JP2007132231A - Fuel injection valve and internal combustion engine mounting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a spray which can exert good performance in both uniform combustion and stratified charge combustion, in a fuel injection valve. <P>SOLUTION: The fuel injection valve has a injection hole group 230 of a plurality of injection holes for injecting fuel. Upstream of the injection hole group, a valve seat, a valve element opening/closing a clearance between the valve element and the valve seat to open/close a fuel passage, and a drive means driving the valve element are provided. The injection hole group 230 has a plurality of injection holes 211 to 216 perforated to be different in angles of directions of axes of the holes, and a plurality of injection hole pairs made by combining these injection holes. The plurality of injection hole pairs have a first combination 230a in which an angle between the axes of the injection holes is large, and a second combination 230b in which an angle between the axes of the injection holes is smaller than that of the first combination 230a. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel injection valve and an internal combustion engine equipped with the same.

  A conventional fuel injection valve is disclosed in Japanese Patent Application Laid-Open No. 2004-28078 (Patent Document 1). In the fuel injection valve of Patent Document 1, fuel spray suitable for both stratified combustion and homogeneous combustion can be injected into the cylinder without relying on a variable mechanism that changes the spray shape, and can be supplied to a piston or an intake valve. In order to suppress the collision of the fuel spray, the first nozzle hole part that forms a flat fuel spray in a specific direction and the fuel spray formed by the first nozzle hole part And a second injection hole portion that forms a fuel spray biased to one side of a direction orthogonal to the specific direction.

  Moreover, as a conventional fuel-injection apparatus, there exists a thing shown by Unexamined-Japanese-Patent No. 2004-76723 (patent document 2). In the fuel injection device of this Patent Document 2, the processing is easy, the strength is high, the degree of freedom of concentration distribution or shape change in flat fan spray is high, and a valve is provided on the inner peripheral surface in order to promote atomization of fuel spray. A valve body having a seat; a nozzle plate having a plurality of nozzle holes for injecting fuel; and a fuel from the nozzle holes by being seated on the valve seat; And a valve member that allows fuel injection from the nozzle hole by being separated from the valve seat and having three or more outermost peripheral nozzle holes on the same circle. Is formed.

Japanese Patent Laid-Open No. 2004-28078 JP 2004-76723 A

  In an in-cylinder direct injection internal combustion engine, fuel is injected during the compression stroke to create a rich portion and a thin portion of the fuel in the mixture, and stratified combustion that ignites the lean mixture as a whole, and an intake stroke It is a common practice to switch between and use homogeneous combustion, in which fuel is injected to form an air-fuel mixture with a mixture ratio close to the stoichiometric air-fuel ratio and to ignite it. Here, as for the characteristics of the spray from the fuel injection valve that injects fuel into the cylinder, desirable characteristics differ between stratified combustion and homogeneous combustion.

  In stratified combustion, in order to improve fuel efficiency, a thinner mixture can be ignited stably, that is, combustion stability is required. In order to ensure combustion stability, it is necessary to be able to form a rich air-fuel mixture in the combustible range in the vicinity of the spark plug. In particular, it is important for ensuring the combustion stability that a rich air-fuel mixture stays in the vicinity of the spark plug even after the time for fuel to evaporate has elapsed since the start of injection. Therefore, as a characteristic required for fuel spray in stratified combustion, spray that has a shape concentrated in the direction of the spark plug and stays in the vicinity of the spark plug is desirable.

  On the other hand, in homogeneous combustion, in order to suppress the emission of unburned fuel component (HC), the fuel and air are sufficiently mixed so that the mixture close to the stoichiometric air-fuel ratio is homogeneous at the ignition timing. It is required that it can be formed. Further, when it collides with a valve, a wall surface or a spark plug in the combustion chamber, the fuel in the vicinity of the collided wall surface is discharged without being burned because of the extinguishing range due to the cooling of the wall surface. Therefore, it is desirable to avoid the collision of fuel in the combustion chamber as much as possible. In particular, the collision of the liquid fuel with the spark plug causes the spark plug to become distorted and impairs the ignitability, or causes carbon deposits to reduce the insulation performance of the spark plug. Therefore, you must avoid as much as possible. For this reason, the characteristics required for fuel spray in homogeneous combustion are required to have a spray shape that is sufficiently spatially dispersed to promote mixing of fuel and air and to avoid collision into the combustion chamber. It is done.

  However, Patent Document 1 does not disclose that the fuel is retained in the vicinity of the spark plug in the stratified combustion or that the reach of the fuel spray is controlled. Also, in Patent Document 1, in order to ensure combustion stability in stratified combustion, if the injection angle is set so that the spray from the second spray section approaches the spark plug, the fuel easily collides with the spark plug in homogeneous combustion. The performance of stratified combustion and homogeneous combustion is in a trade-off relationship. For this reason, if the spray shape is set so that a rich air-fuel mixture is formed in the vicinity of the spark plug after a sufficient vaporization time has elapsed since the start of spray injection, which is important in stratified combustion, the spark plug is liable to be blown in homogeneous combustion. Become. Therefore, in patent document 1, it cannot necessarily be said that it is sufficient as a means to make the performance of stratified combustion and homogeneous combustion compatible.

  On the other hand, Patent Document 2 does not disclose a method of forming a spray for achieving both performance in stratified combustion and homogeneous combustion. In particular, in stratified combustion, it is desirable that there is a rich air-fuel mixture in the vicinity of the spark plug, and it is desirable to be able to form a spray whose concentration in the spray is light or dark. However, Patent Document 2 does not necessarily disclose sufficient information regarding the formation of a spray with dark and light, and the arrangement of the injection holes necessary for that purpose.

  In addition, when the shape of the spray is controlled by a fuel injection valve having a plurality of injection holes, there is a problem that it becomes difficult to obtain a desired spray shape due to interference between fuels injected from the injection holes. If the spray holes are arranged close to each other in order to make the spray thicker or denser when the sprays are shaded or dense, the sprays interfere with each other and the droplet diameter increases or the desired spray It becomes difficult to obtain the shape. Further, when spray interference occurs, there is a problem in that it is difficult to ensure combustion stability in stratified combustion because the spray reach distance increases and fuel does not stay in the vicinity of the spark plug.

  The objective of this invention is providing the fuel injection valve which can form the spray which exhibits favorable performance in both homogeneous combustion and stratified combustion, and an internal combustion engine carrying the same.

  A first aspect of the present invention for achieving the above-described object includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and a valve seat, a valve seat, and a valve seat upstream of the injection hole group. In the fuel injection valve comprising a valve body that opens and closes the fuel passage by opening and closing the gap, and a drive means for driving the valve body, the injection hole groups have different angles at which the axis of the hole faces. A plurality of injection hole pairs each formed by a combination of these injection holes, each of the plurality of injection hole pairs having a large angle formed by the axis of the injection hole; And a second combination in which the angle formed by the axis of the injection hole is smaller than the angle of the first combination.

A more preferable specific configuration example in the first aspect of the present invention is as follows.
(1) The distance between the injection holes of the second combination is configured to be larger than the distance between the injection holes of the first combination.
(2) The piercing positions of the injection holes are arranged sparsely as the angle formed by the axes of the adjacent injection holes is smaller.

  The second aspect of the present invention includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and opens and closes a valve seat and a gap between the valve seat and the upstream side of the injection hole group. In the fuel injection valve comprising a valve body that opens and closes the fuel passage and a drive means that drives the valve body, the injection hole group includes a plurality of injection holes drilled so that the angles at which the axis of the holes face are different. And a plurality of injection hole pairs each having a combination of these injection holes, and the plurality of injection hole pairs is a first combination in which the spatial density of the spray spray is sparse. And a second combination in which the sprayed spray has a dense spatial density.

A more preferable specific configuration example in the second aspect of the present invention is as follows.
(1) The second combination is configured such that when sprayed under atmospheric pressure, the spray is separated, and when sprayed under pressure, the spray is integrated.

  The third aspect of the present invention includes a cylinder, a piston that reciprocates in the cylinder, an intake valve that introduces air into the cylinder, an exhaust valve that exhausts combustion gas from the cylinder, A fuel injection valve for directly injecting fuel into the cylinder; fuel supply means for supplying fuel from the fuel tank to the fuel injection valve; air introduced into the cylinder by the intake valve; and the cylinder by the fuel injection valve An ignition plug that ignites an air-fuel mixture injected into the fuel, and the fuel injection valve includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and upstream of the injection hole group, In an internal combustion engine comprising a valve seat, a valve body that opens and closes a fuel passage by opening and closing a gap between the valve seat, and a drive unit that drives the valve body, the injection hole group of the fuel injection valve includes: , Hole It has a plurality of injection holes perforated so that the angle to which the axis faces differs, and has a plurality of injection hole pairs constituted by a combination of these injection holes, and the plurality of injection hole pairs injected It has the 1st combination from which the spatial density of spray is sparse, and the 2nd combination from which the spatial density of the sprayed spray becomes dense.

A more preferable specific configuration example in the third aspect of the present invention is as follows.
(1) An intake two-valve in-cylinder injection internal combustion engine is used and mounted on the intake valve side, and the injection hole group is provided on the intake valve side. Fuel injection by the second combination is directed in the direction of the spark plug. The fuel injection by the first combination is for injecting fuel to the piston side than the fuel injection by the second combination.

The fourth aspect of the present invention includes a cylinder, a piston that reciprocates in the cylinder, an intake valve that introduces air into the cylinder, an exhaust valve that exhausts combustion gas from the cylinder, A fuel injection valve for directly injecting fuel into the cylinder; fuel supply means for supplying fuel from the fuel tank to the fuel injection valve; air introduced into the cylinder by the intake valve; and the cylinder by the fuel injection valve A spark plug for igniting an air-fuel mixture with fuel injected into the interior;
The fuel injection valve includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and the fuel passage is opened and closed by opening and closing a valve seat and a gap between the valve seat and the upstream side of the injection hole group. In an internal combustion engine comprising a valve body that performs the above and a drive means that drives the valve body,
The injection hole group of the fuel injection valve has a plurality of injection holes perforated so that the angle at which the axis of the hole faces is different, and has a plurality of injection hole pairs configured by a combination of these injection holes. ,
The pair of the plurality of injection holes has a first combination in which the spatial density of the spray spray is sparse and a second combination in which the spatial density of the spray spray is dense.

A more preferable specific configuration example in the fourth aspect of the present invention is as follows.
(1) An intake two-valve in-cylinder injection internal combustion engine is used and mounted on the intake valve side, and the injection hole group is provided on the intake valve side. Fuel injection by the second combination is directed in the direction of the spark plug. The fuel injection by the first combination is for injecting fuel to the piston side than the fuel injection by the second combination.

  ADVANTAGE OF THE INVENTION According to this invention, the fuel injection valve which can form the spray which exhibits favorable performance by both homogeneous combustion and stratified combustion, and an internal combustion engine carrying it can be implement | achieved.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. The same reference numerals in the drawings of the respective embodiments indicate the same or equivalent.
(First embodiment)
A fuel injection valve and an internal combustion engine according to a first embodiment of the present invention will be described with reference to FIGS.

  First, the entire fuel injection valve 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view of a fuel injection valve 1 according to a first embodiment of the present invention.

  The fuel injection valve 1 is a normally closed electromagnetic valve, and at the normal time, the tip of the valve body 110 urged by a spring and the valve seat portion 104 of the valve seat plate 102 are in close contact with each other, and the fuel supply port 115. The supplied fuel is prevented from leaking. When a current is supplied from the connector 114 to the coil 112, a magnetic field is generated in the core 113, a magnetic attractive force is generated between the core 113 and the anchor 108, and the valve body 110 is displaced together with the anchor 108 toward the core 113. At this time, a gap is formed between the valve body 110 and the valve seat portion 104 of the valve seat plate 102, and a plurality of injection holes 211 to 216 drilled in the nozzle plate 116 constituting the injection hole member (FIGS. 2A and 2B). The fuel is injected from (see).

  Next, the fuel injection unit will be described with reference to FIGS. 2A and 2B. 2A is an enlarged sectional view of the vicinity of the valve seat plate 102 and the nozzle plate 116 of FIG. 1, and FIG. 2B is a front view of the nozzle plate 116 of FIG. 2A. Reference numeral 210 in FIG. 2A indicates the axis of the fuel injection valve 1. Angles 216 to 222 in FIG. 2B illustrate angles obtained by projecting solid angles formed by the axes of the injection holes on the front view. The solid angle is an angle formed by the axis of the injection hole, and means an angle in a three-dimensional space.

  The fuel passes through a gap provided between the valve element guide 103 and the nozzle member 105 and the inflow groove 217 and reaches the valve seat 104 of the valve seat plate 102. The fuel that has passed through the valve seat portion 104 passes through the fuel passage 201 of the valve seat plate 102, further passes through the enlarged passage 202 of the valve seat plate 102, and reaches a plurality of injection holes 211 to 216 drilled in the nozzle plate 116. Injected into the atmosphere.

  The plurality of injection holes 211 to 216 constitute the injection hole group 230, and the injection hole group 230 includes a first injection hole group 230 a composed of the plurality of injection holes 211 to 213 and a plurality of injection holes 214. The second injection hole group 230b consisting of ˜216. In addition, each of the injection holes 211 to 216 constituting the injection hole group 230 is perforated so that the angle at which the axis of the hole faces is different.

  Here, the injection holes 214 to 216 constituting the first injection hole group have solid angles formed by the axis of the injection holes in the combination of the respective injection holes, and the injection holes in the combination of the injection holes of the injection holes 211 to 213 are the same. It is provided so as to be smaller than the solid angle formed by the axis. In other words, the injection hole group 230 has a plurality of injection hole pairs configured by a combination of a plurality of injection holes 211 to 216 drilled so that the angles at which the axes of the holes face are different. The pair of holes includes a first combination (first injection hole group) 230a having a large angle formed by the axis of the injection hole and a second combination (angle formed by the axis of the injection hole being smaller than the angle of the first combination). 2nd injection hole group) 230b.

  More specifically, referring to FIG. 2B, the angle 217 formed by the injection holes 214 and 215, the angle 218 formed by the injection holes 214 and 216, and the angle 219 formed by the injection holes 215 and 216 are determined by the injection holes 211 and 212. The combination is smaller than the angle 220 formed, the angle 221 formed by the injection holes 211 and 213, and the angle 222 formed by the injection holes 212 and 213. The solid angle formed by each of the injection holes 214 to 216 and the injection hole 211 is provided such that the inclination angle in the left-right direction on the paper surface is different and the solid angle is large.

  Thus, by drilling the injection holes 211 to 216 so as to have the second combination with a small solid angle made by the axis of the injection hole and the first combination with a large solid angle made by the axis of the injection hole, Density can be formed in the formed spray. For example, in the second combination of the injection holes 214 to 216, the solid angle formed by the axis of the injection holes is small, so that the injected fuel forms a spatially dense spray. Further, since the solid angle formed by the axis of the injection hole is large in the combination of d1 of the injection holes 211 to 213, the injected fuel forms a spatially sparse spray.

  Next, the state of the spray injected from the fuel injection valve 1 will be described with reference to FIGS. 3A, 3B, and 4. FIG.

  3A and 3B are views showing the state of spray formed when the fuel injection valve 1 shown in FIGS. 1 and 2 is used to inject an atmosphere of atmospheric pressure. 3A is a schematic front view showing a state in which fuel is injected from the fuel injection valve 1, and FIG. 3B is a schematic cross-sectional view taken along line AA in FIG. 3A. In FIG. 3A, the tip of the fuel injection valve 1 is depicted as a nozzle 307.

  When the AA cross section at a position sufficiently separated from the injection hole of the nozzle 307 (for example, 15 mm or more) is observed, the inter-spray distance (for example, the inter-spray distance 308 shown in the figure) in the spray injected from each injection hole as shown in FIG. 3A. ˜310) are approximately approximate to the size of the solid angle formed by the injection holes as shown in FIG. 3B. Therefore, the spatially dense sprays 301 to 303 having small distances 308 and 311 between the sprays in FIG. 3B are ejected from the injection holes 214 to 216 having small solid angles, and the distance 309 between the sprays. The spatially sparse sprays 304 to 306 having a large mist are ejected from the ejection holes 211 to 213 having a large solid angle. In addition, the distance 310 between the sprays of the dense part and the sparse part of the spray is set to be larger than the distances 308 and 311 between the sprays that the dense spray makes.

  FIG. 4 is a view showing a state of spray formed when injected into a pressurized atmosphere by the fuel injection valve 1 shown in FIGS. 1 and 2, and corresponds to FIG. 3B. In the spray having spatial density as shown in FIG. 3, the spray shape when the fuel is injected into the pressurized atmosphere is as shown in FIG. In a pressurized atmosphere, the spray itself is easily affected by the air flow induced by the spray. Each spray creates a flow that draws air from the surroundings during injection. For this reason, when spray is spatially densely injected, an air flow toward the center of the dense spray is generated. Due to this effect, when sprayed in a pressurized atmosphere, the spray sprayed densely in space (sprays 301 to 303 in FIG. 3) can form an integral lump spray 401 while diffusing. On the other hand, the fuel (sprays 304 to 306 in FIG. 3) injected spatically and spatially diffuses due to its own air flow, but hardly forms a spray lump and is dispersed like sprays 402 to 404.

  The cross-sectional shape of the spray as shown in FIGS. 3B and 4 can be observed by irradiating the spray with sheet-like light and taking a photograph. Whether the spray is separated or agglomerated can be determined from a photograph within about 1 ms from the moment when the spray reaches the sheet-like light. When the spray is separated, the spray is still separated even after about 1 ms from the moment when the spray reaches the sheet-like light. When the spray is agglomerated, it is observed that the spray is separated at the moment when it reaches the sheet-like light, but it can be observed that it becomes agglomerated in about 1 ms from the arrival.

  Next, an example in which the fuel injection valve 1 is applied to the direct injection internal combustion engine 60 will be described with reference to FIGS. 5A and 5B. FIG. 5A is a schematic perspective view when the fuel injection valve 1 of FIG. 1 is mounted on an in-cylinder in-cylinder internal combustion engine 60 and fuel is injected during the intake stroke, and FIG. 5B is an in-cylinder injection of FIG. 5A. 2 is a schematic cross-sectional view of an internal combustion engine 60. FIG.

  The spraying by the fuel injection valve 1 described above is effective when an injection point 501 constituted by a group of injection holes is provided on the intake valve side of the direct injection internal combustion engine 60 as shown in FIG. 5A.

  In the direct injection internal combustion engine 60, it is important that fuel and air are well mixed when operating in the homogeneous combustion mode. For this purpose, it is desirable that the fuel be injected in a spatially dispersed manner in the combustion chamber. Further, under the condition where the output of the internal combustion engine 60 is large, the flow of air flowing in from the intake port is strongly generated toward the piston 69 (see FIG. 5B), so that the fuel proceeds against this and mixes with the air. It is required to be able to promote Furthermore, since the homogeneous combustion mode is often used under high power conditions, the amount of fuel injection also increases. For this reason, it is necessary to prevent the spark plug 504 from being beaten by preventing the fuel from directly colliding with the spark plug 504. At the same time, if the fuel spray collides with the intake valves 502 and 503 to prevent the fuel from adhering, the mixture of the fuel and the air-fuel mixture is promoted or the adhering fuel is discharged as unburned residue. Can be suppressed.

  In homogeneous combustion, exhaust and unburned fuel components can be suppressed even during EGR (exhaust gas recirculation) by thoroughly mixing air and fuel to suppress the discharge of unburned fuel components. Therefore, combustion is possible while using many EGR gases. In addition, good mixing of fuel and air promotes vaporization of the fuel, lowers the intake air temperature by latent heat of vaporization, reduces the volume of the air, and allows intake of a larger amount of air. It becomes easy to increase.

  The configuration of the internal combustion engine 60 will be specifically described with reference to FIG. 5B. In the internal combustion engine 60, a piston 69 provided in a reciprocating manner in the cylinder 68 moves up and down in the cylinder 68 according to the rotation of a crankshaft (not shown). A cylinder head 63 is attached to the upper portion of the cylinder 68 and forms a sealed space together with the cylinder 68. The cylinder head 63 is formed with an intake manifold 62 that guides external air into the cylinder via an intake air amount control device 61 with a built-in throttle valve, and an exhaust manifold that guides combustion gas burned in the cylinder 68 to the exhaust device. Has been. An intake valve 502 is provided on the intake manifold 62 side of the cylinder head 63, an ignition plug 504 is provided at the center, and an exhaust valve 507 is provided on the opposite side of the intake valve 502. The intake valve 502 and the exhaust valve 507 are provided so as to extend into the combustion chamber 67. Here, the fuel injection valve 1 is attached in the vicinity of the joint of the intake manifold 62 of the cylinder head 63 so that the axis J of the fuel injection valve 1 is slightly downward in the combustion chamber 67 (ignition plug 504). Is set in the opposite direction). Reference numeral 69 denotes a piston. The white arrows in FIG. 5B indicate the flow of intake air, and the hatched arrows indicate the flow of exhaust gas.

  According to the fuel injection valve 1 according to the present embodiment, the dispersibility of the spray can be ensured by directing the spatially sparse portion 506 toward the piston. By dispersing the spray, mixing of air and fuel can be promoted even when the internal combustion engine 60 is operated in the homogeneous combustion mode. Further, the fuel injected toward the spark plug 504 is likely to travel while being mixed with air even under high output conditions because the injection direction is the direction against the intake air flow. In addition, since the spatially dense spray 505 separates and flies during the intake stroke, it can be prevented from hitting the spark plug 504 directly. Due to such effects, mixing of fuel and air can be promoted in the homogeneous combustion mode, and the reduction of unburned fuel components or the improvement of fuel consumption by increasing the amount of EGR (exhaust gas recirculation) gas, the output It becomes possible to improve.

  Furthermore, according to the fuel injection valve 1 according to the present embodiment, not only the homogeneous combustion mode but also the performance in the stratified combustion mode can be improved. In the stratified combustion, the fuel is thinner than the air in the entire combustion chamber. Therefore, the fuel needs to be concentrated in the vicinity of the spark plug 504 in order to ensure ignitability. Furthermore, when performing stratified combustion, in order to inject fuel during the compression stroke, it is necessary to inject fuel into an atmosphere having a high pressure in the combustion chamber. For this reason, in order to form a rich air-fuel mixture in the vicinity of the spark plug 504, it is necessary to use a spray that penetrates the fuel enough to reach the spark plug 504. In the stratified combustion mode, the ability to create a rich combustible air-fuel mixture around the spark plug has the effect of improving combustion stability. By improving the combustion stability, the combustion chamber as a whole can be ignited with a leaner air-fuel mixture, or stratified combustion can be performed over a wider range of operating conditions. This can contribute to lower fuel consumption.

  According to the fuel injection valve according to the present embodiment, a dense air-fuel mixture can be formed in the vicinity of the spark plug 504 by directing the spatially dense portion 505 toward the spark plug. . In particular, under a condition where the pressure in the combustion chamber is high, the spatially dense spray 505 toward the vicinity of the spark plug becomes a lump and travels toward the spark plug 504 as shown in FIG. It can compensate for the decrease in the penetration force of the spray. Due to this effect, higher combustion stability can be obtained in the stratified combustion mode, which can contribute to lower fuel consumption of the internal combustion engine 60. The spatially dense spray toward the vicinity of the spark plug is formed by spray sprayed from a plurality of injection holes. However, in order to form an air-fuel mixture having an appropriate concentration, 2 to 4 spray holes are used. The spray formed should be dense.

  Next, interference between the injected fuels will be described with reference to FIG. FIG. 6 is a perspective view schematically showing a state in which fuel is injected from each injection hole of the fuel injection valve 1 of FIG.

  As described above, according to the fuel injection valve 1 according to the present embodiment, it is possible to obtain a spray having good characteristics in both the homogeneous combustion and the stratified combustion modes. In the fuel injection valve 1 capable of forming such a spray, in order to form a spatially dense spray, it is necessary to form a set of injection holes having a small solid angle, and there is a problem of interference between injected fuels. It is easy to become.

  As shown in FIG. 6, the fuel injected from each of the injection holes 211 to 216 spreads in a substantially conical shape, and flies around the direction corresponding to the drilling angle of each of the injection holes 211 to 216. For this reason, when forming a spatially dense spray, since the solid angle formed by the axes of the injection holes 211 to 216 is small, the sprays injected from the respective injection holes may interfere with each other. . In particular, when spray interference occurs at a relatively short distance of several millimeters from the injection holes 211 to 216, extremely dense concentrations of sprays interfere with each other, and the sprays injected from the plurality of injection holes are integrated and extremely Therefore, it becomes difficult to obtain a desired fuel distribution. Depending on the case, it may be a single spray that forms a spray that has a very strong penetration force but is difficult to diffuse in the direction of travel. Or spray that is undesirable for combustion. For example, in FIG. 6, the sprays injected from the injection holes 214, 215, and 216 have a solid angle relationship in which the sprays easily interfere because the solid angles formed by the respective spray axes are small.

  For this reason, from the viewpoint of preventing spray interference, it is desirable to increase the distance between the respective injection holes. However, if the range in the nozzle plate 116 in which the injection holes are arranged is increased, the enlarged passage 202 must be enlarged. Generally, since the fuel injection valve 1 used for the direct injection internal combustion engine 60 is exposed to a high temperature, if the volume of the downstream portion becomes too large from the valve seat 104, the volatile fuel out of the fuel accumulated in the expansion passage 202 or the like. Only the high components evaporate, and the low-volatility gum remains in the fuel passage, reducing the substantial flow passage cross-sectional area, which may cause clogging of the fuel injection valve 1 and a decrease in the flow rate. Therefore, it is desirable that the injection holes 211 to 216 can be arranged in the smallest possible range.

Therefore, in the present embodiment, the injection holes 214 to 216 having a small solid angle formed by the injection holes are arranged so that the distance between the outlets of the injection holes becomes large. On the other hand, the injection holes 211 to 213 having a large solid angle formed by the injection holes are arranged so as to have a smaller distance between the injection holes than the distance between the injection holes 214 to 216. By arranging in this way, it is possible to arrange the injection holes with small solid angles that are likely to cause spray interference, and to prevent spray interference even when the injection holes are arranged in a relatively small range.
(Second to sixth embodiments)
Hereinafter, second to sixth embodiments of the present invention will be described with reference to FIGS. The second to sixth embodiments differ from the first embodiment in the following points, and are basically the same as the first embodiment in other points.
(Second Embodiment)
The spray having the shape as described in the first embodiment can also be obtained by arranging the injection holes 701 to 706 as shown in FIG. FIG. 7 is a front view of the nozzle plate 116 in the fuel injection valve 1 according to the second embodiment of the present invention.

The second embodiment is an example in which the injection holes are arranged such that the interval between the injection holes having a small solid angle is the widest, and the other injection holes are sufficiently spaced from each other. In FIG. 7, the injection holes that form the spray with a small solid angle are a set of the injection holes 701 and 702. The distance 708 between the injection holes of the injection holes 701 and 702 is provided to be the largest as compared with the combination with the other injection holes. A line segment connecting the centers of the injection holes 701 and 702 passes through the center of the circle 707 within the range of the circle 707 on the upstream side of the injection hole. According to such an arrangement, even when the injection holes are arranged in a narrower range, the distance between the injection holes can be made sufficiently easy even if a set of injection holes having a small solid angle is provided. In addition, the spray injected from the injection holes 701 to 706 of the second embodiment has the same spray shape as that of the first embodiment.
(Third embodiment)
The effect of the present invention can be exhibited even when spraying is formed as shown in FIG. FIG. 8A is a schematic view showing a cross section of the spray under atmospheric pressure in the fuel injection valve 1 of the third embodiment of the present invention, and FIG. 8B is a cross section of the spray under pressure in the fuel injection valve 1 of the same embodiment. It is a schematic diagram which shows.

  In the spray shown in FIG. 8A, the solid angle between the spray 802 and the spray 803 (corresponding to the distance 807 in FIG. 8) is small, and the distance 801 between the spray 801 and the spray 802 and the distance 809 between the sprays 805 and 806 are large. This shows the case.

In such a spray shape, since the spray 802 and the spray 803 injected with a small solid angle are close to each other, the spray 802 and the spray 803 form a lump spray 810 as shown in FIG. 8B under pressure. It becomes like this.
(Fourth embodiment)
The effect of the present invention can be exhibited even when spraying as shown in FIG. 9 is formed. FIG. 9A is a schematic view showing a cross section of the spray shape under atmospheric pressure in the fuel injection valve 1 of the fourth embodiment of the present invention, and FIG. 9B shows the spray shape under pressure in the fuel injection valve 1 of the same embodiment. FIG. 9C is a front view of the nozzle plate 116 in the fuel injection valve 1 according to the embodiment. FIG. 9 is a diagram showing a case where a spray shape is formed such that the sprays 901 and 902 have close solid angles.

  The direction of the injection hole is adjusted so that the distance 903 corresponding to the solid angle between the sprays 901 and 902 is smaller than the distance between other sprays (for example, the distances 904, 905, and 906). For this reason, under pressure, the adjacent sprays 901 and 902 have a shape like a massive spray 907. On the other hand, sprays other than the sprays 901 and 902 can be dispersed, and the same effects as in the first embodiment can be exhibited.

The arrangement of the injection holes for forming such spray is preferably as shown in FIG. 9C. That is, in FIG. 9C, the injection holes that form the sprays 901 and 902 with a small solid angle are the injection holes 911 and 912, and the distance 915 between the injection holes is the distance 916 between the injection holes 913 and 914 with a large solid angle. It is arrange | positioned so that it may become large compared with. With such an arrangement, even when the spray shape as shown in FIGS. 9A and 9B is obtained, it is possible to arrange the injection holes in a limited range while suppressing the interference of the spray.
(Fifth embodiment)
The effects of the present invention can be obtained regardless of the number of injection holes, as will be described below with reference to FIGS. 10A to 10C. FIG. 10A is a schematic view showing a cross section of a spray shape under atmospheric pressure when the fuel injection valve 1 according to the fifth embodiment of the present invention is realized by four injection holes, and FIG. 10B is a fuel injection of the same embodiment. FIG. 10C is a front view of the nozzle plate 116 in the fuel injection valve 1 of the same embodiment. FIG. 10C is a schematic view showing a cross section of the spray shape under pressure in the valve 1.

  In the fifth embodiment in which the number of injection holes is four, the solid angle formed by the injection holes 1012 and 1011 is small. As a result, the distance 1003 between the sprays 1001 and 1002 is reduced to form a dense spray. It has become. On the other hand, the solid angle formed by the injection holes 1013 and 1014 is large, and the distance 1005 between the sprays 1006 and 1007 injected from these injection holes is larger than the distance 1003 between the sprays. A sparse spray is formed. Further, the distance 1004 between the spatially dense spray and the sparse spray is set larger than the distance 1003 between the sprays forming the dense spray.

As a result, the formed spray exhibits a separate spray shape as shown in FIG. 10A under atmospheric pressure, but the spatially dense spray as shown in FIG. It becomes an integral spray. When such a spray is also used in a direct injection internal combustion engine, a spray suitable for both homogeneous combustion and stratified combustion can be formed. The distance 1009 between the injection holes 1012 and 1011 is larger than the distance 1010 between the injection holes 1013 and 1014.
(Sixth embodiment)
FIG. 11A is a schematic view showing a cross section of a spray shape under atmospheric pressure when the fuel injection valve 1 according to the sixth embodiment of the present invention is realized by eight injection holes, and FIG. 11B is a fuel injection of the same embodiment. FIG. 11C is a front view of the nozzle plate 116 in the fuel injection valve 1 of the same embodiment. FIG. 11C is a schematic diagram showing a cross section of the spray shape under pressure in the valve 1.

  In FIG. 11A, the three sprays 1101 to 1103 are spatially dense. The solid angle formed by these sprays is small, for example, as shown by the distance 1107 between sprays. On the other hand, the solid angle formed by the sparse spray is injected so as to be larger than the inter-spray distance 1107 as indicated by the inter-spray distances 1109 and 1108, for example. Further, the distance 1110 between the dense part and the sparse part of the spray is larger than the distance 1107 formed by the dense spray.

  Even in such a spray, the sprays 1101 to 1103 sprayed densely in a space form a lump spray like the spray 1120 under pressure shown in FIG. 11B, and the spray sprayed loosely is dispersed.

  In order to form the spray as shown in FIG. 11A, it is preferable to arrange the injection holes as shown in FIG. 11C. In FIG. 11C, the injection hole 1111 forms the spray 1101, the injection hole 1112 forms the spray 1102, and the injection hole 1113 forms the spray 1103, and the solid angle formed by these injection holes is small, thus forming a dense spray. Further, sprays other than these form sparse sprays, but the injection hole 1114 corresponds to the spray 1104, the injection hole 1115 corresponds to the spray 1105, and the injection hole 1116 corresponds to the spray 1106.

  Since the solid angle formed by the injection holes 1111 to 1113 forming the dense spray is small, these injection holes are preferably arranged apart from each other in order to suppress interference between the sprays. For example, the distance 1119 between the injection holes 1115 and 1116 forming the sparse spray is arranged to be larger than the distance 1117 between the injection holes 1113 and 1112 forming the dense injection holes and the distance 1118 between the injection holes 1112 and 1111. Has been. Since the spray holes that form the spatially sparse spray are each provided with a large solid angle, it is difficult for the spray interference to be placed, and therefore there is no problem even if they are arranged relatively close to each other.

  By arranging in this way, even when the number of injection holes is increased, it is possible to form a spatially dense spray, and the spray can have different shapes under atmospheric pressure and under pressure. In addition, the injection holes can be arranged in a relatively small range while suppressing spray interference.

  According to the embodiment of the present invention, the injection hole group of the fuel injection valve has a plurality of injection holes perforated so that the angles at which the axes of the holes face are different, and is configured by a combination of these injection holes. A plurality of injection hole pairs, the first combination having a large angle formed by the axis of the injection hole and the angle formed by the axis of the injection hole being smaller than the angle of the first combination. And a combination of two. Due to the pair of injection holes formed at such an angle (a group of injection holes), the spray from a pair of injection holes with a small angle formed by the axis of the injection hole forms a densely distributed portion of the fuel and has a large angle. The spray from the pair of injection holes can form a portion where the fuel distribution is sparse.

  Further, at least one of the pair of injection holes having a distance between the injection holes that is shorter than the distance between the drilling positions of the pair of injection holes having a small angle formed by the axis of the adjacent injection holes, the axis of the injection hole is It arranges so that the angle to make becomes large. This means that the injection holes forming the dense portion of the fuel are arranged sparsely and the injection holes forming the sparse portion of the fuel are arranged densely. By arranging the injection holes that form a dense portion of the fuel at farther positions (separately), the dense portion of the fuel can be formed while suppressing interference between sprays. On the other hand, since the injection hole forming the sparse portion of the fuel has a large angle formed by its axis, it is possible to suppress spray interference even when the distance between the injection holes is closely arranged.

  The dense spray formed as described above can be a spray having different characteristics depending on the atmospheric pressure to be injected. In a portion where the fuel in the spray is dense, when the atmospheric pressure is high, the fuel is more concentrated due to the flow of the atmosphere formed by the spray, and the fuel tends to stay for a relatively long time. On the other hand, when the atmospheric pressure is low, since the density of the atmosphere is low, the spray is hardly affected by the flow, and is dispersed as compared with the case where the atmospheric pressure is high.

  By this effect, if the center of the dense portion of the fuel is directed toward the spark plug, the fuel is more concentrated during the stratified combustion in which the injection is performed in the compression stroke having a high atmospheric pressure, and the fuel is retained in the vicinity of the spark plug. Therefore, combustion stability can be improved. On the other hand, when the fuel is injected in the intake stroke having a low atmospheric pressure, the fuel is more easily dispersed and more uniform than in the compression stroke injection. In addition, during homogeneous combustion, the direction of the injection holes that form a dense part of the fuel is set so that the injection holes face slightly away from the direction of the spark plug. Direct fuel collision can be avoided. Even when the fuel injection valve is installed in this way, fuel injected from the plurality of injection holes at the time of stratified combustion can be concentrated in the vicinity of the spark plug by the atmospheric flow, so in each of the homogeneous combustion and the stratified combustion, A desired spray shape can be obtained.

It is sectional drawing of the fuel injection valve which concerns on 1st Embodiment of this invention. It is sectional drawing to which the vicinity of the valve-seat plate and nozzle plate of FIG. 1 was expanded. It is a front view of the nozzle plate of FIG. 2A. It is a front schematic diagram of the state injected from the fuel injection valve of FIG. It is an AA cross section schematic diagram of Drawing 3A. It is the figure which showed the mode of the spray formed when it injects in a pressurized atmosphere with the fuel injection valve of FIG. FIG. 2 is a schematic perspective view when the fuel injection valve of FIG. 1 is mounted on an intake two-valve in-cylinder internal combustion engine and fuel is injected during an intake stroke. It is sectional drawing which shows the principal part of the internal combustion engine of FIG. 5A. It is the perspective view which showed typically a mode that fuel was injected from each injection hole of the fuel injection valve of FIG. It is a front view of the nozzle plate in the fuel injection valve concerning a 2nd embodiment of the present invention. It is a schematic diagram which shows the cross section of the spray under atmospheric pressure in the fuel injection valve of 3rd Embodiment of this invention. It is a schematic diagram which shows the cross section of the spray under pressure in the fuel injection valve of the same 3rd embodiment. It is a schematic diagram which shows the cross section of the spray shape in the atmospheric pressure in the fuel injection valve of 4th Embodiment of this invention. It is a schematic diagram which shows the cross section of the spray shape under pressure in the fuel injection valve of the 4th embodiment. It is a front view of the nozzle plate in the fuel injection valve of the fourth embodiment. It is a schematic diagram which shows the cross section of the spray shape under atmospheric pressure in the case of implement | achieving the fuel injection valve which concerns on 5th Embodiment of this invention with four injection holes. It is a schematic diagram which shows the cross section of the spray shape under pressure in the fuel injection valve of the said 5th Embodiment. It is a front view of the nozzle plate in the fuel injection valve of the fifth embodiment. It is a schematic diagram which shows the cross section of the spray shape under atmospheric pressure in the case of implement | achieving the fuel injection valve which concerns on 6th Embodiment of this invention with eight injection holes. It is a schematic diagram which shows the cross section of the spray shape under pressure in the fuel injection valve of the said 6th Embodiment. It is a front view of the nozzle plate in the fuel injection valve of the sixth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve, 101 ... Injection hole member, 102 ... Valve seat plate, 103 ... Valve body guide, 104 ... Seat part, 105 ... Nozzle member, 106 ... Valve body guide, 107 ... Yoke, 108 ... Anchor, 109 ... Joint 110, valve body 111 111 nozzle holder 113 core 114 connector 115 fuel supply port 116 nozzle plate 201 fuel passage 202 expansion passage 210 valve body axis 211-216 ... injection holes, 230 ... injection hole groups, 230a ... first injection hole group (first combination of injection hole pairs), 230b ... second injection hole group (second combination of injection hole pairs), 301-306 ... spray, 307 ... nozzle, 308-311 ... distance between sprays corresponding to solid angle, 401 ... bulk spray, 402-404 ... spray, 501 ... injection point, 502,503 Intake valve, 504 ... spark plug, 701-706 ... injection hole, 708 ... distance between injection holes, 801-806 ... spray, 807-809 ... distance between sprays corresponding to solid angle, 810 ... lump spray, 901 902 ... spray, 903-906 ... distance between sprays corresponding to solid angle, 907 ... bulky spray, 911-914 ... injection holes, 915,916 ... distance between injection holes, 1001, 1002, 1006, 1007 ... Spray, 1003 to 1005 ... Distance between sprays corresponding to solid angle, 1008 ... Bulk spray, 1009 and 1010 ... Distance between spray holes, 1011 to 1014 ... Spray holes, 1101 to 1106 ... Spray, 1107 to 1110 ... Solid Distance between sprays corresponding to corners, 1111 to 1116... Sprays, 1117 to 1119.

Claims (9)

Including an injection hole group formed with a plurality of injection holes for injecting fuel,
In a fuel injection valve provided upstream of the injection hole group, a valve seat, a valve body that opens and closes a fuel passage by opening and closing a gap between the valve seat, and a driving means that drives the valve body,
The injection hole group has a plurality of injection holes perforated so that the angle at which the axis of the hole faces is different, and a plurality of injection hole pairs configured by a combination of these injection holes,
The pair of the plurality of injection holes includes a first combination in which an angle formed by the axis of the injection hole is large, and a second combination in which an angle formed by the axis of the injection hole is smaller than the angle of the first combination. A fuel injection valve.   2. The fuel injection valve according to claim 1, wherein a distance between the injection holes of the second combination is greater than a distance between the injection holes of the first combination. 3. .   3. The fuel injection valve according to claim 1, wherein the perforation positions of the injection holes are arranged sparsely in a combination with a smaller angle formed by the axes of the adjacent injection holes. 4. Including an injection hole group formed with a plurality of injection holes for injecting fuel,
In a fuel injection valve provided upstream of the injection hole group, a valve seat, a valve body that opens and closes a fuel passage by opening and closing a gap between the valve seat, and a driving means that drives the valve body,
The injection hole group has a plurality of injection holes perforated so that the angle at which the axis of the hole faces is different, and a plurality of injection hole pairs configured by a combination of these injection holes,
The pair of the plurality of injection holes includes a first combination in which a spatial density of the spray spray is sparse and a second combination in which a spatial density of the spray spray is dense. Fuel injection valve.   5. The fuel injection valve according to claim 4, wherein the second combination is configured such that when sprayed under atmospheric pressure, the spray is separated, and when sprayed under pressure, the second combination is integrated. A fuel injection valve characterized by. A cylinder, a piston that reciprocates in the cylinder, an intake valve that introduces air into the cylinder, an exhaust valve that exhausts combustion gas from the cylinder, and a fuel injection that directly injects fuel into the cylinder A fuel supply means for supplying fuel from a fuel tank to the fuel injection valve, an air-fuel mixture of air introduced into the cylinder by the intake valve and fuel injected into the cylinder by the fuel injection valve A spark plug for igniting,
The fuel injection valve includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and the fuel passage is opened and closed by opening and closing a valve seat and a gap between the valve seat and the upstream side of the injection hole group. In an internal combustion engine comprising a valve body that performs the above and a drive means that drives the valve body,
The injection hole group of the fuel injection valve has a plurality of injection holes perforated so that the angle at which the axis of the hole faces is different, and has a plurality of injection hole pairs configured by a combination of these injection holes. ,
The pair of the plurality of injection holes includes a first combination in which an angle formed by the axis of the injection hole is large, and a second combination in which an angle formed by the axis of the injection hole is smaller than the angle of the first combination. A characteristic internal combustion engine.   7. The internal combustion engine according to claim 6, wherein an injecting two-valve in-cylinder injection internal combustion engine is used, mounted on the intake valve side, the injection hole group is provided on the intake valve side, and fuel injection by the second combination is performed. An internal combustion engine characterized by being directed toward the spark plug, wherein fuel injection by the first combination injects fuel to the piston side rather than fuel injection by the second combination. . A cylinder, a piston that reciprocates in the cylinder, an intake valve that introduces air into the cylinder, an exhaust valve that exhausts combustion gas from the cylinder, and a fuel injection that directly injects fuel into the cylinder A fuel supply means for supplying fuel from a fuel tank to the fuel injection valve, an air-fuel mixture of air introduced into the cylinder by the intake valve and fuel injected into the cylinder by the fuel injection valve A spark plug for igniting,
The fuel injection valve includes an injection hole group in which a plurality of injection holes for injecting fuel are formed, and the fuel passage is opened and closed by opening and closing a valve seat and a gap between the valve seat and the upstream side of the injection hole group. In an internal combustion engine comprising a valve body that performs the above and a drive means that drives the valve body,
The injection hole group of the fuel injection valve has a plurality of injection holes perforated so that the angle at which the axis of the hole faces is different, and has a plurality of injection hole pairs configured by a combination of these injection holes. ,
The pair of the plurality of injection holes includes a first combination in which a spatial density of the spray spray is sparse and a second combination in which a spatial density of the spray spray is dense. An internal combustion engine.   9. The internal combustion engine according to claim 8, wherein an injecting two-valve in-cylinder injection internal combustion engine is used, and the injection hole group is provided on the intake valve side so that fuel is injected by the second combination. An internal combustion engine characterized by being directed toward the spark plug, wherein fuel injection by the first combination injects fuel to the piston side rather than fuel injection by the second combination. .

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