JP2632207B2 - Intake device for internal combustion engine - Google Patents

Description

【発明の詳細な説明】 A.発明の目的 （１） 産業上の利用分野 本発明は、燃焼室に臨んで機関本体に設けられる第１
および第２吸気弁口を開閉可能な第１および第２吸気弁
が機関本体に配設され、第１および第２吸気弁には、機
関の低速運転と高速運転とで作動状態を変化可能な動弁
装置が連結される内燃機関の吸気装置に関する。DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Industrial application field The present invention relates to a first engine provided in an engine body facing a combustion chamber.
And first and second intake valves capable of opening and closing a second intake valve port are provided in the engine body, and the first and second intake valves are capable of changing the operating state between low-speed operation and high-speed operation of the engine. The present invention relates to an intake device for an internal combustion engine to which a valve gear is connected.

（２） 従来の技術 従来、かかる装置は、たとえば特開昭61−252832号公
報等により公知である。(2) Prior Art Conventionally, such an apparatus is known, for example, from JP-A-61-252832.

（３） 発明が解決しようとする課題 ところで、上記従来のものでは、機関低速運転時には
両吸気弁を低速運転に対応した作動態様で作動させると
ともに吸気通路面積をスワール制御弁で小さくしてスワ
ール効果を発揮させることにより低速運転でも燃費低減
を図り、また機関高速運転時には両吸気弁を高速運転に
対応した作動態様で作動させるとともに吸気通路面積を
スワール制御弁で大きくして充填効率の向上により出力
増大を図るようにしている。(3) Problems to be Solved by the Invention By the way, in the above-mentioned conventional art, at the time of low-speed operation of the engine, both intake valves are operated in an operation mode corresponding to low-speed operation, and the swirl effect is reduced by reducing the intake passage area with the swirl control valve. To reduce fuel consumption even at low speeds, and to operate both intake valves in an operation mode corresponding to high speed operation at high engine speeds, while increasing the intake passage area with a swirl control valve to improve the filling efficiency and output. We are trying to increase it.

ところが上記従来のものでは、低速運転時に一方の吸
気弁口に通じる吸気ポートをスワール制御弁により遮断
して他方の吸気弁口のみから混合気を燃焼室に導入する
ことによりスワール効果が得られるようにしているが、
一方の吸気弁口を開閉可能な吸気弁は低速運転に対応し
た作動態様で開閉作動しており、燃焼室に通じる一方の
吸気弁口がそのように開閉すると燃焼室内のスワールが
乱されることになる。しかも混合気の燃焼室への吸気制
御に実質的に何の関与もしていない前記一方の吸気弁を
開閉作動するので、その分だけ駆動力が増えることにな
る。さらに、上記従来のものでは吸気ポートに配設され
たスワール制御弁がバタフライ式弁であり、全開状態で
吸気通路内に弁体が存在するので高速運転時には該スワ
ール制御弁により吸気抵抗が増え、出力向上の阻害因子
となる。However, in the above conventional apparatus, the swirl effect can be obtained by shutting off the intake port communicating with one intake valve port by the swirl control valve during low-speed operation and introducing the air-fuel mixture into the combustion chamber only from the other intake valve port. But
The intake valve that can open and close one intake valve port is operated to open and close in an operation mode corresponding to low-speed operation, and if the one intake valve port that opens to the combustion chamber opens and closes that way, the swirl in the combustion chamber may be disturbed. become. In addition, since the one intake valve, which does not substantially participate in controlling the intake of the air-fuel mixture into the combustion chamber, is opened and closed, the driving force is increased accordingly. Furthermore, in the above-mentioned conventional one, the swirl control valve disposed in the intake port is a butterfly valve, and since the valve element is present in the intake passage in the fully opened state, the intake resistance increases due to the swirl control valve during high-speed operation, It becomes an inhibitor of output improvement.

本発明は、かかる事情に鑑みてなされたものであり、
低速運転時に燃焼室でのスワール発生に悪影響が及ぶこ
とを回避しながら駆動力低減を図り、しかも高速運転時
には吸気抵抗の低減を可能とした内燃機関の吸気装置を
提供することを目的とする。The present invention has been made in view of such circumstances,
It is an object of the present invention to provide an intake device for an internal combustion engine that reduces driving force while avoiding adverse effects on swirl generation in a combustion chamber during low-speed operation, and that can reduce intake resistance during high-speed operation.

B.発明の構成 （１） 課題を解決するための手段 本発明によれば、機関本体には、第１および第２吸気
弁口にそれぞれ通じる第１および第２吸気ポートが設け
られ、第１吸気ポートには、機関の低速運転時に第１吸
気弁口に混合気を螺旋状に導くべき位置と機関の高速運
転時に第１吸気ポートを全開にすべく該第１吸気ポート
の壁面側に回動する位置との間で回動可能は可変ウイン
グが配設され、動弁装置では、機関低速運転時に第２吸
気弁を休止もしくはほぼ休止させながら第１吸気弁を低
速運転に対応した作動態様で作動させる状態と、機関高
速運転時に第１および第２吸気弁を高速運転に対応した
作動態様で作動させる状態とを切換可能に構成される。B. Configuration of the Invention (1) Means for Solving the Problems According to the present invention, the engine main body is provided with first and second intake ports communicating with the first and second intake valve ports, respectively. The intake port has a position at which the air-fuel mixture should be spirally guided to the first intake valve port during low-speed operation of the engine and a wall facing the first intake port to fully open the first intake port during high-speed operation of the engine. A variable wing that is rotatable between a moving position and a moving position is provided. In the valve operating device, the first intake valve is operated at a low speed while the second intake valve is stopped or almost stopped during a low speed operation of the engine. And a state in which the first and second intake valves are operated in an operation mode corresponding to high-speed operation during high-speed operation of the engine.

（２） 作用 上記構成によれば、機関の低速運転時には第２吸気弁
が休止もしくはほぼ休止するとともに第１吸気弁が低速
運転に対応した作動態様で開閉作動し、しかも可変ウイ
ングが第１吸気弁口に混合気を螺旋状に導くべき位置ま
で回動するので、第１吸気ポートから第１吸気弁口を経
て比較的高速でかつ旋回しながら燃焼室内に混合気が導
入され、この際、第２吸気弁が休止もしくはほぼ休止し
ているので燃焼室でのスワール発生に悪影響が及ぶこと
はなく、第２吸気弁を休止する分だけ駆動力が減少す
る。また機関の高速運転時には第１および第２吸気弁が
高速運転に対応した作動態様で開閉作動し、第１および
第２吸気ポートから第１および第２吸気弁口を経て燃焼
室内に比較的大量の混合気が導入されることになり、し
かも可変ウイングは第１吸気ポートの壁面側に回動して
いるので、該可変ウイングにより吸気抵抗の増加は小さ
く抑えられる。(2) Operation According to the above configuration, at the time of low-speed operation of the engine, the second intake valve is stopped or almost stopped, and the first intake valve is opened and closed in an operation mode corresponding to the low-speed operation. Since the air-fuel mixture rotates to the position where the air-fuel mixture should be spirally guided to the valve port, the air-fuel mixture is introduced into the combustion chamber from the first intake port through the first intake valve port at a relatively high speed and while turning. Since the second intake valve is at rest or almost at rest, the generation of swirl in the combustion chamber is not adversely affected, and the driving force is reduced by the amount at which the second intake valve is stopped. During high-speed operation of the engine, the first and second intake valves open and close in an operation mode corresponding to the high-speed operation, and a relatively large amount of gas enters the combustion chamber from the first and second intake ports via the first and second intake valve ports. Is introduced, and the variable wing pivots toward the wall surface of the first intake port, so that the increase in the intake resistance is suppressed to a small degree by the variable wing.

（３） 実施例 以下、図面により本発明の一実施例について説明する
と、先ず第１図および第２図において、この車両搭載用
DOHC型多気筒内燃機関では、シリンダブロック１内に複
数のシリンダ２が直列に並んで設けられ、機関本体Ｅを
構成すべくシリンダブロック１の上端に結合されるシリ
ンダヘッド３と、各シリンダ２に摺動可能に嵌合される
ピストン４との間には燃焼室５がそれぞれ画成される。
またシリンダヘッド３には、各燃焼室５の天井面を形成
する部分に、第１および第２吸気弁口6a,6bならびに第
１および第２排気弁口7a,7bが設けられる。一方、シリ
ンダヘッド３には、該シリンダヘッド３における一方の
側面に開口端を共通にして開口される第１および第２吸
気ポート8,9が穿設されており、両吸気ポート8,9はほぼ
直線状に延びて第１および第２吸気弁口6a,6bに連な
る。また第１および第２排気弁口7a,7bはほぼ直線状の
第１および第２排気ポート10,11に連なり、両排気ポー
ト10,11はシリンダヘッド３の他方の側面に共通に開口
する。(3) Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, in FIGS.
In a DOHC type multi-cylinder internal combustion engine, a plurality of cylinders 2 are provided in a cylinder block 1 in series, and a cylinder head 3 coupled to an upper end of the cylinder block 1 to form an engine main body E; Combustion chambers 5 are respectively defined between the slidably fitted pistons 4.
Further, the cylinder head 3 is provided with first and second intake valve ports 6a, 6b and first and second exhaust valve ports 7a, 7b in a portion forming a ceiling surface of each combustion chamber 5. On the other hand, the cylinder head 3 is provided with first and second intake ports 8, 9 that are opened on one side surface of the cylinder head 3 with an open end in common. It extends substantially linearly and continues to the first and second intake valve ports 6a, 6b. The first and second exhaust valve ports 7a, 7b are connected to the substantially linear first and second exhaust ports 10, 11, and both the exhaust ports 10, 11 are commonly opened on the other side surface of the cylinder head 3.

シリンダヘッド３の各シリンダ２に対応する部分に
は、第１および第２吸気弁口6a,6bをそれぞれ開閉可能
な第１および第２吸気弁12a,12bと、第１および第２排
気弁口7a,7bをそれぞれ開閉可能な第１および第２排気
弁13a,13bとを案内すべく、一対ずつ２組のガイド筒14
…がそれぞれ嵌合、固定されており、それらのガイド筒
14…から上方に突出した各吸気弁12a,12bおよび各排気
弁13a,13bの上端にそれぞれ設けられる鍔部15…と、シ
リンダヘッド３との間には弁ばね16…がそれぞれ縮設さ
れ、これらの弁ばね16…により各吸気弁12a,12bおよび
各排気弁13a,13bは、上方すなわち閉弁方向に付勢され
る。A portion corresponding to each cylinder 2 of the cylinder head 3 includes first and second intake valves 12a and 12b capable of opening and closing the first and second intake valve ports 6a and 6b, respectively, and first and second exhaust valve ports. In order to guide the first and second exhaust valves 13a and 13b capable of opening and closing the respective 7a and 7b, two pairs of guide cylinders 14 are provided.
… Are fitted and fixed respectively, and their guide tubes
Valve springs 16 are contracted between the cylinder head 3 and the flanges 15 provided at the upper ends of the intake valves 12a, 12b and the exhaust valves 13a, 13b projecting upward from the cylinder head 3, respectively. Each of the intake valves 12a and 12b and each of the exhaust valves 13a and 13b are biased upward, that is, in the valve closing direction by the valve springs 16.

第１吸気ポート８には、可変ウイング17が回動可能に
配設される。この可変ウイング17は、シリンダヘッド３
に回動可能に支承された軸18に基端が固着されるもので
あり、軸18には駆動モータＭが連結される。而して可変
ウイング17は、機関の低速運転時に第１吸気弁口6aに混
合気を螺旋状に導くべき位置（第２図の鎖線で示す位
置）と機関の高速運転時に第１吸気ポート８を全開にす
べく第１吸気ポート８の壁面側に回動する位置（第２図
の破線で示す位置）との間で回動可能なものであり、駆
動モータＭは、機関の運転状態に応じて可変ウイング17
が上述の位置となるように軸18を回動駆動する。In the first intake port 8, a variable wing 17 is rotatably disposed. This variable wing 17 is used for the cylinder head 3
A base end is fixed to a shaft 18 rotatably supported on the shaft 18, and a drive motor M is connected to the shaft 18. The variable wing 17 is provided at a position where the air-fuel mixture is spirally guided to the first intake valve port 6a at the time of low-speed operation of the engine (a position shown by a chain line in FIG. 2) and at the time of high-speed operation of the engine. Can be turned between a position (the position shown by a broken line in FIG. 2) that turns to the wall surface side of the first intake port 8 so as to fully open the drive motor M. Variable wing 17 depending on
The shaft 18 is rotationally driven so that the position is at the above-mentioned position.

各吸気弁12a,12bには、機関の運転状態に応じた作動
態様で作動せしめられるべく吸気弁側動弁装置19が連結
され、各排気弁13a,13bには、機関の運転状態に応じた
作動態様で作動せしめられるべく排気弁側動弁装置20が
連結される。Each intake valve 12a, 12b is connected to an intake valve side valve operating device 19 to be operated in an operation mode according to the operating state of the engine, and each exhaust valve 13a, 13b is connected to an operating state of the engine according to the operating state of the engine. The exhaust valve side valve gear 20 is connected to be operated in the operation mode.

第３図および第４図を併せて参照して、吸気弁側動弁
装置19は、機関のクランク軸（図示せず）から1/2の減
速比で回転駆動されるカムシャフト21と、カムシャフト
21に設けられる低速用カム22、高速用カム23および休止
用カム24と、カムシャフト21と平行にして固定配置され
るロッカシャフト25と、ロッカシャフト25に枢支される
第１駆動ロッカアーム26、自由ロッカアーム27および第
２駆動ロッカアーム28と、各ロッカアーム26,27,28間に
設けられる油圧式連結切換手段29とを備える。Referring to FIG. 3 and FIG. 4 together, the intake valve-side valve operating device 19 includes a camshaft 21 that is rotationally driven at a reduction ratio of 1/2 from a crankshaft (not shown) of the engine, and a camshaft 21. shaft
A low-speed cam 22, a high-speed cam 23 and a resting cam 24 provided on the camshaft 21, a rocker shaft 25 fixedly arranged in parallel with the camshaft 21, a first drive rocker arm 26 pivotally supported by the rocker shaft 25, A free rocker arm 27 and a second drive rocker arm 28, and a hydraulic connection switching means 29 provided between the rocker arms 26, 27, 28 are provided.

カムシャフト21には第１吸気弁12aに対応した位置に
低速用カム22が、第２吸気弁12bに対応した位置に休止
用カム24が、また両カム22,24間に高速用カム23がそれ
ぞれ一体化される。低速用カム22は機関の低速運転時に
対応した形状を有するものであり、ベース円部22aと該
ベース円部22aから半径方向外方に突出した高位部22bと
を有する。また高速用カム23は、機関の高速運転時に対
応した形状を有するものであり、ベース円部23aと、前
記高位部22bよりも突出量および中心角範囲を大として
ベース円部23aから突出した高位部23bとを有する。さら
に休止用カム24は、ベース円部24aと、該ベース円部24a
から半径方向外方にわずかに突出する高位部24bとを有
するが、高位部24bは、第２吸気弁12bを実質的に休止状
態と判断し得る程度にわずかに開弁作動させる程度の突
出量および中心角範囲を有するようにして、前記低速用
カム22の高位部22bおよび高速用カム23の高位部23bに対
応する位置でベース円部24aから突出される。The camshaft 21 has a low-speed cam 22 at a position corresponding to the first intake valve 12a, a pause cam 24 at a position corresponding to the second intake valve 12b, and a high-speed cam 23 between the two cams 22, 24. Each is integrated. The low-speed cam 22 has a shape corresponding to the low-speed operation of the engine, and has a base circular portion 22a and a high-order portion 22b protruding radially outward from the base circular portion 22a. Further, the high-speed cam 23 has a shape corresponding to the high-speed operation of the engine, and has a base circular portion 23a and a protruding amount and a central angle range larger than those of the high portion 22b. A portion 23b. Further, the rest cam 24 includes a base circle portion 24a and the base circle portion 24a.
And a high-level portion 24b slightly projecting radially outward from the high-level portion 24b. And has a center angle range, and protrudes from the base circle portion 24a at a position corresponding to the high portion 22b of the low speed cam 22 and the high portion 23b of the high speed cam 23.

一方、ロッカシャフト25は、カムシャフト21よりも下
方位置で、該カムシャフト21と平行な軸線を有してシリ
ンダヘッド３に固定的に保持される。このロッカシャフ
ト25には、第１吸気弁12aに連動、連結される第１駆動
ロッカアーム26と、第２吸気弁12bに連動、連結される
第２駆動ロッカアーム28と、第１および第２駆動ロッカ
アーム26,28間に配置される自由ロッカアーム27とが相
互に隣接してそれぞれ枢支される。On the other hand, the rocker shaft 25 is fixed to the cylinder head 3 at a position below the camshaft 21 and has an axis parallel to the camshaft 21. The rocker shaft 25 includes a first drive rocker arm 26 linked to and connected to the first intake valve 12a, a second drive rocker arm 28 linked to and connected to the second intake valve 12b, and first and second drive rocker arms. A free rocker arm 27 disposed between 26 and 28 is pivotally supported adjacent to each other.

第１および第２駆動ロッカアーム26,28にはタペット
ねじ31がそれぞれ進退可能に螺合されており、これらの
タペットねじ31が対応する吸気弁12a,12bの上端に当接
する。したがって両吸気弁12a,12bは両駆動ロッカアー
ム26,28の揺動作動に応じて作動することになる。Tappet screws 31 are respectively screwed to the first and second drive rocker arms 26 and 28 so as to be able to advance and retreat, and these tappet screws 31 contact the upper ends of the corresponding intake valves 12a and 12b. Therefore, both intake valves 12a and 12b operate according to the swinging movement of both drive rocker arms 26 and 28.

自由ロッカアーム27は、シリンダヘッド３との間に介
装した弾発付勢手段30（第１図参照）により高速用カム
23に摺接する方向に弾発付勢される。The free rocker arm 27 is moved by a resilient biasing means 30 (see FIG. 1) interposed between the free rocker arm 27 and the high-speed cam.
It is resiliently biased in the direction of sliding contact with 23.

油圧式連結切換手段29は、第１駆動ロッカアーム26お
よび自由ロッカアーム27間を連結可能な第１切換ピン32
と、自由ロッカアーム27および第２駆動ロッカアーム28
間を連結可能な第２切換ピン33と、第１および第２切換
ピン32,33の移動を規制する規制ピン34と、各ピン32〜3
4を連結解除側に付勢する戻しばね35とを備える。The hydraulic connection switching means 29 includes a first switching pin 32 capable of connecting between the first drive rocker arm 26 and the free rocker arm 27.
And the free rocker arm 27 and the second drive rocker arm 28
A second switching pin 33 capable of connecting between them, a regulating pin 34 for regulating movement of the first and second switching pins 32 and 33, and each of the pins 32 to 3
And a return spring 35 for urging the connection spring 4 toward the connection release side.

第１駆動ロッカアーム26には、自由ロッカアーム27側
に開放した有底の第１ガイド穴36がロッカシャフト25と
平行に穿設されており、円柱状に形成された第１切換ピ
ン32が第１ガイド穴36に摺動可能に嵌合され、第１切換
ピン32の一端と第１ガイド穴36の閉塞端との間に油圧室
37が画成される。しかも第得駆動ロッカアーム26には油
圧室37に連通する通路38が穿設され、ロッカシャフト25
には給油路39が設けられる。該給油路39は第１駆動ロッ
カアーム26の揺動状態にかかわらず通路38を介して油圧
室37に常時連通する。しかも給油路39は、制御弁40を介
して油圧供給源41に接続されており、制御弁40は油圧供
給源41からの油圧を高、低に切換えて給油路39すなわち
油圧室37に供給可能である。The first drive rocker arm 26 has a bottomed first guide hole 36 opened to the free rocker arm 27 side in parallel with the rocker shaft 25, and a first switching pin 32 formed in a columnar shape. The hydraulic chamber is slidably fitted in the guide hole 36 and is provided between one end of the first switching pin 32 and the closed end of the first guide hole 36.
37 is defined. In addition, a passage 38 communicating with the hydraulic chamber 37 is formed in the first drive rocker arm 26, and the rocker shaft 25
Is provided with a refueling passage 39. The oil supply passage 39 is always in communication with the hydraulic chamber 37 via the passage 38 regardless of the swinging state of the first drive rocker arm 26. Moreover, the oil supply passage 39 is connected to a hydraulic supply 41 via a control valve 40, and the control valve 40 can switch the oil pressure from the oil supply 41 to high or low and supply the oil to the oil supply passage 39, that is, the hydraulic chamber 37. It is.

自由ロッカアーム27には、第１ガイド穴36に対応する
ガイド孔42がロッカシャフト25と平行にして両側面間に
わたって穿設されており、第１切換ピン32の他端に一端
が当接される第２切換ピン33がガイド孔42に摺動可能に
嵌合される。A guide hole 42 corresponding to the first guide hole 36 is formed in the free rocker arm 27 so as to be parallel to the rocker shaft 25 and between both side surfaces, and one end of the first switch pin 32 abuts on the other end. The second switching pin 33 is slidably fitted in the guide hole.

第２駆動ロッカアーム28には、前記ガイド孔42に対応
する有底の第２ガイド穴43が自由ロッカアーム27側に開
放してロッカシャフト25と平行に穿設されており、第２
切換ピン33の他端に当接する円盤状の規制ピン34が第２
ガイド穴43に摺動可能に嵌合される。この第２ガイド穴
43の閉塞端には筒状の案内部材44が挿通固定されてお
り、該案内部材44内に移動自在に挿通されるロッド45が
規制ピン34に同軸にかつ一体に設けられる。而して戻し
ばね35は、第２ガイド穴43の閉塞端および規制ピン34間
に縮設されており、この戻しばね35のばね力により相互
に当接した前記各ピン32,33,34が油圧室37側に付勢され
る。A second guide hole 43 having a bottom corresponding to the guide hole 42 is opened in the second drive rocker arm 28 toward the free rocker arm 27 and formed in parallel with the rocker shaft 25.
The disc-shaped regulating pin 34 that contacts the other end of the switching pin 33 is the second
It is slidably fitted in the guide hole 43. This second guide hole
A cylindrical guide member 44 is inserted and fixed to the closed end of 43, and a rod 45 movably inserted into the guide member 44 is provided coaxially and integrally with the regulating pin 34. The return spring 35 is contracted between the closed end of the second guide hole 43 and the restricting pin 34, and the pins 32, 33, and 34, which are in contact with each other due to the spring force of the return spring 35, are connected to each other. It is urged to the hydraulic chamber 37 side.

かかる油圧式連結切換手段29では、油圧室37の油圧が
高くなることにより、第１切換ピン32がガイド孔42に嵌
合するとともに第２切換ピン33が第２ガイド穴43に嵌合
して、各ロッカアーム26,27,28が連結される。また油圧
室37の油圧が低くなると戻しばね35のばね力により第１
切換ピン32が第２切換ピン33との当接面を第１駆動ロッ
カアーム26および自由ロッカアーム27間に対応させる位
置まで戻り、第２切換ピ33が規制ピン34との当接面を自
由ロッカアーム27および第２駆動ロッカアーム28間に対
応させる位置まで戻るので各ロッカアーム26,27,28の連
結状態が解除される。In the hydraulic connection switching means 29, the first switching pin 32 is fitted in the guide hole 42 and the second switching pin 33 is fitted in the second guide hole 43 by increasing the hydraulic pressure in the hydraulic chamber 37. The respective rocker arms 26, 27, 28 are connected. When the oil pressure in the hydraulic chamber 37 decreases, the first force is generated by the spring force of the return spring 35.
The switching pin 32 returns to the position where the contact surface with the second switching pin 33 corresponds between the first drive rocker arm 26 and the free rocker arm 27, and the second switching pin 33 changes the contact surface with the regulating pin 34 into the free rocker arm 27. And the position returns to the position corresponding to the position between the second drive rocker arms 28, so that the connected state of the rocker arms 26, 27, 28 is released.

したがって吸気側動弁装置19では、油圧式連結切換手
段29を連結解除状態としたときに、第１吸気弁12aが低
速用カム22の形状に応じた態様で第５図の曲線L_IAで示
すように開閉作動し、第２吸気弁12bが休止用カム24の
形状に応じた態様、すなわち休止用カム24の高位部24b
に対応する位置で第５図の曲線L_IBで示すように実質的
に休止状態となる程度に作動する。また油圧式連結手段
29を連結状態としたときには、第１および第２吸気弁12
a,12bが第５図の曲線H_Iで示すように、高速用カム23の
形状に応じた態様で開閉作動する。Therefore, in the intake-side valve operating device 19, when the hydraulic connection switching means 29 is in the disconnected state, the first intake valve 12a is indicated by a curve _LIA in FIG. 5 in a manner corresponding to the shape of the low-speed cam 22. Opening / closing operation as described above, and the second intake valve 12b is in a mode corresponding to the shape of the pause cam 24, that is, the high-order portion 24b of the pause cam 24.
At a position corresponding to the state of FIG. 5 to the extent that it is substantially in a rest state as shown by a curve _LIB in FIG. Also hydraulic connection means
When the valve 29 is connected, the first and second intake valves 12
a, 12b is as shown by curve H _I of FIG. 5, opened and closed in a manner corresponding to the shape of the high-speed cam 23.

排気側動弁装置20は、上記吸気側動弁装置19と基本的
にはぼ同一の構成を有するものであるが、休止用カム24
に代えて低速用カムが用いられる。したがって連結解除
状態では第５図の曲線L_Eで示すように両排気弁13a,13b
が低速用カムの形状に応じた態様で開閉作動し、連結状
態では第５図の曲線H_Eで示すように両排気弁13a,13bが
高速用カムの形状に応じた態様で開閉作動する。The exhaust side valve gear 20 has basically the same configuration as the intake side valve gear 19,
Instead, a low speed cam is used. Both exhaust valves 13a as indicated by the curve L _E of FIG. 5 is thus decoupled state, 13b
There was opened and closed in a manner corresponding to the shape of the low-speed cam, the coupling state opened and closed in a manner both exhaust valves 13a, as shown by curve H _E of FIG. 5, 13b is corresponding to the shape of the high-speed cam.

次にこの実施例の作用について説明すると、機関の低
速運転時には、制御弁40により油圧式連結切換手段29に
おける油圧室37の油圧を低圧にしておく。この状態で
は、吸気側動弁装置19は、第２吸気弁12bをほぼ休止状
態とし、第１吸気弁12aを低速用カム22の形状に応じて
機関の低速運転に対応した態様で開閉作動せしめる。一
方、可変ウイング17は駆動モータＭにより第１図の鎖線
で示すように第１吸気弁口6aに混合気を螺旋状に導入し
得る位置まで回動する。それにより第１吸気弁12aの開
弁時には、第１吸気ポート８から第１吸気弁口6aを経て
燃焼室５内に混合気が比較的高速でかつ旋回しながら導
入されることになり、燃焼室５内で強力なスワールが発
生する。したがって機関低速時における燃料希薄状態で
の燃焼性を向上し、燃費の低減を図ることができる。Next, the operation of this embodiment will be described. When the engine is running at a low speed, the control valve 40 keeps the hydraulic pressure in the hydraulic chamber 37 of the hydraulic connection switching means 29 low. In this state, the intake-side valve operating device 19 causes the second intake valve 12b to be substantially in a rest state, and causes the first intake valve 12a to open and close in a manner corresponding to the low-speed operation of the engine according to the shape of the low-speed cam 22. . On the other hand, the variable wing 17 is rotated by the drive motor M to a position where the air-fuel mixture can be spirally introduced into the first intake valve port 6a as shown by a chain line in FIG. Accordingly, when the first intake valve 12a is opened, the air-fuel mixture is introduced into the combustion chamber 5 from the first intake port 8 through the first intake valve port 6a into the combustion chamber 5 at a relatively high speed and swirling. A strong swirl is generated in the chamber 5. Therefore, it is possible to improve the combustibility in a fuel-lean state when the engine is running at a low speed, and to reduce the fuel consumption.

しかもこの低速運転時に第２吸気弁12bはほぼ休止状
態にあるので、燃焼室５内のスワール発生に悪影響を及
ぼすことはなく、また開閉作動による駆動力の増大を回
避することができる。In addition, since the second intake valve 12b is almost in a rest state during the low-speed operation, it does not adversely affect swirl generation in the combustion chamber 5 and can avoid an increase in driving force due to the opening / closing operation.

ただし、第２吸気弁12bは、休止用カム24の高位部24b
により、第１吸気弁12aの開弁時にわずかに開弁するも
のである。これは、第２吸気弁12が閉弁状態で完全に休
止させると、第２吸気ポート９に燃料が溜まるのを防止
するものであり、第２吸気ポート９に溜まった燃料が高
速時に第２吸気弁12bが開弁したときに一度に燃焼室５
に流入してスモーク発生や異常燃焼を生じるのを防止す
ることができる。また完全休止状態にすると、第２吸気
弁口6bのシート部に第２吸気弁12bが貼付いてしまうお
それがあり、また作動潤滑も悪化するおそれがあるが、
そのような心配も解消される。However, the second intake valve 12b is connected to the high-order portion 24b of the rest cam 24.
Accordingly, when the first intake valve 12a is opened, the valve is slightly opened. This is to prevent the accumulation of fuel in the second intake port 9 when the second intake valve 12 is completely stopped in the closed state, and the fuel accumulated in the second intake port 9 becomes the second When the intake valve 12b opens, the combustion chamber 5
And smoke generation and abnormal combustion can be prevented. In addition, when the operation is completely stopped, the second intake valve 12b may be stuck to the seat portion of the second intake valve port 6b, and the operating lubrication may be deteriorated.
Such concerns are also resolved.

機関の高速運転時には制御弁40により油圧式連結切換
手段29の油圧室37に高油圧を作用させ、吸気側動弁装置
19の各ロッカアーム26,27,28を一体的に連結する。それ
により両吸気弁12a,12bは、高速用カム23の形状に応じ
た態様で開閉作動することになり、燃焼室５での充填効
率の向上により高回転、高出力を図ることができる。During high-speed operation of the engine, high hydraulic pressure is applied to the hydraulic chamber 37 of the hydraulic connection switching means 29 by the control valve 40, and the intake-side valve operating device is operated.
The 19 rocker arms 26, 27, 28 are integrally connected. As a result, the intake valves 12a and 12b open and close in a manner corresponding to the shape of the high-speed cam 23, so that high rotation and high output can be achieved by improving the charging efficiency in the combustion chamber 5.

しかも可変ウイング17は、第２図の破線で示すように
第１吸気ポート８の壁面側に回動しているので、この可
変ウイング17による吸気抵抗は極力小さく抑えられ、従
来のものに比べてより充填効率を向上し、出力増大を図
ることができる。In addition, since the variable wing 17 is pivoted toward the wall surface of the first intake port 8 as shown by the broken line in FIG. 2, the intake resistance by the variable wing 17 is suppressed as small as possible, and is compared with the conventional one. The filling efficiency can be further improved, and the output can be increased.

以上の実施例では、機関の低速運転時に第２吸気弁12
bをほぼ休止させるようにしたが、完全に休止させるよ
うにしてもよい。In the above embodiment, the second intake valve 12 is operated during the low-speed operation of the engine.
Although b is almost stopped, it may be completely stopped.

C.発明の効果 以上のように本発明によれば、機関本体には、第１お
よび第２吸気弁口にそれぞれ通じる第１および第２吸気
ポートが設けられ、第１吸気ポートには、機関の低速運
転時に第１吸気弁口に混合気を螺旋状に導くべき位置と
機関の高速運転時に第１吸気ポートを全開にすべく該第
１吸気ポートの壁面側に回動する位置との間で回動可能
な可変ウイングが配設され、動弁装置は、機関低速運転
時に第２吸気弁を休止もしくはほぼ休止させながら第１
吸気弁を低速運転に対応した作動態様で作動させる状態
と、機関高速運転時に第１および第２吸気弁を高速運転
に対応した作動態様で作動させる状態とを切換可能に構
成されるので、低速運転時には、第１吸気弁が低速運転
に対応して開閉作動するとともに可変ウイングが第１吸
気弁口に混合気を螺旋状に導く位置に回動するのに応じ
て第１吸気ポートから燃焼室内に混合気を旋回させなが
ら導入するとともに第２吸気弁を休止もしくはほぼ休止
状態にしてスワール効果を高めて燃費の低減を図り、ま
た駆動力の低減を図ることができる。さらに機関の高速
運転時には両吸気弁を高速運転に対応した態様で開閉作
動せしめ、可変ウイングを第１吸気ポートの壁面側に回
動させて吸気抵抗を低くし、高回転、高出力化に寄与す
ることができる。C. Effects of the Invention As described above, according to the present invention, the engine body is provided with the first and second intake ports communicating with the first and second intake valve ports, respectively, and the first intake port is provided with the engine. Between the position where the air-fuel mixture should be spirally guided to the first intake valve port during low-speed operation of the engine and the position where the air-fuel mixture rotates toward the wall surface of the first intake port to fully open the first intake port during high-speed operation of the engine. A variable wing rotatable in the first direction is provided, and the valve gear operates while the first intake valve is stopped or almost stopped during the low-speed operation of the engine.
Since the state in which the intake valve is operated in the operation mode corresponding to the low-speed operation and the state in which the first and second intake valves are operated in the operation mode corresponding to the high-speed operation during high-speed operation of the engine are configured to be switchable, During operation, the first intake valve opens and closes in response to low-speed operation, and the variable wing pivots to a position where the air-fuel mixture spirals to the first intake valve port. In addition, the air-fuel mixture is introduced while being swirled, and the second intake valve is stopped or almost stopped to enhance the swirl effect, thereby reducing fuel consumption and driving force. In addition, during high-speed operation of the engine, both intake valves are opened and closed in a manner corresponding to high-speed operation, and the variable wing is rotated toward the wall side of the first intake port to reduce intake resistance, contributing to high rotation and high output. can do.

【図面の簡単な説明】[Brief description of the drawings]

図面は本発明の一実施例を示すもので、第１図な内燃機
関の要部縦断面図、第２図は第１図のII−II線矢視図、
第３図は第１図のIII−III線断面図、第４図は第３図の
IV−IV線断面図、第５図は吸気弁および排気弁の開閉タ
イミングおよびリフト量を示す図である。 ５……燃焼室、6a……第１吸気弁口、6b……第２吸気弁
口、８……第１吸気ポート、９……第２吸気ポート、12
a……第１吸気弁、12b……第２吸気弁、17……可変ウイ
ング、19……動弁装置、Ｅ……機関本体The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of a main part of an internal combustion engine, FIG. 2 is a view taken along the line II-II of FIG.
3 is a sectional view taken along the line III-III of FIG. 1, and FIG. 4 is a sectional view of FIG.
FIG. 5 is a sectional view taken along the line IV-IV, and FIG. 5 is a diagram showing the opening / closing timing and lift amount of the intake valve and the exhaust valve. 5 Combustion chamber, 6a First intake valve port, 6b Second intake valve port, 8 First intake port, 9 Second intake port, 12
a ... first intake valve, 12b ... second intake valve, 17 ... variable wing, 19 ... valve gear, E ... engine body

Claims (1)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】燃焼室に臨んで機関本体に設けられる第１
および第２吸気弁口を開閉可能な第１および第２吸気弁
が機関本体に配設され、第１および第２吸気弁には、機
関の低速運転と高速運転とで作動状態を変化可能な動弁
装置が連結される内燃機関の吸気装置において、機関本
体には、第１および第２吸気弁口にそれぞれ通じる第１
および第２吸気ポートが設けられ、第１吸気ポートに
は、機関の低速運転時に第１吸気弁口に混合気を螺旋状
に導くべき位置と機関の高速運転時に第１吸気ポートを
全開にすべく該第１吸気ポートの壁面側に回動する位置
との間で回動可能は可変ウイングが配設され、動弁装置
は、機関低速運転時に第２吸気弁を休止もしくはほぼ休
止させながら第１吸気弁を低速運転に対応した作動態様
で作動させる状態と、機関高速運転時に第１および第２
吸気弁を高速運転に対応した作動態様で作動させる状態
とを切換可能に構成されることを特徴とする内燃機関の
吸気装置。1. A first engine provided on an engine body facing a combustion chamber.
And first and second intake valves capable of opening and closing a second intake valve port are provided in the engine body, and the first and second intake valves are capable of changing the operating state between low-speed operation and high-speed operation of the engine. In an intake device for an internal combustion engine to which a valve operating device is connected, an engine main body has first and second intake valve ports respectively communicating with first and second intake valve ports.
And a second intake port are provided. The first intake port has a position at which the air-fuel mixture should be spirally guided to the first intake valve port during low-speed operation of the engine, and the first intake port is fully opened during high-speed operation of the engine. A variable wing that is rotatable between the first intake port and a position that pivots toward the wall surface side of the first intake port is provided, and the valve gear operates while the second intake valve is stopped or almost stopped during low-speed operation of the engine. (1) a state in which the intake valve is operated in an operation mode corresponding to low-speed operation;
An intake device for an internal combustion engine, wherein the intake valve is configured to be switchable between a state in which an intake valve is operated in an operation mode corresponding to high-speed operation.