JP4628897B2

JP4628897B2 - Sensor

Info

Publication number: JP4628897B2
Application number: JP2005233793A
Authority: JP
Inventors: 康司松尾; 恵一野田; 裕一山田
Original assignee: NGK Spark Plug Co Ltd
Current assignee: Niterra Co Ltd
Priority date: 2005-08-11
Filing date: 2005-08-11
Publication date: 2011-02-09
Anticipated expiration: 2025-08-11
Also published as: JP2007047093A

Description

本発明は、排気ガスなどの被測定ガス中の特定ガス濃度を検出するための酸素センサやＮＯｘセンサ、ＨＣセンサといったガスセンサ、或いは被測定ガスの温度を検出するための温度センサなどのように、測定対象検出用のセンサ素子を備えてなるセンサに関する。 The present invention is a gas sensor such as an oxygen sensor, a NOx sensor, or an HC sensor for detecting a specific gas concentration in a measured gas such as exhaust gas, or a temperature sensor for detecting the temperature of the measured gas. The present invention relates to a sensor including a sensor element for detecting a measurement object.

従来より、ガスセンサ素子、或いは温度センサの感温素子のように、軸線方向に延びる長寸の板状或いは棒状をなす各種のセンサ素子（以下、単に素子ともいう）を用いた各種のセンサがある。このようなセンサ（例えば酸素センサ）は、例えばエンジンの排気ガス管に取付けられるネジ部を備えて筒状に形成された金具本体（主体金具）の内部に、センサ素子を、その先端側に形成された検出部を金具本体の先端から突出させ、後端寄り部位を同金具本体の後端側から突出させるようにして固定している。このようなセンサでは、通常、その素子の後端寄り部位の両側部表面に、検出出力の取り出し用の電極端子や、素子に形成されたヒーターへの通電用などの電極端子を含めた複数の電極端子（端子電極）を素子の幅方向（横方向）に絶縁間隔をおいて備えている。そして、これらの各電極端子と、センサの外部に引き出されるリード線との電気的な接続は、その各電極端子に、各リード線の先端に接続された端子金具（金属端子又はリードフレーム）をそのバネ性を用いて押付けるようにして当接ないし圧接するようにしたものがある（特許文献１，２）。このような端子金具は、各リード線の先端にその一端が取付けられ、例えば先端において折返し状（例えばＵ字状）に曲げられた板バネをなすＵ字部のうちの一方の脚片を電極端子に押付ける接続部（以下、電極接続部という）としている。 Conventionally, there are various sensors using various sensor elements (hereinafter also simply referred to as elements) having a long plate shape or rod shape extending in the axial direction, such as a gas sensor element or a temperature sensing element of a temperature sensor. . Such a sensor (for example, an oxygen sensor) has, for example, a sensor element formed on the tip side inside a metal fitting body (main metal fitting) formed in a cylindrical shape with a screw portion attached to an exhaust gas pipe of an engine. The detection portion thus made protrudes from the front end of the metal fitting body, and the rear end portion is fixed so as to protrude from the rear end side of the metal fitting main body. In such a sensor, normally, a plurality of electrode terminals including an electrode terminal for taking out a detection output and an electrode terminal for energizing a heater formed in the element are formed on both side surfaces near the rear end of the element. Electrode terminals (terminal electrodes) are provided with an insulation interval in the width direction (lateral direction) of the element. The electrical connection between each of these electrode terminals and the lead wire drawn out of the sensor is achieved by connecting a terminal fitting (metal terminal or lead frame) connected to the tip of each lead wire to each of the electrode terminals. There is one that uses the spring property to make contact or press contact (Patent Documents 1 and 2). Such a terminal fitting has one end attached to the tip of each lead wire, for example, one leg piece of a U-shaped portion that forms a leaf spring bent at the tip in a folded shape (for example, U-shape). A connecting portion (hereinafter referred to as an electrode connecting portion) pressed against the terminal is used.

このような端子接続構造においては、図１１−Ａに示したように、複数のリード線（図示せず）の各先端にそれぞれ接続した端子金具５１を、セラミック等の絶縁材からなり筒状に形成された端子金具保持部材（セパレータともいわれる）７１の内側に絶縁を保持して対向状に配置しておき、その対向する端子金具５１の相互間に、上記したセンサ素子２１を、その後端２７側から、同図−Ｂに示したように、同素子２１の長手方向に相対的に挿入することによって、端子金具５１のそれぞれを外向きに弾性変形（圧縮）させて同素子２１の側部表面の各電極端子２５に押付けられるようにされている。すなわち、素子２１の端子金具保持部材７１内への挿入（以下、素子の挿入又は単に挿入とも言う）によって、各端子金具５１をそれ自身のバネ性により外側に押し広げるようにし、対向する端子金具５１間で素子２１の側部表面に形成された各電極端子２５の部位を挟み付けるようにして、両者の電気的な導通をとる構成とされている。 In such a terminal connection structure, as shown in FIG. 11-A, the terminal fittings 51 respectively connected to the respective ends of a plurality of lead wires (not shown) are made of an insulating material such as ceramic and formed into a cylindrical shape. The formed terminal fitting holding member (also referred to as a separator) 71 is insulated and held in an opposing manner, and the sensor element 21 is placed between the opposing terminal fittings 51 between the rear end 27. From the side, as shown in FIG. 5B, the terminal fitting 51 is elastically deformed (compressed) outward by being relatively inserted in the longitudinal direction of the element 21, and the side portion of the element 21. It is configured to be pressed against each electrode terminal 25 on the surface. That is, by inserting the element 21 into the terminal fitting holding member 71 (hereinafter also referred to as element insertion or simply insertion), each terminal fitting 51 is pushed outward by its own spring property, and the terminal fittings facing each other. A portion of each electrode terminal 25 formed on the side surface of the element 21 is sandwiched between 51 so as to establish electrical continuity between them.

ところで、このような端子接続構造に使用される端子金具保持部材７１においては、図１２の横断面図に示したようにその内側面７５において凸となし、端子金具５１が相互に絶縁が保持されて配置されるように絶縁用仕切り壁７６，７７が、図１１に示したように、端子金具保持部材７１の軸線方向に沿って設けられている。そして、その絶縁用仕切り壁７６，７７を介して隣り合う端子金具５１を相互に絶縁を保持した上で、対向する端子金具５１、５１相互間の素子挿入用空孔７２に素子２１が挿入されるように形成されている。ここで、対向する絶縁用仕切り壁７６，７７の相互間（向き合う端面相互の間）の寸法Ｌ１、及び素子２１の幅Ｗ方向を規制する素子挿入用空孔７２の幅寸法Ｌ２は、それぞれ素子２１の厚みＴ又は幅Ｗより若干大き目とされるが、端子金具相互間の絶縁の確実性と共に素子２１の位置精度を高めるため、Ｌ１は素子２１の厚みＴに対して０．３ｍｍ〜０．７ｍｍ大きめとされる程度であり、Ｌ２は素子２１の幅Ｗに対して０．１ｍｍ〜０．５ｍｍ大きめとされる程度であり、その隙間は小さい。 Incidentally, in the terminal fitting holding member 71 used in such a terminal connection structure, as shown in the cross-sectional view of FIG. 12, the terminal fitting 51 is convex on the inner side surface 75, and the terminal fitting 51 is held insulated from each other. Insulating partition walls 76 and 77 are provided along the axial direction of the terminal fitting holding member 71 as shown in FIG. The adjacent terminal fittings 51 are insulated from each other via the insulating partition walls 76 and 77, and the element 21 is inserted into the element insertion hole 72 between the opposing terminal fittings 51 and 51. It is formed so that. Here, the dimension L1 between the opposing insulating partition walls 76 and 77 (between facing end faces) and the width dimension L2 of the element insertion hole 72 that regulates the width W direction of the element 21 are respectively The thickness L is slightly larger than the thickness T or the width W of the element 21, but in order to increase the positional accuracy of the element 21 as well as the reliability of insulation between the terminal fittings, L1 is 0.3 mm to. L2 is about 7 mm larger, L2 is about 0.1 mm to 0.5 mm larger than the width W of the element 21, and the gap is small.

一方、このような端子接続構造を得るには、素子２１の後端寄り部位を金具本体の後端側から突出させるようにした半組立体と、端子金具５１を内側に絶縁を保持して配置してなる端子金具保持部材７１を含む半組立体とを同軸状に位置決めし、その状態において、端子金具保持部材７１内において対向する端子金具５１の相互間に、センサ素子２１をその後端２７側から相対的に挿入することが行われる（図９参照）。ところが、上記したように、素子２１の各部寸法Ｔ，Ｗに対し、素子挿入用空孔７２の各部寸法Ｌ１，Ｌ２は僅かに大きいだけである。このため、この素子２１の挿入において、各半組立体の組立上の誤差（心ずれ等）により、図１３−Ａ，Ｂの模式図に示したように、素子挿入用空孔７２に対し、素子２１の心（軸）ずれ誤差や素子２１の軸線回りの回転等があると、素子２１の後端の一部が絶縁用仕切り壁７６，７７の先端向き面（先端面）７６ａ，７７ａに衝突して、その挿入ができないことや、その挿入が困難となることがある。 On the other hand, in order to obtain such a terminal connection structure, a semi-assembly in which a portion near the rear end of the element 21 protrudes from the rear end side of the metal fitting body, and the terminal metal fitting 51 are arranged with insulation inside. In this state, the sensor element 21 is positioned on the rear end 27 side between the opposing terminal fittings 51 in the terminal fitting holding member 71. Is inserted relatively (see FIG. 9). However, as described above, the dimensions L1 and L2 of the element insertion hole 72 are only slightly larger than the dimensions T and W of the element 21. For this reason, in the insertion of the element 21, due to assembly errors (center misalignment, etc.) of each subassembly, as shown in the schematic diagrams of FIGS. If there is an error in the center (axis) of the element 21 or rotation around the axis of the element 21, a part of the rear end of the element 21 becomes the tip-facing surfaces (tip faces) 76 a and 77 a of the insulating partition walls 76 and 77. Collisions can make it impossible to insert or make it difficult to insert.

この対策としては、図１４に示したように、端子金具保持部材（以下、単に保持部材ともいう）７１の絶縁用仕切り壁７６，７７の先端向き面７６ａ，７７ａを、保持部材７１の後端側に向けて傾斜する傾斜面とすることが考えられる（特許文献１、２）。このようにしておけば、素子２１の後端２７の一部が絶縁用仕切り壁（特許文献１、２における絶縁リブ）７６，７７の先端向き面７６ａ，７７ａに衝突したとしても、その傾斜面にガイドされるため、素子２１の挿入が可能或いは容易となる。すなわち、このように絶縁用仕切り壁７６，７７の先端向き面に傾斜面を設けておくことにより、素子２１の挿入において、それが図１４中に２点差線で示したように、素子挿入用空孔７２に対して多少心ずれしていたとしても、素子２１の後端が絶縁用仕切り壁の傾斜面をなす先端向き面７６ａ，７７ａに衝突した後、その傾斜面に案内される形で同空孔７２内に導き入れることができるためである。
特開２００１−１８８０６０号公報図１特開２００２−２９６２２３号公報図１ As countermeasures against this, as shown in FIG. 14, the front-facing surfaces 76 a and 77 a of the insulating partition walls 76 and 77 of the terminal metal fitting holding member (hereinafter also simply referred to as holding member) 71 are used as the rear end of the holding member 71. It is conceivable that the inclined surface is inclined toward the side (Patent Documents 1 and 2). In this way, even if a part of the rear end 27 of the element 21 collides with the tip-facing surfaces 76a and 77a of the insulating partition walls (insulating ribs in Patent Documents 1 and 2) 76 and 77, the inclined surface thereof. Therefore, it is possible or easy to insert the element 21. That is, by providing an inclined surface on the tip-facing surfaces of the insulating partition walls 76 and 77 as described above, when the element 21 is inserted, as indicated by a two-dot chain line in FIG. Even if the center is slightly deviated from the hole 72, the rear end of the element 21 collides with the front-facing surfaces 76a and 77a forming the inclined surface of the insulating partition wall, and is guided by the inclined surface. This is because it can be introduced into the hole 72.
Japanese Patent Laid-Open No. 2001-188060 FIG. JP 2002-296223 A FIG.

ところが、図１４或いは特許文献１、２に示されるように、絶縁用仕切り壁７６，７７の先端向き面（先端面）７６ａ，７７ａの全体を傾斜面とした場合には、次のような解決すべき課題があった。このように先端向き面（先端面）７６ａ，７７ａの全体を傾斜面とした場合には、その傾斜の分、絶縁用仕切り壁７６，７７の先端においては同壁が存在しないことになる。一方、この種のセンサに使用される端子金具５１は、その先端５６において、折返し状（例えばＵ字状）に曲げられた板バネからなるものが、その壁相互間に配置される。この端子金具５１の先端５６は、素子２１の挿入におけるガイドをなすように外広がり状にされるが、そのＵ字部の折り返しをなす先端５６の部位は、傾斜に対応して先端向き面（先端面）７６ａ，７７ａから飛び出た形態となってしまう。このように、その先端５６のうち、先端向き面（先端面）７６ａ，７７ａより飛び出している部位は、絶縁用仕切り壁７６，７７による規制が不十分となる。このため、その先端５６は、素子２１の挿入時の横向き力や、挿入後における端子金具５１の横振れ等により、その壁を挟んで反対側に配置されている端子金具５１の先端５６に接触してしまう可能性があり、絶縁不良を招く危険性があるという重大な問題があった。そして、ガイド性は、素子２１の挿入方向と、各先端向き面（先端面）７６ａ，７７ａとのなす傾斜角が小さい程高められるのであるが、そのようにする程こうした問題は大きくなる。 However, as shown in FIG. 14 or Patent Documents 1 and 2, when the whole of the tip-facing surfaces (tip surfaces) 76a and 77a of the insulating partition walls 76 and 77 are inclined surfaces, the following solution is provided. There were issues to be addressed. As described above, when the entire tip-facing surfaces (tip surfaces) 76a and 77a are inclined surfaces, the walls do not exist at the tips of the insulating partition walls 76 and 77 corresponding to the inclination. On the other hand, the terminal metal fitting 51 used for this type of sensor has a tip spring 56 made of a leaf spring bent in a folded shape (for example, a U-shape), and is disposed between the walls. The distal end 56 of the terminal fitting 51 is outwardly extended so as to serve as a guide for the insertion of the element 21, but the portion of the distal end 56 that turns back the U-shaped portion corresponds to the tip-facing surface ( It will become the form which protruded from the front-end | tip surfaces 76a and 77a. As described above, in the tip 56, the portion protruding from the tip facing surfaces (tip surfaces) 76 a and 77 a is not sufficiently restricted by the insulating partition walls 76 and 77. For this reason, the tip 56 contacts the tip 56 of the terminal fitting 51 arranged on the opposite side across the wall due to a lateral force when the element 21 is inserted, a lateral deflection of the terminal fitting 51 after the insertion, or the like. There is a serious problem that there is a risk of causing insulation failure. The guide property is enhanced as the inclination angle formed between the insertion direction of the element 21 and each of the tip-facing surfaces (tip surfaces) 76a and 77a is decreased.

こうした問題を解決するためには、端子金具５１をその先端５６が絶縁用仕切り壁７６、７７の先端向き面７６ａ、７７ａより突出しないように、その端子金具５１自体を端子金具保持部材７１の奥所にずらせばよいわけである。しかし、そのようにすれば端子金具保持部材７１の長大化を招き、ひいてはセンサ全体の長大化を招いてしまうことから、コンパクト化、軽量化の要請に反することとなってしまう。さらに、このように端子金具５１自体を端子金具保持部材７１の奥所にずらした場合には、ずらした分、素子２１の後端寄り部位２３における素子挿入用空孔７２内への挿入深さを大きくする必要がある。その結果、素子２１の後端の突出長を大きいものとすることになるため、素子自体の挿入時における折損の危険性が高くなるといった問題もある。 In order to solve such a problem, the terminal fitting 51 itself is placed behind the terminal fitting holding member 71 so that the tip 56 of the terminal fitting 51 does not protrude from the tip facing surfaces 76a and 77a of the insulating partition walls 76 and 77. You just have to shift it. However, if this is done, the length of the terminal fitting holding member 71 will be increased, which in turn will increase the overall length of the sensor, which is against the demand for compactness and weight reduction. Further, when the terminal fitting 51 itself is shifted to the back of the terminal fitting holding member 71 in this way, the insertion depth into the element insertion hole 72 at the rear end portion 23 of the element 21 is the amount of the displacement. Need to be larger. As a result, since the protruding length of the rear end of the element 21 is increased, there is a problem that the risk of breakage when the element itself is inserted increases.

本発明は、上記した端子接続構造を有するセンサにおける、こうした問題点に鑑みてなされたもので、内部に複数の端子金具を絶縁を保持して配置してなる端子金具保持部材内に素子を挿入する際において、そのガイド性が得られると共に、絶縁用仕切り壁を挟んで配置される端子金具相互間のその先端同士の接触による絶縁不良の発生やセンサの長大化等の問題を招くことのない、センサを提供することをその目的とする。 The present invention has been made in view of such problems in the sensor having the above-described terminal connection structure, and an element is inserted into a terminal fitting holding member in which a plurality of terminal fittings are arranged so as to hold insulation. In this case, the guide property can be obtained, and there is no problem such as generation of insulation failure or lengthening of the sensor due to contact between the tips of the terminal fittings arranged with the insulating partition wall interposed therebetween. The object is to provide a sensor.

上記の目的を達成するため、請求項１に記載の発明は、複数の端子金具を内側に配置してなる絶縁材からなる端子金具保持部材内に、測定対象に向けられる先端側に検出部を備えかつ後端寄り部位の側部表面に複数の電極端子を備えてなる長寸のセンサ素子をその後端側からセンサ素子自身の長手方向に相対的に挿入することによって、前記端子金具のそれぞれが弾性変形して該センサ素子の側部表面の各電極端子に押付けられて接続されてなる端子接続構造を有するセンサであって、
前記端子金具保持部材が、その内側面において凸となし前記端子金具を相互に絶縁を保持して配置させる絶縁用仕切り壁をセンサ素子自身の長手方向に沿って備えているものにおいて、
該絶縁用仕切り壁の先端向き面のうち該絶縁用仕切り壁の前記内側面寄り部位に前記センサ素子の長手方向に対して略垂直をなす平坦面を設けると共に、該平坦面と該絶縁用仕切り壁における前記センサ素子の側部表面に対向する内側面とのなす角に面取りを設けてなり、
さらに、前記端子金具は、前記長手方向に延びる支持部を備えており、この支持部の先端において前記センサ素子側に向けて折り曲げられて折返し状をなすとともに、該センサ素子側に向けて凸となす円弧状に湾曲する湾曲部を備えており、この湾曲部の中間部が前記各電極端子に押付けられており、この状態において、前記絶縁用仕切り壁を挟んで配置される該端子金具の先端同士が接触しないように、前記端子金具の前記湾曲部を、前記面取りより前記センサ素子側に突出させない一方、前記端子金具の先端を、前記端子金具保持部材の前記平坦面より先端側に突出させたことを特徴とする。 In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a detection unit is provided on a distal end side directed to a measurement object in a terminal fitting holding member made of an insulating material in which a plurality of terminal fittings are arranged inside. Each of the terminal fittings is provided by inserting a long sensor element comprising a plurality of electrode terminals on the side surface of the part near the rear end and relatively inserting the sensor element from the rear end side in the longitudinal direction of the sensor element itself. A sensor having a terminal connection structure that is elastically deformed and pressed and connected to each electrode terminal on the side surface of the sensor element,
The terminal metal fitting holding member is provided with an insulating partition wall along the longitudinal direction of the sensor element itself so as to be convex on the inner surface thereof and to arrange the terminal metal fittings while maintaining insulation.
A flat surface that is substantially perpendicular to the longitudinal direction of the sensor element is provided at a portion of the insulating partition wall facing the inner surface of the insulating partition wall, the flat surface and the insulating partition. A chamfer is provided at an angle formed with an inner surface facing the side surface of the sensor element on the wall ,
Further, the terminal fitting includes a support portion extending in the longitudinal direction, and is bent toward the sensor element side at the tip of the support portion to form a folded shape, and is convex toward the sensor element side. A curved portion that is curved in an arc shape, and an intermediate portion of the curved portion is pressed against each of the electrode terminals, and in this state, the tip of the terminal fitting disposed across the insulating partition wall The curved portion of the terminal fitting is not protruded toward the sensor element side from the chamfering so that they do not contact each other, while the tip of the terminal fitting is protruded from the flat surface of the terminal fitting holding member to the tip side. It is characterized by that.

請求項２に記載の発明は、前記センサ素子は、その後端面と前記電極端子のある側部表面とのなす角に面取りが設けられていることを特徴とする請求項１に記載のセンサである。請求項３に記載の発明は、前記絶縁用仕切り壁及び前記センサ素子における前記面取りが傾斜面取りであり、そのセンサ素子自身の側部表面に対する傾斜角度をθ１とし、前記絶縁用仕切り壁の前記面取りにおける前記側部表面に対向する前記内側面に対する傾斜角度をθ２としたとき、θ１≦θ２としたことを特徴とする請求項２に記載のセンサである。 The invention according to claim 2 is the sensor according to claim 1, wherein the sensor element is provided with a chamfer at an angle formed by a rear end surface thereof and a side surface having the electrode terminal. . According to a third aspect of the present invention, the chamfering of the insulating partition wall and the sensor element is an inclined chamfer, and an inclination angle with respect to a side surface of the sensor element itself is θ1, and the chamfering of the insulating partition wall is performed. The sensor according to claim 2, wherein θ1 ≦ θ2 is satisfied, where θ2 is an inclination angle with respect to the inner side surface facing the side surface.

本発明においては、絶縁用仕切り壁の先端向き面の全体を傾斜させてガイドとすることなく、上記手段におけるように、該絶縁用仕切り壁の先端向き面のうち該絶縁用仕切り壁の前記内側面寄り部位（根元寄り部位）に前記センサ素子の長手方向に対して略垂直をなす平坦面を設けると共に、該平坦面と該絶縁用仕切り壁における前記センサ素子の側部表面に対向する内側面とのなす角に面取りを設けたものであることから、素子挿入時のガイド作用も得ることができる。すなわち、この種のセンサにおける端子金具の先端は、上記もしたように、折返し状に曲げられてなるのが普通であるが、本願発明におけるように、絶縁用仕切り壁の先端向き面の全体を傾斜させてガイドとすることなく、前記角に面取りを設けることでガイドとした場合には、その面取りを素子挿入における心ずれを吸収できる程度の適当な大きさとすることで、ガイドとしての支障も出ない。このように本発明においては、センサの長大化や、絶縁用仕切り壁を挟んで配置される端子金具の先端同士の接触による絶縁不良を招くこともなく、素子挿入におけるガイドとなすことができる、という特有の効果が得られる。 In the present invention, the inside of the insulating partition wall of the insulating partition wall of the insulating partition wall as in the above-mentioned means, without tilting the entire tip facing surface of the insulating partition wall as a guide. A flat surface that is substantially perpendicular to the longitudinal direction of the sensor element is provided at a side surface portion (base portion portion), and an inner surface that faces the side surface of the sensor element on the flat surface and the insulating partition wall Since the chamfering is provided at the angle formed by, a guide action at the time of element insertion can be obtained. That is, the tip of the terminal fitting in this type of sensor is usually bent in a folded shape as described above, but as in the present invention, the entire surface facing the tip of the partition wall for insulation is used. When the guide is formed by providing a chamfer at the corner without being inclined to be a guide, the chamfer is made to have an appropriate size that can absorb the misalignment in the element insertion, thereby preventing a problem as a guide. Does not appear. As described above, in the present invention, it is possible to serve as a guide for element insertion without causing an increase in the length of the sensor or inferior insulation due to contact between the tips of the terminal fittings arranged across the insulating partition wall. A unique effect is obtained.

前記センサ素子は、請求項２に記載のように、その後端面と前記電極端子のある側部表面とのなす角に面取りが付けられているとよい。センサ素子は、その基材がセラミック等の脆性材料から形成されるので、その挿入時に後端が絶縁用仕切り壁の先端向き面に衝突する際には亀裂やカケ等の損傷が発生しやすい。しかし、請求項２に記載のように、その後端に面取りをつけておけばそのような損傷の発生を有効に防止できる。加えて、その面取りが設けられている場合には、素子挿入時のガイド性も良くなるため、その挿入の円滑化が図られる。そして、この場合においては、請求項３に記載のように、θ１≦θ２なる関係とするのが好ましい。これは図１０−Ａに示したように、同図中の素子２１の挿入時における心ずれ（Ｚ）が大きく、素子２１の面取り２８が、絶縁用仕切り壁７６の面取り７６ｋにおける先端の角Ｐより外側（図左側）にはみ出ているような場合には、その角Ｐに衝突して、その角Ｐが欠けやすい。一方で、θ１≦θ２なる関係にあれば、図１０−Ｂに示したように、その角Ｐに衝突するのを回避できるため、その欠けを防止できるためである。 The sensor element may be chamfered at an angle formed between a rear end surface thereof and a side surface on which the electrode terminal is provided, as described in claim 2. Since the base material of the sensor element is formed from a brittle material such as ceramic, damage such as cracks or chipping is likely to occur when the rear end collides with the front-facing surface of the insulating partition wall during insertion. However, if the rear end is chamfered as described in claim 2, such damage can be effectively prevented. In addition, when the chamfering is provided, the guideability at the time of element insertion is improved, so that the insertion can be facilitated. In this case, it is preferable to have a relation of θ1 ≦ θ2 as described in claim 3. As shown in FIG. 10-A, the misalignment (Z) at the time of insertion of the element 21 in the figure is large, and the chamfer 28 of the element 21 has a tip angle P at the chamfer 76k of the insulating partition wall 76. When it protrudes to the outer side (left side in the figure), it collides with the corner P and the corner P tends to be missing. On the other hand, if there is a relationship of θ1 ≦ θ2, as shown in FIG. 10-B, it is possible to avoid colliding with the angle P, and thus to prevent the chipping.

以下、本発明のセンサを実施するための最良の形態について、図１〜図９に基づいて詳細に説明する。ただし、本形態では、排気ガス中の酸素濃度を検出する全領域空燃比センサにおいて具体化したものであり、したがって、まずこのセンサの全体について詳細に説明する。図中、１は全領域空燃比センサであり、筒状をなす金具本体１１（以下、単に本体１１ともいう）の内側に、測定対象に向けられる先端側（図示下側）に検出部（図示せず）２１ａを備えた長寸で、横断面が矩形をなす板状又は棒状のセラミックを主体として形成されたセンサ素子２１が気密を保持して固定されている。金具本体１１は、その内周面が下から順次大径となるように同心で段付円筒状に形成されており、外周面の下端寄り部位にはエンジンの排気管への固定用のネジ１２が形成されている。このような本体１１の内側であってセンサ素子２１の外側には同素子２１を気密を保持して固定する気密保持、固定手段が充填状に設けられている。この気密保持、固定手段は、本体１１の内側の下方の段部に内ツバが支持されてなる筒体３０が介挿され、その筒体３０の内側であってその内ツバの上に、下からアルミナから形成されたホルダ３１、シール材（本例では滑石）３２、３３が配置されている。そして、シール材３３の上にはスリーブ３５が配置され、リングワッシャ３６を介して、本体１１の後端寄り部位の円筒部１５に連設された薄肉のカシメ用円筒部１６を内側に折り曲げかつ先端側に圧縮し、内部のシール材３２、３３等を圧縮することで、素子２１を金具本体１１の内側に気密状に固定している。なお、スリーブ３５等の内側中央は、軸線Ｇ方向からみて横断面が素子２１の横断面に対応する矩形（長方形）穴とされ、素子２１が本体１１内において同軸状に固定されている。 Hereinafter, the best mode for carrying out the sensor of the present invention will be described in detail with reference to FIGS. However, this embodiment is embodied in an all-range air-fuel ratio sensor that detects the oxygen concentration in the exhaust gas. Therefore, the entire sensor will be described in detail first. In the figure, reference numeral 1 denotes an all-range air-fuel ratio sensor, which is arranged inside a cylindrical metal fitting body 11 (hereinafter also simply referred to as the main body 11), on the tip side (lower side in the figure) directed toward the measurement object (shown in the figure). A sensor element 21 mainly composed of a plate-shaped or rod-shaped ceramic having a rectangular shape in cross section and having a rectangular cross section is fixed while maintaining airtightness. The metal fitting body 11 is concentrically formed in a stepped cylindrical shape so that its inner peripheral surface has a diameter gradually increasing from the bottom, and a screw 12 for fixing to the exhaust pipe of the engine is located near the lower end of the outer peripheral surface. Is formed. Inside the main body 11 and outside the sensor element 21, airtight holding and fixing means for holding the element 21 in an airtight manner is provided in a filling manner. This airtight holding and fixing means includes a cylindrical body 30 in which an inner collar is supported on a lower step inside the main body 11, and is disposed inside the cylindrical body 30 and on the inner collar. A holder 31 made of alumina and sealing materials (talc in this example) 32 and 33 are disposed. A sleeve 35 is disposed on the sealing material 33, and a thin caulking cylindrical portion 16 connected to the cylindrical portion 15 near the rear end of the main body 11 is bent inward via a ring washer 36. The element 21 is airtightly fixed to the inside of the metal fitting body 11 by compressing the tip end side and compressing the internal sealing materials 32 and 33 and the like. The inner center of the sleeve 35 or the like has a rectangular (rectangular) hole whose cross section corresponds to the cross section of the element 21 when viewed from the axis G direction, and the element 21 is coaxially fixed in the main body 11.

なお、このように固定されている素子２１は、検出部２１ａのある先端側（図１下側）を本体１１の先端面より所定量（長さ）突出させ、後端寄り部位２３をスリーブ３５の後端面より所定量（長さ）突出させている。なお、金具本体１１の先端から突出している素子２１の先端（検出部２１ａ）は、本形態では、その周囲を包囲するように、複数の穴の設けられた二重構造からなるプロテクタ（保護カバー）１８が本体１１の先端に固定されている。なお、本体１１の軸線Ｇ方向の中間部において、外周に突出状に形成された大径部１９は、センサ１の排気管（図示せず）への取付けにおいて、本体１１のねじ１２をねじ込む際のねじ込み用の多角形部であり、この多角形部の下面にはシール用のガスケット２０が取着されている。 In the element 21 fixed in this way, the front end side (lower side in FIG. 1) where the detecting portion 21a is provided protrudes a predetermined amount (length) from the front end surface of the main body 11, and the rear end portion 23 is located in the sleeve 35. A predetermined amount (length) is protruded from the rear end surface of the lens. In this embodiment, the tip of the element 21 protruding from the tip of the metal fitting body 11 (detection unit 21a) is a protector (protective cover) having a double structure provided with a plurality of holes so as to surround the periphery. ) 18 is fixed to the tip of the main body 11. A large-diameter portion 19 formed in a projecting shape on the outer periphery of the intermediate portion in the axis G direction of the main body 11 is used when the screw 12 of the main body 11 is screwed in the attachment of the sensor 1 to the exhaust pipe (not shown). A polygonal part for screwing, and a gasket 20 for sealing is attached to the lower surface of the polygonal part.

ここで、このように本体１１内に固定された素子２１について図１及び図２を参照して詳細に説明する。本形態に使用されている素子２１は、そのうち、スリーブ３５から突出している後端寄り部位２３には、図２に示したように、その幅広面をなす各側部表面（以下、単に表面ともいう）２６に３つ又は２つの電極端子２５が横に並んで形成されている。これらの電極端子２５は、検出部２１ａからの検出出力取り出し用のものと、素子２１に形成された図示しないヒーターへの電圧印加用のものであり、いずれも、素子２１の長手方向に沿って細長い矩形状を呈している。なお、この電極端子２５は、印刷されたメタライズベースを素子２１と同時焼成により形成されてなるものであり、その厚みは極めて薄いため、拡大図以外では、その表面は素子２１の表面２６と面一で示している。また、素子２１の後端面２７と電極端子２５のある各幅広面をなす表面２６とのなす角には、その稜線に沿って面取り２８が付けられている。この面取り２８はＣ０．０５〜Ｃ０．４程度とされており、図２中において示したように、素子２１自身の側部表面２６に対する傾斜角度θ１は４５度とされている。なお、本形態のセンサ１は、図９に示したように、このような素子２１が本体１１内に固定されている下部の半組立体１０１と、次に説明する、それ以外の部品からなる上部の半組立体１０２とを後述するように組み付けることで製造される。 Here, the element 21 thus fixed in the main body 11 will be described in detail with reference to FIGS. As shown in FIG. 2, the element 21 used in this embodiment has a wide side surface (hereinafter referred to simply as “surface”), as shown in FIG. 26) three or two electrode terminals 25 are formed side by side. These electrode terminals 25 are for taking out a detection output from the detection unit 21 a and for applying a voltage to a heater (not shown) formed in the element 21, both of which are along the longitudinal direction of the element 21. It has an elongated rectangular shape. The electrode terminal 25 is formed by simultaneously firing a printed metallized base together with the element 21. Since the thickness thereof is extremely thin, the surface thereof is the same as the surface 26 of the element 21 except for the enlarged view. It is indicated by one. Further, a chamfer 28 is attached along the ridgeline at an angle formed by the rear end surface 27 of the element 21 and the surface 26 that forms each wide surface of the electrode terminal 25. The chamfer 28 is about C0.05 to C0.4, and as shown in FIG. 2, the inclination angle θ1 with respect to the side surface 26 of the element 21 itself is 45 degrees. As shown in FIG. 9, the sensor 1 of this embodiment includes a lower half assembly 101 in which such an element 21 is fixed in the main body 11, and other components described below. It is manufactured by assembling the upper subassembly 102 as described later.

次に、上記において説明したセンサ１の下部の半組立体１０１以外の部位について図１に基づいて説明する。すなわち、センサ１の図示上端である後端から外部にはリード線６１が詳細には図示しないが、本形態では５本引き出されており、センサ１内に位置するその各先端の芯線にはカシメによって、端子金具５１がそれぞれ取り付けられている。この端子金具５１は、それぞれが自身のバネ性によって素子２１の後端寄り部位２３を挟み付けるように、本体１１内に配置された絶縁材からなる筒状の端子金具保持部材７１内に配置されている。端子金具５１及び端子金具保持部材７１の詳細については後述する。各端子金具５１は、端子金具保持部材７１内に内挿された素子２１の各電極端子２５に、それぞれ電気的に接続されている。そして、このように端子金具５１を内側に配置してなる端子金具保持部材７１は、本体１１に固定されたケーシングをなす外筒８１の内側に次のように固定されている。すなわち、端子金具保持部材７１は、その外周に形成されたフランジ７３を外筒８１の内側に固定された支持リング８０の上に支持させる一方、端子金具保持部材７１の上端にはリード線６１が通された弾性シール材（ゴム）８５が配置されており、この弾性シール材８５は外筒８１の上端部の小径筒部８３を縮径するように圧縮することで、センサ１の後端部のシールを保持しつつ、外筒８５内に固定されている。 Next, parts other than the subassembly 101 below the sensor 1 described above will be described with reference to FIG. That is, the lead wire 61 is not shown in detail from the rear end, which is the upper end of the sensor 1 in the drawing, but in the present embodiment, five lead wires 61 are drawn out, and the core wire at each tip located in the sensor 1 is caulked. Thus, the terminal fittings 51 are respectively attached. The terminal fittings 51 are arranged in a cylindrical terminal fitting holding member 71 made of an insulating material arranged in the main body 11 so that each of the terminal fittings 51 sandwiches the rear end portion 23 of the element 21 by its own spring property. ing. Details of the terminal fitting 51 and the terminal fitting holding member 71 will be described later. Each terminal fitting 51 is electrically connected to each electrode terminal 25 of the element 21 inserted in the terminal fitting holding member 71. And the terminal metal fitting holding member 71 formed by arranging the terminal metal fitting 51 in this way is fixed inside the outer cylinder 81 forming the casing fixed to the main body 11 as follows. That is, the terminal fitting holding member 71 supports the flange 73 formed on the outer periphery thereof on the support ring 80 fixed to the inner side of the outer cylinder 81, while the lead wire 61 is attached to the upper end of the terminal fitting holding member 71. An elastic sealing material (rubber) 85 that is passed through is disposed, and the elastic sealing material 85 compresses the small-diameter cylindrical portion 83 at the upper end portion of the outer cylinder 81 so as to reduce the diameter, thereby the rear end portion of the sensor 1. This is fixed in the outer cylinder 85 while holding the seal.

ここで、本形態のセンサ１に使用されている端子金具５１について、図１〜図５に基づいて詳述するが、本形態では、リード線６１に対応して５個の各端子金具５１を使用しており、いずれもその基本構成は同じであるが、本形態では、素子２１の一方（図２右）の側部表面２６に形成された２つの電極端子２５に接続されるものは、やや幅広の素材から形成されており、他方（図２左）の側部表面２６に形成された３つの電極端子２５に接続されるものは、やや幅狭の素材から形成されている。なお、本形態では、図２の左に示した３つの電極端子２５に押付けられる端子金具５１のうちの中央に位置するもののみ、図３−Ｂに示した形状を呈しているが、その他の端子金具は図３−Ａに示した形状を呈している。 Here, the terminal fitting 51 used in the sensor 1 of this embodiment will be described in detail with reference to FIGS. 1 to 5. In this embodiment, five terminal fittings 51 corresponding to the lead wires 61 are provided. Although the basic configuration is the same for both, in this embodiment, the one connected to the two electrode terminals 25 formed on one side surface 26 of the element 21 (right of FIG. 2) A material that is formed from a slightly wider material and that is connected to the three electrode terminals 25 formed on the other side surface 26 (left side in FIG. 2) is formed from a slightly narrow material. In this embodiment, only the one located at the center of the terminal fittings 51 pressed against the three electrode terminals 25 shown on the left in FIG. 2 has the shape shown in FIG. The terminal fitting has a shape shown in FIG.

図３−Ａに示した端子金具５１は、バネ性のある金属（例えば、インコネル（ＩＮＣＯ社の登録商標））の板を所定形状に打ち抜き、その後プレス成形されて形成されており、リード線６１の先端（芯線部）を掴むようにカシメられるリード線接続部５２以下、次のように形成されている。すなわち、リード線接続部５２の先端にはそこから下向きに略真直ぐに延びる支持部５５を備えており、この支持部５５の先端５６において、素子２１及び電極端子２５側に折り曲げられて折返し状をなすとともに素子２１側に向けて凸となす円弧状に湾曲する湾曲部５７を備えている。この湾曲部５７の折返された端（自由端）５８は支持部５５の中間部にて支持されるように形成されている。なお、この端子金具５１は、その湾曲部５７の中間部が素子２１の電極端子２５に押付けられる部位（電極接続部）とされているが、同部位には電極端子２５側に突出するＶ字形をなす凸部５７ｂが形成されている。また、支持部５５の一側には端子金具保持部材７１内において横ずれを防止するための横ずれ防止バネ５９ａが設けられているとともに、支持部５５の先端５６の一側には位置決め用のフック５９ｂが設けられている。 The terminal fitting 51 shown in FIG. 3A is formed by punching a metal plate having a spring property (for example, Inconel (registered trademark of INCO)) into a predetermined shape and then press-molding the lead wire 61. The lead wire connecting portion 52 that is crimped so as to grip the tip (core wire portion) of the lead wire is formed as follows. That is, the leading end of the lead wire connecting portion 52 is provided with a supporting portion 55 that extends substantially straight downwardly therefrom, and the leading end 56 of the supporting portion 55 is bent toward the element 21 and the electrode terminal 25 to form a folded shape. In addition, a bending portion 57 that is curved in an arc shape convex toward the element 21 side is provided. The folded end (free end) 58 of the curved portion 57 is formed so as to be supported by an intermediate portion of the support portion 55. In addition, although this intermediate part of the curved part 57 is made into the site | part (electrode connection part) pressed against the electrode terminal 25 of the element 21, this terminal metal fitting 51 is V-shaped which protrudes in the electrode terminal 25 side in the same site | part. The convex part 57b which makes is formed. Further, a lateral displacement prevention spring 59a for preventing lateral displacement in the terminal metal fitting holding member 71 is provided on one side of the support portion 55, and a positioning hook 59b is disposed on one side of the tip 56 of the support portion 55. Is provided.

図３−Ｂに示した端子金具５１は、リード線６１の先端（芯線部）を掴むようにカシメられるリード線接続部５２以下、次のように形成されている。すなわち、リード線接続部５２の先端にはそこから下向きに略真直ぐに延びる中間部５３を備えており、この中間部５３の先端においては素子２１と反対側に約１／４円弧状に曲げられた折り曲げ部５４を備えている。そして、この折り曲げ部５４の外側先端において下向きに略真直ぐに延びる支持部５５を備えており、この支持部５５の先端５６において、素子２１及び電極端子２５側に折り曲げられて折返し状をなすとともに素子２１側に向けて凸となす円弧状に湾曲する湾曲部５７を備えている。この湾曲部５７の折返された端５８は折り曲げ部５４と支持部５５との境界近傍にて支持されるように形成されている。また、その湾曲部５７の中間部が素子２１の電極端子２５に押付けられる部位（電極接続部）とされ、同部位には電極端子２５側に突出するＶ字形をなす凸部５７ｂが形成されている。なお、図３−Ｂの端子金具５１は、図３−Ａに示したそれのように、横ずれ防止バネは５９ａが設けられていないが、支持部５５の先端５６の位置決め用のフック５９ｂは両側に設けられている。 The terminal fitting 51 shown in FIG. 3B is formed in the following manner below the lead wire connecting portion 52 that is crimped so as to grip the tip (core wire portion) of the lead wire 61. In other words, the leading end of the lead wire connecting portion 52 is provided with an intermediate portion 53 extending substantially straight downwardly therefrom, and the leading end of the intermediate portion 53 is bent in an approximately ¼ arc shape on the side opposite to the element 21. A bent portion 54 is provided. A support portion 55 that extends substantially straight downward at the outer front end of the bent portion 54 is provided. The front end 56 of the support portion 55 is bent toward the element 21 and the electrode terminal 25 to form a folded shape. A curved portion 57 that is curved in an arc shape convex toward the 21 side is provided. The folded end 58 of the curved portion 57 is formed to be supported in the vicinity of the boundary between the bent portion 54 and the support portion 55. An intermediate portion of the curved portion 57 is a portion (electrode connecting portion) that is pressed against the electrode terminal 25 of the element 21, and a V-shaped convex portion 57 b that protrudes toward the electrode terminal 25 is formed at the same portion. Yes. The terminal fitting 51 of FIG. 3B is not provided with a lateral displacement prevention spring 59a as shown in FIG. 3-A, but the positioning hook 59b of the tip 56 of the support portion 55 is provided on both sides. Is provided.

次に、このような端子金具５１が内部に配置されている端子金具保持部材７１について図１〜図９に基づいて説明するが、これは本例ではアルミナからなり円筒状に形成されている。そして、その外側には上記したようにフランジ７３を備えており、その内側は次のように構成されている。すなわち、図７，８に示したように、横断面の中央に、素子２１がその長手方向に沿って挿入可能の素子挿入用空孔７２を備えている。また、空孔７２を図において左右に挟む配置で各端子金具５１が絶縁を保持して配置されるように、その内側面７５には、センサ１の軸線Ｇ方向に沿って絶縁用仕切り壁（絶縁リブ）７６、７７が凸となすように形成されている。そして、この絶縁用仕切り壁７６、７７により、端子金具保持部材７１の内側面７５の一方の側（図７左）には、３つの端子金具挿入用凹溝７５ａ〜７５ｃが形成され、他方の側には２つの端子金具挿入用凹溝７５ｄ〜７５ｅが設けられている。 Next, a terminal fitting holding member 71 in which such a terminal fitting 51 is disposed will be described with reference to FIGS. 1 to 9, which in this example is made of alumina and is formed in a cylindrical shape. And the outer side is provided with the flange 73 as mentioned above, The inner side is comprised as follows. That is, as shown in FIGS. 7 and 8, an element insertion hole 72 is provided in the center of the transverse section so that the element 21 can be inserted along its longitudinal direction. In addition, an insulating partition wall (in the direction of the axis G of the sensor 1) is provided on the inner side surface 75 so that the terminal fittings 51 are arranged so as to maintain insulation in such a manner that the holes 72 are sandwiched between the left and right in the drawing. The insulating ribs 76 and 77 are formed to be convex. The insulating partition walls 76 and 77 form three terminal metal fitting insertion grooves 75a to 75c on one side (left side in FIG. 7) of the inner surface 75 of the terminal metal holding member 71, and the other side. Two terminal metal fitting insertion grooves 75d to 75e are provided on the side.

一方、この絶縁用仕切り壁７６、７７の先端向き面７６ａ、７７ａには、センサ１の軸線Ｇ及び素子２１の長手方向に対して略垂直な平面からなる平坦面７６ｈ、７７ｈを、同壁の根元寄り部位に所定の幅Ｆ１で備えている（図６参照）。また、この平坦面７６ｈ、７７ｈと、同壁７６、７７における素子２１の側部表面２６に対向する対向する内側面７６ｓ，７７ｓとのなす角には面取り７６ｋ，７７ｋが形成されており、後端側（図１上端側）に向けて傾斜する傾斜面をなしている。なお、この面取り７６ｋ，７７ｋにおける素子２１の側部表面２６に対向する傾斜角度θ２は、３０度〜６０度の範囲とするのが好ましいが、本形態では４５度とされており、その幅Ｆ２は０．５ｍｍとされている。本形態では、上記したθ１とこのθ２の関係は、θ１≦θ２とされている。 On the other hand, flat surfaces 76h and 77h made of a plane substantially perpendicular to the axis G of the sensor 1 and the longitudinal direction of the element 21 are provided on the tip-facing surfaces 76a and 77a of the insulating partition walls 76 and 77, respectively. A portion closer to the root is provided with a predetermined width F1 (see FIG. 6). Further, chamfers 76k and 77k are formed at angles formed by the flat surfaces 76h and 77h and the inner surfaces 76s and 77s facing the side surface 26 of the element 21 on the walls 76 and 77, respectively. An inclined surface that is inclined toward the end side (upper end side in FIG. 1) is formed. The inclination angle θ2 facing the side surface 26 of the element 21 in the chamfers 76k and 77k is preferably in the range of 30 degrees to 60 degrees, but is 45 degrees in this embodiment, and its width F2 Is 0.5 mm. In this embodiment, the relationship between the above θ1 and θ2 is θ1 ≦ θ2.

他方、向かい合う仕切り壁７６、７７の横断面（図７）における絶縁用仕切り壁７６、７７相互の内側面７６ｓ，７７ｓ間の寸法Ｌ１は、素子２１の厚みＴより若干（例えば０．５ｍｍ）大きめに設定されている。また、素子挿入用空孔７２における素子２１の厚みＴに対応する部位には軸線Ｇ向に沿って横断面が台形をなす凸条部７８が形成され、この対向する凸条部７８相互の間の寸法Ｌ２が素子２１の幅Ｗより若干（例えば０．３ｍｍ）大きめに設定されている。なお、この凸条部７８の側部は、上記した図３−Ａの端子金具５１における横ずれ防止バネ５９が嵌り込む凹部７９をなしている。これにより、端子金具保持部材７１の内側はその先後に向けて図７に示した横断面形状を呈している。また、本形態ではこの凸条部７８の先端向き面についても、絶縁用仕切り壁７６、７７における先端向き面７６ａ、７７ａと同様に、それぞれ平坦面７８ｈと面取り（傾斜面）７８ｋを備えている。ただし、本形態では、端子金具保持部材７１の先端面７４には、端子金具５１の先端寄り部位に形成されたフック５９ｂが係合する係合用凹部７４ｂが切り込まれ、或いは凹設されている（図８参照）。 On the other hand, the dimension L1 between the inner side surfaces 76s, 77s of the insulating partition walls 76, 77 in the cross section (FIG. 7) of the facing partition walls 76, 77 is slightly larger (for example, 0.5 mm) than the thickness T of the element 21. Is set to Further, at the portion corresponding to the thickness T of the element 21 in the element insertion hole 72, a convex strip 78 having a trapezoidal cross section along the direction of the axis G is formed, and between the opposing convex strips 78. Is set to be slightly larger (for example, 0.3 mm) than the width W of the element 21. In addition, the side part of this protruding item | line part 78 has comprised the recessed part 79 into which the lateral slip | shift prevention spring 59 in the above-mentioned terminal metal fitting 51 of FIG. 3-A fits. Thereby, the inner side of the terminal metal fitting holding member 71 has the cross-sectional shape shown in FIG. In this embodiment, the tip-facing surface of the ridge 78 is also provided with a flat surface 78h and a chamfer (inclined surface) 78k, respectively, as with the tip-facing surfaces 76a and 77a of the insulating partition walls 76 and 77. . However, in this embodiment, an engagement recess 74b that engages with a hook 59b formed at a portion closer to the distal end of the terminal fitting 51 is cut or provided in the distal end surface 74 of the terminal fitting holding member 71. (See FIG. 8).

しかして、センサの組立においては、このような端子金具保持部材７１内の絶縁用仕切り壁７６、７７を挟むように、すなわち端子金具挿入用凹溝７５ａ〜７５ｃのそれぞれに、端子金具５１が軸線方向に沿って、湾曲部５７を内側（軸線寄り部位）にして配置され、相互に絶縁が保持されて配置され、その状態において、素子２１がその後端側から対向する端子金具５１の相互間に挿入される。なお、各端子金具５１の先端５６は、端子金具保持部材７１の先端より後端側に位置するようにして配置されておらず、図９中の拡大図に示したように、絶縁用仕切り壁７６、７７の先端向き面７６ａ、７７ａの平坦面７６ｈ、７７ｈと略同じ高さで、先端側に突出させられており、湾曲部５７の先端５６寄り部位が面取り７６ｋ，７７ｋに倣うように位置しており、その先端５６に横向きの力が作用した場合には、絶縁用仕切り壁７６、７７のうち、先端の平坦面７６ｈ、７７ｈ及び面取り７６ｋ，７７ｋにてその動きが規制されるように設定されている。すなわち、絶縁用仕切り壁７６、７７を挟んで配置されている端子金具５１同士が、その先端５６において互いに接触しないようにされている。また、素子２１の挿入前は、それぞれ湾曲部５７が内側に張り出しているが、湾曲部５７相互の間隔は素子２１の厚みより小さいものとなっているか、湾曲部５７相互が押し合うようにされている（図９参照）。ただし、先端５６に向かうに従って湾曲部５７が離間して外広がり状をなしていることから、これが素子２１の後端２７の挿入開始時における入り口ないしガイドをなすようにされている。 Therefore, in assembling the sensor, the terminal fitting 51 is axially disposed so as to sandwich the insulating partition walls 76 and 77 in the terminal fitting holding member 71, that is, in each of the terminal fitting insertion grooves 75a to 75c. Along the direction, the curved portion 57 is disposed on the inner side (site close to the axial line), and is disposed so as to be insulated from each other. In this state, the element 21 is located between the terminal fittings 51 facing each other from the rear end side. Inserted. Note that the tip 56 of each terminal fitting 51 is not disposed so as to be located on the rear end side from the tip of the terminal fitting holding member 71 , and as shown in the enlarged view in FIG. The front surfaces 76a and 77a of the front and rear surfaces 76a and 77a have substantially the same height as the flat surfaces 76h and 77h, and are projected to the front side. The curved portion 57 is positioned so as to follow the chamfers 76k and 77k. When a lateral force is applied to the tip 56, the flat surfaces 76h and 77h and the chamfers 76k and 77k at the tip of the partition walls 76 and 77 for insulation are regulated so that the movement is restricted. Is set. That is, the terminal fittings 51 arranged with the insulating partition walls 76 and 77 interposed therebetween are prevented from contacting each other at the tip 56. Also, before the element 21 is inserted, the curved portions 57 project inward, but the distance between the curved portions 57 is smaller than the thickness of the element 21 or the curved portions 57 are pressed against each other. (See FIG. 9). However, since the curved portion 57 is separated and spreads outwardly toward the tip 56, this forms an entrance or guide when the rear end 27 of the element 21 starts to be inserted.

因みに、このような端子金具５１の配置は、保持部材７１の後端（図１上端）側から、リード線６１の先端に、リード線接続部５２をカシメによって接続した端子金具５１を、各凹溝７５ａ〜７５ｃを通すようにして先端側に引き出し、各端子金具５１の先端のフック５９ｂを保持部材７１の先端７４の係合用凹部７４ｂに嵌るようにし、そしてリード線６１を後端側に引き戻すことで行われる。なお、リード線６１には端子金具５１とともに予め圧縮前の弾性シール材（ゴム）８５を通しておく。また、このような端子金具保持部材７１の外周にはその先端側から支持リング８０を外嵌してフランジ７３に当接するようにし、外筒８１を図示上から下に被せるようにし、外筒８１の中間部位を絞り込み、内側の支持リング８０の外側を絞り込むことで端子金具保持部材７１を外筒８１内に先端側への動きを規制して固定する。そして、外筒８１における弾性シール材８５の外側部位を絞り込むことで、弾性シール材８５を圧縮変形してリード線６１を含めて後端のシールすることで、図９に示した上方の半組立体１０２となる。 Incidentally, the terminal fitting 51 is arranged in such a manner that the terminal fitting 51 in which the lead wire connecting portion 52 is connected by caulking from the rear end (upper end in FIG. 1) side of the holding member 71 to the leading end of the lead wire 61. The grooves 75a to 75c are pulled out to the front end side, the hooks 59b at the front ends of the terminal fittings 51 are fitted into the engaging recesses 74b at the front end 74 of the holding member 71, and the lead wires 61 are pulled back to the rear end side. Is done. The lead wire 61 is previously passed through the elastic metal (rubber) 85 before compression together with the terminal fitting 51. Further, a support ring 80 is externally fitted to the outer periphery of such a terminal fitting holding member 71 so as to come into contact with the flange 73, and the outer cylinder 81 is covered from the upper side to the lower side of the figure. The terminal fitting holding member 71 is restricted and fixed in the outer cylinder 81 by narrowing the middle part of the inner ring and narrowing the outer side of the inner support ring 80. Then, by narrowing the outer portion of the elastic sealing material 85 in the outer cylinder 81, the elastic sealing material 85 is compressed and deformed, and the rear end including the lead wire 61 is sealed, so that the upper half set shown in FIG. It becomes a solid 102.

本形態のセンサ１は、図９に示したように、上記した素子２１を含む下方の半組立体１０１と、端子金具保持部材７１、端子金具５１及び外筒８１等からなる上方の半組立体１０２を得た後、その両者を上下に同軸状に配置する。そして下方の半組立体１０１において突出する素子２１の後端寄り部位２３を、端子金具保持部材７１内の対向する端子金具５１相互間に相対的に挿入する。こうすることで、素子２１の後端寄り部位２３が端子金具保持部材７１内に配置された各端子金具５１の対向する湾曲部５７の間に挿入される。このとき、端子金具５１のそれぞれの湾曲部５７が外側に押し広げられるように弾性変形してセンサ素子２１の側部表面の各電極端子２５にバネによって押付けられて電気的に接続され、端子接続構造が得られる。そして、この挿入において、外筒８１の先端を金具本体１１の後端寄り部位の円筒部１５に外嵌し、その下方の大径筒部８２の先端を金具本体１１の円筒部１５に全周レーザ溶接により固定することで図１のセンサとなる。 As shown in FIG. 9, the sensor 1 according to the present embodiment includes a lower half assembly 101 including the element 21 described above, an upper half assembly including a terminal fitting holding member 71, a terminal fitting 51, an outer cylinder 81, and the like. After obtaining 102, both of them are arranged coaxially up and down. Then, the rear end portion 23 of the element 21 protruding in the lower half assembly 101 is relatively inserted between the opposing terminal fittings 51 in the terminal fitting holding member 71. By doing so, the rear end portion 23 of the element 21 is inserted between the facing curved portions 57 of the respective terminal fittings 51 arranged in the terminal fitting holding member 71. At this time, the respective bent portions 57 of the terminal fitting 51 are elastically deformed so as to be spread outward, and are pressed and electrically connected to the respective electrode terminals 25 on the side surface of the sensor element 21 by a spring. A structure is obtained. In this insertion, the front end of the outer cylinder 81 is externally fitted to the cylindrical portion 15 near the rear end of the metal fitting body 11, and the lower end of the large-diameter cylindrical portion 82 is fitted to the cylindrical portion 15 of the metal fitting body 11 all around. The sensor shown in FIG. 1 is obtained by fixing by laser welding.

しかして、本形態のセンサ１は、その組立における素子２１の挿入において、その後端が端子金具保持部材７１内の対向する端子金具５１相互間に相対的に挿入されるのであるが、その際、図９の拡大図中に示したように、素子２１と端子金具５１相互間に相対的な心ずれ（軸ずれ）があるとしても、素子２１の後端面２７又はその面取り２８の部位が、端子金具保持部材７１における絶縁用仕切り壁７６、７７における先端向き面に面取り７６ｋ，７７ｋがあることから、その挿入においては、同面取り７６ｋ，７７ｋに案内されるため、その心ずれを許容して挿入がなされる。そして、絶縁用仕切り壁７６、７７の先端向き面７６ａ，７７ａの全体を傾斜させてガイドとすることなく、絶縁用仕切り壁７６、７７の先端向き面７６ａ，７７ａのうち同壁の根元寄り部位（内側面７５）には、素子２１の長手方向に対して略垂直をなす平坦面７６ｈ，７７ｈを設けて、その平坦面７６ｈ、７７ｈと、絶縁用仕切り壁７６、７７におけるセンサ素子２１の側部表面に対向する内側面７６ｓ、７７ｓとのなす角に面取り７６ｋ，７７ｋを設けたものである。すなわち、先端向き面７６ａ，７７ａの全体を傾斜させてガイドとした場合には、そのガイド（傾斜面）は、図９の拡大図中に、線Ｍとして示したものとなることから、端子金具５１の先端５６は絶縁用仕切り壁７６、７７の先端向き面７６ａ，７７ａから大きく突出することになりることから、絶縁用仕切り壁７６、７７を挟んで配置された端子金具５１同士の先端が、素子２１の挿入過程や挿入後において接触してしまう危険性がある。これに対して、本形態では、そのような突出を防止することができるため、端子金具５１を端子金具保持部材７１の奥所に移動するまでもなく、絶縁上の問題もないセンサとなすことができる。すなわち、本発明は、素子挿入時のガイドとしては、絶縁用仕切り壁７６、７７における先端向き面７６ａ，７７ａの全体を傾斜させるまでもなく、素子挿入時の心ずれ誤差に対応した適宜の大きさの面取りで十分であることと、そのような面取りとすることで、先端向き面に平坦面を残存させることができ、この平坦面と面取りとで、絶縁用仕切り壁を挟んで配置される端子金具の先端同士の接触が防止できることに着目してなされたものである。 Thus, in the sensor 1 of this embodiment, when the element 21 is inserted in the assembly, the rear end thereof is relatively inserted between the opposing terminal fittings 51 in the terminal fitting holding member 71. As shown in the enlarged view of FIG. 9, even if there is a relative misalignment (axial misalignment) between the element 21 and the terminal fitting 51, the rear end surface 27 of the element 21 or the portion of the chamfer 28 thereof is the terminal. Since there are chamfers 76k and 77k on the front-facing surfaces of the insulating partition walls 76 and 77 in the metal fitting holding member 71, the insertion is guided by the chamfers 76k and 77k. Is made. Then, the tip end facing surfaces 76a and 77a of the insulating partition walls 76 and 77 are not inclined so as to serve as a guide, but the tip portion of the insulating partition walls 76 and 77 near the root of the tip facing surfaces 76a and 77a. The (inner surface 75) is provided with flat surfaces 76h and 77h that are substantially perpendicular to the longitudinal direction of the element 21, and the flat surfaces 76h and 77h and the side of the sensor element 21 in the insulating partition walls 76 and 77 are provided. Chamfers 76k and 77k are provided at angles formed by inner side surfaces 76s and 77s facing the part surface . That is, when the entire tip-facing surfaces 76a and 77a are inclined to form a guide, the guide (inclined surface) is shown as a line M in the enlarged view of FIG. Since the front end 56 of the 51 protrudes greatly from the front-facing surfaces 76a and 77a of the insulating partition walls 76 and 77, the front ends of the terminal fittings 51 arranged with the insulating partition walls 76 and 77 sandwiched therebetween. There is a risk of contact in the process of inserting the element 21 and after the insertion. On the other hand, in this embodiment, since such a protrusion can be prevented, the terminal metal 51 does not need to be moved to the back of the terminal metal holding member 71, and the sensor has no insulation problem. Can do. That is, according to the present invention, as a guide at the time of element insertion, it is not necessary to incline the entire tip facing surfaces 76a and 77a of the insulating partition walls 76 and 77, and an appropriate size corresponding to the misalignment error at the time of element insertion. The chamfering is sufficient, and such a chamfering allows a flat surface to remain on the tip-facing surface, and the flat surface and the chamfering are arranged with an insulating partition wall interposed therebetween. It was made paying attention to the contact between the tips of the terminal fittings being prevented.

加えて、本形態では、素子２１の後端面２７にも面取り２８が付与されている。このため、素子２１側に損傷が発生するのも防止される。その上に、絶縁用仕切り壁７６、７７の先端向き面の面取り７６ｋ，７７ｋとあいまって、高いガイド性が得られる。すなわち、素子２１の後端面２７に面取り２８が付与されている分、挿入時の心ずれを大きく許容できるといった効果もある。とくに本形態では、上記したように、素子２１の面取り２８が傾斜面取りであり、その素子自身の側部表面２６に対する傾斜角度θ１と、絶縁用仕切り壁７６、７７の面取り７６ｋ，７７ｋの傾斜角度θ２とを、θ１≦θ２としたため、次のような効果もある。すなわち、図１０−Ａに示したように、同図中の素子２１の挿入時における心ずれＺが大きく、素子２１の面取り２８が、絶縁用仕切り壁７６の面取り７６ｋにおける先端の角Ｐより外側（図左側）にはみ出ているような場合には、その角Ｐに衝突するためにその角Ｐが欠けやすい。一方で、θ１≦θ２なる関係にあれば、図１０−Ｂに示したように、その角Ｐに衝突するのを回避できるため、その欠けを防止できるため、絶縁用仕切り壁７６、７７の損傷防止に有効である。 In addition, in this embodiment, a chamfer 28 is also provided on the rear end surface 27 of the element 21. For this reason, the occurrence of damage on the element 21 side is also prevented. On top of that, in combination with the chamfers 76k and 77k of the insulating partition walls 76 and 77 at the front end face, a high guide property is obtained. In other words, since the chamfer 28 is given to the rear end surface 27 of the element 21, there is an effect that the misalignment at the time of insertion can be greatly allowed. In particular, in this embodiment, as described above, the chamfer 28 of the element 21 is an inclined chamfer, the inclination angle θ1 with respect to the side surface 26 of the element itself, and the inclination angles of the chamfers 76k and 77k of the partition walls 76 and 77 for insulation. Since θ2 is set to θ1 ≦ θ2, the following effects are also obtained. That is, as shown in FIG. 10A, the misalignment Z is large when the element 21 in the figure is inserted, and the chamfer 28 of the element 21 is outside the corner P at the tip of the chamfer 76k of the insulating partition wall 76. When it protrudes (on the left side of the figure), the corner P tends to be missing because it collides with the corner P. On the other hand, if the relation θ1 ≦ θ2 is satisfied, as shown in FIG. 10-B, it is possible to avoid collision with the corner P, and thus the chipping can be prevented, so that the insulating partition walls 76 and 77 are damaged. It is effective for prevention.

絶縁用仕切り壁７６、７７の先端向き面に設けた平坦面７６ｈ，７７ｈの幅Ｆ１はこれが大きいほど、端子金具５１の先端５６が突出するのを抑えることができるが、逆に面取り７６ｋ，７７ｋの幅Ｆ２が小さくなりガイド性の低下を招くことになる。このため、面取り７６ｋ，７７ｋの幅Ｆ２は、素子挿入時の心ずれ誤差（許容範囲）さらには素子２１の後端の面取り２８の有無、大きさを考慮し、ガイド性が損なわれない範囲において、なるべく小さく設定するのが好ましい。なお、面取り２８、７６ｋ，７７ｋの傾斜角度θ１、θ２は、素子挿入時のガイドとして支障のない範囲で設定すればよい。もつとも、素子の面取りは、なくともよい。また、いずれの面取りも、傾斜面取りでなく円弧状の面取りととして具体化することもできる。 The larger the width F1 of the flat surfaces 76h and 77h provided on the surfaces facing the front ends of the insulating partition walls 76 and 77, the more the protrusion 56 of the terminal fitting 51 can be prevented from protruding, but conversely the chamfers 76k and 77k. The width F2 becomes smaller and the guide performance is lowered. For this reason, the width F2 of the chamfers 76k and 77k is within a range in which the guide property is not impaired in consideration of the misalignment error (allowable range) at the time of element insertion and the presence / absence and size of the chamfer 28 at the rear end of the element 21. It is preferable to set as small as possible. It should be noted that the inclination angles θ1 and θ2 of the chamfers 28, 76k, and 77k may be set in a range that does not hinder the operation when the element is inserted. However, it is not necessary to chamfer the element. Also, any of the chamfers can be embodied as an arc-shaped chamfer instead of an inclined chamfer.

なお、上記形態では絶縁用仕切り壁７６、７７を長手方向に連続する壁として具体化したが、本発明における絶縁用仕切り壁７６、７７は、このように連続していなくともよい。さらに、端子金具の形状、構造、及びその数に関係なく具体化できるなど、適宜に設計変更して具体化できる。また、素子についても、上記においては、素子２１における電極端子２５を一方の側部表面に２個、他方のそれに３個設けたものにおいて具体化したが、本発明はこの数に関係なく具体化できることは言うまでもない。また、端子金具は、素子の両側（側部表面）を挟み付ける形態のものとして端子金具保持部材内に配置されているものとして具体化したが、本発明のセンサは、これ以外に例えば電極端子が素子の一方の側部表面（片面）にのみ形成されている素子を用いるセンサにおいても具体化できることは明らかであり、その場合には端子金具は、端子金具保持部材内の一方の内側面に配置されることになる。これより明らかなように、端子金具保持部材についても、適宜の構造、形状のものとして具体化できる。 In the above embodiment, the insulating partition walls 76 and 77 are embodied as walls that are continuous in the longitudinal direction. However, the insulating partition walls 76 and 77 in the present invention may not be continuous in this way. Furthermore, it can be embodied by changing the design as appropriate, such as being able to be realized regardless of the shape, structure and number of terminal fittings. Further, in the above, the element is embodied in the element 21 in which two electrode terminals 25 are provided on the surface of one side and three in the other, but the present invention is embodied regardless of this number. Needless to say, you can. Moreover, although the terminal metal fitting was embodied as what is arrange | positioned in the terminal metal fitting holding member as a thing of the form which clamps the both sides (side part surface) of an element, the sensor of this invention is an electrode terminal other than this, for example It is obvious that the sensor can be embodied even in a sensor using an element formed only on one side surface (one side) of the element, in which case the terminal metal fitting is attached to one inner surface of the terminal metal holding member. Will be placed. As is clear from this, the terminal fitting holding member can also be embodied as having an appropriate structure and shape.

この他、本発明のセンサは、本発明の要旨を逸脱しない限りにおいて、適宜にその構造、構成を設計変更して具体化できる。また、上記においては全領域空燃比センサにおいて具体化したが、本発明に係るセンサは、温度センサなどその他のセンサにおいても具体化できる。 In addition, the sensor of the present invention can be embodied by appropriately changing the structure and configuration without departing from the gist of the present invention. In the above description, the full-range air-fuel ratio sensor is embodied, but the sensor according to the present invention can also be embodied in other sensors such as a temperature sensor.

本発明のセンサの実施の形態の正面縦断面図及び要部拡大図。The front longitudinal cross-sectional view and principal part enlarged view of embodiment of the sensor of this invention. 素子の中間省略拡大図であって、Ａは側面図、ＢはＡを左から見た図、ＣはＡを右から見た図。It is the intermediate abbreviation enlarged drawing of an element, A is a side view, B is a figure which looked at A from the left, C is a figure which looked at A from the right. 端子金具の拡大斜視図。The expansion perspective view of a terminal metal fitting. 図１のＡ−Ａ線拡大断面図。The AA line expanded sectional view of FIG. 端子金具保持部材内に端子金具を配置したその先端面拡大図。The front end surface enlarged view which arranged the terminal metal fitting in the terminal metal fitting holding member. 図５のＢ−Ｇ−Ｂ線を通る先端寄り部位の拡大断面図。FIG. 6 is an enlarged cross-sectional view of a portion closer to a tip passing through a line B-G-B in FIG. 図６において端子金具を除去したときの端子金具保持部材の横断面図。The cross-sectional view of a terminal metal fitting holding member when the terminal metal fitting is removed in FIG. 端子金具保持部材の先端面拡大斜視図。The front end surface expansion perspective view of a terminal metal fitting holding member. 図１のセンサの組立工程の説明用正面縦断面図及び要部拡大図。The front longitudinal cross-sectional view and principal part enlarged view for description of the assembly process of the sensor of FIG. 素子の後端の面取りが、絶縁用仕切り壁の面取りに衝突する状態の説明用拡大図。The enlarged view for description in the state where the chamfering of the rear end of the element collides with the chamfering of the insulating partition wall. 従来の端子接続構造において素子の挿入を説明する図。The figure explaining insertion of an element in the conventional terminal connection structure. 図１１のＸ−Ｘ線拡大断面図。XX line expanded sectional view of FIG. 端子金具保持部材の先端面と、素子の後端面との心ずれを説明する図。The figure explaining the center shift | offset | difference of the front end surface of a terminal metal fitting holding member, and the rear end surface of an element. 絶縁用仕切り壁の先端向き面の全体を傾斜面とした端子金具保持部材に素子を挿入する説明する図。The figure explaining inserting an element in the terminal metal fitting holding member which made the whole surface facing the tip of an insulating partition wall the inclined surface.

符号の説明Explanation of symbols

１センサ
２１センサ素子
２１ａ素子の検出部
２５電極端子
２６素子の側部表面
２７素子の後端面
２８センサ素子の後端面の面取り
５１端子金具
７１端子金具保持部材
７６，７７絶縁用仕切り壁
７６ａ，７７ａ絶縁用仕切り壁の先端向き面
７６ｈ，７７ｈ絶縁用仕切り壁の平坦面
７６ｋ，７７ｋ絶縁用仕切り壁の面取り
７６ｓ，７７ｓ絶縁用仕切り壁の素子の側部表面に対向する内側面
θ１傾斜面取りのセンサ素子自身の側部表面に対する傾斜角度
θ２傾斜面取りの絶縁用仕切り壁の面取りの内側面に対する傾斜角度 DESCRIPTION OF SYMBOLS 1 Sensor 21 Sensor element 21a Element detection part 25 Electrode terminal 26 Element side surface 27 Element rear end face 28 Sensor element rear end face chamfer 51 Terminal fitting 71 Terminal fitting holding member 76, 77 Insulating partition walls 76a, 77a Front-facing surfaces 76h, 77h of the insulating partition wall Flat surfaces 76k, 77k of the insulating partition wall Chamfers 76s, 77s of the insulating partition wall Inner side surface θ1 facing the side surface of the element of the insulating partition wall Inclination angle θ2 with respect to the side surface of the element itself Inclination angle with respect to the inner side surface of the chamfered insulating partition wall

Claims

複数の端子金具を内側に配置してなる絶縁材からなる端子金具保持部材内に、測定対象に向けられる先端側に検出部を備えかつ後端寄り部位の側部表面に複数の電極端子を備えてなる長寸のセンサ素子をその後端側からセンサ素子自身の長手方向に相対的に挿入することによって、前記端子金具のそれぞれが弾性変形して該センサ素子の側部表面の各電極端子に押付けられて接続されてなる端子接続構造を有するセンサであって、
前記端子金具保持部材が、その内側面において凸となし前記端子金具を相互に絶縁を保持して配置させる絶縁用仕切り壁をセンサ素子自身の長手方向に沿って備えているものにおいて、
該絶縁用仕切り壁の先端向き面のうち該絶縁用仕切り壁の前記内側面寄り部位に前記センサ素子の長手方向に対して略垂直をなす平坦面を設けると共に、該平坦面と該絶縁用仕切り壁における前記センサ素子の側部表面に対向する内側面とのなす角に面取りを設けてなり、
さらに、前記端子金具は、前記長手方向に延びる支持部を備えており、この支持部の先端において前記センサ素子側に向けて折り曲げられて折返し状をなすとともに、該センサ素子側に向けて凸となす円弧状に湾曲する湾曲部を備えており、この湾曲部の中間部が前記各電極端子に押付けられており、この状態において、前記絶縁用仕切り壁を挟んで配置される該端子金具の先端同士が接触しないように、前記端子金具の前記湾曲部を、前記面取りより前記センサ素子側に突出させない一方、前記端子金具の先端を、前記端子金具保持部材の前記平坦面より先端側に突出させたことを特徴とするセンサ。 In the terminal fitting holding member made of an insulating material with a plurality of terminal fittings arranged inside, a detection part is provided on the front end side directed to the measuring object, and a plurality of electrode terminals are provided on the side surface near the rear end. Each of the terminal fittings is elastically deformed and pressed against each electrode terminal on the side surface of the sensor element by relatively inserting the long sensor element from the rear end side in the longitudinal direction of the sensor element. A sensor having a terminal connection structure formed by being connected,
The terminal metal fitting holding member is provided with an insulating partition wall along the longitudinal direction of the sensor element itself so as to be convex on the inner surface thereof and to arrange the terminal metal fittings while maintaining insulation.
A flat surface that is substantially perpendicular to the longitudinal direction of the sensor element is provided at a portion of the insulating partition wall facing the inner surface of the insulating partition wall, the flat surface and the insulating partition. A chamfer is provided at an angle formed with an inner surface facing the side surface of the sensor element on the wall ,
Further, the terminal fitting includes a support portion extending in the longitudinal direction, and is bent toward the sensor element side at the tip of the support portion to form a folded shape, and is convex toward the sensor element side. A curved portion that is curved in an arc shape, and an intermediate portion of the curved portion is pressed against each of the electrode terminals, and in this state, the tip of the terminal fitting disposed across the insulating partition wall The curved portion of the terminal fitting is not protruded toward the sensor element side from the chamfering so that they do not contact each other, while the tip of the terminal fitting is protruded from the flat surface of the terminal fitting holding member to the tip side. A sensor characterized by that .

前記センサ素子は、その後端面と前記電極端子のある側部表面とのなす角に面取りが設けられていることを特徴とする請求項１に記載のセンサ。 The sensor according to claim 1, wherein the sensor element is provided with a chamfer at an angle formed between a rear end surface thereof and a side surface having the electrode terminal.

前記絶縁用仕切り壁及び前記センサ素子における前記面取りが傾斜面取りであり、そのセンサ素子自身の側部表面に対する傾斜角度をθ１とし、前記絶縁用仕切り壁の前記面取りにおける前記側部表面に対向する前記内側面に対する傾斜角度をθ２としたとき、θ１≦θ２としたことを特徴とする請求項２に記載のセンサ。 The chamfering of the insulating partition wall and the sensor element is an inclined chamfer, and an inclination angle with respect to the side surface of the sensor element itself is θ1, and the chamfering of the insulating partition wall is opposed to the side surface of the chamfering. The sensor according to claim 2, wherein θ 1 ≦ θ 2 when the inclination angle with respect to the inner surface is θ 2.