminal part and separator

Claims (4)

A sensor element that extends in the axial direction and has a bottomed cylindrical shape with the tip side closed, and has a detection unit for detecting the detected object on the tip side, and on the outer peripheral surface on the rear end side, A sensor element in which an electrode extraction part for extracting the output of the detection part is formed;
A terminal portion that covers a circumferential direction on the rear end side of the sensor element and is electrically connected to the electrode take-out portion; and a plate-shaped main body portion connected to the rear end side of the terminal portion; A connection terminal that outputs a detection signal from a part to an external circuit, wherein the terminal part is fitted into the sensor element, and the terminal part and the electrode extraction part are in contact with each other,
The sensor element is provided with a housing portion recessed from the outer peripheral surface on the rear end side in the axial direction from the electrode extraction portion,
In the terminal portion of the connection terminal,
A terminal-side protruding portion that is accommodated in the accommodating portion while protruding inward from the inner peripheral surface;
A contact portion that is formed on the tip side of the terminal-side protruding portion and is in contact with the electrode extraction portion; or
Alternatively, an element-side convex portion that protrudes outward from the outer surface of the electrode extraction portion in a direction orthogonal to the axial direction is provided on at least a part of the circumferential direction on the rear end side of the electrode extraction portion of the sensor element. The rear end edge of the terminal portion is located on the front end side of the front end edge of the element side convex portion,
Between the terminal portion of the connection terminal and the main body portion, there is provided a spring portion that has one or more folded portions that are folded back in a direction perpendicular to the axial direction and elastically bends in the axial direction. Sensor. A separator that holds at least a part of the main body portion of the connection terminal and is disposed on the rear end side of the terminal portion apart from the terminal portion;
The sensor according to claim 1, wherein the terminal portion is fitted into the sensor element by pressing the connection terminal toward the distal end side in the axial direction via the separator. The main body portion is provided with a locking portion that protrudes from the main body portion in a direction orthogonal to the axial direction and is locked to the insertion hole of the separator.
The sensor according to claim 2, wherein the spring portion is located on a distal end side with respect to the locking portion. A sensor element that extends in the axial direction and has a bottomed cylindrical shape with the tip side closed, and has a detection unit for detecting the detected object on the tip side, and on the outer peripheral surface on the rear end side, A sensor element in which an electrode extraction part for extracting the output of the detection part is formed;
A terminal portion that covers the circumferential direction on the rear end side of the sensor element and is electrically connected to the electrode; and a plate-shaped main body portion connected to the rear end side of the terminal portion; A connection terminal that outputs a detection signal of
A separator that holds at least a part of the main body portion of the connection terminal and is disposed on the rear end side of the terminal portion so as to be separated from the terminal portion;
In a method for manufacturing a sensor comprising:
The sensor element is provided with a housing portion recessed from the outer peripheral surface on the rear end side in the axial direction from the electrode extraction portion,
In the terminal portion of the connection terminal,
A terminal-side protruding portion that is accommodated in the accommodating portion while protruding inward from the inner peripheral surface;
A contact portion that is formed on the tip side of the terminal-side protruding portion and is in contact with the electrode extraction portion; or
Alternatively, an element-side convex portion that protrudes outward from the outer surface of the electrode extraction portion in a direction orthogonal to the axial direction is provided on at least a part of the circumferential direction on the rear end side of the electrode extraction portion of the sensor element. The rear end edge of the terminal portion is located on the front end side of the front end edge of the element side convex portion,
Between the terminal portion of the connection terminal and the main body portion, there is provided a spring portion that has one or more folded portions that are folded back in a direction perpendicular to the axial direction and elastically bends in the axial direction. And
The separator holding the connection terminal is pressed toward the distal end side in the axial direction, the terminal portion is fitted into the rear end side of the sensor element so that the protruding portion is accommodated in the accommodating portion, and the contact portion is A method for manufacturing a sensor electrically connected to an electrode.

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