JPH0343378Y2 - - Google Patents

Description

【考案の詳細な説明】 （産業上の利用分野） 本考案は、各気筒と吸気拡大室（タンク）とを
互いに独立した吸気通路で接続して、吸気の動的
効果（吸気慣性効果）により出力の向上を図るよ
うにしたエンジンの吸気装置の改良に関するもの
である。[Detailed explanation of the invention] (Field of industrial application) This invention connects each cylinder and the intake expansion chamber (tank) with mutually independent intake passages, and utilizes the dynamic effect of intake air (intake inertia effect). This invention relates to an improvement in an engine intake system designed to improve output.

（従来の技術） 従来から、エンジンの吸気装置において、吸気
開始に伴つて生じる負圧波（負圧の圧力波）が吸
気通路上流側の大気または吸気拡大室への開口端
で反射され正圧波（正圧の圧力波）となつて吸気
ポート方向に戻されることを利用し、上記正圧波
が吸気弁の閉弁寸前に吸気ポートに達して吸気を
燃焼室に押し込むようにする、いわゆる吸気の慣
性効果によつて吸気の充填効率を高めるようにす
ることは知られている。このような技術を用いよ
うとする場合に、吸気通路の形状が一定である
と、吸気通路に生じる圧力波の振動周期と吸気弁
の開閉周期とがマツチングして吸気慣性効果が高
められるのは特定回転域に限られる。(Prior Art) Conventionally, in the intake system of an engine, a negative pressure wave (pressure wave of negative pressure) generated with the start of intake is reflected at the opening end of the intake passage to the atmosphere or the intake expansion chamber on the upstream side of the intake passage, and a positive pressure wave ( The positive pressure wave returns to the intake port as a positive pressure wave, and the positive pressure wave reaches the intake port just before the intake valve closes, pushing the intake air into the combustion chamber. This is the so-called intake inertia. It is known to increase the filling efficiency of intake air by means of effects. When using such technology, if the shape of the intake passage is constant, the oscillation period of the pressure wave generated in the intake passage matches the opening and closing period of the intake valve, and the intake inertia effect is enhanced. Limited to a specific rotation range.

このため、従来、特開昭56−115819号公報にみ
られるように、エンジンの回転数に応じて吸気通
路の長さ等を変えるようにし、例えば、各気筒別
の吸気通路を上流部で２叉に分岐させて長い通路
と短い通路とを形成し、これらの通路の上流端を
吸気拡大室等に開口させるとともに、短い通路に
制御弁を設けて、高回転域でこの制御弁を開くこ
とにより吸気通路の有効長を短縮するようにし
（上記公報の第６図参照）、こうして低回転域と高
回転域とでそれぞれ吸気の慣性効果を高めるよう
にした吸気装置が提案されている。 For this reason, conventionally, as seen in JP-A-56-115819, the length of the intake passage is changed depending on the engine speed, for example, the intake passage for each cylinder is divided into two parts at the upstream part. A long passage and a short passage are formed by branching, and the upstream ends of these passages are opened to an intake expansion chamber, etc., and a control valve is provided in the short passage, and this control valve is opened in a high rotation range. An intake device has been proposed in which the effective length of the intake passage is shortened (see FIG. 6 of the above-mentioned publication), thereby increasing the inertial effect of intake air in both the low-speed range and the high-speed range.

（考案が解決しようとする課題） ところで、上記提案例の如く吸気拡大室（タン
ク）と各気筒とを互いに独立して接続する各独立
吸気通路の途中を上記吸気拡大室に連通する第２
通路を設けるとともに、該第２通路にエンジンの
運転状態に応じて開閉する制御弁を設けたエンジ
ンの吸気装置においては、制御弁の開弁時、第２
通路に制御弁が配置されている関係上、その分、
第２通路を流れる吸気の流通抵抗が大きく、吸気
が独立吸気通路にスムーズに流れないことにな
る。特に、第２通路と独立吸気通路とが交差する
交差角が直角ないし鈍角である場合には、第２通
路を介する独立吸気通路への吸気の流通抵抗の増
大が顕著であり、高回転域で吸気慣性効果を有効
に発揮できないことになる。(Problem to be solved by the invention) By the way, as in the above proposed example, a second passage connecting the intake expansion chamber (tank) and each cylinder independently to each other communicates with the intake expansion chamber in the middle of each independent intake passage.
In an engine intake system in which a passage is provided and a control valve that opens and closes in accordance with the operating state of the engine is provided in the second passage, when the control valve is opened, the second passage
Due to the control valve located in the passage,
The flow resistance of the intake air flowing through the second passage is large, and the intake air does not flow smoothly into the independent intake passage. In particular, when the intersection angle between the second passage and the independent intake passage is a right angle or an obtuse angle, the flow resistance of intake air to the independent intake passage via the second passage increases significantly, and in the high rotation range. This means that the intake inertia effect cannot be effectively utilized.

さらに、上記制御弁の開弁時、各独立吸気通路
が上記各第２通路及び吸気拡大室を介して相互に
連通していることから、エンジンの高回転域にお
いて上述の吸気慣性効果に加えて、上記相互連通
状態を利用して一の気筒で発生した圧力波を他の
気筒へ伝播させ、この気筒相互間の圧力波の伝播
作用（つまり気筒間干渉効果）により吸気の充填
効率を一層高めることが考えられる。しかし、こ
の場合、他気筒への圧力波伝播エネルギーをでき
るだけ減衰させずに上記気筒間干渉効果を促進す
るためには、上記連通部としての吸気拡大室を、
低回転域での吸気慣性効果を得る吸気拡大室の容
積よりも小さいものとする必要がある。このため
に、上記連通部を通常の吸気拡大室とは別途に設
けることは徒らに吸気系のコンパクト化を阻害す
るものとなる。 Furthermore, when the control valve is opened, the independent intake passages communicate with each other via the second passages and the intake expansion chamber, so that in addition to the above-mentioned intake inertia effect in the high engine speed range, , the pressure waves generated in one cylinder are propagated to other cylinders by utilizing the mutual communication state, and the filling efficiency of intake air is further increased by the propagation effect of the pressure waves between the cylinders (i.e., the inter-cylinder interference effect). It is possible that However, in this case, in order to promote the inter-cylinder interference effect without attenuating the pressure wave propagation energy to other cylinders as much as possible, it is necessary to
It needs to be smaller than the volume of the intake expansion chamber to obtain the intake inertia effect in the low rotation range. For this reason, providing the communication portion separately from the normal intake expansion chamber will unnecessarily hinder the miniaturization of the intake system.

本考案はかかる点に鑑みてなされたもので、そ
の目的とするところは、タンクの構造、各第２通
路の通路面積、第２通路の独立吸気通路との交差
角およびその交差部分の形状等を適切に設定する
ことにより、吸気系全体をコンパクトにしなが
ら、低回転域での吸気慣性効果の有効な発揮に加
えて、高回転域において各独立吸気通路相互を連
通する容積室の容積をできるだけ小さくするとと
もに制御弁の開弁時に第２通路から独立吸気通路
へ流れる吸気の流通抵抗を小さくして吸気の流れ
をスムーズなものとすることで気筒間干渉効果を
十分に促進し、よつて高回転域で吸気慣性効果と
気筒間干渉効果とを共に有効に発揮させることに
ある。 The present invention was developed in view of these points, and its objectives include the structure of the tank, the passage area of each second passage, the intersection angle of the second passage with the independent intake passage, and the shape of the intersection. By appropriately setting the intake system, the entire intake system can be made compact, and in addition to effectively exerting the intake inertia effect in the low rotation speed range, the volume of the volume chamber that communicates between the independent intake passages can be minimized as much as possible in the high rotation speed range. By reducing the flow resistance of the intake air flowing from the second passage to the independent intake passage when the control valve is opened, and making the flow of intake air smooth, the inter-cylinder interference effect is sufficiently promoted, and the cylinder height is increased. The objective is to effectively exhibit both the intake inertia effect and the inter-cylinder interference effect in the rotation range.

（課題を解決するための手段） 上記の目的を達成するため、本考案の解決手段
は、タンク内部を仕切板で仕切つて第１容積室と
該第１容積室よりも容積の小さい第２容積室とに
区画し、上記第１容積室と各気筒とを互いに独立
した気筒別の各独立吸気通路で接続するととも
に、該各独立吸気通路の途中をそれぞれ上記第２
容積室に連通する第２通路を設けて該各第２通路
と上記第２容積室とにより上記各独立吸気通路を
相互に連通する。上記各第２通路にエンジンの運
転状態に応じて開閉する制御弁を設ける。上記各
第２通路は、上記各独立吸気通路よりも通路面積
が大きく、かつ該各独立吸気通路と交差する交差
角が鋭角になるように形成されているとともに、
上記第２通路と独立吸気通路との交差部分は滑ら
かな形状に形成されている。上記仕切板は上記第
２通路が合流する独立吸気通路部分の通路軸線と
ほぼ平行になるように設けられているとともに、
上記制御弁はその閉弁状態において上記第２通路
が合流する独立吸気通路部分の通路軸線とほぼ平
行になるように設けられているものとする。(Means for Solving the Problem) In order to achieve the above object, the solution of the present invention is to partition the inside of the tank with a partition plate to form a first volume chamber and a second volume smaller in volume than the first volume chamber. The first volume chamber and each cylinder are connected to each other by independent intake passages for each cylinder, and the middle of each independent intake passage is connected to the second volume chamber.
A second passage communicating with the volume chamber is provided, and each of the second passages and the second volume chamber communicate with each other the independent intake passages. Each of the second passages is provided with a control valve that opens and closes depending on the operating state of the engine. Each of the second passages has a larger passage area than each of the independent intake passages, and is formed such that the intersection angle at which it intersects with each of the independent intake passages is an acute angle;
The intersection between the second passage and the independent intake passage is formed into a smooth shape. The partition plate is provided so as to be substantially parallel to the passage axis of the independent intake passage portion where the second passage joins, and
The control valve is provided so as to be substantially parallel to the passage axis of the independent intake passage portion where the second passage joins in the closed state.

（作用） これにより、本考案では、制御弁が閉じて各第
２通路の閉塞によつて第２容積室による各独立吸
気通路相互間の連通が遮断されている状態では、
各気筒の吸気行程で生じる負圧波が第１容積室ま
で伝播されてここで正圧波に反転されて反射さ
れ、つまり比較的長い通路を通して上記負圧波及
びその反射波としての正圧波が伝播することによ
り、低回転域においてこのような圧力波の振動周
期が吸気弁開閉周期にマツチングすることにな
り、低回転域での吸気慣性効果が高められて吸気
充填効率が高められる。(Function) Accordingly, in the present invention, when the control valve is closed and the second passages are blocked, communication between the independent intake passages by the second volume chamber is cut off.
The negative pressure wave generated during the intake stroke of each cylinder is propagated to the first volume chamber, where it is inverted into a positive pressure wave and reflected. In other words, the negative pressure wave and the positive pressure wave as its reflected wave propagate through a relatively long passage. As a result, the oscillation cycle of such pressure waves matches the intake valve opening/closing cycle in the low rotation range, thereby increasing the intake inertia effect in the low rotation range and increasing the intake air filling efficiency.

一方、上記各制御弁が開かれ各第２通路が開放
されて、第２容積室により各独立吸気通路相互間
が連通している状態では、各気筒の吸気行程で生
じる負圧波が上記第２通路を介して第２容積室で
正圧波に反転されて反射され、この負圧波及びそ
の反射波（正圧波）の伝播に供される通路長さが
短くなることにより、高回転域で吸気慣性効果が
高められるとともに、この運転域では他の気筒か
ら伝播される圧力波も上記容積の小さい第２容積
室を介して減衰せずに有効に作用することにな
り、高回転域での吸気充填効率が大幅に高められ
る。 On the other hand, in a state where each of the control valves is opened and each of the second passages is opened, and the respective independent intake passages are in communication with each other through the second volume chamber, the negative pressure wave generated during the intake stroke of each cylinder is transferred to the second passage. The negative pressure wave and its reflected wave (positive pressure wave) are inverted and reflected in the second volume chamber via the passage, and the length of the passage used for propagation of the negative pressure wave and its reflected wave (positive pressure wave) is shortened, thereby reducing the intake inertia in the high rotation range. The effect is enhanced, and in this operating range, the pressure waves propagated from other cylinders also act effectively without being attenuated through the second volume chamber with a small volume, which improves intake air filling in the high rotation range. Efficiency is greatly increased.

その場合、上記第２通路の通路面積が独立吸気
通路よりも大きいことにより、該第２通路に制御
弁が配置される分の通路面積の減少が補償され
て、制御弁の開弁時の第２通路自体の吸気抵抗が
小さくなる。さらに、第２通路と独立吸気通路と
の交差角が鋭角であつて、かつこの交差部分が滑
らかな形状であるので、制御弁の開弁時、第２通
路から独立吸気通路へ吸気がスムーズに流れてそ
の流通抵抗が小さくなる。この結果、第２通路か
ら独立吸気通路への吸気のスムーズな流入が可能
となり、上記第２容積室の容積が小さいことと相
俟つて、高回転域での吸気慣性効果は無論のこ
と、気筒間干渉効果が十分に確保されることにな
る。 In that case, since the passage area of the second passage is larger than that of the independent intake passage, the decrease in passage area due to the arrangement of the control valve in the second passage is compensated for, and the passage area when the control valve is opened is compensated for. The intake resistance of the two passages themselves is reduced. Furthermore, since the intersection angle between the second passage and the independent intake passage is an acute angle, and this intersection has a smooth shape, intake air flows smoothly from the second passage to the independent intake passage when the control valve is opened. It flows and its flow resistance becomes smaller. As a result, the intake air can flow smoothly from the second passage to the independent intake passage, and together with the small volume of the second volume chamber, the intake inertia effect in the high rotation range is naturally reduced, and the cylinder This will ensure a sufficient interference effect.

さらに、タンクを仕切板で仕切ることによる第
１容積室と第２容積室の形成、並びに該仕切板及
び閉弁状態における制御弁の独立吸気通路軸線に
対する略平行な配置により、タンク全体をコンパ
クトなものに確保することができる。 Furthermore, by partitioning the tank with a partition plate to form a first volume chamber and a second volume chamber, and by arranging the partition plate and the control valve in the closed state approximately parallel to the axis of the independent intake passage, the entire tank can be made compact. Things can be secured.

（実施例） 以下、本考案の実施例について図面に基づいて
詳細に説明する。(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

第１図〜第４図は本考案を４気筒４サイクルエ
ンジンに適用した場合の実施例を示す。同図にお
いて、１はシリンダブロツク２およびシリンダヘ
ツド３等からなるエンジン本体であつて、該エン
ジン本体１にはその長手方向に第１〜第４の４つ
の気筒４，４…が直列状に形成されている。この
各気筒４にはそれぞれ燃焼室５が形成されてい
る。 1 to 4 show an embodiment in which the present invention is applied to a 4-cylinder, 4-cycle engine. In the figure, reference numeral 1 denotes an engine body consisting of a cylinder block 2, a cylinder head 3, etc. In the engine body 1, four cylinders 4, 4, first to fourth, are formed in series in the longitudinal direction. has been done. A combustion chamber 5 is formed in each cylinder 4.

６は気筒別に互いに独立して設けられた独立吸
気通路であつて、該各独立吸気通路６は、シリン
ダヘツド３内に形成され独立吸気通路６の下流端
部を構成する吸気ポート７を介して各気筒４の燃
焼室５に開口している。また、８はエンジン長手
方向に平行に延びる略角筒形状のタンクよりなる
吸気拡大室であつて、該吸気拡大室８は仕切板９
によつて上下に仕切られて上側に比較的大きな容
積の第１容積室８ａと下側に比較的小さな容積の
第２容積室８ｂとに区画されている。そして、上
記各独立吸気通路６，６…の上流端はそれぞれほ
ぼ同一通路長でもつて上記吸気拡大室８の第１容
積室８ａに連通接続されている。該第１容積室８
ａの一端面には外気を導入する吸気導入管１０が
接続されていて、該吸気導入管１０内には吸入空
気量を制御するスロツトル弁１１が配設されてお
り、上記吸気導入管１０により第１容積室８ａに
導入された吸気を各独立吸気通路６を介して各気
筒４の燃焼室５に供給するようになされている。
また、上記吸気ポート７には吸気弁１２が設けら
れている。 Reference numeral 6 denotes independent intake passages provided independently of each other for each cylinder, and each independent intake passage 6 is connected through an intake port 7 formed in the cylinder head 3 and constituting the downstream end of the independent intake passage 6. It opens into the combustion chamber 5 of each cylinder 4. Reference numeral 8 denotes an intake expansion chamber made of a substantially rectangular cylindrical tank extending parallel to the longitudinal direction of the engine.
It is partitioned vertically into a first volume chamber 8a having a relatively large volume on the upper side and a second volume chamber 8b having a relatively small volume on the lower side. The upstream ends of each of the independent intake passages 6, 6, . . . are connected to the first volume chamber 8a of the intake expansion chamber 8 with substantially the same passage length. The first volume chamber 8
An intake air introduction pipe 10 for introducing outside air is connected to one end surface of a, and a throttle valve 11 for controlling the amount of intake air is disposed inside the intake air introduction pipe 10. The intake air introduced into the first volume chamber 8a is supplied to the combustion chamber 5 of each cylinder 4 via each independent intake passage 6.
Further, the intake port 7 is provided with an intake valve 12 .

さらに、上記各独立吸気通路６の途中箇所から
第２通路１３が分岐していて、該各第２通路１
３，１３…の他端はそれぞれほぼ同一通路長でも
つて上記吸気拡大室８の第２容積室８ｂに連通接
続されており、このことから第２容積室８ｂによ
り第２通路１３を介して各独立吸気通路６，６…
を相互に連通するようにしている。 Further, a second passage 13 branches off from a midway point of each of the independent intake passages 6, and each of the second passages 1
The other ends of 3, 13, . Independent intake passages 6, 6...
are made to communicate with each other.

また、上記各第２通路１３にはそれぞれ第２通
路１３を開閉する制御弁１４が設けられている。
この各制御弁１４は、その弁体１４ａが吸気拡大
室８長手方向と平行に延びるバルブシヤフト１５
に一体的に連動可能に固定されていて、図示して
いないが、エンジン回転数検出手段等の出力を受
ける制御回路によりアクチユエータを介して開閉
制御され、上記第２容積室８ｂによる各独立吸気
通路６，６…相互間の連通をエンジン運転状態に
応じて制御し、エンジン回転数が設定値未満の低
回転域では閉じられ、エンジン回転数が設定値以
上の高回転域では開かれるように制御される。な
お、このようなエンジン回転数に応じた制御弁１
４の開閉作動は、少なくとも出力が要求される高
負荷時において行われるようにすればよく、低負
荷時には制御弁１４が開状態または閉状態に保た
れるようにしてもよい。 Further, each of the second passages 13 is provided with a control valve 14 that opens and closes the second passage 13, respectively.
Each control valve 14 has a valve shaft 15 whose valve body 14a extends parallel to the longitudinal direction of the intake expansion chamber 8.
Although not shown, the opening and closing of each independent intake passage by the second volume chamber 8b is controlled via an actuator by a control circuit that receives an output from an engine rotation speed detection means, etc. 6, 6... Control communication between them according to the engine operating state, so that they are closed in the low rotation range where the engine rotation speed is less than the set value, and are controlled to be opened in the high rotation range where the engine rotation speed is higher than the set value. be done. In addition, the control valve 1 according to such engine speed
The opening/closing operation of No. 4 may be performed at least during high loads where output is required, and the control valve 14 may be kept open or closed during low loads.

そして、このような吸気系システムにおいて、
１６は、上記吸気拡大室８、各独立吸気通路６，
６…および各第２通路１３，１３…を形成するた
めの吸気系構造体である。該構造体１６は、吸気
拡大室８（第１容積室８ａおよび第２容積室８
ｂ）を構成するタンク部１７と、該タンク部１７
のエンジン側とは反対側の側辺上部から側辺およ
び下辺にかけてタンク部１７の周囲を迂回して延
び、かつその構成壁の一部つまり側壁および下壁
を利用して各独立吸気通路６，６…の上流側部分
６ａ，６ａ…をその各上流端がタンク部１７（第
１容積室８ａ）側辺上部に開口するように一体的
に形成する一体吸気管部１８，１８…と、該各一
体吸気管部１８，１８…の下辺部からエンジン側
へ向かつて各気筒別に分岐して延び、各独立吸気
通路６，６…の下流側部分６ｂ，６ｂ…を形成す
る分岐吸気管部１９，１９…と、上記各一体吸気
管部１８の分岐吸気管部１９近傍においてタンク
部１７（第２容積室８ｂ）の構成壁のうちの下壁
を利用して各独立吸気通路６の途中を第２容積質
８ｂに連通する第２通路１３を一体的に形成する
連通管部２０，２０…と、上記各分岐吸気管部１
９，１９…の先端部を互いに連結するフランジ部
２１とからなり、該フランジ部２１にてエンジン
本体１に対し各分岐吸気管部１９の独立吸気通路
下流側部分６ｂを各気筒４の吸気ポート７に合致
せしめた状態でボルト２２，２２…を側方から挿
入して締付けることによりエンジン本体１に固定
される。また、上記タンク部１７のエンジン側の
側辺上部はエンジン側に膨出するように形成され
ており、第１容積室８ａの容積を十分に確保する
ようにしている。 In such an intake system,
16 is the intake expansion chamber 8, each independent intake passage 6,
6... and each second passage 13, 13... is an intake system structure for forming them. The structure 16 includes an intake expansion chamber 8 (a first volume chamber 8a and a second volume chamber 8
b) The tank part 17 constituting the tank part 17
The independent intake passages 6, 17 extend around the tank part 17 from the upper part of the side opposite to the engine side to the side and lower sides, and utilize part of the constituent walls, that is, the side wall and the lower wall. integral intake pipe portions 18, 18, . A branch intake pipe section 19 extends from the lower side of each integrated intake pipe section 18, 18... toward the engine side and branches for each cylinder, forming the downstream portions 6b, 6b... of each independent intake passage 6, 6... , 19... and in the vicinity of the branched intake pipe section 19 of each integral intake pipe section 18, the lower wall of the constituent walls of the tank section 17 (second volume chamber 8b) is used to extend the middle of each independent intake passage 6. Communication pipe parts 20, 20... that integrally form the second passage 13 communicating with the second volumetric mass 8b, and each branch intake pipe part 1
The flange portion 21 connects the tips of the branch intake pipe portions 19 to the engine body 1, and the downstream portion 6b of the independent intake passage of each branch intake pipe portion 19 is connected to the intake port of each cylinder 4. 7, the bolts 22, 22... are inserted from the side and tightened to be fixed to the engine body 1. Further, the upper side of the tank portion 17 on the engine side is formed so as to bulge toward the engine, thereby ensuring a sufficient volume of the first volume chamber 8a.

また、上記各分岐吸気管部１９の独立吸気通路
下流側部分６ｂおよび各吸気ポート７は、斜め上
方から燃焼室５に向つてほぼ直線状に延びて燃焼
室５に開口するように形成されている。そして、
該各分岐吸気管部１９の独立吸気通路下流側部分
６ｂの下流端近傍上部には噴射弁装着孔２３が形
成されており、燃料噴射弁２４はその先端噴射口
部がシールリング２３ａを介して装着孔２３に挿
入されて固定されている。この装着孔２３及び燃
料噴射弁２４の取付方向は該噴射弁２４からの燃
料が燃料室５の吸気弁１２に向つて噴射されるよ
うに装着されていて、各燃料噴射弁２４，２４…
はエンジン長手方向に平行に配設された燃料供給
管２５に連通接続されている。このことにより、
燃料噴射弁２４は分岐吸気管部１９にほぼ沿つて
寝た状態で取付けられることとなり、該燃料噴射
弁２４の中心線の延長線上に上記吸気拡大室８
（タンク部１７）が燃料噴射弁２４および燃料供
給管２５に近接して位置することになる。 Further, the downstream side portion 6b of the independent intake passage and each intake port 7 of each of the branched intake pipe portions 19 are formed to extend in a substantially straight line from obliquely upward toward the combustion chamber 5 and open into the combustion chamber 5. There is. and,
An injection valve mounting hole 23 is formed in the upper part near the downstream end of the downstream side portion 6b of the independent intake passage of each branch intake pipe section 19, and the fuel injection valve 24 has its tip injection port inserted through a seal ring 23a. It is inserted into the mounting hole 23 and fixed. The mounting holes 23 and the fuel injection valves 24 are mounted in such a way that the fuel from the injection valves 24 is injected toward the intake valve 12 of the fuel chamber 5, and the fuel injection valves 24, 24, . . .
is connected to a fuel supply pipe 25 arranged parallel to the longitudinal direction of the engine. Due to this,
The fuel injection valve 24 is installed in a lying position almost along the branch intake pipe section 19, and the intake expansion chamber 8 is located on an extension of the center line of the fuel injection valve 24.
(Tank portion 17) is located close to fuel injection valve 24 and fuel supply pipe 25.

さらに、上記各連通管部２０の第２通路１３に
制御弁１４が配設されること、および吸気拡大室
８（タンク部１７）が燃料噴射弁２４の中心延長
線上に位置することから、上記吸気系構造体１
６は、そのタンク部１７において、上記中心延長
線よりも下側の位置でかつ各第２通路１３，１
３…を含む吸気拡大室８の第２容積室８ｂの部分
と吸気拡大室８の第１容積室８ａとの間としての
上記仕切板９の位置で吸気拡大室８の長手方向に
沿つた分割面によつて上下に分割されて形成され
ていて、タンク部１７の上半部および各一体吸気
管部１８，１８…の上半部が一体成形された上側
分割体１６ａと、タンク部１７の下半部、一体吸
気管部１８，１８…の下半部、各分岐吸気管部１
９，１９…、各連通管部２０，２０…およびフラ
ンジ部２１が一体成形された下側分割体１６ｂと
からなり、両分割体１６ａ，１６ｂが上記仕切板
９を介して接合され、ボルト２６，２６…を下方
から挿入して締付けることにより気密的に結合さ
れてなる。 Furthermore, since the control valve 14 is disposed in the second passage 13 of each communication pipe section 20 and the intake expansion chamber 8 (tank section 17) is located on the central extension line of the fuel injection valve 24, the above-mentioned Intake system structure 1
6 is located at a position below the center extension line in the tank portion 17 and is connected to each of the second passages 13, 1.
3 along the longitudinal direction of the intake expansion chamber 8 at the position of the partition plate 9 between the second volume chamber 8b of the intake expansion chamber 8 including the second volume chamber 8b and the first volume chamber 8a of the intake expansion chamber 8. The upper divided body 16a is formed by being divided into upper and lower parts by a surface, and the upper half of the tank part 17 and the upper half of each integral intake pipe part 18, 18... are integrally molded, and the upper divided body 16a of the tank part 17 Lower half part, lower half part of integral intake pipe parts 18, 18..., each branch intake pipe part 1
9, 19..., each communicating pipe part 20, 20... and a lower divided body 16b integrally formed with the flange part 21, both divided bodies 16a, 16b are joined via the partition plate 9, and bolts 26 , 26... are inserted from below and tightened to form an airtight connection.

加えて、上記吸気系構造体１２の各連通管部２
０において、上記各制御弁１４は、第２通路１３
の独立吸気通路６との接続部に、独立吸気通路６
側に近傍して、かつ第１図で仮想線で示す如くそ
の開弁状態で弁体１４ａのほぼ下半部が独立吸気
通路６に張出すように設置されている。また、上
記各第２通路１３は、第４図に詳示するように、
第２容積室８ｂ側からドリルで穴明け加工される
が、その径つまり通路面積が独立吸気通路６より
も少なくとも上記制御弁１４のバルブシヤフト１
５の投影面積分大きくなるように形成されている
とともに、独立吸気通路６と交差する交差角つま
り第１図に示す如く第２通路１３の通路軸線ｐが
独立吸気通路６の通路軸線ｑとなす角度θが90°
より小さい鋭角になるように形成されている。さ
らに、第４図に示す如く、上記第２通路１３と独
立吸気通路６との交差部分２７は滑らかなＲ（ア
ール）形状に形成されている。また、上記仕切板
９は上記第２通路１３が合流する独立吸気通路６
の通路軸線ｑとほぼ平行に、また閉弁状態におけ
る制御弁１４も上記通路軸線ｑとほぼ平行になる
ように設定されている。尚、上記各第２通路１３
の接続部の形状は、制御弁１４の閉弁時に着座す
る第２通路１３の弁座部分から独立吸気通路６ま
での間隔、つまり閉弁状態の制御弁１４と独立吸
気通路６との間の間隔が独立吸気通路６に対して
上流側部分で小さく下流側部分で大きくなるよう
に設定されているとともに、この下流側部分が大
きな曲率半径でもつて滑らかなＲ（アール）状の
曲面になるように設定されている。 In addition, each communication pipe portion 2 of the intake system structure 12
0, each of the control valves 14 is connected to the second passage 13.
The independent intake passage 6 is connected to the independent intake passage 6 at the connection part with the independent intake passage 6.
The valve body 14a is disposed near the side thereof, and substantially the lower half of the valve body 14a protrudes into the independent intake passage 6 in the open state as shown by the imaginary line in FIG. In addition, each of the second passages 13 is, as shown in detail in FIG.
A hole is drilled from the second volume chamber 8b side, and its diameter, that is, the passage area is at least larger than that of the independent intake passage 6 on the valve shaft 1 of the control valve 14.
5, and the intersection angle at which the second passage 13 intersects with the independent intake passage 6, that is, the passage axis p of the second passage 13 as shown in FIG. 1, forms the passage axis q of the independent intake passage 6. Angle θ is 90°
It is formed to have a smaller acute angle. Furthermore, as shown in FIG. 4, the intersection 27 between the second passage 13 and the independent intake passage 6 is formed into a smooth R shape. Further, the partition plate 9 has an independent intake passage 6 with which the second passage 13 joins.
The control valve 14 is set to be substantially parallel to the passage axis q, and the control valve 14 in the closed state is also substantially parallel to the passage axis q. In addition, each of the above-mentioned second passages 13
The shape of the connection part is determined by the distance from the valve seat part of the second passage 13, which is seated when the control valve 14 is closed, to the independent intake passage 6, that is, the distance between the control valve 14 in the closed state and the independent intake passage 6. The interval is set to be smaller in the upstream portion and larger in the downstream portion with respect to the independent intake passage 6, and the downstream portion has a smooth R-shaped curved surface with a large radius of curvature. is set to .

次に、上記実施例の作用について述べるに、各
制御弁１４が閉じて第２通路１３の閉塞によつて
第２容積室８ｂによる各独立吸気通路６，６…相
互間の連通が遮断されている状態では、各気筒４
の吸気行程で生じる負圧波が第１容積室８ａまで
伝播されてここで正圧波に反転されて反射され、
つまり比較的長い通路を通して上記負圧波および
その反射波が伝播することにより、低回転域にお
いてこのような圧力波の振動周期が吸気弁開閉周
期にマツチングすることになり、低回転域での吸
気の慣性効果が高められて、吸気充填効率が高め
られる。一方、上記各制御弁１４が開かれ第２通
路１３が開放されて、第２容積室８ｂにより各独
立吸気通路６，６…相互間が連通している状態で
は、各気筒４の吸気行程で生じる負圧波が上記第
２通路１３を介して第２容積室８ｂで反射されて
この負圧波および反射波の伝播に供される通路長
さが短くなることにより、高回転域で吸気慣性効
果が高められるとともに、この運転域では他の気
筒から伝播される圧力波も容積の小さい第２容積
室８ｂを介して減衰せずに有効に作用することに
なり、高回転域での充填効率が大幅に高められ
る。従つて、少なくとも高負荷時に、上記低回転
域と高回転域との吸気慣性効果が得られる各回転
数の中間回転数に相当する所定回転数を境に、こ
れより低回転側で制御弁１４を閉じ、これより高
回転側で制御弁１４を開くようにしておくことに
より、全回転域で吸気充填効率が高められて出力
を向上させることができる。特に、高回転域での
吸気充填効率は、従来のように単に吸気通路を短
縮させて慣性効果を高めるようにした場合と比べ
ても、気筒間の圧力伝播作用による気筒間干渉効
果でより一層高められることとなる。 Next, to describe the operation of the above embodiment, each control valve 14 closes and the second passage 13 is closed, thereby cutting off the communication between the independent intake passages 6, 6, . . . by the second volume chamber 8b. In this condition, each cylinder 4
The negative pressure wave generated during the intake stroke is propagated to the first volume chamber 8a, where it is reversed into a positive pressure wave and reflected,
In other words, as the negative pressure waves and their reflected waves propagate through a relatively long passage, the oscillation cycle of these pressure waves matches the intake valve opening/closing cycle in the low rotation range, and the intake air flow in the low rotation range is reduced. The inertia effect is enhanced and the intake air filling efficiency is enhanced. On the other hand, when each control valve 14 is opened and the second passage 13 is opened, and the independent intake passages 6, 6... are in communication with each other through the second volume chamber 8b, the intake stroke of each cylinder 4 is The generated negative pressure wave is reflected in the second volume chamber 8b via the second passage 13, and the passage length through which the negative pressure wave and the reflected wave propagate is shortened, thereby reducing the intake inertia effect in the high rotation range. At the same time, in this operating range, the pressure waves propagated from other cylinders also act effectively without being attenuated through the small volume second volume chamber 8b, and the charging efficiency in the high rotation range is greatly improved. It is raised to Therefore, at least when the load is high, the control valve 14 is activated on the lower rotation side after a predetermined rotation speed corresponding to the intermediate rotation speed between the respective rotation speeds at which the intake inertia effect between the low rotation range and the high rotation range is obtained. By closing the control valve 14 and opening the control valve 14 at higher rotation speeds, the intake air filling efficiency can be increased over the entire rotation range and the output can be improved. In particular, the intake air filling efficiency in the high rotation range is improved by the inter-cylinder interference effect due to the pressure propagation effect between the cylinders, compared to the conventional case where the intake passage was simply shortened to increase the inertia effect. It will be enhanced.

なお、以上のような作用を有効に発揮させるに
適当な第１および第２容積室８ａ，８ｂの大きさ
としては、第１容積室８ａは排気量の0.5倍以上
の容量とし、第２容積室８ｂは排気量の1.5倍以
下の容量としておくことが望ましい。さらに、上
記第２容積室８ｂは第１容積室８ａよりも容積を
小さくし、かつ第２容積室８ｂの断面積は各独立
吸気通路６の断面積よりも大きくしておくことが
望ましい。 The sizes of the first and second volume chambers 8a and 8b that are suitable for effectively exerting the above-mentioned effects are such that the first volume chamber 8a has a capacity of 0.5 times or more of the displacement, and the second volume It is desirable that the capacity of the chamber 8b is 1.5 times or less than the exhaust volume. Furthermore, it is desirable that the second volume chamber 8b has a smaller volume than the first volume chamber 8a, and that the cross-sectional area of the second volume chamber 8b is larger than the cross-sectional area of each independent intake passage 6.

そして、この場合、吸気系構造体１６における
吸気拡大室８（第１容積室８ａおよび第２容積室
８ｂ）を構成するタンク部１７と各独立吸気通路
６の上流側部分６ａを構成する一体吸気管部１８
と各独立吸気通路６の下流側部分６ｂを構成する
分岐吸気管部１９と各第２通路１３を構成する連
通管部２０とによつて、各独立吸気通路６が吸気
拡大室８の周囲に迂回しながらかつ吸気拡大室８
（タンク部１７）の構成壁の一部を利用して一体
的に形成されているとともに、各第２通路１３が
吸気拡大室８（第２容積室８ｂ）の構成壁の一部
と一体的に形成されているので、上記独立吸気通
路６の所要長さおよび吸気拡大室８の第１および
第２容積室８ａ，８ｂの各所要容積を得るに当つ
て、これら吸気系をコンパクトに小型のものに形
成することができる。また、タンク（吸気拡大室
８）を仕切板９で仕切つて第１容積室８ａと第２
容積室８ｂとを形成したこと、並びに該仕切板９
及び閉弁状態における制御弁１４を第２通路１３
が合流する独立吸気通路６の通路軸線ｑとほぼ平
行に設定したことにより、タンク全体をもコンパ
クトなものにすることができる。よつて、限られ
たスペース（エンジンルーム）内で上記所要長さ
および所要容積を十分に確保しながら、車載性の
向上を図ることができる。 In this case, the tank portion 17 that constitutes the intake expansion chamber 8 (the first volume chamber 8a and the second volume chamber 8b) in the intake system structure 16 and the integrated intake that constitutes the upstream portion 6a of each independent intake passage 6 Pipe part 18
The branch intake pipe section 19 that constitutes the downstream portion 6b of each independent intake passage 6 and the communication pipe section 20 that constitutes each second passage 13 allow each independent intake passage 6 to extend around the intake expansion chamber 8. While detouring and intake expansion chamber 8
(tank part 17), and each second passage 13 is integrally formed with a part of the wall that constitutes the intake expansion chamber 8 (second volume chamber 8b). Therefore, in order to obtain the required length of the independent intake passage 6 and the required volumes of the first and second volume chambers 8a and 8b of the intake expansion chamber 8, these intake systems can be made compact and small. It can be formed into something. In addition, the tank (intake expansion chamber 8) is partitioned by a partition plate 9 to form a first volume chamber 8a and a second volume chamber 8a.
The volume chamber 8b is formed, and the partition plate 9
and the control valve 14 in the closed state is connected to the second passage 13
By arranging the independent intake passages 6 to be substantially parallel to the passage axis q of the independent intake passages 6, the entire tank can be made compact. Therefore, it is possible to sufficiently secure the above-mentioned required length and required volume within a limited space (engine room) while improving vehicle mountability.

また、この場合、燃料噴射弁２４が上記分岐吸
気管部１９の下流端近傍つまり独立吸気通路６の
下流側においてその噴射燃料をその霧化を良好に
しながら燃焼室５に応答性良く供給すべく燃焼室
５に向けて装着されている関係上、該燃料噴射弁
２４の中心延長線上に近接して吸気系構造体１
６のタンク部１７（吸気拡大室８）が位置するこ
と、および上記各第２通路１３に制御弁１４を配
設することが必要である。そのため、本例では、
上記吸気系構造体１６はそのタンク部１７におい
て上記中心延長線よりも下側即ち分岐吸気管部
１９側の位置でかつ仕切板９の位置で吸気拡大室
８の長手方向に沿つた分割面で上下に上側分割体
１６ａと下側分割体１６ｂとに分割され両分割体
１６ａ，１６ｂが仕切板９を介して結合されてな
るので、下側分割体１６ｂをそのフランジ部２１
にてエンジン本体１に側方からのボルト２２によ
る締付けにより取付けたのち、該下側分割体１６
ｂの各分岐吸気管部１９の噴射弁装着孔２３に燃
料噴射弁２４を中心延長線方向から挿入し燃料
供給管２５を下側分割体１６ｂに固定することに
よつて各燃料噴射弁２４を取付けるとともに、下
側分割体１６ｂの各連通管部２０の第２通路１３
にその上方から制御弁１４の弁体１４ａを挿入し
てバルブシヤフト１５に固定し、しかる後上記下
側分割体１６ｂに対して仕切板９を介在させて上
側分割体１６ａを接合して下方からのボルト２６
の締付けにより両者１６ａ，１６ｂを一体に結合
することによつて、良好な成形性を確保し、かつ
上側および下側分割体１６ａ，１６ｂの組付けを
容易に行い得るのは勿論のこと、制御弁１４およ
び燃料噴射弁２４の組付けを容易に行うことがで
き、良好な組付け性を確保することができる。 Further, in this case, the fuel injection valve 24 is arranged near the downstream end of the branched intake pipe section 19, that is, on the downstream side of the independent intake passage 6, in order to supply the injected fuel to the combustion chamber 5 with good responsiveness while improving its atomization. Since the fuel injector 24 is mounted facing the combustion chamber 5, the intake system structure 1 is located close to the central extension line of the fuel injector 24.
It is necessary that the tank portion 17 (intake expansion chamber 8) of No. 6 be located therein, and that the control valve 14 be disposed in each of the second passages 13. Therefore, in this example,
The intake system structure 16 is located below the center extension line of the tank portion 17, that is, on the side of the branch intake pipe portion 19, and at a dividing plane along the longitudinal direction of the intake expansion chamber 8 at the position of the partition plate 9. Since it is vertically divided into an upper divided body 16a and a lower divided body 16b, and both divided bodies 16a and 16b are connected via a partition plate 9, the lower divided body 16b is connected to its flange portion 21.
After attaching to the engine body 1 by tightening the bolts 22 from the side, the lower divided body 16
Each fuel injection valve 24 is inserted into the injection valve mounting hole 23 of each branch intake pipe section 19 in b from the center extension line direction, and the fuel supply pipe 25 is fixed to the lower divided body 16b. At the same time, the second passage 13 of each communication pipe portion 20 of the lower divided body 16b
The valve body 14a of the control valve 14 is inserted from above and fixed to the valve shaft 15, and then the upper divided body 16a is joined to the lower divided body 16b with the partition plate 9 interposed therebetween, and then inserted from below. bolt 26
By joining the two parts 16a and 16b together by tightening, it is possible to ensure good formability and to easily assemble the upper and lower divided bodies 16a and 16b. The valve 14 and the fuel injection valve 24 can be easily assembled, and good assembly performance can be ensured.

しかも、上記上側分割体１６ａと下側分割体１
６ｂとの結合は、下方からのボルト２６の締付け
によつて行われるので、その良好な組付け性を確
保しながら、上述の如くタンク部１７（吸気拡大
室８）におけるエンジン側の側辺上部の膨出形成
が可能となつて、吸気拡大室８の特に第１容積室
８ａの容積を十分に確保できる利点もある。ま
た、上記第２容積室８ｂは吸気系構造体１６のタ
ンク部１７を仕切板９で上下に分割することによ
つて第１容積室８ａに並設され、第１容積室８ａ
の構成壁と一部（仕切板９）を共用して形成され
ているので、上記吸気系のコンパクト化を一層図
ることができる。 Moreover, the upper divided body 16a and the lower divided body 1
6b is achieved by tightening the bolt 26 from below, while ensuring good assemblability, the upper part of the side of the tank part 17 (intake expansion chamber 8) on the engine side is secured as described above. There is also the advantage that a sufficient volume of the intake expansion chamber 8, particularly the first volume chamber 8a, can be secured. Further, the second volume chamber 8b is arranged in parallel with the first volume chamber 8a by dividing the tank portion 17 of the intake system structure 16 into upper and lower parts with a partition plate 9, and is arranged in parallel with the first volume chamber 8a.
Since it is formed by sharing a part (partition plate 9) with the constituent walls of , the intake system can be made more compact.

さらに、上記第２通路１３はその通路面積が独
立吸気通路６よりも大きく形成されていて、該第
２通路１３に配置した制御弁１４のバルブシヤフ
ト１５による面積の減少分が補償されるので、制
御弁１４の開弁時、第２通路１３を流れる吸気の
流通抵抗を小さいものにすることができる。しか
も、上記第２通路１３と独立吸気通路６との交差
角θが鋭角であるので、制御弁１４が開いている
高回転域において、第２容積室８ｂからの吸気が
第２通路１３から独立吸気通路６に流通抵抗少な
くスムーズに導入されるとともに、上記第２通路
１３と独立吸気通路６との交差部分２７が滑らか
なＲ形状であるので、該交差部分２７の通路断面
積の変化が小さくかつ緩かなものとなり、流通抵
抗およびその変化が小さく抑えられることにな
る。この結果、第２通路１３から独立吸気通路６
への吸気の流れがスムーズとなり、上記第２容積
室８ｂの容積が小さいことと相俟つて、高回転域
での吸気慣性効果は無論のこと、気筒間干渉効果
が有効にかつ十分に発揮されて吸気の充填効率の
向上を確保することができる。 Furthermore, the second passage 13 is formed to have a passage area larger than that of the independent intake passage 6, and the reduction in area due to the valve shaft 15 of the control valve 14 disposed in the second passage 13 is compensated for. When the control valve 14 is opened, the flow resistance of the intake air flowing through the second passage 13 can be reduced. Moreover, since the intersection angle θ between the second passage 13 and the independent intake passage 6 is an acute angle, the intake from the second volume chamber 8b is independent from the second passage 13 in the high rotation range when the control valve 14 is open. It is smoothly introduced into the intake passage 6 with little flow resistance, and since the intersection 27 between the second passage 13 and the independent intake passage 6 has a smooth rounded shape, the change in the passage cross-sectional area of the intersection 27 is small. In addition, the flow resistance becomes gentle, and the flow resistance and its changes are kept small. As a result, from the second passage 13 to the independent intake passage 6
The flow of intake air into the engine becomes smooth, and together with the small volume of the second volume chamber 8b, not only the intake inertia effect in the high rotation range but also the inter-cylinder interference effect are effectively and fully exerted. This makes it possible to ensure an improvement in the filling efficiency of intake air.

尚、本考案は上記実施例に限定されるものでは
なく、その他種々の変形例をも包含するものであ
る。例えば、上記実施例の如く吸気拡大室８を第
１容積室８ａと第２容積室８ｂとに区画して低回
転域と高回転域とでそれぞれ吸気慣性効果を得る
とともに、特に高回転域で気筒相互間の圧力波の
伝播により吸気の充填効率を一層高めるようにし
た吸気系の他に、上記実施例における仕切板９に
上下の第１容積室８ａと第２容積室８ｂとを連通
する連通孔を設けて、さらに低回転域で上下の両
容積室８ａ，８ｂ間での吸気圧力振動を利用して
吸気の充填効率を一層高めるようにした吸気系に
対しても適用可能である。 It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. For example, as in the above embodiment, the intake expansion chamber 8 is divided into a first volume chamber 8a and a second volume chamber 8b to obtain intake inertia effects in the low rotation range and high rotation range, and particularly in the high rotation range. In addition to the intake system in which the filling efficiency of intake air is further increased by the propagation of pressure waves between cylinders, the first volume chamber 8a and the second volume chamber 8b located above and below are connected to the partition plate 9 in the above embodiment. The present invention can also be applied to an intake system in which a communication hole is provided and the intake air filling efficiency is further increased by utilizing intake air pressure vibration between the upper and lower volume chambers 8a and 8b in a low rotation range.

また、本考案は以上の実施例の如く４気筒エン
ジンに限らず、他の多気筒エンジン、例えば５気
筒エンジンや６気筒エンジンにも適用することが
できるのは勿論である。 Furthermore, it goes without saying that the present invention is not limited to the four-cylinder engine as in the embodiments described above, but can also be applied to other multi-cylinder engines, such as five-cylinder engines and six-cylinder engines.

（考案の効果） 以上説明したように、本考案によれば、タンク
全体をコンパクトにしながら、第２容積室の容積
をできるだけ小さくして高回転域での気筒間干渉
効果を促進するとともに、第２通路の独立吸気通
路との交差部の吸気抵抗を小さくし、上記第２容
積室の容積が小さいことと相俟つて他気筒への圧
力波の伝播エネルギーの減衰を小さくでき、十分
な気筒間干渉効果を得ることができるので、低回
転域の吸気慣性効果と高回転域での吸気慣性効果
及び気筒間干渉効果との発揮を有効に行つて吸気
充填効率の向上を図ることができるものである。(Effects of the invention) As explained above, according to the invention, while making the entire tank compact, the volume of the second volume chamber is made as small as possible to promote the inter-cylinder interference effect in the high rotation range. The intake resistance at the intersection with the independent intake passage of the two passages is reduced, and together with the small volume of the second volume chamber, the attenuation of the propagation energy of pressure waves to other cylinders can be reduced, and a sufficient gap between the cylinders can be achieved. Since the interference effect can be obtained, the intake inertia effect in the low rotation range, the intake inertia effect in the high rotation range, and the inter-cylinder interference effect can be effectively exerted, and the intake air filling efficiency can be improved. be.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図〜第４図は本考案の一実施例を示し、第
１図は第３図の−線における縦断側面図、第
２図は第３図の−線における縦断側面図、第
３図は一部破断した平面図、第４図は第１図の
−線における拡大断面図である。 １……エンジン本体、４……気筒、６……独立
吸気通路、８……吸気拡大室、８ａ……第１容積
室、８ｂ……第２容積室、９……仕切板、１３…
…第２通路、１４……制御弁、１６……吸気系構
造体、１７……タンク部、１８……一体吸気管
部、１９……分岐吸気管部、２０……連通管部、
２７……交差部分。 1 to 4 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional side view taken along the - line in FIG. 3, FIG. 2 is a longitudinal sectional side view taken along the - line in FIG. 3, and FIG. 4 is a partially broken plan view, and FIG. 4 is an enlarged sectional view taken along the line - in FIG. 1. DESCRIPTION OF SYMBOLS 1... Engine body, 4... Cylinder, 6... Independent intake passage, 8... Intake expansion chamber, 8a... First volume chamber, 8b... Second volume chamber, 9... Partition plate, 13...
... Second passage, 14 ... Control valve, 16 ... Intake system structure, 17 ... Tank section, 18 ... Integral intake pipe section, 19 ... Branch intake pipe section, 20 ... Communication pipe section,
27...Intersection.

Claims (1)

【実用新案登録請求の範囲】 タンク内部を仕切板で仕切つて第１容積室と該
第１容積室よりも容積の小さい第２容積室とに区
画し、 上記第１容積室と各気筒とを互いに独立した気
筒別の各独立吸気通路で接続するとともに、該各
独立吸気通路の途中をそれぞれ上記第２容積室に
連通する第２通路を設けて該各第２通路と上記第
２容積室とにより上記各独立吸気通路を相互に連
通し、 上記各第２通路にエンジンの運転状態に応じて
開閉する制御弁を設け、 上記各第２通路は、上記各独立吸気通路よりも
通路面積が大きく、かつ該各独立吸気通路と交差
する交差角が鋭角になるように形成されていると
ともに、上記第２通路と独立吸気通路との交差部
分は滑らかな形状に形成されており、 上記仕切板は上記第２通路が合流する独立吸気
通路部分の通路軸線とほぼ平行になるように設け
られているとともに、上記制御弁はその閉弁状態
において上記第２通路が合流する独立吸気通路部
分の通路軸線とほぼ平行になるように設けられて
いることを特徴とするエンジンの吸気装置。[Scope of Claim for Utility Model Registration] The inside of the tank is divided by a partition plate into a first volume chamber and a second volume chamber whose volume is smaller than the first volume chamber, and the first volume chamber and each cylinder are separated from each other. The respective independent intake passages for each cylinder are connected to each other, and a second passage is provided in the middle of each of the independent intake passages to communicate with the second volume chamber, so that the second passage and the second volume chamber are connected to each other. The independent intake passages are connected to each other, and each of the second passages is provided with a control valve that opens and closes depending on the operating state of the engine, and each of the second passages has a passage area larger than that of each of the independent intake passages. , and the intersecting angles at which the independent intake passages intersect each other are acute angles, and the intersections between the second passages and the independent intake passages are formed in a smooth shape, and the partition plate The control valve is provided so as to be substantially parallel to the passage axis of the independent intake passage portion where the second passage joins, and the control valve is arranged so as to be substantially parallel to the passage axis of the independent intake passage portion where the second passage joins. An engine intake device characterized by being provided so as to be substantially parallel to the .