JPH1122583A - Fuel injection device - Google Patents
Fuel injection deviceInfo
- Publication number
- JPH1122583A JPH1122583A JP17747697A JP17747697A JPH1122583A JP H1122583 A JPH1122583 A JP H1122583A JP 17747697 A JP17747697 A JP 17747697A JP 17747697 A JP17747697 A JP 17747697A JP H1122583 A JPH1122583 A JP H1122583A
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- pressure
- fuel injection
- valve
- chamber
- 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.)
- Granted
Links
Landscapes
- High-Pressure Fuel Injection Pump Control (AREA)
- 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、特
に、ディーゼルエンジンに用いられる蓄圧式燃料噴射装
置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device, and more particularly, to an accumulator type fuel injection device used for a diesel engine.
【０００２】[0002]
【従来の技術】一般的に、蓄圧式（コモンレール式）燃
料噴射装置は、蓄圧室から供給される高圧燃料を燃料噴
射弁の内部に設けた制御室に導入して、燃料制御弁のニ
ードル弁を下降させ、このニードル弁を常閉状態に保
ち、さらに、制御室内の燃料を燃料排出路にリークさ
せ、制御室内を減圧することで、ニードル弁を上昇さ
せ、このニードル弁を開いて燃料噴射孔より燃料噴射を
する構成である。2. Description of the Related Art In general, a pressure accumulating type (common rail type) fuel injection device introduces high pressure fuel supplied from a pressure accumulating chamber into a control chamber provided inside a fuel injection valve, and a needle valve of a fuel control valve. , The needle valve is kept in a normally closed state, the fuel in the control chamber is leaked to the fuel discharge path, and the control chamber is depressurized to raise the needle valve. In this configuration, fuel is injected from the hole.
【０００３】このような、従来の燃料噴射装置におい
て、燃料噴射率は、ニードル弁先端の弁開度及び弁孔の
大きさに左右される。すなわち、ニードル弁が上昇し
て、燃料噴射孔への流路を開く課程において、その流路
面積が燃料噴射孔より小さい間は、その流路面積により
燃料噴射率が規定され、燃料噴射孔への流路面積が、燃
料噴射孔の断面積より大きくなった後は、燃料噴射孔の
断面積により燃料噴射率が規定される。In such a conventional fuel injection device, the fuel injection rate depends on the valve opening at the tip of the needle valve and the size of the valve hole. That is, in the process of opening the flow path to the fuel injection hole by raising the needle valve, while the flow path area is smaller than the fuel injection hole, the fuel injection rate is regulated by the flow path area, and After the flow passage area becomes larger than the cross-sectional area of the fuel injection hole, the fuel injection rate is defined by the cross-sectional area of the fuel injection hole.
【０００４】[0004]
【発明が解決しようとする課題】コモンレール式では、
高圧状態で燃料が供給されるため、噴射初期から必要以
上の量の燃料が噴射される。エンジン性能を向上させる
ため、本来は、進角させ、燃料噴射タイミングを早めた
いが、燃料噴射初期の燃料噴射量が多すぎると、燃焼初
期に急激な燃焼による過度の燃焼騒音を伴うこととな
る。そこで、燃料噴射制御の初期には噴射率を下げ噴射
量を抑えることで進角させ、初期の燃焼を抑え燃焼騒音
を低減する必要がある。一方、短期間で噴射を完了しな
ければならないので、噴射中期以降は、燃料噴射率を上
げる必要がある。In the common rail system,
Since fuel is supplied in a high pressure state, an unnecessary amount of fuel is injected from the beginning of injection. In order to improve the engine performance, it is originally desired to advance the fuel injection timing and to advance the fuel injection timing. However, if the fuel injection amount in the initial stage of the fuel injection is too large, excessive combustion noise due to rapid combustion in the initial stage of the combustion will be accompanied. . Therefore, in the early stage of the fuel injection control, it is necessary to advance the angle by lowering the injection rate and suppressing the injection amount, thereby suppressing the initial combustion and reducing the combustion noise. On the other hand, since the injection must be completed in a short period of time, it is necessary to increase the fuel injection rate after the middle stage of the injection.
【０００５】このような要求に対し、前記従来例では、
燃料噴射孔への流路の断面積と、燃料噴射孔の断面積と
で燃料噴射率パターンを決定しているため、燃料噴射率
の変更に自由度がなく対応できない。[0005] In response to such a demand, in the above-mentioned conventional example,
Since the fuel injection rate pattern is determined by the cross-sectional area of the flow path to the fuel injection hole and the cross-sectional area of the fuel injection hole, the fuel injection rate cannot be changed without flexibility.
【０００６】そこで、燃料噴射の初期には低噴射率と
し、噴射後期には高噴射率となるよう制御する燃料噴射
装置が、特開平５−７１４３８号公報に提案されてい
る。この装置は、燃料噴射弁の燃料噴射孔を開閉するノ
ズルニードルに作用する背圧を保持する制御室の圧力を
切替弁によって燃料の供給経路側である高圧室と前記燃
料の戻し経路（燃料排出路）側である低圧室とに切替え
制御して、前記燃料噴射孔より燃料を噴射する燃料噴射
装置において、前記切替弁の前記低圧側と直列に配設さ
れ、該低圧側の燃料の流れを遮断する第１の状態と、前
記前記低圧側の燃料の一部を逃がす第２の状態と、前記
低圧側の燃料を完全に逃がす第３の状態との少なくとも
３つの状態を取る制御弁と、無噴射時には前記切替弁を
高圧側とするとともに前記制御弁を第１の状態とし、噴
射初期では前記切替弁を低圧側に切り替えると同時に前
記制御弁を第２の状態とし、噴射後期では前記切替弁を
低圧側に切り替えたままで前記制御弁を第３の状態とす
る制御装置とを備えた構成である。Japanese Patent Laid-Open Publication No. Hei 5-71438 proposes a fuel injection device that controls the injection rate to be low at the beginning of fuel injection and high at the end of fuel injection. In this device, the pressure in a control chamber that holds a back pressure acting on a nozzle needle that opens and closes a fuel injection hole of a fuel injection valve is switched by a switching valve to a high-pressure chamber on a fuel supply path side and a fuel return path (fuel discharge path). In a fuel injection device that controls switching to a low-pressure chamber that is a (road) side to inject fuel from the fuel injection holes, the fuel injection device is disposed in series with the low-pressure side of the switching valve, and controls the flow of fuel on the low-pressure side. A control valve that takes at least three states of a first state in which shutoff is performed, a second state in which a part of the low-pressure side fuel is released, and a third state in which the low-pressure side fuel is completely released; At the time of non-injection, the switching valve is set to the high pressure side and the control valve is set to the first state. At the beginning of the injection, the switching valve is switched to the low pressure side, and at the same time, the control valve is set to the second state. With the valve switched to the low pressure side In a configuration in which a control device for the control valve and the third state.
【０００７】ここで、当該公報に記載された前記制御弁
は、ピエゾ素子への電圧の印加により駆動されるスプー
ル弁である。そして、この燃料圧力（燃料供給圧力）に
応じて定められた燃料噴射時間と噴射量との関係が、予
めマップの形で記憶されており、燃料蓄圧室内の燃料圧
力の検出信号が制御装置に入力されることで、制御装置
が燃料圧力に応じて切替弁及びスプール弁を制御し、噴
射初期では前記切替弁を低圧側に切り替えると同時に前
記制御弁を第２の状態として、燃料排出路の排出流量を
本来より少な目とし、これにより制御室の圧力を少し抜
き、ノズルニードルを少々上昇させることで燃料噴射孔
からの燃料噴射率を低めにする。その後、前記第３の状
態とすることで、制御室の圧力を完全に抜いて、ノズル
ニードルを完全に上昇させ、高噴射率を達成する。Here, the control valve described in the publication is a spool valve driven by applying a voltage to a piezo element. The relationship between the fuel injection time and the injection amount determined according to the fuel pressure (fuel supply pressure) is stored in the form of a map in advance, and a detection signal of the fuel pressure in the fuel storage chamber is sent to the control device. By being input, the control device controls the switching valve and the spool valve according to the fuel pressure, and switches the switching valve to the low pressure side at the initial stage of the injection, and at the same time, sets the control valve to the second state, thereby setting the fuel discharging path. The discharge flow rate is made smaller than it should be, whereby the pressure in the control chamber is slightly released, and the nozzle needle is slightly raised to lower the fuel injection rate from the fuel injection hole. Then, by setting the third state, the pressure in the control chamber is completely released, the nozzle needle is completely raised, and a high injection rate is achieved.
【０００８】しかし、このような装置では、ピエゾ素子
等の駆動源（電源）や、これを制御するためのマップ等
が必要であり、その分コスト高となる。また、噴射初期
及び噴射後期によって、燃料噴射率を変えるという要求
の他、内燃機関が高回転のときあるいは低回転のときと
いったような運転状況に応じて、燃料噴射率を最適なよ
うに調整したいという要求もある。However, such an apparatus requires a driving source (power supply) such as a piezo element, a map for controlling the driving source, and the like, resulting in an increase in cost. Also, in addition to the requirement that the fuel injection rate be changed depending on the initial injection period and the late injection period, it is also desirable to adjust the fuel injection rate optimally according to the operating conditions such as when the internal combustion engine is rotating at a high speed or at a low speed. There is also a request.
【０００９】本発明は、このような点に鑑み、燃料噴射
率を燃料排出路に設けた弁で制御して運転状況に応じて
燃料噴射率を可変とする技術を安価に提供することを課
題とする。SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a low-cost technique for controlling a fuel injection rate by a valve provided in a fuel discharge path to vary the fuel injection rate in accordance with an operating condition. And
【００１０】[0010]
【課題を解決するための手段】本発明は、前記課題を解
決するため、以下の手段を採用した。すなわち、本発明
の燃料噴射装置は、燃料を蓄圧する燃料蓄圧室と、この
燃料蓄圧室に蓄圧した高圧燃料を制御室に導入し、この
制御室内に導入された高圧燃料の圧力で弁体を押して燃
料噴射孔を閉じ、制御室内の高圧燃料を燃料排出路から
排出して弁体の押圧力を下げることで燃料噴射孔を開く
燃料噴射弁と、を備えた燃料噴射装置において、前記燃
料排出路に設けられるとともに、前記燃料蓄圧室に蓄圧
された高圧燃料によって駆動され、駆動に応じて燃料排
出路の通路断面積を可変とする燃料流出量可変制御手段
（可変バルブ）を備えることを特徴とする。The present invention adopts the following means in order to solve the above-mentioned problems. That is, the fuel injection device of the present invention introduces a fuel pressure accumulating chamber that accumulates fuel, and high-pressure fuel accumulated in the fuel accumulating chamber into a control chamber, and operates the valve body with the pressure of the high-pressure fuel introduced into the control chamber. A fuel injection valve that presses the fuel injection hole to close the fuel injection hole, discharges high-pressure fuel in the control chamber from the fuel discharge path, and opens the fuel injection hole by reducing the pressing force of the valve body. A fuel outflow variable control means (variable valve) that is provided in the passage and is driven by the high-pressure fuel stored in the fuel storage chamber, and that varies the passage cross-sectional area of the fuel discharge passage according to the drive. And
【００１１】ここで、前記燃料流出量可変制御手段（可
変バルブ）は、例えば、燃料蓄圧室内の燃料圧が低いと
き、前記通路断面積を大きくし、燃料蓄圧室内の燃料圧
が高いとき、前記通路面積を小さくする。Here, the fuel outflow variable control means (variable valve) increases the cross-sectional area of the passage when the fuel pressure in the fuel storage chamber is low, and increases the fuel pressure when the fuel pressure in the fuel storage chamber is high. Reduce the passage area.
【００１２】前記燃料噴射弁としては、燃料噴射孔と、
この燃料噴射孔を閉じる弁体と、この弁体を常閉方向に
付勢する付勢手段と、燃料供給源から所定圧力で供給さ
れてくる高圧燃料を前記燃料噴射孔へ導く第１の燃料供
給路と、この第１の燃料供給路から供給される燃料を受
けるとともに前記弁体に開弁方向に燃料圧を加える燃料
溜まりと、燃料供給源から所定圧力で供給されてくる高
圧燃料を受け入れて前記弁体を常閉方向に押圧する制御
室と、制御室内の高圧燃料を排出して制御室内の液圧を
下げる燃料排出路と、制御室からの燃料排出路に介在
し、閉時には制御室に高圧燃料を封じ込め、開時には制
御室から燃料排出路へと燃料を逃がす背圧制御弁と、を
有することが一般的である。The fuel injection valve includes a fuel injection hole,
A valve element for closing the fuel injection hole, an urging means for urging the valve element in a normally closed direction, and a first fuel for guiding high-pressure fuel supplied at a predetermined pressure from a fuel supply source to the fuel injection hole A supply path, a fuel reservoir for receiving fuel supplied from the first fuel supply path and applying fuel pressure to the valve body in a valve opening direction, and receiving high-pressure fuel supplied at a predetermined pressure from a fuel supply source. A control chamber that presses the valve body in the normally closed direction, a fuel discharge path that discharges high-pressure fuel in the control chamber to reduce the hydraulic pressure in the control chamber, and a fuel discharge path from the control chamber, and controls when closed. It is common to have a back pressure control valve that contains high-pressure fuel in the chamber and allows the fuel to escape from the control chamber to the fuel discharge path when opened.
【００１３】このような燃料噴射弁では、背圧制御弁が
閉じているとき制御室に印加される燃料圧が上昇する
が、そのときに弁体が制御室内の燃料圧から受ける押圧
力をＦｍ、弁体が燃料溜まり内の燃料圧から受ける押圧
力をＦｓ、前記付勢手段の付勢力をＦｃとすると、Ｆｍ
＋Ｆｃ＞Ｆｓ、Ｆｃ＜Ｆｓとされ、燃料噴射孔は弁体に
より閉ざされる。これに対し、背圧制御弁が開いて制御
室から燃料排出路へと燃料を逃がすと、制御室内の燃料
圧が下降するので、Ｆｍ＋Ｆｃ＜Ｆｓとなった時点で、
付勢手段の付勢力に抗して弁体がリフトし、燃料噴射孔
が開き、燃料噴射が開始される。In such a fuel injection valve, when the back pressure control valve is closed, the fuel pressure applied to the control chamber rises. At that time, the pressing force received by the valve body from the fuel pressure in the control chamber is represented by Fm. If the pressing force received by the valve element from the fuel pressure in the fuel reservoir is Fs, and the urging force of the urging means is Fc, Fm
+ Fc> Fs and Fc <Fs, and the fuel injection hole is closed by the valve element. On the other hand, when the back pressure control valve is opened and the fuel is released from the control chamber to the fuel discharge path, the fuel pressure in the control chamber decreases, so that when Fm + Fc <Fs,
The valve body lifts against the urging force of the urging means, the fuel injection hole is opened, and fuel injection is started.
【００１４】ところで、燃料流出量可変制御手段が燃料
蓄圧室に蓄圧された高圧燃料によって駆動されるという
ことは、前記した従来例のピエゾ素子によるスプール弁
に必要な駆動用電源は不要となり、また、制御用のマッ
プ等も不要になることを意味する。By the way, the fact that the fuel outflow variable control means is driven by the high-pressure fuel stored in the fuel storage chamber means that the above-mentioned conventional drive power supply required for the spool valve by the piezo element becomes unnecessary, and , Control maps and the like are not required.
【００１５】また、一般に、低負荷時のように、蓄圧室
内の燃料圧が低いとき、燃料噴射弁の制御室内の燃料圧
も低いので、制御室から燃料排出路を経て流出する燃料
の流出速度が遅くなる。In general, when the fuel pressure in the accumulator is low, such as when the load is low, the fuel pressure in the control chamber of the fuel injection valve is also low. Slows down.
【００１６】このような場合に、燃料蓄圧室の燃料圧
（低圧）に応じて、燃料排出路の通路断面積が大きくな
るように燃料圧で燃料流出量可変制御手段を駆動すれ
ば、制御室内からの燃料流出量が多くなるので、燃料噴
射弁の弁体のリフト速度が過度に遅くなり、燃料噴射時
間が長くなることが抑制される。In such a case, if the fuel outflow variable control means is driven by the fuel pressure so as to increase the cross-sectional area of the fuel discharge passage in accordance with the fuel pressure (low pressure) of the fuel accumulator, the control chamber can be controlled. Since the amount of fuel flowing out of the fuel injection valve increases, the lift speed of the valve body of the fuel injection valve becomes excessively slow, and the fuel injection time is suppressed from becoming long.
【００１７】一方、高負荷時のように蓄圧室内の燃料圧
が高い状態においては、燃料噴射弁の制御室内の燃料圧
も高いので、制御室から燃料排出路を経て流出する燃料
の流出速度が速くなる。On the other hand, when the fuel pressure in the accumulator is high, such as when the load is high, the fuel pressure in the control chamber of the fuel injection valve is also high. Be faster.
【００１８】このような場合に、燃料蓄圧室の燃料圧
（高圧）に応じて、燃料排出路の通路断面積が小さくな
るように燃料圧で燃料流出量可変制御手段を駆動すれ
ば、制御室内からの燃料流出量が少なくなるので、燃料
噴射弁の弁体のリフト速度が過度に速くなり、燃料噴射
率が高くなりすぎることが防止される。In such a case, if the fuel outflow variable control means is driven by the fuel pressure in accordance with the fuel pressure (high pressure) of the fuel storage chamber so as to reduce the cross-sectional area of the fuel discharge passage, the control chamber can be controlled. Since the amount of fuel flowing out of the fuel injection valve is reduced, the lift speed of the valve body of the fuel injection valve is excessively increased, and the fuel injection rate is prevented from becoming too high.
【００１９】本件において、より好ましくは、制御室へ
の燃料供給路において、制御室内への燃料供給量を決定
するインレットオリフィスが設けられ、一方、燃料排出
路には、制御室内からの燃料排出量を決定するアウトレ
ットオリフィスが設けられており、インレットオリフィ
ス（３３ａ）の通路断面積より、アウトレットオリフィ
ス（３４ａ、３４ｂ）の通路断面積の方が大きく設定さ
れ、前記燃料流出量可変制御手段は、駆動源として受け
る蓄圧室内の燃料圧が高圧のとき、アウトレットオリフ
ィス（３４ｂ）の通路断面積をインレットオリフィスの
通路断面積と同等とし、蓄圧室内の燃料圧が低圧となっ
たとき、アウトレットオリフィスの通路断面積をインレ
ットオリフィスの通路断面積より大きくするようにする
ことが好ましい。In this case, more preferably, an inlet orifice is provided in the fuel supply passage to the control room to determine the amount of fuel supply into the control room, while the fuel discharge passage is provided in the fuel discharge passage. The outlet cross-sectional area of the outlet orifices (34a, 34b) is set to be larger than the passage cross-sectional area of the inlet orifice (33a). When the fuel pressure in the accumulator received as a source is high, the passage sectional area of the outlet orifice (34b) is made equal to the passage sectional area of the inlet orifice, and when the fuel pressure in the accumulator becomes low, the passage of the outlet orifice is cut off. Preferably, the area is greater than the passage cross-sectional area of the inlet orifice.
【００２０】より思想的に表現すれば、制御室内へ燃料
供給路における通路断面積より、制御室からの燃料排出
路の通路断面積を大きく設定し、前記燃料流出量可変制
御手段は、駆動源として受ける蓄圧室内の燃料圧が高圧
のとき、燃料排出路の通路断面積を燃料供給路の通路断
面積と同等とし、蓄圧室内の燃料圧が低圧となったと
き、燃料排出路の通路断面積を燃料供給路の通路断面積
より大きくするようにするのである。More specifically, the passage cross-sectional area of the fuel discharge passage from the control chamber is set to be larger than the passage cross-sectional area of the fuel supply passage into the control chamber. When the fuel pressure in the accumulator is high, the cross-sectional area of the fuel discharge passage is equal to the cross-sectional area of the fuel supply passage, and when the fuel pressure in the accumulator becomes low, the cross-sectional area of the fuel discharge passage Is made larger than the passage cross-sectional area of the fuel supply passage.
【００２１】[0021]
【発明の実施の形態】以下、本発明の好適実施形態を、
図面を参照して説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described.
This will be described with reference to the drawings.
【００２２】＜装置の全体構成＞図１に、燃料噴射装置
の全体構成を示す。この装置は、燃料供給源である燃料
タンク１から燃料を汲み上げて、所定圧力で送出する燃
料ポンプ２（ロータリーサプライポンプ）と、この燃料
ポンプ２から送出されて来る燃料を受け、所定の供給圧
力に蓄圧する燃料蓄圧室３を備えている。<Overall Configuration of Apparatus> FIG. 1 shows the overall configuration of a fuel injection device. This device pumps up fuel from a fuel tank 1 as a fuel supply source and sends it out at a predetermined pressure, and a fuel pump 2 (rotary supply pump). A fuel pressure accumulating chamber 3 for accumulating pressure is provided.
【００２３】この燃料蓄圧室３には、複数の燃料供給路
４が接続され、各燃料供給路４には、内燃機関に取り付
けられた複数の燃料噴射弁５が接続されている。内燃機
関がたとえば６気筒で、各気筒にそれぞれ１つの燃料噴
射弁５を設けた場合、燃料供給路４、及び、燃料噴射弁
５はそれぞれ６つとなる。A plurality of fuel supply paths 4 are connected to the fuel pressure accumulating chamber 3, and a plurality of fuel injection valves 5 attached to the internal combustion engine are connected to each fuel supply path 4. When the internal combustion engine is, for example, six cylinders and each cylinder is provided with one fuel injection valve 5, the number of fuel supply passages 4 and the number of fuel injection valves 5 are each six.
【００２４】前記燃料蓄圧室３には、燃料圧センサ６が
設けられ、燃料蓄圧室３内の燃料圧を検出するようにな
っている。さらに、この燃料圧センサ６は、コンピュー
タからなる制御装置７に接続されている。A fuel pressure sensor 6 is provided in the fuel accumulator 3 so as to detect the fuel pressure in the fuel accumulator 3. Further, the fuel pressure sensor 6 is connected to a control device 7 composed of a computer.
【００２５】この制御装置７には、アクセルペダルが踏
み込まれた状態か否かを検出するアクセルセンサＳ１、
内燃機関への吸気圧力を検出する吸気圧センサＳ２、内
燃機関の冷却水の温度を検出する水温センサＳ３、内燃
機関の回転数を検出する機関回転数センサ（ＮＥセン
サ）Ｓ４、内燃機関への空気吸入量を検出するエアロフ
ローメータＳ５、車両に加わる慣性力を検出するＧセン
サＳ６他、車両制御に必要な各種センサが接続されてい
る。The control device 7 includes an accelerator sensor S1, which detects whether the accelerator pedal is depressed or not.
An intake pressure sensor S2 for detecting an intake pressure to the internal combustion engine, a water temperature sensor S3 for detecting a temperature of cooling water of the internal combustion engine, an engine speed sensor (NE sensor) S4 for detecting a rotation speed of the internal combustion engine, An aero flow meter S5 for detecting an air intake amount, a G sensor S6 for detecting an inertial force applied to the vehicle, and various sensors required for vehicle control are connected.
【００２６】また、制御装置７には、燃料ポンプ駆動制
御部８、燃料噴射弁駆動制御部９が設けられ、これら
は、前記各種センサからの情報を基に決定される運転条
件に従って、燃料ポンプ２や燃料噴射弁５を駆動制御す
るようになっている。The control device 7 is provided with a fuel pump drive control unit 8 and a fuel injection valve drive control unit 9 which operate according to operating conditions determined based on information from the various sensors. 2 and the fuel injection valve 5 are drive-controlled.
【００２７】制御装置７では、予め設定された定常運転
用の目標圧力となるよう、燃料蓄圧室３内の燃料圧をフ
ィードバック制御する。すなわち、前記燃料圧センサ６
からの検出圧力が、前記目標圧力になるまで、前記燃料
ポンプ２に駆動信号を送り、燃料の供給を継続し、目標
圧力になったところで、前記燃料ポンプ２の駆動を停止
する制御を繰り返す。The control device 7 performs feedback control of the fuel pressure in the fuel storage chamber 3 so as to reach a preset target pressure for steady operation. That is, the fuel pressure sensor 6
The drive signal is sent to the fuel pump 2 until the detected pressure from the target reaches the target pressure, the supply of fuel is continued, and when the target pressure is reached, the control of stopping the driving of the fuel pump 2 is repeated.
【００２８】また、前記燃料蓄圧室３には、前記燃料蓄
圧室３内の圧力が、前記目標圧力を越えた、所定の設定
圧力となったとき、燃料蓄圧室３内の圧力を解放して逃
がすリリーフ弁１１が設けられている。このリリーフ弁
１１は、燃料供給源側すなわち燃料タンク１へと接続さ
れた燃料解放路１２に介在する形で設置される。When the pressure in the fuel storage chamber 3 reaches a predetermined set pressure exceeding the target pressure, the pressure in the fuel storage chamber 3 is released. An escape relief valve 11 is provided. The relief valve 11 is provided so as to be interposed in a fuel release path 12 connected to the fuel supply source side, that is, the fuel tank 1.
【００２９】＜燃料噴射弁＞図２に示したように、前記
燃料噴射弁５は、先端に燃料噴射孔２１を有する筒状本
体２２と、この筒状本体２２の内部に進退移動自在に設
けられ、進出時に前記燃料噴射孔２１を閉じ、後退時に
前記燃料噴射孔２１を開く針状のニードル弁２３（弁
体）と、このニードル弁２３を閉方向に付勢する付勢手
段としてのコイルスプリング２４とを備えている。<Fuel Injection Valve> As shown in FIG. 2, the fuel injection valve 5 has a cylindrical main body 22 having a fuel injection hole 21 at its tip, and is provided inside the cylindrical main body 22 so as to be movable forward and backward. A needle-shaped needle valve 23 (valve element) that closes the fuel injection hole 21 at the time of advance and opens the fuel injection hole 21 at the time of retreat, and a coil as urging means for urging the needle valve 23 in the closing direction. And a spring 24.
【００３０】さらに、燃料噴射弁５は、燃料供給源であ
る蓄圧室３から所定圧力で供給されてくる高圧燃料を前
記燃料噴射孔２１へ導く第１の燃料供給路３１と、高圧
燃料を受け入れて前記ニードル弁２３を閉方向に押圧す
る制御室３２と、前記第１の燃料供給路３１から分岐
し、燃料供給源である蓄圧室から所定圧力で供給されて
くる高圧燃料を前記制御室３２へと導く第２の燃料供給
路３３と、制御室３２内の高圧燃料を排出して制御室３
２内の液圧を下げる燃料排出路３４とを備えている。Further, the fuel injection valve 5 receives a high-pressure fuel from a first fuel supply passage 31 for guiding high-pressure fuel supplied at a predetermined pressure from the pressure accumulating chamber 3 as a fuel supply source to the fuel injection hole 21. A control chamber 32 for pressing the needle valve 23 in the closing direction, and a high-pressure fuel branched from the first fuel supply passage 31 and supplied at a predetermined pressure from a pressure storage chamber serving as a fuel supply source to the control chamber 32. A second fuel supply path 33 leading to the control chamber 3 and a high-pressure fuel in the control chamber 32 are discharged to control the control chamber 3.
And a fuel discharge passage 34 for lowering the fluid pressure in the fuel cell 2.
【００３１】そして、第２の燃料供給路３３には、制御
室３２への燃料流入量を決定するインレットオリフィス
３３ａが設けられる一方、燃料排出路３４には燃料排出
量を決定するアウトレットオリフィス３４ａが設けられ
ている。これらインレットオリフィス３３ａとアウトレ
ットオリフィス３４ａの通路断面積の比は、例えば、
２：３といったように、アウトレットオリフィス３４ａ
をインレットオリフィス３３ａより大きく設定してい
る。The second fuel supply path 33 is provided with an inlet orifice 33a for determining the amount of fuel flowing into the control chamber 32, while the fuel discharge path 34 is provided with an outlet orifice 34a for determining the amount of fuel discharged. Is provided. The ratio of the passage sectional area of the inlet orifice 33a to that of the outlet orifice 34a is, for example,
Outlet orifice 34a, such as 2: 3
Is set larger than the inlet orifice 33a.
【００３２】また、前記ニードル弁２３は、前記制御室
３２に臨み、制御室３２内の燃料圧力を受けてニードル
弁２３を下降させるメイン・ピストン２３ａを有し、こ
のメイン・ピストン２３ａに対し、ニードル弁２３の燃
料噴射孔２１側に、サブ・ピストン２３ｃが設けられて
いる。このサブ・ピストン２３ｃに臨むように、前記燃
料噴射孔２１へと続く第１の燃料供給路３１の途中に燃
料溜まり３１ａが設けられている。このため、燃料溜ま
り３１ａ内の燃料圧がサブ・ピストン２３ｃに加わり、
ニードル弁２３を開く方向（図の上方）に押している。
このサブ・ピストン２３ｃが燃料溜まり３１ａ内の燃料
圧を受ける受圧面積Ｓｓは、前記メイン・ピストン２３
ａが制御室３２内の燃料圧を受ける受圧面積Ｓｍより小
さく設定されている。さらに、サブ・ピストン２３ｃの
メインピストン２３ａ側に、ニードル弁２３を閉弁方向
に付勢する前記コイルスプリング２４が配設されてい
る。The needle valve 23 has a main piston 23a which faces the control chamber 32 and lowers the needle valve 23 by receiving fuel pressure in the control chamber 32. On the fuel injection hole 21 side of the needle valve 23, a sub piston 23c is provided. A fuel reservoir 31a is provided in the middle of the first fuel supply passage 31 leading to the fuel injection hole 21 so as to face the sub piston 23c. Therefore, the fuel pressure in the fuel reservoir 31a is applied to the sub piston 23c,
The needle valve 23 is pushed in the opening direction (upward in the figure).
The pressure receiving area Ss in which the sub piston 23c receives the fuel pressure in the fuel reservoir 31a is equal to the main piston 23
a is set smaller than the pressure receiving area Sm for receiving the fuel pressure in the control chamber 32. Further, the coil spring 24 for urging the needle valve 23 in the valve closing direction is disposed on the side of the main piston 23a of the sub piston 23c.
【００３３】前記メイン・ピストン２３ａが制御室３２
内の燃料圧から受ける押圧力をＦｍ、前記サブ・ピスト
ン２３ｃが燃料溜まり３１ａ内の燃料圧から受ける押圧
力をＦｓ、前記コイルスプリング２４の付勢力をＦｃと
したとき、定常時は、Ｆｍ＋Ｆｃ＞Ｆｓ、Ｆｃ＜Ｆｓで
ある。The main piston 23a is connected to the control chamber 32
When the pressing force received from the fuel pressure in the fuel tank is Fm, the pressing force received by the sub-piston 23c from the fuel pressure in the fuel reservoir 31a is Fs, and the urging force of the coil spring 24 is Fc, Fm + Fc> Fs, Fc <Fs.
【００３４】さらに、制御室３２からの燃料排出路３４
に介在し、閉時には制御室３２に高圧燃料を封じ込め、
開時には制御室３２から燃料排出路３４へと燃料を逃が
す、常閉の背圧制御弁３５が設けられている。この背圧
制御弁３５は、電磁弁で形成され、筒状本体２２内に設
けられている。そして、この背圧制御弁３５が閉じてい
るときは、制御室３２に印加される燃料圧が上昇し、そ
の圧力により、メイン・ピストン２３ａが押され、これ
にスプリング２４の付勢力も加わってニードル弁２３が
下降する。Further, a fuel discharge passage 34 from the control chamber 32
When closed, high-pressure fuel is contained in the control chamber 32,
A normally closed back pressure control valve 35 is provided to allow fuel to escape from the control chamber 32 to the fuel discharge passage 34 when opened. The back pressure control valve 35 is formed by an electromagnetic valve, and is provided in the tubular main body 22. When the back pressure control valve 35 is closed, the fuel pressure applied to the control chamber 32 increases, and the main piston 23a is pushed by the pressure, and the urging force of the spring 24 is also applied thereto. The needle valve 23 descends.
【００３５】その際、第１の燃料供給路３１から燃料溜
まり３１ａにも制御室３２内に印加されたと同圧の燃料
が導入され、サブ・ピストン２３ｃを押すが、その押圧
力Ｆｓは、Ｆｍ＋Ｆｃに抗しきれないので、ニードル弁
２３は燃料噴射孔２１を閉じた状態に保持される。At this time, fuel of the same pressure as that applied to the control chamber 32 is introduced from the first fuel supply passage 31 to the fuel reservoir 31a, and presses the sub piston 23c. The pressing force Fs is Fm + Fc Therefore, the needle valve 23 is kept in a state where the fuel injection hole 21 is closed.
【００３６】その後、背圧制御弁３５が開かれると、燃
料排出路３４から制御室３２内の燃料が排出するが、こ
のとき、アウトレットオリフィス３４ａをインレットオ
リフィス３３ａより大きく設定してあるため、制御室３
２内への燃料流入量より制御室内からの燃料流出量が多
くなり、その結果、制御室３２内の燃料圧が下降する。Thereafter, when the back pressure control valve 35 is opened, the fuel in the control chamber 32 is discharged from the fuel discharge passage 34. At this time, since the outlet orifice 34a is set larger than the inlet orifice 33a, Room 3
The amount of fuel flowing out of the control chamber becomes larger than the amount of fuel flowing into the fuel cell 2, and as a result, the fuel pressure in the control chamber 32 decreases.
【００３７】そして、Ｆｍ＋Ｆｃ＜Ｆｓとなった時点
で、スプリング２４の付勢力に抗してニードル弁２３が
リフトし、燃料噴射孔２１が開き、燃料噴射が開始され
る。次に、前記燃料噴射孔２１と、ニードル弁２３との
関係を図３の詳細図で示す。弁座を形成する燃料噴射孔
２１の内側壁はテーパー状に形成され、これに対応し、
ニードル弁２３の先端もテーパー状の円錐形になってい
る。このような形状のため、ニードル弁２３がリフト
し、弁座である内壁面から離れたときに形成される通路
面積Ｓｐが燃料噴射孔２１の断面積Ｓｆより小さいとき
は、その通路面積により燃料噴射率が決定され、ニード
ル弁２３がさらにリフトして、通路面積Ｓｐが燃料噴射
孔２１の断面積より大きくなった後は、燃料噴射孔２１
の断面積により燃料噴射率が決定する。When Fm + Fc <Fs, the needle valve 23 is lifted against the urging force of the spring 24, the fuel injection hole 21 is opened, and fuel injection is started. Next, the relationship between the fuel injection hole 21 and the needle valve 23 is shown in the detailed view of FIG. The inner wall of the fuel injection hole 21 forming the valve seat is formed in a tapered shape.
The tip of the needle valve 23 also has a tapered conical shape. Due to such a shape, when the passage area Sp formed when the needle valve 23 lifts and separates from the inner wall surface serving as the valve seat is smaller than the cross-sectional area Sf of the fuel injection hole 21, the fuel passage area is determined by the passage area. After the injection rate is determined and the needle valve 23 is further lifted and the passage area Sp becomes larger than the cross-sectional area of the fuel injection hole 21, the fuel injection hole 21
Determines the fuel injection rate.
【００３８】＜燃料流出量可変制御手段＞前記構成に加
え、制御室３２から流出する流出燃料の量を可変とする
可変バルブ４３（燃料流出量可変制御手段）を設ける
と、ニードル弁２３のリフト速度制御が可能となる。<Fuel outflow variable control means> In addition to the above configuration, if a variable valve 43 (fuel outflow variable control means) for varying the amount of fuel flowing out of the control chamber 32 is provided, the lift of the needle valve 23 is increased. Speed control becomes possible.
【００３９】この可変バルブ４３は、燃料排出路３４に
介在したバルブ室５１と、このバルブ室５１内に進退自
在に設けられたピストン５２とを有している。そして、
バルブ室５１に臨む燃料排出路３４の出口が、前記した
アウトレットオリフィス３４ａとなっており、その通路
面積すなわち燃料排出路３４の出口面積が前記ピストン
５２の進退によって可変とされるように形成されてい
る。そして、前記ピストン５２を付勢し、通常は燃料排
出路の出口面積が大となる方向にピストン５２を位置せ
しめるスプリング５３がバルブ室５１内に設けられてい
る。そして、ピストン５２を間にして前記スプリング５
３とは反対側のバルブ室５１と、燃料蓄圧室３または燃
料蓄圧室３から制御室３２までの間の燃料供給路とを連
結する制御用燃圧路５４が設けられ、燃料蓄圧室３内の
燃料圧がバルブ室５１に印加されるように形成されてい
る。The variable valve 43 has a valve chamber 51 interposed in the fuel discharge passage 34, and a piston 52 provided in the valve chamber 51 so as to be able to move forward and backward. And
The outlet of the fuel discharge passage 34 facing the valve chamber 51 is the outlet orifice 34a described above. The outlet orifice 34a is formed so that the passage area, that is, the outlet area of the fuel discharge passage 34 is made variable by the advance and retreat of the piston 52. I have. A spring 53 is provided in the valve chamber 51 to urge the piston 52 and to position the piston 52 in a direction in which the outlet area of the fuel discharge path generally increases. Then, with the piston 52 interposed, the spring 5
3 is provided with a control fuel pressure passage 54 connecting the valve chamber 51 on the opposite side to the fuel accumulator chamber 3 or the fuel supply path between the fuel accumulator chamber 3 and the control chamber 32. The fuel pressure is formed so as to be applied to the valve chamber 51.
【００４０】＜燃料噴射弁駆動制御＞燃料噴射弁駆動制
御は、燃料噴射弁駆動制御部９により行われる。ディー
ゼル機関において、燃料噴射は、圧縮行程から膨張行程
において、機関の所定クランク角、例えば、上死点前１
０°ＣＡ（crank angle）〜上死点後５°ＣＡで所定量
行う。噴射開始時期を上死点前１０°ＣＡとした場合、
これに燃料噴射時間を加算して噴射終了時期とする。<Fuel Injection Valve Driving Control> The fuel injection valve driving control is performed by the fuel injection valve driving control unit 9. In a diesel engine, fuel injection is performed at a predetermined crank angle of the engine during a compression stroke to an expansion stroke, for example, 1 before top dead center.
Perform a predetermined amount from 0 ° CA (crank angle) to 5 ° CA after top dead center. When the injection start timing is 10 ° CA before top dead center,
The fuel injection time is added to this to make the injection end timing.
【００４１】燃料噴射前は、燃料噴射弁駆動制御部９に
より背圧制御弁３５が閉ざされているので、制御室３２
内は、蓄圧室３から第２の燃料供給路３３を介して導入
された高圧燃料で満たされ、その圧力でニードル弁２３
が下降し、燃料噴出孔２１が閉ざされている。Before the fuel injection, since the back pressure control valve 35 is closed by the fuel injection valve drive control unit 9, the control chamber 32
Is filled with high-pressure fuel introduced from the pressure accumulating chamber 3 through the second fuel supply passage 33, and the pressure is used for the needle valve 23.
Is lowered, and the fuel ejection hole 21 is closed.
【００４２】前記燃料噴射タイミングが来ると、燃料噴
射弁駆動制御部９からの指令により、背圧制御弁３５が
開き、制御室３２内の高圧燃料が燃料排出路３４から排
出される。これにより、制御室３２内の燃料圧が下降
し、サブ・ピストン２３ｃで受ける燃料溜まり３１ａ内
の燃料圧により、ニードル弁２３がリフトし、燃料噴射
孔２１が開く。当初、燃料噴射孔２１が完全に開くまで
の間、燃料噴射率は燃料噴射孔２１周りの通路断面積Ｓ
ｐにより決まる。燃料噴射孔２１周りの通路断面積Ｓｐ
が、燃料噴射孔２１の断面積より大きくなったときは、
燃料噴射孔２１が全開状態となる。When the fuel injection timing comes, the back pressure control valve 35 opens according to a command from the fuel injection valve drive control unit 9, and the high pressure fuel in the control chamber 32 is discharged from the fuel discharge passage 34. As a result, the fuel pressure in the control chamber 32 decreases, and the fuel pressure in the fuel reservoir 31a received by the sub-piston 23c lifts the needle valve 23 and opens the fuel injection hole 21. Initially, until the fuel injection hole 21 is completely opened, the fuel injection rate is determined by the cross-sectional area S of the passage around the fuel injection hole 21.
Determined by p. Passage cross section Sp around fuel injection hole 21
Is larger than the cross-sectional area of the fuel injection hole 21,
The fuel injection holes 21 are fully opened.
【００４３】その後、所定の燃料噴射時間が経過する
と、燃料噴射弁駆動制御部９により、背圧制御弁３５が
閉ざされる。すると、制御室３２に高圧燃料が流入して
封入されるので、制御室３２内の圧力が上昇し、この圧
力を受けてニードル弁２３が下降し、燃料噴射孔２１が
閉じる。Thereafter, when a predetermined fuel injection time has elapsed, the back pressure control valve 35 is closed by the fuel injection valve drive control unit 9. Then, since the high-pressure fuel flows into the control chamber 32 and is sealed therein, the pressure in the control chamber 32 increases, and the needle valve 23 descends by receiving this pressure, and the fuel injection hole 21 closes.
【００４４】この間における制御室圧力、制御室３２へ
の燃料供給量、制御室３２からの燃料排出量、ニードル
弁のリフト量、燃料噴射率の関係を、図４のタイミング
チャートに従って説明する。The relationship among the control chamber pressure, the amount of fuel supplied to the control chamber 32, the amount of fuel discharged from the control chamber 32, the lift amount of the needle valve, and the fuel injection rate during this time will be described with reference to the timing chart of FIG.
【００４５】このタイミングチャートにおいて、実線
は、蓄圧室３内の燃料圧が高圧である場合の特性を示し
（本件及び従来の場合の双方）、破線は、従来の装置に
おいて蓄圧室３内の燃料圧が低圧である場合の特性を示
し、一点鎖線は、本例において、蓄圧室３内の燃料圧が
低圧である場合の特性を示す。In this timing chart, the solid line shows the characteristics when the fuel pressure in the accumulator 3 is high (both in the present case and the conventional case), and the broken line shows the fuel in the accumulator 3 in the conventional device. The characteristic when the pressure is low is shown, and the dashed line indicates the characteristic when the fuel pressure in the accumulator 3 is low in this example.
【００４６】燃料蓄圧室３内の燃料圧力は、燃料噴射に
必要な圧力に保持されるが、図５に示したように、内燃
機関が低回転のときは、４０Ｍｐ（メガパスカル）、高
回転、高負荷のときは、１２０Ｍｐ程度になるのが通常
である。The fuel pressure in the fuel accumulator 3 is maintained at a pressure required for fuel injection. As shown in FIG. 5, when the internal combustion engine is running at a low speed, 40 Mp (megapascal) and at a high speed are used. When the load is high, it is usually about 120 Mp.
【００４７】この圧力が直接バルブ室５１に加わり、ピ
ストン５２のリフト量が変化する。内燃機関が、高回
転、高負荷のときは、バルブ室５１に高燃料圧が加わ
り、スプリング５３に抗したピストンリフト量が大き
く、燃料排出路３４の出口面積が小さくなる。このとき
のインレットオリフィス３３ａの通路断面積と、アウト
レットオリフィス３４ａの通路断面積とがほぼ同一にな
っており、制御室圧力、制御室３２への燃料供給量、制
御室３２からの燃料排出量、ニードル弁２３のリフト
量、燃料噴射率の関係は、図４の実線で示したようにな
る。高燃料圧が、制御室３２に加わるとき、制御室３２
から流出する燃料の速度も大きくなるので、燃料噴射率
の変化はより矩形に近くなるのである。This pressure is directly applied to the valve chamber 51, and the lift of the piston 52 changes. When the internal combustion engine is at a high speed and a high load, a high fuel pressure is applied to the valve chamber 51, the piston lift amount against the spring 53 is large, and the exit area of the fuel discharge passage 34 is small. At this time, the passage cross-sectional area of the inlet orifice 33a and the passage cross-sectional area of the outlet orifice 34a are substantially the same, and the control chamber pressure, the amount of fuel supplied to the control chamber 32, the amount of fuel discharged from the control chamber 32, The relationship between the lift amount of the needle valve 23 and the fuel injection rate is as shown by the solid line in FIG. When high fuel pressure is applied to the control room 32, the control room 32
As the velocity of the fuel flowing out of the fuel cell increases, the change in the fuel injection rate becomes closer to a rectangle.
【００４８】これに対し、内燃機関が、低回転、低負荷
の場合は、低燃料圧が、制御室３２に加わるので、制御
室３２に流入する燃料の速度、制御室３２から流出する
燃料の速度は共に小さくなるので、図４の破線で示した
ように燃料噴射率の変化はよりなだらかになってしま
う。このとき、本例では、バルブ室５１に低燃料圧が加
わり、スプリング５３に抗したピストンリフト量が小さ
く、燃料排出路３４の出口面積が大きくなる。よって、
インレットオリフィス３３ａの通路断面積より、アウト
レットオリフィス３４ａの通路断面積の方が大きくな
り、制御室３２内の燃料の流出が速くなり、ニードル弁
２３のリフト速度も速くなり、かつ、リフト量も大きく
なって、燃料噴射率が低噴射率となる。このため、燃料
噴射率特性は、図４に示したように、通常の場合（破
線）に比較し、立ち上がりがよく、低圧であっても従来
より高噴射率を確保できる。On the other hand, when the internal combustion engine has a low rotation speed and a low load, a low fuel pressure is applied to the control chamber 32, so that the speed of the fuel flowing into the control chamber 32 and the rate of the fuel flowing out of the control chamber 32 are reduced. Since the speeds are both reduced, the change in the fuel injection rate becomes gentler as shown by the broken line in FIG. At this time, in this example, a low fuel pressure is applied to the valve chamber 51, the piston lift against the spring 53 is small, and the exit area of the fuel discharge path 34 is large. Therefore,
The passage cross-sectional area of the outlet orifice 34a is larger than the passage cross-sectional area of the inlet orifice 33a, the flow of fuel into the control chamber 32 is increased, the lift speed of the needle valve 23 is increased, and the lift amount is increased. As a result, the fuel injection rate becomes a low injection rate. For this reason, as shown in FIG. 4, the fuel injection rate characteristic has a higher rise than that in the normal case (broken line), and a higher injection rate can be ensured even at a low pressure.
【００４９】[0049]
【発明の効果】本発明によれば、内燃機関の運転状況に
応じ、燃料蓄圧室内の燃料圧制御室が低圧から高圧に変
化するにつれ、好ましい燃料噴射率を得ることができ
る。According to the present invention, a favorable fuel injection rate can be obtained as the fuel pressure control chamber in the fuel accumulator changes from a low pressure to a high pressure according to the operating condition of the internal combustion engine.
【００５０】また、蓄圧室内の燃料圧で駆動される燃料
流出量可変制御手段で制御するようにしたので、安価に
提供できる。Further, since the control is performed by the fuel outflow variable control means driven by the fuel pressure in the accumulator, it can be provided at low cost.
【図１】本件発明にかかる装置の全体構成図FIG. 1 is an overall configuration diagram of an apparatus according to the present invention.
【図２】実施形態の燃料噴射弁を示した図FIG. 2 is a view showing a fuel injection valve according to the embodiment;
【図３】燃料噴射孔周りを示した詳細図FIG. 3 is a detailed view showing the vicinity of a fuel injection hole.
【図４】実施形態の燃料噴射特性を示したタイミングチ
ャート図FIG. 4 is a timing chart showing fuel injection characteristics of the embodiment.
【図５】内燃機関の運転状況と燃料圧との関係を示すグ
ラフ図FIG. 5 is a graph showing the relationship between the operating state of the internal combustion engine and the fuel pressure.
１・・燃料供給源である燃料タンク ２・・燃料ポンプ ３・・燃料蓄圧室 ４・・燃料供給路 ５・・燃料噴射弁 ６・・燃料圧センサ ７・・制御装置 ８・・燃料ポンプ駆動制御部 ９・・燃料噴射弁駆動制御部 １１・・リリーフ弁 １２・・燃料解放路 ２１・・燃料噴射孔 ２２・・筒状本体 ２３・・ニードル弁 ２４・・コイルスプリング ３１・・第１の燃料供給路 ３２・・制御室 ３３・・第２の燃料供給路 ３３ａ・・インレットオリフィス ３４・・燃料排出路 ３４ａ・・アウトレットオリフィス ３５・・背圧制御弁 ４３・・燃料流出量可変制御手段としての可変バルブ ５１・・バルブ室 ５２・・ピストン ５３・・スプリング ５４・・制御用燃圧路 Ｓ１・・アクセルセンサ Ｓ２・・吸気圧センサ Ｓ３・・水温センサ Ｓ４・・機関回転数センサ Ｓ５・・エアロフローメータ Ｓ６・・Ｇセンサ 1. Fuel tank as fuel supply source 2. Fuel pump 3. Fuel accumulator chamber 4. Fuel supply path 5. Fuel injection valve 6. Fuel pressure sensor 7. Control device 8. Fuel pump drive Control unit 9 fuel injection valve drive control unit 11 relief valve 12 fuel release passage 21 fuel injection hole 22 cylindrical body 23 needle valve 24 coil spring 31 first Fuel supply path 32 Control room 33 Second fuel supply path 33a Inlet orifice 34 Fuel discharge path 34a Outlet orifice 35 Back pressure control valve 43 Control means for variable fuel outflow Variable valve 51 ... Valve chamber 52 ... Piston 53 ... Spring 54 ... Control fuel pressure path S1 ... Accelerator sensor S2 ... Intake pressure sensor S3 ... Water temperature sensor S4 ... Engine rotation Sensor S5 · · aero flowmeter S6 · · G sensor
Claims (2)
この制御室内に導入された高圧燃料の圧力で弁体を押し
て燃料噴射孔を閉じ、制御室内の高圧燃料を燃料排出路
から排出して弁体の押圧力を下げることで燃料噴射孔を
開く燃料噴射弁と、 を備えた燃料噴射装置において、 前記燃料排出路に設けられるとともに、前記燃料蓄圧室
に蓄圧された高圧燃料によって駆動され、駆動に応じて
燃料排出路の通路断面積を可変とする燃料流出量可変制
御手段を備えたことを特徴とする燃料噴射装置。1. A fuel accumulation chamber for accumulating fuel, and a high-pressure fuel accumulated in the fuel accumulation chamber is introduced into a control chamber.
The fuel injection hole is closed by pressing the valve body with the pressure of the high-pressure fuel introduced into the control chamber, and the high-pressure fuel in the control chamber is discharged from the fuel discharge path to open the fuel injection hole by reducing the pressing force of the valve body. And a fuel injection device comprising: an injection valve, which is provided in the fuel discharge path and is driven by high-pressure fuel stored in the fuel storage chamber, and varies a passage cross-sectional area of the fuel discharge path according to the drive. A fuel injection device comprising a fuel outflow variable control means.
圧室内の燃料圧が低いとき、前記通路断面積を大きく
し、燃料蓄圧室内の燃料圧が高いとき、前記通路断面積
を小さくすることを特徴とする請求項１記載の燃料噴射
装置。2. The fuel outflow variable control means increases the cross-sectional area of the passage when the fuel pressure in the fuel storage chamber is low, and decreases the cross-sectional area of the passage when the fuel pressure in the fuel storage chamber is high. The fuel injection device according to claim 1, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17747697A JP3743124B2 (en) | 1997-07-02 | 1997-07-02 | Fuel injection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17747697A JP3743124B2 (en) | 1997-07-02 | 1997-07-02 | Fuel injection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1122583A true JPH1122583A (en) | 1999-01-26 |
| JP3743124B2 JP3743124B2 (en) | 2006-02-08 |
Family
ID=16031589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17747697A Expired - Fee Related JP3743124B2 (en) | 1997-07-02 | 1997-07-02 | Fuel injection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3743124B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7040293B2 (en) | 2003-08-26 | 2006-05-09 | Toyota Jidosha Kabushiki Kaisha | Fuel injection system |
-
1997
- 1997-07-02 JP JP17747697A patent/JP3743124B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7040293B2 (en) | 2003-08-26 | 2006-05-09 | Toyota Jidosha Kabushiki Kaisha | Fuel injection system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3743124B2 (en) | 2006-02-08 |
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