KR20180001501A - Injector for injecting a liquid - Google Patents

Abstract

The present invention relates to an injector (1) to inject liquid, preferably fuel in an internal combustion engine, capable of attaining improved ignition and combustion behavior of an air-fuel mixture. According to the present invention, the injector (1) comprises: a housing (2); a closing body (4) capable of linearly moving in an axial direction (3) in the housing (2); a valve seat (5) to support the closing body (4) in the housing (2) to close the injector (1); and a plurality of injection holes (10-15, 20-25) to inject the liquid towards the downstream direction of the valve seat (5) in the housing (2). The plurality of injection holes (10-15, 20-25) include a plurality of main holes (10-15) and at least one auxiliary hole (20-25). The size and position of at least one auxiliary hole (20-25) are formed and disposed to raise the degree of turbulence of the liquid flowing in the main holes (10-15) in comparison with a state of not including the auxiliary holes (20-25).

Description

INJECTOR FOR INJECTING A LIQUID < RTI ID = 0.0 >

The present invention relates to a valve assembly comprising a housing, a closed body axially linearly movable within the housing, a valve seat within the housing, the closed body being supported for closing the injector, and a plurality of injection holes To an injector for injecting liquid, preferably fuel, into the internal combustion engine.

Injectors for injecting a liquid such as fuel into an internal combustion engine are disclosed. Typical configurations include a housing, which includes a valve needle, for example, a linearly movable closed body formed precisely with respect to the associated valve seat, for example a piezoelectric actuator or solenoid valve, controlled by an electromagnet to open and close the injector. This adjustment can also be achieved, for example, in the case of a gasoline engine of an automobile, mainly by means of a central engine control, in accordance with the operating conditions of the vehicle and the ignition behavior in the combustion chamber, in particular with respect to target parameters, The injection can be controlled. It is also included in the prior art of direct injection that the fluid fuel is injected into the combustion chamber through a plurality of injection holes, usually open by a valve needle opening into the interior. A combustible air-fuel mixture is formed in the combustion chamber and ignited.

For example, DE 198 04 463 A1 discloses a fuel injection system for a gasoline engine with injection nozzles. Efficiency of Combustion In order to achieve an optimized condition, at least one row of injection holes is distributed around the circumference of the injection nozzle so that at least one spray jet for ignition is directed towards the spark plug.

According to another example of the prior art, WO 2013 140835 A1 describes how the fuel jets are individually controlled in a fuel injection valve having a plurality of fuel injection holes downstream of the contact surface between the valve body and the valve seat. To this end, the fuel injection valve includes a flow guide opening upstream of the contact surface between the valve body and the valve seat, and the flow guide opening is guided to the valve past the fuel channel. The present invention aims at intentional adjustment of the hydrodynamic ratio at the inlet in front of the valve seat, rather than in the jetting area itself.

SUMMARY OF THE INVENTION The present invention provides an injector that is capable of achieving a significantly improved ignition and combustion behavior of an air-fuel mixture in an internal combustion engine.

The above problem is solved by the injector according to claim 1.

The present invention has the advantage of preferably adjusting the hydrodynamic ratio in the injection area to optimize the inflow behavior and / or spray of the liquid injected downstream of the valve seat. In this case, the positively acting hydrodynamic fluid structure interactions of the injected liquid, which continue to flow dynamically, can be controlled by intentionally and reliably reproducible, by the formation of injectors with interacting injection holes . This provides significant advantages in terms of efficiency, process stability, and durability, especially with respect to the higher-level operation-related processes in the operation of the injector in the overall system. Certainly improved ignition and combustion behavior of the air-fuel mixture, for example a low coking tendency at the valve tip, is positively achieved, for example, in an internal combustion engine using an injector according to the present invention.

All of these advantages include (i) a housing; (ii) a closed body axially linearly movable within the housing; (iii) a valve seat in the housing in which the closed body is supported for closing of the injector; And (iv) an injector for injecting liquid, preferably fuel, into the internal combustion engine, comprising a plurality of injection holes in a housing for injecting liquid downstream of the valve seat. The injector according to the present invention is implemented such that, with respect to a plurality of injection holes, the injection holes include a plurality of main holes and at least one auxiliary hole. In this case, the size and position of the at least one auxiliary hole is formed and arranged to increase the turbulence degree of the liquid flowing into the main holes relative to the state without the auxiliary hole.

The expression of an increase in the degree of turbulence in the context of the present invention is not only an increase in the vortex in the given turbulence characteristics, but also an increase in the number of critical Reynolds Including variations. The expression liquid is understood to mean, inter alia, the fuel injected into the internal combustion engine for the formation of a combustible air-fuel mixture, in particular in the form of a spray jet, and an organic and / or inorganic, ≪ / RTI >

The dependent claims present preferred improvements of the present invention.

Other key parameters indicative of the formation of the hydrodynamic ratio are in particular: the swirling degree of the flow line bundle, the wetting degree of the liquid with respect to the solid area of the injector, the interaction between the flow center being formed and the individual flow cross- .

In a preferred embodiment, the size and position of the at least one auxiliary hole is formed and arranged to increase the degree of turning of the liquid flowing into the main hole as compared to the absence of the auxiliary hole. This corresponds to the magnitude of the rotation pulse moment in the flow of each of the injection holes with respect to the ideal comparison state of the layered tube flow type having the flow line vector not including the rotational component.

Additionally or alternatively, a preferred embodiment includes that the size and position of the at least one auxiliary hole is formed and arranged to reduce or preferably eliminate completely the degree of cavitation of the liquid flowing into the main hole. The degree of cavitation in the context of the present invention represents the degree to which cavitation due to stall occurs when flowing around the inlet and / or outlet edge of the injection hole. Surprisingly, it has been surprisingly found that cavitation tubes or vortex lines can be prevented or at least substantially reduced in relation to the number and average diameter of vapor bubbles by introducing fluctuating radial flow vector components into the inlet flow towards the injection holes lost. Another advantage is that a small amount of shot-to-shot variation does not occur or rarely occurs, whereby a very large penetration depth of the individual spraying beam of the sprayed liquid can be reliably prevented It turned out.

Additionally or alternatively, the size and position of the at least one auxiliary hole may be configured and arranged to reduce the degree of wetting. With respect to the present invention, the degree of fluctuation of the liquid flowing into the main hole from the inner wall of the main hole is defined as the wettability which is important. It has been found to be another advantage that the improved uniformity of the flows formed in the injection holes can be controlled by each of the provided flow cross sections.

Further, the preferred embodiment additionally or alternatively may be arranged such that the size and position of the at least one auxiliary hole is assigned to each of the main holes and is arranged to increase and / or increase the degree of interaction of the flow centers of the liquid flowing into the main hole Formed and arranged. In view of the present invention, it is preferably simple to consider the flow centers in accordance with the position, which are formed as inevitable attracting points of the flow lines in each inflow flow, particularly into the injection holes.

As another positive effect of the improvement of the present invention, it has been found that by the preferred specific geometrical arrangements between the at least one auxiliary hole and the plurality of main holes, in particular in the injector, which varies depending on the rheological properties of the flowing liquid, Can be optimally adjusted, particularly preferably, as desired. Preferably, the arrangements may have an axis of symmetry or a point of symmetry. However, arrangements with irregular and / or eccentric patterns along a total of three spatial axes may be preferred.

Preferably, at least one auxiliary hole has a first center-point spacing measured between a center point of the auxiliary hole and a center point of the first main hole with respect to the first main hole, and at least one auxiliary hole has a first center- Wherein the first center point spacing and the second center point spacing are the same, and / or wherein each of the center points of the auxiliary holes and each of the other main Is smaller than each other center-point spacing, measured between the center points of the holes.

According to a preferred refinement, the injector comprises a maximum number of main holes and a minimum number of auxiliary holes which are half the number of main holes. This means the preferred spatial allocation of one auxiliary hole in each of the two main holes. Sometimes it may be desirable, particularly if at least one auxiliary hole is provided, that at least one main hole does not include auxiliary holes assigned thereto by spatial proximity.

Preferably, the center points of the main holes are arranged in a first circumference having a first circle diameter, which is preferably concentric about the axial direction, and is preferably provided with a first interval of equal distance equally In which case the center point of each of the auxiliary holes does not lie outside the first circumference with the first circumference.

Also preferably, the center points of the auxiliary holes are arranged in one second circumference having a second circumference diameter, which is preferably concentric about the axial direction. In addition, the center points of the auxiliary holes may be provided having substantially uniform, substantially equidistant second intervals with respect to each other.

In a preferred embodiment, the center point of the first and / or second circumference lies in the central axis of the closed body linearly axially movable in the valve seat for the closing of the injector.

In most preferred embodiments of the injector according to the present invention, in the preferred eccentric arrangement of the ejection holes, the center points of the first and second circumferences are offset, so that the circumferences are preferably arranged eccentrically rather than concentrically .

In this case, the eccentricity of this arrangement is defined by the eccentricity of the center point of the first circumference and the center point of the second circumference by a predetermined distance. In this case, the interval is preferably 1% or more, more preferably 5% or more, particularly preferably 10% or more of the first circle diameter.

However, it is preferable that the center points of the main holes are arranged around a virtual first circumference having a first average circle diameter within a predetermined range of variation, and / or the center points of the plurality of auxiliary holes have a second average circle diameter It may be desirable to be disposed about the imaginary second circumference.

A preferred variant of the injector according to the invention is that the second number of integers of the auxiliary hole is less than or equal to half the first number of main holes, reduced by an integer, at least by one. Preferably, this corresponds to a predetermined allocation of one auxiliary hole in two main holes that are closer to the eye, and at least one main hole remains empty without auxiliary holes assigned by geometric proximity.

Preferably at least one auxiliary hole-inlet diameter of the auxiliary holes in all the variants is formed to be smaller than the main hole-inlet diameter of the main holes. However, it may be desirable that at least one auxiliary hole is characterized by an auxiliary hole-inlet diameter greater than the average or maximum main hole-inlet diameter of the main holes. Basically, the present invention also includes any combination of injection holes having different inlet diameters.

Also, preferably, the sum of the auxiliary hole-flow cross-sections of the auxiliary holes is less than the sum of the main hole-flow cross-sections of the main holes. In this case, for example, one auxiliary hole-inlet diameter of the auxiliary holes is formed to be larger than the main hole-inlet diameter of the main holes, but the sum of the auxiliary hole-flow cross sections of the auxiliary holes is larger than that of the main hole- May be less than the sum. The flow cross sections are specified in the inlet diameter.

In a preferred refinement of the invention, at least one of the ejection holes is formed at an angle different from the rest of the ejection holes with respect to the plane formed by the first or second circumference and / or the axial direction. For example, the injection holes, which are implemented in a non-parallel manner with respect to the axial direction, can basically exhibit a further increased degree of turbulence by an intended angle setting of the flow by an associated angle to a total of three spatial axes and / Lt; RTI ID = 0.0 > jetted < / RTI >

Next, embodiments of the injector according to the present invention will be described with reference to the accompanying drawings.

1 is a cross-sectional view of an injector according to the present invention, in accordance with all embodiments;
Fig. 2 is an enlarged view showing a lower region of the cross-sectional view of Fig. 1; Fig.
3 is a vertical plan view schematically showing the arrangement of the ejection holes according to the first embodiment;
4 is a vertical plan view schematically showing the arrangement of the ejection holes according to the second embodiment;
5 is a vertical plan view schematically showing the arrangement of the ejection holes according to the third embodiment.
6 is a vertical plan view schematically showing the arrangement of the ejection holes according to the fourth embodiment;
7 is a vertical plan view schematically showing the arrangement of the ejection holes according to the fifth embodiment.
8 is a schematic view of the flow lines around the arrangement according to the invention of the six injection holes according to the sixth embodiment;
9 is a schematic view of flow lines around the arrangement of six injection holes according to the prior art;

In the different drawings, the same reference numerals denote the same members or members having at least the same function.

1 shows a cross-section of an injector 1 according to the invention in a basic configuration according to all embodiments, and Fig. 2 shows a cross-sectional view of Fig. 1, which includes the arrangement of two injection holes 10, The lower region of the cross section is enlarged.

Since the injector shown in Fig. 1 or 2 for injecting liquid, preferably fuel, into the internal combustion engine has basically a known configuration, the basic configuration and general operation will be briefly described below. The injector 1 has a configuration composed of a plurality of parts, and includes a housing 2, and a valve member is disposed in the housing. The closed body 4 is pressed against the valve seat 5 of the housing 2 because the surface of the valve seat 5 in the valve member is accurately formed in a detentable fitting manner with respect to the closed movable body 4 The closed valve state of the injector 1 is formed. That is, the injector 1 is opened (upward movement direction) and closed again (downward movement direction) by an alternating stroke operation in the axial direction 3 of the reciprocatingly linearly movable closed body 4.

1 or 2, the valve seat 5 is arranged toward an empty injection volume downward (not fully shown here), for example toward the combustion chamber, and in front of the combustion chamber, Liquid is collected.

The liquid to be injected in the closed valve state of the injector 1 flows into the injection holes 10-15 and 20-25 located in the housing 2 downstream from the valve seat 5 (here downward). In the cross-section shown here, two injection holes 10-15, 20-25 embodied as main holes 10, 11 of the injection holes are located in the cut plane shown in the cross-sectional view, .

Wherein the main holes (10 or 11), which are implemented as circular bores and whose bore cross-section is further expanded by the inner shoulder in the flow direction, have a main hole inlet diameter (80 or 82) in the region of the flow cross- Hole-flow cross-section.

The individual spray jets of liquid (not shown here) formed for each of the spray holes 10-15, 20-25 will generally have a finest first order flow due to the stalling effect from the associated surrounding inner wall and discharge edge upon flow discharge Called secondary atomizing beam, which is composed of secondary droplets.

The main holes 10 and 11 have the same angle of about 30 degrees in the axial direction 3 here but at an angle of preferably about 30 degrees and preferably at least one of the injection holes 10-15 and 20-25 Can be aligned at different angles (6) with respect to the axial direction (3).

Fig. 3 schematically shows a preferred arrangement of the injection holes 10-15, 20-25 according to the first embodiment in a vertical plan view along the axial direction 3. Fig. A total of six main holes 10-15 are shown in FIG. 3, and the holes are uniformly disposed along a first outer circumference 41 having a larger first circumferential diameter 51. In this arrangement, three auxiliary holes 20, 21 and 22 appear in the arrangement and the auxiliary holes are arranged uniformly along the second inner circumference 42 with the smaller second circular diameter 52. In this first embodiment, the center point 301 of the first circumference 41 and the center point 302 of the second circumference 42 coincide with each other, so that the two circumferences 41 and 42 are arranged concentrically.

In this figure, not only the positioning of the injection holes 10-15 and 20-22 but also the main hole-inlet diameter 80-85 of the main holes 10-15 And the auxiliary hole-inlet diameter 90-92 of the auxiliary holes 20-22 defining the auxiliary hole-flow cross-section of the auxiliary holes.

For the sake of a good description of the principle, in this schematic of the embodiments according to Figs. 3 to 7, the main holes 10-15 are shown uniformly on the one hand at the main hole-inlet diameter 80-85, The auxiliary holes 20-25 are likewise uniformly shown with auxiliary hole-inlet diameters 90-95. Further, although the auxiliary holes 20-25 are shown here to be uniformly smaller than the main holes 10-15, this is not intended to limit the present invention. Basically, each of the injection holes 10-15, 20-25 can be implemented differently with respect to the main hole-inlet diameter 80-85 or the auxiliary hole-inlet diameter 90-95.

The geometrical arrangement between the individual ejection holes 10-15, 20-25 is characterized by a respective distinct spacing size between them, as shown in Fig. That is, (i) the first center point interval 30 is the distance between the center point of at least one auxiliary hole 20 and the center point of the first main hole 10, (ii) the second center point interval 31 is at least A distance between a center point of one auxiliary hole (20) and a center point of the second main hole (11); (iii) The other center point interval 32-35 is the distance between the center point of at least one auxiliary hole 20 and the other center point of each of the main holes 12-15.

In this first embodiment of Fig. 3, one auxiliary hole 20 of three auxiliary holes is formed by two main holes < RTI ID = 0.0 > 10 and 11, so that a trio shape is obtained.

Another characteristic spacing dimension is the first spacing 60-65 between the main holes 10-15. In this first embodiment, the six main holes 10-15 are equally evenly distributed along the first outer circumference 41, so that the six first intervals 60-65 are substantially equal, It is the same as the fluctuation width.

The second spacing 70-72 between the secondary holes 20-22 can be considered as another characteristic spacing size. Since the auxiliary holes are uniformly disposed along the second inner circumference 42, the three second intervals 70-72 are substantially the same.

Supplementarily, the description of FIG. 3 is referred to in the following description of FIGS. 4 through 7, in accordance with other embodiments, because the arrangement of the injection holes 10-15, Particularly distinguished by their distinctive features.

4 of another preferred arrangement of the ejection holes 10-15, 20-25 has a second number of auxiliary holes, that is, six auxiliary holes, as the auxiliary holes 20-25, Is different from the first embodiment shown in Fig. 3 in that it is disposed equidistantly along the inner circumference 42. [ The first or second center point intervals 30 and 31 between the two main holes 10 or 11 closest to the auxiliary holes 20 and the auxiliary holes 20 are formed in the two main holes 10 The first and second diameters 51, 52 of the two circumferences 41, 42 positioned concentrically with respect to one another are selected to be similar in size so as to be smaller than the first spacing 60 between the two diameters 41,

5 showing the third embodiment is different from the arrangement of Figs. 3 and 4 in that the two center points 301 and 302 of the first circumference 41 and the second circumference 42 are displaced from each other, The arrangement of the first circumference 41 with respect to the two circumferences 42 is realized with an eccentricity. The second circumference 42 is displaced with respect to the first circumference 41 perpendicular to the axial direction 3 and displaced by an interval 500 between the two central points 301 and 302 in particular. Since the distance 500 is at least 10% of the first circle diameter 51 in this embodiment, the eccentricity over the general manufacturing inaccuracy is reliably given.

A mirror symmetrical arrangement about the vertical center axis 501 also appears.

Two auxiliary holes 20, 21 in the second circumference 42 are disposed in the lower circle segment so as to have a second spacing 70 non-equidistantly. In this case, the main holes 11, 12 or 13, 14 are provided at the first intervals 60, 62, 64, respectively, (61 or 63) that is shorter than the first spacing (61 or 63). The latter are substantially matched by mirror symmetry.

A first trio shape around the auxiliary hole 20 appears on the left side of FIG. 5 and the auxiliary hole is equidistant to two main holes 11 and 12 having substantially the same two first center point intervals 31 and 32 .

On the other hand, in the mirror symmetry, on the right side of FIG. 5, another trio shape around the other auxiliary holes 21 assigned to the two main holes 13 and 14 appears.

It should also be noted that in this embodiment the main hole 10 does not include an auxiliary hole 20 or 21 which appears to be visually hollow, i.e., is assigned to the main hole by geometric proximity. This is because the first interval 60 between the main hole and the next main hole 11 and the first center point interval 30 with respect to the center point of the auxiliary hole 20 correspond to the auxiliary hole 20 and the two main holes 11 , 12). ≪ / RTI > The three injection holes 10, 11 and 20 are located at intervals of similar size to each other in a substantially isosceles triangle, i.e., a second center point interval 31, a third center point interval 32 and a first interval 61 .

Fig. 6 schematically shows the arrangement of the ejection holes 10-15, 20-25 according to the fourth embodiment in a vertical plan view, and Fig. 7 is shown according to the fifth embodiment. In this case, Figs. 6 and 7 are explained with reference to Fig. 4 as a modification of arrangements including six main holes 10-15 each equidistant from each other and six auxiliary holes 21-25 each equidistant from each other . 6, the first circumference 41 and the second circumference 42 having the same first circumferential diameter 51 and second circumferential diameter 52 coincide with each other so that the main hole and the auxiliary hole alternate with each other, They are simply spaced apart from each other like a pearl threaded in a thread: 10, 20, 11, 21, 12, 22, 13, 23, 14, 24, 15, 25.

3 to 6, the center point of the auxiliary holes 20-25 is disposed at least on the circumference in the first circumference 41 having the first circumference 51 or in the case of FIG.

7, the second circumference 42 is moved to the outside of the first circumference 41 by selecting the second circumference 52 to be slightly larger than the first circumference 51. In this case, the second circumference 42 in which the center points of the auxiliary holes 20-25 are disposed passes through the area of the main holes 10-15, so that the smaller auxiliary holes 20-25 are larger It appears to be assigned geometrically close to the main holes 10-15.

Figures 8 and 9 illustrate a schematic of a flow line that can be formed (e.g., according to the Runga-Kutta method) using numerical flow simulation calculations. On the other hand, Fig. 8 shows, for example, a flow line formed around the sixth embodiment of the arrangement according to the invention of the injection holes, namely five main holes 10, 14 located on the first circumference 41, And a flow line formed around the eccentrically positioned auxiliary hole (20).

Figure 9, on the other hand, shows an image with a flow line, such as that formed around the conventional arrangement of six main holes 10-15 equidistantly arranged on the first circumference 41 for comparison of the prior art Respectively.

It is well known in the prior art that the main holes 10-15 form six identical flow centers 110-115 as flow sinks, Flow order.

Alternatively, a flow state in which a large vortex passing through the space is formed around the auxiliary hole 20, which is set in the injector according to the present invention, can be grasped according to FIG. In this case, each of the injection holes 10-14, 20 forms at least the first approximation of the respective flow centers 10-14, 20, but preferably several flow lines are formed due to the formation of vortex passing through the area To different flow centers 110-114, which are each farther away. As a result, a significantly increased degree of turbulence relative to the prior art shown in FIG. 9 can result in a significant increase in the degree of interaction between the flow centers 110-114 assigned to the associated main holes 10,14.

1 injector
2 housing
4 closed body
5 valve seat
10-15 Main Hall
20-25 auxiliary hole

Claims (9)

An injector (1) for injecting liquid, preferably fuel, into an internal combustion engine,
- housing (2),
- a closed body (4) linearly movable in the axial direction (3) in the housing (2)
The valve seat (5) in the housing (2) in which the closed body (4) is supported for closing the injector (1)
- a plurality of injection holes (10-15, 20-25) in said housing (2) for injecting liquid to the downstream of said valve seat (5)
The plurality of injection holes 10-15 and 20-25 include a plurality of main holes 10-15 and at least one auxiliary hole 20-25,
The size and position of the at least one auxiliary hole 20-25 are formed to increase the degree of turbulence of the liquid flowing into the main hole 10-15 as compared with the state in which the auxiliary hole 20-25 is not provided Wherein the injector is disposed in the vicinity of the injector. The method according to claim 1, wherein the at least one auxiliary hole (20) is formed with respect to the first main hole (10), a distance between the center point of the auxiliary hole (20) Wherein the at least one auxiliary hole has a center point spacing between the center point of the auxiliary hole and the center point of the second main hole with respect to the second main hole, Wherein the first center point interval 30 and the second center point distance 31 are the same and / or the center point of the auxiliary hole 20 and each of the other main holes (33-35) measured between the center points of the first and second center points (13-15). The method of claim 1 or 2, wherein the number of the auxiliary holes (20-25) is the maximum number of the main holes (10-15) and is at least half of the number of the main holes (10-15) Injector. 4. A method according to any one of the preceding claims, wherein the center points of the main holes (10-15) are preferably concentric with respect to the axial direction (3) And each of the center points of the auxiliary holes 20-25 has a first circular diameter 51 and a second circular diameter 51. The first circle 51 has a first interval 60-65, Of said first circumference (41). 5. A method according to claim 4, characterized in that the center points of the auxiliary holes (20-25) are arranged in one second circumference (42) with a second circumference (52) and are preferably arranged in a substantially equidistant Wherein the center point of the first circumference and the center point of the second circumference are offset from each other by an eccentricity. 6. The injector of claim 5, wherein the number of integers of the auxiliary holes (20-25) is less than or equal to half the number of the main holes (10-15) reduced by at least one. 7. A method according to any one of claims 1 to 6, wherein at least one auxiliary hole-inlet diameter (90-95) of the auxiliary holes (20-25) Diameter (80-85). 8. A method according to any one of claims 1 to 7, wherein the sum of the auxiliary hole-flow cross-sections of said auxiliary holes (20-25) is smaller than the sum of the main hole-flow cross sections of said main holes Features an injector. 9. A method according to any one of claims 1 to 8, wherein at least one of the injection holes (10-15, 20-25) has an injection hole with respect to the axial direction (3) and / Is formed at an angle (6) different from the rest of the injection holes with respect to a plane defined by the projecting walls (41, 42).

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