JP2009167924A

JP2009167924A - Injector

Info

Publication number: JP2009167924A
Application number: JP2008007647A
Authority: JP
Inventors: Tomoaki Fukuoka; 智昭福岡; Ryota Nakamura; 良太中村
Original assignee: Nikki Co Ltd
Current assignee: Nikki Co Ltd
Priority date: 2008-01-17
Filing date: 2008-01-17
Publication date: 2009-07-30

Abstract

<P>PROBLEM TO BE SOLVED: To easily obtain high fuel amount adjusting accuracy in a normally-closed type injector supporting a valve body by a plate-like valve spring. <P>SOLUTION: In this electromagnetic drive type injector 1A, a valve body 4A and a movable iron core 2c are supported by a plate-like valve spring 5 and energized in a valve-closing direction, and a valve-closing state is maintained while a current is not carried. A second coil-like valve spring 6 energizing the valve body 4A in the valve-closing direction is provided, and two valve springs 5, 6 incorporate with each other and act on the valve body 4a by double spring loads. A spring pressure displacing spring 7 is provided as a spring load adjusting mechanism for adjusting a spring load of the second valve spring 6 from the outside, and the spring pressure displacing spring 7 is operated from the outside, so that a spring load finally acting on the valve body 4A can be adjusted and set. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

本発明は、エンジンが要求する流量の燃料を噴射するための電磁駆動式のインジェクタに関し、殊に、開閉弁（燃料調量バルブ）の弁体が板状の弁バネ中央部で支持されるとともに、弁バネのバネ荷重により弁シートに押しつけられて閉弁する常閉式のインジェクタに関する。 The present invention relates to an electromagnetically driven injector for injecting fuel of a flow rate required by an engine, and in particular, a valve body of an on-off valve (fuel metering valve) is supported by a plate-like valve spring central portion. The present invention relates to a normally closed injector that is closed by being pressed against a valve seat by a spring load of a valve spring.

電磁コイルに通電して励磁させることにより可動鉄心を吸引して開閉弁を開弁させる電磁駆動式のインジェクタは、例えば実開昭６１―１０５７５６号公報に記載されており、図２（Ａ）の縦断面部分図に示すように開閉弁の弁体４Ｂを板状の弁バネ５で支持（ホールド）しながらそのシール面をシート部材３の弁シートに押しつけて閉弁状態を維持させるように配置した常閉式のインジェクタ１Ｂが知られている。そして、その弁バネ５は図２（Ｂ）の平面図に示すように、金属製の薄板を円盤状に形成してなるものである。 An electromagnetically driven injector that opens an on-off valve by attracting a movable iron core by energizing and exciting an electromagnetic coil is described in, for example, Japanese Utility Model Laid-Open No. 61-105756, as shown in FIG. As shown in the longitudinal sectional partial view, the valve body 4B of the on-off valve is supported (held) by a plate-like valve spring 5, and the sealing surface is pressed against the valve seat of the seat member 3 to maintain the valve closed state. A normally closed injector 1B is known. The valve spring 5 is formed by forming a thin metal plate into a disk shape as shown in the plan view of FIG.

このような構成のインジェクタ１Ｂは、一般的にはホールド型のインジェクタと呼ばれ、可動鉄心を摺動させるプランジャ型のインジェクタにおいて燃料を潤滑剤として使用できないガス燃料を使用する際に摩耗耐久性の問題が生じていたのに対し、図２（Ｃ）の分解図に示すように弁バネ５で弁体４Ｂを浮遊状態にしてホールドするため、固定鉄心２ｅに対する可動鉄心２ｃまたは弁体４Ｂの摺動部がなく、摩耗耐久性の問題が殆ど生じないという利点がある。 The injector 1B having such a configuration is generally called a hold-type injector, and has wear durability when using a gas fuel that cannot use fuel as a lubricant in a plunger-type injector that slides a movable iron core. Although the problem has occurred, as shown in the exploded view of FIG. 2C, the valve body 4B is floated and held by the valve spring 5, so that the sliding of the movable core 2c or the valve body 4B with respect to the fixed core 2e. There is no moving part, and there is an advantage that the problem of wear durability hardly occurs.

しかしながら、このホールド型のインジェクタ１Ｂは、構成部品寸法の組み合わせでバネ荷重が定まる構成であることから、燃料調量精度は部品組み付けのバラツキによる影響を大きく受ける特性がある。即ち、図３の拡大部分図に示すように、インジェクタ本体ボディの組立て時に弁バネ５の端縁側を固定する際、弁体４Ｂがシート部材３の弁シートに押しつけられた状態での弁バネ５の変形量によるバネ荷重により燃料調量精度が決定される。 However, since the hold type injector 1B has a configuration in which the spring load is determined by a combination of component dimensions, the fuel metering accuracy has a characteristic that it is greatly affected by variations in component assembly. That is, as shown in the enlarged partial view of FIG. 3, the valve spring 5 in a state where the valve body 4 </ b> B is pressed against the valve seat of the seat member 3 when the end edge side of the valve spring 5 is fixed when the injector body is assembled. The fuel metering accuracy is determined by the spring load due to the deformation amount.

そのため、各部品の寸法誤差や組み付けの僅かな誤差が燃料調量精度に大きな影響を与えることになるため、このようなホールド型のインジェクタ１Ａにおいては完成した製品間の燃料調量精度のバラツキ大きくなりやすく、且つ、高い燃料調量精度を実現することが困難となりやすい、という問題がある。
実開昭６１―１０５７５６号公報 For this reason, the dimensional error of each component and the slight error in assembly greatly affect the fuel metering accuracy. In such a hold-type injector 1A, the fuel metering accuracy between finished products greatly varies. There is a problem that it is likely to be difficult and it is difficult to achieve high fuel metering accuracy.
Japanese Utility Model Publication No. 61-105756

本発明は、上記のような問題点を解決しようとするものであり、板状の弁バネで弁体を支持する常閉式のインジェクタについて、高い燃料調量精度を容易に実現できるようにすることを課題とする。 SUMMARY OF THE INVENTION The present invention is intended to solve the above-described problems, and it is possible to easily realize high fuel metering accuracy for a normally closed injector that supports a valve body with a plate-shaped valve spring. Is an issue.

そこで、本発明は、弁体及び可動鉄心が板状の弁バネで支持されるとともに閉弁方向に付勢され、非通電時に閉弁状態を維持する電磁駆動式のインジェクタにおいて、弁体を閉弁方向に付勢するコイル状の第２の弁バネが設けられ、２つの弁バネが協働して二重のバネ荷重で弁体に作用するものとされ、且つ、この第２の弁バネのバネ荷重を外部から調整するためのバネ荷重調整機構を備えており、このバネ荷重調整機構を外部から操作することにより、弁体に最終的に作用するバネ荷重を調整・設定可能とした。 Therefore, the present invention provides an electromagnetically driven injector in which a valve body and a movable iron core are supported by a plate-shaped valve spring and are energized in the valve closing direction to maintain the valve closed state when not energized. A coil-shaped second valve spring that biases in the valve direction is provided, and the two valve springs cooperate to act on the valve body with a double spring load. The second valve spring A spring load adjustment mechanism for adjusting the spring load of the valve body from the outside is provided. By operating the spring load adjustment mechanism from the outside, the spring load that finally acts on the valve body can be adjusted and set.

このように、板状の第１の弁バネに加えてコイル状の第２の弁バネを配置し、第２の弁バネのバネ荷重を外部から調整可能としたことにより、インジェクタの組立て後に所望のバネ荷重に設定することができるため、各部品の寸法精度や組み付け状態にバラツキがあっても、高い燃料調量精度を均一に確保することが容易となる。 As described above, the coil-shaped second valve spring is arranged in addition to the plate-shaped first valve spring, and the spring load of the second valve spring can be adjusted from the outside, so that it is desirable after assembly of the injector. Therefore, even if there is a variation in the dimensional accuracy and assembly state of each part, it is easy to ensure high fuel metering accuracy evenly.

また、この場合、そのバネ荷重調整機構は、固定鉄心の中心軸線を貫通する貫通孔に、その中心軸線に沿ってコイル状の第２の弁バネが挿設されているとともに第２の弁バネ基端側に略円柱状のスライド部材が螺設されて可動鉄心との間に第２の弁バネを圧縮状態にして挟み込んでおり、このスライド部材を外部からネジ式に回動させながら貫通孔中を摺動させることにより、第２の弁バネの圧縮幅を変更して所望のバネ荷重に調整・設定することを特徴としたものとすれば、バネ荷重の設定が極めて容易であるとともにその微調整も容易なものとなる。 In this case, the spring load adjustment mechanism includes a second valve spring in which a coil-shaped second valve spring is inserted along a central axis of a through hole that passes through the central axis of the fixed iron core. A substantially cylindrical slide member is screwed on the base end side, and the second valve spring is sandwiched between the movable iron core in a compressed state, and the through-hole is formed while rotating the slide member from the outside in a screw manner. If the compression width of the second valve spring is changed and adjusted and set to a desired spring load by sliding the inside, setting of the spring load is extremely easy and Fine adjustment is also easy.

板状の第１の弁バネに加えコイル状の第２の弁バネを外部からバネ圧調整可能な状態で設けた本発明によると、高い燃料調量精度を容易に実現することができる。 According to the present invention in which the coil-shaped second valve spring is provided in addition to the plate-shaped first valve spring in a state in which the spring pressure can be adjusted from the outside, high fuel metering accuracy can be easily realized.

以下に、図面を参照しながら本発明を実施するための最良の形態を説明する。 The best mode for carrying out the present invention will be described below with reference to the drawings.

図１（Ａ）は、本発明における実施の形態であるインジェクタ１Ａの開閉弁部分を中心とした縦断面部分図を示している。インジェクタ１Ａは、電磁コイル２ａ、固定鉄心２ｂ、可動鉄心２ｃを備えた電磁駆動式のインジェクタ（燃料噴射弁）であり、可動鉄心２ｃの下側（下流側）には弁体４Ａが設けられ、これらが弁ストローク方向に対し直角に設けられた円形・板状の板バネである、弁バネ５により支持されてなる、所謂ホールド型のインジェクタである。 FIG. 1 (A) shows a longitudinal sectional partial view centering on an opening / closing valve portion of an injector 1A according to an embodiment of the present invention. The injector 1A is an electromagnetically driven injector (fuel injection valve) including an electromagnetic coil 2a, a fixed iron core 2b, and a movable iron core 2c, and a valve body 4A is provided on the lower side (downstream side) of the movable iron core 2c. These are so-called hold-type injectors supported by a valve spring 5 which is a circular / plate-shaped leaf spring provided at a right angle to the valve stroke direction.

また、弁体４Ａの下方には弁シートを構成する筒状のシート部材３が配設されてこれらで開閉弁を構成しており、弁体４Ａのシール面がシート部材３の弁シートに密着する閉弁時において、弁バネ５は中央部が僅かに上向きに持ち上げられて凸状に弾性変形した状態となっており、その弾性反発力により閉弁方向のバネ荷重が発生している。尚、上述した構成部分は、図２に示した従来型のインジェクタ１Ｂとほぼ同様であり周知の構成である。 Further, a cylindrical seat member 3 constituting a valve seat is disposed below the valve body 4A to constitute an on-off valve, and the sealing surface of the valve body 4A is in close contact with the valve seat of the seat member 3 When the valve is closed, the valve spring 5 is in a state where the central portion is lifted slightly upward and elastically deformed in a convex shape, and a spring load in the valve closing direction is generated by the elastic repulsive force. The components described above are substantially the same as the conventional injector 1B shown in FIG.

そして、図１（Ｂ）の弁構造部分の分解図に示すように、可動鉄心２ｃの上面略中央部分には第２の弁バネであるコイル状の弁バネ６が、弁ストローク方向に沿って設けられ、開閉弁の弁体４Ａを閉弁方向に付勢するように上下に圧縮された状態で配設されており、上述した第１の弁バネ５と協働して弁体４Ａを閉弁方向に付勢するようになっており、バネ荷重が二重に作用する。 As shown in the exploded view of the valve structure portion in FIG. 1B, a coiled valve spring 6 as a second valve spring is provided along the valve stroke direction at a substantially central portion of the upper surface of the movable iron core 2c. The valve body 4A of the on-off valve is disposed in a vertically compressed state so as to urge the valve body 4A in the valve closing direction. The valve body 4A is closed in cooperation with the first valve spring 5 described above. The valve is biased in the direction of the valve, and the spring load acts twice.

さらに、本実施の形態においては、外部からバネ荷重を調整可能とするバネ荷重調整機構の一部を構成するバネ変位ネジ７が、その外周面の一部と固定鉄心２ｂの中心を貫通した貫通孔２０の内周面の一部とでネジ構造を構成して貫通孔２０内に螺設され、ネジ式に回動することにより摺動するスライド部材として配設されており、コイル状の弁バネ６の基端側に密着してこれを可動鉄心２ｃとで圧縮状態にして挟み込んでいる。 Further, in the present embodiment, the spring displacement screw 7 constituting a part of the spring load adjusting mechanism capable of adjusting the spring load from the outside penetrates a part of the outer peripheral surface and the center of the fixed iron core 2b. A screw structure is formed with a part of the inner peripheral surface of the hole 20 and is screwed into the through hole 20, and is arranged as a slide member that slides by rotating in a screw manner. The spring 6 is in close contact with the proximal end side and is sandwiched between the movable iron core 2c in a compressed state.

このような構成のインジェクタ１Ａは、弁機構部の反対側の端部外側からドライバー等を用いて外側からバネ変位ネジ７を回動させることにより、固定鉄心２ｂの貫通孔２０内でバネ変位ネジ７を弁ストローク方向（貫通孔２０の中心軸線に一致）に沿って摺動させるとともに所望の位置で固定させることができ、バネ変位ネジ７の先端側と可動鉄心２ｃの基端側との間に挟まれたコイル状の弁バネ６を、所望の圧縮幅にしてそのバネ圧を所望のレベルに調整・設定出来るようになっており、この点が本発明の特徴部分となっている。 The injector 1A having such a configuration is configured such that the spring displacement screw 7 is rotated from the outside by using a screwdriver or the like from the outside of the opposite end of the valve mechanism portion, so that the spring displacement screw is inserted in the through hole 20 of the fixed iron core 2b. 7 can be slid along the valve stroke direction (coincident with the central axis of the through-hole 20) and fixed at a desired position, and between the distal end side of the spring displacement screw 7 and the proximal end side of the movable iron core 2c. The coiled valve spring 6 sandwiched between the two can be set to a desired compression width, and its spring pressure can be adjusted and set to a desired level, which is a feature of the present invention.

これにより、板状の第１の弁バネ５の荷重負担を、従来タイプのインジェクタ１Ｂの場合よりも軽減させてその軽減分の荷重をコイル状の第２の弁バネ６に負担させることができ、且つ、インジェクタ１Ａの組立て後にバネ変位ネジ７を外部から操作して弁バネ６のバネ圧を調整することにより、弁体４Ａにかかる最終的なバネ圧を所望の状態に容易に設定することができる。 As a result, the load on the plate-like first valve spring 5 can be reduced as compared with the case of the conventional injector 1B, and the reduced load can be applied to the coil-like second valve spring 6. In addition, by adjusting the spring pressure of the valve spring 6 by operating the spring displacement screw 7 from the outside after the assembly of the injector 1A, the final spring pressure applied to the valve body 4A can be easily set to a desired state. Can do.

従って、従来タイプのインジェクタ１Ｂにおいて僅かな部品の寸法誤差や僅かな組み付けのバラツキにより、弁バネ５のバネ荷重が大きく変動して高い流量調整精度を実現することが困難となり、製品間のバラツキも大きくなりやすかったのに対し、最終的なバネ荷重を外部から容易に調整できるようにした本実施の形態では、高い流量調整精度を容易に実現することができ、製品間のバラツキも小さくすることができる。 Accordingly, in the conventional type injector 1B, the spring load of the valve spring 5 is greatly fluctuated due to slight dimensional errors of parts and slight assembly variations, and it becomes difficult to achieve high flow rate adjustment accuracy, and there is also variation between products. In this embodiment, the final spring load can be easily adjusted from the outside, although it was easy to increase, high flow rate adjustment accuracy can be easily realized, and variation between products can be reduced. Can do.

以上、述べたように、板状の弁バネで弁体を支持する常閉式のインジェクタについて、本発明により、高い燃料調量精度を容易に実現できるようになった。 As described above, according to the present invention, high fuel metering accuracy can be easily realized for a normally closed injector that supports a valve element with a plate-shaped valve spring.

（Ａ）は、本発明における実施の形態のインジェクタの弁機構部を中心とした縦断面部分図、（Ｂ）は（Ａ）のインジェクタの弁構造部分の分解図。(A) is a longitudinal cross-sectional partial view centering on the valve mechanism part of the injector of embodiment of this invention, (B) is an exploded view of the valve structure part of the injector of (A). （Ａ）は従来例におけるインジェクタの弁機構部を中心とした縦断面部分図、（Ｂ）は（Ａ）のインジェクタの弁バネの平面図、（Ｃ）は（Ａ）のインジェクタの弁構造部分の分解図。(A) is a longitudinal sectional partial view centering on the valve mechanism portion of the injector in the conventional example, (B) is a plan view of the valve spring of the injector of (A), and (C) is a valve structure portion of the injector of (A). Exploded view. 図２のインジェクタの弁構造部の拡大部分図。FIG. 3 is an enlarged partial view of a valve structure portion of the injector of FIG. 2.

符号の説明Explanation of symbols

１Ａインジェクタ、２ａコイル、２ｂ固定鉄心、２ｃ可動鉄心、３シート部材、４Ａ弁体４Ａ，６弁バネ、７バネ圧変位ネジ、２０貫通孔
1A Injector, 2a coil, 2b Fixed iron core, 2c Movable iron core, 3 Seat member, 4A Valve body 4A, 6 Valve spring, 7 Spring pressure displacement screw, 20 Through hole

Claims

弁体及び可動鉄心が板状の弁バネで支持されるとともに閉弁方向に付勢され、非通電時に閉弁状態を維持する電磁駆動式のインジェクタにおいて、前記弁体を閉弁方向に付勢するコイル状の第２の弁バネが設けられ、２つの前記弁バネが協働して二重のバネ荷重で前記弁体に作用し、且つ、前記第２の弁バネのバネ荷重を外部から調整するためのバネ荷重調整機構を備えており、該バネ荷重調整機構を外部から操作することにより、前記弁体に最終的に作用するバネ荷重を調整・設定可能としたことを特徴とするインジェクタ。 In an electromagnetically driven injector in which the valve body and the movable iron core are supported by a plate-shaped valve spring and are energized in the valve closing direction and maintain the valve closed state when not energized, the valve element is energized in the valve closing direction. A coiled second valve spring is provided, the two valve springs cooperate to act on the valve body with a double spring load, and the spring load of the second valve spring is externally applied. An injector comprising a spring load adjusting mechanism for adjusting, and by adjusting the spring load adjusting mechanism from the outside, the spring load that finally acts on the valve body can be adjusted and set. .

前記バネ荷重調整機構は、前記固定鉄心の中心軸線を貫通する貫通孔に、前記中心軸線に沿って前記第２の弁バネが挿設されているとともに前記弁バネ基端側に略円柱状のスライド部材が螺設されて前記可動鉄心との間に前記第２の弁バネを圧縮状態にして挟み込んでおり、前記スライド部材を外部からネジ式に回動させながら前記貫通孔中を摺動させることにより、前記第２の弁バネの圧縮幅を変更して所望のバネ荷重に調整・設定することを特徴とする請求項１に記載したインジェクタ。
The spring load adjusting mechanism includes a through-hole penetrating the central axis of the fixed iron core, the second valve spring being inserted along the central axis, and a substantially cylindrical shape on the proximal side of the valve spring. A slide member is screwed and the second valve spring is compressed and sandwiched between the movable iron core and is slid in the through-hole while rotating the slide member from the outside in a screw manner. Accordingly, the compression width of the second valve spring is changed and adjusted and set to a desired spring load.