JP3568636B2 - Solenoid driven hydraulic control valve - Google Patents

Description

【００１９】
ｄ_ｓ ：バルブシート径（バルブシート部６６の径）
ｄ_ＲＧ：ロッドガイド径（ロッドガイド部８０の径）
Ｐ_Ｏ ：制御ポート圧
Ｆ_Ｓ ：スプリング力
なる作用力が働いている。
【００２０】
以上のような構成において、ソレノイド６７に通電すると、バルブ６３は吸引されて上方に移動するため、バルブ６３のバルブシート部６６は離座し、制御ポート５８とドレーンポート５６は連通して背圧室５７の圧力は降下する。このため、蓄圧された油溜り６１の燃料圧によりニードル６０は押上げられて噴孔１２６は開放される。その結果、油溜り６１及び噴孔の近傍の高圧燃料は該噴孔１２６から一気に噴出し、噴射を開始する。
【００２１】
この時、バランスロッド６８とバルブ６３はロッドシート部８１で着座し、バランスロッド６８とバルブ６３によって囲まれた閉じた空間である蓄圧室（２００）を下部室７１の中に形成する。
次に、噴射を停止しようとする時、ソレノイド６７への通電を停止すると、わずかの間ではあるが、残留磁気が残るため、バルブ６３には若干の残留磁気による吸引力（Ｆ_ｒ ）が働く。
【００２２】
ロッドシート部８１により蓄圧室２００が形成されている時、バルブ６３に働く作用力としては、図中下向きを正とすると、
【００２３】
【数２】

【００２４】
ｄ_ＲＧ：ロッドガイド径（ロッドガイド部８０の径）
ｄ_ＲＳ：ロッドシート径（ロッドシート部８１のシート径）
Ｐ_Ａ ：蓄圧室圧
Ｆ_Ｓ ：スプリング力
Ｆ_ｒ ：残留磁気による吸引力
ここで、ロッドシート部８１とバルブ６３により形成された蓄圧室２００の圧力は、バルブ６３が離座し、制御ポート圧が低下しても、バルブ６３着座時の制御ポート圧（これは、リザーバ５４に蓄圧されている圧力と等しい）と等しいため、わずかな間働く残留磁気による吸引力Ｆ_ｒ を打ち消してなお余りあるだけの十分な閉弁力（バルブ６３を押下げようとする力）を提供できるようにロッドシート径とロッドガイド径及びバルブシート径の組合わせを選択すればよい。
【００２５】
例えばロッドガイド径ｄ_ＲＧ＝３ｍｍ、ロッドシート径ｄ_ＲＳ＝２．９５ｍｍ、スプリング力Ｆ_Ｓ ＝５ｋｇｆ、蓄圧室圧Ｐ_Ａ ＝２０００ｋｇｆ／ｃｍ^２ の時、
【００２６】
【数３】

【００２７】
となる。
このように、バルブ６３を下方に押下げる力が、例えば４．６ｋｇｆ発生し、その力がスプリング６５のバネ力５ｋｇｆに重畳されて９．６ｋｇｆの力がバルブ６３にかかるため、たとえソレノイド６７の残留磁気によるＦ_ｒ が逆に作用しても、従来技術に比して、前記ソレノイド６７の残留磁気による応答遅れを大幅に低減することができる。
【００２８】
なお、図１の燃料噴射部５１はコマンドピストン１０８を有しているが、本発明のソレノイド駆動油圧制御弁５０の作用は、特にコマンドピストン１０８の有無に関係無く成立するものであるので、コマンドピストン１０８を除いた場合も同様の効果が得られる。
図２は本発明の第２実施例としての二方弁式油圧制御弁を内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。燃料圧送ポンプ１５２により圧送された高圧燃料は、リザーバ１５４に蓄圧され、さらにエンジンに装着された燃料噴射装置に供給されるようになっている。油圧制御弁１５０のハウジング１５３には、ドレーンをなす燃料タンク１５５に連通するドレーンポート１５６、及び背圧室１５７に連通する制御ポート１５８が設けられている。燃料圧送ポンプ１５２からリザーバ１５４に蓄圧された高圧燃料は、ニードル１６０周辺にある油溜り１６１へ導入蓄圧されると同時に、絞り１６２を介して背圧室１５７及び制御ポート１５８へと導入されている。背圧室１５７には高圧が作用しているため、ニードル１６０は下降して通常は噴孔２２６を閉鎖している。前記油圧制御弁１５０のハウジング１５３内には、バルブ１６３が上下方向に摺動自在に移動することができるように嵌挿され、上部に設けたスプリング１６５により下方に押付けられて、下部のバルブシート部１６６で着座している。また、ハウジング１５３の上方にはソレノイド１６７が設置され、それに対向してアーマチャ室１７２内にバルブ１６３の一部分であるアーマチャ１６４が設けられている。前記バルブ１６３内には、バランスロッド１６８が上下方向に摺動自在に移動することができるように嵌挿されている。そして、制御ポート１５８に導入された高圧燃料は、バルブ１６３に形成された連通路１７０を介してバランスロッド１６８の下部室１７１まで導入されている。従って、バランスロッド１６８は、通常は、高い燃料圧によって上部に押上げられている。
【００２９】
また、下部室１７１に導入された高圧燃料は、バランスロッド１６８とバルブ１６３との間の２〜３μｍのクリアランスを介してアーマチャ室１７２へと連通している。アーマチャ室１７２の出口には、調圧手段３０１が設けられ、ドレーンポート１５６と合流して燃料タンク１５５へと戻されている。
図２の状態は、噴射停止状態を示している。
【００３０】
この時、バルブ１６３への作用力を図中下向きを正としてみると、
【００３１】
【数４】

【００３２】
ｄ_ＲＧ：ロッドガイド径（ロッドガイド部１８０の径）
ｄ_ＶＳ：バルブシート径（バルブシート部１６６の径）
Ｐ_ｆ ：噴射圧
ｄ_ＶＧ：バルブガイド径（バルブガイド３０２の径）
Ｐ_ｒ ：アーマチャ室の残圧
Ｆ_Ｓ ：スプリング力
なる作用力が働いている。
【００３３】
以上のような構成において、ソレノイド１６７に通電すると、バルブ１６３は吸引されて上方に移動するため、バルブ１６３のバルブシート部１６６は離座し、制御ポート１５８とドレーンポート１５６は連通して背圧室１５７の圧力は降下する。このため、蓄圧された油溜り１６１の燃料圧によりニードル１６０は押上げられて噴孔２２６は開放される。その結果、油溜り１６１及び噴孔の近傍の高圧燃料は該噴孔から一気に噴出し、噴射を開始する。
【００３４】
この時、バルブシート部１６６が離座したことにより、制御ポート１５８はほとんど大気圧まで降下する。従って、バルブ１６３への作用力は同じく図中下向きを正として、
【００３５】
【数５】

【００３６】
となり、閉弁時のＦ_１ の第１項が抜けた形となる。
ここで、例えばｄ_ＲＧ＝３ｍｍ、ｄ_ＶＧ＝６．５ｍｍ、Ｐ_ｒ ＝１０ｋｇ／ｃｍ^２ 、Ｆ_Ｓ ＝８ｋｇｆの時、ｄ_ＶＳ＝３．１４ｍｍを選べば、
Ｆ_１ ＝９．３ｋｇｆ（Ｐ_ｆ ＝２００ｋｇ／ｃｍ^２ の時）；２．７ｋｇｆ（Ｐ_ｆ ＝１２００ｋｇｆ／ｃｍ^２ のとき）、
Ｆ_２ ＝１０．６ｋｇｆ
となる。
【００３７】
噴射を停止しようとソレノイド１６７への通電を停止して、残留磁気による吸引力Ｆ_ｒ がＦ_２ （＝１０．６ｋｇｆ）と逆向きに働いたとしても、スプリング力Ｆ_Ｓ （＝８ｋｇｆ）のみの時よりも、２．６ｋｇｆ閉弁力を高めることができるため、速やかにバルブ１６３が閉弁できる。
従って、第１の実施例と同様に、前記ソレノイド１６７の残留磁気による応答遅れを大幅に低減することができる。
【００３８】
さらに、この第２実施例において特徴的なこととしては、Ｆ_１ の第１項の開弁アシスト方向へ働く力を例示のごとく適切に選べば、閉弁力は常時効果的に作用させることができ、しかも、高噴射圧側で、開弁アシストがより強く作用する。従って、閉弁応答を改善できると共に、高噴射圧側で、よりバルブを開弁するための力が少なくて済むことになり、制御性が向上する。
【００３９】
図２においては調圧手段３０１を油圧制御弁１５０と別体のごとく示してあるが、ハウジング１５３へ組み込んでも作用にかわりはない。
また、アーマチャ室１７２の残圧Ｐ_ｒ は１０ｋｇ／ｃｍ^２ としてあるが、これは特に１０ｋｇ／ｃｍ^２ でなくても良く、噴射圧Ｐ_ｆ が可変できるような燃料圧送ポンプを用いる場合には、噴射圧に連動して残圧を可変してもよい。
【００４０】
また、ここでは調圧手段３０１をポペット弁にして示してあるが、アーマチャ室に残圧を残す手段として、絞りとなるオリフィスを用いてもよい。
図３は図５に従来例として示された三方弁式油圧制御弁に、本発明での調圧手段５００を付加した本発明の第３実施例のソレノイド駆動油圧制御弁を、内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。第２実施例において示した調圧手段３０１に相当する調圧手段５００を、ソレノイド１４１に臨んだアーマチャ部が収容されたアーマチャ室１３３からドレーンへ連通する流路に設けて、三方弁式油圧制御弁に適用しており、アーマチャ室１３３に残圧を残し、スプリング１１２の作用力を助ける。
【００４１】
効果としては、第２実施例と同様である。
本発明の第４実施例を図４に示す。図中６００は第２実施例において示した調圧手段３０１に相当する調圧手段である。これ以外の構成は第１実施例と同様である。すなわち、第４実施例は第１実施例と第２実施例とを組合わせた例であり、第１実施例と同一の構成を同一の符号で示す。６００は具体的にはポペット弁や絞り等の調圧手段を示す。
【００４２】
効果としては、それぞれの実施例で示したことが相乗されて現れ、最も効果が高い。
噴射停止時のバルブ６３への作用力としては、第２実施例のＦ_１ と同様の式となる。
また、噴射中の作用力Ｆ_３ としては第１実施例のＦ_Ｃ からＦ_ｒ を除いた分、
【００４３】
【数６】

【００４４】
に第２実施例のＦ_２ の第１項である
【００４５】
【数７】

【００４６】
をたし合わせたものとなる。
従って、
ｄ_ＲＧ＝３ｍｍ、ｄ_ＶＧ＝６．５ｍｍ、ｄ_ＶＳ＝３．１４ｍｍ、Ｆ_Ｓ ＝８ｋｇｆ、Ｐ_ｆ ＝１２００ｋｇｆ／ｃｍ^２ の時、
Ｆ_１ ＝２．７８ｋｇｆ
【００４７】
【数８】

【００４８】
となり、大きな閉弁力を得ることができる。
【００４９】
【発明の効果】
請求項１から６のソレノイド駆動油圧制御弁においては、バルブへの油圧作用力が、ソレノイドの吸引力とは逆方向に作用するようにロッドガイド径、ロッドシート径、バルブシート径及びバルブガイド径を各々選定しているので、ソレノイドの通電停止後、残留磁気によるバルブの吸引力に対して、スプリングのバネ力と前記油圧作用力との合力が打勝って、バルブは迅速に下方へ移動するため、ソレノイドの残留磁気による応答遅れを大幅に低減することができ、従って、微少な噴射量まで高精度の調量を可能とすることができる。また、前記油圧作用力をソレノイドの残留磁気による吸引力と相殺できる程度に必要最小限にとどめているので、バランスロッドを使用しない構成のバルブを用いた油圧制御弁とは異なり、ソレノイドの大型化も同時に回避させることができる。
【図面の簡単な説明】
【図１】本発明の第１実施例としてのソレノイド駆動油圧制御弁をなす二方弁式油圧制御弁を内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。
【図２】本発明の第２実施例としての二方弁式油圧制御弁を内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。
【図３】図５に従来例として示される三方弁式油圧制御弁に、本発明での調圧手段を付加した本発明の第３実施例のソレノイド駆動油圧制御弁を、内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。
【図４】本発明の第４実施例のソレノイド駆動油圧制御弁を、内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。
【図５】従来のソレノイド駆動油圧制御弁を、内燃機関の蓄圧式燃料噴射装置に適用した場合の構成を示す断面図である。
【符号の説明】
５０、１５０ ソレノイド駆動油圧制御弁
５８、１５８ 制御ポート
６３、１６３ バルブ
６５、１６５、１１２ スプリング
６６ バルブシート部
６７、１４１、１６７ ソレノイド
６８、１１８ バランスロッド
７０ 連通路
７１ 下部室
７９、１１５ 孔
８１ ロッドシート部
１１１ 第１のバルブ
１１６ バルブシート
１１７ 第２のバルブ
１２８ 空間
１３３、１７２ アーマチャ室
１３６、１５５ ドレーン（ドレーンポート、燃料タンク）
１６４ アーマチャ
２００ 蓄圧室
３０１、５００、６００ 調圧手段（ポペット弁、オリフィス）[0001]
[Industrial applications]
The present invention relates to a hydraulic control valve, and more particularly to a solenoid-driven hydraulic control valve applied to an injection device for fuel injection of an internal combustion engine.
[0002]
[Prior art]
Among the conventional solenoid-driven hydraulic control valves, there is a hydraulic control valve using a balance rod, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-332220. The configuration and operation of the hydraulic control valve will be described with reference to FIG.
A well-known nozzle 102 is screwed below a holder 101 of the hydraulic control valve 100 by a retainer 103, and a needle 105 is slidable by a force of a pressure spring 107 via a spring holder 106. It is urged in the seating direction by the fuel pressure acting on the upper end of the command piston 108, which is larger than the clearance and has a clearance of 2-3 μm.
[0003]
An outer valve 111 serving as a first valve is inserted with a clearance of 2 to 3 μm so as to slide in a guide hole 110 formed in the left and right direction inside the holder 101. And is seated on the outer valve seat 113 by being pushed to the right. An inner valve serving as a second valve having a clearance 2 to 3 μm slidably fitted with an inner valve seat 116 serving as a valve seat in a left center hole 115 serving as a hole provided in the outer valve 111. 117 is inserted and pushed to the left by fuel pressure. A balance rod 118 having the same diameter as the inner valve seat 116 and a clearance of 2 to 3 μm is slidably accommodated in the center hole on the right side, and is pushed rightward by fuel pressure.
[0004]
The high-pressure port 120 communicates with the annular high-pressure groove 121, the fuel port 122 in the holder 101, the fuel port 123 in the nozzle 102, and the oil reservoir 125 in this order up to the vicinity of the injection hole 126. Further, since the high-pressure groove 121 communicates with the radial fuel port 127 in the outer valve 111 and the axial fuel port 128 forming a space, the outer valve 111 moves rightward as shown in FIG. When the seat 116 is unseated, it also communicates with the back pressure chamber 130 at the upper end of the command piston 108.
[0005]
The spring chamber 131 in which the pressure spring 107 is housed communicates with the spring chamber 133 in which the spring 112 is housed by the port 132 and the armature chamber facing the solenoid 141 is housed. 133 is connected to a drain port 136 by a port 135. The annular low-pressure groove 137 in the outer valve 111 also communicates with the drain port 136 in the order of the radial port 138 and the annular low-pressure groove 140 in the holder 101.
[0006]
Next, the operation of the conventional hydraulic control valve 100 will be briefly described.
The state of FIG. 5 shows a state in which fuel injection is stopped. When the solenoid 141 is energized at the start of fuel injection, the outer valve 111 is sucked to the left to separate from the outer valve seat 113 and The person sits on the valve seat 116. As a result, the back pressure chamber 130 communicates with the drain port 136 to reduce the oil pressure, so that the needle 105 is pushed upward by the pressure of the oil reservoir 125 communicating with the high pressure port 120 to open the injection hole 126. The fuel injection is started.
[0007]
[Problems to be solved by the invention]
In a hydraulic control valve using a balance rod 118 as disclosed in the above-mentioned JP-A-5-332220, there is no problem when the actuator is an electrostrictive actuator, but when the actuator is a solenoid type, When energization of the solenoid 141 is cut off to close the needle 105, the hydraulic force applied to the outer valve 111 is completely canceled by the balance rod 118 because the diameter of the inner valve seat 116 and the diameter of the balance rod 118 are the same. Therefore, the force for closing the outer valve 111 is only the spring force of the spring. However, even if the energization of the solenoid 141 is stopped, the residual magnetism still remains. Therefore, the time until the residual magnetism disappears depends on the magnetic force of the solenoid 141 acting in the valve opening direction of the valve 111. Therefore, a large response delay occurs when the valve 111 is closed, and there is a problem that a minute injection amount cannot be adjusted. This problem is not limited to the illustrated three-way valve type hydraulic control valve, but can also occur with a two-way valve type hydraulic control valve using a similar balance rod.
[0008]
The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to eliminate a response delay of a valve due to residual magnetism of a solenoid, and thereby to adjust a minute injection amount. It is an object of the present invention to provide a solenoid-operated hydraulic control valve capable of controlling the quantity.
[0009]
[Means for Solving the Problems]
The present invention, in order to achieve the above object,
Claim 1 is used in an accumulator type fuel injection device of an internal combustion engine, wherein a valve is suction-driven by a solenoid to communicate and cut off hydraulic pressure applied to a control port, and the valve is in a direction opposite to a suction force of the solenoid. In a solenoid-operated hydraulic control valve having a spring that biases a balance rod, a balance rod is slidably fitted into a hole provided in the valve having a valve seat portion at a lower portion, and the balance rod is provided. A lower chamber formed by a lower surface and the hole, a communication path formed in the valve that communicates the lower chamber with the control port, and a rod seat provided below the balance rod. The valve is unseated, and the rod seat portion of the balance rod is seated on an opening of the lower chamber of the communication passage to seal the lower chamber to form a pressure accumulation chamber. By forming, solenoid drive hydraulic control valve the hydraulic force acting on the accumulation chamber to the valve is characterized in that so as to act on the suction force in the opposite direction of the solenoid;
A second aspect of the present invention is used in a pressure accumulating type fuel injection device of an internal combustion engine, wherein a valve is suction-driven by a solenoid to communicate and shut off hydraulic pressure applied to a control port, and the valve is in a direction opposite to a suction force of the solenoid. In a solenoid-operated hydraulic control valve having a spring that biases a balance rod, a balance rod is slidably fitted into a hole provided in the valve having a valve seat portion at a lower portion, and the balance rod is provided. A lower chamber formed by a lower surface and the hole, and a hydraulic pressure is supplied from a clearance between the balance rod and the valve to an armature chamber in which an armature above the valve is housed below the solenoid; Pressure regulating means is provided in a flow path communicating from the chamber to the drain so that a residual pressure is generated in the armature chamber; The guide diameter of the lube is set to be larger than the guide diameter of the balance rod, and the residual pressure generated by the pressure adjusting means due to the pressure receiving area difference causes the hydraulic force acting on the valve to act in the opposite direction to the suction force of the solenoid. A solenoid-operated hydraulic control valve, characterized in that:
As a third aspect, the solenoid-operated hydraulic control valve according to any one of the first to second aspects, wherein the solenoid-operated hydraulic control valve is a two-way valve;
According to a fourth aspect of the present invention, the first valve is used for a pressure accumulating fuel injection device of an internal combustion engine, and the first valve is suction-driven by a solenoid to communicate and shut off hydraulic pressure, and the valve is moved in a direction opposite to the suction force of the solenoid. A second valve having a biasing spring and having a valve seat that can be seated on the first valve is slidably inserted into a hole provided in the first valve, and provided. In the solenoid-operated hydraulic control valve, a space is provided in the hole on the side opposite to the solenoid with respect to the second valve, and a balance rod having the same diameter as the valve seat is slidably inserted. Supplying hydraulic pressure from a clearance between the first valve and the second valve to an armature chamber in which the armature facing the solenoid is accommodated by the first valve; And the chamber opposite to the armature chamber is also supplied with a clearance oil pressure between the first valve and the balance rod to cancel the oil pressure acting on the first valve and to communicate with the drain from the armature chamber to the drain. A solenoid-driven hydraulic control valve, characterized in that a pressure regulating means is provided on the road so that residual pressure is generated in the armature chamber;
According to a fifth aspect of the present invention, the pressure regulating means is a poppet valve, and the solenoid-driven hydraulic control valve according to any one of the second and fourth aspects;
As a sixth aspect, the solenoid-operated hydraulic control valve according to any one of the second to fourth aspects, wherein the pressure adjusting means is an orifice.
The technical means is adopted.
[0010]
[Action]
According to the configuration of the first aspect, the rod seat portion of the balance rod is seated in the opening of the lower chamber of the communication passage to seal the lower chamber to form a pressure accumulating chamber. Since it acts in the opposite direction to the attraction force of the solenoid, even if the residual magnetism of the solenoid acts as the valve opening force of the valve, it cancels it out, and the response delay due to the residual magnetism of the solenoid can be greatly reduced.
[0011]
According to the configuration of the second aspect, by providing pressure regulating means in a flow path communicating with the drain from the armature chamber in which the armature at the upper part of the valve is accommodated at the lower part of the solenoid, so that residual pressure is generated in the armature chamber, Due to the difference in pressure receiving area between the valve and the balance rod , the hydraulic force acting on the valve acts in the opposite direction to the attraction force of the solenoid, so even if the residual magnetism of the solenoid works as the valve opening force of the valve, it cancels it out and the solenoid Response delay due to residual magnetism can be greatly reduced.
[0012]
According to the configuration of the third aspect, since the solenoid-driven hydraulic control valve is a two-way valve, the response delay due to the residual magnetism of the solenoid can be greatly reduced with a simple configuration.
According to the configuration of the fourth aspect, the pressure regulating means is provided in the flow path communicating with the drain from the armature chamber in which the armature facing the solenoid is accommodated by the first valve so that residual pressure is generated in the armature chamber. By doing so, the hydraulic force acting on the valve acts in the opposite direction to the attraction force of the solenoid, so even if the residual magnetism of the solenoid works as the valve opening force, it cancels it out and the response delay due to the residual magnetism of the solenoid Can be greatly reduced.
[0013]
According to the configuration of the fifth aspect, since the pressure adjusting means is a poppet valve, highly accurate control can be performed with a relatively simple configuration.
According to the configuration of claim 6, since the pressure adjusting means is an orifice, control can be performed with a very simple configuration.
[0014]
【Example】
FIG. 1 is a cross-sectional view showing a configuration in which a two-way valve type hydraulic control valve 50 serving as a solenoid driven hydraulic control valve according to a first embodiment of the present invention is applied to a pressure accumulating fuel injection device for an internal combustion engine. The accumulator type fuel injection device includes a two-way valve type hydraulic control valve 50 and a fuel injection unit 51 having the same configuration as the conventional example. The high-pressure fuel pumped by the fuel pump 52 is stored in a reservoir 54 and supplied to a fuel injection device mounted on the engine.
[0015]
The housing 53 of the hydraulic control valve 50 is provided with a drain port 56 communicating with a fuel tank 55 forming a drain, and a control port 58 communicating with a back pressure chamber 57 of the fuel injection unit 51. The high-pressure fuel stored in the reservoir 54 from the fuel pump 52 is introduced and stored in an oil sump 61 around the needle 60 of the fuel injection device 51, and at the same time, is transferred to a back pressure chamber 57 and a control port 58 via a throttle 62. Has been introduced. Since high pressure acts on the back pressure chamber 57, the needle 60 descends and normally closes the injection hole 126. A valve 63 is fitted into the housing 53 of the hydraulic control valve 50 so as to be slidable in a vertical direction, and is pressed downward by a spring 65 provided at an upper portion to thereby lower the valve seat portion. He is sitting at 66. A solenoid 67 is provided above the housing 53, and an armature 64, which is a part of the valve 63, is provided in the armature chamber 72 to face the solenoid 67. A hole 79 is provided in the valve 63, and the balance rod 68 is fitted so as to be slidable vertically. Then, the high-pressure fuel introduced into the control port 58 is introduced into the lower chamber 71 of the balance rod 68 via a communication passage 70 formed in the valve 63. Therefore, the balance rod 68 is normally pushed upward by the high fuel pressure.
[0016]
The balance rod 68 has a rod guide 80 and a rod seat 81.
In addition, the two-way valve type hydraulic control valve 50 and the fuel injection unit 51 may be integrally formed coaxially, or may be connected by piping and may be separate bodies.
The state in FIG. 1 shows the injection stop state.
[0017]
At this time, the acting force F _O acting on the valve 63, when the downward in the figure is positive,
[0018]
(Equation 1)

[0019]
d _s : Valve seat diameter (diameter of valve seat part 66)
d _RG : rod guide diameter (diameter of rod guide section 80)
P _O : Control port pressure F _S : Acting force acting as a spring force is acting.
[0020]
In the above-described configuration, when the solenoid 67 is energized, the valve 63 is sucked and moved upward, so that the valve seat portion 66 of the valve 63 is unseated, and the control port 58 and the drain port 56 communicate with each other, thereby causing the back pressure. The pressure in the chamber 57 drops. Therefore, the needle 60 is pushed up by the accumulated fuel pressure of the oil reservoir 61, and the injection hole 126 is opened. As a result, the high-pressure fuel near the oil sump 61 and the injection hole gushes out of the injection hole 126 at once, and starts injection.
[0021]
At this time, the balance rod 68 and the valve 63 are seated on the rod seat portion 81, and a pressure accumulation chamber (200), which is a closed space surrounded by the balance rod 68 and the valve 63, is formed in the lower chamber 71.
Next, when the injection is stopped, when the energization of the solenoid 67 is stopped, the residual magnetism remains for a short time, but a slight attractive force (F _r ) due to the residual magnetism acts on the valve 63. .
[0022]
When the pressure accumulating chamber 200 is formed by the rod seat portion 81, the acting force acting on the valve 63 is as follows.
[0023]
(Equation 2)

[0024]
d _RG : rod guide diameter (diameter of rod guide section 80)
d _RS : rod seat diameter (seat diameter of rod seat part 81)
P _A : Accumulation chamber pressure F _S : Spring force F _r : Attraction force by residual magnetism Here, the pressure of the accumulation chamber 200 formed by the rod seat portion 81 and the valve 63 is such that the valve 63 is unseated and the control port pressure is there is also reduced, the control port pressure at the valve 63 seating (which is equal to the pressure that is accumulated in the reservoir 54) for equal, there too Note counteracts the attractive force F _r by little while acting remanence The combination of the rod seat diameter, the rod guide diameter, and the valve seat diameter may be selected so as to provide a sufficient valve closing force (force for pushing down the valve 63).
[0025]
For example, when the rod guide diameter d _RG = 3 mm, the rod seat diameter d _RS = 2.95 mm, the spring force F _S = 5 kgf, and the pressure in the accumulator chamber P _A = 2000 kgf / cm ² ,
[0026]
(Equation 3)

[0027]
It becomes.
As described above, a force of pushing down the valve 63 is generated, for example, 4.6 kgf, and the force is superimposed on the spring force 5 kgf of the spring 65 and a force of 9.6 kgf is applied to the valve 63. also remanence by F _r acts on the contrary, compared with the prior art, the response delay due to the residual magnetism of the solenoid 67 can be reduced significantly.
[0028]
Although the fuel injection unit 51 shown in FIG. 1 has the command piston 108, the operation of the solenoid-operated hydraulic control valve 50 of the present invention is realized irrespective of the presence or absence of the command piston 108. Similar effects can be obtained when the piston 108 is omitted.
FIG. 2 is a sectional view showing a configuration in which a two-way valve type hydraulic control valve according to a second embodiment of the present invention is applied to a pressure accumulating fuel injection device for an internal combustion engine. The high-pressure fuel pumped by the fuel pump 152 is stored in a reservoir 154 and is supplied to a fuel injection device mounted on the engine. The housing 153 of the hydraulic control valve 150 is provided with a drain port 156 communicating with a fuel tank 155 forming a drain, and a control port 158 communicating with a back pressure chamber 157. The high-pressure fuel stored in the reservoir 154 from the fuel pressure pump 152 is introduced and stored in the oil reservoir 161 around the needle 160, and is also introduced into the back pressure chamber 157 and the control port 158 via the throttle 162. . Since high pressure is acting on the back pressure chamber 157, the needle 160 descends and normally closes the injection hole 226. The valve 163 is inserted into the housing 153 of the hydraulic control valve 150 so as to be slidable in a vertical direction, and is pressed downward by a spring 165 provided at an upper portion, so that a lower valve seat is provided. It is seated at part 166. A solenoid 167 is provided above the housing 153, and an armature 164, which is a part of the valve 163, is provided in the armature chamber 172 to face the solenoid 167. In the valve 163, a balance rod 168 is fitted so as to be slidable in a vertical direction. Then, the high-pressure fuel introduced into the control port 158 is introduced to the lower chamber 171 of the balance rod 168 via the communication passage 170 formed in the valve 163. Accordingly, the balance rod 168 is normally pushed upward by high fuel pressure.
[0029]
The high-pressure fuel introduced into the lower chamber 171 communicates with the armature chamber 172 via a clearance of 2 to 3 μm between the balance rod 168 and the valve 163. At the outlet of the armature chamber 172, a pressure regulating means 301 is provided, which joins with the drain port 156 and returns to the fuel tank 155.
The state of FIG. 2 shows the injection stop state.
[0030]
At this time, assuming that the acting force on the valve 163 is positive in the downward direction in the figure,
[0031]
(Equation 4)

[0032]
d _RG : rod guide diameter (diameter of rod guide section 180)
d _VS : Valve seat diameter (diameter of valve seat part 166)
P _f : injection pressure d _VG : valve guide diameter (diameter of valve guide 302)
P _r : Residual pressure in the armature chamber F _S : Acting force acting as a spring force is acting.
[0033]
In the above-described configuration, when the solenoid 167 is energized, the valve 163 is sucked and moves upward, so that the valve seat portion 166 of the valve 163 is unseated, and the control port 158 and the drain port 156 communicate with each other so that the back pressure is released. The pressure in chamber 157 drops. Therefore, the needle 160 is pushed up by the accumulated fuel pressure of the oil reservoir 161 and the injection hole 226 is opened. As a result, the high-pressure fuel near the oil reservoir 161 and the injection hole gushes out of the injection hole at once, and starts injection.
[0034]
At this time, the control port 158 almost drops to the atmospheric pressure due to the valve seat 166 being unseated. Accordingly, the acting force on the valve 163 is also assumed that the downward direction in the figure is positive,
[0035]
(Equation 5)

[0036]
Next, the form of the first term of F ₁ has passed through during closing.
Here, for example, _{d RG = 3mm, d VG =} 6.5mm, when _{^{P r = 10kg / cm 2,}} F S = 8kgf, if you choose d VS = 3.14 mm,
F ₁ = 9.3 kgf (when P _f = 200 kg / cm ² ); 2.7 kgf (when P _f = 1200 kgf / cm ² );
F ₂ = 10.6kgf
It becomes.
[0037]
Try to stop injection and stops energizing the solenoid 167, even as a suction force _{F r} due to residual magnetism worked _F 2 (= _10.6kgf) opposite to the spring force _F S (= 8kgf) only Since the 2.6 kgf valve closing force can be increased more than at the time, the valve 163 can be closed immediately.
Therefore, similarly to the first embodiment, a response delay due to residual magnetism of the solenoid 167 can be greatly reduced.
[0038]
Furthermore, this as a characteristic that in the second embodiment, if you choose the force acting to the first term of the opening assist direction of F ₁ illustrated as a suitably, the valve closing force can operate effectively at all times In addition, valve opening assist acts more strongly on the high injection pressure side. Therefore, the valve closing response can be improved, and the force for opening the valve on the high injection pressure side can be reduced, and the controllability is improved.
[0039]
Although the pressure adjusting means 301 is shown as a separate body from the hydraulic control valve 150 in FIG. 2, even if it is incorporated in the housing 153, the operation does not change.
Further, when the residual pressure _{P r} of the armature chamber 172 is are a 10 kg / cm ^2, which is particularly may not be 10 kg / cm ^2, the injection pressure _{P f} is used fuel pumping pump that allows variable, The residual pressure may be varied in conjunction with the injection pressure.
[0040]
Although the pressure regulating means 301 is shown as a poppet valve here, an orifice serving as a throttle may be used as a means for leaving a residual pressure in the armature chamber.
FIG. 3 shows a solenoid-operated hydraulic control valve according to a third embodiment of the present invention in which a pressure adjusting means 500 according to the present invention is added to the three-way valve hydraulic control valve shown as a conventional example in FIG. FIG. 2 is a cross-sectional view showing a configuration when applied to a fuel injection device. The pressure regulating means 500 corresponding to the pressure regulating means 301 shown in the second embodiment is provided in a flow passage communicating from the armature chamber 133 in which the armature portion facing the solenoid 141 is accommodated to the drain, and the three-way valve type hydraulic control is performed. Applied to the valve, it leaves residual pressure in the armature chamber 133 to help the spring 112 act.
[0041]
The effect is the same as that of the second embodiment.
FIG. 4 shows a fourth embodiment of the present invention. In the figure, reference numeral 600 denotes a pressure adjusting means corresponding to the pressure adjusting means 301 shown in the second embodiment. Other configurations are the same as those of the first embodiment. That is, the fourth embodiment is an example in which the first embodiment and the second embodiment are combined, and the same components as those in the first embodiment are denoted by the same reference numerals. Reference numeral 600 specifically denotes a pressure adjusting means such as a poppet valve or a throttle.
[0042]
The effects are synergistically shown in the respective embodiments, and are the most effective.
The force acting on the valve 63 at the time of injection stop, the same formula as F ₁ of the second embodiment.
Further, minute as the acting force F ₃ in the injection except for F _r from F _C of the first embodiment,
[0043]
(Equation 6)

[0044]
A first term of _{F 2} of the second embodiment in [0045]
(Equation 7)

[0046]
Will be added together.
Therefore,
_{d RG = 3mm, d VG =} 6.5mm, d VS = 3.14mm, F S = 8kgf, when P f = 1200kgf / cm ^2,
F ₁ = 2.78 kgf
[0047]
(Equation 8)

[0048]
And a large valve closing force can be obtained.
[0049]
【The invention's effect】
In the solenoid-operated hydraulic control valve according to any one of claims 1 to 6, the rod guide diameter, the rod seat diameter, the valve seat diameter, and the valve guide diameter are set so that the hydraulic force acting on the valve acts in a direction opposite to the suction force of the solenoid. After stopping the energization of the solenoid, the combined force of the spring force of the spring and the hydraulic force overcomes the attraction force of the valve due to the residual magnetism, and the valve quickly moves downward. Therefore, the response delay due to the residual magnetism of the solenoid can be greatly reduced, and therefore, it is possible to perform highly accurate metering up to a minute injection amount. Also, since the hydraulic action force is kept to a minimum necessary to cancel the attraction force due to the residual magnetism of the solenoid, unlike a hydraulic control valve using a valve that does not use a balance rod, the size of the solenoid is increased. Can also be avoided at the same time.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration in which a two-way valve type hydraulic control valve serving as a solenoid driven hydraulic control valve according to a first embodiment of the present invention is applied to a pressure accumulating fuel injection device of an internal combustion engine.
FIG. 2 is a sectional view showing a configuration in which a two-way valve type hydraulic control valve as a second embodiment of the present invention is applied to a pressure accumulating fuel injection device of an internal combustion engine.
FIG. 3 shows a solenoid-operated hydraulic control valve according to a third embodiment of the present invention in which a pressure adjusting means according to the present invention is added to a three-way valve hydraulic control valve shown as a conventional example in FIG. FIG. 3 is a cross-sectional view illustrating a configuration when applied to a fuel injection device.
FIG. 4 is a cross-sectional view showing a configuration in which a solenoid-driven hydraulic control valve according to a fourth embodiment of the present invention is applied to a pressure accumulating fuel injection device for an internal combustion engine.
FIG. 5 is a cross-sectional view showing a configuration in which a conventional solenoid-driven hydraulic control valve is applied to a pressure accumulating fuel injection device for an internal combustion engine.
[Explanation of symbols]
50, 150 Solenoid drive hydraulic control valve 58, 158 Control port 63, 163 Valve 65, 165, 112 Spring 66 Valve seat 67, 141, 167 Solenoid 68, 118 Balance rod 70 Communication passage 71 Lower chamber 79, 115 Hole 81 Rod Seat part 111 First valve 116 Valve seat 117 Second valve 128 Space 133, 172 Armature chamber 136, 155 Drain (drain port, fuel tank)
164 Armature 200 Pressure accumulating chambers 301, 500, 600 Pressure regulating means (poppet valve, orifice)

Claims (6)

A spring used in a pressure accumulating fuel injection device of an internal combustion engine, in which a valve is suction-driven by a solenoid to communicate and shut off hydraulic pressure applied to a control port, and urges the valve in a direction opposite to a suction force of the solenoid. In a solenoid-operated hydraulic control valve having a valve, a balance rod is slidably fitted in a hole provided in the valve having a valve seat portion at a lower portion, and a lower surface of the balance rod and the hole are provided. A lower chamber formed by the valve, a communication passage formed in the valve communicating the lower chamber with the control port, and a rod seat portion provided below the balance rod. The balance rod is seated on an opening of the lower chamber of the communication passage to seal the lower chamber to form a pressure accumulation chamber. , Solenoid drive hydraulic control valve, characterized in that the hydraulic force acting on the accumulation chamber to the valve is to act the suction force in the opposite direction of the solenoid. A spring used in a pressure accumulating fuel injection device of an internal combustion engine, in which a valve is suction-driven by a solenoid to communicate and shut off hydraulic pressure applied to a control port, and urges the valve in a direction opposite to a suction force of the solenoid. In a solenoid-operated hydraulic control valve having a valve, a balance rod is slidably fitted in a hole provided in the valve having a valve seat portion at a lower portion, and a lower surface of the balance rod and the hole are provided. And a lower chamber formed by the solenoid, supplies hydraulic pressure from a clearance between the balance rod and the valve to an armature chamber in which an armature above the valve is housed under the solenoid, and communicates with the drain from the armature chamber. A pressure regulating means is provided in the flow path to make a residual pressure in the armature chamber, and the guide diameter of the valve is adjusted. The balance pressure is set larger than the guide diameter of the balance rod, and the residual pressure generated by the pressure regulating means due to the pressure receiving area difference causes the hydraulic force acting on the valve to act in the opposite direction to the suction force of the solenoid. A solenoid driven hydraulic control valve characterized by the following: 3. The solenoid driven hydraulic control valve according to claim 1, wherein the solenoid driven hydraulic control valve is a two-way valve. A spring used in a pressure accumulating fuel injection device of an internal combustion engine, in which a first valve is suction-driven by a solenoid to communicate and shut off hydraulic pressure, and urges the valve in a direction opposite to a suction force of the solenoid. It has, in a hole provided in said first valve is provided with a second valve fitted slidably with the first seating possible valve seat to the valve, into said hole in the second solenoid drive hydraulic control valve disposed in fitted slidably said solenoid and said arranged space on the opposite side the valve seat and the balance rod having the same diameter relative to the valve, the first An oil pressure is supplied from a clearance between the first valve and the second valve to an armature chamber containing an armature facing the solenoid with a valve, and an armature chamber of the first valve is provided. A clearance oil pressure between the first valve and the balance rod is also supplied to the opposite chamber to cancel the oil pressure acting on the first valve, and the pressure is adjusted to the flow path communicating from the armature chamber to the drain. Means for providing a residual pressure in the armature chamber by providing means. 5. The solenoid-operated hydraulic control valve according to claim 2, wherein the pressure regulating means is a poppet valve. 5. The solenoid-operated hydraulic control valve according to claim 2, wherein the pressure adjusting means is an orifice.

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