JPS632578Y2 - - Google Patents
Info
- Publication number
- JPS632578Y2 JPS632578Y2 JP19200882U JP19200882U JPS632578Y2 JP S632578 Y2 JPS632578 Y2 JP S632578Y2 JP 19200882 U JP19200882 U JP 19200882U JP 19200882 U JP19200882 U JP 19200882U JP S632578 Y2 JPS632578 Y2 JP S632578Y2
- Authority
- JP
- Japan
- Prior art keywords
- load
- intake
- low
- piston
- intake port
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000002485 combustion reaction Methods 0.000 claims description 29
- 230000000694 effects Effects 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
Landscapes
- Valve-Gear Or Valve Arrangements (AREA)
- Combustion Methods Of Internal-Combustion Engines (AREA)
Description
【考案の詳細な説明】
本考案はエンジンの燃焼室に関するものであ
る。[Detailed Description of the Invention] The present invention relates to a combustion chamber of an engine.
一般にエンジンにおいてはその出力を大きくす
るため燃焼室の容積を小さくして圧縮比を高くす
ることが行なわれている。従来、このようにして
燃焼性を向上させたエンジンの燃焼室として、特
開昭54−145808号公報に記載されているように、
ピストン上面に燃焼凹部を形成したものがあつ
た。 Generally, in order to increase the output of an engine, the volume of the combustion chamber is reduced to increase the compression ratio. Conventionally, as a combustion chamber of an engine with improved combustibility in this way, as described in Japanese Patent Application Laid-open No. 145808/1982,
There was one with a combustion recess formed on the top surface of the piston.
ところで近年エンジンの高出力化の要請がさら
に高くなり、そのため低負荷用，高負荷用の２つ
の吸気ポートを設け、低負荷時には吸気にスワー
ルを生じさせ、高負荷時には多量の吸気を効率よ
く吸入して高出力を得るようにしたエンジンが開
発されている。しかるにこのようなエンジンにお
いて、上述のように燃焼性の向上を目的としてピ
ストン上面に凹状の燃焼室を形成すると、該ピス
トン上面の燃焼室周縁と上記吸気ポートとの隙間
が小さくなつて吸気が燃焼室に吸入されにくくな
り、そのためエンジンの高負荷時の吸入効率はあ
まり良くないものであつた。 By the way, in recent years the demand for higher engine output has become even higher, so we have created two intake ports, one for low load and one for high load, to create a swirl in the intake air at low loads and to efficiently draw in a large amount of intake air at high loads. Engines that achieve high output have been developed. However, in such an engine, if a concave combustion chamber is formed on the top surface of the piston for the purpose of improving combustibility as described above, the gap between the periphery of the combustion chamber on the top surface of the piston and the intake port becomes small, and the intake air is not combusted. It was difficult for the fuel to be sucked into the engine compartment, and therefore the suction efficiency was not very good when the engine was under high load.
本考案は、かかる状況に鑑みてなされたもの
で、高負荷時には吸入効率を向上でき、しかも低
負荷時にはスワールを強く生じさせることのでき
るエンジンの燃焼室を提供せんとするものであ
る。 The present invention was developed in view of the above situation, and aims to provide a combustion chamber for an engine that can improve suction efficiency under high loads and generate strong swirl under low loads.
本考案にかかるエンジンの燃焼室は少なくとも
低負荷時には吸気を導入する低負荷用吸気ポート
と、高負荷時のみ吸気を導入する高負荷用吸気ポ
ートと、少なくとも１つの排気ポートと、ピスト
ン上死点時にはシリンダヘツド下面と近接する頂
面を持つピストンとを有するエンジンにおいて、
上記ピストンの頂面に、上記低負荷用吸気ポート
の下方に位置する面積より上記高負荷用吸気ポー
トの下方に位置する面積の方が広い燃焼室凹部を
設けたものである。 The combustion chamber of the engine according to the present invention includes at least a low-load intake port that introduces intake air during low loads, a high-load intake port that introduces intake air only during high loads, at least one exhaust port, and a piston top dead center. Sometimes in engines with a piston having a lower cylinder head and an adjacent top surface,
A combustion chamber recess is provided on the top surface of the piston, the area of which is located below the high load intake port is wider than the area located below the low load intake port.
本発明においては上記構成により低負荷時には
低負荷用吸気ポートのみから吸気を導入するが、
該ポートは燃焼室凹部上方に位置する面積が比較
的狭いため、吸気初期時には吸気に有効な開口面
積が狭く高速で吸入されスワールが強化される。
また、高負荷時には少なくとも高負荷用吸気ポー
トから吸気を導入するが、該ポートは燃焼室凹部
上方に位置する面積が比較的広いため、吸気初期
時における吸気に有効な開口面積が広く吸気抵抗
が少なく吸入効率を上げることができる。 In the present invention, with the above configuration, intake air is introduced only from the low-load intake port during low load, but
Since the area of the port located above the combustion chamber recess is relatively small, the effective opening area for intake is narrow at the beginning of intake, and the intake is carried out at high speed, thereby strengthening the swirl.
In addition, at high loads, intake air is introduced from at least the high-load intake port, and since the area of this port located above the combustion chamber recess is relatively large, the effective opening area for intake at the initial stage of intake is wide, reducing intake resistance. Inhalation efficiency can be increased with less.
以下本考案の実施例を図について説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図ないし第４図は本考案の一実施例を示
し、図において１は円筒状のピストン摺動孔１ａ
を有するシリンダブロツクであり、該シリンダブ
ロツク１の上面にはシリンダヘツド２が固着され
ており、該シリンダヘツド２の上記ピストン摺動
孔１ａ上方部分には大略球面状の球面部２ａが凹
設されている。 1 to 4 show an embodiment of the present invention, in which 1 is a cylindrical piston sliding hole 1a.
A cylinder head 2 is fixed to the upper surface of the cylinder block 1, and a substantially spherical spherical portion 2a is recessed in a portion above the piston sliding hole 1a of the cylinder head 2. ing.
また上記シリンダヘツド２には、低負荷用吸気
ポート２ｂ、これより径の大きい高負荷用吸気ポ
ート２ｃ及び２つの排気ポート２ｄ，２ｅが形成
され、これらの各ポート２ｂ〜２ｅは上記球面部
２ａに略90゜角度間隔でもつて開口しており、さ
らに該各開口にはバルブシート３が嵌挿固着され
ている。また上記各開口にはこれと開閉する吸，
排気バルブ４ａ，４ｂが上下動自在に配設されて
いる。なお８は点火プラグで、これは上記シリン
ダヘツド２の上記球面部２ａ中央に螺着されてい
る。また上記低，高負荷用吸気ポート２ｂ，２ｃ
には各々低，高負荷用吸気通路５ａ，５ｂが接続
されており、さらに該高負荷用吸気通路５ｂの途
中には、該通路５ｂを開閉する開閉弁６が取付け
られている。 The cylinder head 2 is also formed with a low-load intake port 2b, a high-load intake port 2c with a larger diameter, and two exhaust ports 2d and 2e, each of which is connected to the spherical portion 2a. There are openings at approximately 90° angular intervals, and a valve seat 3 is fitted and fixed in each opening. In addition, each of the above openings has a suction device that opens and closes.
Exhaust valves 4a and 4b are arranged to be vertically movable. Note that 8 is a spark plug, which is screwed into the center of the spherical portion 2a of the cylinder head 2. In addition, the above-mentioned low and high load intake ports 2b and 2c
Low-load and high-load intake passages 5a and 5b are connected to the intake passages 5a and 5b, respectively, and an on-off valve 6 for opening and closing the passage 5b is installed in the middle of the high-load intake passage 5b.
また上記シリンダブロツク１のピストン摺動孔
１ａ内には、ピストン７が摺動自在に挿入されて
いる。該ピストン７の上面部７ａは上記シリンダ
ヘツド２の球面部２ａと同様の形状、即ち大略球
面状に突出形成されており、また該上面部７ａの
上記吸気ポート２ｂ，２ｃの開口に対向する部分
には吸気側平坦面７ｂが、また該上面部７ａの上
記排気ポート２ｄ，２ｅの開口に対向する部分に
は排気側平坦面７ｃがそれぞれ平坦に形成されて
おり、該吸，排気側平坦面７ｂ，７ｃは各々上記
吸，排気バルブ４ａ，４ｂの下端面と平行になつ
ている。 A piston 7 is slidably inserted into the piston sliding hole 1a of the cylinder block 1. The upper surface portion 7a of the piston 7 has the same shape as the spherical surface portion 2a of the cylinder head 2, that is, it is formed to protrude into a roughly spherical shape, and the portion of the upper surface portion 7a that faces the openings of the intake ports 2b and 2c An intake side flat surface 7b is formed flat on the upper surface portion 7a, and an exhaust side flat surface 7c is formed flat on a portion of the upper surface portion 7a facing the openings of the exhaust ports 2d and 2e. 7b and 7c are parallel to the lower end surfaces of the intake and exhaust valves 4a and 4b, respectively.
そしてさらに上記ピストン７上部の平面から見
て吸気ポート２ｂ，２ｃ側に、かつ高負荷用吸気
ポート２ｃ側に偏心した位置、即ち上記ピストン
７上部の第１図やや左下方部には燃焼室凹部（以
下燃焼凹部と略記する。）７ｄが凹設されており、
該燃焼凹部７ｄは平面円形で断面皿状のもので、
これはエンジンの燃焼室となつている。そして上
記燃焼凹部７ｄを偏心して設けた結果上記高負荷
用吸気ポート２ｃの開口はその略全領域が上記燃
焼凹部７ｄの上方に位置し、また低負荷用吸気ポ
ート２ｂの開口はその1/2以下の領域が上記燃焼
凹部７ｄの上方に位置している。 Further, when viewed from the plane of the upper part of the piston 7, there is a combustion chamber recess at a position eccentric to the intake ports 2b, 2c side and toward the high-load intake port 2c side, that is, at a slightly lower left part of the upper part of the piston 7 in FIG. (Hereinafter abbreviated as combustion recess.) 7d is recessed,
The combustion recess 7d is circular in plan and dish-shaped in cross section;
This is the engine's combustion chamber. As a result of providing the combustion recess 7d eccentrically, almost the entire opening of the high-load intake port 2c is located above the combustion recess 7d, and the opening of the low-load intake port 2b is 1/2 of that area. The following areas are located above the combustion recess 7d.
次に作用について説明する。 Next, the effect will be explained.
まず、エンジンの低負荷運転領域においては、
上記高負荷用吸気通路５ｂの開閉弁６は該通路５
ｂを閉じており、この状態で吸気バルブ４ａが開
くとともにピストン７が下降すると、吸気が低負
荷用吸気ポート２ｂを通つてピストン７の上部と
シリンダヘツド２の球面部２ａで囲まれた空間に
吸入されることとなる。そしてこの際上記吸気は
低負荷用吸気ポート２ｂの開口の1/2以下の領域
だけがピストン７の燃焼凹部７ｄ上方に位置し、
その吸気初期時の有効な開口面積が狭いため、比
較的高速で上記空間内に吸入され、これにより該
吸気は上記空間内で強いスワールを生じさせるこ
ととなる。 First, in the low-load operating range of the engine,
The on-off valve 6 of the high-load intake passage 5b is
b is closed, and in this state, when the intake valve 4a opens and the piston 7 descends, the intake air passes through the low-load intake port 2b and enters the space surrounded by the upper part of the piston 7 and the spherical part 2a of the cylinder head 2. It will be inhaled. At this time, only a half or less area of the opening of the low-load intake port 2b of the intake air is located above the combustion recess 7d of the piston 7,
Since the effective opening area at the initial stage of intake is narrow, the intake air is drawn into the space at a relatively high speed, thereby causing the intake air to generate a strong swirl within the space.
次に、エンジンの高負荷運転領域においては、
上記開閉弁６は高負荷用吸気通路５ｂを開いてお
り、この状態で吸気バルブ４ａが開くとともにピ
ストン７が下降すると、吸気が低，高負荷用吸気
ポート２ｂ，２ｃを通つて吸入されることとな
る。そしてこの際上記吸気は、高負荷用吸気ポー
ト２ｃの開口の略全領域がピストン７の燃焼凹部
７ｄ上方に位置しその吸気初期時の有効な開口面
積が広いため、抵抗なく多量に吸入される。 Next, in the high-load operating range of the engine,
The on-off valve 6 opens the high-load intake passage 5b, and when the intake valve 4a opens and the piston 7 descends in this state, intake air is drawn through the low- and high-load intake ports 2b and 2c. becomes. At this time, a large amount of the intake air is drawn in without resistance because almost the entire area of the opening of the high-load intake port 2c is located above the combustion recess 7d of the piston 7, and the effective opening area at the initial stage of intake is wide. .
このように本実施例では、ピストン７の頂面
に、低負荷用吸気ポート２ｂの下方に位置する面
積より高負荷用吸気ポート２ｃの下方に位置する
面積の方が広い燃焼凹部７ｄを設け、低負荷時に
は低負荷用吸気ポート２ｂのみにより、高負荷時
には低及び高負荷用吸気ポート２ｂ及び２ｃによ
り、吸気を導入するようにしたので、低負荷時に
は吸気にスワールを生ぜしめることができ、また
高負荷時には吸入抵抗が小さくなつて多量の吸気
を効率よく吸入できる。 In this embodiment, the combustion recess 7d is provided on the top surface of the piston 7, and the area below the high-load intake port 2c is wider than the area below the low-load intake port 2b. At low loads, intake air is introduced only through the low load intake port 2b, and at high loads, intake air is introduced through the low and high load intake ports 2b and 2c, so that it is possible to create a swirl in the intake air at low loads, and When the load is high, the suction resistance decreases and a large amount of air can be inhaled efficiently.
なお、上記実施例では、２つの排気ポート２
ｄ，２ｅを有するエンジンについて説明したが、
本考案は排気ポートが１つのエンジンについても
適用できるものであり、また上記実施例では上記
燃焼凹部７ｄが吸気ポート２ｂ，２ｃ側に、かつ
高負荷用吸気ポート２ｃ側に偏心した位置に形成
された場合について説明したが、本考案による燃
焼凹部は少なくとも高負荷用吸気ポート側に偏心
した位置に形成されば良い。 In addition, in the above embodiment, two exhaust ports 2
Although the engine with d and 2e was explained,
The present invention can also be applied to an engine having one exhaust port, and in the above embodiment, the combustion recess 7d is formed at a position eccentric to the intake ports 2b, 2c side and toward the high-load intake port 2c side. Although the case has been described above, the combustion recess according to the present invention may be formed at least at a position eccentric to the high-load intake port side.
以上のように本考案に係るエンジンの燃焼室に
よれば、低，高負荷用の２つの吸気ポートと、ピ
ストン上死点時にはシリンダヘツド下面と近接す
る頂面を持つピストンとを有するエンジンにおい
て、上記ピストンの頂面に、上記低負荷用吸気ポ
ートの下方に位置する面積より上記高負荷用吸気
ポートの下方に位置する面積の方が広い燃焼室凹
部を設けたので、高負荷時の吸気の吸入効率を向
上でき、かつ低負荷時の吸気のスワールを強化で
きる効果がある。 As described above, according to the engine combustion chamber according to the present invention, in an engine having two intake ports for low and high loads, and a piston having a top surface that is close to the bottom surface of the cylinder head when the piston is at top dead center, A combustion chamber recess is provided on the top surface of the piston, the area of which is located below the high-load intake port is wider than the area below the low-load intake port, so that the intake air during high loads is reduced. This has the effect of improving suction efficiency and strengthening the intake swirl at low loads.
第１図は本考案の一実施例によるエンジンの燃
焼室の平面図、第２図は第１図の−線断面側
面図、第３図は上記実施例のピストンの斜視図、
第４図は第１図の−線断面正面図である。
２ａ……シリンダヘツドの球面部、２ｂ……低
負荷用吸気ポート、２ｃ……高負荷用吸気ポー
ト、２ｄ，２ｅ……排気ポート、４ａ，４ｂ……
吸，排気バルブ、７……ピストン、７ｂ，７ｃ…
…吸，排気側平坦面、７ｄ……燃焼室凹部。
FIG. 1 is a plan view of a combustion chamber of an engine according to an embodiment of the present invention, FIG. 2 is a cross-sectional side view taken along the line -- in FIG. 1, and FIG. 3 is a perspective view of the piston of the above embodiment.
FIG. 4 is a sectional front view taken along the - line in FIG. 1. 2a... Spherical part of cylinder head, 2b... Intake port for low load, 2c... Intake port for high load, 2d, 2e... Exhaust port, 4a, 4b...
Intake and exhaust valves, 7...pistons, 7b, 7c...
...Suction and exhaust side flat surfaces, 7d...Combustion chamber recess.
Claims (1)
用吸気ポートと、高負荷時のみ吸気を導入する高
負荷用吸気ポートと、少なくとも１つの排気ポー
トと、ピストン上死点時にはシリンダヘツド下面
と近接する頂面を持つピストンとを有するエンジ
ンにおいて、上記ピストンの頂面に、上記低負荷
用吸気ポートの下方に位置する面積より上記高負
荷用吸気ポートの下方に位置する面積の方が広い
燃焼室凹部を設けたことを特徴とするエンジンの
燃焼室。 A low-load intake port that introduces intake air at least when the load is low, a high-load intake port that introduces intake air only when the load is high, at least one exhaust port, and a top surface that is close to the lower surface of the cylinder head when the piston is at top dead center. A combustion chamber recess is provided on the top surface of the piston, the area of which is located below the high-load intake port is larger than the area below the low-load intake port. The combustion chamber of an engine is characterized by:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19200882U JPS5996323U (en) | 1982-12-18 | 1982-12-18 | engine combustion chamber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19200882U JPS5996323U (en) | 1982-12-18 | 1982-12-18 | engine combustion chamber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5996323U JPS5996323U (en) | 1984-06-29 |
| JPS632578Y2 true JPS632578Y2 (en) | 1988-01-22 |
Family
ID=30413325
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19200882U Granted JPS5996323U (en) | 1982-12-18 | 1982-12-18 | engine combustion chamber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5996323U (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH076468B2 (en) * | 1985-08-30 | 1995-01-30 | マツダ株式会社 | Fuel injection engine |
| JPH0645626Y2 (en) * | 1985-09-19 | 1994-11-24 | いすゞ自動車株式会社 | Combustion chamber structure of diesel engine |
| JPS62255523A (en) * | 1986-04-30 | 1987-11-07 | Isuzu Motors Ltd | Pent roof type piston |
| JPH0623540B2 (en) * | 1986-04-30 | 1994-03-30 | いすゞ自動車株式会社 | Pentorf type direct injection internal combustion engine |
| JPS62255520A (en) * | 1986-04-30 | 1987-11-07 | Isuzu Motors Ltd | Pent roof type piston |
| JPH0621563B2 (en) * | 1986-04-30 | 1994-03-23 | いすゞ自動車株式会社 | Pent roof type piston for direct injection diesel engine |
| JPH086589B2 (en) * | 1986-05-30 | 1996-01-24 | いすゞ自動車株式会社 | Direct injection internal combustion engine |
-
1982
- 1982-12-18 JP JP19200882U patent/JPS5996323U/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5996323U (en) | 1984-06-29 |
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