JP2015078604A - Fluid injection valve and spark ignition engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To combine atomization of spray and improvement in a degree of freedom in designing spray shape, penetration force and distribution of an injection amount by utilizing axis-switching phenomenon.SOLUTION: In a fuel injection valve 1, a plurality of injection holes 39 arranged in the circumferential direction of an injection hole plate 33, include at least one switching injection hole 392. The switching spray produced by the switching injection hole 392, generates axis-switching phenomenon at a prescribed distance from the injection hole 392, and changes directions of a long axis and a short axis in the cross-sectional shape in a face vertical to the injecting direction. Thus the cross-sectional shape of a face vertical to the injecting direction of at least one spray among the sprays forming the whole spray 60, is changed so that it is controlled to be oriented in the desired direction.

Description

  The present invention relates to a fluid injection valve that generates a spray by injecting fluid from a plurality of nozzle holes, a spray generation device including the fluid injection valve, and a spark ignition engine.

  In recent years, in vehicle engines, research and development for reducing exhaust gas when the engine is cold due to atomization of fuel spray and improving fuel efficiency by improving combustibility have been actively promoted. In particular, research and development of a stratified combustion concept in a spark ignition engine equipped with a multi-hole injector that directly injects fuel into a combustion chamber is known.

  The fuel spray in such an engine is composed of a spray directed to the vicinity of the spark plug and a spray not directed to the vicinity of the spark plug. The former realizes stratified combustion particularly near the spark plug, and the latter is stratified combustion. It has the role of realizing the mixture formation in the entire combustion chamber in homogeneous combustion.

  When a spark plug is mounted at the center of the combustion chamber and a multi-hole injector as a fuel injection valve is mounted across the intake valve, the spark plug and the multi-hole injector are not opposed. For this reason, the spray specifications required for the spray directed to the vicinity of the spark plug and the spray not directed to the vicinity of the spark plug are different. In other words, the required spray specifications differ between when stratified combustion is performed at a low speed and low load of the engine and when homogeneous combustion is performed at a high speed and high load.

  On the other hand, in the atomization process of spraying, in order to reduce the size of the droplets, it is effective to make the liquid yarn, which is the previous stage of the division, thin. In order to make the liquid yarn thinner, it is effective to make the liquid film, which is the previous stage of the splitting of the liquid yarn, thinner or thinner, and the liquid film is more advantageous than the liquid column. I know that. Further, as a liquid film flow forming method, a method is known in which a swirl flow is given to the fuel flow before flowing into the nozzle hole to form a liquid film flow in the nozzle hole.

  The inventor of the present application investigated and examined the relationship between these liquid film flow formation methods and atomization processes, and the spray shape, penetration force, and injection amount distribution of the collective spray in which a plurality of single sprays gathered based on these techniques. As a result, it has been found that the collective spray in which single sprays are gathered can be divided into the following two forms.

  One is a case where each single spray is identifiable and the characteristics of each single spray become a collective spray that is almost indistinguishable. This is a collective spray with a solid structure that is relatively homogeneous, and each single spray can be identified, but it has the same characteristics as the collective spray, and is a spray that is difficult to control halfway. is there.

  The other is the case of a collective spray that makes it impossible to identify each single spray. This is a collective spray whose representative example is an injection amount distribution having a conical shape with a central peak, and a plurality of single sprays are gathered and replaced with a single new collective spray that is almost different from the original form, It is a very characteristic and stable phenomenon.

  Which of these forms depends largely on whether the spray behavior is at a certain threshold. The more the single spray is assembled, the closer the spray amount distribution is to axial symmetry and the sharper cone shape, so that the penetration force as a whole spray increases. In either case of the above two forms, a plurality of single sprays gather, and in the collective spray in which the spray shape in the plane perpendicular to the spray direction and the spray amount distribution are substantially axisymmetric, the cross-sectional shape is It is difficult to make a non-target variant and direct a part of the spray in a desired direction.

  Although the atomization technique as described above is being applied to the fuel injection valve, the mainstream of the atomization technique is the small injection hole diameter and multiple injection holes, and the jets from adjacent injection holes interfere with each other. It is designed so that the atomization state does not deteriorate. In other words, the nozzle hole specifications such as nozzle hole arrangement, nozzle hole diameter, inclination, and length are set so that the nozzle hole center axis or the jet flow direction becomes more downstream. Are difficult to balance.

  As a technique for suppressing the spread of the entire spray, it is known that the nozzle hole arrangement and the nozzle hole specifications are such that the nozzle hole central axis or the jet direction intersects each other immediately below the nozzle hole. However, in this method, the relationship from the outlet of the nozzle hole to the position where the liquid film flow can be regarded substantially as a spray flow after breaking or splitting the liquid film flow (breaking length of the liquid film flow) and the atomization Requirements were not considered.

  On the other hand, if the angle of the injection hole central axis with respect to the vertical line of the fluid injection valve is made relatively small in order to suppress the spread of the entire spray, it is disadvantageous for forming a thin liquid film flow. Therefore, the atomization process becomes slow, the jets easily interfere with each other, and the atomization level cannot be realized as expected. In addition, as described above, when the collective spray of a plurality of single sprays is generated due to the interference between the jets, the penetration force is greater than that in the single spray.

  Furthermore, in order to reduce spray collisions on the cylinder liner and promote mixing with air, a method of rapidly attenuating the spray penetration force at a predetermined distance is desired, but there is no method to achieve without significantly changing the spray form. It was. For this reason, in order for each spray to attenuate the penetration force rapidly, it is necessary to accelerate the attenuation of the spray momentum by a method such as flattening the jet flow from the nozzle hole outlet. In order to avoid interference between the jets, it was necessary to further separate the jet directions.

  For example, as a prior art aiming at ensuring both spray penetration force and appropriate dispersion of spray density in a spark ignition engine, in Patent Document 1, the main injection hole and the injection center are the injection center of the main injection hole. And sub-holes pointing in different directions, and by setting the cross-sectional areas of the inlet and outlet of the main nozzle holes to be different, the spray angle is widened while keeping the injection quantity constant, and the fuel density of the spray is increased. A distributed multi-hole injector is presented.

  Further, in Patent Document 2, cavitation bubbles are generated in the first taper portion that contracts in the fuel flow direction in the nozzle hole, and the generated cavitation bubbles collapse to atomize the fuel and atomize the fuel. A fuel injection valve is proposed in which the penetration force is reduced by diffusing by a second taper portion that expands in the flow direction.

  On the other hand, in fluid engineering, an axis-switching phenomenon is known in which the direction of the major axis and the minor axis of a spray having an oval cross-sectional shape ejected from an injection hole changes downstream ( Non-patent literature 1-6). This axis-switching phenomenon does not have to be oval in the cross-sectional shape of the spray, and is established as long as the major axis is substantially line-symmetric with respect to the minor axis.

JP 2007-315276 A JP 2012-14504 A

Proceedings of the Japan Society of Mechanical Engineers (Part B), Vol. ILASS-Europe 2010, “An experimental investigation of discharge coefficient and cavitation length in the elliptical nozzles” (Sung Ryoul Kim) Production Research Volume 50 No. 1, pp 69-72, “Numerical Simulation of Complex Turbulent Jets: Origin of Axis-Switching” (Ayodeji O. DEMUREN) Jet Engineering, Morikita Publishing, pp41-42 Proceedings of the Japan Society of Mechanical Engineers (Part 2) Vol. 25, No. 156, pp 820-826, "Study on the reach of diesel engine fuel spray" (Waguri et al.) Proceedings of the Japan Society of Mechanical Engineers (Part B) Vol. 62, No. 599, pp2867-2873 “Effect of Atmospheric Viscosity on Diesel Spray Structure”

  As described above, in the prior art, in a spark ignition engine equipped with a multi-hole injector, the spray specifications required for each of the spray directed to the vicinity of the spark plug and the spray diffused throughout without directing the vicinity of the spark plug The degree of freedom in designing to achieve the above has been low and has not been fully realized. In particular, atomization of spray, spray shape, and penetration force are characteristics that have a correlation with each other. However, Patent Document 1 and Patent Document 2 do not consider the influence of them, and thus realize an optimal spray specification. It is not possible.

  In a nozzle like patent document 1, it is known that the way of inflow of fuel to each nozzle hole will actually change with the way of flow inside a sac (cavity) upstream of a nozzle hole. That is, when the cross-sectional areas of the injection hole inlet and the outlet are made different, it is not always possible to widen the spray angle while keeping the injection amount constant. In particular, when a plurality of injection holes are not arranged symmetrically with respect to the central axis of the injector, the flow patterns in the injection holes are often not the same, but Patent Document 1 does not consider these.

  In Patent Document 2, since the influence on the cavitation due to the fuel pressure and the peeling state is not shown, the level of atomization is unknown. If the level of atomization is different, the momentum of the entire spray is different and affects the penetration. In particular, as spray directed to the vicinity of the spark plug, a method for more reliably improving the degree of freedom in design such as spray shape and penetration force is desired.

  Further, there has been no conventional fluid injection valve in which the spray direction is controlled by changing the cross-sectional shape in a plane perpendicular to the spray direction of the spray using the above-described axis-switching phenomenon. Furthermore, there has been no design in which the shape of the entire spray, the atomization of the spray, the penetrating force, and the injection amount distribution are designed using the axis-switching phenomenon.

  The present invention has been made in order to solve the above-described problems, and enables the spray direction to be controlled by utilizing an axis-switching phenomenon. The atomization of the spray, the spray shape, and the penetration force are achieved. An object of the present invention is to provide a fluid injection valve and a spray generation device including the fluid injection valve that achieve both improvement in design freedom of injection amount distribution.

  In addition, it is possible to generate a spray directed to the vicinity of the spark plug by utilizing the axis-switching phenomenon, and to achieve both atomization of the spray and improvement in design flexibility of the spray shape, penetration force, and injection amount distribution. The purpose is to obtain a spark ignition engine.

  A fluid injection valve according to the present invention includes a valve seat provided in the middle of a passage through which a fluid flows, a valve body that can contact and separate from the valve seat and controls opening and closing of the passage, and a downstream of the valve seat. A fluid injection valve that generates a spray by injecting fluid from a plurality of nozzle holes arranged in the nozzle hole body, wherein the plurality of nozzle holes are in a plane perpendicular to the injection direction. It includes at least one switching nozzle for generating a switching spray having a major axis and a minor axis different in cross-sectional shape, and the switching spray generated by the switching nozzle is axis-switched at a predetermined distance from the switching nozzle. It is controlled so as to cause a phenomenon, and the direction of the major axis and the minor axis is changed.

  Moreover, the spray production | generation apparatus which concerns on this invention is equipped with said fluid injection valve, the fluid supply means which supplies a fluid to a fluid injection valve, and the control means which controls operation | movement of a fluid injection valve.

  The spark ignition engine according to the present invention is a spark ignition engine including an ignition plug disposed in a fuel chamber and a fuel injection valve for injecting fuel into the combustion chamber. A valve seat provided in the middle of the passage through which the valve flows, a valve body that is provided so as to be able to contact and separate from the valve seat and controls opening and closing of the passage, and a nozzle hole body provided downstream of the valve seat, The fuel is injected from a plurality of nozzle holes arranged in the nozzle hole body to generate spray, and the plurality of nozzle holes have a major axis and a minor axis length in a cross-sectional shape in a plane perpendicular to the injection direction. The switching spray generated by the switching nozzle includes at least one switching nozzle that generates different switching sprays. The switching spray is controlled to generate an axis-switching phenomenon at a predetermined distance from the switching nozzle. Change the direction of the axis It is intended to be.

  According to the fuel injection valve and the spray generation device including the fuel injection valve according to the present invention, at least one of the sprays generated by the plurality of nozzle holes is a switching spray, thereby utilizing the axis-switching phenomenon. Thus, the spray direction can be controlled, and it is possible to achieve both atomization of the spray and improvement in the degree of freedom in design of the spray shape, penetration force, and injection amount distribution.

  Further, according to the spark ignition engine according to the present invention, by using at least one of the sprays generated by the plurality of nozzle holes as a switching spray, the vicinity of the spark plug can be obtained using the axis-switching phenomenon. It is possible to generate a spray that is directed, and it is possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, penetration force, and injection amount distribution.

It is sectional drawing which shows the fuel injection valve which concerns on Embodiment 1 of this invention. It is an expanded sectional view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a top view which shows the nozzle hole plate of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a detailed sectional view explaining the structure of the tip part of the fuel injection valve concerning Embodiment 1 of the present invention. It is a detailed sectional view explaining the structure of the tip part of the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior until two non-switching sprays form a collective spray by the Coanda effect as a reference example. It is a figure explaining the behavior until two non-switching sprays form a collective spray by the Coanda effect as a reference example. It is a figure explaining the behavior in case the Coanda effect does not act on two non-switching sprays in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior when the Coanda effect acts on the non-switching spray and the switching spray in the fuel injection valve according to Embodiment 1 of the present invention. It is a figure explaining the behavior in case the Coanda effect does not act on non-switching spray and switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior in case the Coanda effect does not act on non-switching spray and switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the example of the whole spray formed in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure which shows in a time series until each spray reaches the whole spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the spark ignition type engine which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
Hereinafter, a fluid injection valve and a spray generation device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a fuel injection valve according to the first embodiment, and FIG. 2 is an enlarged cross-sectional view showing a tip portion of the fuel injection valve according to the first embodiment. In the drawing, the same and corresponding parts are denoted by the same reference numerals.

  The spray generation device according to the first embodiment controls the operation of the fuel injection valve 1 that is a fluid injection valve, fuel supply means (not shown) that supplies fuel to the fuel injection valve 1, and the fuel injection valve 1. And a control device (not shown) as control means. In the following description, the fuel injection valve 1 attached to the cylinder head of the internal combustion engine and disposed so that the tip portion for injecting fuel faces the cylinder of the internal combustion engine will be described as an example.

  The fuel injection valve 1 includes a solenoid device 2 that generates electromagnetic force, and a valve device 3 that operates by energizing the solenoid device 2. The solenoid device 2 includes a housing 21 that forms a yoke portion of a magnetic circuit, a core 22 that is a fixed iron core provided inside the housing 21, a coil 23 provided so as to surround the core 22, and an inner side of the coil 23. Is provided with an armature 24 that is a movable iron core that reciprocates.

  The valve device 3 includes a valve body 31 that is cylindrical and press-fitted and welded to the outer diameter portion of the distal end portion of the core 22, and a valve seat 32 that is provided in the passage of fuel inside the valve body 31. I have. Downstream of the valve seat 32, an injection hole plate 33, which is an injection hole body having a plurality of injection holes 39 for injecting fuel, and a cover plate 34 provided upstream of the injection hole plate 33 inside the valve seat 32. The valve body 35 is provided inside the valve body 31 so as to be capable of contacting and separating from the valve seat 32 and controls the opening and closing of the passage, and a compression spring 36 provided upstream of the valve body 35.

  The valve body 35 includes a hollow rod 37 that is press-fitted and welded to the inner surface of the armature 24, and a ball 38 that is fixed to the tip of the rod 37 by welding. The ball 38 includes a chamfered portion 38 a parallel to the Z axis (indicated by an arrow in FIG. 1) of the fuel injection valve 1, a flat surface portion 38 b facing the cover plate 34, and a curved surface portion 38 c in line contact with the valve seat 32. And have.

  The nozzle hole plate 33 has a peripheral edge bent downward and is welded to the distal end surface of the valve seat 32 and the inner peripheral side surface of the valve main body 31. A plurality of nozzle holes 39 penetrating in the plate thickness direction is formed in the nozzle hole plate 33. FIG. 3 is a plan view of the nozzle hole plate 33 as seen from the inside of the valve body 31. A plurality of nozzle holes 39 are arranged in the nozzle plate 33 in the circumferential direction.

  The plurality of nozzle holes 39 includes a non-switching nozzle hole 391 having a circular cross-sectional shape perpendicular to the thickness direction of the nozzle hole plate 33 and an oval switching nozzle hole 392. The switching nozzle hole 392 is arranged such that the major axis of the ellipse is in the direction of reducing the distance from the non-switching nozzle hole 391.

  When the jet of fuel injected from the non-switching injection hole 391 proceeds downstream by a predetermined distance (break length), a non-switching spray having a circular cross-sectional shape in a plane perpendicular to the injection direction is generated. Further, when the jet flow ejected from the switching nozzle 392 proceeds downstream by a predetermined distance (break length), the switching spray in which the major axis and the minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction. Generate.

  The switching spray generated by the switching nozzle hole 392 is controlled to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle hole 392, and changes the direction of the major axis and the minor axis. The behavior of each spray will be described later in detail.

  Next, the operation of the fuel injection valve 1 will be described. When an operation signal is sent from the control device of the internal combustion engine to the drive circuit of the fuel injection valve 1, a current is passed through the coil 23 of the fuel injection valve 1, and the armature 24 is attracted to the core 22 side. As a result, the rod 37 and the ball 38, which are integral with the armature 24, move upward against the elastic force of the compression spring 36, the curved surface portion 38c of the ball 38 is separated from the valve seat surface 32a, and there is a gap between them. Is formed to form a passage, and fuel injection directed to the intake port is started.

  On the other hand, when an operation stop signal is sent from the control device of the internal combustion engine to the drive circuit of the fuel injection valve 1, the energization to the coil 23 is stopped, and the force that the armature 24 is attracted to the core 22 side disappears. 37 is pushed toward the valve seat 32 by the elastic force of the compression spring 36, the curved surface portion 38c of the ball 38 and the valve seat surface 32a are closed, and fuel injection is terminated at this point.

  Here, the detailed structure and position of the nozzle hole plate 33, the cover plate 34, the valve seat 32, and the ball 38 in which the flow in the nozzle hole 39 is converted into a liquid film flow by, for example, contraction flow are shown in FIGS. 5 will be described with reference to the detailed sectional views of FIG. The nozzle hole 39 described here may be either a non-switching nozzle hole 391 or a switching nozzle hole 392. In FIG. 4, X indicates the diameter of the nozzle hole 39, and Y indicates the length of the nozzle hole 39.

  When the valve element 35 is opened, the fuel passes through a path parallel to the Z-axis between the chamfered portion 38a of the ball 38 and the inner surface of the valve seat 32, and then between the curved surface portion 38c of the ball 38 and the valve seat surface 32a. To the downstream and reach the valve seat portion R1. Since the fuel flows parallel to the Z-axis upstream of the valve seat portion R1, the flow of the fuel is mainly along the valve seat surface 32a due to inertia after passing through the valve seat portion R1. The point P1 at the downstream end is reached.

  The point P1 is the end of the valve seat surface 32a, and the valve seat 32 has a surface extending in the vertical direction downstream from the point P1. Therefore, the main flow of fuel is separated from the point P1. The extension line of the valve seat surface 32a intersects the peripheral side surface of the cover plate 34 at the point P2, and the fuel separated from the point P1 faces the point P2, and the annular passage C (the inner peripheral wall surface of the valve seat 32 and the cover plate 34). Between the large-diameter portion 34d) and the radial passage B (the inner peripheral wall surface of the valve seat 32 and the periphery of the small-diameter portion 34c of the cover plate 34) without significant change in the radial direction. Between the sides).

  In addition, since the main flow of the fuel that passes through the valve seat portion R1 flows into the annular passage C, the flow into the clearance passage A (between the bottom surface of the ball 38 and the top surface 34a of the cover plate 34) is suppressed. . A line connecting the sheet portion R1 and the point P3 at the entrance of the injection hole 39 with a straight line intersects with a thin portion 34b which is a large diameter portion of the cover plate 34. That is, the thin portion 34b blocks the linear flow of fuel from the valve seat portion R1 to the inlet of the injection hole 39.

For this reason, at least a part of the fuel flowing into the nozzle hole 39 flows along the radial passage B. The cover plate 34 has a small diameter portion 34 c disposed closer to the nozzle hole 39 on the inner diameter side than the nozzle hole 39. Accordingly, the front flow F1 of the fuel directed toward the inner diameter side along the radial passage B closes the flow path of the return flow F2 flowing into the injection hole 39 from the Z axis of the fuel injection valve 1, and the speed of the return flow F2 is increased. Reduce. By suppressing the return flow F2, the speed of the front flow F1 flowing into the nozzle hole 39 from the valve seat portion R1 side is relatively increased.

  Because at least a portion of the front flow F1 travels along the radial passage B and is forced to undergo a significant change in direction in the nozzle hole 39, and because the front flow F1 is high speed, the fuel is injected into the nozzle hole. In the cross section 39, the fuel injection valve 1 is strongly pressed against the wall surface of the injection hole 39 on the Z-axis side. Thereafter, as shown in FIG. 5, at the inlet of the nozzle hole 39, the low-speed return flow F2 forms a flow F3 along the wall surface of the nozzle hole 39, and the high-speed front flow F1 is a fuel that presses the fuel against the wall surface. Stream F4 is formed.

  In addition, the air flow F5 introduced from the outlet of the nozzle hole 39 acts on the fuel flow F4, and the fuel flow F4 is separated from the point P4 (the outer edge of the fuel inlet of the nozzle hole 39). . The fuel flow F4 is pressed against the wall surface as it travels through the nozzle hole 39, and the direction of the liquid film changes in the direction along the wall surface of the nozzle hole 39 while spreading in the circumferential direction of the wall surface of the nozzle hole 39. .

  As described above, the thinner the liquid film, the thinner the liquid thread and the more effective the atomization of the droplets. Therefore, in the first embodiment, the nozzle hole 39 has a height h (see FIG. 4) of the gap passage A. The length Y is optimized so that the fuel flow F4 is pressed into the thin liquid film flow 30 in the nozzle hole 39. As a result, the liquid film flow 30 of the injected fuel starts to split after a predetermined distance, and droplets atomized through the state of the liquid yarn are generated.

  Next, in the fuel injection valve 1 according to the first embodiment, a method for controlling the spray shape, the penetration force, the injection amount distribution, and the spray direction using the axis-switching phenomenon will be described. First, as a reference example, the behavior until the Coanda effect acts on two non-switching sprays to form a collective spray will be described with reference to FIGS. 6 and 7. Note that the Coanda effect is an effect that induces the proximity of adjacent sprays.

  In FIG. 6, (a) is a side view showing non-switching spray injected from two non-switching nozzle holes, and (b) is EE, FF, GG, HH in (a). It is sectional drawing in the part shown by. As shown to Fig.6 (a), the jets 4a and 4b injected from the two non-switching nozzle holes 391 arrange | positioned by the space | interval L1 become the non-switching sprays 4A and 4B, respectively. The jets 4a and 4b have a jet cross-sectional shape shown in a cross-section EE when a break in a state in which the liquid film flow can be regarded as a spray flow after breaking or splitting occurs.

  The distance between the non-switching nozzle hole 391 and the cross section EE at this time is defined as a break length a. Already at the position of the break length a, the gap c1 between the jets 4a and 4b is smaller than the threshold value at which the Coanda effect acts. Subsequently, in the cross-section FF, the jets 4a and 4b are dispersed to become a single non-switching spray 4A and 4B, and the two non-switching sprays 4A and 4B are located at a distance b from the non-switching nozzle hole 391. , Its outer diameter begins to touch.

  Further, from the cross-section FF, the Coanda effect acts between the two single non-switching sprays 4A, 4B due to the pressure distribution, and the single non-switching spray 4A, 4B approaches the cross-section G- Aggregation proceeds like G. At the same time, entrainment of the ambient air of the non-switching sprays 4A and 4B, and thereby induction of an air flow along the flow direction downstream of the substantially central portion in the non-switching sprays 4A and 4B.

  Note that even if the jet 4a and the jet 4b, or the non-switching spray 4A and the non-switching spray 4B have characteristics that cause an axis-switching phenomenon, before the axis-switching phenomenon occurs, the cross-section E- At the position E, the gap c1 between the jets 4a and 4b is smaller than the threshold value at which the Coanda effect acts, so the Coanda effect begins to act and approaches.

  Here, the entrainment level of the ambient air is not a level that greatly changes the shape of the entire collective spray 40 in which the single non-switching sprays 4A and 4B are assembled. Further, if the conditions are adjusted, the assembly further proceeds from the state of the collective spray 40 having the cross section GG, and is substantially regarded as one solid collective spray 40 like the cross section HH.

  FIG. 7 is a diagram illustrating the behavior of the two non-switching sprays until they form a collective spray due to the Coanda effect, with arrows indicating the entrainment status of the surrounding air, and (a) shows the injection from the two non-switching nozzle holes. The side view which shows the made non-switching spray, (b) is sectional drawing in the part shown by FF, G1-G1, G2-G2, HH in (a).

  As shown to Fig.7 (a), the airflow V along the flow direction downstream is induced in spray by the entrainment of ambient air. As a result, as shown in FIG. 7B, the spray amount distribution of each spray in FF, G1-G1, G2-G2, and HH has a peak at the approximate center of the collective spray 40.

  As described above, when the plurality of non-switching sprays 4A and 4B form the collective spray 40 by the action of the Coanda effect, the air flow along the downstream flow direction is induced in the spray by the entrainment of the ambient air, and the penetration force It becomes difficult to suppress the spraying, and the degree of freedom in design is reduced with respect to atomization of the spray and the spray shape.

  Therefore, the fuel injection valve 1 according to the first embodiment basically forms a collective spray 40 as shown in FIG. 6 even if the jets injected from the plurality of injection holes 39 become sprays downstream. In the end, each spray is designed to form an overall spray 60 (see FIGS. 12 and 13) in an independent state.

  Therefore, the plurality of nozzle holes 39 are arranged at intervals at which the Coanda effect that induces the proximity of the adjacent sprays does not act at least until the switching spray generated by the switching nozzles 392 causes an axis-switching phenomenon. At the same time, the nozzle hole specifications including the nozzle hole diameter, length, and inclination are set.

  Further, each spray generated by the plurality of nozzle holes 39 has a Coanda effect that induces close proximity to the adjacent sprays until at least the switching spray generated by the switching nozzle 392 causes an axis-switching phenomenon. It is set to a non-acting flow rate, particle size, and particle number density.

  Further, the switching nozzle hole 392 includes the nozzle hole diameter, length, and inclination so as to generate a switching spray in which the major axis is axisymmetric with respect to the minor axis in a cross-sectional shape in a plane perpendicular to the injection direction. The nozzle hole specification is set. Further, in the first embodiment, the nozzle hole specifications of the switching nozzle hole 392 are set so as to generate switching spray that changes the direction of the major axis and the minor axis by approximately 90 degrees due to the axis-switching phenomenon.

  That is, in the fuel injection valve 1 according to the first embodiment, the adjacent sprays are deformed close to each other by the action of the Coanda effect only after at least one of them is a switching spray and an axis-switching phenomenon occurs. It is. In this case, by bringing two or more sprays close to each other, a non-circular collective spray having an asymmetric cross-sectional shape in a plane perpendicular to the injection direction is formed.

  FIG. 8 is a view for explaining the behavior of each spray generated by two non-switching nozzle holes in the fuel injection valve according to the first embodiment, wherein (a) is a side view of each spray, and (b). These are sectional drawings in the part shown by EE, FF, GG in (a). As shown to Fig.8 (a), the jets 4a and 4c injected from the two non-switching injection holes 391 arrange | positioned by the space | interval L2 (L2> L1) become the non-switching sprays 4A and 4C, respectively.

  The jets 4a and 4c have a jet cross-sectional shape in a cross-section EE when a break in a state in which the liquid film flow can be regarded as a spray flow after breaking or splitting occurs. At the position of the break length a at this time, the gap between the jets 4a and 4c is larger than the threshold value at which the Coanda effect acts. Further, the gap c2 between the sprays 4A and 4C in the cross section GG is also larger than the threshold value at which the Coanda effect acts, and the Coanda effect does not act on the sprays 4A and 4C. As a result, both the sprays 4A and 4C proceed in the initial traveling direction while remaining independent.

  Next, the behavior of each spray when the non-switching injection hole 391 and the switching injection hole 392 are adjacent to each other in the fuel injection valve according to Embodiment 1 will be described. FIG. 9 is a diagram showing the behavior until the non-switching spray and the switching spray form a collective spray due to the Coanda effect, where (a) is a side view of each spray, and (b) is EE in (a). It is sectional drawing in the part shown by FF, ..., MM.

  As shown in FIG. 9A, the non-switching nozzle hole 391 and the switching nozzle hole 392 are arranged at an interval L3. The jet 4a injected from the non-switching nozzle hole 391 becomes the non-switching spray 4A, and the jet 5a injected from the switching nozzle 392 becomes the switching spray 5A. In FIG. 9, assuming that the break lengths a of the jet 4a and the jet 5a are substantially equal, the cross-sectional shape of the jet at this time is as shown in the section EE.

  The switching spray 5A having an oval cross-sectional shape is opposed to the non-switching spray 4A in the major axis direction before the axis-switching phenomenon occurs. The switching spray 5 </ b> A faces the non-switching spray 4 </ b> A and flows downstream while maintaining the initial flow direction almost directly below the switching nozzle hole 392 while its cross-sectional shape slightly expands in both the major axis and minor axis directions. .

  After that, an axis-switching phenomenon occurs at a predetermined distance from the switching nozzle hole 392, and the major axis and minor axis directions of the switching spray 5A start to change as shown in the section JJ. At this position, the gap c3 between the switching spray 5A and the non-switching spray 4A is larger than the threshold value at which the Coanda effect acts, and the Coanda effect does not occur.

  As the cross-section JJ moves downstream from the cross-section KK, the deformation in which the direction of the major axis and the minor axis of the switching spray 5A changes proceeds, and the switching spray 5A and the non-switching spray 4A come closer. This is because the gap between the switching spray 5A and the non-switching spray 4A is reduced due to the occurrence of the axis-switching phenomenon in the switching spray 5A, and accordingly, the Coanda effect acts between the switching spray 5A and the non-switching spray 4A. It depends.

In the cross section KK, the gap c4 between the switching spray 5A and the non-switching spray 4A is smaller than the threshold value at which the Coanda effect acts. In the cross-section L-L, the opposite ends of the switching spray 5A and the non-switching spray 4A are deformed and moved to start interference. As a result, in the cross section MM, after a predetermined time has elapsed after fuel injection, a collective spray 50 in which the switching spray 5A and the non-switching spray 4A are gathered is formed at a predetermined distance from the non-switching nozzle hole 391 and the switching nozzle hole 392. Is done. The shape, penetration force, injection amount distribution, and the like of the collective spray 50 can be changed by changing the characteristics of the switching spray 5A and the non-switching spray 4A.

  In addition, the switching spray 5A is deformed by changing the direction of the major axis and the minor axis, so that the momentum exchange with the surrounding air greatly proceeds, and the penetration force becomes small. Therefore, by interfering with the non-switching spray 4A, the particles of the non-switching spray 4A and the movement of the air flow dragged by the particles are suppressed, and the penetration force of the non-switching spray 4A is also suppressed.

  The dashed-dotted line d of Fig.9 (a) has shown the spray shape in case the non-switching spray 4A is independent. In this way, the non-switching spray 4A has a reduced penetration force due to interference with the switching spray 5A, and the extension of the tip thereof is shortened compared to the case where it is alone.

  Further, the switching spray 5A is reduced in penetrating force and greatly mixed with the surrounding air, whereby atomization is improved and the difference from the atomization level of the non-switching spray 4A is reduced. That is, it is possible to form a non-circular collective spray 50 that is atomized at a predetermined distance downstream from the non-switching nozzle hole 391 and the switching nozzle hole 392 and has an asymmetric cross section.

  In FIG. 9, when the switching nozzle hole 392 is not used, the adjacency of adjacent sprays does not start until further downstream, and in some cases, aggregation does not occur. Accordingly, each spray continues to spread and the penetration force does not decrease. As a result, the momentum possessed by the spray is difficult to move to the air flow and atomization is insufficient.

  In FIG. 9, when two nozzle holes are switching nozzle holes 392 and the adjacent sprays are switching sprays 5A, the axis-axis switching is performed by setting their long axes to be substantially parallel to each other. A collective spray in which the long axes are connected in the longitudinal direction can be formed by the phenomenon.

  In FIG. 9, the aggregate spray 50 whose cross section is non-target is formed by a combination of one non-switching spray 4 </ b> A and one switching spray 5 </ b> A, but the collective spray is limited to this combination. It is not something. For example, a combination of two non-switching sprays 4A and one switching spray 5A may be used, or two switching sprays 5A may be used.

  In the first embodiment, before the switching spray 5A is deformed by the axis-switching phenomenon, the Coanda effect is reliably suppressed from acting with the non-switching spray 4A. As the method, there is a method of delaying the timing at which the Coanda effect occurs by providing a difference in the characteristics of the switching spray 5A and the non-switching spray 4A.

  Specifically, the method of making the average particle diameter of the switching spray 5A at the same distance from the non-switching nozzle hole 391 and the switching nozzle hole 392 larger than the average particle diameter of the non-switching spray 4A, or the break length of the switching spray 5A There are a method of making the break length of the non-switching spray 4A longer, a method of setting the penetration force of the switching spray 5A larger than the penetration force of the non-switching spray 4A, and the like.

  In realizing these methods, it is possible to utilize the fact that the level and direction of the contracted flow change depending on the nozzle hole shape difference between the non-switching nozzle hole 391 and the switching nozzle hole 392. For example, when the level and direction of the contracted flow are varied, the pressure loss (jet velocity) in the nozzle hole 39, the sectional area of the jet, the sectional shape, the arrangement, the direction, and the like can be varied, and the Coanda effect acts. It is possible to change the threshold value of the gap to be performed.

  Moreover, since the threshold value of the gap in which the Coanda effect acts also varies depending on the flow rate of each spray, the atomization level, the particle number density, the atmospheric pressure, and the like, it can be set to a desired threshold value by adjusting these.

  FIG. 10 is a view showing the behavior of each spray when the Coanda effect does not act on the non-switching spray 4A and the switching spray 5A, (a) is a side view of each spray, (b) is E in FIG. It is sectional drawing in the part shown by -E, FF, ..., LL. As shown in FIG. 10A, the non-switching nozzle hole 391 and the switching nozzle hole 392 are arranged at an interval L4 (L4> L3). The jet 4a injected from the non-switching nozzle hole 391 becomes the non-switching spray 4A, and the jet 5b injected from the switching nozzle 392 becomes the switching spray 5B.

  In FIG. 10, the switching spray 5 </ b> B is opposed to the non-switching spray 4 </ b> A in the major axis direction before the axis-switching phenomenon occurs, but as shown in a cross section JJ at a predetermined distance from the switching nozzle hole 392. The direction of the major axis and minor axis begins to change.

  However, even in the cross-section LL where the non-switching spray 4A and the switching spray 5A are closest to each other, the gap c5 is larger than the threshold at which the Coanda effect acts. For this reason, the Coanda effect does not act on both the sprays 4A and 5B, and they proceed independently in the initial traveling direction. At this time, since the switching spray 5B does not interfere with the non-switching spray 4A, the penetration force of the non-switching spray 4A is not suppressed.

  In addition, when a plurality of switching sprays 5A are included, even after an axis-switching phenomenon occurs in the plurality of switching sprays 5A, the non-switching spray 4A is not affected by proximity, deformation, etc. The deformed shape of the switching spray 5A can be kept stable. Further, since the long axis is symmetrical with respect to the short axis of the switching spray 5A, the shape is axisymmetric even after the occurrence of the axis-switching phenomenon, and the spray is stably stagnated in the vicinity of the spark plug. Convenient for

  10 shows an example in which the long axis direction of the switching spray 5A is opposed to the non-switching spray 4A, but in FIG. 11, the short axis of the switching spray 5C before the occurrence of the axis-switching phenomenon is non-switching. An example of facing the spray 4A will be described.

  11, (a) is a side view of each spray, and (b) is a cross-sectional view at a portion indicated by EE, FF,..., LL in (a). As shown to Fig.11 (a), the non-switching nozzle hole 391 and the switching nozzle hole 392 are arrange | positioned by the space | interval L5. The jet 4a injected from the non-switching nozzle 391 becomes a non-switching spray 4A, and the jet 5c injected from the switching nozzle 392 becomes a switching spray 5C.

  In the example shown in FIG. 11, the gap between the switching spray 5C and the non-switching spray 4A is larger than the threshold at which the Coanda effect acts, even in the cross section HH where both the sprays 4A and 5C are closest to each other. Not. Furthermore, as the cross section JJ moves downstream from the cross section KK, the deformation in which the direction of the major axis and the minor axis of the switching spray 5C changes is advanced, and the gap between the switching spray 5C and the non-switching spray 4A is further increased. .

  For this reason, the Coanda effect does not act on both the sprays 4A and 5C, and both the sprays 4A and 5C proceed substantially in the initial traveling direction while being independent. At this time, since the switching spray 5C does not interfere with the non-switching spray 4A, the penetration force of the non-switching spray 4A is not suppressed.

An example of the shape of the entire spray formed by the fuel injection valve 1 according to the first embodiment will be described with reference to FIGS. 12 and 13. This example shows a case where the Coanda effect does not act between the sprays. FIG. 12 shows the entire spray formed by the sprays ejected from the respective nozzle holes 39 of the nozzle hole plate 33 shown in FIG. 3, and (a) shows the state before the switching spray causes the axis-switching phenomenon ( b) shows the cross-sectional shape in the plane perpendicular to the injection direction after the switching spray causes the axis-switching phenomenon.

  13 shows a case where the entire spray shown in FIG. 12 is viewed from the direction indicated by an arrow x in FIG. 12, that is, a case where the entire spray is viewed from a direction perpendicular to the Z axis of the fuel injection valve 1. . In FIG. 13, (a) to (d) show time-series changes of each spray until the entire spray is reached. Note that, when viewed from the direction of the arrow x, the non-switching spray 4 </ b> A overlaps the front and rear, and therefore, only the non-switching spray 4 </ b> A positioned forward is shown in FIG. 13.

  As shown in FIG. 12, an axis-switching phenomenon occurs in the switching spray 5A at a predetermined distance from the switching nozzle hole 392, and the major axis and minor axis directions in the cross-sectional shape in the plane perpendicular to the ejection direction change. At this time, in the switching spray 5A, a considerable proportion of the momentum moves to the air, and the penetration force is greatly reduced.

  On the other hand, each non-switching spray 4A does not interfere with the adjacent non-switching spray 4A or switching spray 5A, and hence the penetration force is not suppressed. For this reason, each non-switching spray 4A advances in the substantially advancing direction, without changing, independently. Finally, as shown in FIG. 13 (d), it reaches a distance longer than the switching spray 5A.

  In the first embodiment, the case where one switching nozzle hole 392 is included in the plurality of nozzle holes 39 has been described, but two or more switching nozzle holes 392 may be provided. Moreover, although the case where the direction of the major axis and the minor axis of the switching spray changes by 90 degrees has been described, the present invention is not limited to this and can be set to an arbitrary angle. Further, the shape of the switching spray 5A may be flatter in cross-sectional shape. When generating a spray having a large ratio between the major axis and the minor axis, the nozzle hole specifications may be set so that the major axis and minor axis directions change within a range in which the major axis direction is not divided.

  Moreover, the shape of the whole spray 60 can implement | achieve various variations, such as not only a hollow cone shape but a solid cone shape, a triangular shape. Further, in the first embodiment, an electromagnetic fuel injection valve has been described as an example of the fuel injection valve 1. However, the drive source may be other types, such as a piezo type or a mechanical type. Further, it can be applied to both intermittent injection valves and continuous injection valves.

  As described above, in the fuel injection valve 1 according to the first embodiment, the plurality of nozzle holes 39 arranged in the circumferential direction of the nozzle hole plate 33 includes at least one switching nozzle hole 392 and is generated by the switching nozzle hole 392. The switching spray that is generated causes an axis-switching phenomenon at a predetermined distance from the nozzle hole 392, and changes the direction of the major axis and the minor axis in a cross-sectional shape in a plane perpendicular to the ejection direction.

  Thereby, among the sprays forming the entire spray 60, the cross-sectional shape in a plane perpendicular to the spray direction of at least one spray can be changed, and control can be performed so as to direct a desired direction. Become. Further, the switching spray can rapidly attenuate the penetration force of the spray at a predetermined distance by utilizing the fact that the momentum exchange with the surrounding air proceeds due to the deformation and the penetration force decreases. In addition, since the penetration force is reduced, mixing with ambient air proceeds and atomization is improved. Furthermore, the injection amount distribution and the spraying direction can be set according to each nozzle hole specification.

  From the above, according to the first embodiment, at least one of the sprays generated by the plurality of nozzle holes 39 is the switching spray 5A, thereby using the axis-switching phenomenon and the spray direction. It is possible to control the atomization of the spray and to improve the design freedom of the spray shape, penetration force, and injection amount distribution.

  Although the fuel injection valve 1 has been described as an example in the first embodiment, the application of the fluid injection valve according to the present invention is not limited to this. Other applications include a wide range of applications such as painting, coating, pesticide spraying, cleaning, humidification, sprinklers, sprays for sterilization, cooling, and various sprays for agriculture, equipment, household, and personal use. The fluid injection valve according to the present invention can be incorporated in a spray generating device for various uses regardless of the drive source, the nozzle form, and the type of fluid to be sprayed.

Embodiment 2. FIG.
FIGS. 14A and 14B are diagrams schematically showing a spark ignition engine according to Embodiment 2 of the present invention, in which FIG. 14A is during stratified combustion (when the piston is rising), and FIG. 14B is during homogeneous combustion (when the piston is descending). ) State. The spark ignition engine 6 according to the second embodiment includes the fuel injection valve 1 according to the first embodiment as a fuel injection valve that injects fuel into the combustion chamber 7.

  Since the configuration of the fuel injection valve 1 of the spark ignition engine 6 according to the second embodiment is the same as that of the first embodiment, a detailed description thereof will be omitted, but a valve provided in the middle of the passage through which the fuel flows. A seat 32, a valve body 35 that can be brought into contact with and separated from the valve seat 32 and controls the opening and closing of the passage, and an injection hole plate 33 that is provided downstream of the valve seat 32 and has a plurality of injection holes 39. (See FIGS. 1 and 3).

  Further, at least one of the plurality of nozzle holes 39 is a switching nozzle hole 392 that generates a switching spray 5A in which the major axis and the minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction. The switching spray 5A generated by the switching nozzle hole 392 is controlled so as to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle hole 392, and changes the direction of the major axis and the minor axis.

  As shown in FIG. 14, an intake port 8 and an exhaust port 9 communicate with the combustion chamber 7 of the spark ignition engine 6, and each combustion chamber 7 side opening is linked to the piston 10. An intake valve 11 and an exhaust valve 12 that are opened and closed are provided. Further, the fuel injection valve 1 is disposed at a substantially central portion of the ceiling of the combustion chamber 7, and a spark plug 13 is disposed on the side thereof. In addition, arrangement | positioning of the fuel injection valve 1 and the ignition plug 13 is not limited to this.

  In the second embodiment, the switching spray 5A generated by the switching nozzle hole 392 of the fuel injection valve 1 is controlled so as to be directed toward the vicinity of the spark plug 13 by the axis-switching phenomenon. Further, whether or not the switching spray 5A causes an axis-switching phenomenon is controlled by the pressure in the combustion chamber 7 or the air flow.

  In addition, the injection hole specifications including the injection hole diameter, the length, and the inclination of the switching injection hole 392 are set so as to generate the switching spray 5A in which the long axis is axisymmetric with respect to the short axis. Thereby, even after the occurrence of the axis-switching phenomenon, the shape becomes axisymmetric, which is convenient for stably stopping the spray near the spark plug 13.

  Further, the plurality of nozzle holes 39 are arranged at intervals at which the Coanda effect that induces the proximity of the adjacent sprays does not act at least until the switching spray 5A generated by the switching nozzles 392 causes an axis-switching phenomenon. At the same time, the nozzle hole specifications including the nozzle hole diameter, length, and inclination are set.

  Further, each spray generated by the plurality of nozzle holes 39 has a Coanda effect that induces the proximity of the adjacent sprays until at least the switching spray 5A generated by the switching nozzle 392 causes an axis-switching phenomenon. The flow rate, the particle size, and the particle number density are set so as not to interact with each other. In the second embodiment, the Coanda effect is prevented from acting between the sprays adjacent to each other even after the switching spray 5A causes the axis-switching phenomenon.

  The state of the entire spray during stratified combustion and homogeneous combustion in the spark ignition engine 6 according to Embodiment 2 of the present invention will be described with reference to FIG. In the stratified combustion shown in FIG. 14A, the air in the combustion chamber 7 is compressed by the rise of the piston 10, and the pressure in the combustion chamber 7 increases.

  For this reason, the penetration force of each non-switching spray 4A and switching spray 5A becomes smaller than that during homogeneous combustion. The switching spray 5 </ b> A causes an axis-switching phenomenon in the process of passing through the vicinity of the spark plug 13, and is directed near the spark plug 13. At the same time, the penetrating force is greatly reduced, and when passing through the vicinity of the spark plug 13, the penetrating force is lost, and the penetrating force stays in the vicinity of the spark plug 13.

  That is, the penetration force of the switching spray 5 </ b> A can be rapidly attenuated at a desired distance from the injection position to the vicinity of the ignition plug 13, and a desired rich air-fuel mixture can be formed in the vicinity of the ignition plug 13. This is advantageous for establishing stratified combustion.

  Further, each non-switching spray 4A is directed so as to be in a mixed combustion state suitable for stratified combustion, and the penetration force is set so that collision with the cylinder liner 14 and the piston 10 surface is suppressed. As a result, the entire spray 60 is prevented from colliding with the cylinder liner 14 and the piston 10 surface, and forms a rich air-fuel mixture suitable for stratified combustion in the vicinity of the spark plug 13.

  In addition, during the homogeneous combustion shown in FIG. 14B, the intake valve 11 is opened as the piston 10 descends, so that a strong air flow such as a tumble flow is generated in the combustion chamber 7. The switching spray 5 </ b> A follows the air flow in the combustion chamber 7 in the process of passing through the vicinity of the spark plug 13, and does not cause an axis-switching phenomenon and diffuses throughout the combustion chamber 7.

  Thus, the spark ignition engine 6 according to the second embodiment can provide a large characteristic difference between the spray directed to the vicinity of the spark plug 13 and the spray not directed to the spark plug 13 during stratified combustion. By applying the switching spray 5A as spray directed to the vicinity of the spark plug 13, it is possible to form an air-fuel mixture suitable for stratified combustion in the vicinity of the spark plug 13 while avoiding collision with the spark plug 13. Further, at the time of homogeneous combustion, it is possible to follow the air flow in the process of passing through the vicinity of the spark plug 13 and to diffuse to the entire combustion chamber 7 without causing an axis-switching phenomenon.

  As described above, according to the second embodiment, at least one of the sprays generated by the plurality of nozzle holes 39 is the switching spray 5A, so that the ignition plug is utilized by utilizing the axis-switching phenomenon. It is possible to generate a spray directed to the vicinity of 13 and to achieve both atomization of the spray and improvement in the degree of freedom in design of the spray shape, penetration force, and injection amount distribution. It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  INDUSTRIAL APPLICABILITY The present invention can be used as a fluid injection valve, in particular, a fuel injection valve mounted on an internal combustion engine, a spray generation device including the same, and a spark ignition engine.

1 fuel injection valve, 2 solenoid device, 3 valve device,
4a, 4b, 4c, 5a, 5b, 5c jet,
4A, 4B, 4C non-switching spray, 5A, 5B, 5C switching spray,
6 spark ignition engine, 7 combustion chamber, 8 intake port, 9 exhaust port,
10 piston, 11 intake valve, 12 exhaust valve, 13 spark plug,
14 cylinder liner, 21 housing, 22 core, 23 coil,
24 amateur, 30 liquid film flow, 31 valve body, 32 valve seat, 32a valve seat surface,
33 injection hole plate, 34 cover plate, 34a top surface, 34b thin wall portion,
34c Small diameter part, 34d Large diameter part, 35 Valve body, 36 Compression spring, 37 Rod,
38 balls, 38a chamfered portions, 38b flat surface portions, 38c curved surface portions, 39 nozzle holes,
40, 50 collective spray, 60 whole spray,
391 non-switching nozzle holes, 392 switching nozzle holes.

A fluid injection valve according to the present invention includes a valve seat provided in the middle of a passage through which a fluid flows, a valve body that can contact and separate from the valve seat and controls opening and closing of the passage, and a downstream of the valve seat. A fluid injection valve that generates a spray by injecting fluid from a plurality of nozzle holes arranged in the nozzle hole body, wherein the plurality of nozzle holes are in a plane perpendicular to the injection direction. The switching spray generated by the switching nozzle includes at least one switching nozzle that generates a switching spray having a major axis and a minor axis having different lengths in cross-sectional shape. The switching spray generated by the switching nozzle has a long axis at a predetermined distance from the switching nozzle. The direction of the minor axis is changed.

Also, spark ignition engine according to the present invention, a spark plug disposed in the combustion chamber, a spark-ignition engine equipped with a fuel injection valve for injecting fuel into the combustion chamber, the fuel injection valve, A valve seat provided in the middle of the passage through which the fuel flows, a valve body that can be brought into contact with and separated from the valve seat and that controls the opening and closing of the passage, and an injection hole provided downstream of the valve seat The fuel is injected from a plurality of nozzle holes arranged in the nozzle hole body to generate a spray, and the plurality of nozzle holes have a length of a major axis and a minor axis in a cross-sectional shape in a plane perpendicular to the injection direction. Includes at least one switching nozzle that generates different switching sprays, and the switching spray generated by the switching nozzle changes the direction of the major axis and the minor axis at a predetermined distance from the switching nozzle. .

According to the spray generating device comprising a fuel injection valve and this according to the present invention, among the spray generated by the plurality of injection holes, Ri by to the switching spraying at least one, controls the mists direction This makes it possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, penetration force, and injection amount distribution.

Further, according to the spark-ignition engine according to the present invention, among the spray generated by the plurality of injection holes, Ri by to the switching spraying at least one, produce a spray oriented near point fire plug This makes it possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, penetration force, and injection amount distribution.

The present invention relates to a spark ignition engine in fluid ejection Ben'nami beauty to produce a jet spray of fluid from a plurality of injection holes.

  In recent years, in vehicle engines, research and development for reducing exhaust gas when the engine is cold due to atomization of fuel spray and improving fuel efficiency by improving combustibility have been actively promoted. In particular, research and development of a stratified combustion concept in a spark ignition engine equipped with a multi-hole injector that directly injects fuel into a combustion chamber is known.

  The fuel spray in such an engine is composed of a spray directed to the vicinity of the spark plug and a spray not directed to the vicinity of the spark plug. The former realizes stratified combustion particularly near the spark plug, and the latter is stratified combustion. It has the role of realizing the mixture formation in the entire combustion chamber in homogeneous combustion.

  When a spark plug is mounted at the center of the combustion chamber and a multi-hole injector as a fuel injection valve is mounted across the intake valve, the spark plug and the multi-hole injector are not opposed. For this reason, the spray specifications required for the spray directed to the vicinity of the spark plug and the spray not directed to the vicinity of the spark plug are different. In other words, the required spray specifications differ between when stratified combustion is performed at a low speed and low load of the engine and when homogeneous combustion is performed at a high speed and high load.

  On the other hand, in the atomization process of spraying, in order to reduce the size of the droplets, it is effective to make the liquid yarn, which is the previous stage of the division, thin. In order to make the liquid yarn thinner, it is effective to make the liquid film, which is the previous stage of the splitting of the liquid yarn, thinner or thinner, and the liquid film is more advantageous than the liquid column. I know that. Further, as a liquid film flow forming method, a method is known in which a swirl flow is given to the fuel flow before flowing into the nozzle hole to form a liquid film flow in the nozzle hole.

  The inventor of the present application investigated and examined the relationship between these liquid film flow formation methods and atomization processes, and the spray shape, penetration force, and injection amount distribution of the collective spray in which a plurality of single sprays gathered based on these techniques. As a result, it has been found that the collective spray in which single sprays are gathered can be divided into the following two forms.

  One is a case where each single spray is identifiable and the characteristics of each single spray become a collective spray that is almost indistinguishable. This is a collective spray with a solid structure that is relatively homogeneous, and each single spray can be identified, but it has the same characteristics as the collective spray, and is a spray that is difficult to control halfway. is there.

  The other is the case of a collective spray that makes it impossible to identify each single spray. This is a collective spray whose representative example is an injection amount distribution having a conical shape with a central peak, and a plurality of single sprays are gathered and replaced with a single new collective spray that is almost different from the original form, It is a very characteristic and stable phenomenon.

  Which of these forms depends largely on whether the spray behavior is at a certain threshold. The more the single spray is assembled, the closer the spray amount distribution is to axial symmetry and the sharper cone shape, so that the penetration force as a whole spray increases. In either case of the above two forms, a plurality of single sprays gather, and in the collective spray in which the spray shape in the plane perpendicular to the spray direction and the spray amount distribution are substantially axisymmetric, the cross-sectional shape is It is difficult to make a non-target variant and direct a part of the spray in a desired direction.

  Although the atomization technique as described above is being applied to the fuel injection valve, the mainstream of the atomization technique is the small injection hole diameter and multiple injection holes, and the jets from adjacent injection holes interfere with each other. It is designed so that the atomization state does not deteriorate. In other words, the nozzle hole specifications such as nozzle hole arrangement, nozzle hole diameter, inclination, and length are set so that the nozzle hole center axis or the jet flow direction becomes more downstream. Are difficult to balance.

  As a technique for suppressing the spread of the entire spray, it is known that the nozzle hole arrangement and the nozzle hole specifications are such that the nozzle hole central axis or the jet direction intersects each other immediately below the nozzle hole. However, in this method, the relationship from the outlet of the nozzle hole to the position where the liquid film flow can be regarded substantially as a spray flow after breaking or splitting the liquid film flow (breaking length of the liquid film flow) and the atomization Requirements were not considered.

  On the other hand, if the angle of the injection hole central axis with respect to the vertical line of the fluid injection valve is made relatively small in order to suppress the spread of the entire spray, it is disadvantageous for forming a thin liquid film flow. Therefore, the atomization process becomes slow, the jets easily interfere with each other, and the atomization level cannot be realized as expected. In addition, as described above, when the collective spray of a plurality of single sprays is generated due to the interference between the jets, the penetration force is greater than that in the single spray.

  Furthermore, in order to reduce spray collisions on the cylinder liner and promote mixing with air, a method of rapidly attenuating the spray penetration force at a predetermined distance is desired, but there is no method to achieve without significantly changing the spray form. It was. For this reason, in order for each spray to attenuate the penetration force rapidly, it is necessary to accelerate the attenuation of the spray momentum by a method such as flattening the jet flow from the nozzle hole outlet. In order to avoid interference between the jets, it was necessary to further separate the jet directions.

  For example, as a prior art aiming at ensuring both spray penetration force and appropriate dispersion of spray density in a spark ignition engine, in Patent Document 1, the main injection hole and the injection center are the injection center of the main injection hole. And sub-holes pointing in different directions, and by setting the cross-sectional areas of the inlet and outlet of the main nozzle holes to be different, the spray angle is widened while keeping the injection quantity constant, and the fuel density of the spray is increased. A distributed multi-hole injector is presented.

  Further, in Patent Document 2, cavitation bubbles are generated in the first taper portion that contracts in the fuel flow direction in the nozzle hole, and the generated cavitation bubbles collapse to atomize the fuel and atomize the fuel. A fuel injection valve is proposed in which the penetration force is reduced by diffusing by a second taper portion that expands in the flow direction.

  On the other hand, in fluid engineering, an axis-switching phenomenon is known in which the direction of the major axis and the minor axis of a spray having an oval cross-sectional shape ejected from an injection hole changes downstream ( Non-patent literature 1-6). This axis-switching phenomenon does not have to be oval in the cross-sectional shape of the spray, and is established as long as the major axis is substantially line-symmetric with respect to the minor axis.

JP 2007-315276 A JP 2012-14504 A

Proceedings of the Japan Society of Mechanical Engineers (Part B), Vol. ILASS-Europe 2010, “An experimental investigation of discharge coefficient and cavitation length in the elliptical nozzles” (Sung Ryoul Kim) Production Research Volume 50 No. 1, pp 69-72, “Numerical Simulation of Complex Turbulent Jets: Origin of Axis-Switching” (Ayodeji O. DEMUREN) Jet Engineering, Morikita Publishing, pp41-42 Proceedings of the Japan Society of Mechanical Engineers (Part 2) Vol. 25, No. 156, pp 820-826, "Study on the reach of diesel engine fuel spray" (Waguri et al.) Proceedings of the Japan Society of Mechanical Engineers (Part B) Vol. 62, No. 599, pp2867-2873 “Effect of Atmospheric Viscosity on Diesel Spray Structure”

  As described above, in the prior art, in a spark ignition engine equipped with a multi-hole injector, the spray specifications required for each of the spray directed to the vicinity of the spark plug and the spray diffused throughout without directing the vicinity of the spark plug The degree of freedom in designing to achieve the above has been low and has not been fully realized. In particular, atomization of spray, spray shape, and penetration force are characteristics that have a correlation with each other. However, Patent Document 1 and Patent Document 2 do not consider the influence of them, and thus realize an optimal spray specification. It is not possible.

  In a nozzle like patent document 1, it is known that the way of inflow of fuel to each nozzle hole will actually change with the way of flow inside a sac (cavity) upstream of a nozzle hole. That is, when the cross-sectional areas of the injection hole inlet and the outlet are made different, it is not always possible to widen the spray angle while keeping the injection amount constant. In particular, when a plurality of injection holes are not arranged symmetrically with respect to the central axis of the injector, the flow patterns in the injection holes are often not the same, but Patent Document 1 does not consider these.

  In Patent Document 2, since the influence on the cavitation due to the fuel pressure and the peeling state is not shown, the level of atomization is unknown. If the level of atomization is different, the momentum of the entire spray is different and affects the penetration. In particular, as spray directed to the vicinity of the spark plug, a method for more reliably improving the degree of freedom in design such as spray shape and penetration force is desired.

  Further, there has been no conventional fluid injection valve in which the spray direction is controlled by changing the cross-sectional shape in a plane perpendicular to the spray direction of the spray using the above-described axis-switching phenomenon. Furthermore, there has been no design in which the shape of the entire spray, the atomization of the spray, the penetrating force, and the injection amount distribution are designed using the axis-switching phenomenon.

The present invention has been made in order to solve the above-described problems, and enables the spray direction to be controlled by utilizing an axis-switching phenomenon. The atomization of the spray, the spray shape, and the penetration force are achieved. An object is to obtain a fluid injection valve that achieves both improvement in the degree of freedom in design of the injection amount distribution.

  In addition, it is possible to generate a spray directed to the vicinity of the spark plug by utilizing the axis-switching phenomenon, and to achieve both atomization of the spray and improvement in design flexibility of the spray shape, penetration force, and injection amount distribution. The purpose is to obtain a spark ignition engine.

A fluid injection valve according to the present invention includes a valve seat provided in the middle of a passage through which a fluid flows, a valve body that can contact and separate from the valve seat and controls opening and closing of the passage, and a downstream of the valve seat. A fluid injection valve that generates a spray by injecting fluid from a plurality of nozzle holes arranged in the nozzle hole body, wherein the plurality of nozzle holes are in a plane perpendicular to the injection direction. It includes at least one switching nozzle that generates a switching spray having a major axis and a minor axis different in cross-sectional shape, and the switching nozzle generates a switching spray whose major axis is axisymmetric with respect to the minor axis. The nozzle specifications including the nozzle hole diameter, length, and inclination are set, and the switching spray generated by the switching nozzle has an axis-switching phenomenon at a predetermined distance from the switching nozzle, Minor axis direction The plurality of nozzle holes are arranged so that the Coanda effect that induces proximity with adjacent sprays does not act on each other at least until the switching spray generated by the switching nozzles causes an axis-switching phenomenon. The nozzle hole specifications including the nozzle hole diameter, length, and inclination, and the interval between them are set .

The spark ignition engine according to the present invention is a spark ignition engine including an ignition plug disposed in a fuel chamber and a fuel injection valve for injecting fuel into the combustion chamber. A valve seat provided in the middle of the passage through which the valve flows, a valve body that is provided so as to be able to contact and separate from the valve seat and controls opening and closing of the passage, and a nozzle hole body provided downstream of the valve seat, The fuel is injected from a plurality of nozzle holes arranged in the nozzle hole body to generate spray, and the plurality of nozzle holes have a major axis and a minor axis length in a cross-sectional shape in a plane perpendicular to the injection direction. Including at least one switching nozzle that generates different switching sprays, the switching nozzle including its nozzle diameter, length, and inclination so as to generate a switching spray whose major axis is axisymmetric with respect to the minor axis The nozzle hole specifications are set and the switching nozzle hole The switching spray formed changes the direction of the long axis and the short axis by causing an axis-switching phenomenon at a predetermined distance from the switching nozzle hole, and the switching spray generated by the switching nozzle causes the axis-switching phenomenon. Whether it occurs or not is controlled by the pressure in the combustion chamber or the air flow .

According to the fluid injection valve of the present invention, it is possible to control the spray direction using the axis-switching phenomenon by setting at least one of the sprays generated by the plurality of nozzle holes as a switching spray. This makes it possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, penetration force, and injection amount distribution.

Further, according to the spark ignition engine according to the present invention, by using at least one of the sprays generated by the plurality of nozzle holes as a switching spray, the vicinity of the spark plug can be obtained using the axis-switching phenomenon. It is possible to generate a spray that is directed, and it is possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, penetration force, and injection amount distribution.

It is sectional drawing which shows the fuel injection valve which concerns on Embodiment 1 of this invention. It is an expanded sectional view which shows the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a top view which shows the nozzle hole plate of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a detailed sectional view explaining the structure of the tip part of the fuel injection valve concerning Embodiment 1 of the present invention. It is a detailed sectional view explaining the structure of the tip part of the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior until two non-switching sprays form a collective spray by the Coanda effect as a reference example. It is a figure explaining the behavior until two non-switching sprays form a collective spray by the Coanda effect as a reference example. It is a figure explaining the behavior in case the Coanda effect does not act on two non-switching sprays in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior when the Coanda effect acts on the non-switching spray and the switching spray in the fuel injection valve according to Embodiment 1 of the present invention. It is a figure explaining the behavior in case the Coanda effect does not act on non-switching spray and switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior in case the Coanda effect does not act on non-switching spray and switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the example of the whole spray formed in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure which shows in a time series until each spray reaches the whole spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the spark ignition type engine which concerns on Embodiment 2 of this invention.

Embodiment 1 FIG.
Hereinafter, a fluid injection valve and a spray generation device according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a fuel injection valve according to the first embodiment, and FIG. 2 is an enlarged cross-sectional view showing a tip portion of the fuel injection valve according to the first embodiment. In the drawing, the same and corresponding parts are denoted by the same reference numerals.

  The spray generation device according to the first embodiment controls the operation of the fuel injection valve 1 that is a fluid injection valve, fuel supply means (not shown) that supplies fuel to the fuel injection valve 1, and the fuel injection valve 1. And a control device (not shown) as control means. In the following description, the fuel injection valve 1 attached to the cylinder head of the internal combustion engine and disposed so that the tip portion for injecting fuel faces the cylinder of the internal combustion engine will be described as an example.

  The fuel injection valve 1 includes a solenoid device 2 that generates electromagnetic force, and a valve device 3 that operates by energizing the solenoid device 2. The solenoid device 2 includes a housing 21 that forms a yoke portion of a magnetic circuit, a core 22 that is a fixed iron core provided inside the housing 21, a coil 23 provided so as to surround the core 22, and an inner side of the coil 23. Is provided with an armature 24 that is a movable iron core that reciprocates.

  The valve device 3 includes a valve body 31 that is cylindrical and press-fitted and welded to the outer diameter portion of the distal end portion of the core 22, and a valve seat 32 that is provided in the passage of fuel inside the valve body 31. I have. Downstream of the valve seat 32, an injection hole plate 33, which is an injection hole body having a plurality of injection holes 39 for injecting fuel, and a cover plate 34 provided upstream of the injection hole plate 33 inside the valve seat 32. The valve body 35 is provided inside the valve body 31 so as to be capable of contacting and separating from the valve seat 32 and controls the opening and closing of the passage, and a compression spring 36 provided upstream of the valve body 35.

  The valve body 35 includes a hollow rod 37 that is press-fitted and welded to the inner surface of the armature 24, and a ball 38 that is fixed to the tip of the rod 37 by welding. The ball 38 includes a chamfered portion 38 a parallel to the Z axis (indicated by an arrow in FIG. 1) of the fuel injection valve 1, a flat surface portion 38 b facing the cover plate 34, and a curved surface portion 38 c in line contact with the valve seat 32. And have.

  The nozzle hole plate 33 has a peripheral edge bent downward and is welded to the distal end surface of the valve seat 32 and the inner peripheral side surface of the valve main body 31. A plurality of nozzle holes 39 penetrating in the plate thickness direction is formed in the nozzle hole plate 33. FIG. 3 is a plan view of the nozzle hole plate 33 as seen from the inside of the valve body 31. A plurality of nozzle holes 39 are arranged in the nozzle plate 33 in the circumferential direction.

  The plurality of nozzle holes 39 includes a non-switching nozzle hole 391 having a circular cross-sectional shape perpendicular to the thickness direction of the nozzle hole plate 33 and an oval switching nozzle hole 392. The switching nozzle hole 392 is arranged such that the major axis of the ellipse is in the direction of reducing the distance from the non-switching nozzle hole 391.

  When the jet of fuel injected from the non-switching injection hole 391 proceeds downstream by a predetermined distance (break length), a non-switching spray having a circular cross-sectional shape in a plane perpendicular to the injection direction is generated. Further, when the jet flow ejected from the switching nozzle 392 proceeds downstream by a predetermined distance (break length), the switching spray in which the major axis and the minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction. Generate.

  The switching spray generated by the switching nozzle hole 392 is controlled to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle hole 392, and changes the direction of the major axis and the minor axis. The behavior of each spray will be described later in detail.

  Next, the operation of the fuel injection valve 1 will be described. When an operation signal is sent from the control device of the internal combustion engine to the drive circuit of the fuel injection valve 1, a current is passed through the coil 23 of the fuel injection valve 1, and the armature 24 is attracted to the core 22 side. As a result, the rod 37 and the ball 38, which are integral with the armature 24, move upward against the elastic force of the compression spring 36, the curved surface portion 38c of the ball 38 is separated from the valve seat surface 32a, and there is a gap between them. Is formed to form a passage, and fuel injection directed to the intake port is started.

  On the other hand, when an operation stop signal is sent from the control device of the internal combustion engine to the drive circuit of the fuel injection valve 1, the energization to the coil 23 is stopped, and the force that the armature 24 is attracted to the core 22 side disappears. 37 is pushed toward the valve seat 32 by the elastic force of the compression spring 36, the curved surface portion 38c of the ball 38 and the valve seat surface 32a are closed, and fuel injection is terminated at this point.

  Here, the detailed structure and position of the nozzle hole plate 33, the cover plate 34, the valve seat 32, and the ball 38 in which the flow in the nozzle hole 39 is converted into a liquid film flow by, for example, contraction flow are shown in FIGS. 5 will be described with reference to the detailed sectional views of FIG. The nozzle hole 39 described here may be either a non-switching nozzle hole 391 or a switching nozzle hole 392. In FIG. 4, X indicates the diameter of the nozzle hole 39, and Y indicates the length of the nozzle hole 39.

  When the valve element 35 is opened, the fuel passes through a path parallel to the Z-axis between the chamfered portion 38a of the ball 38 and the inner surface of the valve seat 32, and then between the curved surface portion 38c of the ball 38 and the valve seat surface 32a. To the downstream and reach the valve seat portion R1. Since the fuel flows parallel to the Z-axis upstream of the valve seat portion R1, the flow of the fuel is mainly along the valve seat surface 32a due to inertia after passing through the valve seat portion R1. The point P1 at the downstream end is reached.

  The point P1 is the end of the valve seat surface 32a, and the valve seat 32 has a surface extending in the vertical direction downstream from the point P1. Therefore, the main flow of fuel is separated from the point P1. The extension line of the valve seat surface 32a intersects the peripheral side surface of the cover plate 34 at the point P2, and the fuel separated from the point P1 faces the point P2, and the annular passage C (the inner peripheral wall surface of the valve seat 32 and the cover plate 34). Between the large-diameter portion 34d) and the radial passage B (the inner peripheral wall surface of the valve seat 32 and the periphery of the small-diameter portion 34c of the cover plate 34) without significant change in the radial direction. Between the sides).

  In addition, since the main flow of the fuel that passes through the valve seat portion R1 flows into the annular passage C, the flow into the clearance passage A (between the bottom surface of the ball 38 and the top surface 34a of the cover plate 34) is suppressed. . A line connecting the sheet portion R1 and the point P3 at the entrance of the injection hole 39 with a straight line intersects with a thin portion 34b which is a large diameter portion of the cover plate 34. That is, the thin portion 34b blocks the linear flow of fuel from the valve seat portion R1 to the inlet of the injection hole 39.

  For this reason, at least a part of the fuel flowing into the nozzle hole 39 flows along the radial passage B. The cover plate 34 has a small diameter portion 34 c disposed closer to the nozzle hole 39 on the inner diameter side than the nozzle hole 39. Accordingly, the front flow F1 of the fuel directed toward the inner diameter side along the radial passage B closes the flow path of the return flow F2 flowing into the injection hole 39 from the Z axis of the fuel injection valve 1, and the speed of the return flow F2 is increased. Reduce. By suppressing the return flow F2, the speed of the front flow F1 flowing into the nozzle hole 39 from the valve seat portion R1 side is relatively increased.

  Because at least a portion of the front flow F1 travels along the radial passage B and is forced to undergo a significant change in direction in the nozzle hole 39, and because the front flow F1 is high speed, the fuel is injected into the nozzle hole. In the cross section 39, the fuel injection valve 1 is strongly pressed against the wall surface of the injection hole 39 on the Z-axis side. Thereafter, as shown in FIG. 5, at the inlet of the nozzle hole 39, the low-speed return flow F2 forms a flow F3 along the wall surface of the nozzle hole 39, and the high-speed front flow F1 is a fuel that presses the fuel against the wall surface. Stream F4 is formed.

  In addition, the air flow F5 introduced from the outlet of the nozzle hole 39 acts on the fuel flow F4, and the fuel flow F4 is separated from the point P4 (the outer edge of the fuel inlet of the nozzle hole 39). . The fuel flow F4 is pressed against the wall surface as it travels through the nozzle hole 39, and the direction of the liquid film changes in the direction along the wall surface of the nozzle hole 39 while spreading in the circumferential direction of the wall surface of the nozzle hole 39. .

  As described above, the thinner the liquid film, the thinner the liquid thread and the more effective the atomization of the droplets. Therefore, in the first embodiment, the nozzle hole 39 has a height h (see FIG. 4) of the gap passage A. The length Y is optimized so that the fuel flow F4 is pressed into the thin liquid film flow 30 in the nozzle hole 39. As a result, the liquid film flow 30 of the injected fuel starts to split after a predetermined distance, and droplets atomized through the state of the liquid yarn are generated.

  Next, in the fuel injection valve 1 according to the first embodiment, a method for controlling the spray shape, the penetration force, the injection amount distribution, and the spray direction using the axis-switching phenomenon will be described. First, as a reference example, the behavior until the Coanda effect acts on two non-switching sprays to form a collective spray will be described with reference to FIGS. 6 and 7. Note that the Coanda effect is an effect that induces the proximity of adjacent sprays.

  In FIG. 6, (a) is a side view showing non-switching spray injected from two non-switching nozzle holes, and (b) is EE, FF, GG, HH in (a). It is sectional drawing in the part shown by. As shown to Fig.6 (a), the jets 4a and 4b injected from the two non-switching nozzle holes 391 arrange | positioned by the space | interval L1 become the non-switching sprays 4A and 4B, respectively. The jets 4a and 4b have a jet cross-sectional shape shown in a cross-section EE when a break in a state in which the liquid film flow can be regarded as a spray flow after breaking or splitting occurs.

  The distance between the non-switching nozzle hole 391 and the cross section EE at this time is defined as a break length a. Already at the position of the break length a, the gap c1 between the jets 4a and 4b is smaller than the threshold value at which the Coanda effect acts. Subsequently, in the cross-section FF, the jets 4a and 4b are dispersed to become a single non-switching spray 4A and 4B, and the two non-switching sprays 4A and 4B are located at a distance b from the non-switching nozzle hole 391. , Its outer diameter begins to touch.

  Further, from the cross-section FF, the Coanda effect acts between the two single non-switching sprays 4A, 4B due to the pressure distribution, and the single non-switching spray 4A, 4B approaches the cross-section G- Aggregation proceeds like G. At the same time, entrainment of the ambient air of the non-switching sprays 4A and 4B, and thereby induction of an air flow along the flow direction downstream of the substantially central portion in the non-switching sprays 4A and 4B.

  Note that even if the jet 4a and the jet 4b, or the non-switching spray 4A and the non-switching spray 4B have characteristics that cause an axis-switching phenomenon, before the axis-switching phenomenon occurs, the cross-section E- At the position E, the gap c1 between the jets 4a and 4b is smaller than the threshold value at which the Coanda effect acts, so the Coanda effect begins to act and approaches.

  Here, the entrainment level of the ambient air is not a level that greatly changes the shape of the entire collective spray 40 in which the single non-switching sprays 4A and 4B are assembled. Further, if the conditions are adjusted, the assembly further proceeds from the state of the collective spray 40 having the cross section GG, and is substantially regarded as one solid collective spray 40 like the cross section HH.

  FIG. 7 is a diagram illustrating the behavior of the two non-switching sprays until they form a collective spray due to the Coanda effect, with arrows indicating the entrainment status of the surrounding air, and (a) shows the injection from the two non-switching nozzle holes. The side view which shows the made non-switching spray, (b) is sectional drawing in the part shown by FF, G1-G1, G2-G2, HH in (a).

  As shown to Fig.7 (a), the airflow V along the flow direction downstream is induced in spray by the entrainment of ambient air. As a result, as shown in FIG. 7B, the spray amount distribution of each spray in FF, G1-G1, G2-G2, and HH has a peak at the approximate center of the collective spray 40.

  As described above, when the plurality of non-switching sprays 4A and 4B form the collective spray 40 by the action of the Coanda effect, the air flow along the downstream flow direction is induced in the spray by the entrainment of the ambient air, and the penetration force It becomes difficult to suppress the spraying, and the degree of freedom in design is reduced with respect to atomization of the spray and the spray shape.

  Therefore, the fuel injection valve 1 according to the first embodiment basically forms a collective spray 40 as shown in FIG. 6 even if the jets injected from the plurality of injection holes 39 become sprays downstream. In the end, each spray is designed to form an overall spray 60 (see FIGS. 12 and 13) in an independent state.

  Therefore, the plurality of nozzle holes 39 are arranged at intervals at which the Coanda effect that induces the proximity of the adjacent sprays does not act at least until the switching spray generated by the switching nozzles 392 causes an axis-switching phenomenon. At the same time, the nozzle hole specifications including the nozzle hole diameter, length, and inclination are set.

  Further, each spray generated by the plurality of nozzle holes 39 has a Coanda effect that induces close proximity to the adjacent sprays until at least the switching spray generated by the switching nozzle 392 causes an axis-switching phenomenon. It is set to a non-acting flow rate, particle size, and particle number density.

  Further, the switching nozzle hole 392 includes the nozzle hole diameter, length, and inclination so as to generate a switching spray in which the major axis is axisymmetric with respect to the minor axis in a cross-sectional shape in a plane perpendicular to the injection direction. The nozzle hole specification is set. Further, in the first embodiment, the nozzle hole specifications of the switching nozzle hole 392 are set so as to generate switching spray that changes the direction of the major axis and the minor axis by approximately 90 degrees due to the axis-switching phenomenon.

  That is, in the fuel injection valve 1 according to the first embodiment, the adjacent sprays are deformed close to each other by the action of the Coanda effect only after at least one of them is a switching spray and an axis-switching phenomenon occurs. It is. In this case, by bringing two or more sprays close to each other, a non-circular collective spray having an asymmetric cross-sectional shape in a plane perpendicular to the injection direction is formed.

  FIG. 8 is a view for explaining the behavior of each spray generated by two non-switching nozzle holes in the fuel injection valve according to the first embodiment, wherein (a) is a side view of each spray, and (b). These are sectional drawings in the part shown by EE, FF, GG in (a). As shown to Fig.8 (a), the jets 4a and 4c injected from the two non-switching injection holes 391 arrange | positioned by the space | interval L2 (L2> L1) become the non-switching sprays 4A and 4C, respectively.

  The jets 4a and 4c have a jet cross-sectional shape in a cross-section EE when a break in a state in which the liquid film flow can be regarded as a spray flow after breaking or splitting occurs. At the position of the break length a at this time, the gap between the jets 4a and 4c is larger than the threshold value at which the Coanda effect acts. Further, the gap c2 between the sprays 4A and 4C in the cross section GG is also larger than the threshold value at which the Coanda effect acts, and the Coanda effect does not act on the sprays 4A and 4C. As a result, both the sprays 4A and 4C proceed in the initial traveling direction while remaining independent.

  Next, the behavior of each spray when the non-switching injection hole 391 and the switching injection hole 392 are adjacent to each other in the fuel injection valve according to Embodiment 1 will be described. FIG. 9 is a diagram showing the behavior until the non-switching spray and the switching spray form a collective spray due to the Coanda effect, where (a) is a side view of each spray, and (b) is EE in (a). It is sectional drawing in the part shown by FF, ..., MM.

  As shown in FIG. 9A, the non-switching nozzle hole 391 and the switching nozzle hole 392 are arranged at an interval L3. The jet 4a injected from the non-switching nozzle hole 391 becomes the non-switching spray 4A, and the jet 5a injected from the switching nozzle 392 becomes the switching spray 5A. In FIG. 9, assuming that the break lengths a of the jet 4a and the jet 5a are substantially equal, the cross-sectional shape of the jet at this time is as shown in the section EE.

  The switching spray 5A having an oval cross-sectional shape is opposed to the non-switching spray 4A in the major axis direction before the axis-switching phenomenon occurs. The switching spray 5 </ b> A faces the non-switching spray 4 </ b> A and flows downstream while maintaining the initial flow direction almost directly below the switching nozzle hole 392 while its cross-sectional shape slightly expands in both the major axis and minor axis directions. .

  After that, an axis-switching phenomenon occurs at a predetermined distance from the switching nozzle hole 392, and the major axis and minor axis directions of the switching spray 5A start to change as shown in the section JJ. At this position, the gap c3 between the switching spray 5A and the non-switching spray 4A is larger than the threshold value at which the Coanda effect acts, and the Coanda effect does not occur.

  As the cross-section JJ moves downstream from the cross-section KK, the deformation in which the direction of the major axis and the minor axis of the switching spray 5A changes proceeds, and the switching spray 5A and the non-switching spray 4A come closer. This is because the gap between the switching spray 5A and the non-switching spray 4A is reduced due to the occurrence of the axis-switching phenomenon in the switching spray 5A, and accordingly, the Coanda effect acts between the switching spray 5A and the non-switching spray 4A. It depends.

  In the cross section KK, the gap c4 between the switching spray 5A and the non-switching spray 4A is smaller than the threshold value at which the Coanda effect acts. In the cross-section L-L, the opposite ends of the switching spray 5A and the non-switching spray 4A are deformed and moved to start interference. As a result, in the cross section MM, after a predetermined time has elapsed after fuel injection, a collective spray 50 in which the switching spray 5A and the non-switching spray 4A are gathered is formed at a predetermined distance from the non-switching nozzle hole 391 and the switching nozzle hole 392. Is done. The shape, penetration force, injection amount distribution, and the like of the collective spray 50 can be changed by changing the characteristics of the switching spray 5A and the non-switching spray 4A.

  In addition, the switching spray 5A is deformed by changing the direction of the major axis and the minor axis, so that the momentum exchange with the surrounding air greatly proceeds, and the penetration force becomes small. Therefore, by interfering with the non-switching spray 4A, the particles of the non-switching spray 4A and the movement of the air flow dragged by the particles are suppressed, and the penetration force of the non-switching spray 4A is also suppressed.

  The dashed-dotted line d of Fig.9 (a) has shown the spray shape in case the non-switching spray 4A is independent. In this way, the non-switching spray 4A has a reduced penetration force due to interference with the switching spray 5A, and the extension of the tip thereof is shortened compared to the case where it is alone.

  Further, the switching spray 5A is reduced in penetrating force and greatly mixed with the surrounding air, whereby atomization is improved and the difference from the atomization level of the non-switching spray 4A is reduced. That is, it is possible to form a non-circular collective spray 50 that is atomized at a predetermined distance downstream from the non-switching nozzle hole 391 and the switching nozzle hole 392 and has an asymmetric cross section.

  In FIG. 9, when the switching nozzle hole 392 is not used, the adjacency of adjacent sprays does not start until further downstream, and in some cases, aggregation does not occur. Accordingly, each spray continues to spread and the penetration force does not decrease. As a result, the momentum possessed by the spray is difficult to move to the air flow and atomization is insufficient.

  In FIG. 9, when two nozzle holes are switching nozzle holes 392 and the adjacent sprays are switching sprays 5A, the axis-axis switching is performed by setting their long axes to be substantially parallel to each other. A collective spray in which the long axes are connected in the longitudinal direction can be formed by the phenomenon.

  In FIG. 9, the aggregate spray 50 whose cross section is non-target is formed by a combination of one non-switching spray 4 </ b> A and one switching spray 5 </ b> A, but the collective spray is limited to this combination. It is not something. For example, a combination of two non-switching sprays 4A and one switching spray 5A may be used, or two switching sprays 5A may be used.

  In the first embodiment, before the switching spray 5A is deformed by the axis-switching phenomenon, the Coanda effect is reliably suppressed from acting with the non-switching spray 4A. As the method, there is a method of delaying the timing at which the Coanda effect occurs by providing a difference in the characteristics of the switching spray 5A and the non-switching spray 4A.

  Specifically, the method of making the average particle diameter of the switching spray 5A at the same distance from the non-switching nozzle hole 391 and the switching nozzle hole 392 larger than the average particle diameter of the non-switching spray 4A, or the break length of the switching spray 5A There are a method of making the break length of the non-switching spray 4A longer, a method of setting the penetration force of the switching spray 5A larger than the penetration force of the non-switching spray 4A, and the like.

  In realizing these methods, it is possible to utilize the fact that the level and direction of the contracted flow change depending on the nozzle hole shape difference between the non-switching nozzle hole 391 and the switching nozzle hole 392. For example, when the level and direction of the contracted flow are varied, the pressure loss (jet velocity) in the nozzle hole 39, the sectional area of the jet, the sectional shape, the arrangement, the direction, and the like can be varied, and the Coanda effect acts. It is possible to change the threshold value of the gap to be performed.

  Moreover, since the threshold value of the gap in which the Coanda effect acts also varies depending on the flow rate of each spray, the atomization level, the particle number density, the atmospheric pressure, and the like, it can be set to a desired threshold value by adjusting these.

  FIG. 10 is a view showing the behavior of each spray when the Coanda effect does not act on the non-switching spray 4A and the switching spray 5A, (a) is a side view of each spray, (b) is E in FIG. It is sectional drawing in the part shown by -E, FF, ..., LL. As shown in FIG. 10A, the non-switching nozzle hole 391 and the switching nozzle hole 392 are arranged at an interval L4 (L4> L3). The jet 4a injected from the non-switching nozzle hole 391 becomes the non-switching spray 4A, and the jet 5b injected from the switching nozzle 392 becomes the switching spray 5B.

  In FIG. 10, the switching spray 5 </ b> B is opposed to the non-switching spray 4 </ b> A in the major axis direction before the axis-switching phenomenon occurs, but as shown in a cross section JJ at a predetermined distance from the switching nozzle hole 392. The direction of the major axis and minor axis begins to change.

  However, even in the cross-section LL where the non-switching spray 4A and the switching spray 5A are closest to each other, the gap c5 is larger than the threshold at which the Coanda effect acts. For this reason, the Coanda effect does not act on both the sprays 4A and 5B, and they proceed independently in the initial traveling direction. At this time, since the switching spray 5B does not interfere with the non-switching spray 4A, the penetration force of the non-switching spray 4A is not suppressed.

  In addition, when a plurality of switching sprays 5A are included, even after an axis-switching phenomenon occurs in the plurality of switching sprays 5A, the non-switching spray 4A is not affected by proximity, deformation, etc. The deformed shape of the switching spray 5A can be kept stable. Further, since the long axis is symmetrical with respect to the short axis of the switching spray 5A, the shape is axisymmetric even after the occurrence of the axis-switching phenomenon, and the spray is stably stagnated in the vicinity of the spark plug. Convenient for

  10 shows an example in which the long axis direction of the switching spray 5A is opposed to the non-switching spray 4A, but in FIG. 11, the short axis of the switching spray 5C before the occurrence of the axis-switching phenomenon is non-switching. An example of facing the spray 4A will be described.

  11, (a) is a side view of each spray, and (b) is a cross-sectional view at a portion indicated by EE, FF,..., LL in (a). As shown to Fig.11 (a), the non-switching nozzle hole 391 and the switching nozzle hole 392 are arrange | positioned by the space | interval L5. The jet 4a injected from the non-switching nozzle 391 becomes a non-switching spray 4A, and the jet 5c injected from the switching nozzle 392 becomes a switching spray 5C.

  In the example shown in FIG. 11, the gap between the switching spray 5C and the non-switching spray 4A is larger than the threshold at which the Coanda effect acts, even in the cross section HH where both the sprays 4A and 5C are closest to each other. Not. Furthermore, as the cross section JJ moves downstream from the cross section KK, the deformation in which the direction of the major axis and the minor axis of the switching spray 5C changes is advanced, and the gap between the switching spray 5C and the non-switching spray 4A is further increased. .

  For this reason, the Coanda effect does not act on both the sprays 4A and 5C, and both the sprays 4A and 5C proceed substantially in the initial traveling direction while being independent. At this time, since the switching spray 5C does not interfere with the non-switching spray 4A, the penetration force of the non-switching spray 4A is not suppressed.

  An example of the shape of the entire spray formed by the fuel injection valve 1 according to the first embodiment will be described with reference to FIGS. 12 and 13. This example shows a case where the Coanda effect does not act between the sprays. FIG. 12 shows the entire spray formed by the sprays ejected from the respective nozzle holes 39 of the nozzle hole plate 33 shown in FIG. 3, and (a) shows the state before the switching spray causes the axis-switching phenomenon ( b) shows the cross-sectional shape in the plane perpendicular to the injection direction after the switching spray causes the axis-switching phenomenon.

  13 shows a case where the entire spray shown in FIG. 12 is viewed from the direction indicated by an arrow x in FIG. 12, that is, a case where the entire spray is viewed from a direction perpendicular to the Z axis of the fuel injection valve 1. . In FIG. 13, (a) to (d) show time-series changes of each spray until the entire spray is reached. Note that, when viewed from the direction of the arrow x, the non-switching spray 4 </ b> A overlaps the front and rear, and therefore, only the non-switching spray 4 </ b> A positioned forward is shown in FIG. 13.

  As shown in FIG. 12, an axis-switching phenomenon occurs in the switching spray 5A at a predetermined distance from the switching nozzle hole 392, and the major axis and minor axis directions in the cross-sectional shape in the plane perpendicular to the ejection direction change. At this time, in the switching spray 5A, a considerable proportion of the momentum moves to the air, and the penetration force is greatly reduced.

  On the other hand, each non-switching spray 4A does not interfere with the adjacent non-switching spray 4A or switching spray 5A, and hence the penetration force is not suppressed. For this reason, each non-switching spray 4A advances in the substantially advancing direction, without changing, independently. Finally, as shown in FIG. 13 (d), it reaches a distance longer than the switching spray 5A.

  In the first embodiment, the case where one switching nozzle hole 392 is included in the plurality of nozzle holes 39 has been described, but two or more switching nozzle holes 392 may be provided. Moreover, although the case where the direction of the major axis and the minor axis of the switching spray changes by 90 degrees has been described, the present invention is not limited to this and can be set to an arbitrary angle. Further, the shape of the switching spray 5A may be flatter in cross-sectional shape. When generating a spray having a large ratio between the major axis and the minor axis, the nozzle hole specifications may be set so that the major axis and minor axis directions change within a range in which the major axis direction is not divided.

  Moreover, the shape of the whole spray 60 can implement | achieve various variations, such as not only a hollow cone shape but a solid cone shape, a triangular shape. Further, in the first embodiment, an electromagnetic fuel injection valve has been described as an example of the fuel injection valve 1. However, the drive source may be other types, such as a piezo type or a mechanical type. Further, it can be applied to both intermittent injection valves and continuous injection valves.

  As described above, in the fuel injection valve 1 according to the first embodiment, the plurality of nozzle holes 39 arranged in the circumferential direction of the nozzle hole plate 33 includes at least one switching nozzle hole 392 and is generated by the switching nozzle hole 392. The switching spray that is generated causes an axis-switching phenomenon at a predetermined distance from the nozzle hole 392, and changes the direction of the major axis and the minor axis in a cross-sectional shape in a plane perpendicular to the ejection direction.

  Thereby, among the sprays forming the entire spray 60, the cross-sectional shape in a plane perpendicular to the spray direction of at least one spray can be changed, and control can be performed so as to direct a desired direction. Become. Further, the switching spray can rapidly attenuate the penetration force of the spray at a predetermined distance by utilizing the fact that the momentum exchange with the surrounding air proceeds due to the deformation and the penetration force decreases. In addition, since the penetration force is reduced, mixing with ambient air proceeds and atomization is improved. Furthermore, the injection amount distribution and the spraying direction can be set according to each nozzle hole specification.

  From the above, according to the first embodiment, at least one of the sprays generated by the plurality of nozzle holes 39 is the switching spray 5A, thereby using the axis-switching phenomenon and the spray direction. It is possible to control the atomization of the spray and to improve the design freedom of the spray shape, penetration force, and injection amount distribution.

  Although the fuel injection valve 1 has been described as an example in the first embodiment, the application of the fluid injection valve according to the present invention is not limited to this. Other applications include a wide range of applications such as painting, coating, pesticide spraying, cleaning, humidification, sprinklers, sprays for sterilization, cooling, and various sprays for agriculture, equipment, household, and personal use. The fluid injection valve according to the present invention can be incorporated in a spray generating device for various uses regardless of the drive source, the nozzle form, and the type of fluid to be sprayed.

Embodiment 2. FIG.
FIGS. 14A and 14B are diagrams schematically showing a spark ignition engine according to Embodiment 2 of the present invention, in which FIG. 14A is during stratified combustion (when the piston is rising), and FIG. 14B is during homogeneous combustion (when the piston is descending). ) State. The spark ignition engine 6 according to the second embodiment includes the fuel injection valve 1 according to the first embodiment as a fuel injection valve that injects fuel into the combustion chamber 7.

  Since the configuration of the fuel injection valve 1 of the spark ignition engine 6 according to the second embodiment is the same as that of the first embodiment, a detailed description thereof will be omitted, but a valve provided in the middle of the passage through which the fuel flows. A seat 32, a valve body 35 that can be brought into contact with and separated from the valve seat 32 and controls the opening and closing of the passage, and an injection hole plate 33 that is provided downstream of the valve seat 32 and has a plurality of injection holes 39. (See FIGS. 1 and 3).

  Further, at least one of the plurality of nozzle holes 39 is a switching nozzle hole 392 that generates a switching spray 5A in which the major axis and the minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction. The switching spray 5A generated by the switching nozzle hole 392 is controlled so as to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle hole 392, and changes the direction of the major axis and the minor axis.

  As shown in FIG. 14, an intake port 8 and an exhaust port 9 communicate with the combustion chamber 7 of the spark ignition engine 6, and each combustion chamber 7 side opening is linked to the piston 10. An intake valve 11 and an exhaust valve 12 that are opened and closed are provided. Further, the fuel injection valve 1 is disposed at a substantially central portion of the ceiling of the combustion chamber 7, and a spark plug 13 is disposed on the side thereof. In addition, arrangement | positioning of the fuel injection valve 1 and the ignition plug 13 is not limited to this.

  In the second embodiment, the switching spray 5A generated by the switching nozzle hole 392 of the fuel injection valve 1 is controlled so as to be directed toward the vicinity of the spark plug 13 by the axis-switching phenomenon. Further, whether or not the switching spray 5A causes an axis-switching phenomenon is controlled by the pressure in the combustion chamber 7 or the air flow.

  In addition, the injection hole specifications including the injection hole diameter, the length, and the inclination of the switching injection hole 392 are set so as to generate the switching spray 5A in which the long axis is axisymmetric with respect to the short axis. Thereby, even after the occurrence of the axis-switching phenomenon, the shape becomes axisymmetric, which is convenient for stably stopping the spray near the spark plug 13.

  Further, the plurality of nozzle holes 39 are arranged at intervals at which the Coanda effect that induces the proximity of the adjacent sprays does not act at least until the switching spray 5A generated by the switching nozzles 392 causes an axis-switching phenomenon. At the same time, the nozzle hole specifications including the nozzle hole diameter, length, and inclination are set.

  Further, each spray generated by the plurality of nozzle holes 39 has a Coanda effect that induces the proximity of the adjacent sprays until at least the switching spray 5A generated by the switching nozzle 392 causes an axis-switching phenomenon. The flow rate, the particle size, and the particle number density are set so as not to interact with each other. In the second embodiment, the Coanda effect is prevented from acting between the sprays adjacent to each other even after the switching spray 5A causes the axis-switching phenomenon.

  The state of the entire spray during stratified combustion and homogeneous combustion in the spark ignition engine 6 according to Embodiment 2 of the present invention will be described with reference to FIG. In the stratified combustion shown in FIG. 14A, the air in the combustion chamber 7 is compressed by the rise of the piston 10, and the pressure in the combustion chamber 7 increases.

  For this reason, the penetration force of each non-switching spray 4A and switching spray 5A becomes smaller than that during homogeneous combustion. The switching spray 5 </ b> A causes an axis-switching phenomenon in the process of passing through the vicinity of the spark plug 13, and is directed near the spark plug 13. At the same time, the penetrating force is greatly reduced, and when passing through the vicinity of the spark plug 13, the penetrating force is lost, and the penetrating force stays in the vicinity of the spark plug 13.

  That is, the penetration force of the switching spray 5 </ b> A can be rapidly attenuated at a desired distance from the injection position to the vicinity of the ignition plug 13, and a desired rich air-fuel mixture can be formed in the vicinity of the ignition plug 13. This is advantageous for establishing stratified combustion.

  Further, each non-switching spray 4A is directed so as to be in a mixed combustion state suitable for stratified combustion, and the penetration force is set so that collision with the cylinder liner 14 and the piston 10 surface is suppressed. As a result, the entire spray 60 is prevented from colliding with the cylinder liner 14 and the piston 10 surface, and forms a rich air-fuel mixture suitable for stratified combustion in the vicinity of the spark plug 13.

  In addition, during the homogeneous combustion shown in FIG. 14B, the intake valve 11 is opened as the piston 10 descends, so that a strong air flow such as a tumble flow is generated in the combustion chamber 7. The switching spray 5 </ b> A follows the air flow in the combustion chamber 7 in the process of passing through the vicinity of the spark plug 13, and does not cause an axis-switching phenomenon and diffuses throughout the combustion chamber 7.

  Thus, the spark ignition engine 6 according to the second embodiment can provide a large characteristic difference between the spray directed to the vicinity of the spark plug 13 and the spray not directed to the spark plug 13 during stratified combustion. By applying the switching spray 5A as spray directed to the vicinity of the spark plug 13, it is possible to form an air-fuel mixture suitable for stratified combustion in the vicinity of the spark plug 13 while avoiding collision with the spark plug 13. Further, at the time of homogeneous combustion, it is possible to follow the air flow in the process of passing through the vicinity of the spark plug 13 and to diffuse to the entire combustion chamber 7 without causing an axis-switching phenomenon.

  As described above, according to the second embodiment, at least one of the sprays generated by the plurality of nozzle holes 39 is the switching spray 5A, so that the ignition plug is utilized by utilizing the axis-switching phenomenon. It is possible to generate a spray directed to the vicinity of 13 and to achieve both atomization of the spray and improvement in the degree of freedom in design of the spray shape, penetration force, and injection amount distribution. It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

The present invention can be utilized as a spark ignition engine fuel injection Ben'nami beauty fluid injector, in particular mounted on the internal combustion engine.

1 fuel injection valve, 2 solenoid device, 3 valve device,
4a, 4b, 4c, 5a, 5b, 5c jet,
4A, 4B, 4C non-switching spray, 5A, 5B, 5C switching spray,
6 spark ignition engine, 7 combustion chamber, 8 intake port, 9 exhaust port,
10 piston, 11 intake valve, 12 exhaust valve, 13 spark plug,
14 cylinder liner, 21 housing, 22 core, 23 coil,
24 amateur, 30 liquid film flow, 31 valve body, 32 valve seat, 32a valve seat surface,
33 injection hole plate, 34 cover plate, 34a top surface, 34b thin wall portion,
34c Small diameter part, 34d Large diameter part, 35 Valve body, 36 Compression spring, 37 Rod,
38 balls, 38a chamfered portions, 38b flat surface portions, 38c curved surface portions, 39 nozzle holes,
40, 50 collective spray, 60 whole spray,
391 non-switching nozzle holes, 392 switching nozzle holes.

Claims (14)

A valve seat provided in the middle of a passage through which a fluid flows, a valve body provided so as to be capable of contacting and separating from the valve seat and controlling opening and closing of the passage, and a nozzle hole provided downstream of the valve seat; A fluid injection valve for generating a spray by injecting fluid from a plurality of injection holes arranged in the injection hole body,
The plurality of nozzle holes include at least one switching nozzle hole that generates a switching spray in which a major axis and a minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction,
The switching spray generated by the switching nozzle is controlled to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle, and changes the direction of the major axis and the minor axis. Injection valve.   The fluid injection valve according to claim 1, wherein the switching nozzle hole has an oval cross-sectional shape perpendicular to the plate thickness direction of the nozzle hole body.   The switching nozzle hole has a nozzle hole specification including a nozzle hole diameter, a length, and an inclination so as to generate a switching spray in which the major axis is axisymmetric with respect to the minor axis. The fluid injection valve according to claim 1 or 2.   The plurality of nozzle holes are arranged at intervals at which the Coanda effect for inducing proximity to adjacent sprays does not act at least until the switching spray generated by the switching nozzles causes an axis-switching phenomenon. 4. The fluid injection valve according to claim 1, wherein the nozzle hole specifications including the nozzle hole diameter, the length, and the inclination are set. 5.   Each of the sprays generated by the plurality of nozzle holes does not interact with each other by the Coanda effect that induces proximity with the adjacent sprays until at least the switching spray generated by the switching nozzles causes an axis-switching phenomenon. The fluid injection valve according to any one of claims 1 to 4, wherein the fluid injection valve is set to a flow velocity, a particle size, and a particle number density.   A fluid injection valve according to any one of claims 1 to 5, a fluid supply means for supplying fluid to the fluid injection valve, and a control means for controlling the operation of the fluid injection valve. A spray generator characterized by the above. A spark ignition engine comprising a spark plug disposed in a fuel chamber and a fuel injection valve for injecting fuel into the combustion chamber,
The fuel injection valve is provided in the downstream of the valve seat, a valve seat provided in the middle of the passage through which the fuel flows, a valve body that can be brought into contact with and separated from the valve seat, and controls opening and closing of the passage. And a spray is generated by injecting fuel from a plurality of nozzle holes arranged in the nozzle hole body,
The plurality of nozzle holes include at least one switching nozzle hole that generates a switching spray in which a major axis and a minor axis have different lengths in a cross-sectional shape in a plane perpendicular to the ejection direction,
The switching spray generated by the switching nozzle is controlled to cause an axis-switching phenomenon at a predetermined distance from the switching nozzle, and changes the direction of the major axis and the minor axis. Ignition engine.   8. The spark ignition engine according to claim 7, wherein the switching spray generated by the switching nozzle is controlled to be spray directed toward the vicinity of the spark plug by an axis-switching phenomenon.   9. The switching spray generated by the switching nozzle hole is controlled as to whether or not an axis-switching phenomenon occurs by pressure or air flow in the combustion chamber. Spark ignition engine.   The switching nozzle hole has a nozzle hole specification including a nozzle hole diameter, a length, and an inclination so as to generate a switching spray in which the major axis is axisymmetric with respect to the minor axis. The spark ignition engine according to any one of claims 7 to 9.   The plurality of nozzle holes are arranged at intervals at which the Coanda effect for inducing proximity to adjacent sprays does not act at least until the switching spray generated by the switching nozzles causes an axis-switching phenomenon. The spark-ignition engine according to any one of claims 7 to 10, wherein a nozzle hole specification including a nozzle hole diameter, a length, and an inclination thereof is set.   Each of the sprays generated by the plurality of nozzle holes does not interact with each other by the Coanda effect that induces proximity with the adjacent sprays until at least the switching spray generated by the switching nozzles causes an axis-switching phenomenon. The spark ignition engine according to any one of claims 7 to 11, wherein the spark ignition engine is set to a flow velocity, a particle size, and a particle number density.   When stratified combustion is performed in the combustion chamber, the switching spray generated by the switching nozzle causes an axis-switching phenomenon in the process of passing through the vicinity of the spark plug, and is directed to the vicinity of the spark plug and has a reduced penetration force. The spark ignition type according to any one of claims 7 to 12, wherein the spark ignition type is controlled so as to lose a penetration force when it passes through the vicinity of the spark plug and stay in the vicinity of the spark plug. engine.   When homogeneous combustion is performed in the combustion chamber, the switching spray generated by the switching nozzle follows the air flow in the combustion chamber in the process of passing through the vicinity of the spark plug, and the combustion does not occur without causing an axis-switching phenomenon. The spark ignition engine according to any one of claims 7 to 13, wherein the spark ignition engine is controlled so as to be diffused throughout the room.

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