JPH0324836Y2 - - Google Patents
Info
- Publication number
- JPH0324836Y2 JPH0324836Y2 JP9964384U JP9964384U JPH0324836Y2 JP H0324836 Y2 JPH0324836 Y2 JP H0324836Y2 JP 9964384 U JP9964384 U JP 9964384U JP 9964384 U JP9964384 U JP 9964384U JP H0324836 Y2 JPH0324836 Y2 JP H0324836Y2
- Authority
- JP
- Japan
- Prior art keywords
- valve
- intake port
- fresh air
- speed
- speed intake
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000002485 combustion reaction Methods 0.000 claims description 17
- 238000011144 upstream manufacturing Methods 0.000 claims description 15
- 230000000694 effects Effects 0.000 description 6
- 239000000446 fuel Substances 0.000 description 5
- 238000007789 sealing Methods 0.000 description 5
- 230000007257 malfunction Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000000356 contaminant Substances 0.000 description 3
- 238000007664 blowing Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 238000009825 accumulation Methods 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Landscapes
- Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)
Description
【考案の詳細な説明】
〈産業上の利用分野〉
本考案は、内燃機関のアイドリング時等の燃焼
改善技術に関する。[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a technology for improving combustion during idling of an internal combustion engine.
〈従来の技術〉
従来のこの種の公知技術としては、例えば、第
５図〜第７図に示すようなものがある。<Prior Art> Conventional known technologies of this type include, for example, those shown in FIGS. 5 to 7.
これについて説明すると、各気筒毎に備えられ
た低速用吸気弁１及び高速用吸気弁２の開時期を
変え、これら各吸気弁１，２に通じる低速用吸気
ポート３及び高速用吸気ポート４を独立して設け
ると共に、排気弁５とのオーバーラツプの大きな
高速用吸気弁２が装着された高速用吸気ポート４
に開閉弁６を設け、アイドリング時等低速領域で
は前記開閉弁６を閉じて実質的なバルブオーバー
ラツプ期間における排気の吹き返しを阻止するこ
とにより燃焼の改善を図つている（特公昭47−
31724号公報参照）。 To explain this, the opening timing of the low-speed intake valve 1 and high-speed intake valve 2 provided for each cylinder is changed, and the low-speed intake port 3 and high-speed intake port 4 that communicate with these intake valves 1 and 2 are changed. A high-speed intake port 4 is provided independently and is equipped with a high-speed intake valve 2 that has a large overlap with the exhaust valve 5.
An on-off valve 6 is provided in the engine, and the on-off valve 6 is closed in low speed ranges such as during idling to prevent exhaust gas from blowing back during the substantial valve overlap period, thereby improving combustion (Japanese Patent Publication No. 1973-
(See Publication No. 31724).
〈考案が解決しようとする問題点〉
しかしながら、このような従来の吸気ポートを
遮断する方式にあつては、開閉弁６下流の高速用
吸気ポート４の容積を種々の制約から小さくする
ことは困難で、シリンダ容積の15〜20％程度にな
る。この部分の吸気ポート容積が大きいと、特に
吸気負圧の大きなアイドリング時に以下のような
問題が生じる。<Problems to be solved by the invention> However, with such a conventional method of blocking the intake port, it is difficult to reduce the volume of the high-speed intake port 4 downstream of the on-off valve 6 due to various restrictions. Therefore, it becomes about 15 to 20% of the cylinder volume. If the intake port volume in this part is large, the following problems will occur, especially during idling with a large intake negative pressure.
吸気行程が終り、圧縮行程の初期に高速用吸気
弁２が閉じた時点で高速用吸気ポート４内には圧
縮行程初期の混合気が閉じ込められるが、該混合
気の圧力はアイドリング時であるから400mmHg程
度の負圧の状態である。 When the intake stroke ends and the high-speed intake valve 2 closes at the beginning of the compression stroke, the air-fuel mixture at the beginning of the compression stroke is trapped in the high-speed intake port 4, but the pressure of this air-fuel mixture is the same as when idling. It is in a state of negative pressure of about 400mmHg.
このため、排気行程の末期に高速用吸気弁２が
開くと、排圧とこの負圧との差圧により排気が高
速用吸気ポート４内に流入し、該吸気ポート４内
は排圧近くまで圧力上昇し、入り込んだ高速用吸
気ポート４容積の約半分近くを占める排気（既燃
ガス）が続く吸気行程で燃焼室７内の混合気に混
じるため残留ガス濃度を十分に低減することがで
きず、燃費の改善効果は期待した程得られない。 Therefore, when the high-speed intake valve 2 opens at the end of the exhaust stroke, the exhaust gas flows into the high-speed intake port 4 due to the pressure difference between the exhaust pressure and this negative pressure, and the inside of the intake port 4 reaches close to the exhaust pressure. The pressure rises and the exhaust gas (burnt gas), which occupies about half of the volume of the high-speed intake port 4, mixes with the air-fuel mixture in the combustion chamber 7 during the subsequent intake stroke, making it possible to sufficiently reduce the residual gas concentration. However, the effect of improving fuel efficiency is not as much as expected.
そこで、第８図及び第９図に示すように、開閉
弁６下流側の高速用吸気ポート４部分にオリフイ
ス８を介装した新気導入通路９を介して大気圧に
近い新気を導入し、高速用吸気弁２が閉じてから
次に開くまでの間に吸気負圧によつて新気を吸入
させ、排気圧との差圧を小さくして続くオーバー
ラツプ期間に排気が高速用吸気ポート４内に流入
するのを阻止し、混合気に混入する既燃ガス量を
大幅に低減する方式が本願出願人により提案され
ている。 Therefore, as shown in FIGS. 8 and 9, fresh air close to atmospheric pressure is introduced into the high-speed intake port 4 on the downstream side of the on-off valve 6 through a fresh air introduction passage 9 with an orifice 8 interposed therein. After the high-speed intake valve 2 closes until it opens again, fresh air is sucked in by negative intake pressure, and the pressure difference between the high-speed intake valve 2 and the exhaust pressure is reduced. The applicant has proposed a method for significantly reducing the amount of burned gas mixed in the air-fuel mixture.
これら両図において、開閉弁６はダイアフラム
式アクチユエータ１０により開閉制御される。 In both of these figures, the opening and closing valve 6 is controlled to open and close by a diaphragm actuator 10.
即ち、アクチユエータ１０に制御圧力が供給さ
れると、出力ロツド１１が伸長し、これに連結す
るリンク１２、ロツド１３のストローク、レバー
１４の回動を介して各気筒の開閉弁６を閉から開
に回動させる。尚、開閉弁６はレバー１５を介し
て連結するスプリング１６により閉弁方向に付勢
されている。 That is, when control pressure is supplied to the actuator 10, the output rod 11 expands, and the opening/closing valve 6 of each cylinder is opened from closed through the stroke of the link 12 and rod 13 connected thereto, and the rotation of the lever 14. Rotate it. The on-off valve 6 is biased in the valve closing direction by a spring 16 connected via a lever 15.
アクチユエータ１０への制御圧力の供給は電磁
弁１７によつて断続され、この断続の条件は、圧
力センサ１８及び機関回転速度等の機関運転条件
をコントロールユニツト１９で検出して行う。２
０はアクチユエータ１０の作動完了をモニターす
るリミツトスイツチである。 The supply of control pressure to the actuator 10 is interrupted by a solenoid valve 17, and the conditions for this interruption are determined by a pressure sensor 18 and a control unit 19 that detects engine operating conditions such as engine rotational speed. 2
0 is a limit switch that monitors the completion of actuation of the actuator 10.
開閉弁６の下流の高速用吸気ポート４部分は新
気導入通路９を介して絞り弁２１の上流の吸気通
路２２に連通しており、オリフイス８で流量が規
制されている。絞り弁２１の上流の圧力は、常時
大気圧近傍であるから、高速用吸気ポート４内が
負圧の条件下では絞り弁２１上流側の新気がオリ
フイス８を通つて開閉弁６下流の高速用吸気ポー
ト４内に流入する。 A portion of the high-speed intake port 4 downstream of the on-off valve 6 communicates with an intake passage 22 upstream of the throttle valve 21 via a fresh air introduction passage 9, and the flow rate is regulated by an orifice 8. The pressure upstream of the throttle valve 21 is always close to atmospheric pressure, so under conditions of negative pressure in the high-speed intake port 4, fresh air upstream of the throttle valve 21 passes through the orifice 8 and flows to the high-speed downstream of the on-off valve 6. The air flows into the air intake port 4.
このように新気を導入すると、第１０図に実線
で示すように、高速用吸気弁２が閉じた後、開閉
弁６下流の高速用吸気ポート４内は徐々に大気圧
に近づく。 When fresh air is introduced in this manner, as shown by the solid line in FIG. 10, after the high-speed intake valve 2 closes, the pressure inside the high-speed intake port 4 downstream of the on-off valve 6 gradually approaches atmospheric pressure.
オリフイス８は、大気圧に近い新気の流入量を
制御するものであり、高速用吸気弁２が閉じてい
るクランク１回転余りの期間（アイドリング時：
600rpmでは0.1秒）に高速用吸気ポート４内の圧
力を大気圧に十分近づけるのに対して必要十分な
大きさに設定してある（オリフイス８口径はφ1
〜φ2程度）。 The orifice 8 controls the inflow amount of fresh air close to atmospheric pressure, and is used during the period of one crank rotation when the high-speed intake valve 2 is closed (during idling).
The size is set to be necessary and sufficient to bring the pressure inside the high-speed intake port 4 sufficiently close to atmospheric pressure in 0.1 seconds at 600 rpm (orifice 8 has a diameter of φ1).
~φ2 degree).
このようにすれば、高速用吸気弁２が開かれる
排気行程末期に燃焼室７内に満たされた大気圧
（平均値）に近い排気が高速用吸気ポート４内へ
吹き返すことを効果的に抑制でき、燃焼性能の大
幅な改善を図れるのである。 In this way, the exhaust gas filled in the combustion chamber 7 at a pressure close to atmospheric pressure (average value) at the end of the exhaust stroke when the high-speed intake valve 2 is opened is effectively suppressed from blowing back into the high-speed intake port 4. This makes it possible to significantly improve combustion performance.
尚、比較のために新気導入を行わない場合を第
１０図に破線で示す。 For comparison, the case where fresh air is not introduced is shown by a broken line in FIG.
この場合は、高速用吸気弁２を閉じると高速用
吸気ポート４内へのガスの出入りはないために次
に高速用吸気弁２が開くまでは開閉弁６下流の高
速用吸気ポート４内圧力が大気圧の半分程度の負
圧で一定に保たれる。 In this case, when the high-speed intake valve 2 is closed, gas does not enter or exit the high-speed intake port 4, so the pressure inside the high-speed intake port 4 downstream of the on-off valve 6 remains until the high-speed intake valve 2 opens next time. is maintained at a constant negative pressure of about half the atmospheric pressure.
従つて、高速用吸気弁２が開き始めると、燃焼
室７内に満たされた排気が大きな圧力差により急
速に高速用吸気ポート４内に流入し、開閉弁６下
流の高速用吸気ポート４の容積の約半分近くの排
気が大気圧に近い状態で残留し、続く吸気行程で
一気に膨張して燃焼室７内に混入するため、開閉
弁６を設けても相当量の残留ガスが存在すること
になり、燃焼の大幅な改善は望めないのである。 Therefore, when the high-speed intake valve 2 starts to open, the exhaust gas filling the combustion chamber 7 rapidly flows into the high-speed intake port 4 due to a large pressure difference, and the high-speed intake port 4 downstream of the on-off valve 6 is Approximately half of the volume of the exhaust gas remains at near atmospheric pressure, expands at once during the subsequent intake stroke, and mixes into the combustion chamber 7, so even if the on-off valve 6 is provided, a considerable amount of residual gas still exists. Therefore, no significant improvement in combustion can be expected.
ところでこのものでは、アイドリング時以外の
低速領域で開閉弁６が閉じている時はアイドリン
グ時に比較し開閉弁６の前後差圧が減少すると共
に、回転数の増大により新気導入時間が減少する
ため、ある程度排気の吹き返しがあり、これを積
極的に利用して残留ガスによるいわゆる内部
EGRを行い、NOx低減を図ることも可能である。 By the way, in this case, when the on-off valve 6 is closed in a low speed range other than idling, the differential pressure across the on-off valve 6 decreases compared to when idling, and the fresh air introduction time decreases due to the increase in rotational speed. , there is a certain amount of exhaust blowback, and this is actively used to eliminate so-called internal combustion caused by residual gas.
It is also possible to perform EGR to reduce NOx.
しかしながら、このように開閉弁６を閉じた状
態で排気の吹き返しを生じると、開閉弁６に排気
が接触し、排気中のカーボンやタール分が開閉弁
６の外周部分や支軸２３に付着して開閉弁６の作
動不良やシール性不良の原因となることが考えら
れる。 However, if exhaust gas blows back with the on-off valve 6 closed, the exhaust will come into contact with the on-off valve 6, and carbon and tar in the exhaust will adhere to the outer circumference of the on-off valve 6 and the support shaft 23. This may cause malfunction of the on-off valve 6 or poor sealing performance.
本考案は、開閉弁の閉時に高速用吸気ポートに
吹き返された排気が開閉弁に接触するのを防止す
ることにより、開閉弁の作動不良やシール性不良
等の問題点を解決することを目的とする。 The purpose of this invention is to prevent the exhaust gas blown back into the high-speed intake port from coming into contact with the on-off valve when the on-off valve is closed, thereby solving problems such as malfunction and poor sealing of the on-off valve. shall be.
〈問題点を解決するための手段〉
このため本考案は、気筒毎に低速用吸気ポート
と、高速用吸気ポートと、を備えると共に、前記
高速用吸気ポートに低速領域で閉じ、高速領域で
開く開閉弁を備えた内燃機関の吸気装置におい
て、
各気筒の高速用吸気ポートの開閉弁下流部分に
大気圧に近い新気を導く新気導入通路を設け、該
新気導入通路の新気吹き出し口を、開閉弁近傍に
あつて高速用吸気ポートの通路断面と平行、また
は、高速用吸気ポートの上流側に向けて配設した
構成とする。<Means for Solving the Problems> For this reason, the present invention includes a low-speed intake port and a high-speed intake port for each cylinder, and the high-speed intake port is closed in a low-speed region and opened in a high-speed region. In an intake system for an internal combustion engine equipped with an on-off valve, a fresh air introduction passage that introduces fresh air close to atmospheric pressure is provided downstream of the on-off valve of the high-speed intake port of each cylinder, and a fresh air outlet of the fresh air introduction passage is provided. is arranged near the on-off valve and parallel to the passage cross section of the high-speed intake port, or toward the upstream side of the high-speed intake port.
〈作用〉
前記本考案の構成により、高速用吸気ポートに
装着された吸気弁と排気弁とのオーバーラツプ期
間中に燃焼排気が高速用吸気ポート内に流入して
きても絞り弁上流から導入される新気により開閉
弁の下流近傍部分にエアカーテンが形成され、こ
のエアカーテンにより開閉弁の表面が直接排気に
曝されることを防止でき、以て、開閉弁の作動不
良やシール性不良を防止することができる。<Operation> With the configuration of the present invention, even if combustion exhaust flows into the high-speed intake port during the overlap period between the intake valve and exhaust valve installed in the high-speed intake port, the new exhaust gas is introduced from upstream of the throttle valve. An air curtain is formed near the downstream side of the on-off valve, and this air curtain prevents the surface of the on-off valve from being directly exposed to exhaust gas, thereby preventing malfunction and poor sealing of the on-off valve. be able to.
〈実施例〉
以下に第１図〜第４図に示す実施例の説明を行
う。尚、従来例及び先願例と同一要素（実施例図
で示されないものを含む。）については第５図〜
第９図と同一符号を附して説明する。<Example> The example shown in FIGS. 1 to 4 will be described below. The same elements as the conventional example and the prior application example (including those not shown in the embodiment drawings) are shown in FIGS.
The explanation will be given using the same reference numerals as in FIG. 9.
第１図は第１の実施例を示しており、絞り弁２
１上流の吸気通路２２と高速用吸気ポート４の開
閉弁６下流部分とを結んで接続される新気導入通
路４１の新気吹き出し口４１ａは開閉弁６の下流
側近傍部分にあつて、高速用吸気ポート４内壁の
接線方向に向けられ、かつ、少し上流側方向に傾
斜して設けられている。 FIG. 1 shows a first embodiment, in which the throttle valve 2
The fresh air outlet 41a of the fresh air introduction passage 41, which connects the upstream intake passage 22 and the downstream part of the on-off valve 6 of the high-speed intake port 4, is located near the downstream side of the on-off valve 6, and The air intake port 4 is oriented in the tangential direction of the inner wall and is slightly inclined toward the upstream side.
また、新気吹き出し口４１ａの、開閉弁６を内
装したハウジング４２内部にはオリフイス４３が
介装されている。 Further, an orifice 43 is interposed inside the housing 42 in which the on-off valve 6 is housed inside the fresh air outlet 41a.
このようにすれば、新気導入通路４１の新気吹
き出し口４１ａより導入される新気は高速用吸気
ポート４及び開閉弁６の円周方向に沿つて旋回
し、かつ、開閉弁６の表面に向かつて該表面をな
ぞるように吹き出されるため、開閉弁６の下流側
全面を覆うエアカーテンが形成される。 In this way, the fresh air introduced from the fresh air outlet 41a of the fresh air introduction passage 41 swirls along the circumferential direction of the high-speed intake port 4 and the on-off valve 6, and the surface of the on-off valve 6 Since the air is blown out toward and along the surface, an air curtain covering the entire downstream side of the on-off valve 6 is formed.
従つて、開閉弁６の閉じる低速領域で高速用吸
気ポート４側の高速用吸気弁２と排気弁５とのオ
ーバーラツプ期間中に燃焼排気が高速用吸気ポー
ト４内に流入してきても、開閉弁６の下流側近傍
に形成されたエアカーテンにより、開閉弁６の表
面が直接排気に曝されることを効果的に防止で
き、排気中のカーボンやタール分の付着堆積によ
る開閉弁６の作動不良やシール性不良を良好に防
止できるのである。 Therefore, even if combustion exhaust flows into the high-speed intake port 4 during the overlap period between the high-speed intake valve 2 and the exhaust valve 5 on the high-speed intake port 4 side in the low-speed region where the on-off valve 6 closes, the on-off valve 6 closes. The air curtain formed near the downstream side of the on-off valve 6 can effectively prevent the surface of the on-off valve 6 from being directly exposed to the exhaust gas, and prevent malfunction of the on-off valve 6 due to adhesion and accumulation of carbon and tar in the exhaust gas. Therefore, it is possible to effectively prevent problems such as problems and poor sealing performance.
第２図に示す第２の実施例では、新気導入通路
５１の新気吹き出し口５１ａ，５１ｂはハウジン
グ５２内部でＶ字形に分岐して形成され、その分
岐点より上流側にオリフイス５３が介装されてい
る。 In the second embodiment shown in FIG. 2, the fresh air outlet ports 51a and 51b of the fresh air introduction passage 51 are formed by branching into a V-shape inside the housing 52, and an orifice 53 is interposed on the upstream side of the branching point. equipped.
これら２方向に分岐された各新気吹き出し口５
１ａ，５１ｂは、開口方向が各々高速用吸気ポー
ト４内壁の接線方向に向けられ、かつ、上流側に
傾斜して設けられている。 Each fresh air outlet 5 branched into these two directions
1a and 51b are provided so that their opening directions are oriented in the tangential direction of the inner wall of the high-speed intake port 4, and are inclined toward the upstream side.
このようにすれば、２箇所から円周方向に沿つ
て逆向きに新気が導入され、流速大の部分が増大
するので、新気によるエアカーテンとしての効果
が大きくなり、排気中汚染物質の付着堆積防止効
果が大きくなる。 In this way, fresh air is introduced in opposite directions along the circumferential direction from two places, and the part where the flow velocity is high increases, so the effect of the fresh air as an air curtain is increased, and the pollutants in the exhaust are reduced. The effect of preventing adhesion and deposition is increased.
第３図に示す第３の実施例は、開閉弁６の支軸
６１の、開閉弁６を挟む両側部分の開閉弁６の下
流側部分を切り欠いて新気導入通路６２の新気吹
き出し口６２ａ，６２ｂが形成され、これら新気
吹き出し口６２ａ，６２ｂに、開閉弁６の閉時に
連通する分岐通路６２ｃ，６２ｄをハウジング６
３内部に形成し、分岐通路６２ｄ上流側の新気導
入通路６２にオリフイス６４が介装されている。 In the third embodiment shown in FIG. 3, a fresh air outlet of a fresh air introduction passage 62 is formed by cutting out downstream parts of the on-off valve 6 on both sides of the on-off valve 6 on both sides of the support shaft 61 of the on-off valve 6. 62a, 62b are formed, and branch passages 62c, 62d are connected to the housing 6, and these fresh air outlets 62a, 62b communicate with each other when the on-off valve 6 is closed.
3, and an orifice 64 is interposed in the fresh air introduction passage 62 on the upstream side of the branch passage 62d.
このようにすれば、支軸６１のハウジング６３
内壁に摺動自由に支持される両端部近傍から新気
が吹き出すので、特に、この部分への排気中汚染
物質の付着堆積防止効果が大きく、支軸６１の円
滑な回転を良好に維持できる効果が大である。 In this way, the housing 63 of the support shaft 61
Since fresh air is blown out from the vicinity of both ends that are freely slidably supported on the inner wall, the effect of preventing contaminants from adhering to the exhaust gas from accumulating on these parts is particularly great, and the smooth rotation of the support shaft 61 can be maintained well. is large.
尚、この場合、新気吹き出し口６２ａ，６２ｂ
は、開閉弁６に十分近接するので開口方向はそれ
ぞれ開閉弁６と平行で良い。 In this case, the fresh air outlets 62a, 62b
are sufficiently close to the on-off valve 6, so the opening direction may be parallel to the on-off valve 6.
第４図には第４の実施例が示してあり、新気導
入通路７１の新気吹き出し口７１ａ，７１ｂはハ
ウジング７２内部で２方向に分岐して形成され、
開閉弁６の支軸２３と直角な方向にあつて開閉弁
６の閉時、高速用吸気ポート４上流方向に傾斜し
て設けられている。 A fourth embodiment is shown in FIG. 4, in which fresh air outlets 71a and 71b of a fresh air introduction passage 71 are formed to branch into two directions inside a housing 72.
It is provided in a direction perpendicular to the support shaft 23 of the on-off valve 6 and inclined toward the upstream direction of the high-speed intake port 4 when the on-off valve 6 is closed.
新気吹き出し口７１ａ，７１ｂの分岐点より上
流側にオリフイス７３が介装されている。 An orifice 73 is installed upstream from the branch point of the fresh air blow-off ports 71a and 71b.
ところで、開閉弁６の、支軸２３と直角方向の
両端部６ａ，６ｂに排気中汚染物質が付着堆積す
ると、該堆積物の粘性による固着力により開弁作
動時の回転抵抗が増加し大きな始動モーメントが
要求される。 By the way, if pollutants in the exhaust gas adhere and accumulate on both ends 6a and 6b of the opening/closing valve 6 in the direction perpendicular to the support shaft 23, the sticking force due to the viscosity of the deposits will increase the rotational resistance when the valve is opened, resulting in a large start. moment is required.
従つて、本実施例のように前記開閉弁６の支軸
２３と直角な方向から新気が吹き出すようにして
両端部６ａ，６ｂへの前記汚染物質の付着堆積を
防止することにより、開閉弁６の回転抵抗の増大
が抑制され、開閉弁６作動用アクチユエータ１０
の駆動力も軽減できる。 Therefore, as in this embodiment, fresh air is blown out from a direction perpendicular to the support shaft 23 of the on-off valve 6 to prevent the contaminants from adhering and accumulating on both ends 6a and 6b. 6 is suppressed, and the actuator 10 for operating the on-off valve 6 is suppressed.
The driving force can also be reduced.
〈考案の効果〉
以上説明したように本考案によれば、各気筒の
高速用吸気ポートの開閉弁下流部分に大気圧に近
い新気を導く新気導入通路を設け、該新気導入通
路の新気吹き出し口を、開閉弁近傍にあつて高速
用吸気ポートの通路断面と平行、または、高速用
吸気ポートの上流側に向けて配設したことによ
り、高速用吸気弁と排気弁とのオーバーラツプ期
間中に燃焼排気が高速用吸気ポート内に流入して
きても絞り弁上流から導入される新気により高速
用吸気ポート内の開閉弁下流近傍部分にエアカー
テンが形成されるので、開閉弁の表面が直接排気
に曝される恐れがなくなり、排気中のカーボンや
タール等の汚染物質の開閉弁近傍への付着堆積を
防止でき、開閉弁の作動性、シール性を長期に亘
つて良好に維持できるという効果が得られる。<Effects of the invention> As explained above, according to the invention, a fresh air introduction passage for introducing fresh air close to atmospheric pressure is provided downstream of the on-off valve of the high-speed intake port of each cylinder, and the fresh air introduction passage is By arranging the fresh air outlet near the on-off valve and parallel to the passage cross section of the high-speed intake port, or toward the upstream side of the high-speed intake port, the overlap between the high-speed intake valve and the exhaust valve is avoided. Even if combustion exhaust flows into the high-speed intake port during this period, the fresh air introduced from upstream of the throttle valve will form an air curtain in the vicinity of the downstream side of the on-off valve in the high-speed intake port, causing the surface of the on-off valve to This eliminates the risk of direct exposure to exhaust gas, prevents contaminants such as carbon and tar in the exhaust from accumulating near the on-off valve, and maintains good operability and sealing performance of the on-off valve over a long period of time. This effect can be obtained.
第１図Ａは本考案の第１の実施例を示す要部平
面断面図、第１図Ｂは同図Ａの−断面図、第
２図Ａは本考案の第２の実施例を示す要部平面断
面図、第２図Ｂは同図Ａの−断面図、第３図
Ａは本考案の第３の実施例を示す要部平面断面
図、第３図Ｂは同図Ａの−断面図、第４図Ａ
は本考案の第４の実施例を示す要部平面断面図、
第４図Ｂは同図Ａの−断面図、第５図は従来
公知の内燃機関の吸気装置を示す要部横断面図、
第６図は同上機関の吸・排気弁のリフト特性を示
すグラフ、第７図は同上装置の要部縦断面図、第
８図は本願出願人により提案済の内燃機関の吸気
装置の全体概要を示す構成図、第９図Ａは同上装
置で使用される開閉弁の装着部の側面図、第９図
Ｂは同じく平面図、第１０図は同上装置の各部の
特性を示すタイムチヤートである。
１……低速用吸気弁、２……高速用吸気弁、３
……低速用吸気ポート、４……高速用吸気ポー
ト、６……開閉弁、４１，５１，６２，７１……
新気導入通路、４１ａ，５１ａ，５１ｂ，６２
ａ，６２ｂ，７１ａ，７１ｂ……新気吹き出し
口。
FIG. 1A is a plan sectional view of a main part showing a first embodiment of the present invention, FIG. FIG. 2B is a cross-sectional view of the main part of FIG. Figure, Figure 4A
is a plan sectional view of a main part showing a fourth embodiment of the present invention,
FIG. 4B is a cross-sectional view taken from FIG.
Fig. 6 is a graph showing the lift characteristics of the intake and exhaust valves of the above engine, Fig. 7 is a longitudinal sectional view of the main parts of the above device, and Fig. 8 is an overall outline of the intake system for an internal combustion engine proposed by the applicant. FIG. 9A is a side view of the mounting part of the on-off valve used in the above device, FIG. 9B is a plan view of the same, and FIG. 10 is a time chart showing the characteristics of each part of the same device. . 1...Intake valve for low speed, 2...Intake valve for high speed, 3
...Intake port for low speed, 4...Intake port for high speed, 6...Opening/closing valve, 41, 51, 62, 71...
Fresh air introduction passage, 41a, 51a, 51b, 62
a, 62b, 71a, 71b... Fresh air outlet.
Claims (1)
トと、を備えると共に、前記高速用吸気ポートに
低速領域で閉じ、高速領域で開く開閉弁を備えた
内燃機関の吸気装置において、各気筒の高速用吸
気ポートの開閉弁下流部分に大気圧に近い新気を
導く新気導入通路を設け、該新気導入通路の新気
吹き出し口を、開閉弁近傍にあつて高速用吸気ポ
ートの通路断面と平行、または、高速用吸気ポー
トの上流側に向けて配設したことを特徴とする内
燃機関の吸気装置。 In an intake system for an internal combustion engine, each cylinder is provided with a low-speed intake port and a high-speed intake port, and the high-speed intake port is provided with an on-off valve that closes in a low-speed region and opens in a high-speed region. A fresh air introduction passage that introduces fresh air close to atmospheric pressure is provided downstream of the on-off valve of the high-speed intake port, and the fresh air outlet of the fresh air introduction passage is located near the on-off valve and has a cross section of the passage of the high-speed intake port. An intake device for an internal combustion engine, characterized in that it is arranged parallel to or toward the upstream side of a high-speed intake port.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9964384U JPS6114722U (en) | 1984-07-03 | 1984-07-03 | Internal combustion engine intake system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9964384U JPS6114722U (en) | 1984-07-03 | 1984-07-03 | Internal combustion engine intake system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6114722U JPS6114722U (en) | 1986-01-28 |
| JPH0324836Y2 true JPH0324836Y2 (en) | 1991-05-30 |
Family
ID=30659137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9964384U Granted JPS6114722U (en) | 1984-07-03 | 1984-07-03 | Internal combustion engine intake system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6114722U (en) |
-
1984
- 1984-07-03 JP JP9964384U patent/JPS6114722U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6114722U (en) | 1986-01-28 |
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