JP2014235025A

JP2014235025A - Gas sensor

Info

Publication number: JP2014235025A
Application number: JP2013115166A
Authority: JP
Inventors: 大澤　敬正; Takamasa Osawa; 敬正大澤; 銀次郎伊藤; Ginjiro Ito; 邦彦米津; Kunihiko Yonezu; 久治西尾; Hisaharu Nishio
Original assignee: NGK Spark Plug Co Ltd
Current assignee: Niterra Co Ltd
Priority date: 2013-05-31
Filing date: 2013-05-31
Publication date: 2014-12-15

Abstract

PROBLEM TO BE SOLVED: To provide a gas sensor for making it possible to install a gas sensor in an engine room or a flow channel differing for each type of machine by using a common fixing member attachable/detachable to and from the gas sensor, and making it easy to adjusting a fitting part and a gas introduction part of a protector to a specific positional relation, the gas sensor also having excellent heat radiation ability.SOLUTION: Provided is a gas sensor 1 comprising: a detection element; a main body metal fixture 50 forming a polygon when viewed along the direction of an axis line O and having a polygon part 52; a protector 100; and an external cylinder 30 and disposed in a flow channel in which a gas to be measured flows, the gas sensor 1 being further provided with a fixing member, having a flange part attachable to the flow channel, which is a metal fixing member 200 having a polygon hole engaged with the polygon part and attachable/detachable to and from the gas sensor, the polygon hole being engaged with the polygon part 52 while the fitting angle of the polygon hole relative to the polygon part is adjusted so that the flange part and a gas introduction part 140 of the protector have a specific positional relation, whereby the fixing member 200 is secured to the main body metal fixture 50.

Description

本発明はガスセンサに関し、更に詳しくは、酸素センサ、炭化水素センサ、酸化窒素センサなど、測定雰囲気中の特定ガス濃度を検出するためのガスセンサに関する。 The present invention relates to a gas sensor, and more particularly to a gas sensor for detecting a specific gas concentration in a measurement atmosphere, such as an oxygen sensor, a hydrocarbon sensor, and a nitric oxide sensor.

自動車エンジン等の内燃機関の燃費向上や燃焼制御を行うガスセンサとして、被測定ガス（吸気ガスや排気ガス）中の酸素濃度を検出する酸素センサや空燃比センサが知られている。
このようなガスセンサとして、特定ガスの濃度検出を行う検出素子を主体金具に保持すると共に、検出素子の検出部の周囲をプロテクタで取り囲み、検出素子を被水や煤から保護する構造が一般的に用いられている。プロテクタには、検出部に被測定ガスを晒すためのガス導入部（孔）が設けられている。
一方、主体金具の外表面には、ガスセンサを被測定ガスの流路（吸気管等）に取り付けるための雄ねじ部が形成されている。そして、主体金具に設けられた六角部に工具を取り付け、流路の雌ねじ部に主体金具の雄ねじ部を螺合させてガスセンサを流路に固定している。 As gas sensors for improving fuel consumption and combustion control of an internal combustion engine such as an automobile engine, an oxygen sensor and an air-fuel ratio sensor for detecting an oxygen concentration in a gas to be measured (intake gas or exhaust gas) are known.
As such a gas sensor, a structure in which a detection element for detecting the concentration of a specific gas is held by a metal shell, and the detection element is surrounded by a protector, so that the detection element is protected from water and soot. It is used. The protector is provided with a gas introduction part (hole) for exposing the gas to be measured to the detection part.
On the other hand, on the outer surface of the metal shell, a male thread portion for attaching the gas sensor to a flow path (intake pipe or the like) of the gas to be measured is formed. A tool is attached to the hexagonal portion provided in the metal shell, and the male screw portion of the metal shell is screwed into the female screw portion of the flow path to fix the gas sensor to the flow path.

ところで、一般的にエンジンルームや流路のレイアウトは機種毎に異なり、ガスセンサの配置位置も機種毎に異なる。これに対し、ガスセンサを主体金具の雄ねじ部によって取付ける上記方法の場合、ガスセンサの取付位置が一律に決まっているので、エンジンルームや流路のレイアウトに適合できずにガスセンサが流路に取り付けられない虞がある。 By the way, in general, the layout of the engine room and the flow path is different for each model, and the arrangement position of the gas sensor is also different for each model. On the other hand, in the case of the above method in which the gas sensor is mounted by the male threaded portion of the metal shell, the mounting position of the gas sensor is uniformly determined, so that the gas sensor cannot be mounted on the flow path because it cannot be adapted to the engine room or flow path layout There is a fear.

また、被測定ガスには不純物（例えば煤）や水滴が含まれており、例えば、ガス導入部が流路の上流側を向くようにガスセンサが流路に配置されていると、ガス導入部に被測定ガスが接触やすくなり、ガス導入部に不純物が付着してガス導入部を塞いでしまう（以下、目詰まりとも言う）虞やガス検出素子に水滴がついてしまう虞がある。これに対し、ガス導入部を流路の下流側に向くようにガスセンサを流路に配置することで、ガス導入部に被測定ガスが接触しにくくなり、目詰まりや被水を効果的に抑制できる。ところが、ガスセンサの主体金具の雄ねじ部によって取り付ける上記方法の場合、ガス導入部を下流側に向けてガスセンサを流路に取り付けることが困難である。 The gas to be measured contains impurities (for example, soot) and water droplets. For example, if the gas sensor is arranged in the flow path so that the gas introduction section faces the upstream side of the flow path, the gas introduction section The gas to be measured is likely to come into contact, and impurities may adhere to the gas introduction part and block the gas introduction part (hereinafter also referred to as clogging), or there may be water drops on the gas detection element. In contrast, by placing the gas sensor in the flow path so that the gas introduction section faces the downstream side of the flow path, the gas to be measured is less likely to contact the gas introduction section, effectively preventing clogging and water exposure. it can. However, in the case of the above-described method of attaching by the male screw part of the metal shell of the gas sensor, it is difficult to attach the gas sensor to the flow path with the gas introduction part facing downstream.

また、エンジンルームや流路のレイアウトに適合できずにガスセンサが流路に取り付けられない虞や、ガス導入部を下流側に向けてガスセンサを流路に取り付ける困難性を考慮し、機種毎にガスセンサを作製することも可能ではあるものの、作業性、コスト等の問題が生じる。 In addition, considering the possibility that the gas sensor cannot be attached to the flow path because it cannot be adapted to the layout of the engine room or the flow path, and the difficulty of attaching the gas sensor to the flow path with the gas introduction part facing downstream, However, problems such as workability and cost arise.

このようなことから、ガスセンサを流路に取り付ける樹脂製のフランジ部を含む固定部材をガスセンサの外側にインサート成型することで、機種毎に多品種のガスセンサを作製することなく、機種毎に異なるエンジンルームや流路にガスセンサを取付可能とした技術が開発されている（特許文献１）。さらに、特許文献１記載の技術においては、固定部材をインサート成型する際、ガス導入部とフランジ部の向きを特定の位置関係に合わせることで、ガス導入路を下流側にむけてガスセンサを流路に取り付けることができる。
又、酸素センサの円筒状の本体部の外側に金属製のフランジ部を溶接する技術も開発されている（特許文献２）。 For this reason, engines that differ from model to model can be produced by insert molding a fixing member that includes a resin flange that attaches the gas sensor to the flow path on the outside of the gas sensor. A technique has been developed that enables a gas sensor to be attached to a room or a flow path (Patent Document 1). Furthermore, in the technique described in Patent Document 1, when the fixing member is insert-molded, the direction of the gas introduction part and the flange part is adjusted to a specific positional relationship, so that the gas sensor is directed to the downstream side with the gas introduction path facing the downstream side. Can be attached to.
In addition, a technique for welding a metal flange to the outside of the cylindrical main body of the oxygen sensor has been developed (Patent Document 2).

特開２０１０−１２７６６７号公報JP 2010-127667 A 特開昭５６−３０６４１号公報JP-A-56-30461

ところで、上記した特許文献１記載の技術の場合、ガスセンサ本体の周囲が樹脂製の固定部で覆われているため、ガスセンサ内部に配置された樹脂性の封止部材やセンサ信号取り出し用の金属端子の放熱性が低下する虞がある。又、固定部をガスセンサ本体の周囲にインサート成型するための金型（治具）が必要であるため、設備コストが大きくなると共に、機種毎に異なるエンジンルームや流路に応じて治具を変える必要がある。
又、特許文献２記載の技術の場合、フランジ部がガスセンサ本体に対して自由に回転してしまうため、ガス導入部とフランジ部の向きとの位置合わせを作業者が行わなければならず、作業効率が低下する。
そこで、本発明は、ガスセンサと着脱可能な共通の固定部材を用い、機種毎に異なるエンジンルームや流路にガスセンサを取付可能とすると共に、取付部とプロテクタのガス導入部とを特定の位置関係に合わせ易くし、放熱性にも優れたガスセンサの提供を目的とする。 By the way, in the case of the technique described in Patent Document 1, since the periphery of the gas sensor body is covered with a resin-made fixing portion, a resin sealing member disposed inside the gas sensor or a metal terminal for taking out a sensor signal There is a risk that the heat dissipation of the steel will deteriorate. In addition, since a mold (jig) is required to insert-mold the fixed part around the gas sensor body, the equipment cost increases, and the jig is changed depending on the engine room and flow path that differs for each model. There is a need.
In the case of the technique described in Patent Document 2, since the flange portion freely rotates with respect to the gas sensor main body, the operator must perform alignment between the gas introduction portion and the orientation of the flange portion. Efficiency is reduced.
Therefore, the present invention uses a common fixing member that can be attached to and detached from the gas sensor, enables the gas sensor to be mounted in different engine rooms and flow paths for each model, and has a specific positional relationship between the mounting portion and the gas introducing portion of the protector. The purpose is to provide a gas sensor that is easy to match and has excellent heat dissipation.

上記課題を解決するため、本発明のガスセンサは、軸線方向に延び、自身の先端側に被測定ガス中の特定ガス成分を検出するための検出部を有する検出素子と、前記検出部を自身の先端から突出させつつ、前記検出素子の径方向周囲を取り囲む筒状の主体金具であって、前記軸線方向に沿って見たときに多角形をなすと共に、径方向に突出する多角部を有する主体金具と、内部に前記検出素子の前記検出部を収容しつつ、前記主体金具に固定される筒状のプロテクタと、前記主体金具の後端側に接続される金属製の外筒と、を備え、前記被測定ガスが流れる流路に配置されるガスセンサにおいて、前記多角部に嵌合される多角孔を有すると共に、前記ガスセンサに着脱可能な金属製の固定部材であって、前記流路に取り付け可能な取付部を有する固定部材をさらに備え、前記プロテクタは、前記被測定ガスを外部から前記プロテクタ内に導入可能なガス導入部を有し、前記取付部と前記ガス導入部とが特定の位置関係になるように、前記多角部に対する前記多角孔の取付け角度が調整された状態で前記多角孔が前記多角部に嵌め込まれ、前記固定部材が前記主体金具に固定されている。 In order to solve the above-described problems, a gas sensor according to the present invention includes a detection element that extends in the axial direction and has a detection unit for detecting a specific gas component in a gas to be measured on the tip side of the gas sensor. A cylindrical metal shell that surrounds the periphery of the detection element in the radial direction while protruding from the tip, and has a polygonal shape that forms a polygon when viewed along the axial direction and protrudes in the radial direction A metal fitting, a cylindrical protector that is fixed to the metal shell while accommodating the detection portion of the detection element therein, and a metal outer cylinder that is connected to the rear end side of the metal metal fitting. The gas sensor disposed in the flow path through which the gas to be measured flows has a polygonal hole fitted to the polygonal portion, and is a metal fixing member that can be attached to and detached from the gas sensor, and is attached to the flow path Possible mounting part The protector further includes a gas introduction part capable of introducing the gas to be measured into the protector from the outside, and the attachment part and the gas introduction part have a specific positional relationship. The polygonal hole is fitted into the polygonal part in a state where the attachment angle of the polygonal hole with respect to the polygonal part is adjusted, and the fixing member is fixed to the metal shell.

このガスセンサによれば、多角部に対する多角孔の取付け角度（嵌合角度）を変えて固定部材を主体金具に固定することで、機種毎に異なる設置スペースや流路であっても共通の固定部材及び共通のガスセンサを用いてガスセンサを流路に取付けることができ、機種に応じて別個の形状の固定部材を作製したり、機種毎にガスセンサを作製する必要がない。
そして、ガス導入部と取付部とを特定の位置関係にすることで、ガスセンサを流路に取り付けた際に、ガス導入部に被測定ガスが接触しにくくなり、目詰まりや被水を効果的に抑制できる。
さらに、検出素子からの熱は主体金具に伝わるが、主体金具を取り囲むようにして金属製の固定部材を取り付ける。このため、主体金具から固定部材に効果的に放熱することができ、封止部材や金属端子が熱影響を受け難く、放熱性に優れたガスセンサが得られる。又、ガスセンサに一般的に付属する主体金具（多角部）に固定部材を取り付ければよいので、固定部材を取り付けるための新たな部材をガスセンサに設ける必要がなく、部品点数の増大を抑制できる。
なお、多角部に対する多角孔の取付け角度（嵌合角度）が変えることが可能で、且つ多角部に多角孔が嵌め込まれることが可能であれば、多角部及び多角孔の形状は特に限定されるものではない。一方、多角部及び多角孔がそれぞれ正多角形であれば、多角部に対する多角孔の取付け（嵌合）角度の調整範囲は、多角形の内角の整数倍となる。従って、取付け（嵌合）角度を多角形の内角の整数倍に正確に調整することができる。 According to this gas sensor, the fixing member is fixed to the metal shell by changing the mounting angle (fitting angle) of the polygonal hole with respect to the polygonal portion, so that the same fixing member can be used even in different installation spaces and flow paths for each model. In addition, the gas sensor can be attached to the flow path using a common gas sensor, and it is not necessary to produce a fixing member having a different shape depending on the model or to produce a gas sensor for each model.
And, by making the gas introduction part and the attachment part have a specific positional relationship, when the gas sensor is attached to the flow path, it becomes difficult for the gas to be measured to come into contact with the gas introduction part, effectively preventing clogging and water exposure. Can be suppressed.
Furthermore, heat from the detection element is transmitted to the metal shell, but a metal fixing member is attached so as to surround the metal shell. For this reason, it is possible to effectively dissipate heat from the metal shell to the fixing member, and it is possible to obtain a gas sensor excellent in heat dissipation since the sealing member and the metal terminal are hardly affected by heat. Moreover, since it is only necessary to attach a fixing member to a metal shell (polygonal part) generally attached to the gas sensor, it is not necessary to provide a new member for attaching the fixing member to the gas sensor, and an increase in the number of parts can be suppressed.
In addition, if the attachment angle (fitting angle) of the polygon hole with respect to the polygon part can be changed and the polygon hole can be fitted into the polygon part, the shapes of the polygon part and the polygon hole are particularly limited. It is not a thing. On the other hand, if the polygonal part and the polygonal hole are each a regular polygon, the adjustment range of the attachment (fitting) angle of the polygonal hole to the polygonal part is an integral multiple of the interior angle of the polygon. Therefore, the mounting (fitting) angle can be accurately adjusted to an integral multiple of the inner angle of the polygon.

本発明のガスセンサにおいて、前記多角孔は前記多角部と同一の辺の数を持つか、又は前記多角孔は前記多角部の２倍の辺の数を持つ多角形の孔であってもよい。
特に、多角孔が多角部の２倍の辺の数を持つ場合には、多角孔の内角が多角部の内角の１／２となるので、その分だけ多角部に対する取付部の取付け角度をより細かく調整できる。 In the gas sensor of the present invention, the polygonal hole may have the same number of sides as the polygonal part, or the polygonal hole may be a polygonal hole having the number of sides twice that of the polygonal part.
In particular, when the polygonal hole has twice the number of sides as the polygonal part, the inner angle of the polygonal hole is ½ of the inner angle of the polygonal part. Can be finely adjusted.

本発明のガスセンサにおいて、前記固定部材は前記外筒と非接触であってもよい。
このガスセンサによれば、主体金具から固定部材に伝わった熱が外筒に伝わることを抑制し、外筒内部に位置する封止部材や金属端子への熱影響をさらに抑制することができる。 In the gas sensor of the present invention, the fixing member may be in non-contact with the outer cylinder.
According to this gas sensor, it is possible to suppress the heat transmitted from the metal shell to the fixing member from being transmitted to the outer cylinder, and to further suppress the thermal influence on the sealing member and the metal terminal located inside the outer cylinder.

本発明のガスセンサにおいて、前記ガス導入部は、前記プロテクタの周方向の一部の範囲にのみ設けられていてもよい。
このガスセンサによれば、ガス導入部はプロテクタの周方向の一部の範囲にのみ設けられているので、ガス導入部と取付部とを特定の位置関係にすることで、ガスセンサを流路に取り付けた際に、ガス導入部に被測定ガスを効果的に接触させにくくすることができる。その結果、目詰まりや被水性をより効果的に抑制できる。 In the gas sensor of the present invention, the gas introduction part may be provided only in a partial range in the circumferential direction of the protector.
According to this gas sensor, since the gas introduction part is provided only in a partial range in the circumferential direction of the protector, the gas sensor is attached to the flow path by making the gas introduction part and the attachment part have a specific positional relationship. In this case, it is possible to make it difficult to effectively bring the gas to be measured into contact with the gas introduction portion. As a result, clogging and water coverage can be more effectively suppressed.

この発明によれば、ガスセンサと着脱可能な共通の固定部材を用い、機種毎に異なるエンジンルームや流路にガスセンサを取付可能とすると共に、取付部とプロテクタのガス導入部とを特定の位置関係に合わせ易くし、放熱性にも優れたガスセンサが得られる。 According to this invention, the gas sensor can be attached to a different engine room or flow path for each model using a common fixing member that can be attached to and detached from the gas sensor, and the attachment portion and the gas introduction portion of the protector have a specific positional relationship. Therefore, a gas sensor having excellent heat dissipation can be obtained.

本実施形態のガスセンサの部分断面図である。It is a fragmentary sectional view of the gas sensor of this embodiment. ガスセンサの斜視図である。It is a perspective view of a gas sensor. 固定部材の上面斜視図である。It is a top perspective view of a fixing member. 固定部材の下面斜視図である。It is a bottom perspective view of a fixing member. ガスセンサに固定部材を挿通した状態の分解斜視図である。It is a disassembled perspective view of the state which inserted the fixing member in the gas sensor. 取付部を多角部（工具係合部）に位置合わせする態様を示す上面図である。It is a top view which shows the aspect which aligns an attachment part with a polygonal part (tool engagement part). 本実施形態のガスセンサを吸気通路に取り付けた状態を示す図である。It is a figure which shows the state which attached the gas sensor of this embodiment to the intake passage. 外側プロテクタの斜視図である。It is a perspective view of an outside protector. 内側プロテクタの斜視図である。It is a perspective view of an inner side protector. 図１に示すガスセンサのＡ−Ａ断面図である。It is AA sectional drawing of the gas sensor shown in FIG. 変形例に係る取付部を多角部（工具係合部）に位置合わせする態様を示す上面図である。It is a top view which shows the aspect which aligns the attaching part which concerns on a modification with a polygonal part (tool engaging part).

以下、本発明を具体化したガスセンサの一実施の形態について、図面を参照して説明する。まず、一例としてのガスセンサ１の構造について、図１を参照して説明する。図１は、ガスセンサ１の部分断面図である。なお、図１において、ガスセンサ１の軸線Ｏ方向（１点鎖線で示す。）を上下方向として図示し、内部に保持する検出素子１０の検出部１１側をガスセンサ１の先端側、後端部１２側をガスセンサ１の後端側として説明する。 Hereinafter, an embodiment of a gas sensor embodying the present invention will be described with reference to the drawings. First, the structure of the gas sensor 1 as an example will be described with reference to FIG. FIG. 1 is a partial cross-sectional view of the gas sensor 1. In FIG. 1, the axis O direction (indicated by a one-dot chain line) of the gas sensor 1 is shown as the vertical direction, and the detection unit 11 side of the detection element 10 held inside is the front end side and the rear end portion 12 of the gas sensor 1. The side will be described as the rear end side of the gas sensor 1.

図１に示すガスセンサ１は、内燃機関の吸気通路２（図７参照、特許請求の範囲の「流路」に相当）に取り付けられ、内部に保持する検出素子１０の検出部１１が吸気通路２を流通する吸気ガスや吸気再循環ガス中に晒されて、その吸気ガスや吸気再循環ガス中の酸素濃度から空燃比を検出する、いわゆる全領域空燃比センサである。なお、以下の文章では吸気ガス及び吸気再循環ガスをまとめて「ガス」という。
検出素子１０は軸線Ｏ方向に延びる短冊状をなし、酸素濃度の検出を行うガス検出体と、そのガス検出体を早期活性化させるために加熱を行うヒータ体とが互いに貼り合わされ、略角柱状をなす積層体として一体化されたものである。ガス検出体はジルコニアを主体とする固体電解質体と白金を主体とする検出電極と（共に図示しない）から構成され、その検出電極は、検出素子１０の先端側に形成された検出部１１に配置されている。そして、検出電極をガスによる被毒から保護するため、検出素子１０の検出部１１には、その外周面を包むように保護層１５が形成されている。他方、検出素子１０の後端側の後端部１２には、ガス検出体やヒータ体から電極を取り出すための５つの電極パッド１６（図１ではそのうちの１つを図示している。）が形成されている。なお、本実施の形態では検出素子１０を本発明における「検出素子」として説明を行うが、厳密には、検出素子の構成としてヒータ体は必ずしも必要ではなく、ガス検出体が本発明の「検出素子」に相当する。 A gas sensor 1 shown in FIG. 1 is attached to an intake passage 2 of an internal combustion engine (refer to FIG. 7, which corresponds to a “flow path” in claims), and a detection unit 11 of a detection element 10 held inside the intake passage 2 It is a so-called full-range air-fuel ratio sensor that is exposed to the intake gas or intake recirculation gas flowing through the exhaust gas and detects the air-fuel ratio from the oxygen concentration in the intake gas or intake recirculation gas. In the following text, intake gas and intake recirculation gas are collectively referred to as “gas”.
The detection element 10 has a strip shape extending in the direction of the axis O, and a gas detection body for detecting the oxygen concentration and a heater body for heating in order to activate the gas detection body at an early stage are bonded together to form a substantially prismatic shape. Are integrated as a laminated body. The gas detection body is composed of a solid electrolyte body mainly composed of zirconia and a detection electrode mainly composed of platinum (both not shown), and the detection electrode is arranged in a detection section 11 formed on the front end side of the detection element 10. Has been. And in order to protect a detection electrode from poisoning by gas, the protective layer 15 is formed in the detection part 11 of the detection element 10 so that the outer peripheral surface may be wrapped. On the other hand, at the rear end portion 12 on the rear end side of the detection element 10, there are five electrode pads 16 (one of which is shown in FIG. 1) for taking out electrodes from the gas detection body and the heater body. Is formed. In the present embodiment, the detection element 10 is described as the “detection element” in the present invention. However, strictly speaking, the heater element is not necessarily required as the configuration of the detection element, and the gas detection element is the “detection element” of the present invention. It corresponds to “element”.

検出素子１０の胴部１３の中央よりやや先端側には、有底筒状をなす金属製の金属カップ２０が、自身の内部に検出素子１０を挿通させ、その検出部１１を筒底の開口２５から突出させた状態で配置されている。金属カップ２０は主体金具５０内に検出素子１０を保持するための部材であり、筒底の縁部分の先端周縁部２３は外周面にかけてテーパ状に形成されている。金属カップ２０内には、アルミナ製のセラミックリング２１と滑石粉末を圧縮して固めた滑石リング２２とが、自身を検出素子１０に挿通させた状態で収容されている。滑石リング２２は金属カップ２０内で押し潰されて細部に充填されており、これにより、検出素子１０が金属カップ２０内で位置決めされて保持されている。 A metal cup 20 having a bottomed cylindrical shape is inserted into the inside of the body 13 of the body 13 of the detection element 10 slightly from the center, and the detection section 11 is opened at the bottom of the cylinder. It is arranged in a state protruding from 25. The metal cup 20 is a member for holding the detection element 10 in the metal shell 50, and the distal end peripheral portion 23 of the edge portion of the cylinder bottom is formed in a tapered shape toward the outer peripheral surface. In the metal cup 20, an alumina ceramic ring 21 and a talc ring 22 obtained by compressing and solidifying talc powder are accommodated in a state where the detection element 10 is inserted. The talc ring 22 is crushed in the metal cup 20 to fill the details, and thereby the detection element 10 is positioned and held in the metal cup 20.

金属カップ２０と一体となった検出素子１０は、その周囲を筒状の主体金具５０に取り囲まれて保持されている。主体金具５０は、ＳＵＳ４３０等のステンレス鋼からなり通常の場合に外周先端側に吸気流路への取り付け用の雄ねじ部５１が形成されている。この雄ねじ部５１よりも先端側には、後述するプロテクタ１００が係合される先端係合部５６が形成されている。また、主体金具５０の外周中央には、通常の場合に取り付け用の工具が係合する工具係合部５２が形成されており、その工具係合部５２の先端面と雄ねじ部５１の後端との間には、吸気通路２に取り付けた際のガス抜けを防止するためのガスケット５５が嵌挿されている。なお、ガスケット５５の代わりに、Ｏリングやカーボングラファイトを嵌挿されていても良い。更に、工具係合部５２の後端側には、後述する外筒３０が係合される後端係合部５７と、その後端側に、主体金具５０内に検出素子１０を加締め保持するための加締め部５３とが形成されている。
なお、工具係合部５２は軸線方向から見て正六角形をなして径方向に突出し、工具（スパナ等）に係合するようになっている。工具係合部５２が特許請求の範囲の「多角部」に相当する。 The detection element 10 integrated with the metal cup 20 is surrounded and held by a cylindrical metal shell 50. The metal shell 50 is made of stainless steel such as SUS430, and a male screw portion 51 for attachment to the intake flow path is formed on the outer peripheral tip side in a normal case. A distal end engaging portion 56 to which a protector 100 described later is engaged is formed on the distal end side of the male screw portion 51. Further, a tool engaging portion 52 is formed at the center of the outer periphery of the metal shell 50 so that a tool for attachment is engaged in a normal case. The front end surface of the tool engaging portion 52 and the rear end of the male screw portion 51 are formed. A gasket 55 for preventing gas escape when attached to the intake passage 2 is inserted between the two. Instead of the gasket 55, an O-ring or carbon graphite may be inserted. Further, the rear end side of the tool engaging portion 52 is engaged with a rear end engaging portion 57 to which an outer cylinder 30 described later is engaged, and the detection element 10 is caulked and held in the metal shell 50 on the rear end side. For this purpose, a caulking portion 53 is formed.
The tool engaging portion 52 forms a regular hexagon when viewed from the axial direction, protrudes in the radial direction, and engages with a tool (such as a spanner). The tool engaging portion 52 corresponds to a “polygonal portion” in the claims.

また、主体金具５０の内周で雄ねじ部５１付近には段部５４が形成されている。この段部５４には、検出素子１０を保持する金属カップ２０の先端周縁部２３が係止されている。更に、主体金具５０の内周には滑石リング２６が、自身を検出素子１０に挿通させた状態で、金属カップ２０の後端側から装填されている。そして、滑石リング２６を後端側から押さえるように、筒状のスリーブ２７が主体金具５０内に嵌め込まれている。スリーブ２７の後端側外周には段状をなす肩部２８が形成されており、その肩部２８には、円環状の加締めパッキン２９が配置されている。この状態で主体金具５０の加締め部５３が、加締めパッキン２９を介してスリーブ２７の肩部２８を先端側に向けて押圧するように加締められている。スリーブ２７に押圧された滑石リング２６は主体金具５０内で押し潰されて細部にわたって充填され、この滑石リング２６と、金属カップ２０内にあらかじめ装填された滑石リング２２とによって、金属カップ２０および検出素子１０が主体金具５０内で位置決め保持される。主体金具５０内の気密は、加締め部５３とスリーブ２７の肩部２８との間に介在される加締めパッキン２９によって維持され、吸気ガスの流出が防止される。 Further, a step portion 54 is formed in the vicinity of the male screw portion 51 on the inner periphery of the metal shell 50. The step 54 is engaged with the peripheral edge 23 of the tip of the metal cup 20 that holds the detection element 10. Further, a talc ring 26 is loaded on the inner periphery of the metal shell 50 from the rear end side of the metal cup 20 in a state where the talc ring 26 is inserted through the detection element 10. A cylindrical sleeve 27 is fitted into the metal shell 50 so as to hold the talc ring 26 from the rear end side. A shoulder portion 28 having a step shape is formed on the outer periphery of the rear end side of the sleeve 27, and an annular caulking packing 29 is disposed on the shoulder portion 28. In this state, the crimping portion 53 of the metal shell 50 is crimped so as to press the shoulder portion 28 of the sleeve 27 toward the distal end side via the crimping packing 29. The talc ring 26 pressed against the sleeve 27 is crushed in the metal shell 50 and filled in details. The talc ring 26 and the talc ring 22 preloaded in the metal cup 20 are used to detect the metal cup 20 and the detection. The element 10 is positioned and held in the metal shell 50. The airtightness in the metal shell 50 is maintained by the caulking packing 29 interposed between the caulking portion 53 and the shoulder portion 28 of the sleeve 27, thereby preventing the intake gas from flowing out.

検出素子１０は、その後端部１２が主体金具５０の後端（加締め部５３）よりも後方に突出されており、その後端部１２には、絶縁性セラミックスからなる筒状のセパレータ６０が被せられている。セパレータ６０は、検出素子１０の後端部１２に形成された５つの電極パッド１６とそれぞれ電気的に接続される５つの接続端子６１（図１ではそのうちの１つを図示している。）を内部に保持すると共に、それら各接続端子６１と、ガスセンサ１の外部に引き出される５本のリード線６５（図１ではそのうちの３本を図示している。）との各接続部分を収容して保護している。 The detection element 10 has a rear end 12 protruding rearward from the rear end (caulking portion 53) of the metal shell 50, and the rear end 12 is covered with a cylindrical separator 60 made of insulating ceramics. It has been. The separator 60 has five connection terminals 61 (one of which is shown in FIG. 1) electrically connected to the five electrode pads 16 formed at the rear end portion 12 of the detection element 10. While holding inside, each connection part of these connection terminals 61 and the five lead wires 65 (three of them are shown in FIG. 1) drawn out of the gas sensor 1 are accommodated. Protect.

そして、セパレータ６０が嵌められた検出素子１０の後端部１２の周囲を囲うように、筒状の外筒３０が配設されている。外筒３０はステンレス（例えばＳＵＳ３０４）製であり、主体金具５０の後端係合部５７の外周に自身の先端側の開口端３１が係合されている。その開口端３１は、外周側から加締められ、更に外周を一周してレーザ溶接が施されて後端係合部５７に接合されており、外筒３０と主体金具５０とが一体に固定されている。
また、外筒３０とセパレータ６０との間の間隙には、金属製で筒状の保持金具７０が配設されている。保持金具７０は自身の後端を内側に折り曲げて構成した支持部７１を有し、自身の内部に挿通されるセパレータ６０の後端側外周に鍔状に設けられた鍔部６２を支持部７１に係止させて、セパレータ６０を支持している。この状態で、保持金具７０が配置された部分の外筒３０の外周面が加締められ、セパレータ６０を支持した保持金具７０が外筒３０に固定されている。 And the cylindrical outer cylinder 30 is arrange | positioned so that the circumference | surroundings of the rear-end part 12 of the detection element 10 with which the separator 60 was fitted may be enclosed. The outer cylinder 30 is made of stainless steel (for example, SUS304), and the opening end 31 on its front end side is engaged with the outer periphery of the rear end engaging portion 57 of the metal shell 50. The open end 31 is caulked from the outer peripheral side, and further laser-welded around the outer periphery and joined to the rear end engaging portion 57, and the outer cylinder 30 and the metal shell 50 are integrally fixed. ing.
Further, a metal-made cylindrical holding metal fitting 70 is disposed in the gap between the outer cylinder 30 and the separator 60. The holding metal fitting 70 has a support portion 71 formed by bending the rear end of the holding member 70 inward, and a support portion 71 is provided with a flange portion 62 provided in a hook shape on the outer periphery of the rear end side of the separator 60 inserted into the holding metal fitting 70. And the separator 60 is supported. In this state, the outer peripheral surface of the outer cylinder 30 where the holding metal fitting 70 is disposed is crimped, and the holding metal fitting 70 that supports the separator 60 is fixed to the outer cylinder 30.

そして外筒３０の後端側の開口には、フッ素系ゴム製のグロメット７５が嵌合されている。グロメット７５は５つの挿通孔７６（図１ではそのうちの１つを図示している。）を有し、各挿通孔７６に、セパレータ６０から引き出された５本のリード線６５が気密に挿通されている。この状態でグロメット７５は、セパレータ６０を先端側に押圧しつつ、外筒３０の外周から加締められて、外筒３０の後端に固定されている。 A fluorine rubber grommet 75 is fitted into the opening on the rear end side of the outer cylinder 30. The grommet 75 has five insertion holes 76 (one of which is shown in FIG. 1), and the five lead wires 65 drawn from the separator 60 are inserted into each insertion hole 76 in an airtight manner. ing. In this state, the grommet 75 is crimped from the outer periphery of the outer cylinder 30 while pressing the separator 60 toward the front end side, and is fixed to the rear end of the outer cylinder 30.

そして、主体金具５０の先端係合部５６には、センサ素子１０の検出部１１を、ガス中のデポジット（燃料灰分やオイル成分など被毒性の付着物質）による汚損や被水などによる折損等から保護するためのプロテクタ１００が嵌められ、レーザ溶接によって固定されている。
詳しくは後述するが、図１に示すように、プロテクタ１００は、被測定ガスを外部からプロテクタ内に導入可能な外側ガス導入部１４０を有しており、外側ガス導入部１４０が吸気通路２に対して特定の位置関係（本実施形態では吸気通路２の下流側）になるよう、ガスセンサ１がフランジ部２２０を介して吸気通路２に取り付けられる。
なお、「外側ガス導入部１４０」が特許請求の範囲の「ガス導入部」に相当する。 Further, the detection portion 11 of the sensor element 10 is connected to the front end engaging portion 56 of the metal shell 50 from contamination due to deposits in the gas (toxic substances such as fuel ash and oil components), breakage due to water exposure, and the like. A protector 100 for protection is fitted and fixed by laser welding.
As will be described in detail later, as shown in FIG. 1, the protector 100 has an outer gas introduction part 140 that can introduce the gas to be measured into the protector from the outside, and the outer gas introduction part 140 enters the intake passage 2. On the other hand, the gas sensor 1 is attached to the intake passage 2 via the flange portion 220 so as to have a specific positional relationship (in the present embodiment, on the downstream side of the intake passage 2).
The “outside gas introduction part 140” corresponds to the “gas introduction part” in the claims.

プロテクタ１００は、図１、図８〜図１０に示すように、検出素子１０の検知部１１と間隙をおいて配置された内側プロテクタ１２０と、内側プロテクタ１２０と間隙をおいて配置された外側プロテクタ１１０とから構成される２重構造を有する。
なお、図８は、外側プロテクタ１１０の斜視図、図９は内側プロテクタ１２０の斜視図、図１０は、図１に示すＡ−Ａ断面図である。 As shown in FIGS. 1 and 8 to 10, the protector 100 includes an inner protector 120 arranged with a gap from the detection unit 11 of the detection element 10, and an outer protector arranged with a gap from the inner protector 120. 110 and a double structure.
8 is a perspective view of the outer protector 110, FIG. 9 is a perspective view of the inner protector 120, and FIG. 10 is a cross-sectional view taken along line AA shown in FIG.

外側プロテクタ１１０は、ＳＵＳ３０４等のステンレス鋼から形成され、図１、図８に示すように、外側壁部１３０と外側壁部１３０よりも外径が拡径された外側基端部１３１を有する。外側基端部１３１は、主体金具５０の先端径合部５６に係合され、レーザ溶接にて主体金具５０と全周溶接されている。他方、外側壁部１３０は、外側基端部１３１の先端側に円筒状に設けられ、外周面に軸線方向に延びるスリット状の外側ガス導入部１４０が１つ設けられている。この外側ガス導入部１４０を介して外部から外側プロテクタ１１０に吸気ガスや吸気再循環ガスが導入される。さらに、外側壁部１３０の先端側には外側底部１３２が設けられており、この外側底部１３２には、吸気ガスや吸気再循環ガスが導出される導出部１５０が設けられている。なお、後述するように、ガスセンサ１が吸気通路２に配置されると、外側プロテクタ１１０の外側ガス導入部１４０は吸気通路２の下流側に配置されることになる。 The outer protector 110 is made of stainless steel such as SUS304, and has an outer wall portion 130 and an outer base end portion 131 whose outer diameter is larger than that of the outer wall portion 130 as shown in FIGS. The outer base end 131 is engaged with the distal end fitting portion 56 of the metal shell 50 and is welded to the metal shell 50 all around by laser welding. On the other hand, the outer wall portion 130 is provided in a cylindrical shape on the distal end side of the outer base end portion 131, and one slit-like outer gas introduction portion 140 extending in the axial direction is provided on the outer peripheral surface. Intake gas and intake recirculation gas are introduced into the outer protector 110 from the outside via the outer gas introduction part 140. Further, an outer bottom portion 132 is provided on the distal end side of the outer wall portion 130, and the outer bottom portion 132 is provided with a lead-out portion 150 from which intake gas and intake recirculation gas are derived. As will be described later, when the gas sensor 1 is disposed in the intake passage 2, the outer gas introduction part 140 of the outer protector 110 is disposed on the downstream side of the intake passage 2.

また、内側プロテクタ１２０は、ＳＵＳ３０４等のステンレス鋼から形成され、図１、図９に示すように、内側壁部１６０と内側壁部１６０よりも外径が拡径された内側基端部１６１を有する。内側基端部１６１は、主体金具５０の先端径合部５６に係合され、外側基端部１３１と共に、レーザ溶接にて主体金具５０と全周溶接されている。さらに、内側基端部１６１は、主体金具の先端係合部５６の先端面に対しても溶接されている。他方、内側壁部１６０は、内側基端部１６１の先端側に半円弧状に設けられており、検出素子１０の検出部１１のうち、ヒータ体側（図示せず）を覆っている。内側壁部１６０の径方向の端部には内側ガス導入部１７０が設けられており、本実施例では、検知部１１のガス検出体側は、内側ガス導入部１７０よりも突出し、外側プロテクタ１１０の内部空間に露出している。さらに、内側壁部１６０の先端側には内側底部１６２が設けられており、検出素子１０の検出部１１の先端を覆うように設けられている。なお、後述するように、ガスセンサ１が吸気通路２に配置されると、内側プロテクタ１１０の内側ガス導入部１７０は吸気通路２の上流側に配置されることになる。 Further, the inner protector 120 is made of stainless steel such as SUS304, and as shown in FIGS. 1 and 9, an inner base end portion 161 whose outer diameter is larger than that of the inner wall portion 160 and the inner wall portion 160 is formed. Have. The inner base end portion 161 is engaged with the distal end fitting portion 56 of the metal shell 50 and is welded to the metal shell 50 along the entire circumference together with the outer base end portion 131 by laser welding. Furthermore, the inner base end portion 161 is also welded to the front end surface of the front end engaging portion 56 of the metal shell. On the other hand, the inner wall portion 160 is provided in a semicircular arc shape on the distal end side of the inner base end portion 161 and covers the heater body side (not shown) of the detection portion 11 of the detection element 10. An inner gas introduction portion 170 is provided at the radial end portion of the inner wall portion 160. In this embodiment, the gas detection body side of the detection portion 11 protrudes from the inner gas introduction portion 170, and the outer protector 110 It is exposed to the internal space. Furthermore, an inner bottom portion 162 is provided on the distal end side of the inner wall portion 160 and is provided so as to cover the distal end of the detection portion 11 of the detection element 10. As will be described later, when the gas sensor 1 is disposed in the intake passage 2, the inner gas introduction portion 170 of the inner protector 110 is disposed upstream of the intake passage 2.

このガスセンサ１は、図７に示すように、吸気通路２に配置される。この吸気通路２にはガスが上流から下流に向けて流れている（図７の紙面手前から紙面奥方向）。この際、外側プロテクタ１１０の外側ガス導入部１４０が吸気通路２の下流側に配置されることとなる。これにより、ガスは吸気通路２の下流側から巻き込まれて外側プロテクタ１１０へ導入されることになる。
このように、内側プロテクタ１２０と外側プロテクタ１１０とを有するプロテクタ１００とすることで、外側ガス導入部１４０の目詰まりを考慮して、外側ガス導入部１４０を相対的に大きくしても、内側プロテクタ１２０の内側壁部１６０に水分や煤が付着することとなり、検出素子１０に水分や煤が付着することが抑制できる。その結果、検出素子１０がクラックや割れが生じることを抑制したり、検出精度が低下することを抑制できる。
なお、外側底部１３２には、吸気通路２の上流側に外側プロテクタ１１０から被測定ガスを導出可能なガス導出部１５０を有している。これにより、外側プロテクタ１１０内において被測定ガスが吸気経路２の下流側から上流側に流れることで、外側プロテクタ１１０内にて被測定ガスを効率よく置換でき、検出部１１の被測定ガスに対する検出精度が向上する。 The gas sensor 1 is disposed in the intake passage 2 as shown in FIG. Gas flows in the intake passage 2 from the upstream side toward the downstream side (from the front side of the paper in FIG. 7 toward the back of the paper). At this time, the outer gas introduction part 140 of the outer protector 110 is arranged on the downstream side of the intake passage 2. As a result, the gas is drawn from the downstream side of the intake passage 2 and introduced into the outer protector 110.
In this way, by using the protector 100 having the inner protector 120 and the outer protector 110, even if the outer gas introduction part 140 is made relatively large in consideration of the clogging of the outer gas introduction part 140, the inner protector. Moisture and soot adhere to the inner wall portion 160 of 120, and moisture and soot adhere to the detection element 10 can be suppressed. As a result, it is possible to suppress the detection element 10 from being cracked or broken or to suppress the detection accuracy from being lowered.
Note that the outer bottom portion 132 has a gas deriving portion 150 capable of deriving the gas to be measured from the outer protector 110 on the upstream side of the intake passage 2. As a result, the gas to be measured flows from the downstream side to the upstream side of the intake path 2 in the outer protector 110, so that the gas to be measured can be efficiently replaced in the outer protector 110, and the detection unit 11 detects the gas to be measured. Accuracy is improved.

次に、本発明の主要部である固定部材２００について説明する。
図３、図４に示すように、固定部材２００は主体金具５０と別部材の金属材料からなり、主体金具５０に着脱することができる。固定部材２００は、径方向の反対方向に互いに突出する板状のフランジ部２２０と、フランジ部２２０から後端側に突出する正六角形の本体部２１０とを有する。本体部２１０は中心に正六角形の多角孔２１０ｈを有し、多角孔２１０ｈはフランジ部２２０を貫通している。又、本体部２１０の後端縁２１０ｅは多角孔２１０ｈから径方向中心に向かって延び、多角孔２１０ｈより小径の円形の周縁を形成している。なお、多角孔２１０ｈは工具係合部５２よりわずかに大径であり、後端縁２１０ｅの周縁はガスセンサ１の外筒３０よりわずかに大径である。
他方、フランジ部２２０には、ガスセンサ１を吸気通路２に取り付けるための１対の取付孔２２１が、ガスセンサ１を挟んで対称に軸方向に貫通するように設けられている。フランジ部２２０が特許請求の範囲の「取付部」に相当する。 Next, the fixing member 200 that is the main part of the present invention will be described.
As shown in FIGS. 3 and 4, the fixing member 200 is made of a metal material different from the metal shell 50 and can be attached to and detached from the metal shell 50. The fixing member 200 includes a plate-like flange portion 220 that protrudes in the opposite direction to the radial direction, and a regular hexagonal main body portion 210 that protrudes from the flange portion 220 toward the rear end side. The main body 210 has a regular hexagonal polygonal hole 210 h at the center, and the polygonal hole 210 h passes through the flange 220. The rear end edge 210e of the main body 210 extends from the polygonal hole 210h toward the center in the radial direction, and forms a circular peripheral edge having a smaller diameter than the polygonal hole 210h. The polygonal hole 210h is slightly larger in diameter than the tool engaging portion 52, and the peripheral edge of the rear end edge 210e is slightly larger in diameter than the outer cylinder 30 of the gas sensor 1.
On the other hand, the flange portion 220 is provided with a pair of attachment holes 221 for attaching the gas sensor 1 to the intake passage 2 so as to pass through the gas sensor 1 symmetrically in the axial direction. The flange portion 220 corresponds to an “attachment portion” in the claims.

そして、図５に示すように、ガスセンサ１の後端側から固定部材２００を挿通すると、後端縁２１０ｅは外筒３０を通過して工具係合部５２の後端向き面５２ａに係止され、固定部材２００がガスセンサ１（工具係合部５２）の軸線Ｏ方向に位置決めされる。
一方、プロテクタ１００の外側ガス導入部１４０が吸気通路２の下流側（図５の流れＦ）になるよう、本実施形態では、取付孔２２１を結ぶ直線Ｌが流れＦに直交するように固定部材２００が主体金具５０に取り付けられる。このため、工具係合部５２の６つの頂点のうち外側ガス導入部１４０に向く頂点５２ｘに、多角孔２１０ｈの頂点２１０ｘを合わせて多角孔２１０ｈが工具係合部５２に嵌合される。図６（ａ）は、軸線Ｏ方向から見た、頂点５２ｘ、頂点２１０ｘの位置関係を示す。
そして、多角孔２１０ｈが工具係合部５２に位置合わせされ（取付け角度が調整され）、嵌合された状態で、溶接等により固定部材２００が主体金具５０に固定され、図２に示すガスセンサ１が完成する。なお、本実施形態では、本体部２１０の周方向に断続する数か所にてレーザ溶接されているが、固定部材２００が主体金具５０（工具係合部５２）に加締め固定されたり、圧入等によって固定されてもよい。
又、図６（ａ）に示すように、フランジ部２２０の一方の辺２２０ａが直線Ｌに平行な切断面を有していて、弧状に湾曲する他の辺と識別可能になっているとよい。この場合、辺２２０ａを外側ガス導入部１４０（頂点５２ｘ）と反対向きにして固定部材２００を工具係合部５２に嵌合することで、位置合わせが容易となる。 As shown in FIG. 5, when the fixing member 200 is inserted from the rear end side of the gas sensor 1, the rear end edge 210 e passes through the outer cylinder 30 and is locked to the rear end facing surface 52 a of the tool engaging portion 52. The fixing member 200 is positioned in the direction of the axis O of the gas sensor 1 (tool engaging portion 52).
On the other hand, in this embodiment, the fixing member is arranged so that the straight line L connecting the mounting holes 221 is orthogonal to the flow F so that the outer gas introduction part 140 of the protector 100 is on the downstream side of the intake passage 2 (flow F in FIG. 5). 200 is attached to the metal shell 50. For this reason, among the six vertices of the tool engagement portion 52, the vertex 52 x facing the outer gas introduction portion 140 is aligned with the vertex 210 x of the polygon hole 210 h so that the polygon hole 210 h is fitted into the tool engagement portion 52. FIG. 6A shows the positional relationship between the vertex 52x and the vertex 210x as viewed from the direction of the axis O.
The fixing member 200 is fixed to the metal shell 50 by welding or the like in a state where the polygonal hole 210h is aligned with the tool engaging portion 52 (attachment angle is adjusted) and fitted, and the gas sensor 1 shown in FIG. Is completed. In this embodiment, laser welding is performed at several points that are intermittent in the circumferential direction of the main body 210. However, the fixing member 200 is fixed by crimping to the metal shell 50 (tool engaging portion 52) or press-fitted. Or the like.
Also, as shown in FIG. 6A, one side 220a of the flange portion 220 has a cut surface parallel to the straight line L, so that it can be distinguished from the other side curved in an arc. . In this case, alignment is facilitated by fitting the fixing member 200 to the tool engagement portion 52 with the side 220a facing away from the outer gas introduction portion 140 (vertex 52x).

そして、図７に示すように、取付孔２２１に挿通した固定部材（ネジやボルト等）２３０を吸気通路２にネジ止めすることで、フランジ部２２０を介してガスセンサ１が吸気通路２に取り付けられる。なお、本実施形態では、吸気通路２の取付孔２ｈと、ガスセンサ１とのシールをガスケット５５（又は、Ｏリング）で行っている。又、図７の符号２３２はワッシャである。 Then, as shown in FIG. 7, the gas sensor 1 is attached to the intake passage 2 via the flange portion 220 by screwing a fixing member (screw or bolt) 230 inserted into the attachment hole 221 to the intake passage 2. . In this embodiment, the gasket 55 (or O-ring) is used to seal the mounting hole 2h of the intake passage 2 and the gas sensor 1. Reference numeral 232 in FIG. 7 is a washer.

以上のように、本実施形態によれば、工具係合部５２に対する多角孔２１０ｈの取付け角度（嵌合角度）を変えて固定部材２００を主体金具５０に固定することで、機種毎に異なるエンジンルームや流路であっても共通の固定部材２００及び共通のガスセンサ１を用いてガスセンサ１をエンジンルームや流路に取付けることができ、機種に応じて別個の形状の固定部材を作製したり、機種毎にガスセンサを作製する必要がない。
そして、外側ガス導入部１４０とフランジ部２２０とを特定の位置関係にすることで、ガスセンサ１を吸気通路２に取り付けた際に、外側ガス導入部１４０に被測定ガスが接触しにくくなり、目詰まりや被水を効果的に抑制できる。
さらに、検出素子１０からの熱は主体金具５０に伝わるが、主体金具５０を取り囲むようにして金属製の固定部材２００を取り付ける。このため、主体金具５０から固定部材２００に効果的に放熱することができ、グロメット７５や接続端子６１が熱影響を受け難く、放熱性に優れたガスセンサ１が得られる。又、ガスセンサ１に一般的に付属する主体金具（工具係合部５２）に固定部材２００を取り付ければよいので、固定部材２００を取り付けるための新たな部材をガスセンサ１に設ける必要がなく、部品点数の増大を抑制できる。 As described above, according to the present embodiment, the fixing member 200 is fixed to the metal shell 50 by changing the attachment angle (fitting angle) of the polygonal hole 210h with respect to the tool engaging portion 52, whereby different engines are used for different models. The gas sensor 1 can be attached to the engine room or the flow path using the common fixing member 200 and the common gas sensor 1 even in the room or the flow path, and a separate shaped fixing member can be produced according to the model, There is no need to make a gas sensor for each model.
And by making the outer gas introduction part 140 and the flange part 220 into a specific positional relationship, when the gas sensor 1 is attached to the intake passage 2, the measured gas is less likely to come into contact with the outer gas introduction part 140. Clogging and water exposure can be effectively suppressed.
Further, the heat from the detection element 10 is transmitted to the metal shell 50, but the metal fixing member 200 is attached so as to surround the metal shell 50. For this reason, heat can be effectively radiated from the metal shell 50 to the fixing member 200, and the grommet 75 and the connection terminal 61 are hardly affected by heat, and the gas sensor 1 having excellent heat dissipation can be obtained. Further, since the fixing member 200 may be attached to a metal shell (tool engaging portion 52) generally attached to the gas sensor 1, it is not necessary to provide a new member for attaching the fixing member 200 to the gas sensor 1, and the number of parts is reduced. Can be suppressed.

なお、工具係合部５２及び多角孔２１０ｈは正多角形であるので、工具係合部５２に対する多角孔２１０ｈの取付け（嵌合）角度の調整範囲は、多角形の内角（例えば、正六角形であれば、６０度）の整数倍となる。従って、取付け（嵌合）角度を多角形の内角の整数倍に正確に調整することができる。これに対し、例えばフランジ部２２０の取り付け相手材が円筒状である場合には、フランジ部２２０がガスセンサ１に対して自由に回転してしまうので、フランジ部２２０をガスセンサ１に対して特定の位置関係（例えば６０度）に合わせようとすると、取付け角度を作業者が一々調整する必要が生じ、作業効率が低下する。
具体的には、図６（ｂ）に示すように、車両（機種）によっては、例えば直線Ｌと流れＦとが３０度程度をなすような向きでガスセンサ１をエンジンルームや流路に取付けたい場合がある。この場合には、工具係合部５２の頂点５２ｘに、多角孔２１０ｈの頂点２１０ｙを合わせて多角孔２１０ｈを工具係合部５２に嵌合することで、直線Ｌが流れＦと３０度の角度をなし、図６（ａ）と図６（ｂ）の間で取付け角度を正確に６０度変えることができる。なお、多角孔２１０ｈの頂点２１０ｘ、２１０ｙは隣接している。 In addition, since the tool engaging part 52 and the polygonal hole 210h are regular polygons, the adjustment range of the attachment (fitting) angle of the polygonal hole 210h with respect to the tool engaging part 52 is a polygonal internal angle (for example, regular hexagonal). If there is, it is an integral multiple of 60 degrees). Therefore, the mounting (fitting) angle can be accurately adjusted to an integral multiple of the inner angle of the polygon. On the other hand, for example, when the mounting partner material of the flange portion 220 is cylindrical, the flange portion 220 freely rotates with respect to the gas sensor 1, and therefore the flange portion 220 is positioned at a specific position with respect to the gas sensor 1. If it tries to match | combine with a relationship (for example, 60 degree | times), it will be necessary for an operator to adjust an attachment angle one by one, and work efficiency will fall.
Specifically, as shown in FIG. 6B, depending on the vehicle (model), for example, it is desired to attach the gas sensor 1 to the engine room or the flow path in such a direction that the straight line L and the flow F form about 30 degrees. There is a case. In this case, by aligning the vertex 210y of the polygonal hole 210h with the vertex 52x of the tool engaging portion 52 and fitting the polygonal hole 210h to the tool engaging portion 52, the straight line L flows at an angle of 30 degrees with the flow F. The mounting angle can be accurately changed by 60 degrees between FIG. 6 (a) and FIG. 6 (b). The apexes 210x and 210y of the polygonal hole 210h are adjacent to each other.

さらに、図２に示すように、本体部２１０の後端縁２１０ｅと、外筒３０との間に隙間Ｇが生じるようにフランジ部２２０を固定すれば、フランジ部２２０を外筒３０と非接触にすることができる。この場合、主体金具５０からフランジ部２２０に伝わった熱が外筒３０に伝わることを抑制し、外筒３０内部に位置するグロメット７５や接続端子６１への熱影響をさらに抑制することができる。 Further, as shown in FIG. 2, if the flange portion 220 is fixed so that a gap G is generated between the rear end edge 210 e of the main body portion 210 and the outer tube 30, the flange portion 220 is not in contact with the outer tube 30. Can be. In this case, it is possible to suppress the heat transmitted from the metal shell 50 to the flange portion 220 from being transmitted to the outer cylinder 30 and to further suppress the thermal influence on the grommet 75 and the connection terminal 61 located inside the outer cylinder 30.

さらに、外側ガス導入部１４０は、外側プロテクタ１１０の周方向の一部の範囲にのみ設けられている。これにより、外側ガス導入部１４０とフランジ部２２０とを特定の位置関係にすることで、ガスセンサ１を吸気通路２に取り付けた際に、外側ガス導入部１４０に被測定ガスを効果的に接触させにくくすることができる。その結果、目詰まりや被水をより効果的に抑制できる。 Further, the outer gas introduction part 140 is provided only in a partial range of the outer protector 110 in the circumferential direction. Thus, by setting the outer gas introduction part 140 and the flange part 220 to a specific positional relationship, when the gas sensor 1 is attached to the intake passage 2, the gas to be measured is effectively brought into contact with the outer gas introduction part 140. Can be difficult. As a result, clogging and moisture can be more effectively suppressed.

なお、本発明は上記各実施の形態に限られず、各種の変形が可能である。例えば、上記実施形態では、多角孔２１０ｈは多角部５２は同一の辺を持つ正六角形の孔としたが、図１１に示すように多角孔３１０ｈが多角部１５２の２倍の辺の数を持つ正多角形の孔としてもよい。
具体的には、図１１に示す固定部材３００は、フランジ部３２０と、フランジ部３２０から後端側に突出する正八角形の本体部３１０とを有する。フランジ部３２０は図３のフランジ部２２０と同一であり、本体部３１０の中心の多角孔３１０ｈが正八角形である点が図３に示す固定部材２００と異なっている。一方、ガスセンサ１の多角部１５２は軸線方向から見て正四角形をなす点が図１に示す多角部５２と異なっている。 The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, in the above embodiment, the polygonal hole 210h is a regular hexagonal hole in which the polygonal part 52 has the same side, but the polygonal hole 310h has twice the number of sides as the polygonal part 152 as shown in FIG. It may be a regular polygonal hole.
Specifically, the fixing member 300 illustrated in FIG. 11 includes a flange portion 320 and a regular octagonal main body portion 310 protruding from the flange portion 320 toward the rear end side. The flange portion 320 is the same as the flange portion 220 in FIG. 3, and is different from the fixing member 200 shown in FIG. 3 in that the polygonal hole 310 h at the center of the main body portion 310 is a regular octagon. On the other hand, the polygonal part 152 of the gas sensor 1 is different from the polygonal part 52 shown in FIG.

このように、多角孔３１０ｈが多角部１５２の２倍の辺の数を持つ場合、多角部１５２に対するフランジ部３２０の軸線Ｏ周りの取付け角度をより細かく調整できる。つまり、図１１（ａ）に示すように、取付孔３２１を結ぶ直線Ｌが流れＦに直交するように固定部材３００が多角部１５２に取り付けられた位置を基準とし、この基準位置から軸線Ｏ周りに固定部材３００の軸線Ｏ周りの取付け角度を変えた場合を図１１（ｂ）とする。
図１１（ａ）においては、多角部１５２の４つの頂点のうち外側ガス導入部１４０に向く頂点１５２ｘに、多角孔３１０ｈの頂点３１０ｘを合わせて多角孔３１０ｈが多角部１５２に嵌合される。
一方、フランジ部３２０の向き（取付孔３２１を結ぶ直線Ｌ）と、外側ガス導入部１４０との向きを調整したい場合、頂点１５２ｘに、多角孔３１０ｈの頂点３１０ｙを合わせて多角孔３１０ｈを多角部１５２に嵌合する。このとき、多角孔３１０ｈの内角は４５度であるから、直線Ｌが流れＦと４５度の角度をなし、図１１（ａ）と図１１（ｂ）の間で取付け角度を正確に４５度変えることができる。これに対し、仮に多角孔３１０ｈを多角部１５２と同一の正四角形の孔とした場合には、正四角形の内角が９０度であるから取付け角度の調整も最小９０度となる。すなわち、多角孔３１０ｈが多角部１５２の２倍の辺の数を持つことにより、取付け角度をより細かく調整できることになる。 Thus, when the polygonal hole 310h has the number of sides twice that of the polygonal part 152, the attachment angle around the axis O of the flange part 320 with respect to the polygonal part 152 can be adjusted more finely. That is, as shown in FIG. 11A, the position where the fixing member 300 is attached to the polygonal part 152 so that the straight line L connecting the attachment holes 321 is orthogonal to the flow F is used as a reference, and the axis O around the reference position. FIG. 11B shows a case where the mounting angle around the axis O of the fixing member 300 is changed.
In FIG. 11A, the polygon hole 310 h is fitted into the polygon part 152 by aligning the vertex 310 x of the polygon hole 310 h with the vertex 152 x facing the outer gas introduction part 140 among the four vertices of the polygon part 152.
On the other hand, when the orientation of the flange portion 320 (straight line L connecting the attachment holes 321) and the orientation of the outer gas introduction portion 140 are to be adjusted, the vertex hole 310h is aligned with the vertex 310y of the polygon hole 310h, and the polygon hole 310h is changed to the polygon portion. 152. At this time, since the internal angle of the polygonal hole 310h is 45 degrees, the straight line L forms an angle of 45 degrees with the flow F, and the mounting angle is accurately changed 45 degrees between FIG. 11 (a) and FIG. 11 (b). be able to. On the other hand, if the polygonal hole 310h is a regular square hole that is the same as the polygonal part 152, the interior angle of the regular square is 90 degrees, so the adjustment of the mounting angle is also a minimum of 90 degrees. That is, when the polygon hole 310h has the number of sides twice that of the polygon part 152, the attachment angle can be adjusted more finely.

又、本実施形態では、プロテクタ１００を外側プロテクタ１１０及び内側プロテクタ１２０の２重のプロテクタを用いたが、これに限られず、１重のプロテクタであってもよいし、３重以上のプロテクタであってもよい。また、外側ガス導入部１４０の形状は矩形状に限られない。また、本実施形態では全領域空燃比センサを例に説明したが、酸素センサ、ＮＯｘセンサ、ＨＣセンサ、温度センサ等にも同様に適用できる。 In the present embodiment, the protector 100 uses the double protector of the outer protector 110 and the inner protector 120. However, the protector 100 is not limited to this, and may be a single protector or a triple protector. May be. Further, the shape of the outer gas introduction unit 140 is not limited to a rectangular shape. In the present embodiment, the full-range air-fuel ratio sensor has been described as an example, but the present invention can be similarly applied to an oxygen sensor, a NOx sensor, an HC sensor, a temperature sensor, and the like.

１ガスセンサ
２流路
１０検出素子
１１検出部
３０外筒
５０主体金具
５２、１５２多角部（工具係合部）
１００プロテクタ
１５０ガス導入部
２００、３００固定部材
２１０ｈ、３１０ｈ多角孔
２２０、３２０フランジ部
Ｏ軸線方向 DESCRIPTION OF SYMBOLS 1 Gas sensor 2 Flow path 10 Detection element 11 Detection part 30 Outer cylinder 50 Metal shell 52,152 Polygonal part (tool engagement part)
100 protector 150 gas introduction part 200, 300 fixing member 210h, 310h polygonal hole 220, 320 flange part O axial direction

Claims

A detection element that extends in the axial direction and has a detection unit for detecting a specific gas component in the gas to be measured on its tip side;
A cylindrical metal shell that surrounds the periphery of the detection element in the radial direction while protruding from the tip of the detection unit, and forms a polygon when viewed along the axial direction, and protrudes in the radial direction. A metal shell having a polygonal portion to be
A cylindrical protector that is fixed to the metal shell while accommodating the detection portion of the detection element inside,
A metal outer cylinder connected to the rear end side of the metal shell,
A gas sensor disposed in a flow path through which the gas to be measured flows,
A metal fixing member having a polygonal hole fitted to the polygonal portion and detachable from the gas sensor, further comprising a fixing member having an attachment portion attachable to the flow path,
The protector has a gas introduction part capable of introducing the measurement gas into the protector from the outside,
The polygonal hole is fitted into the polygonal part in a state where the attachment angle of the polygonal hole with respect to the polygonal part is adjusted so that the attachment part and the gas introduction part have a specific positional relationship, and the fixing member is A gas sensor fixed to the metal shell.

The gas sensor according to claim 1, wherein the polygonal hole has the same number of sides as the polygonal part, or the polygonal hole is a polygonal hole having twice the number of sides of the polygonal part.

The gas sensor according to claim 1, wherein the attachment portion is not in contact with the outer cylinder.

The gas sensor according to any one of claims 1 to 3, wherein the gas introduction part is provided only in a partial range in a circumferential direction of the protector.