JP2010164025A - Cylinder direct injection type internal combustion engine - Google Patents

Cylinder direct injection type internal combustion engine Download PDF

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JP2010164025A
JP2010164025A JP2009008787A JP2009008787A JP2010164025A JP 2010164025 A JP2010164025 A JP 2010164025A JP 2009008787 A JP2009008787 A JP 2009008787A JP 2009008787 A JP2009008787 A JP 2009008787A JP 2010164025 A JP2010164025 A JP 2010164025A
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fuel
valve
intake
cylinder
intake valve
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Yoshiyuki Kitazume
芳之 北爪
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Toyota Motor Corp
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
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    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
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  • Combustion Methods Of Internal-Combustion Engines (AREA)
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder direct injection type internal combustion engine sufficiently suppressing the exhaustion of unburnt fuel from a cylinder by suppressing the deposition of fuel on three intake valves in a common cylinder. <P>SOLUTION: The cylinder direct injection type internal combustion engine 1 wherein fuel is injected through the injection port 9a of a fuel injection valve 9 into the cylinder 2 toward its predetermined region A, includes three intake valves 7a-7c, and exhaust valves 8a, 8b provided in the cylinder 2, the intake valve 7c which is driven to be opened/closed to pass the fuel through the predetermined region A arranged at a position farther from the exhaust side than each of the intake valves 7a, 7b, and a variable valve gear 10 provided for changing the lift amount of the intake valve 7c. The variable valve gear 10 is controlled to keep the intake valve 7c in a closed condition when the temperature of the internal combustion engine 1 is in a predetermined low temperature range. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、燃料噴射弁から気筒内に直接燃料が噴射される筒内直接噴射式内燃機関に関する。   The present invention relates to an in-cylinder direct injection internal combustion engine in which fuel is directly injected into a cylinder from a fuel injection valve.

噴射口が気筒内に臨むようにして設けられた燃料噴射弁から気筒内に燃料を直接噴射する筒内直接噴射式の内燃機関が知られている。このような内燃機関では、吸気行程時、すなわち吸気弁の開弁時に燃料噴射弁から燃料を噴射するものがある。このように吸気弁の開弁時に気筒内に燃料が噴射されると、噴射された燃料の一部が吸気弁に付着する。そして、始動時など内燃機関の温度が低いときは吸着弁に付着した燃料が気化せず未燃のまま排出されるおそれがある。そこで、内燃機関の温度が低いときは共通の気筒に設けられた２つの吸気弁のうちの一方を閉弁状態で停止させ、これにより吸気弁への燃料の付着を抑制する内燃機関が知られている（特許文献１参照）。また、吸気行程にて燃料噴射を行う運転モードで、かつ所定の低回転・低負荷領域のときに吸気弁のリフト量を減少させる内燃機関が知られている（特許文献２参照）。その他、本発明に関連する先行技術文献として特許文献３〜６が存在する。   2. Description of the Related Art An in-cylinder direct injection internal combustion engine that directly injects fuel into a cylinder from a fuel injection valve provided with an injection port facing the cylinder is known. Some internal combustion engines inject fuel from a fuel injection valve during an intake stroke, that is, when the intake valve is opened. As described above, when the fuel is injected into the cylinder when the intake valve is opened, a part of the injected fuel adheres to the intake valve. When the temperature of the internal combustion engine is low, such as at the time of start-up, the fuel adhering to the adsorption valve may not be vaporized and discharged without being burned. Therefore, there is known an internal combustion engine in which one of two intake valves provided in a common cylinder is stopped in a closed state when the temperature of the internal combustion engine is low, thereby suppressing fuel adhesion to the intake valve. (See Patent Document 1). In addition, an internal combustion engine is known that reduces the lift amount of an intake valve in an operation mode in which fuel injection is performed in an intake stroke and in a predetermined low rotation / low load region (see Patent Document 2). In addition, Patent Documents 3 to 6 exist as prior art documents related to the present invention.

特開２００４−２３９２０１号公報Japanese Patent Laid-Open No. 2004-239201 特開２００４−２６３６４１号公報Japanese Patent Laid-Open No. 2004-263641 特開２００４−３１６４４９号公報JP 2004-316449 A 特開平１１−３５１０１２号公報Japanese Patent Laid-Open No. 11-351012 特開平１１−２９４２０８号公報Japanese Patent Laid-Open No. 11-294208 特開２００７−２９１８８７号公報JP 2007-291887 A

ところで、共通の気筒に３つの吸気弁が設けられた内燃機関が知られている。このような内燃機関では、３つの吸気弁のうちの２つの吸気弁（これらを吸気弁Ａ、Ｂとする。）が排気弁の並び方向と同じ方向に並べて配置され、残りの１つ（これを吸気弁Ｃとする。）がそれら並べて配置された２つの吸気弁Ａ、Ｂの中間、かつこれら２つの吸気弁Ａ、Ｂよりも排気側から遠い位置に配置される。一般に筒内直接噴射式の内燃機関では、噴射口が気筒内のうち排気側から遠い位置に配置されるように燃料噴射弁が設けられている。そして、噴射口からは並べて配置された２つの吸気弁Ａ、Ｂの間に向けて燃料が噴射される。そのため、吸気弁Ｃの開弁時に燃料が噴射されるとこの吸気弁Ｃに燃料が吹き付けられる。また、この吸気弁Ｃは、他の２つの吸気弁Ａ、Ｂと比較して排気側から離れているので、弁の温度が低くなり易い。従って、この吸気弁Ｃには、燃料が付着し易い。特許文献１、２は、共通の気筒に２つの吸気弁が設けられた内燃機関に適用されるものであり、共通の気筒に３つの吸気弁が設けられた内燃機関への適用については開示も示唆もない。   By the way, an internal combustion engine in which three intake valves are provided in a common cylinder is known. In such an internal combustion engine, two of the three intake valves (they are referred to as intake valves A and B) are arranged side by side in the same direction as the arrangement direction of the exhaust valves, and the remaining one (this Is an intake valve C.) between the two intake valves A and B arranged side by side and at a position farther from the exhaust side than the two intake valves A and B. Generally, in a direct injection type internal combustion engine, a fuel injection valve is provided so that an injection port is disposed at a position far from the exhaust side in the cylinder. Then, fuel is injected from the injection port toward two intake valves A and B arranged side by side. Therefore, if fuel is injected when the intake valve C is opened, the fuel is sprayed onto the intake valve C. Further, since the intake valve C is farther from the exhaust side than the other two intake valves A and B, the temperature of the valve tends to be low. Therefore, fuel is likely to adhere to the intake valve C. Patent Documents 1 and 2 are applied to an internal combustion engine in which two intake valves are provided in a common cylinder, and the application to an internal combustion engine in which three intake valves are provided in a common cylinder is also disclosed. There is no suggestion.

そこで、本発明は、共通の気筒に設けられた３つの吸気弁への燃料の付着を抑制し、気筒から未燃燃料が排出されることを十分に抑制することが可能な筒内直接噴射式内燃機関を提供することを目的とする。   In view of this, the present invention provides a direct injection type in-cylinder that can suppress the adhesion of fuel to three intake valves provided in a common cylinder and sufficiently suppress the discharge of unburned fuel from the cylinder. An object is to provide an internal combustion engine.

本発明の筒内直接噴射式内燃機関は、噴射口が気筒内に臨むようにして設けられた燃料噴射弁を備え、前記噴射口から前記気筒内の所定の領域に向けて燃料が噴射される筒内直接噴射式の内燃機関において、前記気筒に３つの吸気弁及び排気弁が設けられ、それら３つの吸気弁のうちの１つの所定吸気弁は前記所定の領域内を通過するように開閉駆動されるとともに残りの２つの吸気弁よりも前記排気弁が設けられている排気側から遠い位置に配置され、前記所定吸気弁のリフト量及び開閉時期の少なくともいずれか一方を変更可能な可変動弁機構と、前記内燃機関の温度が所定の低温域内である場合、前記燃料噴射弁の前記噴射口から燃料が噴射されているときに前記所定の領域内への前記所定吸気弁のリフトが禁止されるように前記可変動弁機構を制御して前記所定吸気弁のリフト量及び開閉時期の少なくともいずれか一方を変更する制御手段と、を備えている（請求項１）。   An in-cylinder direct injection internal combustion engine of the present invention includes a fuel injection valve provided such that an injection port faces a cylinder, and fuel is injected from the injection port toward a predetermined region in the cylinder. In a direct injection internal combustion engine, the cylinder is provided with three intake valves and an exhaust valve, and one of the three intake valves is driven to open and close so as to pass through the predetermined region. And a variable valve mechanism that is disposed at a position farther from the exhaust side where the exhaust valve is provided than the remaining two intake valves and is capable of changing at least one of the lift amount and the opening / closing timing of the predetermined intake valve; When the temperature of the internal combustion engine is within a predetermined low temperature range, lift of the predetermined intake valve into the predetermined region is prohibited when fuel is being injected from the injection port of the fuel injection valve. To the variable By controlling the valve mechanism is provided and a control unit that changes at least one of the lift amount and valve timing of the predetermined intake valve (claim 1).

本発明の筒内直接噴射式内燃機関によれば、内燃機関の温度が所定の低温域内である場合、燃料噴射弁から燃料が噴射されているときに所定吸気弁が所定の領域内にリフトされることを禁止するので、噴射されている燃料中に所定吸気弁が進入することを防止できる。そのため、温度が低い所定吸気弁に燃料が付着することを十分に抑制することができる。そのため、共通の気筒に設けられた３つの吸気弁に燃料が付着することを抑制し、気筒から未燃燃料が排出されることを十分に抑制することができる。   According to the direct injection type internal combustion engine of the present invention, when the temperature of the internal combustion engine is within a predetermined low temperature range, the predetermined intake valve is lifted into the predetermined region when fuel is being injected from the fuel injection valve. Therefore, it is possible to prevent the predetermined intake valve from entering the injected fuel. Therefore, it is possible to sufficiently suppress the fuel from adhering to the predetermined intake valve having a low temperature. Therefore, it is possible to suppress the fuel from adhering to the three intake valves provided in the common cylinder, and to sufficiently suppress the discharge of the unburned fuel from the cylinder.

以上に説明したように、本発明の筒内直接噴射式内燃機関によれば、温度が低い所定吸気弁への燃料の付着を抑制できるので、共通の気筒に設けられた３つの吸気弁への燃料の付着を抑制し、気筒から未燃燃料が排出されることを十分に抑制することができる。   As described above, according to the direct injection type internal combustion engine of the present invention, it is possible to suppress the adhesion of fuel to a predetermined intake valve having a low temperature, so that the intake to three intake valves provided in a common cylinder can be reduced. It is possible to suppress the adhesion of fuel and to sufficiently prevent the unburned fuel from being discharged from the cylinder.

本発明の一形態に係る内燃機関を示す図。The figure which shows the internal combustion engine which concerns on one form of this invention. 図１の矢印II方向から見た気筒を模式的に示す図。The figure which shows typically the cylinder seen from the arrow II direction of FIG. 燃料噴射弁が設けられている側から各吸気弁を見た図。The figure which looked at each intake valve from the side in which the fuel injection valve is provided. 図１のＥＣＵが実行する動弁装置制御ルーチンを示すフローチャート。The flowchart which shows the valve operating apparatus control routine which ECU of FIG. 1 performs. 可変動弁装置が通常制御で制御されたときの各吸気弁のリフト量とクランク角度との関係の一例を示す図。The figure which shows an example of the relationship between the lift amount and crank angle of each intake valve when a variable valve apparatus is controlled by normal control. 可変動弁装置が低温制御で制御されたときの各吸気弁のリフト量とクランク角度との関係の一例を示す図。The figure which shows an example of the relationship between the lift amount and crank angle of each intake valve when a variable valve apparatus is controlled by low temperature control. 可変動弁装置が第１の変形例の低温制御で制御されたときの各吸気弁のリフト量とクランク角度との関係の一例を示す図。The figure which shows an example of the relationship between the lift amount and crank angle of each intake valve when a variable valve apparatus is controlled by the low temperature control of the 1st modification. 可変動弁装置が第２の変形例の低温制御で制御されたときの各吸気弁のリフト量とクランク角度との関係の一例を示す図。The figure which shows an example of the relationship between the lift amount and crank angle of each intake valve when a variable valve apparatus is controlled by the low temperature control of the 2nd modification.

図１は、本発明の一形態に係る内燃機関の要部を示している。この内燃機関（以下、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ものであり、複数（図１では１つのみを示す。）の気筒２を備えている。気筒２内には、ピストン３が往復動自在に挿入されている。また、気筒２の上面略中央には点火プラグ４が設けられている。   FIG. 1 shows a main part of an internal combustion engine according to an embodiment of the present invention. The internal combustion engine (hereinafter sometimes referred to as an engine) 1 is mounted on a vehicle as a driving power source, and includes a plurality of cylinders 2 (only one is shown in FIG. 1). . A piston 3 is inserted into the cylinder 2 so as to be able to reciprocate. A spark plug 4 is provided in the approximate center of the upper surface of the cylinder 2.

図２は、図１の矢印II方向から見た気筒２を模式的に示している。この図に示したように気筒２には、３つの吸気ポート５ａ、５ｂ、５ｃ及び２つの排気ポート６ａ、６ｂが設けられている。吸気ポート５ａ〜５ｃは、吸気弁７ａ〜７ｃにて開閉され、排気ポート６ａ、６ｂは排気弁８ａ、８ｂにて開閉される。２つの排気ポート６ａ、６ｂは、気筒２を中心線ＣＬの方向から見たときにその中心線ＣＬに対する一方の側に並ぶように設けられている。以降、これら排気ポート６ａ、６ｂが設けられている一方の側を排気側と称することがある。３つの吸気ポート５ａ〜５ｃのうち２つの吸気ポート５ａ、５ｂは、気筒２の他方の側に排気ポート６ａ、６ｂの並び方向と同じ方向に並ぶように設けられている。残りの吸気ポート５ｃは、並べて設けられた２つの吸気ポート５ａ、５ｂの中間に配置されるとともに、それらの吸気ポート５ａ、５ｂよりも排気側から遠くなるように設けられている。以降、これら吸気ポート５ａ〜５ｃが設けられている他方の側を吸気側と称することがある。   FIG. 2 schematically shows the cylinder 2 viewed from the direction of arrow II in FIG. As shown in this figure, the cylinder 2 is provided with three intake ports 5a, 5b, 5c and two exhaust ports 6a, 6b. The intake ports 5a to 5c are opened and closed by intake valves 7a to 7c, and the exhaust ports 6a and 6b are opened and closed by exhaust valves 8a and 8b. The two exhaust ports 6a and 6b are provided so as to be arranged on one side with respect to the center line CL when the cylinder 2 is viewed from the direction of the center line CL. Hereinafter, one side on which the exhaust ports 6a and 6b are provided may be referred to as an exhaust side. Of the three intake ports 5a to 5c, two intake ports 5a and 5b are provided on the other side of the cylinder 2 so as to be arranged in the same direction as the arrangement direction of the exhaust ports 6a and 6b. The remaining intake port 5c is arranged in the middle of two intake ports 5a and 5b provided side by side, and is provided farther from the exhaust side than these intake ports 5a and 5b. Hereinafter, the other side on which the intake ports 5a to 5c are provided may be referred to as an intake side.

気筒２には、燃料が噴射される噴射口９ａが気筒２内に臨むようにして燃料噴射弁９が設けられている。図１及び図２に示したように燃料噴射弁９は、気筒２の吸気側に配置されている。また、この燃料噴射弁９は、図２に領域Ａで示したように噴射口９ａから吸気ポート５ａ、５ｂの間に向かって燃料が噴射されるように配置されている。そのため、図３に示したように吸気ポート５ｃの吸気弁７ｃは、燃料噴射弁９から燃料が噴射される領域Ａ内を通過するように開閉駆動される。そのため、この吸気弁７ｃが本発明の所定吸気弁に相当する。   The cylinder 2 is provided with a fuel injection valve 9 such that an injection port 9 a through which fuel is injected faces the cylinder 2. As shown in FIGS. 1 and 2, the fuel injection valve 9 is disposed on the intake side of the cylinder 2. Further, the fuel injection valve 9 is arranged so that fuel is injected from the injection port 9a toward the intake ports 5a and 5b as shown by a region A in FIG. Therefore, as shown in FIG. 3, the intake valve 7 c of the intake port 5 c is driven to open and close so as to pass through the region A in which fuel is injected from the fuel injection valve 9. Therefore, this intake valve 7c corresponds to the predetermined intake valve of the present invention.

吸気弁７ａ〜７ｃは、可変動弁機構としての可変動弁装置１０にて開閉駆動される。この可変動弁装置１０は、エンジン１の運転状態に拘わりなく吸気弁７ｃのリフト量を０に維持可能、言い換えると吸気弁７ｃを閉弁状態に維持可能に構成されている。これにより可変動弁装置１０は、吸気弁７ｃのリフト量を０と所定値とに変更できる。このような可変動弁装置１０としては、例えばエンジン１のクランク軸にて回転駆動されるカム軸とそのカム軸に設けられて吸気弁７ｃを開閉駆動するカムとを有し、それらカム軸とカムとを連結したりその連結を解除したりすることが可能な動弁装置が設けられる。なお、吸気弁７ｃ以外の吸気弁７ａ、７ｂは、エンジン１のクランク軸にて回転駆動されるカムにて開閉駆動される。また、図示は省略したが排気弁８ａ、８ｂもエンジン１のクランク軸にて回転駆動されるカムにて開閉駆動される。これらは内燃機関に設けられる周知の動弁機構でよいため、詳細な説明は省略する。   The intake valves 7a to 7c are driven to open and close by a variable valve apparatus 10 as a variable valve mechanism. The variable valve operating apparatus 10 is configured to be able to maintain the lift amount of the intake valve 7c at 0 regardless of the operating state of the engine 1, in other words, to maintain the intake valve 7c in a closed state. Thereby, the variable valve apparatus 10 can change the lift amount of the intake valve 7c to 0 and a predetermined value. Such a variable valve operating apparatus 10 includes, for example, a camshaft that is rotationally driven by the crankshaft of the engine 1 and a cam that is provided on the camshaft to open and close the intake valve 7c. There is provided a valve operating device capable of connecting to or disconnecting from the cam. The intake valves 7 a and 7 b other than the intake valve 7 c are driven to open and close by cams that are rotationally driven by the crankshaft of the engine 1. Although not shown, the exhaust valves 8 a and 8 b are also opened and closed by cams that are driven to rotate by the crankshaft of the engine 1. Since these may be known valve operating mechanisms provided in the internal combustion engine, detailed description thereof is omitted.

可変動弁装置１０の動作は、制御手段としてのエンジンコントロールユニット（以下、ＥＣＵと称する。）２０にて制御される。ＥＣＵ２０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ユニットとして構成され、エンジン１に設けられた各種のセンサの出力信号に基づいてエンジン１の運転状態を制御する周知のものである。ＥＣＵ２０は、例えばエンジン１の負荷及び回転数に応じて気筒２に供給すべき燃料量を算出し、その算出した量の燃料が供給されるように燃料噴射弁９の動作を制御する。この燃料噴射弁９の制御は、ＥＣＵ２０が燃料噴射弁９に噴射信号を出力することにより行われる。そして、噴射信号がオンの場合に噴射口９ａが開弁されて燃料が噴射され、噴射信号がオフの場合に噴射口９ａが閉弁される。また、ＥＣＵ２０は、気筒２内の燃料混合気が適切な時期に燃焼するように点火プラグ４の動作を制御する。ＥＣＵ２０には、エンジン１の運転状態を検出するためのセンサとして例えばエンジン１の冷却水の温度に対応する信号を出力する水温センサ２１等が接続されている。この他にもＥＣＵ２０には各種センサが接続されているが、それらの図示は省略した。   The operation of the variable valve operating apparatus 10 is controlled by an engine control unit (hereinafter referred to as ECU) 20 as a control means. The ECU 20 is configured as a computer unit including a microprocessor and peripheral devices such as RAM and ROM necessary for its operation, and controls the operating state of the engine 1 based on output signals of various sensors provided in the engine 1. It is well known. The ECU 20 calculates the amount of fuel to be supplied to the cylinder 2 according to, for example, the load and rotation speed of the engine 1 and controls the operation of the fuel injection valve 9 so that the calculated amount of fuel is supplied. The control of the fuel injection valve 9 is performed by the ECU 20 outputting an injection signal to the fuel injection valve 9. When the injection signal is on, the injection port 9a is opened to inject fuel, and when the injection signal is off, the injection port 9a is closed. Further, the ECU 20 controls the operation of the spark plug 4 so that the fuel mixture in the cylinder 2 burns at an appropriate time. For example, a water temperature sensor 21 that outputs a signal corresponding to the coolant temperature of the engine 1 is connected to the ECU 20 as a sensor for detecting the operating state of the engine 1. In addition to this, various sensors are connected to the ECU 20, but they are not shown.

図３に示したように吸気弁７ｃは、領域Ａを通過するようにリフトされるため、他の吸気弁７ａ、７ｂと比較して燃料噴射弁９から噴射された燃料が付着し易い。エンジン１の温度が高い場合は燃料が吸気弁７ｃに付着しても直ぐに気化するが、エンジン１の温度が低いと付着した燃料が気化せずに吸気弁７ｃに残る。そして、この吸気弁７ｃに付着して残った燃料が未燃のまま気筒２から排出されたり、粒子状物質（ＰＭ）の原因となることがある。そこで、吸気弁７ｃへの燃料の付着を抑制すべくＥＣＵ２０は図４に示した動弁装置制御ルーチンを実行する。この制御ルーチンは、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。   As shown in FIG. 3, since the intake valve 7c is lifted so as to pass through the region A, the fuel injected from the fuel injection valve 9 is likely to adhere as compared with the other intake valves 7a and 7b. If the temperature of the engine 1 is high, the fuel vaporizes immediately even if the fuel adheres to the intake valve 7c. However, if the temperature of the engine 1 is low, the adhering fuel does not vaporize and remains in the intake valve 7c. The remaining fuel adhering to the intake valve 7c may be discharged from the cylinder 2 without being burned or may cause particulate matter (PM). Therefore, the ECU 20 executes a valve operating control routine shown in FIG. 4 in order to suppress the fuel from adhering to the intake valve 7c. This control routine is repeatedly executed at a predetermined cycle during operation of the engine 1.

図４の動弁装置制御ルーチンにおいてＥＣＵ２０は、まずステップＳ１１でエンジン１の運転状態を取得する。エンジン１の運転状態としては、例えば水温センサ２１の出力信号に基づいてエンジン１の冷却水の温度（以下、冷却水温と略称することがある。）Ｔｗが取得される。次のステップＳ１２においてＥＣＵ２０は、エンジン１の冷却水温Ｔｗが予め設定した判定温度αより高いか否か判断する。判定温度αは、エンジン１の温度が所定の低温域内か否か判断する基準として設定される。周知のように冷却水温はエンジン１の温度と相関しており、冷却水温が低いほどエンジン１の温度も低い。そして、上述したようにエンジン１の温度が低いと吸気弁７ｃに付着した燃料が気化せずに残り未燃燃料となる。そこで、判定温度αには、例えば吸気弁７ｃに付着した燃料を十分に気化することができ、これによりエンジン１からのＰＭの排出を十分に抑制することが可能なエンジン１の温度範囲の下限値に対応した冷却水温が設定される。   In the valve gear control routine of FIG. 4, the ECU 20 first acquires the operating state of the engine 1 in step S11. As the operating state of the engine 1, for example, based on the output signal of the water temperature sensor 21, the temperature of the cooling water of the engine 1 (hereinafter sometimes abbreviated as cooling water temperature) Tw is acquired. In the next step S12, the ECU 20 determines whether or not the coolant temperature Tw of the engine 1 is higher than a preset determination temperature α. The determination temperature α is set as a reference for determining whether or not the temperature of the engine 1 is within a predetermined low temperature range. As is well known, the coolant temperature correlates with the temperature of the engine 1, and the lower the coolant temperature, the lower the temperature of the engine 1. As described above, when the temperature of the engine 1 is low, the fuel adhering to the intake valve 7c does not vaporize and remains as unburned fuel. Therefore, for example, the determination temperature α is a lower limit of the temperature range of the engine 1 that can sufficiently vaporize the fuel adhering to the intake valve 7c and thereby sufficiently suppress the PM emission from the engine 1. The cooling water temperature corresponding to the value is set.

冷却水温Ｔｗが判定温度αより高いと判断した場合はステップＳ１３に進み、ＥＣＵ２０は可変動弁装置１０を通常制御で制御する。その後、今回の制御ルーチンを終了する。図５を参照して通常制御について説明する。図５は、可変動弁装置１０が通常制御で制御されたときの各吸気弁７ａ〜７ｃのリフト量とクランク角度との関係の一例を示している。また、図５には、燃料噴射弁９への噴射信号とクランク角度との関係の一例も示した。なお、図５の線Ｌ１が吸気弁７ｃのリフトカーブを示し、図５の線Ｌ２が吸気弁７ａ、７ｂのリフトカーブを示している。吸気弁７ａのリフトカーブと吸気弁７ｂのリフトカーブは同じである。この図に示したように通常制御では、各吸気弁７ａ〜７ｃが同じリフトカーブになるようにこれら吸気弁７ａ〜７ｃが開閉駆動される。   When it is determined that the coolant temperature Tw is higher than the determination temperature α, the process proceeds to step S13, and the ECU 20 controls the variable valve apparatus 10 by normal control. Thereafter, the current control routine is terminated. The normal control will be described with reference to FIG. FIG. 5 shows an example of the relationship between the lift amount of each intake valve 7a to 7c and the crank angle when the variable valve apparatus 10 is controlled by normal control. FIG. 5 also shows an example of the relationship between the injection signal to the fuel injection valve 9 and the crank angle. 5 indicates the lift curve of the intake valve 7c, and the line L2 of FIG. 5 indicates the lift curve of the intake valves 7a and 7b. The lift curve of the intake valve 7a and the lift curve of the intake valve 7b are the same. As shown in this figure, in the normal control, the intake valves 7a to 7c are opened and closed so that the intake valves 7a to 7c have the same lift curve.

一方、冷却水温Ｔｗが判定温度α以下と判断した場合はステップＳ１４に進み、ＥＣＵ２０は可変動弁装置１０を低温制御で制御する。その後、今回の制御ルーチンを終了する。この低温制御では、吸気弁７ａ、７ｂは通常制御時と同様に開閉駆動され、吸気弁７ｃは閉弁状態に維持される。図６は、可変動弁装置１０が低温制御で制御されたときの各吸気弁７ａ〜７ｃのリフト量とクランク角度との関係の一例を示している。また、図６には、図５と同様に燃料噴射弁９への噴射信号とクランク角度との関係の一例も示した。なお、図６の線Ｌ３が吸気弁７ｃのリフトカーブを示し、線Ｌ４が吸気弁７ａ、７ｂのリフトカーブを示している。この図に示したように低温制御では、燃料噴射弁９への噴射信号がオンになる期間、すなわち燃料噴射弁９から燃料が噴射されている期間（以下、燃料噴射期間と称することがある。）Ｔ１における吸気弁７ｃのリフトを禁止することができるので、吸気弁７ｃに燃料が付着することを十分に抑制できる。   On the other hand, when it is determined that the coolant temperature Tw is equal to or lower than the determination temperature α, the process proceeds to step S14, and the ECU 20 controls the variable valve apparatus 10 by low temperature control. Thereafter, the current control routine is terminated. In this low temperature control, the intake valves 7a and 7b are opened and closed in the same manner as in normal control, and the intake valve 7c is maintained in a closed state. FIG. 6 shows an example of the relationship between the lift amount of each intake valve 7a to 7c and the crank angle when the variable valve apparatus 10 is controlled by the low temperature control. FIG. 6 also shows an example of the relationship between the injection signal to the fuel injection valve 9 and the crank angle, as in FIG. A line L3 in FIG. 6 indicates the lift curve of the intake valve 7c, and a line L4 indicates the lift curve of the intake valves 7a and 7b. As shown in this figure, in the low temperature control, a period during which the injection signal to the fuel injection valve 9 is turned on, that is, a period during which fuel is injected from the fuel injection valve 9 (hereinafter, referred to as a fuel injection period). ) Since the lift of the intake valve 7c at T1 can be prohibited, it is possible to sufficiently suppress the fuel from adhering to the intake valve 7c.

本発明の内燃機関１によれば、冷却水温Ｔｗが判定温度α以下の場合は吸気弁７ｃが閉弁状態に維持されるので、吸気弁７ｃへの燃料の付着を十分に抑制することができる。そのため、吸気弁７ｃに付着した燃料が未燃のまま気筒２から排出されることを抑制できる。また、このように吸気弁７ｃへの燃料の付着を抑制することにより、エンジン１の温度が低い冷間時のＰＭの発生を抑制することができる。   According to the internal combustion engine 1 of the present invention, when the coolant temperature Tw is equal to or lower than the determination temperature α, the intake valve 7c is maintained in the closed state, so that the fuel can be sufficiently prevented from adhering to the intake valve 7c. . Therefore, it is possible to suppress the fuel adhering to the intake valve 7c from being discharged from the cylinder 2 without being burned. Further, by suppressing the adhesion of fuel to the intake valve 7c in this way, it is possible to suppress the occurrence of PM when the engine 1 is cold and the temperature is low.

なお、低温制御における吸気弁７ｃの制御方法は、上述した方法に限定されない。例えば、低温制御時においても図７に示したように燃料噴射期間Ｔ１における吸気弁７ｃの最大リフト量を通常制御時と比べて小さくして吸気弁７ｃを開閉してもよい。図７は、この第１の変形例の低温制御にて可変動弁装置１０が制御されたときの各吸気弁７ａ〜７ｃのリフト量とクランク角度との関係の一例を示している。なお、図７の線Ｌ５が吸気弁７ｃのリフトカーブを示し、線Ｌ６が吸気弁７ａ、７ｂのリフトカーブを示している。この第１の変形例では、吸気弁７ｃが開閉駆動されるときに吸気弁７ｃの下端が燃料が噴射される領域Ａ内に進入しないように低温制御時の吸気弁７ｃの最大リフト量が設定される。そして、吸気弁７ｃは、リフトカーブの形状が通常制御時と相似し、かつ最大リフト量がこの設定された値になるように開閉駆動される。なお、この第１の変形例においても吸気弁７ａ、７ｂは通常制御時と同様に開閉駆動される。   In addition, the control method of the intake valve 7c in low temperature control is not limited to the method mentioned above. For example, as shown in FIG. 7, the intake valve 7c may be opened and closed by reducing the maximum lift amount of the intake valve 7c during the fuel injection period T1 as compared with that during the normal control as shown in FIG. FIG. 7 shows an example of the relationship between the lift amount of each intake valve 7a to 7c and the crank angle when the variable valve apparatus 10 is controlled by the low temperature control of the first modification. A line L5 in FIG. 7 indicates the lift curve of the intake valve 7c, and a line L6 indicates the lift curve of the intake valves 7a and 7b. In the first modification, the maximum lift amount of the intake valve 7c during low temperature control is set so that the lower end of the intake valve 7c does not enter the region A in which fuel is injected when the intake valve 7c is driven to open and close. Is done. The intake valve 7c is driven to open and close so that the shape of the lift curve is similar to that during normal control, and the maximum lift amount becomes the set value. In the first modification, the intake valves 7a and 7b are driven to open and close as in the normal control.

この第１の変形例では、吸気弁７ｃが燃料噴射期間Ｔ１中に領域Ａ内に進入することを防止できるので、吸気弁７ｃに燃料が付着することを抑制できる。また、この第１の変形例では、低温制御時も吸気弁７ｃが開閉駆動されるので、気筒２内に速やかに吸気を吸入させることができる。   In the first modification, the intake valve 7c can be prevented from entering the region A during the fuel injection period T1, and therefore, fuel can be prevented from adhering to the intake valve 7c. Further, in this first modification, the intake valve 7c is driven to open and close even during low temperature control, so that intake air can be quickly drawn into the cylinder 2.

また、低温制御時に図８に示したように燃料噴射期間Ｔ１後に吸気弁７ｃが開閉駆動されるように吸気弁７ｃの開閉時期を通常制御時と比較して遅角させてもよい。図８は、この第２の変形例の低温制御にて可変動弁装置１０が制御されたときの各吸気弁７ａ〜７ｃのリフト量とクランク角度との関係の一例を示している。なお、図７の線Ｌ７が吸気弁７ｃのリフトカーブを示し、線Ｌ８が吸気弁７ａ、７ｂのリフトカーブを示している。この第２の変形例では、この図に示したように燃料噴射期間Ｔ１中は吸気弁７ｃの開閉が禁止され、燃料噴射期間Ｔ１後に吸気弁７ｃの開閉が行われる。なお、この開閉時における吸気弁７ｃのリフトカーブは通常制御時と同じである。第２の変形例においても吸気弁７ａ、７ｂは通常制御時と同様に開閉駆動される。   Further, as shown in FIG. 8 during the low temperature control, the opening / closing timing of the intake valve 7c may be retarded as compared with that during the normal control so that the intake valve 7c is opened / closed after the fuel injection period T1. FIG. 8 shows an example of the relationship between the lift amount of each of the intake valves 7a to 7c and the crank angle when the variable valve apparatus 10 is controlled by the low temperature control of the second modification. 7 indicates the lift curve of the intake valve 7c, and the line L8 indicates the lift curve of the intake valves 7a and 7b. In this second modified example, as shown in this figure, the opening and closing of the intake valve 7c is prohibited during the fuel injection period T1, and the intake valve 7c is opened and closed after the fuel injection period T1. Note that the lift curve of the intake valve 7c during opening and closing is the same as during normal control. Also in the second modification, the intake valves 7a and 7b are driven to open and close in the same manner as during normal control.

この第２の変形例では、燃料噴射期間Ｔ１中は吸気弁７ｃの開閉が禁止され、燃料噴射期間Ｔ１後に吸気弁７ｃが開閉されるので、吸気弁７ｃへの燃料の付着を抑制しつつ吸気の充填効率を改善することができる。   In the second modification, the opening and closing of the intake valve 7c is prohibited during the fuel injection period T1, and the intake valve 7c is opened and closed after the fuel injection period T1, so that the intake air can be suppressed while preventing the fuel from adhering to the intake valve 7c. The filling efficiency can be improved.

この他、低温制御においては、燃料噴射期間Ｔ１中に吸気弁７ｃが領域Ａ内に進入することが禁止される種々の制御方法で吸気弁７ｃを制御してよい。例えば、上述した第１の変形例の制御方法と第２の変形例の制御方法とを組み合わせた制御方法で吸気弁７ｃを制御してもよい。また、吸気弁７ｃの作用角を吸気弁７ａ、７ｂの作用角より小さくし、かつ吸気弁７ｃの開閉時期が燃料噴射期間Ｔ１から外れるように吸気弁７ｃの開閉時期と吸気弁７ａ、７ｂの開閉時期との間に位相差が設けられるように吸気弁７ｃを制御してもよい。   In addition, in the low temperature control, the intake valve 7c may be controlled by various control methods that prohibit the intake valve 7c from entering the region A during the fuel injection period T1. For example, the intake valve 7c may be controlled by a control method in which the control method of the first modified example and the control method of the second modified example are combined. Further, the operating angle of the intake valve 7c is made smaller than the operating angle of the intake valves 7a, 7b, and the opening / closing timing of the intake valve 7c and the intake valves 7a, 7b are set so that the opening / closing timing of the intake valve 7c deviates from the fuel injection period T1. The intake valve 7c may be controlled so that a phase difference is provided between the opening and closing timing.

なお、このような吸気弁７ｃの制御を行うため、可変動弁装置１０として例えば電磁コイルで排気弁を開閉駆動する電磁駆動機構を用いてもよいし、カムをモータで回転駆動する動弁機構を用いてもよい。この他、吸気弁７ｃのリフト量及び開閉時期を変更可能な種々の動弁機構を用いてよい。   In order to control the intake valve 7c as described above, for example, an electromagnetic drive mechanism that opens and closes an exhaust valve with an electromagnetic coil may be used as the variable valve apparatus 10, or a valve mechanism that rotates a cam with a motor. May be used. In addition, various valve mechanisms that can change the lift amount and opening / closing timing of the intake valve 7c may be used.

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、内燃機関のオイルの温度も内燃機関の温度を相関しているので、冷却水温の代わりに内燃機関のオイルの温度に基づいて通常制御と低温制御の切り替えを行ってもよい。   The present invention is not limited to the above-described form and can be implemented in various forms. For example, since the temperature of the oil in the internal combustion engine also correlates with the temperature of the internal combustion engine, switching between normal control and low temperature control may be performed based on the temperature of the oil in the internal combustion engine instead of the cooling water temperature.

１ 内燃機関
２ 気筒
７ａ、７ｂ、７ｃ 吸気弁
８ａ、８ｂ 排気弁
９ 燃料噴射弁
９ａ 噴射口
１０ 可変動弁装置（可変動弁機構）
２０ エンジンコントロールユニット（制御手段）
Ａ 所定の領域 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Cylinders 7a, 7b, 7c Intake valve 8a, 8b Exhaust valve 9 Fuel injection valve 9a Injection port 10 Variable valve mechanism (variable valve mechanism)
20 Engine control unit (control means)
A Predetermined area

Claims (1)

噴射口が気筒内に臨むようにして設けられた燃料噴射弁を備え、前記噴射口から前記気筒内の所定の領域に向けて燃料が噴射される筒内直接噴射式の内燃機関において、
前記気筒に３つの吸気弁及び排気弁が設けられ、それら３つの吸気弁のうちの１つの所定吸気弁は前記所定の領域内を通過するように開閉駆動されるとともに残りの２つの吸気弁よりも前記排気弁が設けられている排気側から遠い位置に配置され、
前記所定吸気弁のリフト量及び開閉時期の少なくともいずれか一方を変更可能な可変動弁機構と、前記内燃機関の温度が所定の低温域内である場合、前記燃料噴射弁の前記噴射口から燃料が噴射されているときに前記所定の領域内への前記所定吸気弁のリフトが禁止されるように前記可変動弁機構を制御して前記所定吸気弁のリフト量及び開閉時期の少なくともいずれか一方を変更する制御手段と、を備えている筒内直接噴射式内燃機関。 In a direct injection type internal combustion engine that includes a fuel injection valve provided so that an injection port faces the cylinder, and injects fuel from the injection port toward a predetermined region in the cylinder,
The cylinder is provided with three intake valves and exhaust valves, and one of the three intake valves is driven to open and close so as to pass through the predetermined region, and from the remaining two intake valves Is disposed at a position far from the exhaust side where the exhaust valve is provided,
When a variable valve mechanism that can change at least one of the lift amount and opening / closing timing of the predetermined intake valve and the temperature of the internal combustion engine is within a predetermined low temperature range, fuel is supplied from the injection port of the fuel injection valve. The variable valve mechanism is controlled so that the lift of the predetermined intake valve into the predetermined region is prohibited when the fuel is being injected, and at least one of the lift amount and the opening / closing timing of the predetermined intake valve is controlled. A direct injection type internal combustion engine having a control means for changing.
JP2009008787A 2009-01-19 2009-01-19 Cylinder direct injection type internal combustion engine Pending JP2010164025A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009008787A JP2010164025A (en) 2009-01-19 2009-01-19 Cylinder direct injection type internal combustion engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009008787A JP2010164025A (en) 2009-01-19 2009-01-19 Cylinder direct injection type internal combustion engine

Publications (1)

Publication Number Publication Date
JP2010164025A true JP2010164025A (en) 2010-07-29

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009008787A Pending JP2010164025A (en) 2009-01-19 2009-01-19 Cylinder direct injection type internal combustion engine

Country Status (1)

Country Link
JP (1) JP2010164025A (en)

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