JPS6029633Y2 - Combustion chamber of internal combustion engine - Google Patents
Combustion chamber of internal combustion engineInfo
- Publication number
- JPS6029633Y2 JPS6029633Y2 JP109680U JP109680U JPS6029633Y2 JP S6029633 Y2 JPS6029633 Y2 JP S6029633Y2 JP 109680 U JP109680 U JP 109680U JP 109680 U JP109680 U JP 109680U JP S6029633 Y2 JPS6029633 Y2 JP S6029633Y2
- Authority
- JP
- Japan
- Prior art keywords
- combustion chamber
- flat part
- cylinder
- piston
- exhaust valve
- 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
Landscapes
- Ignition Installations For Internal Combustion Engines (AREA)
- Combustion Methods Of Internal-Combustion Engines (AREA)
Description
【考案の詳細な説明】 本考案は火花点火式内燃機関の燃焼室構造に関する。[Detailed explanation of the idea] The present invention relates to a combustion chamber structure of a spark-ignition internal combustion engine.
ピストンの排気行程においてはシリンダ内周壁近傍に存
在する未燃焼成分（ＨＣ）の層即ちクウェンチ層がピス
トンによって掻き上げられ、これが排気行程終端で燃焼
室外に排出されて排気中のＨＣ成分含有量の増大化を招
（と同時に、燃料経済性を劣るものにしていた。During the exhaust stroke of the piston, the layer of unburned components (HC) existing near the inner circumferential wall of the cylinder, that is, the quench layer, is scraped up by the piston, and at the end of the exhaust stroke, this layer is discharged outside the combustion chamber, reducing the HC component content in the exhaust gas. (At the same time, this led to an increase in fuel economy.)
そこで、従来から第１図に示すようにピストン１の上面
から排気弁２を離間させて、その間に主燃焼室３を形成
し、該主燃焼室３内に前記排気行程終端に放出されてい
た未燃ＨＣを放出せずに残留させる一方、吸気弁４はピ
ストン１に接近させて、ピストン圧縮上死点において両
者の間の圧縮混合気を前記主燃焼室３にスキッシュ流と
して噴出し、もって混合気の乱れを形成して燃焼の改善
を図っていた。Therefore, conventionally, as shown in FIG. 1, the exhaust valve 2 is separated from the upper surface of the piston 1, and a main combustion chamber 3 is formed therebetween, and the exhaust gas is discharged into the main combustion chamber 3 at the end of the exhaust stroke. While unburned HC remains without being released, the intake valve 4 is brought close to the piston 1, and the compressed air-fuel mixture between the two is injected into the main combustion chamber 3 as a squish flow at the piston compression top dead center. The aim was to improve combustion by creating turbulence in the air-fuel mixture.
第２図に示す斜線部はかかるスキッシュ流を形成するた
めに圧縮上死点のピストン上面と極めて接近するスキッ
シュエリアであり、５は主燃焼室３に臨設した点火栓、
６はシリンダヘッドである。The shaded area shown in FIG. 2 is the squish area that comes very close to the top surface of the piston at compression top dead center in order to form the squish flow, and 5 is the ignition plug installed in the main combustion chamber 3;
6 is a cylinder head.
しかし、この従来の燃焼室形状では主燃焼室３とスキッ
シュエリアの境界が鋭い縁を形成し、図示の如く急激に
形状変化をなしていたため、ピストン吸気行程で生成さ
れた吸気渦流（筒内スワール）がピストン圧縮行程でシ
リンダヘッドの前記燃焼室内壁によって減衰され、圧縮
上死点までに残留しないという不都合があった（特公昭
５３−３６０８６号公報参照）。However, in this conventional combustion chamber shape, the boundary between the main combustion chamber 3 and the squish area formed a sharp edge, and the shape changed rapidly as shown in the figure. ) is attenuated by the inner wall of the combustion chamber of the cylinder head during the piston compression stroke, and does not remain until compression top dead center (see Japanese Patent Publication No. 53-36086).
燃焼には圧縮上死点近傍においてなされる点火時に充分
なスワールとスキッシュによる混合気乱れが必要である
ことからして、スワールの上記の如き減少は極めて燃焼
の改善に悪影響を及ぼした。Since combustion requires sufficient air-fuel mixture turbulence due to swirl and squish at the time of ignition near compression top dead center, the above-mentioned reduction in swirl had an extremely negative effect on improving combustion.
また前記急激な形状変化により、主燃焼室で点火した火
炎がピストン上面とシリンダへラドスキッシュエリアと
の間のスキッシュクリアランスに良好に導かれないため
、該スキッシュクリアランスにおける混合気の燃焼状態
は極めて悪化した。Furthermore, due to the sudden shape change, the flame ignited in the main combustion chamber is not well guided to the squish clearance between the top surface of the piston and the radial squish area of the cylinder, so the combustion state of the air-fuel mixture in the squish clearance is extremely deteriorated. did.
本考案は上記に鑑みなされたもので、吸気弁のまわりの
スキッシュエリアと排気弁まわりの平面部のシリンダ円
周方向両側を緩傾斜曲面によって連続させ、もって吸気
スワールの減衰を極力避けた構造の燃焼室を提供するも
のである。The present invention was developed in view of the above, and has a structure in which the squish area around the intake valve and the flat part around the exhaust valve are connected on both sides in the cylinder circumferential direction by a gently inclined curved surface, thereby avoiding the attenuation of the intake swirl as much as possible. It provides a combustion chamber.
以下に本考案の実施例を第３図以下の図面に基づいて説
明する。Embodiments of the present invention will be described below based on the drawings from FIG. 3 onwards.
第３図〜第６図に示す実施例において、シリンダヘッド
１１とシリンダブロック１２とはガスケット１３を介し
て連結固定され、シリンダ１４には頂面平担なピストン
１５が往復動自由に嵌挿しである。In the embodiment shown in FIGS. 3 to 6, a cylinder head 11 and a cylinder block 12 are connected and fixed via a gasket 13, and a piston 15 with a flat top is inserted into the cylinder 14 and can freely reciprocate. be.
シリンダヘッド１１の下面には吸気弁１６及び排気弁１
７がその夫々のステム１６ａ、１７ａをシリンダ中心線
Ｃと平行に直立した状態で夫々路面−に臨んでいる。An intake valve 16 and an exhaust valve 1 are provided on the lower surface of the cylinder head 11.
7 faces the road surface with their respective stems 16a and 17a standing upright parallel to the cylinder center line C.
このうち吸気弁１６のまわりに形成した平面部２１は上
死点位置のピストン１５上面に接近して配設し、また排
気弁１７のまわりに形成した平面部２２は上死点位置の
ピストン１５上面よりも大きく離れて配設し、その結果
排気弁１７まわりに形成した平面部２２はシリンダヘッ
ド１１の下面よりも深く凹んだ凹部２３を形成している
。Of these, the flat part 21 formed around the intake valve 16 is disposed close to the upper surface of the piston 15 at the top dead center position, and the flat part 22 formed around the exhaust valve 17 is arranged close to the upper surface of the piston 15 at the top dead center position. The planar portion 22 formed around the exhaust valve 17 as a result of being disposed at a distance from the upper surface forms a recess 23 that is deeper than the lower surface of the cylinder head 11 .
そして前記吸気弁１６まわりの平面部２１、排気弁１７
まわりの平面部２２のシリンダ円周方向両側及びシリン
ダヘッド１１下面の燃焼室周縁部（シリンダヘッド下面
のシリンダ１４外周面より外方近傍部分）２４相互を第
４図に斜線で示す緩傾斜曲面３１を介して連続させ、該
緩傾斜曲面３１と前記凹部２３とピストン１５上面との
間に主燃焼室を構成する。Then, the flat part 21 around the intake valve 16 and the exhaust valve 17
A gently inclined curved surface 31 shown by diagonal lines in FIG. A main combustion chamber is formed between the gently inclined curved surface 31, the recess 23, and the upper surface of the piston 15.
尚、特に緩傾斜曲面３１の外周部は滑らかに丸みをつけ
て形成する。In particular, the outer peripheral portion of the gently inclined curved surface 31 is formed to be smoothly rounded.
又、点火栓３２の先端を前記緩傾斜曲面３１又は排気弁
１７まわりの平面部２２に臨ませる。Further, the tip of the ignition plug 32 is made to face the gently inclined curved surface 31 or the flat part 22 around the exhaust valve 17.
実施例では吸気ポート３３、排気ポート３４をクロスフ
ロー型とし排気ポート３４側に点火栓３２本体が位置す
ると共に点火栓電極を可及的にシリンダ中心線Ｃに近接
させて、吸気ポート３３をできるだけシリンダ１４の周
壁に対して接線方向にかつシリンダ中心線Ｃに対して直
角に（水平）配設することが可能なようにし、吸気ポー
ト３３から主燃焼室内に導入された吸気の筒内スワール
が強化されるようにしている。In this embodiment, the intake port 33 and the exhaust port 34 are of a cross-flow type, and the main body of the ignition plug 32 is located on the exhaust port 34 side, and the ignition plug electrode is brought as close to the cylinder center line C as possible, so that the intake port 33 is as close as possible to the cylinder center line C. It can be arranged tangentially to the peripheral wall of the cylinder 14 and perpendicularly (horizontally) to the cylinder center line C, so that the in-cylinder swirl of intake air introduced from the intake port 33 into the main combustion chamber is prevented. I am trying to strengthen it.
図中３５，３６はバルブシートである。In the figure, 35 and 36 are valve seats.
かかる構成になる燃焼室の作用は次の如くである。The operation of the combustion chamber having such a structure is as follows.
ピストン吸気行程において、吸気ポート３３からシリン
ダ１４の周壁接線方向に流入した吸気混合気は該周壁に
沿ってスワールを生成する。During the piston intake stroke, the intake air-fuel mixture that flows from the intake port 33 in the tangential direction of the circumferential wall of the cylinder 14 generates a swirl along the circumferential wall.
ピストンが圧縮行程に入っても主燃焼室壁に沿う吸気流
は吸気弁１６まわりの平面部２１のシリンダ円周方向側
部から緩傾斜曲面３１、排気弁１７まわりの平面部２２
、緩傾斜曲面３１へと滑らかに導かれてシリンダ中心線
Ｃまわりを減衰することなく運動するスワールを形成し
、これが圧縮上死点に到るまで残留する。Even when the piston enters the compression stroke, the intake air flow along the main combustion chamber wall flows from the cylinder circumferential side of the flat part 21 around the intake valve 16 to the gently inclined curved surface 31 and the flat part 22 around the exhaust valve 17.
, a swirl is formed that is smoothly guided to the gently inclined curved surface 31 and moves around the cylinder center line C without attenuation, and this swirl remains until the compression top dead center is reached.
圧縮上死点においては同時にピストン上面と吸気弁まわ
り平面部２１との間のスキッシュクリアランスからスキ
ッシュ流が主燃焼室内に噴流となって噴出するから主燃
焼室内に乱れが形成され、該乱れと残留スワールとの協
動作用によって点火してから初期燃焼までの期間を短縮
しまたその後の火炎伝播をも促進して燃焼を良くする。At compression top dead center, the squish flow jets out as a jet into the main combustion chamber from the squish clearance between the top surface of the piston and the flat surface around the intake valve 21, so turbulence is formed in the main combustion chamber, and the turbulence and residual By working together with the swirl, the period from ignition to initial combustion is shortened, and subsequent flame propagation is also promoted to improve combustion.
更に前記スキッシュ流は火炎がシリンダ１４周壁まで伝
播する作用を強め、エンドガスの自己着火によるノッキ
ングの発生を抑制し、高圧縮比化を可能とする。Further, the squish flow strengthens the propagation of the flame to the peripheral wall of the cylinder 14, suppresses the occurrence of knocking due to self-ignition of the end gas, and makes it possible to increase the compression ratio.
また排気行程においてはピストンによって掻き上げられ
たシリンダ１４内周壁のクウェンチ層に存在する未燃Ｈ
Ｃは排気弁１７が主燃焼室の最深部に設けられているた
め、排出されずに主燃焼室内に残留し、それが次期燃焼
行程で燃焼に供されるから、排気性能並びに燃費が向上
する。In addition, during the exhaust stroke, unburned H existing in the quench layer on the inner peripheral wall of the cylinder 14 scraped up by the piston
C has the exhaust valve 17 located at the deepest part of the main combustion chamber, so it remains in the main combustion chamber without being exhausted and is used for combustion in the next combustion stroke, improving exhaust performance and fuel efficiency. .
吸気弁まわりの平面部２１から排気弁まわりの平面部２
２に至る緩傾斜曲面３１は比較的急傾斜面とならざるを
得ないがその境界域は丸みをつけて滑らかに接続される
から、ヒートスポットがなくなり高負荷時のノッキング
を防止できる。From the flat part 21 around the intake valve to the flat part 2 around the exhaust valve
Although the gently inclined curved surface 31 leading to the point 2 has to be a relatively steeply inclined surface, the boundary area is rounded and connected smoothly, thereby eliminating heat spots and preventing knocking under high load.
また平面部２１．２２のシリンダ円周方向両側が緩傾斜
曲面３１で連続しているから点火栓３２によって点火さ
れた燃焼火炎は吸気弁まわりの燃焼室の浅い領域に円滑
に伝播するので燃焼が良くなり未燃ＨＣ成分の急増を防
止できる。Furthermore, since both sides of the flat portions 21 and 22 in the cylinder circumferential direction are continuous with gently inclined curved surfaces 31, the combustion flame ignited by the ignition plug 32 propagates smoothly to the shallow area of the combustion chamber around the intake valve, so that combustion is possible. This makes it possible to prevent a sudden increase in unburned HC components.
第７図及び第８図に他の実施例を示す。Other embodiments are shown in FIGS. 7 and 8.
このものは吸気弁１６及び排気弁１７の中心を結ぶ直線
りをシリンダ中心線Ｃから所定距離オフセットし、その
分点火柱３２をシリンダ中心線Ｃに近づけて吸気弁まわ
りの平面部２１に臨ませると共に、吸気弁まわりの平面
部２１の面積をより拡大してスキッシュエリアをシリン
ダ断面積の５０％近くにしたものである。In this case, the straight line connecting the centers of the intake valve 16 and the exhaust valve 17 is offset by a predetermined distance from the cylinder center line C, and the ignition column 32 is brought closer to the cylinder center line C by that amount and faces the flat part 21 around the intake valve. At the same time, the area of the flat portion 21 around the intake valve is further expanded to make the squish area nearly 50% of the cylinder cross-sectional area.
そのため点火栓３２から主燃焼室内壁に至る距離が平均
に短縮されもって燃焼期間の短縮化をはかり、熱効率の
向上、混合気希薄限界、ＥＧＲ限界が拡大される。Therefore, the distance from the spark plug 32 to the wall of the main combustion chamber is shortened on average, thereby shortening the combustion period, improving thermal efficiency, and expanding the air-fuel mixture lean limit and EGR limit.
またスキッシュエリアの拡大化によりスキッシュ流が強
化され、火炎伝播速度を増大し燃費、機関安定性を向上
する。In addition, the squish flow is strengthened by expanding the squish area, increasing the flame propagation speed and improving fuel efficiency and engine stability.
尚、上記実施例において緩傾斜曲面とは可及的に滑らか
な曲面であればその曲率形状を問わないものである。Incidentally, in the above embodiments, the gently inclined curved surface is any curved surface having any shape of curvature as long as it is as smooth as possible.
以上述べたように本考案によればシリンダヘッド下面の
吸気弁まわりの平面部から一段と深い位置に設けられた
排気弁まわりの平面部に至るまでのシリンダ円周方向両
側領域をゆるやかな斜面によって連らね、吸気ポートか
らの吸気渦流がシリンダ内で減衰しないような構成とし
たため、燃焼速度が増大され、その結果オツトーサイク
ルにより近づき燃費の改善ができるとともに、燃焼期間
の短縮化により希薄限界、ＥＧＲ限界を拡大し燃費の悪
化なしにＮＯｘ、ＨＣ，Ｃｏ等の未燃成分排出量を低減
できる。As described above, according to the present invention, the areas on both sides of the cylinder circumference from the flat part around the intake valve on the lower surface of the cylinder head to the flat part around the exhaust valve provided at a deeper position are connected by a gentle slope. In addition, the structure is such that the intake vortex from the intake port does not attenuate within the cylinder, increasing the combustion speed, which brings it closer to the Otto cycle, improving fuel efficiency, and shortening the combustion period to reduce the lean limit. By expanding the EGR limit, emissions of unburned components such as NOx, HC, and Co can be reduced without deteriorating fuel efficiency.
また火炎が燃焼室の深い領域から浅い領域まで円滑に伝
播するから未燃成分の急増を避けることができる。Further, since the flame propagates smoothly from the deep region to the shallow region of the combustion chamber, a sudden increase in unburned components can be avoided.
第１図は従来型燃焼室の縦断面図、第２図は同上のシリ
ンダヘッド下面図、第３図は本考案の燃焼室を示す縦断
面図、第４図は同上のシリンダヘッド下面図、第５図は
第４図のＡ−Ａ矢視断面図、第６図は第４図のＢ−Ｂ矢
視断面図、第７図は本考案の他の実施例を示すシリンダ
ヘッド下面図、第８図は同上のＸ−Ｘ矢視断面図である
。
１１・・・・・・シリンダヘッド、１４・・・・・・シ
リンダ、１５・・・・・・ピストン、１６・・・・・・
吸気弁、１７・・・・・・排気弁、２１・・・・・・吸
気弁まわりの平面部、２２・・・・・・排気弁まわりの
平面部、２４・・・・・・シリンダヘッド下面、３１・
・・・・・緩傾斜曲面。Fig. 1 is a vertical sectional view of the conventional combustion chamber, Fig. 2 is a bottom view of the cylinder head of the same as above, Fig. 3 is a longitudinal sectional view of the combustion chamber of the present invention, Fig. 4 is a bottom view of the cylinder head of the same as above, 5 is a cross-sectional view taken along the line A-A in FIG. 4, FIG. 6 is a cross-sectional view taken along the line B-B in FIG. 4, and FIG. 7 is a bottom view of the cylinder head showing another embodiment of the present invention. FIG. 8 is a sectional view taken along the line X--X of the same as above. 11...Cylinder head, 14...Cylinder, 15...Piston, 16...
Intake valve, 17... Exhaust valve, 21... Flat part around the intake valve, 22... Flat part around the exhaust valve, 24... Cylinder head Lower surface, 31・
......Gently inclined curved surface.
Claims (1)
の平面部とを形成し、前記吸気弁まわりの平面部をこれ
に対向するピストン上面に平行に接近させ、前記排気弁
まわりの平面部を吸気弁まわりの平面部よりもピストン
上面に対して一段と離れた位置に配設し、これら２つの
平面部のシリンダ円周方向両側を緩傾斜曲面によって連
続させると共に、排気弁を含む空間を主燃焼室として該
主燃焼室に面するシリンダヘッド内壁に点火栓を設けた
ことを特徴とする内燃機関の燃焼室。A cylinder head is formed with a flat part around the intake valve and a flat part around the exhaust valve, the flat part around the intake valve is made to approach the upper surface of the piston that faces it in parallel, and the flat part around the exhaust valve is used as the flat part around the exhaust valve. It is located further away from the top surface of the piston than the flat part around the valve, and these two flat parts are connected on both sides in the cylinder circumferential direction by a gently inclined curved surface, and the space containing the exhaust valve is connected to the main combustion chamber. A combustion chamber for an internal combustion engine, characterized in that an ignition plug is provided on the inner wall of the cylinder head facing the main combustion chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP109680U JPS6029633Y2 (en) | 1980-01-11 | 1980-01-11 | Combustion chamber of internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP109680U JPS6029633Y2 (en) | 1980-01-11 | 1980-01-11 | Combustion chamber of internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56103624U JPS56103624U (en) | 1981-08-13 |
| JPS6029633Y2 true JPS6029633Y2 (en) | 1985-09-06 |
Family
ID=29597966
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP109680U Expired JPS6029633Y2 (en) | 1980-01-11 | 1980-01-11 | Combustion chamber of internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6029633Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60156932A (en) * | 1984-01-24 | 1985-08-17 | Mazda Motor Corp | Suction device for engine |
| JP2537528Y2 (en) * | 1991-07-09 | 1997-06-04 | 三菱重工業株式会社 | Two-stroke engine cylinder |
-
1980
- 1980-01-11 JP JP109680U patent/JPS6029633Y2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56103624U (en) | 1981-08-13 |
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