JP4236732B2

JP4236732B2 - Intake system silencer mounting structure

Info

Publication number: JP4236732B2
Application number: JP16736298A
Authority: JP
Inventors: 正規福島; 和浩前野; 立裕永島
Original assignee: SAKAMOTO INDUSTRY CO.,LTD.; Fuji Jukogyo KK
Current assignee: SAKAMOTO INDUSTRY CO.,LTD.; Subaru Corp
Priority date: 1998-06-15
Filing date: 1998-06-15
Publication date: 2009-03-11
Anticipated expiration: 2018-06-15
Also published as: JP2000002161A

Description

【０００１】
【発明の属する技術分野】
本発明は、吸気ダクト本体の中間部に分岐部を設け、該分岐部に消音器の筒状取付部を挿入固定する吸気系消音器の取付構造に関する。
【０００２】
【技術分野】
自動車等のエンジンの吸気ダクトには、例えば、実開昭６３−１９３７６６号公報、実開平３−６８５５５号公報等に開示されるように吸気騒音の低減を図る目的で消音器が取り付けられている。
【０００３】
この種の騒音器の取付構造としては、吸気ダクトの吸気ダクト本体から分岐する分岐部と、消音器に突設された筒状の取付部とを溶接結合するものや、ホースバンドを用いてそれら両者を直接的にまたは間接的に締付固定或いは、筒状取付部に形成された引掛け爪若しくはバルジを上記分岐部に嵌合させる等各種の取付構造が提案されている。
【０００４】
これらの内でも、吸気方式の違い等により、消音器の取付部に高い気密性が要求されない場合には、図４に示すように、消音器５１の消音器本体５２に突設された筒状取付部５３の中間部に形成した引掛け爪或いはバルジ、例えば環状のバルジ５５を、合成樹脂製の吸気ダクト５７の吸気ダクト本体５８から突出する分岐部５９に形成された環状溝５０に嵌め込んで消音器５１を取り付けることが広く一般に行われている。
【０００５】
ところで、このような取付構造において、消音器５１の保持力を十分に高めるためには、筒状取付部５３の嵌合代、換言すると、分岐部５９の吸気ダクト本体５８からの突出長さＬを十分長くすることが必要である。しかし、吸気ダクト５７及び消音器５１等の吸気系の占有スペースの削減が要求に伴うコンパクト化、音響性能上、レイアウト上その他の制限によって、分岐部５９の突出長さＬが確保できない場合には、消音器５１の保持力を十分に高めることができなかった。
【０００６】
この対策として、図５に示すように、筒状取付部５３に引掛け爪或いはバルジ等を設けることに代えて、その筒状取付部５３を、分岐部５９の直径方向に対応する二個所にリベット６３によって機械的に連結することが行われている。
【０００７】
上記のような、図５に示すリベット６３による吸気ダクトと消音器５１の取付構造では、筒状取付部５３の外周面と、分岐部５９の内周面との間に生じる隙間δによって、消音器５１の両リベット６３の軸線と直交する方向の慣性力、外力等を受けた場合に、その消音器５１がリベット６３を支点としてその周りに揺動して、吸気騒音とは全く別個の衝突音を発生させると共に、その揺動に起因するリベット６３の早期の摩耗に加えて、上記衝突に起因する筒状取付部５３及び分岐部５９の早期の摩耗が懸念される。
【０００８】
一方、このような不都合の発生を防止するため、リベット６３の本数を三本以上の複数本とすることがあるが、エンジンルーム内のレイアウト等に起因して作業空間が制限されて、作業者の手、作業工具等を所要の位置まで差し込む余地がない場合には、それさえも不可能であり、またその差し込みが可能であっても、リベット本数、作業工数等の増加、ひいては、製造コストの増加が余儀なくされる。
【０００９】
従って、かかる点に鑑みて成された本発明の目的は、吸気ダクトに形成される分岐部の突出長さの短縮を可能にすると共に、消音器の筒状取付部をリベット本数、作業工数等の増加を招くことなく分岐部に簡単に取り付けできることは勿論、消音器の揺動運動を有効に阻止し、かつ取付部の気密性を大きく向上させることができる吸気系消音器の取付構造を提供することにある。
【００１０】
【課題を解決するための手段】
上記目的を達成する請求項１に記載の吸気系消音器の取付構造の発明は、吸気ダクトの本体から分岐形成された分岐部に消音器の筒状取付部を挿入固定する吸気系消音器の取付構造において、上記分岐部の基部に上記本体と連続する一対の拡径着座部を形成し、上記筒状取付部の先端に上記各拡径着座部のそれぞれに係合する一対のフランジを設け、該フランジとは周方向に隔てた位置において上記分岐部と上記筒状取付部を一対の機械的連結手段により固定することを特徴とする。
【００１１】
この請求項１の発明によると、音響性能上、レイアウト上等の制限で、分岐部の長さを十分長く取れない場合であっても、例えば合成樹脂製の分岐部に同じく合成樹脂製の筒状取付部を挿入するだけで、両者の弾性変形によって消音器を吸気ダクトに簡単に取り付けられて消音器本来の機能を十分に発揮させると共に、筒状取付部の先端に形成したフランジを、分岐部の基部に形成した拡径着座部に、線接触もしくは面接触させることにより、消音器に作用する各方向の慣性力、外力等に対して消音器を常に安定した状態で支持して、消音器の揺動運動を有効に阻止することができる。
【００１２】
従って、消音器が揺動することに起因する衝突音の発生のおそれを除去すると共に、両者の嵌合部における摩滅、摩耗等の発生を防止乃至極めて少なくでき、併せて、フランジと拡径着座部の接触が線もしくは面接触となり、両者の嵌合部の気密性を大きく向上させることができる。
【００１４】
更に、分岐部に挿入される筒状取付部の挿入部分と、分岐部とを機械的連結手段により結合することによって、拡径着座部とフランジとの接触を確実に維持することができ、安定した状態で消音器を吸気ダクトに取り付け維持することが可能になる。
【００１５】
請求項２に記載の発明は、請求項１の吸気系消音器の取付構造において、上記機械的連結手段は、リベット結合であることを特徴とする。
【００１６】
請求項２の発明は、請求項２に記載の機械的連結手段を具体的に例示したものであって、リベットによって効率的に分岐部と筒状取付部を結合することができる。
【００１７】
請求項３に記載の発明は、請求項１または２の吸気系消音器の取付構造において、上記拡径着座部は、吸気ダクト本体の軸線方向に沿って上記分岐部を介して配設され、上記機械的連結手段は、上記拡径着座部及び上記フランジに対して上記筒状取付部及び上記分岐部の周方向に略９０度隔てた位置に配設されることを特徴とする。
【００１８】
この請求項３の発明によると、消音器はリベット等による機械的連結手段の周りで揺動するおそれはあっても、その揺動方向と直交する方向での揺動は、リベット等の機械的連結手段によって確実に阻止され、かつフランジ及び拡径着座部を消音器の揺動のおそれのある方向にだけ形成することで、筒状取付部及び分岐部の形成に際する材料歩留まりの向上をもたらすと共に、成形上の制約を少なくし、機械的連結手段による結合位置の筒状取付部の軸方向位置の自由度が高まり、更には、筒状取付部ひいては、そのフランジの分岐部への挿入取付作業を容易にする。
【００１９】
請求項４に記載の発明は、請求項１〜３のいずれか１項の吸気系消音器の取付構造において、上記フランジは、先端部分が先細りテーパ形状であると共に、基端面が上記筒状取付部の軸線と直交する平面形状であり、上記拡径着座部の上記基端面と当接する着座面が平面形状であることを特徴とする。
【００２０】
請求項４の発明によると、フランジの分岐部への挿入が一層容易になり、かつ挿入後は、フランジの基端面を拡径着座部の着座面に面接触させることで嵌合部の気密性を高めて、気流音等の発生を有効に防止することができる。
【００２１】
【発明の実施の形態】
以下にこの発明による吸気系消音器の取付構造の実施の形態を図によって説明する。
【００２２】
図１は、本実施の形態を示す分解斜視図であり、図中符号１は吸気ダクトであって、吸気ダクト１の吸気ダクト本体２の途中から下方側へ突出する分岐部４が分岐して設けられている。ここでは、吸気ダクト本体２及び分岐部４の各々の軸線２ａと４ａは互いに直交している。
【００２３】
吸気ダクト１の分岐部４に取り付けられる消音器６は、図１に示すように消音器本体７から上方へ突出して、分岐部４内に挿入される筒状取付部８を有している。
【００２４】
そして、図２に消音器６を取り付けた状態での要部断面図を示すように、筒状取付部８の先端には、吸気ダクト本体２の軸線２ａ方向に対応して位置する一対のフランジ１０を設ける一方、分岐部４の基部に、フランジ１０の係合を許容する拡径着座部１２が吸気ダクト２に連続して設けられている。
【００２５】
この拡径着座部１２はフランジ１０と同様に吸気ダクト２の軸線２ａ方向に対応させて分岐部４を介して一対形成され、フランジ１０が嵌合する形状及び寸法を有している。
【００２６】
またフランジ１０は、先端部１０ａが先細りテーパ形状であって、フランジ１０を分岐部４への押し込み装着作業を円滑かつ容易にしている。
【００２７】
なお、この押し込み容易性は、図示のように、フランジ１０を周方向に間欠的に形成して、筒状取付部８の押し込みに際して、その筒状取付部８及び分岐部４の弾性変形を容易にすることによってもまた高めることができる。
【００２８】
加えて、図示のフランジ１０では、その基端側部分１０ｂを、基端方向に向けて次第に小径となるテーパ形状をしており、基端部分１０ｂをテーパ形状にすることによって一旦取り付けた消音器６を、分岐部４からの所要に応じた抜き取りの際の操作性を円滑かつ容易にすることができる。
【００２９】
更に、フランジ１０の基端面１０ｃは、筒状取付部８の軸線８ａと直交する平面上に形成され、拡径着座部１２も筒状取付部８の軸線８ａと直交する着座面１３を有し、これら対向するフランジ１０の基端面１０ｃと、拡径着座部１２の着座面１３を面接触乃至線接触させることで、フランジ１０と筒状取付部８との間の気密性を確保し、吸気音のより有効な低減が得られる。
【００３０】
そして更に、分岐部４及び筒状取付部８の各々の直径方向に対向する二個所、好ましくは吸気ダクト本体２の軸線２ａと直交する方向、換言すると、上記一対の拡径着座部１２及び一対のフランジ１０に対して筒状取付部８及び分岐部４の周方向に略９０度隔てた位置の二個所に消音器６を取付状態で相互に重なり合う貫通孔１４及び１５を設け、貫通孔１４及び１５に挿入されるリベット１８によって分岐部４と筒状取付部８と機械的に互いに連結する。
【００３１】
これによれば、多数本のリベットを用いることなく、少ない作業工数で消音器６を吸気ダクト本体２に簡単に連結して十分な連結強度をもたらすことができる。
【００３２】
また、消音器６を、リベット１８の周りに揺動させる方向の慣性力、外力等が発生或いは作用しても、それら慣性力或いは外力は、フランジ１０の基端面１０ｃと、拡径着座部１２の着座面１３との接触を持って十分に支持されることになって消音器６の揺動は確実に阻止される。更に、リベット１８を筒状取付部８の先端側、即ちフランジ１０側に近づけることが可能になる。
【００３３】
従って、吸気ダクト本体２から突出する分岐部４の長さＬを短縮する事が可能になり、吸気ダクト１及び消音器６が占める占有スペースの縮小が得られ、吸気系のコンパクト化が可能になる。
【００３４】
更に、リベット１８を挿入する貫通孔１４及び１５を吸気ダクト本体２の軸線２ａと直交する方向の二個所に設けることにより、貫通孔１４、１５へのリベット１８の挿入及び挿入されたリベット１８をかしめるリベット１８による分岐部４と筒状取付部８の結合作業の際の作業空間が上方に配置される吸気ダクト本体１２によって制約されることが回避乃至極めて少なくなり、作業が容易になり作業の効率化が得られる。
【００３５】
従って、かかる取付構造によれば、分岐部４の突出長さの如何にかかわらず、消音器６を、吸気ダクト１に適切な状態で確実に簡単かつ容易に取り付けることが可能になり、消音器６の揺動に起因する衝突騒音の発生、各種の摩滅及び摩耗の発生等のおそれを十分に回避することができ、併せて、フランジ１０の基端面１０ｃと、拡径着座部１２の着座面１３との間の優れた気密性をもって消音器６にそれ本来の機能をより効果的に発揮させることができる。
【００３６】
図３は、フランジ１０の参考例を示す図であり、これは、筒状取付部８の先端のフランジ１０を、その筒状取付部８の全周にわたって形成すると共に、そのフランジ１０の周面をフランジ１０の厚みの全体に亘って先細りテーパ形状に形成し、フランジ１０の基端面１０ｃを筒状取付部８の軸線８ａと直交する平面上に形成したものである。
【００３７】
このように形成するフランジ１０によると、フランジ１０の基端面１０ｃと拡径着座部１２の着座面１３との接触面積を上記の場合に比し、先細りテーパ部等の形成態様の相違により、一層大ならしめることができ、フランジ１０と拡径着座部１２の間の気密性をより高めることができる。
【００３８】
しかも、取付部の全周に亘って形成したフランジ１０を、その全体に亘って形成された拡径着座部１２に接触させることで、気密性をより一層高めて吸気音の更なる低減を得ることができる。
【００３９】
この発明の実施の形態を図によって説明したが、例えば図２に示すフランジ１０から基端側部分１０ｂのテーパ部を省くことで、その側面形状を略台形状とすることができる。
【００４０】
以上説明した実施の形態では、吸気ダクト１の分岐部４と筒状取付部８をリベット１８によって結合したが、リベット１８に代えてボルトやクリップによる機械的結合手段によって結合することも可能であり、本発明は上記の実施形態に限定されることなく発明の趣旨を逸脱しない範囲で種々変更可能である。
【００４１】
【発明の効果】
従って、以上説明した本発明の吸気系消音器の取付構造によれば、筒状取付部の先端に設けたフランジを、分岐部への挿入によって、分岐部の基部に設けた拡径着座部に係合させることで、消音器の取付が常に適正にかつ確実に行え、消音器の取付を分岐部の突出長さの短縮が可能になり吸気系のコンパクト化が得られる。
【００４２】
また、拡径着座部とフランジとの係合状態では、消音器に作用することのある揺動方向の力を、そのフランジと拡径着座部との接触によって十分に支持することができるので、消音器の揺動に起因して生じる不具合を解決することができる。
【００４３】
そして更に、フランジと拡径着座部との接触によってそれらの間の気密性を高めることで、吸気音の一層の低減をもたらして消音器にそれ本来の機能をより十分に発揮させることができる等本発明特有の効果を有する。
【図面の簡単な説明】
【図１】本発明による吸気系消音器の取付構造の実施の形態を示す分解斜視図である。
【図２】同じく、消音器の取付状態での要部断面図である。
【図３】フランジの参考例を示す要部断面図である。
【図４】従来の技術を示す部分縦断面図である。
【図５】他の従来技術を示す部分縦断面図である。
【符号の説明】
１吸気ダクト
２吸気ダクト
２ａ軸線
４分岐部
６消音器
８筒状取付部
８ａ軸線
１０フランジ
１０ｃ基端面
１２拡径着座部
１３着座面
１４貫通孔
１５貫通孔
１８リベット[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intake silencer mounting structure in which a branch portion is provided at an intermediate portion of an intake duct body, and a cylindrical mounting portion of the silencer is inserted and fixed to the branch portion.
[0002]
【Technical field】
A silencer is attached to an intake duct of an engine of an automobile or the like for the purpose of reducing intake noise as disclosed in, for example, Japanese Utility Model Publication No. 63-193766, Japanese Utility Model Publication No. 3-68555, and the like. .
[0003]
This type of noise leveler mounting structure includes a welded connection between the branching portion of the intake duct that branches off from the intake duct body and a cylindrical mounting portion that protrudes from the silencer, or a hose band. Various attachment structures have been proposed, such as direct or indirect clamping and fixing, or hooking claws or bulges formed on a cylindrical attachment portion to be fitted to the branch portion.
[0004]
Among these, when high airtightness is not required for the mounting portion of the silencer due to a difference in the intake system or the like, as shown in FIG. 4, a cylindrical shape protruding from the silencer body 52 of the silencer 51 is provided. A hooking claw or bulge, for example, an annular bulge 55 formed in the intermediate portion of the attachment portion 53 is fitted into an annular groove 50 formed in a branching portion 59 protruding from the intake duct body 58 of the synthetic resin intake duct 57. In general, the silencer 51 is generally attached.
[0005]
By the way, in such a mounting structure, in order to sufficiently increase the holding force of the silencer 51, the fitting allowance of the cylindrical mounting portion 53, in other words, the protruding length L of the branch portion 59 from the intake duct body 58. Must be long enough. However, when the projecting length L of the branching portion 59 cannot be secured due to reductions in the space occupied by the intake system such as the intake duct 57 and the silencer 51 due to other requirements such as downsizing, acoustic performance, and layout. The holding power of the silencer 51 could not be sufficiently increased.
[0006]
As a countermeasure, as shown in FIG. 5, instead of providing a hooking claw or a bulge or the like on the cylindrical mounting portion 53, the cylindrical mounting portion 53 is placed at two locations corresponding to the diameter direction of the branching portion 59. The mechanical connection by the rivet 63 is performed.
[0007]
In the mounting structure of the intake duct and the silencer 51 by the rivet 63 shown in FIG. 5 as described above, the noise reduction is caused by the gap δ generated between the outer peripheral surface of the cylindrical mounting portion 53 and the inner peripheral surface of the branch portion 59. When an inertial force, an external force, or the like in a direction orthogonal to the axis of both rivets 63 of the vessel 51 is applied, the silencer 51 swings around the rivet 63 as a fulcrum, and is completely separated from the intake noise. In addition to generating sound, in addition to the early wear of the rivet 63 due to the swinging, there is a concern about the early wear of the cylindrical mounting portion 53 and the branching portion 59 due to the collision.
[0008]
On the other hand, in order to prevent such inconvenience, the number of rivets 63 may be three or more, but the work space is limited due to the layout in the engine room, etc. If there is no room to insert the hand, work tool, etc. to the required position, even that is impossible, and even if the insertion is possible, the increase in the number of rivets, work man-hours, etc., and the manufacturing cost. Will be forced to increase.
[0009]
Accordingly, an object of the present invention made in view of such a point is to enable shortening of the projecting length of the branch portion formed in the intake duct, and to reduce the cylindrical mounting portion of the silencer with the number of rivets, the number of work steps, etc. Provided with an intake silencer mounting structure that can be easily attached to a branching section without causing an increase in the amount of noise, and can effectively block the rocking motion of the silencer and greatly improve the airtightness of the mounting section. There is to do.
[0010]
[Means for Solving the Problems]
The invention of the mounting structure for an intake system silencer according to claim 1 that achieves the above object is an intake system silencer in which a cylindrical mounting portion of the silencer is inserted and fixed into a branch portion branched from the main body of the intake duct. In the mounting structure, a pair of enlarged diameter seating portions that are continuous with the main body are formed at the base of the branching portion, and a pair of flanges that are engaged with the respective enlarged diameter seating portions are provided at the distal ends of the cylindrical attachment portions. The branch portion and the cylindrical mounting portion are fixed by a pair of mechanical connecting means at a position separated from the flange in the circumferential direction .
[0011]
According to the first aspect of the present invention, even if the length of the branch portion cannot be made sufficiently long due to limitations on acoustic performance, layout, etc., for example, a synthetic resin cylinder is also formed on the synthetic resin branch portion. By simply inserting the cylindrical mounting part, the silencer can be easily attached to the intake duct by elastic deformation of both, so that the original function of the silencer can be fully exerted, and the flange formed at the tip of the cylindrical mounting part is branched The silencer is always supported in a stable state against inertial force, external force, etc. acting on the silencer by making line contact or surface contact with the enlarged diameter seating part formed at the base of the part. The rocking motion of the vessel can be effectively prevented.
[0012]
Accordingly, it is possible to eliminate the possibility of occurrence of collision sound due to the vibration of the silencer, and to prevent or extremely reduce the occurrence of wear and wear at the fitting portion between them, and at the same time, the flange and the enlarged-diameter seat. The contact of the part becomes a line or surface contact, and the airtightness of the fitting part of both can be greatly improved.
[0014]
Furthermore, by connecting the insertion part of the cylindrical mounting part to be inserted into the branch part and the branch part by a mechanical connecting means, the contact between the enlarged seat portion and the flange can be reliably maintained, and stable. In this state, the silencer can be attached to the intake duct and maintained.
[0015]
According to a second aspect of the invention, the mounting structure of the intake system silencer of claim 1, said mechanical coupling means, characterized in that it is a rivet coupling.
[0016]
A second aspect of the present invention, there is as specifically illustrated mechanical coupling means according to claim 2, capable of binding efficiently bifurcation and the tubular attachment portion by rivets.
[0017]
The invention described in claim 3 is the mounting structure of the intake system silencer according to claim 1 or 2, the enlarged diameter seating portion is arranged through the branching portion along the axial direction of the intake duct body, It said mechanical connecting means, characterized in that to the upper Ki拡 sized seat and the flange is disposed at a position spaced approximately 90 degrees in the circumferential direction of the tubular mounting portion and the branch portion.
[0018]
According to the third aspect of the present invention, even though the silencer may swing around the mechanical connecting means such as a rivet, the swing in the direction orthogonal to the swinging direction is a mechanical force such as a rivet. By forming the flange and the diameter-enlarged seating portion only in the direction in which the silencer may be swung, which is reliably prevented by the connecting means, the material yield can be improved when forming the cylindrical mounting portion and the branch portion. In addition, the restriction on molding is reduced, the degree of freedom of the axial position of the cylindrical mounting portion at the coupling position by the mechanical connecting means is increased, and further, the cylindrical mounting portion and, further, the insertion of the flange into the branch portion thereof Makes installation work easier.
[0019]
According to a fourth aspect of the present invention, in the attachment structure of the intake silencer according to any one of the first to third aspects, the flange has a tapered end at a distal end, and a base end surface of the tubular mounting. The seating surface is perpendicular to the axis of the portion, and the seating surface in contact with the base end surface of the diameter-enlarged seating portion is planar.
[0020]
According to the invention of claim 4 , the insertion of the flange into the branching portion becomes easier, and after the insertion, the base end surface of the flange is brought into surface contact with the seating surface of the enlarged-diameter seating portion, thereby airtightness of the fitting portion. And the generation of airflow noise and the like can be effectively prevented.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an intake-system silencer mounting structure according to the present invention will be described below with reference to the drawings.
[0022]
FIG. 1 is an exploded perspective view showing the present embodiment. In FIG. 1, reference numeral 1 denotes an intake duct, and a branch portion 4 protruding downward from the middle of an intake duct body 2 of the intake duct 1 is branched. Is provided. Here, the axes 2a and 4a of the intake duct main body 2 and the branch part 4 are orthogonal to each other.
[0023]
As shown in FIG. 1, the silencer 6 attached to the branch portion 4 of the intake duct 1 has a cylindrical attachment portion 8 that protrudes upward from the silencer body 7 and is inserted into the branch portion 4.
[0024]
2, a pair of flanges positioned corresponding to the direction of the axis 2a of the intake duct main body 2 are provided at the tip of the cylindrical mounting portion 8 as shown in a cross-sectional view of the main part with the silencer 6 attached. On the other hand, a diameter-enlarged seating portion 12 that allows the engagement of the flange 10 is provided continuously to the intake duct 2 at the base portion of the branching portion 4.
[0025]
Like the flange 10, the diameter-enlarged seating portion 12 is formed as a pair via the branch portion 4 so as to correspond to the direction of the axis 2 a of the intake duct 2, and has a shape and a size with which the flange 10 is fitted.
[0026]
Further, the flange 10 has a tapered end portion 10a, and the flange 10 is pushed into the branch portion 4 so as to make the mounting operation smooth and easy.
[0027]
In addition, as shown in the drawing, this ease of pushing is formed by intermittently forming the flange 10 in the circumferential direction so that the cylindrical mounting portion 8 and the branching portion 4 can be easily elastically deformed when the cylindrical mounting portion 8 is pushed. You can also increase it.
[0028]
In addition, in the illustrated flange 10, the base end side portion 10 b has a tapered shape with a gradually decreasing diameter toward the base end direction, and the silencer once attached by making the base end portion 10 b tapered. 6 can be smoothly and easily operated at the time of extraction from the branch portion 4 as required.
[0029]
Further, the base end surface 10 c of the flange 10 is formed on a plane orthogonal to the axis 8 a of the cylindrical mounting portion 8, and the diameter-enlarged seating portion 12 also has a seating surface 13 orthogonal to the axis 8 a of the cylindrical mounting portion 8. The base end surface 10c of the opposing flange 10 and the seating surface 13 of the diameter-enlarged seating portion 12 are brought into surface contact or line contact, thereby ensuring airtightness between the flange 10 and the cylindrical mounting portion 8 and intake air. A more effective reduction of sound is obtained.
[0030]
Further, two portions of each of the branching portion 4 and the cylindrical mounting portion 8 facing each other in the diametrical direction, preferably in a direction perpendicular to the axis 2a of the intake duct body 2, in other words, the pair of enlarged diameter seating portions 12 and the pair Through holes 14 and 15 that overlap each other in a mounted state are provided at two positions that are approximately 90 degrees apart from each other in the circumferential direction of the cylindrical mounting portion 8 and the branching portion 4 with respect to the flange 10. And the branch part 4 and the cylindrical attachment part 8 are mechanically connected to each other by a rivet 18 inserted into 15 and 15.
[0031]
According to this, the silencer 6 can be simply connected to the intake duct body 2 with a small number of work steps without using a large number of rivets, and sufficient connection strength can be provided.
[0032]
Further, even if an inertial force, an external force, or the like in the direction of swinging the silencer 6 around the rivet 18 is generated or acts, the inertial force or the external force is applied to the base end face 10c of the flange 10 and the diameter-enlarged seating portion 12. Therefore, the silencer 6 is reliably prevented from swinging because it is sufficiently supported with contact with the seating surface 13. Furthermore, the rivet 18 can be brought closer to the distal end side of the cylindrical mounting portion 8, that is, the flange 10 side.
[0033]
Accordingly, the length L of the branching portion 4 protruding from the intake duct main body 2 can be shortened, the occupied space occupied by the intake duct 1 and the silencer 6 can be reduced, and the intake system can be made compact. Become.
[0034]
Further, by providing the through holes 14 and 15 into which the rivets 18 are inserted at two positions in the direction perpendicular to the axis 2a of the intake duct body 2, the rivets 18 are inserted into the through holes 14 and 15 and the inserted rivets 18 are inserted. It is avoided or extremely reduced that the working space when the branching portion 4 and the cylindrical mounting portion 8 are joined by the caulking rivet 18 is restricted by the intake duct body 12 disposed above, and the work becomes easier and easier. Efficiency improvement can be obtained.
[0035]
Therefore, according to such an attachment structure, the silencer 6 can be reliably and easily attached to the intake duct 1 in an appropriate state regardless of the protruding length of the branch portion 4. It is possible to sufficiently avoid the possibility of occurrence of collision noise, various wear and wear due to the swing of 6, and in addition, the base end surface 10 c of the flange 10 and the seating surface of the enlarged-diameter seating portion 12. The silencer 6 can exhibit its original function more effectively with an excellent airtightness between 13.
[0036]
FIG. 3 is a view showing a reference example of the flange 10, in which the flange 10 at the tip of the cylindrical mounting portion 8 is formed over the entire circumference of the cylindrical mounting portion 8 and the peripheral surface of the flange 10. Are formed in a tapered shape over the entire thickness of the flange 10, and the base end face 10 c of the flange 10 is formed on a plane orthogonal to the axis 8 a of the cylindrical mounting portion 8.
[0037]
According to the flange 10 formed in this way, the contact area between the base end surface 10c of the flange 10 and the seating surface 13 of the diameter-enlarged seating portion 12 is larger than that in the above case, due to the difference in the formation mode of the tapered portion and the like. The airtightness between the flange 10 and the enlarged diameter seating portion 12 can be further increased.
[0038]
In addition, the flange 10 formed over the entire circumference of the mounting portion is brought into contact with the enlarged-diameter seating portion 12 formed over the entirety thereof, thereby further improving the airtightness and further reducing the intake noise. be able to.
[0039]
Although the embodiment of the present invention has been described with reference to the drawings, for example, by omitting the tapered portion of the base end side portion 10b from the flange 10 shown in FIG. 2, the side surface shape can be made substantially trapezoidal .
[0040]
In the embodiment described above, the branch portion 4 and the cylindrical mounting portion 8 of the intake duct 1 are coupled by the rivet 18, but it is also possible to couple them by mechanical coupling means such as bolts or clips instead of the rivet 18. The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the invention.
[0041]
【The invention's effect】
Therefore, according to the mounting structure of the intake silencer of the present invention described above, the flange provided at the tip of the cylindrical mounting portion is inserted into the branching portion to the enlarged seating portion provided at the base of the branching portion. By engaging, the silencer can always be properly and reliably attached, and the silencer can be attached with a shortened projecting length of the branch portion, and the intake system can be made compact.
[0042]
Further, in the engaged state between the enlarged diameter seating portion and the flange, the swinging direction force that may act on the silencer can be sufficiently supported by the contact between the flange and the enlarged diameter seating portion. Problems caused by the vibration of the silencer can be solved.
[0043]
Furthermore, by increasing the airtightness between the flange and the enlarged seating portion by bringing them into contact with each other, it is possible to further reduce the intake noise and make the silencer perform its full function more fully. It has an effect peculiar to the present invention.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an embodiment of a mounting structure for an intake silencer according to the present invention.
FIG. 2 is a cross-sectional view of the main part when the silencer is mounted.
FIG. 3 is a cross-sectional view of a main part showing a reference example of a flange.
FIG. 4 is a partial longitudinal sectional view showing a conventional technique.
FIG. 5 is a partial longitudinal sectional view showing another conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Intake duct 2 Intake duct 2a Axis 4 Branching part 6 Silencer 8 Cylindrical attachment part 8a Axis 10 Flange 10c Base end surface 12 Expanded seating part 13 Seating surface 14 Through hole 15 Through hole 18 Rivet

Claims

In the mounting structure of the intake system silencer that inserts and fixes the cylindrical mounting portion of the silencer into the branch portion branched from the main body of the intake duct,
Forming a pair of enlarged diameter seating portions that are continuous with the main body at the base of the branching portion;
A pair of flanges that engage with each of the diameter-enlarged seating portions are provided at the tip of the cylindrical mounting portion,
The branch portion and the cylindrical mounting portion are fixed by a pair of mechanical connecting means at a position separated from the flange in the circumferential direction.
An intake silencer mounting structure characterized by that .

It said mechanical connecting means, the mounting structure of the intake system silencer according to claim 1, characterized in that the rivet coupling.

The enlarged diameter seating portion is arranged through the branching portion along the axial direction of the intake duct body,
It said mechanical connecting means, claims, characterized in that it is disposed at a position spaced approximately 90 degrees in the circumferential direction of the tubular mounting portion and the branch portion with respect to the upper Ki拡 sized seat and the flange The mounting structure of the intake system muffler according to 1 or 2.

The flange has a tapered shape with a tapered tip, a base end surface having a planar shape perpendicular to the axis of the cylindrical mounting portion, and a seating surface in contact with the base end surface of the enlarged diameter seating portion having a planar shape. The mounting structure for an intake silencer according to any one of claims 1 to 3 .