JP2007132190A

JP2007132190A - Control device for internal combustion engine

Info

Publication number: JP2007132190A
Application number: JP2005323090A
Authority: JP
Inventors: Toshio Ito; 敏雄伊藤
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2005-11-08
Filing date: 2005-11-08
Publication date: 2007-05-31

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine, suppressing the output deterioration of the internal combustion engine by using a mask wall for changing the flow of intake air in a combustion chamber. <P>SOLUTION: The control device to be applied for the engine 1 comprises the mask wall 23 provided on part of the periphery of a combustion chamber side opening portion of an intake port 10 connected to the combustion chamber 7 and having an opposite face 23a opposite to the flow of intake air flowing from the intake port 10 into the combustion chamber 7, a turbocharger 13 for turbocharging the intake air to the combustion chamber 7, and a waste gate valve 17 for changing the turbocharging pressure of the turbocharger 13. Herein, a combustion pressure sensor 22 is provided for acquiring combustion pressure in the combustion chamber 7. An ECU 30 controls the operation of the waste gate valve 17 in accordance with the combustion pressure acquired by the combustion pressure sensor 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、吸気ポートから燃焼室に流入する吸気の流れを変更するマスク壁を備えた内燃機関の制御装置に関する。 The present invention relates to a control device for an internal combustion engine including a mask wall that changes the flow of intake air flowing into an air combustion chamber from an intake port.

吸気ポートから燃焼室に導入される吸気の流れを偏流させる吸気マスク壁を燃焼室内に備えた内燃機関が知られている（特許文献１参照）。
特開平７−７１３１０号公報 There is known an internal combustion engine provided with an intake mask wall in the combustion chamber for drifting the flow of intake air introduced from the intake port into the combustion chamber (see Patent Document 1).
Japanese Patent Laid-Open No. 7-71310

この吸気マスク壁は吸気流れの抵抗となるため、燃焼室に吸入される吸入空気量が減少して内燃機関の出力が低下するおそれがある。 Since this intake mask wall provides resistance to the intake air flow, the amount of intake air taken into the combustion chamber may decrease and the output of the internal combustion engine may decrease.

そこで、本発明は、マスク壁等により燃焼室内の吸気流れを変更でき、かつ内燃機関の出力低下を抑制可能な内燃機関の制御装置を提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a control device for an internal combustion engine that can change the intake air flow in the combustion chamber by a mask wall or the like and can suppress a decrease in output of the internal combustion engine.

本発明の内燃機関の制御装置は、燃焼室に接続される吸気ポートの燃焼室側開口部の周囲の一部、及び前記吸気ポートを開閉する吸気弁の傘部の少なくともいずれか一方に設けられ、前記吸気ポートから前記燃焼室に流入する吸気の流れと対向する対向面を有する吸気流れ変更手段と、前記燃焼室に吸気を過給する過給機と、前記過給機の過給圧を変更する過給圧変更手段と、を備えた内燃機関に適用される制御装置において、前記燃焼室の燃焼圧を取得する燃焼圧取得手段と、前記燃焼圧取得手段により取得された燃焼圧に基づいて前記過給圧変更手段の動作を制御する動作制御手段と、を備えていることにより、上述した課題を解決する（請求項１）。 The control device for an internal combustion engine of the present invention is provided in at least one of a part around the combustion chamber side opening of the intake port connected to the combustion chamber and an umbrella portion of the intake valve that opens and closes the intake port. An intake flow changing means having an opposing surface facing the flow of intake air flowing into the combustion chamber from the intake port, a supercharger for supercharging intake air into the combustion chamber, and a supercharging pressure of the supercharger. In a control device applied to an internal combustion engine provided with a supercharging pressure changing means for changing, based on the combustion pressure acquiring means for acquiring the combustion pressure of the combustion chamber and the combustion pressure acquired by the combustion pressure acquiring means And the operation control means for controlling the operation of the supercharging pressure changing means to solve the above-mentioned problem (claim 1).

燃焼圧は、燃焼室内における燃料の燃焼状態と相関関係を有している。例えば、燃焼室に供給された燃料量に対して吸入空気量が不足すると燃焼室内にて燃料が適切に燃焼しないため、燃焼圧が低下する。本発明の内燃機関によれば、この燃焼圧に基づいて過給機の過給圧を変更することができるので、燃焼室に燃料が適切に燃焼する量の吸気を供給できる。そのため、吸気抵抗吸気流れ変更手段によって燃焼室内の吸気流れを変更しつつ、燃焼室内にて燃料を適切に燃焼させて内燃機関の出力低下を抑制できる。 The combustion pressure has a correlation with the combustion state of the fuel in the combustion chamber. For example, if the amount of intake air is insufficient with respect to the amount of fuel supplied to the combustion chamber, the fuel will not burn properly in the combustion chamber, and the combustion pressure will decrease. According to the internal combustion engine of the present invention, since the supercharging pressure of the supercharger can be changed based on this combustion pressure, it is possible to supply intake air in an amount that allows fuel to burn appropriately to the combustion chamber. Therefore, while changing the intake flow in the combustion chamber by the intake resistance intake flow changing means, it is possible to appropriately burn the fuel in the combustion chamber and suppress the output reduction of the internal combustion engine.

本発明の制御装置の一形態において、前記動作制御手段は、前記内燃機関の運転状態に基づいて設定される判定燃焼圧よりも前記燃焼圧取得手段により取得された燃焼圧が低い場合に前記過給機の過給圧が上昇するように前記過給圧変更手段の動作を制御してもよい（請求項２）。燃焼室に供給される燃料量は内燃機関の運転状態に基づいて設定され、この燃料量に対して吸入空気量が不足すると燃焼圧が低下する。そこで、内燃機関の運転状態に基づいて設定される判定燃焼圧よりも燃焼圧が低い場合は、過給圧を上昇させて吸入空気量を増加させ、内燃機関の出力低下を抑制する。 In one form of the control device of the present invention, the operation control means is configured to detect the excess when the combustion pressure acquired by the combustion pressure acquisition means is lower than a determination combustion pressure set based on an operating state of the internal combustion engine. The operation of the supercharging pressure changing means may be controlled so that the supercharging pressure of the charger increases (Claim 2). The amount of fuel supplied to the combustion chamber is set based on the operating state of the internal combustion engine. If the amount of intake air is insufficient with respect to this amount of fuel, the combustion pressure decreases. Therefore, when the combustion pressure is lower than the determination combustion pressure set based on the operating state of the internal combustion engine, the boost pressure is increased to increase the intake air amount, thereby suppressing the output decrease of the internal combustion engine.

この形態においては、前記過給機としてターボ過給機が設けられるとともに、前記燃焼室に接続される排気ポートを開閉する排気弁の開弁時期を変更可能な可変動弁機構をさらに備え、前記動作制御手段は、前記判定燃焼圧よりも前記燃焼圧取得手段により取得された燃焼圧が低い場合に前記排気弁の開弁時期が進角されるように前記可変動弁機構の動作を制御してもよい（請求項３）。排気弁の開弁時期を進角させる、すなわち排気弁の開弁時期を早めることにより、ターボ過給機に開弁時期を進角させる前よりも高温の排気を供給して過給圧を上昇させることができる。そのため、吸入空気量を増加させて内燃機関の出力低下を抑制できる。 In this embodiment, a turbocharger is provided as the supercharger, and further includes a variable valve mechanism that can change an opening timing of an exhaust valve that opens and closes an exhaust port connected to the combustion chamber, The operation control means controls the operation of the variable valve mechanism so that the opening timing of the exhaust valve is advanced when the combustion pressure acquired by the combustion pressure acquisition means is lower than the determined combustion pressure. (Claim 3). By increasing the opening timing of the exhaust valve, that is, by accelerating the opening timing of the exhaust valve, the turbocharger is supplied with higher-temperature exhaust than before the opening timing is advanced, and the boost pressure is increased. Can be made. Therefore, the intake air amount can be increased to suppress a decrease in the output of the internal combustion engine.

本発明の制御装置の一形態において、前記対向面は、前記吸気ポートから前記燃焼室が形成されるシリンダの中心に向かって流入する吸気の流れと対向するように設けられていてもよい（請求項４）。このように対向面を設けることで、シリンダの中心側への吸気の流れを阻害し、吸気をシリンダの外周側に偏って流すことができる。そのため、吸気によってシリンダ内壁を冷却することができる。 In one form of the control device of the present invention, the facing surface may be provided so as to face a flow of intake air flowing from the intake port toward a center of a cylinder in which the combustion chamber is formed (claim). Item 4). By providing the opposing surface in this way, it is possible to inhibit the flow of intake air toward the center of the cylinder and flow the intake air toward the outer peripheral side of the cylinder. Therefore, the cylinder inner wall can be cooled by intake air.

以上に説明したように、本発明によれば、燃焼圧に基づいて過給圧を変更し、燃焼室に燃料が適切に燃焼可能な量の吸気を供給するので、吸気流れ変更手段によって燃焼室内の吸気の流れを変更しつつ内燃機関の出力低下を抑制できる。 As described above, according to the present invention, the supercharging pressure is changed based on the combustion pressure, and the intake air is supplied to the combustion chamber in such an amount that the fuel can be combusted appropriately. The output reduction of the internal combustion engine can be suppressed while changing the flow of intake air.

図１は、本発明の制御装置が組み込まれた内燃機関の一例を示している。内燃機関（以降、エンジンと称することもある。）１は車両に走行用動力源として搭載される火花点火式ガソリンエンジンであり、シリンダブロック２とシリンダヘッド３とを備えている。シリンダブロック２には複数のシリンダ４（図１では一つのみを示す。）が形成され、各シリンダ４にはピストン５が往復動自在にそれぞれ挿入され、ピストン５はコンロッド６によって不図示のクランク軸と連結されている。各シリンダ４には、シリンダ４の内壁、ピストン５、及びシリンダヘッド３によって燃焼室７がそれぞれ形成される。エンジン１は吸気通路８及び排気通路９を備えており、各燃焼室７には吸気通路８の一部を形成する吸気ポート１０と、排気通路９の一部を形成する排気ポート１１とがそれぞれ接続されている。吸気通路８には、スロットルバルブ１２、ターボ過給機１３のコンプレッサ１３ａ、及び吸気を冷却するインタークーラ１４が設けられている。排気通路９には、ターボ過給機１３のタービン１３ｂ、及び排気を浄化するための排気浄化触媒１５が設けられている。また、排気通路９にはターボ過給機１３のタービン１３ｂをバイパスするバイパス通路１６が設けられ、バイパス通路１６にはバイパス通路１６を通過する排気の流量を調整するウェイストゲートバルブ１７が設けられている。ウェイストゲートバルブ１７はアクチュエータ１７ａと弁体１７ｂとを備えており、弁体１７ｂはアクチュエータ１７ａによって開閉駆動される。また、エンジン１は、吸気ポート１０を開閉する吸気弁１８と、排気ポート１１を開閉する排気弁１９と、吸気弁１８及び排気弁１９の開弁時期、閉弁時期、作用角、及びリフト量などの動弁特性をそれぞれ変更可能な可変動弁機構２０とを備えている。 FIG. 1 shows an example of an internal combustion engine in which the control device of the present invention is incorporated. An internal combustion engine (hereinafter also referred to as an engine) 1 is a spark ignition gasoline engine mounted on a vehicle as a driving power source, and includes a cylinder block 2 and a cylinder head 3. A plurality of cylinders 4 (only one is shown in FIG. 1) are formed in the cylinder block 2, and pistons 5 are inserted into the respective cylinders 4 so as to be reciprocally movable. It is connected to the shaft. In each cylinder 4, a combustion chamber 7 is formed by the inner wall of the cylinder 4, the piston 5, and the cylinder head 3. The engine 1 includes an intake passage 8 and an exhaust passage 9. Each combustion chamber 7 has an intake port 10 that forms part of the intake passage 8 and an exhaust port 11 that forms part of the exhaust passage 9. It is connected. The intake passage 8 is provided with a throttle valve 12, a compressor 13a of the turbocharger 13, and an intercooler 14 for cooling the intake air. The exhaust passage 9 is provided with a turbine 13b of the turbocharger 13 and an exhaust purification catalyst 15 for purifying exhaust. The exhaust passage 9 is provided with a bypass passage 16 that bypasses the turbine 13 b of the turbocharger 13, and the bypass passage 16 is provided with a waste gate valve 17 that adjusts the flow rate of exhaust gas that passes through the bypass passage 16. Yes. The waste gate valve 17 includes an actuator 17a and a valve body 17b, and the valve body 17b is driven to open and close by the actuator 17a. Further, the engine 1 includes an intake valve 18 that opens and closes the intake port 10, an exhaust valve 19 that opens and closes the exhaust port 11, and valve opening timing, valve closing timing, operating angle, and lift amount of the intake valve 18 and the exhaust valve 19. And a variable valve mechanism 20 that can change the valve characteristics.

図２は、燃焼室７を図１の下側から見た図を示している。図１及び図２に示したように燃焼室７には、吸気弁１８、排気弁１９、燃焼室７内の燃焼混合気に点火する点火プラグ２１、燃焼室７の燃焼圧（シリンダ内圧力）に対応した信号を出力する燃焼圧取得手段としての燃焼圧センサ２２が設けられている。吸気ポート１０は共通の吸気ポート上流部１０ａから分岐する２つの吸気ポート下流部１０ｂを備えており、これら２つの吸気ポート下流部１０ｂはシリンダ４の一方の側（図１の左側）に並んで接続されている。排気ポート１１は、シリンダ４の他方の側（図１の右側）に並んで接続される２つの排気ポート上流部１１ａと、これら２つの排気ポート上流部１１ａが合流する排気ポート下流部１１ｂとを備えている。このように燃焼室７には２つの吸気ポート下流部１０ｂ及び２つの排気ポート上流部１１ａがそれぞれ接続されるため、図２に示したように吸気弁１８及び排気弁１９がそれぞれ２つずつ設けられる。 FIG. 2 shows a view of the combustion chamber 7 as viewed from the lower side of FIG. As shown in FIGS. 1 and 2, the combustion chamber 7 includes an intake valve 18, an exhaust valve 19, a spark plug 21 that ignites a combustion mixture in the combustion chamber 7, and a combustion pressure (cylinder pressure) in the combustion chamber 7. A combustion pressure sensor 22 is provided as combustion pressure acquisition means for outputting a signal corresponding to the above. The intake port 10 includes two intake port downstream portions 10b branched from a common intake port upstream portion 10a, and these two intake port downstream portions 10b are arranged on one side of the cylinder 4 (left side in FIG. 1). It is connected. The exhaust port 11 includes two exhaust port upstream portions 11a connected side by side on the other side of the cylinder 4 (right side in FIG. 1), and an exhaust port downstream portion 11b where the two exhaust port upstream portions 11a merge. I have. As described above, since the two intake port downstream portions 10b and the two exhaust port upstream portions 11a are respectively connected to the combustion chamber 7, two intake valves 18 and two exhaust valves 19 are provided as shown in FIG. It is done.

また、図１及び図２に示したように、燃焼室７にはシリンダヘッド３から燃焼室７内に突出するマスク壁２３が、２つの吸気ポート下流部１０ｂに対してそれぞれ設けられる。図２に示したように、各マスク壁２３は、各吸気ポート下流部１０ｂの開口部の周囲のうち吸気ポート下流部１０ｂの並び方向内側でかつシリンダ４の中心側の部分にそれぞれ設けられ、各吸気ポート下流部１０ｂからシリンダ４の中心に向かって流入する吸気の流れに対向する対向面２３ａを備えている。各マスク壁２３は、各吸気ポート下流部１０ｂからシリンダ４の中心側に向かって流れる吸気の流れを対向面２３ａによって阻害し、図１及び図２に矢印Ａで示したように各吸気ポート下流部１０ｂから流入した吸気の流れをシリンダ４の外周側にそれぞれ偏らせる。このように吸気の流れを変更することにより、マスク壁２３は本発明の吸気流れ変更手段として機能する。 As shown in FIGS. 1 and 2, the combustion chamber 7 is provided with mask walls 23 protruding from the cylinder head 3 into the combustion chamber 7 with respect to the two intake port downstream portions 10b. As shown in FIG. 2, each mask wall 23 is provided on the inner side in the arrangement direction of the intake port downstream portion 10 b and on the center side portion of the cylinder 4 in the periphery of the opening portion of each intake port downstream portion 10 b. A counter surface 23 a is provided to face the flow of intake air flowing from the respective intake port downstream portions 10 b toward the center of the cylinder 4. Each mask wall 23 inhibits the flow of intake air flowing from each intake port downstream portion 10b toward the center side of the cylinder 4 by the facing surface 23a, and as shown by an arrow A in FIGS. The flow of the intake air flowing in from the portion 10 b is biased toward the outer peripheral side of the cylinder 4. By changing the intake air flow in this way, the mask wall 23 functions as the intake air flow changing means of the present invention.

ウェイストゲートバルブ１７のアクチュエータ１７ａ及び可変動弁機構２０の動作はエンジンコントロールユニット（ＥＣＵ）３０によってそれぞれ制御されている。ＥＣＵ３０は、マイクロプロセッサ、及びその動作に必要なＲＡＭ、ＲＯＭ等の周辺機器を含んだコンピュータとして構成され、点火プラグ２１の動作などを制御してエンジン１の運転状態を制御する周知のコンピュータユニットである。例えばＥＣＵ３０は、ターボ過給機１３のコンプレッサ１３ａよりも下流の吸気の圧力、すなわち過給圧が予め設定した許容値を超えた場合、ウェイストゲートバルブ１７を開けてバイパス通路１６に排気を流し、過給圧を低下させる。このように過給圧を変更することで、ウェイストゲートバルブ１７は本発明の過給圧変更手段として機能する。なお、以降、このように過給圧によってウェイストゲートバルブ１７の開度を調整する制御を通常制御と呼ぶ。この通常制御の方法は周知のウェイストゲートバルブ１７の制御方法と同様でよいため、ここでの詳細な説明は省略する。ＥＣＵ３０には、エンジン１の運転状態を制御する際に参照する情報を取得するために燃焼圧センサ２２、クランク角センサ（不図示）などの種々のセンサが接続されている。 The operations of the actuator 17a of the waste gate valve 17 and the variable valve mechanism 20 are controlled by an engine control unit (ECU) 30, respectively. The ECU 30 is a known computer unit that is configured as a computer including a microprocessor and peripheral devices such as a RAM and a ROM necessary for its operation, and controls the operation state of the engine 1 by controlling the operation of the spark plug 21 and the like. is there. For example, when the pressure of the intake air downstream of the compressor 13 a of the turbocharger 13, that is, the supercharging pressure exceeds a preset allowable value, the ECU 30 opens the waste gate valve 17 to flow the exhaust through the bypass passage 16, Reduce supercharging pressure. By changing the supercharging pressure in this way, the waste gate valve 17 functions as the supercharging pressure changing means of the present invention. Hereinafter, the control for adjusting the opening degree of the waste gate valve 17 by the supercharging pressure is referred to as normal control. Since this normal control method may be the same as the well-known waste gate valve 17 control method, a detailed description thereof is omitted here. Various sensors such as a combustion pressure sensor 22 and a crank angle sensor (not shown) are connected to the ECU 30 in order to acquire information to be referred to when controlling the operating state of the engine 1.

図３は、ＥＣＵ３０がウェイストゲートバルブ１７及び可変動弁機構２０の動作を制御してターボ過給機１３の過給圧を制御するために実行する過給圧制御ルーチンを示している。図３の制御ルーチンは、エンジン１の運転中に所定の周期で繰り返し実行される。 FIG. 3 shows a supercharging pressure control routine executed by the ECU 30 to control the supercharging pressure of the turbocharger 13 by controlling the operations of the waste gate valve 17 and the variable valve mechanism 20. The control routine of FIG. 3 is repeatedly executed at a predetermined cycle while the engine 1 is operating.

図３の過給圧制御ルーチンにおいてＥＣＵ３０は、まずステップＳ１１において燃焼圧センサ２２によって検出されたエンジン１の燃焼圧（以降、実燃焼圧と称する。）が判定燃焼圧よりも低いか否か判定する。エンジン１の燃焼圧はエンジン１の運転状態に応じて変化する。例えばエンジン１への負荷が大きい、すなわちエンジン１に大きな出力が要求されるほど、燃料量を増加させるので燃焼圧が上昇する。このとき吸入空気量が不足し、燃焼室７にて燃料が適切に燃焼しないとエンジン１の出力が低下する。そこで、燃焼室７にて燃料が適切に燃焼し、エンジン１への負荷に対応できる出力が発生した場合の燃焼圧を判定燃焼圧として設定する。エンジン１の負荷と判定燃焼圧との関係は、予め実験や数値計算などで求め、マップとしてＥＣＵ３０に記憶させておく。なお、この処理において判定に使用する実燃焼圧は、例えばエンジン１のクランク軸が所定角度回転する間、例えば７２０°回転する間に燃焼圧センサ２２によって一回検出を行い、このときに検出された値を使用してもよいし、所定角度回転する間に燃焼圧センサ２２によって複数回検出を行い、これら検出された値の最大値又は平均値など複数回検出された値の代表値を使用してもよい。 In the supercharging pressure control routine of FIG. 3, the ECU 30 first determines whether or not the combustion pressure of the engine 1 (hereinafter referred to as actual combustion pressure) detected by the combustion pressure sensor 22 in step S11 is lower than the determination combustion pressure. To do. The combustion pressure of the engine 1 changes according to the operating state of the engine 1. For example, the greater the load on the engine 1, that is, the greater the required output of the engine 1, the greater the amount of fuel, so the combustion pressure increases. At this time, if the amount of intake air is insufficient and the fuel does not combust properly in the combustion chamber 7, the output of the engine 1 is reduced. Therefore, the combustion pressure when the fuel combusts appropriately in the combustion chamber 7 and an output that can correspond to the load on the engine 1 is generated is set as the determination combustion pressure. The relationship between the load of the engine 1 and the determined combustion pressure is obtained in advance by experiments or numerical calculations, and is stored in the ECU 30 as a map. The actual combustion pressure used for the determination in this process is detected once by the combustion pressure sensor 22, for example, while the crankshaft of the engine 1 rotates by a predetermined angle, for example, 720 °, and is detected at this time. May be used, or may be detected multiple times by the combustion pressure sensor 22 while rotating by a predetermined angle, and the representative value of the value detected multiple times such as the maximum value or average value of these detected values is used. May be.

実燃焼圧が判定燃焼圧よりも低いと判断した場合はステップＳ１２に進み、ＥＣＵ３０はウェイストゲートバルブ１７の開度を調整してターボ過給機１３の過給圧を上昇させる。ＥＣＵ３０は、例えば、ウェイストゲートバルブ１７が開いていた場合にウェイストゲートバルブ１７を閉じてタービン１３ｂに流入する排気量を増加させ、過給圧を上昇させる。なお、このように開いているウェイストゲートバルブ１７を閉じる場合は、実燃焼圧と判定燃焼圧との差が大きいほど過給圧を上昇させるように実燃焼圧と判定燃焼圧との差に基づいて閉じる角度を設定し、この設定した角度分閉じてもよい。このように実燃焼圧と判定燃焼圧との差に応じてウェイストゲートバルブ１７の開度を調整することで、過給圧の制御精度を向上させることができる。一方、ウェイストゲートバルブ１７が閉じていた場合は過給圧が予め設定した許容値を超えてもウェイストゲートバルブ１７を閉弁状態に維持して過給圧を上昇させる。続くステップＳ１３においてＥＣＵ３０は、可変動弁機構２０の動作を制御して両方の排気弁１９の開弁時期を進角させる。すなわち、排気弁１９の開弁時期を早める。なお、開弁時期は予め設定した所定角度進角させてもよいし、実燃焼圧と判定燃焼圧との差に基づいて進角させるべき角度を算出し、この算出した角度分進角させてもよい。その後、今回の制御ルーチンを終了する。 When it is determined that the actual combustion pressure is lower than the determination combustion pressure, the process proceeds to step S12, and the ECU 30 adjusts the opening degree of the waste gate valve 17 to increase the supercharging pressure of the turbocharger 13. For example, when the waste gate valve 17 is open, the ECU 30 closes the waste gate valve 17 to increase the amount of exhaust gas flowing into the turbine 13b and increase the supercharging pressure. When closing the open waste gate valve 17 in this way, based on the difference between the actual combustion pressure and the determined combustion pressure so that the boost pressure is increased as the difference between the actual combustion pressure and the determined combustion pressure is larger. It is also possible to set a closing angle and close by the set angle. Thus, the control accuracy of the supercharging pressure can be improved by adjusting the opening degree of the waste gate valve 17 in accordance with the difference between the actual combustion pressure and the determined combustion pressure. On the other hand, when the waste gate valve 17 is closed, even if the supercharging pressure exceeds a preset allowable value, the waste gate valve 17 is kept closed to increase the supercharging pressure. In the subsequent step S13, the ECU 30 controls the operation of the variable valve mechanism 20 to advance the opening timing of both the exhaust valves 19. That is, the opening timing of the exhaust valve 19 is advanced. The valve opening timing may be advanced by a predetermined angle set in advance, or an angle to be advanced is calculated based on the difference between the actual combustion pressure and the determined combustion pressure, and is advanced by the calculated angle. Also good. Thereafter, the current control routine is terminated.

一方、実燃焼圧が判定燃焼圧以上と判断した場合はステップＳ１４に進み、ＥＣＵ３０はウェイストゲートバルブ１７の開度を通常制御によって制御する。続くステップＳ１５においてＥＣＵ３０は、排気弁１９の開弁時期をステップＳ１３の処理において進角させる前の標準時期に戻す。その後、今回の制御ルーチンを終了する。 On the other hand, when it is determined that the actual combustion pressure is equal to or higher than the determination combustion pressure, the process proceeds to step S14, and the ECU 30 controls the opening degree of the waste gate valve 17 by normal control. In subsequent step S15, the ECU 30 returns the valve opening timing of the exhaust valve 19 to the standard timing before the advance in the processing of step S13. Thereafter, the current control routine is terminated.

この形態によれば、燃焼圧センサ２２によって検出された実燃焼圧が判定燃焼圧よりも低い場合、すなわち吸入空気量が不足して燃焼室７内において燃料が適切に燃焼していない場合は、ウェイストゲートバルブ１７の開度と排気弁１９の閉弁時期とを調整してターボ過給機１３の過給圧を上昇させるので、吸入空気量を増加させて燃焼室７内にて燃料を適切に燃焼させることができる。そのため、エンジン１の出力低下を抑制できる。また、燃焼室７内にマスク壁２３を設け、吸気ポート１０から燃焼室７に流入する吸気の流れをシリンダ４の外周側に偏らせるので、この吸気によってシリンダ４の内壁を冷却することができる。なお、このように燃焼圧センサ２２によって検出された実燃焼圧に基づいてターボ過給機１３の過給圧を変更することでＥＣＵ３０は本発明の動作制御手段として機能する。 According to this embodiment, when the actual combustion pressure detected by the combustion pressure sensor 22 is lower than the determination combustion pressure, that is, when the amount of intake air is insufficient and the fuel is not properly burned in the combustion chamber 7, Since the boost pressure of the turbocharger 13 is increased by adjusting the opening degree of the waste gate valve 17 and the closing timing of the exhaust valve 19, the amount of intake air is increased and fuel is appropriately supplied in the combustion chamber 7. Can be burned. Therefore, a decrease in output of the engine 1 can be suppressed. Further, the mask wall 23 is provided in the combustion chamber 7 and the flow of the intake air flowing into the combustion chamber 7 from the intake port 10 is biased toward the outer peripheral side of the cylinder 4, so that the inner wall of the cylinder 4 can be cooled by this intake air. . The ECU 30 functions as an operation control means of the present invention by changing the supercharging pressure of the turbocharger 13 based on the actual combustion pressure detected by the combustion pressure sensor 22 in this way.

本発明は、上述した形態に限定されることなく、種々の形態にて実施することができる。例えば、燃焼室に流入する吸気の流れを変更する手段はシリンダヘッドから突出させるマスク壁に限定されない。例えば吸気弁の傘部に吸気ポートからシリンダの中心に向かって流入する吸気の流れに対向する対向面を備えた整流板を設け、この整流板によって吸気の流れを変更してもよい。 The present invention is not limited to the above-described form and can be implemented in various forms. For example, the means for changing the flow of intake air flowing into the combustion chamber is not limited to the mask wall protruding from the cylinder head. For example, a rectifying plate having a facing surface facing the flow of intake air flowing from the intake port toward the center of the cylinder may be provided in the umbrella portion of the intake valve, and the flow of intake air may be changed by this rectifying plate.

本発明が適用される内燃機関の過給機には、過給圧が変更可能な種々の過給機が含まれる。例えば、電動モータによってタービンの回転をアシスト可能な電動モータ付きターボ過給機を備えた内燃機関に本発明を適用してもよい。この場合は、電動モータの動作を制御して過給圧を上昇させる。また、本発明が適用される内燃機関の可変動弁機構には、動弁特性のうち少なくとも排気弁の開弁時期を変更可能な種々の動弁機構が含まれる。例えば、電動モータによってカムを駆動して排気弁を開閉する動弁機構、電磁弁によって排気弁を開閉駆動する動弁機構などを備えた内燃機関に本発明が適用される。 The supercharger of the internal combustion engine to which the present invention is applied includes various superchargers capable of changing the supercharging pressure. For example, you may apply this invention to the internal combustion engine provided with the turbocharger with an electric motor which can assist rotation of a turbine with an electric motor. In this case, the supercharging pressure is increased by controlling the operation of the electric motor. The variable valve mechanism for the internal combustion engine to which the present invention is applied includes various valve mechanisms that can change at least the valve opening timing of the exhaust valve among the valve characteristics. For example, the present invention is applied to an internal combustion engine having a valve operating mechanism that opens and closes an exhaust valve by driving a cam by an electric motor, and a valve operating mechanism that opens and closes an exhaust valve by an electromagnetic valve.

本発明の制御装置が組み込まれた内燃機関の一例を示す図。The figure which shows an example of the internal combustion engine in which the control apparatus of this invention was integrated. 燃焼室を図１の下側から見た図。The figure which looked at the combustion chamber from the lower side of FIG. ＥＣＵが実行する過給圧制御ルーチンを示すフローチャート。The flowchart which shows the supercharging pressure control routine which ECU performs.

Explanation of symbols

１エンジン（内燃機関）
４シリンダ
７燃焼室
１０吸気ポート
１１排気ポート
１３ターボ過給機
１７ウェイストゲートバルブ（過給圧変更手段）
１８吸気弁
１９排気弁
２０可変動弁機構
２２燃焼圧センサ（燃焼圧取得手段）
２３マスク壁（吸気流れ変更手段）
２３ａ対向面
３０エンジンコントロールユニット（動作制御手段） 1 engine (internal combustion engine)
4 Cylinder 7 Combustion chamber 10 Intake port 11 Exhaust port 13 Turbocharger 17 Waste gate valve (supercharging pressure changing means)
18 Intake valve 19 Exhaust valve 20 Variable valve mechanism 22 Combustion pressure sensor (combustion pressure acquisition means)
23 Mask wall (intake flow changing means)
23a Opposing surface 30 Engine control unit (operation control means)

Claims

Provided in at least one of a portion around the combustion chamber side opening of the intake port connected to the combustion chamber and an umbrella portion of the intake valve that opens and closes the intake port, and flows into the combustion chamber from the intake port An intake flow changing means having a facing surface facing the intake air flow, a supercharger for supercharging intake air into the combustion chamber, and a supercharging pressure changing means for changing the supercharging pressure of the supercharger. In a control device applied to an internal combustion engine provided,
Combustion pressure acquisition means for acquiring the combustion pressure of the combustion chamber, and operation control means for controlling the operation of the supercharging pressure changing means based on the combustion pressure acquired by the combustion pressure acquisition means. A control device for an internal combustion engine.

The operation control means is configured to increase the supercharging pressure of the supercharger when the combustion pressure acquired by the combustion pressure acquisition means is lower than a determination combustion pressure set based on an operating state of the internal combustion engine. 2. The control device for an internal combustion engine according to claim 1, wherein operation of the supercharging pressure changing means is controlled.

A turbocharger is provided as the supercharger, and further includes a variable valve mechanism capable of changing an opening timing of an exhaust valve that opens and closes an exhaust port connected to the combustion chamber,
The operation control means controls the operation of the variable valve mechanism so that the opening timing of the exhaust valve is advanced when the combustion pressure acquired by the combustion pressure acquisition means is lower than the determined combustion pressure. The control device for an internal combustion engine according to claim 2, wherein:

The said opposing surface is provided so that it may oppose with the flow of the intake air which flows in toward the center of the cylinder in which the said combustion chamber is formed from the said intake port. The control apparatus for an internal combustion engine according to the item.