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
  • F02M69/00—Low-pressure fuel-injection apparatus ; Apparatus with both continuous and intermittent injection; Apparatus injecting different types of fuel
  • F02M69/04—Injectors peculiar thereto
  • F02M69/041—Injectors peculiar thereto having vibrating means for atomizing the fuel, e.g. with sonic or ultrasonic vibrations
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M51/00—Fuel-injection apparatus characterised by being operated electrically
  • F02M51/06—Injectors peculiar thereto with means directly operating the valve needle
  • F02M51/0603—Injectors peculiar thereto with means directly operating the valve needle using piezoelectric or magnetostrictive operating means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
  • F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
• • 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
  • F02M61/1866—Valve seats or member ends having multiple cones

Definitions

• the invention relates to a device for injecting a fluid, for example a fuel, in particular for an internal combustion engine.
• the invention relates, according to a first aspect, to a fluid injection device, said injector, having a main axis of elongation and comprising at least one nozzle extending longitudinally along said axis, and having a seat and at least one injection orifice for the outlet of the fluid from the nozzle, the injection orifice communicating with a supply conduit for this fluid, and at least one needle mounted axially movable in the nozzle and having along said axis, a first, free end defining a valve with the seat of the nozzle, in a contact zone between them.
• Such an injector is well known to those skilled in the art as shown, for example, in European Patent Application EP 1 172 552 in which the first end of an outgoing needle needle oscillates axially on the seat of the immobile nozzle.
• EP 1 172 552 in which the first end of an outgoing needle needle oscillates axially on the seat of the immobile nozzle.
• a large axial force is generated at the first end of the needle which can alter its axial mobility relative to the seat and, ultimately, an expected operation of the valve resulting in its opening and / or closure ordered.
• the present invention which is based on this original observation, is primarily intended to provide a fluid injection device for at least reducing at least one of the limitations mentioned above.
• the injection device which is also in accordance with the generic definition given in the preamble above, is essentially characterized in that the nozzle extends axially towards its free end until beyond the first end of the needle, where it has, transversely to this axis, a bumper wall where said seat is defined.
• the first end of the needle is protected against axial counterpressures in the pressurized medium in which the fluid is injected by a screen formed by the bumper wall of the nozzle.
• the opening and / or the ordered closure of the valve are provided without the need to use the oversized means of setting axial movement of the needle.
• the invention relates to an internal combustion engine using the fluid injection device according to the invention, that is to say, such a motor where is disposed this injection device.
• FIG. 1 schematically represents a simplified view in longitudinal section of an injection device according to the invention arranged in a motor and equipped with a needle with a so-called incoming head and a nozzle having a stop wall at its free end,
• FIG. 2 is a diagrammatic view in simplified view in partial longitudinal section of a first end of FIG. the needle disposed in the nozzle to form a valve, the valve being in the "open" position with two fluid sheets dispersed outwards through two lateral injection ports,
• FIG. 3 represents the same view as FIG. 2 with the flap in the "closed” position
• Figure 4 schematically shows a simplified external perspective view in perspective the same part of the injector as that already shown in Figure 2 with the valve in the "open" position.
• the invention relates to an injection device, or injector (FIGS. 1-4), for injecting a fluid 1, referred to as a supply fluid (for example, a pressurized fuel derived from a treatment device comprising, for example, a tank, a pump, a filter), in the form of angular sheets (films) 10 in a combustion chamber 2 of an internal combustion engine 3, or in an air intake duct (not shown), or in an exhaust gas conduit not shown.
• a supply fluid for example, a pressurized fuel derived from a treatment device comprising, for example, a tank, a pump, a filter
• angular sheets (films) 10 in a combustion chamber 2 of an internal combustion engine 3
• air intake duct not shown
• exhaust gas conduit not shown.
• the injector has a main axis of elongation AB, for example, its axis of symmetry, and comprises at least one nozzle 4 extending longitudinally, along the axis AB, and having a seat 40 and at least one orifice of injection 41 for the fluid outlet 1 out of the nozzle 4, the injection port 41 communicating with a supply conduit 51 of the fluid 1.
• Figures 1-3 shows an example of the injector with two orifices injection 41 arranged symmetrically with respect to the axis AB.
• the injector comprises at least one needle 5 mounted axially inside the nozzle 4, in an axial bore 44 of the nozzle 4 and having, along the axis AB, a first end 50, free, defining a valve with the seat 40 of the nozzle 4, in a contact zone 52 between them.
• the nozzle 4 extends axially towards its end free 42, beyond the first end 50 of the needle 5, where it has, transversely to the axis AB, a stop wall 43 for the first end 50 of the needle 5 incoming) where is defined seat 40.
• the needle 5 in the event of an unexpected rupture of the needle 5 (following, for example, an alloy defect, premature fatigue), it can not fall into the combustion chamber 2 under the effect of gravity, but will remain inside the nozzle 4, in the bore 44 of the nozzle 4 "trapped" by the end wall 43, with the first end 50 bearing on the seat 40 of the nozzle 4, closing thus at least partially the valve of the injector.
• the bumper wall 43 comprises an element 431 attached which is disposed inside the nozzle 4, in the bore 44 of the nozzle 4, preferably coaxially, facing the first free end 50 of the needle. 5 and accessible from outside the nozzle 4 for its attachment to the latter 4 ( Figures 2-3).
• the element 431 closes axially, at least partially, the nozzle 4.
• the element 431 constituting the end wall 43 can be manufactured independently of the nozzle 4 which makes this operation easier on an industrial scale (in terms of handling, and / or access to machining, and / or precision machining control, and / or grinding machining etc.).
• the nozzle 4 (and, more particularly, the bore 44 of the nozzle 4) internally has a neck 430 which opens on the outside and where is received a portion of the element 431 reported ( Figures 2-3).
• the neck 430 has a first portion 4300 narrowed axially in the direction of the free end 42 of the nozzle 4 (in the direction of the axis AB towards the combustion chamber 2 in FIG. 2), connecting to a second portion 4301 of reduced section opening to the outside.
• the element 431 attached to the abutment wall 43 introduced axially inside the nozzle 4, via the bore 44 of the nozzle 4, is then engaged locally, along the axis AB, in the second portion 4301 of the neck 430 .
• the second portion 4301 of reduced section opening to the outside allows, d on the one hand, a fixation of the stopper wall 43 in a plane perpendicular to the axis AB, for example, under the effect of gravity, and, on the other hand, a control (for example, visual from the outside of the nozzle 4) of the quality of the assembly of the bumper wall 43 on the neck 430.
• the element 431 attached to the end wall 43 may be secured to the neck 430 by an external attachment 432, such as welding. The realization of the latter is facilitated by access to the element 431 reported from outside the nozzle 4.
• the supply duct 51 of the fluid 1 towards the valve passes through the needle 5 longitudinally (the supply duct 51 is therefore internal to the nozzle 4 and to the needle 5). .
• the fluid 1 is separated from the nozzle 4 by the needle 5 which makes it more difficult leaks between these two bodies, along the bore 44 thereby contributing to annihilate any recirculation of fluid 1 in the injector.
• the axis AB is that of symmetry of the supply duct 51.
• Each injection orifice 41 is arranged in the nozzle 4 transversely to the main axis of elongation AB, laterally with respect to the valve (FIGS. 2 and 3), and is in communication, each time the valve is opened (FIG.
• the section of the injection orifice 41 (of the order of one millimeter) may be greater than that of an injection passage 6 (of the order of a few tens of microns) that defines the valve when it is open ( Figure 2).
• the fluid 1 (web 10) ejected through the injection passage 6 does not impact walls of the injection port 41 at least on a part of its perimeter. This tends to reduce any unexpected flow of fluid 1 along the free end of the nozzle 4 on the side of the combustion chamber 2 can lead to combustion with a detonation.
• this arrangement contributes in forming the angular sheets 10 (delimited by the dimension of the injection orifice 41 in a plane perpendicular to the axis AB, as shown in FIG. 3) of drops of uniform size (their section average being comparable with that of the injection passage 6) fluid 1, dispersed directly (without impacting the nozzle 4) and homogeneously in the combustion chamber 2 when the valve is open.
• the needle 5 may have at least one peripheral shoulder 53, 54 for its guidance in movement in the nozzle 4
• the peripheral shoulder 53 is disposed towards the first end 50 of the needle 5.
• this reduces a lever effect of the lateral forces exerted on the first end 50 of the needle 5 by the counterpressure propagating in the combustion chamber 2.
• it makes it more difficult fluid leaks 1 between the needle 5 and the nozzle 4, along the bore 44 thereby contributing to reduce, as already mentioned above, any recirculation of fluid 1 in the injector.
• the first end 50 of the enlarged needle 5 in a plane perpendicular to the axis AB by means of the peripheral shoulder 53 forms a head of the needle 5.
• the needle 5 may have, facing the abutment wall 43, a first zone 500 flared, preferably frustoconical, the stop wall 43 having a second zone 4310 complementary, preferably frustoconical, with which the first zone 500 flared comes into contact when the flap is closed (Figure 3).
• This arrangement contributes to improving the tightness of the closed valve.
• the injector comprises a housing 7 connected (for example, with a thread) to the nozzle 4 opposite the valve, along the main axis of elongation AB.
• the linear dimensions of the housing 7, for example, its width measured perpendicular to the axis AB and / or its length measured along the axis AB, may be greater than that of the nozzle 4.
• the housing 7 comprises a cover 72 located axially opposite the free end 42 of the nozzle 4.
• the cover 72 may be provided with a recess to let in the supply conduit 51 of the fluid 1.
• the injector also comprises an actuator 8 movably mounted in the housing 7 and connected (for example, by means of a weld) to the needle 5 at a second end 55 thereof axially opposite the first 50.
• the actuator 8 is intended to put the needle 5 reciprocating axial relative relative to the nozzle 4, able to open ( Figure 2) and close ( Figure 3) alternately the valve.
• the actuator 8 has a stack with two opposite faces C, D axially (the face D coinciding with the second end 55 of the needle 5 in FIG. 1) and including at least one electroactive part 80 comprising an electroactive material 800 ( axially away from the needle 5).
• the latter is intended to produce vibrations with a predetermined frequency v, for example, ultrasound that can spread between about 20 kHz and 60 kHz, that is to say, with the vibration reference period ⁇ between respectively about 50 ⁇ s and 16 ⁇ s.
• the stack can be confused with the actuator 8 ( Figure 1).
• the stack comprises at least one portion, called amplifier 81, axially connected with the needle 5 at the location of a D of said faces
• the electroactive portion 80 and the needle 5 being disposed axially on either side of the amplifier 81.
• the latter is intended, firstly, to transmit the vibrations with the predetermined frequency v of the electroactive material 800 to the needle 5 and, in particular at its first end 50, which then vibrates relative to the seat of the nozzle (4) to open or and alternately close the valve with the frequency (v) predetermined.
• the amplifier 81 is intended to amplify the vibrations of the incoming needle and in particular of its first end 50 so that the movements of the needle 5 at the valve are greater than the integral. deformations of the electroactive material 800.
• the amplifier 81 may have a cylindrical or frustoconical shape, or another shape coupling at least one cylindrical portion with at least one other frustoconical portion narrowed axially in the direction of the needle 5.
• the amplifier 81 is traversed longitudinally by an axial bore constituting a portion of the supply duct 51 of the fluid 1 ( Figure 1).
• the needle 5 and the amplifier 81 are made by machining in a one-piece piece made of material having the same density and the same velocity of the sound (FIG. 1). Indeed, the machining in a single piece provides a simplest solution to implement during a manufacturing of said parts on an industrial scale. In addition, this solution makes the "needle 5 + actuator 8" assembly more robust in fatigue time.
• the stack comprises at least one other part, called the rear mass 82, which plays a homogeneous distribution role of the stresses on the electroactive material 800.
• the amplifier 81 and the rear mass 82 are disposed axially on either side of the electroactive part. 80.
• the rear mass 82 has a wall opposite axially to the electroactive portion 80, said wall being coincident with the face C of the stack opposite axially to the needle 5.
• the prestressing means 83 may be a screw 830 comprising, on the one hand, a head having a sufficient volume to accommodate the supply duct 51 of the fluid 1, and, on the other hand, an axial bore passing through the longitudinally prestressing means 83 and constituting a portion of the supply duct 51 of the fluid 1 ( Figure 1).
• the prestressing means 83 may be merged with the rear mass 82.
• the electroactive material 800 is piezoelectric which may be, for example, one or more ceramic piezoelectric washers stacked axially on each other to form the electroactive portion 80 of the stack.
• the selective deformations of the electroactive material 800 for example, the periodic deformations with the reference period ⁇ , generating the Acoustic waves in the injector ultimately result in relative longitudinal movements of the first end 50 of the needle 5 relative to the seat 40 of the nozzle 4 or vice versa, able to open and close alternately the valve, as mentioned above.
• These selective deformations are controlled by corresponding excitation means (not shown) adapted to put the electroactive part 80 in vibration with the reference period ⁇ , for example, using an electric field created by a potential difference.
• the Electroactive material 800 is magnetostrictive which may be present as, for example, one or more magnetostrictive rings (cores) stacked axially on each other to form the electroactive portion 80 of the stack.
• the selective deformations of said magnetostrictive washers (cores) are controlled by corresponding excitation means adapted to put the electroactive part 80 in vibration with the reference period ⁇ , for example, by means of a magnetic induction resulting from a selective magnetic field obtained using, for example, an exciter not shown separate from the actuator 8, and in particular by at least one coil integral with the housing 7, preferably disposed outside the housing 7 .
• the injector may comprise a sealing means 9 (for example, a seal of rubber-like preference in the form of a ring, an elastic washer), interposed (preferably housed at least partially in a groove arranged for this purpose in the casing 7, as illustrated in FIG.
• a sealing means 9 for example, a seal of rubber-like preference in the form of a ring, an elastic washer
• the casing 7 comprises at least one lateral discharge orifice 70 of said leaks located (axially) between the sealing zone and the nozzle 4, and at least one recovery channel 71 of said leaks communicating with the orifice lateral evacuation 70.
• the housing 7 comprises a support
• a threaded end 45 of the nozzle 4 axially opposite the valve, connected to the housing 7 is, preferably conical and narrowed axially towards the end free of the nozzle 4.
• the threaded end 45 of the nozzle 4 and the support 73 of the casing 7 are placed in coaxial contact with one another when the nozzle 4 is attached to the casing 7. so as to reinforce a thread sealing by an intimate contact of the two facing inclined surfaces (one being that of the support 73 and the other being that of the threaded end 45).
• Reminder means 11 of the actuator 8 may be provided to maintain the first end 50 of the needle 5 bearing against the seat 40 of the nozzle 3 ( Figure 1).
• the return means 11 ensure the closure (FIG. 3) of the valve for a given pressure of the fluid 1 in the supply channel 51 irrespective of the pressure in the combustion chamber 2.
• the return means 11 may be represented by a prestressed spiral spring arranged axially between, for example, the cover 72 of the housing 7 and the face C of the stack axially opposed to the needle 5. In the example in FIG.
• the return means 11 are capable of deforming, for example, elastically, exerting a predetermined force for a very small elongation, for example, less than 100 microns, so as to push the first end 50 of the needle against the seat 40 of the nozzle 4 following the AB axis.
• the return means 11 may be formed by a fluidic means, for example of the hydraulic cylinder type, with the fluid 1 as a working fluid (not shown). The clearances due to the expansion of the various elements of the casing 7 are thus advantageously caught by the return means 11 so that the flow of the fluid 1 through the valve tends to remain insensitive to thermal variations at different operating speeds of the engine 3.
• the first step consists in separately assembling, on the one hand, the actuator 8 with the needle 5, and, on the other hand, the casing 7 with the nozzle 4.
• the fact that ability to assemble the actuator 8 with the needle 5 outside the housing 7 (which does not prevent access to the actuator 8 or the needle 5) is an advantage both to manipulate the actuator 8 and / or the needle 5 to control the quality of their assembly.
• the second step is to introduce the actuator 8 with the needle 5 in the housing 7 with the nozzle 4 by making the needle 5 enter the nozzle 4 via the threaded end 45.
• the last step is to introduce into the housing 7 the return means 11, then to close the housing 7 by the cover 72.
• the actuator 8 connected with the needle 5 entering and confused, as shown in Figure 1, with the stack comprising the amplifier 81, the electroactive part 80 and the rear mass 82 clamped together by the prestressing means 83, remains movable relative to the housing (7) of the injector thus assembled.
• the injection orifice 41 is constituted by a first segment oriented towards the free end 42 of the nozzle 4 and formed by the neck 430 and by a second segment disposed axially opposite the first segment, the first and the second segments merging (to form the orifice 41) in two lateral junction areas with respect to the axis AB.
• the injection orifice 41 has a maximum dimension along the axis AB, called height, which is less than a maximum dimension taken in a plane perpendicular to the axis AB, called the width, arranged, for example halfway up the injection port 41.
• said lateral junction areas of the injection port 41 are further spaced from each other. This contributes, on the one hand, to angularly widen the ply 10 of the fluid 1 to make the mixture "intake air / fluid 1" more homogeneous, and, on the other hand, to marginalize disturbances of the ply 10 by the injection port 41 in said lateral joining areas.
• the nozzle 4 has a thickness defining, transversely to the axis AB, a depth of the injection port 41. Said depth is less than the height of the injection port 41 to minimize a distance separating the injection passage 6 from the combustion chamber 2. Preferably, said depth is comparable with a length (in a plane radial to the axis AB) of the injection passage 6.
• Figures 2 and 3 we see that along the axis AB, the end wall 43 is offset in height relative to the respectively upper and lower portions of the orifice 41, hence the existence, open valve as shown in Figure 4, d an opening (here a slot) appearing in the intermediate part (step 510) of a wall visible through the widest port 41.
• the small passage 40 is, parallel to AB, substantially centered in the middle of the large orifice 41.
• the element 431 reported extends longitudinally, opposite the free end 42 of the nozzle 4, along the axis AB, inside the bore 44 of the nozzle 4 to beyond said first segment and is axially distant from said second segment.
• the seat 42 of the valve is axially offset from the first and second segments of the injection port 41 in the plane l-l parallel to the axis AB.
• the seat 42 is disposed equidistantly with respect to the first and second segments of the injection orifice 41, that is to say, at half height along the axis AB of the orifice d injection 41.
• the angular ply of the fluid 1 remains substantially away from the first and second segments of the injection orifice 41 in the plane parallel to the axis AB, as illustrated in FIGS. 2 and 4. This contributes to reducing any unexpected flow of the fluid 1 along the first and second segments of the injection orifice 41 (and, in particular, outside the lateral joining zones mentioned above) which can generate drops of larger sizes. to the thickness of the web 10 detrimental to the homogeneous mixture "fluid 1 / intake air" in the combustion chamber 2.
• the section in the plane 11 (excluding lateral junction zones) of the injection orifice 41 is always greater than that of the injection passage 6 (FIG. 2). regardless of the predetermined frequency v vibrations and displacements (transmitted by the amplifier 81) of the first end 50 of the 5 incoming needle at the valve.
• said section of the injection port 41 is at least about one hundred times larger than that of said injection passage 6 (FIG. 2).

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Fuel-Injection Apparatus (AREA)

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Family Cites Families (8)

• 2007
  • 2007-10-16 FR FR0758353A patent/FR2922289A1/fr not_active Withdrawn
• 2008
  • 2008-10-16 WO PCT/FR2008/051871 patent/WO2009053651A2/fr not_active Ceased
  • 2008-10-16 EP EP08843329A patent/EP2198148A2/de not_active Withdrawn

Non-Patent Citations (1)

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