EP0056916A1 - Device for fuel injection for an internal-combustion engine - Google Patents

Device for fuel injection for an internal-combustion engine Download PDF

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Publication number
EP0056916A1
EP0056916A1 EP81401902A EP81401902A EP0056916A1 EP 0056916 A1 EP0056916 A1 EP 0056916A1 EP 81401902 A EP81401902 A EP 81401902A EP 81401902 A EP81401902 A EP 81401902A EP 0056916 A1 EP0056916 A1 EP 0056916A1
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EP
European Patent Office
Prior art keywords
chamber
pressure
injection
control
needle
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP81401902A
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German (de)
French (fr)
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EP0056916B1 (en
Inventor
Jean-Pierre Jourde
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Renault SAS
Regie Nationale des Usines Renault
Original Assignee
Renault SAS
Regie Nationale des Usines Renault
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Application filed by Renault SAS, Regie Nationale des Usines Renault filed Critical Renault SAS
Priority to AT81401902T priority Critical patent/ATE21729T1/en
Publication of EP0056916A1 publication Critical patent/EP0056916A1/en
Application granted granted Critical
Publication of EP0056916B1 publication Critical patent/EP0056916B1/en
Expired legal-status Critical Current

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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
    • F02M47/025—Hydraulically 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
    • 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

Definitions

  • the subject of the present invention is a device and a method for injecting fuel for an internal combustion engine, in particular for a diesel engine, allowing both a predosing of the quantity of fuel injected per cylinder and an amplification of the injection pressure.
  • the injection device can be easily controlled by electronic means.
  • the injection system includes pre-metering means with pressure amplification by means of a differential piston, it can be seen that the injection pressure is a function, for low loads, of the quantity injected, due to the response time. fuel control and delivery pistons in the injector.
  • the subject of the present invention is a device and a method for injecting fuel which makes it possible to eliminate these drawbacks and which combines the advantages of injection at constant pressure and predosed injection.
  • the fuel to be injected is subjected to high pressure around the needle of the injector which is controlled by a piston which can be subjected to high pressure of a control fluid.
  • the pre-metering of the quantity of fuel to be injected is also carried out, which allows this quantity of fuel at low pressure to be determined with great precision.
  • the predosed fuel is subjected to a pressure increase with pressure amplification making it possible to obtain a high injection pressure from an average control pressure.
  • the fuel injection device for an internal combustion engine comprises an injection chamber closed by an injector needle.
  • the injector is subjected to the action of a closing spring and to the action of a hydraulic fluid pressure prevailing in a chamber called the discharge chamber. These two actions are added in order to urge the injector needle towards its closed position in contact with its seat.
  • the injection device comprises a control system with two differential pistons integral with one another.
  • a delivery piston delimits a metering chamber in communication with the injection chamber of the injector and supplied with fuel at an intermediate pressure or booster pressure.
  • the device further comprises control means in order to discharge, that is to say to place at zero or low pressure, the discharge chamber whose pressure acts on the needle of the injector, when the quantity of metered fuel in the metering chamber has been subjected to pressure injection by the action of the high control pressure on the control piston delimiting the control chamber
  • the discharge chamber the pressure of which acts on the injector needle, is subjected before the injection phase to the action of the high pressure of the control.
  • the dimensions of the discharge chamber as well as the characteristics of the injector are such that the needle remains in its seat in the closed position when the injection chamber is at the injection pressure prevailing in the dosing chamber. This situation arises when the high control pressure is exerted on the control piston delimiting the control chamber.
  • the injection chamber can also be discharged, that is to say connected to the zero pressure of a hydraulic fluid reservoir, via a passage discovered by the movement of the differential piston control system. and in particular in the position corresponding to the end of the injection phase.
  • An adjustable restriction is advantageously interposed between the discharge chamber and the aforementioned three-way solenoid valve.
  • control means making it possible to connect the discharge chamber to the tank comprise a spool valve controlled by the high control pressure and by the pressure prevailing in the dosing chamber.
  • the fuel injection method according to the invention consists in operating successively in the following manner. Firstly, the injector needle is kept in the closed position by the action of the high control pressure. During this time, a metering chamber is filled with fuel at a lower intermediate pressure. higher than the high control pressure, and the fuel thus predosed contained in the metering chamber is subjected to a pressure increase up to the injection pressure.
  • the injection chamber is discharged so as to facilitate movement of the needle to its closed position.
  • the injection device comprises an injector 1 provided with an injection needle 2 capable of coming into contact with its seat 3 in order to close the passage to the injection orifices 4.
  • a chamber 5 surrounds the injection needle 2 and allows the supply of fuel to be injected.
  • the needle 2 of the injector 1 is secured to a pusher 6 by means of a portion of larger diameter 7.
  • the end of the pusher 6 opposite the needle 2 acts on a pilot piston 8 delimiting a discharge chamber 9.
  • a compression spring 10 also acts by means of the shoulder 11 on the needle 2 in the direction tending to close the passage to the injection orifices 4.
  • a control system 12 with two differential pistons integral with one another is mounted on the injector holder not shown in the figure.
  • the control system 12 comprises a delivery piston 13 of section S r delimiting a metering chamber 14.
  • the piston 13 is integral with a rod 15 which acts at the lower part of a control piston 16 of section S c greater than the section S r of the delivery piston 13.
  • the control piston 16 delimits a control chamber 17.
  • a drawer distributor 18 includes a drawer provided two portions 19 and 20 of larger diameter connected by a rod 21 which moves in a body having three chambers 22, 23 and 24 delimited by bearing surfaces of the bore of said body.
  • two end chambers 25 and 26 can be subjected to a pressure acting on one or the other of the ends of the distributor valve 18.
  • a compression spring 27 is mounted in the end chamber 25.
  • the fuel for example diesel in the case of a diesel engine, is at atmospheric pressure in the reservoir 28. 'It is drawn by a low pressure 29 providing a constant pressure maintained by the pump regulator 30 connected between the outlet of the pump 29 and the return to the reservoir 28.
  • a high pressure pump 31 is boosted by the low pressure pump 29 and puts the fuel at the constant high pressure Pc which can reach 200 bars and which is the control pressure.
  • the control pressure is kept constant by two regulating devices placed in series 32 and 33 between the outlet of the high pressure pump 31 and the return to the reservoir 28.
  • the constant pressure appearing between the two regulators 32 and 33 is an intermediate pressure P g said booster pressure lower than the high control pressure P.
  • the fuel at the booster pressure can therefore penetrate through a damping nozzle 34 and a non-return valve 35 mounted in the line 36 as far as the lower part of the metering chamber 14.
  • the fuel at the high-pressure control P feeds via the line 37 a hydraulic accumulator 38, the chamber 22 of the slide valve 18 as well as the end chamber 26 of the same valve by means of a three-way solenoid valve. 39 mounted in the bypass line 40.
  • the high pressure fuel can pass from chamber 22 into chamber 23 depending on the position of the drawer and supply via line 41, the control chamber 17 of the control system 12 with differential piston.
  • the fuel at the high control pressure P is also supplied via the line 42 to a second three-way solenoid valve 43 connected by an adjustable nozzle 44 to the discharge chamber 9 of the injector 1.
  • the lower part of the metering chamber 14 is connected by the pipe 45, 46 to the injection chamber 5.
  • the end chamber 27 of the distributor 18 is connected by the pipe 47 to the pipe 48 returning to the reservoir 28.
  • the rod side of the control piston 16 is also connected by the line 48a, 48 to the reservoir 28.
  • the bore inside which the delivery piston 13 can move has in its lower part an opening communicating with the pipe 45 and in its upper part an opening communicating with a pipe 50.
  • the spacing of these two openings is such that in the rest position, the delivery piston 13 discovers the opening of the pipe 50 and closes the opening of the pipe 45.
  • the two pipes 45 and 50 are connected to the injection chamber 5.
  • the line 50 and therefore the injection chamber 5 are in communication with the rod side of the control piston 16, that is to say with the low pressure of the fluid reservoir 28 via the line back 48a, 48.
  • Fig. 1 which has just been described illustrates the position of the various elements of the injection device according to the invention during the rest phase. We will now describe the different phases of operation with reference to Figs. 2 to 5.
  • the three-way solenoid valve 39 allows the fuel to penetrate at the high control pressure P into the lower chamber 26 of the distributor 18, the upper face of which bears on the compression spring 27.
  • the latter is chosen so that that the force developed by the high control pressure P in the lower chamber 26 is greater than that of the spring.
  • the dispenser drawer 18 is therefore moved in a position such that it allows communication between the chambers 22 and 23 as shown in FIG. 1.
  • the control chamber 17 is filled with fuel at the high control pressure P c via the pipe 41.
  • the discharge chamber 14 has a minimum volume, the discharge piston 13 filling it almost completely taking into account from the low position of the differential piston system 12.
  • the three-way solenoid valve 43 is controlled so as to subject the discharge chamber 9 to the high control pressure P c through the nozzle 44 so that the needle 2 of the injector 1 is kept in the closed position.
  • Fig. 2 illustrates the predosing phase of the fuel to be injected.
  • the solenoid valve 39 is controlled so as to put the chamber 26 of the distributor 18 into communication with the pipe 48 returning to the reservoir 28. Under the action of the spring 27, the distributor slide 18 therefore moves so as to put in communication the chambers 23 and 24 also communicating via the nozzle 49 the control chamber 17 with the reservoir 28 via the pipes 41 and 48.
  • the metering chamber 14 is subjected to the booster pressure P.
  • P g x S r / S c the differential piston system 12 rises under the effect of the boost pressure P g in the chamber 14. Fuel therefore enters the metering chamber 14 from of the pipe 36. During this phase, the nozzles 49 and 34 make it possible to damp the movement of the differential piston system 12 in order to avoid any oscillation.
  • Fig. 3 illustrates the accumulation phase.
  • the electrical supply voltage of the solenoid valve 39 is cut off as illustrated in FIG. 3.
  • the high control pressure P again enters the end chamber 26 of the distributor 18 which moves so as to put the chambers 22 and 23 into communication again subjecting the control chamber 17 to the high control pressure P via the line 41.
  • the fuel cannot flow towards the injector 1 since the high control pressure P c still prevails in the discharge chamber 9, the solenoid valve 43 remaining in the initial position.
  • the fuel in the accumulator 38 facilitates the filling of the control chamber 17 despite a large instantaneous flow.
  • the dimensions of the discharge chamber 9 are chosen so that its section S d as well as the structure of the injector and in particular the force of the spring 10 are such that the needle 2 remains in the closed position even when the chamber injection 5 is subjected to the injection pressure which then prevails in the metering chamber 14. It suffices indeed that one has the following inequality: where F is the force developed by the spring 10, Sa is the section of the portion 7 and S s is the section of the portion of the needle 2 in contact with its seat 3.
  • Fig. 4 illustrates the injection phase.
  • the solenoid valve 39 remains in the position illustrated in FIG. 3.
  • the solenoid valve 43 is energized at a precise instant so as to control it in order to put the discharge chamber 9 in communication via the adjustable nozzle 44 with the reservoir 28 via the pipe 43a.
  • the pressure P d prevailing in the discharge chamber 9 drops from its initial value equal to the high control pressure P to a value such that there is the following relationship: the needle 2 of the injector 1 lifts and the injection begins at an injection pressure P i which is equal to the pressure P r prevailing in the metering chamber 14.
  • the delivery piston 13 delivers the quantity of pre-dosed fuel located in the metering chamber 14 to the injection chamber 5 via the pipes 45 and 46.
  • variable nozzle 44 makes it possible to adjust the speed of the pressure drop in the discharge chamber 9 and therefore to adjust the speed of the lifting movement of the needle 2 of the injector. An action on the restriction formed by the nozzle 44 therefore allows the injection law to be easily modified.
  • Fig. 5 illustrates the phase corresponding to the end of the injection.
  • the two solenoid valves 39 and 43 initially remain in the positions illustrated in FIG. 4.
  • the underside of the discharge piston 13 closes the opening of the line 45 connecting the metering chamber 14 via the line 46 to the injection chamber 5.
  • the dimensions of the delivery piston 13 as well as the spacing openings communicating with the pipes 45 and 50 are such that at the same time the upper face of the delivery piston 13 uncovers the orifice of the pipe 50 thus allowing the pressure prevailing in the injection chamber 5 to be discharged by the pipes 46, 50, 48a and 48 returning to the reservoir 28.
  • the needle 2 of the injector 1 then closes under the effect of the calibration spring 10.
  • the electrical supply to the three-way solenoid valve 43 is then cut off, which returns to the position illustrated in FIG. 1 allowing the high pressure P to recharge the discharge chamber 9.
  • the various elements of the device return to the position illustrated in FIG. 1.
  • the variant which has just been described is more particularly suited to an application which requires the injection of a minimum quantity of fuel of approximately 6 mm 3 per stroke, which is the case for example for engines intended for light vehicles.
  • a minimum quantity of fuel of approximately 6 mm 3 per stroke
  • the dispenser drawer 51 has two larger diameter portions 52 and 53 connected together by a rod 54 and moves in a bore comprising three chambers 55, 56 and 57 delimited by ranges and two pilot chambers 58 and 59 for moving the drawer.
  • the first control chamber 58 is connected to the high control pressure by the line 61 which is itself connected to the line 42.
  • the line 60 also makes it possible to convey the fuel at the high control pressure P c as far as the room 57.
  • the chamber 55 is connected to the reservoir 28 via the pipe 62 which contains a damping nozzle Variable Restriction 63.
  • the pipe 64 connects the chamber 56 to the discharge chamber 9 of the injector 1. '
  • the second control chamber 59 communicates via the pipe 65 with a low passage 66 opening into the metering chamber 14 and being able to be closed by the delivery piston 13 during its downward movement.
  • the pipe 65 also communicates with a high passage 67 which communicates with the rod side of the control piston 16 and by the pipe 48a and 48 with the reservoir 28.
  • the passage 67 can be closed by the delivery piston 13 in its movement towards the high.
  • the spacing of the top and bottom passages 66 and 67 as well as the height of the piston 13 are chosen so that one of the two passages is always clear regardless of the position of the delivery piston 13.
  • the orifices of the conduits 45 and 50 which connect the injection chamber 5 respectively to the metering chamber 14 and to the reservoir via the pipe 48a, are each offset downward relative to the orifices of the low and high passages 66 and 67. From in this way, the orifices of the conduits 45 and 50 are closed by the delivery piston 13 in its movement, either up or down, after the respective low and high passages 66 and 67. Thus in its downward movement, the delivery piston 13 firstly closes the orifice communicating with the pipe 66 of the bottom passage, then when it continues its downward movement, the orifice communicating with the pipe 45. In the same way, when the delivery piston 13 moves upwards, it first closes the orifice of the pipe 50 then the orifice of the high passage 67.
  • the second control chamber 59 of the slide valve distributor 51 is in communication with the low pressure of the fluid reservoir 28 by the pipes 65 and 67 which make it communicate with the pipes 48a and 48 and the tank 28.
  • the delivery piston 13 discovers the orifice of the high passage 67.
  • the high control pressure P prevailing in the first pilot chamber 58 causes a displacement of the dispenser drawer 51 connecting the chambers 56 and 57.
  • the high control pressure P c coming from the pipe 60 therefore prevails through the pipe 64 in the discharge chamber 9.
  • the needle 2 of the injector 1 is in the closed position.
  • Fig. 7 illustrates the pre-metering phase which is done as in the previous variant by a control action on the three-way solenoid valve 39.
  • the opening of the solenoid valve 39 allows the dispenser drawer 18 and the filling the metering chamber 14 at the booster pressure P, the differential piston 12 moving upwards.
  • the second control chamber 59 is subjected to the booster pressure P 9 which prevails in the metering chamber 14 via the bottom passage 66 and the pipe 65.
  • the quantity metered at the end of this step in the metering chamber 14 is proportional to the opening time of the solenoid valve 39.
  • Fig. 8 illustrates the injection phase.
  • the solenoid valve 39 returns to its initial position, which also causes the distributor valve 18 to return to the rest position, the high control pressure P is established in the control chamber 17.
  • the pressure P r which prevails in the metering chamber 14 gradually increases.
  • the distributor valve 51 is caused to move under the action of the higher pressure prevailing in the second control chamber 59.
  • This movement illustrated in FIG. 8 connects the chambers 55 and 56 of the spool valve 51.
  • the pressure prevailing in the discharge chamber 9 can therefore drop via the conduits 64 and 62 and the variable nozzle 63.
  • Fig. 9 illustrates the phase corresponding to the start of the end of the injection.
  • the piston 13 In its downward movement, the piston 13 first discovers the top passage 67. At the same time it closes the bottom passage 66. At this time the opening of the pipe 50 is still closed while the opening of the pipe 45 is discovered allowing the injection to continue.
  • the high control pressure P c prevailing in the first control chamber 58 therefore again becomes preponderant over the pressure prevailing in the second control chamber 59 which is connected by the pipes 48a and 48 to the reservoir 28.
  • the distributor drawer 51 therefore moves again to its rest position bringing the chambers 56 and 57 into communication and allowing the high control pressure P to re-enter the discharge chamber 9.

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  • 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)

Abstract

1. A fuel injection arrangement for an internal combustion engine comprising : an injection chamber (5) which is closed by a needle subjected to the force of a closure spring and the pressure in a discharge chamber (9) ; a control system (12) having two differential pistons which are fixed with respect to each other and comprising : - a delivery piston (13) delimiting a metering chamber (14) communicating with the injection chamber (5) and supplied with fuel at an intermediate feed pressure ; - a control piston (16) which is larger in section than the delivery piston (13), delimiting a control chamber (17) which can be subjected to a high control pressure by means of a three-way electrically operated valve system ; and - control means for discharging the discharge chamber (9) when the metered amount of fuel has been subjected to the injection pressure by the action of the high control pressure on the control piston (16) ; the dimensions of said discharge chamber (9) and the characteristics of the injector (1) being such that prior to injection the needle (2) remains in the closure position, when the injection chamber (5) is at the injection pressure obtaining in the metering chamber (14), the high control pressure being applied to the control piston (16) and the discharge chamber (9) being subjected to the control pressure ; the section (Sd ) of the discharge chamber (9) where the control pressure occurs and the closure spring (10) of the injector being such that the forces which result therefrom tending to hold the needle in the closure position are greater thant the force tending to open the needle and resulting from the action of the injection pressure in the metering chamber (14), the arrangement being characterised in that the control means for discharging the discharge chamber (9) comprise a sliding spool-type distributor (51) which is pilot-controlled by the high control pressure and by the pressure obtaining in the metering chamber (14) and that the spool of the distributor (51) is subjected on the one hand to the action of the high control pressure obtaining in a first pilot-control chamber (58) and on the other hand to the action of the pressure obtaining in a second pilot-control chamber (59), the second chamber communicating with a lower passage (66) opening into the metering chamber (14) and being capable of being closed by the delivery piston (13) and with an upper passage (67) communicating with the low pressure of the tank and being capable of being closed by the delivery piston (13), on of the said two passages being opened irrespective of the position of the delivery piston (13).

Description

La présente invention a pour objet un dispositif et un procédé d'injection de carburant pour moteur à combustion interne en particulier pour moteur Diesel, permettant à la fois un prédosage de la quantité de carburant injecté par cylindre et une amplification de la pression d'injection. La commande du dispositif d'injection peut se faire de manière aisée par des moyens électroniques.The subject of the present invention is a device and a method for injecting fuel for an internal combustion engine, in particular for a diesel engine, allowing both a predosing of the quantity of fuel injected per cylinder and an amplification of the injection pressure. . The injection device can be easily controlled by electronic means.

L'injection de carburant à pression constante en particulier dans les moteurs Diesel, nécessite la présence de carburant à haute pression autour de l'aiguille d'injection afin de permettre l'obtention d'une haute pression d'injection dès l'ouverture de l'aiguille. Cette haute pression autour de l'aiguille à la fermeture de l'injecteur entraîne un risque d'injections parasites dues à des phénomènes de rebond de l'aiguille de l'injecteur. Par ailleurs, dans les systèmes d'injection à pression constante, on rencontre des difficultés pour la mise au point d'un organe unique de commande de la pression d'asservissement de l'aiguille d'injection, qui soit suffisamment rapide pour assurer une bonne régularité dans les mouvements de l'aiguille de l'injecteur pour les faibles quantités de carburant injecté. Il est également nécessaire de prévoir, dans les systèmes d'injection à pression constante, un organe limiteur de débit afin d'éviter tout afflux de carburant dans la chambre de combustion en cas de défaillance de l'injecteur.The injection of fuel at constant pressure, in particular in diesel engines, requires the presence of fuel at high pressure around the injection needle in order to allow a high injection pressure to be obtained as soon as the the needle. This high pressure around the needle when the injector closes causes a risk of parasitic injections due to rebound phenomena of the injector needle. In addition, in constant pressure injection systems, difficulties are encountered in developing a single member for controlling the control pressure of the injection needle, which is fast enough to ensure good regularity in the movements of the injector needle for small amounts of fuel injected. It is also necessary to provide, in constant pressure injection systems, a flow limiting device in order to avoid any influx of fuel into the combustion chamber in the event of failure of the injector.

Lorsque le système d'injection comprend des moyens de prédosage avec amplification de pression au moyen d'un piston différentiel, on constate que la pression d'injection est fonction, pour les faibles charges, de la quantité injectée, en raison du temps de réponse des pistons de commande et de refoulement du carburant dans l'injecteur.When the injection system includes pre-metering means with pressure amplification by means of a differential piston, it can be seen that the injection pressure is a function, for low loads, of the quantity injected, due to the response time. fuel control and delivery pistons in the injector.

La présente invention a pour objet un dispositif et un procédé d'injection de carburant qui permette d'éliminer ces inconvénients et qui réunisse les avantages de l'injection à pression constante et de l'injection prédosée. C'est ainsi que dans le dispositif d'injection selon l'invention, le carburant à injecter se trouve soumis à la haute pression autour de l'aiguille de l'injecteur laquelle est pilotée par un piston qui peut être soumis à la haute pression d'un fluide de commande. Selon l'invention, on effectue en outre le prédosage de la quantité de carburant à injecter ce qui permet la détermination avec grande précision de cette quantité de carburant à basse pression. Enfin, le carburant prédosé est soumis à une augmentation de pression avec amplification de pression permettant d'obtenir une haute pression d'injection à partir d'une pression de commande moyenne.The subject of the present invention is a device and a method for injecting fuel which makes it possible to eliminate these drawbacks and which combines the advantages of injection at constant pressure and predosed injection. Thus, in the injection device according to the invention, the fuel to be injected is subjected to high pressure around the needle of the injector which is controlled by a piston which can be subjected to high pressure of a control fluid. According to the invention, the pre-metering of the quantity of fuel to be injected is also carried out, which allows this quantity of fuel at low pressure to be determined with great precision. Finally, the predosed fuel is subjected to a pressure increase with pressure amplification making it possible to obtain a high injection pressure from an average control pressure.

Le dispositif d'injection de carburant pour moteur à combustion interne selon l'invention comporte une chambre d'injection obturée par une aiguille d'injecteur. L'injecteur est soumis à l'action d'un ressort de fermeture et à l'action d'une pression de fluide hydraulique régnant dans une chambre dite chambre de décharge. Ces deux actions s'ajoutent afin de solliciter l'aiguille de l'injecteur en direction de sa position de fermeture en contact avec son siège. Selon l'invention, le dispositif d'injection comprend un système de commande à deux pistons différentiels solidaires l'un de l'autre. Un piston de refoulement délimite une chambre de dosage en communication avec la chambre d'injection de l'injecteur et alimentée en carburant à une pression intermédiaire ou pression de gavage. Par ailleurs, un piston de commande de section supérieure à celle du piston de refoulement, constituant la deuxième partie du système de piston différentiel, délimite une chambre de commande qui peut être soumise à une haute pression de commande par l'intermédiaire d'un système d'électrovanne à trois voies, cette haute pression étant supérieure à la pression intermédiaire de gavage précitée. Le dispositif -comprend en outre des moyens de commande afin de décharger, c'est-à-dire de placer à la pression zéro ou basse pression, la chambre de décharge dont la pression agit sur l'aiguille de l'injecteur, lorsque la quantité de carburant dosée se trouvant dans la chambre de dosage a été soumise à la pression d'injection par l'action de la haute pression de commande sur le piston de commande délimitant la chambre de commanderThe fuel injection device for an internal combustion engine according to the invention comprises an injection chamber closed by an injector needle. The injector is subjected to the action of a closing spring and to the action of a hydraulic fluid pressure prevailing in a chamber called the discharge chamber. These two actions are added in order to urge the injector needle towards its closed position in contact with its seat. According to the invention, the injection device comprises a control system with two differential pistons integral with one another. A delivery piston delimits a metering chamber in communication with the injection chamber of the injector and supplied with fuel at an intermediate pressure or booster pressure. Furthermore, a control piston with a cross section greater than that of the delivery piston, constituting the second part of the differential piston system, delimits a control chamber which can be subjected to a high control pressure by means of a system. three-way solenoid valve, this high pressure being greater than the aforementioned intermediate booster pressure. The device further comprises control means in order to discharge, that is to say to place at zero or low pressure, the discharge chamber whose pressure acts on the needle of the injector, when the quantity of metered fuel in the metering chamber has been subjected to pressure injection by the action of the high control pressure on the control piston delimiting the control chamber

La chambre de décharge dont la pression agit sur l'aiguille de l'injecteur est soumise avant la phase d'injection à l'action de la haute pression de la commande. Selon l'invention, les dimensions de la chambre de décharge ainsi que les caractéristiques de l'injecteur sont telles que l'aiguille reste sur son siège en position de fermeture lorsque la chambre d'injection se trouve à la pression d'injection régnant dans la chambre de dosage. Cette situation se présente lorsque la haute pression de commande s'exerce sur le piston de commande délimitant la chambre de commande.The discharge chamber, the pressure of which acts on the injector needle, is subjected before the injection phase to the action of the high pressure of the control. According to the invention, the dimensions of the discharge chamber as well as the characteristics of the injector are such that the needle remains in its seat in the closed position when the injection chamber is at the injection pressure prevailing in the dosing chamber. This situation arises when the high control pressure is exerted on the control piston delimiting the control chamber.

La chambre d'injection peut en outre être déchargée, c'est-à-dire reliée à la pression zéro d'un réservoir de fluide hydraulique, par l'intermédiaire d'un passage découvert par le déplacement du système de commande à piston différentiel et notamment dans la position correspondant à la fin de la phase d'injection.The injection chamber can also be discharged, that is to say connected to the zero pressure of a hydraulic fluid reservoir, via a passage discovered by the movement of the differential piston control system. and in particular in the position corresponding to the end of the injection phase.

Dans un premier mode de réalisation de l'invention, les moyens de commande permettant de mettre en communication la chambre de décharge avec le réservoir comprennent une électrovanne à trois voies. Une restriction réglable est avantageusement interposée entre la chambre de décharge et l'électrovanne à trois voies précitée.In a first embodiment of the invention, the control means making it possible to put the discharge chamber in communication with the reservoir comprise a three-way solenoid valve. An adjustable restriction is advantageously interposed between the discharge chamber and the aforementioned three-way solenoid valve.

Dans un autre mode de réalisation plus particulièrement adapté au cas où la quantité de carburant injectée est plus importante, les moyens de commande permettant de relier la chambre de décharge au réservoir comprennent un distributeur à tiroir piloté par la haute pression de commande et par la pression régnant dans la chambre de dosage.In another embodiment more particularly suited to the case where the quantity of fuel injected is greater, the control means making it possible to connect the discharge chamber to the tank comprise a spool valve controlled by the high control pressure and by the pressure prevailing in the dosing chamber.

D'une manière générale le procédé d'injection de carburant selon l'invention consiste à opérer successivement de la manière suivante. On maintient tout d'abord en position de fermeture l'aiguille de l'injecteur par action de la haute pression de commande. Pendant ce temps, on remplit de carburant une chambre de dosage à une pression intermédiaire inférieure à la haute pression de commande, et on soumet le carburant ainsi prédosé contenu dans la chambre de dosage à une amplification de pression jusqu'à la pression d'injection.In general, the fuel injection method according to the invention consists in operating successively in the following manner. Firstly, the injector needle is kept in the closed position by the action of the high control pressure. During this time, a metering chamber is filled with fuel at a lower intermediate pressure. higher than the high control pressure, and the fuel thus predosed contained in the metering chamber is subjected to a pressure increase up to the injection pressure.

On supprime alors l'action de la haute pression de commande sur l'aiguille de l'injecteur, ce qui permet le déplacement de l'aiguille en position d'ouverture et l'injection de la quantité de carburant prédosé à la pression d'injection.The action of the high control pressure on the injector needle is then eliminated, which allows the needle to move to the open position and the injection of the quantity of fuel predosed at the pressure of injection.

Enfin, on décharge la chambre d'injection de façon à faciliter le déplacement de l'aiguille jusqu'à sa position de fermeture.Finally, the injection chamber is discharged so as to facilitate movement of the needle to its closed position.

L'invention sera mieux comprise à l'étude de la description détaillée de deux modes de réalisation préférés faite à partir des dessins annexés, sur lesquels :

  • les fig. 1 à 5 illustrent différentes phases du fonctionnement d'un premier mode de réalisation de l'invention à partir d'un schéma hydraulique; et
  • les fig. 6 à 9 illustrent les mêmes phases de fonctionnement pour une variante représentée sous la forme d'un deuxième schéma hydraulique.
The invention will be better understood on studying the detailed description of two preferred embodiments made from the appended drawings, in which:
  • fig. 1 to 5 illustrate different phases of the operation of a first embodiment of the invention from a hydraulic diagram; and
  • fig. 6 to 9 illustrate the same operating phases for a variant shown in the form of a second hydraulic diagram.

Tel qu'il est illustré sur la fig. 1, le dispositif d'injection selon l'invention comprend un injecteur 1 muni d'une aiguille d'injection 2 capable d'entrer en contact avec son siège 3 afin d'obturer le passage vers les orifices d'injection 4. Une chambre d'injection 5 entoure l'aiguille d'injection 2 et permet l'alimentation du carburant à injecter. L'aiguille 2 de l'injecteur 1 est solidaire d'un poussoir 6 par l'intermédiaire d'une partie de plus grand diamètre 7. L'extrémité du poussoir 6 opposée à l'aiguille 2 agit sur un piston de pilotage 8 délimitant une chambre de décharge 9. Un ressort de compression 10 agit en outre par l'intermédiaire de l'épaulement 11 sur l'aiguille 2 dans le sens tendant à fermer le passage vers les orifices d'injection 4.As illustrated in fig. 1, the injection device according to the invention comprises an injector 1 provided with an injection needle 2 capable of coming into contact with its seat 3 in order to close the passage to the injection orifices 4. A chamber 5 surrounds the injection needle 2 and allows the supply of fuel to be injected. The needle 2 of the injector 1 is secured to a pusher 6 by means of a portion of larger diameter 7. The end of the pusher 6 opposite the needle 2 acts on a pilot piston 8 delimiting a discharge chamber 9. A compression spring 10 also acts by means of the shoulder 11 on the needle 2 in the direction tending to close the passage to the injection orifices 4.

Un système de commande 12 à deux pistons différentiels solidaires l'un de l'autre est monté sur le porte-injecteur non représenté sur la figure. Le système de commande 12 comprend un piston de refoulement 13 de section Sr délimitant une chambre de dosage 14. Le piston 13 est solidaire d'une tige 15 qui agit à la partie inférieure d'un piston de commande 16 de section Sc supérieure à la section Sr du piston de refoulement 13. Le piston de commande 16 délimite une chambre de commande 17. Un distributeur à tiroir 18 comporte un tiroir muni de deux portions 19 et 20 de plus grand diamètre reliées par une tige 21 qui se déplace dans un corps présentant trois chambres 22, 23 et 24 délimitées par des portées de l'alésage dudit corps. Par ailleurs, deux chambres d'extrémité 25 et 26 peuvent être soumises à une pression agissant sur l'une ou l'autre des extrémités du tiroir du distributeur 18. Un ressort de compression 27 est monté dans la chambre d'extrémité 25.A control system 12 with two differential pistons integral with one another is mounted on the injector holder not shown in the figure. The control system 12 comprises a delivery piston 13 of section S r delimiting a metering chamber 14. The piston 13 is integral with a rod 15 which acts at the lower part of a control piston 16 of section S c greater than the section S r of the delivery piston 13. The control piston 16 delimits a control chamber 17. A drawer distributor 18 includes a drawer provided two portions 19 and 20 of larger diameter connected by a rod 21 which moves in a body having three chambers 22, 23 and 24 delimited by bearing surfaces of the bore of said body. Furthermore, two end chambers 25 and 26 can be subjected to a pressure acting on one or the other of the ends of the distributor valve 18. A compression spring 27 is mounted in the end chamber 25.

Le carburant, par exemple du gas-oil dans le cas d'un moteur Diesel, se trouve à la pression atmosphérique dans le réservoir 28. 'Il est aspiré par une pompe basse pression 29 fournissant une pression maintenue constante par le régulateur 30 monté entre la sortie de la pompe 29 et le retour au réservoir 28. Une pompe haute pression 31 est gavée par la pompe basse pression 29 et met le carburant à la haute pression constante Pc qui peut atteindre 200 bars et qui est la pression de commande. La pression de commande est maintenue constante par deux dispositifs régulateurs placés en série 32 et 33 entre la sortie de la pompe haute pression 31 et le retour au réservoir 28. La pression constante apparaissant entre les deux régulateurs 32 et 33 est une pression intermédiaire Pg dite pression de gavage inférieure à la haute pression de commande P . Le carburant à la pression de gavage peut donc pénétrer par un ajutage d'amortissement 34 et un clapet anti- retour 35 monté dans la canalisation 36 jusque dans la partie basse de la chambre de dosage 14.The fuel, for example diesel in the case of a diesel engine, is at atmospheric pressure in the reservoir 28. 'It is drawn by a low pressure 29 providing a constant pressure maintained by the pump regulator 30 connected between the outlet of the pump 29 and the return to the reservoir 28. A high pressure pump 31 is boosted by the low pressure pump 29 and puts the fuel at the constant high pressure Pc which can reach 200 bars and which is the control pressure. The control pressure is kept constant by two regulating devices placed in series 32 and 33 between the outlet of the high pressure pump 31 and the return to the reservoir 28. The constant pressure appearing between the two regulators 32 and 33 is an intermediate pressure P g said booster pressure lower than the high control pressure P. The fuel at the booster pressure can therefore penetrate through a damping nozzle 34 and a non-return valve 35 mounted in the line 36 as far as the lower part of the metering chamber 14.

Le carburant à la haute-pression de commande P alimente par la canalisation 37 un accumulateur hydraulique 38, la chambre 22 du distributeur à tiroir 18 ainsi que la chambre d'extrémité 26 du même distributeur par l'intermédiaire d'une électrovanne à trois voies 39 montée dans la canalisation de dérivation 40. Le carburant à haute pression peut passer de la chambre 22 dans la chambre 23 selon la position du tiroir et alimenter par la canalisation 41, la chambre de commande 17 du système de commande 12 à piston différentiel.The fuel at the high-pressure control P feeds via the line 37 a hydraulic accumulator 38, the chamber 22 of the slide valve 18 as well as the end chamber 26 of the same valve by means of a three-way solenoid valve. 39 mounted in the bypass line 40. The high pressure fuel can pass from chamber 22 into chamber 23 depending on the position of the drawer and supply via line 41, the control chamber 17 of the control system 12 with differential piston.

Le carburant à la haute pression de commande P est également amené par la canalisation 42 à une deuxième électrovanne à trois voies 43 reliée par un ajutage réglable 44 à la chambre de décharge 9 de l'injecteur 1.The fuel at the high control pressure P is also supplied via the line 42 to a second three-way solenoid valve 43 connected by an adjustable nozzle 44 to the discharge chamber 9 of the injector 1.

La partie basse de la chambre de dosage 14 est reliée par la canalisation 45, 46 à la chambre d'injection 5.The lower part of the metering chamber 14 is connected by the pipe 45, 46 to the injection chamber 5.

La chambre d'extrémité 27 du distributeur 18 est reliée par la canalisation 47 à la canalisation 48 de retour au réservoir 28. Il en est de même de la chambre 24 du distributeur 18 par l'intermédiaire d'un gicleur d'amortissement 49. Le côté tige du piston de commande 16 est également relié par la canalisation 48a, 48 au réservoir 28. Il en est de même du côté tige du piston de pilotage 8 de l'injecteur 1 par la canalisation 8a ainsi que de la troisième voie des deux électrovannes à trois voies 39 et 43 par les canalisations 48 et 43a.The end chamber 27 of the distributor 18 is connected by the pipe 47 to the pipe 48 returning to the reservoir 28. The same is true of the chamber 24 of the distributor 18 by means of a damping nozzle 49. The rod side of the control piston 16 is also connected by the line 48a, 48 to the reservoir 28. The same is true of the rod side of the control piston 8 of the injector 1 by the line 8a as well as the third channel of the two three-way solenoid valves 39 and 43 via lines 48 and 43a.

L'alésage à l'intérieur duquel peut se déplacer le piston de refoulement 13 comporte dans sa partie basse une ouverture communiquant avec la canalisation 45 et dans sa partie haute une ouverture communiquant avec une canalisation 50. L'écartement de ces deux ouvertures est tel qu'en position de repos, le piston de refoulement 13 découvre l'ouverture de la canalisation 50 et obture l'ouverture de la canalisation 45. Les deux canalisations 45 et 50 sont connectées à la chambre d'injection 5. En position de repos, la canalisation 50 et de ce fait la chambre d'injection 5 se trouvent en communication avec le côté tige du piston de commande 16 c'est-à-dire avec la basse pression du réservoir de fluide 28 par l'intermédiaire de la canalisation de retour 48a, 48.The bore inside which the delivery piston 13 can move has in its lower part an opening communicating with the pipe 45 and in its upper part an opening communicating with a pipe 50. The spacing of these two openings is such that in the rest position, the delivery piston 13 discovers the opening of the pipe 50 and closes the opening of the pipe 45. The two pipes 45 and 50 are connected to the injection chamber 5. In the rest position , the line 50 and therefore the injection chamber 5 are in communication with the rod side of the control piston 16, that is to say with the low pressure of the fluid reservoir 28 via the line back 48a, 48.

La fig. 1 qui vient d'être décrite illustre la position des différents éléments du dispositif d'injection selon l'invention lors de la phase de repos. On va maintenant décrire les différentes phases du fonctionnement en se référant aux fig. 2 à 5.Fig. 1 which has just been described illustrates the position of the various elements of the injection device according to the invention during the rest phase. We will now describe the different phases of operation with reference to Figs. 2 to 5.

Sur toutes ces figures où les éléments identiques portent les mêmes références, le passage du carburant à travers' les deux électrovannes 39 et 43 est schématisé par les triangles noirs qui correspondent à la position d'ouverture faisant communiquer deux voies des électrovannes respectives.In all these figures where the identical elements bear the same references, the passage of fuel through the two solenoid valves 39 and 43 is shown diagrammatically by the black triangles which correspond to the open position making two paths of the respective solenoid valves communicate.

En position de repos telle que représentée sur la fig. 1, l'électrovanne à trois voies 39 laisse pénétrer le carburant à la haute pression de commande P dans la chambre inférieure 26 du distributeur 18 dont la face supérieure est en appui sur le ressort de compression 27. Celui-ci est choisi de telle sorte que la force développée par la haute pression de commande P dans la chambre inférieure 26 soit supérieure à celle du ressort. Le tiroir du distributeur 18 se trouve donc déplacé dans une position telle qu'il permette la communication entre les chambres 22 et 23 comme représenté sur la fig. 1. La chambre de commande 17 se trouve remplie de carburant à la haute pression de commande Pc par l'intermédiaire de la canalisation 41. La chambre de refoulement 14 présente un volume minimal, le piston de refoulement 13 la remplissant presque complétement compte tenu de la position basse du système de piston différentiel 12.In the rest position as shown in FIG. 1, the three-way solenoid valve 39 allows the fuel to penetrate at the high control pressure P into the lower chamber 26 of the distributor 18, the upper face of which bears on the compression spring 27. The latter is chosen so that that the force developed by the high control pressure P in the lower chamber 26 is greater than that of the spring. The dispenser drawer 18 is therefore moved in a position such that it allows communication between the chambers 22 and 23 as shown in FIG. 1. The control chamber 17 is filled with fuel at the high control pressure P c via the pipe 41. The discharge chamber 14 has a minimum volume, the discharge piston 13 filling it almost completely taking into account from the low position of the differential piston system 12.

Toujours dans cette position de repos, l'électrovanne à trois voies 43 est commandée de façon à soumettre la chambre de décharge 9 à la haute pression de commande Pc à travers l'ajutage 44 de façon que l'aiguille 2 de l'injecteur 1 soit maintenue en position fermée.Still in this rest position, the three-way solenoid valve 43 is controlled so as to subject the discharge chamber 9 to the high control pressure P c through the nozzle 44 so that the needle 2 of the injector 1 is kept in the closed position.

La fig. 2 illustre la phase de prédosage du carburant à injecter. L'électrovanne 39 est commandée de façon à mettre en communication la chambre 26 du distributeur 18 avec la canalisation 48 de retour au réservoir 28. Sous l'action du ressort 27, le tiroir du distributeur 18 se déplace donc de façon à mettre en communication les chambres 23 et 24 mettant également en communication par l'intermédiaire de l'ajutage 49 la chambre de commande 17 avec le réservoir 28 par l'intermédiaire des canalisations 41 et 48.Fig. 2 illustrates the predosing phase of the fuel to be injected. The solenoid valve 39 is controlled so as to put the chamber 26 of the distributor 18 into communication with the pipe 48 returning to the reservoir 28. Under the action of the spring 27, the distributor slide 18 therefore moves so as to put in communication the chambers 23 and 24 also communicating via the nozzle 49 the control chamber 17 with the reservoir 28 via the pipes 41 and 48.

La chambre de dosage 14 est soumise à la pression de gavage P . Lorsque la pression régnant dans la chambre de commande 17 atteint une valeur inférieure à Pg x Sr/Sc le système de piston différentiel 12 remonte sous l'effet-de la pression de gavage Pg dans la chambre 14. Du carburant pénètre donc dans la chambre de dosage 14 provenant de la canalisation 36. Lors de cette phase, les ajutages 49 et 34 permettent d'amortir le mouvement du système de piston différentiel 12 afin d'éviter toute oscillation.The metering chamber 14 is subjected to the booster pressure P. When the pressure in the control 17 reaches a value lower than P g x S r / S c the differential piston system 12 rises under the effect of the boost pressure P g in the chamber 14. Fuel therefore enters the metering chamber 14 from of the pipe 36. During this phase, the nozzles 49 and 34 make it possible to damp the movement of the differential piston system 12 in order to avoid any oscillation.

Dans cette phase, l'électrovanne à trois voies 43 reste dans la position initiale, la haute pression de commande P régnant donc dans la chambre de décharge 9 ce qui maintient l'aiguille 2 de l'injecteur 1 en position fermée.In this phase, the three-way solenoid valve 43 remains in the initial position, the high control pressure P therefore prevailing in the discharge chamber 9 which keeps the needle 2 of the injector 1 in the closed position.

La fig. 3 illustre la phase d'accumulation. Lorsque la quantité de combustible correspondant à celle que l'on désire injecter a pénétré dans la chambre de dosage 14, la tension d'alimentation électrique de l'électrovanne 39 est coupée comme illustré sur la fig. 3. La haute pression de commande P pénètre à nouveau dans la chambre d'extrémité 26 du distributeur 18 qui se déplace de façon à mettre en communication les chambres 22 et 23 soumettant à nouveau la chambre de commande 17 à la haute pression de commande P par l'intermédiaire de la canalisation 41. La quantité de combustible prédosée se trouvant dans la chambre de dosage 14 est donc mise à une pression d'injection amplifiée égale à la pression Pr = P c x Sc/Sr. Le carburant ne peut s'écouler en direction de l'injecteur 1 étant donné que la haute pression de commande Pc règne toujours dans la chambre de décharge 9, l'électrovanne 43 restant dans la position initiale. Le carburant se trouvant dans l'accumulateur 38 permet de faciliter le remplissage de la chambre de commande 17 malgré un débit instantané important.Fig. 3 illustrates the accumulation phase. When the quantity of fuel corresponding to that which it is desired to inject has entered the metering chamber 14, the electrical supply voltage of the solenoid valve 39 is cut off as illustrated in FIG. 3. The high control pressure P again enters the end chamber 26 of the distributor 18 which moves so as to put the chambers 22 and 23 into communication again subjecting the control chamber 17 to the high control pressure P via the line 41. The quantity of pre-dosed fuel found in the metering chamber 14 is therefore brought to an amplified injection pressure equal to the pressure P r = P c x S c / S r . The fuel cannot flow towards the injector 1 since the high control pressure P c still prevails in the discharge chamber 9, the solenoid valve 43 remaining in the initial position. The fuel in the accumulator 38 facilitates the filling of the control chamber 17 despite a large instantaneous flow.

On choisit les dimensions de la chambre de décharge 9 de sorte que sa section Sd ainsi que la structure de l'injecteur et notamment la force du ressort 10 soient telles que l'aiguille 2 reste en position de fermeture même lorsque la chambre d'injection 5 se trouve soumise à la pression d'injection qui règne alors dans la chambre de dosage 14. Il suffit en effet que l'on ait l'inégalité suivante :

Figure imgb0001
où F est la force développée par le ressort 10, Sa est la section de la portion 7 et Ss est la section de la portion de l'aiguille 2 en contact avec son siège 3.The dimensions of the discharge chamber 9 are chosen so that its section S d as well as the structure of the injector and in particular the force of the spring 10 are such that the needle 2 remains in the closed position even when the chamber injection 5 is subjected to the injection pressure which then prevails in the metering chamber 14. It suffices indeed that one has the following inequality:
Figure imgb0001
 where F is the force developed by the spring 10, Sa is the section of the portion 7 and S s is the section of the portion of the needle 2 in contact with its seat 3.

La fig. 4 illustre la phase d'injection. L'électrovanne 39 reste dans la position illustrée sur la fig. 3. Suivant le calage nécessité par le fonctionnement du moteur thermique, on met sous tension à un instant précis l'électrovanne 43 de façon à la commander pour mettre en communication la chambre de décharge 9 par l'intermédiaire de l'ajutage réglable 44 avec le réservoir 28 par l'intermédiaire de la canalisation 43a. Lorsque la pression Pd régnant dans la chambre de décharge 9 chute de sa valeur initiale égale à la haute pression de commande P jusqu'à une valeur telle que l'on ait la relation suivante :

Figure imgb0002
l'aiguille 2 de l'injecteur 1 se soulève et l'injection commence à une pression d'injection Pi qui est égale à la pression Pr régnant dans la chambre de dosage 14. Sous l'effet de la haute pression de commande Pc agissant sur le piston de commande 16, le piston de refoulement 13 refoule la quantité de carburant prédosée se trouvant dans la chambre de dosage 14 vers la chambre d'injection 5 par les canalisations 45 et 46.Fig. 4 illustrates the injection phase. The solenoid valve 39 remains in the position illustrated in FIG. 3. Depending on the timing required by the operation of the heat engine, the solenoid valve 43 is energized at a precise instant so as to control it in order to put the discharge chamber 9 in communication via the adjustable nozzle 44 with the reservoir 28 via the pipe 43a. When the pressure P d prevailing in the discharge chamber 9 drops from its initial value equal to the high control pressure P to a value such that there is the following relationship:
Figure imgb0002
 the needle 2 of the injector 1 lifts and the injection begins at an injection pressure P i which is equal to the pressure P r prevailing in the metering chamber 14. Under the effect of the high control pressure P c acting on the control piston 16, the delivery piston 13 delivers the quantity of pre-dosed fuel located in the metering chamber 14 to the injection chamber 5 via the pipes 45 and 46.

L'ajutage variable 44 permet de régler la vitesse de la chute de pression dans la chambre de décharge 9 et donc de régler la rapidité du mouvement de levée de l'aiguille 2 de l'injecteur. Une action sur la restriction formée par l'ajutage 44 permet donc de modifier aisément la loi d'injection.The variable nozzle 44 makes it possible to adjust the speed of the pressure drop in the discharge chamber 9 and therefore to adjust the speed of the lifting movement of the needle 2 of the injector. An action on the restriction formed by the nozzle 44 therefore allows the injection law to be easily modified.

La fig. 5 illustre la phase correspondant à la fin de l'injection. Les deux électrovannes 39 et 43 restent initialement dans les positions illustrées sur la fig. 4. Lorsque la quantité de carburant prédosée se trouvant dans la chambre de dosage 14 a été complétement refoulée, la face inférieure du piston de refoulement 13 vient obturer l'ouverture de la canalisation 45 reliant la chambre de dosage 14 par l'intermédiaire de la canalisation 46 à la chambre d'injection 5. Les dimensions du piston de refoulement 13 ainsi que l'écartement des ouvertures communiquant avec les canalisations 45 et 50 sont telles qu'en même temps la face supérieure du piston de refoulement 13 découvre l'orifice de la canalisation 50 permettant ainsi à la pression qui règne dans la chambre d'injection 5 de se décharger par les canalisations 46, 50, 48a et 48 en revenant au réservoir 28. L'aiguille 2 de l'injecteur 1 se ferme alors sous l'effet du ressort de tarage 10.Fig. 5 illustrates the phase corresponding to the end of the injection. The two solenoid valves 39 and 43 initially remain in the positions illustrated in FIG. 4. When the quantity of predosed fuel in the metering chamber 14 has been completely discharged, the underside of the discharge piston 13 closes the opening of the line 45 connecting the metering chamber 14 via the line 46 to the injection chamber 5. The dimensions of the delivery piston 13 as well as the spacing openings communicating with the pipes 45 and 50 are such that at the same time the upper face of the delivery piston 13 uncovers the orifice of the pipe 50 thus allowing the pressure prevailing in the injection chamber 5 to be discharged by the pipes 46, 50, 48a and 48 returning to the reservoir 28. The needle 2 of the injector 1 then closes under the effect of the calibration spring 10.

On coupe alors l'alimentation électrique de l'électrovanne à trois voies 43 qui se remet dans la position illustrée sur la fig. 1 permettant à la haute pression P de recharger la chambre de décharge 9. Les différents éléments du dispositif se remettent dans la position illustrée sur la fig. 1.The electrical supply to the three-way solenoid valve 43 is then cut off, which returns to the position illustrated in FIG. 1 allowing the high pressure P to recharge the discharge chamber 9. The various elements of the device return to the position illustrated in FIG. 1.

La variante qui vient d'être décrite est plus particulièrement adaptée à une application qui nécessite l'injection d'une quantité minimale de carburant d'environ 6 mm3 par coup ce qui est le cas par exemple pour des moteurs destinés à des véhicules légers. Dans le cas où il est nécessaire d'injecter au ralenti une quantité plus importante de carburant (par exemple environ 15 à 20 mm3 par coup) c'est-à-dire pour des moteurs de véhicules industriels, on préfère remplacer comme illustré sur la fig. 6 l'électrovanne à trois voies 43 du mode de réalisation précédent par un distributeur à tiroir 51 piloté par la haute pression de commande P et par la pression de refoulement P régnant dans la chambre de dosage 14.The variant which has just been described is more particularly suited to an application which requires the injection of a minimum quantity of fuel of approximately 6 mm 3 per stroke, which is the case for example for engines intended for light vehicles. In the case where it is necessary to inject a larger quantity of fuel at idle (for example approximately 15 to 20 mm 3 per stroke), that is to say for engines of industrial vehicles, it is preferable to replace as illustrated in the fig. 6 the three-way solenoid valve 43 of the previous embodiment by a slide valve distributor 51 controlled by the high control pressure P and by the discharge pressure P prevailing in the metering chamber 14.

Dans cette variante où les éléments identiques portent les mêmes références, le tiroir du distributeur 51 comporte deux portions de plus grand diamètre 52 et 53 reliées entre elles par une tige 54 et se déplace dans un alésage comportant trois chambres 55, 56 et 57 délimitées par des portées ainsi que deux chambres de pilotage 58 et 59 pour le déplacement du tiroir. La première chambre de pilotage 58 est reliée à la haute pression de commande par la canalisation 61 qui est elle-même connectée à la canalisation 42. La canalisation 60 permet en outre de véhiculer le carburant à la haute pression de commande P c jusque dans la chambre 57.In this variant where the identical elements have the same references, the dispenser drawer 51 has two larger diameter portions 52 and 53 connected together by a rod 54 and moves in a bore comprising three chambers 55, 56 and 57 delimited by ranges and two pilot chambers 58 and 59 for moving the drawer. The first control chamber 58 is connected to the high control pressure by the line 61 which is itself connected to the line 42. The line 60 also makes it possible to convey the fuel at the high control pressure P c as far as the room 57.

La chambre 55 est reliée au réservoir 28 par l'intermédiaire de la canalisation 62 qui renferme un gicleur d'amortissement à restriction variable 63. La canalisation 64 relie la chambre 56 à la chambre de décharge 9 de l'injecteur 1.'The chamber 55 is connected to the reservoir 28 via the pipe 62 which contains a damping nozzle Variable Restriction 63. The pipe 64 connects the chamber 56 to the discharge chamber 9 of the injector 1. '

La deuxième chambre de pilotage 59 communique par la canalisation 65 avec un passage bas 66 débouchant dans la chambre de dosage 14 et pouvant être obturé par le piston de refoulement 13 lors de son mouvement vers le bas. La canalisation 65 communique également avec un passage haut 67 qui communique avec le côté tige du piston de commande 16 et par la canalisation 48a et 48 avec le réservoir 28. Le passage 67 peut être obturé par le piston de refoulement 13 dans son mouvement vers le haut. L'écartement des passages haut et bas 66 et 67 ainsi que la hauteur du piston 13 sont choisis de sorte que l'un des deux passages soit toujours dégagé quelle que soit la position du piston de refoulement 13. Par ailleurs, les orifices des conduits 45 et 50 qui relient la chambre d'injection 5 respectivement à la chambre de dosage 14 et au réservoir par l'intermédiaire de la canalisation 48a, sont chacun décalés vers le bas par rapport aux orifices des passages bas et haut 66 et 67. De cette manière, les orifices des conduits 45 et 50 sont obturés par le piston de refoulement 13 dans son mouvement soit le haut, soit vers le bas, après les passages bas et haut 66 et 67 respectifs. C'est ainsi que dans son mouvement vers le bas, le piston de refoulement 13 obture tout d'abord l'orifice communiquant avec la canalisation 66 du passage bas, puis lorsqu'il poursuit son mouvement vers le bas, l'orifice communiquant avec la canalisation 45. De la même manière, lorsque le piston de refoulement 13 se déplace vers le haut, il obture tout d'abord l'orifice de la canalisation 50 puis l'orifice du passage haut 67.The second control chamber 59 communicates via the pipe 65 with a low passage 66 opening into the metering chamber 14 and being able to be closed by the delivery piston 13 during its downward movement. The pipe 65 also communicates with a high passage 67 which communicates with the rod side of the control piston 16 and by the pipe 48a and 48 with the reservoir 28. The passage 67 can be closed by the delivery piston 13 in its movement towards the high. The spacing of the top and bottom passages 66 and 67 as well as the height of the piston 13 are chosen so that one of the two passages is always clear regardless of the position of the delivery piston 13. Furthermore, the orifices of the conduits 45 and 50 which connect the injection chamber 5 respectively to the metering chamber 14 and to the reservoir via the pipe 48a, are each offset downward relative to the orifices of the low and high passages 66 and 67. From in this way, the orifices of the conduits 45 and 50 are closed by the delivery piston 13 in its movement, either up or down, after the respective low and high passages 66 and 67. Thus in its downward movement, the delivery piston 13 firstly closes the orifice communicating with the pipe 66 of the bottom passage, then when it continues its downward movement, the orifice communicating with the pipe 45. In the same way, when the delivery piston 13 moves upwards, it first closes the orifice of the pipe 50 then the orifice of the high passage 67.

Dans la position de repos représentée sur la fig. 6, la deuxième chambre de pilotage 59 du distributeur à tiroir 51 se trouve en communication avec la basse pression du réservoir de fluide 28 par les canalisations 65 et 67 qui la font communiquer avec les canalisations 48a et 48 et le réservoir 28. Dans cette position en effet, le piston de refoulement 13 découvre l'orifice du passage haut 67. La haute pression de commande P régnant dans la première chambre de pilotage 58 entraîne un déplacement du tiroir du distributeur 51 mettant en communication les chambres 56 et 57. La haute pression de commande Pc provenant de la canalisation 60 règne donc par la canalisation 64 dans la chambre de décharge 9. Il en résulte que l'aiguille 2 de l'injecteur 1 est en position fermée.In the rest position shown in FIG. 6, the second control chamber 59 of the slide valve distributor 51 is in communication with the low pressure of the fluid reservoir 28 by the pipes 65 and 67 which make it communicate with the pipes 48a and 48 and the tank 28. In this position indeed, the delivery piston 13 discovers the orifice of the high passage 67. The high control pressure P prevailing in the first pilot chamber 58 causes a displacement of the dispenser drawer 51 connecting the chambers 56 and 57. The high control pressure P c coming from the pipe 60 therefore prevails through the pipe 64 in the discharge chamber 9. As a result, the needle 2 of the injector 1 is in the closed position.

La fig. 7 illustre la phase de prédosage qui se fait comme dans la variante précédente par une action de commande sur l'électrovanne à trois voies 39. Comme-précédemment, l'ouverture de l'électrovanne 39 permet le déplacement du tiroir du distributeur 18 et le remplissage de la chambre de dosage 14 à la pression de gavage P , le piston différentiel 12 se déplaçant vers le haut. Pendant cette phase, on notera que la deuxième chambre de pilotage 59 se trouve soumise à la pression de gavage P9 qui règne dans la chambre de dosage 14 par l'intermédiaire du passage bas 66 et de la canalisation 65. Comme précédemment, la quantité dosée se trouvant à la fin de cette étape dans la chambre de dosage 14 est proportionnelle au temps d'ouverture de l'électrovanne 39.Fig. 7 illustrates the pre-metering phase which is done as in the previous variant by a control action on the three-way solenoid valve 39. As above, the opening of the solenoid valve 39 allows the dispenser drawer 18 and the filling the metering chamber 14 at the booster pressure P, the differential piston 12 moving upwards. During this phase, it will be noted that the second control chamber 59 is subjected to the booster pressure P 9 which prevails in the metering chamber 14 via the bottom passage 66 and the pipe 65. As before, the quantity metered at the end of this step in the metering chamber 14 is proportional to the opening time of the solenoid valve 39.

La fig. 8 illustre la phase d'injection. Dès que l'électrovanne 39 revient dans sa position initiale ce qui entraîne également le retour en position de repos du tiroir du distributeur 18, la haute pression de commande P s'établit dans la chambre de commande 17. La pression Pr qui règne dans la chambre de dosage 14 croît progressivement. Dès que cette pression devient supérieure à la haute pression de commande P , le tiroir du distributeur 51 est amené à se déplacer sous l'action de la pression supérieure régnant dans la deuxième chambre de pilotage 59. Ce mouvement illustré sur la fig. 8 met en communication les chambres 55 et 56 du distributeur à tiroir 51. La pression régnant dans la chambre de décharge 9 peut donc chuter par l'intermédiaire des canalisations 64 et 62 et l'ajutage variable 63.Fig. 8 illustrates the injection phase. As soon as the solenoid valve 39 returns to its initial position, which also causes the distributor valve 18 to return to the rest position, the high control pressure P is established in the control chamber 17. The pressure P r which prevails in the metering chamber 14 gradually increases. As soon as this pressure becomes greater than the high control pressure P, the distributor valve 51 is caused to move under the action of the higher pressure prevailing in the second control chamber 59. This movement illustrated in FIG. 8 connects the chambers 55 and 56 of the spool valve 51. The pressure prevailing in the discharge chamber 9 can therefore drop via the conduits 64 and 62 and the variable nozzle 63.

Compte tenu des temps de retard des différents tiroirs mobiles du distributeur 51 et du distributeur 18, la pression d'injection Pi = P x Sc/Sr se trouve établie avant l'ouverture de l'aiguille 2 de l'injecteur qui se déplace comme précédemment sous l'action de cette pression régnant dans la chambre d'injection 5.Given the delay times of the various movable drawers of the distributor 51 and of the distributor 18, the injection pressure P i = P x S c / S r is established before the opening of the needle 2 of the injector which moves as before under the action of this pressure prevailing in the injection chamber 5.

La fig. 9 illustre la phase correspondant au début de la fin de l'injection. Dans son mouvement vers le bas, le piston 13 découvre tout d'abord le passage haut 67. En même temps il obture le passage bas 66. A ce moment l'ouverture de la canalisation 50 est encore obturée tandis que l'ouverture de la canalisation 45 est découverte permettant la poursuite de l'injection. La haute pression de commande Pc régnant dans la première chambre de pilotage 58 devient donc à nouveau prépondérante sur la pression régnant dans la deuxième chambre de pilotage 59 qui se trouve reliée par les canalisations 48a et 48 au réservoir 28. Le tiroir du distributeur 51 se déplace donc à nouveau vers sa position de repos mettant en communication les chambres 56 et 57 et permettant à la haute pression de commande P de pénétrer à nouveau dans la chambre de décharge 9. Il en résulte un effort complémentaire à la fermeture de l'aiguille 2 de l'injecteur, effort qui est favorable à une fin d'injection très nette. Lors de la poursuite de son mouvement vers le bas le piston 13 découvre ensuite l'ouverture de la canalisation 50 permettant la décharge de la chambre d'injection 5 et le déplacement de l'aiguille 2 vers sa position de fermeture.Fig. 9 illustrates the phase corresponding to the start of the end of the injection. In its downward movement, the piston 13 first discovers the top passage 67. At the same time it closes the bottom passage 66. At this time the opening of the pipe 50 is still closed while the opening of the pipe 45 is discovered allowing the injection to continue. The high control pressure P c prevailing in the first control chamber 58 therefore again becomes preponderant over the pressure prevailing in the second control chamber 59 which is connected by the pipes 48a and 48 to the reservoir 28. The distributor drawer 51 therefore moves again to its rest position bringing the chambers 56 and 57 into communication and allowing the high control pressure P to re-enter the discharge chamber 9. This results in a force complementary to the closing of the needle 2 of the injector, effort which is favorable to a very clear end of injection. During the continuation of its downward movement the piston 13 then discovers the opening of the pipe 50 allowing the discharge of the injection chamber 5 and the movement of the needle 2 towards its closed position.

Claims (8)

1. Dispositif d'injection de carburant pour moteur à combustion interne comprenant : une chambre d'injection (5) obturée par une aiguille soumise à l'action d'un ressort de fermeture et de la pression régnant dans une chambre de décharge (9); un système de commande à deux pistons différentiels solidaires (12) comprenant: - un piston de refoulement (13) délimitant une chambre de dosage (14) en communication avec la chambre d'injection (5) et alimenté en carburant à une pression intermédiaire de gavage; - un piston de commande (16) de section supérieure à celle du piston de refoulement (13) délimitant une chambre de commande (17) pouvant être soumise à une haute pression de- commande par l'intermédiaire d'un système d'électrovanne à trois voies; et des moyens de commande pour décharger la chambre de décharge (9) lorsque la quantité de carburant dosée a été soumise à la pression d'injection par l'action de la haute pression de commande sur le piston de commande (16); dispositif caractérisé par le fait que les dimensions de ladite chambre de décharge (9) ainsi que les caractéristiques de l'injecteur (1) sont telles qu'avant l'injection, l'aiguille (2) reste en position de fermeture, lorsque la chambre d'injection (5) est à la pression d'injection régnant dans la chambre de dosage (14), la haute pression de commande s'exerçant sur le piston de commande (16) et la chambre de décharge (9) étant soumise à la pression de commande. 1. Fuel injection device for internal combustion engine comprising: an injection chamber (5) closed by a needle subjected to the action of a closing spring and the pressure prevailing in a discharge chamber (9 ); a control system with two integral differential pistons (12) comprising: - a delivery piston (13) delimiting a metering chamber (14) in communication with the injection chamber (5) and supplied with fuel at an intermediate booster pressure; - a control piston (16) of cross section greater than that of the delivery piston (13) delimiting a control chamber (17) which can be subjected to a high control pressure by means of a solenoid valve system three ways; and control means for discharging the discharge chamber (9) when the quantity of metered fuel has been subjected to the injection pressure by the action of the high control pressure on the control piston (16); device characterized in that the dimensions of said discharge chamber (9) as well as the characteristics of the injector (1) are such that before injection, the needle (2) remains in the closed position, when the injection chamber (5) is at the injection pressure prevailing in the metering chamber (14), the high control pressure acting on the control piston (16) and the discharge chamber (9) being subjected at the control pressure. 2. Dispositif d'injection selon la revendication 1, caractérisé par le fait que la section (Sd) de la chambre de décharge (9) où s'exerce la pression de commande et le ressort de fermeture (10) de l'injecteur sont telles que les forces qui en résultent tendant à maintenir l'aiguille en position de fermeture soient supérieures à la force tendant à ouvrir l'aiguille et résultant de l'action de la pression d'injection dans la chambre de dosage (14).2. Injection device according to claim 1, characterized in that the section (S d ) of the discharge chamber (9) where the control pressure is exerted and the closing spring (10) of the injector are such that the resulting forces tending to hold the needle in the closed position are greater than the force tending to open the needle and resulting from the action of the injection pressure in the metering chamber (14). 3. Dispositif d'injection selon les revendications 1 ou 2, caractérisé par le fait que les moyens de commande pour décharger la chambre de décharge (9) comprennent un distributeur à tiroir (51) piloté par la haute pression de commande et par la pression régnant dans la chambre de dosage (14).3. Injection device according to claims 1 or 2, characterized in that the control means for discharging the discharge chamber (9) comprise a slide valve (51) controlled by the high control pressure and by the pressure prevailing in the metering chamber (14). 4. Dispositif d'injection selon la revendication 3, caractérisé par le fait que le tiroir du distributeur (51) est soumis d'une part à l'action de la haute pression de commande régnant dans une première chambre de pilotage (58) et d'autre part à l'action de la pression régnant dans une deuxième chambre de pilotage (59), la deuxième chambre communiquant avec un passage bas (66) débouchant dans la chambre de dosage (14) et pouvant être obturé par le piston de refoulement (13) et avec un passage haut (67) communiquant avec le réservoir et pouvant être obturé par le piston de refoulement (13), l'un des deux passages précités étant dégagé quelle que soit la position du piston de refoulement (13).4. Injection device according to claim 3, characterized in that the distributor slide (51) is subjected on the one hand to the action of the high control pressure prevailing in a first control chamber (58) and on the other hand to the action of the pressure prevailing in a second control chamber (59), the second chamber communicating with a low passage (66) opening into the metering chamber (14) and being able to be closed by the piston of discharge (13) and with a high passage (67) communicating with the reservoir and capable of being closed by the discharge piston (13), one of the two aforementioned passages being clear regardless of the position of the discharge piston (13) . 5. Dispositif d'injection selon la revendication 4, caractérisé par le fait que les orifices des conduits (45, 50) reliant la chambre d'injection respectivement à la chambre de dosage (14) et à la décharge (28) sont obturés par le piston de refoulement (13) respectivement après les passages haut et bas précités (67, 66).5. Injection device according to claim 4, characterized in that the orifices of the conduits (45, 50) connecting the injection chamber respectively to the metering chamber (14) and to the discharge (28) are closed by the delivery piston (13) respectively after the above and bottom passages above (67, 66). 6. Dispositif d'injection selon l'une quelconque des revendications précédentes, caractérisé par le fait que la chambre d'injection (5) peut être déchargée par l'intermédiaire d'un passage (50) découvert par le système de commande (12) à deux pistons différentiels dans la position correspondant à la fin de l'injection.6. Injection device according to any one of the preceding claims, characterized in that the injection chamber (5) can be discharged via a passage (50) uncovered by the control system (12 ) with two differential pistons in the position corresponding to the end of injection. 7. Dispositif selon l'une quelconque des revendications précédentes, caractérisé par le fait que les moyens de commande pour décharger la chambre de décharge (9) comprennent une électrovanne à trois voies (43) et une restriction réglable (44) interposée entre la chambre de décharge (9) et l'électrovanne à trois voies (43).7. Device according to any one of the preceding claims, characterized in that the control means for discharging the discharge chamber (9) comprise a three-way solenoid valve (43) and an adjustable restriction (44) interposed between the chamber relief valve (9) and the three-way solenoid valve (43). 8. Procédé d'injection de carburant pour moteur à combustion interne avec prédosage, accumulation et amplification de pression, caractérisé par le fait qu'il comprend les étapes suivantes : - on maintient fermée l'aiguille (2) d'un injecteur (1) se trouvant dans une chambre d'injection (5) par action d'une haute pression de commande, pendant que l'on remplit de carburant une chambre de dosage (14) à une pression intermédiaire puis que l'on soumet progressivement le carburant ainsi prédosé contenu dans la chambre de dosage (14) à une amplification de pression jusqu'à la pression d'injection; - on supprime l'action de la haute pression de commande sur l'aiguille (2) de l'injecteur, ce qui permet le déplacement de l'aiguille (2) en position d'ouverture et l'injection de la quantité de carburant prédosée à la pression d'injection; - et on décharge la chambre d'injection (5) de façon à faciliter le déplacement de l'aiguille (2) en position de fermeture. 8. Fuel injection method for internal combustion engine with pre-metering, accumulation and amplification of pressure, characterized in that it comprises the following stages: - the needle (2) of an injector (1) located in an injection chamber (5) is kept closed by the action of a high control pressure, while a metering chamber is filled with fuel (14) at an intermediate pressure then the fuel thus predosed contained in the metering chamber (14) is gradually subjected to a pressure boost up to the injection pressure; - the action of the high control pressure on the needle (2) of the injector is eliminated, which allows the movement of the needle (2) in the open position and the injection of the quantity of fuel predosed at the injection pressure; - And the injection chamber (5) is discharged so as to facilitate the movement of the needle (2) in the closed position.
EP81401902A 1981-01-15 1981-12-01 Device for fuel injection for an internal-combustion engine Expired EP0056916B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81401902T ATE21729T1 (en) 1981-01-15 1981-12-01 DEVICE FOR INJECTING FUEL INTO AN INTERNAL COMBUSTION ENGINE.

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Application Number Priority Date Filing Date Title
FR8100679 1981-01-15
FR8100679A FR2497876B1 (en) 1981-01-15 1981-01-15 FUEL INJECTION DEVICE AND METHOD FOR AN INTERNAL COMBUSTION ENGINE

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EP0056916A1 true EP0056916A1 (en) 1982-08-04
EP0056916B1 EP0056916B1 (en) 1986-08-27

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AT (1) ATE21729T1 (en)
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0119894B1 (en) * 1983-02-21 1987-06-16 Regie Nationale Des Usines Renault Electromagnetically driven pressure time-dependent injection system for diesel engines, the valve needle being driven by discharging and charging a capacity
WO2000055496A1 (en) * 1999-03-12 2000-09-21 Robert Bosch Gmbh Fuel injection system
US6675773B1 (en) * 1999-08-20 2004-01-13 Robert Bosch Gmbh Method and apparatus for performing a fuel injection

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6575137B2 (en) 1994-07-29 2003-06-10 Caterpillar Inc Piston and barrel assembly with stepped top and hydraulically-actuated fuel injector utilizing same

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2140018A1 (en) * 1971-05-28 1973-01-12 Bosch
FR2140063A1 (en) * 1971-05-28 1973-01-12 Bosch
US3983855A (en) * 1973-07-12 1976-10-05 C.A.V. Limited Fuel injection system
DE2558789A1 (en) * 1975-12-24 1977-07-14 Bosch Gmbh Robert HIGH PRESSURE FUEL INJECTION DEVICE FOR DIESEL ENGINES
DE2809762A1 (en) * 1977-03-07 1978-10-05 Nippon Denso Co FUEL INJECTION SYSTEM FOR A COMBUSTION ENGINE
DE2759187A1 (en) * 1977-12-31 1979-07-12 Bosch Gmbh Robert FUEL INJECTION SYSTEM WITH AT LEAST ONE FUEL INJECTION VALVE, ESPECIALLY FOR LARGE ENGINES

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3000960A1 (en) * 1980-01-12 1981-09-10 Robert Bosch Gmbh, 7000 Stuttgart FUEL INJECTION DEVICE FOR INTERNAL COMBUSTION ENGINES, ESPECIALLY FOR DIESEL ENGINES

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2140018A1 (en) * 1971-05-28 1973-01-12 Bosch
FR2140063A1 (en) * 1971-05-28 1973-01-12 Bosch
US3983855A (en) * 1973-07-12 1976-10-05 C.A.V. Limited Fuel injection system
DE2558789A1 (en) * 1975-12-24 1977-07-14 Bosch Gmbh Robert HIGH PRESSURE FUEL INJECTION DEVICE FOR DIESEL ENGINES
DE2809762A1 (en) * 1977-03-07 1978-10-05 Nippon Denso Co FUEL INJECTION SYSTEM FOR A COMBUSTION ENGINE
DE2759187A1 (en) * 1977-12-31 1979-07-12 Bosch Gmbh Robert FUEL INJECTION SYSTEM WITH AT LEAST ONE FUEL INJECTION VALVE, ESPECIALLY FOR LARGE ENGINES

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0119894B1 (en) * 1983-02-21 1987-06-16 Regie Nationale Des Usines Renault Electromagnetically driven pressure time-dependent injection system for diesel engines, the valve needle being driven by discharging and charging a capacity
WO2000055496A1 (en) * 1999-03-12 2000-09-21 Robert Bosch Gmbh Fuel injection system
US6453875B1 (en) * 1999-03-12 2002-09-24 Robert Bosch Gmbh Fuel injection system which uses a pressure step-up unit
KR100676642B1 (en) * 1999-03-12 2007-02-01 로베르트 보쉬 게엠베하 Fuel injection system
US6675773B1 (en) * 1999-08-20 2004-01-13 Robert Bosch Gmbh Method and apparatus for performing a fuel injection

Also Published As

Publication number Publication date
FR2497876A1 (en) 1982-07-16
DE3175234D1 (en) 1986-10-02
ATE21729T1 (en) 1986-09-15
EP0056916B1 (en) 1986-08-27
FR2497876B1 (en) 1986-02-07

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