JPH0932696A - Two-stage opening valve pressure type fuel injection valve - Google Patents
Two-stage opening valve pressure type fuel injection valveInfo
- Publication number
- JPH0932696A JPH0932696A JP17853695A JP17853695A JPH0932696A JP H0932696 A JPH0932696 A JP H0932696A JP 17853695 A JP17853695 A JP 17853695A JP 17853695 A JP17853695 A JP 17853695A JP H0932696 A JPH0932696 A JP H0932696A
- Authority
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- Japan
- Prior art keywords
- valve
- fuel injection
- fuel
- valve opening
- stage
- 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.)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、内燃エンジンの燃
焼室内へ燃料を噴射させるための二段開弁圧式燃料噴射
弁に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-stage valve opening type fuel injection valve for injecting fuel into a combustion chamber of an internal combustion engine.
【０００２】[0002]
【従来の技術】ディーゼルエンジンは、ピストンにより
圧縮された空気中に燃料（軽油）を噴射させて、同燃料
を圧縮熱で着火し燃焼させて動力を得るエンジンであ
る。一般にこうしたディーゼルエンジンに用いられる燃
料噴射装置には、列型などの燃料噴射ポンプから圧送さ
れる燃料をシリンダヘッドに装着されている燃料噴射ノ
ズルから、燃焼室内へ噴射させる構造が用いられてい
る。2. Description of the Related Art A diesel engine is an engine that injects fuel (light oil) into the air compressed by a piston and ignites and burns the fuel with compression heat to obtain power. In general, a fuel injection device used for such a diesel engine has a structure in which fuel that is pressure-fed from a fuel injection pump of a column type or the like is injected into a combustion chamber from a fuel injection nozzle mounted on a cylinder head.
【０００３】ディーゼルエンジンは、噴射した燃料がシ
リンダ内で空気と混合し着火燃焼する際、その混合した
燃料が圧縮熱によって一気に着火燃焼し、燃焼中に混合
した燃料が拡散燃焼をする。In the diesel engine, when the injected fuel is mixed with air in the cylinder and ignited and burned, the mixed fuel is ignited and burned at once by the compression heat, and the fuel mixed during the combustion is diffused and burned.
【０００４】このため、ディーゼルエンジンの燃焼騒音
は大きな傾向にあり、特にアイドリングのときは大きく
感じる。そこで、二段の開弁圧が設定された燃料噴射弁
を用いて、噴射特性を噴射経過時間に応じて可変とし、
初期噴射率を低下させて、着火燃焼を緩慢にする提案が
なされている。For this reason, the combustion noise of the diesel engine tends to be large, and particularly when idling, it feels great. Therefore, by using a fuel injection valve with a two-stage valve opening pressure set, the injection characteristics are made variable according to the injection elapsed time,
Proposals have been made to slow the ignition combustion by reducing the initial injection rate.
【０００５】従来、このような二段開弁圧式燃料噴射弁
は、図１５に示されるように通常のニードル弁構造、す
なわちニードル弁１（針弁に相当）が先端側に収容され
た細長のノズル本体２（ノズルボディに相当）の先端部
内に円錐状の着座面３（第１シール面に相当）を形成
し、ニードル弁１の先端に形成された円錐状のシール面
４（第２シール面に相当）との接離にしたがってノズル
本体２の先端に在るノズルサック部５から流出する燃料
の流れを遮断する構造に加え、ノズル本体２内に二段開
弁圧機構６を設けている。Conventionally, such a two-stage valve-opening pressure type fuel injection valve has a normal needle valve structure as shown in FIG. 15, that is, an elongated valve having a needle valve 1 (corresponding to a needle valve) accommodated on the tip side. A conical seating surface 3 (corresponding to the first sealing surface) is formed in the tip portion of the nozzle body 2 (corresponding to the nozzle body), and a conical sealing surface 4 (second seal) formed at the tip of the needle valve 1. (Corresponding to the surface), a two-stage valve opening pressure mechanism 6 is provided in the nozzle body 2 in addition to a structure for shutting off the flow of fuel flowing out from the nozzle sack portion 5 at the tip of the nozzle body 2. There is.
【０００６】二段開弁圧機構６は、例えばニードル弁１
の基端部に短軸状のプッシュロッド７を設け、このプッ
シュロッド７から離れたノズル本体２内の上段側の地点
に、プッシュロッド７と直列に並ぶように長軸状のプッ
シュロッド８を軸方向に変位可能に配設し、一段目の開
弁圧（初期開弁圧）を設定するスプリング部材９にてプ
ッシュロッド７およびニードル弁１を閉方向に付勢し、
二段目の開弁圧（全噴射時の開弁圧）を設定するスプリ
ング部材１０にてプッシュロッド８をニードル弁１の閉
じ方向に付勢している。The two-stage valve opening pressure mechanism 6 includes, for example, the needle valve 1
A push rod 7 having a short axis is provided at the base end of the push rod 7, and a push rod 8 having a long axis is arranged at a point on the upper stage side in the nozzle body 2 which is separated from the push rod 7 so as to be arranged in series with the push rod 7. The push rod 7 and the needle valve 1 are urged in the closing direction by a spring member 9 that is arranged so as to be displaceable in the axial direction and that sets a valve opening pressure of the first stage (initial valve opening pressure).
The push rod 8 is biased in the closing direction of the needle valve 1 by the spring member 10 that sets the valve opening pressure of the second stage (the valve opening pressure at the time of full injection).
【０００７】そして、この付勢したプッシュロッド８
が、プッシュロッド７の先端から所定の距離、離れた地
点に位置決められ、プレリフトに必要な間隙が保たれる
ようにしてある。Then, the push rod 8 which is biased
However, the push rod 7 is positioned at a predetermined distance from the tip of the push rod 7 so that a gap necessary for pre-lifting can be maintained.
【０００８】なお、１１はノズル本体２に設けた燃料入
口部、１２は燃料入口部１１から圧送される燃料をニー
ドル弁１の先端に導くフィードホール、１３はニードル
弁１の途中の外周に在る受圧部１ａを囲むように形成さ
れた燃料溜まり部、１４はノズルサック部５に形成され
た噴孔を示す。但し、燃料溜まり部１３はフィードホー
ル１２に連通している。Reference numeral 11 designates a fuel inlet portion provided in the nozzle body 2, 12 a feed hole for guiding the fuel pressure-fed from the fuel inlet portion 11 to the tip of the needle valve 1, and 13 an intermediate outer periphery of the needle valve 1. Is a fuel reservoir portion formed so as to surround the pressure receiving portion 1a, and 14 is an injection hole formed in the nozzle sack portion 5. However, the fuel reservoir 13 communicates with the feed hole 12.
【０００９】これにより、ニードル弁１は、燃料噴射ポ
ンプが噴射作動に入り、燃料圧力が初期開弁圧に達する
と、ニードル弁１の途中に設けた受圧部１ａが燃料圧を
受けて、プッシュロッド８と当接するまで上昇し、その
位置で一旦停止する。As a result, when the fuel injection pump enters the injection operation and the fuel pressure reaches the initial valve opening pressure, the needle valve 1 is pushed by the pressure receiving portion 1a provided in the middle of the needle valve 1 receiving the fuel pressure. It rises until it comes into contact with the rod 8 and stops at that position.
【００１０】この状態がプレリフトで、図１６に示され
るようにノズル本体２の着座面３とニードル弁１のシー
ル面４との間には、プレリフト量に応じた狭い流路Ａが
形成される。This state is pre-lift, and as shown in FIG. 16, a narrow passage A corresponding to the pre-lift amount is formed between the seating surface 3 of the nozzle body 2 and the seal surface 4 of the needle valve 1. .
【００１１】そして、燃料溜まり部１３の燃料が、この
流路Ａを通じて、開かれた噴孔１４から噴射される。こ
の初期噴射の後、燃料溜まり部１３の燃料圧力が高くな
り、全噴射の開弁圧を越えると、プッシュロッド８を押
し上げ、ニードル弁１はスプリング部材９，１０に抗し
て上昇する。Then, the fuel in the fuel reservoir 13 is injected through the flow passage A from the opened injection hole 14. After this initial injection, the fuel pressure in the fuel reservoir 13 rises, and when the valve opening pressure for all injections is exceeded, the push rod 8 is pushed up and the needle valve 1 rises against the spring members 9 and 10.
【００１２】これにより、ニードル弁１は、図１６に示
されるようにフルリフトまで上昇し、大きく開かれた着
座面３とシール面４との間を通じて、燃料溜まり部１３
の燃料が噴孔１４から噴射される。つまり、全噴射が行
なわれる（主燃料噴射）。As a result, the needle valve 1 ascends to the full lift as shown in FIG. 16, and passes through between the seating surface 3 and the sealing surface 4 which are widely opened, and the fuel reservoir 13
Fuel is injected from the injection hole 14. That is, full injection is performed (main fuel injection).
【００１３】ところで、二段開弁圧式燃料噴射弁のプレ
リフト量は、小さくなればなる程、流路Ａの流路抵抗が
増加して、初期噴射率が低下するようになる。つまり、
流路Ａの流路抵抗が増加すると、燃料が流れずらくなっ
て、噴射される燃料の勢いがなくなる。By the way, as the pre-lift amount of the two-stage valve opening type fuel injection valve becomes smaller, the flow resistance of the flow path A increases and the initial injection rate decreases. That is,
When the flow path resistance of the flow path A increases, it becomes difficult for the fuel to flow, and the momentum of the injected fuel disappears.
【００１４】このように初期噴射率の低下が進むと、次
第に着火燃焼が緩慢となり、その分、エンジンの燃焼騒
音が低減するようになる。ところが、プレリフト量は、
燃料噴射弁の工作，組立精度の制約などから、実際には
限界がある。When the initial injection rate decreases in this way, the ignition combustion gradually becomes slower, and the combustion noise of the engine decreases correspondingly. However, the pre-lift amount is
There are practical limits due to factors such as the work of the fuel injection valve and restrictions on assembly accuracy.
【００１５】現在、出願人の実験によれば、プレリフト
の設定の最小値としては約０．０６mmが限界であり、そ
れ以下のプレリフト量を設定しても、設定プレリフトの
通りに燃料が噴射されなくなるおそれがある。At present, according to the experiments by the applicant, the minimum value for setting the pre-lift is about 0.06 mm, and even if the pre-lift amount is set less than that, the fuel is injected according to the set pre-lift. It may run out.
【００１６】これでは、ディーゼルエンジンの騒音低減
効果、さらにはディーゼルエンジンの排気ガス性能がば
らついてしまう。そこで、特開平１−１６３４６４号公
報に見られるようにプレリフト時、流路Ａに、大きな流
路抵抗を発生させる試みがなされている。In this case, the noise reduction effect of the diesel engine and the exhaust gas performance of the diesel engine vary. Therefore, as disclosed in JP-A-1-163464, an attempt has been made to generate a large flow path resistance in the flow path A during prelift.
【００１７】これは、図１８および図１９に示されるよ
うにニードル弁１の先端に、先端側に向かうにしたがっ
て順次、段階的に外径が縮径された軸部１５を突設し
て、プレリフトのとき、流路Ａの前方に、大きな流通抵
抗をもたらす第２の流路Ｂが形成される構造にしてあ
る。As shown in FIGS. 18 and 19, the needle valve 1 is provided at its tip with a shaft portion 15 whose outer diameter is gradually reduced in a stepwise manner toward the tip side. At the time of pre-lifting, the structure is such that the second flow path B that causes a large flow resistance is formed in front of the flow path A.
【００１８】[0018]
【発明が解決しようとする課題】これによると、確か
に、一層の初期燃料噴射率の低下は見られるものの、こ
の構造はノズルサック部５の大きさが軸部１５の分、大
きくなる。ところが、ノズルサック部５は、できるだけ
大形になるのを抑制したい部分である。According to this, although it is true that the initial fuel injection rate is further lowered, in this structure, the size of the nozzle sack portion 5 is increased by the amount of the shaft portion 15. However, the nozzle sack portion 5 is a portion that is desired to be prevented from becoming as large as possible.
【００１９】すなわち、燃料の噴射を終えた後のノズル
サック部５内には、燃料が充満してする。ところが、大
形化によってノズルサック部５の容量が大きくなると、
エンジンのピストン下降行程の際に作用する負圧によっ
て、内部の燃料がシリンダ内へ流出しやすくなる。That is, the nozzle sack portion 5 after the fuel injection is completed is filled with the fuel. However, when the capacity of the nozzle sack portion 5 increases due to the increase in size,
Due to the negative pressure that acts during the downward stroke of the piston of the engine, the internal fuel easily flows into the cylinder.
【００２０】つまり、上記のような構造を採用すると、
ディーゼルエンジンの排出ガス性能が悪くなるおそれが
ある。このため、ゼィーゼルエンジンに影響を与えず
に、一層、初期噴射率を下げられる技術が要望されてい
る。That is, if the above structure is adopted,
Exhaust gas performance of diesel engine may deteriorate. Therefore, there is a demand for a technique capable of further reducing the initial injection rate without affecting the diesel engine.
【００２１】特に、燃料噴射ポンプは高圧噴射で燃料を
噴射させる傾向が多く、従来のプレリフト量では初期燃
料噴射率の低下が困難となることが予想されるので、こ
のような要望は強い。In particular, the fuel injection pump tends to inject fuel by high-pressure injection, and it is expected that it will be difficult to reduce the initial fuel injection rate with the conventional pre-lift amount, so such a demand is strong.
【００２２】本発明は上記事情に着目してなされたもの
で、その目的とするところは、エンジン性能に影響を与
えずに、一層、初期燃料噴射率を低減させることができ
る二段開弁圧式燃料噴射弁を提供することにある。The present invention has been made by paying attention to the above circumstances, and an object thereof is a two-stage valve opening pressure type which can further reduce the initial fuel injection rate without affecting the engine performance. To provide a fuel injection valve.
【００２３】[0023]
【課題を解決するための手段】上記目的を達成するため
に請求項１に記載した発明は、針弁のシール面に、針弁
の軸心回りに沿う環状の溝部を設けたことにある。請求
項２に記載した発明は、上記目的に加え、有効な効果が
得られるようにするため、請求項１に記載の溝部は、初
期噴射の開弁圧でリフトする針弁のプレリフト量の２倍
以上の深さ寸法で、かつ４倍以上の幅寸法を有して形成
したことにある。In order to achieve the above object, the invention described in claim 1 is to provide an annular groove portion around the axis of the needle valve on the sealing surface of the needle valve. In addition to the above-mentioned object, the invention according to claim 2 provides an effective effect. Therefore, the groove portion according to claim 1 has a pre-lift amount of 2 which is lifted by the valve opening pressure of the initial injection. The depth dimension is more than twice and the width dimension is more than four times.
【００２４】請求項１に記載した発明によると、燃料圧
力が初期開弁に達すると、針弁はリフトして、プレリフ
ト量に達する。これにより、針弁のシール面とノズルボ
ディのシール面との間には、プレリフト量に応じた狭い
流路が形成される。According to the invention described in claim 1, when the fuel pressure reaches the initial valve opening, the needle valve lifts to reach the pre-lift amount. As a result, a narrow channel corresponding to the pre-lift amount is formed between the seal surface of the needle valve and the seal surface of the nozzle body.
【００２５】この狭い流路を通じて、燃料が噴孔から噴
射される。このとき、針弁のシール面に形成されている
環状の溝部は、同流路の面積を拡大・縮小する方向に変
化させる。Fuel is injected from the injection hole through the narrow passage. At this time, the annular groove portion formed on the sealing surface of the needle valve changes the area of the flow passage in the direction of enlarging or reducing.
【００２６】この流路面積の変化は、狭い流路に対して
は大きく作用するから、同流路面積の変化は、燃料の流
れを乱す。と共に燃料が溝部内に流入、さらには同溝部
内から流出するという流れを生じさせるという具合に作
用する。Since the change in the flow passage area has a large effect on the narrow flow passage, the change in the flow passage area disturbs the fuel flow. At the same time, the fuel flows into the groove portion and further flows out from the groove portion.
【００２７】この結果、流路抵抗は、プレリフト量で得
られるときよりも、一層、大きくなり、上記流路を通じ
て、噴孔から噴射される燃料は、一層、勢いが減衰され
る。このことは、プレリフト量で得られるときよりも、
初期燃料噴射率は低下され、一層、着火燃焼は緩慢にな
る。As a result, the flow passage resistance becomes even larger than when the pre-lift amount is obtained, and the fuel injected from the injection hole through the flow passage is further damped. This is more than when it is obtained with the pre-lift amount.
The initial fuel injection rate is reduced, and the ignition combustion becomes slower.
【００２８】これにより、燃焼騒音は、プレリフト量で
得られるときよりも、低減されるようになる。しかも、
針弁が全噴射までリフトすると、溝部による流路面積変
化は相対的に小さくなるから（流路抵抗が小）、主燃料
噴射への影響は小さく、エンジンに影響を与えずにす
む。As a result, the combustion noise is reduced as compared with when the pre-lift amount is obtained. Moreover,
When the needle valve is lifted up to the full injection, the change in the flow passage area due to the groove is relatively small (the flow passage resistance is small), so the influence on the main fuel injection is small and the engine is not affected.
【００２９】また針弁のシール面に溝部を形成するの
で、ノズルサック部を大きくせずにすむ。請求項２に記
載した発明によると、出願人が実験を行った結果、針弁
のプレリフト量の２倍以上の深さ寸法で、かつ４倍以上
の幅寸法を有する溝部であれば、有効な効果が約束され
る。Since the groove portion is formed on the sealing surface of the needle valve, the nozzle sack portion does not need to be large. According to the invention described in claim 2, as a result of the experiment conducted by the applicant, it is effective if the groove portion has a depth dimension of at least twice the pre-lift amount of the needle valve and a width dimension of at least four times. The effect is promised.
【００３０】[0030]
【発明の実施の形態】以下、本発明を図１ないし図９に
示す第１の実施形態にもとづいて説明する。なお、図面
において、先の「従来の技術」の項で説明した二段開弁
圧式燃料噴射弁と同じ部分には同一符号を付してその説
明を省略し、この項では異なる部位（発明の要部）につ
いて説明することにする。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on a first embodiment shown in FIGS. In the drawings, the same parts as those of the two-stage valve opening type fuel injection valve described in the above-mentioned "Prior Art" are designated by the same reference numerals, and the description thereof will be omitted. The main part) will be explained.
【００３１】本実施形態は、ニードル弁１の円錐状をな
したシール面４（ノズル本体２に形成された着座面３と
接離して、燃料流れを遮断する部分）に環状の溝部２０
を設けた点で異なる。In this embodiment, an annular groove portion 20 is formed in the conical sealing surface 4 of the needle valve 1 (the portion that comes into contact with and separates from the seating surface 3 formed on the nozzle body 2 to block the fuel flow).
Is different in that it is provided.
【００３２】具体的には、図１および図２に示されるよ
うに溝部２０は、噴孔１４と干渉しないシール面４の上
流側の部位に形成してある。また溝部２０は、例えばニ
ードル弁１の軸心方向と直角な方向から加工してなる断
面が四角形をなしている。Specifically, as shown in FIGS. 1 and 2, the groove portion 20 is formed in a portion on the upstream side of the seal surface 4 which does not interfere with the injection hole 14. Further, the groove portion 20 has a quadrangular cross section formed by, for example, processing in a direction perpendicular to the axial direction of the needle valve 1.
【００３３】この断面四角形の溝部２０により、プレリ
フト時、着座面３とシール面との間に形成される狭い流
路Ａの一部を拡大・縮小変化させるようにしてある。つ
ぎに、このように構成された二段開弁圧式燃料噴射弁の
作用について説明する。The groove 20 having a quadrangular cross section allows a part of the narrow channel A formed between the seating surface 3 and the seal surface to be enlarged or reduced during pre-lifting. Next, the operation of the two-stage valve opening pressure type fuel injection valve configured as described above will be described.
【００３４】今、燃料噴射ポンプ（図示しない）が噴射
作動に入り、二段開弁圧式燃料噴射弁に供給される燃料
圧力が初期開弁圧に達したとする。すると、受圧部１ａ
が燃料圧を受けて、ニードル弁１は図３に示されるよう
にプッシュロッド８と当接するまで上昇し、その位置で
一旦停止する。Now, it is assumed that the fuel injection pump (not shown) enters the injection operation and the fuel pressure supplied to the two-stage valve opening type fuel injection valve reaches the initial valve opening pressure. Then, the pressure receiving portion 1a
Receives the fuel pressure, the needle valve 1 rises until it comes into contact with the push rod 8 as shown in FIG. 3, and temporarily stops at that position.
【００３５】このプレリフトにより、ニードル弁１のシ
ール面４とノズル本体２の着座面３との間には、プレリ
フト量に応じた狭い流路Ａが形成される。ここで、シー
ル面４に形成されている環状の溝部２０は、同流路Ａの
面積を拡大・縮小する方向に変化させている。Due to this pre-lift, a narrow channel A corresponding to the pre-lift amount is formed between the seal surface 4 of the needle valve 1 and the seating surface 3 of the nozzle body 2. Here, the annular groove portion 20 formed on the sealing surface 4 changes the area of the flow path A in a direction of enlarging or reducing.
【００３６】リフトが小なる狭い流路Ａに対しては、こ
の流路面積の変化は大きく作用するから、流路Ａを流れ
る燃料には狭い流路Ａで発生する流通抵抗に加え、流路
Ａの一部が拡大・縮小する部分で発生する流路抵抗が加
えられる。Since the change of the flow passage area has a large effect on the narrow flow passage A having a small lift, in addition to the flow resistance generated in the narrow flow passage A for the fuel flowing through the flow passage A, The flow path resistance generated in the part where part of A expands or contracts is added.
【００３７】具体的には、図４に示されるように溝部２
０内で渦流ａが発生して流路Ａを流通する燃料の流れを
乱したり、溝部２０内に燃料の流れが流入してこの燃料
が再び狭い流路部分へ流出したりする。Specifically, as shown in FIG. 4, the groove portion 2
The vortex flow a is generated in 0 to disturb the flow of the fuel flowing through the flow path A, or the flow of the fuel flows into the groove portion 20 and the fuel flows out to the narrow flow path portion again.
【００３８】これにより、流路抵抗は、プレリフト量で
得られるときよりも、一層、大きくなる。この結果、流
路Ａを流れる燃料は、プレリフト量で得られるときより
も、一層、勢いが減衰されて、噴孔１４から燃焼室内へ
噴射される。As a result, the flow path resistance becomes even greater than when the prelift amount is obtained. As a result, the fuel flowing through the flow path A is injected into the combustion chamber through the injection holes 14 with the momentum further attenuated as compared with when the pre-lift amount is obtained.
【００３９】このことは、初期燃料噴射率は、プレリフ
ト量の設定で得られるときよりも、一層、低下され、そ
の分、燃焼室内で行われる着火燃焼は緩慢になる。それ
故、燃焼騒音は、一層、低減される。特にアイドル燃焼
騒音は格段に低減される。This means that the initial fuel injection rate is further reduced as compared with the case where the prelift amount is set, and the ignition and combustion performed in the combustion chamber becomes slower accordingly. Therefore, combustion noise is further reduced. In particular, idle combustion noise is significantly reduced.
【００４０】しかも、初期噴射の後、燃料圧力が全噴射
の開弁圧を越えて、図５に示されるようにニードル弁１
が大きくリフトすると、流路Ａに対する溝部２０の流路
面積変化は相対的に小さくなるから（流路抵抗が小）、
主燃料噴射への影響は小さくなる。つまり、ディーゼル
エンジンに影響を与えずにすむようになる。Moreover, after the initial injection, the fuel pressure exceeds the valve opening pressure for all injections, and as shown in FIG.
Is greatly lifted, the change in the flow passage area of the groove portion 20 relative to the flow passage A becomes relatively small (the flow passage resistance is small).
The influence on the main fuel injection is reduced. In other words, it will not affect the diesel engine.
【００４１】実験によれば、溝部２０がニードル弁１に
在る二段開弁圧式燃料噴射弁と、溝部２０がない二段開
弁圧式燃料噴射弁との性能を対比する試験を行なった結
果、図６に示されるようにアイドル燃焼騒音は、溝部２
０が在る二段開弁圧式燃料噴射弁の方が、ほとんどの周
波数領域で２〜３ｄＢ程度、騒音が低減したことが確認
された。この低減は、音エネルギーから見ると、音エネ
ルギーがおよそ半分になったことに相当するもので、か
なりの効果である。According to the experiment, the result of a test comparing the performance of the two-stage valve opening type fuel injection valve having the groove portion 20 in the needle valve 1 and the two-stage valve opening type fuel injection valve having no groove portion 20 was conducted. As shown in FIG. 6, the idle combustion noise is generated by the groove 2
It was confirmed that the two-stage valve opening type fuel injection valve in which 0 is present reduced noise by about 2 to 3 dB in most frequency regions. From the viewpoint of sound energy, this reduction corresponds to about half the sound energy, which is a considerable effect.
【００４２】またエンジン回転数を含め同一な条件で燃
料を噴射させて、そのときの燃料消費率、スモーク、Ｎ
Ｏx、燃料噴射量を調べると、図７に示されるように、
それぞれの性能の面で、溝部２０が在る二段開弁圧式燃
料噴射弁は、溝部２０がない二段開弁圧式燃料噴射弁を
用いたときと、ほとんど変わりのない性能が得られた。Fuel is injected under the same conditions including the engine speed, and the fuel consumption rate, smoke, N
When O x and the fuel injection amount are examined, as shown in FIG.
In terms of the respective performances, the two-stage valve opening pressure type fuel injection valve having the groove 20 has almost the same performance as when the two-stage valve opening pressure type fuel injection valve having no groove 20 is used.
【００４３】つまり、ディーゼルエンジンに影響を与え
ずに、燃焼騒音だけを低減することが確認された。さら
に溝部２０の大きさとの関係を調べた結果、図８に示さ
れるように溝部２０の幅寸法は、プレリフト量の４倍相
当の溝幅を有する溝部２０、プレリフト量の８倍相当の
溝幅を有する溝部２０では、上記したときと同じく、騒
音のほとんどの周波数領域で、かなりの騒音低減効果が
期待できることがわかった。That is, it was confirmed that only the combustion noise was reduced without affecting the diesel engine. Further, as a result of examining the relationship with the size of the groove portion 20, as shown in FIG. 8, the width dimension of the groove portion 20 has a groove width of 4 times the pre-lift amount and a groove width of 8 times the pre-lift amount. It has been found that, in the groove portion 20 having the same as above, a considerable noise reduction effect can be expected in most frequency regions of noise.
【００４４】また図９に示されるように溝部２０の深さ
寸法では、溝部２０の深さと幅とを掛けた値を同一（１
２Ｌ）とし、そのときの深さを変えるべく、プレリフト
量の３倍相当の深さを有する溝部２０、プレリフト量の
２倍相当の深さを有する溝部２０を用いて、アイドル燃
焼騒音を調べた結果、いずれも溝部２０が在る二段開弁
圧式燃料噴射弁の方が騒音が低減したことが確認され
た。Further, as shown in FIG. 9, in the depth dimension of the groove portion 20, the value obtained by multiplying the depth of the groove portion 20 by the width is the same (1
2L), in order to change the depth at that time, idle combustion noise was investigated using the groove portion 20 having a depth equivalent to three times the pre-lift amount and the groove portion 20 having a depth equivalent to twice the pre-lift amount. As a result, it was confirmed that the two-stage valve opening type fuel injection valve having the groove 20 reduced noise.
【００４５】このことから、溝部２０はプレリフト量の
２倍以上の深さ寸法で、かつ４倍以上の幅寸法を有して
形成されていれば、有効な効果が得られると考える。こ
の他、ニードル弁１のシール面４に溝部２０を設ける
と、ノズルサック部５も大きくせずにすみ、それによる
ディーゼルエンジンの影響、すなわち排出ガス性能が損
なわれたりすることはない。From this, it is considered that the effective effect can be obtained if the groove portion 20 is formed so as to have a depth dimension of at least twice the pre-lift amount and a width dimension of at least four times. In addition, if the groove portion 20 is provided on the seal surface 4 of the needle valve 1, the nozzle sack portion 5 does not have to be made large, and the influence of the diesel engine, that is, the exhaust gas performance is not impaired.
【００４６】なお、本発明は、第１の実施形態に限ら
ず、図１０に示す第２の実施形態、図１１に示す第３の
実施形態、図１２に示す第４の実施形態、図１３に示す
第５の実施形態、図１４に示す第６の実施形態のように
してもよい。The present invention is not limited to the first embodiment, but the second embodiment shown in FIG. 10, the third embodiment shown in FIG. 11, the fourth embodiment shown in FIG. 12, and the third embodiment shown in FIG. The fifth embodiment shown in FIG. 14 and the sixth embodiment shown in FIG. 14 may be used.
【００４７】すなわち、図１０に示す第２の実施形態
は、断面がほぼ三角形状をなした環状の溝部２０を採用
したものである。図１１に示す第３の実施形態は、断面
がほぼ円弧形をなした環状の溝部２０を採用したもので
ある。That is, the second embodiment shown in FIG. 10 employs an annular groove 20 having a substantially triangular cross section. The third embodiment shown in FIG. 11 employs an annular groove portion 20 having a substantially arcuate cross section.
【００４８】図１２に示す第４の実施形態は、断面がほ
ぼ逆Ｌ字形をなした環状の溝部２０を採用したものであ
る。図１３に示す第５の実施形態は、シール面４を形成
する斜面に対して直角をなす断面四角形状を有する環状
の溝部２０を採用したものである。特にこの溝部２０は
第１の実施形態の溝部２０に比べ加工がしやすい。The fourth embodiment shown in FIG. 12 employs an annular groove portion 20 having a substantially inverted L-shaped cross section. The fifth embodiment shown in FIG. 13 employs an annular groove 20 having a quadrangular cross section that is perpendicular to the slope forming the seal surface 4. In particular, the groove portion 20 is easier to process than the groove portion 20 of the first embodiment.
【００４９】こうした各溝部２０を採用しても、第１の
実施形態と同様の効果を奏する。むろん、図１４に示す
第６の実施形態のようにノズルサック部５が無いタイプ
の燃料噴射弁にも適用できることはいうまでもない。Even if each of the groove portions 20 is adopted, the same effect as that of the first embodiment can be obtained. Of course, it goes without saying that the present invention can also be applied to a fuel injection valve of the type that does not have the nozzle sack portion 5 as in the sixth embodiment shown in FIG.
【００５０】但し、図１０〜図１４において第１の実施
形態と同じ部分には、同一符号を付してその説明を省略
した。また上述したいずれの実施形態も、一条の溝部を
設けた例を挙げているが、複数の溝部、すなわち複数条
の溝部を採用しても構わない。なお、本発明をディーゼ
ルエンジンに適用したが、これに限らず、他の内燃機
関、例えば直接噴射式ガソリンエンジンにも適用しても
よい。However, in FIGS. 10 to 14, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted. Further, in each of the above-described embodiments, an example in which one groove portion is provided is given, but a plurality of groove portions, that is, a plurality of groove portions may be adopted. Although the present invention is applied to the diesel engine, the present invention is not limited to this, and may be applied to other internal combustion engines such as a direct injection gasoline engine.
【００５１】[0051]
【発明の効果】以上説明したように請求項１に記載の発
明によれば、針弁のシール面に在る環状の溝部は、初期
燃料噴射時だけに大きな流路抵抗として作用する。この
結果、エンジンに影響をあたえずに、初期燃料噴射率だ
けを、一層、低下させることができ、一層、着火燃焼を
緩慢にして、燃焼騒音を低減させることができる。As described above, according to the invention described in claim 1, the annular groove portion on the sealing surface of the needle valve acts as a large flow passage resistance only at the time of initial fuel injection. As a result, only the initial fuel injection rate can be further reduced without affecting the engine, and ignition combustion can be further slowed down and combustion noise can be reduced.
【００５２】しかも、針弁のシール面に溝部を形成する
ので、ノズルサック部を大きくせずにすむ。請求項２に
記載の発明によれば、上記請求項１の発明の効果に加
え、常に溝部による有効な効果が期待できる。Moreover, since the groove portion is formed on the sealing surface of the needle valve, it is not necessary to enlarge the nozzle sack portion. According to the invention of claim 2, in addition to the effect of the invention of claim 1, an effective effect of the groove can be expected at all times.
【図１】本発明の第１の実施形態の二段開弁式燃料噴射
弁の先端部回りを示す断面図。FIG. 1 is a cross-sectional view showing the vicinity of a front end portion of a two-stage valve opening type fuel injection valve according to a first embodiment of the present invention.
【図２】図１中のＸ−Ｘ線に沿うニードル弁の平断面
図。FIG. 2 is a plan sectional view of the needle valve taken along line XX in FIG.
【図３】同二段開弁式燃料噴射弁における初期燃料噴射
時の状態を説明するための断面図。FIG. 3 is a sectional view for explaining a state at the time of initial fuel injection in the two-stage valve opening type fuel injection valve.
【図４】同初期燃料噴射時において燃料が溝部を流れる
ときの挙動を説明するための断面図。FIG. 4 is a cross-sectional view for explaining the behavior when the fuel flows through the groove portion during the initial fuel injection.
【図５】二段開弁式燃料噴射弁における全噴射時の状態
を説明するための断面図。FIG. 5 is a cross-sectional view for explaining a state of full injection in a two-stage valve opening type fuel injection valve.
【図６】溝部が在る二段開弁式燃料噴射弁と、溝部がな
い二段開弁式燃料噴射弁とのアイドル燃焼騒音を対比し
て示す線図。FIG. 6 is a diagram showing the idle combustion noises of a two-stage open valve fuel injection valve having a groove portion and a two-stage open valve fuel injection valve having no groove portion for comparison.
【図７】同じく燃費、スモーク、ＮＯxなどを対比して
示す線図。FIG. 7 is a diagram showing a comparison of fuel consumption, smoke, NO x, etc.
【図８】溝部の溝幅とアイドル燃焼騒音との関係を示す
線図。FIG. 8 is a diagram showing a relationship between a groove width of a groove portion and idle combustion noise.
【図９】溝部の溝深さとアイドル燃焼騒音との関係を示
す線図。FIG. 9 is a diagram showing the relationship between the groove depth of the groove and the idle combustion noise.
【図１０】本発明の第２の実施形態の要部を示す断面
図。FIG. 10 is a sectional view showing a main part of a second embodiment of the present invention.
【図１１】本発明の第３の実施形態の要部を示す断面
図。FIG. 11 is a sectional view showing a main part of a third embodiment of the present invention.
【図１２】本発明の第４の実施形態の要部を示す断面
図。FIG. 12 is a sectional view showing a main part of a fourth embodiment of the present invention.
【図１３】本発明の第５の実施形態の要部を示す断面
図。FIG. 13 is a sectional view showing a main part of a fifth embodiment of the present invention.
【図１４】本発明の第６の実施形態の要部を示す断面
図。FIG. 14 is a sectional view showing a main part of a sixth embodiment of the present invention.
【図１５】従来の二段開弁式燃料噴射弁を説明するため
の断面図。FIG. 15 is a sectional view for explaining a conventional two-stage valve opening type fuel injection valve.
【図１６】同二段開弁式燃料噴射弁の初期燃料噴射時の
状態を説明するための断面図。FIG. 16 is a sectional view for explaining a state of the same two-stage valve opening type fuel injection valve at the time of initial fuel injection.
【図１７】同全噴射時の状態を説明するための断面図。FIG. 17 is a sectional view for explaining a state at the time of full injection.
【図１８】従来、提案されていた流路抵抗を増す構造を
説明するための断面図。FIG. 18 is a cross-sectional view for explaining a conventionally proposed structure for increasing flow path resistance.
【図１９】同初期燃料噴射時の状態を説明するための断
面図。FIG. 19 is a sectional view for explaining a state at the time of initial fuel injection.
１…ニードル弁 ２…ノズル本体 ３…着座面（第１のシール面） ４…シール面
（第２のシール面） ６…二段開弁圧機構 ７，８…プッシュロ
ッド ９，１０…スプリング部材 １４…噴孔 ２０…溝部 Ａ…流路。1 ... Needle valve 2 ... Nozzle body 3 ... Seating surface (first sealing surface) 4 ... Sealing surface (second sealing surface) 6 ... Two-stage valve opening pressure mechanism 7, 8 ... Push rod 9, 10 ... Spring member 14 ... Injection hole 20 ... Groove A ... Flow path.
Claims (2)
有し、針弁に前記シール面と接離して燃料の流れを遮断
する第２シール面を有し、かつ前記針弁が二段開弁圧機
構にて初期噴射時の開弁圧、全噴射の二段の開弁圧に規
制される二段開弁式燃料噴射弁において、 前記第２シール面に前記針弁の軸心回りに沿って環状の
溝部を形成したことを特徴とする二段開弁圧式燃料噴射
弁。1. A nozzle body having a conical first sealing surface, a needle valve having a second sealing surface that comes into contact with and separates from the sealing surface and blocks the flow of fuel, and the needle valve has a two-stage structure. In a two-stage valve opening type fuel injection valve in which the valve opening pressure mechanism regulates the valve opening pressure at the time of initial injection and the two-stage valve opening pressure of full injection, in the second seal surface, the axial center of the needle valve is rotated. A two-stage valve-opening pressure type fuel injection valve, characterized in that an annular groove is formed along the groove.
フトする針弁のプレリフト量の２倍以上の深さ寸法で、
かつ４倍以上の幅寸法を有して形成されていることを特
徴とする請求項１に記載の二段開弁圧式燃料噴射弁。2. The groove portion has a depth dimension which is at least twice the pre-lift amount of the needle valve lifted by the valve opening pressure of the initial injection,
The two-stage valve opening pressure type fuel injection valve according to claim 1, wherein the two-stage valve opening pressure fuel injection valve is formed to have a width dimension of four times or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17853695A JP3213515B2 (en) | 1995-07-14 | 1995-07-14 | Two-stage valve opening pressure type fuel injection valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17853695A JP3213515B2 (en) | 1995-07-14 | 1995-07-14 | Two-stage valve opening pressure type fuel injection valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0932696A true JPH0932696A (en) | 1997-02-04 |
| JP3213515B2 JP3213515B2 (en) | 2001-10-02 |
Family
ID=16050198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17853695A Expired - Lifetime JP3213515B2 (en) | 1995-07-14 | 1995-07-14 | Two-stage valve opening pressure type fuel injection valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3213515B2 (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002001065A1 (en) * | 2000-06-27 | 2002-01-03 | Robert Bosch Gmbh | Fuel injection valve for internal combustion engines |
| WO2002036961A1 (en) * | 2000-11-02 | 2002-05-10 | Siemens Aktiengesellschaft | Injection needle with elastic needle tip |
| JP2003508684A (en) * | 1999-09-04 | 2003-03-04 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Injection nozzle for internal combustion engine with ring groove in nozzle needle |
| JP2012007529A (en) * | 2010-06-24 | 2012-01-12 | Toyota Motor Corp | Fuel injection valve |
| JP2013234586A (en) * | 2012-05-08 | 2013-11-21 | Nippon Soken Inc | Fuel injection valve |
| CN106762303A (en) * | 2016-12-15 | 2017-05-31 | 江苏大学 | Jetting stability hole type nozzle during the commercial diesel engine for automobile of one kind control small oil mass |
| KR20220078488A (en) | 2020-12-03 | 2022-06-10 | 가부시키가이샤 자판엔진코포레숀 | Fuel injection valve and internal combustion engine for ship |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE69824555T2 (en) * | 1997-02-27 | 2005-06-30 | Asahi Kasei Kabushiki Kaisha | CONTINUOUSLY MOLDED ARTICLES OF POLYURETHANE, AND METHOD FOR THE PRODUCTION THEREOF |
-
1995
- 1995-07-14 JP JP17853695A patent/JP3213515B2/en not_active Expired - Lifetime
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003508684A (en) * | 1999-09-04 | 2003-03-04 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Injection nozzle for internal combustion engine with ring groove in nozzle needle |
| JP4709451B2 (en) * | 1999-09-04 | 2011-06-22 | ローベルト ボツシユ ゲゼルシヤフト ミツト ベシユレンクテル ハフツング | Injection nozzle for internal combustion engines with a ring groove in the nozzle needle |
| WO2002001065A1 (en) * | 2000-06-27 | 2002-01-03 | Robert Bosch Gmbh | Fuel injection valve for internal combustion engines |
| WO2002036961A1 (en) * | 2000-11-02 | 2002-05-10 | Siemens Aktiengesellschaft | Injection needle with elastic needle tip |
| JP2012007529A (en) * | 2010-06-24 | 2012-01-12 | Toyota Motor Corp | Fuel injection valve |
| JP2013234586A (en) * | 2012-05-08 | 2013-11-21 | Nippon Soken Inc | Fuel injection valve |
| CN106762303A (en) * | 2016-12-15 | 2017-05-31 | 江苏大学 | Jetting stability hole type nozzle during the commercial diesel engine for automobile of one kind control small oil mass |
| CN106762303B (en) * | 2016-12-15 | 2019-08-27 | 江苏大学 | Jetting stability hole type nozzle when a kind of commercial diesel engine for automobile of control small oil mass |
| KR20220078488A (en) | 2020-12-03 | 2022-06-10 | 가부시키가이샤 자판엔진코포레숀 | Fuel injection valve and internal combustion engine for ship |
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| JP3213515B2 (en) | 2001-10-02 |
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