JP2007239563A - Combustion chamber structure for internal combustion engine - Google Patents

Combustion chamber structure for internal combustion engine Download PDF

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JP2007239563A
JP2007239563A JP2006061762A JP2006061762A JP2007239563A JP 2007239563 A JP2007239563 A JP 2007239563A JP 2006061762 A JP2006061762 A JP 2006061762A JP 2006061762 A JP2006061762 A JP 2006061762A JP 2007239563 A JP2007239563 A JP 2007239563A
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combustion chamber
squish
squish area
internal combustion
combustion engine
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Katsuyoshi Suzuki
克由 鈴木
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Nissan Motor Co Ltd
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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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Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion chamber structure capable of efficiently using reverse squish flow. <P>SOLUTION: In a combustion chamber structure for an internal combustion engine having a combustion chamber 2 formed by a piston crown surface 3a and a cylinder head inner surface 4a and having a squish area 8 for generating squish flow formed at an outer circumference part of the combustion chamber 2 and between the piston crown surface 3a and the cylinder head inner surface 4a, a hollow 11 extending in a direction from a combustion chamber center side to a squish area deepest part 10 is provided on the piston crown surface 3a of a part forming the squish area 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、ピストン冠面とシリンダヘッド内面とにより燃焼室が形成され、この燃焼室の外周部で且つピストン冠面とシリンダヘッド内面との間にスキッシュ流を生成するためのスキッシュエリアが形成された内燃機関の燃焼室構造に関する。   In the present invention, a combustion chamber is formed by the piston crown surface and the cylinder head inner surface, and a squish area for generating a squish flow is formed at the outer periphery of the combustion chamber and between the piston crown surface and the cylinder head inner surface. The present invention relates to a combustion chamber structure of an internal combustion engine.

従来、内燃機関の燃焼室構造において、スワールの方向と、スキッシュ流の方向とを一致させるため、スキッシュエリアを横切るようにしてガイド溝を形成することが知られている（特許文献１）。これにより、スキッシュエリアで生成したスキッシュ流に、ガイド溝から燃焼室内に排出されるスキッシュ流を加算することで、スキッシュ流によるスワールの強化（乱れの強化）を行うことができる。そして、燃焼室内の混合気に強い乱れを生成し、燃焼時の火炎伝播速度を高め、燃焼性の向上を狙っている。
特開平１−１７０７１５号公報 Conventionally, in a combustion chamber structure of an internal combustion engine, it is known to form a guide groove so as to cross the squish area in order to make the swirl direction coincide with the squish flow direction (Patent Document 1). Thus, by adding the squish flow discharged from the guide groove into the combustion chamber to the squish flow generated in the squish area, it is possible to enhance the swirl (intensification of turbulence) by the squish flow. And the strong turbulence is produced | generated by the air-fuel | gaseous mixture in a combustion chamber, the flame propagation speed at the time of combustion is raised, and the combustibility is aimed at.
JP-A-1-170715

しかしながら、特許文献１に記載の内燃機関の燃焼室構造では、リバーススキッシュ流を考慮した場合には、ガイド溝による空気流れ案内方向とスワールの方向とは正反対となり、スキッシュ流を逆方向に引き込まなければならず、効率的にリバーススキッシュ流を生成できないという問題があった。
また、スキッシュ流の方向とスワールの方向とが一致するようにガイド溝を設けるためには、スキッシュエリア内を斜めに横切らなければならず、スキッシュエリア内に占める溝の割合が大きくなる。これによって、燃焼室の容積に対する表面積の比、いわゆるＳ／Ｖ比が大きくなる。そして、熱効率が低下し、出力の低下や燃費の低下をもたらすという問題があった。 However, in the combustion chamber structure of the internal combustion engine described in Patent Document 1, when the reverse squish flow is considered, the air flow guide direction by the guide groove and the swirl direction are opposite to each other, and the squish flow must be drawn in the reverse direction. In other words, there is a problem that the reverse squish flow cannot be generated efficiently.
Further, in order to provide the guide groove so that the direction of the squish flow and the direction of the swirl coincide with each other, the squish area must be crossed obliquely, and the ratio of the groove in the squish area increases. This increases the ratio of the surface area to the volume of the combustion chamber, the so-called S / V ratio. And there existed a problem that a thermal efficiency fell and brought about a fall of output and a fuel consumption.

本発明は、上記問題に鑑みなされたものであり、リバーススキッシュ流を効率的に活用できる燃焼室構造にすることを目的とする。   The present invention has been made in view of the above problems, and an object thereof is to provide a combustion chamber structure that can efficiently utilize a reverse squish flow.

そのため本発明では、ピストン冠面およびシリンダヘッド内面の少なくとも一方の、スキッシュエリアを形成する部分に、燃焼室中心側からスキッシュエリア最深部方向へ伸びるくぼみを設けた。   Therefore, in the present invention, at least one of the piston crown surface and the cylinder head inner surface is provided with a recess extending from the combustion chamber center side toward the deepest portion of the squish area in the portion forming the squish area.

本発明によれば、リバーススキッシュ流をくぼみから勢いよくスキッシュエリア内に流入させることで、くぼみ近傍における混合気の乱れを強化し、燃焼室外周部の火炎伝播速度を高め、熱効率向上による出力の向上およびノッキング素質の向上を図ることができるという効果を奏する。   According to the present invention, the reverse squish flow is vigorously flowed into the squish area from the indentation, thereby strengthening the turbulence of the air-fuel mixture in the vicinity of the indentation, increasing the flame propagation speed in the outer periphery of the combustion chamber, and improving the heat efficiency. There exists an effect that improvement and improvement of knocking quality can be aimed at.

以下、図面に基づき、本発明の実施形態について説明する。
図１は、本発明の第１の実施形態における４バルブ式の内燃機関１の燃焼室構造を示す上面図である。図２は、図１のＡ−Ａ線矢視断面図である。図３は、図１のＸ領域における拡大図である。図４は、図２のＹ領域における拡大図である。図５は、図１のＢ−Ｂ線矢視断面図である。なお、これらの図は、ピストンが上死点近傍に達した時の状態を示している。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a top view showing a combustion chamber structure of a four-valve internal combustion engine 1 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is an enlarged view of a region X in FIG. FIG. 4 is an enlarged view of a Y region in FIG. 5 is a cross-sectional view taken along line BB in FIG. In addition, these figures have shown the state when a piston reaches the top dead center vicinity.

内燃機関１の燃焼室２は、ピストン３の冠面３ａおよびシリンダヘッド４の内面４ａにより形成されている。この燃焼室２は、吸気側と排気側との略中央位置に稜線２ａが形成されるペントルーフ型であり、このペントルーフの裾部２ｂは、吸気側および排気側において稜線２ａと平行に形成されている。シリンダヘッド４の吸気側には、燃焼室２内に空気を吸入する吸気バルブ５が２つ配置されている。一方、シリンダヘッド４の排気側には、燃焼室２内の排気ガスを排出する排気バルブ６が２つ配置されている。燃焼室２の略中央位置のシリンダヘッド４には、点火栓７が配置されている。   A combustion chamber 2 of the internal combustion engine 1 is formed by a crown surface 3 a of the piston 3 and an inner surface 4 a of the cylinder head 4. The combustion chamber 2 is a pent roof type in which a ridge line 2a is formed at a substantially central position between the intake side and the exhaust side, and a skirt 2b of the pent roof is formed in parallel with the ridge line 2a on the intake side and the exhaust side. Yes. Two intake valves 5 for sucking air into the combustion chamber 2 are arranged on the intake side of the cylinder head 4. On the other hand, two exhaust valves 6 for exhausting the exhaust gas in the combustion chamber 2 are arranged on the exhaust side of the cylinder head 4. A spark plug 7 is disposed in the cylinder head 4 at a substantially central position of the combustion chamber 2.

燃焼室２の外周部で且つピストン冠面３ａとシリンダヘッド内面４ａとの間には、スキッシュ流を生成するためのスキッシュエリア８が形成されている。
図１に示すように、スキッシュエリア８は、ペントルーフの裾部２ｂからＡ−Ａ線の吸気側および排気側の壁面９に向かって深く形成されている。Ａ−Ａ線は、燃焼室２の稜線２ａと直交し、燃焼室２の中央位置を含み、吸気側と排気側とを結ぶ線である。Ａ−Ａ線と燃焼室壁面９との交点部分は、スキッシュエリア最深部１０になっている。 A squish area 8 for generating a squish flow is formed at the outer periphery of the combustion chamber 2 and between the piston crown surface 3a and the cylinder head inner surface 4a.
As shown in FIG. 1, the squish area 8 is formed deeply from the skirt 2b of the pent roof toward the intake-side and exhaust-side wall surfaces 9 along the line AA. The AA line is a line that is orthogonal to the ridge line 2 a of the combustion chamber 2, includes the center position of the combustion chamber 2, and connects the intake side and the exhaust side. The intersection of the AA line and the combustion chamber wall surface 9 is the squish area deepest portion 10.

スキッシュエリア８には、燃焼室２とスキッシュエリア８との境界であるペントルーフの裾部２ｂの位置からスキッシュエリア最深部１０方向へ伸びるくぼみ１１が形成されている。くぼみ１１は、シリンダ軸方向に見て、長方形状に形成され、且つ、スキッシュエリア最深部１０側の辺１１ａと、この辺の両端から垂直に形成された両辺１１ｂ，１１ｃ（稜線方向と垂直に形成された辺）との３辺がスキッシュエリア８に外周を囲まれている（図３）。すなわち、くぼみ１１は、燃焼室壁面９まで連通させず、スキッシュエリア８を分割しない形状にしており、更に極力スキッシュエリア８の表面積を低減させない形状にしている。   In the squish area 8, a dent 11 is formed extending from the position of the bottom part 2 b of the pent roof that is the boundary between the combustion chamber 2 and the squish area 8 toward the deepest part 10 of the squish area. The recess 11 is formed in a rectangular shape when viewed in the cylinder axial direction, and the side 11a on the squish area deepest portion 10 side, and both sides 11b and 11c formed perpendicularly from both ends of the side (formed perpendicular to the ridge line direction). The three sides of the squish area 8 are surrounded by the squish area 8 (FIG. 3). That is, the recess 11 does not communicate with the combustion chamber wall surface 9, does not divide the squish area 8, and further has a shape that does not reduce the surface area of the squish area 8 as much as possible.

この形状は例えば、くぼみ１１を、燃焼室２の稜線２ａ方向における幅を狭くし、シリンダ軸方向の深さを深くすると共に、スキッシュエリア最深部方向への深さを短くすることで実現する。これにより、くぼみ１１からスキッシュエリア８内にスキッシュ流を導入することで、スキッシュエリア８内の混合気を乱れさせ、燃焼室２の外周部における火炎伝播速度を高め、燃焼性の向上を図る。そして、燃焼室２の容積に対する表面積比であるＳ／Ｖ比の増大を抑制する。この結果、熱効率の向上、出力の向上や燃費の向上を図る。   This shape is realized, for example, by reducing the width of the indentation 11 in the direction of the ridge line 2a of the combustion chamber 2, increasing the depth in the cylinder axis direction, and shortening the depth in the deepest part of the squish area. Thereby, by introducing a squish flow from the recess 11 into the squish area 8, the air-fuel mixture in the squish area 8 is disturbed, the flame propagation speed in the outer peripheral portion of the combustion chamber 2 is increased, and the combustibility is improved. And the increase in S / V ratio which is a surface area ratio with respect to the volume of the combustion chamber 2 is suppressed. As a result, the thermal efficiency is improved, the output is improved, and the fuel consumption is improved.

くぼみ１１は、吸気側と排気側とに対称に設けられている。図４および図５に示したくぼみ１１は、スキッシュエリア８からシリンダ軸方向下方に向かって凹状に形成され、スキッシュエリア８側の端部１１ｄがエッジ状に形成される。なお、くぼみ１１は、端部１１ｄがエッジ状であれば、例えば、ピストン冠面３ａのシリンダ軸方向にＵ字状に形成されたものであってもよい。   The recess 11 is provided symmetrically on the intake side and the exhaust side. The recess 11 shown in FIGS. 4 and 5 is formed in a concave shape from the squish area 8 downward in the cylinder axial direction, and an end portion 11d on the squish area 8 side is formed in an edge shape. In addition, if the edge part 11d is edge shape, the hollow 11 may be formed in the U-shape in the cylinder axial direction of the piston crown surface 3a, for example.

そして、くぼみ１１を形成する位置は、ピストン冠面３ａおよびシリンダヘッド内面４ａの少なくとも一方の、スキッシュエリア８を形成する部分であればよいため、例えば、スキッシュエリア８を形成するシリンダヘッド内面４ａのみに設けても、シリンダヘッド内面４ａおよびピストン冠面３ａに設けてもよい。
次に、内燃機関１の燃焼室構造による空気の流れについて説明する。 The position where the recess 11 is formed may be a portion that forms the squish area 8 of at least one of the piston crown surface 3a and the cylinder head inner surface 4a. For example, only the cylinder head inner surface 4a that forms the squish area 8 is used. Or may be provided on the cylinder head inner surface 4a and the piston crown surface 3a.
Next, the flow of air by the combustion chamber structure of the internal combustion engine 1 will be described.

従来の内燃機関の燃焼構造においては、図６に示すように、ペントルーフ型の燃焼室２の外周部にて、ピストン冠面２ａとシリンダヘッド内面４ａとの間にスキッシュ流を生成するためのスキッシュエリア８が設けられており、ピストン３が上死点手前まで上昇した時に、スキッシュエリア８から燃焼室２（稜線２ａ）に向かって流れるスキッシュ流を生成する。これにより、燃焼室２内の混合気に強い乱れを与え、燃焼時の火炎伝播速度を高め、燃焼性の向上を図っている。   In the combustion structure of a conventional internal combustion engine, as shown in FIG. 6, a squish for generating a squish flow between the piston crown surface 2a and the cylinder head inner surface 4a at the outer peripheral portion of the pent roof type combustion chamber 2. An area 8 is provided, and a squish flow that flows from the squish area 8 toward the combustion chamber 2 (ridge line 2a) is generated when the piston 3 rises up to the top dead center. As a result, the air-fuel mixture in the combustion chamber 2 is strongly disturbed, the flame propagation speed during combustion is increased, and the combustibility is improved.

また、図７に示すように、従来の内燃機関の燃焼構造においては、ピストン２が上死点を経過した後に生成されるリバーススキッシュ流は、燃焼室２からスキッシュエリア８に向けて流れ、燃焼室２の略中心に配置された点火栓７から広がる火炎を急速に燃焼室外周部（スキッシュエリア８内の壁面９）に導くことによって、燃焼時の火炎伝播速度を高め、燃焼性の向上を図ろうとしている。   Further, as shown in FIG. 7, in the combustion structure of the conventional internal combustion engine, the reverse squish flow generated after the piston 2 has passed the top dead center flows from the combustion chamber 2 toward the squish area 8 and burns. The flame spreading from the spark plug 7 disposed substantially in the center of the chamber 2 is rapidly guided to the outer periphery of the combustion chamber (the wall surface 9 in the squish area 8), thereby increasing the flame propagation speed during combustion and improving the combustibility. I am trying to figure it out.

しかしながら、従来の燃焼室構造では、燃焼室外周部のピストン冠面３ａおよびシリンダヘッド内面４ａの間が狭く形成されており、リバーススキッシュ流がスキッシュエリア最深部１０まで十分に到達しないため、火炎伝播が促進せず、スキッシュエリア最深部１０でノッキングの発生などの影響が出ることがあった。
そこで、本発明の内燃機関１の燃焼室構造では、図３および図４に示すように、スキッシュエリア８を形成するピストン冠面３ａにくぼみ１１を設け、スキッシュエリア最深部１０には、このくぼみ１１を通してリバーススキッシュ流を十分に導くようにしている。 However, in the conventional combustion chamber structure, the space between the piston crown surface 3a and the cylinder head inner surface 4a in the outer peripheral portion of the combustion chamber is formed narrow, and the reverse squish flow does not reach the squish area deepest portion 10 sufficiently. May not be promoted, and knocking may occur at the deepest part 10 of the squish area.
Therefore, in the combustion chamber structure of the internal combustion engine 1 of the present invention, as shown in FIGS. 3 and 4, a recess 11 is provided in the piston crown surface 3 a forming the squish area 8, and the squish area deepest portion 10 has this recess. 11 to fully guide the reverse squish flow.

これにより、リバーススキッシュ流をくぼみ１１から勢いよくスキッシュエリア８内に流入させることで、くぼみ１１近傍（特にスキッシュエリア最深部１０）における混合気の乱れを強化し、燃焼室外周部での火炎伝播速度を高めることによる機関出力の向上およびノッキングの低減を図る。特に、図５に示すように、スキッシュエリア８からシリンダ軸方向下方に向かって凹状に形成され、スキッシュエリア８側の端部１１ｄがエッジ状に形成されたくぼみ１１を設けることで、スキッシュ流がくぼみ１１からスキッシュエリア８へ流入する際に、スキッシュエリア８内の混合気の乱れが強化されるため、燃焼室外周部の火炎伝播速度を高め、熱効率向上による出力の向上と共にノッキング素質を向上できる。   As a result, the reverse squish flow is vigorously flowed into the squish area 8 from the dent 11, thereby enhancing the turbulence of the air-fuel mixture in the vicinity of the dent 11 (particularly the deepest portion 10 of the squish area) and propagating flames at the outer periphery of the combustion chamber. Increase engine output and reduce knocking by increasing speed. In particular, as shown in FIG. 5, a squish flow is formed by providing a recess 11 that is formed in a concave shape from the squish area 8 downward in the cylinder axial direction and has an edge 11d on the squish area 8 side. When the air flows into the squish area 8 from the recess 11, the turbulence of the air-fuel mixture in the squish area 8 is strengthened, so that the flame propagation speed in the outer periphery of the combustion chamber can be increased, and the knocking quality can be improved along with the improvement of the output by improving the thermal efficiency. .

本実施形態によれば、ピストン冠面３ａとシリンダヘッド内面４ａとにより燃焼室２が形成され、この燃焼室２の外周部で且つピストン冠面３ａとシリンダヘッド内面４ａとの間にスキッシュ流を生成するためのスキッシュエリア８が形成された内燃機関の燃焼室構造において、ピストン冠面３ａおよびシリンダヘッド内面４ａの少なくとも一方の、スキッシュエリア８を形成する部分に、燃焼室中心側からスキッシュエリア最深部１０方向へ伸びるくぼみ１１を設けた。このため、リバーススキッシュ流をくぼみ１１から勢いよくスキッシュエリア８内に流入させることで、くぼみ１１近傍（特に、スキッシュエリア最深部１０近傍）における混合気の乱れを強化し、燃焼室外周部の火炎伝播速度を高め、熱効率向上による出力の向上およびノッキング素質の向上が図れる。   According to this embodiment, the combustion chamber 2 is formed by the piston crown surface 3a and the cylinder head inner surface 4a, and a squish flow is generated between the piston crown surface 3a and the cylinder head inner surface 4a at the outer peripheral portion of the combustion chamber 2. In the combustion chamber structure of the internal combustion engine in which the squish area 8 for generation is formed, at least one of the piston crown surface 3a and the cylinder head inner surface 4a, the portion forming the squish area 8 is the deepest squish area from the combustion chamber center side. A recess 11 extending in the direction of the portion 10 was provided. For this reason, the reverse squish flow is vigorously flowed into the squish area 8 from the dent 11, thereby enhancing the turbulence of the air-fuel mixture in the vicinity of the dent 11 (particularly in the vicinity of the deepest portion 10 of the squish area) and The propagation speed can be increased, and the output and the knocking quality can be improved by improving the thermal efficiency.

また本実施形態によれば、くぼみ１１は、シリンダ軸方向に見て、スキッシュエリア８に外周を囲まれるように設けられる。このため、くぼみ１１におけるスキッシュエリア最深部１０近傍からスキッシュエリア８内にスキッシュ流を導くことができ、スキッシュエリア８内の混合気の乱れを促進できる。
また本実施形態によれば、くぼみ１１は、スキッシュエリア８側の端部１１ｄがエッジ状に形成される。このため、スキッシュ流がくぼみ１１からスキッシュエリア８へ流入する際、スキッシュエリア８内の混合気の乱れを強化し、燃焼室外周部の火炎伝播速度を高め、熱効率向上による出力の向上と共にノッキング素質の向上を図ることができる。 Further, according to the present embodiment, the recess 11 is provided so as to be surrounded by the squish area 8 when viewed in the cylinder axial direction. For this reason, the squish flow can be guided into the squish area 8 from the vicinity of the squish area deepest portion 10 in the recess 11, and the disturbance of the air-fuel mixture in the squish area 8 can be promoted.
Moreover, according to this embodiment, as for the hollow 11, the edge part 11d by the side of the squish area 8 is formed in edge shape. For this reason, when the squish flow flows into the squish area 8 from the indentation 11, the disturbance of the air-fuel mixture in the squish area 8 is strengthened, the flame propagation speed in the outer periphery of the combustion chamber is increased, and the output is improved by improving the thermal efficiency and knocking quality Can be improved.

また本実施形態によれば、くぼみ１１は、吸気側および排気側のスキッシュエリア８を構成する部分にそれぞれ設けられる。このため、例えば図８に示すように、吸気側および排気側のくぼみ１１からペントルーフの稜線２ａと垂直な方向にスキッシュ流を生成でき、または図９に示すように、燃焼室２から吸気側および排気側のくぼみ１１へ向けてペントルーフの稜線２ａと垂直な方向にリバーススキッシュ流を生成できる。   Further, according to the present embodiment, the depressions 11 are provided in the portions constituting the intake side and exhaust side squish areas 8 respectively. For this reason, for example, as shown in FIG. 8, a squish flow can be generated in the direction perpendicular to the ridgeline 2a of the pent roof from the intake-side and exhaust-side depressions 11, or as shown in FIG. A reverse squish flow can be generated in the direction perpendicular to the ridgeline 2a of the pent roof toward the exhaust-side depression 11.

次に、本発明の第２の実施形態について説明する。
本実施形態では、図８に示すように、くぼみ１１は、燃焼室２との接続部分の断面積が大きく、スキッシュエリア最深部１０に向かうほど断面積が縮小するようにシリンダ軸方向に見て、スキッシュエリア最深部１０近傍にて頂点を形成する三角形状にしている。すなわち、本実施形態におけるくぼみ１１の形状は、シリンダ軸方向に見て、燃焼室２のペントルーフの裾部２ｂの位置からスキッシュエリア最深部１０方向へ伸びるにつれてくぼみ１１の断面積が小さくなるようにしている。 Next, a second embodiment of the present invention will be described.
In this embodiment, as shown in FIG. 8, the indentation 11 is viewed in the cylinder axial direction so that the cross-sectional area of the connection portion with the combustion chamber 2 is large and the cross-sectional area decreases toward the deepest portion 10 of the squish area. The squish area has a triangular shape that forms a vertex in the vicinity of the deepest portion 10. That is, the shape of the recess 11 in the present embodiment is such that the cross-sectional area of the recess 11 decreases as it extends from the position of the skirt 2b of the pent roof of the combustion chamber 2 toward the squish area deepest portion 10 when viewed in the cylinder axial direction. ing.

このため、燃焼室２の稜線２ａと垂直な方向にリバーススキッシュ流が生成するときに、くぼみ１１の裾部から頂部に向けてリバーススキッシュ流のエネルギーを高めつつ、リバーススキッシュ流をスキッシュエリア８内に取り入れることができ、スキッシュエリア最深部１０近傍において、燃焼室２内の混合気の乱れを強化できる。
また、本発明の第３の実施形態では、図９に示すように、くぼみ１１を、吸気側および排気側のスキッシュエリア８に、シリンダ軸と垂直且つペントルーフ型の燃焼室２の稜線方向に２個ずつ形成している。これにより、燃焼室２からのリバーススキッシュ流をより多く取り入れ、混合気の乱れをより強化することができる。 Therefore, when a reverse squish flow is generated in a direction perpendicular to the ridge line 2 a of the combustion chamber 2, the reverse squish flow is increased in the squish area 8 while increasing the energy of the reverse squish flow from the bottom to the top of the recess 11. In the vicinity of the deepest part 10 of the squish area, the turbulence of the air-fuel mixture in the combustion chamber 2 can be strengthened.
Further, in the third embodiment of the present invention, as shown in FIG. 9, the depressions 11 are formed in the intake side and exhaust side squish areas 8 in the direction of the ridgeline of the pent roof type combustion chamber 2 perpendicular to the cylinder axis. Individually formed. Thereby, more reverse squish flows from the combustion chamber 2 can be taken in, and the turbulence of the air-fuel mixture can be further strengthened.

本発明の第１の実施形態における内燃機関の燃焼構造を示す平面図The top view which shows the combustion structure of the internal combustion engine in the 1st Embodiment of this invention 図１のＡ−Ａ線矢視断面図1 is a cross-sectional view taken along line AA in FIG. くぼみ部分の拡大図Enlarged view of the indentation くぼみ部分の拡大図Enlarged view of the indentation 図１のＢ−Ｂ線矢視断面図BB sectional view taken on line in FIG. 従来の内燃機関の燃焼構造においてスキッシュ流が発生した状態を示す平面図The top view which shows the state which the squish flow generate | occur | produced in the combustion structure of the conventional internal combustion engine 従来の内燃機関の燃焼構造においてリバーススキッシュ流が発生した状態を示す平面図The top view which shows the state which the reverse squish flow generate | occur | produced in the combustion structure of the conventional internal combustion engine 本発明の第２の実施形態における内燃機関の燃焼構造を示す平面図The top view which shows the combustion structure of the internal combustion engine in the 2nd Embodiment of this invention 本発明の第３の実施形態における内燃機関の燃焼構造を示す平面図The top view which shows the combustion structure of the internal combustion engine in the 3rd Embodiment of this invention

符号の説明Explanation of symbols

１ 内燃機関
２ 燃焼室
２ａ 稜線
２ｂ 裾部
３ ピストン
３ａ 冠面
４ シリンダヘッド
４ａ 内面
５ 吸気バルブ
６ 排気バルブ
８ スキッシュエリア
９ 壁面
１０ スキッシュエリア最深部
１１ くぼみ DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Combustion chamber 2a Ridge line 2b Bottom part 3 Piston 3a Crown surface 4 Cylinder head 4a Inner surface 5 Intake valve 6 Exhaust valve 8 Squish area 9 Wall surface 10 Squish area deepest part 11 Indentation

Claims (6)

ピストン冠面とシリンダヘッド内面とにより燃焼室が形成され、この燃焼室の外周部で且つピストン冠面とシリンダヘッド内面との間にスキッシュ流を生成するためのスキッシュエリアが形成された内燃機関の燃焼室構造において、
前記ピストン冠面および前記シリンダヘッド内面の少なくとも一方の、前記スキッシュエリアを形成する部分に、燃焼室中心側からスキッシュエリア最深部方向へ伸びるくぼみを設けたことを特徴とする内燃機関の燃焼室構造。 A combustion chamber is formed by the piston crown surface and the cylinder head inner surface, and an internal combustion engine in which a squish area for generating a squish flow is formed at the outer periphery of the combustion chamber and between the piston crown surface and the cylinder head inner surface. In the combustion chamber structure,
A combustion chamber structure for an internal combustion engine, characterized in that a recess extending from the combustion chamber center side toward the deepest part of the squish area is provided in a portion of at least one of the piston crown surface and the cylinder head inner surface forming the squish area. . 前記くぼみは、シリンダ軸方向に見て、前記スキッシュエリアに外周を囲まれるように設けられることを特徴とする請求項１記載の内燃機関の燃焼室構造。   The combustion chamber structure of an internal combustion engine according to claim 1, wherein the recess is provided so as to be surrounded by the squish area when viewed in the cylinder axial direction. 前記くぼみは、前記スキッシュエリア側の端部がエッジ状に形成されることを特徴とする請求項１又は請求項２記載の内燃機関の燃焼室構造。   The combustion chamber structure of an internal combustion engine according to claim 1 or 2, wherein the recess has an edge on the squish area side. 前記くぼみは、スキッシュエリア最深部方向へ伸びるにつれて断面積が減少する形状であることを特徴とする請求項１〜請求項３のいずれか１つに記載の内燃機関の燃焼室構造。   The combustion chamber structure of an internal combustion engine according to any one of claims 1 to 3, wherein the recess has a shape in which a cross-sectional area decreases as it extends toward the deepest part of the squish area. 前記くぼみは、シリンダ軸と垂直且つペントルーフ型の燃焼室の稜線方向に複数設けられることを特徴とする請求項１〜請求項４のいずれか１つに記載の内燃機関の燃焼室構造。   The combustion chamber structure for an internal combustion engine according to any one of claims 1 to 4, wherein a plurality of the recesses are provided in a direction perpendicular to the cylinder axis and in a ridgeline direction of a pent roof type combustion chamber. 前記くぼみは、吸気側および排気側のスキッシュエリアを構成する部分にそれぞれ設けられることを特徴とする請求項１〜請求項５のいずれか１つに記載の内燃機関の燃焼室構造。   The combustion chamber structure for an internal combustion engine according to any one of claims 1 to 5, wherein the recess is provided in a portion constituting a squish area on an intake side and an exhaust side.
JP2006061762A 2006-03-07 2006-03-07 Combustion chamber structure for internal combustion engine Pending JP2007239563A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016089651A (en) * 2014-10-30 2016-05-23 本田技研工業株式会社 Internal combustion engine
JP2016121638A (en) * 2014-12-25 2016-07-07 マツダ株式会社 Combustion chamber structure of direct injection engine
CN114592965A (en) * 2022-03-17 2022-06-07 中国第一汽车股份有限公司 Piston combustion chamber structure of gasoline engine and gasoline engine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016089651A (en) * 2014-10-30 2016-05-23 本田技研工業株式会社 Internal combustion engine
JP2016121638A (en) * 2014-12-25 2016-07-07 マツダ株式会社 Combustion chamber structure of direct injection engine
CN114592965A (en) * 2022-03-17 2022-06-07 中国第一汽车股份有限公司 Piston combustion chamber structure of gasoline engine and gasoline engine
CN114592965B (en) * 2022-03-17 2023-10-27 中国第一汽车股份有限公司 Piston combustion chamber structure of gasoline engine and gasoline engine

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