JP2005139971A - Fuel injection valve - Google Patents

Fuel injection valve Download PDF

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JP2005139971A
JP2005139971A JP2003376058A JP2003376058A JP2005139971A JP 2005139971 A JP2005139971 A JP 2005139971A JP 2003376058 A JP2003376058 A JP 2003376058A JP 2003376058 A JP2003376058 A JP 2003376058A JP 2005139971 A JP2005139971 A JP 2005139971A
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valve
armature
fuel
passage
fuel injection
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JP3923935B2 (en
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Minoru Igura
穣 井倉
Masayuki Aota
雅之 青田
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve decreasing speed of a needle valve at a time of valve close while maintaining control response at a time of valve open. <P>SOLUTION: This valve is provided with a hollow cylinder type valve body 3, a valve seat 5 provided on one end of the valve body 3 and having a fluid injection hole 4 at a center thereof, the needle valve 6 moving in the valve body 3 and contacting and separating from the valve seat 5 with one end thereof to open and close the injection hole 4, an armature 8 fixed on another end of the needle valve 6 and including a fuel passage 20 therein, a hollow cylindrical core 9 provided with facing the armature 8, a solenoid device 15 provided on an outer circumference thereof, and a yoke 16 provide with keeping a predetermined gap from the outer circumference of the armature 8 and constructing a magnetic circuit as one body with the core 9. A fuel passage 20 provided in the armature 8 is formed in a shape gradually reducing area toward passage downstream side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

この発明は、内燃機関の燃焼室内に直接燃料を噴射する燃料噴射弁に関するものである。   The present invention relates to a fuel injection valve that injects fuel directly into a combustion chamber of an internal combustion engine.

従来の内燃機関用燃料噴射弁は、例えば、噴孔，これに連なる弁座，およびこの弁座の入口側に形成される案内孔を有する弁本体と、案内孔に往復動可能に案内され一端側に弁座に当接可能な当接部を有し他端側に平坦面をもつ頭部を有して弁座に接離可能な弁部材（ニードル弁）と、内部に燃料通路を有しその内周壁が弁部材の頭部に固定される筒状の可動鉄心（アマチュア）と、この可動鉄心の燃料入口側に隙間を介して設けられ、内部に燃料通路を有する筒状の固定鉄心（コア）と、弁座に弁部材の当接部を着座する方向に可動鉄心を付勢する付勢手段と、可動鉄心と固定鉄心の外周部に設けられ通電により励磁されて可動鉄心を固定鉄心側に吸引する電磁吸引力を発生する電磁コイルとを備え、弁部材の頭部の外壁と可動鉄心の内壁とにより区画形成される燃料通路部分は、可動鉄心の燃料入口側から燃料出口側まで、燃料通路面積変化率がほぼ一様になるように構成されている（特許文献１参照）。   A conventional fuel injection valve for an internal combustion engine has, for example, a valve body having an injection hole, a valve seat connected to the injection hole, and a guide hole formed on the inlet side of the valve seat, and is guided to the guide hole so as to be reciprocally movable. A valve member (needle valve) that has a contact portion that can contact the valve seat on the side and a head that has a flat surface on the other end and that can contact and separate from the valve seat, and a fuel passage inside A cylindrical movable iron core having an inner peripheral wall fixed to the head of the valve member, and a cylindrical fixed iron core provided with a fuel passage inside the movable iron core via a gap at the fuel inlet side (Core), an urging means for urging the movable iron core in the direction in which the contact portion of the valve member is seated on the valve seat, and an outer peripheral portion of the movable iron core and the fixed iron core that are excited by energization to fix the movable iron core. An electromagnetic coil that generates an electromagnetic attracting force attracted to the iron core side, the outer wall of the valve member head and the inner wall of the movable iron core Fuel passage portion is partitioned and formed from the fuel inlet side of the movable iron core to the fuel outlet, a fuel passage area change rate is configured to be substantially uniform by (see Patent Document 1).

特開平８−２３２８０１号公報（第２頁、図１および図２）JP-A-8-232801 (second page, FIGS. 1 and 2)

最近の内燃機関は、高出力化等の要求に応えるため、燃圧を高くする等の処置がとられる場合がある。従来の燃料噴射弁は、上記のように構成されており、可動鉄心部に形成された燃料通路のうち、ニードル弁頭部の円柱部に二面取り加工した面と円柱部が嵌合する可動鉄心内周面とで囲まれた部分の通路は、面積が上流側と下流側で同じになっている。従って、燃圧を高くするとそれに応じて閉弁時のニードル弁の速度は速くなる。弁速度が速くなると弁磨耗が促進される。また、特に閉弁時の速度が速くなると、ニードル弁が弁座に衝突するときの衝突音が大きくなり、更に、閉弁時のバウンスが大きくなって、ニードル弁と弁座の隙間から燃料が漏れてしまう、いわゆる後だれが発生し、デポジットの原因となる。そこで、閉弁時の速度を遅くするために従来の燃料通路の形状で断面積を小さくすれば、開弁時の応答性が悪くなるという問題点があった。   In recent internal combustion engines, measures such as increasing the fuel pressure may be taken in order to meet the demand for higher output. The conventional fuel injection valve is configured as described above, and in the fuel passage formed in the movable core portion, the movable core in which the cylindrical portion of the cylindrical portion of the needle valve head is fitted with the cylindrical portion is fitted. The passage surrounded by the inner peripheral surface has the same area on the upstream side and the downstream side. Accordingly, when the fuel pressure is increased, the speed of the needle valve when the valve is closed is correspondingly increased. As the valve speed increases, valve wear is promoted. In particular, when the speed at the time of closing the valve increases, the collision noise when the needle valve collides with the valve seat increases, and further, the bounce at the time of closing the valve increases, so that fuel flows from the gap between the needle valve and the valve seat. Leakage, or so-called sag occurs, causing deposits. Therefore, if the cross-sectional area is reduced in the shape of the conventional fuel passage in order to slow down the valve closing speed, there is a problem that the responsiveness at the time of valve opening becomes worse.

この発明は、上記のような問題点を解消するためになされたもので、開弁時の制御応答性を維持しつつ、閉弁時のニードル弁の速度を遅くすることにより、ニードル弁の摩耗と閉弁時の動作衝撃音を低減し、ニードル弁のバウンズを抑制することができる燃料噴射弁を得ることを目的とする。   The present invention has been made in order to solve the above-described problems. By maintaining the control responsiveness at the time of valve opening, the needle valve at the time of valve closing is slowed down so that the wear of the needle valve is reduced. An object of the present invention is to obtain a fuel injection valve that can reduce an operational impact sound when the valve is closed and can suppress bounce of the needle valve.

この発明に係わる燃料噴射弁は、中空円筒型の弁本体と、弁本体の一端に設けられ中心に流体の噴射孔を有する弁座と、弁本体内を移動し一端が上記弁座に離接して噴射孔を開閉するニードル弁と、ニードル弁の他端に固着させて設けられ内部に燃料通路を有するアマチュアと、アマチュアに対向して設けられた中空円筒状のコアと、コアの外周に設けられニードル弁を駆動させるソレノイド装置と、アマチュアの外周と所定の間隙をあけて設けられコアと一体で磁気回路を構成するヨークとを備え、コアの中空部に導入した燃料をアマチュアの燃料通路を経由して噴射孔から噴射させる燃料噴射弁において、アマチュアに設けた燃料通路は通路下流側に向けて面積が次第に小さくなるように形成したものである。   A fuel injection valve according to the present invention includes a hollow cylindrical valve body, a valve seat provided at one end of the valve body and having a fluid injection hole at the center thereof, and moves through the valve body, and one end is separated from the valve seat. A needle valve that opens and closes the injection hole, an armature that is fixed to the other end of the needle valve and that has a fuel passage inside, a hollow cylindrical core that faces the armature, and an outer periphery of the core A solenoid device that drives the needle valve, and a yoke that is provided with a predetermined gap from the outer periphery of the armature and forms a magnetic circuit integrally with the core, and the fuel introduced into the hollow portion of the core is disposed in the armature fuel passage. In the fuel injection valve that is injected from the injection hole via, the fuel passage provided in the amateur is formed so that the area gradually decreases toward the downstream side of the passage.

この発明の燃料噴射弁によれば、アマチュア部に設けられた燃料通路を通路下流側に向けて面積が次第に小さくなるように形成したので、開弁時の制御応答性を維持しつつ、閉弁時のニードル弁の速度を遅くすることができる。従って、ニードル弁の摩耗と閉弁時の動作衝撃音を低減でき、また、閉弁時のニードル弁のバウンズを抑制して後だれを防止することができる。   According to the fuel injection valve of the present invention, the fuel passage provided in the armature portion is formed so that the area gradually decreases toward the downstream side of the passage, so that the control responsiveness at the time of valve opening is maintained and the valve closing is performed. The speed of the needle valve at the time can be reduced. Accordingly, it is possible to reduce the wear of the needle valve and the operation impact sound when the valve is closed, and it is possible to prevent the needle valve from bouncing when the valve is closed and to prevent the back.

実施の形態１．
図１はこの発明の実施の形態１による燃料噴射弁の正面断面図である。図において、燃料噴射弁１は、その先端部に弁装置２を備えており、この弁装置２は、小径円筒部３ａおよび大径円筒部３ｂを持つ段付中空円筒形の弁本体３と、この弁本体３の小径円筒部３ａの先端に固着されて噴射孔４を有する弁座５と、弁本体３内を軸方向に移動し一端が弁座５に離接して噴射孔４を開閉するニードル弁６と、このニードル弁６を軸方向に案内するとともに噴射孔４に流れ込もうとする燃料に旋回運動を与える旋回体７とを備えている。ニードル弁６の他端、すなわち噴射孔４側と反対側には内部に後述の燃料通路２０を有するアマチュア８が溶接等により固着されて設けられており、ニードル弁６と一体で動くように構成されている。 Embodiment 1 FIG.
1 is a front sectional view of a fuel injection valve according to Embodiment 1 of the present invention. In the figure, the fuel injection valve 1 is provided with a valve device 2 at its tip, which is a stepped hollow cylindrical valve body 3 having a small diameter cylindrical portion 3a and a large diameter cylindrical portion 3b, The valve seat 5 is fixed to the tip of the small-diameter cylindrical portion 3a of the valve body 3 and has an injection hole 4. The valve seat 5 moves in the axial direction within the valve body 3, and one end is separated from the valve seat 5 to open and close the injection hole 4. A needle valve 6 and a swirling body 7 that guides the needle valve 6 in the axial direction and imparts a swirling motion to the fuel that is about to flow into the injection hole 4 are provided. On the other end of the needle valve 6, that is, on the side opposite to the injection hole 4 side, an armature 8 having a fuel passage 20 to be described later is fixed by welding or the like, and is configured to move integrally with the needle valve 6. Has been.

ニードル弁６およびアマチュア８の軸線上にアマチュア８と対向して所定の間隔を保ち中空円筒状のコア９が配置され、このコア９の中空部９ａにはスリーブ１０が位置調整されて固定されている。そして、スリーブ１０に一端を係止したスプリング１１によって、ニードル弁６を噴射孔４へ押圧する方向に付勢している。また、コア９の周囲にはにボビン１２に巻回されたコイル１３とコネクタ１４とを備えたソレノイド装置１５が配置されている。   A hollow cylindrical core 9 is disposed on the axis of the needle valve 6 and the armature 8 so as to face the armature 8 at a predetermined interval, and a sleeve 10 is positioned and fixed to the hollow portion 9a of the core 9. Yes. The needle valve 6 is urged in the direction of pressing the injection hole 4 by a spring 11 whose one end is locked to the sleeve 10. A solenoid device 15 including a coil 13 wound around a bobbin 12 and a connector 14 is disposed around the core 9.

アマチュア８の外周と所定の間隙をあけてヨーク１６が設けられており、この一端側は、ボビン１２とコイル１３とを包み込んでコア９に接続され、コア９と一体で磁気回路を構成している。他端側は、ストッパープレート１７を介して弁本体３の大径円筒部３ｂが挿入され、ヨーク１６の先端に設けた結合部１６ａを大径円筒部３ｂと小径円筒部３ａとの肩部３ｃ上に折り曲げて、かしめ等により固定されている。このように、ヨーク１６は弁本体３とアマチュア８とソレノイド装置１５の主要部とを収納するハウジングも兼ねている。このヨーク１６と同軸上に、コア９とコネクタ１４とを収納するハウジング１８が設けられており、こハウジング１８の先端部（図では上端側）は図示しない燃料供給管に接続され、燃料フィルタ１９を介してコア９の中空部９ａに燃料が導入されるようになっている。   A yoke 16 is provided with a predetermined gap from the outer periphery of the amateur 8, and one end side of the armature 8 encloses the bobbin 12 and the coil 13 and is connected to the core 9, and forms a magnetic circuit integrally with the core 9. Yes. On the other end side, the large-diameter cylindrical portion 3b of the valve body 3 is inserted through the stopper plate 17, and the joint portion 16a provided at the tip of the yoke 16 is connected to the shoulder portion 3c between the large-diameter cylindrical portion 3b and the small-diameter cylindrical portion 3a. It is bent upward and fixed by caulking or the like. Thus, the yoke 16 also serves as a housing that houses the valve body 3, the armature 8, and the main part of the solenoid device 15. A housing 18 for housing the core 9 and the connector 14 is provided coaxially with the yoke 16, and a front end portion (upper end side in the drawing) of the housing 18 is connected to a fuel supply pipe (not shown), and a fuel filter 19. The fuel is introduced into the hollow portion 9a of the core 9 via the.

図２は図１のＡ部の拡大図であり、（ａ）は正面断面図，（ｂ）は（ａ）を矢印Ｂ−Ｂから見た要部の図である。太矢印は燃料の流れ方向を示している。図のように、アマチュア８に設けた中空部にニードル弁６の一端を挿入し溶接等で固定しているが、このアマチュア８とニードル弁６との接合部を利用して燃料通路２０を形成している。すなわち、ニードル弁６のアマチュア８へ挿入される大径円柱部に、上流側（図で上部側）のほうを大きく下流側の方を小さく斜めに面カットを施し、このカット面とアマチュア８の内周面とで囲まれた空間を燃料通路２０とするものである。燃料通路２０の流路断面積は上流の流路断面積＞下流の流路断面積で、かつ、上流側から下流側に行くに従いなめらかに次第に小さくなるように形成されている。面積の割合は、上流側面積を下流側面積の約２倍以上にすることが望ましい。   2 is an enlarged view of a portion A in FIG. 1, (a) is a front sectional view, and (b) is a view of a main portion when (a) is viewed from an arrow BB. Thick arrows indicate the direction of fuel flow. As shown in the figure, one end of the needle valve 6 is inserted into a hollow portion provided in the armature 8 and fixed by welding or the like. A fuel passage 20 is formed by utilizing a joint portion between the armature 8 and the needle valve 6. doing. That is, a large-diameter cylindrical portion inserted into the armature 8 of the needle valve 6 is subjected to a surface cut obliquely on the upstream side (upper side in the figure) and on the downstream side in a small diagonal direction. A space surrounded by the inner peripheral surface is the fuel passage 20. The cross-sectional area of the fuel passage 20 is formed such that the upstream cross-sectional area> the downstream cross-sectional area, and gradually decreases gradually from the upstream side toward the downstream side. As for the ratio of the area, the upstream area is desirably about twice or more the downstream area.

次に動作について説明する。エンジンのマイコンより燃料噴射弁１の駆動回路であるソレノイド装置１５に動作信号が送られてコイル１３に電流が通電されると、アマチュア８と、コア９と、ヨーク１６とで構成される磁気回路に磁束が発生し、アマチュア８はコア９側へ吸引動作し、アマチュア８と一体構造であるニードル弁６が弁座５から離れてその部分に間隙が形成される。これにより、図示しない燃料供給管から供給される燃料圧力２ＭＰａ以上の高圧の燃料は、コア９の中空部９ａを通りアマチュア８に形成した燃料通路２０を経由して弁座５の噴射孔４から図示しない内燃機関のシリンダー内に噴射される。コイル１３への給電が遮断されると、スプリング１１の付勢力によってニードル弁６が弁座５側に移動し噴射孔４を閉孔する。   Next, the operation will be described. When an operation signal is sent from the microcomputer of the engine to the solenoid device 15 which is a drive circuit of the fuel injection valve 1 and a current is passed through the coil 13, a magnetic circuit composed of the armature 8, the core 9 and the yoke 16. Thus, the armature 8 is attracted to the core 9 side, and the needle valve 6 that is integral with the armature 8 is separated from the valve seat 5 so that a gap is formed in that portion. As a result, high-pressure fuel having a fuel pressure of 2 MPa or more supplied from a fuel supply pipe (not shown) passes through the hollow portion 9a of the core 9 and the fuel passage 20 formed in the armature 8 from the injection hole 4 of the valve seat 5. It is injected into a cylinder of an internal combustion engine (not shown). When the power supply to the coil 13 is cut off, the urging force of the spring 11 moves the needle valve 6 toward the valve seat 5 and closes the injection hole 4.

前述のように、アマチュア８に設けられた燃料通路２０は、その流路断面積が上流の流路断面積＞下流の流路断面積で、かつ、燃料通路の下流方向に向けてスムーズに流路面積が縮小しているので、開弁時には燃料通路２０は大きな流体抵抗を受けることがなくニードル弁６が高速で移動し、閉弁時には燃料通路２０部で流体抵抗を大きく受けるので、ニードル弁６の速度は遅くなる。   As described above, the fuel passage 20 provided in the armature 8 has a flow passage cross-sectional area that is upstream flow passage cross-sectional area> downstream flow passage cross-sectional area, and flows smoothly toward the downstream direction of the fuel passage. Since the road area is reduced, the fuel passage 20 does not receive a large fluid resistance when the valve is opened, and the needle valve 6 moves at a high speed. When the valve is closed, the fuel passage 20 receives a large fluid resistance. The speed of 6 becomes slow.

以上のように、本実施の形態の発明によれば、開弁時の制御応答性を維持しつつ、閉弁時のニードル弁の速度を遅くすることができるので、流量ダイナミックレンジの低下を抑制しながら、弁摩耗が低減でき、また、閉弁時の衝撃作動音を低減でき、更に、閉弁時にニードル弁が弁座に衝突するときのバウンズを抑制して、デポジットの原因となる燃料の後だれを防止することができる。   As described above, according to the invention of the present embodiment, the speed of the needle valve at the time of valve closing can be slowed while maintaining control responsiveness at the time of valve opening, thereby suppressing a decrease in flow rate dynamic range. However, it is possible to reduce valve wear, reduce the impact noise when the valve is closed, and suppress the bounce when the needle valve collides with the valve seat when the valve is closed, thereby reducing the fuel that causes deposits. It is possible to prevent any later.

なお、図２ではカット面を２箇所設けた場合について説明したが、１箇所または３箇所以上としても同様の効果を得ることができる。   In addition, although FIG. 2 demonstrated the case where two cut surfaces were provided, the same effect can be acquired even if it is one place or three places or more.

実施の形態２．
図３はこの発明の実施の形態２による燃料噴射弁の要部の拡大図であり、（ａ）は正面断面図，（ｂ）は（ａ）を矢印Ｃ−Ｃから見た要部の図である。図３に示す部分以外の全体構成については、実施の形態１で説明した図1と同等なので、それらの部分の符号と動作の説明は省略する。図１と異なるのは、図１のＡ部一点鎖線内の部分であり、この部分を拡大したものが図３である。（図１と同等部分は同一符号で示している。）本実施の形態では、図のように、ニードル弁２１の大径円柱部をアマチュア２２の内径部に密着挿入し、溶接などで固着している。そして、アマチュア２２の外周近傍の数箇所（図では４箇所）に、軸方向に貫通させたテーパ形状の孔を設けこれを燃料通路２３とするものである。テーパ方向は、上流（図では上部）を大きくし下流を小さくしている。 Embodiment 2. FIG.
3 is an enlarged view of a main part of a fuel injection valve according to Embodiment 2 of the present invention. FIG. 3 (a) is a front sectional view, and FIG. 3 (b) is a view of the main part as viewed from arrow CC. It is. Since the entire configuration other than the portion shown in FIG. 3 is the same as that of FIG. 1 described in the first embodiment, the description of the reference numerals and operations of those portions will be omitted. What is different from FIG. 1 is a portion in the A-dot chain line in FIG. 1, and FIG. 3 is an enlarged view of this portion. In this embodiment, as shown in the figure, the large diameter cylindrical portion of the needle valve 21 is closely inserted into the inner diameter portion of the armature 22 and fixed by welding or the like. ing. And the taper-shaped hole penetrated to the axial direction is provided in several places (4 places in a figure) of the outer periphery vicinity of the armature 22, and this is made into the fuel channel | path 23. FIG. In the taper direction, the upstream (upper part in the figure) is made larger and the downstream is made smaller.

次に動作について説明する。実施の形態１と同様に、ソレノイド装置のコイルへの電流のＯＮ−ＯＦＦによりニードル弁２１が上下しその先端が噴射孔に離接する。燃料噴射弁の外部から供給される燃料は、コア９の中空部９ａを通り、図の太矢印の方向に流れ、燃料通路２３を通り弁装置先端の噴射孔から噴射される。アマチュア２２に設けられた燃料通路２３は、上述のように上流の流路断面積＞下流の流路断面積で下流へ向かいスムーズに縮小しているので、開弁時は燃料通路２３による大きな流体抵抗を受けることなくニードル弁２１が図で上方へ移動し、閉弁時はスプリング１１の付勢力により図で下方に移動するが、このとき、燃料通路２３の面積が下流側で小さくなっているめ流体抵抗を大きく受けニードル弁２１の速度は遅くなる。   Next, the operation will be described. Similar to the first embodiment, the needle valve 21 is moved up and down by the ON / OFF of the current to the coil of the solenoid device, and the tip of the needle valve 21 comes into contact with the injection hole. The fuel supplied from the outside of the fuel injection valve flows through the hollow portion 9a of the core 9, flows in the direction of the thick arrow in the figure, passes through the fuel passage 23, and is injected from the injection hole at the tip of the valve device. As described above, the fuel passage 23 provided in the amateur 22 is smoothly reduced toward the downstream with the upstream flow passage cross-sectional area> the downstream flow passage cross-sectional area. The needle valve 21 moves upward in the figure without receiving resistance, and moves downward in the figure due to the urging force of the spring 11 when the valve is closed. At this time, the area of the fuel passage 23 is reduced on the downstream side. Therefore, the fluid resistance is greatly increased, and the speed of the needle valve 21 is decreased.

以上のように、本実施の形態の発明によれば、アマチュアに設けた燃料通路を下流に行くに従い狭くしたことによる実施の形態１と同様の効果を得られ、加えて、燃料通路をアマチュアとニードル弁の接合部ではなくアマチュア単体に孔開け加工により形成したので、通路加工時の寸法管理と加工が容易となる。   As described above, according to the present embodiment, the same effect as that of the first embodiment can be obtained by narrowing the fuel passage provided in the amateur as it goes downstream. Since the hole is formed in the armature alone, not in the joint portion of the needle valve, the dimension management and processing at the time of passage processing become easy.

実施の形態３．
図４はこの発明の実施の形態３による燃料噴射弁の要部の拡大図であり、（ａ）は正面断面図，（ｂ）は（ａ）を矢印Ｄ−Ｄから見た要部の図である。図４に示す部分以外の全体構成については、実施の形態１で説明した図1と同等なので、それらの部分の符号と動作の説明は省略する。図１と異なるのは、図１のＡ部一点鎖線内の部分であり、この部分を拡大したものが図４である。（図１と同等部分は同一符号で示している。）図のように、本実施の形態では、ニードル弁６は図１と同じであるが、アマチュア２４は外周側面の軸方向の一部に全周にわたり他の部分より外径を大きくした大径部２４ａを設け、外周側面とヨーク１６との隙間２５を軸方向の一部において他の部分より狭くした形状としている。 Embodiment 3 FIG.
4 is an enlarged view of a main part of a fuel injection valve according to Embodiment 3 of the present invention. FIG. 4 (a) is a front sectional view, and FIG. 4 (b) is a view of the main part as viewed from arrow DD. It is. Since the entire configuration other than the portion shown in FIG. 4 is the same as that of FIG. 1 described in the first embodiment, the reference numerals and operations of those portions are omitted. What is different from FIG. 1 is a portion in the A-dot chain line in FIG. 1, and FIG. 4 is an enlarged view of this portion. (Equivalent parts in FIG. 1 are denoted by the same reference numerals.) As shown in the figure, in this embodiment, the needle valve 6 is the same as in FIG. A large-diameter portion 24a having an outer diameter larger than that of other portions is provided over the entire circumference, and a gap 25 between the outer peripheral side surface and the yoke 16 is narrower than other portions in a part of the axial direction.

次に動作について説明する。燃料噴射弁の基本動作は実施の形態１と同様なので、説明は省略する。アマチュア２４の外周側面とヨーク１６との隙間２５（以下サイドギャップと称する）は、磁気通路として作用している。従って、サイドギャップ２５は狭い方が好ましいが、狭すぎると電流ＯＦＦ時（磁気回路遮断時）の応答性が悪くなる。そこで、仕様によっても異なるが、通常２００μｍ前後を確保している。このため、サイドギャップ２５にも燃料の一部が流れる。アマチュア２４に設けた燃料通路２０は下流に行くほど狭く絞っているために、燃料通路をストレートに形成した従来のものに比べ、サイドギャップ２５側に流れる（漏れる）燃料が増えてくる。そこで、磁気通路としての適正な間隔を確保しつつサイドギャップ２５側への燃料の流れを少なくするために、大径部２４ａを設けたものである。従って、大径部２４ａの軸方向の寸法はわずかでよい。また、大径部２４ａにおけるサイドギャップ２５の間隙は１００μｍ程度以下にするのが望ましい。   Next, the operation will be described. Since the basic operation of the fuel injection valve is the same as that of the first embodiment, the description thereof is omitted. A gap 25 (hereinafter referred to as a side gap) between the outer peripheral side surface of the amateur 24 and the yoke 16 acts as a magnetic path. Accordingly, the side gap 25 is preferably narrow, but if it is too narrow, the response when the current is OFF (when the magnetic circuit is cut off) is deteriorated. Therefore, although it depends on the specifications, it is usually secured around 200 μm. For this reason, part of the fuel also flows in the side gap 25. Since the fuel passage 20 provided in the amateur 24 is narrowed toward the downstream, the fuel flowing (leaking) to the side gap 25 side is increased as compared with the conventional one in which the fuel passage is formed straight. Therefore, a large diameter portion 24a is provided in order to reduce the flow of fuel to the side gap 25 side while ensuring an appropriate interval as a magnetic path. Therefore, the dimension of the large diameter portion 24a in the axial direction may be small. In addition, the gap of the side gap 25 in the large diameter portion 24a is desirably about 100 μm or less.

以上のように、本実施の形態の発明によれば、実施の形態１の効果に加え、アマチュアの外周側面に大径部を設けてその部分でサイドギャップの間隔を狭めるようにしたため、磁気通路としての適正な間隔を保ちながらサイドギャップへの燃料の流れを抑制できるので、閉弁時にニードル弁の速度を減速させる効果を更に高めることができる。   As described above, according to the invention of the present embodiment, in addition to the effects of the first embodiment, the large-diameter portion is provided on the outer peripheral side surface of the amateur and the interval of the side gap is narrowed at that portion. Since the fuel flow to the side gap can be suppressed while maintaining an appropriate interval, the effect of reducing the speed of the needle valve when the valve is closed can be further enhanced.

なお、燃料通路２０は図のようにニードル弁とアマチュアの嵌合部に形成したものについて説明したが、実施の形態２で説明した図３の燃料通路２３のようなものでも良い。   The fuel passage 20 has been described as being formed in the fitting portion between the needle valve and the armature as shown in the figure, but may be the fuel passage 23 of FIG. 3 described in the second embodiment.

実施の形態４．
図５はこの発明の実施の形態４による燃料噴射弁の要部の拡大図であり、（ａ）は正面断面図，（ｂ）は（ａ）を矢印Ｅ−Ｅから見た要部の図である。図５に示す部分以外の全体構成については、実施の形態１で説明した図1と同等なので、それらの部分の符号と動作の説明は省略する。図１と異なるのは、図１のＡ部一点鎖線内の部分であり、この部分を拡大したものが図５である。（図１と同等部分は同一符号で示している。）また、図５のニードル弁２１，アマチュア２２，燃料通路２３は実施の形態２の図３で説明したものと同等なので、それらの説明も省略し、異なる部分のみを以下に説明する。 Embodiment 4 FIG.
5 is an enlarged view of a main part of a fuel injection valve according to Embodiment 4 of the present invention. FIG. 5 (a) is a front cross-sectional view, and FIG. 5 (b) is a view of the main part as viewed from arrow EE. It is. Since the entire configuration other than the portion shown in FIG. 5 is the same as that of FIG. 1 described in the first embodiment, the reference numerals and description of the operation of those portions are omitted. What is different from FIG. 1 is a portion in the A-dot chain line in FIG. 1, and FIG. 5 is an enlarged view of this portion. (The same parts as those in FIG. 1 are denoted by the same reference numerals.) Further, the needle valve 21, the armature 22 and the fuel passage 23 in FIG. 5 are equivalent to those described in FIG. Omitted and only the different parts will be described below.

本実施の形態のアマチュア２２には、その外周側面に非磁性材料からなるメッキ２６を、アマチュア２２の移動を妨げない範囲の厚さで施している。アマチュア２２とヨーク１６との隙間であるサイドギャップ２５は磁気通路として作用しているので狭い方が好ましいが、狭すぎると電流ＯＦＦ時（磁気回路遮断時）の応答性が悪くなる。そこで、仕様によっても異なるが、通常２００μｍ前後を確保している。従って、サイドギャップ２５にも燃料の一部が流れる（漏れる）が、メッキ２６を施すことによりサイドギャップ２５が狭まるので、燃料はサイドギャップ２５側にはほとんど流れなくなり、アマチュア２２に設けた燃料通路２３を主に流れるようになる。アマチュア２２とヨーク１６と隙間を約２００μｍとした場合、最終的なサイドギャップ２５は１００μｍ以下程度にするのが望ましいので、メッキの厚さは例えば１００μｍ程度とる。一度のメッキで厚さを確保するのが難しければ多層メッキとすればよい。メッキの厚さを変えることで、自由にギャップを調整することができる。   The armature 22 of the present embodiment is provided with a plating 26 made of a nonmagnetic material on the outer peripheral side thereof with a thickness that does not hinder the movement of the armature 22. The side gap 25, which is the gap between the amateur 22 and the yoke 16, acts as a magnetic path, so it is preferable that the side gap 25 be narrow. However, if it is too narrow, the responsiveness when the current is OFF (when the magnetic circuit is cut off) deteriorates. Therefore, although it depends on the specifications, it is usually secured around 200 μm. Accordingly, a part of the fuel flows (leaks) also in the side gap 25, but the side gap 25 is narrowed by applying the plating 26, so that the fuel hardly flows to the side gap 25 side, and the fuel passage provided in the armature 22 23 mainly flows. When the gap between the amateur 22 and the yoke 16 is about 200 μm, the final side gap 25 is desirably about 100 μm or less, and therefore the plating thickness is about 100 μm, for example. If it is difficult to ensure the thickness with a single plating, a multilayer plating may be used. By changing the plating thickness, the gap can be adjusted freely.

以上のように、本実施の形態の発明によれば、アマチュアに設けた燃料通路を下流側ほど狭くしたための実施の形態１，２の効果に加え、アマチュアとヨークとの隙間であるサイドギャップをアマチュアの側面に非磁性のメッキを施すことにより狭くしたので、磁気通路としての適正な間隔を保ちながらサイドギャップに流れる燃料の流路を絞ることができ、閉弁時にニードル弁の速度を減速させる効果を更に高めることができる。また、ギャップ調整はメッキ厚さを変えることにより、簡単にコントロールできる。   As described above, according to the invention of the present embodiment, in addition to the effects of the first and second embodiments for narrowing the fuel passage provided in the amateur toward the downstream side, the side gap that is the gap between the amateur and the yoke is reduced. Since it is narrowed by applying non-magnetic plating to the side of the amateur, the flow path of the fuel flowing in the side gap can be narrowed while maintaining an appropriate interval as a magnetic path, and the speed of the needle valve is reduced when the valve is closed The effect can be further enhanced. The gap adjustment can be easily controlled by changing the plating thickness.

なお、アマチュアに設けた燃料通路は、軸方向に貫通させたテーパ形状の孔として説明したが、実施の形態１で説明した図２の燃料通路２０のようなものでも良い。   Although the fuel passage provided in the amateur has been described as a tapered hole penetrating in the axial direction, it may be the fuel passage 20 of FIG. 2 described in the first embodiment.

内燃機関の燃料室内に直接燃料を噴射する燃料噴射弁で、特に、燃圧が高く弁速度の高い燃料噴射弁に適用して効果を上げることができる。   A fuel injection valve that directly injects fuel into a fuel chamber of an internal combustion engine, and in particular, can be applied to a fuel injection valve that has a high fuel pressure and a high valve speed, thereby improving the effect.

この発明の実施の形態１による燃料噴射弁を示す正面断面図である。It is front sectional drawing which shows the fuel injection valve by Embodiment 1 of this invention. 図１の要部拡大図である。It is a principal part enlarged view of FIG. この発明の実施の形態２による燃料噴射弁の要部拡大図である。It is a principal part enlarged view of the fuel injection valve by Embodiment 2 of this invention. この発明の実施の形態３による燃料噴射弁の要部拡大図である。It is a principal part enlarged view of the fuel injection valve by Embodiment 3 of this invention. この発明の実施の形態４による燃料噴射弁の要部拡大図である。It is a principal part enlarged view of the fuel injection valve by Embodiment 4 of this invention.

符号の説明Explanation of symbols

３ 弁本体 ４ 噴射孔
５ 弁座 ６，２１ ニードル弁
８，２２，２４ アマチュア ９ コア
１５ ソレノイド装置 １６ ヨーク
２０，２３ 燃料通路 ２４ａ 大径部
２５ サイドギャップ ２６ メッキ。 3 Valve body 4 Injection hole 5 Valve seat 6, 21 Needle valve 8, 22, 24 Amateur 9 Core 15 Solenoid device 16 Yoke 20, 23 Fuel passage 24a Large diameter part 25 Side gap 26 Plating.

Claims (4)

中空円筒型の弁本体と、上記弁本体の一端に設けられ中心に流体の噴射孔を有する弁座と、上記弁本体内を移動し一端が上記弁座に離接して上記噴射孔を開閉するニードル弁と、上記ニードル弁の他端に固着させて設けられ内部に燃料通路を有するアマチュアと、上記アマチュアに対向して設けられた中空円筒状のコアと、上記コアの外周に設けられ上記ニードル弁を駆動させるソレノイド装置と、上記アマチュアの外周と所定の間隙をあけて設けられ上記コアと一体で磁気回路を構成するヨークとを備え、上記コアの中空部に導入した燃料を上記アマチュアの上記燃料通路を経由して上記噴射孔から噴射させる燃料噴射弁において、上記アマチュアに設けた上記燃料通路は通路下流側に向けて面積が次第に小さくなるように形成したことを特徴とする燃料噴射弁。   A hollow cylindrical valve main body, a valve seat provided at one end of the valve main body and having a fluid injection hole at the center, and moving through the valve main body, one end being separated from the valve seat and opening and closing the injection hole A needle valve, an armature fixed to the other end of the needle valve and having a fuel passage therein; a hollow cylindrical core provided facing the armature; and the needle provided on the outer periphery of the core A solenoid device that drives the valve; and a yoke that is provided with a predetermined gap from the outer periphery of the armature and that forms a magnetic circuit integrally with the core, and the fuel introduced into the hollow portion of the core is the armature of the armature In the fuel injection valve for injecting from the injection hole through the fuel passage, the fuel passage provided in the armature is formed so that the area gradually decreases toward the downstream side of the passage. Fuel injection valve for the butterflies. 請求項１記載の燃料噴射弁において、上記燃料通路は通路下流側の方が小さいテーパ形状の孔であることを特徴とする燃料噴射弁。   2. The fuel injection valve according to claim 1, wherein the fuel passage is a tapered hole which is smaller on the downstream side of the passage. 請求項１または請求項２記載の燃料噴射弁において、上記アマチュアの外周側面の軸方向の一部に全周にわたり他の部分より外径を大きくした大径部を設け、上記外周側面と上記ヨークとの間隙を上記大径部において上記他の部分より狭くしたことを特徴とする燃料噴射弁。   3. The fuel injection valve according to claim 1, wherein a large-diameter portion having an outer diameter larger than that of the other part is provided on a part of the outer peripheral side surface of the armature in an axial direction, and the outer peripheral side surface and the yoke. A fuel injection valve characterized in that the large-diameter portion is narrower than the other portions. 請求項１または請求項２記載の燃料噴射弁において、上記アマチュアの外周側面に非磁性材料からなるメッキを施したことを特徴とする燃料噴射弁。   3. The fuel injection valve according to claim 1, wherein the outer peripheral side surface of the armature is plated with a nonmagnetic material.
JP2003376058A 2003-11-05 2003-11-05 Fuel injection valve Expired - Fee Related JP3923935B2 (en)

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Cited By (6)

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Publication number Priority date Publication date Assignee Title
WO2008038396A1 (en) * 2006-09-25 2008-04-03 Hitachi, Ltd. Fuel injection valve
WO2008038395A1 (en) * 2006-09-25 2008-04-03 Hitachi, Ltd. Fuel injection valve
WO2013031422A1 (en) * 2011-08-31 2013-03-07 日立オートモティブシステムズ株式会社 Control apparatus for fuel injection valve
CN103016226A (en) * 2011-09-27 2013-04-03 日立汽车***株式会社 Fuel injector
JP2014169706A (en) * 2014-06-27 2014-09-18 Denso Corp Fuel injection valve
JP2016217242A (en) * 2015-05-20 2016-12-22 株式会社デンソー Fuel injection device

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008038396A1 (en) * 2006-09-25 2008-04-03 Hitachi, Ltd. Fuel injection valve
WO2008038395A1 (en) * 2006-09-25 2008-04-03 Hitachi, Ltd. Fuel injection valve
CN101506511B (en) * 2006-09-25 2011-10-26 株式会社日立制作所 Fuel injection valve
US8104698B2 (en) 2006-09-25 2012-01-31 Hitachi, Ltd. Fuel injection valve
CN101506510B (en) * 2006-09-25 2012-07-11 株式会社日立制作所 Fuel injection valve
US8230839B2 (en) 2006-09-25 2012-07-31 Hitachi, Ltd. Fuel injection valve
WO2013031422A1 (en) * 2011-08-31 2013-03-07 日立オートモティブシステムズ株式会社 Control apparatus for fuel injection valve
JP2013050065A (en) * 2011-08-31 2013-03-14 Hitachi Automotive Systems Ltd Control device for fuel injection valve
CN103732890A (en) * 2011-08-31 2014-04-16 日立汽车***株式会社 Control apparatus for fuel injection valve
US9376982B2 (en) 2011-08-31 2016-06-28 Hitachi Automotive Systems, Ltd. Control apparatus for fuel injector
CN103016226A (en) * 2011-09-27 2013-04-03 日立汽车***株式会社 Fuel injector
JP2013072298A (en) * 2011-09-27 2013-04-22 Hitachi Automotive Systems Ltd Fuel injection valve
JP2014169706A (en) * 2014-06-27 2014-09-18 Denso Corp Fuel injection valve
JP2016217242A (en) * 2015-05-20 2016-12-22 株式会社デンソー Fuel injection device

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