JPH10339239A - Accumulating type fuel injection device - Google Patents
Accumulating type fuel injection deviceInfo
- Publication number
- JPH10339239A JPH10339239A JP9146589A JP14658997A JPH10339239A JP H10339239 A JPH10339239 A JP H10339239A JP 9146589 A JP9146589 A JP 9146589A JP 14658997 A JP14658997 A JP 14658997A JP H10339239 A JPH10339239 A JP H10339239A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- fuel
- chamber
- injection
- fuel injection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、燃料噴射装置に関
し、特に蓄圧室で蓄圧した高圧燃料を電磁制御式のイン
ジェクタに供給するディーゼルエンジンの蓄圧式燃料噴
射装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device and, more particularly, to a pressure accumulation type fuel injection device for a diesel engine which supplies high pressure fuel accumulated in a pressure accumulation chamber to an electromagnetically controlled injector.
【０００２】[0002]
【従来の技術】従来より、高圧供給ポンプから供給され
る高圧燃料を直接または蓄圧室で蓄圧して一定圧にして
からインジェクタに供給し、インジェクタの噴孔を開閉
する弁部材の反噴孔側に設けた圧力制御室内の燃料圧力
を電磁弁で制御することにより、燃料噴射時期および燃
料噴射量を調整する燃料噴射装置として特開平５−１３
３２９６号公報に示されるものが知られている。このよ
うな燃料噴射装置は、高圧燃料通路と圧力制御室との間
に高圧燃料通路から圧力制御室に流入する燃料流量を制
限する入口絞り穴が形成され、圧力制御室と低圧側空間
との間に圧力制御室から低圧側空間に流出する燃料流量
を制限する出口絞り穴が形成されている。2. Description of the Related Art Conventionally, high-pressure fuel supplied from a high-pressure supply pump is stored directly or in an accumulator to a constant pressure and then supplied to an injector. JP-A-5-13 describes a fuel injection device that adjusts the fuel injection timing and fuel injection amount by controlling the fuel pressure in a pressure control chamber provided in a solenoid valve by an electromagnetic valve.
The one disclosed in Japanese Patent No. 3296 is known. In such a fuel injection device, an inlet throttle hole is formed between the high-pressure fuel passage and the pressure control chamber to limit the flow rate of fuel flowing from the high-pressure fuel passage into the pressure control chamber. An outlet throttle hole is formed between the pressure control chamber and the outlet to restrict the flow rate of fuel flowing out of the pressure control chamber into the low pressure side space.
【０００３】従来の燃料噴射装置の駆動信号入力から燃
料噴射に至るまでの燃料噴射装置の各部の挙動を図５に
示す。図５において、燃料噴射率の変化率であるα（mm
3/s2) およびβ（mm3/s2) が排気エミッションに大きく
影響する。近年、エンジンの出力を向上し、排気ガス中
の窒素酸化物および黒煙を低減するため、上記のαおよ
びβを大きくし、燃料噴射率の波形をいわゆる矩形形状
にする要求がある。FIG. 5 shows the behavior of each part of a conventional fuel injection device from the input of a drive signal to the injection of fuel. In FIG. 5, α (mm
3 / s 2 ) and β (mm 3 / s 2 ) greatly affect exhaust emissions. In recent years, in order to improve engine output and reduce nitrogen oxides and black smoke in exhaust gas, there has been a demand for increasing the above α and β and making the waveform of the fuel injection rate a so-called rectangular shape.
【０００４】[0004]
【発明が解決しようとする課題】燃料噴射率の変化率β
（mm3/s2) を大きくするためには、インジェクタの噴孔
を速く閉じる必要があり、そのため入口絞り穴を大きく
する必要がある。また、燃料噴射率の変化率α（mm3/
s2) を大きくするためには、インジェクタの噴孔を速く
開く必要があり、そのため入口絞り穴に対する出口絞り
穴の径比を大きくする必要がある。The change rate of the fuel injection rate β
In order to increase (mm 3 / s 2 ), it is necessary to close the injection hole of the injector quickly, and therefore, it is necessary to enlarge the inlet throttle hole. Also, the change rate of the fuel injection rate α (mm 3 /
In order to increase s 2 ), it is necessary to quickly open the injection hole of the injector, and therefore, it is necessary to increase the diameter ratio of the outlet throttle hole to the inlet throttle hole.
【０００５】入口絞り穴を大きくし、かつ入口絞り穴に
対する出口絞り穴の径比を大きくした場合、圧力制御室
内の燃料圧力は抜け易くなり、この圧力が急激に変化す
るため、電磁弁がフルストロークする前に燃料噴射が始
まる。このときの電磁弁の駆動信号、電磁弁の可動部材
変位および燃料噴射率の経時変化を図６に示す。電磁弁
がフルストロークする前に燃料噴射が始まったとき、図
６の実線で示すように、電磁弁開弁時の電磁弁バウンド
により電磁弁の駆動信号幅が長くなるにも関わらず、電
磁弁の開弁時間が短くなり燃料噴射量が減少する。ここ
で、図６の点線は電磁弁バウンド前の電磁弁の駆動信
号、電磁弁の可動部材変位および燃料噴射率の経時変化
を示す。電磁弁バウンドが起こった場合、図７のＡ部分
に示すように、燃料噴射量が電磁弁の駆動信号幅の増加
にともなわず、連続的に増加しないという問題がある。[0005] When the inlet throttle hole is enlarged and the diameter ratio of the outlet throttle hole to the inlet throttle hole is increased, the fuel pressure in the pressure control chamber is easily released, and this pressure changes rapidly. Fuel injection starts before the stroke. FIG. 6 shows the change over time in the drive signal of the solenoid valve, the displacement of the movable member of the solenoid valve, and the fuel injection rate at this time. When fuel injection starts before the full stroke of the solenoid valve, as shown by the solid line in FIG. 6, despite the fact that the drive signal width of the solenoid valve becomes longer due to the solenoid valve bound when the solenoid valve is opened, the solenoid valve And the fuel injection amount decreases. Here, the dotted line in FIG. 6 shows the change over time in the drive signal of the solenoid valve, the displacement of the movable member of the solenoid valve, and the fuel injection rate before the solenoid valve bounces. When the solenoid valve bounces, there is a problem that the fuel injection amount does not increase continuously with the increase in the drive signal width of the solenoid valve, as shown in part A of FIG.
【０００６】したがって、燃料噴射率の波形を矩形形状
にし、かつ電磁弁がフルストロークする前に燃料噴射が
始まらないようにするためには、圧力制御室の容積を比
較的大きくし圧力制御室内の燃料圧力が噴孔の開弁圧に
達するまでの時間を長くすることが考えられる。しかし
ながら、燃料噴射装置を圧力制御室の容積の比較的大き
なものとすると、圧力制御室の容積の増加にともなって
圧力制御室に蓄えられる燃料の弾性係数が低下し、図８
の実線に示すように、弁部材が滑らかに作動しない場合
がある。このため、図９の実線に示すように、燃料噴射
量の電磁弁駆動時間に対する直線性が悪化する恐れがあ
る。ここで、図８の点線は圧力制御室の容積が比較的小
さい場合の電磁弁の可動部材変位および弁部材変位の経
時変化を示し、図９の点線は圧力制御室の容積が比較的
小さい場合の燃料噴射量と電磁弁駆動時間との関係を示
す。Accordingly, in order to make the waveform of the fuel injection rate rectangular and prevent the fuel injection from starting before the full stroke of the solenoid valve, the volume of the pressure control chamber is made relatively large, and It is conceivable to lengthen the time until the fuel pressure reaches the valve opening pressure of the injection hole. However, if the volume of the pressure control chamber is relatively large, the elastic coefficient of the fuel stored in the pressure control chamber decreases with the increase in the volume of the pressure control chamber.
As shown by the solid line, the valve member may not operate smoothly. For this reason, as shown by the solid line in FIG. 9, there is a possibility that the linearity of the fuel injection amount with respect to the solenoid valve driving time may be deteriorated. Here, the dotted line in FIG. 8 shows the change with time of the movable member displacement and the valve member displacement of the solenoid valve when the volume of the pressure control chamber is relatively small, and the dotted line in FIG. 9 shows the case where the volume of the pressure control chamber is relatively small. The relationship between the fuel injection amount and the solenoid valve driving time is shown.
【０００７】本発明は、このような問題を解決するため
になされたものであり、燃料噴射率の波形を矩形形状と
し、かつ、燃料噴射量の電磁弁駆動時間に対する直線性
を向上することができる蓄圧式燃料噴射装置を提供する
ことを目的とする。The present invention has been made in order to solve such a problem, and it is an object of the present invention to make the waveform of the fuel injection rate rectangular and improve the linearity of the fuel injection amount with respect to the solenoid valve driving time. It is an object of the present invention to provide a pressure accumulating type fuel injection device that can be used.
【０００８】[0008]
【課題を解決するための手段】本発明の請求項１記載の
蓄圧式燃料噴射装置によると、蓄圧された高圧燃料をイ
ンジェクタの噴孔に供給可能な高圧燃料通路と噴孔とを
断続する弁部材と、高圧燃料通路から高圧燃料が導入さ
れ電磁二方弁により低圧側空間に断続可能かつ容積が固
定される中間室と、油圧力により弁部材を噴孔遮断方向
に付勢する燃料が蓄えられる圧力制御室と、高圧燃料通
路から中間室に流入する燃料流量を制限する入口絞り穴
と、中間室から低圧側空間に流出する燃料流量を制限す
る出口絞り穴と、変位不能な部材に形成され中間室と圧
力制御室とに流通する燃料流量を制限する中間絞り穴と
を備える。このため、中間室の容積効果により、電磁弁
がフルストロークする前に燃料噴射が始まるのを防ぐこ
とができる。さらに、圧力制御室の容積を比較的小さく
することができるので、中間絞り穴の絞り効果により、
圧力制御室に蓄えられる燃料の弾性係数が増加し、弁部
材の作動を滑らかにすることができ、燃料噴射量の電磁
弁駆動時間に対する直線性を向上することができる。According to the first aspect of the present invention, there is provided a pressure-accumulation type fuel injection device, wherein a high-pressure fuel passage capable of supplying accumulated high-pressure fuel to an injection hole of an injector and a valve for intermittently connecting the injection hole. A member, an intermediate chamber in which high-pressure fuel is introduced from a high-pressure fuel passage and can be intermittently connected to a low-pressure side space by an electromagnetic two-way valve and has a fixed volume, and a fuel that urges the valve member in an injection hole blocking direction by oil pressure is stored. Pressure control chamber, an inlet throttle hole for restricting a flow rate of fuel flowing from the high pressure fuel passage into the intermediate chamber, an outlet throttle hole for restricting a fuel flow rate flowing from the intermediate chamber to the low pressure side space, and a non-displaceable member. And an intermediate throttle hole that restricts the flow rate of fuel flowing through the intermediate chamber and the pressure control chamber. For this reason, the fuel injection can be prevented from starting before the solenoid valve makes a full stroke due to the volume effect of the intermediate chamber. Further, since the volume of the pressure control chamber can be made relatively small, the throttle effect of the intermediate throttle hole allows
The elastic coefficient of the fuel stored in the pressure control chamber increases, the operation of the valve member can be made smooth, and the linearity of the fuel injection amount with respect to the electromagnetic valve driving time can be improved.
【０００９】本発明の請求項２記載の蓄圧式燃料噴射装
置によると、噴孔遮断時の圧力制御室の容積を中間室の
容積よりも小さくすることで、より弁部材の作動を滑ら
かにすることができる。したがって、燃料噴射量の電磁
弁駆動時間に対する直線性をさらに向上することができ
る。According to the pressure accumulating fuel injection device of the second aspect of the present invention, the operation of the valve member is made smoother by making the volume of the pressure control chamber smaller than the volume of the intermediate chamber when the injection hole is shut off. be able to. Therefore, the linearity of the fuel injection amount with respect to the solenoid valve driving time can be further improved.
【００１０】[0010]
【発明の実施の形態】以下、本発明の実施の形態を示す
複数の実施例を図面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装置
を図１および図２に示す。図２に示す電磁制御式のイン
ジェクタ１は、図示しないディーゼルエンジンの燃焼室
内へ間欠的に燃料を噴射するものであって、高圧燃料を
蓄圧する図示しない蓄圧室から図示しない燃料配管がイ
ンレット６０に接続されており、蓄圧室から高圧燃料が
供給されている。また、図示しない電子制御装置（以
下、「電子制御装置」をＥＣＵという）からインジェク
タ１に制御信号を送出するワイヤハーネスがコネクタ７
０に接続されており、ＥＣＵから送出される制御信号に
よりインジェクタ１の燃料噴射が制御される。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 and 2 show a fuel injection device according to a first embodiment of the present invention. The electromagnetically controlled injector 1 shown in FIG. 2 injects fuel intermittently into a combustion chamber of a diesel engine (not shown). A fuel pipe (not shown) is connected to an inlet 60 from a pressure accumulation chamber (not shown) for accumulating high-pressure fuel. It is connected, and high-pressure fuel is supplied from the accumulator. A wire harness for transmitting a control signal from an electronic control unit (not shown) (hereinafter, “electronic control unit” to an ECU) to the injector 1 is connected to the connector 7.
0, and the fuel injection of the injector 1 is controlled by a control signal sent from the ECU.
【００１１】インジェクタ１の噴孔側に設けられた噴射
ノズル１０のノズルボディ１１には、噴孔１１ａを開閉
するニードル弁２０が往復移動可能に収容されている。
ノズルボディ１１およびインジェクタボディ１３はパッ
キンチップ１２を挟んでリテーナ１４で結合されてい
る。ニードル弁２０の反噴孔側にはプレッシャピン２１
が配設されており、プレッシャピン２１の反噴孔側には
プレッシャピン２１に接触あるいは連結する制御ピスト
ン２２が配設されている。ニードル弁２０、プレッシャ
ピン２１および制御ピストン２２は、特許請求の範囲に
記載された弁部材に相当する。プレッシャピン２１はス
プリング２３内に貫挿されており、スプリング２３はプ
レッシャピン２１を図２の下方、つまり噴孔閉塞方向に
付勢している。制御ピストン２２の反噴孔側には圧力制
御室５１が設けられている。A needle valve 20 for opening and closing the injection hole 11a is accommodated in the nozzle body 11 of the injection nozzle 10 provided on the injection hole side of the injector 1 so as to be reciprocally movable.
The nozzle body 11 and the injector body 13 are connected by a retainer 14 with the packing tip 12 interposed therebetween. A pressure pin 21 is provided on the side of the needle valve 20 opposite the injection hole.
A control piston 22 that is in contact with or is connected to the pressure pin 21 is provided on the side opposite to the injection hole of the pressure pin 21. The needle valve 20, the pressure pin 21, and the control piston 22 correspond to a valve member described in the claims. The pressure pin 21 is inserted through a spring 23, and the spring 23 urges the pressure pin 21 downward in FIG. 2, that is, in the injection hole closing direction. A pressure control chamber 51 is provided on the side opposite to the injection hole of the control piston 22.
【００１２】インレット６０内に収容された燃料フィル
タ６１から導入された高圧燃料は、高圧燃料通路６２と
高圧燃料通路６３とに分岐する。高圧燃料通路６２に分
岐した高圧燃料はニードル弁２０の周囲に環状に形成さ
れた燃料溜まり２４に供給され、高圧燃料通路６３に分
岐した高圧燃料は中間室５５に供給され、圧力制御室５
１に導かれている。燃料溜まり２４内の高圧燃料の圧力
は図２の上方、つまり燃料溜まり２４と噴孔１１ａとが
連通するリフト方向にニードル弁２０を付勢し、圧力制
御室５１内の高圧燃料の圧力は図２の下方、つまりニー
ドル弁２０が噴孔１１ａを閉塞する方向に制御ピストン
２２を付勢する。The high-pressure fuel introduced from the fuel filter 61 housed in the inlet 60 branches into a high-pressure fuel passage 62 and a high-pressure fuel passage 63. The high-pressure fuel branched to the high-pressure fuel passage 62 is supplied to the fuel reservoir 24 formed in an annular shape around the needle valve 20, and the high-pressure fuel branched to the high-pressure fuel passage 63 is supplied to the intermediate chamber 55,
Led by one. The pressure of the high-pressure fuel in the fuel reservoir 24 urges the needle valve 20 in the upward direction of FIG. 2, that is, in the lift direction in which the fuel reservoir 24 and the injection hole 11a communicate with each other. 2, the control piston 22 is urged in a direction in which the needle valve 20 closes the injection hole 11a.
【００１３】低圧燃料通路６６は制御ピストン２２およ
びニードル弁２０の摺動クリアランスからのリーク燃料
を回収するための燃料通路であり、スプリング２３を収
容するばね室２７と連通している。低圧燃料通路６６
は、平板プレート５４および平板プレート５３にそれぞ
れ形成された燃料通路５４ａ、５３ａを介して低圧側空
間としての低圧燃料室６７に連通している。低圧燃料室
６７の燃料は、シリンダ４１内に設けられた低圧燃料通
路４１ａ、アーマチャ３４を貫通する貫通孔３４ａ、コ
ア３１の中心を連通する低圧燃料通路３１ａ、ハウジン
グ５０内に設けられた低圧燃料通路６９を経て、インジ
ェクタ１の外部に排出される。The low-pressure fuel passage 66 is a fuel passage for recovering leaked fuel from the sliding clearance between the control piston 22 and the needle valve 20, and communicates with the spring chamber 27 in which the spring 23 is housed. Low pressure fuel passage 66
Communicates with a low-pressure fuel chamber 67 as a low-pressure side space through fuel passages 54a and 53a formed in the flat plate 54 and the flat plate 53, respectively. The fuel in the low-pressure fuel chamber 67 is supplied to the low-pressure fuel passage 41 a provided in the cylinder 41, the through-hole 34 a penetrating the armature 34, the low-pressure fuel passage 31 a communicating the center of the core 31, and the low-pressure fuel provided in the housing 50. The fuel is discharged to the outside of the injector 1 through the passage 69.
【００１４】図１に示すように、平板プレート５３と平
板プレート５４とはインジェクタボディ１３とシリンダ
４１との間に重ねられて挟持されている。平板プレート
５４には、高圧燃料通路６３から中間室５５へ流入する
燃料量を規制する入口絞り穴５６と、中間室５５と圧力
制御室５１とを流通する燃料量を規制する中間絞り穴５
２とが形成されている。平板プレート５４の反噴孔側に
設けられた平板プレート５３には、平板プレート５３を
軸方向に貫通し、中間室５５から低圧燃料室６７へ流出
する燃料流量を規制する出口絞り穴５７が形成されてい
る。As shown in FIG. 1, the flat plate 53 and the flat plate 54 are sandwiched between the injector body 13 and the cylinder 41 in an overlapping manner. The flat plate 54 has an inlet throttle hole 56 for regulating the amount of fuel flowing from the high-pressure fuel passage 63 into the intermediate chamber 55, and an intermediate throttle hole 5 for regulating the amount of fuel flowing between the intermediate chamber 55 and the pressure control chamber 51.
2 are formed. In the flat plate 53 provided on the side opposite to the injection hole of the flat plate 54, an outlet throttle hole 57 which penetrates the flat plate 53 in the axial direction and regulates a flow rate of fuel flowing from the intermediate chamber 55 to the low-pressure fuel chamber 67 is formed. Have been.
【００１５】図１に示す電磁弁３０は、中間室５５と低
圧燃料室６７とを断続する電磁二方弁であり、リーテー
ニングナット５９とインジェクタボディ１３との間に配
設されている。ピン６５はコア３１とハウジング５０と
の回転方向の位置決めを行うものであり、かつリテーニ
ングナット５９を締めつけるときにコア３１とハウジン
グ５０とが互いに相対回動しコイル３２に給電する図示
しない給電ターミナルに負荷が加わることを防止するも
のである。The electromagnetic valve 30 shown in FIG. 1 is an electromagnetic two-way valve that connects and disconnects the intermediate chamber 55 and the low-pressure fuel chamber 67, and is disposed between the retaining nut 59 and the injector body 13. The pin 65 is used to position the core 31 and the housing 50 in the rotational direction, and the power supply terminal (not shown) for rotating the core 31 and the housing 50 relative to each other and supplying power to the coil 32 when the retaining nut 59 is tightened. This is to prevent the load from being applied to the vehicle.
【００１６】コイル３２はコア３１内に巻装されてお
り、コネクタ７０に埋設されたターミナル７１から電力
が供給される。コア３１の内周にプッシュロッド４４が
貫挿されている。可動部材４０とプッシュロッド４４と
は、圧力制御室５１の燃料圧力から受ける力とスプリン
グ４５の付勢力とにより互いに押圧されており、別体に
形成されてはいるが離反しないで往復移動する。プッシ
ュロッド４４は磁気回路への影響を避けるために非磁性
ステンレス等で構成されている。可動部材４０はコア３
１の噴孔側に配設されたシリンダ４１に往復移動可能に
支持されており、耐摩耗性に優れた材質で形成されてい
る。可動部材４０は磁気回路外にあるので磁性体で構成
してもかまわない。可動部材４０の噴孔側の端部には円
筒状に形成された支持部材４２および球状部材４３が圧
入、かしめ、溶接のいずれかまたは複数の手段で固定さ
れている。可動部材４０のコア側には径方向および軸方
向に正確に位置決めされたアーマチャ３４が圧入、かし
め、溶接のいずれかまたは複数の手段で固定されてお
り、可動部材４０はアーマチャ３４とともに往復移動す
る。アーマチャ３４は耐摩耗性よりも磁気回路の一部と
しての特性が要求されるので、例えば珪素鋼により形成
されている。アーマチャ３４には燃料中の移動抵抗を低
減するために複数の貫通孔３４ａが形成されている。The coil 32 is wound around the core 31, and power is supplied from a terminal 71 embedded in the connector 70. A push rod 44 is inserted through the inner periphery of the core 31. The movable member 40 and the push rod 44 are pressed against each other by the force received from the fuel pressure in the pressure control chamber 51 and the urging force of the spring 45, and reciprocate without being separated from each other although they are formed separately. The push rod 44 is made of non-magnetic stainless steel or the like in order to avoid affecting the magnetic circuit. The movable member 40 is the core 3
It is reciprocally supported by a cylinder 41 disposed on the side of one of the injection holes, and is formed of a material having excellent wear resistance. Since the movable member 40 is outside the magnetic circuit, it may be made of a magnetic material. A support member 42 and a spherical member 43 formed in a cylindrical shape are fixed to one end of the movable member 40 on the injection hole side by any one or more of press-fitting, caulking, and welding. An armature 34 accurately positioned in the radial and axial directions is fixed to the core side of the movable member 40 by any one or more of press-fitting, caulking, and welding, and the movable member 40 reciprocates with the armature 34. . The armature 34 is required to have a characteristic as a part of the magnetic circuit rather than the wear resistance, and is made of, for example, silicon steel. A plurality of through holes 34a are formed in the armature 34 in order to reduce the movement resistance in the fuel.
【００１７】次に、第１実施例における各部の寸法を示
す。入口絞り穴５６の直径＝φ０．２４mm、出口絞り穴
５７の直径＝φ０．３３mm、中間絞り穴５２の直径＝φ
０．３０mm、中間室５５の容積＝６０mm3 、噴孔１１ａ
の遮断時の圧力制御室５１の容積＝１０mm3 である。次
に、インジェクタ１の作動について説明する。Next, the dimensions of each part in the first embodiment will be described. Diameter of inlet throttle hole 56 = φ0.24 mm, diameter of outlet throttle hole 57 = φ0.33 mm, diameter of intermediate throttle hole 52 = φ
0.30 mm, volume of the intermediate chamber 55 = 60 mm 3 , injection hole 11a
The volume of the pressure control chamber 51 at the time of shutting off is 10 mm 3 . Next, the operation of the injector 1 will be described.
【００１８】(1) コイル３２の通電オフ時、スプリング
４５の付勢力によりプッシュロッド４４が図１の下方に
押下される。可動部材４０の噴孔側の端部が平板プレー
ト５３に着座し、圧力制御室５１と低圧燃料室６７との
連通が遮断される。電磁弁３０の可動部材４０を閉弁方
向に付勢するためのスプリング４５のセット荷重が蓄圧
室から導入される燃料圧力により電磁弁３０を開弁方向
に作用させる荷重よりも大きく設定されているので、コ
イル３２への通電がオフされている限り可動部材４０は
リフトしない。(1) When the coil 32 is turned off, the push rod 44 is pushed downward in FIG. The end on the injection hole side of the movable member 40 is seated on the flat plate 53, and the communication between the pressure control chamber 51 and the low-pressure fuel chamber 67 is shut off. The set load of the spring 45 for urging the movable member 40 of the solenoid valve 30 in the valve closing direction is set to be larger than the load that causes the solenoid valve 30 to act in the valve opening direction by the fuel pressure introduced from the accumulator. Therefore, the movable member 40 does not lift as long as the power supply to the coil 32 is turned off.
【００１９】また、制御ピストン２２の受圧面積はニー
ドル弁２０の受圧面積よりも大きく設定されており、さ
らに、スプリング２３の付勢力は噴孔閉塞方向に働いて
いるので、コイル３２への通電がオフされている限り、
圧力制御室５１の燃料圧力から制御ピストン２２が噴孔
閉塞方向に受ける力とスプリング２３の付勢力との和
は、燃料溜まり２４の燃料圧力からニードル弁２０がリ
フト方向に受ける力よりも大きい。したがって、ニード
ル弁２０により噴孔１１ａは閉塞され燃料噴射は行われ
ない。The pressure receiving area of the control piston 22 is set to be larger than the pressure receiving area of the needle valve 20, and the urging force of the spring 23 acts in the injection hole closing direction. As long as it is off
The sum of the force that the control piston 22 receives in the injection hole closing direction from the fuel pressure in the pressure control chamber 51 and the urging force of the spring 23 is greater than the force that the needle valve 20 receives in the lift direction from the fuel pressure in the fuel reservoir 24. Therefore, the injection hole 11a is closed by the needle valve 20, and fuel injection is not performed.
【００２０】(2) コイル３２の通電をオンすることによ
り発生するアーマチャ３４を吸引する電磁力と圧力制御
室５１の燃料圧力から可動部材４０が開弁方向に受ける
力との和がスプリング４５の付勢力よりも大きくなるの
で、可動部材４０がリフトし、球状部材４３は平板プレ
ート５３から離座する。球状部材４３が平板プレート５
３から離座すると、出口絞り穴５７と低圧燃料室６７と
が連通し、中間室５５の燃料が出口絞り穴５７から低圧
燃料室６７に流出する。出口絞り穴５７および中間絞り
穴５２の通路抵抗は入口絞り穴５６の通路抵抗よりも小
さいので、球状部材４３が平板プレート５３から離座し
中間室５５と低圧燃料室６７とが連通すると中間室５５
および圧力制御室５１の燃料圧力がほぼ等圧を保って低
下する。圧力制御室５１の燃料圧力が低下し、圧力制御
室５１の燃料圧力から制御ピストン２２が噴孔閉塞方向
に受ける力とスプリング２３の付勢力との和が、燃料溜
まり２４の燃料圧力からニードル弁２０がリフト方向に
受ける力よりも小さくなると、ニードル弁２０がリフト
し、噴孔１１ａから燃料が噴射される。(2) The sum of the electromagnetic force for attracting the armature 34 generated by turning on the energization of the coil 32 and the force received by the movable member 40 in the valve opening direction from the fuel pressure in the pressure control chamber 51 is equal to the force of the spring 45. Since the force becomes larger than the urging force, the movable member 40 is lifted, and the spherical member 43 is separated from the flat plate 53. The spherical member 43 is a flat plate 5
When the user moves away from the position 3, the outlet throttle hole 57 and the low-pressure fuel chamber 67 communicate with each other, and the fuel in the intermediate chamber 55 flows out of the outlet throttle hole 57 into the low-pressure fuel chamber 67. Since the passage resistance of the outlet throttle hole 57 and the intermediate throttle hole 52 is smaller than the passage resistance of the inlet throttle hole 56, when the spherical member 43 is separated from the flat plate 53 and the intermediate chamber 55 communicates with the low-pressure fuel chamber 67, the intermediate chamber is closed. 55
In addition, the fuel pressure in the pressure control chamber 51 decreases while maintaining substantially equal pressure. The fuel pressure in the pressure control chamber 51 decreases, and the sum of the force received by the control piston 22 in the injection hole closing direction and the urging force of the spring 23 is calculated from the fuel pressure in the pressure control chamber 51 by the fuel pressure in the fuel reservoir 24. When the force applied to the valve 20 in the lift direction becomes smaller, the needle valve 20 is lifted and fuel is injected from the injection hole 11a.
【００２１】上記状態が続き、所定の噴射終了時期がく
るとコイル３２への通電を遮断する。このとき、アーマ
チャ３４を吸引するための電磁力がゼロになるため、可
動部材４０を閉弁方向に付勢するスプリング４５の付勢
力によって電磁弁３０は閉弁する。すると、高圧燃料通
路６３から入口絞り穴５６、中間室５５および中間絞り
穴５２を介して圧力制御室５１に流入する高圧燃料によ
り圧力制御室５１の圧力が上昇し、圧力制御室５１の燃
料圧力から制御ピストン２２が噴孔閉塞方向に受ける力
とスプリング２３の付勢力との和が、燃料溜まり２４の
燃料圧力からニードル弁２０がリフト方向に受ける力よ
りも大きくなるので、ニ一ドル弁２０が噴孔１１ａを閉
塞し噴射が終了する。When the above condition continues and a predetermined injection end time comes, the power supply to the coil 32 is cut off. At this time, since the electromagnetic force for sucking the armature 34 becomes zero, the electromagnetic valve 30 is closed by the urging force of the spring 45 that urges the movable member 40 in the valve closing direction. Then, the pressure in the pressure control chamber 51 is increased by the high-pressure fuel flowing from the high-pressure fuel passage 63 into the pressure control chamber 51 through the inlet throttle hole 56, the intermediate chamber 55, and the intermediate throttle hole 52, and the fuel pressure in the pressure control chamber 51 is increased. Therefore, the sum of the force that the control piston 22 receives in the injection hole closing direction and the urging force of the spring 23 becomes larger than the force that the needle valve 20 receives in the lift direction due to the fuel pressure of the fuel reservoir 24. Closes the injection hole 11a and the injection ends.
【００２２】以上の噴射開始から噴射終了までの可動部
材４０の変位量、圧力制御室５１の圧力、中間室５５の
圧力およびニ一ドル弁２０の変位量の経時変化を図３に
示す。インジェクタ１の噴射特性は、入口絞り穴５６か
ら中間室５５および中間絞り穴５２を介して圧力制御室
５１に流入する燃料流量と、圧力制御室５１から中間絞
り穴５２、中間室５５および出口絞り穴５７を介して低
圧燃料室６７に流出する燃料流量によって概ね決定され
る。噴射特性の内、噴射開始時期および初期噴射率の上
昇度合いは、電磁弁３０が開弁した後に圧力制御室５１
へ流入する燃料流量と、圧力制御室５１から低圧燃料室
６７に流出する燃料流量との差によって決定される。ま
た噴射特性の内、噴射切れは、入口絞り穴５６および中
間絞り穴５２の通路抵抗により決定される。FIG. 3 shows the change with time of the displacement of the movable member 40, the pressure of the pressure control chamber 51, the pressure of the intermediate chamber 55, and the displacement of the needle valve 20 from the start of the injection to the end of the injection. The injection characteristics of the injector 1 include the fuel flow rate flowing from the inlet throttle hole 56 to the pressure control chamber 51 via the intermediate chamber 55 and the intermediate throttle hole 52, and the fuel flow from the pressure control chamber 51 to the intermediate throttle hole 52, the intermediate chamber 55 and the outlet throttle. It is largely determined by the flow rate of fuel flowing into the low-pressure fuel chamber 67 through the hole 57. Among the injection characteristics, the injection start timing and the degree of increase in the initial injection rate are determined by the pressure control chamber 51 after the solenoid valve 30 is opened.
And the flow rate of fuel flowing out of the pressure control chamber 51 to the low-pressure fuel chamber 67. In addition, out of the injection characteristics, the injection stop is determined by the passage resistance of the inlet throttle hole 56 and the intermediate throttle hole 52.
【００２３】図３に示すように、電磁弁３０の可動部材
４０のリフトにともなって中間室５５および圧力制御室
５１の燃料圧力はほぼ等圧を保って低下する。そして、
圧力制御室５１の燃料圧力がニ一ドル弁２０の開弁圧に
達すると、ニ一ドル弁２０がリフトし始めるが、このと
き、圧力制御室５１の容積を比較的小さくすることによ
り、ニ一ドル弁２０の作動を滑らかにすることができ
る。As shown in FIG. 3, as the movable member 40 of the solenoid valve 30 is lifted, the fuel pressure in the intermediate chamber 55 and the pressure control chamber 51 decreases while maintaining substantially equal pressure. And
When the fuel pressure in the pressure control chamber 51 reaches the valve opening pressure of the needle valve 20, the needle valve 20 starts to lift. At this time, by reducing the volume of the pressure control chamber 51 to a relatively small value, The operation of the dollar valve 20 can be smoothed.
【００２４】以上のように第１実施例では、高圧燃料通
路６３から中間室５５へ流入する燃料量を規制する入口
絞り穴５６と、中間室５５と圧力制御室５１とを流通す
る燃料量を規制する中間絞り穴５２とを平板プレート５
４に形成し、中間室５５から低圧燃料室６７へ流出する
燃料流量を規制する出口絞り穴５７を平板プレート５３
に形成した。このため、圧力制御室５１の内部の燃料圧
力が急激に下降するのを抑えることができるので、電磁
弁３０がフルストロークする前に燃料噴射が始まるのを
防ぐことができる。さらに、圧力制御室５１の容積を比
較的小さくすることができるので、ニ一ドル弁２０の作
動を滑らかにすることができ、燃料噴射量の電磁弁３０
の駆動時間に対する直線性を向上することができる。As described above, in the first embodiment, the inlet throttle hole 56 for regulating the amount of fuel flowing from the high-pressure fuel passage 63 into the intermediate chamber 55, and the fuel amount flowing between the intermediate chamber 55 and the pressure control chamber 51 are determined. The intermediate drawing hole 52 to be regulated and the flat plate 5
And an outlet throttle hole 57 for regulating the flow rate of fuel flowing from the intermediate chamber 55 to the low-pressure fuel chamber 67 is formed in the flat plate 53.
Formed. For this reason, it is possible to suppress the fuel pressure inside the pressure control chamber 51 from rapidly dropping, so that it is possible to prevent the fuel injection from starting before the solenoid valve 30 performs a full stroke. Furthermore, since the volume of the pressure control chamber 51 can be made relatively small, the operation of the needle valve 20 can be made smooth, and the fuel injection amount of the electromagnetic valve 30 can be reduced.
Linearity with respect to the driving time can be improved.
【００２５】以上説明した本発明の第１実施例では、噴
孔１１ａの遮断時の圧力制御室５１の容積、中間室５５
の容積、入口絞り穴５６の直径、出口絞り穴５７の直径
および中間絞り穴５２の直径の好ましい寸法を示した
が、本発明においては、各部の寸法は限定されるもので
はない。 （第２実施例）本発明の第２実施例による燃料噴射装置
を図４に示す。In the first embodiment of the present invention described above, the volume of the pressure control chamber 51 when the injection hole 11a is shut off and the intermediate chamber 55
Although the preferred dimensions of the volume of the inlet throttle hole 56, the diameter of the outlet throttle hole 57, and the diameter of the intermediate throttle hole 52 have been shown, the dimensions of each part are not limited in the present invention. (Second Embodiment) FIG. 4 shows a fuel injection device according to a second embodiment of the present invention.
【００２６】高圧燃料通路６３と圧力制御室５１とは、
平板プレート５８に設けられた入口絞り穴５６および中
間室５５と、平板プレート５４に設けられた中間絞り穴
５２とを介して連通している。その他の部分は第１実施
例と同じ構成であり、第１実施例と実質的に同一構成部
分には同一符号を付す。第２実施例では、作用において
第１実施例と同じであり、部品点数において第１実施例
に比べて増えるが、入口絞り穴５６と中間絞り穴５２と
をそれぞれ独立に選択することができるので、燃料噴射
特性の調整精度を向上することができる。The high-pressure fuel passage 63 and the pressure control chamber 51
The inlet throttle hole 56 and the intermediate chamber 55 provided in the flat plate 58 communicate with the intermediate throttle hole 52 provided in the flat plate 54. The other parts have the same configuration as the first embodiment, and the same reference numerals are given to the same constituent parts as the first embodiment. In the second embodiment, the operation is the same as that of the first embodiment, and the number of parts increases as compared with the first embodiment. However, since the inlet throttle hole 56 and the intermediate throttle hole 52 can be selected independently, In addition, the accuracy of adjusting the fuel injection characteristics can be improved.
【図１】本発明の第１実施例によるインジェクタの主要
部を示す断面図である。FIG. 1 is a sectional view showing a main part of an injector according to a first embodiment of the present invention.
【図２】本発明の第１実施例によるインジェクタを示す
断面図である。FIG. 2 is a sectional view showing an injector according to a first embodiment of the present invention.
【図３】本発明の第１実施例の可動部材変位、圧力制御
室の圧力、中間室の圧力、ニードル弁変位の経時変化を
示す特性図である。FIG. 3 is a characteristic diagram showing temporal changes in displacement of a movable member, pressure in a pressure control chamber, pressure in an intermediate chamber, and displacement of a needle valve according to the first embodiment of the present invention.
【図４】本発明の第２実施例によるインジェクタの主要
部を示す断面図である。FIG. 4 is a sectional view showing a main part of an injector according to a second embodiment of the present invention.
【図５】従来技術の駆動信号、可動部材変位、圧力制御
室の圧力、弁部材変位、噴射率の経時変化を示す特性図
である。FIG. 5 is a characteristic diagram showing a temporal change of a drive signal, a movable member displacement, a pressure of a pressure control chamber, a valve member displacement, and an injection rate according to the related art.
【図６】従来技術の駆動信号、可動部材変位、噴射率の
経時変化を示す特性図である。FIG. 6 is a characteristic diagram showing a temporal change of a drive signal, a displacement of a movable member, and an injection rate according to the related art.
【図７】従来技術の燃料噴射量と駆動時間との関係を示
す特性図である。FIG. 7 is a characteristic diagram showing a relationship between a fuel injection amount and a driving time according to a conventional technique.
【図８】従来技術の可動部材変位と弁部材変位の経時変
化を示す特性図である。FIG. 8 is a characteristic diagram showing a temporal change in displacement of a movable member and displacement of a valve member according to a conventional technique.
【図９】従来技術の燃料噴射量と駆動時間との関係を示
す特性図である。FIG. 9 is a characteristic diagram showing a relationship between a fuel injection amount and a driving time according to a conventional technique.
１ インジェクタ １０ 噴射ノズル １１ ノズルボディ １１ａ 噴孔 １３ インジェクタボディ ２０ ニードル弁（弁部材） ２１ プレッシャピン（弁部材） ２２ 制御ピストン（弁部材） ３０ 電磁弁 ３１ コア ３２ コイル ３４ アーマチャ ４０ 可動部材 ４１ シリンダ ５１ 圧力制御室 ５２ 中間絞り穴 ５３、５４ 平板プレート ５５ 中間室 ５６ 入口絞り穴 ５７ 出口絞り穴 ５８ 平板プレート ６２、６３ 高圧燃料通路 ６６ 低圧燃料通路 ６７ 低圧燃料室 Reference Signs List 1 injector 10 injection nozzle 11 nozzle body 11a injection hole 13 injector body 20 needle valve (valve member) 21 pressure pin (valve member) 22 control piston (valve member) 30 solenoid valve 31 core 32 coil 34 armature 40 movable member 41 cylinder 51 Pressure control chamber 52 Intermediate throttle hole 53, 54 Flat plate 55 Intermediate chamber 56 Inlet throttle hole 57 Outlet throttle hole 58 Flat plate 62, 63 High-pressure fuel passage 66 Low-pressure fuel passage 67 Low-pressure fuel chamber
Claims (2)
の各気筒に設けられたインジェクタに供給し、前記イン
ジェクタの電磁二方弁により燃料噴射時期および期間を
制御する蓄圧式燃料噴射装置であって、 蓄圧された高圧燃料を前記インジェクタの噴孔に供給可
能な高圧燃料通路と前記噴孔とを断続する弁部材と、 前記高圧燃料通路から高圧燃料が導入され、前記電磁二
方弁により低圧側空間に断続可能かつ容積が固定される
中間室と、 油圧力により前記弁部材を前記噴孔遮断方向に付勢する
燃料が蓄えられる圧力制御室と、 前記高圧燃料通路から前記中間室に流入する燃料流量を
制限する入口絞り穴と、 前記中間室から前記低圧側空間に流出する燃料流量を制
限する出口絞り穴と、 変位不能な部材に形成され、前記中間室と前記圧力制御
室とに流通する燃料流量を制限する中間絞り穴と、 を備えることを特徴とする蓄圧式燃料噴射装置。A pressure-accumulation fuel injection device that supplies high-pressure fuel accumulated in a pressure accumulation chamber to an injector provided in each cylinder of an engine, and controls a fuel injection timing and a period by an electromagnetic two-way valve of the injector. A high-pressure fuel passage capable of supplying the accumulated high-pressure fuel to the injection hole of the injector and a valve member for intermittently connecting the injection hole; high-pressure fuel is introduced from the high-pressure fuel passage; An intermediate chamber that is intermittent in the side space and has a fixed volume; a pressure control chamber in which fuel for urging the valve member in the injection hole blocking direction by hydraulic pressure is stored; and an inflow from the high-pressure fuel passage into the intermediate chamber An inlet throttle hole for limiting a fuel flow rate to be controlled, an outlet throttle hole for limiting a fuel flow rate flowing out of the intermediate chamber to the low-pressure side space, and a non-displaceable member formed of the intermediate chamber and the pressure control. An intermediate pressure restricting hole for restricting a flow rate of fuel flowing to the control room, and a pressure accumulating fuel injection device.
が前記中間室の容積よりも小さいことを特徴とする請求
項１記載の蓄圧式燃料噴射装置。2. The pressure accumulating fuel injection device according to claim 1, wherein the volume of the pressure control chamber when the injection hole is shut off is smaller than the volume of the intermediate chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9146589A JPH10339239A (en) | 1997-06-04 | 1997-06-04 | Accumulating type fuel injection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9146589A JPH10339239A (en) | 1997-06-04 | 1997-06-04 | Accumulating type fuel injection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10339239A true JPH10339239A (en) | 1998-12-22 |
Family
ID=15411139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9146589A Pending JPH10339239A (en) | 1997-06-04 | 1997-06-04 | Accumulating type fuel injection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10339239A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6978766B2 (en) | 2001-11-09 | 2005-12-27 | Siemens Aktiengesellschaft | Control module for a storage-type injection system injector |
| JP2008014296A (en) * | 2006-06-08 | 2008-01-24 | Denso Corp | Fuel injection valve |
-
1997
- 1997-06-04 JP JP9146589A patent/JPH10339239A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6978766B2 (en) | 2001-11-09 | 2005-12-27 | Siemens Aktiengesellschaft | Control module for a storage-type injection system injector |
| JP2008014296A (en) * | 2006-06-08 | 2008-01-24 | Denso Corp | Fuel injection valve |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1701031B1 (en) | An electromagnetic drive mechanism of a high-pressure fuel supply pump | |
| US7827967B2 (en) | Low noise fuel pump with variable pressure regulation | |
| JP4455470B2 (en) | Controller for high pressure fuel pump and normally closed solenoid valve of high pressure fuel pump | |
| JPH11200990A (en) | Fuel injection controller | |
| JP2003120845A (en) | Metering valve device and fuel injection pump using the same | |
| JP2005521830A (en) | Adjustable pressure regulating valve for fuel injection system | |
| JP2002004977A (en) | Flow control device | |
| JP2002522706A (en) | Control valve | |
| US5150684A (en) | High pressure fuel injection unit for engine | |
| JP4345096B2 (en) | Fuel injection device | |
| JP3296529B2 (en) | Fuel injection device | |
| JP2002539360A (en) | Control valve assembly for pump and injector | |
| JPH10339239A (en) | Accumulating type fuel injection device | |
| KR20020063100A (en) | Fuel injector assembly and internal combustion engine including same | |
| JP5293237B2 (en) | Metering valve for fuel injection system | |
| JP3738921B2 (en) | Accumulated fuel injection system | |
| JPH08261019A (en) | Injection timing control device for fuel injection pump | |
| JP2003269281A (en) | Fuel injector for internal combustion engine | |
| JP2004156552A (en) | Fuel injector | |
| US20040099246A1 (en) | Fuel injector with multiple control valves | |
| JP2001090634A (en) | Injection valve for internal combustion engine | |
| JP4051847B2 (en) | Fuel injection device | |
| JPH1182220A (en) | Fuel injection controller of diesel engine | |
| JPH11270435A (en) | Delivery valve | |
| JPH10121989A (en) | Hydraulic control valve |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080330 Year of fee payment: 14 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090330 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090330 Year of fee payment: 15 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100330 Year of fee payment: 16 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 16 Free format text: PAYMENT UNTIL: 20100330 |