EP0730091B1 - Fuel injection valve for an internal combustion engine - Google Patents

Description

State of the art

The invention is based on a fuel injector for an internal combustion engine according to the preamble of the claim 1. A fuel injector is already known (DE-OS 37 16 402), the downstream of a metering point for the Fuel has a perforated plate to by means of Perforated plate to a line beam or several line beams generate the inside of a deflection sleeve of the Fuel injector approximately parallel to one Longitudinal valve axis of the fuel injector run and approximately in the end region of the deflection sleeve on an inner ring hit. The inner ring is made up of individual inner surfaces inclined with respect to the longitudinal axis of the valve together, at which those striking the inner surface Cord rays are reflected, after which this from a Spray opening of the deflection sleeve inclined to the longitudinal axis of the valve emerge.

However, such an inner ring must be extremely precise manufactured and with a precise rotational position in the deflection sleeve be installed, since even the smallest deviations Fuel jet image and the orientation of the Can significantly change fuel jets. At a Mass production of fuel injectors are therefore time-consuming review processes and if necessary Readjustments of the inner ring in the deflection sleeve necessary, but this involves considerable manufacturing costs caused.

It is also known from FR-A-608840 to use a spoon-shaped deflection surface in a fuel injector.

Advantages of the invention

The fuel injector according to the invention with the characteristic features of claim 1 has in contrast the advantage of being inexpensive Fuel injectors for generating a Fuel jet or multiple fuel jets can be produced with a precise alignment, with the most varied in a simple manner Have fuel jet shapes implemented. In particular it is in a mass production of Fuel injectors possible without much effort, one consistently precise orientation and shape of the Fuel jet, for example with a narrow, wide fanning out or conical fuel jet, too guarantee.

By the measures listed in the subclaims advantageous further developments and improvements of the Claim 1 specified fuel injector possible.

drawing

Embodiments of the invention are in the drawing shown in simplified form and in the following Description explained in more detail. 1 shows a Section through a partially shown, according to the invention trained fuel injector, Figure 2 a Top view of a baffle plate after a first one embodiment according to the invention, Figure 3 a Side view of a section along a line III-III in Figure 2, Figure 4 shows a section along a line IV-IV in Figure 3, Figure 5 is a plan view of the baffle plate after a second embodiment of the invention, Figure 6 a Side view of a section along the line VI-VI in Figure 5, Figure 7 is a plan view of the baffle plate after a third embodiment of the invention, Figure 8 a Top view of the baffle plate after a fourth Embodiment according to the invention, Figure 9 a Side view of a section along a line IX-IX in Figure 8, Figure 10 is a plan view of the baffle a fifth embodiment of the invention, figure 11 is a plan view of the baffle plate after a sixth embodiment according to the invention, Figure 12 a Top view of the baffle plate after a seventh embodiment according to the invention, Figure 13 a Side view of a section along a line XIII-XIII in Figure 12, Figure 14 is a plan view of the baffle an eighth exemplary embodiment according to the invention, FIG. 15 a section along a line XV-XV in Figure 14.

Description of the embodiments

Figure 1 shows a section through an only partially illustrated fuel injector 3, in particular for mixture-compressing, spark-ignition internal combustion engines is provided. The fuel injector 3 is for example, plugged into an intake pipe 5 Internal combustion engine attached. The intake pipe 5 limits a flow cross section 6, in which of the Air sucked into the internal combustion engine for combustion flows.

The direction of flow of the intake air is through corresponding arrows 17 marked in FIG. 1. The Fuel injector 3 has a valve housing 7 for example, electromagnetically actuated and gives the fuel from a at its spray end 4 Spray opening 19 of a deflection sleeve 18 in the Flow cross section 6 from. The deflection sleeve 18 has one elongated shape and is on the valve housing 7 of the Fuel injector 3, for example, pluggable attached and made of plastic, for example. The Fuel leaves the fuel injector 3 in shape a single or double or multi-jet fuel jet 14. The fuel jet 14 decays after, for example short spray distance in the finest fuel droplets and mixes with the air flowing in the intake pipe 5, so that there is as homogeneous a fuel-air mixture as possible forms, which is then not closer downstream one shown intake valve in the combustion chambers Internal combustion engine burns. The fuel jet 14 can different fuel jet images according to the invention assume, for example, a narrow, wide fanning out or conical fuel jet image. The Fuel jet 14 is usually not on that shown intake valve of the internal combustion engine directed. Preferably, the fuel is approximately in the middle of the Suction pipe 5 limited flow cross-section 6 delivered. The delivery of fuel in the middle of the Flow cross section 6 prevents the formation of a Burning disruptive wall film made of fuel, which is otherwise in particular on the walls of the intake pipe 5 and Inlet valve precipitates.

The fuel is inside the fuel injector 3 in a known manner from a valve closing body or a valve closing needle and a valve seat. in the Embodiment is the valve closing body of a Valve closing ball 8 formed in the closed position for example a conical valve seat 9 is applied to the fuel flow to a downstream of the Shut off valve seat 9 located metering opening 12. In The valve closing ball 8 from the valve seat 9 is in the open position lifted off so that fuel from the metering opening 12 flows out. The metering opening 12 is, for example, in a so-called spray plate 13 is formed. The Fuel leaves the metering opening 12 in a bundled manner Shape in the form of a cord beam 15, which is located inside the deflection sleeve 18, for example in the direction of a Longitudinal valve axis 16 of fuel injector 3, extends. The metering opening 12 is coaxial with Longitudinal valve axis 16. However, several can also Dosing openings 12 are provided in the spray plate 13 his. Approximately in the end region of the deflection sleeve 18 Cord beam 15 on a deflection surface 21, which of a surface of a thin, for example rectangular baffle 22 is formed. The Baffle 22 is, for example, as an embossed part made of metal manufactured and one-sided on a short side surface a fastening end 31, for example in a groove 23 introduced and held in an inner wall 24 of the Deflection sleeve 18 for example in the end region of the Spray opening 19 is provided. When installed the deflection plate 22, the deflection surface 21 is the valve seat 9 facing and closes with its facing the groove 23 Side with the valve longitudinal axis 16 an angle of attack α, which is greater than zero and less than 90 degrees. Preferably lies the angle of attack α of the baffle 22 in a range of about 30 degrees to 60 degrees. The angle of attack α and the Distance from the metering opening 12 to the baffle 22 is chosen such that a fuel jet 14 or more Fuel jets 14 are generated, for example in the center of the flow cross section 6 from the deflection sleeve 18 emerge and onto an intake valve or more Intake valves of the internal combustion engine are directed.

The cord beam 15 strikes in the area of one in FIG a line II shown in broken lines, free plate end 32 on the baffle 22 and leaves it essentially parallel to the deflection surface 21 the baffle 22, with a reflection of the cord beam 15 on the baffle 22 is largely avoided. The Direction of the baffle 22 leaving Fuel jet 14 is by the employment of the Baffle 22, or by changing the Angle of attack α extremely variable, so that for the fuel injector 3 different Installation positions and locations on the intake pipe 5 can result. As shown in Figure 1, this can Fuel injector 3 also perpendicular to Flow direction 17 are installed in the intake pipe 5. The fuel jet 14 leaves it Fuel injection valve 3 from the spray opening 19 in essentially with the angle of attack α of the baffle 22 and is thus opposite to the longitudinal valve axis 16 and opposite Flow direction 17 in the intake pipe 5 inclined to for example on an intake valve of the internal combustion engine to aim. But it is also possible that Fuel injection valve 3 inclined to flow direction 17 To be installed in the intake pipe 5, so that a smaller Angle of attack α of the baffle 22 is required to Dispense fuel jet 14 toward the inlet valve. Due to the inclined position of the fuel injector 3 results there is also a shorter distance of the fuel jet 14 to the inlet valve, causing condensation of Fuel on cold walls, especially on walls of the Intake pipe 5 and the inlet valve is avoided.

The cord beam 15 striking the deflection surface 21 leaves it essentially parallel to the deflection surface 21 the deflection plate 22 in the direction of the deflection surface 21 symmetrically dividing plate longitudinal axis 25. To do this without To accomplish reflection of the cord beam 15 are in the deflection surface 21 in the area of incidence of the cord beam 15 recesses 26, 27 designed according to the invention are provided, which, as shown in Figures 2 to 4, from the Deflection surface 21 of the baffle 22 are excluded. By the shape of the recesses 26, 27 may be the shape of the Deflection plate 22 leaving fuel jet 14 such be influenced, for example, one or two Multi-jet fuel jets 14 arise which the Deflection plate 22 with predetermined from the recesses 26, 27 Leave fuel jet forms. For example possible a fuel jet 14 or more To generate fuel jets 14 which are a narrowly limited wide or conical fuel jet image have, the fuel for example after certain spray distance in the finest fuel droplets disintegrates.

Figure 1 shows a first invention Embodiment of the in Figure 2 only partially shown baffle plate 22. The depressions 26, 27th serve on the one hand to redirect the single jet striking line 15 substantially in the direction the plate longitudinal axis 25 and on the other hand for dividing the Cord beam 15 in, for example, two individual ones Fuel jets 14. The following as Collection well 26 designated well 26 is in shape excluding a trough from the deflection surface 21. The hollow for example, has an approximately semicircular one Impact cross section 41 of the longitudinal axis 25 of the plate is divided symmetrically. The longitudinal axis 25 of the plate closes with the longitudinal valve axis 16 of the Fuel injection valve 3 also the angle of attack α on. The catch recess 26 is in communication with two further recesses 27, which are referred to below as Drain wells 27 are referred to. The Drainage wells 27 are in the form of channels from the Deflection surface 21, which is different from the Collection recess 26 spreading apart for free Extend plate end 32 out. The free plate end 32 has one of two tapering plate side surfaces, for example 34 formed, pointed end 40, for example on the Longitudinal plate axis 25. It should be noted that the invention does not apply to a pointed plate end 32 is limited. Rather, this can be very different Take shape, whereby the design of the 32 different types of fuel jet let it be realized. A pointed plate end 32 is suitable especially for two-jet fuel jets. It is but it is also possible to make the free plate end 32 blunt, for example with a perpendicular to the valve longitudinal axis 16 rectangular plate end 32, for example to generate a single jet fuel jet.

As in Figure 3, a sectional view along a Line III-III in Figure 2, shown, meets the in Fuel injection valve 3 from the metering opening 12 emitted cord beam 15 in the deflection sleeve 18 initially on the catch recess 26 to in this collect and then in the drain wells 27 in To continue flowing towards the free plate end 32 finally at the plate end 32 over the plate side surfaces 34 stream. To when the line beam 15 strikes the catch recess 26 is a reflection of the cord beam 15 to avoid as far as possible, this has a beveled Bottom 36, which is approximately in the direction of the Collection recess 26 striking line beam 15 inclined is. The bottom 36 of the collecting recess 26 goes downstream towards the free plate end 32 in floors 29 of the drain wells 27 over that with constant Lead depth to the plate end 32 to the in the Collection well 26 collected fuel without if possible Flow obstruction via the drain depressions 27 to derive. The fuel flows from the drain wells 27 over the free plate end 32, the direction of emerging fuel jet 14 through the directions of Drainage wells 27 is predetermined so that by means of two drainage wells 27 a double jet Fuel jet 14 is generated. By design the catch recess 26 can impingement differences of the Cord beam 15, for example due to Manufacturing tolerances of the metering opening 12 resulting Eccentricity between the metering opening 12 and the Collection recess 26, advantageously balanced be, so that always a consistently precise alignment and shape of the fuel jet 14 is present.

As in Figure 4, a side view of a section is shown along a line IV-IV in Figure 3, the drain wells have 27 floors 29 with for example triangular cross section. It is also possible the floors 29 with a semi-circular or U-shaped Form cross-section. Through the Cross-sectional shape of the bottoms 29 of the drain depressions 27 as well as the degree of spreading of the Drain recesses 27 in the direction of the plate end 32 and by the design of the free plate end 32 it is possible, fuel jets 14 with different To generate fuel jet images, for example with a narrow, broad or one cone-shaped fuel spray pattern.

FIG. 5 shows a top view of the baffle plate 22 corresponding to a second invention Embodiment in which all the same or equivalent parts with the same reference numerals of first exemplary embodiment according to FIGS. 1 to 4 Marked are. As in the first embodiment the line beam 15 hitting the baffle 22 in split two individual fuel jets 14. In contrast for the first embodiment, the baffle 22 no catch recess 26, but only two Drainage wells 27, which are in the area of impact of the Fuel jet 14 open into each other and in the direction of free plate end 32 diverge, in the form of Thighs of a triangle. As in Figure 6, one Side view of a section along a line VI-VI in Figure 5, is shown, the bottom 29 in Impact area of the cord beam 15 also in the direction of the impinging cord beam 15 is inclined to the cord beam 15 as far as possible in without flow restriction to divert the drain recesses 27 so that a reflection of the cord beam 15 is largely avoided. As in 6 is shown in dashed lines, it is possible, the bottom 29 in the impact area of the cord beam 15 trough-shaped, for example in the form of a Hemispherical shell to train.

FIG. 7 shows a third in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 6 Marked are. As shown in FIG. 7, the collecting recess 26 can also have a circular shape Have impact cross-section 41, in which in turn two Drain wells 27 open towards the free Plate end 32 diverge.

FIG. 8 shows a fourth in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 7 Marked are. As shown in FIG. 8, the collecting recess 26 can also have a triangular shape Have impact cross-section 41, in which in turn two Drain recesses 27 open out, as in FIG. 8 is shown in dashed lines, in the direction of the free Plate end 32 also diverge to one to generate two-jet fuel jet 14. The triangular impact cross section 41 tapers in Direction of the free plate end 32. To create a die Baffle 22 leaving single jet fuel jet 14 can dispense with the drain depressions 27, or this with a diamond-shaped step 38 for example, constant depth can be replaced. The Fuel of the impingement well 26 Cord beam 15 is thereby over the collecting recess 26 diverted along the step 38 towards the plate end 32, after which the fuel over a portion of the plate end 32 flows off over the tip end 40. As in the figure 9, a side view along a line IX-IX in FIG. 8, is shown, the catch recess 26 also has a beveled bottom 36 which in the area of impact of the Cord ray 15 in the direction of the striking cord ray 15 is employed to reflect the line beam 15 to be avoided as far as possible and this towards the step 38 redirect.

FIG. 10 shows a fifth in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 9 Marked are. As shown in FIG. 10, can the collecting recess 26 with the step 38 according to FIG 8 also have the outer shape of a pen to to generate a single jet fuel jet 14. The Fuel flows over the tip end 40 of stage 38 from. However, it is also possible to blunt the end 40 train, for example with a right angle to Plate longitudinal axis 25 extending plate side surface 34.

FIG. 11 shows a sixth in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 10 Marked are. As shown in FIG. 11, can the free plate end 32 with the plate side surfaces 34 also have a serrated shape, for example symmetrical to the plate longitudinal axis 25 left and right a pointed end 40 is provided so that the free Plate end 32 assumes a W shape. The catchment well 26 has a circular impact cross section 41 and goes from this to level 38 to the fourth Embodiment a single-jet fuel jet 14th to create.

FIG. 12 shows a seventh in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 11 Marked are. As shown in FIG. 12, can completely dispense with the drain wells 27 and only one catch recess 26 can be used. Like in the Figure 13, a side view of a section along a Line XIII-XIII shown in Figure 12, the Collection recess 26, for example, an inner surface have that of the outer surface of a hemispherical shell corresponds to after the impact of the cord beam 15 the catch recess 26 a single-beam To generate fuel jet 14. As in Figures 12 and 13 is shown in dashed lines, the Collection recess 26 also from two individual, circular Partial troughs 44, 45 put together on the Longitudinal plate axis 25 merge and the Impact cross section 41 in the form of a transverse figure eight form to form a two-jet fuel jet 14 produce.

FIG. 14 shows an eighth in a top view embodiment of the baffle 22 according to the invention, where all the same or equivalent parts with the same reference numerals from the previous Exemplary embodiments according to FIGS. 1 to 13 Marked are. As shown in FIG. 14, the catch recess 26 may correspond to the third Embodiment according to Figure 7, for example have circular impact cross section 41. Instead of trough-shaped drainage depressions 27 can be diamond-shaped Level 38 should be provided, which is different from the Collection recess 26 to the plate end 32, for example with constant depth. As in Figure 15, 14 shows a sectional illustration of a section XV-XV in FIG. 14, step 38 can also be a curved one Have floor 50 that faces plate side surfaces 34 deepened to by means of the catch recess 26 and the Step 38 to a two-jet fuel jet 14 produce.

Claims (7)

1. Fuel injection valve for an internal combustion engine, which has at least one metering opening (12), from which fuel emerges in the form of a cord-like jet and, in the interior of the fuel injection valve, strikes a deflection surface (21), after which the fuel emerges from the fuel injection valve obliquely to a valve longitudinal axis (16) of the fuel injection valve, characterized in that at least one depression (26; 27), which deflects and shapes the fuel jet (15), is recessed into the deflection surface (21) in the region of impact of the fuel jet (15).
2. Fuel injection device according to Claim 1, characterized in that the deflection surface (21) is formed by a top surface of a deflector plate (22).
3. Fuel injection device according to Claim 2, characterized in that the deflector plate (22) has a pointed end (40) via which the fuel leaves the deflector plate (22).
4. Fuel injection device according to Claim 2 or 3, characterized in that the depression (26), of which there is at least one, on which the fuel jet (15) impinges in the form of a cord-like jet is recessed into the deflection surface (21) of the deflector plate (22) in the form of a trough.
5. Fuel injection device according to Claim 2 or 3, characterized in that the depression (27), of which there is at least one, is recessed into the deflection surface (21) of the deflector plate (22) in the form of a channel (27) which extends as far as a free plate end (32).
6. Fuel injection device according to Claim 4, characterized in that the trough-shaped depression (26) is connected to two channel-shaped depressions (27).
7. Fuel injection device according to Claim 4, characterized in that the trough-shaped depression (26) has a bevelled bottom (36).

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