JP2749862B2 - Diesel engine fuel injection system - Google Patents
Diesel engine fuel injection systemInfo
- Publication number
- JP2749862B2 JP2749862B2 JP1081527A JP8152789A JP2749862B2 JP 2749862 B2 JP2749862 B2 JP 2749862B2 JP 1081527 A JP1081527 A JP 1081527A JP 8152789 A JP8152789 A JP 8152789A JP 2749862 B2 JP2749862 B2 JP 2749862B2
- Authority
- JP
- Japan
- Prior art keywords
- fuel
- small
- diameter
- check valve
- working 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.)
- Expired - Fee Related
Links
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
-
- 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
- F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
- F02M63/0012—Valves
- F02M63/0031—Valves characterized by the type of valves, e.g. special valve member details, valve seat details, valve housing details
- F02M63/005—Pressure relief valves
-
- 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
- F02M55/00—Fuel-injection apparatus characterised by their fuel conduits or their venting means; Arrangements of conduits between fuel tank and pump F02M37/00
- F02M55/04—Means for damping vibrations or pressure fluctuations in injection pump inlets or outlets
-
- 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
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
- F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
- F02M59/105—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive hydraulic drive
-
- 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
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
- F02M59/46—Valves
-
- 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
- F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
- F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
- F02M59/46—Valves
- F02M59/462—Delivery valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B3/00—Engines characterised by air compression and subsequent fuel addition
- F02B3/06—Engines characterised by air compression and subsequent fuel addition with compression ignition
-
- 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
- F02M2200/04—Fuel-injection apparatus having means for avoiding effect of cavitation, e.g. erosion
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Fuel-Injection Apparatus (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明はディーゼル機関の燃料噴射装置に関する。Description: TECHNICAL FIELD The present invention relates to a fuel injection device for a diesel engine.
従来の燃料噴射装置としては、例えば米国特許3,516,
395号明細書に記載されたものがある。この装置は第３
図に示すように燃料タンク01と、燃料ポンプ02と、噴射
ユニット03と、該ユニットのピストンストローク制御手
段04とから構成されている。噴射ユニット03は大径シリ
ンダ05内に摺動自在に支持されたサーボピストン06と、
小径ピストン07内に摺動自在に支持されたポンプピスト
ン08と、これらの両ピストン06,08に接するように付勢
するばね09とを有しており、大径シリンダ05のサーボ圧
力室010には三方切換弁011を介して、また小径シリンダ
07のポンプ作動室012には電磁弁013およびチェック弁01
4を介して、それぞれ燃料ポンプ02から所定圧力下の燃
料が供給されるようになされている。また前記作動室01
2は図示しない噴射ノズルに連通している。また015は大
径シリンダ05のリーク室を示し、このリーク室に漏出し
た燃料は燃料タンク01へリターンされる。前記電磁弁01
3は制御回路016によって開閉制御され、また前記三方切
換弁011はサーボ圧力室010と燃料タンク01または燃料ポ
ンプ02とを選択的に連通する。なお017は調圧弁であ
る。前述した電磁弁013、制御回路016、燃料ポンプ02、
チェック弁014は全体として噴射ユニット03のピストン0
6,08のストロークを制御するピストンストローク制御手
段04を構成している。As a conventional fuel injection device, for example, U.S. Pat.
No. 395 is described. This device is the third
As shown in the figure, the fuel tank includes a fuel tank 01, a fuel pump 02, an injection unit 03, and a piston stroke control means 04 of the unit. The injection unit 03 includes a servo piston 06 slidably supported in a large-diameter cylinder 05,
It has a pump piston 08 slidably supported in a small-diameter piston 07 and a spring 09 for urging the two pistons 06 and 08 to come into contact with each other. Is a small-diameter cylinder via the three-way switching valve 011
The solenoid valve 013 and the check valve 01 are installed in the pump operation chamber 012 of 07.
The fuel under a predetermined pressure is supplied from the fuel pump 02 via each of the pumps 4. The working chamber 01
Numeral 2 communicates with an injection nozzle (not shown). Reference numeral 015 denotes a leak chamber of the large-diameter cylinder 05, and fuel leaking into this leak chamber is returned to the fuel tank 01. The solenoid valve 01
3 is controlled to open and close by a control circuit 016, and the three-way switching valve 011 selectively communicates the servo pressure chamber 010 with the fuel tank 01 or the fuel pump 02. 017 is a pressure regulating valve. The aforementioned solenoid valve 013, control circuit 016, fuel pump 02,
Check valve 014 as a whole is piston 0 of injection unit 03
It constitutes a piston stroke control means 04 for controlling the stroke of 6,08.
従ってこのような燃料噴射装置にあっては、燃料ポン
プ02によって加圧された燃料は、一方では三方切換弁01
1を介してサーボ圧力室010に、他方では電磁弁013を介
してポンプ作動室012にそれぞれ供給され、サーボピス
トン06とポンプピストン08との受圧面積に比例してポン
プ作動室012内の燃料は増圧された後、図示しない噴射
ノズルより燃料が噴射される。Therefore, in such a fuel injection device, the fuel pressurized by the fuel pump 02, on the other hand, receives the three-way switching valve 01
1 is supplied to the servo pressure chamber 010 via the solenoid valve 013 and to the pump working chamber 012 via the solenoid valve 013, and the fuel in the pump working chamber 012 is proportional to the pressure receiving area between the servo piston 06 and the pump piston 08. After the pressure is increased, fuel is injected from an injection nozzle (not shown).
ところが、このような従来形の燃料噴射装置は、ポン
プ作動室012より下流の噴射性能を良好にするための構
成について明らかでない。However, the configuration of such a conventional fuel injection device for improving the injection performance downstream of the pump working chamber 012 is not clear.
即ち、第３図において、噴射ユニット03と噴射ノズル
間は一般的に噴射管にて接続される。この噴射管は長さ
と容積を有し、噴射ノズルは放出面積が絞られているた
め、該噴射ユニット03が燃料の加圧、つまり送出を停止
した後、噴射管内の圧力は時間をかけて降下し、燃料供
給圧力以下になった時点でチェック弁014が開弁し、燃
料が作動室012に供給される。That is, in FIG. 3, the injection unit 03 and the injection nozzle are generally connected by an injection pipe. Since the injection pipe has a length and a volume, and the injection nozzle has a narrow discharge area, the pressure in the injection pipe decreases over time after the injection unit 03 stops pressurizing the fuel, that is, stopping the delivery. Then, when the pressure becomes lower than the fuel supply pressure, the check valve 014 opens, and the fuel is supplied to the working chamber 012.
通常、前記噴射管内の圧力降下が緩やか過ぎる場合、
噴射ノズルが再開して燃料を再噴射する二次噴射が発生
し、一方、圧力降下が急な場合は噴射管内の油圧が負圧
となるキャビテーション現象が発生する。Usually, when the pressure drop in the injection pipe is too slow,
Secondary injection occurs in which the injection nozzle restarts and fuel is re-injected. On the other hand, when the pressure drop is sharp, a cavitation phenomenon occurs in which the hydraulic pressure in the injection pipe becomes negative.
かかる二次噴射及びキャビテーションの両現像は噴射
系として望ましくないため、いずれも発生しないように
制御するのが一般的である。Since both the secondary injection and the cavitation development are not desirable as an injection system, it is general to control such that neither of them is generated.
しかしながら、第３図に示す従来装置においては、前
記のような二次噴射やキャビテーションの発生を防止す
る手段は施されていない。However, in the conventional apparatus shown in FIG. 3, means for preventing the occurrence of secondary injection and cavitation as described above is not provided.
さらに第３図の従来装置においてポンプ作動室012へ
の燃料は、ばね09の付勢力に打勝って供給される必要が
あるため供給圧力が高くなる。又ピストンストローク制
御手段04に異常が発生した場合に燃料噴射量を制限して
機関を保護するための機械的な安全装置がない等、本噴
射ユニット03は実用的に不十分な構成となっている。Further, in the conventional apparatus shown in FIG. 3, the fuel needs to be supplied to the pump working chamber 012 by overcoming the urging force of the spring 09, so that the supply pressure increases. In addition, the present injection unit 03 has a practically inadequate configuration such that there is no mechanical safety device for limiting the fuel injection amount and protecting the engine when an abnormality occurs in the piston stroke control means 04. I have.
本発明の目的は前記従来装置の課題を解消し、二次噴
射を防止すると共にキャビテーションを未然に防ぐこと
ができるディーゼル機関の燃料噴射装置を提供するにあ
る。SUMMARY OF THE INVENTION It is an object of the present invention to provide a fuel injection device for a diesel engine which can solve the problems of the conventional device and can prevent secondary injection and also prevent cavitation.
本発明のディーゼル機関の燃料噴射装置は、大径シリ
ンダと小径シリンダとが直列に形成されるとともに、そ
れぞれのシリンダに摺動自在に嵌合された大径のサーボ
ピストンと小径ピストンとを備え、前記サーボピストン
のピストンストロークを制御する手段と前記小径シリン
ダ内に前記小径ピストンの上面が臨んで形成されたポン
プ作動室とに燃料が供給される通路を有する燃料噴射ポ
ンプにおいて；前記小径ピストンをサーボピストン側へ
引き戻す方向に付勢するばねを設けると共に、前記ポン
プ作動室に隣接してその下流に設けられ高圧噴射管内の
燃料を吸い戻すカラー付の送出用の逆止弁を具えた噴射
燃料の送出路と、前記ポンプ作動室への燃料供給路を開
閉するチェック弁とキャビテーション防止用の逆止弁と
を有する戻し油路とを前記ポンプ作動室と燃料の吐出通
路との間に並列に設けたことを特徴としている。The fuel injection device for a diesel engine of the present invention has a large-diameter cylinder and a small-diameter cylinder formed in series, and includes a large-diameter servo piston and a small-diameter piston slidably fitted to each cylinder, A fuel injection pump having a passage for supplying fuel to a means for controlling a piston stroke of the servo piston and a pump working chamber formed in the small diameter cylinder with an upper surface of the small diameter piston facing; A spring is provided for biasing in the direction of pulling back to the piston side, and is provided with a check valve with a collar provided adjacent to and downstream of the pump working chamber and sucking back the fuel in the high-pressure injection pipe. A delivery path, a return oil path having a check valve for opening and closing the fuel supply path to the pump working chamber and a check valve for preventing cavitation; It is characterized in that provided in parallel between the discharge passage of the pump working chamber and fuel.
小径ピストン３を押し下げる方向に付勢したばね８は
ポンプ作動室15への燃料供給を容易にして動力損失を低
減し、ポンプ作動室15下流の送出路30に設けられた逆止
弁21、及び同送出路30と並列に設けられた戻し油路35の
逆止弁25は二次噴射とキャビテーションを防止する。こ
れにより、燃料噴射装置系の耐久性と機関性能を向上さ
せることができる。The spring 8 urged in the direction to push down the small-diameter piston 3 facilitates fuel supply to the pump working chamber 15 to reduce power loss, and includes a check valve 21 provided in a delivery path 30 downstream of the pump working chamber 15; The check valve 25 of the return oil passage 35 provided in parallel with the delivery passage 30 prevents secondary injection and cavitation. Thereby, the durability and engine performance of the fuel injection system can be improved.
以下第１〜２図を参照し本発明の一実施例について説
明する。An embodiment of the present invention will be described below with reference to FIGS.
第１図（ａ）〜（ｃ）は上記噴射ユニットのピスト
ン、シリンダ部の構成図である。1 (a) to 1 (c) are configuration diagrams of a piston and a cylinder of the injection unit.
１は噴射ユニットの本体、２は本体１内に支持された
小径シリンダ、51は大径シリンダ、52は該大径シリンダ
51に摺動自在に支持された大径のサーボピストン、３は
該サーボピストン52により案内７を介して小径シリンダ
２内で上下摺動されかつ回動自在に支持される小径ピス
トン、４は前記小径シリンダ２をその上部の油密を保ち
つつ本体１内に弁座20を介してボルトにより固定する押
え金物である。17は前記弁座20の周囲に形成された上部
室である。５はスリーブで前記小径シリンダ２の外周に
回動自在に支持されている。該スリーブ５の下部には切
り溝があり、これに小径ピストン３のつば部が挿入され
ている。このため、該小径ピストン３は前記スリーブ５
の回転によりその軸心のまわりに回動可能となる。６は
ラック6aを介して前記スリーブ５を軸心のまわりに回復
せしめて燃料吐出量を制限するラック棒、８はばね受９
を介して小径ピストン３を下方に付勢するばね、10は前
記小径シリンダ２に設けられた排油路11に挿入された整
流棒である。21は弁座20に摺動自在に支持され、ばね22
により下方に付勢され、吸い戻し用のカラー21aを有す
る逆出用の逆止弁である。また23は弁座20に摺動自在に
支持さればね24により下方に付勢されたチェック弁、25
は押え金物４に摺動自在に支持され、ばね26により上方
に付勢された逆止弁である。1 is a main body of the injection unit, 2 is a small-diameter cylinder supported in the main body 1, 51 is a large-diameter cylinder, and 52 is the large-diameter cylinder.
The large-diameter servo piston 3 slidably supported by 51 is a small-diameter piston slidably supported vertically by the servo piston 52 through the guide 7 in the small-diameter cylinder 2 and rotatably supported. A presser foot for fixing the small-diameter cylinder 2 in the main body 1 with a bolt via a valve seat 20 while keeping the upper portion oil-tight. Reference numeral 17 denotes an upper chamber formed around the valve seat 20. A sleeve 5 is rotatably supported on the outer periphery of the small-diameter cylinder 2. At the lower part of the sleeve 5, there is a kerf into which the collar of the small diameter piston 3 is inserted. For this reason, the small-diameter piston 3 is
By the rotation of, it becomes rotatable around its axis. Reference numeral 6 denotes a rack bar for recovering the sleeve 5 around the axis through a rack 6a to limit the amount of fuel discharged, and 8 denotes a spring support 9
A spring 10 for urging the small-diameter piston 3 downward via a spring 10 is a rectifying rod inserted into an oil-discharge passage 11 provided in the small-diameter cylinder 2. 21 is slidably supported by a valve seat 20, and a spring 22
This is a check valve for return that is urged downward by the valve and has a collar 21a for sucking back. A check valve 23 is slidably supported by the valve seat 20 and urged downward by a spring 24.
Is a check valve slidably supported by the presser foot 4 and urged upward by a spring 26.
また12は本体１に設けられた燃料入口、13は本体１に
設けられた燃料出口、14は油溜、15は小径シリンダ２内
の上部に形成されたポンプ作動室、16は油溜14と上部室
17を接続する小径シリンダ２に切欠かれた複数個の油
路、18はチェック弁23の上下動によりシート19を開閉し
てポンプ作動室15へ燃料を供給する給油路、30は逆出用
の逆止弁21の上下動によりシート31が開閉して通路32と
ポンプ作動室15を接続する送出路である。35は、前記ポ
ンプ作動室15と出口側の通路32との間に、前記逆出路30
と並列に設けられた戻し油路である。33は絞りで、逆止
弁25の上下動により開閉するシート34と通路32間に設け
られ前記戻し通路35を介いてポンプ作動室15へ連通して
いる。さらに小径ピストン３にはその上部に噴射量制御
用のリード3aが２ケ所設けられている。Reference numeral 12 denotes a fuel inlet provided in the main body 1, 13 denotes a fuel outlet provided in the main body 1, 14 denotes an oil reservoir, 15 denotes a pump working chamber formed at an upper part in the small diameter cylinder 2, and 16 denotes an oil reservoir 14. Upper room
A plurality of oil passages notched in the small-diameter cylinder 2 connecting the 17, a reference numeral 18 denotes an oil supply passage for opening and closing the seat 19 by the up and down movement of the check valve 23 and supplying fuel to the pump working chamber 15, and a reference numeral 30 denotes a return passage. This is a delivery path that connects the passage 32 and the pump working chamber 15 by opening and closing the seat 31 by the vertical movement of the check valve 21. 35 is provided between the pump working chamber 15 and the passage 32 on the outlet side,
And a return oil passage provided in parallel. Reference numeral 33 denotes a throttle, which is provided between a seat 34 which is opened and closed by the up-and-down movement of the check valve 25 and the passage 32, and which communicates with the pump working chamber 15 via the return passage 35. Further, the small diameter piston 3 is provided with two injection amount control leads 3a at the upper part thereof.
5aはスリーブ５の下端に一体的に設けられた平面で、
小径ピストン３に形成された平面部に相対回転不能に連
結されるとともに、該平面部を摺動自在に案内する。こ
れにより、前記小径ピストン３は、スリーブ５、ラック
6aを介して、ラック棒６により回動自在となり、ラック
棒６を操作することにより、例えば第２図RC2〜RC1のよ
うにリード3aと排油路11の関係を変更することができ
る。5a is a plane provided integrally with the lower end of the sleeve 5,
It is connected to a flat portion formed on the small-diameter piston 3 so as not to rotate relatively, and guides the flat portion slidably. As a result, the small-diameter piston 3 is
Through 6a, become rotatable by the rack bar 6, by operating the rack bar 6, it is possible to change the relationship between lead 3a and the oil discharge passage 11, for example, as Figure 2 R C2 to R C1 .
次に本発明の作用について説明する。 Next, the operation of the present invention will be described.
第１図（ｂ），（ｃ）において、まず、燃料は燃料入
口12から油溜14に入り、油路16を経て上部室17に充填さ
れる。そして、サーボピストン52により案内７を介して
小径ピストン３が上動されると、ポンプ作動室15の燃料
油は加圧され、この加圧燃料は逆止弁21をばね22に抗し
て上方に移動させ、カラー21aがシート31より上方へ移
動して開弁し、逆出路30、通路32、図示しない噴射管を
へて噴射ノズルからシリンダへ噴射される。このとき逆
止弁25及びチェック弁23は内圧により第１図（ｂ），
（ｃ）のようにシート19,34が閉となっている。必要燃
料が噴射されると、小径ピストン３の上動が止まり、こ
れに伴ないポンプ作動室15の圧力は急激に低下して送出
用の逆止弁21はばね22により下方へ押し戻され閉弁す
る。このとき噴射管内の燃料油は （ここで、ｌは逆止弁21のリフト）だけ吸戻されるの
で、噴射管内の圧力は急激に低下して噴射ノズルの開弁
圧力近くまで下降する。逆止弁25の開弁圧以上の管内圧
力波が通路32に帰ってくると、絞り33をへて逆止弁25に
伝わり逆止弁25が下降し、シート34が開いて戻し油路35
を介して噴射管内の燃料油が吸戻され、次第に噴射管内
の圧力は噴射ノズルの開弁圧力以下に低下する。その後
逆止弁25は閉弁するので、噴射ノズルの再開つまり二次
噴射を防止することができ、噴射を完了する。絞り33の
穴径は噴射管内圧力が負圧となってキャビテーションが
発生しないように最適に決められる。噴射が終ると小径
ピストン３は下動するように制御される。小径ピストン
３の下動に伴ないポンプ作動室15の圧力は上部室17より
も低下するので、これの段部23aに作用する上部室17の
圧力により、チェック弁23がばね24の付勢力に抗して上
動し、シート19が開弁して上部室17の燃料油は給油路1
8、シート19をへてポンプ作動室15へ供給され、燃料油
の供給は小径ピストン３の下動終了とともに完了する。
このときばね８は小径ピストン３を下方へ動かし燃料の
供給を容易にする。1 (b) and 1 (c), first, the fuel enters the oil reservoir 14 from the fuel inlet 12, and is charged into the upper chamber 17 via the oil passage 16. When the small-diameter piston 3 is moved upward by the servo piston 52 via the guide 7, the fuel oil in the pump working chamber 15 is pressurized, and this pressurized fuel moves the check valve 21 upward against the spring 22. The collar 21a moves upward from the seat 31 to open the valve, and is ejected from the ejection nozzle to the cylinder through the return passage 30, the passage 32, and an ejection pipe (not shown). At this time, the check valve 25 and the check valve 23 are actuated by the internal pressure as shown in FIG.
The seats 19 and 34 are closed as shown in FIG. When the required fuel is injected, the upward movement of the small-diameter piston 3 stops, and the pressure in the pump working chamber 15 drops rapidly, and the check valve 21 for delivery is pushed back downward by a spring 22 to close the valve. I do. At this time, the fuel oil in the injection pipe (Here, l is the lift of the check valve 21), so that the pressure in the injection pipe rapidly drops and drops to near the valve opening pressure of the injection nozzle. When the pressure wave in the pipe equal to or higher than the valve opening pressure of the check valve 25 returns to the passage 32, the check wave is transmitted to the check valve 25 through the throttle 33, the check valve 25 is lowered, the seat 34 is opened, and the return oil passage 35
, The fuel oil in the injection pipe is sucked back, and the pressure in the injection pipe gradually falls below the valve opening pressure of the injection nozzle. Thereafter, the check valve 25 closes, so that the restart of the injection nozzle, that is, the secondary injection can be prevented, and the injection is completed. The hole diameter of the throttle 33 is optimally determined so that cavitation does not occur due to negative pressure in the injection pipe. When the injection is completed, the small diameter piston 3 is controlled to move downward. Since the pressure of the pump working chamber 15 is lower than that of the upper chamber 17 due to the downward movement of the small-diameter piston 3, the pressure of the upper chamber 17 acting on the step portion 23 a causes the check valve 23 to act on the urging force of the spring 24. The seat 19 opens and the fuel oil in the upper chamber 17
8. The fuel oil is supplied to the pump working chamber 15 through the seat 19, and the supply of the fuel oil is completed when the downward movement of the small-diameter piston 3 is completed.
At this time, the spring 8 moves the small diameter piston 3 downward to facilitate the supply of fuel.
以上の作動においてポンプ作動室15と排油路11の間は
リード3aにより遮断されており、排油路11からのポンプ
作動室15の燃料油の排出及び供給は行われない。第２図
はリード3aと排油路11の関係を示したもので、リード3a
と排油路11の作動について第２図により説明する。リー
ド3aの使用域を変えるにはラック棒６のラック位置Rc1,
Rc2をかえ、スリーブ５を介して小径ピストン３を回動
してなされる。上記燃料噴射のための小径ピストン３の
上下動ストロークはS1である。何らかの原因で図示を省
略したピストンストローク制御手段に異常が発生し、小
径ピストン３のストロークがS1を越えて付加ストローク
ΔS1に至ると、ポンプ作動室15は油路3bを経て排油路11
と連通しはじめ、さらに小径ピストン３が上方へストロ
ークするとポンプ作動室15の加圧燃料油は排油路11を介
して油溜14へ放出され、燃料油圧は圧力が低下し、エン
ジンシリンダへの噴射は行われなくなる。即ちラック位
置RC1において最大ストロークは（S1＋ΔS1）であり、
このΔS1は機関の過負荷を防止し、機関を保護できる量
の制限ストロークである。同様にラック位置RC2におい
てS2が通常の噴射ストローク、ΔS2が制限ストロークで
ある。In the above operation, the space between the pump working chamber 15 and the oil discharge passage 11 is shut off by the lead 3a, and the fuel oil in the pump working chamber 15 from the oil discharge passage 11 is neither discharged nor supplied. FIG. 2 shows the relationship between the lead 3a and the oil drain passage 11, and the lead 3a
The operation of the oil drain passage 11 will be described with reference to FIG. To change the use area of the lead 3a, the rack position R c1 of the rack bar 6 is changed.
By changing R c2 , the small diameter piston 3 is rotated via the sleeve 5. Vertical movement stroke of the small-diameter piston 3 for the fuel injection is S 1. Abnormality occurs in the piston stroke control means not shown for some reason, the stroke of the small-diameter piston 3 reaches the additional stroke [Delta] S 1 exceeds the S 1, the oil discharge passage pumping chamber 15 through the oil passage 3b 11
When the small-diameter piston 3 further moves upward, the pressurized fuel oil in the pump working chamber 15 is discharged to the oil reservoir 14 via the oil drain passage 11, and the fuel oil pressure decreases, and No injection is performed. That is, the maximum stroke at the rack position R C1 is (S 1 + ΔS 1 ),
This ΔS 1 is a limit stroke of an amount capable of preventing overload of the engine and protecting the engine. Normal injection stroke S 2, ΔS 2 is a limiting stroke in the same manner as the rack position R C2.
前述のように、この実施例に係る燃料噴射装置の加圧
終了は、第１図（ｂ）において排油路11がリード3aより
も下方にきた時点であり、このとき小径ピストン３は上
動しており、このためポンプ作動室15の圧力はある程度
の速さで降下し、該作動室15の油圧が管内圧力以下にな
ると、逆止弁21が下動してこのとき管内の油量をΔＱだ
け吸い戻すので管内圧力はさらに降下する。As described above, the pressurization of the fuel injection device according to this embodiment ends when the oil discharge passage 11 comes below the lead 3a in FIG. 1B, and at this time, the small-diameter piston 3 moves upward. Therefore, the pressure in the pump working chamber 15 drops at a certain speed, and when the oil pressure in the working chamber 15 becomes lower than the pipe pressure, the check valve 21 moves down, and at this time the amount of oil in the pipe is reduced. Since the pressure is sucked back by ΔQ, the pressure in the pipe further decreases.
その後、逆止弁25が開弁して管内の油量は絞り33を経
て吸戻され、さらに管内圧力は降下する。前述の作用に
おいて、吸戻量ΔＱと絞り33を選択することで圧力降下
を最適にし、二次噴射、キャビテーションの双方を防止
できる。Thereafter, the check valve 25 is opened, the amount of oil in the pipe is sucked back through the throttle 33, and the pressure in the pipe further decreases. In the above operation, by selecting the suction amount ΔQ and the throttle 33, the pressure drop is optimized, and both the secondary injection and the cavitation can be prevented.
又実施例において、弁座20に絞り33以上の油路を、チ
ェック弁23と並列に設け得るだけの空間があれば、逆止
弁25とチェック弁23は直列に配置する必要はなく並列に
配置してもよい。Also, in the embodiment, if there is enough space in the valve seat 20 to provide an oil passage having a throttle 33 or more in parallel with the check valve 23, the check valve 25 and the check valve 23 do not need to be arranged in series, and may be arranged in parallel. It may be arranged.
本発明は前記のとおり構成したので、小径ピストン３
の上動停止に伴ない、噴射管内の燃料油は逆止弁21のカ
ラー21aによりまず吸戻され、さらに噴射管内の圧力変
動に応じて絞り33を介して逆止弁25より吸戻されるの
で、二次噴射が防止できるとともにキャビテーションの
発生を未然に防止することができる。Since the present invention is configured as described above, the small-diameter piston 3
With the stop of the upward movement, the fuel oil in the injection pipe is first sucked back by the collar 21a of the check valve 21, and further sucked back from the check valve 25 through the throttle 33 in accordance with the pressure fluctuation in the injection pipe. In addition, secondary injection can be prevented, and cavitation can be prevented from occurring.
又、小径ピストン３を下方へ付勢するばね３を設けた
ことによりポンプ作動室15への燃料供給が容易となり動
力損失を低減することができる。Further, the provision of the spring 3 for urging the small-diameter piston 3 downward facilitates the supply of fuel to the pump working chamber 15 and reduces power loss.
第１〜２図は本発明に係わるもので、第１図（ａ）は燃
料噴射ポンプ用サーボ機構の断面図、第１図（ｂ）は燃
料噴射ポンプの断面図、第１図（ｃ）は燃料噴射装置上
部の拡大断面図、第２図はリード3aと排油路11の関係線
図である。 第３図は従来形燃料噴射装置の概略図である。 ２……小径シリンダ、３……小径ピストン、3a……リー
ド、８……ばね、15……ポンプ作動室、19……シート、
20……弁座、21……逆止弁、22……ばね、23……チェッ
ク弁、25……逆止弁、33……絞り、51……大径シリン
ダ、52……サーボピストン、61〜65……ピストンストロ
ークの制御手段。1 and 2 relate to the present invention. FIG. 1 (a) is a sectional view of a servo mechanism for a fuel injection pump, FIG. 1 (b) is a sectional view of a fuel injection pump, and FIG. 1 (c). FIG. 2 is an enlarged cross-sectional view of the upper part of the fuel injection device, and FIG. 2 is a relationship diagram between the lead 3a and the oil discharge passage 11. FIG. 3 is a schematic view of a conventional fuel injection device. 2 ... Small diameter cylinder, 3 ... Small diameter piston, 3a ... Reed, 8 ... Spring, 15 ... Pump working chamber, 19 ... Seat,
20 ... valve seat, 21 ... check valve, 22 ... spring, 23 ... check valve, 25 ... check valve, 33 ... throttle, 51 ... large diameter cylinder, 52 ... servo piston, 61 ~ 65 ...... Piston stroke control means.
Claims (1)
成されるとともに、それぞれのシリンダに摺動自在に嵌
合された大径のサーボピストンと小径ピストンとを備
え、前記サーボピストンのピストンストロークを制御す
る手段と前記小径シリンダ内に前記小径ピストンの上面
が臨んで形成されたポンプ作動室とに燃料が供給される
通路を有する燃料噴射ポンプにおいて；前記小径ピスト
ンをサーボピストン側へ引き戻す方向に付勢するばねを
設けると共に、前記ポンプ作動室に隣接してその下流に
設けられ高圧噴射管内の燃料を吸い戻すカラー付の送出
用の逆止弁を具えた噴射燃料の送出路と、前記ポンプ作
動室への燃料供給路を開閉するチェック弁とキャビテー
ション防止用の逆止弁とを有する戻し油路とを前記ポン
プ作動室と燃料の吐出通路との間に並列に設けたことを
特徴とするディーゼル機関の燃料噴射装置。A large-diameter cylinder and a small-diameter cylinder are formed in series, and a large-diameter servo piston and a small-diameter piston slidably fitted to each cylinder are provided. A fuel injection pump having a passage for supplying fuel to the control means and a pump working chamber formed with the upper surface of the small-diameter piston facing the inside of the small-diameter cylinder; in a direction in which the small-diameter piston is pulled back to the servo piston side. A delivery path for the injected fuel having a biasing spring, a delivery check valve provided with a collar, which is provided adjacent to and downstream of the pump working chamber and sucks back the fuel in the high-pressure injection pipe; A return oil passage having a check valve for opening and closing the fuel supply passage to the working chamber and a check valve for preventing cavitation is provided between the pump working chamber and the fuel discharge passage. The fuel injection system of a diesel engine, characterized in that provided in parallel between the passage.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1081527A JP2749862B2 (en) | 1989-04-03 | 1989-04-03 | Diesel engine fuel injection system |
| DE69006882T DE69006882T2 (en) | 1989-04-03 | 1990-03-30 | Fuel injection system for diesel engines. |
| EP90250087A EP0391509B1 (en) | 1989-04-03 | 1990-03-30 | Fuel injection system for diesel engines |
| DK90250087.5T DK0391509T3 (en) | 1989-04-03 | 1990-03-30 | Fuel injection system for diesel engines |
| KR1019900004583A KR930008513B1 (en) | 1989-04-03 | 1990-04-03 | Fuel injecting system for diesel engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1081527A JP2749862B2 (en) | 1989-04-03 | 1989-04-03 | Diesel engine fuel injection system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02264147A JPH02264147A (en) | 1990-10-26 |
| JP2749862B2 true JP2749862B2 (en) | 1998-05-13 |
Family
ID=13748798
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1081527A Expired - Fee Related JP2749862B2 (en) | 1989-04-03 | 1989-04-03 | Diesel engine fuel injection system |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0391509B1 (en) |
| JP (1) | JP2749862B2 (en) |
| KR (1) | KR930008513B1 (en) |
| DE (1) | DE69006882T2 (en) |
| DK (1) | DK0391509T3 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2731997B1 (en) * | 1995-03-22 | 1997-05-09 | Kodak Pathe | TAPE PRODUCT REWINDER |
| KR100715657B1 (en) * | 2006-09-26 | 2007-05-07 | 쌍용자동차 주식회사 | Assembling device for a piston oil injection nozzle of automobile |
| DE102017205949B3 (en) * | 2017-04-07 | 2018-09-27 | Continental Automotive Gmbh | Valve arrangement for a fuel injection system of an internal combustion engine |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR803260A (en) * | 1935-06-11 | 1936-09-26 | Improvements to injection pumps for internal combustion engines | |
| GB690563A (en) * | 1950-06-14 | 1953-04-22 | Cav Ltd | Liquid fuel pumps |
| FR1377870A (en) * | 1963-12-20 | 1964-11-06 | Sulzer Ag | Fuel injection pump for internal combustion piston engine |
| GB1211346A (en) * | 1967-01-13 | 1970-11-04 | Bryce Berger Ltd | Liquid fuel injection pumps |
| FR2456221B1 (en) * | 1979-05-07 | 1986-07-11 | Benaroya Henry | IMPROVEMENTS TO FUEL INJECTION SYSTEMS FOR INTERNAL COMBUSTION ENGINES |
| DE3141654A1 (en) * | 1981-10-21 | 1983-05-05 | L'Orange GmbH, 7000 Stuttgart | FUEL INJECTION PUMP, ESPECIALLY FOR A DIESEL INTERNAL COMBUSTION ENGINE |
| JPH057500Y2 (en) * | 1987-04-21 | 1993-02-25 | ||
| JPS6415460A (en) * | 1987-07-09 | 1989-01-19 | Mitsubishi Heavy Ind Ltd | Fuel injection device |
-
1989
- 1989-04-03 JP JP1081527A patent/JP2749862B2/en not_active Expired - Fee Related
-
1990
- 1990-03-30 DK DK90250087.5T patent/DK0391509T3/en active
- 1990-03-30 DE DE69006882T patent/DE69006882T2/en not_active Expired - Fee Related
- 1990-03-30 EP EP90250087A patent/EP0391509B1/en not_active Expired - Lifetime
- 1990-04-03 KR KR1019900004583A patent/KR930008513B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE69006882D1 (en) | 1994-04-07 |
| KR900016608A (en) | 1990-11-13 |
| KR930008513B1 (en) | 1993-09-09 |
| DK0391509T3 (en) | 1994-03-28 |
| EP0391509B1 (en) | 1994-03-02 |
| DE69006882T2 (en) | 1994-06-16 |
| EP0391509A1 (en) | 1990-10-10 |
| JPH02264147A (en) | 1990-10-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |