EP3165759A1 - Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur - Google Patents

Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur Download PDF

Info

Publication number
EP3165759A1
EP3165759A1 EP15193750.5A EP15193750A EP3165759A1 EP 3165759 A1 EP3165759 A1 EP 3165759A1 EP 15193750 A EP15193750 A EP 15193750A EP 3165759 A1 EP3165759 A1 EP 3165759A1
Authority
EP
European Patent Office
Prior art keywords
fuel
atomizer
seat
channels
sealing seat
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Withdrawn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
EP15193750.5A
Other languages
German (de)
English (en)
Other versions
EP3165759A8 (fr
Inventor
Sergio Stucchi
Raffaele Ricco
Onofrio De Michele
Marcello Gargano
Carlo Mazzarella
Domenico Lepore
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.)
Centro Ricerche Fiat SCpA
Original Assignee
Centro Ricerche Fiat SCpA
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 Centro Ricerche Fiat SCpA filed Critical Centro Ricerche Fiat SCpA
Priority to EP15193750.5A priority Critical patent/EP3165759A1/fr
Publication of EP3165759A1 publication Critical patent/EP3165759A1/fr
Publication of EP3165759A8 publication Critical patent/EP3165759A8/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Withdrawn legal-status Critical Current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
    • F02M61/042—The valves being provided with fuel passages
    • 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
    • F02M61/06—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 the valves being furnished at seated ends with pintle or plug shaped extensions
    • 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
    • F02M61/08—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 the valves opening in direction of fuel flow
    • 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
    • F02M61/12—Other injectors with elongated valve bodies, i.e. of needle-valve type characterised by the provision of guiding or centring means for valve bodies
    • 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
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1806—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for characterised by the arrangement of discharge orifices, e.g. orientation or size
    • 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
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1806—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for characterised by the arrangement of discharge orifices, e.g. orientation or size
    • F02M61/1833—Discharge orifices having changing cross sections, e.g. being divergent
    • 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
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1873—Valve seats or member ends having circumferential grooves or ridges, e.g. toroidal
    • 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
    • F02M61/18—Injection nozzles, e.g. having valve seats; Details of valve member seated ends, not otherwise provided for
    • F02M61/1893—Details of valve member ends not covered by groups F02M61/1866 - F02M61/188

Definitions

  • the present invention relates to an injection method for injecting fuel into a combustion chamber of an internal-combustion engine.
  • the present invention refers to a fuel-injection system of the common-rail type for a diesel-cycle engine.
  • fuel injectors are provided with an atomizer having a nozzle and a needle, which translates under the action of an actuator for opening and closing a sealing seat provided on the nozzle.
  • the needle is actuated by means of a servo-actuation system, hence in an indirect way, basically on account of the strong forces of actuation that are necessary for getting the needle to translate, even though there is increasingly felt the need to design injectors with direct actuation of the needle, in particular to enable more complex actuation laws (for example, the so-called "boot shape” ones).
  • the atomizer is designed, in general, with the aim of obtaining a fuel spray such as to render as homogeneous as possible the distribution of the fuel with the air in the combustion chamber of the respective engine cylinder.
  • a good homogenisation guarantees efficiency of combustion and hence reduces pollutant emissions.
  • high penetration is an essential condition, especially at high loads, i.e., at full power, to cause the fuel not to remain in the proximity of the outlet of the atomizer and to mix with the air.
  • the pressure in the combustion chamber may assume values higher than 120 bar (according to the compression ratio and the pressure of supercharged air), and consequently the density of the air assumes values of approximately 40 kg/m 3 .
  • the density of the air assumes values of approximately 40 kg/m 3 .
  • a good atomization enables increase of the contact surface between fuel and air, given the same injected amount, to render combustion uniform.
  • the nozzle of the atomizer has a series of holes of preset dimensions (for example, 0.12 mm), arranged at equal distances apart about the axis of the injector.
  • the needle axially translates under the control of the electric actuator so as to open/close an annular passage for supplying the fuel to such holes.
  • the needle lift determines a discrete variation of the fuel flow rate, basically of an on-off type. Consequently, the amount of injected fuel at each injection is determined by the times of opening of the nozzle and by the supply pressure of the fuel, and not by the needle lift.
  • the sole exception is represented by the pilot injections, when volumes of fuel of less than 3-4 mm 3 are introduced. In this case, in fact, the times of actuation of the needle are extremely short and do not enable the needle to rise completely. In any case, the volume of fuel introduced once again depends upon the time of actuation of the electric actuator.
  • this type of atomizers does not enable a variable penetration and consequently is not compatible with injection strategies that envisage injection of the fuel markedly anticipated with respect to the top dead centre of the piston.
  • the anticipated injections occur in a condition of low density of the air in the combustion chamber so that the solid-cone spray at high penetration would come to touch the wall of the cylinder, with consequent problems (dilution of the engine oil and greater formation of unburnt fuel and particulate).
  • the atomizer has a needle of so-called “pintle” type, i.e. the nozzle is opened via a displacement of the needle outwards (“outwardly opening nozzle type”), by pushing the needle via an actuator of a piezoelectric or magnetostrictive type.
  • the electrical command supplied to the actuator causes a lengthening of the actuator itself, proportional to the electrical command supplied, and such lengthening in turn causes a translation of the needle in a direction concordant with the aforesaid lengthening.
  • the actuator shortens automatically and re-assumes its initial length.
  • a spring thus brings the needle back into the closing position.
  • the end of the needle is defined, in general, by a head delimited by a frustoconical surface that comes to bear upon a sealing seat defined by an annulus on the nozzle when the latter is closed.
  • the spray deriving from this type of atomizer is shaped like a cone or an umbrella, commonly referred to as “hollow cone”, in so far as it extends throughout the circumference of the sealing seat on the nozzle. It is evident that the axial position of the needle and, hence, the circular outflow area for the fuel vary in a continuous, and non-discrete, way as a function of the electrical command supplied to the actuator.
  • the solution with hollow-cone spray enables drops to be obtained having a relatively small diameter at the atomizer outlet (approximately 1/10 of the exiting drops of a solid-cone spray).
  • first drops for the hollow-cone spray we have that, at the sealing seat (i.e., at the outflow area of the atomizer) there is hence formed a plane and continuous fuel film, which generates the drops of the spray; the thickness of this film is hence very close to the needle lift.
  • the modality of formation of the first drops (the so-called primary "break-up"), for this type of atomizer, is illustrated in Figure 10A , and is referred to as "Linearized Instability Sheet Atomization" (LISA). It emerges that the diameter of the first drops generated is very close to the needle lift. Consequently, in the case considered, the first drops will have diameter of approximately 10 ⁇ m.
  • the first drops that are formed have a diameter equal to the diameter of the hole of the atomizer.
  • the drops of fuel generated by the circular outflow area for the hollow-cone spray have a kinetic energy decidedly lower (approximately 1/1000) than that of the drops exiting in the case of the solid-cone spray, in so far as they have a mean radius that is smaller (approximately 1/10), which is determined basically by the needle lift, as explained above.
  • This substantial difference of kinetic energy obviously leads the drops of fuel to follow a shorter path in the combustion chamber (approximately one half or one third, on the basis of experimental photographic findings) as compared to the solution with solid-cone spray.
  • the drops of fuel of the solution with hollow-cone spray are already relatively small at outlet from the atomizer, they present a low tendency to break up further into even smaller drops.
  • This tendency is generally evaluated on the basis of a parameter referred to as "Weber number", which is the ratio of the inertial forces of the drops in the air to the surface-tension forces of the drops themselves. The higher the Weber number, the greater the tendency of the fuel to break up into smaller drops.
  • Weber number is directly proportional to the diameter of the drop so that it indicates clearly that the smaller drops of the hollow-cone spray have a lower tendency to break up than the larger ones of the solid-cone spray.
  • the times of injection could be reduced and the instantaneous fuel flow rate could be increased, for example by doubling the needle lift.
  • an error in the times of injection that is small in percentage terms would have significant repercussions on the amount of injected fuel.
  • the electric actuators have a minimum command time, below which it is not possible to obtain actuation.
  • an engine operating mode of a mixed type namely, an HCCI (Homogeneous-Charge Compression-Ignition) mode at low and medium loads, with high atomization of the fuel in the combustion chamber and with contained penetration to prevent the phenomenon of impact or impingement of the fuel on the cylinder wall, and a traditional CI (Compressed Ignition) mode at high loads, with high penetration of the fuel into the combustion chamber.
  • HCCI Homogeneous-Charge Compression-Ignition
  • a traditional CI Compressed Ignition
  • the aim of the present invention is to provide an injection method for injecting fuel into a combustion chamber of an internal-combustion engine that will enable the drawbacks set forth above to be overcome in a simple and inexpensive way.
  • an injection method for injecting fuel into a combustion chamber of an internal-combustion engine is provided as defined in claim 1.
  • an atomizer is provided as defined in claim 4, as well as a process for producing such atomizer, as defined in claim 14.
  • the reference number 1 designates a fuel electro-injector (illustrated in a simplified way) forming part of a high-pressure fuel-injection system, for injecting fuel into a combustion chamber 2 (schematically illustrated in Figure 3 ) of an internal-combustion engine.
  • the injection system is of the common-rail type, for a diesel-cycle internal-combustion engine.
  • the electro-injector 1 comprises an injector body 4, which extends along a longitudinal axis 5, is preferably constituted by a number of pieces fixed together, and has an inlet 6 for receiving fuel supplied at high pressure, in particular at a pressure of between 600 and 2800 bar.
  • the inlet 6 is connected in a way not illustrated to a common rail, which in turn is connected to a high-pressure pump (not illustrated), which also forms part of the injection system.
  • the electro-injector 1 ends with a fuel atomizer 10 comprising a nozzle 11, which is fixed to the injector body 4 and has a seat 13 obtained in a through way along the axis 5.
  • the atomizer 10 further comprises a valve needle 12, which extends along the axis 5 and is axially mobile in the seat 13 so as to open/close the nozzle 11, performing an opening stroke, or lift, that is directed axially towards the outside of the seat 13, and a closing stroke that is directed axially towards the inside of the nozzle 11 and of the injector body 4.
  • this electro-injector 1 is of the type generally referred to as "outwardly opening nozzle", or else as “hollow-cone spray”.
  • valve needle 12 has a rear end portion 15 resting axially against a transmission rod 28, defined by a distinct piece set in an area in intermediate the injector body 4.
  • the valve needle 12 and the rod 28 form a single piece.
  • the nozzle 11 has a sealing seat 21, which, together with a head 20 of the valve needle 12, defines a outflow area 14 for the fuel.
  • the outflow area 14 is shaped like a continuous annulus, with a width that is constant along the circumference, but increases axially in a continuous way as the opening stroke of the valve needle 12 progresses.
  • the fuel is injected into the combustion chamber 2 with a spray that is continuous along the circumference of the outflow area 14, i.e., with a spray that, immediately downstream of the outflow area 14, is conical or else umbrella-shaped, as may be seen also in Figure 5 .
  • the flow rate of the injected fuel through the outflow area 14 is variable, in a way proportional to the axial stroke of the valve needle 12.
  • the sealing seat 21 is not defined by a sharp edge, but by an annulus corresponding to a chamfer or to a radiusing that joins together a front surface 17, external to the seat 13 and to the sealing seat 21, and a cylindrical surface 18 of the seat 13.
  • the chamfer or radiusing of the sealing seat 21 reduces the specific pressure or load of the head 20 on the nozzle 11 during closing and hence reduces the stresses and the risks of failure due to fatigue.
  • the head 20 has an external diameter greater than the maximum diameter of the sealing seat 21 and of the remaining part of the valve needle 12. Towards the nozzle 11, the head 20 is delimited by a surface 19 that is designed to come to bear upon the sealing seat 21 and is defined by a truncated cone or else by a convex cap symmetrical with respect to the axis 5. When these two components are coupled together in contact, they define a single static seal, i.e., a seal that guarantees a perfect closing of the outlet of the nozzle 11.
  • the sealing seat 21 and the valve needle 12 are sized in such a way as to define a outflow area 14 that varies in a continuous way, and not in a discrete stepwise way, as the axial position of the valve needle 12 varies.
  • the opening stroke towards the outside of the valve needle 12 causes an initial opening of the nozzle 11 and then a progressive increase of the outflow area 14 for the fuel.
  • the outflow area 14 is also relatively small so that the fuel is injected with a marked atomization and a spray characterized by contained penetration and by a substantial homogeneity in the circumferential direction, if examined with a system of cylindrical co-ordinates.
  • the outflow area 14 is also relatively wide.
  • the fuel is injected with a spray characterized by high penetration.
  • This variability in the configuration of the spray as a function of the lift of the valve needle 12 proves advantageous, for example, for providing an engine operating mode of a mixed type, i.e., an HCCI mode at low and medium loads, with high atomization of the fuel in the combustion chamber 2, and a traditional CI mode at high loads, with high penetration of the fuel into the combustion chamber 2.
  • the atomizer 10 has a passage 16, which is defined radially by a stem 41 of the valve needle 12 and by the seat 13 of the nozzle 11.
  • the passage 16 comprises an end zone 42 that communicates permanently with the inlet 6 by means of at least one channel (not illustrated), provided in the injector body 4 and in the nozzle 11, so that it defines a high-pressure environment.
  • the end zone 42 in particular, is defined by an annular chamber, which is generally referred to as "cardioid" and has a cross section that is wider than the remaining part of the passage 16.
  • the injector body 4 also has a low-pressure environment 22, which communicates with an outlet 23 connected, in use, with ducts (not illustrated), which get the fuel to recirculate towards a reservoir and are at low pressure, for example at approximately 2 bar.
  • the passage 16 comprises an annular chamber 43, which is delimited radially by the surface 18 and by an axial end 44 of the stem 41.
  • the axial ends of the annular chamber 43 are defined by the surface 19 of the head 20 and by an intermediate portion 45 of the stem 41, which will be described in detail in what follows.
  • the annular chamber 43 axially ends at the sealing seat 21, so that the fuel is injected into the combustion chamber 2 through the outflow area 14.
  • the nozzle 11 comprises a rear guide portion 46 having a guide hole 47, defined by a zone of the seat 13 and engaged in an axially slidable way by a slide portion 25 of the valve needle 12.
  • the coupling zone between the portion 25 and the guide hole 47 defines a so-called “dynamic seal”.
  • dynamic seal is meant a sealing area defined by a coupling of the shaft/hole type, with sliding and/or guiding between the two components, where the play in a radial direction is sufficiently small as to render the amount of leaking fuel negligible.
  • radial coupling play is smaller than or equal to 2 ⁇ m.
  • a relatively small amount of fuel leaks from the end zone 42 of the passage 16. This fuel will then flow towards the outlet 23 and recirculate towards the reservoir.
  • the aforesaid dynamic seal separates axially the passage 16 directly from the low-pressure environment 22.
  • the diameter of the surface 18 is equal to that of the guide hole 47, whereas in the other areas of the passage 16 the internal diameter of the seat 13 is greater than or equal to this value.
  • the mean diameter of the sealing seat 21 is slightly greater than the diameter of the guide hole 47 and of the surface 18. Consequently, the difference between the diameter of the dynamic seal at the guide hole 47 and the mean diameter of the static seal at the sealing seat 21 causes an unbalancing in opening of the axial forces exerted by the pressure of the fuel on the valve needle 12 when the nozzle 11 is closed by the head 20 of the valve needle 12. It is in any case a controlled unbalancing pre-defined in the design stage, which must not exceed the force exerted by the spring 54 (described in what follows).
  • the relation between the mean diameter of the sealing seat 21 and the diameter of the guide hole 46 is different from the one indicated above for the preferred embodiments illustrated and described.
  • the electro-injector 1 comprises an actuator device 50, which in turn comprises an electrical-command actuator 51, i.e., an actuator governed by an electronic control unit (not illustrated), which is programmed for supplying to the actuator 51, for each step of fuel injection and corresponding combustion cycle in the combustion chamber 2, one or more electrical commands to provide corresponding fuel injections.
  • an electrical-command actuator 51 i.e., an actuator governed by an electronic control unit (not illustrated)
  • an electronic control unit not illustrated
  • the type of the actuator 51 is such as to define an axial displacement proportional to the electrical command received: for example, the actuator 51 is defined by a piezoelectric actuator or by a magnetostrictive actuator.
  • the actuator device 50 further comprises a spring 52, which is pre-loaded so as to exert an axial compression of the actuator 51 in order to increase the efficiency thereof.
  • the excitation provided by the electrical command causes a corresponding axial extension of the actuator 51 and hence a corresponding axial translation of a piston 53, which is coaxial and fixed with respect to an axial end of the actuator 51.
  • a piston 53 which is coaxial and fixed with respect to an axial end of the actuator 51.
  • it is the spring 52 itself that keeps the piston 53 in a fixed position with respect to the actuator 51.
  • Axial translation of the piston 53 causes a thrust to be exerted on the valve needle 12, via the rod 28, and hence opening of the nozzle 11, against the action of a spring 54, which is pre-loaded so as to push the valve needle 12 axially inwards and thus close the nozzle 11.
  • the spring 54 is set axially between an axial end shoulder of the nozzle 11, designated by the reference number 55, and the end portion 15 of the valve needle 12.
  • the spring 54 rests axially, on one side, against a half-ring 57, which in turn axially bears upon the end portion 15, and, on the other side, against a spacer 58, which in turn axially bears upon a half-ring 59 resting on the shoulder 55.
  • the spacer 58 may be set between the spring 54 and the half-ring 57.
  • the axial thickness of the spacer 58 may be chosen in such a way it is appropriate for adjusting pre-loading of the spring 54.
  • the half-ring 57 is simply fitted on the valve needle 12, or else is fixed to the valve needle 12 itself, for example via welding or via interference fit.
  • the half-ring 59 is not present, whereas the spacer 58 rests directly on the shoulder 55.
  • the spring 54 is arranged in a cavity forming part of the low-pressure environment 22.
  • the spring 54 advantageously has a pre-loading comprised between 60 N and 150 N so as to exert a closing force sufficient to overcome the aforesaid unbalancing and to bring the valve needle 12 promptly back into the closing position once the action of the actuator 51 has ceased.
  • the value of pre-loading of the spring 54 must be chosen in the design stage in a way proportional to the static-seal diameter, i.e., to the mean diameter of the sealing seat 21, and in a way proportional to the maximum value of the supply pressure of the fuel.
  • the actuator 51 is coupled to the valve needle 12 via a hydraulic connection 61.
  • the hydraulic connection 61 comprises a pressure chamber 62, which is coaxial to the valve needle 12 and to the piston 53, and defines a control volume filled with fuel, which, once compressed, transmits the axial thrust from the piston 53 to the valve needle 12.
  • the amount of fuel in the control volume of the pressure chamber 62 varies automatically so as to compensate the axial play and the dimensional variations of the valve needle 12 and of the rod 28 during operation, in a way not described in detail.
  • the hydraulic connection 61 is sealed with respect to the external hydraulic circuit for the fuel and is filled with a fluid without dissolved air (which would increase compressibility) and/or with a bulk modulus higher than that of the fuel.
  • the intermediate portion 45 is set at an axial distance from the portion 25 and is constituted by a plurality of sectors 65, which project radially outwards so as to couple in an axially sliding way to a surface 66 of the seat 13.
  • the sectors 65 are separated from one another in the circumferential direction by channels 67, which allow passage of the fuel towards the annular chamber 43.
  • the channels 67 are in a number greater than or equal to three and are set at equal distances apart about the axis 5.
  • the channels 67 are obtained on the outer surface of the portion 45 so that they are delimited radially on the outside by the surface 66.
  • the channels 67 may be obtained in the stem 41 by removal of stock, for example by electro-erosion or by laser etching.
  • the channels 67 and the sectors 65, i.e., the portion 45 may be defined by a bushing that defines a piece separate from the rest of the valve needle 12 and is fixed, for example interference fitted, on the stem 41 during the production stages.
  • the channels 67 comprise respective end portions 68, which exit directly into the annular chamber 43 and extend along respective axes 69 parallel to the axis 5 with passage section areas that are constant along such axes 69.
  • the portions 68 channel or guide the respective fuel flows, which then exit into the annular chamber 43, and do not bestow any swirling motion on such fuel flows in the annular chamber 43.
  • the channels 67 further comprise respective initial portions 70, which define a passage section area greater than that of the portions 68 and are connected to the portions 68 via respective flared intermediate portions 71.
  • the latter define a lead-in portion, with a passage section area that decreases progressively, without any steps, as far as the inlet of the portions 68 to limit the pressure losses at said inlet.
  • each pair of portions 70, 71 is aligned to the respective portion 68 along the axis 69.
  • the minimum passage section area is defined by the portions 68.
  • the presence of the initial portions 70, which are widened, has the function of limiting the axial length of the portions 68.
  • the sectors 65 also have a function of guide for the valve needle 12 with respect to the nozzle 11 so that, practically, they cannot have an axial length smaller than 2 mm to carry out this function.
  • the portions 68 were as long as the sectors 65.
  • the minimum passage section area totally available for the fuel at the channels 67 is in any case relatively large.
  • the passage restriction defined by the channels 67 introduces a drop in pressure not higher than 35% of the pressure present at the inlet of the channels 67 themselves.
  • the fuel exiting from the portions 68 in the annular chamber 43 has a pressure that is at least 65% of the pressure at the inlet, with a velocity proportional substantially to the pressure difference (according to Bernoulli's principle, assuming the fuel to a first approximation as being incompressible and neglecting the losses by fluid friction).
  • the channels 67 do not have the function of determining the fuel flow rate delivered. In fact, their function is rather that of converting part of the pressure into velocity of the fuel within the annular chamber 43, without a substantial decrease in the total pressure of the fuel itself (the conservation of the total pressure depending, as explained hereinafter, upon the fluid friction).
  • the passage area at the outflow area 14 is approximately 0.15 mm 2 : applying the law of conservation of the flow rate in the portions 68 and in the outflow area 14 and resorting to Bernoulli's theorem applied between the inlet of the channels 67 and the outlets in the annular chamber 43, and moreover to Bernoulli's theorem applied between the inlet of the channels 67 and the outflow area 14, imposing that the pressure at the outlet of the portions 68 is at least 65% of the pressure in said inlet, neglecting moreover losses by fluid friction and/or by thermal dissipation, and considering the fluid as being incompressible, we can write a system of three equations in three unknowns (velocity of the fluid through the channels 67, velocity of the fluid through the outflow area 14,
  • the pressure at the outlet of the portions 68 will be approximately 650 bar and the velocity through the outflow area 14 will be approximately 365 m/s, while the velocity at the outlets into the annular chamber 43 will be approximately 210 m/s.
  • the area or passage section area available for the fuel at the channels 67 is smaller than the one available in the passage 16 upstream and downstream of the intermediate portion 45 so that the channels 67 define a hydraulic resistance and determine a total pressure drop between the end zone 42 and the annular chamber 43 when the fuel flows.
  • the outflow area 14, in turn, defines another hydraulic resistance, which can be adjusted by varying the lift of the valve needle 12.
  • Figure 3 shows a block diagram regarding this hydraulic configuration of the atomizer 10 during an injection.
  • the end zone 42 there is substantially the supply pressure (prail) set by the injection system, whereas in the combustion chamber 2 there is the pressure (pcyl) of the air in the cylinder during injection.
  • the mean pressure (p) within the annular chamber 43 assumes a value that is intermediate between prail and pcyl during delivery of the fuel and, once the geometry of the channels 67 and of the atomizer 10 as a whole is fixed, and the operating conditions of the electro-injector 1 (prail, pcyl, fuel flow rate) are fixed, can be calculated via the system of equations referred to above or else determined via appropriate fluid-dynamic simulations on a computer for evaluating more exactly the amount of the losses by fluid friction and by turbulence.
  • outlets of the portions 68 of the channels 67 are designated in Figures 2 and 4 by the reference numbers 72.
  • the fuel exiting from the channels 67 locally has a velocity greater than that of the fuel present in the annular chamber 43 in the points 73 that are intermediate between the outlets 72 along the same circumference (as may be noted from the flow lines that are schematically represented in Figure 4 and that derive from computer simulations).
  • the annular chamber 43 has dimensions sufficiently small as not to manage to render the velocity of the fuel uniform before the fluid fillets exiting from the channels 67 reach the outflow area 14, at least in a reference operating condition, for example the one in which the supply pressure (prail) assumes the maximum value allowed by the injection system, and the lift of the valve needle 12 assumes also the maximum value allowed (i.e., in operating conditions of maximum power or load).
  • a reference operating condition for example the one in which the supply pressure (prail) assumes the maximum value allowed by the injection system, and the lift of the valve needle 12 assumes also the maximum value allowed (i.e., in operating conditions of maximum power or load).
  • Figure 5 is obtained from fluid-dynamic simulations made on a computer, and shows schematically the distribution of the velocity on three cylindrical surfaces within a wedge of the umbrella spray exiting from the nozzle 11, centred on the axis 5.
  • the innermost cylindrical surface lies at the outflow area 14, whereas the other two lie on two different circumferences downstream of the outflow area 14.
  • Figure 7 is similar to Figure 5 and shows some flow lines that, qualitatively, represent the paths of respective fluid fillets through the annular chamber 43 and downstream of the outflow area 14 in the combustion chamber 2.
  • the velocity of the fuel film of the spray is not uniform along the circumference, but how it presents peaks of the velocity modulus in areas that are equal in number to the channels 67 and are substantially aligned with the outlets 72 along the respective axes 69.
  • the exiting fuel film is constituted by spray portions 75 that correspond to these areas at higher velocity, and by spray portions 76 that correspond to areas at lower velocity and are in an angular position intermediate between the channels 67.
  • the difference in the velocity modulus between the maximum value and the minimum value must be appreciable, i.e., at least 10% of the maximum value.
  • the fuel film that exits from the outflow area 14 is not hence homogeneous in terms of velocity modulus, but has faster portions, the ones in the radial planes in which the axes 69 of the channels 67 lie, and slower portions, in the intermediate angular positions between the channels 67.
  • both of them exit from the outlet 72 of the portion 68 at the same rate.
  • Figure 6 refers to a test on a first prototype of atomizer, performed in quiescent chamber with gaseous means equivalent to air at a pressure of 30 bar and a temperature of 700 K, with a spray obtained by governing a lift of a few microns on a mean seal diameter of approximately 3 mm, with a relatively low injection pressure (700 bar). It may be hence understood that Figure 6 merely provided by way of illustration of the phenomenon.
  • the spray is very similar to the one obtained by an atomizer with solid-cone spray.
  • Appropriate fluid-dynamic simulations made on a computer have, for example, highlighted spray patterns such as the ones illustrated in Figures 8A, 8B, and 8C .
  • Figure 8A shows the evolution in time, for a series of successive instants, of the spray generated by an atomizer according to the method of the present invention, provided with five channels 67 each with a passage section area of 0.4 mm 2 , with mean seal diameter of 3 mm, an injection pressure of 800 bar, and a lift of the valve needle 12 of 0.015 mm.
  • the smaller diameter of the central part 77 in addition to the further cusp, there may be noted the smaller diameter of the central part 77.
  • the diameter of the central part 77 can also be modulated by means of variations of the lift and/or of the supply pressure, once the geometry of the atomizer 10 has been defined.
  • Figures 8B and 8C illustrate the comparison of two spray patterns, which also have different diameters of the central part 77 (the diameter of the central part 77 in Figure 8C is greater), obtained in this case in the same operating conditions of supply pressure and lift of the valve needle, but characterized by two different passage areas in the channels 67.
  • the spray of the solution of Figure 8B is obtained with a minimum passage area of a single channel of 0.04 mm 2 , as against a minimum passage area of 0.055 mm 2 for the channel of the solution of Figure 8C .
  • each of the spray portions 75 tends to divide into in two sub-portions 75a and 75b, basically as a result of the resistance opposed by the air in the combustion chamber 2.
  • the sub-portions 75a and 75b generated by a given channel 67 move progressively away from one another in the circumferential direction, within the portions 76, as the distance of the fuel from the outflow area 14 increases. In other words, it is as if the flow lines followed by the fuel at a higher velocity were sucked back in the circumferential direction towards the areas where the fuel has a lower velocity.
  • the annular chamber 43 As mentioned above, to obtain this configuration of the fuel spray it is essential for the annular chamber 43 to have sufficiently small dimensions, also in relation to the type of fuel used, to the value of supply pressure (prail) and to the value of the lift of the valve needle 12 when the nozzle 11 is open.
  • the further away the outflow area 14 is from the outlets 72 the more uniform is the velocity modulus of the fuel along the circumference at the outflow area 14, in so far as the velocity of the fuel exiting from the channels 67 has sufficient time and space to become uniform in the annular chamber 43 so that there is the risk that no cusp 78 will form.
  • the distance along the axes 69 between the outlets 72 and the outflow area 14 is preferable for the distance along the axes 69 between the outlets 72 and the outflow area 14 not to be greater than 1/3 of the mean diameter of the sealing seat 21. For instance, if this diameter is approximately 3 mm, the distance between the outlets 72 and the outflow area 14 is preferably smaller than or equal to 1 mm.
  • the shape and/or the volume of the annular chamber 43 can affect to a certain extent the profile of velocity of the fuel in the outflow area 14.
  • a non-uniform profile of velocity is obtained that is increasingly evident as the volume of the annular chamber 43 decreases.
  • the maximum volume can be assumed as being equal to the volume of a hollow cylinder having an external diameter equal to the mean diameter of the sealing seat 21, a height equal to 1/3 of said mean diameter, and an internal diameter equal to 80% of the external diameter.
  • a further factor that may affect the uniform or non-uniform profile of velocity of the fuel along the outflow area 14 is given by the minimum passage section area of each channel 67, as mentioned above.
  • said minimum passage section area decreases, it is possible to obtain a higher velocity of the fuel at the outlet 72 and hence a channelling and a more marked differentiation of the flow lines (L1 and L2) in the annular chamber 43, in the path of the fuel from the outlet 72 to the outflow area 14.
  • the passage section area of a single channel 67 at the outlet 72 is smaller than 0.05 mm 2 .
  • the pressure of supercharged air (pcyl) and the supply pressure (prail) of the fuel are known and/or controllable.
  • the atomizer 10 can be obtained via the following design steps:
  • the process for producing the atomizer 10 envisages a design step in which the channels 67 are sized so as to respect the requirements of pressure and flow rate referred to above.
  • the cross section total is equal to 0.25 mm 2 .
  • the passage section area of each channel 67 will be obtained by dividing the total passage section area by the number of the channels established above (hence it will be equal to 0.05 mm 2 ).
  • the atomizer 10 is obtained via one or more design steps that envisage appropriate sizing the annular chamber 43 to obtain as result the formation of the cusps 78 in the fuel spray, at least in a reference operating condition, for example the full-load condition.
  • these design steps envisage appropriate positioning the outlets 72 of the channels 67 with respect to the sealing seat 21.
  • the outlets 72 are positioned in such a way as to be located at an axial distance from the sealing seat 21 less than one third of the value of the mean diameter of seal previously calculated. In the example considered above, this distance will be less than 0.8 mm.
  • the inner diameter of the annular chamber 43 i.e., the minimum diameter of the end 44
  • the inner diameter of the annular chamber 43 is greater than 80% of an external diameter so that in the example considered it will be greater than 2 mm.
  • the atomizer 10 enables an operation to be obtained that constitutes a compromise between the ones of the known art with solid-cone spray and the ones of the known art with hollow-cone spray.
  • a particular shape of the spray in the combustion chamber 2 i.e., a shape constituted by a central umbrella-shaped portion 77 and by a plurality of cusps 78, at least in a reference operating condition, for example in the one that corresponds to full power or full load of the engine.
  • This particular shape of the spray enables a traditional CI mode to be obtained at high loads, i.e., a high penetration of the fuel into the combustion chamber 2, in a way similar to what happens with atomizers of the known art with solid-cone spray.
  • an operating mode of the HCCI type may possibly be maintained, with high atomization of the fuel and without cusps 78.
  • the annular chamber 43 can render the velocity of the fuel uniform notwithstanding its small dimensions to obtain thus a velocity modulus that is substantially uniform in the circular direction along the outflow area 14 in the operating conditions at low and medium engine loads.
  • the lateral drift of the flow lines L2 downstream of the outflow area 14 also causes a partial re-thickening or coalescence of the drops of fuel at higher velocity, initially detached from the continuous film. These drops hence tend to increase in volume in the first part of their path. Thanks to this partial coalescence, the drops that will come to form the cusps 78 are larger and, hence, are distinguished by a higher kinetic energy and by a higher Weber number than the drops present in a spray with velocity modulus substantially constant along the circumference.
  • the shape and dimensions of the channels 67 contribute to optimising the phenomenon of formation of the cusps 78 in the fuel spray, in so far as they determine a greater or smaller effect of guiding and channelling on the flow lines of the fuel exiting from the outlets 72 at the outflow area 14 and a greater or smaller conversion of the pressure into velocity, across the portion 45.
  • the surface roughness of the channels 67 and the conformation of the initial portions 70 can reduce the energy losses of the flow during traversal of the channels 67.
  • the geometry of the annular chamber 43 could be sized so as to have a non-homogeneous shape, i.e., a cross section that is not constant along the circumference so as to favour channelling and hence non-uniformity of the flow lines in the annular chamber 43, as may be seen by way of example in the variant of Figure 9 .
  • the annular chamber 43 could be provided so as to create portions of divergent shape 80, i.e., with progressively increasing width, starting from the outlets 72 in the two opposite directions in the circumferential direction, as illustrated in the example of Figure 9 .
  • This divergence slows down further the fluid fillets L1, thus favouring formation of the cusps 78, as described above in detail.
  • the nozzle 11 could be defined by a end portion of the injector body 4, without being a distinct piece from the latter, and/or the guide portion 45 could form part of a body distinct from the nozzle 11, and/or the valve needle 12 could be operated directly, i.e., the injector 1 could be without the pressure chamber 62.
  • the shape of the annular chamber 43 could be different from the one illustrated by way of example in cross section in the attached figures.
  • the channels 67 could have a shape different from the preferred one that has been illustrated by way of example, and/or could be provided completely within the intermediate portion 45 of the stem 41, and/or could be in a number different from the one illustrated.
  • the channels 67 could be constituted only by the portions 68, i.e., have a constant passage section area along the axes 69 and hence be without the portions 70, 71.
  • an actuator of a solenoid type could be used, which, albeit operating basically only in two or three discrete positions, would be in any case able to generate a spray of the type illustrated in Figure 6 , for example by regulating the injection pressure and/or the time of actuation of the electromagnet.
  • the atomizer 10 could be applied to fuels different from diesel, so that it might be necessary to set different dimensions of the annular chamber 43 and/or of the channels 67 to obtain an absence of uniformity of the profile of velocity of the fuel along the outflow area 14 and hence the same resulting effect of the cusps 78 illustrated in the attached figures.
  • annular chamber 43 for example like the one of a convergent/divergent type illustrated in Figure 9 , could be obtained by shaping the inner surface of the seat 13 of the nozzle 11, as an alternative or in combination to shaping of the stem 41 of the valve needle 12.
  • the channels 67 may be arranged in non-uniform positions about the axis 5, and closer to one another in the area of the combustion chamber 2 where a greater penetration of the spray is required. Especially in this case, it is also possible to obtain an asymmetry in the width or penetration of the cusps 78 in the spray itself.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP15193750.5A 2015-11-09 2015-11-09 Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur Withdrawn EP3165759A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP15193750.5A EP3165759A1 (fr) 2015-11-09 2015-11-09 Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP15193750.5A EP3165759A1 (fr) 2015-11-09 2015-11-09 Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur

Publications (2)

Publication Number Publication Date
EP3165759A1 true EP3165759A1 (fr) 2017-05-10
EP3165759A8 EP3165759A8 (fr) 2017-08-23

Family

ID=55027222

Family Applications (1)

Application Number Title Priority Date Filing Date
EP15193750.5A Withdrawn EP3165759A1 (fr) 2015-11-09 2015-11-09 Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur

Country Status (1)

Country Link
EP (1) EP3165759A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11008991B2 (en) 2016-09-22 2021-05-18 C.R.F. Società Consortile Per Azioni Fuel electro-injector atomizer, in particular for a diesel cycle engine

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE723801C (de) * 1940-04-14 1942-08-11 Saurer Ag Adolph Ringspaltduese zur Einspritzung von Brennstoff bei Brennkraftmaschinen
US2376292A (en) * 1941-09-26 1945-05-15 Reconstruction Finance Corp Fuel injection nozzle
US3249308A (en) * 1962-08-02 1966-05-03 Citroen Sa Andre Fuel injector for internal combustion engines
US4355620A (en) * 1979-02-08 1982-10-26 Lucas Industries Limited Fuel system for an internal combustion engine
US5829688A (en) * 1996-01-13 1998-11-03 Robert Bosch Gmbh Injection valve for directly injecting fuel into an internal combustion engine
US6460779B1 (en) * 1998-09-23 2002-10-08 Robert Bosch Gmbh Fuel injection valve
EP1559904A1 (fr) 2004-01-28 2005-08-03 Siemens VDO Automotive S.p.A. Corps de soupape, injecteur de fluides et procédé de fabrication pour un corps de soupape
WO2011022821A1 (fr) * 2009-08-31 2011-03-03 Lewis Johnson Soupape d’injection pour moteur à combustion interne
US7942349B1 (en) 2009-03-24 2011-05-17 Meyer Andrew E Fuel injector

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE723801C (de) * 1940-04-14 1942-08-11 Saurer Ag Adolph Ringspaltduese zur Einspritzung von Brennstoff bei Brennkraftmaschinen
US2376292A (en) * 1941-09-26 1945-05-15 Reconstruction Finance Corp Fuel injection nozzle
US3249308A (en) * 1962-08-02 1966-05-03 Citroen Sa Andre Fuel injector for internal combustion engines
US4355620A (en) * 1979-02-08 1982-10-26 Lucas Industries Limited Fuel system for an internal combustion engine
US5829688A (en) * 1996-01-13 1998-11-03 Robert Bosch Gmbh Injection valve for directly injecting fuel into an internal combustion engine
US6460779B1 (en) * 1998-09-23 2002-10-08 Robert Bosch Gmbh Fuel injection valve
EP1559904A1 (fr) 2004-01-28 2005-08-03 Siemens VDO Automotive S.p.A. Corps de soupape, injecteur de fluides et procédé de fabrication pour un corps de soupape
US7942349B1 (en) 2009-03-24 2011-05-17 Meyer Andrew E Fuel injector
WO2011022821A1 (fr) * 2009-08-31 2011-03-03 Lewis Johnson Soupape d’injection pour moteur à combustion interne

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11008991B2 (en) 2016-09-22 2021-05-18 C.R.F. Società Consortile Per Azioni Fuel electro-injector atomizer, in particular for a diesel cycle engine

Also Published As

Publication number Publication date
EP3165759A8 (fr) 2017-08-23

Similar Documents

Publication Publication Date Title
US9506439B2 (en) Ducted combustion systems utilizing adjustable length ducts
US7685990B2 (en) Dual mode combustion apparatus and method
US5299919A (en) Fuel injector system
EP2302197B1 (fr) Soupape d'injection de carburant et dispositif d'injection de carburant
US9657701B2 (en) Fuel injection nozzle
US8186609B2 (en) Fuel injector having an additional outlet restrictor or having an improved arrangement of same in the control valve
US10767610B2 (en) Liquid fuel injector having dual nozzle outlet sets, fuel system, and method
US7404526B2 (en) Injection nozzle
US5853124A (en) Bottom seated pintle nozzle
CN103967671A (zh) 一种双阀可变喷孔面积燃油喷嘴
JP5044335B2 (ja) 燃料噴射ノズル
US20030201344A1 (en) Nozzle assembly for injecting fuel at multiple angles
EP3165759A1 (fr) Procédé d'injection de carburant dans une chambre de combustion d'un moteur à combustion interne, atomiseur d'un electro-injecteur de carburant pour mettre un tel procédé d'injection et procédé de production dudit atomiseur
JP2011220132A (ja) 燃料噴射弁
US11008991B2 (en) Fuel electro-injector atomizer, in particular for a diesel cycle engine
US10364785B2 (en) Fuel injection nozzle
US20140175192A1 (en) Mixed-mode fuel injector with a variable orifice
CN112074660B (zh) 燃料喷射装置和操作活塞发动机的方法
US6616063B2 (en) Injector for injecting fuel, with downstream pressure control element
US7210640B2 (en) Fuel injector spray alteration through a moveable tip sleeve
US6918549B2 (en) Fuel injector tip for control of fuel delivery
WO2011022821A1 (fr) Soupape d’injection pour moteur à combustion interne
GB2261477A (en) Fuel-injection pumps for internal combustion engines
US20030102390A1 (en) Method and apparatus to control a moveable tip sleeve.
JP7303400B1 (ja) 大型ターボ過給式２ストロークユニフロークロスヘッド内燃機関用燃料バルブ

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): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

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: 20171111