JPH03194117A - Combustion chamber for internal combustion engine - Google Patents
Combustion chamber for internal combustion engineInfo
- Publication number
- JPH03194117A JPH03194117A JP1331135A JP33113589A JPH03194117A JP H03194117 A JPH03194117 A JP H03194117A JP 1331135 A JP1331135 A JP 1331135A JP 33113589 A JP33113589 A JP 33113589A JP H03194117 A JPH03194117 A JP H03194117A
- Authority
- JP
- Japan
- Prior art keywords
- combustion chamber
- fuel
- swirl
- side walls
- piston
- 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
Links
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 85
- 239000000446 fuel Substances 0.000 claims abstract description 49
- 238000002347 injection Methods 0.000 claims abstract description 11
- 239000007924 injection Substances 0.000 claims abstract description 11
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 10
- 239000007921 spray Substances 0.000 claims description 15
- 239000012528 membrane Substances 0.000 abstract 2
- 238000009966 trimming Methods 0.000 abstract 1
- 239000010408 film Substances 0.000 description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 229910002804 graphite Inorganic materials 0.000 description 7
- 239000010439 graphite Substances 0.000 description 7
- 239000000779 smoke Substances 0.000 description 7
- 238000000926 separation method Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000002828 fuel tank Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
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
- F02B23/0672—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
- 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
- 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
- F02B23/0678—Unconventional, complex or non-rotationally symmetrical shapes of the combustion space, e.g. flower like, having special shapes related to the orientation of the fuel spray jets
-
- 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)
- Combustion Methods Of Internal-Combustion Engines (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
この発明は内燃機関の燃焼室に係り、特に水平断面が四
角形の燃焼室の側壁に燃料膜を剥離させる凹部を形成し
た内燃機関の燃焼室に関する。[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a combustion chamber of an internal combustion engine, and more particularly to a combustion chamber of an internal combustion engine in which a side wall of a combustion chamber having a rectangular horizontal cross section is formed with a recess for peeling off a fuel film. Regarding.
［従来の技術］
燃料噴霧を直接ピストンの頂部に形成された燃焼室へ供
給し自発燃焼させるディーゼル機関では、燃焼性を向上
させるために、スワール化した燃焼用空気を燃焼室に導
入して燃料噴霧と燃焼用空気とを効果的に混合するよう
にしている６しかしスワール化された燃焼用空気を燃焼
室内に導入するだけでは燃焼性の大きな向上を得ること
が困難であることから、スワール及び燃料噴霧との関係
を充分に考慮した形状の燃焼室の開発か要求されている
。[Prior Art] In diesel engines that supply fuel spray directly to a combustion chamber formed at the top of a piston for spontaneous combustion, swirled combustion air is introduced into the combustion chamber to improve combustibility. 6 However, it is difficult to obtain a large improvement in combustibility by simply introducing swirled combustion air into the combustion chamber, so swirl and combustion air are mixed effectively. There is a need to develop a combustion chamber with a shape that takes into account the relationship with fuel spray.
従来この種の課題を解決するために第５図に示す形状の
燃焼室が形成されている。Conventionally, in order to solve this kind of problem, a combustion chamber having the shape shown in FIG. 5 has been formed.
この燃焼室ａは、ピストン頂部すを窪ませて形成する燃
焼室Ｃの水平断面を四角形とすることによって、燃焼室
内でＣ円周方向に旋回するスワールＳを適度に減衰する
と共に、燃焼室Ｃの側壁ｄに衝突して液膜化された燃料
を燃焼室Ｃの円孤状の各コーナ部ｅで積極的に剥離させ
、蒸気化させ、その結果として燃焼室Ｃ内に着火性およ
び火炎伝播性の優れた予混合気を生成するようにしたも
のである。By making the horizontal cross section of the combustion chamber C formed by recessing the top of the piston into a rectangular shape, this combustion chamber a moderately damps the swirl S rotating in the circumferential direction of the combustion chamber C. The fuel that has collided with the side wall d and turned into a liquid film is actively separated and vaporized at each arc-shaped corner e of the combustion chamber C, and as a result, the ignitability and flame propagation within the combustion chamber C are increased. This is designed to generate a premixture with excellent properties.
したがって、着火遅れの改善、スモーク、燃焼騒音の改
善が可能になる。Therefore, it is possible to improve ignition delay, smoke, and combustion noise.
［発明が解決しようとする課題］
しかし、スワールは、燃焼用空気を燃焼室内に吸入させ
る吸気ボートのスワールチャンバによって生成され、そ
のスワールの強度はピストンの下降速度によって一義的
に決定されるため、機関の高速回転側と低速回転側とで
はスワール強度に大きな差異が発生し、燃焼性能に大き
な影響を与えてしまう問題がある。[Problems to be Solved by the Invention] However, the swirl is generated by the swirl chamber of the intake boat that sucks combustion air into the combustion chamber, and the strength of the swirl is uniquely determined by the descending speed of the piston. There is a problem in that there is a large difference in swirl strength between the high-speed rotation side and the low-speed rotation side of the engine, which greatly affects combustion performance.
つまり、ピストン下降速度が高い高速回転でオバスワー
ルが生成されると、このスワールによって燃料噴霧の殆
どか燃焼室の側壁に付着させられるようになり、燃焼用
空気との混合性能が悪化し黒鉛を発生させるようになる
。また、極低速回転ではスワール強度が極端に低く噴射
された燃料が側壁に付着して高速回転側と同様に黒鉛が
発生ずるようになる。特に低温時には燃焼室内雰囲気が
低温となるために燃料が蒸発せずにそのまま白煙として
排出される。In other words, when an oval swirl is generated at high speed rotation with a high piston descending speed, most of the fuel spray is deposited on the side wall of the combustion chamber due to this swirl, which deteriorates the mixing performance with combustion air and generates graphite. You will be able to do it. Further, at very low speed rotation, the swirl strength is extremely low, and the injected fuel adheres to the side wall, causing graphite to be generated as in the case of high speed rotation. Particularly at low temperatures, the atmosphere in the combustion chamber is so low that the fuel does not evaporate and is emitted as white smoke.
なお関連する技術として水平断面が円形の燃焼室側壁に
これを窪ませて円柱状空間を形成すると共に、その円柱
状空間内に積極的に供給した燃料噴霧流を再度燃焼室の
中央側へ反転させるようにした「エンジンの燃焼室構造
」 （実開昭５９−１４８４２４号公報）か提案されて
いる。しかし、スワールは円柱状空間内に侵入せずに燃
焼室の側壁に沿って円周方向に旋回すること、及び燃料
噴霧の貫徹力を考慮すると、提案の構成では円柱状空間
を形成する側壁に燃料が過渡に付着して液化するために
、ミキシング効果が低下し、本発明の問題とする燃料膜
の付着による黒煙、ＨＣの悪化を改善づることは困難に
なる。A related technology involves recessing the side wall of a combustion chamber with a circular horizontal cross section to form a cylindrical space, and then reversing the fuel spray flow that was actively supplied into the cylindrical space to the center of the combustion chamber. ``Engine combustion chamber structure'' (Japanese Utility Model Application Publication No. 148424/1983) has been proposed. However, considering that the swirl does not enter the cylindrical space but instead rotates in the circumferential direction along the side wall of the combustion chamber and the penetration force of the fuel spray, the proposed configuration Since the fuel transiently adheres and liquefies, the mixing effect deteriorates, and it becomes difficult to improve the black smoke and HC deterioration caused by the adhesion of the fuel film, which is the problem of the present invention.
［課題を解決するための手段］
この発明は上記課題を解決することを目的とし、ピスト
ン頂部を窪ませて水平断面が四角形の燃焼室を形成する
と共に、この燃焼室の側壁に円弧状コーナ部の下流側と
ラップさせて軸方向に沿う円弧状の凹部を形成し、上記
コーナ部と凹部との接続部よりスワール上流（ＩＩｌｌ
へ燃料噴霧を供給する燃料噴射ノズルを配設したもので
ある。[Means for Solving the Problems] The present invention aims to solve the above problems, and the top of the piston is recessed to form a combustion chamber having a rectangular horizontal cross section, and an arcuate corner portion is formed on the side wall of the combustion chamber. An arcuate concave portion along the axial direction is formed by wrapping the downstream side of the concave portion, and a swirl upstream (IIll
A fuel injection nozzle is installed to supply fuel spray to the fuel tank.
［作用コ
燃料噴射ノズルがら噴射された燃料噴霧は、その貫徹力
に応じて側壁に衝突する。側壁に衝突後その一部は反射
され、燃焼室内を旋回するスヮル中に取り込まれつつ蒸
気化し燃焼室内の空気と混合して予混合気化する。衝突
した燃料の一部は側壁に付着しスワールによって下流側
へ薄膜状に拡散し燃料膜化する。この燃料膜は拡散下流
側が上流側に対して薄く、かつ下流側で剥離、蒸気化さ
れやすい状態にある。ここで燃料噴霧の衝突点を円弧状
コーナ部よりスワール方向上流側とすると燃料膜は円弧
状コーナ部に拡散状態で運ばれるが、この円弧状コーナ
部のスワール方向下流側に一部をラップさせて凹部を形
成したことによってそのコーナ部と凹部との境界でメカ
ニカル的に剥離すると共に、剥離した燃料とスワールと
が側壁寄りから燃焼室の中心寄りへ方向修正されて流下
するようになる。この結果、剥離後の燃料は、燃焼室の
中心側の燃焼用空気と混合して予混合気化する。[Operation] The fuel spray injected from the fuel injection nozzle collides with the side wall depending on its penetration force. After colliding with the side wall, a part of it is reflected, vaporized while being taken into the swirl swirling inside the combustion chamber, and mixed with the air inside the combustion chamber to form a premixed gas. A part of the collided fuel adheres to the side wall and spreads downstream in a thin film due to the swirl, forming a fuel film. This fuel film is thinner on the diffusion downstream side than on the upstream side, and is in a state where it is easily peeled off and vaporized on the downstream side. If the collision point of the fuel spray is set upstream in the swirl direction from the arcuate corner, the fuel film will be transported to the arcuate corner in a diffused state, but a part of it will be wrapped downstream of the arcuate corner in the swirl direction. By forming the recessed portion, the fuel is mechanically separated at the boundary between the corner portion and the recessed portion, and the separated fuel and swirl are directed from the side wall to the center of the combustion chamber and flow downward. As a result, the separated fuel mixes with the combustion air on the center side of the combustion chamber to form a premixed gas.
［実施例］
以下にこの発明の好適一実施例を添付図面に基づいて説
明する。[Embodiment] A preferred embodiment of the present invention will be described below based on the accompanying drawings.
第１図に示すようにピストン１の頂部２には、頂面３を
基準として軸方向に窪まぜられた燃焼室４か形成されて
いる。この燃焼室４の水平断面は、はぼ正四角形に形成
され、コーナ部５を形成する側壁は、円弧状の囲壁とし
て形成されている。まな燃焼室４の底部中央には、円錐
体状の突起６が形成されている。そして、燃焼室４の上
部開口縁には、これに沿う部分を半径方向内方へリップ
状に延出させた縁取り部７が形成されている。As shown in FIG. 1, a combustion chamber 4 is formed in the top 2 of the piston 1 and is recessed in the axial direction with respect to the top surface 3. The horizontal cross section of this combustion chamber 4 is formed into a substantially regular square, and the side wall forming the corner portion 5 is formed as an arcuate surrounding wall. A conical projection 6 is formed at the center of the bottom of the combustion chamber 4 . An edge portion 7 is formed at the upper opening edge of the combustion chamber 4 and extends radially inward in a lip shape along the edge.
このように形成された燃焼室４では、スワールチャンバ
たる吸気ボート（図示せず）からスワルＳ化された燃焼
用空気が供給されと、燃焼用空気は燃焼室４の側壁８と
上記突起６との間に形成された空間を旋回し、燃焼室４
内を流動化させるようになる。一方、上記縁取り部７は
圧縮打栓の終期に燃焼室４内にスキッシュＶを生成し燃
焼室４内に上下方向に旋回する空気流動流を生成する。In the combustion chamber 4 formed in this way, when combustion air converted into swirl S is supplied from an intake boat (not shown) serving as a swirl chamber, the combustion air is heated between the side wall 8 of the combustion chamber 4 and the projection 6. The combustion chamber 4
It becomes fluid inside. On the other hand, the edge portion 7 generates a squish V in the combustion chamber 4 at the end of compression plugging, and generates an air flow that swirls in the vertical direction in the combustion chamber 4.
さてこの発明の目的は、上記燃焼室４の側壁８にｆ−ｆ
−着される燃料膜を良好に剥離させて燃焼用空気に効果
的に混合させることにある。Now, the object of this invention is to provide f-f on the side wall 8 of the combustion chamber 4.
- To effectively separate the deposited fuel film and mix it with the combustion air.
そこで、］二１燃焼室４の燃料膜を積極的に剥離させる
なめに、軸方向に沿う凹部９を第１図に示すように燃焼
室４の側壁８に形成する。凹部９が形成する側壁８は、
燃焼室４の中心側へ中心をおく所定曲率半径の曲面状に
形成される。凹部９の形成位置は、凹部９のスワールＳ
方向上流側の一端が」１記コーナ部５の下流側に接続さ
れ、スワルＳ方向下流側の他端が上記コ〜す部５より下
流側の側壁８に接続される位置に形成される。Therefore, in order to actively peel off the fuel film in the combustion chamber 4, a recess 9 along the axial direction is formed in the side wall 8 of the combustion chamber 4 as shown in FIG. The side wall 8 formed by the recess 9 is
It is formed into a curved surface with a predetermined radius of curvature centered toward the center of the combustion chamber 4 . The formation position of the recess 9 is the swirl S of the recess 9.
One end on the upstream side in the direction is connected to the downstream side of the corner section 5, and the other end on the downstream side in the swirl S direction is connected to the side wall 8 on the downstream side of the corner section 5.
このようにコーナ部５のスワールＳ方向下流側に一部を
ラッグさせて凹部９を形成すると、そのコーナ部５と凹
部９との境界でスワールＳがメカニカル的に剥離される
ようになり、スワールＳが側壁８寄りから燃焼室４の中
心寄りへ流下方向を修正されるようになる。ここで側壁
８の輪郭線に対する凹部９の最大窪み深さＨは、スワー
ルＳの最大強度に対応させて凹部９の底側にスワールＳ
が侵入することのない深さに決定され、上記凹部９を形
成する曲率半径はＲ１は、基本的に上記燃焼室４の一辺
の長さＷに対して１／２以下とし、上記コ−す部５に対
するスワールＳの剥離を良好にする曲率半径に決定され
る。When the recess 9 is formed by lugging a part of the corner 5 on the downstream side in the direction of the swirl S, the swirl S is mechanically separated at the boundary between the corner 5 and the recess 9, and the swirl The direction of flow of S is corrected from near the side wall 8 to near the center of the combustion chamber 4. Here, the maximum depression depth H of the recess 9 with respect to the contour line of the side wall 8 is set so that the swirl S on the bottom side of the recess 9 corresponds to the maximum strength of the swirl S.
The radius of curvature R1 forming the recess 9 is basically set to 1/2 or less of the length W of one side of the combustion chamber 4. The radius of curvature is determined to allow good separation of the swirl S from the portion 5.
このように形成した燃焼室４の中央位置には、この燃焼
室４内に垂下状態で燃料噴射ノズル１０が配設される。At the center of the combustion chamber 4 thus formed, a fuel injection nozzle 10 is disposed in a hanging state within the combustion chamber 4.
燃料噴射ノズル１０はその先端に４個の噴口１１を有し
て形成され、各噴口１１の向きは上記コーナ部５よりス
ワールＳ方向上流側の側壁８へ向けてそれぞれ燃料噴霧
ｆを供給するように決定される。The fuel injection nozzle 10 is formed with four nozzles 11 at its tip, and each nozzle 11 is oriented so as to supply fuel spray f toward the side wall 8 on the upstream side in the swirl S direction from the corner portion 5. determined.
次に実施例の作用を説明する。Next, the operation of the embodiment will be explained.
燃料噴射ノズル１０の各噴口１１からそれぞれ噴射され
た燃料噴霧ｆは、機関の回転速度に応じた貫徹力でコー
ナ部５よりスワールＳ方向上流側の側壁８に供給され、
その供給途上て一部が蒸発されてスワールＳにより拡散
され蒸気化する。各側壁８に衝突した燃料噴霧ｆの一部
は反射され、燃焼室４内を旋回するスワールＳ及びスキ
ッシュＶ中に取り込まれつつ蒸気化し燃焼室４内の空気
と混合して予混合気化する。そして衝突した燃料の残部
は側を８に１４着しスワールＳによって下流側へ薄膜状
に拡散し燃料膜となる。燃ｆｌｌＩ！は拡散下流側が上
流側に対して薄く、かつ下流側で剥離、蒸気化されやす
くなる。つまりコーナ部５と凹部９との境界で剥離しそ
の剥離によって流下方向が側壁８寄りから燃焼室４の中
心寄りへ方向修正され、これらが二ノーナ部５内に侵入
することがなく、燃料噴霧ｆの殆どが蒸気化して予混合
気となる。The fuel spray f injected from each injection port 11 of the fuel injection nozzle 10 is supplied to the side wall 8 on the upstream side in the swirl S direction from the corner portion 5 with a penetration force according to the rotational speed of the engine,
A part of it is evaporated during its supply, diffused by the swirl S, and vaporized. A portion of the fuel spray f that collides with each side wall 8 is reflected, vaporized while being taken into the swirl S and squish V rotating within the combustion chamber 4, and mixed with the air within the combustion chamber 4 to form a premixed vapor. The remainder of the collided fuel lands on the sides 8 and 14 and is diffused downstream in a thin film form by the swirl S, forming a fuel film. Moe full I! The diffusion downstream side is thinner than the upstream side, and it is easily separated and vaporized on the downstream side. In other words, separation occurs at the boundary between the corner part 5 and the recessed part 9, and due to the separation, the flow direction is corrected from closer to the side wall 8 to closer to the center of the combustion chamber 4, and these do not enter into the second corner part 5, resulting in fuel spray. Most of f is vaporized and becomes a premixture.
したがってこのようなメカニカル的な剥離を促進したこ
とによって剥離後の燃料がスワールＳ及びスキッシュＶ
により燃焼用空気に混合され着火性能、火炎伝播性能の
優れた予混合気となる。Therefore, by promoting such mechanical separation, the fuel after separation becomes swirl S and squish V.
This mixture is mixed with the combustion air to form a premixture with excellent ignition performance and flame propagation performance.
この結果、燃料膜の過度な付着による黒鉛や白煙（ＨＣ
）の極めて少ない燃焼が可能になり、着火遅れが短縮さ
れて燃焼騒音を大巾に減少できるようになる。As a result, graphite and white smoke (HC) due to excessive adhesion of the fuel film
), the ignition delay is shortened, and combustion noise can be greatly reduced.
したがって、黒鉛の発生量を減少させて機関高速回転時
の燃料噴射量を増加させること及び機関出力を向上させ
ることが可能になり、極低速回転での黒鉛の改善、そし
て低温始動時の白煙を改善できるようになる。Therefore, it is possible to reduce the amount of graphite generated, increase the amount of fuel injection at high engine speeds, improve engine output, improve graphite generation at extremely low speeds, and white smoke at low temperature starts. will be able to improve.
第３図及び第４図は、ピストン１の頂部２に、ピストン
１の軸心方向下方に水平断面を順次拡大して連続させた
燃焼室４を形成し、この燃焼室・１の円弧状のコーナ部
５に対して上記実施例同様部をラップさせて凹部９を形
成した実施例を示すものである。3 and 4, a combustion chamber 4 is formed in the top part 2 of the piston 1, and the combustion chamber 4 has a continuous horizontal cross-section enlarged sequentially downward in the axial direction of the piston 1. This shows an embodiment in which a concave portion 9 is formed by wrapping the corner portion 5 with a portion similar to the above embodiment.
このように形成した燃焼室４は上記実施例の燃焼室４に
対してスキッシュＶの旋回範囲が拡大され、このスキッ
シュＶによって空気が大きく流動化されることによって
拡散燃焼が行われるようになる。そして凹部９による燃
料膜の剥離が促進され、上記実施例同様、高速回転時の
黒鉛の発生量が減少し、極低速回転時の白煙（未燃燃料
）の排出量が減少するようになる。In the combustion chamber 4 formed in this way, the swirling range of the squish V is expanded compared to the combustion chamber 4 of the above embodiment, and the air is greatly fluidized by the squish V, so that diffusive combustion is performed. The separation of the fuel film by the recesses 9 is promoted, and as in the above embodiment, the amount of graphite generated during high speed rotation is reduced, and the amount of white smoke (unburnt fuel) discharged during extremely low speed rotation is reduced. .
［発明の効果コ
以上説明したことから明らかなようにこの発明によれば
次の如き優れた効果を発揮する。[Effects of the Invention] As is clear from the above explanation, the present invention provides the following excellent effects.
０
ピストン頂部を窪ませて水平断面が四角形の燃焼室を形
成すると共に、この燃焼室の側壁に円弧状コ−す部の下
流側とラップさせて軸方向に沿う円弧状の凹部を形成し
、上記コ−す部と凹部との接続部よりスワール上流側へ
燃料噴霧を供給する燃料噴射ノズルを配設したので、燃
料膜を剥離させて予混合気化できるので機関高速回転お
よび極低速回転時の黒鉛の排出量、低温始動時の白煙の
排出量を大巾に低減できると共に、着火遅れを短縮して
燃焼騒音を大巾に減少できる。0 The top of the piston is recessed to form a combustion chamber with a square horizontal cross section, and the side wall of this combustion chamber is overlapped with the downstream side of the arcuate course to form an arcuate recess along the axial direction, A fuel injection nozzle is installed to supply fuel spray to the upstream side of the swirl from the connection between the above-mentioned course part and the recessed part, so that the fuel film can be separated and premixed vaporization can be performed. The amount of graphite discharged and the amount of white smoke discharged during low-temperature startup can be significantly reduced, and ignition delay can be shortened to greatly reduce combustion noise.
第１図はこの発明の好適一実施例を示す断面図平面図、
第２図は第１図の■−■線断面図、第３図は他の実施例
を示す平面図、第４図は第３図のＩＶ −ＩＶ線断面図
、第５図は従来例を示す平面図である。
図中、１はピストン、２はピストンの頂部、４は燃焼室
、５は円弧状のコーナ部、８は側壁９は凹部、１０は燃
料噴射ノズル、Ｓはスワ−１
ｆは燃料噴霧である。FIG. 1 is a cross-sectional plan view showing a preferred embodiment of the present invention;
Fig. 2 is a sectional view taken along the line ■-■ of Fig. 1, Fig. 3 is a plan view showing another embodiment, Fig. 4 is a sectional view taken along the line IV-IV of Fig. 3, and Fig. 5 shows the conventional example. FIG. In the figure, 1 is the piston, 2 is the top of the piston, 4 is the combustion chamber, 5 is the arc-shaped corner, 8 is the side wall 9 is the recess, 10 is the fuel injection nozzle, S is the swath, and f is the fuel spray. .
Claims (1)
を形成すると共に、該燃焼室の側壁に円弧状コーナ部の
下流側とラップさせて軸方向に沿う円弧状の凹部を形成
し、上記コーナ部と凹部との接続部よりスワール上流側
へ燃料噴霧を供給する燃料噴射ノズルを配設したことを
特徴とする内燃機関の燃焼室。1. The top of the piston is recessed to form a combustion chamber with a square horizontal cross section, and the side wall of the combustion chamber is overlapped with the downstream side of the arc-shaped corner to form an arc-shaped recess along the axial direction. A combustion chamber for an internal combustion engine, characterized in that a fuel injection nozzle is provided for supplying fuel spray to a swirl upstream side from a connection part between a corner part and a recessed part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1331135A JPH03194117A (en) | 1989-12-22 | 1989-12-22 | Combustion chamber for internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1331135A JPH03194117A (en) | 1989-12-22 | 1989-12-22 | Combustion chamber for internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH03194117A true JPH03194117A (en) | 1991-08-23 |
Family
ID=18240262
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1331135A Pending JPH03194117A (en) | 1989-12-22 | 1989-12-22 | Combustion chamber for internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH03194117A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020084550A (en) * | 2001-05-03 | 2002-11-09 | 현대자동차주식회사 | Piston structure of diesel engine |
| WO2018168692A1 (en) * | 2017-03-17 | 2018-09-20 | マツダ株式会社 | Diesel engine |
-
1989
- 1989-12-22 JP JP1331135A patent/JPH03194117A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20020084550A (en) * | 2001-05-03 | 2002-11-09 | 현대자동차주식회사 | Piston structure of diesel engine |
| WO2018168692A1 (en) * | 2017-03-17 | 2018-09-20 | マツダ株式会社 | Diesel engine |
| JP2018155161A (en) * | 2017-03-17 | 2018-10-04 | マツダ株式会社 | diesel engine |
| CN110382835A (en) * | 2017-03-17 | 2019-10-25 | 马自达汽车株式会社 | Diesel engine |
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