EP0962649A1 - Dispositif d'injection de combustible - Google Patents

Dispositif d'injection de combustible Download PDF

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Publication number
EP0962649A1
EP0962649A1 EP98110177A EP98110177A EP0962649A1 EP 0962649 A1 EP0962649 A1 EP 0962649A1 EP 98110177 A EP98110177 A EP 98110177A EP 98110177 A EP98110177 A EP 98110177A EP 0962649 A1 EP0962649 A1 EP 0962649A1
Authority
EP
European Patent Office
Prior art keywords
piston
fuel
pressure
metering
storage
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP98110177A
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German (de)
English (en)
Inventor
Wolfgang Dr. Heimberg
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.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to EP98110177A priority Critical patent/EP0962649A1/fr
Priority to AU45067/99A priority patent/AU4506799A/en
Priority to EP99927875A priority patent/EP1084343A1/fr
Priority to PCT/EP1999/003876 priority patent/WO1999063217A1/fr
Publication of EP0962649A1 publication Critical patent/EP0962649A1/fr
Withdrawn legal-status Critical Current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
    • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
    • F02M51/04—Pumps peculiar thereto
    • 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
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • 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
    • F02M59/107—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 pneumatic drive, e.g. crankcase pressure 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
    • F02M59/20—Varying fuel delivery in quantity or timing
    • 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
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/205—Quantity of fuel admitted to pumping elements being metered by an auxiliary metering device
    • 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
    • F02M59/20—Varying fuel delivery in quantity or timing
    • F02M59/22—Varying quantity or timing by adjusting cylinder-head space
    • 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
    • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
    • F02M69/12—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel comprising a fuel-displaced free-piston for intermittently metering and supplying fuel to injection nozzles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B13/00—Pumps specially modified to deliver fixed or variable measured quantities

Definitions

  • the invention relates to a fuel injection device for Injecting fuel into a combustion chamber by means of a Injector.
  • Such fuel injection devices can be used as a reciprocating pump be formed in a connecting line between the fuel injector and the injection pump fuel under pressure. From a predetermined Flow pressure opens the injector and sprays fuel into the combustion chamber. If the piston pump falls generated pressure below the forward pressure, so closes the injector and ends the injection process.
  • the one consisting of a reciprocating piston pump and an injection nozzle System is referred to as a unit injector.
  • Known injection devices e.g. DD-PS 213 472, DE 42 06 817 C2 and DE 195 15 782 A1
  • DD-PS 213 472, DE 42 06 817 C2 and DE 195 15 782 A1 refer to the pressure build-up a high precision. Nevertheless, it is with such pump-nozzle systems not possible over a longer period of use, from e.g. several years, fuel in precisely metered amounts of fuel to inject. These changes in quantity are based e.g. to a passage pressure that changes with time of the injectors.
  • the injectors that are directly connected to the The combustion chamber is adjacent to the pressures generated in the combustion chamber and exposed to thermal loads. As a consequence, that the injectors age, i.e. that there is one in the injector located, the passage pressure controlling spring puts.
  • the stroke of an injection nozzle can become deformed of the sealing seat and / or the needle change over time.
  • coking in the nozzle changes their Passage cross section.
  • the injectors must be used because of the tight space Space be very compact, so that long-term stable Constructions become complex.
  • the invention is therefore based on the object of a fuel injection device for creating a unit injector with a long-term stable metering of the fuel quantity is possible.
  • the fuel injection device has a Pump device and a metering device.
  • the pumping device is designed as a reciprocating pump, and can be in one preferred embodiment, a two-part from an actuating piston and an accumulator piston existing exhibit.
  • the accumulator piston is the actuating piston in the conveying direction upstream. There is a stop provided limits the path of the accumulator piston in the conveying direction.
  • the accumulator piston is between two injections of the metering device by a predetermined variable storage stroke moved against the direction of conveyance, one predetermined amount of fuel is stored. In this withdrawn Position, the accumulator piston is held until until the actuating piston moves the accumulator piston in the conveying direction presses. The accumulator piston is activated by the actuating piston pushed as far as it will go, with the accumulator piston holding the intake fuel displaced. This will make a pre exactly defined conveying stroke and exactly that in advance sucked or stored by the accumulator stroke of the accumulator piston Amount of fuel sprayed.
  • the Krattscherin injection device can with their metering device the amount of fuel to be injected set exactly.
  • the amount of fuel to be injected is alone due to the precisely definable stroke of the accumulator piston and not due to the passage pressure, which cannot be precisely adjusted in the long run the injector.
  • Injection device is thus a long-term stable, exact Dosage of fuel quantity guaranteed.
  • Fig. 1 is a pump-nozzle system with a first schematically Embodiment of a fuel injection device according to the invention 1 shown.
  • the fuel injection device 1 is via a high pressure line 2 connected to an injection nozzle 3.
  • the injector 3 is on a combustion chamber (not shown) of an internal combustion engine for injecting fuel into the combustion chamber arranged.
  • the fuel injection device 1 has a pump device 5 and a metering device 6.
  • the pump device 5 is an electromagnetically operated reciprocating pump with a two-part from an actuating piston 8 and a storage piston 9 existing pistons.
  • the actuating piston 8 is an armature of an electromagnet 11 and is stored in a cylindrical armature space 12, which is one first tube section 13 of a housing body 14 limited becomes. On the outside sits on the first pipe section 13 tubular electromagnet 11.
  • the pipe section 13 and the electromagnet 11 are of one Pump housing 15 includes that also in the direction of delivery 16th rear end of the pipe section 13 with a cover section 17 completes. Sitting on the inside of the cover section 17 one from e.g. an elastomer material, thermosetting material or brass existing tubular guide bushing 19. Die Guide bushing 19 also serves as a stop for the actuating piston 8th.
  • the actuating piston 8 has a tubular, on the inner surface of the first pipe section 13 adjacent anchor body 22 and one arranged in the anchor body 22 and with it firmly connected anchor guide tube 23.
  • the anchor guide tube 23 closes flush with the anchor body in the conveying direction 16 22 and is on the rear with respect to the conveying direction 16 Side of the anchor body 22 on the anchor body 22 in front. With this protruding section is the armature guide tube 23 in the guide bush 19 stored.
  • the actuating piston shown in Fig. 1 is made in two parts the armature body 22 and the armature guide tube 23 are formed. It can equally well be in one piece and it is it is also possible to run one only through the pipe section 13 To provide anchors without a guide tube.
  • Longitudinal grooves are made in the lateral surface of the armature body 22 and the anchor guide tube is hollow, for example, if the anchor space is flooded with fuel so that when moving of the actuating piston 8 in the conveying direction 16 or counter a fuel located in the armature space to the conveying direction 16 can flow past the actuating piston 8 and its movement does not inhibit.
  • the armature space 12 is preferably opposite the fuel-carrying areas are sealed and free of fuel. In such an embodiment there are none Provide longitudinal grooves on the anchor body.
  • the housing body 14 Forms at the front end of the armature space 12 in the conveying direction 16 the housing body 14 one with respect to the inner diameter of the Anchor space 12 thinner delimited by an annular web 24 Passage in which a stop bush 25 is inserted.
  • the Stop bushing 25 projects from the ring web 24 into the armature space 12 before and forms with their opposite to the conveying direction 16 Front edge a stop edge 26.
  • the storage piston is slidably supported in the stop bushing 25 9.
  • the accumulator piston 9 points at its opposite to the conveying direction 16 end showing a stop edge 26 of the Stop disc 25 overlapping stop disc 27.
  • At the The edge area of the stop disc 27 is a thin one in the armature space 12 projecting annular web 28 is formed.
  • the diameter of the stop disc 27 is smaller than the inside diameter of the armature space 12.
  • An armature spring 29 is between the ring web 24 of the housing body 14 and in the conveying direction 16 facing end face of the actuating piston 8 used.
  • a storage piston spring 30 is between the stop disc 27 and the end face pointing in the conveying direction 16 of the actuating piston 8 used. On this face a recess 31 is made in which the Accumulator piston spring 30 sits and in which the accumulator piston spring 30 when the same is compressed.
  • the Pressure chamber 32 has a connection opening 33 for connection the high pressure line 2 leading to the injection nozzle 3 as well an opening 34 leading to the metering device 6.
  • a parking pressure valve 35 is used only from a certain passage pressure within the pressure chamber 32 releases the connection opening.
  • an overflow valve 36 that a in Check valve opening direction to the pressure chamber 32 is.
  • the pressure chamber 32 extends into the interior of FIG Stop bushing 25 so that it can the inner wall of the stop bush 25 and that in the conveying direction 16 front end face of the storage piston 9 limited is.
  • the metering device 6 is on the same housing body 14 as the pump device 5 is formed and has a second one Pipe section 38 which is transverse to the conveying direction 16 of the Pump device 5, namely in the injection direction 37, extends.
  • a metering piston is slidably supported in the second tube section 38 40, which consists of a tubular anchor body 41 and a guide pin protruding on its two faces 42 exists.
  • the guide pin 42 is supported with its two ends each in a fixed position in the second pipe section used guide bushing 44, 45.
  • an inwardly projecting ring web 47 is formed. Between the ring web 47 and the front face of the anchor body 41, a metering spring 48 is used, which the metering piston 40 towards the rear guide bush 45 presses.
  • the electromagnet 49 and the second pipe sections 38 are from a metering device housing 50 includes that also the rear in the injection direction 37 End of the metering device 6 with a cover section 51 completes.
  • a fuel supply line 52 In the area between the overflow valve 36 and the stroke area of the metering piston 40 opens into the second pipe section 38 a fuel supply line 52.
  • a Check valve 53 At the mouth of the fuel supply line 52 to the second pipe section 38 is a Check valve 53 arranged that a backflow into the Fuel supply line 52 prevented.
  • the first pipe section is 13 and the second pipe section 38 of the housing body 14 in the right Angle to each other.
  • the two Pipe sections can be at any other angle to each other be arranged; e.g. it is also possible that the Pump device 5 and the metering device 6 diametrically opposite are arranged to the pressure chamber 32.
  • a Dosing process carried out by the dosing piston 40 of the dosing device 6 is actuated by the electromagnet 49, so that he delivers fuel into the pressure chamber 32.
  • the delivery pressure is less than the passage pressure of the parking pressure valve 35 so that the fuel is not in the injector 3 leading high pressure line 2 can drain.
  • the fuel fed into the pressure chamber 32 pushes the Accumulator piston 9 by a precisely definable, variable accumulator stroke in the armature chamber 12 of the pump device 5 against the Effect of the accumulator piston spring 30.
  • the overflow valve 36 prevents the fuel from flowing back into the metering device 6.
  • the magnet 49 of the dosing device 6 switched off and the dosing piston 40 by the dosing spring 48 pressed into its initial state, whereby Fuel is drawn from the fuel supply line 52.
  • the actuating piston 8 of the electromagnet 11 Pump device accelerated in the conveying direction 16. This works the actuating piston alone against the relatively soft trained springs 29, 30 so that it strikes until the accumulator piston 9 stores kinetic energy. The kinetic Energy is transferred to the storage piston 9 and this is pressed into the stop bush 25 by the actuating piston 8. The movement of the accumulator piston 9 is caused by the impact its stop disc 27 on the stop edge 26 of the Stop bush 25 stopped.
  • the storage piston 9 displaces during its movement in the conveying direction 16 located in the stop bush 25 in the area of his Fuel stroke located fuel.
  • the fuel is thus, by the parking pressure valve 35, the High pressure line 2 and the injector 3 in the combustion chamber promoted an internal combustion engine.
  • the delivery stroke of the accumulator piston 9 corresponds to the accumulator stroke, which is precisely preset by means of the metering device 6 is the amount of fuel to be displaced by the delivery piston 9 or the amount of fuel injected into the combustion chamber exactly defined.
  • the fuel injection device therefore not the amount of fuel to be injected by one Passage pressure of an injection nozzle, but by means of adjustable storage stroke of the metering device.
  • the stroke of the accumulator piston 9 is not subject to any signs of aging, so that long-term stable metering of the injection quantity is guaranteed.
  • a metering device 6 By providing a metering device 6 according to the invention and a pump device 5 is the metering of the amount of fuel decoupled from the generation of the fuel injection pressure.
  • the acceleration path of the actuating piston 8 at larger amounts of fuel to be injected than at smaller amounts of fuel.
  • the length of the acceleration path is less than be smaller Amounts of fuel, resulting in that stored by the actuating piston kinetic energy with larger amounts of fuel to be injected is lower than with smaller amounts of fuel.
  • smaller amounts of fuel with higher Pressure can be injected as larger amounts of fuel.
  • small amounts of fuel are atomized very finely and braked in the combustion chamber directly in the area behind the nozzle.
  • Fig. 2 is a second embodiment of the invention Fuel injector shown. It owns in essentially the same structure as the first embodiment, which is why the same parts have the same reference numerals and a detailed description are omitted can be.
  • the second embodiment differs from the first Embodiment in that the actuating piston 8 immediately abuts the accumulator piston 9 and in the pump device 5 only a single spring 55 between the actuating piston 8 and the rear guide bushing in the conveying direction 16 19 is arranged.
  • the spring 55 acts on the actuating piston 8 together with the accumulator piston 9 in the conveying direction 16, that is towards the pressure chamber 32.
  • the actuating piston 8 and the accumulator piston 9 lead together both the storage stroke and the delivery stroke.
  • the actuating piston 8 and Accumulator piston 9 can also be formed in one piece.
  • FIG. 3 A third embodiment of the fuel injection device according to the invention is shown in Fig. 3.
  • This fuel injection device In this fuel injection device are the pump device 5 and the metering device 6 arranged along a line.
  • This fuel injection device has a essential tubular housing body 14, which consists of a first Pipe section 13 and a second pipe section 38, which are arranged coaxially with each other, with between the first and second pipe sections 13, 38 a cross plate 57 is formed.
  • a cross plate 57 In the area of the first pipe section is the pump device 5 and in the region of the second pipe section 38 is adjacent to the cross plate 57, the metering device 6 and in the conveying direction 16 subsequently the pressure chamber 32 trained.
  • the pump device 5 has a bearing in an armature chamber 12 Actuating piston 8, which consists of a tubular armature body 22 and an anchor body 22 in the longitudinal direction penetrating anchor pin 23, the on both end faces of the Anchor body 22 protrudes.
  • the anchor space 12 is from first tube section 13 of the housing body 14 limited.
  • On the outer surface of the first tube section 13 is an electromagnet 11.
  • the pipe section 13 and the electromagnet 11 are comprised of a pump housing 15, which also in the direction of delivery 16 rear end of the pipe section 13 with a Cover section 17 completes.
  • the metering device arranged on the second pipe section 38 6 has a metering piston 40 which consists of a tubular Anchor body 41 and one protruding on its two end faces Guide pin 42 is made.
  • the guide pin 42 is supported with its two ends each inserted in the cross plate Guide bush 59 or in a stop bush 25.
  • the stop bush 25 is used in one pass, the from an inwardly projecting on the second pipe section 38 Ring web 24 is limited.
  • Pressure chamber 32 is laterally delimited by the second pipe section 38.
  • This pipe section 38 delimiting the pressure chamber 32 is at the front in the conveying direction 16 with a connection opening 33 for connecting the high pressure line leading to the injector 3 2 provided.
  • a fuel supply 54 into the pressure chamber 32.
  • a check valve 53 is arranged which a backflow in a fuel supply line connected to the fuel supply 54 52 prevented.
  • the magnet 49 of the dosing device 6 energized so that the metering piston 40th executes a storage stroke counter to the conveying direction 16 and Sucks fuel from the fuel supply line 52.
  • the one in Area of the stop bush 25 fuel can be because of the standing pressure valve 35 and the check valve 52 does not escape and prevents the metering piston from moving back 40.
  • the magnet 44 is de-energized switched, the metering piston 40 in the position of the Storage stroke remains because on the one hand its return movement is locked and on the other hand, the metering spring 48 the metering piston 40 acted upon in the conveying direction 16.
  • the magnet 11 of the pump device 5 energized so that the actuating piston 8 in the conveying direction is moved, during an acceleration phase stores kinetic energy.
  • the actuating piston 8 hits the metering piston 40 and transfers its kinetic energy to it.
  • the delivery stroke thus corresponds to the storage stroke and the amount of fuel displaced by the metering piston 40 during the Dosing process sucked and stored amount of fuel.
  • Fuel injector shown is a fourth embodiment of the invention Fuel injector shown. It owns in essentially the same structure as the third embodiment, which is why the same parts with the same reference number are provided and a detailed description is omitted can be.
  • the pressure chamber 32 opens out a passage 121 leading to a delay chamber 120.
  • the delay chamber 120 is like a blind hole with a jacket wall 122 and a bottom wall 123 executed and points a hollow cylindrical shape.
  • a recess for receiving a compression spring 126 in introduced the bottom wall 123, which is between the deceleration piston 125 and that in the bottom wall 123 inserted recess is inserted.
  • the dosing process is identical to that of the third Embodiment executed.
  • the actuating piston 8 is removed from the magnet 11 accelerated in the conveying direction 16, during a Acceleration phase stores kinetic energy.
  • the acceleration piston hits the actuating piston 8 the metering piston 40 and transmits its kinetic energy on this, whereby fuel from the pressure chamber 32 to Injector 3 is displaced.
  • the spring hardness of the compression spring 126 is selected such that the deceleration process continues at least during the opening phase of the injection valve.
  • the spring hardness of the compression spring 126 and the stroke of the delay piston 125 are preferably selected so that the delay piston 125 strikes the bottom wall 123 at a final pressure of P end from 1.5P nozzle to 3P nozzle .
  • This delay device delays the pressure build-up during the opening process of the injector, thereby avoided is that pressure waves at the only partially opened injector be reflected and the movement of the dosing piston slow down. This will improve energy transfer and a more uniform pressure level during the injection process achieved.
  • This delay device can in all embodiments of the present application are provided, wherein it opens to the pressure chamber 32 or to the high pressure line 2 is arranged; an arrangement as close as possible to the dosing piston is preferred, however.
  • the delay device can be replaced with a separate one Chamber also with e.g. between the actuating piston and the metering piston arranged spring or damping element be formed, the energy transfer from the actuating piston delayed on the dosing piston.
  • FIG. 5 is a fifth embodiment of the invention Fuel injector shown. It owns in essentially the same structure as the third embodiment, which is why the same parts have the same reference numerals and a detailed description are omitted can be.
  • the fifth embodiment differs from the third Embodiment in that the actuating piston 8 immediately abuts the metering piston 40 and in the pump device 5 only a single spring 55 between the actuating piston 8 and the rear guide bush 19 in the conveying direction 16 is arranged.
  • the spring 55 acts on the actuating piston 8 together with the metering piston 40 in the conveying direction 16, that is, in the direction of the pressure chamber 32.
  • the actuating piston 8 and the one acting as a storage piston Dosing piston 40 together lead both the storage stroke also the delivery stroke.
  • the Actuating piston 8 and the metering piston 40 are formed in one piece be.
  • a pump-nozzle system with a sixth embodiment the fuel injection device according to the invention is in Fig. 6 shown.
  • this fuel injection device corresponds to essentially that of the first embodiment and differs differ from this only in the design of the pumping device 5.
  • the pump device 5 is operated pneumatically. She points a pump housing 60. There is a hollow cylindrical one in the pump housing 60 Actuating piston chamber 62 formed in which an actuating piston 8 is slidably disposed.
  • the actuating piston 8 is a hollow cylindrical one that is open at one end Piston with a piston crown 63 and a piston wall 64.
  • the piston wall 64 is form-fitting on the inner wall the actuating piston chamber 62.
  • Actuating piston spring 67 used the actuating piston 8 applied with a force in the conveying direction 16.
  • the storage bore 65 is in the conveying direction 16 in front of the actuating piston chamber 62 arranged and has a smaller diameter than the actuating piston chamber 62 so that at the mouth of the Storage bore 65 with respect to the actuating piston chamber 62 Ring step 66 is formed.
  • the actuating piston 8 is with its piston crown 63 pointing towards the storage bore 65 arranged.
  • control valve 70 is arranged at the control opening 68, via a pneumatic line with a combustion chamber connected is.
  • the control valve 70 is a known one Electromagnetically operated pneumatic valve for opening and Closing a passage.
  • This pneumatically operated pump device 5 is connected to the Pump housing 60 to outward opening storage bore 65 an opening of the rest of the housing body 14, the pressure chamber 32 limiting area set so that the pressure chamber 32 extends into the inner region of the storage bore 65 and them with respect to the pump device 5 from the inner wall the storage bore 65 and the front in the conveying direction 16 End face of the storage piston 9 is limited.
  • the fuel injection device is located after an injection process in the state shown in Fig. 6, i.e. that the actuating piston 8 from the actuating piston spring 67 pressed against the ring step 66 and the metering piston 40 in its initial state, in which it is controlled by the dosing spring 48 from the pressure chamber 32 away from the rear guide bush 45 is pressed.
  • control valve 70 briefly opens the control opening 68, which is between the ring step 66 and the piston crown 63 forms a gas pressure that the actuating piston 8 against the action of the actuating piston spring 67 of the Ring stage 66 lifts off. From this gas pressure the storage piston 9 pressed into the storage bore 65, due to the different However, cross sections on the accumulator pistons 9 force acting much less than that on the actuating piston 8 is acting force.
  • the control valve 70 opens the control opening for the injection process 68, whereby that located in the actuating piston chamber 62 Gas flows out, the actuating piston 8 from the actuating piston spring 67 is accelerated in the conveying direction 16 and the accumulator piston after an acceleration phase into the Storage hole presses.
  • the actuating piston hits 8 on the ring step 66 or the accumulator piston 9 on the housing body 14, the conveying process is stopped, the conveying stroke again corresponds exactly to the storage stroke. Because the storage stroke can be set exactly by the metering device 6, can be a predetermined variable amount of fuel regardless of Signs of aging can be dosed in the unit injector system.
  • Fig. 7 is a pump-nozzle system with a schematic seventh embodiment of an inventive, pneumatic driven fuel injector shown.
  • This injector has an essentially tubular housing body 14.
  • the housing body is at the rear end in the injection direction 16 completed with an end plate 75.
  • On in the injection direction 16 front end portion of the tubular housing body 14 is a connection opening 33 for connecting the to the injection nozzle 3 leading high pressure line 2 is provided.
  • a stop bush 25 is adjacent to the connection opening 33 provided in an inward protruding Ring web limited passage is used.
  • the dosing piston 40 in turn has a tubular anchor body 41 with a guiding pin 42 protruding from both ends thereof on. With the area pointing forward in the injection direction 16 of the guide pin 42 supports the metering piston 40 in the Stop bushing 25. Between the stop bushing 25 and the connection opening 33, a standing pressure valve 35 is arranged.
  • a fuel supply 54 in the pressure chamber 32 In the area of the stop bush 25 opens between the parking pressure valve 35 and the metering piston 40 a fuel supply 54 in the pressure chamber 32. In the fuel supply 54 a check valve 53 is arranged which a backflow in a fuel supply line connected to the fuel supply 54 52 prevented.
  • the actuating piston 8 has an approximately cup-shaped body with a jacket wall 76 and a bottom wall 77. With the actuating piston 8 is positively supported by its jacket wall 76 in the tubular housing 14 and is with its Bottom wall 77 arranged in the injection direction 16 to the rear. In the limited by the cup-shaped actuating piston 8 the metering piston supports a cylindrical recess 40 with its protruding rearward in the injection direction 16 Guide pin 42.
  • the actuating piston 8 has at the rear jacket area a recess in which an actuating piston spring 67 sits, which is supported on the end plate 75 of the housing 14.
  • a pneumatic opening 80 at the rear on the ring web 24 educated.
  • a control valve 70 scheduled, which is a pneumatic connection between the pneumatic opening 80 and a pressurized gas reservoir and can shut off.
  • the control valve 70 is a known one Electromagnetically operated pneumatic valve for opening and closing a passage. In the room in which the metering piston 40 and the actuating piston 8 are the Armature chamber 12 can thus be supplied with gas under pressure become.
  • the metering piston 40 has in the jacket area of its armature body 41 at least one longitudinal groove 82 through which one into the anchor space entering gas in the back of the metering piston 40 Range can be forwarded.
  • the metering piston 40 is removed from the magnet 11 actuated counter to the injection direction 16, so that Fuel drawn from the fuel supply and in the Pressure chamber 32 in the area between the standing pressure valve 35 and the metering piston 40 is stored. Because of the fuel of the check valve 53 does not escape from the pressure chamber 32 can, the metering piston 40 is fixed in its position.
  • the actuating piston is used to actuate the metering piston 40 8 biased by a pressurized gas.
  • the Gas is supplied to the armature chamber via the pneumatic opening 80 and through the longitudinal groove 82 in made in the metering piston 40 the area between the metering piston 40 and the actuating piston 8 introduced so that the actuating piston 8 due the increased gas pressure to the rear against the actuating piston spring 67 pressed and the actuating piston spring 67 biased becomes.
  • the dosing piston remains in its position because he both from the metering spring 48 and the one under pressure standing gas is injected in the direction of injection 16 and its movement due to the fuel in the pressure chamber 32 is blocked in the injection direction 16.
  • the actuation piston 8 can also be preloaded in time the metering piston 40 is actuated by means of the magnet 11, however, the order described above, at first the dosing process and then the pretensioning of the actuating piston is carried out, is preferred because then the Dosing piston 40 when dosing only against the actuating piston spring 67 works and not against an elevated one Gas pressure must work.
  • the combustion chamber can be used as the gas pressure reservoir with that of the invention PDS system equipped internal combustion engine used become.
  • 9 is the pressure curve during a Working cycle shown in a combustion chamber. In the area before top dead center the pressure rises due to the by the Piston motion gradually produced compression from atmospheric pressure to a compression pressure. After the ignition that usually shortly after reaching top dead center is triggered, the pressure suddenly rises to a multiple of the compression pressure and then falls through the Piston movement steeply, after opening the exhaust valve the pressure in the combustion chamber drops to atmospheric pressure.
  • the time of The injector is unloaded by the time of Injection process set so that it is in a single-cylinder engine always coincides with the increase in pressure.
  • a Multi-cylinder engine can be assigned to a specific cylinder Injector with another cylinder's gas can be controlled so that the discharge process of the injector can coincide with the phase during which there is atmospheric pressure in the combustion chamber.
  • the pneumatic connection line between the combustion chamber and the injector can be provided with an additional valve with which the gas is discharged when the injector in a room with low, i.e. e.g. atmospheric Pressure that can be derived.
  • crankcase can be used instead of the combustion chamber be used as a gas pressure reservoir in which the Air in it cyclically due to the piston movement is compressed.
  • FIGS. 8a and 8b A preferred metering device is in FIGS. 8a and 8b shown. Same parts as for the dosing devices described above are provided with the same reference numerals.
  • This metering device 6 in turn has a pipe section 38, which is surrounded by a magnet 49. Of the Pipe section 38 and magnet 49 are from a housing 50 includes.
  • a metering piston 40 which consists of a Armature body 41 and a piston body 42a is formed.
  • Piston body 42a is rod-shaped with a smaller diameter formed as the anchor body 41 and in the conveying direction 81 of the metering device 6 arranged coaxially in front of the armature body 41.
  • the piston body 42a is in with its front end a guide bush 44 slidably mounted.
  • On his the piston body 42a has a radially rearward end externally projecting ring web 83, between the ring web 83 and the guide bush 44, a metering spring 48 clamped is.
  • Lekagerrohr 85 extends through an opening in the housing 50 to the outside and forms a stop with its front-facing end face 86 for the metering piston 40.
  • the metering piston 40 lies in its starting position, i.e. in the due to the spring force the metering spring 48 in the rearwardly shifted position, at the stop 86.
  • the guide bush 44 points at its in the conveying direction 81 a radially outwardly projecting washer 88 on.
  • the washer 88 is on its back with a Sealed ring against the pipe section 38 and has on the front in the area of the through opening shallow approximately spherical recess 90.
  • a valve device 91 is arranged upstream of the recess 90.
  • the valve device 91 has one directly on the Washer 88 of the tubular section 38 abutting circular Metal disc 92 and a circular valve disc 93.
  • the metal disc has an inlet hole 94 and an outlet hole 95 provided.
  • the inlet hole 94, the outlet hole 95, the spherical recess 90 and that extending to the metering piston Passage of the guide bush 44 delimit a valve chamber 89.
  • the valve disk 93 is preferably a thin metal plate made of spring steel, preferably with rubber on both sides or plastic is coated. On the valve disk 93 is each an inlet tongue 96 and an outlet tongue 97 with a cut into a narrow u-shaped cut.
  • the two disks 92, 93 are held by a housing cover 98, which is detachable is attached to the housing 50 and a circular recess has, in which the two disks 92, 93 are arranged.
  • a fuel supply channel 100 is formed in the housing cover 98, the one in the area of the inlet tongue 96 on the valve disk 93 ends.
  • Fuel outlet passage 101 introduced with an opening 105 opens in the region of the outlet tongue 97 on the valve disk 93.
  • the opening 104 of the fuel supply channel opening at the inlet tongue 96 100 is so small that it is completely different from the Inlet tongue 96 can be covered. That is, the opening 104 lies within the free cut of the inlet tongue (Fig. 8b).
  • the inlet opening 94 of the metal disc 92 is so large that it completely includes the inlet tab 96. If the inlet tongue 96 located in the disc plane, it completely covers the fuel supply passage 100 so that the supply of fuel is interrupted. Since the inlet opening 94 of the metal disc 92 completely encloses the tongue 96, the inlet tongue 96, are bent into the inlet opening 94 so that they a passage between the fuel supply passage 100 and the Valve chamber 89 releases. The inlet tongue 96 thus forms the openings 94 and 104 a designed as a check valve Intake valve 110, which is a flow of fuel from the valve chamber 89 prevented in the fuel supply channel 100.
  • the outlet opening 95 of the metal disk 92 is so small that they are within the free cut of the outlet tongue 97 (Fig. 8b), i.e. the outlet opening is so small that it can be completely covered by the outlet tongue 97. If the outlet tongue 97 is in the disk plane, covers they completely exhaust port 95 so that the passage from the valve chamber 89 to the outlet duct 101 is interrupted.
  • the opening 105 of the outlet duct 101 is larger than that Cut the outlet tongue 97 so that the outlet tongue 97 in the opening 105 can be bent and a passage between the valve chamber 89 and the outlet channel 101 releases.
  • the outlet tongue 97 thus forms with the openings 95, 105 designed as a check valve outlet valve 111, the one Fuel flow from the exhaust port 101 into the valve chamber 89 prevents.
  • This special configuration of the metering device is not only advantageous for injectors, but can also used with any other reciprocating pump equipment become.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Fuel-Injection Apparatus (AREA)
EP98110177A 1998-06-04 1998-06-04 Dispositif d'injection de combustible Withdrawn EP0962649A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP98110177A EP0962649A1 (fr) 1998-06-04 1998-06-04 Dispositif d'injection de combustible
AU45067/99A AU4506799A (en) 1998-06-04 1999-06-04 Pumping device
EP99927875A EP1084343A1 (fr) 1998-06-04 1999-06-04 Dispositif de pompage
PCT/EP1999/003876 WO1999063217A1 (fr) 1998-06-04 1999-06-04 Dispositif de pompage

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP98110177A EP0962649A1 (fr) 1998-06-04 1998-06-04 Dispositif d'injection de combustible

Publications (1)

Publication Number Publication Date
EP0962649A1 true EP0962649A1 (fr) 1999-12-08

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP98110177A Withdrawn EP0962649A1 (fr) 1998-06-04 1998-06-04 Dispositif d'injection de combustible

Country Status (1)

Country Link
EP (1) EP0962649A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010112856A1 (fr) * 2009-03-31 2010-10-07 Scion-Sprays Limited Injecteur de fluide comportant un nouvel agencement de soupape d'entrée

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2015078A (en) * 1978-02-23 1979-09-05 Bosch Gmbh Robert Fuel injection system for internal combustion engines
DE3133288A1 (de) * 1981-08-22 1983-03-03 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8900 Augsburg "brennstoffeinspritzsystem an einer brennkraftmaschine"
EP0077235A1 (fr) * 1981-10-01 1983-04-20 Regie Nationale Des Usines Renault Injecteur pompe à pression d'injection constante et prédosage et système dérivé
US4463901A (en) * 1982-07-29 1984-08-07 Cummins Engine Company, Inc. Unit fuel injector having independently controlled timing and metering
US4593664A (en) * 1984-09-04 1986-06-10 Nippondenso Co., Ltd. Fuel injection apparatus
DE4206817A1 (de) * 1991-10-07 1993-04-29 Ficht Gmbh Kraftstoff-einspritzvorrichtung nach dem festkoerper-energiespeicher-prinzip fuer brennkraftmaschinen

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2015078A (en) * 1978-02-23 1979-09-05 Bosch Gmbh Robert Fuel injection system for internal combustion engines
DE3133288A1 (de) * 1981-08-22 1983-03-03 M.A.N. Maschinenfabrik Augsburg-Nürnberg AG, 8900 Augsburg "brennstoffeinspritzsystem an einer brennkraftmaschine"
EP0077235A1 (fr) * 1981-10-01 1983-04-20 Regie Nationale Des Usines Renault Injecteur pompe à pression d'injection constante et prédosage et système dérivé
US4463901A (en) * 1982-07-29 1984-08-07 Cummins Engine Company, Inc. Unit fuel injector having independently controlled timing and metering
US4593664A (en) * 1984-09-04 1986-06-10 Nippondenso Co., Ltd. Fuel injection apparatus
DE4206817A1 (de) * 1991-10-07 1993-04-29 Ficht Gmbh Kraftstoff-einspritzvorrichtung nach dem festkoerper-energiespeicher-prinzip fuer brennkraftmaschinen

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010112856A1 (fr) * 2009-03-31 2010-10-07 Scion-Sprays Limited Injecteur de fluide comportant un nouvel agencement de soupape d'entrée
US8757131B2 (en) 2009-03-31 2014-06-24 Robert Bosch Gmbh Fluid injector having a novel inlet valve arrangement

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