JP2007170206A - Cylinder fuel injection type internal combustion engine - Google Patents

Cylinder fuel injection type internal combustion engine Download PDF

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JP2007170206A
JP2007170206A JP2005365446A JP2005365446A JP2007170206A JP 2007170206 A JP2007170206 A JP 2007170206A JP 2005365446 A JP2005365446 A JP 2005365446A JP 2005365446 A JP2005365446 A JP 2005365446A JP 2007170206 A JP2007170206 A JP 2007170206A
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fuel injection
fuel
cylinder
internal combustion
injection
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Eriko Matsumura
恵理子 松村
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Toyota Motor Corp
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Toyota Motor Corp
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B23/104—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the injector being placed on a side position of the cylinder
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B23/00—Other engines characterised by special shape or construction of combustion chambers to improve operation
    • F02B23/08—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition
    • F02B23/10—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder
    • F02B2023/103—Other engines characterised by special shape or construction of combustion chambers to improve operation with positive ignition with separate admission of air and fuel into cylinder the injector having a multi-hole nozzle for generating multiple sprays
    • 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
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Methods Of Internal-Combustion Engines (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylinder fuel injection type internal combustion engine capable of increasing output performance by suitably enhancing the homogeneity of an air-fuel mixture even when a strong gas flow is not generated in a cylinder. <P>SOLUTION: This cylinder fuel injection type internal combustion engine 100 comprises a fuel injection valve 2 so disposed as to inject the fuel into a combustion chamber 6 and a cylinder head 4 in which first and second intake valves 21, 22 and first and second exhaust valves 23, 24 corresponding to the combustion chamber 6 are disposed. Each of the first and second exhaust valves 23, 24 has spray guide parts 1A, 1B on the front surface of its valve element. The fuel injection valve 2 has first and second injection holes injecting the fuel toward the spray guide parts 1A, 1B. The spray guide parts 1A, 1B has recessed parts 1aA, 1aB including the portions collided with the sprays F1, F2 of the fuel injected from the first and second injection holes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、筒内燃料噴射式内燃機関に関し、特に筒内に強いガス流動を発生させない場合でも、混合気の均質性を好適に向上させて出力性能の向上を図ることが可能な筒内燃料噴射式内燃機関に関する。   The present invention relates to an in-cylinder fuel injection internal combustion engine, and more particularly to an in-cylinder fuel that can improve the homogeneity of an air-fuel mixture and improve output performance even when a strong gas flow is not generated in the cylinder. The present invention relates to an injection type internal combustion engine.

筒内に燃料を噴射する内燃機関としては、従来から自然着火式のディーゼルエンジンが存在するが、近年では大幅な燃費向上を図ることを主な目的として筒内に燃料を噴射する火花点火式のガソリンエンジン（以下、単に直噴ガソリン機関と称す）も実用化されている。これら筒内燃料噴射式内燃機関を対象として、例えば噴射方向や噴射位置などに関し種々の態様で燃料を噴射する技術が提案されている。   As an internal combustion engine that injects fuel into a cylinder, there has been a self-ignition type diesel engine. However, in recent years, a spark ignition type engine that injects fuel into a cylinder mainly for the purpose of significantly improving fuel consumption. Gasoline engines (hereinafter simply referred to as direct injection gasoline engines) have also been put into practical use. For these in-cylinder fuel injection type internal combustion engines, techniques for injecting fuel in various modes with respect to, for example, the injection direction and the injection position have been proposed.

例えば特許文献１では、第１の噴孔から吸気弁または排気弁の弁体前面に向けて燃料を噴射するとともに、第１の噴孔よりも断面積が大きい第２の噴孔からピストン頂面に形成したキャビティに向けて燃料を噴射する燃料噴射弁を、シリンダヘッド内壁面の中央部に配置した圧縮着火式内燃機関が提案されている。特許文献２では、吸気弁または排気弁の弁体前面に向けて燃料を噴射する燃料噴射弁を、シリンダヘッド内壁面の中央部に配置した筒内噴射式内燃機関が提案されている。特許文献３では、燃焼室内に旋回流を形成する手段を備える筒内直接燃料噴射式の内燃機関において、旋回方向に沿う向きに流れる方向と、この旋回方向とは逆の旋回方向に沿う向きで、点火プラグ近傍に向かって流れる方向との２方向に燃料の噴霧の流れを分割する手段を備えた燃料噴射装置が提案されている。   For example, in Patent Document 1, fuel is injected from the first injection hole toward the front surface of the valve body of the intake valve or the exhaust valve, and the top surface of the piston from the second injection hole having a larger cross-sectional area than the first injection hole. A compression ignition type internal combustion engine has been proposed in which a fuel injection valve for injecting fuel toward a cavity formed in the center is arranged at the center of the inner wall surface of a cylinder head. Patent Document 2 proposes an in-cylinder injection internal combustion engine in which a fuel injection valve that injects fuel toward the front surface of a valve body of an intake valve or an exhaust valve is arranged at the center of the inner wall surface of a cylinder head. In Patent Document 3, in a cylinder direct fuel injection type internal combustion engine provided with means for forming a swirl flow in a combustion chamber, a direction flowing in a direction along the swirl direction and a direction along a swirl direction opposite to the swirl direction. There has been proposed a fuel injection device provided with means for dividing the flow of fuel spray into two directions, ie, the direction of flowing toward the vicinity of the spark plug.

特許文献４では、噴孔を以て燃焼室に臨むノズルを備えた燃料噴射装置において、噴孔に対して衝突面を対向配置するとともに、この衝突面の周囲にメッシュ部材を配置した燃料拡散構造が提案されている。特許文献５では、インジェクションノズルを取り囲むバルブ（吸排気弁）の下面に、インジェクションノズルからの燃料噴霧の流路中に突出する突部を設けたディーゼルエンジンの燃焼室が提案されている。特許文献６では、シリンダブロックに設けられるとともに、吸気弁側に近いシリンダボア側面から複数の排気弁に向かう燃料噴射口を有する筒内噴射エンジンが提案されている。   Patent Document 4 proposes a fuel diffusion structure in which, in a fuel injection device having a nozzle facing a combustion chamber with an injection hole, a collision surface is arranged opposite to the injection hole, and a mesh member is arranged around the collision surface. Has been. Patent Document 5 proposes a diesel engine combustion chamber in which a protrusion projecting into a flow path of fuel spray from an injection nozzle is provided on the lower surface of a valve (intake and exhaust valve) surrounding the injection nozzle. Patent Document 6 proposes an in-cylinder injection engine that is provided in a cylinder block and has fuel injection ports directed from a cylinder bore side surface close to the intake valve side to a plurality of exhaust valves.

特開２０００−３２８９８３号公報JP 2000-328983 A 特開２０００−３２０３３５号公報JP 2000-320335 A 特開平１１−３０１２４号公報Japanese Patent Laid-Open No. 11-30124 特開平９−８８６０９号公報Japanese Patent Laid-Open No. 9-88609 特開平８−４５３４号公報JP-A-8-4534 特開平９−１１９３１５号公報JP-A-9-119315

ここで、直噴ガソリン機関で成層燃焼を実現させる方式の一つとして、ウォールガイド方式がある。ウォールガイド方式とは、ピストン頂面に形成したキャビティに向けて噴射した燃料の噴霧を、キャビティの壁面に沿わせて点火プラグ近傍に案内する方式である。ウォールガイド方式を採用する直噴ガソリン機関では、成層燃焼を実現するにあたってタンブル流やスワール流といった旋回気流による強い筒内ガス流動を必要としない。このことからウォールガイド方式を採用する直噴ガソリン機関には、例えば旋回気流の生成に必要となる気流制御弁やヘリカルポートの形状などの影響を受けて流量係数が低下しない、といった利点がある。その一方で、ウォールガイド方式を採用する直噴ガソリン機関では、均質燃焼を行う際にも筒内に強いガス流動が発生しないことから、係るガス流動を発生させる内燃機関と比較して混合気の均質性が低くなってしまう。   Here, there is a wall guide method as one of methods for realizing stratified combustion in a direct injection gasoline engine. The wall guide system is a system in which fuel spray injected toward the cavity formed on the piston top surface is guided to the vicinity of the spark plug along the wall surface of the cavity. In a direct injection gasoline engine that employs a wall guide system, a strong in-cylinder gas flow due to a swirling air flow such as a tumble flow or a swirl flow is not required to realize stratified combustion. For this reason, the direct injection gasoline engine employing the wall guide system has an advantage that the flow coefficient does not decrease under the influence of, for example, the shape of the airflow control valve and the helical port necessary for generating the swirling airflow. On the other hand, in a direct injection gasoline engine that employs a wall guide system, a strong gas flow does not occur in the cylinder even when performing homogeneous combustion. The homogeneity is lowered.

係る状況に対して上述の各特許文献が提案する技術のうち、例えば特許文献１または５が提案する技術は混合気の均質性を向上させる効果を有している。しかしながらこれらの技術は構造上、燃料噴射弁を燃焼室の中央上部に配設し易いディーゼルエンジンを対象とした技術であるため、同様の技術を直噴ガソリン機関に適用する場合には、点火プラグと燃料噴射弁とを両立させることが配設スペース上困難となり、また、これらを両立させて配設した場合でも燃料噴射弁と点火プラグとが近接するため、飛散した噴霧が衝突して点火プラグが被り易くなるといった他の技術的課題を抱えることにもなる。これは、ディーゼルエンジンに適用が限られない特許文献２が提案する技術についても同様である。また、特許文献３が提案する技術は旋回気流を利用したものであり、特許文献４が提案する技術は混合気の均一化を図るにあたっての解決手段の発想が大きく異なるものであるため、上述の状況には適用できない。一方、特許文献６が提案する技術は上述の状況に対しても適用可能であるが、排気弁の弁体前面に燃料を噴射することで噴射した燃料の気化、或いは霧化の促進を図ることを目的とした技術であるため、混合気の均質性を向上させるという観点からは、より有効な技術であるとは言い難い。そのため、特に上述の状況でも混合気の均質性をより好適に向上させ、内燃機関の出力性能の向上を図ることが可能な技術が望まれる。   Among the techniques proposed by the above-mentioned patent documents for such a situation, for example, the technique proposed by Patent Document 1 or 5 has an effect of improving the homogeneity of the air-fuel mixture. However, these techniques are structurally directed to a diesel engine in which a fuel injection valve is easily disposed at the upper center of the combustion chamber. Therefore, when applying the same technique to a direct injection gasoline engine, an ignition plug is used. It is difficult to make both the fuel injection valve and the fuel injection valve compatible, and even if they are both compatible, the fuel injection valve and the spark plug are close to each other. Other technical problems such as being easy to wear. The same applies to the technique proposed by Patent Document 2 that is not limited to application to diesel engines. In addition, the technique proposed in Patent Document 3 uses a swirling airflow, and the technique proposed in Patent Document 4 differs greatly in the idea of the solution means for achieving uniform air-fuel mixture. Not applicable to the situation. On the other hand, the technique proposed in Patent Document 6 can be applied to the above-described situation, but it is intended to promote the vaporization or atomization of the injected fuel by injecting the fuel to the front face of the exhaust valve body. Therefore, it is difficult to say that the technique is more effective from the viewpoint of improving the homogeneity of the air-fuel mixture. Therefore, a technique that can improve the homogeneity of the air-fuel mixture more suitably and improve the output performance of the internal combustion engine is desired particularly in the above-described situation.

そこで本発明は上記の課題に鑑みてなされたものであり、筒内に強いガス流動を発生させない場合でも、混合気の均質性を好適に向上させて出力性能の向上を図ることが可能な筒内燃料噴射式内燃機関を提供することを目的とする。   Therefore, the present invention has been made in view of the above problems, and even when a strong gas flow is not generated in the cylinder, the cylinder can suitably improve the homogeneity of the air-fuel mixture and improve the output performance. An object is to provide an internal fuel injection type internal combustion engine.

上記課題を解決するために、本発明は、燃焼室内に燃料を噴射するように配設された燃料噴射弁と、前記燃焼室に対応する吸気弁と排気弁とがそれぞれ少なくとも１つ以上配設されたシリンダヘッドとを有して構成される筒内燃料噴射式内燃機関であって、前記排気弁のうち少なくとも１つの排気弁が、該排気弁の弁体前面に噴霧案内部を備えるとともに、前記燃料噴射弁が、該噴霧案内部に向かって燃料を噴射する噴射孔を備え、さらに前記噴霧案内部が、前記噴射孔から噴射される燃料の噴霧が衝突する部分を含む凹部を有することを特徴とする。本発明によれば、衝突した燃料の噴霧を凹部の壁面に沿うように反射及び飛散させて、燃焼室内の雰囲気の乱れを増大させることが可能である。これにより、混合気の均質性を向上させ、その結果、内燃機関の出力性能を向上させることが可能である。なお、雰囲気の乱れを偏った状態で発生させないという観点からは、凹部は噴射される噴霧に対向するように開口していることが好ましく、さらに少なくとも燃焼室内側に向かって開口していることが好ましい。これにより、混合気の均質性をより向上させるとともに、さらに噴射した燃料がシリンダ壁面に付着し、その結果潤滑油が希釈されることも抑制可能である。   In order to solve the above problems, the present invention provides a fuel injection valve disposed to inject fuel into a combustion chamber, and at least one or more intake valves and exhaust valves corresponding to the combustion chamber. An in-cylinder fuel injection type internal combustion engine configured with a cylinder head, wherein at least one of the exhaust valves includes a spray guide portion on a front surface of the exhaust valve, The fuel injection valve includes an injection hole for injecting fuel toward the spray guide portion, and the spray guide portion further includes a recess including a portion where a spray of fuel injected from the injection hole collides. Features. According to the present invention, it is possible to increase the disturbance of the atmosphere in the combustion chamber by reflecting and scattering the collided fuel spray along the wall surface of the recess. Thereby, the homogeneity of the air-fuel mixture can be improved, and as a result, the output performance of the internal combustion engine can be improved. In addition, from the viewpoint of preventing the turbulence of the atmosphere from being biased, it is preferable that the concave portion is opened so as to face the spray to be injected, and at least toward the combustion chamber side. preferable. As a result, it is possible to further improve the homogeneity of the air-fuel mixture and to prevent the injected fuel from adhering to the cylinder wall surface and consequently diluting the lubricating oil.

また、本発明は、頂面にキャビティが形成されたピストンをさらに有して構成され、前記燃料噴射弁が、前記キャビティに向かって燃料を噴射可能な他の噴射孔をさらに備えてもよい。前述の発明は、本発明のように燃料を噴射する場合にも実現可能であり、特に、強い筒内ガス流動を発生させない場合における混合気の均質性向上に対して有効な効果を発揮することが可能である。   The present invention may further include a piston having a cavity formed on the top surface, and the fuel injection valve may further include another injection hole capable of injecting fuel toward the cavity. The above-described invention can also be realized when fuel is injected as in the present invention, and in particular, exhibits an effective effect for improving the homogeneity of the air-fuel mixture when a strong in-cylinder gas flow is not generated. Is possible.

また、本発明は、前記燃料噴射弁が、前記燃焼室の中心軸線を含み、且つクランク軸線に略平行な平面よりも吸気弁側に配設されていてもよい。より具体的には、例えば燃料噴射弁が少なくとも上述のように配設されていれば、噴射される燃料の噴霧に対向するように、且つ燃焼室内側に向かって開口させた凹部を容易に実現可能である。   In the present invention, the fuel injection valve may be disposed closer to the intake valve than a plane including the central axis of the combustion chamber and substantially parallel to the crank axis. More specifically, for example, if the fuel injection valve is disposed at least as described above, a recess that opens toward the combustion chamber side and easily faces the spray of the injected fuel is easily realized. Is possible.

また、本発明は、前記凹部は、前記噴射孔の噴射方向へ延伸する軸線と前記燃焼室の中心軸線とに略平行な断面で、前記燃料噴射弁側に向かってスムースに拡大された形状となっていてもよい。例えば本発明のような凹部であれば、噴射された燃料が有する運動エネルギーが反射の際に無駄に消費されることを抑制でき、その分より大きな雰囲気の乱れが発生するため、混合気の均質性をより向上させることが可能である。   Further, according to the present invention, the recess has a cross section substantially parallel to an axis extending in the injection direction of the injection hole and a center axis of the combustion chamber, and has a shape that is smoothly expanded toward the fuel injection valve side. It may be. For example, in the case of the recess as in the present invention, it is possible to suppress the kinetic energy of the injected fuel from being consumed unnecessarily during reflection, and the turbulence of the atmosphere that is larger is generated accordingly. It is possible to improve the property.

また、本発明は、前記形状が円弧であってもよい。より具体的には、例えば本発明のようにスムースに拡大された形状を円弧で実現することが可能である。   In the present invention, the shape may be an arc. More specifically, for example, a smoothly enlarged shape can be realized by an arc as in the present invention.

また、本発明は、前記排気弁が前記噴射案内部を備える代わりに、前記シリンダヘッドが、前記燃焼室を形成する壁面に該噴射案内部を備えてもよい。例えば本発明のように、シリンダヘッドに噴射案内部を備えさせることも可能である。   In the present invention, instead of the exhaust valve having the injection guide portion, the cylinder head may have the injection guide portion on a wall surface forming the combustion chamber. For example, as in the present invention, the cylinder head can be provided with an injection guide.

本発明によれば、筒内に強いガス流動を発生させない場合でも、混合気の均質性を好適に向上させて出力性能の向上を図ることが可能な筒内燃料噴射式内燃機関を提供できる。   ADVANTAGE OF THE INVENTION According to this invention, even when it does not generate | occur | produce a strong gas flow in a cylinder, the in-cylinder fuel injection type internal combustion engine which can aim at the improvement of output performance by improving the homogeneity of air-fuel | gaseous mixture suitably can be provided.

以下、本発明を実施するための最良の形態を図面と共に詳細に説明する。   Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

図１は、本実施例に係る筒内燃料噴射式内燃機関（以下、単に内燃機関と称す）１００の要部を示す図である。より具体的には、図１（ａ）では、内燃機関１００について、シリンダ２ａを関連する要部とともに側面視で概念的に示しており、図１（ｂ）では、内燃機関１００について、シリンダ２ａを関連する要部とともに上面視で概念的に示している。本実施例に示す内燃機関１００は直噴ガソリン機関である。但し、ディーゼルエンジンも混合気の均質性向上により出力性能の向上が期待されることから、内燃機関１００はディーゼルエンジンであってもよい。なお、ディーゼルエンジンの場合には後述する点火プラグ７は不要である。また、内燃機関１００は直列４気筒の内燃機関であるが、これに限られず適宜の気筒配列及び気筒数であってよい。また、本実施例では内燃機関１００に関し、各気筒の代表としてシリンダ２ａについて示しているが他の気筒についても同様である。   FIG. 1 is a diagram showing a main part of a direct injection type internal combustion engine (hereinafter simply referred to as an internal combustion engine) 100 according to the present embodiment. More specifically, in FIG. 1A, the internal combustion engine 100 is conceptually shown in a side view with the relevant main parts of the cylinder 2a, and in FIG. Is conceptually shown in top view along with the relevant parts. The internal combustion engine 100 shown in the present embodiment is a direct injection gasoline engine. However, since the diesel engine is also expected to improve the output performance by improving the homogeneity of the air-fuel mixture, the internal combustion engine 100 may be a diesel engine. In the case of a diesel engine, a spark plug 7 described later is not necessary. The internal combustion engine 100 is an in-line four-cylinder internal combustion engine, but is not limited thereto, and may have an appropriate cylinder arrangement and number of cylinders. In the present embodiment, the internal combustion engine 100 is shown with respect to the cylinder 2a as a representative of each cylinder, but the same applies to other cylinders.

図１（ａ）に示すように、内燃機関１００は、シリンダブロック３、シリンダヘッド４等を有して構成されている。シリンダブロック３には、略円筒状のシリンダ３ａが形成されており、このシリンダ３ａ内にはピストン５が収容されている。ピストン５の頂面には、後述する燃料噴射弁２から噴射される燃料の噴霧Ｆ３を壁面に沿わせて点火プラグ７近傍に案内するキャビティ５ａが形成されている。ピストン５がシリンダ３ａ内で往復運動すると、コネクティングロッド（図示省略）を介してクランクシャフト（図示省略）に動力が伝達され、さらにクランクシャフトによって往復運動が回転運動に変換される。なお、クランクシャフトは、その軸線（クランク軸線）が図１（ｂ）に示す中心軸線Ｐ２と略平行になるように内燃機関１００に配設されている。   As shown in FIG. 1A, the internal combustion engine 100 includes a cylinder block 3, a cylinder head 4, and the like. The cylinder block 3 is formed with a substantially cylindrical cylinder 3a, and a piston 5 is accommodated in the cylinder 3a. A cavity 5 a is formed on the top surface of the piston 5 to guide a fuel spray F 3 injected from a fuel injection valve 2 (described later) along the wall surface to the vicinity of the spark plug 7. When the piston 5 reciprocates in the cylinder 3a, power is transmitted to a crankshaft (not shown) via a connecting rod (not shown), and the crankshaft converts the reciprocating motion into a rotational motion. The crankshaft is disposed in the internal combustion engine 100 so that its axis (crank axis) is substantially parallel to the central axis P2 shown in FIG.

シリンダブロック３の上面にはシリンダヘッド４が固定されており、燃焼室６は、シリンダブロック３、シリンダヘッド４及びピストン５によって囲われた空間として形成されている。シリンダヘッド４には、吸気を燃焼室６に導くための構成である第１及び第２の吸気ポート１１、１２が形成されている。さらに、シリンダヘッド４には、第１の吸気ポート１１に対応させて第１の吸気弁２１が、同様に第２の吸気ポート１２に対応させて第２の吸気弁２２がそれぞれ配設されている。これら吸気弁２１、２２は、第１及び第２の吸気ポート１１、１２の流路をそれぞれ開閉するための構成である。これら吸気ポート１１、１２のほか、シリンダヘッド４には燃焼後に発生するガスを燃焼室６から排気するために第１及び第２の排気ポート１３、１４が形成され、さらにこれら排気ポート１３、１４の流路を開閉するために第１及び第２の排気弁２３、２４が配設されている。また、シリンダヘッド４には点火用の火花を発生させるための構成である点火プラグ７が、燃焼室６内略中央上部に電極を突出させた状態で配設されている。なお、本実施例ではシリンダ３ａで吸排気２弁構造を採用しているが、これに限られず吸排気ともに適宜の数量の弁を備えた構造であってよい。   A cylinder head 4 is fixed to the upper surface of the cylinder block 3, and the combustion chamber 6 is formed as a space surrounded by the cylinder block 3, the cylinder head 4 and the piston 5. The cylinder head 4 is formed with first and second intake ports 11 and 12 that are configured to guide intake air to the combustion chamber 6. Further, the cylinder head 4 is provided with a first intake valve 21 corresponding to the first intake port 11 and similarly a second intake valve 22 corresponding to the second intake port 12. Yes. The intake valves 21 and 22 are configured to open and close the flow paths of the first and second intake ports 11 and 12, respectively. In addition to these intake ports 11 and 12, the cylinder head 4 is formed with first and second exhaust ports 13 and 14 for exhausting the gas generated after combustion from the combustion chamber 6, and these exhaust ports 13 and 14 are further formed. First and second exhaust valves 23 and 24 are provided to open and close the flow path. The cylinder head 4 is provided with a spark plug 7, which is a configuration for generating sparks for ignition, in a state where an electrode protrudes from a substantially upper center in the combustion chamber 6. In this embodiment, the cylinder 3a adopts the intake / exhaust two-valve structure. However, the present invention is not limited to this, and the intake / exhaust may be provided with an appropriate number of valves.

第１の排気弁２３の弁体前面には噴霧案内部１Ａが設けられている。第１の噴霧案内部１Ａは燃焼室６内で混合気の燃焼に曝されることから、より高い強度を確保するために第１の排気弁２３と一体で形成されることが好ましい。但し、これに限られず、第１の排気弁２３と噴霧案内部１Ａとを個別に形成した後に一体化してもよい。同様に、第２の排気弁２４の弁体前面には第２の噴霧案内部１Ｂが設けられている。なお、本実施例では、第１及び第２の排気弁２３、２４それぞれが第１及び第２の噴霧案内部１Ａ、１Ｂを備えているが、これら排気弁２３、２４のうち、少なくともいずれかが第１または第２の噴霧案内部１Ａ、１Ｂを備えていれば、相応の効果を得ることが可能である。   A spray guide portion 1 </ b> A is provided on the front surface of the valve body of the first exhaust valve 23. Since the first spray guide portion 1A is exposed to the combustion of the air-fuel mixture in the combustion chamber 6, it is preferably formed integrally with the first exhaust valve 23 in order to ensure higher strength. However, it is not restricted to this, You may integrate, after forming the 1st exhaust valve 23 and the spray guide part 1A separately. Similarly, a second spray guide portion 1 </ b> B is provided on the front surface of the second exhaust valve 24. In the present embodiment, each of the first and second exhaust valves 23 and 24 includes the first and second spray guide portions 1A and 1B, but at least one of the exhaust valves 23 and 24 is used. If it has 1st or 2nd spray guide part 1A, 1B, it is possible to acquire a suitable effect.

一方、シリンダヘッド４には、燃料を噴射するための構成である燃料噴射弁２が、燃焼室６内に噴射部２ａを突出させた状態で配設されている。より具体的には、燃料噴射弁２は、図１（ａ）に示すように第１及び第２の吸気ポート１１、１２よりもシリンダブロック３側に配設されており、また、図１（ｂ）に示すようにその本体の軸線が燃焼室６の中心軸線Ｐ１を含み、且つクランク軸線に略直交する、言い換えれば中心軸線Ｐ３に略平行な平面に含まれるように配設されている。なお、燃料噴射弁２は、少なくとも燃焼室６の中心軸線Ｐ１を含み、且つクランク軸線に略平行な平面よりも第１及び第２の吸気弁２１、２２側に配設されていることが、第１及び第２の噴霧案内部１Ａ、１Ｂとの相対的な位置関係を好適なものとする上で好ましい。また、燃料噴射弁２はシリンダブロック３に配設されていてもよい。   On the other hand, the cylinder head 4 is provided with a fuel injection valve 2, which is a structure for injecting fuel, with the injection portion 2 a protruding into the combustion chamber 6. More specifically, the fuel injection valve 2 is disposed closer to the cylinder block 3 than the first and second intake ports 11 and 12 as shown in FIG. As shown in b), the axis of the main body includes the central axis P1 of the combustion chamber 6 and is disposed so as to be included in a plane substantially perpendicular to the crank axis, in other words, substantially parallel to the central axis P3. The fuel injection valve 2 includes at least the central axis P1 of the combustion chamber 6 and is disposed closer to the first and second intake valves 21 and 22 than a plane substantially parallel to the crank axis. It is preferable for making the relative positional relationship with the first and second spray guide portions 1A and 1B suitable. The fuel injection valve 2 may be disposed in the cylinder block 3.

燃料噴射弁２は、上述のように配設された状態で、所定のタイミングでキャビティ５ａに向かって燃料を噴射可能な図示しない主噴射孔（他の噴射孔）を噴射部２ａに備えている。主噴射孔は矩形の噴口形状を有するスリットノズルであり、主噴射孔から噴射された燃料は、偏平な扇状の噴霧（以下、ファンスプレーとも称す）Ｆ３に形成される。本実施例に係る内燃機関１００は、成層燃焼を実現するにあたってウォールガイド方式を採用しており、この方式においてさらにファンスプレーＦ３を形成することで、より好適に成層燃焼を実現している。但しこれに限られず、主噴射孔には他のノズル形状を採用してもよい。また、燃料噴射弁２は、第１及び第２の噴霧案内部１Ａ及び１Ｂそれぞれに向かって燃料を噴射するための第１及び第２の噴射孔（図示省略）を噴射部２ａに備えている。これら噴射孔から噴射された燃料は、図１（ｂ）に示すような中実の噴霧Ｆ１及びＦ２に形成される。   The fuel injection valve 2 includes a main injection hole (other injection holes) (not shown) in the injection unit 2a that can inject fuel toward the cavity 5a at a predetermined timing in the state of being arranged as described above. . The main injection hole is a slit nozzle having a rectangular injection hole shape, and fuel injected from the main injection hole is formed into a flat fan-shaped spray (hereinafter also referred to as fan spray) F3. The internal combustion engine 100 according to the present embodiment employs a wall guide method in realizing stratified combustion, and further forms stratified combustion by forming a fan spray F3 in this method. However, the present invention is not limited to this, and other nozzle shapes may be adopted for the main injection holes. In addition, the fuel injection valve 2 includes first and second injection holes (not shown) in the injection unit 2a for injecting fuel toward the first and second spray guide units 1A and 1B, respectively. . The fuel injected from these injection holes is formed into solid sprays F1 and F2 as shown in FIG.

図２は、第１の噴射孔の噴射方向へ延伸する軸線Ｐ４を含み、中心軸線Ｐ１に略平行な断面で、燃料噴射弁２と第１の噴霧案内部１Ａとを概念的に示す図である。図２に示すように、第１の噴射案内部１Ａは、第１の噴射孔から噴射される燃料の噴霧Ｆ１が衝突する部分を含む凹部１ａＡを有している。この凹部１ａＡは噴霧Ｆ１に対向するように開口しており、さらに、図１（ｂ）に示すように燃焼室６の内側に向かって開口している。また、図２に示すように、上述の断面で凹部１ａＡは、燃料噴射弁２側に向かってスムースに拡大された円弧形状となる。さらに、凹部１ａＡは、軸線Ｐ４と中心軸線Ｐ１とに略平行な他の断面でも図２に示す円弧形状となる。すなわち、凹部１ａＡは円筒内面の一部と同様に形成されている。   FIG. 2 is a diagram conceptually showing the fuel injection valve 2 and the first spray guide portion 1A in a cross section that includes an axis P4 extending in the injection direction of the first injection hole and is substantially parallel to the central axis P1. is there. As shown in FIG. 2, the first injection guide portion 1 </ b> A has a recess 1 a </ b> A including a portion with which the fuel spray F <b> 1 injected from the first injection hole collides. The recess 1aA is opened so as to face the spray F1, and further opens toward the inside of the combustion chamber 6 as shown in FIG. Further, as shown in FIG. 2, the recess 1aA in the above-described cross section has an arc shape that is smoothly enlarged toward the fuel injection valve 2 side. Further, the recess 1aA has an arc shape shown in FIG. 2 even in another cross section substantially parallel to the axis P4 and the center axis P1. That is, the recess 1aA is formed in the same manner as a part of the inner surface of the cylinder.

次に、燃料噴射弁２から噴射された燃料の噴霧Ｆ１が凹部１ａＡに案内される過程について、図２を用いて詳述する。噴霧Ｆ１は、燃料噴射弁２から噴射された後、凹部１ａＡに衝突する。衝突した噴霧Ｆ１は凹部１ａＡの壁面に沿うように反射する。また、反射の際に凹部１ａＡの壁面がスムースに拡大されているため、噴霧Ｆ１は運動エネルギーを無駄に消費することなく反射する。さらに、凹部１ａＡは燃焼室６内側に向かって開口しているため、反射した噴霧Ｆ１は燃焼室６内側に向かって飛散する。これにより、燃焼室６内の雰囲気の乱れを増大させて混合気の均質性を好適に向上させることが可能になるとともに、反射して飛散する燃料がシリンダ３ａの壁面に付着し、その結果、潤滑油が希釈されることを抑制可能である。また、上述のようにして混合気の均質性を向上させることは、本実施例に係る内燃機関１００のように筒内に強いガス流動を発生させないような内燃機関に対して相性がよく、そのため係る内燃機関で特に有効な効果を発揮することが可能である。   Next, the process in which the fuel spray F1 injected from the fuel injection valve 2 is guided to the recess 1aA will be described in detail with reference to FIG. The spray F1 is injected from the fuel injection valve 2 and then collides with the recess 1aA. The collided spray F1 is reflected along the wall surface of the recess 1aA. In addition, since the wall surface of the recess 1aA is smoothly enlarged during reflection, the spray F1 reflects without consuming kinetic energy. Furthermore, since the recess 1aA opens toward the inside of the combustion chamber 6, the reflected spray F1 scatters toward the inside of the combustion chamber 6. As a result, the turbulence of the atmosphere in the combustion chamber 6 can be increased to suitably improve the homogeneity of the air-fuel mixture, and the reflected and scattered fuel adheres to the wall surface of the cylinder 3a. It is possible to prevent the lubricating oil from being diluted. Further, improving the homogeneity of the air-fuel mixture as described above is compatible with an internal combustion engine that does not generate a strong gas flow in the cylinder like the internal combustion engine 100 according to the present embodiment. Such an internal combustion engine can exhibit particularly effective effects.

なお、図２に係る上述の説明では、噴霧Ｆ１と噴射案内部１Ａとの場合について詳述したが、噴霧Ｆ２と噴射案内部１Ｂとの場合についても同様である。また、本実施例で示した噴射案内部１Ａ及び１Ｂは種々の変形が可能である。以下、噴射案内部１Ａに関していくつかの変形例を示すが、これらは噴射案内部１Ｂについても同様に適用可能である。例えば噴射案内部１Ａが凹部１ａＡの代わりに、軸線Ｐ４を含み、クランク軸線と略平行な断面で燃料噴射弁２側に向かってスムースに拡大された形状となる凹部を有してもよい。言い換えれば、第１の排気弁２３が噴霧案内部１Ａの代わりに、図２に示す第１の噴射孔の噴射方向に延伸する軸線周りに、噴霧案内部１Ａを９０度回転したような噴霧案内部を備えてもよい。また、噴射案内部１Ａが凹部１ａＡの代わりに、図２に示す断面に略直交する方向の両端、または一端が平面、または曲面で閉じた凹部を有してもよい。また、噴霧案内部１Ａが凹部１ａＡの代わりに、球面状の凹部を有してもよい。これらの場合には、反射して飛散する燃料がシリンダ３ａの壁面に付着することをより好適に抑制可能である。   In the above description of FIG. 2, the case of the spray F1 and the injection guide 1A has been described in detail, but the same applies to the case of the spray F2 and the injection guide 1B. Further, the injection guide portions 1A and 1B shown in the present embodiment can be variously modified. Hereinafter, although some modifications regarding the injection guide part 1A are shown, these are similarly applicable to the injection guide part 1B. For example, instead of the recess 1aA, the injection guide 1A may include a recess that includes the axis P4 and has a shape that is smoothly expanded toward the fuel injection valve 2 in a cross section substantially parallel to the crank axis. In other words, instead of the spray guide portion 1A, the first exhaust valve 23 is spray guide in which the spray guide portion 1A is rotated 90 degrees around the axis extending in the injection direction of the first injection hole shown in FIG. May be provided. Further, instead of the concave portion 1aA, the injection guide portion 1A may have a concave portion whose both ends or one end in a direction substantially orthogonal to the cross section shown in FIG. Further, the spray guide portion 1A may have a spherical concave portion instead of the concave portion 1aA. In these cases, it is possible to more suitably suppress the fuel that is reflected and scattered from adhering to the wall surface of the cylinder 3a.

また、凹部１ａＡは曲面で形成されているが、噴射案内部１Ａが凹部１ａＡの代わりに、平面、または円弧以外の曲面、または平面と曲面との組合せで形成された凹部を有してもよい。また、本実施例では凹部１ａＡが噴霧Ｆ１に対向するように開口しているが、これに限られず適宜の方向に向かって開口させることも可能であり、例えば噴射案内部１Ａが上述のような凹部１ａＡの変形例と組み合わせて中心軸線Ｐ１に向かって開口させた凹部を有してもよい。また、第１の排気弁２３が噴射案内部１Ａを備える代わりに、シリンダヘッド３が燃焼室６を形成する壁面に噴射案内部１Ａを備えてもよい。さらに、この場合には、噴射案内部１Ａの代わりに、この壁面に凹部を形成することで噴射案内部を実現してもよい。以上により、筒内に強いガス流動を発生させない場合でも、混合気の均質性を好適に向上させて出力性能の向上を図ることが可能な内燃機関１００を実現可能である。   Moreover, although the recessed part 1aA is formed with the curved surface, the injection guide part 1A may have a recessed part formed with a curved surface other than a flat surface or an arc, or a combination of a flat surface and a curved surface, instead of the recessed portion 1aA. . Further, in this embodiment, the recess 1aA is opened so as to face the spray F1, but the present invention is not limited to this, and it is possible to open it in an appropriate direction. You may have the recessed part opened toward the central axis P1 combining with the modification of the recessed part 1aA. Further, instead of the first exhaust valve 23 including the injection guide 1 </ b> A, the cylinder head 3 may include the injection guide 1 </ b> A on the wall surface forming the combustion chamber 6. Further, in this case, instead of the injection guide portion 1A, the injection guide portion may be realized by forming a recess in the wall surface. As described above, even when a strong gas flow is not generated in the cylinder, the internal combustion engine 100 capable of improving the homogeneity of the air-fuel mixture and improving the output performance can be realized.

上述した実施例は本発明の好適な実施の例である。但し、これに限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変形実施可能である。   The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

本実施例に係る内燃機関１００の要部を示す図である。It is a figure which shows the principal part of the internal combustion engine 100 which concerns on a present Example. 第１の噴射孔の噴射方向へ延伸する軸線Ｐ４を含み、中心軸線Ｐ１に略平行な断面で、燃料噴射弁２と第１の噴霧案内部１Ａとを概念的に示す図である。It is a figure which shows notionally the fuel injection valve 2 and the 1st spray guide part 1A in the cross section which contains the axis line P4 extended in the injection direction of a 1st injection hole, and is substantially parallel to the center axis line P1.

符号の説明Explanation of symbols

１ 噴霧案内部
２ 燃料噴射弁
３ シリンダブロック
４ シリンダヘッド
５ ピストン
６ 燃焼室
７ 点火プラグ
１１ 第１の吸気ポート
１２ 第２の吸気ポート
１３ 第１の排気ポート
１４ 第２の排気ポート
２１ 第１の吸気弁
２２ 第２の吸気弁
２３ 第１の排気弁
２４ 第２の排気弁
１００ 筒内燃料噴射式内燃機関
DESCRIPTION OF SYMBOLS 1 Spray guide part 2 Fuel injection valve 3 Cylinder block 4 Cylinder head 5 Piston 6 Combustion chamber 7 Spark plug 11 1st intake port 12 2nd intake port 13 1st exhaust port 14 2nd exhaust port 21 1st exhaust port 21 Intake valve 22 Second intake valve 23 First exhaust valve 24 Second exhaust valve 100 In-cylinder fuel injection internal combustion engine

Claims (6)

燃焼室内に燃料を噴射するように配設された燃料噴射弁と、前記燃焼室に対応する吸気弁と排気弁とがそれぞれ少なくとも１つ以上配設されたシリンダヘッドとを有して構成される筒内燃料噴射式内燃機関であって、
前記排気弁のうち少なくとも１つの排気弁が、該排気弁の弁体前面に噴霧案内部を備えるとともに、前記燃料噴射弁が、該噴霧案内部に向かって燃料を噴射する噴射孔を備え、
さらに前記噴霧案内部が、前記噴射孔から噴射される燃料の噴霧が衝突する部分を含む凹部を有することを特徴とする筒内燃料噴射式内燃機関。 A fuel injection valve arranged to inject fuel into the combustion chamber, and a cylinder head provided with at least one intake valve and one exhaust valve corresponding to the combustion chamber. An in-cylinder fuel injection internal combustion engine,
At least one exhaust valve of the exhaust valves includes a spray guide portion on a front surface of the exhaust valve, and the fuel injection valve includes an injection hole for injecting fuel toward the spray guide portion,
The in-cylinder fuel injection type internal combustion engine, wherein the spray guide portion further includes a recess including a portion where fuel spray injected from the injection hole collides. 頂面にキャビティが形成されたピストンをさらに有して構成され、
前記燃料噴射弁が、前記キャビティに向かって燃料を噴射可能な他の噴射孔をさらに備えることを特徴とする請求項１記載の筒内燃料噴射式内燃機関。 It further comprises a piston having a cavity formed on the top surface,
The in-cylinder fuel injection internal combustion engine according to claim 1, wherein the fuel injection valve further includes another injection hole capable of injecting fuel toward the cavity. 前記燃料噴射弁が、前記燃焼室の中心軸線を含み、且つクランク軸線に略平行な平面よりも吸気弁側に配設されていることを特徴とする請求項１または２記載の筒内燃料噴射式内燃機関。 3. The in-cylinder fuel injection according to claim 1, wherein the fuel injection valve is disposed closer to the intake valve than a plane including a central axis of the combustion chamber and substantially parallel to the crank axis. Internal combustion engine. 前記凹部は、前記噴射孔の噴射方向へ延伸する軸線と前記燃焼室の中心軸線とに略平行な断面で、前記燃料噴射弁側に向かってスムースに拡大された形状となることを特徴とする請求項１から３いずれか１項記載の筒内燃料噴射式内燃機関。 The recess has a cross section substantially parallel to an axis extending in the injection direction of the injection hole and a central axis of the combustion chamber, and has a shape that is smoothly expanded toward the fuel injection valve. The in-cylinder fuel injection internal combustion engine according to any one of claims 1 to 3. 前記形状が円弧であることを特徴とする請求項４記載の筒内燃料噴射式内燃機関。 The in-cylinder fuel injection internal combustion engine according to claim 4, wherein the shape is an arc. 前記排気弁が前記噴射案内部を備える代わりに、前記シリンダヘッドが、前記燃焼室を形成する壁面に該噴射案内部を備えることを特徴とする請求項１から５いずれか１項記載の筒内燃料噴射式内燃機関。
6. The in-cylinder unit according to claim 1, wherein the cylinder head includes the injection guide portion on a wall surface forming the combustion chamber, instead of the exhaust valve including the injection guide portion. Fuel injection internal combustion engine.
JP2005365446A 2005-12-19 2005-12-19 Cylinder fuel injection type internal combustion engine Pending JP2007170206A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2105595A1 (en) 2008-03-24 2009-09-30 Mazda Motor Corporation Internal combustion engine of spark-Ignition direct-injection type and fuel injection method thereof
JP2010038096A (en) * 2008-08-07 2010-02-18 Yamaha Motor Co Ltd Engine
JP2010174697A (en) * 2009-01-28 2010-08-12 Toyota Motor Corp Exhaust valve of internal combustion engine
JP2010249125A (en) * 2009-03-23 2010-11-04 Denso Corp Fuel injection valve

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2105595A1 (en) 2008-03-24 2009-09-30 Mazda Motor Corporation Internal combustion engine of spark-Ignition direct-injection type and fuel injection method thereof
US8196560B2 (en) 2008-03-24 2012-06-12 Mazda Motor Corporation Internal combustion engine of spark-ignition direct-injection type and fuel injecting method thereof
JP2010038096A (en) * 2008-08-07 2010-02-18 Yamaha Motor Co Ltd Engine
JP2010174697A (en) * 2009-01-28 2010-08-12 Toyota Motor Corp Exhaust valve of internal combustion engine
JP2010249125A (en) * 2009-03-23 2010-11-04 Denso Corp Fuel injection valve

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