JP2006249949A - Exhaust gas recirculation device for internal combustion engine - Google Patents

Exhaust gas recirculation device for internal combustion engine Download PDF

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JP2006249949A
JP2006249949A JP2005064173A JP2005064173A JP2006249949A JP 2006249949 A JP2006249949 A JP 2006249949A JP 2005064173 A JP2005064173 A JP 2005064173A JP 2005064173 A JP2005064173 A JP 2005064173A JP 2006249949 A JP2006249949 A JP 2006249949A
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internal combustion
combustion engine
exhaust gas
passage
intake
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Tsugufumi Aikawa
嗣史 藍川
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Toyota Motor Corp
トヨタ自動車株式会社
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/52Systems for actuating EGR valves
    • F02M26/59Systems for actuating EGR valves using positive pressure actuators; Check valves therefor
    • F02M26/60Systems for actuating EGR valves using positive pressure actuators; Check valves therefor in response to air intake pressure
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02EGR systems specially adapted for supercharged engines
    • F02M26/04EGR systems specially adapted for supercharged engines with a single turbocharger
    • F02M26/05High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M26/00Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
    • F02M26/02EGR systems specially adapted for supercharged engines
    • F02M26/09Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine
    • F02M26/10Constructional details, e.g. structural combinations of EGR systems and supercharger systems; Arrangement of the EGR and supercharger systems with respect to the engine having means to increase the pressure difference between the exhaust and intake system, e.g. venturis, variable geometry turbines, check valves using pressure pulsations or throttles in the air intake or exhaust system

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust gas recirculation device for an internal combustion engine capable of promoting introduction of exhaust gas at supercharging time for the internal combustion engine while suppressing reduction of output of the internal combustion engine and worsening of response property of the exhaust gas recirculation device. <P>SOLUTION: This exhaust gas recirculation device 15 is applied to the internal combustion engine 1 provided with a mechanical supercharger 5 in an intake passage 3. The intake passage of the internal combustion engine 1 has a first branched passage 31 and a second branched passage 32 branched from a branched position 3a on the downstream side of the mechanical supercharger 5 to lead intake into the same cylinder 2 of the internal combustion engine 1 separately. This device 15 is provided with an exhaust gas recirculation passage 16 for leading exhaust gas from an exhaust passage 4 into the first branched passage 31 of the internal combustion engine 1 and a supercharging pressure adjusting valve 18 arranged in the first branched passage 31 between the branched position 3a in the intake passage 3 and an exhaust gas introducing position 3b for introducing exhaust gas in the exhaust gas recirculating passage 16 and capable of adjusting opening between a fully closed position for closing the first branched passage 31 fully and a fully opened position for opening the first branched passage 31 fully. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

本発明は、内燃機関の排気を内燃機関に還流させる排気還流装置に関する。   The present invention relates to an exhaust gas recirculation device that recirculates exhaust gas from an internal combustion engine to the internal combustion engine.
内燃機関の排気還流装置として、機械式過給機によって加圧された下流側の吸気通路にベンチュリを設け、そのベンチュリを介して内燃機関の排気を導入するもの、或いは機械式過給機の上流側の吸気通路に内燃機関の排気を導入するものがある(特許文献1)。その他本発明に関連する先行技術文献として特許文献2が存在する。   As an exhaust gas recirculation device for an internal combustion engine, a venturi is provided in a downstream intake passage pressurized by a mechanical supercharger, and exhaust of the internal combustion engine is introduced through the venturi, or upstream of a mechanical supercharger There is an engine that introduces exhaust gas from an internal combustion engine into a side intake passage (Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.
特許第3085982号公報Japanese Patent No. 3085882 特開2001−82259号公報JP 2001-82259 A
機械式過給機は内燃機関のクランク軸の回転を利用して駆動される。このため、排気エネルギーを利用するターボチャージャーのように、過給機の作動に伴ってタービン上流の排気通路の圧力が上昇することがない。従って、過給時において機械式過給機下流の吸気通路と排気通路との圧力差が小さくなり、ときには吸気通路の圧力が排気通路の圧力を上回り、吸気通路への排気の導入が妨げられて内燃機関に対する排気の還流が制限を受ける。そのため、特許文献1に開示された排気還流装置は、機械式過給機による過給時に、ベンチュリや機械式過給機による吸い込みを利用して排気ガスの導入を促進させている。   The mechanical supercharger is driven by utilizing the rotation of the crankshaft of the internal combustion engine. Therefore, unlike a turbocharger that uses exhaust energy, the pressure in the exhaust passage upstream of the turbine does not increase with the operation of the turbocharger. Therefore, during supercharging, the pressure difference between the intake passage and the exhaust passage downstream of the mechanical supercharger becomes small, and sometimes the pressure in the intake passage exceeds the pressure in the exhaust passage, preventing the introduction of exhaust into the intake passage. The exhaust gas recirculation to the internal combustion engine is limited. Therefore, the exhaust gas recirculation device disclosed in Patent Document 1 promotes the introduction of exhaust gas by using suction by a venturi or a mechanical supercharger at the time of supercharging by a mechanical supercharger.
しかしながら、ベンチュリを用いる場合には吸入空気量が増えるとベンチュリが吸気の抵抗となり内燃機関の出力性能の低下を招くおそれがある。また、機械式過給機の上流側に排気を導入する場合には排気導入位置から内燃機関の気筒までの容積が必然的に大きくなってしまうので排気還流装置の応答性が悪化するおそれがある。   However, when a venturi is used, if the amount of intake air increases, the venturi becomes a resistance to intake air, which may cause a decrease in output performance of the internal combustion engine. In addition, when exhaust is introduced upstream of the mechanical supercharger, the volume from the exhaust introduction position to the cylinder of the internal combustion engine inevitably increases, so the responsiveness of the exhaust gas recirculation device may deteriorate. .
そこで、本発明は、内燃機関の出力低下及び排気還流装置の応答性悪化を抑えつつ、内燃機関に対する過給時において排気の導入を促進できる内燃機関の排気還流装置を提供することを目的とする。   Therefore, an object of the present invention is to provide an exhaust gas recirculation device for an internal combustion engine that can promote introduction of exhaust gas when the internal combustion engine is supercharged while suppressing a decrease in output of the internal combustion engine and a deterioration in response of the exhaust gas recirculation device. .
本発明の内燃機関の排気還流装置は、内燃機関のクランク軸の回転を利用して又は電動機の回転を利用して駆動される過給機が吸気通路に設けられた内燃機関に適用される内燃機関の排気還流装置において、前記内燃機関の前記吸気通路が、前記過給機の下流側の分岐位置から分岐されて前記内燃機関の同一の気筒に対して別々に吸気を導く第1分岐通路と第2分岐通路とを有し、前記内燃機関の排気通路から前記第1分岐通路へ排気を導く排気還流通路と、前記吸気通路の前記分岐位置と前記排気還流通路にて排気が導入される排気導入位置との間の前記第1分岐通路に配置され、前記第1分岐通路を全閉する全閉位置から前記第1分岐通路を全開する全開位置までの間で開度調整可能な調整弁と、を備えることにより、上述した課題を解決する(請求項1)。   The exhaust gas recirculation apparatus for an internal combustion engine according to the present invention is an internal combustion engine that is applied to an internal combustion engine in which a supercharger that is driven by using rotation of a crankshaft of the internal combustion engine or by using rotation of an electric motor is provided in an intake passage. In the exhaust gas recirculation apparatus for an engine, the intake passage of the internal combustion engine is branched from a branch position on the downstream side of the supercharger, and the first branch passage guides intake air separately to the same cylinder of the internal combustion engine An exhaust gas recirculation passage that has a second branch passage and guides exhaust gas from the exhaust passage of the internal combustion engine to the first branch passage; and exhaust gas that is introduced into the branch position of the intake passage and the exhaust gas recirculation passage An adjustment valve disposed in the first branch passage between the introduction position and capable of adjusting an opening between a fully closed position for fully closing the first branch passage and a fully open position for fully opening the first branch passage; To solve the above-mentioned problems. To (claim 1).
この排気還流装置によれば、第1分岐通路に配置された調整弁を全閉位置から全開位置までの間で開度調整できるので、第1分岐通路を介して行われる過給を制限できる。このため、過給機による過給の実行中に排気を還流させる場合には、第1分岐通路を介して行われる過給を調整弁にて制限して排気導入位置の圧力の上昇を抑えることにより排気の導入を促進させると同時に第2分岐通路を介して行われる過給を継続させることができる。従って、内燃機関のクランク軸の回転を利用して又は電動機の回転を利用して駆動される過給機による過給が排気の還流の妨げとはならず、過給を行いながら内燃機関に対して排気の還流を行うことができる。また、排気を還流させる必要がないときには、調整弁を調整することにより第1分岐通路を介して行われる過給の制限を解除することもできる。これにより、第1分岐通路及び第2分岐通路のそれぞれを介して過給が行われて内燃機関の性能低下を抑えることもできる。更に、第1分岐通路の排気導入位置を可能な限り内燃機関の気筒に近づけて排気導入位置から気筒までの容積の増大を抑えることができるので、排気還流装置の応答性の悪化を抑制できる。   According to this exhaust gas recirculation device, the opening degree of the adjustment valve disposed in the first branch passage can be adjusted from the fully closed position to the fully open position, so that supercharging performed via the first branch passage can be limited. For this reason, when the exhaust gas is recirculated during the supercharging by the supercharger, the supercharging performed through the first branch passage is limited by the regulating valve to suppress the increase in the pressure at the exhaust introduction position. Thus, the introduction of exhaust gas can be promoted, and at the same time, the supercharging performed through the second branch passage can be continued. Therefore, the supercharging by the supercharger driven by using the rotation of the crankshaft of the internal combustion engine or by using the rotation of the electric motor does not hinder the recirculation of the exhaust gas. Thus, the exhaust gas can be recirculated. Further, when it is not necessary to recirculate the exhaust gas, the restriction of supercharging performed via the first branch passage can be canceled by adjusting the adjustment valve. Thereby, supercharging is performed via each of the 1st branch passage and the 2nd branch passage, and it can also control the performance fall of an internal-combustion engine. Furthermore, since the exhaust introduction position of the first branch passage can be as close as possible to the cylinder of the internal combustion engine and an increase in volume from the exhaust introduction position to the cylinder can be suppressed, deterioration of the responsiveness of the exhaust gas recirculation device can be suppressed.
本発明の内燃機関の排気還流装置においては、調整弁の開度調整は適宜に行ってよいが、前記第1分岐通路を介して前記内燃機関に排気を還流させる場合に、前記第1分岐通路を介しての過給が制限されるように前記調整弁の開度を閉じ側に制御する調整弁制御手段を更に備えてもよい(請求項2)。この態様によれば、調整弁の開度が閉じ側に制御することにより第1分岐通路を介して行われる過給を制限することができる。   In the exhaust gas recirculation device for an internal combustion engine of the present invention, the opening degree of the adjustment valve may be adjusted as appropriate, but when the exhaust gas is recirculated to the internal combustion engine via the first branch passage, the first branch passage An adjustment valve control means for controlling the opening of the adjustment valve to the closed side so as to limit supercharging via the valve may be further provided (Claim 2). According to this aspect, the supercharging performed via the first branch passage can be limited by controlling the opening degree of the regulating valve to the closed side.
本発明の内燃機関の排気還流装置において、前記第1分岐通路が有する第1吸気ポートは、その流量係数が前記第2分岐通路が有する第2吸気ポートの流量係数よりも大きくなるように構成されてもよい(請求項3)。ここで言う「吸気ポートの流量係数」とは、吸気ポートへの流体の流れ易さを示す無次元数である。吸気ポートの前後の差圧が同一の場合には流量係数が大きいものほど流量が大きくなる。   In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, the first intake port of the first branch passage is configured such that the flow coefficient thereof is larger than the flow coefficient of the second intake port of the second branch passage. (Claim 3). The “flow coefficient of the intake port” referred to here is a dimensionless number indicating the ease of fluid flow to the intake port. When the differential pressure before and after the intake port is the same, the flow rate increases as the flow rate coefficient increases.
調整弁にて第1分岐通路を介して行われる過給が制限されて第1吸気ポートの上流圧力よりも第2吸気ポートの上流圧力が高くなったときに第1吸気ポート及び第2吸気ポートのそれぞれの流量係数が同一となるように構成されていると、場合によって第1吸気ポートと第2吸気ポートとの間に流量の格差が発生し、第2吸気ポートから気筒へ導かれた吸気が第1吸気ポート側へ噴き戻されたり、第1吸気ポートからの排気の導入が制限されることが起こり得る。この態様によれば、第1分岐通路を介して行われる過給が調整弁により制限されて第1吸気ポートの上流圧力と第2吸気ポートの上流圧力との間に差が生じても、第1吸気ポートの流量係数が第2吸気ポートの流量係数よりも大きく構成されて排気が流れ易いため、結果として第1吸気ポートと第2吸気ポートとの流量の格差が平準化されて第2吸気ポート側から第1吸気ポート側へ吸気が噴き戻されたり、第1吸気ポートからの排気の導入が制限されることを抑制できる。   The first intake port and the second intake port when the supercharging performed via the first branch passage is restricted by the regulating valve and the upstream pressure of the second intake port becomes higher than the upstream pressure of the first intake port If the flow rate coefficients of the two intake ports are configured to be the same, a flow rate difference may occur between the first intake port and the second intake port in some cases, and the intake air introduced from the second intake port to the cylinder. May be ejected back to the first intake port side, or introduction of exhaust gas from the first intake port may be restricted. According to this aspect, even if the supercharging performed through the first branch passage is limited by the regulating valve and a difference occurs between the upstream pressure of the first intake port and the upstream pressure of the second intake port, Since the flow coefficient of one intake port is configured to be greater than the flow coefficient of the second intake port and the exhaust flows easily, the difference in flow rate between the first intake port and the second intake port is leveled, resulting in the second intake air. It is possible to prevent the intake air from being blown back from the port side to the first intake port side or the introduction of exhaust gas from the first intake port being restricted.
二つの吸気ポート間に流量係数の差を与える手段は特に制限されないが、例えば、一方の吸気ポートの径を他方の径よりも大きくする、一方の吸気ポートを直線状に形成し、他方を湾曲させる、等の手段を適用できる。これらの他に、前記第2吸気ポートがヘリカルポートとして構成されてもよい(請求項4)。この場合には、第2吸気ポートがヘリカルポートとして構成されて第1吸気ポートよりも相対的に流量係数が小さくされるので、上述した流量差の緩和効果と同時にスワールが気筒内に発生し、燃料と空気との混合が促進されて良好な燃焼を実現できる。   The means for giving a difference in flow coefficient between the two intake ports is not particularly limited. For example, one intake port is made larger in diameter than the other, one intake port is formed in a straight line, and the other is curved. It is possible to apply means such as In addition to these, the second intake port may be configured as a helical port. In this case, since the second intake port is configured as a helical port and the flow coefficient is relatively smaller than that of the first intake port, a swirl is generated in the cylinder simultaneously with the above-described effect of reducing the flow difference, Mixing of fuel and air is promoted and good combustion can be realized.
本発明の内燃機関の排気還流装置において、前記第1分岐通路が有する第1吸気ポートに設けられた第1吸気弁及び前記第2分岐通路が有する第2吸気ポートに設けられた第2吸気弁のそれぞれを、前記第1吸気ポートの流量係数が前記第2吸気ポートの流量係数よりも大きくなるように、リフト量及びバルブタイミングの少なくとも一方を相違させて駆動する弁駆動装置を備えてもよい(請求項5)。ここで言う「吸気ポートの流量係数」とは、吸気ポートへの流体の流れ易さを示す無次元数である。吸気ポートの前後の差圧が同一の場合には流量係数が大きいものほど流量が大きくなる。   In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, a first intake valve provided in a first intake port included in the first branch passage and a second intake valve provided in a second intake port included in the second branch passage. Each of the first and second intake ports may be provided with a valve drive device that drives at least one of the lift amount and the valve timing so that the flow coefficient of the first intake port is larger than the flow coefficient of the second intake port. (Claim 5). The “flow coefficient of the intake port” referred to here is a dimensionless number indicating the ease of fluid flow to the intake port. When the differential pressure before and after the intake port is the same, the flow rate increases as the flow rate coefficient increases.
第1吸気ポート及び第2吸気ポートのそれぞれの流量係数が同一となるように第1吸気弁及び第2吸気弁のそれぞれが駆動される態様では、調整弁にて第1分岐通路を介して行われる過給が制限されて第1吸気ポートの上流圧力よりも第2吸気ポートの上流圧力が高くなったときに、場合によって第1吸気ポートと第2吸気ポートとの間に流量の格差が発生し、第2吸気ポートから気筒へ導かれた吸気が第1吸気ポート側へ噴き戻されたり、第1吸気ポートからの排気の導入が制限されることが起こり得る。この態様によれば、第1分岐通路を介して行われる過給が調整弁により制限されて第1吸気ポートの上流圧力と第2吸気ポートの上流圧力との間に差が生じても、第1吸気弁及び第2吸気弁のそれぞれが、第1吸気ポートの流量係数が第2吸気ポートの流量係数よりも大きくなるようにリフト量及びバルブタイミングの少なくとも一方を相違させて弁駆動装置にて駆動されるので、結果として第1吸気ポートと第2吸気ポートとの流量の格差が平準化されて第2吸気ポート側から第1吸気ポート側へ吸気が噴き戻されたり、第1吸気ポートからの排気の導入が制限されることを抑制できる。   In a mode in which each of the first intake valve and the second intake valve is driven so that the flow rate coefficients of the first intake port and the second intake port are the same, the adjustment valve performs the operation via the first branch passage. When the supercharging is limited and the upstream pressure of the second intake port becomes higher than the upstream pressure of the first intake port, a flow rate difference may occur between the first intake port and the second intake port. Then, it is possible that the intake air introduced from the second intake port to the cylinder is jetted back to the first intake port side or the introduction of exhaust gas from the first intake port is restricted. According to this aspect, even if the supercharging performed through the first branch passage is limited by the regulating valve and a difference occurs between the upstream pressure of the first intake port and the upstream pressure of the second intake port, In each of the first intake valve and the second intake valve, at least one of the lift amount and the valve timing is made different by the valve drive device so that the flow coefficient of the first intake port is larger than the flow coefficient of the second intake port. As a result, the difference in flow rate between the first intake port and the second intake port is leveled, and intake air is jetted back from the second intake port side to the first intake port side, or from the first intake port. It is possible to prevent the introduction of exhaust gas from being restricted.
この態様においては、二つの吸気ポート間でリフト量及びバルブタイミングいずれか一方を相違させてもよいし、両方を相違させてもよい。リフト量及びバルブタイミングの少なくとも一方を相違させる手段に制限はないが、例えば、互いにプロファイルの相違する少なくとも一対のカムを備えたカム機構を設けて弁駆動装置を構成してもよい。また、弁駆動装置が前記第1吸気弁及び前記第2吸気弁のそれぞれに対する前記リフト量及び前記バルブタイミングの少なくとも一方の変更が可能な可変バルブ機構を備えてもよい(請求項6)。この場合には、可変バルブ機構によって内燃機関の運転状態や、目標とする吸入ガスに対する排気の割合(EGR率)等に応じてリフト量及びバルブタイミングの少なくも一方を変更できるので、EGR率の厳格な制御が必要な場合に好都合である。   In this aspect, either the lift amount or the valve timing may be different between the two intake ports, or both may be different. The means for making at least one of the lift amount and the valve timing different is not limited. For example, a valve mechanism may be configured by providing a cam mechanism including at least a pair of cams having different profiles. In addition, the valve drive device may include a variable valve mechanism capable of changing at least one of the lift amount and the valve timing with respect to each of the first intake valve and the second intake valve. In this case, since the variable valve mechanism can change at least one of the lift amount and the valve timing according to the operating state of the internal combustion engine, the ratio of exhaust to the target intake gas (EGR rate), etc., the EGR rate This is convenient when strict control is required.
また、本発明の内燃機関の排気還流装置において、前記内燃機関には、前記過給機と直列又は並列に前記吸気通路に配置されたコンプレッサと前記コンプレッサと一体回転可能に前記排気通路に配置されたタービンとを有し、前記内燃機関の排気エネルギーを利用して駆動される他の過給機が更に設けられていてもよい(請求項7)。この態様によれば、内燃機関に対して上述した過給機と排気エネルギーを利用して駆動される他の過給機とによって二段過給が実現され、このような内燃機関に対して本発明の排気還流装置を適用することができる。   In the exhaust gas recirculation apparatus for an internal combustion engine according to the present invention, the internal combustion engine is disposed in the exhaust passage so as to be rotatable integrally with the compressor disposed in the intake passage in series or in parallel with the supercharger. And another turbocharger that is driven by using the exhaust energy of the internal combustion engine (claim 7). According to this aspect, the two-stage supercharging is realized by the supercharger described above with respect to the internal combustion engine and the other supercharger driven using the exhaust energy. The exhaust gas recirculation device of the invention can be applied.
以上説明したように、本発明によれば、内燃機関の吸気通路が過給機の下流側の分岐位置から分岐されて内燃機関の同一の気筒に対して別々に吸気を導く第1分岐通路と第2分岐通路とを有し、第1分岐通路の分岐位置と排気が導入される排気位置との間に開度調整可能な調整弁を備えているので、第1分岐通路を介して行われる過給を調整弁にて制限できるので、第1分岐通路への排気の導入を促進させると同時に第2分岐通路を介して行われる過給を継続させることができる。従って、過給機による過給が排気の還流の妨げとはならず、過給を行いながら内燃機関に対して排気の還流を行うことができる。   As described above, according to the present invention, the intake passage of the internal combustion engine is branched from the branch position on the downstream side of the supercharger, and the first branch passage that guides intake air separately to the same cylinder of the internal combustion engine, The second branch passage is provided, and an adjustment valve whose opening degree can be adjusted is provided between the branch position of the first branch passage and the exhaust position where the exhaust gas is introduced. Since supercharging can be limited by the regulating valve, introduction of exhaust gas into the first branch passage can be promoted, and at the same time, supercharging performed through the second branch passage can be continued. Accordingly, the supercharging by the supercharger does not hinder the exhaust gas recirculation, and the exhaust gas can be recirculated to the internal combustion engine while performing the supercharging.
図1は本発明の排気還流装置を適用した内燃機関の全体構成を示している。内燃機関1は4つ(図1では2つ)の気筒2が一列に並べられた直列4気筒4サイクルのディーゼルエンジンである。内燃機関1には、吸気通路3に配置されクランク軸(不図示)の回転を利用して駆動される機械式過給機(過給機)5と、排気エネルギーを利用して駆動されるターボチャージャー(他の過給機)6とが設けられている。ターボチャージャー6は、排気通路4に配置されたタービン6aと、タービン5aと一体回転可能に吸気通路3に配置されたコンプレッサ6bとを有している。機械式過給機5及びターボチャージャー6により内燃機関1に対して2段過給が実現されている。機械式過給機5は、内燃機関1に対して低速域から急加速が要求された場合のように、ターボチャージャー6のみでは過給の応答性が悪化する領域をカバーし、ターボチャージャー6の過給を補助するために設けられている。なお、機械式過給機5は内燃機関1の運転と連動して作動する形態でもよいし、クラッチ手段を利用して作動、非作動が制御される形態でもよい。ターボチャージャー6はタービン6aの上流側に可変ノズル6cが設けられた可変容量式である。この可変ノズル6cの開度は最大絞り位置(最小開度)から最小絞り位置(最大開度)までの間で調整可能であり、可変ノズル6cは内燃機関1の運転状態を適正に制御するために設けられたエンジンコントロールユニット(ECU)14に接続されて制御される。ECU14はマイクロプロセッサ、RAM、ROM等を含む周知のコンピュータである。   FIG. 1 shows an overall configuration of an internal combustion engine to which an exhaust gas recirculation apparatus of the present invention is applied. The internal combustion engine 1 is an in-line four-cylinder four-cycle diesel engine in which four (two in FIG. 1) cylinders 2 are arranged in a line. The internal combustion engine 1 includes a mechanical supercharger (supercharger) 5 that is disposed in an intake passage 3 and is driven using rotation of a crankshaft (not shown), and a turbo that is driven using exhaust energy. A charger (another supercharger) 6 is provided. The turbocharger 6 includes a turbine 6a disposed in the exhaust passage 4 and a compressor 6b disposed in the intake passage 3 so as to be rotatable integrally with the turbine 5a. The mechanical supercharger 5 and the turbocharger 6 realize two-stage supercharging for the internal combustion engine 1. The mechanical supercharger 5 covers a region where the responsiveness of supercharging is deteriorated only by the turbocharger 6 as in the case where the internal combustion engine 1 is requested to accelerate rapidly from a low speed range. It is provided to assist supercharging. The mechanical supercharger 5 may be configured to operate in conjunction with the operation of the internal combustion engine 1 or may be configured to be operated or inactivated using clutch means. The turbocharger 6 is a variable displacement type in which a variable nozzle 6c is provided on the upstream side of the turbine 6a. The opening of the variable nozzle 6c can be adjusted from the maximum throttle position (minimum opening) to the minimum throttle position (maximum opening), and the variable nozzle 6c controls the operating state of the internal combustion engine 1 appropriately. And connected to an engine control unit (ECU) 14 provided for control. The ECU 14 is a known computer including a microprocessor, RAM, ROM and the like.
内燃機関1の吸気通路3には、上流側から順番に、吸気濾過用のエアクリーナ8、吸気流量に応じた信号を出力するエアフローメータ9、コンプレッサ6b、コンプレッサ6bで圧縮された吸気を冷却する第1インタークーラ10A、スーパーチャージャ5、機械式過給機5で圧縮された吸気を冷却する第2インタークーラ10B、及び吸気流量を調整するためのスロットル弁11がそれぞれ設けられる。また、吸気通路3には機械式過給機5の上流側と第2インタークーラ10Bの下流側とを結ぶバイパス通路12が設けられ、バイパス通路12には流量調整用のバイパス弁13が設けられている。バイパス弁13の開度を適宜に調整することにより、機械式過給機5による過給圧の調整を行うことができる。バイパス弁13はECU14に接続されて制御される。   In the intake passage 3 of the internal combustion engine 1, the air cleaner 8 for filtering the intake air, the air flow meter 9 for outputting a signal corresponding to the intake air flow, the compressor 6 b, and the intake air compressed by the compressor 6 b are cooled in order from the upstream side. A first intercooler 10A, a supercharger 5, a second intercooler 10B for cooling the intake air compressed by the mechanical supercharger 5, and a throttle valve 11 for adjusting the intake air flow rate are provided. The intake passage 3 is provided with a bypass passage 12 connecting the upstream side of the mechanical supercharger 5 and the downstream side of the second intercooler 10B, and the bypass passage 12 is provided with a bypass valve 13 for adjusting the flow rate. ing. By adjusting the opening degree of the bypass valve 13 appropriately, the supercharging pressure by the mechanical supercharger 5 can be adjusted. The bypass valve 13 is connected to the ECU 14 and controlled.
吸気通路3は機械式過給機5の下流に位置する分岐位置3aからそれぞれ分岐する第1分岐通路31及び第2分岐通路32を有している。第1分岐通路31及び第2分岐通路32は同一の気筒2に対して別々に、言い換えれば同一の気筒2に対して独立に設けられている。吸気脈動を抑制するために第1分岐通路31はサージタンク33を、第2分岐通路32はサージタンク34をそれぞれ有している。サージタンク33、34の容量は互いに同一でもよく異なっていてもよい。   The intake passage 3 has a first branch passage 31 and a second branch passage 32 that respectively branch from a branch position 3 a located downstream of the mechanical supercharger 5. The first branch passage 31 and the second branch passage 32 are provided separately for the same cylinder 2, in other words, independently for the same cylinder 2. In order to suppress intake pulsation, the first branch passage 31 has a surge tank 33, and the second branch passage 32 has a surge tank 34. The capacity of the surge tanks 33 and 34 may be the same or different from each other.
図2に簡略化して示したように、第1分岐通路31は各気筒2に対してサージタンク33から分岐する分岐部31aと、各分岐部31aに設けられた第1吸気ポート35とを有し、第2分岐通路32は各気筒2に対してサージタンク34から分岐する分岐部32aと、各分岐部32aに設けられた第2吸気ポート36とを有している。各吸気ポート35、36は対応する気筒2に連通する。第1吸気ポート35は、流量係数が第2吸気ポート36の流量係数よりも大きくなるように構成されている。このため、吸気ポートの前後差圧が同一の場合には、第1吸気ポート35の方が第2吸気ポート36よりも流量が大きくなる。特に本実施形態では、詳細な図示は省略したが、第2吸気ポート36がいわゆるヘリカルポートで構成されて、第1吸気ポート35との間に流量係数の差が与えられている。従って、スワールが各気筒2内に発生し、燃料と空気との混合が促進されて良好な燃焼を実現できる。   As shown in FIG. 2 in a simplified manner, the first branch passage 31 has a branch portion 31a that branches from the surge tank 33 for each cylinder 2, and a first intake port 35 provided in each branch portion 31a. The second branch passage 32 has a branch portion 32a branching from the surge tank 34 to each cylinder 2 and a second intake port 36 provided in each branch portion 32a. Each intake port 35, 36 communicates with the corresponding cylinder 2. The first intake port 35 is configured such that the flow coefficient is larger than the flow coefficient of the second intake port 36. For this reason, when the differential pressure across the intake port is the same, the flow rate of the first intake port 35 is greater than that of the second intake port 36. In particular, in the present embodiment, although detailed illustration is omitted, the second intake port 36 is configured as a so-called helical port, and a difference in flow coefficient is given to the first intake port 35. Therefore, a swirl is generated in each cylinder 2 and the mixing of fuel and air is promoted, and good combustion can be realized.
また、内燃機関1は第1吸気ポート35を開閉する第1吸気弁37と、第2吸気ポートを開閉する第2吸気弁38と、これらの吸気弁37、38をそれぞれ開閉駆動する弁駆動装置39と、を備えている。詳細な図示は略したが、弁駆動装置39はクランク軸の回転をカム軸に伝達するものであり、このカム軸には第1吸気弁37及び第2吸気弁38のそれぞれに対応する位置に同一プロファイルの一対のカムが設けられている。これにより、これらの吸気弁37、38は同一の気筒2に対して同一リフト量及び同一バルブタイミングで弁駆動装置39にて開閉駆動される。   The internal combustion engine 1 also includes a first intake valve 37 that opens and closes the first intake port 35, a second intake valve 38 that opens and closes the second intake port, and a valve drive device that drives the intake valves 37 and 38 to open and close, respectively. 39. Although not shown in detail, the valve drive device 39 transmits the rotation of the crankshaft to the camshaft, and the camshaft is located at a position corresponding to each of the first intake valve 37 and the second intake valve 38. A pair of cams having the same profile is provided. As a result, the intake valves 37 and 38 are opened and closed by the valve drive device 39 with the same lift amount and the same valve timing with respect to the same cylinder 2.
図1に示したように、内燃機関1の排気通路4は各気筒2から排出された排気が導かれる排気マニホールド41を有し、排気マニホールド41の下流側の排気通路4には、ターボチャージャー6のタービン6aと、タービン6aの下流側に排気中の有害物質を削減するための排気浄化装置42とが設けられている。また、内燃機関1には、排気中の窒素酸化物を低減するため、排気を内燃機関1に還流させる排気還流装置15が設けられている。排気還流装置15は、排気マニホールド41と第1分岐通路31のサージタンク33とを結ぶ排気還流通路16と、排気還流通路16に設けられ、内燃機関1に還流させる排気(以下、EGRガスという場合がある。)の量を調整する排気還流弁17と、を備えている。排気還流弁17はECU14に接続されて目標となるEGR率が実現されるように制御される。EGRガスが導入される排気導入位置3bは吸気通路3の分岐位置3aよりも下流側であれば、必ずしもサージタンク33に設けなくてもよい。なお、図示しないがEGRガスを冷却する冷却装置を排気還流通路16に設けてもよい。   As shown in FIG. 1, the exhaust passage 4 of the internal combustion engine 1 has an exhaust manifold 41 through which the exhaust discharged from each cylinder 2 is guided. The exhaust passage 4 on the downstream side of the exhaust manifold 41 has a turbocharger 6. Turbine 6a and an exhaust purification device 42 for reducing harmful substances in the exhaust are provided downstream of the turbine 6a. Further, the internal combustion engine 1 is provided with an exhaust gas recirculation device 15 that recirculates the exhaust gas to the internal combustion engine 1 in order to reduce nitrogen oxide in the exhaust gas. The exhaust gas recirculation device 15 is provided in the exhaust gas recirculation passage 16 connecting the exhaust manifold 41 and the surge tank 33 of the first branch passage 31, and the exhaust gas recirculating to the internal combustion engine 1 (hereinafter referred to as EGR gas). And an exhaust gas recirculation valve 17 for adjusting the amount of the exhaust gas recirculation valve 17. The exhaust gas recirculation valve 17 is connected to the ECU 14 and controlled so as to achieve a target EGR rate. As long as the exhaust introduction position 3b into which the EGR gas is introduced is downstream of the branch position 3a of the intake passage 3, it is not necessarily provided in the surge tank 33. Although not shown, a cooling device for cooling the EGR gas may be provided in the exhaust gas recirculation passage 16.
一般に、排気還流装置15によりEGRガスを吸気系に導入する際には、EGRガスを導入する吸気系の圧力よりもEGRガスを取り出す排気系の圧力が高いことが必要である。しかしながら、本実施形態の如く、クランク軸の回転を利用して駆動される機械式過給機を含んだ過給システムの場合、機械式過給機の作動により吸気系の圧力が排気系の圧力の上昇を伴わずに上昇するため、排気系と吸気系との圧力バランスが崩れ、ときには排気系よりも吸気系の圧力が高くなり、圧力バランスが逆転してEGRガスの導入が制限される場合もある。   Generally, when the EGR gas is introduced into the intake system by the exhaust gas recirculation device 15, it is necessary that the pressure of the exhaust system for extracting the EGR gas is higher than the pressure of the intake system that introduces the EGR gas. However, in the case of a supercharging system including a mechanical supercharger driven using the rotation of the crankshaft as in this embodiment, the pressure of the intake system is changed by the operation of the mechanical supercharger. When the pressure balance between the exhaust system and the intake system is lost, sometimes the pressure in the intake system is higher than that in the exhaust system, and the pressure balance is reversed to restrict the introduction of EGR gas. There is also.
そこで、本実施形態では、内燃機関1に対して2段過給が行われている際、即ち機械式過給機5とターボチャージャー6とにより同時に過給が行われている際にEGRガスの導入を促進するため、吸気通路3の分岐位置3aとEGRガスが導入される排気導入位置3bとの間に過給圧調整弁(調整弁)18が設けられている。過給圧調整弁18は第1分岐通路31を全閉する全閉位置からこれを全開する全開位置までの間で開度調整可能であり、ECU14と接続されて適宜に開度制御が行われる。これにより、第1分岐通路31を介して行われる過給を制限できる。なお、過給圧調整弁18の形態には特に制限がなく、開度調整が可能なものであれば、バタフライ弁や仕切り弁等の形態で実現してもよい。   Therefore, in the present embodiment, when the internal combustion engine 1 is being supercharged in two stages, that is, when supercharging is simultaneously performed by the mechanical supercharger 5 and the turbocharger 6, the EGR gas In order to facilitate introduction, a supercharging pressure adjustment valve (regulation valve) 18 is provided between the branch position 3a of the intake passage 3 and the exhaust introduction position 3b into which EGR gas is introduced. The supercharging pressure adjustment valve 18 can be adjusted in opening from a fully closed position where the first branch passage 31 is fully closed to a fully opened position where the first branch passage 31 is fully opened, and is connected to the ECU 14 to appropriately control the opening. . Thereby, the supercharging performed via the 1st branch passage 31 can be restricted. The form of the supercharging pressure adjustment valve 18 is not particularly limited, and may be realized in the form of a butterfly valve, a gate valve or the like as long as the opening degree can be adjusted.
次に、ECU14による、可変ノズル6c、バイパス弁13、排気還流弁17、及び過給圧調整弁18のそれぞれの開度制御の概要について説明する。図3〜図6は各制御対象の開度を内燃機関1の機関回転数(回転速度)及び負荷に関連づけた制御マップの概略を示している。まず、機関回転数及び負荷がともに低いときは、タービン6aを通過する排気の量が少ないので、排気取出位置4b(図1)の圧力を高めてEGRガスを入れ易くするため、図3に示すように、可変ノズル6cの開度を閉じ側に制御して排気がタービン6aを通過しにくくする。バイパス弁13の開度は、図4に示すように、機械式過給機5によって過給圧が上がり過ぎないように開き側に制御される。排気還流弁17の開度は、図5に示すように、EGRガスが通り易くするように開き側に制御される。過給圧調整弁18の開度は、図6に示すように、第1分岐通路31を介して行われる過給が制限されるように閉じ側に制御される。   Next, an outline of the opening control of the variable nozzle 6c, the bypass valve 13, the exhaust gas recirculation valve 17, and the supercharging pressure adjustment valve 18 by the ECU 14 will be described. 3 to 6 schematically show a control map in which the opening degree of each control object is associated with the engine speed (rotational speed) and the load of the internal combustion engine 1. First, when both the engine speed and the load are low, the amount of exhaust passing through the turbine 6a is small, so that the EGR gas can be easily introduced by increasing the pressure at the exhaust extraction position 4b (FIG. 1). Thus, the opening degree of the variable nozzle 6c is controlled to the closed side to make it difficult for the exhaust to pass through the turbine 6a. As shown in FIG. 4, the opening degree of the bypass valve 13 is controlled by the mechanical supercharger 5 so that the supercharging pressure does not increase too much. As shown in FIG. 5, the opening degree of the exhaust gas recirculation valve 17 is controlled to the open side so that the EGR gas can easily pass therethrough. As shown in FIG. 6, the opening degree of the supercharging pressure adjusting valve 18 is controlled to the closed side so that supercharging performed via the first branch passage 31 is limited.
一方、機関回転数及び負荷がともに高いときは、タービン6aを通過する排気の量が多いので、図3に示すように、排気取出位置4bの圧力が上がり過ぎないように可変ノズル6cの開度を開き側に制御して排気がタービン6aを通過し易くする。バイパス弁13の開度は、図4に示すように、機械式過給機5によって過給を効かせるため閉じ側に制御される。排気還流弁17の開度は、図5に示すように、EGRガスの通過量が多くなり過ぎないように閉じ側に制御される。過給圧調整弁18の開度は、図6に示すようにEGRガスが導入され過ぎないように開き側に制御される。   On the other hand, when both the engine speed and the load are high, the amount of exhaust gas passing through the turbine 6a is large. Therefore, as shown in FIG. 3, the opening of the variable nozzle 6c is set so that the pressure at the exhaust extraction position 4b does not rise too much. Is controlled to the open side so that the exhaust gas easily passes through the turbine 6a. As shown in FIG. 4, the opening degree of the bypass valve 13 is controlled to the closed side in order to effect supercharging by the mechanical supercharger 5. As shown in FIG. 5, the opening degree of the exhaust gas recirculation valve 17 is controlled to the closed side so that the passing amount of the EGR gas does not increase too much. The opening degree of the supercharging pressure adjustment valve 18 is controlled to the opening side so that EGR gas is not introduced excessively as shown in FIG.
このように、ECU14が内燃機関1の運転状態に応じて各制御対象の開度を制御することにより運転状態に応じた排気還流量(EGR量)を得ることができる。   Thus, the ECU 14 can obtain the exhaust gas recirculation amount (EGR amount) according to the operating state by controlling the opening degree of each control object according to the operating state of the internal combustion engine 1.
以上の形態によれば、内燃機関1に対して2段過給が行われている際に、調整弁18の開度が閉じ側に制御されることにより、つまり第1分岐通路31が絞られることにより第1分岐通路31を介して行われる過給が制限され調整弁16の下流側に位置する排気導入位置3bの圧力上昇を抑えることができる。このため、排気還流装置15によってEGRガスを導入する際に、排気導入位置3bとEGRガスを取り出す排気取出位置4bとの圧力バランスの崩れを抑制できるので、EGRガスの導入を促進できる。そして、第2分岐通路32を介して行われる過給はそのまま継続できる。従って、EGRガスの導入のために機械式過給機5による過給を停止する必要が生じたり、或いは機械式過給機5による過給を必要とする領域でEGRガスの導入が制限される等の不都合を回避できる。また、排気を還流させる必要がないときには、過給圧調整弁18の開度を開き側に調整することにより第1分岐通路31を介して行われる過給の制限を解除することもできる。これにより、第1分岐通路31及び第2分岐通路32のそれぞれを介して過給が行われて内燃機関1の性能低下を抑えることもできる。更に、第1分岐通路31の排気導入位置3bを可能な限り内燃機関1の気筒2側に近づけて排気導入位置3bから気筒2までの容積の増大を抑えることもできる。このため、排気還流装置15の応答性の悪化を抑制できる。   According to the above embodiment, when the two-stage supercharging is performed on the internal combustion engine 1, the opening degree of the regulating valve 18 is controlled to the closed side, that is, the first branch passage 31 is throttled. As a result, the supercharging performed via the first branch passage 31 is limited, and an increase in pressure at the exhaust introduction position 3b located on the downstream side of the regulating valve 16 can be suppressed. For this reason, when the EGR gas is introduced by the exhaust gas recirculation device 15, the collapse of the pressure balance between the exhaust introduction position 3b and the exhaust extraction position 4b from which the EGR gas is taken out can be suppressed, so that the introduction of the EGR gas can be promoted. And the supercharging performed via the 2nd branch passage 32 can be continued as it is. Therefore, it is necessary to stop the supercharging by the mechanical supercharger 5 for the introduction of the EGR gas, or the introduction of the EGR gas is limited in a region where the supercharging by the mechanical supercharger 5 is required. Etc. can be avoided. Further, when it is not necessary to recirculate the exhaust gas, the restriction of supercharging performed via the first branch passage 31 can be canceled by adjusting the opening of the supercharging pressure adjusting valve 18 to the open side. Thereby, supercharging is performed via each of the 1st branch passage 31 and the 2nd branch passage 32, and it can also control the performance fall of internal combustion engine 1. Further, the exhaust introduction position 3b of the first branch passage 31 can be brought as close as possible to the cylinder 2 side of the internal combustion engine 1 to suppress an increase in volume from the exhaust introduction position 3b to the cylinder 2. For this reason, the deterioration of the responsiveness of the exhaust gas recirculation device 15 can be suppressed.
また、気筒2毎に設けられた第1吸気ポート35及び第2吸気ポート36のそれぞれについて、第1吸気ポート35の流量係数が第2吸気ポート36の流量係数よりも大きくなるように構成されているので、第1分岐通路31を介して行われる過給が過給圧調整弁18により制限されて第1吸気ポート35の上流圧力と第2吸気ポート36の上流圧力との間に差が生じても、結果として第1吸気ポート35と第2吸気ポート36との流量の格差が平準化されて第2吸気ポート36側から第1吸気ポート35側へ吸気が噴き戻されたり、第1吸気ポート35からの排気の導入が制限されることを抑制できる。   Further, each of the first intake port 35 and the second intake port 36 provided for each cylinder 2 is configured such that the flow coefficient of the first intake port 35 is larger than the flow coefficient of the second intake port 36. Therefore, the supercharging performed through the first branch passage 31 is limited by the supercharging pressure adjusting valve 18, and a difference occurs between the upstream pressure of the first intake port 35 and the upstream pressure of the second intake port 36. However, as a result, the difference in flow rate between the first intake port 35 and the second intake port 36 is leveled, and the intake air is blown back from the second intake port 36 side to the first intake port 35 side, or the first intake port 35 It is possible to prevent the introduction of exhaust from the port 35 from being restricted.
本発明は、以上の実施形態に限定されず、種々の形態で実施してもよい。内燃機関1に搭載される過給システムは、図1の形態に制限されず、機械式過給機5の代わりに電動機の回転を利用して駆動される電動コンプレッサ等の電動式過給機を設けてもよい。また、このような過給機とターボチャージャーとが吸気通路に直列に配置される形態に限らず、これらが吸気通路に並列に配置される形態でもよい。また、このような過給機とターボチャージャーとの間で2段過給が行われることは必ずしも必要なく、ターボチャージャーが設けられていない形態でもよい。要は、機械式過給機や電動式過給機のように作動に際して内燃機関の排気系の圧力上昇を伴わない過給機、言い換えると内燃機関の排気エネルギー以外を駆動源とした過給機を含む過給システムを搭載した内燃機関に対して本発明を適用できる。   The present invention is not limited to the above embodiment, and may be implemented in various forms. The supercharging system mounted on the internal combustion engine 1 is not limited to the form shown in FIG. 1, and instead of the mechanical supercharger 5, an electric supercharger such as an electric compressor driven using the rotation of the electric motor is used. It may be provided. Further, the supercharger and the turbocharger are not limited to be arranged in series in the intake passage, and may be arranged in parallel in the intake passage. Further, it is not always necessary to perform the two-stage supercharging between the supercharger and the turbocharger, and a form in which no turbocharger is provided may be used. In short, a turbocharger that does not increase the pressure of the exhaust system of the internal combustion engine during operation like a mechanical supercharger or an electric supercharger, in other words, a supercharger that uses a drive source other than the exhaust energy of the internal combustion engine. The present invention can be applied to an internal combustion engine equipped with a supercharging system including
以上の実施形態では、第2吸気ポート36をヘリカルポートとして第1吸気ポート36との間に流量係数の差を与えたが、例えば、第1吸気ポート35の径を第2吸気ポート36の径よりも大きくする、或いは、第1吸気ポート35を直線状に形成し、第2吸気ポート36を湾曲させる、等の形態でもよい。   In the above embodiment, the second intake port 36 is used as a helical port and a difference in flow coefficient is given to the first intake port 36. For example, the diameter of the first intake port 35 is changed to the diameter of the second intake port 36. The first intake port 35 may be formed in a straight line and the second intake port 36 may be curved.
二つの吸気ポート自体の形態を互いに相違させずとも、各ポートを開閉する第1吸気弁及び第2吸気弁のリフト量及びバルブタイミングの少なくとも一方を相違させることにより二つの吸気ポート間に流量係数の差を付与することもできる。例えば、図2に示した弁駆動装置39を、互いにプロファイルの相違する少なくとも一対のカムを備えたカム機構を備えたものに変更し、リフト量及びバルブタイミングの少なくとも一方を相違させてもよい。また、弁駆動装置39を、リフト量及びバルブタイミングの少なくとも一方の変更が可能な周知の可変バルブ機構を備えたものに変更し、可変バルブ機構を図1のECU14で制御してもよい。この場合には可変バルブ機構によって内燃機関1の運転状態や、目標とするEGR率等に応じてリフト量及びバルブタイミングの少なくも一方を変更できるので、EGR率の厳格な制御が必要な場合に好都合である。なお、二つの吸気ポート自体の形態を相違させ、かつ各吸気ポートを開閉する吸気弁のリフト量及びバルブタイミングの少なくとも一方を相違させてもよい。   The flow coefficient between the two intake ports can be reduced by making at least one of the lift amount and the valve timing of the first intake valve and the second intake valve that open and close each port without making the forms of the two intake ports themselves different from each other. It is also possible to give the difference. For example, the valve drive device 39 shown in FIG. 2 may be changed to one having a cam mechanism including at least a pair of cams having different profiles, and at least one of the lift amount and the valve timing may be made different. Further, the valve driving device 39 may be changed to a known variable valve mechanism that can change at least one of the lift amount and the valve timing, and the variable valve mechanism may be controlled by the ECU 14 in FIG. In this case, at least one of the lift amount and the valve timing can be changed by the variable valve mechanism in accordance with the operating state of the internal combustion engine 1, the target EGR rate, etc., so that strict control of the EGR rate is necessary. Convenient. It should be noted that the shapes of the two intake ports themselves may be different, and at least one of the lift amount and valve timing of the intake valve that opens and closes each intake port may be different.
なお、本発明はディーゼルエンジンに好適に適用されるが、ガソリンエンジンに適用することもできる。   In addition, although this invention is applied suitably for a diesel engine, it can also be applied to a gasoline engine.
本発明の排気還流装置を適用した内燃機関の全体構成を示した図。The figure which showed the whole structure of the internal combustion engine to which the exhaust gas recirculation apparatus of this invention is applied. サージタンク下流付近の詳細を簡略化して示した図。The figure which simplified and showed the detail of the surge tank downstream vicinity. 可変ノズルの開度を内燃機関の機関回転数及び負荷に関連づけた制御マップの概略を示した図。The figure which showed the outline of the control map which linked | related the opening degree of the variable nozzle with the engine speed and load of the internal combustion engine. バイパス弁の開度を内燃機関の機関回転数及び負荷に関連づけた制御マップの概略を示した図。The figure which showed the outline of the control map which linked | related the opening degree of the bypass valve with the engine speed and load of the internal combustion engine. 排気還流弁の開度を内燃機関の機関回転数及び負荷に関連づけた制御マップの概略を示した図。The figure which showed the outline of the control map which linked | related the opening degree of the exhaust gas recirculation valve with the engine speed and load of the internal combustion engine. 過給圧調整弁の開度を内燃機関の機関回転数及び負荷に関連づけた制御マップの概略を示した図。The figure which showed the outline of the control map which linked | related the opening degree of the supercharging pressure adjustment valve with the engine speed and load of the internal combustion engine.
符号の説明Explanation of symbols
1 内燃機関
2 気筒
3 吸気通路
3a 分岐位置
3b 排気導入位置
4 排気通路
5 機械式過給機(過給機)
6 ターボチャージャー(他の過給機)
6a タービン
6b コンプレッサ
14 ECU(調整弁制御手段)
15 排気還流装置
16 排気還流通路
18 過給圧調整弁(調整弁)
31 第1分岐通路
32 第2分岐通路
35 第1吸気ポート
36 第2吸気ポート
37 第1吸気弁
38 第2吸気弁
39 弁駆動装置
DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinder 3 Intake passage 3a Branch position 3b Exhaust introduction position 4 Exhaust passage 5 Mechanical supercharger (supercharger)
6 Turbocharger (other turbochargers)
6a Turbine 6b Compressor 14 ECU (regulating valve control means)
15 Exhaust gas recirculation device 16 Exhaust gas recirculation passage 18 Supercharging pressure regulating valve (regulating valve)
31 First branch passage 32 Second branch passage 35 First intake port 36 Second intake port 37 First intake valve 38 Second intake valve 39 Valve drive device

Claims (7)

  1. 内燃機関のクランク軸の回転を利用して又は電動機の回転を利用して駆動される過給機が吸気通路に設けられた内燃機関に適用される内燃機関の排気還流装置において、
    前記内燃機関の前記吸気通路が、前記過給機の下流側の分岐位置から分岐されて前記内燃機関の同一の気筒に対して別々に吸気を導く第1分岐通路と第2分岐通路とを有し、
    前記内燃機関の排気通路から前記第1分岐通路へ排気を導く排気還流通路と、前記吸気通路の前記分岐位置と前記排気還流通路にて排気が導入される排気導入位置との間の前記第1分岐通路に配置され、前記第1分岐通路を全閉する全閉位置から前記第1分岐通路を全開する全開位置までの間で開度調整可能な調整弁と、を備えることを特徴とする内燃機関の排気還流装置。
    In an exhaust gas recirculation apparatus for an internal combustion engine that is applied to an internal combustion engine in which a supercharger that is driven using rotation of a crankshaft of the internal combustion engine or using rotation of an electric motor is provided in an intake passage,
    The intake passage of the internal combustion engine has a first branch passage and a second branch passage that are branched from a branch position on the downstream side of the supercharger and separately guide intake air to the same cylinder of the internal combustion engine. And
    The exhaust gas recirculation passage for introducing exhaust gas from the exhaust passage of the internal combustion engine to the first branch passage, and the first position between the branch position of the intake passage and the exhaust introduction position where the exhaust gas is introduced in the exhaust gas recirculation passage. And an adjustment valve that is disposed in the branch passage and is capable of adjusting an opening between a fully closed position where the first branch passage is fully closed and a fully open position where the first branch passage is fully opened. Engine exhaust gas recirculation device.
  2. 前記第1分岐通路を介して前記内燃機関に排気を還流させる場合に、前記第1分岐通路を介して行われる過給が制限されるように前記調整弁の開度を閉じ側に制御する調整弁制御手段を更に備えることを特徴とする請求項1に記載の内燃機関の排気還流装置。   Adjustment for controlling the opening degree of the adjusting valve to the closed side so that supercharging performed through the first branch passage is limited when exhaust gas is recirculated to the internal combustion engine through the first branch passage. The exhaust gas recirculation apparatus for an internal combustion engine according to claim 1, further comprising valve control means.
  3. 前記第1分岐通路が有する第1吸気ポートは、その流量係数が前記第2分岐通路が有する第2吸気ポートの流量係数よりも大きくなるように構成されていることを特徴とする請求項1又は2に記載の内燃機関の排気還流装置。   The first intake port of the first branch passage is configured such that the flow coefficient thereof is larger than the flow coefficient of the second intake port of the second branch passage. 2. An exhaust gas recirculation device for an internal combustion engine according to 2.
  4. 前記第2分岐通路が有する前記第2吸気ポートがヘリカルポートとして構成されていることを特徴とする請求項3に記載の内燃機関の排気還流装置。   The exhaust gas recirculation apparatus for an internal combustion engine according to claim 3, wherein the second intake port of the second branch passage is configured as a helical port.
  5. 前記第1分岐通路が有する第1吸気ポートに設けられた第1吸気弁及び前記第2分岐通路が有する第2吸気ポートに設けられた第2吸気弁のそれぞれを、前記第1吸気ポートの流量係数が前記第2吸気ポートの流量係数よりも大きくなるように、リフト量及びバルブタイミングの少なくとも一方を相違させて駆動する弁駆動装置を備えることを特徴とする請求項1〜4のいずれか一項に記載の内燃機関の排気還流装置。   The first intake valve provided in the first intake port of the first branch passage and the second intake valve provided in the second intake port of the second branch passage are respectively connected to the flow rate of the first intake port. 5. The valve drive device according to claim 1, further comprising: a valve drive device that drives the valve by varying at least one of a lift amount and a valve timing so that the coefficient is larger than the flow coefficient of the second intake port. An exhaust gas recirculation device for an internal combustion engine according to the item.
  6. 前記弁駆動装置は、前記第1吸気弁及び前記第2吸気弁のそれぞれに対する前記リフト量及び前記バルブタイミングの少なくとも一方の変更が可能な可変バルブ機構を備えることを特徴とする請求項5に記載の内燃機関の排気還流装置。   The said valve drive apparatus is provided with the variable valve mechanism in which at least one of the said lift amount with respect to each of the said 1st intake valve and the said 2nd intake valve and the said valve timing can be changed. An exhaust gas recirculation device for an internal combustion engine.
  7. 前記内燃機関には、前記過給機と直列又は並列に前記吸気通路に配置されたコンプレッサと前記コンプレッサと一体回転可能に前記排気通路に配置されたタービンとを有し、前記内燃機関の排気エネルギーを利用して駆動される他の過給機が更に設けられていることを特徴とする請求項1〜6のいずれか一項に記載の内燃機関の排気還流装置。   The internal combustion engine includes a compressor disposed in the intake passage in series or in parallel with the supercharger, and a turbine disposed in the exhaust passage so as to rotate integrally with the compressor, and the exhaust energy of the internal combustion engine The exhaust gas recirculation apparatus for an internal combustion engine according to any one of claims 1 to 6, further comprising another supercharger that is driven by using the engine.
JP2005064173A 2005-03-08 2005-03-08 Exhaust gas recirculation device for internal combustion engine Pending JP2006249949A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011007051A (en) * 2009-06-23 2011-01-13 Hino Motors Ltd Diesel engine
JP2012057491A (en) * 2010-09-06 2012-03-22 Toyota Motor Corp Engine control device
JP2012057490A (en) * 2010-09-06 2012-03-22 Toyota Motor Corp Engine control device
CN113250810A (en) * 2021-06-29 2021-08-13 四川迅联达智能科技有限公司 Method and system for stabilizing intake pressure of two-stroke engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011007051A (en) * 2009-06-23 2011-01-13 Hino Motors Ltd Diesel engine
JP2012057491A (en) * 2010-09-06 2012-03-22 Toyota Motor Corp Engine control device
JP2012057490A (en) * 2010-09-06 2012-03-22 Toyota Motor Corp Engine control device
CN113250810A (en) * 2021-06-29 2021-08-13 四川迅联达智能科技有限公司 Method and system for stabilizing intake pressure of two-stroke engine

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