JP6012693B2 - Fluid injection valve and spray generating apparatus having the same - Google Patents

Description

The present invention relates a fluid injection valve for generating a jet spray of fluid from a plurality of injection holes and the spray generation equipment having the same.

  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. For example, research and development of a stratified combustion concept in a spark ignition direct injection engine equipped with a fuel injection valve that directly injects fuel into a combustion chamber is known.

  The fuel spray in a spark ignition direct injection 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 Realizes mixture formation in the entire combustion chamber by stratified combustion or homogeneous combustion. When the ignition plug is attached to the center of the combustion chamber and the fuel injection valve is attached at a position straddling the intake valve, the ignition plug and the fuel injection valve are not opposed to each other. For this reason, the required spray specifications are different between the spray directed to the vicinity of the spark plug and the spray not directed to the vicinity of the spark plug.

  Also, the spray specifications of the overall spray required when the piston is raised and when the piston is lowered are different in the combustion chamber of the compression ignition type direct injection engine. Convenient for establishing compression ignition combustion when the piston rises is a rich air-fuel mixture having a desired cross-sectional shape, and a compact spray with a reduced penetration force. When the piston is lowered, a spray that diffuses throughout the combustion chamber is required. As described above, the required specifications for the spray form including the number of sprays of the fuel injection valve differ depending on the shape of the combustion chamber, the in-cylinder air flow, and the position and direction of the fuel injection valve.

  On the other hand, for atomization of the spray, it is effective to make the liquid thread, which is the previous stage of droplet breakup, thin, and in order to make the liquid thread thinner, the liquid film, which is the previous stage of liquid thread breakup, is made thinner. It is effective to make the liquid column thinner. Furthermore, liquid films have been found to be advantageous over liquid columns. In addition, as a liquid film flow forming method, 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, or the nozzle hole is formed into an elongated slit shape according to the slit shape. A method of forming a fan-shaped thin film flow is known.

  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 shape, make the injection amount distribution asymmetric, or direct at least a part of the spray in a desired direction.

  In addition, the atomization technique as described above is being applied to the fuel injection valve, but the mainstream of the so-called hole nozzle atomization technique is the small injection hole diameter and multiple injection holes, and the jet flow from the adjacent injection holes It is designed not to deteriorate the atomization state by interfering with each other. 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. In other words, in order to suppress the spread of the spray, the atomization must be sacrificed by crossing a plurality of jets at positions up to the break length.

  On the other hand, in order to suppress the spread of the entire spray, if the angle of the injection hole center axis relative to the plane perpendicular to the operation center axis of the fluid injection valve is made relatively small, it is thin due to flow separation or contraction at the injection hole inlet. It is disadvantageous for forming a liquid film flow. That is, the atomization process becomes slow and the jets easily interfere with each other, and the atomization level cannot be achieved 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 extremely flattening the jet flow from the outlet of the nozzle hole. In order to avoid the interference of the jets at the outlet, it was necessary to further separate the jet directions.

  As a prior patent related to the above-described conventional technology, Patent Document 1 includes a main injection hole and a sub injection hole whose injection center is directed in a direction different from the injection center of the main injection hole, and is an entrance to the main injection hole. And a multi-hole injector in which the spray angle is widened and the fuel density of the spray is dispersed by setting the cross-sectional areas of the nozzle and the outlet different from each other.

  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.

  Further, in Patent Document 3, in at least one group of a plurality of spray flows, a virtual plane perpendicular to the spray axis of the nozzle hole member and located at a predetermined distance in the injection direction from the nozzle hole member and the flow path axis of the nozzle hole are used as fuel. Fuel is injected from the nozzle hole so that the intersection with the virtual straight line extending in the injection direction is not only the outer intersection located on the outer convex polygon or circle, but also at least one inner intersection on the inner side. A fuel injection valve for injection is presented. In this prior example, the arrangement is devised so that the sprays from the respective nozzle holes do not interfere with each other to promote atomization and to reduce the deviation of the injection amount distribution.

  Further, Patent Document 4 presents a fuel injection nozzle in which the flow path shafts of a plurality of injection holes are separated from the injection shaft in the injection direction and are separated from each other in the fuel injection direction. In this prior example, the fuel injected from each nozzle hole does not collide and each spray is uniformly atomized, and each spray advances while attracting each other by the Coanda effect, thereby preventing variations in the traveling direction of the spray flow. I have to.

  Further, in Patent Document 5, the nozzle hole formed in the slit shape is divided into two slit portions, and the fuel temperature is lowered by utilizing the fact that the spread angle of the fuel spray from each slit portion changes depending on the fuel temperature. Sometimes, two flat sprays interfere with each other to form one flat spray, and when the fuel temperature is high, two independent flat sprays improve the degree of freedom of the spray shape.

  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 switching spray having an oval cross-sectional shape ejected from an injection hole changes downstream. (Nonpatent 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.

  That is, in order to generate the axis-switching phenomenon, the nozzle hole specification including the nozzle hole diameter, length, and inclination is a specification that generates switching spray whose major axis is axisymmetric with respect to the minor axis. Need to be. Further, whether or not the switching spray causes an axis-switching phenomenon can be controlled by an external factor such as an injection condition such as an injection pressure or a spray amount, or an atmospheric pressure.

  For example, in Non-Patent Document 1, various non-circular vortex structures are formed due to differences in nozzle hole specifications, and non-circular vortex structures generated from non-circular nozzles are deformed due to the influence of self-induced velocity due to non-uniform curvature. It describes what to do. Non-Patent Document 2 describes that the degree of the axis-switching greatly depends on the aspect ratio (aspect ratio) of the nozzle nozzle hole.

  In patent document 6 by this inventor, the fluid injection valve provided with the switching nozzle hole which produces | generates the switching spray which deform | transforms with an axis-switching phenomenon, and the collective nozzle hole which forms the collective spray which each single spray collected by the Coanda effect Presents. In this example, switching sprays and collective sprays are gathered by the Coanda effect to form an overall spray, realizing different combustion chamber shapes for each engine specification and variable sprays suitable for each intake flow. Yes.

JP 2007-315276 A JP 2012-14504 A JP 2008-169766 A JP 2000-104647 A JP 2010-151109 A Japanese Patent No. 5491612

Proceedings of the Japan Society of Mechanical Engineers (Part B), Vol. 55, No. 514, pp1542-1545, "Study on vortex structure in non-circular jet" (Toyota et al.) ILASS-Europe 2010, “An experimental investigation of discharge coefficient and cavitation length in the elliptical nozzles” (Sung RyoulKim) 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”

  In conventional fluid injection valves, it is difficult to achieve both atomization improvement of spray and improvement in design flexibility such as spray shape, spray direction, penetration force, and injection amount distribution, and the required spray specifications are sufficient. It could not be realized. In particular, the atomization of the spray, the spray shape, and the penetrating force are characteristics that have a correlation with each other, but it has not been possible to realize an optimal spray specification in consideration of them.

  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, the fuel injection valve described in Patent Document 3 merely avoids the interference of the spray, and the spray pattern formed from a plurality of sprays and the shape of the entire spray are indispensable from a geometrical viewpoint. However, the design freedom is small, and the applicable combustion chamber shape and intake valve arrangement are limited. In addition, in order to promote atomization by promoting atomization and to reduce spray penetration force and to suppress spray adhesion in the combustion chamber, it is necessary to expand each atomization and atomize. Expand further.

  Moreover, in this prior example, the injection hole is also arranged on the inner side to reduce the deviation of the injection amount distribution, but it is only relatively reduced compared to the case where the injection hole is not arranged on the inner side. Yes, there is no explanation about the measures that the independent liquid column jets from each nozzle hole atomize while avoiding interference and become an injection amount distribution with reduced bias, so the applicable combustion chamber shape and intake valve arrangement etc. It is unknown.

  That is, when the spray holes are also arranged on the inner side to bring the sprays close to each other and try to reduce the unevenness of the spray amount distribution, the Coanda effect automatically acts between the sprays, and the assembly of the sprays begins. The injection amount distribution in the cross section in the downstream injection direction becomes one collective spray that has a substantially conical shape with a peak at the center, and the spray angle as a whole spray is relatively small in the market. It is clear from the characteristics of the fuel injection valve used and the known literature. Conversely, in order to suppress the aggregation of each spray due to the Coanda effect, it is necessary to ensure a certain distance between adjacent sprays (which varies depending on the injection conditions and atmospheric conditions), and the entire spread as described above. It becomes spraying.

  In addition, as in the fuel injection nozzle described in Patent Document 4, it is static to suppress the Coanda effect so that each spray does not spread, and on the other hand, each spray does not collect. Even under atmospheric conditions, it is difficult to maintain the balance of the spray direction. Moreover, in the intake port, it is affected by ambient air pressure, temperature, intake air flow, spray volume (weight) flow rate, spray speed, etc., so it is realized with an injection system for a gasoline engine with many unsteady states during transient operation. It is very difficult.

  If the action of the Coanda effect becomes stronger, each spray gathers and becomes compact, the injection amount distribution of the cross section in the injection direction becomes a cone with a peak at the center, and conversely, if the suppression of the Coanda effect works, The spray is usually separated as it goes downstream, and as a whole, the spray flow is generally very wide angle. As a result, the spray shape, spray pattern, and injection amount distribution of the entire spray are in accordance with the setting of the main axis direction of each nozzle hole or the main injection direction of each jet.

  In addition, since the fuel injection device described in Patent Document 5 changes the spray shape by using the change in the fuel temperature, it is necessary to install a heater and a heater control circuit as fuel temperature adjusting means. Since it is necessary to embed a heater inside the main body of the injection valve and to ensure reliability, it is considered that this leads to a significant cost increase.

  As described above, Patent Documents 1 to 5 show measures that can achieve both improvement in atomization of spray and improvement in design flexibility such as spray shape, spray direction, penetration force, and injection amount distribution. It has not been. Therefore, these prior examples are not a guideline for determining an optimum spray specification for each combustion chamber shape and each intake flow different for each engine specification. In particular, there is hardly any indication of the above-mentioned guideline regarding flat spray spread in a fan shape generated by a slit-like nozzle hole as shown in Patent Document 5.

  The slit-shaped nozzle hole can form a fan-shaped thin film flow according to its shape, and the flat spray generated from the fan-shaped thin film flow diffuses throughout the combustion chamber to form a homogeneous mixture. It is suitable for. Although it is desired to further deform this flat spray to a desired spray form, no such prior art is found. Even in the technique of designing the entire spray using the switching spray of Cited Document 6, there is no mention of the entire spray including the flat spray spread in a fan shape, and there is room for improvement in design flexibility.

The present invention has been made in order to solve the above-described problems, and it is possible to change the shape of the flat spray spread in a fan shape by using the switching spray generated by the switching nozzle hole. It is an object of the present invention to provide a fluid injection valve that achieves both atomization of the spray and improvement in design freedom of the spray shape, spray direction, penetration force, and injection amount distribution, and a spray generation device including the fluid injection valve. you.

A fluid injection valve according to the present invention is provided on a downstream side of a valve seat that is provided in the middle of a passage through which a fluid flows, a valve body that controls opening and closing of the passage by contact and separation with the valve seat, and A fluid injection valve that includes a nozzle hole body and injects fluid from a plurality of nozzle holes arranged in the nozzle hole body to generate a spray of a desired form, wherein the plurality of nozzle holes are flat sprays that expand in a fan shape a slit nozzle hole for generating, at least including one at the switching injection hole length of the major axis and minor axis in the cross-sectional shape in a plane perpendicular to the injection direction of the fluid to produce a different switching spraying, slit nozzle holes , Which generates a flat spray that does not cause an axis-switching phenomenon, and the switching nozzle hole has a nozzle hole diameter, length, and inclination so as to generate a switching spray whose major axis is axisymmetric with respect to the minor axis. injection hole specifications, including the is set, Sui Switching spray produced by quenching nozzle holes, axis at a predetermined position on the downstream from the switching injection holes - are those that can result in deformation of the generated switching phenomenon cross-sectional shape changing the direction of the long axis and a minor axis, The switching spray after this deformation is generated is a Coanda effect between the flat spray generated by the slit nozzle holes and approaches or aggregates with the flat spray.

  Moreover, the spray production | generation apparatus which concerns on this invention is provided with the 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.

  According to the fluid injection valve and the spray generating apparatus including the same according to the present invention, the switching spray generated by the switching nozzle hole changes the direction of the major axis and the minor axis at a predetermined position downstream from the switching nozzle hole. The shape of the flat spray generated by the slit nozzle can be deformed three-dimensionally using the deformation of the cross-sectional shape, so the design of the spray shape, spray direction, penetration force and injection amount distribution is free. The degree is improved. In addition, the switching spray and the flat spray after deformation are brought close to each other or gathered by the Coanda effect, so that the penetration force can be rapidly attenuated, and the effective surface area of the spray is increased by the deformation and atomized. Therefore, it is possible to achieve both atomization of the spray and improvement of the design freedom of the spray shape, the spray direction, the penetration force, and the injection amount distribution.

It is sectional drawing which shows the whole structure of the fuel injection valve which concerns on Embodiment 1 of this invention. It is the expanded sectional view and top view which show the front-end | tip part of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a side view explaining the behavior of the switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is sectional drawing explaining the behavior of the switching spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a side view explaining the behavior of the switching spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the behavior of switching spray at the time of carrying out the two-part injection in the fuel injection valve concerning Embodiment 1 of the present invention. It is a side view explaining the behavior of switching spray at the time of carrying out the two-part injection in the fuel injection valve concerning Embodiment 1 of the present invention. It is a side view explaining the behavior of switching spray at the time of carrying out the three-part injection in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure explaining the spray behavior of the basic spray pattern concerning the present invention. It is a figure explaining the spray behavior at the time of carrying out divided injection of the basic spray pattern concerning the present invention. It is a figure explaining the entrainment situation of ambient air in the basic spray pattern concerning the present invention. It is a figure explaining the spray behavior of the basic spray pattern concerning the present invention. It is a figure explaining the spray behavior at the time of carrying out divided injection of the basic spray pattern concerning the present invention. It is the side view and front view explaining the behavior of switching spray and flat spray in the fuel injection valve concerning Embodiment 1 of the present invention. It is sectional drawing explaining the behavior of the switching spray and the flat spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a top view which shows the example of arrangement | positioning of the nozzle hole in the nozzle hole plate of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a front view explaining the behavior of the flat spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is sectional drawing explaining the behavior of the switching spray and the flat spray in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a figure explaining the behavior of switching spray and flat spray at the time of split injection in the fuel injection valve concerning Embodiment 1 of the present invention. It is a figure which shows typically the spark ignition type direct injection engine which concerns on Embodiment 3 of this invention. It is a figure which shows typically the compression ignition type direct injection engine which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
Below, the fluid injection valve which concerns on Embodiment 1 of this invention is demonstrated based on drawing. 1 is a cross-sectional view showing a fuel injection valve according to the first embodiment, FIG. 2A is an enlarged cross-sectional view showing a tip portion of the fuel injection valve according to the first embodiment, and FIG. These are the top views of the nozzle hole plate seen from the direction shown by arrow A in Fig.2 (a). In the drawings, the same reference numerals are given to the same and corresponding parts in the drawings.

  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 engine and injecting fuel 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 having an injection hole 39 for injecting fuel and an inner side of the valve main body 31 are provided, and the passage is opened and closed by contact with and separation from the valve seat 32. 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. As shown in FIG. 2A, the ball 38 includes a chamfered portion 38a parallel to the Z axis (indicated by an arrow in FIG. 1) of the fuel injection valve 1, and a flat portion 38b facing the nozzle hole plate 33. And a curved surface portion 38c in line contact with the valve seat 32.

  The nozzle hole plate 33 may be formed integrally with the valve seat 32. Further, the valve body 35 may be formed integrally with a rod 37 and a ball 38. Furthermore, the ball | bowl 38 should just be a shape which can sheet | seat with respect to the valve seat 32, and can seal a fluid, for example, may be the edge-shaped seat part formed in the taper. The shape of the dead volume 34 formed by these is not limited to the illustrated shape, and a shape suitable for the flat spray 6A and the switching spray 5A described later may be selected. The rod 37 need not be hollow.

  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. The nozzle hole plate 33 has at least one slit nozzle hole 390 and one switching nozzle hole 391 penetrating in the plate thickness direction. The switching nozzle hole 391 is, for example, an elliptical nozzle hole whose cross-sectional shape perpendicular to the plate thickness direction (that is, the Z-axis direction) of the nozzle hole plate 33 has a major axis and a minor axis. In the following description, the nozzle hole 39 is a general term for all the nozzle holes including the slit nozzle hole 390 and the switching nozzle hole 391, and is used when it is not necessary to distinguish between them.

  The slit nozzle hole 390 forms a fan-shaped thin film flow according to its shape, and the flat spray generated from the fan-shaped thin film flow is suitable for forming a homogeneous air-fuel mixture and also for atomization. Is suitable. The flat spray basically has the atomization level, the spray shape, the spray direction, the penetration force and the injection amount distribution depending on the flatness (fuel flow film thickness and film spread angle) and the injection speed (injection fuel pressure). Determined. In addition, the flat spray can be regarded as having a major axis and a minor axis in a cross-sectional shape in a plane perpendicular to the fluid ejection direction, like the switching spray, but the behavior is completely different from the switching spray. A thin film that divides into liquid yarns spreads like a fan. Therefore, an axis-switching phenomenon that deforms the major axis and the minor axis does not occur.

  The switching nozzle hole 391 generates a 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 fluid ejection direction. Note that the nozzle hole specifications including the nozzle hole diameter, the length, and the inclination of the switching nozzle hole 391 are set so that the major axis is substantially line-symmetric with respect to the minor axis. Switching spray can cause deformation of its cross-sectional shape by changing the direction of the major axis and the minor axis at a predetermined position downstream from the switching nozzle hole 391. The nozzle hole plate 33 shown in FIG. 2B has one switching nozzle hole 391, but it may have a plurality.

  The operation of the fuel injection valve 1 will be described. When an operation signal is sent from the engine control device 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 is started.

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

  The fuel injection valve 1 according to the first embodiment performs divided injection in which the required fuel (fluid) injection amount is divided into a plurality of times and is also applicable to the case where the divided injection is not performed. In divided injection, each injection is performed in an injection period shorter than the original predetermined injection period when not divided. The required injection amount is determined according to the engine speed and load, and it is necessary to realize a spray form corresponding to the air-fuel mixture formation required in the operating conditions and the injection amount at that time.

In addition, since the split injection can change the injection rate shape and can improve the degree of freedom of the spray form, it has been performed for diesel engines from before. By performing the split injection, and may inhibit PM (Particulate Mattar) and NO _x generation by improving the conditions of mixture formation, the possibility of realizing the formation of the spray form suitable for homogeneous combustion and stratified combustion is there.

  As described above, the switching spray generated by the switching nozzle hole 391 can cause deformation of the cross-sectional shape by changing the direction of the major axis and the minor axis at a predetermined position downstream from the switching nozzle hole 391. Furthermore, at least one of the plurality of parameters set as the fuel injection condition can be classified into cases where the deformation of the cross-sectional shape of the switching spray generated by the switching nozzle hole 391 occurs and does not occur. An injection condition for each injection of the divided injection is set or adjusted based on this threshold. That is, by adjusting the injection conditions for each of the divided injections based on the threshold value, the specification of the entire spray is variable.

  Parameters having such a threshold include an injection period, an injection amount, an injection pressure, and the like in each injection of divided injection. When a plurality of parameters are set, the type of spray form that can be realized is the product of the number of divided injections and the combination of parameters.

  For example, when the above three parameters are set, combinations of parameters are (1) injection period, (2) injection amount, (3) injection pressure, (4) injection period and injection amount, (5) injection period and injection pressure, (6) Injection amount and injection pressure, (7) Injection period, injection amount and injection pressure are considered. In the case where the number of divided injections is 2, there are 14 types of injection conditions that can be set, and spray forms based on the respective injection conditions can be realized. Actually, since there are combinations including numerical values for the injection period, the injection amount, and the injection pressure, more spray forms can be realized.

  2B has one switching nozzle hole 391. When the nozzle plate 33 has a plurality of switching nozzle holes 391, the nozzle hole includes the nozzle hole diameter, length, and inclination. The thresholds of the switching nozzle holes 391 having the same specifications (specifications) are almost the same. In other words, for different nozzle hole specifications, different results are obtained for a certain threshold at the same injection opportunity. For example, the switching spray generated by a certain switching nozzle hole 391 can be deformed, and the switching spray generated by another switching nozzle 391 can be prevented from deforming. In such a case, for each switching nozzle hole 391, it is preferable to investigate the influence of parameters such as the injection period, the injection amount, and the injection pressure in advance, and to create three-dimensional map data.

  In the fuel injection valve 1 according to the first embodiment, the whole formed by the flat spray generated by the slit nozzle hole 390 and the switching spray generated by the switching nozzle hole 391, using the axis-switching phenomenon and the divided injection. A method for controlling spray specifications (spray shape, spray structure such as concentration distribution, penetration force, injection amount distribution, and spray direction) will be described.

  The whole spray is configured to include a switching spray that can change the direction of the major axis and the minor axis in accordance with the injection conditions set based on the threshold value and cause deformation of the cross-sectional shape. That is, it is also possible to configure the spray so as not to change the direction of the major axis and the minor axis according to the injection conditions set based on the threshold value.

  3 and 4 are diagrams for explaining the behavior of the jet flow and the spray from the switching nozzle hole 391 in the nozzle hole plate 33 of the fuel injection valve 1 according to the first embodiment, and FIG. It is a side view which shows the switching spray seen from the direction shown by arrow b. 4 is a cross-sectional view of a portion indicated by EE, FF,..., LL in FIG. In FIG. 3, ΔL1 and ΔL2 indicate the difference in penetration force. In FIG. 4, arrow L indicates the direction of the major axis, and arrow S indicates the direction of the minor axis.

  3 and 4, (a) is a switching spray 5A in which the injection condition does not reach the threshold value causing the axis-switching phenomenon, and (b) shows that the injection condition reaches the threshold value causing the axis-switching phenomenon. In the case of the switching spray 5A, (c) shows the behavior when the injection condition of the preceding switching spray 5A-1 reaches the threshold value causing the axis-switching phenomenon in the two-part injection. In the two-split injection shown in (c), each injection is performed in an injection period shorter than the original predetermined injection period shown in (a) and (b).

  When the fuel jet 5a injected from the switching nozzle 391 advances downstream by a predetermined distance a (break length), the lengths of the major axis L and the minor axis S in the cross-sectional shape in a plane perpendicular to the injection direction. Different switching sprays 5A are generated. The switching spray 5A generated from the switching nozzle hole 391 is controlled so as to be deformed by causing an axis-switching phenomenon at a predetermined distance from the switching nozzle hole 391 and changing the directions of the major axis L and the minor axis S. Is possible.

  In the example of FIG. 3A, the conditions of the jet 5a from the switching nozzle hole 391 and the switching spray 5A do not reach the threshold value for causing the axis-switching phenomenon, and the axis-switching phenomenon does not occur. In this case, as shown in FIG. 4A, there is no change in which the major axis L and the minor axis S are reversed.

  In the example of FIG. 3B, the conditions of the jet 5a from the switching nozzle hole 391 and the switching spray 5A reach the threshold value at which the axis-switching phenomenon occurs, and the axis-switching phenomenon occurs. In this case, as shown in FIG. 4B, the directions of the major axis L and the minor axis S change and reverse, and the cross-sectional shape is deformed. At this time, since the change and deformation of the long axis L and the short axis S are caused by a large exchange of momentum with the surrounding air due to asymmetry, the momentum of the spray greatly moves to the surrounding air. The penetrating force of the spray 5A rapidly decreases from the middle, and the penetrating force becomes smaller than that in FIG.

  Further, in the example of FIG. 3C, the switching spray 5A-1 at the previous stage has reached a threshold value at which various conditions of the jet 5a from the switching nozzle 391 and the switching spray 5A-1 cause an axis-switching phenomenon. . However, the switching spray 5A-2 at the latter stage may be either generated or not caused to cause an axis-switching phenomenon.

  The switching spray 5A-1 in the previous stage is a spray that has been divided due to a short injection period in addition to losing a large momentum by causing an axis-switching phenomenon. In such a case, since the momentum from the subsequent flow is not replenished, the ratio of the momentum that moves by interfering with the surrounding air is larger than the momentum that the spray has, and the cross-sectional shape of the spray changes and deforms. In addition to the momentum movement by the spray, the momentum that the spray has decreases. As a result, the penetrating force is further reduced as compared with FIG.

  FIG. 5 (a) shows a change in the overall spray with the lapse of time shown in FIG. 3 (a), and FIG. 5 (b) shows the whole with the lapse of time shown in FIG. 3 (b). It shows how the spray changes. As shown in FIG. 5 (a), in the case of the switching spray 5A that does not cause an axis-switching phenomenon, the entire spray (penetration force L1) at the time t5 maintains the basic form with respect to the time t1, It moves downstream with a slight spread due to mixing with ambient air (momentum transfer). This situation can be easily inferred from ordinary knowledge about conventional spraying.

  Further, as shown in FIG. 5 (b), in the case of the switching spray 5A in which the axis-switching phenomenon occurs, the spray form at time t1 is broader than that in FIG. 5 (a), and further at time t5 There exists a tendency for the spread rate of spray (penetration force L2) to become large. However, the basic form is maintained as in FIG. 5 (a), and it can be easily inferred from ordinary knowledge about conventional spraying.

  FIG. 6 (a) shows how the entire spray changes with time in each spray in the two-split injection shown in FIG. 3 (c), and FIG. 6 (b) shows the time t5 in FIG. 6 (a). The whole spray seen from the direction shown by arrow A in FIG. As shown in FIG. 6 (a), the switching spray 5A-1 in the previous stage has a very low penetration force, so that the spread in the injection direction is suppressed, and the spread in the direction perpendicular to the injection direction becomes large. ing. On the other hand, when the switching spray 5A-2 in the subsequent stage does not cause an axis-switching phenomenon, the penetrating force does not greatly decrease, and it is possible to gradually approach and aggregate the front stage spray (penetrating force). L3 <L2 <L1).

  In this case, for example, a cross-sectional shape perpendicular to the injection direction, or a projection shape or an injection amount distribution (integral value) in a plane perpendicular to the injection direction is made to be a substantially cross shape as shown in FIG. Is possible. Conditionally, for example, the switching spray 5A-1 at the front stage secures the momentum held by the spray as a divided injection of a slightly longer injection period at a predetermined fuel pressure, and the switching spray 5A-2 at the rear stage is based on the front spray 5A-1. Before the decrease in fuel injection pressure has been recovered, split injection is performed with a slightly shorter injection period. Thereby, a difference can be given to the momentum which each switching spray 5A-1, 5A-2 holds, and the above-mentioned behavior becomes realizable.

  As shown in FIG. 6 (a), the switching spray 5A-1 that changes the direction of the major axis and the minor axis and the switching spray 5A-2 that does not change the direction of the major axis and the minor axis are divided injections. By making use of the fact that the penetration force at a predetermined time after each injection is different, by setting the pause time interval of the divided injection to a predetermined value, the sprays by the respective injections are brought closer or assembled at a predetermined downstream position A whole spray can be formed. The entire spray in which the sprays of the divided sprays are brought close to each other or gathered is less spread and the penetrating power is reduced compared to the total spray when the total spray amount by the split spray is performed by one injection. . In addition, the entire spray has a time at which the cross-sectional shape or projected shape in a plane perpendicular to the fluid ejection direction becomes a substantially cross shape, a substantially diamond shape, or a substantially square shape.

  Further, FIG. 7 shows a state of change of the entire spray with the passage of time of each spray in the case of two-split injection when an axis-switching phenomenon different from that in FIG. 6 is set. In the example of FIG. 7, the entire spray is formed such that the flat-shaped switching sprays 5A-1 and 5A-2 are vertically stacked (penetration force L4 <L2 <L1). Further, by considering the condition of split injection and the interference level between sprays, the stacking method, that is, the level of proximity or aggregation can be changed.

  FIG. 8 shows how the entire spray changes as time passes for each spray in the three-split injection. In this example, in the switching sprays 5A-1, 5A-2, 5A-3 at each stage, the deformation due to the change of the major axis and the minor axis due to the axis-switching phenomenon is reduced, and the number of divided injections is increased. In this way, the entire spray in which the sprays of the divided injections are brought close to each other or aggregated is less spread compared to the total spray when the total injection amount by the split injection is performed by one injection, and the penetration force Decreases (penetration force L5 <L2 <L1).

  As described above, a tertiary as shown in FIG. 6B is obtained by combining the use / non-use of the axis-switching phenomenon, the order of use / non-use, the number of divisions, the division pause time, and the threshold (injection period, injection amount, injection pressure, etc.). It is possible to freely realize and change the type of structure such as the original overall spray shape and spray concentration distribution, the level of penetration of the overall spray, and the like.

  As a method of changing the direction of the major axis and minor axis of the spray to change the cross-sectional shape, in addition to using the axis-switching phenomenon, the fuel particles are charged and the charges are used at a predetermined downstream position. Then there is a method of controlling the flight direction of the fuel particles. For example, the particles of the switching spray 5A shown in FIG. 3 (a) are charged, and the charged fuel particles are attracted or repelled from the right or left side of the paper, thereby causing the long axis as shown in FIG. 3 (b). The cross-sectional shape can be changed by changing the direction of the short axis.

  Next, as a basic spray pattern, basic behavior regarding interference and assembly of each spray generated by two non-switching nozzle holes arranged adjacent to each other will be described with reference to FIGS. 9 to 11 show the behavior until the Coanda effect acts on two non-switching sprays to form a collective spray. The Coanda effect is an effect that induces proximity to adjacent sprays.

  In FIG. 9, (a) is a side view at time t1 of non-switching spray generated by one injection from two non-switching nozzle holes, and (b) is EE, FF, It is sectional drawing in the part shown by GG and HH. As shown to Fig.9 (a), the jets 4a and 4b injected from the two non-switching nozzle holes 392 arrange | positioned by the space | interval x1 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 392 and the cross section EE at this time is 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 into 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 392. , 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. In FIG. 9A, the penetration force of the collective spray 40 at time t1 is L6.

  FIG. 10 shows how the entire spray changes over time when the two non-switching sprays shown in FIG. 9 are divided and injected. As shown in FIG. 10, even when split injection is performed, the interval between the two is smaller than the threshold value at which the Coanda effect acts, so basically, both sprays tend to gather close together for each injection. Become. In addition, when the pause time of the divided injection is short, the latter spray is performed in a state where the air flow in the injection direction generated because the former spray involves the surrounding air and proceeds, so the latter spray relatively However, the decrease in the penetration force is suppressed, and the latter-stage spray tends to catch up with the former-stage spray (the penetration force at time t1 is L7 <L6).

  FIG. 11 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. FIG. 11 (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 in FIG. 11A, an air flow V is induced in the spray in the downstream flow direction due to the entrainment of ambient air. As a result, as shown in FIG. 11B, the injection amount distribution of the non-switching sprays 4A and 4B in FF, G1-G1, G2-G2, and HH has a peak at the approximate center of the collective spray 40. it can. 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.

  Moreover, FIG. 12 is a figure explaining the behavior until the Coanda effect does not act on two non-switching sprays generated by one injection and forms independent sprays. In FIG. 12, (a) is a side view at time t1 of non-switching spray injected from two non-switching nozzle holes, and (b) is indicated by EE, FF, and GG in (a). It is sectional drawing in a part. As shown to Fig.12 (a), the jets 4a and 4c injected from the two non-switching nozzle holes 392 arrange | positioned by the space | interval x2 (x2> x1) become the non-switching sprays 4A and 4C, respectively.

  In this example, at the position of the break length a in the section EE, the gap between the two 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 continue in the initial traveling direction while being independent (the penetration force at time t1 is L8).

  FIG. 13 shows how the entire spray changes over time when the two non-switching sprays shown in FIG. 12 are divided and injected. In this case, the Coanda effect does not act between the two sprays, and therefore, a simple spray lump tends to be arranged at intervals. In addition, when the pause time of the divided injection is short, the same tendency as described above is obtained. The penetration force at time t1 is L9 <L8.

  9 to 13, the non-switching spray holes 4A, 4B, and 4C generated by the two non-switching nozzle holes 392 are described as examples of the basic spray pattern. Even in the case of the combination of the nozzle holes 391, it is possible to design so that the Coanda effect does not act between both sprays and each forms an independent spray.

  Next, in the fuel injection valve 1 according to the first embodiment, when the nozzle hole plate 33 shown in FIG. 2B is used, that is, one switching nozzle hole 391 and one slit nozzle hole 390 are provided. The basic behavior regarding the interference and assembly of the spray from each nozzle hole will be described. The switching nozzle hole 391 and the slit nozzle hole 390 are arranged such that the direction of the long axis L before the switching spray 5A generated by the switching nozzle 391 causes the deformation of the cross-sectional shape is the flat spray 6A generated by the slit nozzle 390. It arrange | positions so that it may become the same direction as a longitudinal direction.

  Further, the switching nozzle hole 391 and the slit nozzle hole 390 are arranged such that the switching spray 5A generated by the switching nozzle hole 391 has a slit injection nozzle downstream from a predetermined position where the direction of the major axis L and the minor axis S is changed by the axis-switching phenomenon. The flat spray 6 </ b> A generated by the holes 390 and the Coanda effect are combined to form a collective spray 50 (corresponding to the entire spray here). That is, at least one of the characteristics of the spray shape, penetrating force, injection amount distribution, and spray direction of the entire spray is determined downstream from a predetermined position where the switching spray 5A causes the axis-switching phenomenon.

  14 and 15 show the behavior until the flat spray and the switching spray generated by the slit nozzle holes and the switching nozzles adjacent to each other form a collective spray by the Coanda effect. 14A is a side view (partially a cross-sectional view) of each spray viewed from the direction indicated by the arrow B in FIG. 2B, and FIG. 14B is an arrow C in FIG. 2B. It is a front view of the spray seen from the direction shown. FIG. 15 is a cross-sectional view taken along lines GG, JJ, KK, and LL in FIG. 14A. In the drawing, arrow L indicates the direction of the long axis, and arrow S. Indicates the direction of the minor axis.

  As shown in FIG. 14A and FIG. 15, the slit nozzle holes 390 and the switching nozzle holes 391 arranged at the interval x3 are formed before the switching spray 5A generated by the switching nozzle holes 391 is deformed in cross-sectional shape. It arrange | positions so that the direction of the long axis L may turn into the same direction as the longitudinal direction of the flat spray 6A produced | generated by the slit nozzle hole 390. FIG. The switching spray 5A is opposed to the flat spray 6A, and its cross-sectional shape slightly expands in both the major axis L and the minor axis S, while maintaining the initial flow direction almost immediately below the switching nozzle hole 391 and downstream. Flowing.

  Thereafter, an axis-switching phenomenon occurs at a predetermined distance from the switching nozzle hole 391, and the direction of the major axis L and the minor axis S of the switching spray 5A starts to change as shown in the section JJ. At this position, the gap c3 between the switching spray 5A and the flat spray 6A 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, deformation in which the direction of the major axis L and the minor axis S of the switching spray 5A changes, and the switching spray 5A and the flat spray 6A come closer. This is because the gap between the switching spray 5A and the flat spray 6A 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 flat spray 6A. .

  In the cross section KK, the gap c4 between the switching spray 5A and the flat spray 6A 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 flat spray 6A are deformed and moved to start interference. As a result, a collective spray 50 in which the switching spray 5A and the flat spray 6A are integrated is formed at a predetermined distance from the slit nozzle hole 390 and the switching nozzle hole 391 after a lapse of a predetermined time after fuel injection. The shape, size, direction, penetration force, and injection amount distribution of the collective spray 50 can be changed by changing the characteristics and arrangement of the switching spray 5A and the flat spray 6A.

  Further, the switching spray 5A is deformed by changing the directions of the long axis L and the short axis S, so that the momentum exchange with the surrounding air greatly proceeds and the penetration force becomes small. Therefore, by interfering with the flat spray 6A, the movement of each particle of the flat spray 6A and the air flow dragged by each particle is suppressed, and the penetration force of the flat spray 6A is also suppressed.

  The end d1 of the flat spray 6A shown in FIG. 14 is a portion where the Coanda effect does not act. Further, the bent portion d2 at the end of the flat spray 6A is a portion where the Coanda effect is acting. In this way, the flat spray 6A is deformed by interference with the switching spray 5A, the penetrating force is reduced, and the extension of the tip thereof is shortened compared to the case where it is alone (the penetrating force at time t1 is L10).

  In addition, since the effective surface area of the flat spray 6A increases due to the deformation, atomization further proceeds, and it becomes easy to mix with ambient air, so that a homogeneous air-fuel mixture can be formed at an early stage. Due to the deformation, it is possible to prevent the width W1 of the tip portion of the flat spray 6A from being excessively widened. Since the overall spray shape greatly affects the mixing with the ambient air, the specifications of the flat spray 6A and the switching spray 5A are determined so as to obtain an optimum collective spray 50 shape according to the combustion chamber shape and the in-cylinder air flow. That's fine.

  In the example shown in FIGS. 14 and 15, the flat spray 6 </ b> A and the switching spray 5 </ b> A are combined to form the collective spray 50 whose cross section is not intended. The collective spray 50 is formed in this combination. The number and arrangement of sprays are not limited. For example, one flat spray 6A and a plurality of switching sprays 5A, or two flat sprays 6A and one or a plurality of switching sprays 5A may be used.

  FIG. 16 shows another arrangement example of the injection holes in the injection hole plate of the fuel injection valve 1 according to the first embodiment. An injection hole plate 33A shown in FIG. 16A combines one slit injection hole 390 and two switching injection holes 391. The nozzle hole plate 33B shown in FIG. 16 (b) combines one slit nozzle hole 390 and three switching nozzle holes 391.

  FIG. 17 is a front view showing the behavior of the flat spray viewed from the direction indicated by the arrow C in FIG. 16, and FIG. 18 is a cross-sectional view of the collective spray at the portion indicated by LL in FIG. In the case of the nozzle hole arrangement of the nozzle hole plate 33A shown in FIG. 16A, deformation of the flat spray 6A as shown in FIG. 17A occurs, and the collective spray 50 as shown in FIG. Become. Further, in the case of the nozzle hole arrangement of the nozzle hole plate 33B shown in FIG. 16B, deformation of the flat spray 6A as shown in FIG. 17B occurs, and the collective spray as shown in FIG. 18B. 50. Here, the penetration force of the collective spray 50 is (L10-3) <(L10-2) <(L10-1), and the width of the collective spray 50 when viewed from the direction of the arrow C is W3 <W2 <W1. It becomes.

  In this way, the flat spray 6A and the switching spray 5A rapidly attenuate the penetrating force due to the Coanda effect acting by the deformation of the switching spray 5A and being brought close to each other or assembled. Further, the switching spray 5A has a reduced penetrating force and greatly mixed with the surrounding air, whereby the atomization is improved and the difference from the atomization level of the flat spray 6A is reduced. That is, the non-circular shaped collective spray 50 is formed which is atomized at a predetermined distance downstream from the slit nozzle hole 390 and the switching nozzle hole 391 and has an asymmetric cross section.

  If the switching nozzle hole 391 is not disposed adjacent to the slit nozzle hole 390 and the switching spray 5A is not used, the proximity of the adjacent spray does not start until further downstream. Does not lead to aggregation. Therefore, each spray continues to expand 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.

  Moreover, the case where division | segmentation injection is performed using the nozzle hole plate 33 shown in FIG.2 (b) is demonstrated using FIG. FIG. 19 (a) shows how the entire spray changes as time passes for each spray in the two-split injection, and FIG. 19 (b) shows from the direction indicated by arrow a at time t3 in FIG. 19 (a). The overall spray seen is shown. In the example shown in FIG. 19, the injection condition is set based on the threshold value so that the upstream switching spray 5A-1 causes an axis-switching phenomenon, and the latter switching spray 5A-2 does not cause an axis-switching phenomenon. doing. In this case, the penetration force can be further suppressed as compared with the case where the divided injection is not performed (penetration force L11 <(L10-1) at time t1).

  As described above, three examples of the arrangement of the slit injection holes 390 and the switching injection holes 391 in the fuel injection valve 1 according to Embodiment 1 are shown in FIGS. In any arrangement example, the plurality of nozzle holes 39 provided in the nozzle hole plate 33 are close to the adjacent sprays until at least the switching spray 5A generated by the switching nozzle holes 391 causes an axis-switching phenomenon. The nozzle specifications including the nozzle hole diameter, length, and inclination, and the interval between them are set so that the Coanda effect that induces the above does not act on each other.

  In addition, 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 391 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.

  As a method for suppressing the Coanda effect from acting between adjacent sprays, for example, 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 392 and the switching nozzle hole 391 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 order to realize these methods, the pressure loss (jet velocity) in the nozzle hole 39, the cross-sectional area of the jet, the cross-sectional shape, and the arrangement are utilized by changing the level and direction of the contracted flow depending on the nozzle hole shape. By changing the direction and the like, the threshold value of the gap where the Coanda effect acts can be changed. In addition, this threshold value varies depending on the flow rate of each spray, the atomization level, the particle number density, the atmospheric pressure, and the like, and can be set to a desired threshold value by adjusting them.

  As described above, according to the fuel injection valve 1 and the spray generation device including the fuel injection valve 1 according to the first embodiment, the switching spray 5A generated by the switching nozzle 391 is at a predetermined position downstream from the switching nozzle 391. Since the shape of the flat spray 6A generated by the slit nozzle hole 390 can be three-dimensionally deformed by utilizing the deformation of the cross-sectional shape by changing the direction of the long axis and the short axis, the spray The degree of freedom in designing the shape, spray direction, penetration force, and injection amount distribution is improved.

  Further, the switching spray 5A and the flat spray 6A after deformation are brought close to each other or gathered by the Coanda effect, so that the penetration force can be rapidly attenuated and the effective surface area of the spray is increased by the deformation. Since atomization proceeds, it is possible to achieve both atomization of the spray and improvement in the design freedom of the spray shape, the spray direction, the penetration force, and the injection amount distribution.

  In addition, when split injection is performed in the fuel injection valve 1 according to the first embodiment, split fuel is divided based on a threshold value that can distinguish between cases where the cross-sectional shape of the switching spray 5A is deformed and cases where it does not occur. By setting the injection conditions for each injection, the spray shape is variable, and the design flexibility of the spray shape, spray direction, penetration force, and injection amount distribution is further improved.

Embodiment 2.
In the fuel injection valve 1 similar to that in the first embodiment, in order to inject a minute injection amount by split injection and contribute to the sophisticated mixture formation and combustion, the injection operation in the minute injection period is stably realized. It is necessary to. When the injection period is shortened, the valve body 35 is in a region where the full lift from the fully closed state to the fully open state is not performed. In the second embodiment, when the valve is closed without being fully opened in the divided injection, it is possible to distinguish between cases where the cross-sectional shape of the switching spray is deformed and cases where it does not occur, as in the first embodiment. A threshold value is found, and the injection conditions for each of the divided injections are set based on this threshold value.

  As a specific measure, it is possible to estimate the injection amount by detecting the valve element operation even in a region where the full lift is not performed. By combining the injection in this region, more sophisticated injection control can be performed. Further, by narrowing down the injection conditions in the region where the full lift is not performed, it is possible to cause deformation due to a change in the direction of the major axis and the minor axis due to the axis-switching phenomenon. For example, when the injection time is short and the injection amount decreases, the momentum of the spray decreases. In order to compensate for this, the injection speed may be increased by further shortening the injection period and increasing the injection pressure.

  As described above, in the first to second embodiments, the following sprays (a) to (f) have been described as the basic spray pattern according to the present invention. (A) Switching spray in which the injection condition does not reach the threshold value causing the axis-switching phenomenon (FIG. 3A), (A) Switching spray in which the injection condition reaches the threshold value causing the axis-switching phenomenon (FIG. 3 ( b)), (c) Sprays that are gathered by the Coanda effect acting on the two non-switching sprays (FIG. 9), (D) Sprays that remain independent without the Coanda effect acting on the two non-switching sprays (FIG. 12) (E) Sprays that are gathered by the Coanda effect on flat sprays and switching sprays (FIG. 14).

  In these basic spray patterns (a) to (e), the number, type, and arrangement of sprays are arbitrarily combined and arranged, and further, the number of divisions in divided injection, the injection period, the injection pause time, the injection amount, By arbitrarily combining specifications such as injection pressure, any three-dimensional overall spray shape and spray concentration distribution structure that could not be realized in the past, spray penetration force (including penetration force setting for each divided injection), It is possible to realize the injection amount distribution and the like including the change setting over time.

  In addition, regarding spray patterns, it is possible to provide fuel injection valves having different specifications for overall spray shapes in not only one spray but also multi-sprays such as two sprays and three sprays. Further, the drive source of the fuel injection valve 1 may be a system other than the electromagnetic system, and may be a piezoelectric system, a mechanical system, or the like. Moreover, it can apply to both an intermittent injection valve and a continuous injection valve.

  Furthermore, in addition to the fuel injection valve 1, the fluid injection valve according to the present invention is used for various industrial sprays such as painting, coating, agricultural chemical application, cleaning, humidification, sprinkler, sterilization, cooling, etc. There are uses for home use, personal use, etc., and spray forms required for each can be realized. By incorporating the fluid injection valve according to the present invention, it is possible to obtain a spray generating apparatus capable of realizing an unprecedented spray form regardless of the drive source, the nozzle form, and the spray fluid.

  In Embodiment 3 and Embodiment 4 shown below, in the in-cylinder direct injection engine, the basic spray pattern described in Embodiment 1 and Embodiment 2 above is applied to realize various spray forms. Will be described.

Embodiment 3 FIG.
FIG. 20 is a diagram schematically showing a spark ignition direct injection engine according to Embodiment 3 of the present invention, in which (a) is during stratified combustion (during piston rise), and (b) is during homogeneous combustion (piston) The state of descent) is shown. The spark ignition direct injection engine 100 according to the third embodiment includes the fuel injection valve 1 according to the first embodiment or the second embodiment as a fuel injection valve that injects fuel into the combustion chamber 7. The nozzle hole plate 33 shown in 2 (b) is provided.

  An intake port 8 and an exhaust port 9 communicate with the combustion chamber 7 of the spark ignition direct injection engine 100, and an intake valve 11 that opens and closes in conjunction with the piston 10 at the opening on each combustion chamber 7 side. And an exhaust valve 12 is 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 Embodiment 3 and Embodiment 4 to be described later, the in-cylinder state in which the axis-switching phenomenon is about to occur is a condition normally used in gasoline direct-injection engines in various companies on the market. Of “a cylinder state at room temperature at a pressure slightly lower than atmospheric pressure” and “an in-cylinder state at a pressure slightly higher than atmospheric pressure and a little higher temperature” in the relatively first half of the compression stroke.

  Note that the in-cylinder pressure in the compression stroke gradually increases, but when spraying is about 0.3 MPa to 0.5 MPa, the influence of in-cylinder air flow is slight, and the penetration force is normal or large. The penetrating power hardly decreases. For this reason, it is possible to cause an axis-switching phenomenon as in a normal temperature and normal pressure atmosphere.

  In the third embodiment, the switching spray 5A generated by the switching nozzle hole 391 of the fuel injection valve 1 is spray directed to 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 391 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.

  The state of the entire spray during stratified combustion and homogeneous combustion in the spark ignition direct injection engine 100 according to Embodiment 3 of the present invention will be described with reference to FIG. At the time of stratified combustion shown in FIG. 20A, the air in the combustion chamber 7 is compressed by the rise of the piston 10, and the pressure in the combustion chamber 7 rises. For this reason, the penetration force of the flat spray 6A and the switching spray 5A is 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 to 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 due to the proximity or assembly with the flat spray 6 </ b> A generated by the slit nozzle hole 390, 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, the flat spray 6A is directed so as to be in a mixed combustion state suitable for stratified combustion, and the penetration force is set so that the collision with the cylinder liner 14 and the piston 10 surface is suppressed. As a result, the entire spray 60 in which the switching spray 5A and the flat spray 6A are brought close to each other or gathered is prevented from colliding with the cylinder liner 14 or the piston 10 surface, and in the vicinity of the spark plug 13 is a rich mixture suitable for stratified combustion. Form a mind.

  On the other hand, during the homogeneous combustion shown in FIG. 20B, 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. At this time, the switching spray 5A does not aggregate with the flat spray 6A generated by the slit nozzle hole 390 and the Coanda effect. The flat spray 6A diffuses throughout the combustion chamber 7 to form a homogeneous air-fuel mixture.

  Thus, the spark ignition direct injection engine 100 according to the third 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 vicinity of the spark plug 13 during stratified combustion. By applying the switching spray 5A as a spray directed to the vicinity of the spark plug 13, an air-fuel mixture suitable for stratified combustion is obtained by aggregating with the flat spray 6A near the spark plug 13 while avoiding a collision with the spark plug 13. Can be formed. At the time of homogeneous combustion, the switching spray 5A can follow the air flow, and can be diffused throughout the combustion chamber 7 together with the flat spray 6A without causing an axis-switching phenomenon.

  According to the third embodiment, the spray directed to the vicinity of the ignition plug 13 can be generated by using at least one switching spray 5 </ b> A using the axis-switching phenomenon, and diffused into the combustion chamber 7 to be homogeneous. By forming the collective spray integrated with the flat spray 6A that easily forms a simple air-fuel mixture, the combustion performance required for the stratified combustion and the homogeneous combustion in the spark ignition direct injection engine 100, and hence the engine performance, can be made compatible. It becomes possible. In addition, by separately injecting these sprays, the degree of freedom in designing the sprays is improved further particularly during stratified combustion.

Embodiment 4 FIG.
FIG. 21 is a diagram schematically showing a compression ignition type direct injection engine according to Embodiment 4 of the present invention, in which (a) shows a state when the piston is raised, and (b) shows a state when the piston is lowered. The compression ignition direct injection engine 101 according to the fourth embodiment includes the fuel injection valve 1 according to the first embodiment or the second embodiment as a fuel injection valve that injects fuel into the combustion chamber 7. The nozzle hole plate 33 shown in 2 (b) is provided.

  An intake port 8 and an exhaust port 9 communicate with the combustion chamber 7 of the compression ignition direct injection engine 101, and an intake valve 11 that opens and closes in conjunction with the piston 10 at the opening on each combustion chamber 7 side. And an exhaust valve 12 is provided. In addition, the fuel injection valve 1 is disposed at a substantially central portion of the ceiling of the combustion chamber 7. The arrangement of the fuel injection valve 1 is not limited to this.

  In the fourth embodiment, the switching spray 5A generated by the switching nozzle hole 391 of the fuel injection valve 1 is close to the flat spray 6A generated by the slit nozzle hole 390 after the occurrence of the axis-switching phenomenon by the Coanda effect. Thus, the entire spray 60 is formed into a shape suitable for mixture formation or combustion in the combustion chamber 7. 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.

  The state of the entire spray when the piston is raised and when the piston is lowered in the compression ignition type direct injection engine 101 according to the fourth embodiment will be described with reference to FIG. When fuel injection is performed when the piston is lifted as shown in FIG. 21A, the air in the combustion chamber 7 is compressed by the lift of the piston 10, and the pressure in the combustion chamber 7 is increased. For this reason, the penetration force of the flat spray 6A and the switching spray 5A is smaller than that under atmospheric pressure.

  The switching spray 5A generated by the switching nozzle 391 deforms by causing an axis-switching phenomenon in the process of passing through the cylinder, and between the switching spray 5A and the flat spray 6A generated by the slit nozzle 390. Proximity or aggregation occurs due to the Coanda effect. Thereby, the penetration force of each spray is significantly reduced, and a compact whole spray 60 is formed in the combustion chamber 7 near the compression top dead center.

  Note that the compression ignition type direct injection engine has a very high compression temperature and pressure in the vicinity of the compression top dead center, and when fuel is injected in this state, it is ignited before an appropriate air-fuel mixture is formed. And uneven combustion may occur. On the other hand, the compression ignition type direct injection engine 101 according to the fourth embodiment abruptly attenuates the penetration force of the switching spray 5A at a desired distance from the injection position to the cylinder inner surface, and thus a rich air-fuel mixture having a desired cross-sectional shape. It is convenient to spread the spray in the cylinder and establish the compression ignition combustion.

  In addition, each spray is directed so as to be in a mixed state suitable for compression ignition combustion, and a 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 or the piston 10 surface, and forms an air-fuel mixture suitable for compression ignition combustion.

  On the other hand, when the piston is lowered as shown in FIG. 21B, the intake valve 11 is opened as the piston 10 is lowered, 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 process of passing through the combustion chamber 7, and does not cause an axis-switching phenomenon and diffuses throughout the combustion chamber 7. At this time, the switching spray 5A does not aggregate with the flat spray 6A generated by the slit nozzle hole 390 and the Coanda effect. The flat spray 6A diffuses throughout the combustion chamber 7 to form a homogeneous air-fuel mixture.

  As described above, the compression ignition type direct injection engine 101 according to the fourth embodiment is suitable for compression ignition combustion by assembling with the flat spray 6A using the axis-switching phenomenon of the switching spray 5A when the piston is raised. It is possible to form a rich mixture. Further, when the piston descends, the switching spray 5A can follow the air flow, and can be diffused throughout the combustion chamber 7 together with the flat spray 6A without causing an axis-switching phenomenon.

  The engine to which the fuel injection valve 1 according to the present invention is applied is not limited to a gasoline engine, a diesel engine, a gas engine, a composite fuel engine, or the like, and an ignition (ignition) method is not limited. Within the scope of the present invention, the present invention can be freely combined with each other, or can be appropriately modified or omitted.

The present invention is a fluid injection valve, in particular fuel injection valve to be mounted on the engine, and can be utilized as a spray generating equipment having the same.

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, 6A flat spray, 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, 31 Valve body, 32 Valve seat, 32a Valve seat surface,
33, 33A, 33B Injection hole plate, 34 Dead volume, 35 Valve body,
36 compression spring, 37 rod, 38 ball, 38a chamfered part, 38b flat part,
38c curved surface part, 39 nozzle hole, 40, 50 collective spray, 60 whole spray,
100 spark ignition direct injection engine, 101 compression ignition direct injection engine,
390 slit nozzle hole, 391 switching nozzle hole, 392 non-switching nozzle hole.

Claims (13)

A valve seat provided in the middle of a passage through which fluid flows, a valve body that controls opening and closing of the passage by contact and separation with the valve seat, and a nozzle hole provided downstream of the valve seat A fluid injection valve for injecting a fluid from a plurality of injection holes arranged in the injection hole body to generate a spray of a desired form,
The plurality of nozzle holes include a slit nozzle hole that generates a flat spray spread in a fan shape, and a switching nozzle that generates switching sprays having different major axis and minor axis lengths in a cross-sectional shape in a plane perpendicular to the fluid ejection direction. Including at least one nozzle hole,
The slit nozzle hole generates a flat spray that does not cause an axis-switching phenomenon,
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. switching spray generated is axis at a predetermined position downstream from the switching injection holes - are those that can result in deformation of the front SL sectional shape occurs a switching phenomenon by changing the direction of the short axis and the long axis, The fluid spray valve according to claim 1, wherein the switching spray after the deformation causes a Coanda effect between the flat spray generated by the slit nozzle hole and approaches or collects the flat spray.   A fluid injection valve that generates a spray of a desired form by performing divided injection in which a required fluid injection amount is divided into a plurality of times, and at least one of parameters set as a fluid injection condition is the switching The switching spray generated by the nozzle hole has a threshold value capable of distinguishing between the case where the cross-sectional shape deformation occurs and the case where the deformation does not occur, and the injection condition in each injection of the divided injection is based on the threshold value The fluid injection valve according to claim 1, wherein the fluid injection valve is set.   The fluid injection valve according to claim 2, wherein the parameter having the threshold includes at least one of an injection period, an injection amount, and an injection pressure in each injection of the divided injection.   The interval time of the divided injection is set so as to make the sprays by the injections of the divided injections approach or gather at a predetermined position downstream from the nozzle hole. The fluid injection valve described in 1.   Obtaining the threshold value of the parameter when the valve body closes without reaching full valve, and setting the injection condition in the injection in which the valve body closes without reaching full valve based on the threshold value; The fluid injection valve according to any one of claims 2 to 4, wherein the fluid injection valve is characterized.   The said threshold value is equivalent when the said several nozzle hole contains two or more said switching nozzle holes with the same nozzle hole specification including a nozzle hole diameter, length, and inclination. Item 6. The fluid injection valve according to any one of Items 5 to 6. The switching injection hole, the fluid injector of claim 1, wherein a perpendicular cross section in the thickness direction of the injection hole body is oval. The switching nozzle hole and the slit nozzle hole are such that the direction of the major axis before the switching spray generated by the switching nozzle causes deformation of the cross-sectional shape is the length of the flat spray generated by the slit nozzle. The fluid injection valve according to any one of claims 1 to 7 , wherein the fluid injection valve is disposed so as to be in the same direction as the direction. Spray shape of the entire spray, penetration, at least one of the characteristics of the injection quantity distribution and spray direction, the switching spray Axis - claim 1, characterized in that defined in the downstream of the predetermined position causing switching phenomenon The fluid injection valve described. The switching nozzle hole and the slit nozzle hole are gathered by the flat spray generated by the slit nozzle hole and the Coanda effect downstream of a predetermined position where the switching spray generated by the switching nozzle causes an axis-switching phenomenon. The fluid injection valve according to claim 8 or 9 , wherein the fluid injection valve is arranged to form a collective spray. The plurality of nozzle holes are arranged so that the Coanda effect that induces proximity to adjacent sprays does not act at least until the switching spray generated by the switching nozzles causes an axis-switching phenomenon. pore size, length, and the injection hole specifications and fluid injector of claim 1, wherein their spacing is characterized in that it is set comprising a slope. 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 claim 11 , 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 12 , fluid supply means for supplying fluid to the fluid injection valve, and control means for controlling the operation of the fluid injection valve. A spray generator characterized by the above.