Gas sensor

Abstract

To provide a gas sensor in which breakage of a terminal metal fitting in a back end side of a separator is suppressed.SOLUTION: A gas sensor 10 includes: a plate-like sensor element 20 extending in the direction of an axial line O, the sensor element having electrode pads 21a and 21b in main surfaces 20m1 and 20m in a back end side; a terminal metal fitting 71 electrically connected to an electrode pad; a separator 50 having a storage part 50h storing the back end side of the sensor element and the terminal metal fitting, the separator holding the terminal metal fitting; and a grommet 47 located closer to the back end side than the separator. The storage part has a tapered surface 50s becoming wider to a direction perpendicular to a main surface in a site closer to the surface of the separator facing the back end. The grommet has a protrusion part 47b in the top end side, and the top edge of the protrusion part is inserted closer to the back end side than the top end side of the tapered surface along the axial direction. The terminal metal fitting is in contact with the protrusion part.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a gas sensor suitably used for detecting the gas concentration of specific gases contained in combustion gases or exhaust gases, such as in combustors or internal combustion engines.

Background Art

[0002] As a gas sensor for detecting the concentration of oxygen or NO in exhaust gases of automobiles or the like, there is known one having a plate-shaped sensor element using a solid electrolyte. x As this type of gas sensor, a plurality of electrode pads are provided on the rear end side of the opposing main surfaces of the plate-shaped sensor element, and terminal fittings are electrically contacted to each of these electrode pads to extract the sensor output signal from the sensor element to the outside (Patent Document 1).

[0003] In the gas sensor of Patent Document 1, each terminal fitting is held by a two-piece insulating connector (separator). This connector houses each terminal fitting in a box-shaped housing of the same shape, and the respective housings are fixed together with a metal clamp. Then, when the rear end side of the sensor element is inserted into the insertion hole of the connector, the terminal fitting inside the connector comes into electrical contact with the electrode pad. On the other hand, at the rear end side of the connector, the insertion hole faces the rear end-facing surface and expands in the radially outer direction in a direction perpendicular to the main surface of the sensor element. Thereby, interference between the terminal fitting drawn out to the rear end side of the connector and the inner surface of the connector is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, it has been found that if the rear end side of the connector has an enlarged diameter, the distance between the terminal fitting and the connector increases, and the terminal fitting is likely to swing and break within the connector due to vibrations during the use of the gas sensor. Therefore, an object of the present invention is to provide a gas sensor that suppresses breakage of the terminal fitting on the rear end side of the separator.

Means for Solving the Problems

[0006] To solve the above problems, the gas sensor of the present invention includes a plate-shaped sensor element that extends in the axial direction and has an electrode pad on the main surface on the rear end side, a terminal fitting that extends in the axial direction and is electrically connected to the electrode pad, a separator that has a housing portion that penetrates in the axial direction and houses the rear end side of the sensor element and the terminal fitting, and holds the terminal fitting, and a grommet that is disposed on the rear end side of the separator. The housing portion has a tapered surface that expands in a direction perpendicular to the main surface as it faces the rear end-facing surface of the separator. The grommet has a protruding portion on the tip side, and along the axial direction, the tip of the protruding portion is fitted into the rear end side of the separator more than the tip of the tapered surface, and the terminal fitting is in contact with the protruding portion.

[0007] According to this gas sensor, the protruding portion provided on the tip side of the grommet fits into the inside of the separator, so that the terminal fitting is brought into contact with the protruding portion. As a result, since the terminal fitting is held by the protruding portion, the vibration of the terminal fitting is suppressed and the breakage of the terminal fitting can be suppressed.

[0008] In the gas sensor of the present invention, the tip of the protruding portion may be fitted into the inside of the separator up to the tip side of the axial length L of the tapered surface by more than 1 / 2. According to this gas sensor, the protruding portion can be brought into further contact with the terminal fitting.

[0009] In the gas sensor of the present invention, the protruding portion has a grommet hole into which the terminal fitting is inserted, and the terminal fitting may abut against the protruding portion inside the grommet hole.

[0010] In the gas sensor of the present invention, the side surface of the protruding portion may narrow toward the tip side along the tapered surface, and the terminal fitting may be sandwiched between the side surface of the protruding portion and the tapered surface.

[0011] In the gas sensor of the present invention, the protruding portion may be arranged inside the terminal fitting.

[0012] In the gas sensor of the present invention, the protruding portion may be arranged between the terminal fitting and the tapered surface.

Advantages of the Invention

[0013] According to this invention, a gas sensor that suppresses breakage of the terminal fitting on the rear end side of the separator can be obtained.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view taken along the direction of the axis O of the gas sensor (sensor) 10 according to the first embodiment of the present invention, FIG. 2 is a perspective view of the separator 50, FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2, and FIG. 4 is a perspective view of the connection terminal 71.

[0016] As shown in FIG. 1, the gas sensor 10 includes a sensor element 20 that measures a specific gas component in the gas to be measured, a protector 30 that protects the tip of the sensor element 20, and a sensor assembly 40 that includes a separator 50 that houses the rear end side of the sensor element 20. The gas sensor 10 is used, for example, to measure gas components such as NOx and O2 contained in the gas to be measured (exhaust gas) when attached to the exhaust pipe of a vehicle.

[0017] The sensor element 20 is an elongated plate-like element extending in the direction of the axis O, and is formed by laminating a ceramic substrate or the like made of an oxygen ion conductive solid electrolyte layer such as zirconia (ZrO2). Note that the end on the protector 30 side of the sensor element 20 is referred to as the tip, and the end on the separator 50 side is referred to as the rear end.

[0018] A plurality of electrode pads 21a and 21b (FIG. 3) are formed on the main surfaces 20m1 and 20m2 (FIGS. 2 and 3) on the rear end side of the sensor element 20. Specifically, as shown in FIG. 3, on one main surface 20m1 of the sensor element 20, a plurality of electrode pads 21a are arranged at intervals in the width direction of the sensor element 20. Similarly, on the other main surface 20m2 of the sensor element 20, a plurality of electrode pads 21b are arranged at intervals in the width direction of the sensor element 20. Note that the plurality of electrode pads may be arranged only on one of the main surfaces 20m1 or 20m2 of the sensor element 20. The electrode pads 21a and 21b are used to apply a voltage to the sensor element 20, output a detection signal of the sensor element 20, or supply power to a heater when the sensor element 20 has a heater.

[0019] As shown in FIG. 1, the protector 30 is arranged to surround the periphery of the tip of the sensor element 20. This protector 30 includes an inner protector 31 that covers the tip of the sensor element 20 and an outer protector 32 that covers the inner protector 31. The inner protector 31 is formed in a cylindrical shape and has an inner gas introduction hole 31a for introducing the gas to be measured into the tip of the sensor element 20. The outer protector 32 is formed in a bottomed cylindrical shape and has an outer gas introduction hole 32a for introducing the gas to be measured on the side surface. The inner protector 31 and the outer protector 32 are made of a metal such as SUS, for example.

[0020] The sensor assembly 40 includes a metal main fitting 41, a cylindrical inner cylinder 42 and an outer cylinder 46 welded and fixed to the main fitting 41, and a separator 50 connected to the rear end of the sensor element 20. The main fitting 41 is attached to, for example, an exhaust pipe of a vehicle by a male screw portion 41a. Inside the inner cylinder 42, a plurality of ceramic sleeves 43a to 43c and powder filling layers 44a and 44b such as talc filled between the ceramic sleeves 43a and 43b and between the ceramic sleeves 43b and 43c are enclosed, and these are sandwiched between a metal ring 45 and the inner wall of the main fitting 41 and sealed.

[0021] The outer cylinder 46 covers the inner cylinder 42, the sensor element 20, and the separator 50. Also, a grommet 47 made of rubber closes the opening on the rear end side of the outer cylinder 46. And a lead wire 48 is connected to the connection part 71g (Fig. 4) on the rear end side of the terminal fitting 71 by means of crimping or the like, and the lead wire 48 is drawn out to the outside from the rear end of the grommet 47 through a grommet hole 47a that penetrates the grommet 47 in the direction of the axis O. Note that the connection part 71g of the terminal fitting 71 and the lead wire 48 are inserted through the grommet hole 47a.

[0022] Next, the separator 50 will be described. As shown in Fig. 2, the separator 50 includes a first member 51a and a second member 51b made of ceramics such as an alumina sintered body, and a metal clamp 90 that sandwiches and fixes the first member 51a and the second member 51b. And the terminal fitting 71 is held by the first member 51a or the second member 51b, and the terminal fitting 71 is arranged so as to be in one-to-one opposition and contact with the electrode pads 21a and 21b of the sensor element 20.

[0023] The first member 51a and the second member 51b each hold four terminal fittings 71 arranged side by side in the width direction orthogonal to the longitudinal direction of the terminal fitting 71 (= the direction of the axis O). Since the first member 51a and the second member 51b have the same box shape, the same reference numerals will be given to the same components for description. Also, the first member 51a and the second member 51b are collectively referred to as the housing 51. The housing 51 includes a housing part 50h that penetrates in the direction of the axis O, four locking grooves 52 that lock the tip side of the terminal fitting 71, four insertion holes 53 into which the upright part 71d at the center of the terminal fitting 71 is inserted, and locking parts 54 that are formed in each insertion hole 53 and lock the terminal fitting 71.

[0024] Further, the housing 51 is provided with a convex portion 55 on one side surface in the width direction with the sensor element 20 interposed therebetween, and is provided with regulating members 56 and 57 for regulating the distance in the thickness direction between the first member 51a and the second member 51b on the other side surface (see FIG. 2). The convex portion 55 is inserted into a recess between the regulating member 56 and the regulating member 57 of the opposing housing 51, thereby regulating the relative position in the thickness direction between the first member 51a and the second member 51b.

[0025] As shown in FIG. 4, the terminal fitting 71 is a metal member held by the housing 51 at a position facing the electrode pads 21a and 21b of the sensor element 20 one-to-one, and has a plate-shaped main body portion 71f. The main body portion 71f has a tip portion 71a locked to the locking groove 52 by a curved shape, a protruding portion 71b curved and protruding toward the sensor element 20, a contact portion 71c curved and protruding toward the sensor element 20 to contact the electrode pads 21a and 21b, and an upright portion 71d inserted into the insertion hole 53. Further, the rear end side of the main body portion 71f is integrally provided with a connection portion 71g for crimping and holding a plurality of core wires 48a of the lead wire 48 outside the separator 50. The rear end side of the upright portion 71d of the terminal fitting 71 is drawn out to the outside of the separator 50.

[0026] The protruding portion 71b and the contact portion 71c are arranged along the longitudinal direction of the terminal fitting 71, and the contact portion 71c is arranged at a position closer to the connection portion 71g than the protruding portion 71b. Both the protruding portion 71b and the contact portion 71c are formed to be elastically deformable. The upright portion 71d is provided with a locking portion 71e locked to the locking portion 54 by a curved shape. Note that the contact portion 71c of the terminal fitting 71 held by the first member 51a contacts the electrode pad 21a of the sensor element 20 one-to-one, and the contact portion 71c of the terminal fitting 71 held by the second member 51b contacts the electrode 21b of the sensor element 20 one-to-one (FIG. 3). On the other hand, as shown in FIG. 3, the electrode pads 21a and 21b are formed from the rear end of the sensor element 20 to a position between the contact portion 71c and the protruding portion 71b.

[0027] As shown in Fig. 2, the clamp 90 is formed by bending a plate-shaped metal and has an elastic force capable of sandwiching the first member 51a and the second member 51b and pressing them in a direction approaching each other. When the first member 51a and the second member 51b are sandwiched by this elastic force, the regulating members 56 and 57 of the first member 51a come into contact with the second member 51b and the regulating members 56 and 57 of the second member 51b come into contact with the first member 51a. Thereby, the distance between the first member 51a and the second member 51b is fixed.

[0028] Further, when the clamp 90 sandwiches the first member 51a and the second member 51b with the sensor element 20 and the terminal fitting 71 sandwiched between the first member 51a and the second member 51b so that the contact portion 71c of the terminal fitting 71 faces the electrode pads 21a and 21b of the sensor element 20, the protruding portions 71b and the contact portion 71c are elastically deformed by the pressing force from the clamp 90 to sandwich and fix the sensor element 20. At this time, by elastically deforming and pressing the protruding portions 71b and the contact portion 71c, the sensor element 20 can be surely sandwiched and fixed. Further, since the contact portion 71c is elastically deformed, the electrical contact between the contact portion 71c and the electrode pads 21a and 21b can be more surely maintained.

[0029] Next, the characteristic part of the present invention will be described. First, as shown in Fig. 3, the separator 50 has a housing portion 50h penetrating in the direction of the axis O, and the housing portion 50h houses the rear end side of the sensor element 20 and the terminal fitting 71. More specifically, the housing portion 50h opens in a rectangular shape slightly larger than the outer shape of the sensor element 20 at the front end surface of the housing 51 and communicates with each insertion hole 53 at the rear end side thereof. The housing portion 50h may be an insertion hole that opens only at the front end and the rear end of the housing 51. In this example, the housing portion 50h is formed by recessing a part of the opposing surfaces of the first member 51a and the second member 51b, respectively.

[0030] Furthermore, the accommodating portion 50h has a tapered surface 50s that expands in diameter in a direction (the vertical direction in FIG. 3) perpendicular to the two main surfaces 20m1 and 20m2 of the sensor element 20 as it faces the rear-end-facing surface of the separator 50. Note that "in a direction perpendicular to the main surfaces 20m1 and 20m2" means that it only needs to have a direction component perpendicular to the main surfaces 20m1 and 20m2, and includes cases where the degree of diameter expansion of the tapered surface 50s varies depending on the location. For example, those where the tapered surface 50s is not parallel to the main surfaces 20m1 and 20m2, those where the tapered surface 50s is a curved surface, those where the tapered surface 50s itself is parallel to the main surfaces 20m1 and 20m2 but the leading-edge or trailing-edge of the tapered surface 50s is not parallel to the main surfaces 20m1 and 20m2 (where the lengths and positions of the line segments when the tapered surface 50s is cut along the main surfaces 20m1 and 20m2 are different), etc. are also included.

[0031] On the other hand, in this example, the terminal fitting 71 is plate-shaped and the plate surface faces the main surfaces 20m1 and 20m2 of the sensor element 20. Since the plate-shaped terminal fitting 71 swings in a direction perpendicular to the plate surface, due to vibrations during the use of the gas sensor 10 etc., the terminal fitting 71 swings in a direction (the V direction in FIG. 3) perpendicular to the main surfaces 20m1 and 20m2 and is likely to break.

[0032] Therefore, as shown in FIG. 1, by fitting the protruding portion 47p provided on the tip side of the grommet 47 into the inside of the separator 50, the terminal fitting 71 is brought into contact with the protruding portion 47p. As a result, since the terminal fitting 71 is held by the protruding portion 47p, the vibration of the terminal fitting 71 is suppressed and the breakage of the terminal fitting 71 can be suppressed.

[0033] Referring to FIGS. 5 and 6, the function of the protruding portion 47p of the grommet 47 will be described in more detail. FIG. 5 is a perspective view of the grommet 47 as viewed from the tip side, and FIG. 6 is a partially enlarged cross-sectional view around the grommet 47 and the separator 50.

[0034] As shown in FIG. 5, eight protruding portions 47p standing upright in a U-shape are formed on the tip side of the grommet 47. Here, as shown in FIG. 2, in this example, four (a total of eight) terminal fittings 71 are arranged on the main surfaces 20m1 and 20m2 of the sensor element 20, respectively. And each terminal fitting 71 is inserted into a grommet hole 47a (FIG. 1). Each protruding portion 47p is arranged so as to surround each grommet hole 47a and so that a U-shaped opening faces the radially inner side of the grommet 47.

[0035] Then, as shown in FIG. 6(a), the terminal fitting 71 that has been previously assembled to the separator 50 and to which the lead wire 48 is crimped at the connecting portion 71g is inserted into the grommet hole 47a from the tip side of the grommet 47. Here, the grommet hole 47a has a hole diameter through which the connecting portion 71g with a larger diameter can be inserted, and since the main body portion 71f (thick line in FIG. 6) of the terminal fitting 71 is thinner than the connecting portion 71g, it is offset to the radially inner side of the grommet hole 47a. That is, before the protruding portion 47p is fitted into the separator 50, there is a gap between the side wall on the radially outer side of the protruding portion 47p and the main body portion 71f, and the terminal fitting 71 is not held by the protruding portion 47p.

[0036] Furthermore, as shown in FIG. 6(b), when the grommet 47 is further advanced, the protruding portion 47p is fitted into the separator 50, and the side wall on the radially outer side of the protruding portion 47p is deformed (bent) radially inward along the tapered surface 50s of the separator 50 so as to contact the terminal fitting 71. Here, along the direction of the axis O, the tip of the protruding portion 47p is fitted into the separator 50 on the rear end side with respect to the tip of the tapered surface 50s. Thereby, the protruding portion 47p can be surely deformed and brought into contact with the terminal fitting 71. In particular, it is preferable that when the tip of the protruding portion 47p is fitted into the separator 50 up to the tip side of more than 1 / 2 of the length L of the tapered surface 50s in the direction of the axis O, the protruding portion 47p can be further brought into contact with the terminal fitting 71.

[0037] Thus, in the first embodiment, the protruding portion 47p has a grommet hole 47a (surrounding the grommet hole 47a), and the terminal fitting 71 is adapted to contact the protruding portion 47p inside the grommet hole 47a. FIG. 7 shows a grommet 47 according to a modification of the first embodiment, in which a cylindrical protruding portion 47p2 surrounds the periphery of each grommet hole 47a.

[0038] Next, referring to FIGS. 8 and 9, a second embodiment of the present invention will be described. FIG. 8 is a perspective view of a grommet 147 of the second embodiment as viewed from the tip side, and FIG. 9 is a partially enlarged cross-sectional view of the periphery of the grommet 147 and the separator 50 in the second embodiment. Note that the second embodiment is the same as the first embodiment except for the configuration of the grommet 147. Therefore, the same reference numerals are given to the remaining configurations, or the illustration and description thereof are omitted. Also, FIGS. 8 and 9 correspond to FIGS. 5 and 6 of the first embodiment.

[0039] As shown in FIG. 8, one protruding portion 147p protruding in a substantially cylindrical shape is formed at the center of the tip side of the grommet 147. The side surface of the corner portion of the protruding portion 147p is chamfered and has a tapered shape that narrows toward the tip along the tapered surface 50s.

[0040] Then, as shown in FIG. 9(a), the terminal fitting 71, which is pre-assembled to the separator 50 and to which the lead wire 48 is crimped at the connecting portion 71g, is inserted into the grommet hole 147a from the tip side of the grommet 147.

[0041] Furthermore, as shown in FIG. 9(b), when the grommet 147 is further advanced, the protruding portion 147p is fitted into the separator 50. At this time, the terminal fitting 71 contacts the protruding portion 147p (side surface) and the tapered surface 50s, deforms into a shape along the protruding portion 147p and the tapered surface 50s, and is sandwiched therebetween. Also in the second embodiment, along the direction of the axis O, the tip of the protruding portion 147p is fitted inside the rear end side of the tip of the tapered surface 50s. As a result, the terminal fitting 71 can be surely brought into contact with the protruding portion 147p.

[0042] In this way, in the second embodiment, the side surface of the protruding portion 147p tapers toward the tip side along the tapered surface 50s, and the terminal fitting 71 is sandwiched between the side surface of the protruding portion 147p and the tapered surface 50s.

[0043] Next, referring to FIGS. 10 and 11, a third embodiment of the present invention will be described. FIG. 10 is a perspective view of the grommet 247 of the third embodiment as viewed from the tip side, and FIG. 11 is a partially enlarged cross-sectional view of the periphery of the grommet 247 and the separator 50 in the third embodiment. Note that the third embodiment is the same as the first embodiment except that the configuration of the grommet 247 is different. Therefore, the same reference numerals are given to the remaining configurations, or the illustration and description thereof are omitted. Moreover, FIGS. 10 and 11 correspond to FIGS. 5 and 6 for the first embodiment.

[0044] As shown in FIG. 10, one protruding portion 247p protruding in a substantially cylindrical shape is formed at the center of the tip side of the grommet 247. This protruding portion 247p does not chamfer the corner portion of the protruding portion 147p of the second embodiment and has a smaller diameter than the protruding portion 147p.

[0045] Then, as shown in FIG. 11(a), the terminal fitting 71 that has been previously assembled to the separator 50 and to which the lead wire 48 is crimped to the connecting portion 71g is inserted into the grommet hole 247a from the tip side of the grommet 247.

[0046] Furthermore, as shown in FIG. 11(b), when the grommet 247 is further advanced, the protruding portion 247p is fitted into the separator 50. At this time, the terminal fitting 71 is pressed toward the protruding portion 247p (toward the right side in FIG. 11(b)) while contacting the tapered surface 50s and comes into contact with the protruding portion 247p. Also in the third embodiment, along the direction of the axis O, the tip of the protruding portion 247p is inserted into the rear end side of the tip of the tapered surface 50s. Thereby, the terminal fitting 71 can be surely brought into contact with the protruding portion 247p. In the third embodiment, in the radial direction, the protruding portion 247p and the tapered surface 50s are separated from each other.

[0047] Thus, in the third embodiment, the protruding portion 247p is disposed inside the terminal fitting 71.

[0048] Next, with reference to FIGS. 12 and 13, a fourth embodiment of the present invention will be described. FIG. 12 is a perspective view of the grommet 347 of the fourth embodiment as viewed from the tip side, and FIG. 13 is a partial enlarged cross-sectional view around the grommet 347 and the separator 50 in the fourth embodiment. The fourth embodiment is the same as the first embodiment except that the configuration of the grommet 347 is different. Therefore, for the remaining configurations, the same reference numerals are given, the illustration is omitted, and the description is omitted. Further, FIGS. 12 and 13 are views corresponding to FIGS. 5 and 6 of the first embodiment.

[0049] As shown in FIG. 12, on the tip side of the grommet 347, one protruding portion 347p protruding in a rectangular frame shape so as to surround eight grommet holes 347a is formed.

[0050] Then, as shown in FIG. 13(a), the terminal fitting 71, which is assembled to the separator 50 in advance and to which the lead wire 48 is crimped to the connection portion 71g, is inserted through the grommet hole 347a from the tip side of the grommet 347.

[0051] Further, as shown in FIG. 13(b), when the grommet 347 is further advanced, the protruding portion 347p is inserted into the separator 50. At this time, the outer wall of the protruding portion 347p is pressed toward the terminal fitting 71 (toward the right side in FIG. 13(b)) while contacting the tapered surface 50s, and contacts the terminal fitting 71. Also in the fourth embodiment, along the direction of the axis O, the tip of the protruding portion 347p is inserted into the rear end side rather than the tip of the tapered surface 50s. Thereby, the terminal fitting 71 can be reliably brought into contact with the protruding portion 347p. In the fourth embodiment, contrary to the first embodiment, the main body portion 71f is arranged so as to face the radially outer side with respect to the connecting portion 71g of the terminal fitting 71. Thereby, the terminal fitting 71 can be brought into contact with the protruding portion 347p by simply pressing the protruding portion 347p a little. Of course, the main body portion 71f may be arranged so as to face the radially inner side with respect to the connecting portion 71g, and the protruding portion 347p may be further pressed and deformed.

[0052] Thus, in the fourth embodiment, the protruding portion 347p is disposed between the terminal fitting 71 and the tapered surface 50s. In the second to fourth embodiments, although the tip of the protruding portion is inserted into the inside of the separator 50 up to the tip side rather than 1 / 2 of the length L in the axis O direction of the tapered surface, the present invention is not limited thereto.

[0053] Needless to say, the present invention is not limited to the above embodiments, and various modifications and equivalents included in the spirit and scope of the present invention are covered. The shape, position, and number of the protruding portions are not limited. The separator 50 is not limited to a two-part box shape, and may be a cylindrical shape such as a cylinder.

Explanation of reference numerals

[0054] 10 Gas sensor 20 Sensor element 20m1, 20m Main surfaces of the sensor element 21a, 21b Electrode pads 47, 147, 247, 347 Grommet 47p, 47p2, 147p, 247p, 347p Protruding portion 47a, 147a, 247a, 347a Grommet hole 50 Separator 50h Accommodating portion 50s Tapered surface 71 Terminal fitting O axis

Claims

1. A plate-shaped sensor element extending in the axial direction and having electrode pads on the main surface on the rear end side, A terminal fitting extending in the axial direction and electrically connected to the electrode pads, A separator having a housing portion that penetrates in the axial direction and houses the rear end side of the sensor element and the terminal fitting, and holds the terminal fitting, A grommet disposed on the rear end side of the separator, A gas sensor comprising: The housing portion has a tapered surface that expands in diameter in a direction perpendicular to the main surface as it faces the rear end-facing surface of the separator, The grommet has a protrusion on the tip side, and along the axial direction, the tip of the protrusion is fitted inside the separator on the rear end side of the tip of the tapered surface, The gas sensor, wherein the terminal fitting abuts against the protrusion.

2. The gas sensor according to claim 1, wherein the tip of the protrusion is fitted inside the separator up to a position on the tip side of half of the axial length L of the tapered surface.

3. The protrusion has a grommet hole into which the terminal fitting is inserted, The gas sensor according to claim 1 or 2, wherein the terminal fitting abuts against the protrusion inside the grommet hole.

4. The side surface of the protrusion narrows toward the tip side along the tapered surface, The gas sensor according to claim 1 or 2, wherein the terminal fitting is sandwiched between the side surface of the protrusion and the tapered surface.

5. The gas sensor according to claim 1 or 2, wherein the protrusion is disposed inside the terminal fitting.

6. The gas sensor according to claim 1 or 2, wherein the protrusion is disposed between the terminal fitting and the tapered surface.

Images