JP7453201B2

JP7453201B2 - intake manifold

Info

Publication number: JP7453201B2
Application number: JP2021175746A
Authority: JP
Inventors: 孝平杉原; 琢磨久力; 剛士森口; 智久仙田; 卓未山田; 文浩新海
Original assignee: Aisin Seiki Co Ltd; Daihatsu Motor Co Ltd; Aisin Corp
Current assignee: Daihatsu Motor Co Ltd; Aisin Corp
Priority date: 2021-10-27
Filing date: 2021-10-27
Publication date: 2024-03-19
Anticipated expiration: 2041-10-27
Also published as: JP2023065124A

Description

本願発明は、車両用等の多気筒エンジンに使用する吸気マニホールドに関するもので、特に、合成樹脂製の吸気マニホールドを好適な対象にしている。 The present invention relates to an intake manifold used in a multi-cylinder engine for vehicles, and is particularly suitable for intake manifolds made of synthetic resin.

内燃機関の吸気マニホールドは、近年、軽量化やコストダウン等のために合成樹脂で製造されているが、吸気マニホールドは中空であって一体物としては成型できないため、射出成形法で製造された複数の部材を振動溶着法等の溶着によって一体に接合して製造している。 In recent years, intake manifolds for internal combustion engines have been manufactured from synthetic resin to reduce weight and cost. However, since intake manifolds are hollow and cannot be molded as one piece, they are made of multiple pieces manufactured using injection molding. It is manufactured by joining these members together by welding such as vibration welding.

他方、車両用の内燃機関においては、排気ガスの浄化促進等を目的として、排気ガスの一部であるＥＧＲガスを吸気系に還流させることが広く行われている。また、クランク室に吹き抜けたＰＣＶガス（ブローバイガス）を吸気系に還流させることも、広く行われている。 On the other hand, in internal combustion engines for vehicles, it is widely practiced to recirculate EGR gas, which is part of the exhaust gas, to the intake system for the purpose of promoting purification of the exhaust gas. Furthermore, it is widely practiced to circulate PCV gas (blow-by gas) that has blown into the crank chamber back into the intake system.

そして、これらＥＧＲガスやＰＣＶガスのような補助ガスを吸気系に還流させるに当たっては、補助ガスをサージタンクに戻して、サージタンク内において吸気と混合させて各ブランチ管に送り込むサージタンク戻し方式（例えば特許文献１）と、吸気マニホールドに補助ガスの分岐通路を形成して、分岐通路から各ブランチ管に戻すポート戻し方式とがある。 In order to recirculate these auxiliary gases such as EGR gas and PCV gas to the intake system, the auxiliary gas is returned to the surge tank, mixed with intake air in the surge tank, and sent to each branch pipe using a surge tank return method ( For example, there is a method disclosed in Patent Document 1) and a port return method in which a branch passage for auxiliary gas is formed in the intake manifold and the auxiliary gas is returned from the branch passage to each branch pipe.

特開２０１１－２２０２９９号（特許第５４４０３４４号）公報JP 2011-220299 (Patent No. 5440344) Publication

ポート戻し方式は均一な分配という点では優れているが、分岐通路を形成するために吸気マニホールドの構造が複雑化するという問題がある。具体的には、吸気マニホールドを合成樹脂製とする場合、基本的には、シリンダヘッドの吸気側面と直交した方向から見て前後方向に重なった３つの部材で形成できるが、分岐通路を設けると別の部材が必要になって部材点数が増えるという問題がある。 Although the port return method is excellent in terms of uniform distribution, it has the problem that the structure of the intake manifold becomes complicated due to the formation of branch passages. Specifically, when the intake manifold is made of synthetic resin, it can basically be formed from three members that overlap in the front and back direction when viewed from a direction perpendicular to the intake side of the cylinder head, but if a branch passage is provided, There is a problem in that another member is required and the number of parts increases.

他方、サージタンク戻し方式は追加の部材を必要としてないため、それだけ構造を簡単化できるが、補助ガスを吸気に均一に混合させることが困難で、このため、各気筒において補助ガスの量にバラツキが発生しやすいという問題がある。特に、補助ガスがＥＧＲガスである場合、各気筒間でＥＧＲガスの還流量のバラツキが許容値を越えると、各気筒間での燃焼にアンバランスが生じて、運転の安定性が低下したり排気ガスの成分が悪化したりするといった問題が発生することになり、すると、ＥＧＲガスの導入量を抑制せざるをえずにＥＧＲシステムの効果を十分に享受できなくなってしまう。 On the other hand, the surge tank return method does not require any additional parts, so the structure can be simplified accordingly, but it is difficult to mix the auxiliary gas uniformly into the intake air , and as a result, the amount of auxiliary gas varies in each cylinder. There is a problem that this is likely to occur. In particular, when the auxiliary gas is EGR gas, if the variation in the amount of EGR gas recirculated between each cylinder exceeds the allowable value, an imbalance will occur in the combustion between each cylinder, resulting in a decrease in operational stability. Problems such as deterioration of the components of the exhaust gas will occur, and the amount of EGR gas introduced will have to be suppressed, making it impossible to fully enjoy the effects of the EGR system.

そこで、サージタンク戻し方式において補助ガスの混合性を向上できると好適であり、このための手段として、サージタンクに開口したガス導入口を複数設けることが考えられる。この点、特許文献１には、ＥＧＲガスやＰＣＶガスに含まれている水分の凍結を防止することを課題として、サージタンクの内部のうち吸気導入口と反対側の部位に、サージタンクの内部に向けて張り出した独立小部屋を設け、独立小部屋に２つのガス導入口（排出口）を開口させることが開示されている。 Therefore, it would be preferable to improve the mixing properties of the auxiliary gas in the surge tank return method, and one possible means for this purpose would be to provide a plurality of gas inlet ports open to the surge tank. In this regard, Patent Document 1 discloses that , in order to prevent the moisture contained in EGR gas and PCV gas from freezing, a portion of the inside of the surge tank opposite to the intake inlet is It is disclosed that an independent small room is provided that extends toward the room, and two gas inlets (exhaust ports) are opened in the independent small room.

そこで、特許文献１を補助ガスの分配性の点から検討するに、特許文献１では、吸気導入口はサージタンクの一端部に開口して、独立小部屋はサージタンクの他端部に配置されているため、補助ガスが吸気によってサージタンクの他端部に押し込まれる傾向を呈して、補助ガスが特定のサージタンクの他端部に開口したブランチ管に多く流入すると推測され、従って、複数のガス導入口を設けても補助ガスの分配性の向上には貢献しないと解される。 Therefore, considering Patent Document 1 from the viewpoint of distribution of auxiliary gas, in Patent Document 1, the intake inlet is opened at one end of the surge tank, and the independent small room is arranged at the other end of the surge tank. Therefore, it is assumed that the auxiliary gas tends to be pushed into the other end of the surge tank by the intake air, and a large amount of auxiliary gas flows into the branch pipe opened at the other end of the surge tank. It is understood that even if a gas inlet is provided, it does not contribute to improving the distribution of the auxiliary gas.

また、補助ガスが独立小部屋に押し戻される逆流現象も懸念される。更に、特許文献１のように独立小部屋をサージタンクの内部に突出するように設けると、吸気のスムースな流れが阻害されるおそれも懸念される。 There is also a concern about the backflow phenomenon in which the auxiliary gas is pushed back into the independent small room. Furthermore, if the independent small chamber is provided so as to protrude into the inside of the surge tank as in Patent Document 1, there is a concern that the smooth flow of intake air may be obstructed.

本願発明はこのような現状を背景に成されたものであり、補助ガスの還流手段としてサージサージタンク戻し方式を採用しつつ、補助ガスの分配性を向上させんとするものである。 The present invention has been made against the background of this current situation, and aims to improve the distribution of the auxiliary gas while employing a surge tank return method as the auxiliary gas recirculation means.

本願発明の吸気マニホールドは、
「吸気導入口を一端部に設けたサージタンクと、前記サージタンクを巻くような姿勢でクランク軸線方向に並んで配置された複数本のブランチ管と、を備え、
前記吸気導入口は、前記ブランチ管の並び方向と交差した方向から前記サージタンクに開口して、吸気は、前記サージタンクの一端部において方向変換して前記サージタンクの内部に流れ込んで前記各ブランチ管の入口に流入するように設定されており、
かつ、前記サージタンクには、ＥＧＲガス又は他の補助ガスを内部に取り込むガス導入口が、前記サージタンクのうち前記吸気導入口が設けられている一端部に寄った部位において前記ブランチ管の並び方向に分かれて複数形成されている」
という基本構成を採用している。 The intake manifold of the present invention is
"Equipped with a surge tank having an intake inlet at one end, and a plurality of branch pipes arranged in line in the direction of the crank axis in a position that wraps around the surge tank,
The intake air inlet opens into the surge tank from a direction crossing the direction in which the branch pipes are lined up, and the intake air changes direction at one end of the surge tank and flows into the surge tank to flow into each branch. It is set to flow into the inlet of the pipe,
In addition, the surge tank has a gas inlet for taking EGR gas or other auxiliary gas into the surge tank, and the branch pipes are arranged in a portion of the surge tank that is closer to one end where the intake inlet is provided. There are multiple formations that are divided in different directions.”
The basic configuration is adopted.

そして、請求項１の発明は、上記基本構成において、
「前記ガス導入口は、前記ブランチ管の並び方向に長いガス通路から分岐して、前記ガス通路の上流端に連通したガス取り込み口が外向きに開口しており、
前記ガス取り込み口と吸気導入口とは、シリンダヘッドの吸気側面と直交した方向から見て前記吸気導入口と前後方向に並ぶと共に、主として上向きに開口している」
という構成を付加している。 In the above basic configuration, the invention of claim 1 has the following features:
“ The gas inlet is branched from a long gas passage in the direction in which the branch pipes are lined up, and a gas intake port that communicates with the upstream end of the gas passage opens outward;
The gas intake port and the intake air introduction port are aligned with the intake air introduction port in the front-rear direction when viewed from a direction perpendicular to the intake side surface of the cylinder head, and are mainly opened upward.
This configuration is added.

本願発明は、異なる構成も含んでいる。その例として請求項２の発明は、請求項１と同じ基本構成において、
「前記サージタンクは、前記吸気導入口が形成された第１部材と前記各ブランチ管の入口が形成された第２部材とを接合することによって中空に形成されていて、前記両部材の内面は滑らかに連続しており、
前記第１部材に、前記第２部材と滑らかに連続した内面の外側において前記第２部材に向けて開口したガス通路が、前記サージタンクの一端の側から他端の側に向けて補助ガスが流れるように形成されて、前記第１部材と第２部材との合わせ面に、前記ガス通路と連通しつつ前記サージタンクの内部に開口した前記複数のガス導入口が形成されており、
前記複数のガス導入口は、上流側に位置したものが下流側に位置したものよりも開口面積が大きくなっている」
という構成になっている。 The present invention also includes different configurations. As an example, the invention of claim 2 has the same basic configuration as claim 1,
“The surge tank is formed hollow by joining a first member in which the intake inlet is formed and a second member in which the inlets of the branch pipes are formed, and the inner surfaces of both members are Smoothly continuous,
A gas passage in the first member that opens toward the second member on the outside of an inner surface that is smoothly continuous with the second member allows auxiliary gas to flow from one end of the surge tank to the other end. The plurality of gas inlet ports are formed to flow and are open to the inside of the surge tank while communicating with the gas passageway and are formed on the mating surfaces of the first member and the second member ,
Among the plurality of gas inlet ports, those located on the upstream side have a larger opening area than those located on the downstream side.
The structure is as follows.

また、請求項３の発明は、請求項１と同じ基本構成において、
「前記サージタンクは、相対向するように開口した凹所を有する２つの部材を接合して中空に形成されていて、前記両部材の合わせ面に前記ガス導入口が形成されていると共に、前記２つの部材のうち一方の部材に、前記複数のブランチ管の入口が他方の部材に向けて開口するように並べて形成されており、
かつ、前記両部材のうちいずれか一方又は両方に、前記ガス導入口から排出された補助ガスの流れを分散させると共に吸気が前記各ブランチ管の入口に分散して流入するように制御する整流リブが、前記両部材の開口方向と同じ方向に延びると共に前記サージタンクの底面と対向するように形成されており、
前記整流リブは、隣り合った前記ブランチ管の入口の間に配置されたものを含んでいる」という構成になっている。 Further, the invention of claim 3 has the same basic configuration as claim 1,
"The surge tank is formed hollow by joining two members having recesses that are open to face each other, and the gas inlet is formed in the mating surface of both the members , and the The inlets of the plurality of branch pipes are arranged in one of the two members so as to open toward the other member,
and a rectifying rib that disperses the flow of the auxiliary gas discharged from the gas inlet and controls the intake air to flow into the inlet of each of the branch pipes in a distributed manner on one or both of the two members. is formed to extend in the same direction as the opening direction of both members and to face the bottom surface of the surge tank ,
The rectifying rib includes one disposed between the inlets of the adjacent branch pipes .

本願各発明では、まず、吸気がサージタンクの一端部において方向変換することにより、吸気の直進性が減殺されるため、サージタンクは高いバッファ機能を発揮する。その結果、各ブランチ管の吸気圧力を均一化して各気筒の充填効率の均一化に貢献できる。 In each invention of the present application, first, by changing the direction of intake air at one end of the surge tank, the straightness of the intake air is reduced, so that the surge tank exhibits a high buffer function. As a result, it is possible to equalize the intake pressure of each branch pipe and contribute to equalizing the filling efficiency of each cylinder.

また、ガス導入口は吸気導入口に寄った部位に設けているため、補助ガスは吸気の流れに乗ってサージタンクの内部に送り込まれるが、吸気はサージタンクの内部に直進しつつ旋回しながら各ブランチ管に入り込むため、補助ガスが吸気と一緒にサージタンクの内部を流れる距離（或いは時間）は特許文献１に比べて格段に長く、従って、補助ガスの分散性（吸気との混合性）を向上できる。更に、補助ガスは吸気の流れによってサージタンク内に引かれるため、補助ガスの逆流現象は発生せずに、補助ガスを各気筒に的確に送気できる。 In addition, since the gas inlet is located close to the intake inlet, the auxiliary gas rides the flow of intake air and is sent into the surge tank, but the intake air goes straight into the surge tank while swirling around. Since the auxiliary gas enters each branch pipe, the distance (or time) that the auxiliary gas flows inside the surge tank together with the intake air is much longer than that in Patent Document 1, and therefore the dispersibility of the auxiliary gas (mixability with the intake air) is significantly longer. can be improved. Furthermore, since the auxiliary gas is drawn into the surge tank by the flow of intake air, the auxiliary gas can be accurately supplied to each cylinder without causing a backflow phenomenon of the auxiliary gas.

そして、吸気はサージタンクの内部で方向性を持って流れるため、ガス導入口が１箇所だけであると、各ブランチ管への分散性が不十分になるおそれがあるが、本願発明では、ガス導入口がブランチ管の並び方向に複数配置されているため、吸気が各ブランチ管に分かれていく流れを利用して、各ブランチ管に補助ガスを略均一に送り込むことができる。実際に、本願発明者たちが実機で計測したところ、各ブランチ管でのＥＧＲガスのバラツキを許容値である３％以内に押さえることができて、効果を実証できた。 Since the intake air flows directionally inside the surge tank, if there is only one gas inlet, there is a risk that the dispersion to each branch pipe will be insufficient.However, in the present invention, the gas Since a plurality of inlets are arranged in the direction in which the branch pipes are lined up, the auxiliary gas can be sent substantially uniformly to each branch pipe by utilizing the flow of intake air being divided into each branch pipe. In fact, when the inventors of the present application conducted measurements using an actual machine, they were able to suppress the variation in EGR gas in each branch pipe to within the permissible value of 3%, proving the effectiveness.

このように、本願各発明では、サージタンク戻し方式を採用しつつ各ブランチ管（気筒）への補助ガスの分配性を向上できるため、コストを抑制しつつ、安定した運転を実現できる。特にＥＧＲシステムに適用すると、ＥＧＲガスの導入量を増大できるため、燃費の向上や排気ガスの浄化性能向上などの利点を享受できて好適である。 In this way, in each of the inventions of the present application, it is possible to improve the distribution of auxiliary gas to each branch pipe (cylinder) while employing the surge tank return method, and therefore it is possible to realize stable operation while suppressing costs. In particular, when applied to an EGR system, it is possible to increase the amount of EGR gas introduced, so it is suitable to enjoy benefits such as improved fuel efficiency and improved exhaust gas purification performance.

請求項２の構成では、ガス通路を設けた部位はサージタンクの内部に突出していないため、吸気のスムースな流れを阻害することはない。また、複数のガス導入口は、上流側のものの開口面積が大きくなっているため、直進性を持ってガス通路を流れるガス導入口が下流部のガス導入口から多く流れ過ぎることを防止して、各ガス導入口からの補助ガスの排出量を適正に設定できる（補助ガスが、吸気導入口の側に位置したブランチ管を素通りしてしまう現象を防止できる。）。 In the structure of the second aspect, since the portion provided with the gas passage does not protrude into the inside of the surge tank, the smooth flow of intake air is not obstructed. In addition, since the opening area of the multiple gas inlets on the upstream side is larger, the gas inlets that flow straight through the gas passage are prevented from flowing too much from the downstream gas inlet. , the amount of auxiliary gas discharged from each gas inlet can be appropriately set (it is possible to prevent the auxiliary gas from passing through the branch pipe located on the side of the intake inlet).

請求項３の構成では、ガス導入口からサージタンクの内部に排出された補助ガスの流れを制御できるため、補助ガスを吸気の流れに乗せて分散・混合させる効果を助長できる。そして、整流リブが形成されている部材は、凹所の開口方向と同じに相対動する金型を使用して製造されるが、整流リブは部材の開口方向と同じ方向に延びているため、リブは問題なく型抜きできる状態に形成される。従って、吸気マニホールドの製造の容易性を損なうことなく、補助ガスの分散性を更に向上できる。 In the structure of claim 3, since the flow of the auxiliary gas discharged into the surge tank from the gas inlet can be controlled, the effect of dispersing and mixing the auxiliary gas along with the flow of intake air can be enhanced. The member on which the rectifying rib is formed is manufactured using a mold that relatively moves in the same direction as the opening direction of the recess, but since the rectifying rib extends in the same direction as the opening direction of the member, The ribs are formed in such a way that they can be cut out without any problems. Therefore, the dispersibility of the auxiliary gas can be further improved without impairing the ease of manufacturing the intake manifold.

請求項１の構成を採用すると、吸気導入口とガス取り込み口を吸気マニホールドの一端部に寄せて配置できるため、ストロットルボデーと補助ガス用配管も、同じ方向に延びるように配置できる。従って、吸気マニホールド周りの部材をコンパクトに纏めて、エンジンの大型化を防止できる。従って、エンジンルームのスペースに余裕がないハイブリット車にも好適である。 When the configuration of claim 1 is adopted, the intake inlet and the gas intake port can be arranged closer to one end of the intake manifold, so the throttle body and the auxiliary gas piping can also be arranged so as to extend in the same direction. Therefore, the members around the intake manifold can be made compact and the engine can be prevented from becoming larger. Therefore, it is suitable for hybrid vehicles that do not have enough space in the engine compartment.

また、請求項１では、吸気と同様に、補助ガスはガス通路の一端部で方向変換して流れるため、補助ガスの直進性を抑制して各ガス導入口への分配量を適正化できる利点もある。 Further, in claim 1 , since the auxiliary gas changes direction and flows at one end of the gas passage, like the intake air, the straightness of the auxiliary gas can be suppressed and the amount of distribution to each gas inlet can be optimized. There is also.

実施形態を示す図で、シリンダヘッドの吸気側面と対向した方向から見た側面図である。FIG. 2 is a side view showing the embodiment, as seen from a direction facing the intake side of the cylinder head. 図１と反対側から見た側面図である。2 is a side view seen from the opposite side to FIG. 1. FIG. 図２を左側から見た背面図である。FIG. 3 is a rear view of FIG. 2 seen from the left side. 中間部材の斜視図である。It is a perspective view of an intermediate member. 外側部材の側面図である。FIG. 3 is a side view of the outer member. 図１のVI-VI 視断面図（第３ブランチ管の中心線に沿って切断した縦断面図）である。FIG. 2 is a sectional view taken along VI-VI in FIG. 1 (a vertical sectional view taken along the center line of the third branch pipe).

次に、本願発明の実施形態を図面に基づいて説明する。本実施形態は、自動車用エンジンの吸気マニホールドに適用している。エンジンは、クランク軸線を車幅方向に長い姿勢でエンジンルームに配置されており、自動車の前進方向に向かって排気側面を前、吸気側面を後ろに向けている。従って、実施形態の吸気マニホールドは、自動車の前進方向に向いて後ろからシリンダヘッドの吸気側面に重なっている。 Next, embodiments of the present invention will be described based on the drawings. This embodiment is applied to an intake manifold of an automobile engine. The engine is placed in the engine compartment with its crank axis extending in the vehicle width direction, with the exhaust side facing forward and the intake side facing rearward as the vehicle moves forward. Therefore, the intake manifold of the embodiment overlaps the intake side surface of the cylinder head from the rear facing the forward direction of the automobile.

以下では、方向を特定するため前後・左右の文言を使用するが、前後方向はクランク軸線方向（カム軸線方向）であり、左右方向は、クランク軸線及びシリンダボア軸心と直交した方向（シリンダヘッドの吸気側面と略直交した方向）である。 In the following, words such as front and rear and left and right are used to specify the direction, but the front and rear direction is the direction of the crank axis (cam axis direction), and the left and right direction is the direction perpendicular to the crank axis and the cylinder bore axis (the direction of the cylinder head). (direction substantially perpendicular to the intake side).

前と後ろについては、タイミングチェーンが配置される側を前として、ミッションケースが配置される側を後ろとしている。エンジンは、排気側が少し前倒れするようにシリンダボア軸線を若干スラントさせているが、基本的には縦型であるので、上下方向は鉛直方向と同じである。方向は、各図に適宜表示している。 Regarding the front and rear, the side where the timing chain is placed is the front, and the side where the transmission case is placed is the back. The cylinder bore axis of the engine is slightly slanted so that the exhaust side leans forward a little, but since it is basically a vertical engine, the vertical direction is the same as the vertical direction. Directions are appropriately indicated in each figure.

(1).基本構造
吸気マニホールドは、前後方向から見るとラグビーボール又は卵形の形態を成して、側面視では、大まかにはいびつな四角形の形態を成している。そして、図３及び図６から理解できるように、吸気マニホールドは、シリンダヘッド１（図６参照）の近い側に位置した内側部材２（第１パーツ）と、シリンダヘッド１から遠い側に位置した外側部材３（第２パーツ）と、両者に挟まれた中間部材４（第３パーツ）とによって中空構造に構成されており、重なりあった部材２，３，４は高周波又は超音波による振動溶着によって一体に接合されている。図１～３において、部材の境界を太線で表示している。 (1).Basic structure The intake manifold has the shape of a rugby ball or an egg when viewed from the front and back, and roughly has the shape of an irregular quadrangle when viewed from the side. As can be understood from FIGS. 3 and 6, the intake manifold has an inner member 2 (first part) located near the cylinder head 1 (see FIG. 6), and an inner member 2 (first part) located on the side far from the cylinder head 1. It has a hollow structure consisting of an outer member 3 (second part) and an intermediate member 4 (third part) sandwiched between the two, and the overlapping members 2, 3, and 4 are vibration welded using high frequency or ultrasonic waves. are joined together by. In FIGS. 1 to 3, the boundaries of members are indicated by thick lines.

図６から理解できるように、内側部材２と中間部材４とは、対向するように開口した凹所を有しており、このため、吸気マニホールドの内部には前後方向に長いサージタンク５が形成されている。そして、サージタンク５を外側から巻くように、３本のブランチ管６，７，８が形成されている。従って、本実施形態が適用されるエンジンは３気筒である。ブランチ管６，７，８は、前から順に、第１ブランチ管６，第２ブランチ管７，第３ブランチ管８と呼ぶこととする。 As can be understood from FIG. 6, the inner member 2 and the intermediate member 4 have recesses that open to face each other, and therefore a surge tank 5 that is long in the front and back direction is formed inside the intake manifold. has been done. Three branch pipes 6, 7, and 8 are formed so as to wrap around the surge tank 5 from the outside. Therefore, the engine to which this embodiment is applied has three cylinders. The branch pipes 6, 7, and 8 will be referred to as a first branch pipe 6, a second branch pipe 7, and a third branch pipe 8 in order from the front.

図６に示すように、各ブランチ管６，７，８はサージタンク５を巻くように形成されており、各ブランチ管６，７，８の入口９と出口１０は内側部材２に形成されている。ブランチ管６，７，８は、中間部材４と外側部材３とで形成されている部分が最も長いが、出口１０に寄った水平状の部位は中間部材４に形成されている。吸気は、各ブランチ管６，７，８に下向きに流入してから上向きに方向変換し、最終的には水平方向（正確には斜め下向き）に流れてシリンダヘッド１の吸気ポート１１に流入する。 As shown in FIG. 6, each branch pipe 6, 7, 8 is formed to wrap around the surge tank 5, and the inlet 9 and outlet 10 of each branch pipe 6, 7, 8 are formed in the inner member 2. There is. The branch pipes 6, 7, and 8 have the longest part formed by the intermediate member 4 and the outer member 3, but the horizontal part near the outlet 10 is formed in the intermediate member 4. The intake air flows downward into each of the branch pipes 6, 7, and 8, changes its direction upward, and finally flows horizontally (to be precise, diagonally downward) and flows into the intake port 11 of the cylinder head 1. .

内側部材２の上端部には、各ブランチ管６，７，８の出口１０が開口すると共に、シリンダヘッド１の吸気側面１２に重なるフランジ１３が形成されており、フランジ１３が複数箇所においてボルト（図示せず）でシリンダヘッド１の吸気側面１２に締結される。ボルトによる締結部を、図１，２に符号１４で表示している。 At the upper end of the inner member 2, the outlet 10 of each branch pipe 6, 7, 8 is opened, and a flange 13 is formed which overlaps the intake side surface 12 of the cylinder head 1. The flange 13 has bolts ( (not shown) is fastened to the intake side surface 12 of the cylinder head 1. A fastening portion using a bolt is indicated by reference numeral 14 in FIGS. 1 and 2.

図１及び図２に示すように、各ブランチ管６，７，８は、内側部材２に形成された上流側では、上下長手の姿勢でかつ互いに近接して平行に並んでいるが、中間部材４及び外側部材３で形成された部分は下から上に向けて曲っており、出口１０の間隔は入口９の間隔よりも大きくなっている。 As shown in FIGS. 1 and 2, the branch pipes 6, 7, and 8 are vertically longitudinal on the upstream side formed in the inner member 2, and are arranged in parallel in close proximity to each other. 4 and the outer member 3 is curved from bottom to top, and the spacing between the outlets 10 is greater than the spacing between the inlets 9.

エンジンは２ポート・２インジェクタの方式であるため、図６に示すように吸気ポート１１は隔壁１５で２つに仕切られている。これに対応して、各シリンダヘッド１の出口１０の箇所に仕切り壁１６を設けている。なお、図２，図４において符号１７で示すのは、ブレーキブースターのための負圧取り出しポートであり、図１，３において符号１８で示すのは、ＰＣＶガス導入ポートである。 Since the engine is of a two-port, two-injector type, the intake port 11 is partitioned into two by a partition wall 15, as shown in FIG. Correspondingly, a partition wall 16 is provided at the outlet 10 of each cylinder head 1. Note that in FIGS. 2 and 4, reference numeral 17 is a negative pressure outlet port for the brake booster, and in FIGS. 1 and 3, reference numeral 18 is a PCV gas introduction port.

(2).吸気及びＥＧＲガスの取り込み構造
図１，３から理解できるように、中間部材４の後部に、スロットルボデー（図示せず）がボルトで固定される吸気受け座２１と、ＥＧＲパイプがボルトでフランジ接合されるＥＧＲ受け座２２とが形成されている。吸気受け座２１とＥＧＲ受け座２２とは、ＥＧＲ受け座２２がシリンダヘッド１の近くに寄ってかつ高い位置になるようにして、左右に離れて配置されている。 (2). Intake and EGR gas intake structure As can be understood from Figures 1 and 3, the intake seat 21 to which the throttle body (not shown) is fixed with bolts and the EGR pipe are installed at the rear of the intermediate member 4. An EGR receiving seat 22 is formed which is flange-joined with bolts. The intake receiving seat 21 and the EGR receiving seat 22 are arranged apart from each other in the left and right directions, with the EGR receiving seat 22 being closer to the cylinder head 1 and at a higher position.

当然ながら、吸気受け座２１には吸気導入口２３が開口し、ＥＧＲ受け座２２にはＥＧＲガス取り込み口２４が開口しており、両者の開口方向（開口軸心）２５，２６は、背面視では、図３のとおり、上に向けてシリンダヘッド１から遠ざかるようにフランジ１３の接合面に対して傾斜して、側面視では、図１のとおり、上に向けてブランチ管６，７，８の群から離れるように傾斜している。両者の開口方向２５，２６は平行になっている。 Naturally, the intake intake port 23 is opened in the intake seat 21, and the EGR gas intake port 24 is opened in the EGR receiver seat 22. As shown in FIG. 3, the branch pipes 6, 7, 8 are tilted upwardly and away from the cylinder head 1 with respect to the joint surface of the flange 13, and in side view, as shown in FIG. tilted away from the group. The opening directions 25 and 26 of both are parallel to each other.

吸気導入口２３はサージタンク５の内部に開口しているが、サージタンク５の長手軸線に対して交差しているため、図４及び図６に点線で示すように、吸気は、サージタンク５の底面２７に当たってから、前向きに方向変換しつつ旋回流となって各ブランチ管６，７，８の入口９に流入していく。 The intake inlet 23 opens into the inside of the surge tank 5, but since it crosses the longitudinal axis of the surge tank 5, the intake air flows into the surge tank 5, as shown by the dotted line in FIGS. 4 and 6. After hitting the bottom surface 27 of the pipe, the flow changes direction forward and becomes a swirling flow, flowing into the inlet 9 of each branch pipe 6, 7, 8.

図４に示すように、中間部材４及び内側部材２の後部（の合わせ面）には、ＥＧＲガス取り込み口２４と連通したＥＧＲガス通路２８が前後方向に延びるように形成されている。ＥＧＲガス通路２８は、サージタンク５と第３ブランチ管８の上部とで挟まれた部位に形成されている。従って、ＥＧＲガス通路２８の下面は、中間部材４においてサージタンク５の上内面を構成する上面壁２９と、内側部材２においてサージタンク５の上面を構成する上面壁３０とで構成されており、中間部材４に位置したＥＧＲガス通路２８の上面の一部は、第３ブランチ管８を構成する壁で構成されている。両部材４，２における上面壁２９，３０の下面は滑らかに連続している。 As shown in FIG. 4, an EGR gas passage 28 communicating with the EGR gas intake port 24 is formed at the rear (mating surfaces) of the intermediate member 4 and the inner member 2 so as to extend in the front-rear direction. The EGR gas passage 28 is formed at a portion sandwiched between the surge tank 5 and the upper part of the third branch pipe 8. Therefore, the lower surface of the EGR gas passage 28 is composed of an upper surface wall 29 that constitutes the upper inner surface of the surge tank 5 in the intermediate member 4, and an upper surface wall 30 that constitutes the upper surface of the surge tank 5 in the inner member 2, A part of the upper surface of the EGR gas passage 28 located in the intermediate member 4 is constituted by a wall forming the third branch pipe 8. The lower surfaces of the upper walls 29, 30 of both members 4, 2 are smoothly continuous.

図６に示すように、中間部材４の上面壁２９と内側部材２の上面壁３０とは互いに当接して接合されているが、上面壁２９，３０を切欠くことにより、ＥＧＲガス通路２８とサージタンク５とを連通させる第１ＥＧＲガス導入口３１及び第２ＥＧＲガス導入口３２が形成されている。この場合、ＥＧＲガス取り込み口２４に近い第１ＥＧＲガス導入口３１の開口面積が、第２ＥＧＲガス導入口３２の開口面積よりも大きくなるように設定している。 As shown in FIG. 6, the upper wall 29 of the intermediate member 4 and the upper wall 30 of the inner member 2 are in contact with each other and joined together, but by cutting out the upper walls 29 and 30, the EGR gas passage 28 and A first EGR gas inlet 31 and a second EGR gas inlet 32 that communicate with the surge tank 5 are formed. In this case, the opening area of the first EGR gas inlet 31 near the EGR gas intake port 24 is set to be larger than the opening area of the second EGR gas inlet 32.

更に、図４に明示するように、中間部材４に、第１ＥＧＲガス導入口３１の箇所に位置した第１整流リブ３３と、第２ＥＧＲガス導入口３２の箇所に位置した第２整流リブ３４とが、中間部材４の開口方向と同じ方向（左右方向）に長い姿勢で形成されている。 Furthermore, as clearly shown in FIG. 4, the intermediate member 4 includes a first rectifying rib 33 located at the first EGR gas inlet 31 and a second rectifying rib 34 located at the second EGR gas inlet 32. is formed in a long posture in the same direction (left-right direction) as the opening direction of the intermediate member 4.

この場合、第１整流リブ３３はサージタンク５の底の段部３５まで延びているが、第２整流リブ３４は、サージタンク５の壁面の中途高さまでしか延びていない。従って、第１整流リブ３３の面積は第２整流リブ３４の面積よりも大きくなっている。他方、整流リブ３３，３４の前端は中間部材４の開口面近くまで延びている。従って、両整流リブ３３，３４は、それぞれＥＧＲガス導入口３１，３２を前後に分断する機能も備えている。 In this case, the first rectifying rib 33 extends to the stepped portion 35 at the bottom of the surge tank 5, but the second rectifying rib 34 extends only to the middle of the wall surface of the surge tank 5. Therefore, the area of the first rectifying rib 33 is larger than the area of the second rectifying rib 34. On the other hand, the front ends of the rectifying ribs 33 and 34 extend close to the opening surface of the intermediate member 4. Therefore, both the rectifying ribs 33 and 34 also have the function of dividing the EGR gas introduction ports 31 and 32 into front and rear parts, respectively.

図４に示すように、サージタンク５を構成する中間部材４には、第１整流リブ３３及び第２整流リブ３４に加えて、吸気が第１ブランチ管６と第２ブランチ管７とに分かれるように方向づける第３整流リブ３６を設けている。従って、第３整流リブ３６は、第１ブランチ管６と第２ブランチ管７との入口９の間の部位に位置している。各整流リブ３３，３４，３６はサージタンク５の底面２７と対向している。また、第３整流リブ３６は、サージタンク５の上面と底面とに跨がって形成されている。 As shown in FIG. 4, in addition to the first rectifying rib 33 and the second rectifying rib 34, the intermediate member 4 constituting the surge tank 5 has intake air divided into a first branch pipe 6 and a second branch pipe 7. A third rectifying rib 36 is provided to direct the flow in this direction. Therefore, the third straightening rib 36 is located between the inlets 9 of the first branch pipe 6 and the second branch pipe 7. Each of the flow regulating ribs 33, 34, 36 faces the bottom surface 27 of the surge tank 5. Further, the third rectifying rib 36 is formed across the top surface and bottom surface of the surge tank 5.

図４及び図６に示すように、サージタンク５の前部でかつ底部には、隆起状の段上がり部３７を形成している。このため、吸気は第１ブランチ管６に入りやすくなっている。 As shown in FIGS. 4 and 6, a raised stepped portion 37 is formed at the front and bottom of the surge tank 5. Therefore, the intake air easily enters the first branch pipe 6.

(3).まとめ
本実施形態は上記の構成であり、吸気はサージタンク５に噴出してから、サージタンク５の底面２７に衝突して前向きに方向変換するため、吸気の直進性が減殺されて、各ブランチ管６，７，８に等しい圧力で流入する。従って、各気筒において充填効率を一定化して、出力を安定化できる。 (3).Summary This embodiment has the above configuration, and since the intake air blows out into the surge tank 5 and then collides with the bottom surface 27 of the surge tank 5 and changes its direction forward, the straightness of the intake air is reduced. and flows into each branch pipe 6, 7, 8 at equal pressure. Therefore, the charging efficiency can be made constant in each cylinder, and the output can be stabilized.

そして、吸気が各ブランチ管６，７，８に均等に流れていく基本構成の下で、ＥＧＲガスは吸気と同じ方向からサージタンク５に流入するため、ＥＧＲガスを吸気の流れに乗せて分散性・混合性を向上できるが、第１ＥＧＲガス導入口３１と第２ＥＧＲガス導入口３２とが前後に分かれて開口しているため、吸気の流れを有効に利用して、各ブランチ管６，７，８に対するＥＧＲガスの流入量を均一化できる。 Under the basic configuration in which the intake air flows equally into each branch pipe 6, 7, and 8, the EGR gas flows into the surge tank 5 from the same direction as the intake air, so the EGR gas is dispersed along with the flow of the intake air. However, since the first EGR gas inlet 31 and the second EGR gas inlet 32 are opened separately into the front and back, each branch pipe 6, 7 can be effectively utilized to utilize the flow of intake air. , 8 can be made uniform.

さて、サージタンク５に流入した吸気は、サージタンク５の一端部（後端部）では、第３ブランチ管８に向かう流れ（主として旋回流）と、第１，２ブランチ管６，７に向かう流れ（直進流）とに分かれ、第１，２ブランチ管６，７に向かった流れは旋回流に変化して当該第１，２ブランチ管６，７の入口９に流れていくため、サージタンク５の一端部近傍では複雑な流れになっている。 Now, at one end (rear end) of the surge tank 5, the intake air flowing into the surge tank 5 flows toward the third branch pipe 8 (mainly a swirling flow) and flows toward the first and second branch pipes 6 and 7. The surge tank The flow is complicated near one end of 5.

このため、ガス導入口がサージタンク５の一端部にしか存在しないと、ＥＧＲガスを第３ブランチ管８に向かう流れと第１，２ブランチ管６，７に向かう流れとに分けて適量ずつ乗せることが難しく、第３ブランチ管８の流入量が過少になったり過大になったりしやすいが、本実施形態のように２つのＥＧＲガス導入口３１，３２を設けると、ＥＧＲガスを、主として第３ブランチ管８に向かう流れと、主として第１，２ブランチ管６，７に向かう流れとに分けることができるため、ＥＧＲガスを各ブランチ管６，７，８に均等に流し込むことができる。 For this reason, if the gas inlet is present only at one end of the surge tank 5, the EGR gas is divided into a flow toward the third branch pipe 8 and a flow toward the first and second branch pipes 6 and 7, and appropriate amounts are loaded. However, if two EGR gas inlets 31 and 32 are provided as in this embodiment, the EGR gas is mainly transferred to the third branch pipe 8. Since the EGR gas can be divided into the flow toward the three branch pipes 8 and the flow mainly toward the first and second branch pipes 6 and 7, the EGR gas can be uniformly flowed into each of the branch pipes 6, 7, and 8.

そして、実施形態のように２枚の整流リブ３３，３４を設けると、２つのガス導入口３１，３２をそれぞれ前後に仕切って４つのガス導入口を設けたのと同じ状態を生成できることと、サージタンク５に流入したＥＧＲガスの流れを整流リブ３３，３４によって制御できる（ブランチ管６，７，８に向かうように方向付けることができる）こととにより、各ブランチ管６，７，８への分配の均等化に更に貢献できる。 By providing two rectifying ribs 33 and 34 as in the embodiment, it is possible to create the same state as when four gas inlets are provided by partitioning the two gas inlets 31 and 32 back and forth, respectively. The flow of EGR gas that has flowed into the surge tank 5 can be controlled by the rectifying ribs 33 and 34 (it can be directed toward the branch pipes 6, 7, and 8). This can further contribute to equalizing the distribution of

この場合、吸気はサージタンク５の一端部で強い攪拌作用が生じるが、実施形態のように第１整流リブ３３の面積を大きくしておくと、吸気の流れに負けずにＥＧＲガスを的確に方向付けできるため、特に第３ブランチ管８への流入性を向上できる利点がある（ＥＧＲガスが第３ブランチ管８を素通りしてしまう傾向を是正できる。）。 In this case, a strong stirring action occurs on the intake air at one end of the surge tank 5, but if the area of the first rectifying rib 33 is made large as in the embodiment, the EGR gas can be accurately distributed without being defeated by the flow of the intake air. Since it can be directed, there is an advantage that the inflow into the third branch pipe 8 can be particularly improved (it is possible to correct the tendency of the EGR gas to pass through the third branch pipe 8).

更に、実施形態のように、第３整流リブ３６を設けると、ＥＧＲガスが第１ブランチ管６に向かい過ぎることを防止して、分散性を更に助長できる。サージタンク５の前部に形成した隆起状の段上がり部３７も同じであり、段上がり部３７を設けるとサージタンク５の前部の容積が減少することにより、吸気が第１ブランチ管６に向かい過ぎることを防止できるため、結果として、ＥＧＲガスが吸気の直進流によって第１ブランチ管６に流れ込み過ぎることを防止できる。 Furthermore, if the third rectifying rib 36 is provided as in the embodiment, it is possible to prevent the EGR gas from heading too far toward the first branch pipe 6, thereby further promoting dispersibility. The same applies to the raised stepped portion 37 formed at the front of the surge tank 5. When the stepped raised portion 37 is provided, the volume of the front portion of the surge tank 5 is reduced, so that intake air flows into the first branch pipe 6. Since it is possible to prevent the EGR gas from flowing too far toward the first branch pipe 6, it is possible to prevent the EGR gas from flowing too much into the first branch pipe 6 due to the straight flow of intake air.

中間部材４は、その開口方向（図６で左右方向）に接近・離反する金型を使用して成型されるが、各整流リブ３３，３４，３６は中間部材４を成型する金型の相対動方向に延びているため、スライド型のような部材を要することなく容易に成型できる。 The intermediate member 4 is molded using molds that approach and move away from each other in the opening direction (left and right direction in FIG. Since it extends in the direction of movement, it can be easily molded without requiring a member such as a slide mold.

吸気受け座２１とＥＧＲ受け座２２とは左右に近接して配置されているため、ＥＧＲパイプとスロットボデーとを左右に近接して纏めて配置できる。従って、吸気マニホールド周りの部材をコンパクトに纏めて、スペースを有効利用できる。また、吸気導入口２３とＥＧＲガス取り込み口２４とは同じ方向に開口しているため、射出成型法で成型するに際してスライド型を共通化できて、それだけ成型装置を簡単化できる。 Since the intake receiving seat 21 and the EGR receiving seat 22 are arranged close to each other on the left and right, the EGR pipe and the slot body can be arranged close to each other on the left and right. Therefore, the members around the intake manifold can be compacted and the space can be used effectively. Further, since the intake air inlet 23 and the EGR gas intake port 24 are opened in the same direction, a slide mold can be used in common when molding by injection molding, and the molding apparatus can be simplified accordingly.

実施形態では、第１及び第２の整流リブ３３，３４はそれぞれＥＧＲガス導入口３１，３２の前後中途部に設けたが、これらの整流リブ３３，３４のうちいずれか一方又は両方を、ＥＧＲガス導入口３１，３２の下流端の箇所に配置することも可能である。また、整流リブ３３，３４の前端はＥＧＲガス通路２８の底面と同じ高さに設定してもよい。 In the embodiment, the first and second rectifying ribs 33, 34 are provided at the front and rear midpoints of the EGR gas inlet ports 31, 32, respectively. It is also possible to arrange it at the downstream end of the gas introduction ports 31 and 32. Further, the front ends of the rectifying ribs 33 and 34 may be set at the same height as the bottom surface of the EGR gas passage 28.

更に、ＥＧＲガス通路２８を中間部材４のみに形成することは可能であるし、整流リブ３３，３４を内側部材２のみ又は内側部材２と中間部材４との両方に形成することも可能である。 Furthermore, it is possible to form the EGR gas passage 28 only in the intermediate member 4, and it is also possible to form the rectifying ribs 33, 34 only in the inner member 2 or in both the inner member 2 and the intermediate member 4. .

更に、本願発明は図示した実施形態の他にも様々に具体化できる。例えば、本願発明は、３気筒エンジン用の吸気マニホールドには限らず、２気筒又は４気筒以上の吸気マニホールドにも適用できる。ＰＣＶガスの導入構造にも適用できる。 Furthermore, the present invention can be embodied in various ways other than the illustrated embodiments. For example, the present invention is not limited to an intake manifold for a three-cylinder engine, but can also be applied to an intake manifold for two or more cylinders. It can also be applied to a PCV gas introduction structure.

更に、ガス通路として、ブランチ管の並び方向に長いパイプを使用して、これをサージタンクにその一端部から挿通して、パイプに複数のガス導入口（穴）を空けておくことも可能である。或いは、複数本のパイプを用意して、各パイプを吸気マニホールドに挿通して先端をサージタンクに向けて開口させるといったことも可能である。 Furthermore, it is also possible to use a long pipe as a gas passage in the direction in which the branch pipes are lined up, insert it into the surge tank from one end, and make multiple gas inlets (holes) in the pipe. be. Alternatively, it is also possible to prepare a plurality of pipes, insert each pipe into the intake manifold, and open the tip toward the surge tank.

本願発明は、吸気マニホールドに具体化できる。従って、産業上利用できる。 The present invention can be embodied in an intake manifold. Therefore, it can be used industrially.

１シリンダヘッド
２内側部材
３外側部材
４中間部材
５サージタンク
６～８ブランチ管
９ブランチ管の入口
１０ブランチ管の出口
１２吸気側面
１３シリンダヘッドに締結されるフランジ
２１吸気受け座
２２ＥＧＲ受け座
２３吸気導入口
２４ＥＧＲガス取り込み口
２８ＥＧＲガス通路
３１，３２ＥＧＲガス導入口
３３，３４，３６整流リブ 1 Cylinder head 2 Inner member 3 Outer member 4 Intermediate member 5 Surge tank 6 to 8 Branch pipe 9 Inlet of branch pipe 10 Outlet of branch pipe 12 Intake side 13 Flange fastened to cylinder head 21 Intake receiver 22 EGR receiver 23 Intake intake port 24 EGR gas intake port 28 EGR gas passage 31, 32 EGR gas introduction port 33, 34, 36 Rectification rib

Claims

A surge tank having an air intake inlet at one end, and a plurality of branch pipes arranged in a line in the crank axis direction in a manner to wrap around the surge tank,
The intake air inlet opens into the surge tank from a direction crossing the direction in which the branch pipes are lined up, and the intake air changes direction at one end of the surge tank and flows into the surge tank to flow into each branch. It is set to flow into the inlet of the pipe,
In addition, the surge tank has a gas inlet for introducing EGR gas or other auxiliary gas into the surge tank , and a gas inlet that takes in EGR gas or other auxiliary gas is connected to the branch pipe at a portion of the surge tank near one end where the intake inlet is provided. A plurality of intake manifolds are formed in a direction in which the intake manifolds are arranged,
The gas inlet is branched from a gas passage that is long in the direction in which the branch pipes are lined up, and a gas intake port that communicates with an upstream end of the gas passage opens outward;
The gas intake port and the intake air introduction port are aligned with the intake air introduction port in the front-rear direction when viewed from a direction perpendicular to the intake side surface of the cylinder head, and are mainly opened upward.
intake manifold.

A surge tank having an air intake inlet at one end, and a plurality of branch pipes arranged in a line in the crank axis direction in a manner to wrap around the surge tank,
The intake air inlet opens into the surge tank from a direction crossing the direction in which the branch pipes are lined up, and the intake air changes direction at one end of the surge tank and flows into the surge tank to flow into each branch. It is set to flow into the inlet of the pipe,
In addition, the surge tank has a gas inlet for taking EGR gas or other auxiliary gas into the surge tank, and the branch pipes are arranged in a portion of the surge tank that is closer to one end where the intake inlet is provided. An intake manifold formed in multiple directions divided into directions,
The surge tank is formed hollow by joining a first member in which the intake inlet is formed and a second member in which inlets of the branch pipes are formed, and the inner surfaces of both members are smooth. It is continuous to
A gas passage in the first member that opens toward the second member on the outside of an inner surface that is smoothly continuous with the second member allows auxiliary gas to flow from one end of the surge tank to the other end. The plurality of gas inlet ports are formed to flow and are open to the inside of the surge tank while communicating with the gas passageway and are formed on the mating surfaces of the first member and the second member ,
Of the plurality of gas inlets, those located on the upstream side have a larger opening area than those located on the downstream side,
intake manifold.

A surge tank having an air intake inlet at one end, and a plurality of branch pipes arranged in a line in the crank axis direction in a manner to wrap around the surge tank,
The intake air inlet opens into the surge tank from a direction crossing the direction in which the branch pipes are lined up, and the intake air changes direction at one end of the surge tank and flows into the surge tank to flow into each branch. It is set to flow into the inlet of the pipe,
In addition, the surge tank has a gas inlet for taking EGR gas or other auxiliary gas into the surge tank, and the branch pipes are arranged in a portion of the surge tank that is closer to one end where the intake inlet is provided. An intake manifold formed in multiple directions divided into directions,
The surge tank is formed hollow by joining two members having recesses that are open so as to face each other, and the gas inlet is formed in the mating surface of the two members , and the The inlets of the plurality of branch pipes are formed in one of the two members so as to be arranged so as to open toward the other member,
and a rectifying rib that disperses the flow of the auxiliary gas discharged from the gas inlet and controls the intake air to flow into the inlet of each of the branch pipes in a distributed manner on one or both of the two members. is formed to extend in the same direction as the opening direction of both members and to face the bottom surface of the surge tank ,
The straightening rib includes one disposed between the inlets of the adjacent branch pipes,
intake manifold.