EP1666719A1 - Dispositif d'injection de carburant - Google Patents

Dispositif d'injection de carburant Download PDF

Info

Publication number
EP1666719A1
EP1666719A1 EP05110930A EP05110930A EP1666719A1 EP 1666719 A1 EP1666719 A1 EP 1666719A1 EP 05110930 A EP05110930 A EP 05110930A EP 05110930 A EP05110930 A EP 05110930A EP 1666719 A1 EP1666719 A1 EP 1666719A1
Authority
EP
European Patent Office
Prior art keywords
chamber
piston
damper
nozzle needle
pressure
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Withdrawn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
EP05110930A
Other languages
German (de)
English (en)
Inventor
Michael Kurz
Martin Kropp
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.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
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 Robert Bosch GmbH filed Critical Robert Bosch GmbH
Publication of EP1666719A1 publication Critical patent/EP1666719A1/fr
Withdrawn legal-status Critical Current

Links

Images

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
    • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
    • F02M61/04—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00 having valves, e.g. having a plurality of valves in series
    • F02M61/10—Other injectors with elongated valve bodies, i.e. of needle-valve type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
    • F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
    • F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M57/00—Fuel-injectors combined or associated with other devices
    • F02M57/02—Injectors structurally combined with fuel-injection pumps
    • F02M57/022—Injectors structurally combined with fuel-injection pumps characterised by the pump drive
    • F02M57/025—Injectors structurally combined with fuel-injection pumps characterised by the pump drive hydraulic, e.g. with pressure amplification
    • 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 present invention relates to an injection device for injecting fuel for an internal combustion engine, in particular in a motor vehicle, having the features of the preamble of claim 1.
  • Such Kraflstoffeinspritz sympathy is known for example from DE 102 18 904 A1 and has a stroke-adjustable nozzle needle, with the aid of which the injection of standing under injection pressure fuel can be controlled by at least one spray hole.
  • the nozzle needle has a closing pressure surface, which is arranged in a closing pressure chamber.
  • This closing pressure chamber is connected via a hydraulic control path to a control valve which can be switched between a first switching position and a second switching position.
  • the control valve acts on the control path for closing the nozzle needle with a high pressure.
  • the high pressure in the closing pressure chamber generates at the closing pressure surface a force driving the nozzle needle in the closing direction.
  • the control valve in its second switching position acts on the control path with a low pressure. This leads to a pressure drop in the closing pressure chamber, which reduces the forces acting in the closing direction.
  • the known injector is also equipped with a pressure booster, which is also operated via the control valve.
  • An outlet pressure chamber of the pressure booster is connected via an injection pressure line connected to a nozzle chamber in which the nozzle needle has an effective compression in the opening direction and which has a controlled by the nozzle needle connection to the at least one injection hole.
  • the pressure in the closing pressure chamber of the nozzle needle is lowered on the one hand.
  • the pressure intensifier is controlled to generate the high injection pressure in the output pressure chamber to the other. This injection pressure builds up in the sequence in the nozzle chamber, which generates an effective force in the opening direction of the pressure stage.
  • nozzle needle Due to the increase in pressure in the nozzle chamber and the pressure reduction in the closing pressure chamber, there is an effective in the opening direction of the nozzle needle resultant force in the nozzle needle, so that it lifts from its seat and the connection from the nozzle chamber to the at least one spray hole releases and as a result fuel through the at least one injection hole can be injected under injection pressure.
  • the nozzle needle is so far pressure controlled.
  • the Kraflstoffeinspritz listening invention with the features of the independent claim has the advantage that the nozzle needle can open extremely quickly up to the predetermined advance, which allows an extremely rapid construction of the injection pressure at the at least one injection hole and thus a quasi-instantaneous injection with the high injection pressure.
  • the damping of the opening movement of the nozzle needle starting from the forward stroke ensures that the opening stroke then only increases comparatively slowly, so that the path which the nozzle needle has to cover to close increases only slowly. In this way, extremely short injection times can be realized because the nozzle needle can reduce this comparatively short way in a correspondingly short time.
  • this is achieved by means of a hydraulically operated damper device, which is arranged in the control path.
  • the hydraulic damping effect of the damper device throttles the outflow of fuel from the closing pressure chamber in the loaded with the low pressure control path. By throttling this outflow, the opening stroke of the nozzle needle is correspondingly damped.
  • the damper device is designed such that the described hydraulic damping effect only occurs from the predetermined forward stroke of the nozzle needle. This means that the fuel can flow out of the closing pressure chamber into the control path essentially unthrottled until reaching this forward stroke. As a result, the nozzle needle can open substantially unattenuated. Only from the predetermined forward stroke of the nozzle needle is the damping effect, so that the outflow from the closing pressure chamber is throttled and the opening movement of the nozzle needle is damped in the sequence.
  • the invention is based i.a. on the knowledge that adjusts a seat throttle effect immediately after lifting the nozzle needle from its seat, which substantially throttles the injection of fuel through the at least one injection hole in this opening phase of the nozzle needle.
  • the seat throttle effect results fluidically or fluidically from the present in this opening phase small distance between the nozzle needle and the needle seat.
  • the damper device which allows for a predetermined advance a substantially undamped opening movement for the nozzle needle, it is achieved that the nozzle needle relatively quickly, the opening phase in which the seat throttle effect occurs, passes, resulting in a corresponding reduction in time of seat throttle effect and their influence on the injection process is reduced.
  • the forward stroke can be so dimensioned that the nozzle needle, upon reaching the pre-stroke, the opening phase in which the throttle seat created by the seat of the nozzle needle significantly throttles the injection of fuel through the at least one injection hole leaves. On In this way, the forward stroke is adjusted so that the opening phase with seat throttle effect is as short as possible.
  • the forward stroke is dimensioned so that upon reaching the Vorhubs the seat throttle effect generated by the seat of the nozzle needle is about the same size as or smaller than a hole throttle effect generated by the at least one injection hole.
  • the injection of the fuel through the at least one injection hole is determined only by the Lochdrossel Quantum as soon as the pre-stroke is reached.
  • the forward stroke and thus the undamped opening path of the nozzle needle can be optimized to a particularly small value, which ultimately allows the realization of particularly short injection times.
  • the damper device can basically be realized in an arbitrary manner. For example, it is conceivable to equip the damper device with an unthrottled path and in parallel with a throttled path, which connect the closing pressure chamber with the control path.
  • the unthrottled path is controlled in response to the opening stroke of the nozzle needle.
  • the nozzle needle or a nozzle needle having needle assembly with a control edge in the closing pressure chamber overflows a mouth of the unthrottled path upon reaching the predetermined Vorhubs, whereby the unthrottled path is blocked and then only the throttled path is open.
  • the damper device comprises a stroke-adjustable damper piston which separates a compensation chamber from a damper chamber, wherein also a throttle path is provided, which connects the compensation chamber with the damper chamber.
  • the compensation chamber communicates with the closing pressure chamber, while the damper chamber is connected via the control path to the control valve.
  • the damper piston is adjustable between a first piston position and a second piston position. In the first piston position, the damper chamber has a maximum volume, while at the same time the compensation chamber occupies a minimum volume. In contrast, the damper chamber has a minimal volume in the second piston position, while at the same time the compensation chamber occupies a maximum volume.
  • the piston stroke required to move the damper piston from the first To transfer piston position in the second piston position is such that when opening the nozzle needle, the nozzle needle reaches the forward stroke, as soon as the damper piston reaches its second piston position.
  • the damper chamber is subjected to the low pressure in the second switching position of the control valve, which leads to a pressure difference between the damper chamber and the expansion chamber.
  • the damper piston moves out of its first piston position, resulting in a reduction of the damper volume and an increase in the volume of the balancing space. Consequently, the pressure in the expansion chamber and consequently also in the closing pressure chamber decreases in the expansion chamber. In this way, the Düsennadel, lift the needle assembly off the seat and perform an opening stroke.
  • the opening stroke reduces the volume of the closing pressure chamber.
  • the thereby displaced hydraulic volume can pass substantially unrestricted in the expansion chamber, since its volume increases in a corresponding manner.
  • the opening movement of the nozzle needle is thereby quasi unattenuated.
  • the damper piston assumes its second piston position.
  • the volume of the damper chamber has then reached its minimum value, while the volume of the compensation chamber has its maximum.
  • the opening movement of the nozzle needle then leads in the closing pressure chamber to a pressure increase, since the hydraulic fluid from the closing pressure chamber or from the communicating therewith compensating space can flow out throttled only through the throttle path.
  • there is a damping of the opening stroke of the nozzle needle By providing the compensation chamber, it is possible to transfer the fuel displaced during the opening stroke by the nozzle needle or needle assembly quasi unthrottled in the expansion chamber, whereby a particularly high dynamics for the opening movement of the nozzle needle can be achieved.
  • the needle assembly may have a closing pressure piston, which has the closing pressure surface and is supported loosely axially on the nozzle needle.
  • the nozzle needle then has a Hilfssch constitu Kunststoff Kunststoff Structure, which is arranged in a Hilfssch Anlagen horrraum, which is connected via a throttled connecting line to the control path. Due to this design, the nozzle needle can be separated from the rest of the needle assembly when closing, ie from the closing pressure piston when in Auxiliary closing pressure chamber, the pressure build-up is realized faster than in the closing pressure chamber. At the same time, the nozzle needle has a smaller inertial mass than the entire needle assembly, which also leads to increased dynamics for the nozzle needle.
  • a short opening time in conjunction with an extremely short closing time leads to correspondingly short injection times, which can be realized with the aid of the injection device according to the invention.
  • Short injection times in conjunction with a high injection pressure lead to high specific power of the internal combustion engine with simultaneously reduced pollutant emissions.
  • an injection device 1 which is used in an internal combustion engine, in particular in a motor vehicle, for injecting fuel into an injection space 2, which may be a combustion chamber and / or a mixture formation space, comprises at least one nozzle needle 3 which is in one Injector body 4 is mounted adjustable in stroke.
  • the nozzle needle 3 serves in a known manner for controlling an injection of fuel through at least one injection port 5.
  • the nozzle needle 3 cooperates with a needle seat 6.
  • the nozzle needle 3 In a closed position shown here, the nozzle needle 3 is seated in the seat 6 and thereby blocks a connection of the at least one injection hole 5 with a nozzle chamber 7.
  • this lifts from its seat 6, which the connection of the nozzle chamber 7 to the at least one Spray hole 5 opens.
  • the nozzle needle 3 is here part of a needle assembly 8, which in addition to the nozzle needle 3 also has a closing pressure piston 9 here.
  • the closing pressure piston 9 is supported loosely on the nozzle needle 3 in the axial direction, ie in the stroke direction. That is, closing pressure piston 9 and nozzle needle 3 are not attached to each other, but can transmit compressive forces in the stroke direction.
  • the needle assembly 8 forms a common hubver ause unit.
  • the needle assembly 8 has a closing pressure surface 10, which is formed here on the closing pressure piston 9 and which is arranged in a closing pressure chamber 11.
  • a closing compression spring 12 is also arranged, which is supported on the one hand on the injector body 4 and on the other hand on the closing pressure piston 9.
  • the closing pressure spring 12 biases the closing pressure piston 9 and thus the needle dressing 8 in the closing direction of the nozzle needle 3.
  • the closing pressure chamber 11 is connected via a hydraulic control path 13 to a control valve 14 of the injector 1.
  • the control valve 14 is switchable between a first switching position shown here and a second switching position.
  • the control valve 14 has three ports, namely a first port 15, a second port 16 and a third port 17 to the first port 15 is directly or indirectly connected to a high pressure source 18, which is realized here by a high-pressure fuel line.
  • this high-pressure fuel line 18 serves to jointly supply a plurality of such injection devices 1 with high-pressure fuel.
  • To the second terminal 16 of the control path 13 is connected.
  • the third connection 17 is connected to a low-pressure source 19 or to a pressure sink 19, which may be suitably formed by a comparatively pressure-free return.
  • the control valve 14 is designed in the embodiment shown here so that it is hydraulically actuated, wherein it is also designed as a servo valve.
  • a switching valve 20 is provided here, which is preferably electrically or electromagnetically actuated.
  • the switching valve 20 has a first switching valve chamber 21, which is connected to the low-pressure source 19, and a second switching valve chamber 22, which is connected to a first control valve chamber 23 of the control valve 14.
  • This first control valve chamber 23 is bounded by a valve body 24 of the control valve 14, which cooperates in the first switching position with a first control valve seat 25 and in the second switching position with a second control valve seat 26.
  • the third port 17 opens into a second control valve chamber 27, while the second port 16 opens into a third control valve chamber 28.
  • the first port 15 opens into a fourth control valve chamber 29 or is formed by the fourth control valve chamber 29.
  • the injection device 1 also has a pressure booster 30, by means of which the high pressure of the high-pressure fuel line 18 can be translated to a significantly higher injection pressure.
  • the pressure booster 30 has a booster piston 31 which is mounted Hubver mich and thereby separates an input pressure chamber 32 from a control pressure chamber 33, while also an output pressure chamber 34 axially limited.
  • the booster piston 31 is biased by means of a return spring 35 in the initial position shown.
  • the input pressure chamber 32 is connected to the high-pressure source 18. At the same time, the input pressure chamber 32 is connected to the first port 15 of the control valve 14.
  • the first port 15 of the control valve 14 is formed directly at the inlet pressure chamber 32, so that the fourth control valve chamber 29 merges directly into the inlet pressure chamber 32.
  • the control pressure chamber 33 is connected to the control path 13 and connected via this to the second connection 16 of the control valve 14.
  • the outlet pressure chamber 34 is connected to the nozzle chamber 7 via an injection pressure line 36, so that the injection pressure building up in the outlet pressure chamber 34 is transmitted to the nozzle chamber 7.
  • a damper device 37 is arranged, which operates hydraulically and thereby damps the opening stroke of the nozzle needle 3 and the needle assembly 8 from a predetermined advance stroke 38.
  • the needle seat 6 facing the end of the nozzle needle 3 is indicated on reaching the Vorhubs 38 with a broken line.
  • the forward stroke 38 is shown exaggerated here for clarity.
  • the damper device 37 comprises a damper piston 39, which is mounted in a stroke-adjustable manner in the injector body 4. While the compensation chamber 40 communicates with the closing pressure chamber 11, the damper chamber 41 is connected via the control path 13 to the control valve 14 and to the second terminal 16 thereof.
  • the damper device 37 has a throttle path 42, which throttles the compensation chamber 40 connects with the damper chamber 41.
  • this throttle path 42 as here, have a damper throttle 43, which is formed in the damper piston 39.
  • the damper throttle 43 in this way connects the compensation chamber 40 throttled by the damper piston 39 with the damper space 41.
  • the throttle path 42 may be e.g. be formed by at least one longitudinal groove or by a radial play between the damper piston 39 and the axial guide.
  • the damper piston 39 is adjustable between a first Kobengnagna shown here and a offset by a predetermined piston stroke 44 second piston position.
  • the damper chamber 41 In the first piston position, the damper chamber 41 has a maximum volume, while the compensation chamber 40 has a minimal volume.
  • the damper chamber 41 occupies a minimum volume in the second piston position, while at the same time the expansion chamber 40 has a maximum volume.
  • the dimensioning of the damper piston 39 is selected so that its piston stroke 44, which is required to move the damper piston 39 between the first piston position and the second piston position, is determined so that the nozzle needle 3 when opening reaches the aforementioned predetermined advance stroke 38, as soon as the damper piston 39 reaches its second piston position.
  • a seat 45 is provided for the damper piston 39, with which the damper piston 39 cooperates in its first piston position.
  • This piston seat 45 is designed in such a way that a hydraulically effective surface 46 (see FIG. 2), which is formed on a piston side facing the compensation chamber 40, is smaller in the first piston position than in a position of the damper piston 39 lifted from the seat 45.
  • a hydraulically effective surface 46 see FIG. 2
  • a seat surface which is not described here in more detail
  • seat surface and surface portion 47 are flat; In principle, a conical shape is possible.
  • the nozzle needle 3 expediently has an auxiliary closing pressure surface 50, which faces away from the at least one injection hole 5 and is arranged in an auxiliary closing pressure chamber 51.
  • the auxiliary closing pressure chamber 51 is connected to the control path 13 via a throttled connecting line 52.
  • the throttling effect of this connecting line 52 can be achieved, for example, by means of a corresponding throttle 53.
  • the throttle 53 or the throttling effect of the connecting line 52 is dimensioned smaller than the damper nozzle 143 or the throttling action of the throttle path 42.
  • the auxiliary closing pressure chamber 51 is connected via a return check valve 54 to the injection pressure line 36, wherein the return check valve 54 is oriented so that it blocks the auxiliary closing pressure chamber 51 and opens to the injection pressure line 36 out.
  • a compensation path 55 is also provided, via which the auxiliary closing pressure chamber 51 communicates with the closing pressure chamber 11.
  • this compensation path 55 can have at least one bore 56 which is passed through the closing pressure piston 9 and opens at one end in the closing pressure chamber 11 and at the other end in the auxiliary closing pressure chamber 51.
  • the bore 56 is also positioned so that it opens within an annular ridge 57 in the auxiliary closing pressure chamber 51.
  • This annular web 57 can be designed such that it separates an area of the auxiliary closing pressure chamber 51 located within the annular web 57 from a region of the auxiliary closing pressure chamber 51 lying outside of the annular web 57 when the closing pressure piston 9 adjoins the nozzle web 3. In that regard, then the guided through the bore 56 compensating path 55 is locked.
  • the injection device 1 operates as follows:
  • the nozzle needle 3 is closed, that is, there is no injection of fuel into the injection chamber 2 instead.
  • the switching valve 20 assumes the first position shown, in which an internal connection between the two switching valve chambers 21 and 22 is blocked. Accordingly, in the first switching valve chamber 21, the low pressure prevails, while in the second switching valve chamber 22, the high pressure prevails, which propagates from the high pressure source 18 through the inlet pressure chamber 32 of the pressure booster 30 to the fourth control valve chamber 29 fortp and from there by a throttled connection 58 into the first control valve chamber 23 propagates, which in turn communicates with the second switching valve chamber 22.
  • the control valve 14 is located in the first switching position shown, in which the valve body 24 is seated in its first control valve seat 25 and is lifted from its second control valve seat 26. Accordingly, the second control valve room 27 separated from the third control valve chamber 28 and the fourth control valve chamber 29. In the second control valve chamber 27 there is low pressure in the sequence.
  • the fourth control valve chamber 29 is connected via the first port 15 and here through the inlet pressure chamber 32 of the pressure booster 30 through to the high pressure source 18, so that prevails in the fourth control valve chamber 29 of the high pressure. Since the valve body 24 releases the second control valve seat 26 in the first switching position, the high pressure also prevails in the third control valve chamber 28. In other words, in the first switching position of the control valve 14, the first port 15 is connected to the second port 16, while the third port 17 is locked.
  • inlet pressure chamber 32 prevails by its connection to the high pressure source 18 of the high pressure.
  • the high pressure is also planted in the control pressure chamber 33 of the pressure booster 30, in the damper chamber 41, in the compensation chamber 40, in the closing pressure chamber 11 and in the auxiliary closing pressure chamber 51 continues.
  • the return check valve 54 also prevails in the injection pressure line 36 is substantially the high pressure, which propagates via the injection pressure line 36 into the outlet pressure chamber 34 of the pressure booster 30 and into the nozzle chamber 7 of the nozzle needle 3.
  • the switching valve 20 In order to open the nozzle needle 3, the switching valve 20 is transferred to its second position, in which the two switching valve chambers 21 and 22 communicate with each other. Accordingly, there is a pressure drop in the second switching valve chamber 22. This pressure drop propagates into the first control valve chamber 23 and leads to an adjusting movement of the valve body 24. The valve body 24 is thus transferred to the second switching position of the control valve 14, in which the valve body 24 lifts off from the first control valve seat 25 and retracts into the second control valve seat 26 , As a result, the second control valve room 27 and the third control valve room 28 communicate with each other while the communication between the third control valve room 28 and the fourth control valve room 29 is blocked.
  • the pressure drop in the control pressure chamber 33 of the pressure booster 30 causes the booster piston 31 to move, thereby compressing the fuel in the output pressure space 34 and generating therein the desired high injection pressure.
  • This injection pressure propagates through the injection pressure line 36 into the nozzle chamber 7.
  • the nozzle needle 3 has at least one pressure step 59, which results from a cross-sectional difference between a nozzle needle cross-section 60 in an axial guidance of the nozzle needle 3 and a seat cross-section 61 in the needle seat 6.
  • the pressure increase in the nozzle chamber 7 leads to the pressure stage 59 for the introduction of effective in the opening direction of the nozzle needle 3 forces.
  • the pressure drop in the damper chamber 41 leads to a pressure difference between the damper chamber 41 and the compensation chamber 40.
  • This pressure difference results in a resultant force in the damper piston 39 which allows the damper piston 39 to be lifted out of its seat 45 and thus out of its first piston position.
  • the hydraulically effective surface 46 facing the compensation chamber 40 is enlarged, which at the same time also amplifies the force driving the damper piston 39 into the second piston position.
  • the volume of the expansion space 40 increases, resulting in a pressure drop therein.
  • This pressure drop propagates into the closing pressure chamber 11 and reduces the forces acting on the closing pressure surface 10 closing forces.
  • a resultant force acting in the opening direction results in a comparatively large force in the needle dressing 8.
  • the nozzle needle 3 lifts off from its needle seat 6.
  • the volume of the expansion chamber 40 can not increase further.
  • the opening stroke of the needle assembly 8 leads to an increase in pressure in the closing pressure chamber 11, since the volume of fuel trapped therein can escape only through the throttle path 42, that is throttled from the closing pressure chamber 11 or from the compensation chamber 40.
  • the opening stroke of the nozzle needle 3 it comes for the opening stroke of the nozzle needle 3 to a damping.
  • the nozzle needle 3 has then reached the predetermined advance stroke 38, up to which the opening movement of the nozzle needle 3 should be as undamped as possible and from which the opening movement of the nozzle needle 3 should be damped.
  • the damped opening movement of the nozzle needle 3 from the pre-stroke 38 causes the nozzle needle 3 from the pre-stroke 38 only relatively slowly removed from the needle seat 6. This is advantageous if the nozzle needle 3 is to be closed again within a short time in order to realize extremely short injection times.
  • the preliminary stroke 38 is dimensioned so that the nozzle needle. 3 when reaching the pre-stroke 38 already leaves the said beginning or opening phase.
  • the seat throttle effect significantly throttles the injection of the fuel through the at least one spray hole 5 before reaching the pre-stroke 38
  • the seat throttle effect is insignificant or of subordinate importance upon reaching or passing the pre-stroke 38 on the injection of the fuel.
  • the pre-stroke 38 is dimensioned so that the seat throttle effect when reaching the pre-stroke 38 is equal to or preferably even smaller than a hole throttle effect generated by the at least one spray hole 5.
  • the injection is determined only by the injection pressure and the dimensioning of the at least one injection hole 5, while the seat throttle effect is without influence.
  • the switching valve 20 is switched back to the first position shown.
  • the two switching valve chambers 21, 22 are again separated from each other, so that the high pressure can build up again in the second switching valve chamber 22.
  • This high pressure then inevitably builds up in the first control valve chamber 23 and ultimately leads to an adjustment of the control valve body 24 in the first switching position of the control valve 14.
  • the third port 17 is blocked while the first port 15 is connected to the second port 16 , Consequently, the high pressure can build up in the control path 13 again, which then builds up again in the control pressure chamber 33 and leads to a discharge in the output pressure chamber 34.
  • This pressure relief propagates via the injection pressure line 36 into the nozzle chamber 7.
  • the pressure in the damper chamber 41 and delayed in the auxiliary closing pressure chamber 51 increases.
  • the damper piston 39 transfers the pressure building up in the damper chamber 41 to the compensation chamber 40. From this, the high pressure in the closing pressure chamber 11 and via the compensation path 55 first enters the region of the auxiliary closing pressure chamber located inside the annular web 57 51 and after the lifting of the nozzle needle 3 from the closing pressure piston 9 and in the area lying outside of the annular web 57 of the auxiliary closing pressure chamber 51st
  • the pressure can build up faster than in the closing pressure chamber 11 in the auxiliary closing pressure chamber 51, since the throttle 53 in the connecting line 52 has a smaller throttle effect than the damper throttle 43 in the throttle path 42 Pressure increase in the auxiliary closing pressure chamber 51 to the fact that the nozzle needle 3 is particularly strong or additionally driven in the closing direction via the auxiliary closing pressure surface 50. Due to the separation of the nozzle needle 3 from the closing pressure piston 9, only the inertial mass of the nozzle needle 3 has to be accelerated in the direction of the needle seat 6. Accordingly, the nozzle needle 3 reacts very quickly to the closing command, which allows the realization of extremely short injection times.
  • the pressure increase in the damper chamber 41 simultaneously leads to a provision of the damper piston 39 in the first piston position. Since in this first piston position the damper piston 39 sits in its seat 45 and thus has only the reduced hydraulically effective surface 46 on the side facing the compensation chamber 40, the damper piston 39 remains in its first piston position.
  • the booster piston 31 which is driven substantially by the return spring 35, it comes in the output pressure chamber 34 to a pressure drop. As soon as the pressure there drops below the high pressure, the return check valve 34 opens, whereby the transitional pressure chamber 34 can be refilled.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Fuel-Injection Apparatus (AREA)
EP05110930A 2004-12-06 2005-11-18 Dispositif d'injection de carburant Withdrawn EP1666719A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE200410058689 DE102004058689A1 (de) 2004-12-06 2004-12-06 Kraftstoffeinspritzeinrichtung

Publications (1)

Publication Number Publication Date
EP1666719A1 true EP1666719A1 (fr) 2006-06-07

Family

ID=35432406

Family Applications (1)

Application Number Title Priority Date Filing Date
EP05110930A Withdrawn EP1666719A1 (fr) 2004-12-06 2005-11-18 Dispositif d'injection de carburant

Country Status (2)

Country Link
EP (1) EP1666719A1 (fr)
DE (1) DE102004058689A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0641931A1 (fr) * 1993-09-06 1995-03-08 Servojet Electronic Systems, Ltd. Système d'injection de combustible à accumulateur
US20010039935A1 (en) * 1998-07-31 2001-11-15 Denso Corporation Fuel injection system having pre-injection and main injection
DE10218904A1 (de) 2001-05-17 2002-12-05 Bosch Gmbh Robert Kraftstoffeinspritzeinrichtung
WO2004003377A1 (fr) * 2002-06-29 2004-01-08 Robert Bosch Gmbh Dispositif permettant d'amortir la course de l'aiguille sur des injecteurs de carburant commandes par pression
WO2004003375A1 (fr) * 2002-06-29 2004-01-08 Robert Bosch Gmbh Dispositif d'amortissement de levee de l'aiguille d'un injecteur de carburant

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0641931A1 (fr) * 1993-09-06 1995-03-08 Servojet Electronic Systems, Ltd. Système d'injection de combustible à accumulateur
US20010039935A1 (en) * 1998-07-31 2001-11-15 Denso Corporation Fuel injection system having pre-injection and main injection
DE10218904A1 (de) 2001-05-17 2002-12-05 Bosch Gmbh Robert Kraftstoffeinspritzeinrichtung
WO2004003377A1 (fr) * 2002-06-29 2004-01-08 Robert Bosch Gmbh Dispositif permettant d'amortir la course de l'aiguille sur des injecteurs de carburant commandes par pression
WO2004003375A1 (fr) * 2002-06-29 2004-01-08 Robert Bosch Gmbh Dispositif d'amortissement de levee de l'aiguille d'un injecteur de carburant

Also Published As

Publication number Publication date
DE102004058689A1 (de) 2006-06-14

Similar Documents

Publication Publication Date Title
EP1577538B1 (fr) Dispositif d'injection de combustible pour des moteurs à combustion interne avec amortissement de la levée de l'aiguille
EP1636484B1 (fr) Injecteur pour moteurs a combustion interne
EP1654456B1 (fr) Dispositif d'injection de carburant pour moteur a combustion interne
EP1584813A2 (fr) Injecteur pour moteur à combustion avec une aiguille d'injection contrôlée directement
EP1853813A1 (fr) Injecteur
EP1763628A1 (fr) Injecteur
DE10221384A1 (de) Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine
EP1865192B1 (fr) Injecteur de carburant doté d'une assistance adaptative à la direction
EP1929149B1 (fr) Injecteur
WO2007000371A1 (fr) Injecteur equipe d'un multiplicateur de pression raccordable
WO2004022929A1 (fr) Actionneur hydraulique de soupape servant a actionner une soupape d'echange de gaz
EP1655477B1 (fr) Servo-valve électro-hydraulique
EP1697628A1 (fr) Injecteur
EP1377745B1 (fr) Procede pour actionner une unite pompe-ajutage et unite pompe-ajutage correspondante
EP1666719A1 (fr) Dispositif d'injection de carburant
EP1655479B1 (fr) Installation d'injection de carburant
EP1704322B1 (fr) Injecteur
DE102004038189A1 (de) Kraftstoffeinspritzeinrichtung für Brennkraftmaschinen mit direkt ansteuerbaren Düsennadeln
EP1519032A1 (fr) Injecteur de carburant
WO2005038230A1 (fr) Gicleur pour un moteur a combustion interne
WO2004018866A1 (fr) Systeme d'injection de carburant destine a un moteur a combustion interne
EP1778967B1 (fr) Injecteur
WO2005026525A1 (fr) Soupape d'injection de carburant pour moteur a combustion interne
WO2005068826A1 (fr) Injecteur et procede associe permettant de faire fonctionner ledit injecteur
DE10323562A1 (de) Kraftstoffeinspritzeinrichtung für eine Brennkraftmaschine

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA HR MK YU

AKX Designation fees paid
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20061208

REG Reference to a national code

Ref country code: DE

Ref legal event code: 8566