JP4096243B2

JP4096243B2 - Ventilation duct

Info

Publication number: JP4096243B2
Application number: JP2002348867A
Authority: JP
Inventors: 浩杉浦
Original assignee: Inoac Corp
Current assignee: Inoac Corp
Priority date: 2002-11-29
Filing date: 2002-11-29
Publication date: 2008-06-04
Anticipated expiration: 2022-11-29
Also published as: JP2004182024A

Description

【０００１】
【発明の属する技術分野】
この発明は、通気ダクトに関し、更に詳細には、相互に対向してダクト壁を形成する第１壁部および第２壁部と、前記第１壁部の端部に開設した吹出口とを有し、上流側から通入された空気等を、その流通方向と略直交する方向へ変向させつつ前記吹出口から通出させるようにした通気ダクトに関するものである。
【０００２】
【従来の技術】
例えば、乗用車等の各種車両では、車体に搭載されたエアコンユニットから送出される調温空気により、乗員室内の空調を行なうようになっている。このため、インストルメントパネルやルーフパネル等の車両内装部材の所要位置には、前記調温空気を乗員室内へ吹出すための空気吹出口が配設されており、これらエアコンユニットと空気吹出口とは、前記調温空気を流通案内するための通気ダクトで連通接続されている。
【０００３】
ここで前記通気ダクトは、前記車両内装部材の裏側において、該車両内装部材と車体との間に画成される狭い空間内に配設されるため、幅狭扁平状の外形形状とされたり、更には複雑な凹凸状の外面形状に成形せざるを得ない場合が多い。すなわち通気ダクト１０は、例えば図１１に概略図示する如く、相互に対向してダクト本体１２のダクト壁を形成する第１壁部１４および第２壁部１６とから形成され、前記第２壁部１６の一方の端部にエアコンユニットの空気送出部(図示せず)または別の通気ダクト等に接続される通入口１８が開設されると共に、前記第１壁部１４の他方の端部に前記車両内装部材の所要位置から乗員室内へ臨む吹出口２０が開設されている。これにより、上流側の通入口１８から通入された調温空気を、ダクト本体１２内を移動させた後、前記吹出口２０から順次通出させるようになっている。なお、前記通気ダクトに関連する技術は、例えば特許文献１等に開示されている。
【０００４】
【特許文献１】
特開２０００−１０３２２３号公報
【０００５】
【発明が解決しようとする課題】
ところで図１１に例示の通気ダクト１０は、図１２(ａ)に示すように、▲１▼扁平形状を呈する前記ダクト本体１２における断面積に比べて、横長矩形状に開設された前記吹出口２０の開口面積の方がかなり大きくなっている、▲２▼吹出口２０からの調温空気の吹出方向は、ダクト本体１２内における流通方向(長手方向)に対して略直交した短手方向となっている。従って、上流側の通入口１８から通入された調温空気は、断面積が小さいダクト本体１２内で適宜加速されて移動するため、吹出口２０に臨接したダクト下流壁に一端衝突するようになり、この衝突後に略直交する方向へ急激に変向して吹出口２０の側へ移動するようになる(図１２(ａ))。従って、前記吹出口２０から通出される調温空気は、図１２(ｂ)に示した吹出口２０の風速分布態様図から明らかな如く、その主流が当該吹出口２０の左側領域(下流側領域)の狭い領域に偏ってしまい、該吹出口２０の右側領域(上流側領域)からは殆ど吹出さない。すなわち、規定風速(例えば１２ｍ／ｓ)となっている適正風速領域(図１２(ｂ)の網掛表示部分)Ｗは、吹出口２０の左側領域に偏ると共にその面積もかなり狭くなるため、配風性能が極めて低いものとなっていた。従って、(a)局部的に風速が上昇した領域が形成されるために吹出し騒音が大きくなる、(b)乗員室内の効率的かつ快適な空調を実施し得ない、等の不都合を招来することとなっていた。
【０００６】
そこで、前述した不都合を回避するために、前記第２壁部１６において前記吹出口２０の開口領域に臨む背面部位を、例えば図１３に示すように曲面部２２として形成したり、図１５に示すように傾斜面部２４として形成して、所謂調温空気の変向案内面とする対策が講じられていた。しかしながら、図１３に例示の通気ダクト１０では、前記曲面部２２の曲率半径等の設定により多少の差異があるが、図１４(ａ)および図１４(ｂ)に示すように、図１１の通気ダクト１０と比較すると配風性能の向上が殆ど図られていない。一方、図１５に例示の通気ダクト１０では、前記傾斜面部２４の傾斜角度や長さ等の設定より多少の差異があるが、図１６(ａ)および図１６(ｂ)に示すように、図１１の通気ダクト１０と比較すると若干の配風性能の向上は確認できるとしても、依然として満足し得る配風性能が得られていない。
【０００７】
このため、乗員が吹出方向を調整可能としたエアアウトレットを別途装着する場合以外でも、別部材としての吹出変向装置や整流網等を準備して、これを前記吹出口２０の前側に追加配設することで規定風速となる適正風速領域Ｗの面積拡大および位置補正を図り、配風性能を向上するための対策を講ずる必要があった。しかしながら、前記変向装置や整流網等を別途製作することになるから、部品代や人件費等が追加加算されて製造コストが嵩んでしまう問題が発生していた。
【０００８】
【発明の目的】
本発明は、前述した課題を好適に解決するべく提案されたもので、吹出口から通出される空気に対する配風性能の向上を図った通気ダクトを提供することを目的とする。
【０００９】
【課題を解決するための手段】
前記課題を解決して、所期の目的を達成するため本発明は、相互に対向してダクト壁を形成する第１壁部および第２壁部と、前記第１壁部の端部に開設した吹出口とを有し、上流側から通入された空気等を、その流通方向と略直交する方向へ変向させつつ前記吹出口から通出させるようにした通気ダクトにおいて、
前記第２壁部において前記吹出口の開口領域に臨む背面部位を、該第２壁部から該吹出口の側へ湾曲的に延在する曲面壁部と、この曲面壁部の端縁から該吹出口に沿って延在する平面壁部とで形成し、
上流側から通入された前記空気等を、前記曲面壁部に沿って移動させる過程で前記吹出口側へ分散状態で変向させることで、該吹出口から広く通出させ得るよう構成したことを特徴とする。
【００１０】
【発明の実施の形態】
次に、本発明に係る通気ダクトにつき、好適な実施例を挙げて、添付図面を参照しながら以下説明する。なお、図１１，図１３および図１５等に例示した従来の通気ダクト１０と同一の部位・部材等に関しては、同一の符号を付して説明する。
【００１１】
図１は、本発明の好適実施例に係る通気ダクトを一部省略して例示した概略斜視図、図２は図１のII−II線断面図である。実施例の通気ダクト３０は、相互に対向してダクト本体１２のダクト壁を形成する第１壁部１４および第２壁部１６から形成され、例えば既知のブロー成形技術に基いて一体的に成形された合成樹脂(ポリエチレン)製の中空体である。そして、前記第２壁部１６における一方の端部に、図示しないエアコンユニットの空気送出部または別の通気ダクト等に接続される通入口１８が開設されると共に、前記第１壁部１４における他方の端部に、車両内装部材等の所要位置から乗員室内へ臨む吹出口２０が開設されている。すなわち、図１における図面右側が通気ダクト３０の上流側であり、図面左側が該通気ダクト３０の下流側となっている。
【００１２】
ここで、実施例の通気ダクト３０における空気流通部分の内面寸法は、次のように設定されている。先ず、上流端から下流端に至る各部位の縦寸法Ｇは、長手方向の何れの部位でも略同一で、例えば約５０ｍｍに設定されている。これに対して空気流通部分の幅寸法は、長手方向の各部位毎に異なっており、主体とされるダクト本体１２の幅寸法Ｃは約２０ｍｍに設定されている。すなわちダクト本体１２は、当該通気ダクト３０の空気流通部分において最も幅狭となっており、縦長の扁平形状を呈している。なお、ダクト本体１２の下流端側は適宜拡開状に形成されており、吹出口２０に臨む出口部分の幅寸法Ｄは約３５ｍｍに設定されている。
【００１３】
一方、第１壁部１４に開設された前記吹出口２０は、横寸法Ｅ＝１００ｍｍ、縦寸法Ｆ＝５０ｍｍの横長矩形状とされている。従って、前記吹出口２０の開口面積は、前記ダクト本体１２の出口部分における空気流通面積の約３倍、該ダクト本体１２の中央部分における空気流通面積の約５倍となっている。
【００１４】
そして実施例の通気ダクト３０では、前記ダクト本体１２内を移動して該ダクト本体１２の出口部分から抜け出た調温空気を、前記吹出口２０の側へ適切に変向させると共に該吹出口２０の広い領域に吹出させるために、次のようなダクト壁構造を採用して調温空気の配風性能の向上を図っている。すなわち、前記第２壁部１６において前記吹出口２０の開口領域に臨む背面部位を、該第２壁部１６から該吹出口２０の側へ湾曲的に延在する曲面壁部３２と、この曲面壁部３２の端縁から該吹出口２０に沿って延在する平面壁部３４とで形成してある。従って、第２壁部１６の前記吹出口２０に臨む背面部位は、図２から明らかなように、前記曲面壁部３２と平面壁部３４との境界部である折曲連接部分３６が、前記ダクト本体１２の出口部分と前記吹出口２０との間で前記調温空気の流通方向に突出しており、これによりダクト本体１２から抜け出た当該調温空気を、前記曲面壁部３２に沿って移動する過程で前記吹出口２０側へ分散状態で変向させ、これにより該吹出口２０から広く通出させ得るようになっている。
【００１５】
そして実施例の通気ダクト３０では、前記ダクト本体１２の出口部分における幅寸法Ｄ＝３５ｍｍ、吹出口２０の横寸法Ｅ＝１００ｍｍ、該吹出口２０の縦寸法Ｆ＝５０ｍｍに設定したもとで、前記通入口１８から通入された調温空気が、流速１４ｍ／ｓで該ダクト本体１２内を移動した後、規定風速１２ｍ／ｓで吹出口２０から広く吹出させることが要求されている。そこで、配風性能の向上を図るために、前記曲面壁部３２および平面壁部３４に関連する各部位の寸法を、次のように設定してある。なお、曲面壁部３２および平面壁部３４に関連する諸寸法は、本願出願人が実施した実験結果に基いて導き出されたものであって、その実験内容および実験結果については後で詳細に説明する。
【００１６】
先ず前記曲面壁部３２は、前記第２壁部１６に対して接線方向に接合された曲率半径Ｒの円弧状に延在形成され、前記ダクト本体１２内を移動した調温空気を、前記吹出口２０の側へスムーズに変向させ得るようになっている。ここで前記曲率半径Ｒは、前記ダクト本体１２の出口部分における幅寸法Ｄ＝３５ｍｍとされる場合、４０〜９０ｍｍの範囲、好ましくは５０〜８０ｍｍ程度に設定するのが最適とされている。すなわち曲面壁部３２の曲率半径Ｒは、前記ダクト本体１２の出口部分における幅寸法Ｄの１.２〜２.５倍(１.２Ｄ〜２.５Ｄ)程度に設定される。
【００１７】
また平面壁部３４は、ダクトの下流端壁部と前記曲面壁部３２との間に形成されて、前記第２壁部１６の延長ラインＬよりも前記吹出口２０の側へ所要量だけ離間して位置しており、前記第２壁部１６と同一方向(延長ラインＬと平行方向)へ延在している。なお平面壁部３４は、前記第２壁部１６と同一方向へ延在するように形成する必要はなく、例えば曲面壁部３２の側より下流端壁部の側が吹出口２０と反対方向へ変位した傾斜状態や、曲面壁部３２の側より下流端壁部の側が吹出口２０の側へ変位した傾斜状態等となるようにしてもよい。
【００１８】
また、曲面壁部３２と平面壁部３４との前記折曲連接部分３６の設定位置は、ダクトの長手方向における該曲面壁部３２の形成位置と、ダクトの短手方向における該平面壁部３４の形成位置との関係により決定される。先ず、ダクトの長手方向における折曲連接部分３６の設定位置は、前記吹出口２０の上流側端縁３８から下流側へ所要距離離間した第１位置Ｐ１と、該第１位置Ｐ１から更に下流側へ所要距離離間した第２位置Ｐ２との間とされる(図３)。具体的に、前記吹出口２０の横寸法Ｅ＝１００ｍｍとされる場合では、該吹出口２０の上流側端縁３８と前記第１位置Ｐ１との間隔Ｓ１は３０ｍｍ程度とされ、該第１位置Ｐ１と前記第２位置Ｐ２との間隔Ｓ２は３０ｍｍ程度(上流側端縁３８との間隔(Ｓ１＋Ｓ２)は６０ｍｍ)とされる。換言すると、前記吹出口２０の上流側端縁３８と前記第１位置Ｐ１との間隔Ｓ１は、該吹出口２０における横寸法Ｅの０.３倍(０.３Ｅ)程度とされ、前記第１位置Ｐ１と前記第２位置Ｐ２との間隔Ｓ２は、前記吹出口２０における横寸法Ｅの０.３倍(０.３Ｅ)程度とされ、ダクトの長手方向における前記折曲連接部分３６の設定位置は、これら第１位置Ｐ１と第２位置Ｐ２との間における適宜位置とされる。なお、前記吹出口２０の中心ラインＣＬを基準としてみると、中心ラインＣＬから上流側へ、該吹出口２０における横寸法Ｅの０.２倍(０.２Ｅ)離間した第１位置Ｐ１と、該中心ラインＣＬから下流側へ、該吹出口２０における横寸法Ｅの０.１倍(０.１Ｅ)離間した第２位置Ｐ２との間ということになる。
【００１９】
更に、ダクトの短手方向における前記折曲連接部分３６の設定位置は、前記第２壁部１６の延長ラインＬから前記吹出口２０の側へ所要距離離間した第３位置Ｐ３と、この第３位置Ｐ３から更に該吹出口２０の側へ所要距離離間した第４位置Ｐ４との間とされる(図３)。具体的に、前記ダクト本体１２の出口部分における幅寸法Ｄ＝３５ｍｍとされる場合では、前記延長ラインＬと前記第３位置Ｐ３との間隔Ｈ１は１５ｍｍ程度とされ、該第３位置Ｐ３と前記第４位置Ｐ４との間隔Ｈ２は１０ｍｍ程度(延長ラインＬとの間隔(Ｈ１＋Ｈ２)は２５ｍｍ)とされる。換言すると、前記延長ラインＬと前記第３位置Ｐ３との間隔Ｈ１は、前記ダクト本体１２の出口部分における幅寸法Ｄの０.４倍(０.４Ｄ)程度とされ、該第３位置Ｐ３と前記第４位置Ｐ４との間隔Ｈ２は、該ダクト本体１２の出口部分における幅寸法Ｄの０.３倍(０.３Ｄ)程度とされ、ダクトの短手方向における前記折曲連接部分３６の設定位置は、これら第３位置Ｐ３および第４位置Ｐ４との間における適宜位置とされる。なお、前記延長ラインＬを基準としてみると、該延長ラインＬと前記第４位置Ｐ４との間隔(Ｈ１＋Ｈ２)は、前記ダクト本体１２の出口部分における幅寸法Ｄの０.７倍(０.７Ｄ)程度ということになる。
【００２０】
このように形成された実施例の通気ダクト３０では、前記第２壁部１６において前記吹出口２０の開口領域に臨む背面部位を、該第２壁部１６から該吹出口２０の側へ湾曲的に延在する曲面壁部３２と、この曲面壁部３２の端縁から該吹出口２０に沿って延在する平面壁部３４とで形成したことにより、ダクト本体１２からの調温空気を前記曲面壁部３２に沿って移動する過程で前記吹出口２０側へ分散状態で変向させ、これにより該吹出口２０から広く通出させ得る。そして、前記曲面壁部３２および平面壁部３４に関連する諸寸法を前述したように設定したことにより、吹出口２０から吹出す調温空気の適正風速領域Ｗの拡大化および位置適正化を好適に図り得る。そして、調温空気の適正風速領域Ｗが拡大するために、局部的な風速の変化が減少して吹出し騒音が減少するようになると共に、乗員室内の効率的かつ快適な空調を実施し得る。更には、配風性能の向上を図るに際して、乗員が吹出方向を調整可能としたエアアウトレットを別途装着する場合以外は吹出変向装置や整流網等の別部材を準備する必要がないと共に、ブロー成形技術等により一体成形できるため、コストが嵩むこともない。
【００２１】
次に、実施例の通気ダクト３０において、前記曲面壁部３２および平面壁部３４に関連する諸寸法の設定根拠につき、本願出願人が実施した実験内容および実験結果に基いて説明する。前述したように、通気ダクト３０において調温空気の配風性能を左右するのは、(1)ダクトの長手方向における前記曲面壁部３２の形成位置、(2)ダクトの短手方向における前記平面壁部３４の形成位置、(3)曲面壁部３２の曲率半径Ｒの大きさ、等である。そこで、前記曲面壁部３２の曲率半径Ｒおよび形成位置を決定するための実験１と、前記平面壁部３４の形成位置を決定するための実験２とを実施した。
【００２２】
実験１は、ダクトの短手方向における前記平面壁部３４の形成位置を一定としたもとで(前記第２壁部１６の延長ラインＬからの間隔Ｈ＝２０ｍｍとしたもとで)、曲面壁部３２の曲率半径Ｒを２０ｍｍ、５０ｍｍ、８０ｍｍに設定した３種類の各通気ダクト３０Ａ,３０Ｂ,３０Ｃにおいて、ダクトの長手方向における該曲面壁部３２の形成位置を変化させた４タイプに関して夫々配風性能を実験した。すなわち、曲面壁部３２の曲率半径Ｒ＝２０ｍｍとした第１通気ダクト３０Ａ(図５(ａ))、曲面壁部３２の曲率半径Ｒ＝５０ｍｍとした第２通気ダクト３０Ｂ(図５(ｂ))、曲面壁部３２の曲率半径Ｒ＝８０ｍｍとした第３通気ダクト３０Ｃ(図５(ｃ))において、ダクトの長手方向における該曲面壁部３２の形成位置を変向することで、ダクトの長手方向における前記折曲連接部分３６の設定位置を、▲１▼吹出口２０の上流側端縁３８からの間隔Ｓａ(３０ｍｍ)とした第１設定位置、▲２▼上流側端縁３８からの間隔Ｓｂ(５０ｍｍ)とした(吹出口２０の中央ラインＣＬと一致)第２設定位置、▲３▼上流側端縁３８からの間隔Ｓｃ(７０ｍｍ)とした第３設定位置、▲４▼上流側端縁３８からの間隔Ｓｄ(９０ｍｍ)とした第４設定位置、の合計４タイプについて配風性能の実験を行なった。
【００２３】
ここで、配風性能の評価において考慮するべき点としては、
▲１▼吹出口２０から吹出す調温空気において、規定風速で吹出す適正風速領域Ｗの面積
▲２▼吹出口２０から吹出す調温空気において、規定風速で吹出す適正風速領域Ｗの位置
▲３▼圧損値、
等が挙げられ、これら種々データを総合的に勘案する必要がある。但し、適正風速領域Ｗの面積および／または位置を評価の重要ポイントとする場合は前記▲１▼および▲２▼を優先して考慮すべきであり、圧損値を重要ポイントする場合は前記▲１▼，▲２▼，▲３▼の全てを考慮する必要がある。
【００２４】
前記▲１▼の評価方法は、図４(ａ)に示すように、吹出口２０における調温空気の吹出分布態様図をもとに、該吹出口２０の開口面積(横寸法Ｅ×縦寸法Ｆ)＝Ａとし、調温空気の適正風速領域(図の網掛部分)Ｗの面積＝Ｂとして、両者の面積比率Ｂ／Ａを算出して実施される。例えば、吹出口２０の全域から調温空気が適正風速で吹出すようになった場合には、Ｂ／Ａ＝１となるのでこれを１０点(満点)と評価するようにし、吹出口２０の略半分から調温空気が適正風速で吹出す場合は、Ｂ／Ａ＝０.５となるのでこれを５点と評価する。
【００２５】
前記▲２▼の評価方法は、図４(ｂ)に示すように、調温空気の適正風速領域Ｗの中心が、吹出口２０の中央ラインＣＬに対してどれだけ右方向または左方向へ偏倚しているかを判定して実施される。例えば、適正風速領域Ｗが吹出口２０の中央ラインＣＬと一致する場合は５点と評価し、適正風速領域Ｗの左側または右側への偏倚量が大きくなる程に減点されて、該適正風速領域Ｗが吹出口２０の左端または右端に位置する場合は１点と評価する。これを前提とした図示例の場合は、適正風速領域Ｗの中心が吹出口２０の中央ラインＣＬよりやや左側に偏倚していて、４点のラインに略一致しているので４点と評価される。
【００２６】
また前記▲３▼の圧損値については、図１１〜図１６に示した従来の各通気ダクト１０が１１６〜１１９(Ｐａ)であることに鑑み(表２参照)、表１に示すような評価基準を設定した。すなわち、従来の各通気ダクト１０より良好な結果が出た場合(圧損値が低くなった場合)は５点とし、同一程度であれば４点とすると共に、これより悪化した場合(圧損値が高くなった場合)はその値に応じて３点、２点、１点として評価する。
【００２７】
【表１】

【００２８】
図６〜図８は、実験１における実験結果を図示したもので、前述した各設定条件での吹出口２０における調温空気の風速分布態様を示している。すなわち図６は、曲面壁部３２の曲率半径Ｒ＝２０ｍｍとした前記第１通気ダクト３０Ａ(図５(ａ))の４タイプにおける各吹出口２０の風速分布態様を示し、また図７は、曲面壁部３２の曲率半径Ｒ＝５０ｍｍとした前記第２通気ダクト３０Ｂ(図５(ｂ))の４タイプにおける各吹出口２０の風速分布態様を示し、更に図８は、曲面壁部３２の曲率半径Ｒ＝８０ｍｍとした前記第３通気ダクト３０Ｃ(図５(ｃ))の４タイプにおける各吹出口２０の風速分布態様を示したものである。
【００２９】
また表２は、図５および図６〜図８に例示した実験１の実験結果に基き、前記第１〜第３の各通気ダクト３０Ａ,３０Ｂ,３０Ｃにおける４タイプの評価結果を示した一覧表である。なお表２の下部に、図１１〜図１６に例示した従来の３タイプの各通気ダクト１０を、前記▲１▼〜▲３▼の評価方法によって評価した場合を併記した。すなわち、図１１および図１２に示した従来の通気ダクト１０では、前記▲１▼〜▲３▼の評価を合計した総合評価が７.５点となり、同様に図１３および図１４に示した従来の別の通気ダクト１０では総合評価が７.５となり、図１５および図１６に示した従来の更に別の通気ダクト１０では総合評価が８.５となった。
【００３０】
【表２】

【００３１】
前記実験１では、曲面壁部３２の曲率半径Ｒ＝２０ｍｍに設定した第１通気ダクト３０Ａにおいて４タイプ、曲面壁部３２の曲率半径Ｒ＝５０ｍｍに設定した第２通気ダクト３０Ｂにおいて４タイプ、曲面壁部３２の曲率半径Ｒ＝８０ｍｍに設定した第３通気ダクト３０Ｃにおいて４タイプ、合計１２種類の通気ダクトにおける配風性能の実験を行なった。これら１２種類の各通気ダクト３０に対する各々の総合評価は８.５(最低)〜１３.０(最高)の範囲となり、何れの通気ダクトにあっても図１１〜図１６に示した従来の各通気ダクト１０と同等または良好な総合評価が得られ、その殆どは従来の各通気ダクト１０よりも良好となった。換言すると、前記第２壁部１６において前記吹出口２０の開口領域に臨む背面部位を、該第２壁部１６から該吹出口２０の側へ湾曲的に延在する曲面壁部３２と、この曲面壁部３２の端縁から該吹出口２０に沿って延在する平面壁部３４とで形成した実施例の通気ダクト３０は、これら曲面壁部３２および平面壁部３４の形成位置に殆ど関係なく、少なくとも図１１〜図１６に示した従来の各通気ダクト１０よりも、配風性能の向上が図られていると評価できる。
【００３２】
前記吹出口２０と調温空気の適正風速領域Ｗとの面積比率Ｂ／Ａに関しては、表２から明らかなように、１２種類の殆どの通気ダクトにおいて、従来よりも良好な結果が得られた。そして、第１〜第３の各通気ダクト３０Ａ,３０Ｂ,３０Ｃの何れにも共通する傾向として、該曲面壁部３２の形成位置をダクトの上流側(第１形成位置)に設定する程に調温空気の適正風速領域Ｗを拡大化することができ、更には第１通気ダクト３０Ａよりも、第２通気ダクト３０Ｂおよび第３通気ダクト３０Ｃの方がより良好な結果が得られた。このことから、調温空気の適正風速領域Ｗの拡大化を図る場合には、曲面壁部３２の曲率半径Ｒを５０ｍｍまたは８０ｍｍに設定した場合に良好な結果が得られたことから、実際には該曲率半径Ｒ＝４０〜９０ｍｍ程度とするのが適当である。
【００３３】
前記吹出口２０に対する調温空気の適正風速領域Ｗの位置に関しては、表２から明らかなように、第１〜第３の各通気ダクト３０Ａ,３０Ｂ,３０Ｃの何れにも共通する傾向として、曲面壁部３２の形成位置を前記第１形成位置とした場合に、適正風速領域Ｗが吹出口２０の中央または略中央となった。しかしながら、折曲連接部分３６の設定位置を前記第３形成位置または第４形成位置とした場合には、適正風速領域Ｗが吹出口２０の左側または左端に偏倚してしまう。このことから、調温空気の適正風速領域Ｗの位置を吹出口２０の中央または略中央としたい場合には、ダクトの長手方向における折曲連接部分３６の設定位置を、吹出口２０の上流側端縁３８から３０ｍｍ離間した位置(第１位置Ｐ１)と、該吹出口２０の上流側端縁３８から６０ｍｍ離間した位置(第２位置Ｐ２)との間とすることが適当である。
【００３４】
前記圧損値に関しては、表２から明らかなように、第１〜第３の各通気ダクト３０Ａ,３０Ｂ,３０Ｃの何れにも共通する傾向として、曲面壁部３２の形成位置を前記第１形成位置に設定した場合が最大となり、逆に該曲面壁部３２の形成位置を前記第４形成位置に設定した場合に最小となる傾向が顕著に現れた。従って、圧損値の軽減化をも考慮する場合には、ダクトの長手方向における折曲連接部分３６の設定位置を、可能な限り前記第２位置Ｐ２に近づけるようにするのが望ましい。
【００３５】
そして、前記▲１▼〜▲３▼の各評価を加算合計した総合評価では、１０点以上となったのは次の設定条件であった。先ず、曲面壁部３２の曲率半径Ｒ＝２０ｍｍに設定した第１通気ダクト３０Ａの場合では、総合評価が１０点以上となる場合はなかった。また、曲面壁部３２の曲率半径Ｒ＝５０ｍｍに設定した第２通気ダクト３０Ｂの場合では、該曲面壁部３２の形成位置を第１形成位置または第２形成位置としたときに、総合評価が夫々１３点および１２点となった。更に、曲面壁部３２の曲率半径Ｒ＝８０ｍｍに設定した第３通気ダクト３０Ｃの場合では、該曲面壁部３２の形成位置を第１形成位置および第２形成位置としたときに、総合評価が夫々１２点および１１点となった。
【００３６】
従って、実験１の結果から、曲面壁部３２の曲率半径Ｒは、前述したように４０〜９０ｍｍ程度が適当であることから、前記ダクト本体１２の出口部分における幅寸法Ｄ(３５ｍｍ)の１.２倍〜２.５倍(１.２Ｄ〜２.５Ｄ)程度に設定するのが望ましいと結論付けができる。
【００３７】
また、ダクトの長手方向における前記折曲連接部分３６の設定位置は、吹出口２０の上流側端縁３８から下流側へ３０ｍｍ離間した前記第１位置Ｐ１と、この第１位置Ｐ１から下流側へ３０ｍｍ離間した(吹出口２０の上流側端縁３８から下流側へ６０ｍｍ離間した)前記第２位置Ｐ２との間とするのが望ましい。換言すると、ダクトの長手方向における前記折曲連接部分３６の設定位置は、吹出口２０の上流側端縁３８から下流側へ、該吹出口２０の横寸法Ｅの０.３倍(０.３Ｅ)に相当する距離だけ離間した第１位置Ｐ１と、この第１位置Ｐ１から下流側へ、前記吹出口２０の横寸法Ｅの０.３倍(０.３Ｅ)に相当する距離だけ離間した第２位置Ｐ２との間とするのが望ましいと結論付けができる。
【００３８】
実験２は、前記曲面壁部３２の曲率半径Ｒを一定とし、かつ該曲面壁部３２の形成位置を一定としたもとで、ダクトの短手方向における平面壁部３４の形成位置を変化させた４タイプに関して夫々配風性能を実験した。すなわち、前記曲面壁部３２の曲率半径Ｒを８０ｍｍとし、ダクトの長手方向における折曲連接部分３６の設定位置を、吹出口２０の上流側端縁３８からの間隔Ｓを３０ｍｍ(前記第１形成位置)とした場合において、図９に示すように、ダクトの短手方向における前記折曲連接部分３６の設定位置を、▲１▼第２壁部１６の延長ラインＬからの間隔Ｈａ(１０ｍｍ)とした第５形成位置、▲２▼延長ラインＬからの間隔Ｈｂ(１５ｍｍ)とした第６形成位置、▲３▼延長ラインＬからの間隔Ｈｃ(２０ｍｍ)とした第７設定位置、▲４▼延長ラインＬからの間隔Ｈｄ(２５ｍｍ)とした第８設定位置、の合計４タイプについて配風性能の実験を行なった。従って、前記第７形成位置位置(間隔Ｈｃ＝２０ｍｍ)に関しては、前記実験１に含まれている。
【００３９】
図１０は、実験２における実験結果を図示したもので、前述した４タイプにおける吹出口２０の風速分布態様を示している。また表３は、図１０に例示した実験結果に基づき、前記▲１▼〜▲３▼の評価方法によって前記４タイプの評価結果を示した一覧表である。
【００４０】
【表３】

【００４１】
前記実験２では、平面壁部３４の形成位置が異なる合計４種類の通気ダクト３０における配風性能の実験を行なった。これら４種類の各通気ダクト３０に対する各々の総合評価は９.５(最低)〜１３.０(最高)の範囲となり、何れの通気ダクト３０にあっても、図１１〜図１６に示した従来の各通気ダクト１０より良好な総合評価が得られた。換言すると、前記第２壁部１６において前記吹出口２０の開口領域に臨む背面部位を、該第２壁部１６から該吹出口２０の側へ湾曲的に延在する曲面壁部３２と、この曲面壁部３２の端縁から該吹出口２０に沿って延在する平面壁部３４とで形成した実施例の通気ダクト３０は、前述したように、これら曲面壁部３２および平面壁部３４の形成位置に関係なく、少なくとも図１１〜図１６に示した従来の各通気ダクト１０よりも配風性能の向上が図られていると評価できる。
【００４２】
そして、ダクトの短手方向における前記折曲連接部分３６の設定位置を、吹出口２０の側に近づける程(前記延長ラインＬとの間隔Ｈを大きくする程)、前記吹出口２０の面積と調温空気の適正風速領域Ｗの面積との面積比率Ｂ／Ａが良好となり(評価▲１▼)、前記吹出口２０における調温空気の適正風速領域Ｗの位置が良好となる(評価▲２▼)。しかしながら圧損値は、これとは逆に、ダクトの短手方向における前記折曲連接部分３６の設定位置を吹出口２０の側に近づける程、大きくなる傾向にある(評価▲３▼)。このことから、ダクトの短手方向における前記折曲連接部分３６の設定位置は、前記第２壁部１６の延長ラインＬから前記吹出口２０の側へ１５ｍｍ離間した前記第３位置Ｐ３と、この第３位置Ｐ３から更に該吹出口２０の側へ１５ｍｍ離間した前記第４位置Ｐ４との間とするのが望ましい。
【００４３】
換言すると、ダクトの短手方向における前記折曲連接部分３６の設定位置は、第２壁部１６の延長ラインＬから前記吹出口２０の側へ、前記ダクト本体１２の出口部分における幅寸法Ｄの０.４倍(０.４Ｄ)程度に相当する距離だけ離間した第３位置Ｐ３と、この第３位置Ｐ３から更に該吹出口２０の側へ、前記ダクト本体１２の出口部分における幅寸法Ｄの０.３倍(０.３Ｄ)程度に相当する距離だけ離間した第４位置Ｐ４との間とするのが望ましいと結論付けができる。
【００４４】
なお本願の通気ダクトは、車両内装部材の裏側に配設されるものに限定されるものではなく、様々な分野において空気等の各種気体を流通案内した後に吹出すのに実施される種々のダクトとして実施可能である。
【００４５】
【発明の効果】
以上説明した如く、本発明に係る通気ダクトによれば、第２壁部において吹出口の開口領域に臨む背面部位を、該第２壁部から該吹出口の側へ湾曲的に延在する曲面壁部と、この曲面壁部の端縁から該吹出口に沿って延在する平面壁部とで形成したことにより、上流側から通入された空気等を前記曲面壁部に沿って移動する過程で前記吹出口の側へ分散状態で変向させ、これにより該吹出口から広く通出させ得る。そして、前記曲面壁部および平面壁部に関連する諸寸法を前述したように設定したことにより、吹出口から吹出す空気等の適正風速領域の拡大化および位置適正化を好適に図り得る利点がある。
また、調温空気の適正風速領域が拡大するために、局部的な風速の変化が減少して吹出し騒音が減少するようになると共に、乗員室内の効率的かつ快適な空調を実施し得る。更には、配風性能の向上を図るに際して、乗員が吹出方向を調整可能としたエアアウトレットを別途装着する場合以外は吹出変向装置や整流網等の別部材を準備する必要がないと共に、ブロー成形技術等により一体成形できるため、製造コストが嵩むこともない等の極めて有益な効果を奏する。
【図面の簡単な説明】
【図１】本発明の好適実施例に係る通気ダクトを一部省略して例示した概略斜視図である。
【図２】図２は図１のII−II線断面図である。
【図３】曲面壁部と平面壁部との折曲連接部分に関し、ダクトの長手方向における設定位置およびダクトの短手方向における設定位置を示した説明図である。
【図４】 (ａ)は、吹出口の開口面積と調温空気の適正風速領域の面積との面積比率を評価する方法を示した説明図であり、(ｂ)は、吹出口に対する調温空気の適正風速領域の位置を評価する方法を示した説明図である。
【図５】 (ａ)は、曲面壁部の曲率半径Ｒ＝２０ｍｍに設定した第１通気ダクトに関し、該曲面壁部の形成位置を変更した４タイプの形態を例示した説明断面図、(ｂ)は、曲面壁部の曲率半径Ｒ＝５０ｍｍに設定した第２通気ダクトに関し、該曲面壁部の形成位置を変更した４タイプの形態を例示した説明断面図、(ｃ)は、曲面壁部の曲率半径Ｒ＝８０ｍｍに設定した第２通気ダクトに関し、該曲面壁部の形成位置を変更した４タイプの形態を例示した説明断面図である。
【図６】図５(ａ)に示した４タイプの各第１通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図７】図５(ｂ)に示した４タイプの各第２通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図８】図５(ｃ)に示した４タイプの各第３通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図９】平面壁部の形成位置を変更した４タイプの通気ダクトの形態を例示した説明断面図である。
【図１０】図９に示した４タイプの各通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図１１】従来の通気ダクトを一部省略して例示した部分斜視図である。
【図１２】 (ａ)は、図１１のＸ−Ｘ線断面図、(ｂ)は、図１１に例示した通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図１３】従来の別の通気ダクトを一部省略して例示した部分斜視図である。
【図１４】 (ａ)は、図１３のＹ−Ｙ線断面図、(ｂ)は、図１３に例示した通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【図１５】従来の更に別の通気ダクトを一部省略して例示した部分斜視図である。
【図１６】 (ａ)は、図１５のＺ−Ｚ線断面図、(ｂ)は、図１５に例示した通気ダクトの吹出口から吹出す調温空気の風速分布態様を示した説明図である。
【符号の説明】
１２ダクト本体
１４第１壁部
１６第２壁部
２０吹出口
３２曲面壁部
３４平面壁部
３６折曲連接部分
３８上流側端縁(吹出口２０の)
Ｄ幅寸法(ダクト本体１２の出口部分)
Ｅ横寸法(吹出口２０の)
Ｌ延長ライン(第２壁部１６の)
Ｐ１第１位置
Ｐ２第２位置
Ｐ３第３位置
Ｐ４第４位置
Ｒ曲率半径(曲面壁部３２の)[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ventilation duct, and more specifically, includes a first wall portion and a second wall portion that form a duct wall facing each other, and an air outlet opened at an end of the first wall portion. In addition, the present invention relates to a ventilation duct that allows air or the like that has been introduced from the upstream side to pass through the air outlet while being diverted in a direction substantially perpendicular to the flow direction.
[0002]
[Prior art]
For example, in various vehicles such as passenger cars, passenger cabin air conditioning is performed by temperature-controlled air sent from an air conditioner unit mounted on the vehicle body. For this reason, an air outlet for blowing out the temperature-controlled air into the passenger compartment is disposed at a required position of a vehicle interior member such as an instrument panel or a roof panel. Are connected by a ventilation duct for circulating and guiding the temperature-controlled air.
[0003]
Here, the ventilation duct is disposed in a narrow space defined between the vehicle interior member and the vehicle body on the back side of the vehicle interior member, and thus has a narrow flat outer shape, Furthermore, there are many cases in which it is unavoidable to form a complex uneven outer surface shape. That is, the ventilation duct 10 is formed of, for example, a first wall portion 14 and a second wall portion 16 that form a duct wall of the duct body 12 so as to face each other, as schematically shown in FIG. An air inlet 18 connected to an air delivery unit (not shown) of the air conditioner unit or another ventilation duct is opened at one end of the air conditioner unit 16 and the other end of the first wall 14 is An air outlet 20 is opened from the required position of the vehicle interior member to the passenger compartment. As a result, the temperature-controlled air introduced from the upstream side inlet 18 is sequentially discharged from the outlet 20 after being moved through the duct body 12. In addition, the technique relevant to the said ventilation duct is disclosed by patent document 1 etc., for example.
[0004]
[Patent Document 1]
JP 2000-103223 A
[0005]
[Problems to be solved by the invention]
By the way, the ventilation duct 10 illustrated in FIG. 11 is, as shown in FIG. 12 (a), (1) the air outlet 20 opened in a horizontally long rectangular shape compared to the cross-sectional area of the duct body 12 having a flat shape. (2) The direction in which the temperature-controlled air is blown from the outlet 20 is a short direction substantially perpendicular to the flow direction (longitudinal direction) in the duct body 12. ing. Therefore, the temperature-controlled air introduced from the upstream inlet 18 is accelerated and moved appropriately in the duct body 12 having a small cross-sectional area, so that it will collide with the downstream wall of the duct adjacent to the outlet 20 at one end. Then, after this collision, it suddenly changes in a direction substantially orthogonal to move toward the outlet 20 (FIG. 12 (a)). Therefore, as shown in FIG. 12 (b), the temperature-controlled air discharged from the outlet 20 has a main flow in the left side region (downstream side region) of the outlet 20 as apparent from the wind speed distribution pattern of the outlet 20. ) In a narrow area, and hardly blows out from the right area (upstream area) of the outlet 20. That is, the appropriate wind speed region (for example, the shaded display portion in FIG. 12 (b)) W having a specified wind speed (for example, 12 m / s) is biased toward the left region of the outlet 20 and its area is considerably narrow. The performance was extremely low. Therefore, inconveniences such as (a) a region where the wind speed is locally increased are formed and blowing noise increases, and (b) efficient and comfortable air conditioning in the passenger compartment cannot be performed. It was.
[0006]
Therefore, in order to avoid the above-mentioned inconvenience, a back surface portion facing the opening region of the outlet 20 in the second wall portion 16 is formed as a curved surface portion 22 as shown in FIG. 13, for example, or as shown in FIG. Thus, a countermeasure has been taken to form the inclined surface portion 24 as a so-called diverted guide surface for temperature-controlled air. However, in the ventilation duct 10 illustrated in FIG. 13, there is a slight difference depending on the setting of the curvature radius of the curved surface portion 22, but as shown in FIGS. 14A and 14B, the ventilation in FIG. Compared with the duct 10, the improvement of the air distribution performance is hardly achieved. On the other hand, in the ventilation duct 10 illustrated in FIG. 15, although there are some differences from the setting of the inclination angle and length of the inclined surface portion 24, as shown in FIGS. 16 (a) and 16 (b), Although a slight improvement in the air distribution performance can be confirmed as compared with the ventilation duct 10 of 11, the air distribution performance that is still satisfactory cannot be obtained.
[0007]
For this reason, even when an air outlet that allows the occupant to adjust the blowing direction is separately installed, a blowing diverting device, a rectifying network, etc. are prepared as separate members, and these are additionally arranged on the front side of the outlet 20. It was necessary to take measures to improve the air distribution performance by expanding the area and correcting the position of the appropriate wind speed region W that provides the specified wind speed. However, since the diverting device, the rectifying network, and the like are separately manufactured, there has been a problem that the manufacturing cost increases due to the additional addition of parts cost, labor cost, and the like.
[0008]
OBJECT OF THE INVENTION
The present invention has been proposed to suitably solve the above-described problems, and an object of the present invention is to provide a ventilation duct that improves the air distribution performance with respect to the air discharged from the air outlet.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problems and achieve the intended object, the present invention is established at the first wall portion and the second wall portion that form a duct wall facing each other, and at the end of the first wall portion. In the ventilation duct that has the air outlet, and the air or the like introduced from the upstream side is made to pass out from the air outlet while turning in a direction substantially orthogonal to the flow direction thereof,
A back wall portion facing the opening region of the air outlet in the second wall portion is curved from a curved wall portion extending from the second wall portion to the air outlet side, and from an edge of the curved wall portion. Formed with a flat wall extending along the air outlet,
The air or the like introduced from the upstream side is configured to be widely discharged from the outlet by changing the direction of the air in a dispersed state toward the outlet in the process of moving along the curved wall portion. It is characterized by.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Next, the ventilation duct according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments. In addition, about the site | part and member, etc. which are the same as the conventional ventilation duct 10 illustrated in FIG.11, FIG.13, FIG.15 etc., the same code | symbol is attached | subjected and demonstrated.
[0011]
FIG. 1 is a schematic perspective view illustrating a ventilation duct according to a preferred embodiment of the present invention with a part thereof omitted, and FIG. 2 is a sectional view taken along line II-II in FIG. The ventilation duct 30 of the embodiment is formed of a first wall portion 14 and a second wall portion 16 that are opposed to each other to form a duct wall of the duct body 12, and are integrally molded based on, for example, a known blow molding technique. A hollow body made of synthetic resin (polyethylene). Then, at one end portion of the second wall portion 16, an inlet 18 connected to an air delivery portion of an air conditioner unit (not shown) or another ventilation duct is opened, and the other end of the first wall portion 14 is opened. An air outlet 20 is provided at the end of the vehicle so as to face the passenger compartment from a required position such as a vehicle interior member. That is, the right side of the drawing in FIG. 1 is the upstream side of the ventilation duct 30, and the left side of the drawing is the downstream side of the ventilation duct 30.
[0012]
Here, the inner surface dimension of the air circulation part in the ventilation duct 30 of the embodiment is set as follows. First, the vertical dimension G of each part from the upstream end to the downstream end is substantially the same in any part in the longitudinal direction, and is set to about 50 mm, for example. On the other hand, the width dimension of the air circulation portion is different for each part in the longitudinal direction, and the width dimension C of the duct body 12 as a main body is set to about 20 mm. That is, the duct body 12 is narrowest in the air circulation portion of the ventilation duct 30 and has a vertically long flat shape. In addition, the downstream end side of the duct main body 12 is appropriately formed in an expanded shape, and the width dimension D of the outlet portion facing the air outlet 20 is set to about 35 mm.
[0013]
On the other hand, the air outlet 20 opened in the first wall portion 14 has a horizontally long rectangular shape with a lateral dimension E = 100 mm and a longitudinal dimension F = 50 mm. Accordingly, the opening area of the outlet 20 is about three times the air circulation area at the outlet portion of the duct body 12 and about five times the air circulation area at the center portion of the duct body 12.
[0014]
In the ventilation duct 30 of the embodiment, the temperature-controlled air that has moved through the duct main body 12 and escaped from the outlet portion of the duct main body 12 is appropriately redirected toward the air outlet 20 and the air outlet 20. In order to blow out to a wide area, the following duct wall structure is adopted to improve the air distribution performance of the temperature-controlled air. That is, a curved wall 32 extending in a curved manner from the second wall 16 toward the outlet 20, and a curved surface of the rear surface facing the opening area of the outlet 20 in the second wall 16. A flat wall portion 34 extending from the edge of the wall portion 32 along the air outlet 20 is formed. Therefore, as is apparent from FIG. 2, the back surface portion of the second wall portion 16 facing the air outlet 20 includes a bent connection portion 36 that is a boundary portion between the curved wall portion 32 and the flat wall portion 34. The temperature-controlled air protrudes in the flow direction of the temperature-controlled air between the outlet portion of the duct body 12 and the air outlet 20, and thereby moves the temperature-controlled air that has escaped from the duct body 12 along the curved wall portion 32. In the process, the direction is changed in a dispersed state toward the air outlet 20, so that the air can be widely discharged from the air outlet 20.
[0015]
And in the ventilation duct 30 of the embodiment, the width dimension D = 35 mm at the outlet portion of the duct body 12, the lateral dimension E = 100 mm of the outlet 20, and the longitudinal dimension F = 50 mm of the outlet 20, It is required that the temperature-controlled air that has been introduced from the inlet 18 moves through the duct body 12 at a flow velocity of 14 m / s and then is widely blown from the outlet 20 at a specified wind speed of 12 m / s. Therefore, in order to improve the air distribution performance, the dimensions of the portions related to the curved wall portion 32 and the flat wall portion 34 are set as follows. The dimensions related to the curved wall portion 32 and the flat wall portion 34 are derived based on the experimental results conducted by the applicant of the present application, and the details of the experiments and the experimental results will be described in detail later. To do.
[0016]
First, the curved wall 32 extends in an arc shape having a radius of curvature R joined in a tangential direction with respect to the second wall 16, and the temperature-controlled air that has moved through the duct body 12 is blown into the blowing wall 12. It can be smoothly turned to the outlet 20 side. Here, when the width D at the outlet portion of the duct body 12 is set to 35 mm, the curvature radius R is optimally set in the range of 40 to 90 mm, preferably about 50 to 80 mm. That is, the curvature radius R of the curved wall portion 32 is set to about 1.2 to 2.5 times (1.2D to 2.5D) the width dimension D at the outlet portion of the duct body 12.
[0017]
The flat wall portion 34 is formed between the downstream end wall portion of the duct and the curved wall portion 32, and is separated from the extension line L of the second wall portion 16 toward the outlet 20 by a required amount. And extends in the same direction as the second wall portion 16 (a direction parallel to the extension line L). The flat wall portion 34 does not need to be formed so as to extend in the same direction as the second wall portion 16, for example, the downstream end wall portion side is displaced in the direction opposite to the outlet 20 from the curved wall portion 32 side. The inclined state or the inclined state in which the downstream end wall portion side is displaced from the curved wall portion 32 side to the outlet 20 side may be used.
[0018]
In addition, the setting position of the bent connection portion 36 between the curved wall portion 32 and the flat wall portion 34 is the formation position of the curved wall portion 32 in the longitudinal direction of the duct and the flat wall portion 34 in the short direction of the duct. It is determined by the relationship with the formation position. First, the setting position of the bent connecting portion 36 in the longitudinal direction of the duct is a first position P1 that is a required distance away from the upstream end edge 38 of the air outlet 20 to the downstream side, and further downstream from the first position P1. And a second position P2 that is a required distance away (FIG. 3). Specifically, when the lateral dimension E of the air outlet 20 is set to 100 mm, the interval S1 between the upstream edge 38 of the air outlet 20 and the first position P1 is about 30 mm, and the first position The distance S2 between P1 and the second position P2 is about 30 mm (the distance (S1 + S2) from the upstream edge 38 is 60 mm). In other words, the interval S1 between the upstream end edge 38 of the air outlet 20 and the first position P1 is about 0.3 times (0.3E) the lateral dimension E at the air outlet 20, and the first The interval S2 between the position P1 and the second position P2 is about 0.3 times (0.3E) the lateral dimension E at the outlet 20, and the set position of the bent connecting portion 36 in the longitudinal direction of the duct Is an appropriate position between the first position P1 and the second position P2. When the center line CL of the outlet 20 is taken as a reference, a first position P1 that is separated from the center line CL upstream by 0.2 times (0.2E) the lateral dimension E at the outlet 20; From the center line CL to the downstream side, it is between the second position P2 spaced 0.1 times (0.1E) the lateral dimension E at the outlet 20.
[0019]
Further, the setting position of the bent connecting portion 36 in the short direction of the duct is a third position P3 spaced from the extension line L of the second wall portion 16 to the outlet 20 side by a required distance, and the third position P3. It is set between the position P3 and the fourth position P4 further away from the outlet 20 by a required distance (FIG. 3). Specifically, when the width D at the exit portion of the duct body 12 is set to 35 mm, the distance H1 between the extension line L and the third position P3 is about 15 mm, and the third position P3 and the The distance H2 from the fourth position P4 is about 10 mm (the distance from the extension line L (H1 + H2) is 25 mm). In other words, the distance H1 between the extension line L and the third position P3 is set to about 0.4 times (0.4D) the width dimension D at the outlet portion of the duct body 12, and the third position P3 The interval H2 with respect to the fourth position P4 is about 0.3 times (0.3D) the width D at the outlet portion of the duct body 12, and the setting of the bent connecting portion 36 in the short direction of the duct is set. The position is appropriately set between the third position P3 and the fourth position P4. When the extension line L is taken as a reference, the distance (H1 + H2) between the extension line L and the fourth position P4 is 0.7 times (0.7D) the width D at the outlet portion of the duct body 12. ) It will be about.
[0020]
In the ventilation duct 30 of the embodiment formed as described above, the back surface portion facing the opening area of the air outlet 20 in the second wall portion 16 is curved from the second wall portion 16 to the air outlet 20 side. Formed by the curved wall portion 32 extending to the edge and the planar wall portion 34 extending from the end edge of the curved wall portion 32 along the outlet 20, thereby controlling the temperature-controlled air from the duct body 12. In the process of moving along the curved wall portion 32, the direction can be changed in a dispersed state toward the air outlet 20, so that the air can be widely discharged from the air outlet 20. And by setting the various dimensions related to the curved wall portion 32 and the flat wall portion 34 as described above, it is preferable to enlarge and position properly the appropriate wind speed region W of the temperature-controlled air blown out from the air outlet 20. It can be planned. And since the appropriate wind speed area | region W of temperature-controlled air expands, while the local change of the wind speed reduces and a blowing noise reduces, efficient and comfortable air conditioning in a passenger | crew interior can be implemented. Furthermore, when improving the air distribution performance, it is not necessary to prepare a separate member such as a blowing diverter or a rectifying network, except when an air outlet that allows the occupant to adjust the blowing direction is separately installed. Since it can be integrally formed by a molding technique or the like, the cost does not increase.
[0021]
Next, in the ventilation duct 30 of the embodiment, the basis for setting various dimensions related to the curved wall portion 32 and the flat wall portion 34 will be described based on the contents of experiments and the results of experiments conducted by the applicant of the present application. As described above, the air distribution performance of the temperature-controlled air in the ventilation duct 30 affects (1) the formation position of the curved wall portion 32 in the longitudinal direction of the duct, and (2) the plane in the short direction of the duct. The formation position of the wall 34, (3) the radius of curvature R of the curved wall 32, and the like. Therefore, Experiment 1 for determining the radius of curvature R and the formation position of the curved wall portion 32 and Experiment 2 for determining the formation position of the planar wall portion 34 were performed.
[0022]
Experiment 1 is a curved surface with the formation position of the flat wall portion 34 in the short direction of the duct being constant (the distance H from the extension line L of the second wall portion 16 is 20 mm). In each of the three types of ventilation ducts 30A, 30B, and 30C in which the curvature radius R of the wall portion 32 is set to 20 mm, 50 mm, and 80 mm, four types in which the formation position of the curved wall portion 32 in the longitudinal direction of the duct is changed. The wind distribution performance was tested. That is, the first ventilation duct 30A (FIG. 5A) in which the curvature radius R of the curved wall portion 32 is 20 mm (FIG. 5A), and the second ventilation duct 30B in which the curvature radius R of the curved wall portion 32 is 50 mm (FIG. 5B). ), In the third ventilation duct 30C (FIG. 5C) in which the radius of curvature R of the curved wall portion 32 is 80 mm (FIG. 5C), by changing the formation position of the curved wall portion 32 in the longitudinal direction of the duct, (1) a first setting position where the setting position of the bent connecting portion 36 in the longitudinal direction is a distance Sa (30 mm) from the upstream edge 38 of the outlet 20; (2) from the upstream edge 38; Second set position with spacing Sb (50 mm) (matches the center line CL of the outlet 20), (3) Third set position with spacing Sc (70 mm) from the upstream edge 38, (4) Upstream side 4 types in total, 4th set position with spacing Sd (90mm) from edge 38 Experiments on wind distribution performance were conducted.
[0023]
Here, as points to consider in the evaluation of wind distribution performance,
(1) The area of the appropriate wind speed region W blown out at the specified wind speed in the temperature-controlled air blown from the outlet 20
(2) The position of the appropriate wind speed region W that is blown out at the specified wind speed in the temperature-controlled air blown from the outlet 20
(3) Pressure loss value,
It is necessary to consider these various data comprehensively. However, when the area and / or position of the appropriate wind speed region W is an important point for evaluation, the above points (1) and (2) should be taken into consideration, and when the pressure loss value is an important point, the above point (1) It is necessary to consider all of ▼, ▲ 2 ▼, ▲ 3 ▼.
[0024]
As shown in FIG. 4 (a), the evaluation method (1) is based on the distribution pattern of the temperature-controlled air at the outlet 20, and the opening area of the outlet 20 (lateral dimension E × vertical dimension). F) = A, and an appropriate wind speed region (shaded portion in the figure) W of the temperature-controlled air = B = area B / A is calculated and calculated. For example, when the temperature-controlled air is blown out from the entire area of the air outlet 20 at an appropriate wind speed, since B / A = 1, this is evaluated as 10 points (full score). When temperature-controlled air is blown out from approximately half at an appropriate wind speed, B / A = 0.5, and this is evaluated as 5 points.
[0025]
In the evaluation method (2), as shown in FIG. 4B, the center of the appropriate air velocity region W of the temperature-controlled air is displaced to the right or left with respect to the center line CL of the air outlet 20. It is carried out by determining whether it is doing. For example, when the appropriate wind speed region W coincides with the center line CL of the air outlet 20, it is evaluated as 5 points, and the point is decremented as the amount of deviation to the left or right side of the appropriate wind speed region W increases. When W is located at the left end or the right end of the outlet 20, it is evaluated as one point. In the case of the illustrated example based on this assumption, the center of the appropriate wind speed region W is slightly deviated to the left of the center line CL of the air outlet 20 and is substantially coincident with the four lines, so it is evaluated as four points. The
[0026]
Further, the pressure loss value of (3) is evaluated as shown in Table 1 in view of the fact that the conventional ventilation ducts 10 shown in FIGS. 11 to 16 are 116 to 119 (Pa) (see Table 2). A standard was set. That is, when a better result is obtained than each conventional ventilation duct 10 (when the pressure loss value is low), it is 5 points, and when it is the same level, it is 4 points, and when it is worse than this (pressure loss value is If it becomes higher), it is evaluated as 3 points, 2 points, 1 point according to the value.
[0027]
[Table 1]

[0028]
FIGS. 6 to 8 illustrate the experimental results in Experiment 1, and show the wind speed distribution mode of the temperature-controlled air at the outlet 20 under the above-described setting conditions. That is, FIG. 6 shows the wind speed distribution mode of each outlet 20 in the four types of the first ventilation duct 30A (FIG. 5A) in which the curvature radius R of the curved wall portion 32 is 20 mm, and FIG. FIG. 8 shows a wind speed distribution mode of each outlet 20 in the four types of the second ventilation duct 30B (FIG. 5B) in which the curvature radius R of the curved wall portion 32 is 50 mm, and FIG. The wind velocity distribution mode of each outlet 20 in the four types of the third ventilation duct 30C (FIG. 5 (c)) with a curvature radius R = 80 mm is shown.
[0029]
Table 2 is a list showing four types of evaluation results in the first to third ventilation ducts 30A, 30B, and 30C based on the experimental results of Experiment 1 illustrated in FIGS. 5 and 6 to 8. It is. In the lower part of Table 2, the cases where the conventional three types of ventilation ducts 10 illustrated in FIGS. 11 to 16 are evaluated by the evaluation methods (1) to (3) are also shown. That is, in the conventional ventilation duct 10 shown in FIG. 11 and FIG. 12, the total evaluation obtained by summing up the evaluations (1) to (3) is 7.5 points. Similarly, the conventional ventilation duct 10 shown in FIG. 13 and FIG. In the other ventilation duct 10, the overall evaluation was 7.5, and in the other conventional ventilation duct 10 shown in FIGS. 15 and 16, the overall evaluation was 8.5.
[0030]
[Table 2]

[0031]
In the experiment 1, four types are used in the first ventilation duct 30A in which the curvature radius R of the curved wall 32 is set to 20 mm, and four types are used in the second ventilation duct 30B in which the curvature radius R of the curved wall 32 is set to 50 mm. Experiments were made on the air distribution performance of 12 types of ventilation ducts in total, with four types in the third ventilation duct 30C set to have a radius of curvature R of the wall portion 32 = 80 mm. The overall evaluation of each of these 12 types of ventilation ducts 30 is in the range of 8.5 (minimum) to 13.0 (maximum), and each of the conventional ventilation ducts shown in FIGS. A comprehensive evaluation equal to or better than that of the ventilation duct 10 was obtained, and most of them were better than the conventional ventilation ducts 10. In other words, a curved wall 32 extending from the second wall 16 to the side of the air outlet 20 in a curved manner at a back surface portion facing the opening area of the air outlet 20 in the second wall 16, The ventilation duct 30 of the embodiment formed by the flat wall portion 34 extending from the end edge of the curved wall portion 32 along the air outlet 20 is almost related to the positions where the curved wall portion 32 and the flat wall portion 34 are formed. Therefore, it can be evaluated that the air distribution performance is improved at least as compared with the conventional ventilation ducts 10 shown in FIGS.
[0032]
Regarding the area ratio B / A between the air outlet 20 and the appropriate air speed region W of the temperature-controlled air, as is clear from Table 2, in 12 types of ventilation ducts, better results than before were obtained. . As a tendency common to all of the first to third ventilation ducts 30A, 30B, and 30C, the curved wall portion 32 is adjusted to the upstream side (first formation position) of the duct. The appropriate air velocity region W of warm air can be enlarged, and more favorable results were obtained with the second ventilation duct 30B and the third ventilation duct 30C than with the first ventilation duct 30A. From this, when attempting to enlarge the appropriate wind speed region W of the temperature-controlled air, good results were obtained when the curvature radius R of the curved wall portion 32 was set to 50 mm or 80 mm. It is appropriate that the radius of curvature R is about 40 to 90 mm.
[0033]
As is apparent from Table 2, the position of the appropriate air speed region W of the temperature-controlled air with respect to the air outlet 20 has a curved surface as a tendency common to all of the first to third ventilation ducts 30A, 30B, 30C. When the formation position of the wall portion 32 is the first formation position, the appropriate wind speed region W is the center or substantially the center of the air outlet 20. However, when the setting position of the bent connecting portion 36 is set to the third forming position or the fourth forming position, the appropriate wind speed region W is biased to the left side or the left end of the air outlet 20. Therefore, when the position of the appropriate air velocity region W of the temperature-controlled air is desired to be the center or substantially the center of the outlet 20, the setting position of the bent connection portion 36 in the longitudinal direction of the duct is set to the upstream side of the outlet 20. It is appropriate to be between a position 30 mm away from the end edge 38 (first position P1) and a position 60 mm away from the upstream end edge 38 of the outlet 20 (second position P2).
[0034]
As is apparent from Table 2, the pressure loss value has a tendency to be common to all of the first to third ventilation ducts 30A, 30B, 30C, and the formation position of the curved wall portion 32 is defined as the first formation position. In contrast, the tendency to become the smallest when the formation position of the curved wall portion 32 is set to the fourth formation position is conspicuous. Therefore, when considering the reduction of the pressure loss value, it is desirable to set the setting position of the bent connecting portion 36 in the longitudinal direction of the duct as close as possible to the second position P2.
[0035]
In addition, in the comprehensive evaluation obtained by adding and totaling the evaluations (1) to (3), the following setting conditions were 10 points or more. First, in the case of the 1st ventilation duct 30A set to the curvature radius R = 20mm of the curved wall part 32, the comprehensive evaluation did not become 10 points or more. Further, in the case of the second ventilation duct 30B where the curvature radius R of the curved wall portion 32 is set to 50 mm, when the formation position of the curved wall portion 32 is set to the first formation position or the second formation position, the comprehensive evaluation is performed. The scores were 13 and 12 respectively. Further, in the case of the third ventilation duct 30C where the curvature radius R of the curved wall portion 32 is set to 80 mm, the overall evaluation is performed when the formation position of the curved wall portion 32 is set as the first formation position and the second formation position. They were 12 and 11 points, respectively.
[0036]
Therefore, from the result of Experiment 1, the curvature radius R of the curved wall portion 32 is appropriately about 40 to 90 mm as described above, so that the width dimension D (35 mm) of the outlet portion of the duct body 12 is 1. It can be concluded that it is desirable to set to about 2 to 2.5 times (1.2D to 2.5D).
[0037]
In addition, the setting position of the bent connecting portion 36 in the longitudinal direction of the duct is the first position P1 30 mm away from the upstream end edge 38 of the air outlet 20 to the downstream side, and the first position P1 to the downstream side. It is desirable that the distance between the second position P2 and the second position P2 is 30 mm apart (separated 60 mm downstream from the upstream edge 38 of the air outlet 20). In other words, the set position of the bent connecting portion 36 in the longitudinal direction of the duct is 0.3 times (0.3E) the lateral dimension E of the air outlet 20 from the upstream edge 38 of the air outlet 20 to the downstream side. ) And a first position P1 separated by a distance corresponding to 0.3 times (0.3E) the lateral dimension E of the outlet 20 from the first position P1 to the downstream side. It can be concluded that it is desirable to be between the two positions P2.
[0038]
In Experiment 2, the curved wall portion 32 has a constant radius of curvature R and the curved wall portion 32 is formed at a constant position, and the formation position of the flat wall portion 34 in the short direction of the duct is changed. The wind distribution performance was tested for each of the four types. That is, the curvature radius R of the curved wall portion 32 is set to 80 mm, the setting position of the bent connecting portion 36 in the longitudinal direction of the duct is set to the interval S from the upstream end edge 38 of the outlet 20 by 30 mm (the first formation). 9), as shown in FIG. 9, the setting position of the bent connecting portion 36 in the short direction of the duct is set to (1) the distance Ha (10 mm) from the extension line L of the second wall portion 16. (5) the sixth formation position, (2) the sixth formation position, which is the distance Hb (15 mm) from the extension line L, (3) the seventh set position, which is the distance Hc (20 mm) from the extension line L, (4) Experiments on the air distribution performance were performed on a total of four types, that is, the eighth set position with a distance Hd (25 mm) from the extension line L. Therefore, the seventh formation position (interval Hc = 20 mm) is included in Experiment 1.
[0039]
FIG. 10 illustrates experimental results in Experiment 2, and shows the wind speed distribution mode of the outlet 20 in the four types described above. Table 3 is a list showing the four types of evaluation results by the evaluation methods (1) to (3) based on the experimental results illustrated in FIG.
[0040]
[Table 3]

[0041]
In the experiment 2, an experiment was conducted on the air distribution performance in a total of four types of ventilation ducts 30 in which the formation position of the flat wall portion 34 is different. The overall evaluation of each of these four types of ventilation ducts 30 is in the range of 9.5 (minimum) to 13.0 (maximum). Overall evaluation better than each ventilation duct 10 was obtained. In other words, a curved wall 32 extending from the second wall 16 to the side of the air outlet 20 in a curved manner at a back surface portion facing the opening area of the air outlet 20 in the second wall 16, As described above, the ventilation duct 30 of the embodiment formed by the flat wall portion 34 extending from the end edge of the curved wall portion 32 along the air outlet 20 includes the curved wall portion 32 and the flat wall portion 34. Regardless of the formation position, it can be evaluated that the air distribution performance is improved at least as compared with the conventional ventilation ducts 10 shown in FIGS.
[0042]
Then, as the setting position of the bent connecting portion 36 in the short direction of the duct is brought closer to the outlet 20 side (as the distance H from the extension line L is increased), the area of the outlet 20 is adjusted. The area ratio B / A with the area of the appropriate air velocity region W of warm air becomes good (evaluation (1)), and the position of the appropriate air velocity region W of temperature-controlled air at the outlet 20 becomes good (evaluation (2)). ). However, conversely, the pressure loss value tends to increase as the set position of the bent connecting portion 36 in the short direction of the duct is brought closer to the outlet 20 (evaluation (3)). From this, the setting position of the bent connecting portion 36 in the short direction of the duct is the third position P3 spaced 15 mm from the extension line L of the second wall portion 16 to the outlet 20 side, and this It is desirable to be between the third position P3 and the fourth position P4 which is further 15 mm away from the outlet 20 side.
[0043]
In other words, the setting position of the bent connecting portion 36 in the short direction of the duct is the width D at the outlet portion of the duct body 12 from the extension line L of the second wall portion 16 to the outlet 20 side. A third position P3 that is separated by a distance corresponding to about 0.4 times (0.4D), and a width dimension D at the outlet portion of the duct body 12 from the third position P3 to the outlet 20 side. It can be concluded that it is desirable to be between the fourth position P4 separated by a distance corresponding to about 0.3 times (0.3D).
[0044]
In addition, the ventilation duct of this application is not limited to what is arrange | positioned at the back side of a vehicle interior member, but is various ducts implemented in order to blow out after guiding various gas, such as air, in various fields. It can be implemented as.
[0045]
【The invention's effect】
As described above, according to the ventilation duct according to the present invention, the back surface portion facing the opening region of the outlet in the second wall portion is curvedly extended from the second wall portion to the side of the outlet. By forming the wall portion and the flat wall portion extending from the edge of the curved wall portion along the air outlet, air or the like introduced from the upstream side moves along the curved wall portion. In the process, the direction can be changed in a dispersed state toward the air outlet, and thus the air can be widely discharged from the air outlet. And, by setting the dimensions related to the curved wall portion and the flat wall portion as described above, there is an advantage that the appropriate wind speed region such as the air blown out from the outlet can be appropriately enlarged and the position can be appropriately optimized. is there.
In addition, since the appropriate wind speed region of the temperature-controlled air is expanded, the local change in the wind speed is reduced to reduce the blowing noise, and the passenger compartment can be efficiently and comfortably air-conditioned. Furthermore, when improving the air distribution performance, it is not necessary to prepare a separate member such as a blowing diverter or a rectifying network, except when an air outlet that allows the occupant to adjust the blowing direction is separately installed. Since it can be integrally formed by a molding technique or the like, it has extremely beneficial effects such as no increase in manufacturing cost.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view illustrating a ventilation duct according to a preferred embodiment of the present invention with a part omitted.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is an explanatory diagram showing a set position in the longitudinal direction of the duct and a set position in the short direction of the duct with respect to the bent connection portion between the curved wall portion and the flat wall portion.
4A is an explanatory diagram showing a method for evaluating the area ratio between the opening area of the air outlet and the area of the appropriate wind speed region of the temperature-controlled air, and FIG. 4B is a temperature control for the air outlet. It is explanatory drawing which showed the method of evaluating the position of the appropriate wind speed area | region of air.
FIG. 5A is an explanatory sectional view illustrating four types of forms in which the formation position of the curved wall portion is changed with respect to the first ventilation duct set to a curvature radius R = 20 mm of the curved wall portion; ) Is an explanatory cross-sectional view illustrating four types of configurations in which the curved wall portion is changed in the formation position with respect to the second ventilation duct set to a curvature radius R = 50 mm of the curved wall portion, and (c) is a curved wall portion. It is explanatory sectional drawing which illustrated the 4 types form which changed the formation position of this curved-surface wall part regarding the 2nd ventilation duct set to the curvature radius R = 80mm.
6 is an explanatory view showing a wind speed distribution mode of temperature-controlled air blown out from the outlet of each of the four types of first ventilation ducts shown in FIG. 5 (a).
7 is an explanatory view showing a wind speed distribution mode of temperature-controlled air blown out from the outlet of each of the four types of second ventilation ducts shown in FIG. 5 (b).
FIG. 8 is an explanatory diagram showing a wind speed distribution mode of temperature-controlled air blown out from the outlet of each of the four types of third ventilation ducts shown in FIG. 5 (c).
FIG. 9 is an explanatory sectional view illustrating the form of four types of ventilation ducts in which the formation position of the flat wall portion is changed.
10 is an explanatory diagram showing a wind speed distribution mode of the temperature-controlled air blown out from the outlet of each of the four types of ventilation ducts shown in FIG. 9. FIG.
FIG. 11 is a partial perspective view illustrating a conventional ventilation duct with a part thereof omitted.
12A is a cross-sectional view taken along the line XX of FIG. 11, and FIG. 12B is an explanatory diagram showing a wind speed distribution mode of the temperature-controlled air blown out from the air outlet of the ventilation duct illustrated in FIG. is there.
FIG. 13 is a partial perspective view illustrating another conventional ventilation duct with a part omitted.
14A is a cross-sectional view taken along the line YY of FIG. 13, and FIG. 14B is an explanatory diagram showing a wind speed distribution mode of the temperature-controlled air blown out from the air outlet of the ventilation duct illustrated in FIG. is there.
FIG. 15 is a partial perspective view illustrating another conventional ventilation duct with a part omitted.
16A is a cross-sectional view taken along the line ZZ in FIG. 15, and FIG. 16B is an explanatory diagram showing a wind speed distribution mode of the temperature-controlled air blown out from the air outlet of the ventilation duct illustrated in FIG. is there.
[Explanation of symbols]
12 Duct body
14 First wall
16 Second wall
20 outlet
32 Curved wall
34 Plane wall
36 bent joints
38 upstream edge (of outlet 20)
D width dimension (exit part of duct body 12)
E Horizontal dimension (of outlet 20)
L extension line (for second wall 16)
P1 1st position
P2 2nd position
P3 3rd position
P4 4th position
R radius of curvature (of curved wall 32)

Claims

A first wall portion (14) and a second wall portion (16) forming a duct wall facing each other, and a blower outlet (20) opened at an end of the first wall portion (14) In the ventilation duct that is made to pass out from the air outlet (20) while turning the air or the like introduced from the upstream side in a direction substantially orthogonal to the flow direction thereof,
A curved wall extending in a curved manner from the second wall portion (16) to the side of the air outlet (20) at a back surface portion facing the opening region of the air outlet (20) in the second wall portion (16). A portion (32) and a planar wall portion (34) extending from the edge of the curved wall portion (32) along the air outlet (20),
From the air outlet (20), the air or the like introduced from the upstream side is changed in a dispersed state toward the air outlet (20) in the process of moving along the curved wall portion (32). A ventilation duct characterized by being configured to allow wide passage.

The bent joint portion (36) between the curved wall portion (32) and the flat wall portion (34) is a duct body (12) formed by the first wall portion (14) and the second wall portion (16). Projecting in the flow direction of the air or the like between the outlet portion of the air outlet and the air outlet (20), whereby the air or the like from the duct body (12) can be diverted toward the air outlet (20). The ventilation duct according to claim 1.

The curved wall portion (32) extends in an arc shape, and its radius of curvature (R) is about 1.2 to 2.5 times the width dimension (D) at the outlet portion of the duct body (12). The ventilation duct according to claim 1 or 2, which is set.

The set position of the bent connecting portion (36) in the longitudinal direction of the duct is the first position (P1) spaced from the upstream end edge (38) of the outlet (20) by a required distance to the downstream side, and the first position (P1). The ventilation duct according to claim 2 or 3, wherein the ventilation duct is between a first position (P1) and a second position (P2) that is further away from the downstream by a required distance.

The distance between the upstream edge (38) and the first position (P1) is about 0.3 times the lateral dimension (E) of the air outlet (20) provided in a rectangular shape. 4. The ventilation duct according to 4.

The distance between the first position (P1) and the second position (P2) is about 0.3 times the lateral dimension (E) of the air outlet (20) provided in a rectangular shape. Or the ventilation duct of 5.

The setting position of the bent connecting portion (36) in the short direction of the duct is a third position separated from the extension line (L) of the second wall portion (16) toward the outlet (20) by a required distance. The point between (P3) and the fourth position (P4) that is further away from the third position (P3) toward the outlet (20) by a required distance. Ventilation duct.

The ventilation duct according to claim 7, wherein a distance between the extension line (L) and the third position (P3) is about 0.4 times a width dimension (D) at an outlet portion of the duct body (12). .

The distance between the third position (P3) and the fourth position (P4) is about 0.3 times the width dimension (D) at the outlet portion of the duct body (12). Ventilation ducts.