JP2013044308A - Device for preventing water from adhering to gas sensor - Google Patents

Device for preventing water from adhering to gas sensor Download PDF

Info

Publication number
JP2013044308A
JP2013044308A JP2011184225A JP2011184225A JP2013044308A JP 2013044308 A JP2013044308 A JP 2013044308A JP 2011184225 A JP2011184225 A JP 2011184225A JP 2011184225 A JP2011184225 A JP 2011184225A JP 2013044308 A JP2013044308 A JP 2013044308A
Authority
JP
Japan
Prior art keywords
intake
wall
groove
water
air
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2011184225A
Other languages
Japanese (ja)
Other versions
JP5769076B2 (en
Inventor
Hiroyuki Kimura
洋之 木村
Kojiro Okada
公二郎 岡田
Kiyoka Tsunekawa
希代香 恒川
Seiji Matsuda
征二 松田
Yusuke Isobe
雄輔 磯部
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Motors Corp
Original Assignee
Mitsubishi Motors Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Motors Corp filed Critical Mitsubishi Motors Corp
Priority to JP2011184225A priority Critical patent/JP5769076B2/en
Publication of JP2013044308A publication Critical patent/JP2013044308A/en
Application granted granted Critical
Publication of JP5769076B2 publication Critical patent/JP5769076B2/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Measuring Oxygen Concentration In Cells (AREA)

Abstract

PROBLEM TO BE SOLVED: To protect a gas sensor, which is provided in an intake pipe of an internal combustion engine, against a thermal shock of condensed water contained in intake air, and to keep gas component detection accuracy high.SOLUTION: An air-fuel ratio sensor 10 is mounted on a vertical pipe wall 30 of an intake manifold. A detection part 18 of the air-fuel ratio sensor 10 is protrusively arranged in an intake channel. A plurality of ring-shaped recessed grooves 36 and 37 are engraved on the inner walls of the vertical pipe walls 30 on the intake upstream side and intake downstream side of the detection part 18, respectively. The ring-shaped recessed groove 36 inhibits a water droplet w, which adheres to the inner wall of the vertical pipe wall 30 on the intake upstream side of the detection part 18, from advancing toward the detection part 18. The ring-shaped recessed groove 37 inhibits the water droplet w, which flows down from the upper vertical pipe wall 30, from flowing down.

Description

本発明は、内燃機関の吸気管に設けられたガスセンサの検出部が、吸気に含まれる凝縮水の付着によって熱衝撃を受け損傷するのを防止可能にしたガスセンサの被水防止装置に関する。   TECHNICAL FIELD The present invention relates to a water sensor for preventing moisture from being detected by a gas sensor provided in an intake pipe of an internal combustion engine, which can be prevented from being damaged by thermal shock due to adhesion of condensed water contained in intake air.

ディーゼルエンジンやガソリンエンジン等の内燃機関の吸気管や排気管には、吸気中の特定ガス成分を検出するセンサが設けられている。このようなセンサとして、例えば、ジルコニアなどの固体電解質からなるガス検出素子を用いて、Ｏ２濃度を検出する空燃比センサや、排気中のＮＯＸ濃度を検出するＮＯＸセンサ等がある。これらのガスセンサは、ガス検出素子を内蔵した検出部が吸気又は排気に曝される位置に配置され、この検出部で特定ガス成分を検出する。例えば、空燃比センサにおいては、検出部にはヒータが内蔵され、このヒータを用いてガス検出素子を高温に加熱し活性化することで、特定ガス成分を検出する。 A sensor for detecting a specific gas component in the intake air is provided in an intake pipe or an exhaust pipe of an internal combustion engine such as a diesel engine or a gasoline engine. Such sensors, for example, by using a gas detecting element comprising a solid electrolyte such as zirconia, and the air-fuel ratio sensor for detecting the O 2 concentration, there is a NO X sensor for detecting the concentration of NO X in the exhaust gas. These gas sensors are arranged at a position where a detection unit including a gas detection element is exposed to intake air or exhaust gas, and the detection unit detects a specific gas component. For example, in the air-fuel ratio sensor, a heater is built in the detection unit, and the gas detection element is heated to high temperature and activated using the heater, thereby detecting a specific gas component.

エンジンの停止後など、吸気又は排気の温度が低下した時、凝縮水が析出する。前記センサのガス検出素子は、熱衝撃に弱いセラミックで形成されているため、低温の凝縮水がガス検出素子に付着すると、ガス検出素子が急冷され、熱衝撃によりガス検出素子にクラックや割れが発生するおそれがある。運転中高温の排気は、凝縮水の析出量は少ないため、あまり問題とならない。一方、吸気流路のうち、インタークーラの下流側では、インタークーラで吸気が冷却されるため、凝縮水が析出しやすい。燃料の燃焼により水蒸気が生成されるため、吸気より排気のほうが水蒸気分圧が高い。そのため、特に、排気を吸気流路に再循環するＥＧＲ装置を備えた内燃機関では、インタークーラの下流側吸気流路で凝縮水の析出量が多い。   Condensed water is deposited when the intake or exhaust temperature drops, such as after the engine has stopped. Since the gas detection element of the sensor is formed of ceramic that is vulnerable to thermal shock, if low-temperature condensed water adheres to the gas detection element, the gas detection element is rapidly cooled, and the gas detection element is cracked or cracked by thermal shock. May occur. High temperature exhaust during operation is not a problem because the amount of condensed water deposited is small. On the other hand, on the downstream side of the intercooler in the intake passage, the intake air is cooled by the intercooler, so that condensed water is likely to precipitate. Since water vapor is generated by the combustion of fuel, the partial pressure of water vapor is higher in the exhaust than in the intake air. Therefore, in particular, in an internal combustion engine equipped with an EGR device that recirculates exhaust gas into the intake passage, the amount of condensed water deposited in the intake passage downstream of the intercooler is large.

特許文献１に開示された手段は、ガスセンサの上流側排気流路に水溜室を設け、排気流路と該水溜室とを連通する孔を設けたものであり、排気流路に滞留した凝縮水を該孔を通して該水溜室に溜めるようにしている。   The means disclosed in Patent Document 1 is provided with a water reservoir chamber in the upstream exhaust flow path of the gas sensor, and a hole that communicates the exhaust flow path and the water reservoir chamber, and the condensed water staying in the exhaust flow path. Is stored in the water reservoir through the hole.

特許文献２に開示された手段は、水平方向に配置された排気流路で、ガスセンサの上流側排気流路に排気流路内を上下に分割する仕切板を設けている。この仕切板によって排気流路の底部に溜まった滞留水の巻上げを抑制し、滞留水がガス検出素子に付着しにくくしたものである。   The means disclosed in Patent Document 2 is an exhaust passage arranged in a horizontal direction, and a partition plate that divides the inside of the exhaust passage into upper and lower portions is provided in the upstream exhaust passage of the gas sensor. This partition plate suppresses the hoisting of the accumulated water accumulated at the bottom of the exhaust flow path, and makes it difficult for the accumulated water to adhere to the gas detection element.

図６〜図９に、吸気マニホールドに装着された空燃比センサの構成を示す。吸気マニホールド１２０は、垂直部１２０ａと水平部１２０ｂとで構成され、垂直部１２０ａの管壁に空燃比センサ１００が設けられている。水平部１２０ｂは、４本の分岐管１２２ａ〜ｄに分かれ、各分岐管は、夫々がシリンダブロック１２４に設けられた４個のシリンダヘッドに接続されている。吸気ａは凝縮水を含み、吸気マニホールド１２０の壁面に付着した大きな水滴w１は、壁面を旋回しながら進み、小さな水滴ｗ２は吸気に含まれて、吸気ａと共に流れる。内燃機関の停止後、吸気マニホールド１２０の上部壁に付着した水滴ｗ３は、空燃比センサ１００の検出部１０６のほうへ落下してくる。   6 to 9 show the configuration of the air-fuel ratio sensor mounted on the intake manifold. The intake manifold 120 includes a vertical portion 120a and a horizontal portion 120b, and the air-fuel ratio sensor 100 is provided on the pipe wall of the vertical portion 120a. The horizontal portion 120b is divided into four branch pipes 122a to 122d, and each branch pipe is connected to four cylinder heads provided in the cylinder block 124, respectively. The intake air a includes condensed water, and the large water droplets w1 attached to the wall surface of the intake manifold 120 travel while turning around the wall surface, and the small water droplets w2 are included in the intake air and flow together with the intake air a. After the internal combustion engine is stopped, the water droplet w3 adhering to the upper wall of the intake manifold 120 falls toward the detection unit 106 of the air-fuel ratio sensor 100.

ガスセンサ１００の軸方向中央に雄ネジ１０２及びナット１０４が一体形成されている。垂直部１２０ａの管壁に設けられたボス部１２６に雌ネジ孔１２８が形成され、該雌ネジ孔１２８に雄ネジ１０２が螺合している。ガスセンサ１００の検出部１０６が、垂直部１２０ａの管壁から吸気流路内に突設されている。検出部１０６のケースは外壁１０８及び内壁１１０からなり、夫々に吸気導入孔１１２が穿設されている。内壁１１０の内側にガス検出素子１１４が配置され、ガス検出素子１１４の内側にヒータ１１６が配置されている。   A male screw 102 and a nut 104 are integrally formed at the center of the gas sensor 100 in the axial direction. A female screw hole 128 is formed in a boss portion 126 provided on the tube wall of the vertical portion 120 a, and the male screw 102 is screwed into the female screw hole 128. The detection unit 106 of the gas sensor 100 protrudes from the tube wall of the vertical part 120a into the intake passage. The case of the detection unit 106 includes an outer wall 108 and an inner wall 110, and an intake introduction hole 112 is formed in each case. A gas detection element 114 is arranged inside the inner wall 110, and a heater 116 is arranged inside the gas detection element 114.

特開２００７−２７２３号公報JP 2007-2723 A 特開２０１０−１１２２２２号公報JP 2010-112222 A

特許文献１に開示された被水防止手段は、排気流路に水溜室を設けるため、排気管の製造工程が増加し、高コストになるという問題がある。特許文献２に開示された被水防止手段は、排気流路に仕切板を設けるため、排気管の製造工程が増加し、高コストになると共に、排気の圧力損失が増加し、内燃機関の熱効率を低下させるという問題がある。   The water-preventing means disclosed in Patent Document 1 has a problem in that since a water reservoir chamber is provided in the exhaust passage, the manufacturing process of the exhaust pipe is increased and the cost is increased. Since the moisture prevention means disclosed in Patent Document 2 is provided with a partition plate in the exhaust passage, the manufacturing process of the exhaust pipe increases, the cost increases, the pressure loss of the exhaust increases, and the thermal efficiency of the internal combustion engine There is a problem of lowering.

図９において、吸気ａは、管壁の近傍で管壁との摩擦により流速が小さく、かつ圧力が高い。逆に流速が大きい流路中央域では圧力が低い。そのため、吸気ａは、管壁近傍に配置された吸気導入孔１１２から検出部１０６の内部に進入し、ガス検出素子１１４に接触した後、流路中央側の吸気導入孔１１２から出て行く。この時、吸気ａに含まれる水滴がガス検出素子１１４に付着することで、前述の熱衝撃による破損の問題が起こる。   In FIG. 9, the intake air a has a low flow rate and a high pressure due to friction with the tube wall in the vicinity of the tube wall. Conversely, the pressure is low in the central region of the flow path where the flow velocity is large. Therefore, the intake air a enters the inside of the detection unit 106 from the intake air introduction hole 112 disposed in the vicinity of the pipe wall, contacts the gas detection element 114, and then exits from the intake air introduction hole 112 on the center side of the flow path. At this time, water droplets contained in the intake air a adhere to the gas detection element 114, thereby causing the above-described damage due to thermal shock.

本発明は、かかる従来技術の課題に鑑み、簡易かつ低コストな手段で、吸気流路内に突設された検出部が、吸気に含まれる凝縮水による熱衝撃で損傷するのを防止することを目的とする。   In view of the problems of the prior art, the present invention prevents the detection unit protruding in the intake flow path from being damaged by the thermal shock caused by the condensed water contained in the intake air by simple and low-cost means. With the goal.

かかる目的を達成するため、本発明のガスセンサの被水防止装置は、内燃機関の吸気流路内に突設された検出部を備えたガスセンサの被水防止装置において、少なくとも検出部より吸気流れ方向において上流側吸気管の内壁に、吸気流れ方向と交差し、吸気管壁面に付着した内壁に付着した水滴が検出部に接触することを抑制する凹溝を設けたものである。   In order to achieve this object, a water sensor for preventing water in a gas sensor according to the present invention is a water sensor for preventing water in a gas sensor provided with a detector projecting in an intake passage of an internal combustion engine. In FIG. 2, a concave groove is provided on the inner wall of the upstream intake pipe that crosses the intake flow direction and prevents water droplets attached to the inner wall attached to the wall surface of the intake pipe from coming into contact with the detection unit.

吸気流路では、管壁に付着した凝縮水は、吸気流によって壁面を旋回しながら進む。ガスセンサの検出部の少なくとも吸気上流側に、前記凹溝を設けたことにより、該凹溝が凝縮水の前進に対する抵抗となり、凝縮水の前進を阻止する。これによって、検出部に凝縮水が付着するのを防止でき、ガス検出素子が凝縮水によって破損するのを防止できる。なお、ガスセンサが取り付けられる管壁が上下方向に配置された吸気管においては、ガスセンサの下流側上方管壁にも凹溝を設けるとよい。これによって、管壁を伝って流下する凝縮水がガスセンサの検出部に到達するのを防止できる。   In the intake flow path, the condensed water adhering to the tube wall advances while turning around the wall surface by the intake flow. By providing the concave groove at least on the upstream side of the intake air of the detection part of the gas sensor, the concave groove becomes a resistance against the forward movement of the condensed water and prevents the forward movement of the condensed water. Thereby, it is possible to prevent the condensed water from adhering to the detection unit, and it is possible to prevent the gas detection element from being damaged by the condensed water. In addition, in the intake pipe in which the pipe wall to which the gas sensor is attached is arranged in the vertical direction, a concave groove may be provided in the upper pipe wall on the downstream side of the gas sensor. Thereby, it is possible to prevent the condensed water flowing down along the tube wall from reaching the detection part of the gas sensor.

本発明において、前記凹溝が、吸気流れ方向に複数配置された凹溝で構成されているとよい。凹溝を吸気流れ方向に複数配置することで、壁面に付着した凝縮水の前進抑止効果を向上できる。   In the present invention, it is preferable that the concave groove is constituted by a plurality of concave grooves arranged in the intake flow direction. By arranging a plurality of concave grooves in the direction of intake air flow, it is possible to improve the forward deterrent effect of the condensed water adhering to the wall surface.

本発明において、前記凹溝が、前記検出部の吸気上流側及び吸気下流側に配設された螺旋状凹溝と、該螺旋状凹溝を結ぶ連絡用凹溝とから構成されているとよい。螺旋状凹溝に付着した凝縮水は、吸気流で押され、螺旋状凹溝に沿って吸気下流側へ前進する。そして、連絡用凹溝を経由して下流側の螺旋状凹溝に流出する。そのため、検出部に凝縮水が付着するのを防止できる。   In the present invention, it is preferable that the concave groove is composed of a spiral concave groove disposed on the intake upstream side and the intake downstream side of the detection unit, and a communication concave groove connecting the spiral concave grooves. . Condensed water adhering to the spiral groove is pushed by the intake air flow and advances along the spiral groove toward the intake downstream side. And it flows out into the spiral groove on the downstream side via the communication groove. Therefore, it can prevent that condensed water adheres to a detection part.

なお、管壁が上下方向に配置された吸気管においては、上方の管壁に付着し該管壁を伝って流下する凝縮水は、螺旋状凹溝に流入し、該螺旋状凹溝及び連絡用凹溝を伝って上流側（下方領域）に刻設された螺旋状凹溝に流下する。そのため、検出部の上方から流下する凝縮水が検出部に付着するのを防止できる。   In the intake pipe in which the pipe wall is arranged in the vertical direction, the condensed water that adheres to the upper pipe wall and flows down through the pipe wall flows into the spiral groove and communicates with the spiral groove. It flows down to the spiral concave groove carved on the upstream side (lower region) through the concave groove for use. Therefore, it is possible to prevent the condensed water flowing from above the detection unit from adhering to the detection unit.

本発明において、ガスセンサの検出部の周囲に該検出部に設けられた吸気導入口を覆う位置まで吸気流路内に突出配置された筒状カバーを備え、該筒状カバーの内壁が突出方向の先端側で拡径されたテーパ壁で形成され、かつ該テーパ壁の先端部から前記吸気導入口に至るまでの領域に螺旋溝が形成されているとよい。該筒状カバーによって吸気に含まれる凝縮水が直接吸気導入孔から検出部の内部に浸入するのを防止できる。   In the present invention, a cylindrical cover is provided around the detection portion of the gas sensor so as to protrude into the intake passage to a position covering the intake inlet provided in the detection portion, and the inner wall of the cylindrical cover extends in the protruding direction. It is preferable that a spiral groove is formed in a region extending from the tip end portion of the tapered wall to the intake inlet port. The cylindrical cover can prevent the condensed water contained in the intake air from directly entering the detection portion through the intake air introduction hole.

また、筒状カバーの先端部から筒状カバーの内部に進入した吸気は、螺旋溝に沿って旋回する。筒状カバーの内径は根元部に向かって徐々に狭まるので、吸気は旋回速度を増しながら筒状カバーの奥に進入し、検出部に設けられた吸気導入孔から検出部の内部へ進入する。そのため、吸気導入孔が検出部の根元側に設けられているときでも、吸気の主流のガス成分を検出できると共に、吸気の流速を増大できるので、ガス成分を応答性良く検出できる。   The intake air that has entered the inside of the cylindrical cover from the tip of the cylindrical cover turns along the spiral groove. Since the inner diameter of the cylindrical cover gradually decreases toward the root portion, the intake air enters the interior of the cylindrical cover while increasing the turning speed, and enters the inside of the detection unit through an intake introduction hole provided in the detection unit. Therefore, even when the intake air introduction hole is provided on the base side of the detection unit, the mainstream gas component of the intake air can be detected and the flow velocity of the intake air can be increased, so that the gas component can be detected with good responsiveness.

本発明によれば、内燃機関の吸気流路内に突出配置された検出部を備えたガスセンサの被水防止装置において、少なくとも検出部より吸気流れ方向において上流側吸気管の内壁に、吸気流れ方向と交差し、吸気管壁面に付着した水滴が検出部に接触するするのを防止した凹溝を設けたので、検出部の吸気上流側で管壁に付着した凝縮水が検出部の内部へ浸入するのを防止でき、これによって、ガス検出素子の熱衝撃による損傷を防止できる。   According to the present invention, in a water sensor for a water sensor of a gas sensor provided with a detection unit that protrudes in an intake flow path of an internal combustion engine, at least an intake flow direction on an inner wall of an upstream intake pipe in an intake flow direction from the detection unit The condensate adhering to the pipe wall enters the inside of the detection unit on the upstream side of the intake of the detection unit because a ditch is provided to prevent water droplets attached to the intake pipe wall from contacting the detection unit. This can prevent the gas detection element from being damaged by thermal shock.

本発明装置の第１実施形態に係る吸気マニホールドの断面図である。It is sectional drawing of the intake manifold which concerns on 1st Embodiment of this invention apparatus. 本発明装置の第２実施形態に係る吸気マニホールドの断面図である。It is sectional drawing of the intake manifold which concerns on 2nd Embodiment of this invention apparatus. 本発明装置の第３実施形態に係る吸気マニホールドの断面図である。It is sectional drawing of the intake manifold which concerns on 3rd Embodiment of this invention apparatus. 図３中のＣ方向から視た図である。It is the figure seen from the C direction in FIG. 本発明装置の第４実施形態に係る吸気マニホールドの断面図である。It is sectional drawing of the intake manifold which concerns on 4th Embodiment of this invention apparatus. 内燃機関に設けられた吸気マニホールドの正面図である。It is a front view of the intake manifold provided in the internal combustion engine. 図６中のＡ―Ａ線に沿う断面図である。It is sectional drawing which follows the AA line in FIG. 図６中のＢ―Ｂ線に沿う断面図である。It is sectional drawing which follows the BB line in FIG. 従来の空燃比センサの断面図である。It is sectional drawing of the conventional air fuel ratio sensor.

以下、本発明を図に示した実施形態を用いて詳細に説明する。但し、この実施形態に記載されている構成部品の寸法、材質、形状、その相対配置などは特に特定的な記載がない限り、この発明の範囲をそれのみに限定する趣旨ではない。   Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

（実施形態１）
本発明装置の第１実施形態を図１に基づいて説明する。本実施形態は、内燃機関に設けられた吸気マニホールド又は吸気管の垂直管壁に装着された空燃比センサに適用された例である。吸気マニホールド又は吸気管の垂直管壁３０に、雌ネジ孔３４が設けられている。この雌ネジ孔３４に空燃比センサ１０が螺着されている。空燃比センサ１０は、出力端子が内蔵され、リード線１１が接続された基部１２と、雌ネジ孔３４に螺合する雄ネジ１６と、雄ネジ１６と一体形成されたナット１４と、垂直管壁３０から吸気流路内に突出配置される検出部１８とで構成され、雄ネジ１６が雌ネジ孔３４に螺合することで、垂直管壁３０に固定されている。 (Embodiment 1)
1st Embodiment of this invention apparatus is described based on FIG. The present embodiment is an example applied to an air-fuel ratio sensor attached to an intake manifold provided in an internal combustion engine or a vertical pipe wall of an intake pipe. A female screw hole 34 is provided in the vertical pipe wall 30 of the intake manifold or the intake pipe. The air-fuel ratio sensor 10 is screwed into the female screw hole 34. The air-fuel ratio sensor 10 includes an output terminal, a base 12 to which a lead wire 11 is connected, a male screw 16 that is screwed into the female screw hole 34, a nut 14 that is integrally formed with the male screw 16, and a vertical pipe. It is comprised with the detection part 18 arrange | positioned in the intake flow path from the wall 30, and it is being fixed to the vertical pipe wall 30 by the male screw 16 screwing in the female screw hole 34. As shown in FIG.

検出部１８の垂直管壁３０に近い根元部には、周方向に複数の吸気導入孔２０が穿設されている。吸気導入孔２０から検出部１８の内部に進入した吸気ａが、検出部１８に内蔵されたガス検出素子（図示省略）に接触することで、吸気中の酸素濃度を検出する。空燃比センサ１０の取付け場所の近傍で吸気上流側、即ち、下方領域の垂直管壁３０の内壁に、４条のリング状凹溝３６が刻設されている。また、空燃比センサ１０の近傍で吸気下流側、即ち上方管壁に３条のリング状凹溝３７が刻設されている。   A plurality of intake air introduction holes 20 are formed in the base portion of the detection unit 18 near the vertical tube wall 30 in the circumferential direction. The intake air a that has entered the detection unit 18 through the intake introduction hole 20 comes into contact with a gas detection element (not shown) built in the detection unit 18 to detect the oxygen concentration in the intake air. Four ring-shaped concave grooves 36 are formed on the intake upstream side, that is, on the inner wall of the vertical pipe wall 30 in the lower region in the vicinity of the mounting location of the air-fuel ratio sensor 10. Further, three ring-shaped concave grooves 37 are formed in the vicinity of the air-fuel ratio sensor 10 on the intake downstream side, that is, on the upper pipe wall.

リング状凹溝３６及び３７は、四角断面を有し、垂直管壁３０の軸方向と直角方向の面に平行で、互いに等間隔に配置されている。また、空燃比センサ１０の上流側吸気流路には、インタークーラ及びＥＧＲガスの導入口（図示省略）が設けられている。インタークーラで冷却された吸気ａ及びＥＧＲガスは凝縮した水滴ｗを含んでいる。   The ring-shaped concave grooves 36 and 37 have a square cross section, are parallel to the plane perpendicular to the axial direction of the vertical tube wall 30 and are arranged at equal intervals. In addition, an intercooler and an EGR gas inlet (not shown) are provided in the upstream intake passage of the air-fuel ratio sensor 10. The intake air a and the EGR gas cooled by the intercooler contain condensed water droplets w.

かかる構成において、空燃比センサ１０の吸気上流側で、垂直管壁３０に付着した水滴ｗは、４条のリング状凹溝３６により前進を阻まれる。これによって、垂直管壁３０を伝う水滴ｗが検出部１８に到達するのを防止できる。そのため、検出部５８ａに内蔵されたガス検出素子に水滴ｗが付着し、その熱衝撃によってガス検出素子が破損するのを防止できる。   In such a configuration, the water droplets w adhering to the vertical pipe wall 30 on the upstream side of the intake air of the air-fuel ratio sensor 10 are prevented from advancing by the four ring-shaped concave grooves 36. Thereby, it is possible to prevent the water droplets w traveling along the vertical tube wall 30 from reaching the detection unit 18. Therefore, it is possible to prevent water droplets w from adhering to the gas detection element built in the detection unit 58a and damaging the gas detection element due to the thermal shock.

また、検出部１８の吸気下流側、即ち上方の垂直管壁３０に付着した水滴ｗは、重力により垂直管壁３０を伝って下方へ流下する。この流下する水滴ｗはリング状凹溝３７で流下を阻止され、検出部１８に到達するのを防止できる。この水滴ｗの一部は、稼動している内燃機関の熱で気化し、吸気ａと共に下流側に運ばれる。   Further, the water droplets w attached to the intake pipe downstream side of the detection unit 18, that is, the upper vertical pipe wall 30, flow downward through the vertical pipe wall 30 due to gravity. The flowing water droplets w are prevented from flowing down by the ring-shaped concave groove 37 and can be prevented from reaching the detection unit 18. A part of this water droplet w is vaporized by the heat of the operating internal combustion engine, and is carried downstream along with the intake air a.

（実施形態２）
次に、本発明装置の第２実施形態を図２によって説明する。本実施形態は、第１実施形態と同様に、内燃機関に設けられた吸気マニホールド又は吸気管の垂直管壁３０に空燃比センサ１０が装着されている。空燃比センサ１０は、第１実施形態の空燃比センサ１０と同一構成を有している。空燃比センサ１０の取付け場所より吸気上流側（下方領域）の垂直管壁３０の内壁に、螺旋状の凹溝３８が刻設されている。また、空燃比センサ１０の吸気下流側（上方領域）の垂直管壁３０に、螺旋状の凹溝４０が刻設され、螺旋状凹溝３８と螺旋状凹溝４０とを連絡する螺旋状の連絡用凹溝４２が刻設されている。 (Embodiment 2)
Next, a second embodiment of the device of the present invention will be described with reference to FIG. In the present embodiment, as in the first embodiment, the air-fuel ratio sensor 10 is mounted on the intake manifold or the vertical pipe wall 30 of the intake pipe provided in the internal combustion engine. The air-fuel ratio sensor 10 has the same configuration as the air-fuel ratio sensor 10 of the first embodiment. A spiral groove 38 is formed in the inner wall of the vertical pipe wall 30 on the upstream side (lower region) of the intake air from the mounting location of the air-fuel ratio sensor 10. In addition, a spiral groove 40 is formed in the vertical pipe wall 30 on the intake air downstream side (upper region) of the air-fuel ratio sensor 10 so as to connect the spiral groove 38 and the spiral groove 40. A communication concave groove 42 is formed.

螺旋状凹溝３８，４０及び連絡用凹溝４２は、図示のように、四角断面をもつ。螺旋状凹溝３８又は螺旋状凹溝４０は、互いに等間隔に配置されている。連絡用凹溝４２は、空燃比センサ１０と干渉しない位置に刻設される。空燃比センサ１０の上流側吸気流路には、インタークーラ（図示省略）が設けられている。インタークーラで冷却された吸気ａは凝縮した水滴ｗを含んでいる。   The spiral concave grooves 38 and 40 and the communication concave groove 42 have a square cross section as shown. The spiral grooves 38 or the spiral grooves 40 are arranged at equal intervals. The communication groove 42 is formed at a position where it does not interfere with the air-fuel ratio sensor 10. An intercooler (not shown) is provided in the upstream intake passage of the air-fuel ratio sensor 10. The intake air a cooled by the intercooler contains condensed water droplets w.

かかる構成において、空燃比センサ１０の吸気上流側で、螺旋状凹溝３８に付着した水滴ｗは、吸気ａの流れで下流側に押され、螺旋状凹溝３８の底面を螺旋状凹溝３８に沿って吸気下流側へ前進する。そして、連絡用凹溝４２を経由し、再飛散することなく、下流側の螺旋状凹溝４０に流出する。そのため、検出部１８に水滴ｗが付着するのを防止できる。そのため、検出部１８に内蔵されたガス検出素子に水滴ｗが付着し、その熱衝撃によってガス検出素子が破損するのを防止できる。   In such a configuration, the water droplet w adhering to the spiral groove 38 on the upstream side of the intake air of the air-fuel ratio sensor 10 is pushed downstream by the flow of the intake air a, and the bottom surface of the spiral groove 38 is moved to the spiral groove 38. Along the intake air. And it flows out into the spiral groove 40 on the downstream side via the communication groove 42 without re-scattering. Therefore, it is possible to prevent the water droplet w from adhering to the detection unit 18. Therefore, it is possible to prevent water droplets w from adhering to the gas detection element built in the detection unit 18 and damaging the gas detection element due to the thermal shock.

なお、検出部１８の上方の垂直管壁３０に付着した水滴ｗは、重力により垂直管壁３０を伝って流下し、螺旋状凹溝４０に流入する。螺旋状凹溝４０に流入した水滴ｗは、重力により螺旋状凹溝４０を下方へ流れ、連絡用凹溝４２を経由して螺旋状凹溝３８に至る。そのため、この流下する水滴ｗが検出部１８に到達するのを防止できる。   The water droplet w attached to the vertical tube wall 30 above the detection unit 18 flows down along the vertical tube wall 30 by gravity and flows into the spiral groove 40. The water droplet w that has flowed into the spiral groove 40 flows downward through the spiral groove 40 due to gravity, and reaches the spiral groove 38 via the communication groove 42. Therefore, it is possible to prevent the flowing water droplets w from reaching the detection unit 18.

（実施形態３）
次に、本発明装置の第３実施形態を図３及び図４により説明する。内燃機関に設けられた吸気マニホールド又は吸気管の垂直管壁３０に空燃比センサ１０が装着されている。空燃比センサ１０は、第１実施形態の空燃比センサ１０と同一構成を有している。垂直管壁３０には、雌ネジ孔３４を有するボス部３２が、圧入又はねじ込み等の手段で固定されている。空燃比センサ１０は、雄ネジ１４が雌ネジ孔３４に螺合することで、垂直管壁３０に固定される。 (Embodiment 3)
Next, a third embodiment of the device of the present invention will be described with reference to FIGS. An air-fuel ratio sensor 10 is mounted on an intake manifold or a vertical pipe wall 30 of the intake pipe provided in the internal combustion engine. The air-fuel ratio sensor 10 has the same configuration as the air-fuel ratio sensor 10 of the first embodiment. A boss portion 32 having a female screw hole 34 is fixed to the vertical tube wall 30 by means such as press fitting or screwing. The air-fuel ratio sensor 10 is fixed to the vertical pipe wall 30 when the male screw 14 is screwed into the female screw hole 34.

空燃比センサ１０の上流側垂直管壁３０には、第１実施形態と同一構成の４条のリング状凹溝３６が、垂直管壁３０の軸方向と直角方向にかつ互いに等間隔に刻設され、下流側の垂直管壁３０には、第１実施形態と同一構成の３条のリング状凹溝３７が、垂直管壁３０の軸方向と直角方向にかつ互いに等間隔に刻設されている。   On the upstream vertical pipe wall 30 of the air-fuel ratio sensor 10, four ring-shaped concave grooves 36 having the same configuration as that of the first embodiment are formed at equal intervals in a direction perpendicular to the axial direction of the vertical pipe wall 30. On the downstream vertical pipe wall 30, three ring-shaped concave grooves 37 having the same configuration as in the first embodiment are engraved in the direction perpendicular to the axial direction of the vertical pipe wall 30 at equal intervals. Yes.

ボス部３２と一体に円筒形の保護カバー２２が設けられ、保護カバー２２は検出部１８の周囲に配置され、吸気流路に突出配置されている。保護カバー２２の吸気流路への突出量Ｌは、少なくとも吸気導入孔２０を覆うように設定され、例えば、検出部１８の突出量の２／３程度とする。保護カバー２２の内壁２２ａは、先端側が拡径された円錐形のテーパ面を形成している。吸気導入孔２０より先端側の内壁２２ａには、螺旋形状に刻設された円弧状断面の螺旋溝２４が設けられている。螺旋溝２４の根元側終端部に貫通孔２６が刻設されている。   A cylindrical protective cover 22 is provided integrally with the boss portion 32, and the protective cover 22 is disposed around the detection portion 18 and is disposed so as to protrude from the intake passage. The amount of protrusion L of the protective cover 22 into the intake passage is set so as to cover at least the intake introduction hole 20 and is, for example, about 2/3 of the amount of protrusion of the detection unit 18. The inner wall 22a of the protective cover 22 forms a conical tapered surface whose tip end is enlarged in diameter. A spiral groove 24 having an arc-shaped cross section that is engraved in a spiral shape is provided on the inner wall 22a on the distal end side of the intake air introduction hole 20. A through-hole 26 is formed in the base end portion of the spiral groove 24.

貫通孔２６の内壁側開口は螺旋溝２４の根元側終端部に配置されている。貫通孔２６は内壁２２ａの接線方向に配置され、保護カバー２２の外壁における貫通孔２６の外壁開口２６ａは、図４に示すように、保護カバー２２の中心より吸気下流側に配置されている。螺旋溝２４の根元側終端部及び貫通孔２６は、吸気導入孔２０より保護カバー２２の先端側に配置されている。保護カバー２２の外壁側先端部には、平坦なテーパ面２２ｂが形成されている。テーパ面２２ｂは、垂直管壁３０の軸方向と直角方向の面に対し、θ（＜９０°、好ましくは３０〜６０°）の角度をもつように形成されている。   The opening on the inner wall side of the through hole 26 is disposed at the base end portion of the spiral groove 24. The through hole 26 is arranged in the tangential direction of the inner wall 22a, and the outer wall opening 26a of the through hole 26 in the outer wall of the protective cover 22 is arranged on the intake downstream side from the center of the protective cover 22, as shown in FIG. The base end portion of the spiral groove 24 and the through hole 26 are arranged on the distal end side of the protective cover 22 from the intake air introduction hole 20. A flat tapered surface 22 b is formed at the outer wall side tip of the protective cover 22. The tapered surface 22b is formed to have an angle of θ (<90 °, preferably 30 to 60 °) with respect to a surface perpendicular to the axial direction of the vertical tube wall 30.

テーパ面２２ｂより根元側の保護カバー２２の外壁には、周方向に複数のスリット状溝２８が刻設されている。スリット状溝２８はリング状をなし、並列に配置されている。また、空燃比センサ１０の上流側吸気流路には、インタークーラ（図示省略）が設けられている。インタークーラで冷却された吸気ａは凝縮した水滴ｗを含んでいる。   A plurality of slit-shaped grooves 28 are formed in the circumferential direction on the outer wall of the protective cover 22 closer to the root side than the tapered surface 22b. The slit-shaped grooves 28 have a ring shape and are arranged in parallel. Further, an intercooler (not shown) is provided in the upstream intake passage of the air-fuel ratio sensor 10. The intake air a cooled by the intercooler contains condensed water droplets w.

かかる構成において、かかる吸気ａが吸気マニホールドの垂直管壁３０を上方へ流れると、水滴ｗが垂直管壁３０に付着する。空燃比センサ１０の上流側（下方領域）で、垂直管壁３０に付着した水滴ｗは、リング状凹溝３６が抵抗となって上方へ進入するのを阻まれる。また、吸気ａに含まれる水滴ｗは、保護カバー２２に阻まれ、吸気導入孔２０に浸入するのを阻止される。保護カバー２２の外壁に設けられたスリット状溝２８に付着した水滴ｗは、吸気流によりスリット状溝２８に沿って滑り、保護カバー２２の下流側へ流出する。   In such a configuration, when the intake air a flows upward through the vertical pipe wall 30 of the intake manifold, water droplets w adhere to the vertical pipe wall 30. On the upstream side (lower region) of the air-fuel ratio sensor 10, the water droplets w adhering to the vertical tube wall 30 are prevented from entering upward by the ring-shaped concave groove 36 acting as a resistance. Further, the water droplet w contained in the intake air a is blocked by the protective cover 22 and is prevented from entering the intake air introduction hole 20. The water droplet w attached to the slit-like groove 28 provided on the outer wall of the protective cover 22 slides along the slit-like groove 28 by the intake air flow and flows out downstream of the protective cover 22.

保護カバー２２の先端部近辺の吸気ａは、テーパ面２２ｂに沿って流れ、吸気流路の中心側に偏向される。吸気流路の中央領域を流れる吸気ａの一部は、保護カバー２２の先端部から保護カバー２２の内部に回り込み、螺旋溝２４に沿って旋回を開始する。旋回を開始した吸気ａは、内壁２２ａが根元側に向かって徐々に縮径しているので、徐々に旋回速度を増す。そのため、吸気中に含まれる重い水滴ｗに大きな遠心力が付加され、水滴ｗは螺旋溝２４の底に押し付けられる。   The intake air a in the vicinity of the tip of the protective cover 22 flows along the tapered surface 22b and is deflected toward the center of the intake flow path. A part of the intake air a flowing through the central region of the intake flow channel enters the inside of the protective cover 22 from the tip end portion of the protective cover 22 and starts turning along the spiral groove 24. The intake air a that has started to turn gradually increases in turning speed because the inner wall 22a is gradually reduced in diameter toward the base side. Therefore, a large centrifugal force is applied to the heavy water droplet w contained in the intake air, and the water droplet w is pressed against the bottom of the spiral groove 24.

大きな遠心力を付加された水滴ｗは、貫通孔２６を通って外壁開口２６ａから保護カバー２２の吸気下流側へ流れる。貫通孔２６は、内壁２２ａの接線方向に配置されているので、水滴ｗはスムーズに貫通孔２６に流入する。保護カバー２２の吸気下流側は、負圧になっているので、水滴ｗの下流側への流出が助長される。内燃機関の停止後、上方の垂直管壁３０を伝って流下してくる水滴ｗは、リング状凹溝３７に流入し、それ以上の流下を阻止される。一部の水滴ｗが保護カバー２２に到達した場合でも、スリット状溝２８によってガイドされ、上流側（下方領域）へ流下する。また、リング状凹溝３６及び３７に滞留した水滴ｗは、稼動中の内燃機関の熱で蒸発し、水蒸気となって下流側に流れるか、あるいは内燃機関の停止後、下方へ流下する。   The water droplet w to which a large centrifugal force is applied flows through the through hole 26 from the outer wall opening 26 a to the intake downstream side of the protective cover 22. Since the through hole 26 is disposed in the tangential direction of the inner wall 22a, the water droplet w flows into the through hole 26 smoothly. Since the intake downstream side of the protective cover 22 has a negative pressure, the outflow of the water droplet w to the downstream side is promoted. After the internal combustion engine is stopped, the water droplet w flowing down along the upper vertical pipe wall 30 flows into the ring-shaped concave groove 37 and is prevented from further flowing down. Even when some water droplets w reach the protective cover 22, they are guided by the slit-like groove 28 and flow down to the upstream side (lower region). Further, the water droplets w staying in the ring-shaped concave grooves 36 and 37 are evaporated by the heat of the operating internal combustion engine and flow into the downstream side as water vapor, or flow down downward after the internal combustion engine is stopped.

本実施形態によれば、吸気ａに含まれ垂直管壁３０の内壁に付着した水滴ｗは、吸気流に抗して４条のリング状凹溝３６により前進を阻まれる。これによって、垂直管壁３０を伝う水滴ｗが検出部１８に到達するのを防止できる。また、保護カバー２２で検出部１８を覆うことで、吸気ａに含まれる水滴ｗが吸気導入孔２０から検出部１８の内部へ浸入するのを防止できる。さらに、保護カバー２２の先端側から保護カバー２２の内部へ進入した水滴ｗを含む吸気ａは、水滴ｗが貫通孔２６から保護カバー外に排出され、水滴ｗが離脱した吸気のみが螺旋溝２４に沿って速い旋回速度で吸気導入孔２０に導入されるので、ガス検出素子への水滴ｗの付着を防止できると共に、吸気ａの主流のガス成分を応答性良く検出できる。   According to the present embodiment, the water droplets w included in the intake air a and attached to the inner wall of the vertical pipe wall 30 are prevented from advancing by the four ring-shaped concave grooves 36 against the intake air flow. Thereby, it is possible to prevent the water droplets w traveling along the vertical tube wall 30 from reaching the detection unit 18. In addition, by covering the detection unit 18 with the protective cover 22, it is possible to prevent water droplets w included in the intake air a from entering the detection unit 18 from the intake air introduction hole 20. Further, the intake air a including the water droplet w that has entered the protective cover 22 from the front end side of the protective cover 22 is discharged from the through hole 26 to the outside of the protective cover, and only the intake air from which the water droplet w has separated is the spiral groove 24. Accordingly, the water droplet w can be prevented from adhering to the gas detection element and the mainstream gas component of the intake air a can be detected with good responsiveness.

このように、リング状凹溝３６と、保護カバー２２と、保護カバー２２に設けられた貫通孔２６とによって、検出部１８に内蔵されたガス検出素子が水滴の熱衝撃により損傷するのを防止できる。また、螺旋溝２４に沿って旋回する水滴ｗは、大きな遠心力が働き、螺旋溝２４の底に押し付けられ、かつ貫通孔２６の外壁開口２６ａは、負圧状態の保護カバー下流側にあるので、水滴ｗを貫通孔２６からスムーズに保護カバー外に流出させることができる。   As described above, the ring-shaped concave groove 36, the protective cover 22, and the through hole 26 provided in the protective cover 22 prevent the gas detection element built in the detection unit 18 from being damaged by the thermal shock of water droplets. it can. Further, since the water droplet w swirling along the spiral groove 24 has a large centrifugal force, it is pressed against the bottom of the spiral groove 24, and the outer wall opening 26a of the through hole 26 is on the downstream side of the protective cover in the negative pressure state. The water droplet w can smoothly flow out of the protective cover from the through hole 26.

また、保護カバー２２の外壁に周方向にスリット状溝２８が刻設されているので、スリット状溝２８に付着した水滴ｗは、飛散することなく、吸気流によって下流側に押される。そして、スリット状溝２８に沿って保護カバー２２の下流側にスムーズに流出できる。また、保護カバー２２の先端部にテーパ面２２ｂを形成したので、テーパ面２２ｂに付着した水滴ｗは、テーパ面２２ｂに沿って吸気流路の中心側へ流出させることができる。そのため、この水滴ｗが保護カバー２２の内部に進入するのを防止できる。   Further, since the slit-like groove 28 is formed in the outer wall of the protective cover 22 in the circumferential direction, the water droplets w attached to the slit-like groove 28 are pushed downstream by the intake air flow without being scattered. Then, it can smoothly flow out downstream of the protective cover 22 along the slit-like groove 28. Further, since the tapered surface 22b is formed at the distal end portion of the protective cover 22, the water droplets w attached to the tapered surface 22b can flow out to the center side of the intake flow path along the tapered surface 22b. Therefore, the water droplet w can be prevented from entering the inside of the protective cover 22.

また、検出部１８の上方の垂直管壁３０に付着し流下する水滴ｗは、リング状凹溝３７に入り込むことで流下を阻止される。また、一部の水滴ｗがリング状凹溝３７より下方へ流下した場合でも、保護カバー２２によって検出部１８に付着するのを防止できる。保護カバー２２の外壁に流下した水滴ｗは、保護カバー２２の外壁に刻設されたスリット状溝２８によってガイドされ、上流側（下方領域）へ流下させることができる。   Further, the water droplets w adhering to the vertical pipe wall 30 above the detection unit 18 and flowing down enter the ring-shaped concave groove 37 and are prevented from flowing down. Even when a part of the water droplets w flows downward from the ring-shaped concave groove 37, it can be prevented that the protective cover 22 adheres to the detection unit 18. The water droplet w that has flowed down to the outer wall of the protective cover 22 is guided by the slit-like groove 28 formed in the outer wall of the protective cover 22 and can flow down to the upstream side (lower region).

なお、保護カバー２２の外壁及び内壁の表面に、例えば、フッ素樹脂などの撥水性材料からなる被膜を被覆するとよい。これによって、保護カバー２２の外壁に付着した水滴を保護カバー２２の外壁に沿って下流側へ流出させるのが容易になる。また、保護カバー２２の内部に進入した水滴の旋回速度が増加し、水滴に働く遠心力を増大できるので、貫通孔２６を通して保護カバー２２の外側へ流出させるのが促進される。   Note that the outer cover and the inner wall of the protective cover 22 may be coated with a film made of a water repellent material such as a fluororesin. This makes it easy for water droplets attached to the outer wall of the protective cover 22 to flow out downstream along the outer wall of the protective cover 22. In addition, the swirling speed of the water droplets that have entered the inside of the protective cover 22 is increased, and the centrifugal force acting on the water droplets can be increased, so that it is facilitated to flow out of the protective cover 22 through the through holes 26.

（実施形態４）
次に、本発明装置の第４実施形態を図５により説明する。本実施形態は、図３に示す保護カバー付き空燃比センサ１０の上流側及び下流側の垂直管壁３０に、図２に示す第２実施形態と同一構成の螺旋状凹溝３８，４０及び連絡用凹溝４２を設けたものである。空燃比センサ１０の吸気上流側で、螺旋状凹溝３８に付着した水滴ｗは、吸気ａの流れで下流側に押され、螺旋状凹溝３８の底面を螺旋状凹溝３８に沿って吸気下流側へ前進する。そして、連絡用凹溝４２を経由して下流側の螺旋状凹溝４０に流出する。 (Embodiment 4)
Next, a fourth embodiment of the device of the present invention will be described with reference to FIG. In the present embodiment, spiral concave grooves 38 and 40 having the same configuration as that of the second embodiment shown in FIG. 2 are connected to the upstream and downstream vertical pipe walls 30 of the air-fuel ratio sensor 10 with a protective cover shown in FIG. A concave groove 42 is provided. The water droplet w attached to the spiral groove 38 on the upstream side of the intake air of the air-fuel ratio sensor 10 is pushed downstream by the flow of the intake air a, and the bottom surface of the spiral groove 38 is sucked along the spiral groove 38. Advance downstream. Then, it flows into the spiral groove 40 on the downstream side via the communication groove 42.

吸気ａに含まれる水滴は、保護カバー２２に阻まれ、保護カバー２２の先端部から進入した吸気ａは、螺旋溝２４で旋回力を付与されて、根元側へ進入すると共に、この吸気ａに含まれる水滴ｗは貫通孔２６から保護カバー外へ排出される。そして、水滴ｗが離脱した吸気が大きな旋回速度で吸気導入孔２０から検出部１８の内部に進入する。そのため、検出部１８に内蔵されたガス検出素子が、水滴ｗによる熱衝撃で損傷するのを防止できると共に、吸気の主流をガス検出素子まで積極的に導入でき、ガス成分を応答性良く検出できる。   The water droplets contained in the intake air a are blocked by the protective cover 22, and the intake air a that has entered from the front end of the protective cover 22 is given a turning force by the spiral groove 24 and enters the root side. The contained water droplets w are discharged from the through hole 26 to the outside of the protective cover. Then, the intake air from which the water droplets w have separated enters the inside of the detection unit 18 from the intake introduction hole 20 at a high turning speed. Therefore, the gas detection element built in the detection unit 18 can be prevented from being damaged by the thermal shock caused by the water droplet w, and the mainstream of the intake air can be actively introduced to the gas detection element, so that the gas component can be detected with good responsiveness. .

また、上方の垂直管壁３０に付着し垂直管壁３０を伝って流下する水滴ｗは、螺旋状凹溝４０に流入し、連絡用凹溝４２を伝って螺旋状凹溝３８に流下するので、検出部１８に付着するのを防止できる。一部の水滴ｗが螺旋状凹溝４０を越えても、保護カバー２２で阻止されるので、検出部１８に付着するのを防止できる。   Further, the water droplet w attached to the upper vertical tube wall 30 and flowing down through the vertical tube wall 30 flows into the spiral groove 40 and flows down to the spiral groove 38 through the communication groove 42. , It can be prevented from adhering to the detection unit 18. Even if a part of the water droplets w passes over the spiral concave groove 40, it can be prevented from adhering to the detection unit 18 because it is blocked by the protective cover 22.

なお、第４実施形態の変形例として、螺旋状の連絡用凹溝４２の代わりに、図５に示すように、上流側螺旋状凹溝３８の最下流側領域と下流側螺旋状凹溝４０の最上流側領域とを、垂直管壁３０の軸方向に配置された直線状の連絡用凹溝４４で連絡するようにしてもよい。これによって、連絡用凹溝の加工が容易になる。   As a modification of the fourth embodiment, instead of the spiral connecting groove 42, as shown in FIG. 5, the most downstream region of the upstream spiral groove 38 and the downstream spiral groove 40. The uppermost stream side region may be communicated with a linear communication groove 44 arranged in the axial direction of the vertical pipe wall 30. This facilitates the processing of the connecting groove.

第３実施形態及び第４実施形態で用いられた保護カバー２２の代わりに、吸気導入孔２０を覆うだけの突出量Ｌを有し、内壁がテーパ面を形成せず、かつ貫通孔２６を有しない単純な円筒形状の保護カバーを設けるようにしてもよい。   Instead of the protective cover 22 used in the third embodiment and the fourth embodiment, the protrusion L is sufficient to cover the intake air introduction hole 20, the inner wall does not form a tapered surface, and the through hole 26 is provided. Alternatively, a simple cylindrical protective cover may be provided.

本発明によれば、内燃機関の吸気管に設けられたガスセンサを、吸気に含まれる凝縮水による熱衝撃から保護し、かつガス成分の検出精度を高く維持できる。   ADVANTAGE OF THE INVENTION According to this invention, the gas sensor provided in the intake pipe of the internal combustion engine can be protected from the thermal shock caused by the condensed water contained in the intake air, and the detection accuracy of the gas component can be maintained high.

１０ 空燃比センサ（ガスセンサ）
１１ リード線
１２ 基部
１４ ナット
１６ 雄ネジ
１８ 検出部
２０ 吸気導入孔
２２ 保護カバー（筒状カバー）
２２ａ 内壁
２２ｂ テーパ面
２４ 螺旋溝
２６ 貫通孔
２６ａ 外壁開口
２８ スリット状溝
３０ 垂直管壁
３２ ボス部
３４ 雌ネジ孔
３６，３７ リング状凹溝
３８、４０ 螺旋状凹溝
４２，４４ 連絡用凹溝
ａ 吸気
ｗ 水滴（凝縮水） 10 Air-fuel ratio sensor (gas sensor)
DESCRIPTION OF SYMBOLS 11 Lead wire 12 Base 14 Nut 16 Male screw 18 Detection part 20 Intake inlet hole 22 Protective cover (cylindrical cover)
22a Inner wall 22b Tapered surface 24 Spiral groove 26 Through hole 26a Outer wall opening 28 Slit groove 30 Vertical tube wall 32 Boss part 34 Female thread hole 36, 37 Ring-shaped groove 38, 40 Spiral groove 42, 44 Connection groove a Intake w Water droplet (Condensed water)

Claims (4)

内燃機関の吸気流路内に突設された検出部を備えたガスセンサの被水防止装置において、
少なくとも前記検出部より吸気流れ方向において上流側吸気管の内壁に、吸気流れ方向と交差し、吸気管壁面に付着した水滴が前記検出部に接触することを抑制する凹溝を設けたことを特徴とするガスセンサの被水防止装置。 In a water sensor for a water sensor of a gas sensor provided with a detection part protruding in an intake passage of an internal combustion engine,
At least an inner wall of the upstream intake pipe in the intake flow direction from the detection section is provided with a concave groove that crosses the intake flow direction and suppresses water droplets attached to the intake pipe wall surface from contacting the detection section. A device for preventing water in a gas sensor. 前記凹溝が、吸気流れ方向に複数配置された凹溝で構成されていることを特徴とする請求項１に記載のガスセンサの被水防止装置。   The said groove is comprised with the groove | channel which was arranged with two or more by the intake flow direction, The moisture prevention apparatus of the gas sensor of Claim 1 characterized by the above-mentioned. 前記凹溝が、前記検出部の吸気上流側及び吸気下流側に配設された螺旋状凹溝と、該螺旋状凹溝を結ぶ連絡用凹溝とから構成されていることを特徴とする請求項１又は２に記載のガスセンサの被水防止装置。   The groove is composed of a spiral groove disposed on the intake upstream side and the intake downstream side of the detection unit, and a communication groove connecting the spiral grooves. Item 3. A device for preventing water exposure of a gas sensor according to Item 1 or 2. 前記検出部の周囲に該検出部に設けられた吸気導入口を覆う位置まで吸気流路内に突出配置された筒状カバーを備え、
該筒状カバーの内壁が突出方向の先端側で拡径されたテーパ壁で形成され、かつ該テーパ壁の先端部から前記吸気導入口に至るまでの領域に螺旋溝が形成されていることを特徴とする請求項１から３のいずれかに記載のガスセンサの被水防止装置。 A cylindrical cover is provided around the detection unit so as to project into the intake flow path up to a position covering the intake port provided in the detection unit.
The inner wall of the cylindrical cover is formed of a tapered wall whose diameter is enlarged on the distal end side in the protruding direction, and a spiral groove is formed in a region from the distal end of the tapered wall to the intake inlet. The water prevention device for a gas sensor according to any one of claims 1 to 3, wherein
JP2011184225A 2011-08-26 2011-08-26 Gas sensor wet prevention device Expired - Fee Related JP5769076B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2011184225A JP5769076B2 (en) 2011-08-26 2011-08-26 Gas sensor wet prevention device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2011184225A JP5769076B2 (en) 2011-08-26 2011-08-26 Gas sensor wet prevention device

Publications (2)

Publication Number Publication Date
JP2013044308A true JP2013044308A (en) 2013-03-04
JP5769076B2 JP5769076B2 (en) 2015-08-26

Family

ID=48008397

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2011184225A Expired - Fee Related JP5769076B2 (en) 2011-08-26 2011-08-26 Gas sensor wet prevention device

Country Status (1)

Country Link
JP (1) JP5769076B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180009124A (en) * 2016-07-18 2018-01-26 현대자동차주식회사 Intake manifold for vehicle

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62203451U (en) * 1986-06-16 1987-12-25
JP2002257608A (en) * 2001-02-28 2002-09-11 Hitachi Ltd Heat type flow rate measuring device
JP2007303394A (en) * 2006-05-11 2007-11-22 Toyota Motor Corp Internal combustion engine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62203451U (en) * 1986-06-16 1987-12-25
JP2002257608A (en) * 2001-02-28 2002-09-11 Hitachi Ltd Heat type flow rate measuring device
JP2007303394A (en) * 2006-05-11 2007-11-22 Toyota Motor Corp Internal combustion engine

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20180009124A (en) * 2016-07-18 2018-01-26 현대자동차주식회사 Intake manifold for vehicle
KR102383217B1 (en) 2016-07-18 2022-04-05 현대자동차 주식회사 Intake manifold for vehicle

Also Published As

Publication number Publication date
JP5769076B2 (en) 2015-08-26

Similar Documents

Publication Publication Date Title
RU2704382C9 (en) System (embodiments) and method of detecting solid particles
US9915637B2 (en) Gas sensor
US10041455B2 (en) Humidity sensor device arranged in a choke portion of an internal combustion engine intake air passage
JP2007224877A (en) Installation structure of exhaust sensor to exhaust pipe of internal combustion engine
JP4649428B2 (en) engine
US20160153814A1 (en) Gas sensor
JP6740023B2 (en) Gas sensor
JP6654516B2 (en) Gas sensor
JP5494068B2 (en) Engine exhaust system
JP2007321593A (en) Structure for reducing water splash of sensor mounted in exhaust pipe
JP5779471B2 (en) Humidity detector
US20140174176A1 (en) Intake gas sensor with vortex for internal combustion engine
JP5641439B2 (en) Gas sensor wet prevention device
US11835439B2 (en) Sensor device having an element cover including inner and outer covers
JP5769076B2 (en) Gas sensor wet prevention device
JP2017040224A (en) Exhaust emission control device for internal combustion engine
JP6512033B2 (en) Gas sensor mounting structure
JP2011226824A (en) Exhaust sensor
JP5811446B2 (en) Gas sensor wet prevention device
JP2006162631A (en) Thermal flow measurement device
JP2007327790A (en) Heat generation resistor type flow measuring instrument
WO2019107262A1 (en) Sensor device
JP6538334B2 (en) Exhaust purification system
US11391610B2 (en) Flow rate measurement device
JP5942636B2 (en) Sensor protection structure

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20131025

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20140814

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20140815

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20141010

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20150529

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20150611

R151 Written notification of patent or utility model registration

Ref document number: 5769076

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

LAPS Cancellation because of no payment of annual fees