JPH10103184A - Accumulator type fuel injection valve - Google Patents
Accumulator type fuel injection valveInfo
- Publication number
- JPH10103184A JPH10103184A JP25169796A JP25169796A JPH10103184A JP H10103184 A JPH10103184 A JP H10103184A JP 25169796 A JP25169796 A JP 25169796A JP 25169796 A JP25169796 A JP 25169796A JP H10103184 A JPH10103184 A JP H10103184A
- Authority
- JP
- Japan
- Prior art keywords
- pressure
- fuel
- chamber
- needle
- injection valve
- 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.)
- Withdrawn
Links
- 239000000446 fuel Substances 0.000 title claims abstract description 88
- 238000002347 injection Methods 0.000 title claims abstract description 44
- 239000007924 injection Substances 0.000 title claims abstract description 44
- 238000009825 accumulation Methods 0.000 claims description 8
- 238000011144 upstream manufacturing Methods 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000004904 shortening Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 abstract 1
- 229910000831 Steel Inorganic materials 0.000 description 14
- 239000010959 steel Substances 0.000 description 14
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 5
- 230000008602 contraction Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
- F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
- F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/21—Fuel-injection apparatus with piezoelectric or magnetostrictive elements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/40—Fuel-injection apparatus with fuel accumulators, e.g. a fuel injector having an integrated fuel accumulator
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Fuel-Injection Apparatus (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、内燃機関、特には
ディーゼルエンジンに設けられる燃料噴射弁に関し、よ
り詳しくは、アキュムレータノズルとして知られる蓄圧
式の燃料噴射弁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 valve provided in an internal combustion engine, in particular, a diesel engine, and more particularly, to an accumulator type fuel injection valve known as an accumulator nozzle.
【０００２】[0002]
【従来の技術】従来技術の蓄圧式燃料噴射弁としては特
公平４−６７０２６号公報及び４弁エンジン搭載用に分
割した特開平６−４５５６１号公報がある。ところで、
近年、燃料噴射期間の短縮が望まれている。そのため一
般的には燃料圧力の高圧化が検討されているが、貫徹力
によるボア、ピストンへの燃料付着が避けられないこと
や、アクチュエータにかかる荷重が増加するため、信頼
性が問題となっている。また、流量の増大を狙い流路面
積を大きくするため、ニードルのシート面の直径の拡
大、またはリフト量を増大することも検討されている
が、ニードルを開弁保持するためにポンプ室の減圧量を
大きくする必要があり、アクチュエータの体格が大きく
なること及び駆動回路の負荷が大きくなるという問題が
あった。2. Description of the Related Art Japanese Patent Publication No. Hei 4-67026 and Japanese Patent Laid-Open Publication No. Hei 6-45561, which are divided for mounting on a four-valve engine, are known as accumulator type fuel injection valves of the prior art. by the way,
In recent years, it has been desired to shorten the fuel injection period. For this reason, increasing the fuel pressure is generally considered, but the inevitability of fuel sticking to the bore and piston due to the penetrating force and the increase in the load on the actuator increase reliability. I have. In order to increase the flow rate and increase the flow area, it has been considered to increase the diameter of the seat surface of the needle or to increase the lift amount. However, in order to hold the needle open, the pressure in the pump chamber is reduced. It is necessary to increase the amount, and there is a problem that the physical size of the actuator increases and the load on the drive circuit increases.
【０００３】[0003]
【発明が解決しようとする課題】本発明はアクチュエー
タの体格および駆動エネルギーを大きくさせずにニード
ルのシート面の直径を拡大したノズルを作動させ、燃料
噴射期間の短縮を図ることを目的とする。SUMMARY OF THE INVENTION It is an object of the present invention to reduce the fuel injection period by operating a nozzle having an enlarged needle surface without increasing the size and driving energy of an actuator.
【０００４】[0004]
【課題を解決するための手段】本発明は前記課題を解決
するために請求項１ないし請求項３の構成を採用する。
これによれば、ポンプ室作動前のニードル背圧室圧力を
蓄圧室圧力より低く保っておくことができ、従来の、ニ
ードル背圧室の圧力と燃料蓄圧室の圧力が等しいニード
ル背圧室の圧力を設定しない噴射弁に比べて、燃料イン
レット圧力と本背圧設定部による設定圧力の差に相当す
る分だけニードル背圧室の増減圧量を小さくでき、アク
チュエータの伸縮に要する駆動エネルギーを小さくする
ことができる。SUMMARY OF THE INVENTION The present invention employs the features of claims 1 to 3 to solve the above-mentioned problems.
According to this, it is possible to keep the pressure of the needle back pressure chamber before the operation of the pump chamber lower than the pressure of the pressure accumulation chamber, and in the conventional case, the pressure of the needle back pressure chamber is equal to the pressure of the needle back pressure chamber and the pressure of the fuel pressure accumulation chamber. Compared with an injection valve that does not set pressure, the amount of pressure increase and decrease in the needle back pressure chamber can be reduced by the amount corresponding to the difference between the fuel inlet pressure and the pressure set by this back pressure setting unit, and the driving energy required for expansion and contraction of the actuator is reduced. can do.
【０００５】従って、ニードルを開弁保持するためにポ
ンプ室の減圧量を大きくする必要のある流量の増大を狙
ったニードルのシート面の直径及びリフトを拡大したノ
ズルもアクチュエータの体格及び駆動エネルギーを増す
ことなく作動することが可能となり、噴射率が高まり、
燃料噴射期間を短縮できるという効果がある。Therefore, a nozzle having an enlarged seat surface diameter and a lift for increasing the flow rate which requires an increase in the pressure reduction amount of the pump chamber in order to hold the needle open also reduces the size and drive energy of the actuator. It is possible to operate without increasing, the injection rate increases,
There is an effect that the fuel injection period can be shortened.
【０００６】[0006]
【発明の実施の形態】図１は本発明の蓄圧式燃料噴射弁
の実施形態を示す断面系統図である。分割型蓄圧式燃料
噴射弁は、直噴型ディーゼルエンジンの燃焼室内に燃料
を噴射するために用いられるものであって、各気筒に１
個ずつ、例えば４気筒の場合は４個、装着される。公知
の間欠圧送ポンプ３００から圧送されてきた燃料は、後
述するように、燃料インレット１９からこの分割型蓄圧
式燃料噴射弁内に流入、充填され、ニードル弁９の開閉
動作によって噴孔１３から噴射される。間欠圧送ポンプ
３００による送油時期は通常のように各々の気筒の圧縮
上死点近辺でなく、その充分前、例えば圧縮上死点前１
８０°クランクアングルには既に終了している。間欠圧
送ポンプ３００による１回の送油量は、従来公知のよう
に間欠圧送ポンプ３００のレバー開度で調量される。FIG. 1 is a sectional system diagram showing an embodiment of a pressure-accumulation type fuel injection valve according to the present invention. The split pressure accumulator type fuel injection valve is used for injecting fuel into a combustion chamber of a direct injection type diesel engine.
Each is mounted, for example, in the case of four cylinders, four are mounted. The fuel pressure-fed from the known intermittent pressure feed pump 300 flows from the fuel inlet 19 into the split type accumulator type fuel injection valve and is filled therein, as described later, and is injected from the injection hole 13 by the opening and closing operation of the needle valve 9. Is done. The oil supply timing by the intermittent pressure feed pump 300 is not near the compression top dead center of each cylinder as usual, but sufficiently before that, for example, 1 before the compression top dead center.
The 80 ° crank angle is already over. The amount of oil supplied by the intermittent pressure pump 300 at one time is adjusted by the lever opening of the intermittent pressure pump 300 as is conventionally known.
【０００７】分割型蓄圧式燃料噴射弁はニードル背圧制
御部１、蓄圧噴射弁部２、背圧設定部３の３部品より構
成され、制御用鋼管１００、１０１及び燃料供給用鋼管
２００にて、燃料通路の形成および接続がなされてい
る。ニードル背圧制御１のハウジングはピエゾホルダ１
４及びチェック弁ホルダ１５より形成されている。ピエ
ゾホルダ１４は有底筒状をなし、その中に電歪式アクチ
ュエータ４、ピストンポンプ１６、皿バネ１７が収納さ
れている。電歪式アクチュエータ４の上端はピエゾホル
ダ１４の底部に固定され、下端はピストンポンプ１６に
接している。各部品を収納したピエゾホルダ１４はチェ
ック弁ホルダ１５とネジにより締結し、ピストンポンプ
１６の下面とチェック弁ホルダ１５によりポンプ室５を
形成する。ピストンポンプ１６はピエゾホルダ１４内で
電歪式アクチュエータ４の伸縮に追随して摺動可能とな
っている。またその時皿バネ１７は、ピストンポンプ１
６を図中上方に付勢し、電歪式アクチュエータ４に当接
させている。これにより、電歪式アクチュエータ４には
約５０ｋｇｆのプリセット荷重をかけている。ポンプ室
５は電歪式アクチュエータ４が伸張し、ピストンポンプ
１６を皿バネ１７に抗して押し下げた時縮小して増圧
し、電歪式アクチュエータ４が収縮した時拡大して減圧
する。The split accumulator type fuel injection valve is composed of three parts, a needle back pressure control unit 1, a pressure accumulation injection valve unit 2, and a back pressure setting unit 3, and includes control steel pipes 100 and 101 and a fuel supply steel pipe 200. , And a fuel passage is formed and connected. Needle back pressure control 1 housing is piezo holder 1
4 and a check valve holder 15. The piezo holder 14 has a bottomed cylindrical shape, in which the electrostrictive actuator 4, the piston pump 16, and the disc spring 17 are housed. The upper end of the electrostrictive actuator 4 is fixed to the bottom of the piezo holder 14, and the lower end is in contact with the piston pump 16. The piezo holder 14 accommodating each part is fastened to the check valve holder 15 by screws, and the pump chamber 5 is formed by the lower surface of the piston pump 16 and the check valve holder 15. The piston pump 16 is slidable in the piezo holder 14 following the expansion and contraction of the electrostrictive actuator 4. At that time, the disc spring 17 is connected to the piston pump 1.
6 is urged upward in the figure to make contact with the electrostrictive actuator 4. As a result, a preset load of about 50 kgf is applied to the electrostrictive actuator 4. The pump chamber 5 expands and contracts when the electrostrictive actuator 4 expands and pushes down the piston pump 16 against the disc spring 17, and expands and decompresses when the electrostrictive actuator 4 contracts.
【０００８】電歪式アクチュエータ４は直径２０ｍｍ、
厚さ０．５ｍｍの円板状のＰＺＴ素子と、直径１５ｍ
ｍ、厚さ０．０２ｍｍのステンレス板とを交互に積層し
て円柱状にしたものであり、各々のＰＺＴ素子の厚み方
向に並列に電圧を印加できるようにリード線１８とステ
ンレス板とが結合されている。リード線１８はピエゾホ
ルダ１４の外部へ延びており、駆動回路ＥＤＵ及び電子
制御回路ＥＣＵと電気的に結合されている。ＰＺＴ素子
はチタン酸ジルコン酸鉛を主成分とし焼結させた強誘電
体セラミックスであり、ピエゾ効果を有する代表的な素
子である。その物性は、厚み方向に５００Ｖの電圧を印
加すると０．５μｍ厚みが増し、逆に５００Ｖの電圧を
印加しておきショートさせると０．５μｍ厚みが減る。
本実施形態の電歪式アクチュエータ４はＰＺＴ素子を２
００枚、機械的には直列に、電気的には並列に結合して
いるため、５００Ｖの電圧を印加することで１００μｍ
の伸縮が得られる。The electrostrictive actuator 4 has a diameter of 20 mm,
0.5mm thick disc-shaped PZT element and 15m diameter
m and a stainless steel plate having a thickness of 0.02 mm are alternately laminated to form a columnar shape. The lead wire 18 and the stainless steel plate are connected so that a voltage can be applied in parallel in the thickness direction of each PZT element. Have been. The lead wire 18 extends outside the piezo holder 14 and is electrically connected to the drive circuit EDU and the electronic control circuit ECU. The PZT element is a ferroelectric ceramic sintered with lead zirconate titanate as a main component, and is a typical element having a piezo effect. As for the physical properties, when a voltage of 500 V is applied in the thickness direction, the thickness increases by 0.5 μm, and when a voltage of 500 V is applied and short-circuited, the thickness decreases by 0.5 μm.
The electrostrictive actuator 4 of the present embodiment includes two PZT elements.
00 sheets are mechanically connected in series and electrically connected in parallel, so that 100 μm
Is obtained.
【０００９】チェック弁ホルダ１５には２つのチェック
弁が、燃料インレット１９から蓄圧噴射弁部２の蓄圧室
８に燃料供給用鋼管２００によって接続されるアウトレ
ット２０の燃料通路の間に第２のチェック弁７が燃料イ
ンレット１９から蓄圧室８への流通を許す方向に、燃料
インレット１９からポンプ室５への通路の間に第１のチ
ェック弁６が燃料インレット１９からポンプ室５への流
通を許す方向に、間欠圧送ポンプ３００からの間欠圧送
された燃料を保持するために設けてある。チェック弁
６、７は燃料通路に設けられ、上流側に尖る円錐状の座
面、鋼球及びスプリングより成り、間欠圧送ポンプ３０
０からの燃料が圧送されない限り、スプリング力により
鋼球を上流側に付勢して座面との間でシールし、燃料を
遮断するように設置している。The check valve holder 15 has two check valves between the fuel inlet 19 and the fuel passage of the outlet 20 connected to the accumulator chamber 8 of the accumulator injection valve section 2 by the fuel supply steel pipe 200. The first check valve 6 allows the flow from the fuel inlet 19 to the pump chamber 5 between the fuel inlet 19 and the pump chamber 5 in the direction in which the valve 7 allows the flow from the fuel inlet 19 to the pressure accumulating chamber 8. In the direction, the fuel is intermittently pumped from the intermittent pressure pump 300 to hold the fuel. The check valves 6 and 7 are provided in the fuel passage, and include a conical seating surface, a steel ball, and a spring that are pointed toward the upstream side.
As long as the fuel from 0 is not pumped, the steel ball is urged to the upstream side by the spring force to seal the steel ball with the seat surface and to shut off the fuel.
【００１０】制御用鋼管１００、１０１は内容積が小さ
いことが好ましくその内径は１〜２ｍｍのものが、燃料
供給用鋼管２００は圧損が小さく速やかに燃料が供給さ
れるように、その内径が１．６〜４ｍｍのものが用いら
れる。蓄圧噴射弁部２のハウジングはノズルホルダ２
２、及びノズルボディ１０をリテーナ２３にて締結して
構成されている。噴射弁ホルダ２２にはノズルボディ１
０の燃料孔につながり高圧燃料をためる蓄圧室８と、ニ
ードル背圧制御部１及びニードル背圧室２４及び背圧設
定部３につながる制御用燃料通路４００が設けてある。The control steel pipes 100 and 101 preferably have a small internal volume and an inner diameter of 1 to 2 mm. However, the fuel supply steel pipe 200 has an inner diameter of 1 to reduce pressure loss and supply fuel quickly. 0.6 to 4 mm is used. The housing of the accumulator injection valve unit 2 is the nozzle holder 2
2 and the nozzle body 10 are fastened by a retainer 23. The injection valve holder 22 has the nozzle body 1
A pressure accumulating chamber 8 that connects to the fuel hole 0 and stores high-pressure fuel, and a control fuel passage 400 that connects to the needle back pressure control unit 1, the needle back pressure chamber 24, and the back pressure setting unit 3 are provided.
【００１１】蓄圧室８の容量は３〜１５ｃｃであり、要
求噴射量及び噴射形態により設定される。ニードル背圧
室２４はノズルホルダ２２の下端面とニードル９の大径
部２６の上端面で形成され、ニードルリフト時の位置を
決めるべく、その内径はニードル９の大径部２６よりも
小さくしてあり、中にニードル９を図中下向きに付勢す
るコイルバネ２５が嵌合されている。ノズルボディ１０
には大径部２９及び小径部３０よりなる段付空間が形成
され、その中にニードル９が上下に摺動自在に収納され
ている。そして段付空間の下端面は下方に尖る円錐面状
のシート面２８が形成され、更にその下方に１個または
複数個の噴孔１３が形成されている。ニードル９は大径
部２６及び小径部２７よりなる段付形状をなし、ノズル
ボディ１０の段付空間とのクリアランスは大径部は数μ
ｍであるが、小径部は数百μｍと大きく、燃料孔と連通
する燃料溜まりを形成する。ニードル９の下端は円錐状
に成形されておりシート面２８に密着可能であり、これ
により噴孔１３を燃料溜まりから遮断することができ、
シート面２８から離座したとき噴孔１３を燃料溜まりと
連通させる。ノズルボディ１０の燃料孔とノズルホルダ
２２の蓄圧室８からの通路との位置決めは、ノズルボデ
ィ１０の上面とノズルホルダ２２の下面とにニードル９
位置における図１の上下方向に設けた位置決め用の孔を
使い、図示しないノックピンにて行う。The capacity of the accumulator 8 is 3 to 15 cc, and is set according to the required injection amount and injection mode. The needle back pressure chamber 24 is formed by the lower end surface of the nozzle holder 22 and the upper end surface of the large-diameter portion 26 of the needle 9, and has an inner diameter smaller than that of the large-diameter portion 26 of the needle 9 in order to determine the position during needle lift. A coil spring 25 for urging the needle 9 downward in the figure is fitted therein. Nozzle body 10
Is formed with a stepped space including a large diameter portion 29 and a small diameter portion 30, in which the needle 9 is slidably accommodated up and down. The lower end surface of the stepped space is formed with a conical sheet surface 28 which is pointed downward, and one or more injection holes 13 are further formed below the sheet surface 28. The needle 9 has a stepped shape including a large diameter portion 26 and a small diameter portion 27, and the clearance between the stepped space of the nozzle body 10 and the large diameter portion is several μm.
m, but the small diameter portion is as large as several hundred μm, and forms a fuel reservoir communicating with the fuel hole. The lower end of the needle 9 is formed in a conical shape and can be in close contact with the seat surface 28, whereby the injection hole 13 can be shut off from the fuel pool.
When the user is away from the seat surface 28, the injection holes 13 communicate with the fuel pool. The positioning of the fuel hole of the nozzle body 10 and the passage from the pressure accumulation chamber 8 of the nozzle holder 22 is performed by positioning the needle 9 between the upper surface of the nozzle body 10 and the lower surface of the nozzle holder 22.
Using a positioning hole provided in the vertical direction in FIG.
【００１２】背圧設定部３はニードル背圧制御部１と蓄
圧噴射弁部２に連通する制御用鋼管１００、１０１に連
通するように設置され、制御用鋼管圧力を設定値に保つ
ためにオリフィス１１及び第３のチェック弁１２及びド
レンが設けられている。第３のチェック弁１２は制御用
流路から分岐した燃料排出通路に設けられ、制御用流路
側に尖る円錐状の座面、鋼球及びスプリングよりなり、
スプリング力により鋼球を上流側に付勢し座面とでシー
ルして、設定圧力以上の時のみ燃料をドレンにリークす
るように設置している。The back pressure setting section 3 is installed so as to communicate with the control steel pipes 100 and 101 communicating with the needle back pressure control section 1 and the accumulator injection valve section 2, and has an orifice for maintaining the control steel pipe pressure at a set value. 11 and a third check valve 12 and a drain are provided. The third check valve 12 is provided in a fuel discharge passage branched from the control flow path, and includes a conical seating surface, a steel ball, and a spring that is pointed toward the control flow path,
The steel ball is urged to the upstream side by the spring force, sealed with the seat surface, and installed so that the fuel leaks to the drain only when the pressure is equal to or higher than the set pressure.
【００１３】次に本実施形態の作動について説明する。
図２は本蓄圧式燃料噴射弁の作動時のタイムチャートで
ある。図１と図２とを用いて作動を説明する。時刻ｔ１
の時、間欠圧送ポンプ３００より燃料がニードル背圧制
御部１のインレット１９へ間欠圧送される。第１のチェ
ック弁６及び第２のチェック弁７は燃料噴射弁インレッ
ト圧力が高まり、チェック弁６、７のスプリング力に勝
る時刻ｔ２の時チェック弁６、７は開き燃料が流入す
る。第１のチェック弁６を通過した燃料はポンプ室５、
制御用鋼管１００、１０１、背圧設定部３の制御用通路
及び蓄圧噴射弁部２のニードル背圧室２４に供給され
る。同時に第２のチェック弁７を通った燃料は燃料供給
用鋼管２００、蓄圧噴射弁部２の蓄圧室８及びノズルボ
ディ１０の燃料溜まりに燃料が供給される。Next, the operation of this embodiment will be described.
FIG. 2 is a time chart when the pressure accumulating fuel injection valve is operated. The operation will be described with reference to FIGS. Time t1
At this time, the fuel is intermittently fed from the intermittent pressure pump 300 to the inlet 19 of the needle back pressure controller 1. The first check valve 6 and the second check valve 7 increase the fuel injector inlet pressure, and at time t2 when the spring force of the check valves 6 and 7 exceeds the spring force, the check valves 6 and 7 open and fuel flows in. The fuel that has passed through the first check valve 6 is pump chamber 5,
It is supplied to the control steel pipes 100 and 101, the control passage of the back pressure setting unit 3, and the needle back pressure chamber 24 of the accumulator injection valve unit 2. At the same time, the fuel that has passed through the second check valve 7 is supplied to the fuel supply steel pipe 200, the accumulator chamber 8 of the accumulator injection valve unit 2, and the fuel reservoir of the nozzle body 10.
【００１４】ポンプの圧送が終わり燃料噴射弁インレッ
ト圧力が最大となった時刻ｔ３の時、チェック弁６、７
はスプリング力により閉じ、燃料通路を遮断する。燃料
供給が終了した後、蓄圧室圧力はチェック弁７により保
持される。また、時刻ｔ３の時、ニードル背圧室圧力が
設定以上の圧力に達するため、第３のチェック弁１２
は、その燃料圧力がスプリング力に勝るため開いてお
り、オリフィス１１及びチェック弁１２を通りドレンに
わずかずつ燃料がリークしているが、間欠圧送ポンプ３
００の吐出量が大きく、オリフィス１１によりリーク量
を制限しているために、一旦はニードル背圧室圧力は蓄
圧室圧力と同様に増圧した後、減圧してゆく。At time t3 when the pumping is completed and the fuel injector inlet pressure reaches a maximum, the check valves 6, 7
Is closed by the spring force and shuts off the fuel passage. After the fuel supply is completed, the pressure in the accumulator is maintained by the check valve 7. Further, at time t3, the needle back pressure chamber pressure reaches a pressure equal to or higher than the set pressure.
Is open because its fuel pressure exceeds the spring force, and the fuel leaks little by little through the orifice 11 and the check valve 12 to the drain.
Since the discharge amount of 00 is large and the amount of leak is restricted by the orifice 11, the pressure of the needle back pressure chamber is increased once in the same manner as the pressure of the accumulator, and then reduced.
【００１５】ニードル背圧室圧力が設定圧になった時刻
ｔ４のとき第３のチェック弁１２のスプリング力が勝っ
て閉弁し、設定圧に保たれる。その後、時刻ｔ５の時、
噴射信号が印加されると、予め充電し伸ばしておいた電
歪式アクチュエータ４は放電し縮むことによりポンプ室
５が拡大し、連通するニードル背圧室圧力が減圧され
る。At time t4 when the needle back pressure chamber pressure reaches the set pressure, the spring force of the third check valve 12 wins and closes and is maintained at the set pressure. Then, at time t5,
When the injection signal is applied, the electrostrictive actuator 4 that has been charged and extended in advance discharges and contracts, thereby expanding the pump chamber 5 and reducing the pressure of the communicating needle back pressure chamber.
【００１６】ニードル９にかかるニードル背圧室圧力及
びスプリング力よりなる閉弁方向の力が、蓄圧室圧力よ
りなる開弁方向の力より小さくなる時刻ｔ６の時、ニー
ドル９は開弁し、燃料を噴射し始める。時刻ｔ７の時、
ニードル９がフルリフトした後蓄圧室８の圧力が燃料を
噴射することにより減圧されるため、噴射率は次第に低
下する。At time t6, when the force in the valve closing direction consisting of the needle back pressure chamber pressure and the spring force applied to the needle 9 becomes smaller than the force in the valve opening direction consisting of the pressure accumulating chamber pressure, the needle 9 opens and the fuel is released. Start spraying. At time t7,
After the needle 9 is fully lifted, the pressure in the accumulator 8 is reduced by injecting fuel, so that the injection rate gradually decreases.
【００１７】時刻ｔ８の時、閉弁信号が印加されると、
電歪式アクチュエータは充電されて伸び、ポンプ室５を
縮小することでニードル背圧室圧力を増圧し、再び閉弁
方向の力が大きくなりニードル９は下降して閉弁し噴射
を終了する。時刻ｔ９の時、再び間欠圧送ポンプ３００
から燃料が圧送され始める。以下同じ繰り返しとなり、
時刻ｔ１から時刻ｔ９までが１サイクルである。At time t8, when a valve closing signal is applied,
The electrostrictive actuator is charged and expanded, and the pressure in the needle back pressure chamber is increased by reducing the size of the pump chamber 5, the force in the valve closing direction is increased again, the needle 9 descends, closes the valve, and terminates the injection. At time t9, the intermittent pressure feed pump 300
Starts pumping fuel. The same is repeated below,
One cycle from time t1 to time t9 is one cycle.
【００１８】本実施形態では、ニードル背圧室２４の制
御を行うため、連通するポンプ室５の拡大、縮小を電歪
式アクチュエータ４を伸縮させて当接するピストンポン
プ１６を直接摺動させているが、他の実施形態として、
ピストンポンプ１６の背圧側にオリフィスを通して高圧
燃料を導き、ソレノイド弁を使用してドレンに排出する
ことで圧力差を生ぜしめ、それによりピストンポンプ１
６を間接的に制御してポンプ室５を拡大、縮小させる蓄
圧式燃料噴射弁としてもソレノイド弁にかかる圧力を軽
減でき、体格の小型化、駆動エネルギの低減を図ること
ができる。In the present embodiment, in order to control the needle back pressure chamber 24, the expansion and contraction of the communicating pump chamber 5 is performed by expanding and contracting the electrostrictive actuator 4 and directly sliding the piston pump 16 which is in contact therewith. However, as another embodiment,
High pressure fuel is directed through the orifice to the back pressure side of the piston pump 16 and is discharged to a drain using a solenoid valve to create a pressure differential, thereby causing the piston pump 1
The pressure applied to the solenoid valve can also be reduced as a pressure-accumulating fuel injection valve that indirectly controls the pump chamber 5 to expand or reduce the pump chamber 5, thereby reducing the physical size and driving energy.
【図１】本発明の蓄圧式燃料噴射弁の実施形態を示す断
面系統図である。FIG. 1 is a sectional system diagram showing an embodiment of an accumulator type fuel injection valve of the present invention.
【図２】本蓄圧式燃料噴射弁の作動時のタイムチャート
である。FIG. 2 is a time chart when the pressure accumulating fuel injection valve is operated.
４ アクチュエータ（電歪式アクチュエータ） ５ ポンプ室 ６ 第１のチェック弁 ７ 第２のチェック弁 ８ 蓄圧室 ９ ニードル １１ オリフィス １２ 第３のチェック弁 １９ 燃料インレット ２４ ニードル背圧室 ２６ ニードルの大径部 ２８ ニードルのシート面 ３００ 間欠圧送ポンプ Reference Signs List 4 Actuator (electrostrictive actuator) 5 Pump chamber 6 First check valve 7 Second check valve 8 Accumulation chamber 9 Needle 11 Orifice 12 Third check valve 19 Fuel inlet 24 Needle back pressure chamber 26 Large diameter portion of needle 28 Needle seat surface 300 Intermittent pump
Claims (3)
送ポンプにより燃料が圧送される蓄圧式燃料噴射弁にお
いて、該蓄圧式燃料噴射弁の燃料入口である燃料インレ
ットからニードル背圧室への燃料通路のうち前記ニード
ル背圧室の圧力制御を行うためのアクチュエータにより
増減圧されるポンプ室の上流側に前記燃料インレットか
ら前記ポンプ室への流通を許す方向に設けた第１のチェ
ック弁と、前記蓄圧式燃料噴射弁の燃料入口である前記
燃料インレットから蓄圧室への燃料通路に前記燃料イン
レットから前記蓄圧室への流通を許す方向に設けた第２
のチェック弁と、前記ポンプ室と前記ニードル背圧室と
を結ぶ燃料通路の途中に前記ニードル背圧室から一定以
上の圧力の時燃料を排出するオリフィス１１および第３
のチェック弁とを具備し、前記ニードル背圧室の圧力が
前記蓄圧室の圧力より低い状態から前記ポンプ室を作動
させるように構成したことを特徴とする蓄圧式燃料噴射
弁。1. A pressure accumulating type fuel injection valve having a pressure accumulating chamber in a pressure accumulating injection valve section, in which fuel is pressure-fed by an intermittent pressure feed pump, wherein a needle back pressure chamber extends from a fuel inlet which is a fuel inlet of the pressure accumulating fuel injection valve. A first check provided in the fuel passage upstream of the pump chamber, which is increased and reduced in pressure by an actuator for controlling the pressure of the needle back pressure chamber, in a direction allowing flow from the fuel inlet to the pump chamber; A second valve provided in a fuel passage from the fuel inlet, which is a fuel inlet of the pressure accumulating type fuel injection valve, to the pressure accumulating chamber in a direction allowing flow from the fuel inlet to the pressure accumulating chamber.
And a third orifice 11 that discharges fuel from the needle back pressure chamber in the middle of a fuel passage connecting the pump chamber and the needle back pressure chamber when the pressure is higher than a certain level.
A pressure-accumulation type fuel injection valve, wherein the pump chamber is operated from a state in which the pressure of the needle back pressure chamber is lower than the pressure of the pressure accumulation chamber.
される１サイクル中に、前記蓄圧室及び前記ポンプ室の
圧力が、前記燃料インレットの圧力以上において前記第
１のチェック弁及び前記第２のチェック弁が閉じ、その
後前記第３のチェック弁から燃料が排出され、前記蓄圧
室の圧力より低い設定圧にて前記第３のチェック弁が閉
じた後、噴射信号を入力して前記アクチュエータを作動
し、燃料を噴射することを特徴とする請求項１に記載の
蓄圧式燃料噴射弁。2. During one cycle in which fuel is intermittently fed from the intermittent pressure feed pump, the pressure in the accumulator and the pump chamber is equal to or higher than the pressure of the fuel inlet, and the first check valve and the second After the check valve is closed, fuel is discharged from the third check valve, and after the third check valve is closed at a set pressure lower than the pressure of the accumulator, an injection signal is input to operate the actuator. The accumulator type fuel injection valve according to claim 1, wherein the fuel is injected.
ニードル背圧室の圧力を 蓄圧室圧力＞ニードル背圧室圧力＞蓄圧室圧力×（ｄg
2 −ｄs 2 ）／ｄg 2 （ｄg はニードルの大径部の直径，ｄs はニードルのシ
ート面の直径）の範囲内に設定することを特徴とする請
求項１もしくは請求項２のいずれかに記載の蓄圧式燃料
噴射弁。3. The pressure of the needle back pressure chamber when the third check valve is closed is: pressure accumulator pressure> needle back pressure chamber pressure> pressure accumulator pressure × (d g
2 -d s 2) / d g 2 (d g is the diameter of the large diameter portion of the needle, d s is claim 1 or claim 2, characterized in that in the range of diameter) of the seat surface of the needle An accumulator type fuel injection valve according to any one of the above.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25169796A JPH10103184A (en) | 1996-09-24 | 1996-09-24 | Accumulator type fuel injection valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25169796A JPH10103184A (en) | 1996-09-24 | 1996-09-24 | Accumulator type fuel injection valve |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10103184A true JPH10103184A (en) | 1998-04-21 |
Family
ID=17226667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25169796A Withdrawn JPH10103184A (en) | 1996-09-24 | 1996-09-24 | Accumulator type fuel injection valve |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH10103184A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10147830A1 (en) * | 2001-09-27 | 2003-04-30 | Orange Gmbh | Fuel injector, for an IC motor, has a high pressure fuel store in the housing between the control valve and the actuator and sealed off from the valve rod guide |
-
1996
- 1996-09-24 JP JP25169796A patent/JPH10103184A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE10147830A1 (en) * | 2001-09-27 | 2003-04-30 | Orange Gmbh | Fuel injector, for an IC motor, has a high pressure fuel store in the housing between the control valve and the actuator and sealed off from the valve rod guide |
| DE10147830B4 (en) * | 2001-09-27 | 2008-05-08 | L'orange Gmbh | fuel injector |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 20031202 |