JP3912641B2 - Fuel injection nozzle - Google Patents

Fuel injection nozzle Download PDF

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Publication number
JP3912641B2
JP3912641B2 JP24697698A JP24697698A JP3912641B2 JP 3912641 B2 JP3912641 B2 JP 3912641B2 JP 24697698 A JP24697698 A JP 24697698A JP 24697698 A JP24697698 A JP 24697698A JP 3912641 B2 JP3912641 B2 JP 3912641B2
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Prior art keywords
fuel
fuel injection
injection
valve member
nozzle
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JP24697698A
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JP2000073915A (en
Inventor
展久 掛橋
崇満 伊藤
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Denso Corp
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Denso Corp
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Priority to JP24697698A priority Critical patent/JP3912641B2/en
Priority to DE1999141357 priority patent/DE19941357A1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/06—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series the valves being furnished at seated ends with pintle or plug shaped extensions

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Electrical Control Of Air Or Fuel Supplied To Internal-Combustion Engine (AREA)

Description

【０００１】
【発明の属する技術分野】
エンジン負荷に応じて噴霧角を調整する燃料噴射ノズルに関する。
【０００２】
【従来の技術】
噴孔を開閉する弁部材のリフト量が所定量以下の場合に燃料噴射量を抑えて初期噴射を行い、弁部材のリフト量が所定量を越えると燃料噴射量を増加して主噴射を行う燃料噴射ノズルとして、実開昭５９−１４１１６４号公報および特開昭６０−１１９３６８号公報に開示されるものが知られている。このような燃料噴射ノズルでは、初期噴射において予め少量の燃料を噴射して燃焼させておくことにより、主噴射における急激な燃焼を防止しエンジンからの騒音発生を防止している。前述した両公報に開示される燃料噴射ノズルは、弁部材のリフト量が小さい初期噴射において噴霧角を大きくし、弁部材のリフト量が大きい主噴射において噴霧角を小さくしている。以下、噴霧角の大きい噴射を広角噴射、噴霧角の小さい噴射を狭角噴射という。
【０００３】
エンジンの低負荷時において少量の燃料を噴射し、エンジンの高負荷時において低負荷時よりも多くの燃料を噴射する燃料噴射ノズルとして、前述した公報に開示された燃料噴射ノズルを用いることができる。つまり、低負荷時に初期噴射を行い、高負荷時に主に主噴射を行えばエンジン負荷に応じて燃料噴射量を調整することができる。
【０００４】
【発明が解決しようとする課題】
しかしながら、低負荷時においては僅かなエンジン負荷の変動や弁部材先端部へのカーボン付着により弁部材のリフト量が変動することがある。したがって、エンジンの低負荷時において広角噴射を行うと、弁部材のリフト量の僅かな変動により噴霧角が大幅に変動してしまう。すると、噴霧形状が不安定となり、燃焼状態がばらつき、結果として未燃成分が排気ガス中に排出され、排気ガスの悪化を招く恐れがある。
【０００５】
また、弁部材のリフト量が大きく燃料噴射量が多いエンジンの高負荷時において狭角噴射を行うと、狭角噴射により燃料噴霧の直進力が大きくなるので、副燃焼室または主燃焼室の壁面に燃料が付着して液滴化し、この液滴化した燃料が未燃成分となって排気ガス中に排出され、排気ガスの悪化を招く恐れがある。また、未燃成分が生じると、燃料の噴射量よりも燃焼量が減少するので、エンジンの出力低下を招く。
【０００６】
本発明の目的は、エンジン負荷の高低に関わらず排気ガス中に排出される未燃成分を低減する燃料噴射ノズルを提供することにある。
【０００７】
【課題を解決するための手段】
本発明の請求項１記載の燃料噴射ノズルによると、低負荷時に狭角噴射を行うことにより、低負荷時においてエンジン負荷が変動したり、弁部材先端にカーボンが付着しても噴霧角の変動が少なく燃焼状態のばらつきを防止する。これにより、未燃成分の発生を低減できる。
【０００８】
また高負荷時に広角噴射を行うことにより、燃料の直進力を抑制し、副燃焼室または主燃焼室の内壁に燃料が付着して液滴化することを防止している。高負荷時における燃料の液滴化を防止することにより、排気ガス中の未燃成分の発生を低減できるとともに、エンジンの出力低下を防止できる。
【０００９】
さらに、本発明の請求項１記載の燃料噴射ノズルによると、弁部材は当接部の燃料噴射側にピン部を有している。ピン部は、円柱部と、円柱部の燃料噴射側に燃料噴射方向に向けて拡径する円錐台部とを有し、円柱部および円錐台部の周方向同一位置に弁部材の軸方向に沿って切欠を形成している。弁部材のリフト量が小さい低負荷時において、噴孔を形成する弁ボディの内周壁と、円柱部に設けた切欠との間に形成された流路の抵抗は、噴孔を形成する弁ボディの内周壁と切欠以外の円柱部の外周壁に形成される流路の抵抗よりも小さい。したがって、噴孔を形成する弁ボディの内周壁と円柱部に設けた切欠との間を燃料が軸方向に沿って通過し、この燃料が円錐台部に殆ど衝突することなく円錐台部に設けた切欠に沿って弁部材の軸方向に噴射されることにより、低負荷時において燃料が狭角に噴射される。
【００１０】
また、高負荷時において弁部材の円柱部が噴孔を形成する弁ボディの内壁と対向しない位置まで弁部材がリフトすると、燃料が弁部材の全周から噴孔に流入するので、燃料が円錐台部に衝突し、燃料が広角に噴射される。
【００１１】
本発明の請求項２記載の燃料噴射ノズルによると、平面で切欠を形成することにより、細径のピン部に切欠を容易に形成できる。
本発明の請求項３記載の燃料噴射ノズルによると、円柱部と円錐台部との間に円柱部よりも小径の連結部を有することにより、狭角噴射と広角噴射との間で噴霧角が変動する遷移領域が形成される。連結部の長さや円錐台部の切欠量を調整することにより遷移領域の範囲をエンジン要求特性に応じて任意に設定できる。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態を示す複数の実施例を図に基づいて説明する。
（第１実施例）
本発明の第１実施例による燃料噴射ノズルを図１に示す。
弁ボディ１０は、弁部材としてのノズルニードル２０を往復自在に収容している。弁ボディ１０の噴射側端部内周壁に、噴射方向に向けて縮径しノズルニードル２０の当接部２１が着座可能な弁座としてのテーパ面１１が形成されている。テーパ面１１のさらに噴射側に同一内径の円筒面１２が形成されている。円筒面１２は噴孔１３を形成している。
【００１３】
ノズルニードル２０は、当接部２１の噴射側に噴孔１３に貫挿されているピン部２２を有している。ピン部２２は、円柱部２３、縮径部２４、円錐台部２６を当接部２１から噴射方向に向けてこの順で形成している。円柱部２３の外径ｄ2は、噴孔１３の内径ｄ1よりも僅かに小さい。円柱部２３と縮径部２４との境界２５からテーパ面１１と円筒面１２との境界１４までの距離Ｌをスロットル距離という。図示しない高圧燃料ポンプからノズルニードル周囲に供給される燃料圧力によりテーパ面１１から離座する方向にノズルニードル２０が受ける力と、ノズルニードル２０をテーパ面１１に向けて付勢する図示しないスプリングの付勢力との釣り合いによりノズルニードル２０のリフト量は規定される。燃料圧力が低い、つまり低負荷の場合ノズルニードル２０のリフト量は小さくなり、噴孔１３から噴射される燃料量は少なくなる。燃料圧力が高い、つまり高負荷の場合ノズルニードル２０のリフト量は大きくなり、噴孔１３から噴射される燃料量は多くなる。
【００１４】
図２に示すように、円柱部２３および円錐台部２６には、周方向同一位置にノズルニードル２０の軸に沿って切欠としての平面２３ａ、２６ａがそれぞれ一箇所形成されている。平面２３ａと平面２６ａとは互いに平行であり、径方向の幅は等しいかまたは平面２６ａの方が平面２３ａよりも広い。さらに、平面２６ａは平面２３ａよりもノズルニードル２０の軸中心に近くなるように形成されている。平面２３ａと円筒面１２とが形成する流路は、横断面が弓状をしており、平面２３ａを除く円柱部２３の外周面と円筒面１２とが形成する流路の抵抗よりも流路抵抗が小さい。
【００１５】
次に、エンジン負荷に応じたノズルニードル２０のリフト量と噴霧角との関係について説明する。
当接部２１がテーパ面１１に着座した状態からノズルニードル２０の周囲に供給されている燃料の圧力が上昇すると、当接部２１がテーパ面１１から離座し、ピン部２２の周囲に燃料が流入する。このとき、前述したように平面２３ａと円筒面１２とが形成する流路の抵抗は平面２３ａを除く円柱部２３の外周面と円筒面１２とが形成する流路の抵抗よりも小さい。したがって、ピン部２２の周囲に流入した燃料は平面２３ａと円筒面１２との間を流れる。平面２６ａは平面２３ａよりも軸中心に近く、平面２６ａの径方向の幅は平面２３ａの径方向の幅と等しいか広いので、平面２３ａと円筒面１２との間を流れた燃料は円錐台部２６の外周面に衝突することなく平面２６ａに沿ってノズルニードル２０の軸方向に噴射される。低負荷の場合、ノズルニードル２０はスロットル距離Ｌ以上リフトしないので、狭角噴射が行われる。
【００１６】
高負荷の場合、図３に示すようにノズルニードル２０はスロットル距離Ｌよりもリフトし、円錐台部２６の周囲全体に燃料が流入する。円錐台部２６の周囲全体に流入した燃料は円錐台部２６に衝突するので、広角噴射が行われる。
【００１７】
（第２実施例）
本発明の第２実施例を図４に示す。第１実施例と実質的に同一構成部分に同一符号を付し説明を省略する。
【００１８】
ノズルニードル３０は、当接部２１の噴射側に噴孔１３に貫挿されているピン部３１を有している。ピン部３１は、円柱部２３、縮径部２４、連結部３２、円錐台部２６を当接部２１から噴射方向に向けてこの順で形成している。連結部３２は円柱状に形成されており、円柱部２３よりも径が小さい。
【００１９】
低負荷の場合、ノズルニードル３０はスロットル距離Ｌ以上リフトしないので、第１実施例と同様に狭角噴射が行われる。
高負荷の場合、ノズルニードル３０がスロットル距離Ｌよりもリフトすると、縮径部２４および連結部３２の外周を通り燃料が円錐台部２６の周囲全体に衝突するようになり、図５に示すように噴霧角が広がっていく。
【００２０】
第２実施例では、円柱部２３と円錐台部２６との間に連結部３２を設けているので、図５に示すように噴霧角が狭角噴射と広角噴射との間で変動する遷移領域が形成される。連結部３２の長さ、または平面２６ａの切欠量をエンジンの要求特性に応じて調整することにより、遷移領域の範囲を調整することができる。
【００２１】
以上説明した本発明の実施の形態を示す上記複数の実施例では、低負荷時において狭角噴射を行うことにより、ノズルニードルのリフト量が変動したりノズルニードルの先端部にカーボン等が付着しても、噴霧角の変動が小さく燃焼状態のばらつきを低減できる。したがって、未燃成分が排ガス中に排出されることを防止できる。
【００２２】
さらに高負荷時において広角噴射を行うことにより、燃料噴霧の過度の直進力を抑制し、例えば副燃焼室の内壁に燃料噴霧が付着して液滴化することを防止している。したがって、液滴化した燃料が未燃成分になり排ガス中に排出されることを防止するとともに、エンジンの出力低下を防止する。
【００２３】
上記複数の実施例ではピン部の円柱部および円錐台部の周方向にそれぞれ一箇所切欠としての平面を形成したが、周方向に複数個所平面を設けてもよい。平面ではなく、切欠として例えば凹部を形成してもよい。
【図面の簡単な説明】
【図１】本発明の第１実施例による燃料噴射ノズルを示す断面図である。
【図２】第１実施例のノズルニードル先端部を示す図１のII方向矢視図である。
【図３】第１実施例においてノズルニードルがリフトした状態を示す断面図である。
【図４】本発明の第２実施例による燃料噴射ノズルを示す断面図である。
【図５】第１実施例および第２実施例におけるリフト量と噴霧角との関係を示す特性図である。
【符号の説明】
１０ 弁ボディ
１１ テーパ面（弁座）
１３ 噴孔
２０、３０ ノズルニードル（弁部材）
２１ 当接部
２２、３１ ピン部
２３ 円柱部
２３ａ 平面（切欠）
２６ 円錐台部
２６ａ 平面（切欠）
３２ 連結部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection nozzle that adjusts a spray angle according to an engine load.
[0002]
[Prior art]
When the lift amount of the valve member that opens and closes the nozzle hole is equal to or less than a predetermined amount, the initial injection is performed while suppressing the fuel injection amount. When the lift amount of the valve member exceeds the predetermined amount, the fuel injection amount is increased and the main injection is performed. As fuel injection nozzles, those disclosed in Japanese Utility Model Laid-Open Nos. 59-141164 and 60-119368 are known. In such a fuel injection nozzle, a small amount of fuel is injected and burned in advance in initial injection, thereby preventing rapid combustion in main injection and noise generation from the engine. The fuel injection nozzles disclosed in both of the above publications increase the spray angle in the initial injection with a small lift amount of the valve member and decrease the spray angle in the main injection with a large lift amount of the valve member. Hereinafter, injection with a large spray angle is referred to as wide-angle injection, and injection with a small spray angle is referred to as narrow-angle injection.
[0003]
The fuel injection nozzle disclosed in the aforementioned publication can be used as a fuel injection nozzle that injects a small amount of fuel when the engine is under low load and injects more fuel when the engine is under high load than when under low load. . That is, if the initial injection is performed at a low load and the main injection is mainly performed at a high load, the fuel injection amount can be adjusted according to the engine load.
[0004]
[Problems to be solved by the invention]
However, when the load is low, the lift amount of the valve member may fluctuate due to slight fluctuations in engine load or carbon adhering to the valve member tip. Therefore, when the wide angle injection is performed at a low load of the engine, the spray angle greatly varies due to a slight variation in the lift amount of the valve member. Then, the spray shape becomes unstable, the combustion state varies, and as a result, unburned components are discharged into the exhaust gas, which may cause deterioration of the exhaust gas.
[0005]
Also, if the narrow angle injection is performed at high engine load when the lift amount of the valve member is large and the fuel injection amount is large, the straight traveling force of the fuel spray is increased by the narrow angle injection, so the wall surface of the auxiliary combustion chamber or the main combustion chamber The fuel adheres to the liquid and forms droplets, and the fuel that is formed into droplets becomes an unburned component and is discharged into the exhaust gas, which may cause deterioration of the exhaust gas. Further, when unburned components are generated, the combustion amount is reduced rather than the fuel injection amount, which causes a reduction in engine output.
[0006]
An object of the present invention is to provide a fuel injection nozzle that reduces unburned components discharged into the exhaust gas regardless of the engine load.
[0007]
[Means for Solving the Problems]
According to the fuel injection nozzle of claim 1 of the present invention, by performing narrow angle injection at low load, the engine load varies at low load, or the spray angle varies even if carbon adheres to the valve member tip. There are few, and the variation of a combustion state is prevented. Thereby, generation | occurrence | production of an unburned component can be reduced.
[0008]
Further, by performing wide-angle injection at a high load, the straight running force of the fuel is suppressed, and the fuel is prevented from adhering to the inner wall of the sub-combustion chamber or the main combustion chamber to form droplets. By preventing the fuel from becoming droplets at high loads, it is possible to reduce the generation of unburned components in the exhaust gas and to prevent a decrease in engine output.
[0009]
Furthermore, according to the fuel injection nozzle according to the first aspect of the present invention, the valve member has a pin portion to the fuel injection side of the contact portion. The pin portion has a cylindrical portion and a truncated cone portion that expands in the fuel injection direction on the fuel injection side of the cylindrical portion, and the axial direction of the valve member is the same in the circumferential direction of the cylindrical portion and the truncated cone portion. A notch is formed along. The resistance of the flow path formed between the inner peripheral wall of the valve body that forms the nozzle hole and the notch provided in the cylindrical portion at the time of low load when the lift amount of the valve member is small is the valve body that forms the nozzle hole It is smaller than the resistance of the flow path formed in the outer peripheral wall of the cylindrical portion other than the inner peripheral wall and the notch. Therefore, the fuel passes along the axial direction between the inner peripheral wall of the valve body forming the nozzle hole and the notch provided in the cylindrical portion, and the fuel is provided in the truncated cone portion with almost no collision with the truncated cone portion. The fuel is injected at a narrow angle at low load by being injected along the notch in the axial direction of the valve member.
[0010]
Further, when the valve member is lifted to a position where the cylindrical portion of the valve member does not face the inner wall of the valve body forming the injection hole at a high load, the fuel flows into the injection hole from the entire circumference of the valve member. It collides with the platform and fuel is injected at a wide angle.
[0011]
According to the fuel injection nozzle of claim 2 of the present invention, the notch can be easily formed in the pin portion having a small diameter by forming the notch in the plane.
According to the fuel injection nozzle of claim 3 of the present invention, the spray angle between the narrow angle injection and the wide angle injection is reduced by having the connecting portion having a smaller diameter than the cylindrical portion between the cylindrical portion and the truncated cone portion. A variable transition region is formed. By adjusting the length of the connecting portion and the notch amount of the truncated cone portion, the range of the transition region can be arbitrarily set according to the engine required characteristics.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a plurality of examples showing embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A fuel injection nozzle according to a first embodiment of the present invention is shown in FIG.
The valve body 10 accommodates a nozzle needle 20 as a valve member in a reciprocating manner. A tapered surface 11 is formed on the inner peripheral wall of the injection side end of the valve body 10 as a valve seat that is reduced in diameter in the injection direction and on which the contact portion 21 of the nozzle needle 20 can be seated. A cylindrical surface 12 having the same inner diameter is formed further on the ejection side of the tapered surface 11. The cylindrical surface 12 forms a nozzle hole 13.
[0013]
The nozzle needle 20 has a pin portion 22 that is inserted into the injection hole 13 on the injection side of the contact portion 21. The pin part 22 forms the column part 23, the reduced diameter part 24, and the truncated cone part 26 in this order from the contact part 21 toward the injection direction. The outer diameter d 2 of the cylindrical portion 23 is slightly smaller than the inner diameter d 1 of the injection hole 13. A distance L from a boundary 25 between the cylindrical portion 23 and the reduced diameter portion 24 to a boundary 14 between the tapered surface 11 and the cylindrical surface 12 is referred to as a throttle distance. A force received by the nozzle needle 20 in a direction away from the tapered surface 11 due to fuel pressure supplied from a high pressure fuel pump (not shown) around the nozzle needle, and a spring (not shown) that urges the nozzle needle 20 toward the tapered surface 11. The lift amount of the nozzle needle 20 is defined by the balance with the urging force. When the fuel pressure is low, that is, when the load is low, the lift amount of the nozzle needle 20 is small, and the amount of fuel injected from the nozzle hole 13 is small. When the fuel pressure is high, that is, when the load is high, the lift amount of the nozzle needle 20 increases, and the amount of fuel injected from the injection hole 13 increases.
[0014]
As shown in FIG. 2, the cylindrical portion 23 and the truncated cone portion 26 are each formed with one plane 23 a and 26 a as a notch along the axis of the nozzle needle 20 at the same position in the circumferential direction. The plane 23a and the plane 26a are parallel to each other, and the radial widths are equal or the plane 26a is wider than the plane 23a. Furthermore, the flat surface 26a is formed closer to the axial center of the nozzle needle 20 than the flat surface 23a. The flow path formed by the flat surface 23a and the cylindrical surface 12 has an arcuate cross section, and the flow path is larger than the resistance of the flow path formed by the outer peripheral surface of the cylindrical portion 23 excluding the flat surface 23a and the cylindrical surface 12. Resistance is small.
[0015]
Next, the relationship between the lift amount of the nozzle needle 20 according to the engine load and the spray angle will be described.
When the pressure of the fuel supplied to the periphery of the nozzle needle 20 rises from the state where the contact portion 21 is seated on the tapered surface 11, the contact portion 21 is separated from the taper surface 11 and the fuel around the pin portion 22 is fueled. Flows in. At this time, as described above, the resistance of the flow path formed by the flat surface 23a and the cylindrical surface 12 is smaller than the resistance of the flow path formed by the outer peripheral surface of the column portion 23 excluding the flat surface 23a and the cylindrical surface 12. Therefore, the fuel that has flowed into the periphery of the pin portion 22 flows between the flat surface 23 a and the cylindrical surface 12. The plane 26a is closer to the axial center than the plane 23a, and the radial width of the plane 26a is equal to or larger than the radial width of the plane 23a, so that the fuel that flows between the plane 23a and the cylindrical surface 12 is the truncated cone portion. The nozzle needle 20 is injected in the axial direction along the flat surface 26 a without colliding with the outer peripheral surface of the nozzle 26. In the case of a low load, the nozzle needle 20 does not lift more than the throttle distance L, so narrow angle injection is performed.
[0016]
In the case of a high load, as shown in FIG. 3, the nozzle needle 20 is lifted more than the throttle distance L, and the fuel flows into the entire periphery of the truncated cone portion 26. Since the fuel that has flowed into the entire periphery of the truncated cone part 26 collides with the truncated cone part 26, wide-angle injection is performed.
[0017]
(Second embodiment)
A second embodiment of the present invention is shown in FIG. Components that are substantially the same as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
[0018]
The nozzle needle 30 has a pin portion 31 that is inserted into the injection hole 13 on the injection side of the contact portion 21. The pin part 31 is formed in this order with the cylindrical part 23, the reduced diameter part 24, the connecting part 32, and the truncated cone part 26 from the contact part 21 toward the injection direction. The connecting portion 32 is formed in a columnar shape and has a smaller diameter than the columnar portion 23.
[0019]
In the case of a low load, the nozzle needle 30 does not lift more than the throttle distance L, so that narrow-angle injection is performed as in the first embodiment.
In the case of a high load, when the nozzle needle 30 is lifted more than the throttle distance L, the fuel passes through the outer periphery of the reduced diameter portion 24 and the connecting portion 32 and collides with the entire periphery of the truncated cone portion 26, as shown in FIG. The spray angle spreads.
[0020]
In the second embodiment, since the connecting portion 32 is provided between the cylindrical portion 23 and the truncated cone portion 26, the transition region where the spray angle varies between the narrow angle injection and the wide angle injection as shown in FIG. Is formed. The range of the transition region can be adjusted by adjusting the length of the connecting portion 32 or the cutout amount of the flat surface 26a in accordance with the required characteristics of the engine.
[0021]
In the above-described embodiments showing the embodiment of the present invention described above, by performing narrow angle injection at low load, the lift amount of the nozzle needle fluctuates or carbon or the like adheres to the tip of the nozzle needle. However, variation in the spray angle is small, and variations in the combustion state can be reduced. Therefore, it is possible to prevent unburned components from being discharged into the exhaust gas.
[0022]
Further, by performing wide-angle injection at high load, the excessive straight traveling force of the fuel spray is suppressed, and for example, the fuel spray is prevented from adhering to the inner wall of the sub-combustion chamber to form droplets. Accordingly, it is possible to prevent the fuel droplets from becoming unburned components and being discharged into the exhaust gas, and to prevent a decrease in engine output.
[0023]
In the above embodiments, a plane as a notch is formed in the circumferential direction of the cylindrical portion and the truncated cone portion of the pin portion, but a plurality of planes may be provided in the circumferential direction. For example, a recess may be formed as a notch instead of a flat surface.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a fuel injection nozzle according to a first embodiment of the present invention.
FIG. 2 is a view taken in the direction of the arrow II in FIG. 1 showing the nozzle needle tip of the first embodiment.
FIG. 3 is a cross-sectional view showing a state in which the nozzle needle is lifted in the first embodiment.
FIG. 4 is a cross-sectional view showing a fuel injection nozzle according to a second embodiment of the present invention.
FIG. 5 is a characteristic diagram showing the relationship between the lift amount and the spray angle in the first embodiment and the second embodiment.
[Explanation of symbols]
10 Valve body 11 Tapered surface (valve seat)
13 Injection hole 20, 30 Nozzle needle (valve member)
21 Contact part 22, 31 Pin part 23 Cylindrical part 23a Plane (notch)
26 truncated cone part 26a plane (notch)
32 connecting part

Claims (3)

噴孔から噴射する燃料を断続する弁部材と、
前記噴孔を形成し、前記弁部材が着座することにより燃料噴射が遮断され、前記弁部材が離座することにより燃料が噴射される弁座を有する弁ボディとを備え、
前記弁部材は、前記弁座に着座可能な当接部と、前記当接部の燃料噴射側に設けられ前記噴孔に貫挿されるピン部とを有し、前記ピン部は、円柱部と、前記円柱部の燃料噴射側に設けられ燃料噴射方向に向けて拡径する円錐台部とを有し、前記円柱部および前記円錐台部の周方向同一位置に前記弁部材の軸方向に沿って切欠を形成しており、
エンジンの低負荷時に狭角噴射を行い、高負荷時に広角噴射を行うことを特徴とする燃料噴射ノズル。A valve member for intermittently injecting fuel injected from the nozzle hole;
A valve body having a valve seat that forms the nozzle hole, shuts off fuel injection when the valve member is seated, and injects fuel when the valve member is seated;
The valve member includes an abutting portion that can be seated on the valve seat, and a pin portion that is provided on a fuel injection side of the abutting portion and is inserted into the nozzle hole. And a truncated cone part that is provided on the fuel injection side of the cylindrical part and expands in the fuel injection direction, and is located along the axial direction of the valve member at the same circumferential position of the cylindrical part and the truncated cone part. Forming a notch,
A fuel injection nozzle that performs narrow-angle injection when the engine is under a low load and performs a wide-angle injection when the engine is under a high load. 前記両切欠は互いに平行な平面であることを特徴とする請求項１記載の燃料噴射ノズル。The fuel injection nozzle according to claim 1, wherein the two notches are planes parallel to each other. 前記円柱部と前記円錐台部との間に前記円柱部よりも小径の連結部を有することを特徴とする請求項１または２記載の燃料噴射ノズル。The fuel injection nozzle according to claim 1, further comprising a connecting portion having a smaller diameter than the columnar portion between the columnar portion and the truncated cone portion.
JP24697698A 1998-09-01 1998-09-01 Fuel injection nozzle Expired - Fee Related JP3912641B2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP24697698A JP3912641B2 (en) 1998-09-01 1998-09-01 Fuel injection nozzle
DE1999141357 DE19941357A1 (en) 1998-09-01 1999-08-31 Fuel injection nozzle comprises body with spray hole for fuel injection and valve seat together with valve component having part locating on valve seat to stop fuel injection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24697698A JP3912641B2 (en) 1998-09-01 1998-09-01 Fuel injection nozzle

Publications (2)

Publication Number Publication Date
JP2000073915A JP2000073915A (en) 2000-03-07
JP3912641B2 true JP3912641B2 (en) 2007-05-09

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
JP24697698A Expired - Fee Related JP3912641B2 (en) 1998-09-01 1998-09-01 Fuel injection nozzle

Country Status (2)

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JP (1) JP3912641B2 (en)
DE (1) DE19941357A1 (en)

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DE19941357A1 (en) 2000-03-02
JP2000073915A (en) 2000-03-07

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