JPH0893479A - Combustion chamber of direct injection diesel engine - Google Patents

Combustion chamber of direct injection diesel engine

Info

Publication number
JPH0893479A
JPH0893479A JP6229430A JP22943094A JPH0893479A JP H0893479 A JPH0893479 A JP H0893479A JP 6229430 A JP6229430 A JP 6229430A JP 22943094 A JP22943094 A JP 22943094A JP H0893479 A JPH0893479 A JP H0893479A
Authority
JP
Japan
Prior art keywords
piston
cavity
circumferential direction
center
fuel
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.)
Pending
Application number
JP6229430A
Other languages
Japanese (ja)
Inventor
Isao Chiba
勲 千葉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hino Motors Ltd
Original Assignee
Hino Motors Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hino Motors Ltd filed Critical Hino Motors Ltd
Priority to JP6229430A priority Critical patent/JPH0893479A/en
Publication of JPH0893479A publication Critical patent/JPH0893479A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0645—Details related to the fuel injector or the fuel spray
    • F02B23/0669—Details related to the fuel injector or the fuel spray having multiple fuel spray jets per injector nozzle
    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0618—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston having in-cylinder means to influence the charge motion
    • F02B23/0627—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston having in-cylinder means to influence the charge motion having additional bores or grooves machined into the piston for guiding air or charge flow to the piston bowl
    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0645—Details related to the fuel injector or the fuel spray
    • F02B23/0648—Means or methods to improve the spray dispersion, evaporation or ignition
    • F02B23/0651—Means or methods to improve the spray dispersion, evaporation or ignition the fuel spray impinging on reflecting surfaces or being specially guided throughout the combustion space
    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0672—Omega-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder center axis
    • 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
    • F02B2275/00—Other engines, components or details, not provided for in other groups of this subclass
    • F02B2275/14—Direct injection into combustion chamber
    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0618—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston having in-cylinder means to influence the charge motion
    • F02B23/0621—Squish flow
    • 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
    • F02B23/02—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition
    • F02B23/06—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston
    • F02B23/0618—Other engines characterised by special shape or construction of combustion chambers to improve operation with compression ignition the combustion space being arranged in working piston having in-cylinder means to influence the charge motion
    • F02B23/0624—Swirl flow
    • 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
    • F02B3/00—Engines characterised by air compression and subsequent fuel addition
    • F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
    • 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

Landscapes

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

Abstract

PURPOSE: To reduce the amount of the black smoke in the exhaust gas to be exhausted by promoting the mixing of the air with the fuel in the expansion stroke to realize the perfect combustion even in the timing retard. CONSTITUTION: A cavity 10 which is provided with an opening part 7 in the top side, forms a smooth and conical projecting part 9 at the center of the bottom side, and forms a lip part 11 extending toward the center side of a piston 3 on the circumferential edge part of the opening part 7 in the top side is formed on the upper part of a piston to be elevatably fitted in a cylinder liner 2. A plurality of longitudinal grooves 12 are formed at approximately regular intervals in the circumferential direction, and a spiral groove 13 which extends spirally in the same circumferential direction from the lower end of the longitudinal groove 12 and becomes gradually small downward is provided on a side wall surface 8 of the cavity 10.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、直接噴射式ディーゼル
機関の燃焼室に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion chamber of a direct injection diesel engine.

【０００２】[0002]

【従来の技術】直接噴射式ディーゼル機関の従来の一例
を図４、５により説明すると、図中、１はシリンダブロ
ック、２は該シリンダブロック１に嵌合された中空円筒
状のシリンダライナ、３は図示していないクランクシャ
フトの回転により往復動するコンロッドによって前記シ
リンダライナ２内を上下方向へ往復動するピストン、４
は該ピストン３の外周に嵌合されピストン３の往復動時
に前記シリンダライナ２内面を摺動するピストンリン
グ、５は前記シリンダブロック１の上面に取り付けられ
たシリンダヘッド、６は該シリンダヘッド５内に配設さ
れた燃料噴射ノズルであり、前記ピストン３の上部中央
に、円形の上面開口部７及び凹弧状の側壁面８を有しし
かも底面の中央部になだらかな円錐状の凸部９を有する
キャビティ１０を設けて燃焼室を構成してあり、又前記
キャビティ１０の上面開口部７周縁部に、ピストン３中
心側に向かい張り出すリップ部１１を形成してある。2. Description of the Related Art A conventional example of a direct injection diesel engine will be described with reference to FIGS. 4 and 5. In the drawings, 1 is a cylinder block, 2 is a hollow cylindrical cylinder liner fitted in the cylinder block, and 3 is a cylinder liner. Is a piston that reciprocates up and down in the cylinder liner 2 by a connecting rod that reciprocates due to rotation of a crankshaft (not shown).
Is a piston ring fitted on the outer circumference of the piston 3 and sliding on the inner surface of the cylinder liner 2 when the piston 3 reciprocates, 5 is a cylinder head mounted on the upper surface of the cylinder block 1, and 6 is the cylinder head 5. Is a fuel injection nozzle disposed at the center of the upper portion of the piston 3 and has a circular upper surface opening 7 and a concave arcuate side wall surface 8 and a gentle conical convex portion 9 at the center of the bottom surface. The cavity 10 is provided to form a combustion chamber, and a lip portion 11 projecting toward the center of the piston 3 is formed at the peripheral edge of the upper opening 7 of the cavity 10.

【０００３】上記した直接噴射式ディーゼル機関におい
ては、圧縮行程でピストン３が略上死点まで上昇する
と、燃焼室内の空気は高圧縮により高温となり、このと
き、図４に示すように、燃料噴射ノズル６の複数の噴射
孔から燃料がキャビティ１０の側壁面８に向けやや斜め
下方に放射状に噴射され、噴射された燃料は、霧状とな
ってキャビティ１０内に導かれ、空気と混合して着火し
燃焼する。In the above-mentioned direct injection type diesel engine, when the piston 3 rises to approximately the top dead center in the compression stroke, the air in the combustion chamber becomes high in temperature due to high compression. At this time, as shown in FIG. 4, fuel injection is performed. The fuel is radially injected from the plurality of injection holes of the nozzle 6 to the side wall surface 8 of the cavity 10 in a slightly obliquely downward direction, and the injected fuel is atomized into the cavity 10 and mixed with air. Ignite and burn.

【０００４】一般に燃料の噴射は、上述のようにピスト
ン３が略上死点まで上昇した際に行なわれ、この場合、
燃焼温度が高くなるので排ガス中のＮＯx濃度が高くな
り、好ましくない。Generally, fuel injection is performed when the piston 3 rises to approximately the top dead center as described above. In this case,
Since the combustion temperature becomes high, the NOx concentration in the exhaust gas becomes high, which is not preferable.

【０００５】[0005]

【発明が解決しようとする課題】そこで、最近は、ＮＯ
xの濃度を低減させるため、燃料の噴射タイミングを遅
延させることにより着火時期を遅らせて燃焼温度を下げ
る、いわゆるタイミングリタードが試みられている。Therefore, recently, NO
In order to reduce the concentration of x, so-called timing retardation has been attempted, in which the ignition timing is delayed by lowering the fuel injection timing to lower the combustion temperature.

【０００６】この場合、ピストン３が上死点から下降す
る膨張行程において、図５に示すように、キャビティ１
０内からシリンダライナ２内へ吹き出す気流Ａの逆スキ
ッシュと吸入行程で空気に与えられているスワールとの
作用により燃料と空気の混合が行なわれ、着火、燃焼が
行なわれるが、燃料と空気の混合が十分に行なわれない
と、燃焼が阻害されて煤が生じ、排ガス中に多量の黒煙
が発生しやすくなるという問題を有していた。In this case, in the expansion stroke in which the piston 3 descends from the top dead center, as shown in FIG.
Fuel and air are mixed by the action of the reverse squish of the air flow A blown from 0 into the cylinder liner 2 and the swirl given to the air in the intake stroke, and ignition and combustion are performed. If the mixing is not sufficiently performed, combustion is hindered, soot is generated, and there is a problem that a large amount of black smoke is likely to be generated in the exhaust gas.

【０００７】本発明は、上述の実情に鑑み、タイミング
リタードを行っても膨張行程における空気と燃料の混合
を促進させて完全燃焼を可能とし、排出される排ガス中
の黒煙の低減を図る直接噴射式ディーゼル機関の燃焼室
を提供しようとするものである。In view of the above situation, the present invention directly promotes mixing of air and fuel in the expansion stroke to enable complete combustion even if timing retardation is performed, and directly reduces black smoke in exhaust gas to be discharged. It is intended to provide a combustion chamber for an injection diesel engine.

【０００８】[0008]

【課題を解決するための手段】本発明は、シリンダライ
ナ内に昇降自在に嵌装されるピストンの上部に、上面に
開口部を有し且つ底面の中央部に凸部を形成ししかも上
面開口部の周縁部にピストン中心側に向かい張り出すリ
ップ部を形成したキャビティを設け、又前記リップ部の
内周縁部側に周方向へ略等間隔に上下方向へ延びる複数
の縦溝を設け、前記キャビティの側壁面に、前記各縦溝
の下端から同一周方向へ螺旋状に延び且つ下方に向かい
徐々に細くなる渦巻き溝を前記縦溝と連なるよう設けた
ものである。SUMMARY OF THE INVENTION According to the present invention, an upper surface of a piston, which is vertically movable in a cylinder liner, has an opening on its upper surface and a convex portion is formed on the center of its bottom surface. A cavity having a lip portion projecting toward the piston center side is provided at the peripheral edge portion of the portion, and a plurality of vertical grooves extending in the vertical direction at substantially equal intervals in the circumferential direction are provided at the inner peripheral edge side of the lip portion, A spiral groove extending spirally in the same circumferential direction from the lower end of each vertical groove and gradually narrowing downward is provided on the side wall surface of the cavity so as to be continuous with the vertical groove.

【０００９】[0009]

【作用】本発明においては、膨張行程においてピストン
が下降する際、キャビティ内からシリンダライナ内に向
けて逆スキッシュの気流が発生するが、この気流のうち
一部がキャビティ側壁面に設けた渦巻き溝及びリップ部
に設けた縦溝に沿って流れ、前記縦溝からシリンダライ
ナ内の空間へ噴出するときに縦溝の外周部によって強制
的に乱されるため、通常の逆スキッシュの気流と強制的
に乱された逆スキッシュの気流がぶつかり合って乱気流
が形成され、膨張行程における空気と燃料の混合が促進
される。In the present invention, when the piston descends in the expansion stroke, an inverse squish air flow is generated from the inside of the cavity toward the inside of the cylinder liner. A part of this air flow is a spiral groove provided on the side wall surface of the cavity. And flows along the vertical groove provided in the lip portion and is forcibly disturbed by the outer peripheral portion of the vertical groove when ejected from the vertical groove into the space inside the cylinder liner, so that it is forced to flow with the normal reverse squish air flow. The air flow of the reverse squish disturbed by each other collides with each other to form a turbulent air flow, which promotes mixing of air and fuel in the expansion stroke.

【００１０】[0010]

【実施例】以下本発明の実施例を図面を参照しつつ説明
する。Embodiments of the present invention will be described below with reference to the drawings.

【００１１】図１〜図３は、本発明の直接噴射式ディー
ゼル機関の燃焼室の一実施例を示しており、基本的な構
成は図４、５に示す従来のものと同様であり、同一のも
のには同一の符号を付して詳細な説明は省略する。FIGS. 1 to 3 show an embodiment of a combustion chamber of a direct injection type diesel engine of the present invention. The basic structure is the same as the conventional one shown in FIGS. The same reference numerals are given to those, and detailed description will be omitted.

【００１２】図１〜図３に示すように、ピストン３上部
に形成したキャビティ１０のリップ部１１の内周縁部側
に、燃料噴射ノズル６の噴射孔から噴射される燃料の噴
射方向位置に略合致するよう、横断面形状が半円弧状で
且つ上下方向へ延びる縦溝１２を平面的に見て開口部７
が花冠状となるよう形成し（縦溝１２の数は、図では５
個）、又前記キャビティ１０の側壁面８に、前記各縦溝
１２の下端に連なると共に該下端から同一周方向へキャ
ビティ１０に対し螺旋状に延び、下方に向かい徐々に細
くなる渦巻き溝１３を形成する。渦巻き溝１３は、平面
的に見て円周方向へ隣り合う縦溝１２の近傍まで延び、
下端位置は前記キャビティ１０の最大内径位置近傍まで
延びている。As shown in FIGS. 1 to 3, on the inner peripheral edge side of the lip portion 11 of the cavity 10 formed in the upper portion of the piston 3, the fuel is injected from the injection hole of the fuel injection nozzle 6 substantially in the injection direction position. For matching, the vertical groove 12 having a semicircular cross section and extending in the up-down direction is seen in plan view, and the opening 7 is formed.
To form a corolla (the number of vertical grooves 12 is 5 in the figure).
), And a spiral groove 13 continuous with the lower end of each vertical groove 12 on the side wall surface 8 of the cavity 10 and extending spirally with respect to the cavity 10 in the same circumferential direction from the lower end and gradually narrowing downward. Form. The spiral groove 13 extends to the vicinity of the adjacent vertical grooves 12 in the circumferential direction in plan view,
The lower end position extends to the vicinity of the maximum inner diameter position of the cavity 10.

【００１３】次に、本実施例の作用について説明する。Next, the operation of this embodiment will be described.

【００１４】圧縮行程でピストン３が上死点まで上昇し
た後、膨張行程に移行する際、従来よりも噴射タイミン
グを遅らせて燃料噴射ノズル６の複数の噴射孔から燃料
がキャビティ１０の側壁面８に向けやや斜め下方に放射
状に噴射され、噴射された燃料は、霧状となり吸入行程
で吸入されている空気と混合し、膨張行程の開始直後に
着火燃焼する。When the piston 3 moves up to the top dead center in the compression stroke and then shifts to the expansion stroke, the injection timing is delayed as compared with the conventional case, and the fuel is injected from the plurality of injection holes of the fuel injection nozzle 6 to the side wall surface 8 of the cavity 10. Radially injected slightly obliquely downward toward the air, and the injected fuel becomes mist and mixes with the air taken in in the intake stroke, and is ignited and burned immediately after the start of the expansion stroke.

【００１５】ピストン３が下降する際には、リップ部１
１の縦溝１２がない部分には、従来の場合と同様、キャ
ビティ１０内からシリンダライナ２内に向けて逆スキッ
シュの気流Ａが発生し、また渦巻き溝１３及び縦溝１２
の部分においては、渦巻き溝１３及び縦溝１２に案内さ
れてキャビティ１０からシリンダライナ２内に向けて逆
スキッシュの気流Ｂが発生する。When the piston 3 descends, the lip portion 1
In the portion where the vertical groove 12 is not present, a reverse squish air flow A is generated from the inside of the cavity 10 toward the inside of the cylinder liner 2, and the spiral groove 13 and the vertical groove 12 are provided.
In the portion (1), the reverse squish airflow B is generated from the cavity 10 toward the inside of the cylinder liner 2 by being guided by the spiral groove 13 and the vertical groove 12.

【００１６】この逆スキッシュの気流Ｂは、縦溝１２か
らシリンダライナ２内の空間へ噴出する際、縦溝１２の
円弧部によって強制的に乱されるため、気流Ａと気流Ｂ
とがぶつかり合って乱気流が形成され、この乱気流と吸
気行程における空気のスワールにより膨張行程における
空気と燃料の混合が促進される。When the reverse squish airflow B is jetted from the vertical groove 12 into the space inside the cylinder liner 2, it is forcibly disturbed by the arc portion of the vertical groove 12, so that the airflows A and B are generated.
The turbulence and the swirl of the air in the intake stroke promote the mixing of the air and the fuel in the expansion stroke.

【００１７】よって、拡散燃焼が活発になって完全燃焼
が可能となるため、煤の発生が抑制され、排ガス中の黒
煙の低減を図ることができ、ＮＯxの低減も従来と同様
に行なうことができる。Therefore, since diffusion combustion becomes active and complete combustion becomes possible, soot generation is suppressed, black smoke in exhaust gas can be reduced, and NOx can be reduced in the same manner as in the conventional case. You can

【００１８】なお、本発明の実施例においては、縦溝１
２を燃料噴射ノズル６から噴射される燃料の噴射方向位
置に略合致するように噴射孔と同数形成してあるが、燃
料の噴射方向位置からずらして形成するようにしても良
いこと、その他、本発明の要旨を逸脱しない範囲内で種
々変更を加え得ることは勿論である。In the embodiment of the present invention, the vertical groove 1
The number of the injection holes 2 is the same as that of the injection holes of the fuel injected from the fuel injection nozzle 6, but it may be formed so as to be shifted from the position of the fuel injection direction. Needless to say, various changes can be made without departing from the scope of the present invention.

【００１９】[0019]

【発明の効果】本発明においては、ＮＯx濃度を低減さ
せるために燃料の噴射タイミングを遅延させる、いわゆ
るタイミングリタードを行なう場合でも、膨張行程にお
ける空気と燃料の混合が促進されるので、完全燃焼が可
能となって煤の発生が抑制され、排ガス中の黒煙の低減
を図ることができるという優れた効果を奏し得る。According to the present invention, even when the fuel injection timing is delayed in order to reduce the NOx concentration, that is, when so-called timing retard is performed, the mixing of air and fuel in the expansion stroke is promoted, so that complete combustion is achieved. As a result, the generation of soot can be suppressed, and the excellent effect that black smoke in exhaust gas can be reduced can be achieved.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明の一実施例においてピストンが上死点に
位置した状態を示す縦断側面図である。FIG. 1 is a vertical sectional side view showing a state in which a piston is located at a top dead center in one embodiment of the present invention.

【図２】本発明の一実施例においてピストンが上死点か
ら下降している状態を示す縦断側面図である。FIG. 2 is a vertical cross-sectional side view showing a state in which a piston is descending from a top dead center in one embodiment of the present invention.

【図３】図１、２におけるピストンの平面図である。FIG. 3 is a plan view of the piston shown in FIGS.

【図４】従来例においてピストンが上死点に位置した状
態を示す縦断側面図である。FIG. 4 is a vertical cross-sectional side view showing a state in which a piston is located at a top dead center in a conventional example.

【図５】従来例においてピストンが上死点から下降して
いる状態を示す縦断側面図である。FIG. 5 is a vertical cross-sectional side view showing a state in which a piston is descending from a top dead center in a conventional example.

【符号の説明】[Explanation of symbols]

２ シリンダライナ ３ ピストン ７ 開口部 ８ 側壁面 ９ 凸部 １０ キャビティ １１ リップ部 １２ 縦溝 １３ 渦巻き溝 2 Cylinder Liner 3 Piston 7 Opening 8 Side Wall 9 Convex 10 Cavity 11 Lip 12 Vertical Groove 13 Spiral Groove

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 シリンダライナ内に昇降自在に嵌装され
るピストンの上部に、上面に開口部を有し且つ底面の中
央部に凸部を形成ししかも上面開口部の周縁部にピスト
ン中心側に向かい張り出すリップ部を形成したキャビテ
ィを設け、又前記リップ部の内周縁部側に周方向へ略等
間隔に上下方向へ延びる複数の縦溝を設け、前記キャビ
ティの側壁面に、前記各縦溝の下端から同一周方向へ螺
旋状に延び且つ下方に向かい徐々に細くなる渦巻き溝を
前記縦溝と連なるよう設けたことを特徴とする直接噴射
式ディーゼル機関の燃焼室。1. A piston, which is fitted in a cylinder liner so as to be able to move up and down, has an opening on the upper surface and a convex portion at the center of the bottom surface, and has a piston center side at the peripheral edge of the upper opening. Is provided with a cavity formed with a lip portion projecting toward, and a plurality of vertical grooves extending in the vertical direction at substantially equal intervals in the circumferential direction are provided on the inner peripheral edge side of the lip portion. A combustion chamber of a direct injection diesel engine, characterized in that a spiral groove extending spirally in the same circumferential direction from the lower end of the vertical groove and gradually narrowing downward is provided so as to be continuous with the vertical groove.
JP6229430A 1994-09-26 1994-09-26 Combustion chamber of direct injection diesel engine Pending JPH0893479A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6229430A JPH0893479A (en) 1994-09-26 1994-09-26 Combustion chamber of direct injection diesel engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6229430A JPH0893479A (en) 1994-09-26 1994-09-26 Combustion chamber of direct injection diesel engine

Publications (1)

Publication Number Publication Date
JPH0893479A true JPH0893479A (en) 1996-04-09

Family

ID=16892110

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6229430A Pending JPH0893479A (en) 1994-09-26 1994-09-26 Combustion chamber of direct injection diesel engine

Country Status (1)

Country Link
JP (1) JPH0893479A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20030043373A (en) * 2001-11-28 2003-06-02 현대자동차주식회사 Piston for diesel engine
EP1316710A1 (en) * 2001-11-30 2003-06-04 Renault s.a.s. Piston for an internal combustion engine and engine provided therewith
FR2886982A1 (en) * 2005-06-09 2006-12-15 Renault Sas Combustion chamber for diesel engine with direct injection has piston face cavity with notches in cavity rim aligned with injector orifices
EP3557022A4 (en) * 2017-03-17 2020-03-04 Mazda Motor Corporation Diesel engine
CN112324556A (en) * 2020-11-09 2021-02-05 赵伟 Lip jet combustion system of direct-injection diesel engine

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20030043373A (en) * 2001-11-28 2003-06-02 현대자동차주식회사 Piston for diesel engine
EP1316710A1 (en) * 2001-11-30 2003-06-04 Renault s.a.s. Piston for an internal combustion engine and engine provided therewith
FR2833042A1 (en) * 2001-11-30 2003-06-06 Renault PISTON FOR INTERNAL COMBUSTION ENGINE AND ASSOCIATED ENGINE
FR2886982A1 (en) * 2005-06-09 2006-12-15 Renault Sas Combustion chamber for diesel engine with direct injection has piston face cavity with notches in cavity rim aligned with injector orifices
EP3557022A4 (en) * 2017-03-17 2020-03-04 Mazda Motor Corporation Diesel engine
CN112324556A (en) * 2020-11-09 2021-02-05 赵伟 Lip jet combustion system of direct-injection diesel engine
CN112324556B (en) * 2020-11-09 2022-01-25 赵伟 Lip jet combustion system of direct-injection diesel engine

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