JPH04175437A - In-cylinder injection type two-cycle internal combustion engine - Google Patents
In-cylinder injection type two-cycle internal combustion engineInfo
- Publication number
- JPH04175437A JPH04175437A JP29991290A JP29991290A JPH04175437A JP H04175437 A JPH04175437 A JP H04175437A JP 29991290 A JP29991290 A JP 29991290A JP 29991290 A JP29991290 A JP 29991290A JP H04175437 A JPH04175437 A JP H04175437A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- fuel injection
- valve
- injection valve
- injected
- 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
- 238000002347 injection Methods 0.000 title claims abstract description 156
- 239000007924 injection Substances 0.000 title claims abstract description 156
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 52
- 239000000446 fuel Substances 0.000 claims abstract description 238
- 239000007921 spray Substances 0.000 claims description 31
- 239000000203 mixture Substances 0.000 abstract description 14
- 238000009792 diffusion process Methods 0.000 abstract description 3
- 239000000779 smoke Substances 0.000 abstract description 3
- 238000007664 blowing Methods 0.000 abstract 1
- 238000005507 spraying Methods 0.000 abstract 1
- 230000002093 peripheral effect Effects 0.000 description 8
- 230000006835 compression Effects 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 238000009834 vaporization Methods 0.000 description 4
- 230000008016 vaporization Effects 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 238000013459 approach Methods 0.000 description 2
- 230000002238 attenuated effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000008240 homogeneous mixture Substances 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
- F02F1/00—Cylinders; Cylinder heads
- F02F1/24—Cylinder heads
- F02F1/42—Shape or arrangement of intake or exhaust channels in cylinder heads
- F02F1/4214—Shape or arrangement of intake or exhaust channels in cylinder heads specially adapted for four or more valves per cylinder
-
- 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
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- 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
- F02B75/00—Other engines
- F02B75/12—Other methods of operation
- F02B2075/125—Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
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)
- Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)
Abstract
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は筒内噴射式２サイクル内燃機関に関する。[Detailed description of the invention] [Industrial application field] The present invention relates to a direct injection two-stroke internal combustion engine.
燃焼室内に１個の燃料噴射弁を配置し、ピストン頂面上
に凹溝を形成してこの凹溝内に噴射された燃料を点火栓
により着火するようにし、機関中負荷運転時において燃
料噴射弁から吸気行程と圧縮行程とに分割して夫々凹溝
に向けて燃料を噴射するようにした筒内噴射式４サイク
ル内燃機関が公知である（特開平２−１６９８３４号公
報参照）。この筒内噴射式４サイクル内燃機関では機関
中負荷運転時に、圧縮行程において噴射された燃料によ
り点火栓近傍に形成された比較的濃い混合気によって良
好な着火が得られると共に、吸気行程において噴射され
た燃料により筒内全体に形成された火炎伝播用の希薄混
合気によって空気利用率の高い燃焼が得られる。One fuel injector is placed in the combustion chamber, a groove is formed on the top surface of the piston, and the fuel injected into the groove is ignited by a spark plug. A four-stroke internal combustion engine with direct injection is known in which fuel is injected from a valve into a groove in an intake stroke and a compression stroke, respectively (see Japanese Patent Laid-Open No. 2-169834). In this direct-injection four-stroke internal combustion engine, when the engine is operated under medium load, good ignition is achieved by a relatively rich mixture formed near the spark plug by the fuel injected during the compression stroke, and the fuel injected during the intake stroke provides good ignition. Combustion with a high air utilization rate can be achieved due to the lean mixture for flame propagation that is formed throughout the cylinder by the fuel.
しかしながら筒内噴射式２サイクル内燃機関では上述の
筒内噴射式４サイクル内燃機関のように中負荷運転時に
おいて機関１サイクル中に１個の燃料噴射弁から２回に
分けて燃料を噴射しようとすると次のような問題を生ず
る。即ち、２サイクル内燃機関では４サイクル内燃機関
に比べて機関の１サイクルの時間が短（なるので、１個
の燃料噴射弁から２回に分けて燃料を噴射するためには
非常に応答性の速い燃料噴射弁を用いなければならず、
従って燃料噴射弁のコストが高くなってしまうという問
題がある。また、２サイクル内燃機関では４サイクル内
燃機関に比べて第１回目の燃料噴射から燃焼開始までの
期間が短い。このため、噴霧角の狭い燃料噴射弁を用い
た場合には、噴射燃料が拡散しにくく且つ燃焼開始まで
の期間が短いために第１回目の噴射燃料と空気とが筒内
全体に亘って十分にミキシングされず、その結果燃焼が
悪化して出力が低下してしまうという問題を生ずる。一
方、第１回目の噴射燃料と空気とのミキシングが良好に
行われるように噴霧角の広い燃料噴射弁を用いると今度
は、第２回目の噴射燃料の一部が拡散力が大きいために
ピストン頂面上に形成された凹溝内部から逃げてしまい
、その結果点火栓の周りに集まる燃料が少くなる。従っ
て良好な着火性能を確保するために第２回目の燃料噴射
量を増大させる必要が生じ、斯（して燃料消費率が悪化
するという問題を生ずる。このように筒内噴射式２サイ
クル内燃機関では１個の燃料噴射弁から２回に分けて燃
料を噴射しようとすると種々の問題が生じることになる
。However, in a direct injection type two-stroke internal combustion engine, like the above-mentioned direct injection type four-stroke internal combustion engine, during medium load operation, fuel is injected twice from one fuel injection valve during one engine cycle. Then, the following problem arises. In other words, in a 2-stroke internal combustion engine, the time for one cycle of the engine is shorter than in a 4-stroke internal combustion engine, so in order to inject fuel in two parts from one fuel injector, the response must be very high. fast fuel injectors must be used,
Therefore, there is a problem that the cost of the fuel injection valve becomes high. Furthermore, in a two-stroke internal combustion engine, the period from the first fuel injection to the start of combustion is shorter than that in a four-stroke internal combustion engine. For this reason, when a fuel injector with a narrow spray angle is used, the injected fuel is difficult to diffuse and the period until the start of combustion is short, so that the first injected fuel and air are sufficient to cover the entire cylinder. This results in poor combustion and reduced output. On the other hand, if a fuel injector with a wide spray angle is used to ensure good mixing of the first injected fuel and air, a portion of the second injected fuel will have a large dispersion force, causing the piston to drop to the piston. The fuel escapes from inside the groove formed on the top surface, resulting in less fuel collecting around the spark plug. Therefore, in order to ensure good ignition performance, it becomes necessary to increase the amount of fuel injected at the second time, resulting in the problem of deterioration of the fuel consumption rate. If fuel is to be injected twice from one fuel injection valve, various problems will occur.
上記問題点を解決するために本発明によれば燃焼室内に
燃料噴射弁を配置して少くとも機関中負荷運転時に燃料
噴射弁から２回に分けて燃料を噴射するようにした筒内
噴射式２サイクル内燃機関において、噴霧角の広い第１
の燃料噴射弁と噴霧角の狭い第２の燃料噴射弁とを具備
し、ピストン頂面上に凹溝を形成して凹溝内に噴射され
た燃料を点火栓により着火するようにし、排気弁が閉弁
する前後において第１燃料噴射弁から第１回目の噴射を
行うと共にその後第２燃料噴射弁から凹溝に向けて第２
回目の噴射を行うようにしている。In order to solve the above problems, the present invention provides a direct injection type in which a fuel injection valve is disposed within the combustion chamber and fuel is injected from the fuel injection valve in two parts at least during engine medium load operation. In a two-stroke internal combustion engine, the first one with a wide spray angle
and a second fuel injection valve with a narrow spray angle, a concave groove is formed on the top surface of the piston so that the fuel injected into the concave groove is ignited by a spark plug, and an exhaust valve is provided. Before and after the valve closes, the first injection is performed from the first fuel injection valve, and after that, the second injection is made from the second fuel injection valve toward the concave groove.
I am trying to perform the second injection.
噴霧角の広い第１燃料噴射弁から噴射された第１回目の
燃料噴射により、燃料と空気とが良好にミキシングされ
た火炎伝播用の均質な混合気が筒内全体に形成される。By the first fuel injection from the first fuel injection valve having a wide spray angle, a homogeneous air-fuel mixture for flame propagation in which fuel and air are well mixed is formed throughout the cylinder.
また、第１回目の噴射を排気弁の閉弁する前後において
行うことにより噴射燃料が排気弁を介して吹き抜けるこ
とがない。更に、その後噴霧角の狭い第２燃料噴射弁か
ら凹溝に向けて噴射された第２回目の噴射燃料が凹溝に
より点火栓の周りに集められ、斯くして点火栓の周りに
比較的濃い点火用の混合気が形成される。Furthermore, by performing the first injection before and after the exhaust valve closes, the injected fuel will not blow through through the exhaust valve. Furthermore, the second injection fuel, which is then injected from the second fuel injection valve with a narrow spray angle toward the groove, is collected around the ignition plug by the groove, and is thus relatively concentrated around the ignition plug. A mixture for ignition is formed.
第１図および第３図を参照すると、１はシリンダブロッ
ク、２はシリンダブロック１内で往復動するピストン、
３はシリンダブロック１上に固定されたシリンダヘッド
、４はシリンダヘッド３の内壁面３ａとピストン２の頂
面間に形成された燃焼室を夫々示す。シリンダヘッド内
壁面３ａ上には凹溝５が形成され、この凹溝５の底壁面
をなすシリンダヘッド内壁面部分３ｂ上に一対の給気弁
６が配置される。一方、凹溝５を除くシリンダヘッド内
壁面部分３ｃは傾斜したほぼ平坦をなし、このシリンダ
ヘッド内壁面部分３ｃ上に一対の排気弁７が配置される
。シリンダヘッド内壁面部分３ｂとシリンダヘッド内壁
面部分３ｃは凹溝５の周壁８を介して互いに接続されて
いる。この凹溝周壁８は給気弁６の周縁部に極めて近接
配置されかつ給気弁６の周縁部に沿って円弧状に延びる
一対のマスク壁８ａと、給気弁６間に位置する新気ガイ
ド壁８ｂと、シリンダヘッド内壁面３ａの周壁と給気弁
６間に位置する一対の新気ガイド壁８Ｃとにより構成さ
れる。各マスク壁８ａは最大リフト位置にある給気弁６
よりも下方まで燃焼室４に向けて延びており、従って排
気弁７側に位置する給気弁６周縁部と弁座９間の開口は
給気弁６の開弁期間全体に亙ってマスク壁８ａにより閉
鎖されることになる。また、点火栓ｌＯはシリンダヘッ
ド内壁面３ａのほぼ中心に位置するようにシリンダヘッ
ド内壁面部分３ｃ上に配置されている。Referring to FIGS. 1 and 3, 1 is a cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
Reference numeral 3 indicates a cylinder head fixed on the cylinder block 1, and reference numeral 4 indicates a combustion chamber formed between the inner wall surface 3a of the cylinder head 3 and the top surface of the piston 2. A recessed groove 5 is formed on the cylinder head inner wall surface 3a, and a pair of air supply valves 6 are arranged on the cylinder head inner wall surface portion 3b forming the bottom wall surface of the recessed groove 5. On the other hand, the cylinder head inner wall surface portion 3c excluding the groove 5 is inclined and substantially flat, and a pair of exhaust valves 7 are arranged on this cylinder head inner wall surface portion 3c. The cylinder head inner wall surface portion 3b and the cylinder head inner wall surface portion 3c are connected to each other via the peripheral wall 8 of the groove 5. This concave groove peripheral wall 8 is arranged very close to the peripheral edge of the air supply valve 6 and extends in an arc shape along the peripheral edge of the air supply valve 6. It is constituted by a guide wall 8b and a pair of fresh air guide walls 8C located between the peripheral wall of the cylinder head inner wall surface 3a and the air supply valve 6. Each mask wall 8a has an air supply valve 6 in its maximum lift position.
The opening between the peripheral edge of the intake valve 6 and the valve seat 9 located on the exhaust valve 7 side is masked throughout the opening period of the intake valve 6. It will be closed by the wall 8a. Further, the ignition plug IO is arranged on the cylinder head inner wall surface portion 3c so as to be located approximately at the center of the cylinder head inner wall surface 3a.
一方、排気弁７に対しては排気弁７と弁座１１間の開口
を覆うマスク壁が設けられておらず、従って排気弁７が
開弁すると排気弁７と弁座１１間に形成される開口はそ
の全体が燃焼室４内に開口することになる。On the other hand, the exhaust valve 7 is not provided with a mask wall that covers the opening between the exhaust valve 7 and the valve seat 11. Therefore, when the exhaust valve 7 opens, a mask wall is formed between the exhaust valve 7 and the valve seat 11. The entire opening opens into the combustion chamber 4.
シリンダヘッド３内には給気弁６に対して給気ポート１
２が形成され、排気弁７に対して排気ポート１３が形成
される。また、一対の給気弁６近傍のシリンダヘッド内
壁面３ａの周縁部には噴霧角の広い第１の燃料噴射弁１
４ａと噴霧角の狭い第２の燃料噴射弁１４ｂとが夫々配
置される。これら第１燃料噴射弁１４ａと第２燃料噴射
弁１４ｂとは互いに平行をなしてシリンダヘッド３に取
付けられ、第１燃料噴射弁１４ａおよび第２燃料噴射弁
１４ｂから燃料が燃焼室４内に向けて噴射される。In the cylinder head 3, there is an air intake port 1 for the air intake valve 6.
2 is formed, and an exhaust port 13 is formed for the exhaust valve 7. Further, a first fuel injection valve 1 having a wide spray angle is provided at the peripheral edge of the cylinder head inner wall surface 3a near the pair of intake valves 6.
4a and a second fuel injection valve 14b having a narrow spray angle are respectively arranged. The first fuel injection valve 14a and the second fuel injection valve 14b are attached to the cylinder head 3 in parallel with each other, and the fuel is directed into the combustion chamber 4 from the first fuel injection valve 14a and the second fuel injection valve 14b. is injected.
第５図に第１燃料噴射弁１４ａの先端部の構造を示す。FIG. 5 shows the structure of the tip of the first fuel injection valve 14a.
第５図を参照すると、２０はノズル、２１はノズル２０
内に挿入されたニードル、２２はノズル２０とニードル
２１間に形成された燃料室を夫々示す。ニードル大径部
２１ａの外周面上にはスリット２３がノズル２０の軸線
に対して斜めに形成されている。図示しないソレノイド
が付勢され、ニードル２１が上昇して弁部２４が弁座部
２５から離れると、スリット２３によってスワール（旋
回流）が与えられた燃料噴霧流がノズル口２６から旋回
しなから噴霧角の広い円錐状をなして噴射される。この
噴霧角α１は４０°から６０°程度である。なお、第４
図および第１０図に示されるように噴射燃料の噴射軸線
Ｚａが点火栓１０の下方に向くように、ノズル口２６は
ノズル２０の軸線に対して斜めに指向している。Referring to FIG. 5, 20 is a nozzle, 21 is a nozzle 20
The needles 22 inserted therein indicate the fuel chambers formed between the nozzle 20 and the needle 21, respectively. A slit 23 is formed obliquely with respect to the axis of the nozzle 20 on the outer peripheral surface of the needle large diameter portion 21a. When a solenoid (not shown) is energized and the needle 21 is raised and the valve part 24 is separated from the valve seat part 25, the fuel spray flow, which has been swirled by the slit 23, does not swirl from the nozzle port 26. It is sprayed in a conical shape with a wide spray angle. This spray angle α1 is about 40° to 60°. In addition, the fourth
As shown in the drawings and FIG. 10, the nozzle opening 26 is oriented obliquely to the axis of the nozzle 20 so that the injection axis Za of the injected fuel is directed below the ignition plug 10.
第６図に第２燃料噴射弁１４ｂの先端部の構造を示す。FIG. 6 shows the structure of the tip of the second fuel injection valve 14b.
第６図を参照すると、３０はノズル、３１はノズル３０
内に挿入されたニードル、３２はノズル３０とニードル
３１間に形成された燃料室を夫々示す。図示しないソレ
ノイドが付勢され、ニードル３１が上昇して弁部３４が
弁座部３５から離れると、燃料がノズル口３６から噴霧
角の狭い比較的棒状をなして噴射される。この噴霧角α
ゎは５°から１０’程度である。なお、第４図および第
９図（Ａ）に示されるように噴射燃料の噴射軸線Ｚ、が
点火栓１０の下方に向くように、ノズル口３６はノズル
３０の軸線に対して斜めに指向している。Referring to FIG. 6, 30 is a nozzle, 31 is a nozzle 30
The needles 32 inserted therein indicate fuel chambers formed between the nozzle 30 and the needle 31, respectively. When a solenoid (not shown) is energized and the needle 31 is raised and the valve portion 34 is separated from the valve seat portion 35, fuel is injected from the nozzle port 36 in a relatively rod-like shape with a narrow spray angle. This spray angle α
ゎ is about 5° to 10'. The nozzle port 36 is oriented diagonally with respect to the axis of the nozzle 30 so that the injection axis Z of the injected fuel is directed downward to the spark plug 10 as shown in FIGS. 4 and 9(A). ing.
第２図および第３図に示されるようにピストン２の頂面
上には点火栓１０の下方から第２燃料噴射弁１４ｂの先
端部の下方まで延びる凹溝１５が形成される。第２図お
よび第３図に示される実施例ではこの凹溝１５は点火栓
１０と第２燃料噴射弁１４ｂのノズル口３６とを含む垂
直平面に−Ｋに対して対称なほぼ球面状をなす。また、
ピストン２の頂面の中心部には凹溝１５よりも曲率の大
きな球面状をなす凹所１６が形成される。この凹所１６
も垂直平面に−に上に形成されており、この凹所１６は
凹溝１５の凹状内壁面の上方部に開口している。第３図
に示すように、ピストン２が上死点に達すると点火栓１
０が凹所１６内に侵入する。一方、凹所１６に関して第
１燃料噴射弁１４ａおよび第２燃料噴射弁１４ｂと反対
側のピストン２の頂面部分２ａは傾斜したほぼ平坦面か
ら形成され、第３図に示すようにピストン２が上死点に
達するとシリンダヘッド内壁面部分３ｃとピストン頂面
部分２ａ間にはスキッシュエリア１７が形成される。As shown in FIGS. 2 and 3, a groove 15 is formed on the top surface of the piston 2 and extends from below the ignition plug 10 to below the tip of the second fuel injection valve 14b. In the embodiment shown in FIGS. 2 and 3, this groove 15 has a substantially spherical shape symmetrical with respect to -K in a vertical plane that includes the spark plug 10 and the nozzle port 36 of the second fuel injection valve 14b. . Also,
A recess 16 having a spherical shape with a larger curvature than the recess groove 15 is formed in the center of the top surface of the piston 2 . This recess 16
The recess 16 is also formed above the vertical plane, and the recess 16 opens at the upper part of the recessed inner wall surface of the recess 15 . As shown in Fig. 3, when the piston 2 reaches the top dead center, the ignition plug 1
0 enters into the recess 16. On the other hand, the top surface portion 2a of the piston 2 on the opposite side of the first fuel injection valve 14a and the second fuel injection valve 14b with respect to the recess 16 is formed from an inclined, substantially flat surface, and as shown in FIG. When the top dead center is reached, a squish area 17 is formed between the cylinder head inner wall surface portion 3c and the piston top surface portion 2a.
第７図に示されるように第１図から第６図に示す実施例
では排気弁７が給気弁６よりも先に開弁し、排気弁７お
よび給気弁６がほぼ同時に閉弁する。また、第７図にお
いて１１は機関低負荷運転時における燃料噴射時期を示
しており、■１および■１□は機関中負荷運転時におけ
る燃料噴射時期を示しており、ＩｋｌおよびＩｈｚは機
関高負荷運転時における燃料噴射時期を示している。燃
料噴射Ｆ 、Ｉ＋＋＋４およびＩｈｚは第２燃料噴射弁
１４ｂによって行われる。一方、燃料噴射■、およびＩ
ｋｌは第１燃料噴射弁１４ａによって行われる。従って
第７図から機関低負荷運転時には圧縮行程中期に第２燃
料噴射弁１４ｂから燃料噴射１１が行われることがわか
る。また、機関中負荷運転時には２回に分けて燃料噴射
が行われ、即ち、排気弁７が閉弁する前後において第１
燃料噴射弁１４ａから第１回目の燃料噴射■、が行われ
ると共にその後圧縮行程中期において第２燃料噴射弁１
４ｂから第２回目の燃料噴射１１が行われることがわか
る。また、機関高負荷運転時には排気弁７が閉弁する前
後において第１燃料噴射弁１４ａからの燃料噴射１ｋｌ
および第２燃料噴射弁１４ｂからの燃料噴射風２がほぼ
同時に行われることがわかる。As shown in FIG. 7, in the embodiment shown in FIGS. 1 to 6, the exhaust valve 7 opens before the intake valve 6, and the exhaust valve 7 and the intake valve 6 close almost simultaneously. . Furthermore, in Fig. 7, 11 indicates the fuel injection timing when the engine is running at low load, ■1 and ■1□ indicate the fuel injection timing when the engine is running at medium load, and Ikl and Ihz indicate the timing when the engine is running at high load. It shows the fuel injection timing during operation. Fuel injections F 1 , I+++4 and Ihz are performed by the second fuel injection valve 14b. On the other hand, fuel injection ■, and I
kl is performed by the first fuel injection valve 14a. Therefore, it can be seen from FIG. 7 that during low-load engine operation, fuel injection 11 is performed from the second fuel injection valve 14b in the middle of the compression stroke. Also, during engine medium load operation, fuel injection is performed in two parts, that is, the first injection occurs before and after the exhaust valve 7 closes.
The first fuel injection (2) is performed from the fuel injection valve 14a, and then the second fuel injection valve 1 is injected in the middle of the compression stroke.
It can be seen from 4b that the second fuel injection 11 is performed. Also, during high-load engine operation, 1 kl of fuel is injected from the first fuel injection valve 14a before and after the exhaust valve 7 closes.
It can be seen that the fuel injection air 2 from the second fuel injection valve 14b is performed almost simultaneously.
次に第８図から第１２図を参照しつつ低負荷運転時、中
負荷運転時および高負荷運転時における噴射方式につい
て説明する。Next, injection methods during low load operation, medium load operation, and high load operation will be described with reference to FIGS. 8 to 12.
第８図に示すように給気弁６および排気弁７が開弁する
と給気弁６を介して燃焼室４内に空気が流入する。この
とき、排気弁７側の給気弁６の開口はマスク壁８ａによ
って覆われているので空気はマスク壁８ａと反対側の給
気弁６の開口から燃焼室４内に流入する。この空気は矢
印Ｗで示すように給気弁６下方のシリンダボア内壁面に
沿い下鋒し、次いでピストン２０頂面に沿い進んで排気
弁７下方のシリンダボア内壁面に沿い上昇し、斯くして
空気は燃焼室４内をループ状に流れることになる。この
ループ状に流れる空気Ｗによって燃焼室４内の既燃ガス
が排気弁７を介して排出され、更にこのループ状に流れ
る空気Ｗによって燃焼室４内には垂直面内で旋回する旋
回流Ｘが発生せじめられる。次いでピストン２が下死点
ＢＤＣを過ぎて上昇を開始し、暫らくすると排気弁７お
よび給気弁６がほぼ同時に閉弁する。このように排気弁
７および給気弁６がほぼ同時に閉弁すると矢印Ｘで示す
ように旋回している空気が給気ボー１−１２内に吹き返
すことがなく、従って旋回流Ｘが急激に減衰せしめられ
ることがなくなる。その結果、燃焼室４内に発生した旋
回流Ｘはそのまま強力に旋回し続けることになる。一方
、給気弁６および排気弁７が閉弁すると第１燃料噴射弁
１４ａまたは第２燃料噴射弁１４ｂからの燃料噴射が行
われる。As shown in FIG. 8, when the intake valve 6 and the exhaust valve 7 are opened, air flows into the combustion chamber 4 via the intake valve 6. At this time, since the opening of the intake valve 6 on the side of the exhaust valve 7 is covered by the mask wall 8a, air flows into the combustion chamber 4 from the opening of the intake valve 6 on the side opposite to the mask wall 8a. As shown by arrow W, this air flows downward along the inner wall surface of the cylinder bore below the intake valve 6, then advances along the top surface of the piston 20, and rises along the inner wall surface of the cylinder bore below the exhaust valve 7. flows in a loop inside the combustion chamber 4. The air W flowing in a loop causes the burnt gas in the combustion chamber 4 to be discharged through the exhaust valve 7, and the air W flowing in a loop causes a swirling flow X in the combustion chamber 4 that swirls in a vertical plane. occurs. Next, the piston 2 passes the bottom dead center BDC and begins to rise, and after a while, the exhaust valve 7 and the air supply valve 6 close almost simultaneously. In this way, when the exhaust valve 7 and the air supply valve 6 close almost simultaneously, the swirling air does not blow back into the air supply bow 1-12 as shown by the arrow X, and therefore the swirling flow X is rapidly attenuated. You will no longer be forced to do anything. As a result, the swirling flow X generated within the combustion chamber 4 continues to swirl strongly. On the other hand, when the intake valve 6 and the exhaust valve 7 are closed, fuel is injected from the first fuel injection valve 14a or the second fuel injection valve 14b.
第９図は機関低負荷運転時を示しており、第１０図およ
び第１１図は機関中負荷運転時を示しており、第１２図
は機関高負荷運転時を示している。FIG. 9 shows the engine running at a low load, FIGS. 10 and 11 show the engine running at a medium load, and FIG. 12 shows the engine running at a high load.
上述したように、スワール型の第１燃料噴射弁１４ａか
らは噴霧角α、の広い燃料噴霧が第４図および第１Ｏ図
に示すように旋回しつつ円錐状をなして点火栓１０の下
方に向けて噴射される。この燃料の噴霧は噴霧角α１が
広くかつ拡散力が大きい。As described above, from the swirl-type first fuel injection valve 14a, fuel spray with a wide spray angle α swirls and forms a conical shape below the ignition plug 10 as shown in FIGS. 4 and 1O. It is sprayed towards. This fuel spray has a wide spray angle α1 and a large dispersion force.
一方、ホール型の第２燃料噴射弁１４ｂからは噴霧角α
、の狭い比較的棒状の燃料が第４図および第９図（Ａ）
に示すように凹溝１５の凹状内壁面に向けて噴射される
。この噴射燃料の噴射軸線２．は第２図に示す垂直平面
に−に内に位置している。On the other hand, from the Hall-type second fuel injection valve 14b, the spray angle α
, a relatively narrow rod-shaped fuel is shown in Figures 4 and 9 (A).
As shown in FIG. The injection axis of this injected fuel 2. is located within the vertical plane shown in FIG.
この燃料の噴霧は噴霧角αゎが狭くかつ比較的貫徹力が
強い。This fuel spray has a narrow spray angle αゎ and relatively strong penetration power.
機関低負荷運転時には第９図（Ａ）に示されるように第
２燃料噴射弁１４ｂから燃料噴射ＩＩが行われ、噴射軸
線Ｚｂに沿う噴射燃料が鋭角θ１をなして斜めに凹溝１
５の凹状内壁面上に衝突する。During low-load engine operation, fuel injection II is performed from the second fuel injection valve 14b as shown in FIG.
It collides with the concave inner wall surface of No.5.
この噴射燃料は噴霧角α１が狭くかつ貫徹力が強いので
、すべての噴射燃料が凹溝１５内に確実にとらえられる
。このように噴射燃料が凹溝１５の凹状内壁面上に斜め
に衝突すると、衝突した燃料は第９図（Ｂ）においてＦ
で示されるように慣性力によって凹溝１５の凹状内壁面
に沿い気化しつつ点火栓１０の下方に進むと共に、凹溝
１５が垂直平面に−Ｋに対して対称なほぼ球面状をなす
のでこの球面形状の傾斜によって燃料が垂直平面に−に
の方に集められ、次いでこれらの燃料が凹所１６内に送
り込まれる。機関低負荷運転時には噴射量が少ないがこ
のとき大部分の噴射燃料が点火栓１０の下方に運ばれる
ので点火栓１０の周りには着火可能な混合気が形成され
ることになる。また、第８図に示されるように燃焼室４
内に発生した旋回流Ｘはピストン２が上昇するにつれて
減衰しつつ旋回半径が次第に小さくなり、ピストン２が
上死点に近づくと第９図（Ａ）に示されるように凹溝１
５の凹状内壁面に沿う旋回流Ｘとなる。少しずつ減衰す
ると云っても最初に強力な旋回流Ｘが発生せしめられて
いるので凹溝１５内に発生する旋回流Ｘはかなり強く、
噴射燃料はこの強力な旋回流Ｘによっても点火栓ｌＯの
下方に向かう力が与えられる。また、ピストン２が更に
上死点に近づくと第９図（Ｂ）において矢印Ｓで示すよ
うにスキッシュエリア１７からスキッシュ流が噴出し、
このスキッシュ流Ｓも凹溝１５の凹状内壁面に沿って進
む。従って噴射燃料はこのスキッシュ流Ｓによっても点
火栓１ｏの下方に向かう力が与えられる。また、凹溝１
５の凹状内壁面二こ沿い点火栓１０の下方に向かう燃Ｊ
４５よ旋回流Ｘおよびスキンシュ流Ｓによって気化せし
められ、斯くして点火栓１０の周りには十分に気化した
可燃混合気が集まることになる。斯くして噴射量が少な
い機関低負荷運転時であっても良好な着火と、それに続
く良好な燃料が得られることになる。Since this injected fuel has a narrow spray angle α1 and a strong penetrating force, all of the injected fuel is reliably captured within the groove 15. When the injected fuel obliquely collides with the concave inner wall surface of the concave groove 15 in this way, the collided fuel becomes F in FIG. 9(B).
As shown in the figure, the inertial force causes the gas to vaporize along the concave inner wall surface of the concave groove 15 and move downward to the ignition plug 10, and since the concave groove 15 forms a substantially spherical shape symmetrical to -K in the vertical plane, this occurs. The slope of the spherical shape concentrates the fuel towards the vertical plane, and these fuels are then pumped into the recess 16. When the engine is operating at low load, the injection amount is small, but at this time most of the injected fuel is carried below the ignition plug 10, so an ignitable air-fuel mixture is formed around the ignition plug 10. In addition, as shown in FIG. 8, the combustion chamber 4
The swirling flow X generated inside the piston 2 is attenuated as the piston 2 rises, and the swirl radius gradually becomes smaller, and as the piston 2 approaches the top dead center, the concave groove 1
5 becomes a swirling flow X along the concave inner wall surface. Although it is said to attenuate little by little, since a strong swirling flow X is generated at first, the swirling flow X generated in the groove 15 is quite strong.
This strong swirling flow X also gives the injected fuel a force directed downward toward the spark plug lO. Furthermore, as the piston 2 approaches the top dead center, a squish flow is ejected from the squish area 17 as shown by arrow S in FIG. 9(B).
This squish flow S also advances along the concave inner wall surface of the concave groove 15. Therefore, the squish flow S also gives the injected fuel a downward force to the ignition plug 1o. Also, groove 1
5 along the two concave inner wall surfaces of the ignition plug 10.
45, is vaporized by the swirling flow X and the Skinsch flow S, and thus a sufficiently vaporized combustible air-fuel mixture gathers around the spark plug 10. In this way, even when the engine is operating at low load with a small injection amount, good ignition and subsequent good fuel can be obtained.
次に機関中負荷運転時における燃料噴射方法について説
明する。機関中負荷運転時には上述したように排気弁７
が閉弁する前後において第１燃料噴射弁１４ａから第１
回目の燃料噴射Ｌｌが行われる。このように第１回目の
燃料噴射１ ｆｆｉ＋は排気弁７が閉弁する前後におい
て行われるので噴射燃料が排気弁７を介して排気ポー目
３内に吹き抜けることがない。また、この第１燃料噴射
弁１４ａからの噴射燃料は噴霧角α、が広くかつ拡散力
が大きく、第１回目の燃料噴射１１が行われるときには
第１０図に示されるようにピストン２の位置が低い。Next, a fuel injection method during engine medium load operation will be explained. During engine medium load operation, the exhaust valve 7
Before and after the first fuel injection valve 14a closes,
The second fuel injection Ll is performed. In this way, the first fuel injection 1 ffi+ is performed before and after the exhaust valve 7 closes, so that the injected fuel does not blow through into the exhaust port 3 through the exhaust valve 7. Further, the fuel injected from the first fuel injection valve 14a has a wide spray angle α and a large diffusion force, and when the first fuel injection 11 is performed, the position of the piston 2 is changed as shown in FIG. low.
従って噴射燃料はピストン２頂面の広い範囲に亘って衝
突せしめられることになる。このときピストン２は噴射
燃料によって冷却され、噴射燃料はピストン２から熱を
受けるために噴射燃料の気化が促進されることになる。Therefore, the injected fuel is made to collide over a wide range of the top surface of the piston 2. At this time, the piston 2 is cooled by the injected fuel, and since the injected fuel receives heat from the piston 2, vaporization of the injected fuel is promoted.
また、このとき燃焼室４内には第８図に示すような強力
な旋回流Ｘが発生しているので噴射燃料と空気とが良好
にミキシングされ、また噴射時期が早いために噴射燃料
に対して燃料が気化するのに十分な時間が与えられる。At this time, a strong swirling flow X as shown in Fig. 8 is generated in the combustion chamber 4, so the injected fuel and air are mixed well, and since the injection timing is early, the injected fuel This allows sufficient time for the fuel to vaporize.
従って点火栓１０による点火が行われる以前に燃焼室４
内に均一の混合気が形成されることになる。なお、燃料
噴射が２回に分けて行われるので第１回目の燃料噴射ｌ
。１によって燃焼室４内に形成される混合気はかなり稀
薄な混合気であり、従って燃焼室４内全体に火炎伝播用
のかなり稀薄な均一混合気が形成される。Therefore, before the spark plug 10 ignites, the combustion chamber 4
A uniform air-fuel mixture will be formed within. Note that the fuel injection is performed in two parts, so the first fuel injection l
. The mixture formed in the combustion chamber 4 by the combustion chamber 4 is a fairly lean mixture, and therefore a fairly lean homogeneous mixture for flame propagation is formed throughout the combustion chamber 4.
次いで第１１図に示されるように機関低負荷運転時に比
べてピストン２が低い位置にあるときに第２燃料噴射弁
１４ｂから第２回目の燃料噴射１１□が開始される。こ
のときには第１１図に示されるように噴射軸線Ｚｂに沿
う噴射燃料は凹溝１５の凹状内壁面上に角度θ２をなし
て衝突する。この衝突角度θ２は機関低負荷運転時の場
合の衝突角度θ１（第９図（Ａ）参照）よりも大きい。Next, as shown in FIG. 11, the second fuel injection 11□ is started from the second fuel injection valve 14b when the piston 2 is at a lower position than when the engine is operating at low load. At this time, as shown in FIG. 11, the injected fuel along the injection axis Zb collides with the concave inner wall surface of the groove 15 at an angle θ2. This collision angle θ2 is larger than the collision angle θ1 (see FIG. 9(A)) during low engine load operation.
また、この噴射燃料は噴霧角α、が狭くかつ貫徹力が強
いので、すべての噴射燃料が凹溝１５内に確実にとらえ
られる。このように噴射燃料が凹溝１５の凹状内壁面上
に比較的大きな角度θ２をなして衝突すると、衝突した
燃料は点火栓ｌＯの下方に向かう方向以外にも広がり、
即ち、衝突した燃料は噴射軸線Ｚｂに沿う噴射燃料の衝
突点を中心として凹溝１５の凹状内壁面上を比較的四方
に広がることになる。従ってこの場合には衝突した噴射
燃料の一部が点火栓１０の下方に進み、次いで凹所１６
内に送り込まれる。このように機関低負荷運転時に比べ
て噴射量の多い機関中負荷運転時には噴射燃料の一部が
点火栓１０の周りに送り込まれるので点火栓１０の周り
に形成される混合気は過濃とならず、斯くして点火栓１
０の周りには良好に着火可能な混合気が形成される。ま
た、機関中負荷運転時には噴射燃料が高温の凹溝１５の
凹状内壁面上に広範囲に分散されるので噴射燃料の気化
が促進され、しかも２回に分けて噴射されているために
凹溝１５内二こ噴射される燃料量が少ないので噴射燃料
は十分に気化せしめられる。従って凹溝１５内に噴射さ
れた燃料は十分な空気の存在下で燃焼せしめられるので
スモークが発生することがない。また、機関中負荷運転
時にも第９図（Ａ）に示すような旋回流Ｘおよび第９図
（Ｂ）に示すようなスキッシュ流Ｓが発生し、従ってこ
れら旋回流Ｘ−およびスキッシュ流Ｓによって噴射燃料
１１□と空気とが十分にミキシングされるのでスモーク
が発生することのない良好な燃焼を得ることができる。Further, since this injected fuel has a narrow spray angle α and a strong penetration force, all of the injected fuel is reliably captured within the groove 15. When the injected fuel collides with the concave inner wall surface of the concave groove 15 at a relatively large angle θ2, the collided fuel spreads in directions other than the downward direction of the ignition plug lO.
That is, the collided fuel spreads in relatively four directions on the concave inner wall surface of the concave groove 15 centering on the collision point of the injected fuel along the injection axis Zb. Therefore, in this case, a part of the collided injected fuel travels below the spark plug 10 and then into the recess 16.
sent inside. In this way, when the engine is operating at a medium load where the injection amount is larger than when the engine is operating at a low load, a portion of the injected fuel is sent around the spark plug 10, so the air-fuel mixture formed around the spark plug 10 does not become overrich. So, the spark plug 1
A mixture that can be ignited well is formed around 0. In addition, during medium load operation of the engine, the injected fuel is dispersed over a wide range on the high-temperature concave inner wall surface of the groove 15, so vaporization of the injected fuel is promoted. Since the amount of fuel injected is small, the injected fuel can be sufficiently vaporized. Therefore, the fuel injected into the groove 15 is combusted in the presence of sufficient air, so no smoke is generated. Furthermore, even during engine medium load operation, a swirling flow X as shown in FIG. 9(A) and a squishing flow S as shown in FIG. 9(B) are generated. Since the injected fuel 11□ and air are sufficiently mixed, it is possible to obtain good combustion without generating smoke.
このように機関中負荷運転時において２回に分けて燃料
噴射が行われ、排気弁７が閉弁する前後において噴霧角
の広い第１燃料噴射弁１４ａから第１回目の燃料噴射１
．が行われると共に、その後噴霧角の狭い第２燃料噴射
弁１４ｂから凹溝１５に向けて第２回目の燃料噴射１１
１Ｚが行われる。このように２回の燃料噴射に用いる燃
料噴射弁を使い分けることにより、第１回目の燃料噴射
Ｉ Ｉｌｌでは噴射燃料の噴霧角α１が広（かつ拡散力
が大きいので噴射燃料の気化が促進されると共に噴射燃
料と空気とのミキシングが促進される。その結果燃焼室
４内全体に火炎伝播用のかなり稀薄な均一混合気が形成
されることが促進される。、一方、第２回目の燃料噴射
Ｌ２では噴射燃料の噴霧角α５が狭くかつ貴徹力が強い
ので、噴射燃料が凹溝１５内から外に逃げ出すことが防
止されて噴射燃料が確実に凹溝１５内にとらえられる。In this way, fuel injection is performed in two times during engine medium load operation, and the first fuel injection 1 is performed from the first fuel injection valve 14a having a wide spray angle before and after the exhaust valve 7 closes.
．． is performed, and then a second fuel injection 11 is performed from the second fuel injection valve 14b with a narrow spray angle toward the groove 15.
1Z will be performed. By using different fuel injection valves for the two fuel injections in this way, the spray angle α1 of the injected fuel is wide (and the diffusion force is large, so vaporization of the injected fuel is promoted in the first fuel injection I Ill). At the same time, the mixing of the injected fuel and air is promoted.As a result, the formation of a fairly lean homogeneous mixture for flame propagation throughout the combustion chamber 4 is promoted.On the other hand, the second fuel injection At L2, the spray angle α5 of the injected fuel is narrow and the penetration force is strong, so the injected fuel is prevented from escaping from inside the groove 15 to the outside, and the injected fuel is reliably captured within the groove 15.
その結果点火栓ＩＯの周りに良好に着火可能な比較的濃
い混合気が形成されることが促進される。斯くして、良
好な着火とそれに続く空気利用率の高い良好な燃焼を得
ることができる。As a result, formation of a relatively rich air-fuel mixture that can be well ignited is promoted around the ignition plug IO. In this way, good ignition and subsequent good combustion with high air utilization can be obtained.
また、１個の燃料噴射弁からではなく、２個の燃料噴射
弁から２回に分けて燃料噴射を行うので、第１燃料噴射
弁１４ａおよび第２燃料噴射弁１４ｂは夫々さほど応答
性の速い燃料噴射弁である必要がなく、本実施例のよう
に通常のソレノイドにより駆動される型式の燃料噴射弁
を夫々用いることができる。また、２個の燃料噴射弁か
ら燃料噴射を行うので燃料噴射時間が多少長い場合でも
２回に分けた燃料噴射を吹き分けることが可能であり、
従って３ ＭＰａから１０ＭＰａ程度の比較的低い燃料
圧力でも適切な燃料噴射を行うことができる。Furthermore, since fuel is injected in two steps from two fuel injectors instead of from one fuel injector, the first fuel injector 14a and the second fuel injector 14b each have a relatively fast response. The fuel injection valves do not need to be fuel injection valves, and fuel injection valves of the type driven by ordinary solenoids can be used, as in this embodiment. In addition, since fuel is injected from two fuel injection valves, even if the fuel injection time is somewhat long, it is possible to separate the two separate fuel injections.
Therefore, appropriate fuel injection can be performed even at a relatively low fuel pressure of about 3 MPa to 10 MPa.
次に機関高負荷運転時における燃料噴射方法について説
明する。機関高負荷運転時には上述したように排気弁７
が閉弁する前後において第１１料噴射弁１４ａからの燃
料噴射１ｈｌおよび第２燃料噴射弁１４ｂからの燃料噴
射１ｋＺがほぼ同時に行われる。このように燃料噴射１
ｋｌおよびＩｈ２は排気弁７が閉弁する前後において行
われるので噴射燃料が排気弁７を介して排気ボート１３
内に吹き抜けることがない。また、燃料噴射１ｋｌおよ
びＩｈ２が行われるときには第１２図に示されるように
ピストン２の位置が低く、従って機関高負荷運転時に噴
射される多量の噴射燃料はピストン２頂面の広い範囲に
亘って衝突せしめられることになる。このときピストン
２は噴射燃料によって冷却され、噴射燃料はピストン２
から熱を受けるために噴射燃料の気化が促進されること
になる。また、このとき燃焼室４内には第８図に示すよ
うな強力な旋回流Ｘが発生しているので多量の噴射燃料
と空気とが良好にミキシングされ、また噴射時期が早い
ために多量の噴射燃料に対して燃料が気化するのに十分
な時間が与えられる。従って点火栓１０４こよる点火が
行われる以前に燃焼室４内全体に均一の混合気が形成さ
れ、斯くして所要の機関高出力を得ることができる。Next, a fuel injection method during high engine load operation will be explained. During high engine load operation, the exhaust valve 7
Before and after the valve closes, fuel injection 1hl from the eleventh fuel injection valve 14a and fuel injection 1kZ from the second fuel injection valve 14b are performed almost simultaneously. In this way fuel injection 1
Since kl and Ih2 are performed before and after the exhaust valve 7 closes, the injected fuel flows through the exhaust valve 7 to the exhaust boat 13.
There is no way to blow inside. Furthermore, when the fuel injections 1kl and Ih2 are performed, the piston 2 is at a low position as shown in FIG. They will be forced to collide. At this time, the piston 2 is cooled by the injected fuel, and the injected fuel
The vaporization of the injected fuel is promoted because it receives heat from the injected fuel. At this time, a strong swirling flow X as shown in Fig. 8 is generated in the combustion chamber 4, so a large amount of injected fuel and air are mixed well, and because the injection timing is early, a large amount of injected fuel is mixed well. Sufficient time is allowed for the injected fuel to vaporize. Therefore, a uniform air-fuel mixture is formed throughout the combustion chamber 4 before ignition by the spark plug 104, and thus the required high engine output can be obtained.
このように機関高負荷運転時において１個の燃料噴射弁
からではなく、２個の燃料噴射弁１４ａおよび１４ｂか
らほぼ同時に燃料噴射ＩｈｌおよびＩｈ２を行うので、
機関高負荷運転時における夫々の燃料噴射弁１４ａ、１
４ｂからの燃料噴射量が少くて済む。従って各燃料噴射
弁１４ａ、１４ｂについて、機関低負荷運転時から機関
高負荷運転時に亘る運転状態において噴射される燃料噴
射量の最大値と最小値との比率を小さくすることができ
る。その結果、機関の各運転状態における燃料噴射量（
燃料噴射時間）を精度良く制御することができる。In this way, during high-load engine operation, fuel injections Ihl and Ih2 are performed almost simultaneously from two fuel injection valves 14a and 14b, rather than from one fuel injection valve.
Respective fuel injection valves 14a, 1 during high engine load operation
The amount of fuel injected from 4b can be small. Therefore, for each of the fuel injection valves 14a, 14b, it is possible to reduce the ratio between the maximum value and the minimum value of the amount of fuel injected in the operating state ranging from engine low load operation to engine high load operation. As a result, the fuel injection amount (
fuel injection time) can be controlled with high precision.
また、第１図に示されるように第１燃料噴射弁１４ａお
よび第２燃料噴射弁１４ｂは互いに平行をなして同し取
付角度でシリンダヘット３に取付けられている。従って
、第１燃料噴射弁１４ａおよび第２燃料噴射弁１４ｂに
燃料を分配するための一体の燃料分配管を用いることが
できる。その結果、第１燃料噴射弁１４ａおよび第２燃
料噴射弁１４ｂに燃料を供給するための配管の組付けが
容易になるばかりでなく、配管の取付はスペースも小さ
くすることができる。このことは本実施例を多気筒内燃
機関に用いた場合に特に有利な点である。Further, as shown in FIG. 1, the first fuel injection valve 14a and the second fuel injection valve 14b are mounted on the cylinder head 3 in parallel with each other and at the same mounting angle. Therefore, an integral fuel distribution pipe can be used to distribute fuel to the first fuel injector 14a and the second fuel injector 14b. As a result, it is not only easy to assemble the piping for supplying fuel to the first fuel injection valve 14a and the second fuel injection valve 14b, but also the installation space for the piping can be reduced. This is particularly advantageous when this embodiment is used in a multi-cylinder internal combustion engine.
なお、本実施例では噴霧角の広い第１燃料噴射弁１４ａ
として第５図に示されるスワール型の燃料噴射弁を用い
た。第５図に示す実施例ではスリット２３によって燃料
流にスワールを与えているが、他の手段によってスワー
ルを与えるようにしてもよい。更に、噴射燃料流にスワ
ールを与えることなく広い噴霧角を有する燃料噴射弁を
第１燃料噴射弁１４ａとして用いることができる。Note that in this embodiment, the first fuel injection valve 14a with a wide spray angle
A swirl type fuel injection valve shown in FIG. 5 was used as the fuel injection valve. In the embodiment shown in FIG. 5, swirl is imparted to the fuel flow by the slit 23, but swirl may be imparted by other means. Furthermore, a fuel injection valve having a wide spray angle without swirling the injected fuel flow can be used as the first fuel injection valve 14a.
なお、これまで第１図に示すように２個の給気弁６およ
び２個の排気弁７を具えた２サイクル内燃機関に本発明
を適用した実施例について説明してきた。しかしながら
給気弁６の個数および排気弁７の個数はこれに限定され
ず、例えば第１３図に示すように３個の給気弁６および
３個の排気弁７を具えた２サイクル内燃機関にも本発明
を同様に適用することができる。Note that, so far, an embodiment has been described in which the present invention is applied to a two-stroke internal combustion engine equipped with two intake valves 6 and two exhaust valves 7 as shown in FIG. However, the number of intake valves 6 and the number of exhaust valves 7 are not limited to this. For example, as shown in FIG. The present invention can also be applied in the same manner.
［発明の効果］
機関中負荷運転時に第１回目の噴射を排気弁が閉弁する
前後において第１燃料噴射弁から行い、その後第２回目
の噴射を第２燃料噴射弁からピストン頂面に形成した凹
溝内に行うことによって、燃料が吹き抜けることがなく
、良好な着火とそれに続く空気利用率の高い良好な燃焼
を得ることができる。[Effect of the invention] During engine medium load operation, the first injection is performed from the first fuel injection valve before and after the exhaust valve closes, and then the second injection is formed from the second fuel injection valve on the top surface of the piston. By doing so in the groove, the fuel does not blow through, and it is possible to obtain good ignition and subsequent good combustion with a high air utilization rate.
第１図は２サイクル内燃機関のシリンダヘッドの底面図
、第２図はピストンの平面図、第３図は第１図のｍ−ｍ
ｌに沿ってみた断面図、第４図は燃料噴射方向を示した
シリンダヘッドの底面図、第５図は第１燃料噴射弁の先
端部の構造を示す断面図、第６図は第２燃料噴射弁の先
端部の構造を示す断面図、第７図は給排気弁の開弁時期
および燃料噴射時期を示す線図、第８図は機関運転中の
燃焼室内の様子を示す第１図の■−■線に沿ってみた断
面図、第９図は機関低負荷運転時における燃焼室内の様
子を説明するための第１図の■−■線に沿ってみた断面
図、第１０図は機関中負荷運転時の第１回目の燃料噴射
における燃焼室内の様子を説明するための第１図のＸ−
Ｘ線に沿ってみた断面図、第１１図は機関中負荷運転時
の第２回目の燃料噴射における燃焼室内の様子を説明す
るための第１図の■−■線に沿ってみた断面図、第１２
図は機関高負荷運転時における燃焼室内の様子を説明す
るための第１図のＸ−Ｘ線に沿ってみた断面図、第１３
図は別の実施例におけるシリンダヘットの底面図である
。
２・・・ピストン、 ４・・・燃焼室、６・・・
給気弁、 ７・・・排気弁、１０・・・点火栓、
１４ａ・・・第１の燃料噴射弁、１４ｂ・・・
第２の燃料噴射弁、
１５・・・凹溝、 １６・・・凹所。Figure 1 is a bottom view of the cylinder head of a two-stroke internal combustion engine, Figure 2 is a plan view of the piston, and Figure 3 is m-m of Figure 1.
4 is a bottom view of the cylinder head showing the fuel injection direction, FIG. 5 is a sectional view showing the structure of the tip of the first fuel injector, and FIG. 6 is a sectional view of the second fuel injection valve. FIG. 7 is a cross-sectional view showing the structure of the tip of the injection valve, FIG. 7 is a line diagram showing the opening timing of the intake and exhaust valves and fuel injection timing, and FIG. 8 is a diagram showing the inside of the combustion chamber during engine operation. Figure 9 is a sectional view taken along the line ■-■ in Figure 1 to explain the state inside the combustion chamber during low engine load operation, Figure 10 is the engine taken along the line ■-■. X- in Figure 1 to explain the state inside the combustion chamber during the first fuel injection during medium load operation
Fig. 11 is a sectional view taken along the line ■-■ of Fig. 1 for explaining the state inside the combustion chamber during the second fuel injection during engine medium load operation; 12th
The figure is a sectional view taken along the line X-X of Figure 1 to explain the state inside the combustion chamber during high-load engine operation,
The figure is a bottom view of a cylinder head in another embodiment. 2...Piston, 4...Combustion chamber, 6...
Air supply valve, 7... Exhaust valve, 10... Spark plug,
14a...first fuel injection valve, 14b...
Second fuel injection valve, 15...concave groove, 16...concavity.
Claims (1)
転時に燃料噴射弁から２回に分けて燃料を噴射するよう
にした筒内噴射式２サイクル内燃機関において、噴霧角
の広い第１の燃料噴射弁と噴霧角の狭い第２の燃料噴射
弁とを具備し、ピストン頂面上に凹溝を形成して凹溝内
に噴射された燃料を点火栓により着火するようにし、排
気弁が閉弁する前後において上記第１燃料噴射弁から第
１回目の噴射を行うと共にその後上記第２燃料噴射弁か
ら該凹溝に向けて第２回目の噴射を行うようにした筒内
噴射式２サイクル内燃機関。In a direct injection type two-stroke internal combustion engine in which a fuel injection valve is arranged in the combustion chamber and fuel is injected from the fuel injection valve in two parts at least during engine medium load operation, the first type with a wide spray angle is used. It is equipped with a fuel injection valve and a second fuel injection valve with a narrow spray angle, a concave groove is formed on the top surface of the piston, and the fuel injected into the concave groove is ignited by a spark plug. A two-cycle in-cylinder injection type in which a first injection is performed from the first fuel injection valve before and after closing, and a second injection is then performed from the second fuel injection valve toward the groove. Internal combustion engine.
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29991290A JPH04175437A (en) | 1990-11-07 | 1990-11-07 | In-cylinder injection type two-cycle internal combustion engine |
| EP91110534A EP0463613B1 (en) | 1990-06-27 | 1991-06-26 | A two-stroke engine |
| DE69113329T DE69113329T2 (en) | 1990-06-27 | 1991-06-26 | Two stroke internal combustion engine. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29991290A JPH04175437A (en) | 1990-11-07 | 1990-11-07 | In-cylinder injection type two-cycle internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04175437A true JPH04175437A (en) | 1992-06-23 |
Family
ID=17878431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29991290A Pending JPH04175437A (en) | 1990-06-27 | 1990-11-07 | In-cylinder injection type two-cycle internal combustion engine |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04175437A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003049651A (en) * | 2001-08-02 | 2003-02-21 | Nissan Motor Co Ltd | Cylinder direct-injection engine |
-
1990
- 1990-11-07 JP JP29991290A patent/JPH04175437A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003049651A (en) * | 2001-08-02 | 2003-02-21 | Nissan Motor Co Ltd | Cylinder direct-injection engine |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5327864A (en) | Stratified-charge internal combustion engine with fuel injection and dual ignition | |
| JP3163906B2 (en) | In-cylinder injection spark ignition engine | |
| US5115776A (en) | Internal combustion engine | |
| KR100471202B1 (en) | Gasoline direct injection | |
| US5140958A (en) | Two-stroke engine | |
| US6338327B1 (en) | Combustion chamber structure of in-cylinder direct fuel injection engine | |
| US6269790B1 (en) | Combustion chamber for DISI engines with exhaust side piston bowl | |
| US6708667B2 (en) | Combustion chamber structure of in-cylinder fuel injection type engine | |
| JP3896605B2 (en) | Direct in-cylinder spark ignition engine | |
| JP2007162631A (en) | Control device of internal combustion engine | |
| JP2841748B2 (en) | In-cylinder two-stroke internal combustion engine | |
| US6070566A (en) | Piston for direct injection combustion chamber used in internal combustion engine | |
| JPH04166612A (en) | Cylinder injection type internal combustion engine | |
| JPH04224231A (en) | Inner cylinder injection type internal combustion engine | |
| JP2841791B2 (en) | Fuel injection type internal combustion engine | |
| JPH0494413A (en) | Two-stroke diesel engine | |
| JPH04370319A (en) | Cylinder fuel injection type internal combustion engine | |
| JPH04175437A (en) | In-cylinder injection type two-cycle internal combustion engine | |
| JP3799675B2 (en) | In-cylinder direct injection spark ignition engine | |
| JPH09242550A (en) | Spark ignition engine of direct cylinder fuel injection type | |
| JPH04112904A (en) | Combustion chamber of 2-cycle internal combustion engine | |
| JP2936806B2 (en) | In-cylinder internal combustion engine | |
| JPH0510137A (en) | Cylinder injection type internal combustion engine | |
| JP3820688B2 (en) | In-cylinder direct injection spark ignition engine | |
| JP2828093B2 (en) | In-cylinder internal combustion engine |