EP1662133A1 - Injecteur - Google Patents

Injecteur Download PDF

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Publication number
EP1662133A1
EP1662133A1 EP05025818A EP05025818A EP1662133A1 EP 1662133 A1 EP1662133 A1 EP 1662133A1 EP 05025818 A EP05025818 A EP 05025818A EP 05025818 A EP05025818 A EP 05025818A EP 1662133 A1 EP1662133 A1 EP 1662133A1
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EP
European Patent Office
Prior art keywords
pressure
valve
spring chamber
injection
injection valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP05025818A
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German (de)
English (en)
Inventor
Maximilian Kronberger
Dejan Jovovic
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.)
Continental Automotive GmbH
Original Assignee
Siemens AG
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
Priority claimed from DE102004057151A external-priority patent/DE102004057151B4/de
Application filed by Siemens AG filed Critical Siemens AG
Publication of EP1662133A1 publication Critical patent/EP1662133A1/fr
Withdrawn legal-status Critical Current

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    • 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
    • F02M59/36—Varying fuel delivery in quantity or timing by variably-timed valves controlling fuel passages to pumping elements or overflow passages
    • F02M59/366—Valves being actuated electrically
    • 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
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/46—Valves
    • F02M59/466—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means
    • F02M59/468—Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means using piezoelectric operating means
    • 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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
    • F02M61/20—Closing valves mechanically, e.g. arrangements of springs or weights or permanent magnets; Damping of valve lift
    • F02M61/205—Means specially adapted for varying the spring tension or assisting the spring force to close the injection-valve, e.g. with damping of valve lift
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/04—Fuel-injection apparatus having means for avoiding effect of cavitation, e.g. erosion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/70—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger
    • F02M2200/703—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic
    • F02M2200/705—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic with means for filling or emptying hydraulic chamber, e.g. for compensating clearance or thermal expansion

Definitions

  • the invention relates to an injection valve or injection nozzle for injecting a fluid, in particular for injecting fuel into a combustion chamber of an automobile engine, in particular a diesel engine.
  • the fuel depending on the combustion process, with a pressure between 350 and more than 2,000 bar injected into a combustion chamber of an engine and thereby with the greatest possible accuracy per injection (pre-injection and main injection, possibly. clocked) are dosed.
  • pre-injection and main injection possibly. clocked
  • emission limits emission limits
  • One such injection system is the unit injector (UIS) unit, in which a pump, a control valve and the injector form a unit.
  • UAS unit injector
  • a pump, a control valve and the injector form a unit.
  • Per engine cylinder such a unit injector unit is installed in the cylinder head of a diesel engine and driven either directly via a plunger or indirectly via a rocker arm of an overhead camshaft.
  • the required injection pressure is generated in each case at the time of injection, wherein the injection rate course not only by the design of the cam contour, but also by the control of the control valve (magnet or piezobetätigt) can be influenced.
  • the higher the fuel pressure the more fuel that can be forced through the injector's small holes in the short amount of time available (a few thousandths of a second).
  • the pump-nozzle system can build up the high pressure well because it is generated in a very small space directly where it is injected.
  • Injector injector systems are prone to increased noise emissions in idle mode, which are mechanically and hydraulically excited.
  • the mechanical noise emissions arise as a result of a sudden loading and unloading of the power-conducting components of the pump-nozzle drive during control and Ab juryn, whereas the hydraulically induced noise emissions result in relief of high-pressure chambers.
  • such a pump-nozzle arrangement in which fuel from a fuel tank is provided to a fuel pump via a control valve.
  • the fuel pump is connected via a line to a pressure chamber in which an injection needle of the injection valve is arranged.
  • the injection needle has a pressure shoulder in the pressure chamber, on which the injection needle can be raised by means of a fuel pressure from its sealing seat.
  • the injection needle is biased by a biasing spring, which is arranged in a spring chamber, against the sealing seat.
  • the spring chamber is connected via a fuel line to an overflow valve seat and to a check valve. By coupling the spring chamber to the supply line, the injection needle is pressed by the fuel pressure in addition to the biasing spring against the sealing seat.
  • the fuel compressed by the fuel pump is fed back into the pressure chamber or via the supply line to the fuel tank.
  • An injection begins when the overflow valve is closed during the compression process of the pump and thereby the fuel pressure in the pressure chamber rises above a predetermined value, so that the injection needle is lifted due to the pressure in the pressure chamber against the bias of the biasing spring and against the fuel pressure in the spring chamber from the sealing seat.
  • the object of the invention is achieved on the one hand by an injection valve in which a pressure-maintaining valve is provided in or on a spring chamber of the injection valve, by means of which it is possible to couple the spring chamber to a pressure in the inlet.
  • This applied to the spring chamber fluid pressure, together with a spring preferably acts on a piston in the spring and forth movable piston, which is acted upon by the force of the spring and the force due to the fluid pressure in the spring chamber, the piston these two forces in Substantially axially transfers to the injection needle of the injection valve.
  • the object of the invention is realized by reducing a pump piston diameter of a pump associated with the injection valve, which supplies the injection valve with fuel.
  • a pump piston diameter is currently 7.65 mm.
  • a reduction to about 6.0 to 6.5 mm, in particular 6.25 mm is achieved due to the concomitant reduction of the pump piston area, a reduction in peak forces in the drive by about 30%, which the mechanical noise excitation at the same pressure level significantly reduced.
  • the criterion for the lower limit of the nozzle opening pressure is the safety against gas entry from the engine cylinder. This lower limit is the drop in nozzle orifice pressure over the life of the injector - typically 25 to 30 bar - from the hydraulic closing force due to the pressure in the spring chamber, from the mechanical closing force due to the force of the spring in the spring chamber to the piston and from the maximum Engine cylinder pressure determined during nozzle closing.
  • the device according to the invention for a timed injection is very well suited because due to the Ab Kunststoffns a pilot injection, the resulting pressure wave opens the pressure-holding valve and increases the pressure in the spring chamber.
  • the opening pressure for the main injection and thus the pulse with which the fuel can be injected into the combustion chamber which is advantageous in particular for lower pollutant emissions, also increases.
  • the pressure-holding valve is provided at the top in the spring chamber, wherein an inlet of the pressure-holding valve branches off from an inlet bore, through which the fuel is conveyed into a pump chamber of the pump.
  • a valve member of the pressure relief valve seals this inlet bore biased.
  • An abutment of the pressure holding valve is preferably located above in the spring chamber and preferably consists of a spring in the chamber via a press-fitted sleeve, which supports on its upper side a valve spring of the valve member of the pressure holding valve. At the bottom of the sleeve, a biasing spring provided in the spring chamber is supported by the injection needle.
  • This embodiment is particularly advantageous because already existing pump-nozzle concepts can be equipped with elaborate design measures with the pressure-holding valve.
  • the pressure-holding valve is not provided at the top in the spring chamber, but outside the spring chamber, wherein the valve member of the pressure-holding valve seals a branch (portion of an inlet bore, which connects the inlet channel with the spring chamber) biased by the inlet bore.
  • valve member, the sealing seat, inlet channel and branch can be arranged such that the valve member is guided to reduce fluttering.
  • the abutment of the pressure holding valve is in a preferred embodiment, a simple bore in which a valve spring is arranged, which has a valve body at its free end.
  • this valve spring chamber is relieved by means of a vent hole.
  • the vent hole leads from an upper portion of the valve spring space to an upper portion of the spring chamber, wherein the vent hole is formed as a throttle.
  • a sealing portion (valve body) of the valve member of the pressure holding valve is a ball, in particular a hemisphere, which is sealingly seated on a correspondingly shaped sealing seat, preferably a conical seat, in a closed state of the pressure retaining valve.
  • valve member or valve body ball, hemisphere
  • this is preferably performed at its outer diameter with a close game.
  • this game is 3 to 5 ⁇ m, in particular 4 ⁇ m.
  • a throttled connection between the sealing section / seat and the spring chamber for reducing a flutter tendency of the valve is particularly advantageous. This is particularly advantageous for small pressure differences and for influencing the pressure rise in the spring chamber.
  • a dynamic throttle is provided in the inlet channel (from the fuel reservoir) of the injection valve, wherein the inlet to the pressure retaining valve branches off downstream of the dynamic throttle downstream of the inlet channel. Downstream to mean that in an intake stroke of the pump of the injection valve, the fuel is conveyed from the fuel reservoir through the inlet channel into the pump chamber of the pump, wherein the inlet bore is arranged behind the dynamic throttle.
  • the surface of the dynamic throttle is designed so that up to medium engine speeds of the back pressure in the inlet channel (and the inlet bore to the pressure relief valve) and consequently held by the pressure holding valve pressure in the spring chamber increase only slightly.
  • the increase of the Opening pressure of the injection needle before the first closing (pilot injection) of the control valve small, which has a favorable effect on the metering accuracy of small pilot injection quantities in an emission-determining region of the engine map.
  • the pressure in the spring chamber for a pre-injection of an injection does not increase significantly, whereby a fast opening (low opening force) of the injection needle is ensured.
  • the dynamic throttle a portion of the inlet channel and preferably also the inlet bore and its branch downstream of the throttle in a plate is provided, which closes and seals the spring chamber upwards.
  • the sealing seat of the pressure holding valve is formed in the plate.
  • the space below the needle piston which can be moved up and down in the spring chamber and presses substantially axially onto the injection needle, is connected to the inlet channel upstream of the dynamic throttle by means of a bore or a channel. Furthermore, it is possible, this room not with the inlet channel, but with another drainage or leakage line, the z. B. leads to the fuel tank to connect.
  • the game of the needle piston on the inner wall of the Spring chamber selected such that the pressure in the spring chamber in each case a first injection (pre-injection) is substantially completely degraded and corresponds to the pressure in the inlet channel.
  • each injection or each injection cycle: pilot / pilot injection, single or multiple main injections
  • pilot / pilot injection single or multiple main injections
  • a Abgnan a control valve 3 of an injection valve 1 to mean that the control valve piston is moved to its rest position (not energized state of the control valve 3), wherein the control valve 3 is open, i. allows fluid communication between a fuel supply and a pump 2 of the injection valve 1.
  • a control of the control valve 3 is intended to mean that the control piston of the control valve 3 is closed (control valve 3 is in the energized state), whereby a high-pressure region of the injection valve 1 is separated from the fuel reservoir and compressing a fuel 192 by means of the pump. 2 is possible.
  • Fig. 1 shows a schematic embodiment of a pump-nozzle unit without additional Fluiddruckbeetzstoffung the injection needle in the spring chamber.
  • the pump piston 210 is driven directly or indirectly via an unillustrated, overhead camshaft of the internal combustion engine.
  • the compression space of the pump cylinder 230 is the pump space 220, which is connected via a fuel line 240 to a valve seat of a piezoelectrically or electromagnetically operated control valve 3.
  • the control valve 3 serves to either close the fuel line 240 or to connect it to a fuel low pressure region, represented by an inlet channel 140, from which fuel can be drawn.
  • a fuel low pressure region represented by an inlet channel 140
  • fuel is drawn from the fuel reservoir via a line in the cylinder head, the inlet channel 140 and via the cylinder piston of the control valve 3 into the pump chamber 220 with a movement of the pump piston 210 directed upward in relation to FIG.
  • the control valve 3 is still in its open position and the pump piston 210 is moving downwards, fuel previously drawn into the pump chamber 220 can be pushed back again into the fuel low pressure region.
  • control valve 3 closes off this fluid communication between fuel pipe 240 and the inlet conduit 140.
  • the fuel in the pump chamber 220 is compressed, whereby a high pressure p 220 generated in the pump chamber 220 becomes.
  • the pump-nozzle unit comprises an injection nozzle 1, which has an injection needle 170 which can be moved back and forth between a closed position and an open position.
  • a biasing spring 110 acts via a needle piston 115 and a shaft 117 with a closing force determined by the spring constant of the biasing spring 110.
  • the biasing spring 110 is clamped between the needle piston 115 and the upper end of the spring chamber 105 (blind hole).
  • a section of the injection needle 170 having a pressure shoulder 172 is surrounded by a pressure chamber 176, which communicates with the pump chamber 220 via a pressure channel 145.
  • a third pressure p 176 is built up by the pressure p 220 prevailing in the pump chamber 220 in the pressure chamber 176.
  • the fuel standing in the pressure chamber 176 under the pressure p 176 exerts an upward opening force on the pressure shoulder 172 with respect to the illustration of FIG. 1 on the injection needle 170.
  • the injection needle 170 assumes its open position as soon as the opening force caused by the pressure p 176 is greater than the sum of the opening of the injection needle 170 opposite Friction forces and the force exerted by the biasing spring 110 downward force on the injection needle 170 is.
  • the space above the needle piston 115 is acted upon by a fluid pressure which, via the needle piston 115, further biases the injection needle 170 with respect to its sealing seat above an engine compartment 190. Since a complete and permanent sealing of the spring chamber 105 with respect to the injection needle 170 or the needle piston 115 and the shaft 117 is not possible, the needle piston 115 is guided in the spring chamber 105 with a sealing gap, the space (with respect to FIG Spring chamber 105 is connected via a bore to the inlet channel 140.
  • Start of injection and injection quantity of the injection valve 1 are determined by the fast switching control valve 3 (solenoid valve or, preferably, piezoelectrically actuated valve), these variables are freely selectable in the map.
  • the control valve 3 allows in the open state, a free passage from the fuel inlet of the low pressure region via the pump 2 to the high pressure region and back to the low pressure region in the cylinder head of the engine, whereby filling the pump chamber 220 during a suction stroke of the pump piston 210 and a squeezing of fuel during a delivery stroke the pump piston 210 is made possible.
  • the control valve 3 receives its control signals from an electronic control, the known input information such.
  • the injection period is initiated by energizing and closing the control valve 3 during the delivery stroke of the pump piston 210. After pressure build-up in the high-pressure range and reaching the nozzle opening pressure P 176 , the pre-injection begins.
  • the end of the pilot injection results in addition to a Fluiddruckbeaufschung the spring chamber 105 by means of the provision according to the invention of a pressure holding valve 4 (see below) on the spring chamber 105 z. B. additionally by the opening of a valve (bypass piston), which abruptly lowers the pressure in the high-pressure chamber 176 and the injection needle 170 closes. Hub and shaft diameter of the bypass piston determine the time interval between the end of the pilot injection and the beginning of the main injection, ie the break in spraying.
  • Fig. 2 shows a pump-nozzle unit according to the invention with the injection valve 1 according to the invention, wherein mainly the low-pressure region in Fig. 2 can be seen.
  • a fuel inlet 142 as well as the inlet channel 140 in a section of the injection valve 1, in which the spring chamber 105 is also formed.
  • a plate 150 which closes the section above fluid-tight.
  • U. a. the inlet channel 140 is guided through this plate 150 and an inlet bore 152 of a pressure holding valve 4 is formed in the plate 150, wherein the pressure-maintaining valve 4 is explained in more detail below.
  • the biasing spring 110 acts via a needle piston 115 and the shaft 117 substantially axially from above on the injection needle 170, which is movable in a lower portion of the injection valve 1 via a small stroke up and down.
  • the pressure shoulder 172 of the injection needle 170 is in the Pressure chamber 176 is arranged, which is in fluid communication with the pressure channel 145 and the fuel line 240.
  • the pressure holding valve 4 is provided at the top of the spring chamber 105, which is supported on an abutment 405.
  • the abutment 405 of the pressure holding valve 4 is fixed in an upper region of the spring chamber 105, wherein a press fit is well suited for the attachment.
  • the biasing spring 110 Down to the abutment 405 abuts in this embodiment, the biasing spring 110, wherein the abutment 405 is also an abutment of the biasing spring 110.
  • this abutment 405 is a U-shaped sleeve, wherein the horizontal portion of the sleeve 405 is disposed further down in the spring chamber 105.
  • abutments 405 of the pressure holding valve 4 are also possible, such as. B. a pressed-in disc or recesses in the spring chamber inner wall, on which the biasing spring 110 and / or pressure-maintaining valve 4 are supported.
  • the abutment 405 allows due to holes or slots fluid communication between the space above the abutment 405 and the space below, the actual spring chamber 105, too.
  • Preferred for the pressure equalization between these two spaces is a central bore in the horizontal portion of the sleeve 405th
  • a valve spring 415 is supported on the abutment 405 and biases a valve member 410 against a sealing seat 430.
  • the valve member 410 consists in a simple embodiment only of an at least partially spherical body 420, z. As a ball or a hemisphere, sitting directly on the valve spring 415, which is supported on the abutment 405 and biases the body 420 against the sealing seat 430.
  • the partially spherical body 420 in particular the hemisphere, sits on a disc 440, which in turn is connected to the valve spring 415.
  • the outer dimensions of the disc 440 are slightly smaller than the inner dimensions of the spring chamber 105, so that this disc 440 is guided in the spring chamber 105 with some play, which is the Sealing body 420 of the pressure holding valve 4 gives a sufficient vertical guidance in the spring chamber 105. Further, the disc 440 may be seated at the top of the vertical portions of the sleeve 405 (FIG. 3), giving the pressure holding valve 4 a defined maximum lift and preventing the valve member 410 from fluttering or uncontrolled movements. Thus, when the disc 440 resting on the vertical sections of the sleeve 405 still a pressure exchange between the area above the pressure holding valve 4 and below in sufficient time is possible, the disc 440 holes or grooves on its underside / peripheral side have.
  • the sealing seat 430 of the pressure retaining valve 4 is preferably formed in the plate 150, wherein the sealing seat 430 cooperates with the sealing portion 422 of the valve member 410 such that in a closed position of the pressure retaining valve 4 over this area no fluid can be transported.
  • the sealing seat 430 is a conical seat, from which a blind hole continues upward into the plate 150, wherein the inlet bore 152 branches off from the blind hole bore to the inlet channel 140. It is also possible that the inlet bore 152 leads away directly from the sealing seat 430.
  • a bore is further provided, which is part of the inlet channel 140 of the injection valve 1, so that the inlet channel 140 from the lower portion of the injector 1 coming, can continue to the valve seat of the control valve 3 through the plate 150 therethrough.
  • the portion of the inlet channel 140, which is located in the plate 150 formed with a dynamic throttle 154, which narrows the inlet channel 140.
  • the inlet bore 152 preferably branches off within the plate 150 to the pressure retaining valve 4, whereby a fluid connection between inlet channel 140 and sealing seat 430 of the pressure retaining valve 4 is created.
  • the inlet bore 152 z. B. branch off directly from Staudrossel 154.
  • the pressure-maintaining valve 4 is designed such that it only allows the pressure in the inlet channel 140 to be impressed on the spring chamber 105, whereby a pressure P 140 in the inlet channel 140 (downstream of the vertical throttle 154) must be above the pressure p 105 in the spring chamber 105. If the spring chamber pressure P 105 is greater than the pressure P 140 in the inlet channel 140 (downstream of the dynamic throttle 154), the pressure-maintaining valve 4 remains closed and the pressure p 105 in the spring chamber 105 is maintained.
  • the pump chamber 220 adjoins the plate 150 upwardly (FIG. 3), allowing for a compact unit injector.
  • Fig. 4 shows a lower portion of the spring chamber 105, in which the needle piston 115 is guided.
  • the shaft 117 Down to the needle piston 115, the shaft 117 connects, which can be configured integrally either with the needle piston 115 or with the injection needle 170.
  • the needle piston 117 may also be guided as a separate part in a bore above the injection needle 170.
  • On the needle piston 115 act two forces, a static, due to the biasing spring 110, and a hydraulic, due to the fluid pressure P 105 in the spring chamber 105. These two forces are by means of the needle piston 115 and the shaft 117 to the injection needle 170th forwarded, which bias this with a force in the direction of their sealing seat.
  • the shaft 117 is preferably formed in an upper region over almost its entire length as a triflate, so that a fluid connection between the spring chamber 105 and an annular space 120 which is provided in an upper region of the injection needle 170.
  • the shaft 117 preferably acts as a damping element for the injection needle 170, wherein for damping a movement of the injection needle 170, a control edge 118 of the shaft 117 cooperates with a control edge 119 in the injection valve 1, said portion (with control edge 119) in the injection valve body z. B. may be formed as so-called. Damping plate.
  • the two control edges 118, 119 cooperate in such a way that with a corresponding position of the injection needle 170, the annular space 120 is separated from the spring chamber 105.
  • the profile of the control edges 118 and / or 119 as a continuously differentiable function is designed such that there is a dependent on the speed of the motor damping effect. At high speed and correspondingly fast stroke movement of the injection needle 170 results due to fluid mechanical processes increased damping effect. At low engine speed, however, results in a reduced damping effect.
  • the space under the needle piston 115 there is a pressure which is either lower (after pre-injection and during the main injection phase) or equal to (immediately before the pre-injection) the pressure P 105 in the spring chamber 105.
  • the pressure in the space below the needle piston 115 is reduced in each case during a first injection (usually pre-injection) such that it corresponds to a pressure p 140 in the inlet channel 140 upstream of the dynamic throttle 154, or another low pressure.
  • the space below the needle piston 115 is connected by means of a fluid connection 180 to the inlet channel 140.
  • this fluid connection 180 may also be led to other drainage or leakage channels, whereby the pressure below the needle piston 115 is different than in the inlet channel 140 upstream of the dynamic throttle 154.
  • the game (sealing gap 445) between the needle piston 115 and the inner wall of the spring chamber bore 105 is designed such that the pressure p 105 is degraded in the spring chamber 105 via the fluid connection 180 in each case before a first injection. Ie. During a break in spraying, the pressure p 105 in the spring chamber 105 must be reduced via the sealing gap 445 such that rapid opening of the injection needle 170 is still possible.
  • the thus set pressure in the spring chamber 105 corresponds either to the pressure in the inlet channel 140 upstream Staudrossel 154 or the pressure of another drainage line.
  • the pressure below the needle piston 115 is reduced prior to a first injection over the entire speed range. If one wants to realize this also for high speeds, then a pressure drop in the low to medium speed range before a main injection is too high, which can run counter to a safe keeping closed the injection needle 170 in this speed range at a selected biasing spring 110. It would then have a stronger biasing spring 110 can be selected, which would lead to an increased opening pressure of the injection needle 170.
  • the needle piston 115 In order to compensate for tilting of the needle piston 115 and to avoid tilting of the needle piston 115 is the needle piston 115 preferably rounded on its circumference.
  • Fig. 5 shows a preferred embodiment of a sealing portion of the pressure holding valve 4 in a closed and an open position, wherein the sealing body 420 is guided with a small clearance.
  • This small clearance is preferably realized by means of a guide bore 450, which has a diameter of approximately 1 to 6 ⁇ m, preferably 3 to 5 ⁇ m, particularly preferably 4 ⁇ 0.5 ⁇ m, larger diameter than the outer diameter of the sealing body 420.
  • the guide bore 450 is formed in the plate 150, preventing transverse movement of the valve member 410.
  • a fluid connection between the spring chamber 105 and the sealing seat 430 of the pressure holding valve 4 is carried out by means of at least one throttle 435.
  • a favorable area ratio of seat and guide bore for the sealing body 420 is about 1: 1.1 to 1: 3, preferably 1: 1.2 to 1: 2.5, particularly preferably 1: 1.5 to 1: 2, 0th
  • FIGS 6, 7a and 7b and Figures 8a to 8d show a second variant of the invention, wherein like reference numerals are used for like components with the above embodiments.
  • the pressure holding valve 4 is not arranged in the spring chamber 105, but outside of the spring chamber 105, wherein the pressure-holding valve 4 is preferably adjacent to an upper region of the spring chamber 105. This in turn allows for easy production and provision of dimensionally machined portions of the pressure holding valve 4 in the plate 150. Another position of the pressure holding valve 4 in the injection valve 1 is of course possible, with corresponding line holes to the valve body 420 back and from Valve body 420 away to the spring chamber 105 must be provided.
  • the valve body 420 of the pressure holding valve 4 centrally seals an inlet bore 153, which branches off from the inlet channel 140 and leads into an upper region of the spring chamber 105, which can be seen in FIGS. 7a and 7b.
  • an upstream portion of the inlet bore 153 (see Fig. 7a) extends vertically through the plate 150, wherein in a lower portion of the plate 150, the sealing seat 430 of the pressure holding valve 4 adjoins the upstream portion of the inlet bore 153.
  • an annular space adjoins, from which an oblique section (see Fig. 7b) of the inlet bore 153 opens into an upper region of the spring chamber 105.
  • This section may, for. B. be designed as a throttle.
  • the pressure-maintaining valve has a valve member 410, which comprises a valve spring 415 and at the free end thereof a valve body 420 which is preferably designed as a hemisphere, the valve spring 415 being seated in a bore 460 provided in a part of the injection valve which also the spring chamber 105 is configured.
  • the valve body 420 is biased in its sealing position on preferably designed as a conical seat sealing seat 430. In its open position, the valve body 420 is seated with its lower edge preferably on the component of the injection valve, in which also the spring chamber 105 is executed.
  • valve body 420 is guided vertically at its outer diameter to reduce a flutter tendency in the plate 150 in a short dimensionally accurate guide bore 450. Relief of the space below the valve member 420 can be done via the sealing gap between the guide bore 450 and valve body 420.
  • the inlet channel 140 is guided past the pressure-maintaining valve 4 (see Fig. 7a).
  • the Fig. 7a in the plate 150 obliquely extending portion of the inlet channel 140 may be designed as a throttle 154.
  • FIGS. 8a and 8b show a preferred embodiment of the pressure retaining valve 8d according to the invention.
  • a fluid connection 462 which is designed as a vent hole 462 and the valve spring chamber 460 vented.
  • the vent hole 462 branches off in an upper region of the spring chamber 105, preferably above the sleeve 405, and extends obliquely down to the valve spring chamber 460 and opens into it.
  • the oblique course allows a simple and cost-effective production of the vent hole 462 in the injection valve body, wherein the vent hole 462 preferably has defined hydraulic properties and is preferably designed as a throttle 464.
  • venting bore 462 may also be provided at a different location in the injection valve 1 between the valve spring chamber 460 and the spring chamber 105. Furthermore, it is possible for purposes of venting the valve spring chamber 462 not fluidly connected to the spring chamber 105 but with a different space at least partially a lower pressure level than the valve spring chamber 460th
  • the inlet bore 153 may be configured as a simple bore, or as a throttle 435, wherein the pressure in the inlet bore 153 is slightly delayed the spring chamber 105 is impressed.
  • the effective diameter of the vent hole 462 at the same pressures less than or equal to the effective diameter of the inlet bore 153 and the throttle 435, so that the spring chamber 105, a sufficiently high pressure can be impressed and the pressure-maintaining valve 4 does not close too quickly or even open.
  • FIG. 8c A special embodiment of the vent hole 462 in the region of the valve spring chamber 460 is shown in FIG. 8c. Such a widening in the region of the opening of the venting bore 462 enables a more homogeneous pressure reduction and reduces the fluttering tendency of the pressure-retaining valve 4.
  • a preferred radius of the valve body 420 designed as a hemisphere is approximately 1-6 mm, with radii of 2.5 mm or 4 mm being particularly preferred.
  • the stroke of the valve member is about 100-250 ⁇ m, with 150 ⁇ m are particularly preferably realized.

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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)
  • Electromagnetism (AREA)
  • Fuel-Injection Apparatus (AREA)
EP05025818A 2004-11-26 2005-11-25 Injecteur Withdrawn EP1662133A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102004057151A DE102004057151B4 (de) 2004-11-26 2004-11-26 Einspritzventil mit einem Druckhalteventil zur Fluiddruckbeaufschlagung eines Federraums
DE102005007133 2005-02-17

Publications (1)

Publication Number Publication Date
EP1662133A1 true EP1662133A1 (fr) 2006-05-31

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4979676A (en) * 1988-12-31 1990-12-25 Robert Bosch Gmbh Fuel injection device for internal combustion engines
US5282574A (en) * 1991-12-19 1994-02-01 Caterpillar Inc. Hydraulic flow shutoff device for a unit fuel pump/injector
EP0844384A1 (fr) * 1996-11-26 1998-05-27 Lucas Industries Public Limited Company Injecteur
EP0675282B1 (fr) 1994-03-03 1998-08-12 Lucas Industries Public Limited Company Circuits de carburant
DE10160080A1 (de) * 2001-12-07 2003-06-26 Siemens Ag Pumpe-Düse-Einheit
US20030178001A1 (en) * 2002-02-25 2003-09-25 Robert Bosch Gmbh Noise-optimized device for injecting fuel
WO2003106836A1 (fr) * 2002-06-13 2003-12-24 Siemens Aktiengesellschaft Unite pompe-injecteur
US20040045529A1 (en) * 2001-04-21 2004-03-11 Gerard Duplat Fuel injection system for an internal combustion engine

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4979676A (en) * 1988-12-31 1990-12-25 Robert Bosch Gmbh Fuel injection device for internal combustion engines
US5282574A (en) * 1991-12-19 1994-02-01 Caterpillar Inc. Hydraulic flow shutoff device for a unit fuel pump/injector
EP0675282B1 (fr) 1994-03-03 1998-08-12 Lucas Industries Public Limited Company Circuits de carburant
EP0844384A1 (fr) * 1996-11-26 1998-05-27 Lucas Industries Public Limited Company Injecteur
US20040045529A1 (en) * 2001-04-21 2004-03-11 Gerard Duplat Fuel injection system for an internal combustion engine
DE10160080A1 (de) * 2001-12-07 2003-06-26 Siemens Ag Pumpe-Düse-Einheit
US20030178001A1 (en) * 2002-02-25 2003-09-25 Robert Bosch Gmbh Noise-optimized device for injecting fuel
WO2003106836A1 (fr) * 2002-06-13 2003-12-24 Siemens Aktiengesellschaft Unite pompe-injecteur

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