JPH05272338A - Combustion chamber of direct injection type diesel engine - Google Patents
Combustion chamber of direct injection type diesel engineInfo
- Publication number
- JPH05272338A JPH05272338A JP4065849A JP6584992A JPH05272338A JP H05272338 A JPH05272338 A JP H05272338A JP 4065849 A JP4065849 A JP 4065849A JP 6584992 A JP6584992 A JP 6584992A JP H05272338 A JPH05272338 A JP H05272338A
- Authority
- JP
- Japan
- Prior art keywords
- combustion chamber
- piston
- nozzle
- diesel engine
- combustion
- 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.)
- Granted
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
- F02B23/0696—W-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 wall
-
- 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
- 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
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、スモークおよびＮＯX
の大幅な低減を図るための直接噴射式ディーゼル機関の
燃焼室に関する。BACKGROUND OF THE INVENTION This invention is, smoke and NO X
The present invention relates to a combustion chamber of a direct injection diesel engine for achieving a significant reduction of
【０００２】[0002]
【従来の技術】ディーゼル機関において、ＮＯX の生成
を抑えかつスモークの生成を抑えるには、燃焼室壁面ま
での混合気形成を抑え、つまり噴霧を乱さず理論混合比
に近い混合気を少なくし、濃混合気の状態で燃焼させ
（予混合燃焼の抑制によるＮＯXの低減）、その後、燃
焼室壁面に衝突した噴霧火炎への空気の混合速度を増大
させること（拡散燃焼の活発化によるスモークの低減）
が重要である。BACKGROUND OF THE INVENTION Diesel engine and to reduce suppressed and generation of smoke generation of NO X, suppress the mixture formation to the combustion chamber wall, i.e. to reduce the air-fuel mixture close to the theoretical mixture ratio without disturbing the spray , Burning in a rich mixture state (reduction of NO X by suppressing premixed combustion), and then increasing the mixing speed of air to the spray flame colliding with the wall of the combustion chamber (smoke caused by activation of diffusion combustion Reduction)
is important.
【０００３】この燃焼方式に最も近い方式が、図４に示
す予燃焼室式ディーゼル機関である。１はピストン、２
はピストンリング、３はシリンダライナー、４はガスケ
ット、５はシリンダヘッド、６は燃料噴射弁、７は噴口
を示し、燃料噴射弁６と噴口７との間には予燃焼室８が
形成され、ピストン１とシリンダヘッドの間には主燃焼
室９が形成され、予燃焼室８内で濃混合気の状態で燃焼
させ、主燃焼室９内で希薄混合気状態で燃焼させる方式
である。しかし、この方式は、予燃焼室８での燃焼速度
が遅く、また、予燃焼室８から燃焼ガスが噴出するとき
の絞り損失および予燃焼室８からの冷却損失が大きいた
め燃費が悪化し、さらに、熱負荷が高いため過給には適
さないので、現在では大型車用としては殆ど採用されて
いない。一方、直接噴射式は、予燃焼室式に比べ燃費が
良いが上記のような燃焼を実現することは非常に困難で
ある。これらを解決するために、予燃焼室をベースとし
て直接噴射式と予燃焼室式の間をねらった構造として、
主燃焼室と副室との間に開閉弁を設ける方式（特開昭６
３−１０６３２１号公報）や、ピストン頭部に突出ピン
を設け上死点近くで予燃焼室の噴口を絞る方式（内燃機
関１９巻２４１号第３２頁）や、主燃焼室と副室の両方
に燃料噴射弁を設ける方式（特開昭６３−２１９８３１
号公報）等が提案されているが、いずれも装置が複雑で
あり満足する性能が得られず実用化には至っていない。The system closest to this combustion system is the pre-combustion chamber type diesel engine shown in FIG. 1 is a piston, 2
Is a piston ring, 3 is a cylinder liner, 4 is a gasket, 5 is a cylinder head, 6 is a fuel injection valve, 7 is an injection port, and a pre-combustion chamber 8 is formed between the fuel injection valve 6 and the injection port 7. A main combustion chamber 9 is formed between the piston 1 and the cylinder head, and the pre-combustion chamber 8 burns in a rich mixture state and the main combustion chamber 9 burns in a lean mixture state. However, in this method, the combustion speed in the pre-combustion chamber 8 is slow, and the throttle loss when the combustion gas is ejected from the pre-combustion chamber 8 and the cooling loss from the pre-combustion chamber 8 are large, which deteriorates the fuel consumption. Further, since it has a high heat load and is not suitable for supercharging, it is rarely used for large vehicles at present. On the other hand, the direct injection type has better fuel consumption than the pre-combustion chamber type, but it is very difficult to realize the above combustion. In order to solve these, as a structure aiming between the direct injection type and the pre-combustion chamber type based on the pre-combustion chamber,
A system in which an open / close valve is provided between the main combustion chamber and the sub chamber
3-106321), a method of narrowing the injection port of the pre-combustion chamber near the top dead center by providing a protruding pin on the piston head (internal combustion engine 19 No. 241, page 32), both main combustion chamber and sub chamber A method of providing a fuel injection valve in the vehicle (Japanese Patent Laid-Open No. 63-219831)
However, none of them has been put to practical use because the device is complicated and satisfactory performance cannot be obtained.
【０００４】ところで直接噴射式ディーゼル機関におい
ては、スモークおよびＮＯX の低減に向けて排気ガス再
循環法（ＥＧＲ）や燃焼方式の改善等において種々の提
案が行われている。このうちＥＧＲには、燃費の悪化、
スモークの増大、排ガスによるＥＧＲ装置の腐食、或い
は機能低下等、耐久性および信頼性の問題がある。[0004] In a direct injection diesel engine, various proposals have been made in the improvement of the exhaust gas recirculation method (EGR) and combustion method towards the reduction of smoke and NO X. Of these, EGR is associated with worse fuel economy,
There are problems of durability and reliability such as increase of smoke, corrosion of EGR device due to exhaust gas, or deterioration of function.
【０００５】また、燃焼方式の観点から見れば、現在広
く用いられている低圧噴射の場合、噴霧はノズル近傍で
着火した後、全体が火炎に包まれながら進行し、この
時、噴霧は、空気と同時に自己の生成した既燃ガスを巻
き込みながら燃焼するので、噴霧中心部において高温
部、酸素不足部が形成されスモークの生成要因となり、
既燃ガスの巻き込みはマイナス要因として働くと言われ
ている。このためスモークを低減するには、燃料と空気
を迅速に混合する必要があり、スワール、スキッシュ等
により空気利用率を向上する方法が採られているが、こ
れでは着火遅れの間の燃料、空気混合速度も増大するた
め、予混合燃焼の増加により燃焼初期の熱発生率が増大
し、ＮＯX の増大を招くという相反する問題を有してお
り、これがスモークとＮＯX の同時低減を困難にしてい
る。From the viewpoint of the combustion system, in the case of low-pressure injection, which is widely used at present, after the spray is ignited in the vicinity of the nozzle, it progresses while being entirely wrapped in flame. At this time, the spray is air. At the same time, it burns while energizing the burned gas generated by itself, so a high temperature part and an oxygen deficient part are formed in the center of the spray, which becomes a cause of smoke generation,
It is said that the inclusion of burnt gas acts as a negative factor. Therefore, in order to reduce smoke, it is necessary to mix fuel and air quickly, and methods such as swirl and squish are used to improve the air utilization rate. Since the mixing speed also increases, there is a contradictory problem that the heat generation rate in the early stage of combustion increases due to the increase in premixed combustion, leading to an increase in NO x , which makes simultaneous reduction of smoke and NO x difficult. ing.
【０００６】上記問題を解決するために、高圧噴射（１
０００ｋｇ／ｃｍ2 以上）、小噴口径ノズル、浅皿燃焼
室および低スワールを組合せる方式が提案されている。
これを図５により説明すると、１はピストン、２はピス
トンリング、３はシリンダライナー、４はガスケット、
５はシリンダヘッド、６はノズル７を有する燃料噴射弁
を示し、ピストン１の頂部には燃焼室９が形成されてい
る。ピストン１が上昇し上死点付近に達したとき、ノズ
ル７から噴射された燃料の噴霧Ｆは、壁面１０近傍で一
気に着火した後、火炎Ｈは燃焼室９中心に向かって膨張
するが、噴射の終了まで燃焼室中心部は不燃域として残
る。すなわち、噴霧Ｆは壁面１０に到達するまで燃焼室
９中心に近い不燃域側で十分に新気Ａを巻き込みながら
進行し、壁面１０側では既燃ガスを導入しながら壁面１
０に衝突する二段の燃焼経路をたどる。高圧噴射の場
合、噴射時期を大幅に遅らせても火がつくため噴射時期
遅延との組み合わせで、低圧噴射と比較してスモークお
よびＮＯX の同時低減を図ることができる。In order to solve the above problem, high pressure injection (1
000 kg / cm 2 or more), a small nozzle nozzle, a shallow dish combustion chamber, and a low swirl system have been proposed.
Referring to FIG. 5, 1 is a piston, 2 is a piston ring, 3 is a cylinder liner, 4 is a gasket,
Reference numeral 5 denotes a cylinder head, 6 denotes a fuel injection valve having a nozzle 7, and a combustion chamber 9 is formed at the top of the piston 1. When the piston 1 rises and reaches the vicinity of the top dead center, the spray F of the fuel injected from the nozzle 7 ignites at once in the vicinity of the wall surface 10, and then the flame H expands toward the center of the combustion chamber 9, but is injected. Until the end of, the center of the combustion chamber remains as a non-combustible area. That is, the spray F progresses while sufficiently entraining the fresh air A on the non-combustible region side near the center of the combustion chamber 9 until reaching the wall surface 10, and the wall surface 1 side while introducing burned gas.
Follow a two-stage combustion path that collides with zero. In the case of high-pressure injection, even if the injection timing is significantly delayed, ignition will occur, so in combination with the injection timing delay, it is possible to reduce smoke and NO X simultaneously as compared with low-pressure injection.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、高圧噴
射は低圧噴射と比較して、噴霧の持つエネルギーが大き
いため、火炎Ｈは噴射エネルギーにより燃焼室９の中心
に向かって広がるのが抑制される。従って、噴霧Ｆはノ
ズル７側で常に新気Ａを導入しながら燃焼するので、拡
散燃焼が活発化しスモークは大幅に低減するが、着火ま
での空気の導入量が多く既燃ガスの巻き込みが少ないた
め、前述したように壁面近傍で一気に着火し初期燃焼が
増加し、同一噴射タイミングで比較するとどうしてもＮ
ＯX の発生量が多くなるという問題を有している。However, since the high-pressure injection has a larger energy than the low-pressure injection, the flame H is suppressed from spreading toward the center of the combustion chamber 9 due to the injection energy. Therefore, the spray F burns while constantly introducing the fresh air A on the nozzle 7 side, so that diffusion combustion is activated and smoke is greatly reduced, but the amount of air introduced until ignition is large and burned gas is less entrained. As a result, as described above, the ignition near the wall suddenly ignites and the initial combustion increases.
Generation amount of O X has a problem that increases.
【０００８】本発明は、上記問題を解決するものであっ
て、従来の単純な浅皿燃焼室の構造を改善するだけで、
スモーク及びＮＯX を同時にかつ大幅に低減させること
ができる直接噴射式ディーゼル機関の燃焼室を提供する
ことを目的とする。The present invention solves the above-mentioned problems by improving the structure of a conventional simple shallow dish combustion chamber.
And to provide a combustion chamber of a direct injection diesel engine capable of simultaneously and significantly reduce the smoke and NO X.
【０００９】[0009]
【課題を解決するための手段】そのために本発明の直接
噴射式ディーゼル機関の燃焼室は、シリンダヘッド５に
設けられる燃料噴射弁６と、燃料噴射弁６のノズル７に
形成される複数の噴口と、ピストン１の上部に形成され
る外周平坦部１ａと、外周平坦部１ａの内側に形成され
る燃焼室９と、燃焼室９の底面１ｂに、ノズル７の噴口
からの燃料噴射方向に沿って形成される溝部１０と、溝
部１０とピストン１の外周平坦部１ａとを連通する貫通
口１２とを備えることを特徴とする。なお、上記構成に
付加した番号は、理解を容易にするために図面と対比さ
せるためのもので、これにより本発明の構成が何ら限定
されるものではない。Therefore, the combustion chamber of the direct injection type diesel engine of the present invention has a plurality of nozzles formed in a fuel injection valve 6 provided in a cylinder head 5 and a nozzle 7 of the fuel injection valve 6. An outer peripheral flat portion 1a formed on the upper part of the piston 1, a combustion chamber 9 formed inside the outer peripheral flat portion 1a, and a bottom surface 1b of the combustion chamber 9 along the fuel injection direction from the injection port of the nozzle 7. It is characterized in that it is provided with a groove portion 10 formed as described above, and a through hole 12 that connects the groove portion 10 and the outer peripheral flat portion 1 a of the piston 1. It should be noted that the numbers added to the above-mentioned configurations are for comparison with the drawings for easy understanding, and the configurations of the present invention are not limited thereby.
【００１０】[0010]
【作用】本発明においては、着火迄の混合気形成をでき
るだけ抑え、濃混合気の状態で燃焼させることにより、
予混合燃焼の抑制によるＮＯX の低減を図り、その後、
空気導入を増加させることにより、拡散燃焼の活発化に
よるスモークの低減を図る。In the present invention, formation of the air-fuel mixture until ignition is suppressed as much as possible, and combustion is carried out in a rich air-fuel mixture state.
Aiming to reduce NO X by suppressing premixed combustion, then
By increasing the amount of air introduced, smoke is reduced due to activation of diffusion combustion.
【００１１】[0011]
【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。図１は、本発明の直接噴射式ディーゼル機関の
燃焼室の１実施例を示し、図Ａはピストンの平面図、図
Ｂは図ＡのＹ−Ｙ線に沿って矢印方向に見た断面図、図
Ｃおよび図Ｄは図ＡのＸ−Ｘ線に沿って矢印方向に見た
断面図であり、図Ｃはピストンが上死点での噴射直後の
状態を、図Ｄはピストンが下降した状態を示している。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows one embodiment of a combustion chamber of a direct injection type diesel engine of the present invention, FIG. A is a plan view of a piston, and FIG. B is a sectional view taken along the line YY of FIG. C and D are cross-sectional views as seen in the direction of the arrow along the line X-X in FIG. A. FIG. C shows the piston immediately after injection at top dead center, and FIG. D shows the piston descended. It shows the state.
【００１２】１はピストン、２はピストンリング、３は
シリンダライナー、４はガスケット、５はシリンダヘッ
ド、６はノズル７を有する燃料噴射弁、９は燃焼室を示
している。ノズル７には、燃料を噴射する６つの噴口が
設けられている。なお、ノズル７の噴口の数は図の実施
例に限定されるものではなく適宜、変更が可能である。Reference numeral 1 is a piston, 2 is a piston ring, 3 is a cylinder liner, 4 is a gasket, 5 is a cylinder head, 6 is a fuel injection valve having a nozzle 7, and 9 is a combustion chamber. The nozzle 7 is provided with six nozzles for injecting fuel. The number of nozzles of the nozzle 7 is not limited to the embodiment shown in the figures, and can be changed as appropriate.
【００１３】ピストン１の上部には、外周平坦部１ａが
形成され、その内側に皿形状の燃焼室９が形成される。
燃焼室９の底面１ｂは中心部から外周にいくに従い深く
なるように形成される。燃焼室９の底面１ｂには、底面
１ｂの傾斜に沿って中心部から径方向に溝部１０が形成
される。この溝部１０は、ノズル７の噴口からの燃料噴
射方向に沿って形成されるとともに、溝部１０の先端に
はピストン１の外周平坦部１ａの下部まで延設される円
口１１が切削され、さらに、この円口１１とピストン１
の外周平坦部１ａとを連通させる貫通口１２が切削され
る。An outer peripheral flat portion 1a is formed in the upper portion of the piston 1, and a dish-shaped combustion chamber 9 is formed inside thereof.
The bottom surface 1b of the combustion chamber 9 is formed so as to become deeper from the central portion toward the outer periphery. On the bottom surface 1b of the combustion chamber 9, a groove portion 10 is formed in the radial direction from the center portion along the inclination of the bottom surface 1b. The groove 10 is formed along the direction of fuel injection from the nozzle of the nozzle 7, and the tip of the groove 10 is cut with a circular opening 11 extending to a lower portion of the outer peripheral flat portion 1a of the piston 1, and , This round mouth 11 and piston 1
The through hole 12 that communicates with the outer peripheral flat portion 1a is cut.
【００１４】上記構成からなる本発明の作用について説
明する。前述したように、着火迄の混合気形成をできる
だけ抑え、濃混合気の状態で燃焼させることにより予混
合燃焼の抑制によるＮＯX の低減を図り、その後、空気
導入を増加させることにより拡散燃焼の活発化によるス
モークの低減を図ることが望ましい。本発明は以下の理
由によりこれを実現することができる。The operation of the present invention having the above structure will be described. As described above, Minimize the mixture formation until ignition, achieving a reduction of the NO X by suppressing the premixed combustion by combusting in a rich mixture condition, then the diffusion combustion by increasing the air introduction It is desirable to reduce smoke due to activation. The present invention can realize this for the following reasons.
【００１５】ピストン１の上死点直前あるいは上死点
後、燃料は、ノズル７の噴口から燃焼室９に向けて噴射
される。このとき、噴霧は、燃焼室９の底面１ｂに形成
された溝部１０に沿ってのみ噴射されるため、燃焼初期
における噴霧への空気導入が抑えられる。燃料噴霧の一
部は、燃焼室９の壁面に衝突し着火し、また一部の燃料
噴霧は、溝部１０の先端に形成された円口１１から貫通
口１２を通ってシリンダヘッド５側に噴き出し、濃混合
気状態で燃焼し予混合燃焼割合が減少するため、ＮＯX
の発生が抑制される。ピストン１が下降するに伴い、噴
霧は溝部１０より上方に噴射されるため、空気導入が促
進され拡散燃焼が活発となりスモークが低減する。Immediately before or after the top dead center of the piston 1, fuel is injected from the nozzle of the nozzle 7 toward the combustion chamber 9. At this time, since the spray is injected only along the groove 10 formed on the bottom surface 1b of the combustion chamber 9, the introduction of air into the spray at the initial stage of combustion is suppressed. A part of the fuel spray collides with the wall surface of the combustion chamber 9 and is ignited, and a part of the fuel spray is ejected from the circular opening 11 formed at the tip of the groove portion 10 through the through hole 12 to the cylinder head 5 side. since the combusted premix combustion ratio in dense mixture state is reduced, NO X
Is suppressed. As the piston 1 descends, the spray is injected above the groove portion 10, so that air introduction is promoted, diffusion combustion becomes active, and smoke is reduced.
【００１６】図２および図３は、本発明の直接噴射式デ
ィーゼル機関の燃焼室の他の実施例を示し、それぞれ図
Ａはピストンの平面図、図Ｂは図ＡのＸ−Ｘ線に沿って
矢印方向に見た断面図である。なお、図１の実施例と同
一の構成および作用については同一番号を付けて説明を
省略する。2 and 3 show another embodiment of the combustion chamber of the direct injection type diesel engine of the present invention. FIG. A is a plan view of the piston, and FIG. B is a view taken along the line XX of FIG. FIG. 4 is a sectional view as seen in the direction of the arrow. The same components and operations as those of the embodiment shown in FIG. 1 are designated by the same reference numerals and their description is omitted.
【００１７】図２の実施例においては、円口１１および
貫通口１２を、図１の実施例のような切削加工ではな
く、中子を使って鋳造により形成している。In the embodiment of FIG. 2, the circular opening 11 and the through-hole 12 are formed by casting using a core instead of the cutting work as in the embodiment of FIG.
【００１８】図３の実施例においては、図２の実施例に
さらに、貫通口１２の底部すなわち円口１１と貫通口１
２の交点の部分に環状通路１３を形成している。これに
より、既燃ガスの一部が環状通路１３内に溜まり、吸入
行程においてこの既燃ガスがシリンダ内に放出されるた
め、内部ＥＧＲ作用により効果的にＮＯX の低減を図る
ことができる。In the embodiment of FIG. 3, in addition to the embodiment of FIG.
An annular passage 13 is formed at the intersection of the two. As a result, a part of the burnt gas is collected in the annular passage 13 and is discharged into the cylinder during the intake stroke, so that the internal EGR action can effectively reduce NO x .
【００１９】[0019]
【発明の効果】以上の説明から明らかなように本発明に
よれば、ピストンの上部に形成される外周平坦部と、該
外周平坦部の内側に形成される燃焼室と、該燃焼室の底
面に、ノズルの噴口からの燃料噴射方向に沿って形成さ
れる溝部と、該溝部と前記ピストンの外周平坦部とを連
通する貫通口とを備える構成のため、従来の単純な浅皿
燃焼室の構造を改善するだけで、スモーク及びＮＯX を
同時にかつ大幅に低減させることができる。As is apparent from the above description, according to the present invention, the outer peripheral flat portion formed on the upper part of the piston, the combustion chamber formed inside the outer peripheral flat portion, and the bottom surface of the combustion chamber. In addition, since the groove portion formed along the direction of fuel injection from the nozzle orifice, and the through hole that communicates the groove portion and the outer peripheral flat portion of the piston, the structure of the conventional simple shallow dish combustion chamber only improves the structure, it is possible to simultaneously and significantly reduce the smoke and NO X.
【図１】本発明の直接噴射式ディーゼル機関の燃焼室の
１実施例を示し、図Ａはピストンの平面図、図Ｂは図Ａ
のＹ−Ｙ線に沿って矢印方向に見た断面図、図Ｃおよび
図Ｄは図ＡのＸ−Ｘ線に沿って矢印方向に見た断面図で
あり、図Ｃはピストンが上死点での噴射直後の状態を、
図Ｄはピストンが下降した状態を示している。1 shows an embodiment of a combustion chamber of a direct injection type diesel engine of the present invention, FIG. A is a plan view of a piston, and FIG.
Is a cross-sectional view taken along the line Y-Y in the direction of the arrow, and FIGS. C and D are cross-sectional views taken along the line X-X in the direction of the arrow A shown in FIG. State immediately after injection in
FIG. D shows the state in which the piston is lowered.
【図２】本発明の直接噴射式ディーゼル機関の燃焼室の
他の実施例を示し、図Ａはピストンの平面図、図Ｂは図
ＡのＸ−Ｘ線に沿って矢印方向に見た断面図2 shows another embodiment of the combustion chamber of the direct injection type diesel engine of the present invention, FIG. A is a plan view of a piston, and FIG. 2B is a cross section taken along line XX of FIG. Figure
【図３】本発明の直接噴射式ディーゼル機関の燃焼室の
他の実施例を示し、図Ａはピストンの平面図、図Ｂは図
ＡのＸ−Ｘ線に沿って矢印方向に見た断面図3 shows another embodiment of the combustion chamber of the direct injection type diesel engine of the present invention, FIG. A is a plan view of the piston, and FIG. 3B is a cross section taken along line XX of FIG. Figure
【図４】従来の予燃焼室式ディーゼル機関の例を示す断
面図FIG. 4 is a sectional view showing an example of a conventional pre-combustion chamber type diesel engine.
【図５】従来の直接噴射式ディーゼル機関の燃焼室の例
を示し、図Ａは断面図、図Ｂは平面図FIG. 5 shows an example of a combustion chamber of a conventional direct injection diesel engine, FIG. A being a sectional view and FIG. B being a plan view.
１…ピストン、１ａ…外周平坦部、１ｂ…底面、５…シ
リンダヘッド ６…燃料噴射弁、７…ノズル、９…燃焼室、１０…溝
部、１２…貫通口 １３…環状通路DESCRIPTION OF SYMBOLS 1 ... Piston, 1a ... Flat outer periphery, 1b ... Bottom surface, 5 ... Cylinder head 6 ... Fuel injection valve, 7 ... Nozzle, 9 ... Combustion chamber, 10 ... Groove, 12 ... Through hole 13 ... Annular passage
───────────────────────────────────────────────────── フロントページの続き (72)発明者 辻村欽司 茨城県つくば市苅間2530番地 財団法人 日本自動車研究所内 株式会社新燃焼シス テム研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kinji Tsujimura 2530, Kuma, Tsukuba-shi, Ibaraki Japan Automobile Research Institute Co., Ltd. Shin Combustion System Research Co., Ltd.
Claims (2)
と、燃料噴射弁のノズルに形成される複数の噴口と、ピ
ストンの上部に形成される外周平坦部と、該外周平坦部
の内側に形成される燃焼室と、該燃焼室の底面に、前記
ノズルの噴口からの燃料噴射方向に沿って形成される溝
部と、該溝部と前記ピストンの外周平坦部とを連通する
貫通孔とを備える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 fuel injection valve provided in a cylinder head, a plurality of injection ports formed in a nozzle of the fuel injection valve, an outer peripheral flat portion formed on an upper portion of a piston, and an inner peripheral flat portion. A combustion chamber, a groove formed on the bottom surface of the combustion chamber along the direction of fuel injection from the nozzle nozzle, and a through hole that connects the groove and the outer peripheral flat portion of the piston. The combustion chamber of the direct injection diesel engine, which is a feature.
設けることを特徴とする請求項１に記載の直接噴射式デ
ィーゼル機関の燃焼室。2. The combustion chamber of a direct injection diesel engine according to claim 1, wherein an annular passage is provided which communicates the bottom of the through hole.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4065849A JPH0768903B2 (en) | 1992-03-24 | 1992-03-24 | Combustion chamber of direct injection diesel engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4065849A JPH0768903B2 (en) | 1992-03-24 | 1992-03-24 | Combustion chamber of direct injection diesel engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05272338A true JPH05272338A (en) | 1993-10-19 |
| JPH0768903B2 JPH0768903B2 (en) | 1995-07-26 |
Family
ID=13298877
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4065849A Expired - Lifetime JPH0768903B2 (en) | 1992-03-24 | 1992-03-24 | Combustion chamber of direct injection diesel engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0768903B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8967129B2 (en) | 2011-01-26 | 2015-03-03 | Caterpillar Inc. | Ducted combustion chamber for direct injection engines and method |
| US9909549B2 (en) | 2014-10-01 | 2018-03-06 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
| US10138855B2 (en) | 2015-07-01 | 2018-11-27 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection with ignition assist |
| US10161626B2 (en) | 2015-07-01 | 2018-12-25 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
| US10801395B1 (en) | 2016-11-29 | 2020-10-13 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
-
1992
- 1992-03-24 JP JP4065849A patent/JPH0768903B2/en not_active Expired - Lifetime
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8967129B2 (en) | 2011-01-26 | 2015-03-03 | Caterpillar Inc. | Ducted combustion chamber for direct injection engines and method |
| US9909549B2 (en) | 2014-10-01 | 2018-03-06 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
| US10138855B2 (en) | 2015-07-01 | 2018-11-27 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection with ignition assist |
| US10161626B2 (en) | 2015-07-01 | 2018-12-25 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
| US10801395B1 (en) | 2016-11-29 | 2020-10-13 | National Technology & Engineering Solutions Of Sandia, Llc | Ducted fuel injection |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0768903B2 (en) | 1995-07-26 |
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