JP2014001660A - Fuel injection valve of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape of a diffusion region of an injection hole that secures the minimum thickness of a valve seat plate while securing a short guide region to avoid interference with fuel spray as much as possible, and to provide an arrangement method of the injection hole.SOLUTION: A fuel injection valve has a plurality of injection holes (112) spraying fuel into a combustion chamber of a gasoline engine, and each of the injection holes includes a guide region (114) for allowing the fuel to pass through to determine an amount and an injection direction of the sprayed fuel and a diffusion region (116) for changing the fuel passing through the guide region to fuel spray. At least one of the plurality of injection holes is configured such that a central axis (118b) of the diffusion region is parallel to a central axis (118a) of the guide region, and is eccentrically-formed on a far side from a central axis (120) of the fuel injection valve further than the central axis of the guide region.

Description

  The present invention relates to a fuel injection valve for an internal combustion engine.

  A fuel injection valve for a general gasoline engine has a plurality of injection holes. The distance (penetration) that the spray injected into the combustion chamber reaches within a predetermined period depends on the momentum of the spray from each nozzle hole, and the momentum of the spray injected from the nozzle hole of the same diameter is the same Therefore, the penetration of each spray is the same. In general, it is considered that the penetration increases because the flow rate of the fuel spray increases and the momentum increases as the nozzle hole diameter increases. As the nozzle hole length increases, the straightness of the fuel improves, and the amount of air entrained after exiting the nozzle hole decreases, making it difficult to decelerate with air, and penetration is considered to increase. Therefore, in order to optimize the state of the spray injected into the combustion chamber, the diameters of the plurality of nozzle holes formed in one fuel injection valve are not necessarily the same.

  As a prior art disclosed in the gazette regarding the shape and arrangement method of the diffusion region of the nozzle hole that avoids the interference with the spray, for example, in a valve closed orifice (VCO) type fuel injection valve, the injection amount of a plurality of nozzle holes VCO type injection valve needle conical cone with the aim of preventing variation and improving the uniformity of spray formed by each nozzle hole, improving exhaust gas performance and reducing operating noise The outer peripheral surface of the small-diameter end portion of the sheet portion having a shape is chamfered so that the chamfered portion faces the opening end of the nozzle hole in the seat surface of the nozzle body when the needle valve is fully lifted. Further, there is a technique for disclosing a needle valve passage that opens at a small-diameter end of the seat portion in the needle valve, and that the needle valve passage communicates with a fuel reservoir in the nozzle body when the needle valve is lifted. (Patent Document 1).

  Further, the nozzle hole of the nozzle plate is composed of an equal-diameter hole portion and an enlarged-diameter hole portion, so that the atomization of the fuel and the stabilization of the injection direction can be achieved. The nozzle plate 15 is mounted on the front end side of the valve seat member, and the nozzle holes 16 and 17 are expanded in a taper shape with equal diameter holes 16A and 17A extending linearly with an equal hole diameter d. It is comprised by the enlarged diameter hole parts 16B and 17B formed by diameter. Thereby, at the time of fuel injection, the fuel injection flow rate and the injection direction are determined by the equal diameter holes 16A and 17A, and the jet flow is expanded to a certain region by the diameter expansion holes 16B and 17B. Thus, there is a technique for disclosing that the fuel is atomized while stabilizing the directionality of the injected fuel (Patent Document 2).

  Furthermore, with the goal of improving the combustion performance of the internal combustion engine during stratified combustion, the amount of fuel injected to the intake side of the piston cavity is increased from the exhaust side (the side closer to the spark plug), etc. The injected fuel is received by the piston by the action of tumble flow, and when it is rolled up above the combustion chamber, the intake side becomes leaner or the exhaust side becomes lean even if the intake side is mixed and diffused more than the exhaust side There is a technology that discloses that a stratified air-fuel mixture can be formed in which the concentrations on the intake and exhaust sides are equal, and the combustion is stable, fuel efficiency and exhaust purification performance are improved (patented) Reference 3).

  Furthermore, in order to form a spray that exhibits good performance in both homogeneous combustion and stratified combustion in the fuel injection valve, the fuel injection valve has an injection hole group 230 in which a plurality of injection holes for injecting fuel are formed. And a valve body that opens and closes the fuel passage by opening and closing a gap between the valve seat and a drive means for driving the valve body. The injection hole group 230 includes a plurality of injection holes 211 to 216 drilled so that the angles at which the axes of the holes face are different, and a plurality of injection hole pairs configured by a combination of these injection holes. The plurality of injection hole pairs have a first combination 230a having a large angle formed by the axis of the injection hole and a second combination 230b having an angle formed by the axis of the injection hole that is smaller than the angle of the first combination 230a. There is also a technique for disclosing (Patent Document 4).

Japanese Patent Laid-Open No. 08-312500 JP 2001-214839 A JP 2004-232583 A JP 2007-132231 A

  By the way, in a general direct-injection gasoline engine, a fuel injection valve (injector) that injects fuel into the combustion chamber may be attached to the side surface of the cylinder inclined with respect to the center axis of the cylinder (side mount system). . The fuel injection valve has a plurality of injection holes at the tip. Then, the opening angle of each injection hole of the fuel injection valve is determined so that the fuel spray injected from the injection hole generates an optimal air-fuel mixture in the combustion chamber. For example, a homogeneous combustion mode that generates a substantially homogeneous air-fuel mixture in the combustion chamber, or a stratified combustion mode that uses a leaner air-fuel mixture in the entire combustion chamber while concentrating fuel spray in the vicinity of the spark plug to ensure ignitability. . That is, corresponding to various combustion states, the opening angle of each injection hole is not necessarily symmetrical with respect to the central axis of the fuel injection valve.

  This will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an example of a main part of an engine with an intake two-valve gasoline engine 1 equipped with a fuel injection valve 10 when fuel is injected during an intake process.

  FIG. 1 shows an example of a two-valve type gasoline engine 1 that employs a side-mount type fuel injection valve 10. An intake valve 16 is provided on the side of the intake manifold 14 of the cylinder head 12, and an ignition plug 18 is provided at the center. However, an exhaust valve 20 is provided on the side opposite to the intake valve 16. The intake valve 16 and the exhaust valve 20 are provided so as to extend into the combustion chamber 22.

  The piston 26 provided in the cylinder 24 of the gasoline engine 1 so as to be able to reciprocate moves up and down in the cylinder 24 according to the rotation of a crankshaft (not shown). A cylinder head 12 is attached to the upper part of the cylinder 24, and forms a sealed space (combustion chamber 22) together with the cylinder 24. In the cylinder head 12, an intake manifold 14 that guides external air 30 into the combustion chamber 22 via an intake air amount control device 28 that includes a throttle valve (not shown), and combustion gas 32 burned in the combustion chamber 22. An exhaust manifold 34 leading to an exhaust device (not shown) is formed.

  The fuel injection valve 10 is attached in the vicinity of the coupling portion of the intake manifold 14 of the cylinder head 12. In the example of FIG. 1, the axis of the fuel injection valve 10 is set to be slightly downward in the combustion chamber 22. Yes.

  In the gasoline engine 1 having such a configuration, generation of an air-fuel mixture in the combustion chamber 22 when fuel is injected from the fuel injection valve 10 into the combustion chamber 22 will be described. FIG. 2 is a schematic perspective view showing an injection state of the air-fuel mixture in the combustion chamber 22 when fuel is injected during the intake process in the gasoline engine 1 shown in FIG.

  When a plurality of nozzle holes (not shown in FIG. 2) provided at the tip (injection point 30 in FIG. 2) have the same diameter, a general fuel injection valve 10 has a fuel spray 32 that exits from each nozzle hole. The momentum is the same. The distance (penetration) that the spray 32 injected from each of the plurality of nozzle holes into each region in the combustion chamber 22 arrives within a predetermined period of time is a deceleration caused by contact with the air in the combustion chamber 22 after leaving the nozzle holes. to be influenced. Generally, if the nozzle hole diameter increases, the flow rate of the spray 32 increases and the momentum increases, so that the penetration is considered to increase. If the nozzle hole length of the nozzle hole is increased, the straightness of the fuel is improved, the amount of air drawn after coming out of the nozzle hole is reduced and it is difficult to decelerate with air, and the penetration is considered to increase.

  In order to generate an optimal air-fuel mixture in the combustion chamber 22 corresponding to various combustion states, a plurality of injection holes are provided at the tip of the fuel injection valve (not shown in FIG. 2), and the spray 32 is The angle of the axis of each nozzle hole is optimized so as to be dispersed and injected into each region in the combustion chamber 22. As a result, some nozzle holes are not parallel to the central axis (not shown in FIG. 2) of the fuel injection valve, and the axis of each injection hole is not necessarily symmetrical with respect to the central axis of the fuel injection valve.

  Next, the fuel injection valve 10 of the gasoline engine 1 will be described. FIG. 3 is a longitudinal sectional view of the fuel injection valve 10 used in the gasoline engine 1 shown in FIG.

  The fuel injection valve 10 is a normally closed (NC) type electromagnetic valve, and normally the ball-shaped tip 44 of the valve element 42 urged by the spring 40 and the valve seat 48 ( 4) is in close contact with each other so that fuel supplied from the fuel supply port 50 does not leak from the nozzle hole 52 (FIG. 4). When energized, the valve body 42 is displaced together with the anchor 1054 toward the core 1056, and a gap is generated between the valve body 42 and the valve seat portion 48 (FIG. 4) of the valve seat plate 46. The fuel is supplied from the fuel supply port 50, passes through the space next to the valve body 42, passes through the inflow groove 64 (FIG. 5), and from the plurality of injection holes 52 (FIG. 4) drilled in the valve seat plate 46. It is injected as a fuel spray.

  The fuel injection part of the fuel injection valve 10 having such a configuration will be described with reference to FIGS. 4 is an enlarged longitudinal sectional view of the vicinity of the valve seat plate 46 in FIG. 3, FIG. 5 is a transverse sectional view taken along line VV in FIG. 3, and FIG. 6 is a valve seat plate in FIG. It is a longitudinal cross-sectional view for demonstrating the minimum thickness of 46. FIG. The lumen of the valve seat plate 46 has a dome shape that fits the ball-shaped tip 44 of the valve body 42 (FIG. 3). A valve seat portion 48 is formed on the inner surface of the valve seat plate 46 at a portion where the tip portion 44 contacts, and a seal is formed when the tip portion 44 and the valve seat portion 48 contact each other. Further, a sack portion 60 is formed at the inner front end of the valve seat plate 46. The sack portion 60 has a function of stabilizing the spray to be injected when the fuel injection valve 10 (FIG. 3) injects fuel because the tip end portion 44 is separated from the valve seat portion 48.

  The fuel passes through a clearance and an inflow groove 64 (FIG. 5) provided inside the fuel injection valve 10 (FIG. 3) and reaches the valve seat portion 48 of the valve seat plate 46. The fuel that has passed through the narrowed portion between the distal end portion 44 of the valve body 42 and the valve seat portion 48 of the valve seat plate 46 is directed toward the central axis 62 of the fuel injection valve 10 (FIG. 3), and the valve seat plate 46. To the plurality of nozzle holes 52 perforated through the nozzle hole 52 and injected through the nozzle holes 52 into the combustion chamber 22 (FIG. 2). Each nozzle hole 52 is drilled so that the angle of the shaft is different.

  As shown in FIG. 4, the injection hole 52 of the fuel injection valve 10 has a small-diameter guide region 54 formed on the inflow side and a diffusion formed on the injection side and having a larger diameter than the guide region 54. An area 56 is formed. On the bottom surface of the diffusion region 56, for example, a step portion perpendicular to the central axis 58 of the guide region 54 is formed. The fuel jet flowing out from the guide region 54 to the combustion chamber 22 (FIG. 2) through the diffusion region 56 is diffused as fuel spray as shown in FIG.

  The fuel that passes through the narrowed portion between the tip end portion 44 of the valve body 42 and the valve seat portion 48 of the valve seat plate 46 and reaches the injection hole 52 from the outside direction is the central axis 62 of the fuel injection valve 10 (FIG. 3). Therefore, in the guide region 54 of the injection hole 52, the flow is separated from the wall surface at a portion far from the central axis 62 of the fuel injection valve 10 (FIG. 3), and as a result, the guide region 54. Disturbance of the flow field occurs inside. For example, the disturbance occurs at the location indicated by the symbol A in FIG. The fuel that has flowed out of the guide region 54 into the diffusion region 56 due to the influence of the disturbance of the flow field does not diffuse evenly from the central axis 58 of the guide region 54 in a conical shape, but instead of the fuel injection valve 10. Diffusion with a larger spray angle is observed on the side farther from the central axis 62 (FIG. 3).

  Such fuel spray has a shortest distance between the outlet end of the diffusion region 56 on the side far from the central axis 62 of the fuel injection valve 10 (FIG. 3), and in some cases, the fuel spray is at the outlet end of the diffusion region. There was a possibility of interfering with the wall at the part.

  On the other hand, in order to avoid spray interference, it is conceivable to increase the countersink diameter and increase the diffusion region 56 symmetrically with respect to the central axis 58. However, if the countersink diameter is increased, the minimum thickness of the valve seat plate 46 is reduced. There is a fear that it cannot be secured. For example, there is a possibility that the minimum thickness of the member that can be allowed in the design of the valve seat plate 46 cannot be secured near the bottom surface of the diffusion region 56 indicated by the symbol B in FIG. 4 and the sack portion 60 of the valve seat plate 46. The minimum allowable thickness in the design of the member includes, for example, the minimum thickness required to withstand a pressure difference inside and outside the member in the environment where the fuel injection valve is used. If the diffusion region (spotting) 56 is made shallow in order to ensure the minimum thickness of such a member, the fuel will flow through the small-diameter guide region 54 for a long time, and the straightness of the fuel jet will be improved, and the diffusion region 56 will be improved. This may lead to a deterioration in atomization performance and / or an increase in the penetration of the spray, and a good fuel spray may not be generated.

Further details will be described with reference to FIG. The case of the valve seat plate 46 in which the sack portion 60 is formed is shown in FIG. 6 (1), and the case of the valve seat plate 46 in which the sack portion is not formed is shown in FIG. 6 (2). A minimum thickness portion (L _{1 to} L ₃ in FIG. 6 (1), L _{4 to} L ₆ in FIG. 6 (2)) occurs between the bottom corner of the diffusion region 56 and the sack portion 60. If the shape of the nozzle hole 52 corresponding to L _{1 in} FIG. 6 (1) or L ₄ in FIG. 6 (2) is used as a reference, L ₁ (L ₄₎ prevents the spray from interfering with the wall surface at the exit end of the diffusion region. When the countersink diameter of the diffusion region 56 is increased with respect to (), a minimum thickness portion is generated at the position of L ₂ (L ₅ ). L ₁ (L ₄ ) is smaller than L ₂ (L ₅ ). That is, L ₂ (L ₅ ) may fall below the design allowable minimum thickness due to a change that increases the counterbore diameter. When the guide region 54 is made longer than L ₁ (L ₄ ) and the countersink diameter of the diffusion region 56 is increased, a minimum thickness portion is generated at the position of L ₃ (L ₆ ). In this case, it is possible to make L ₃ (L ₆ ) equal to or greater than L ₁ (L ₄ ), but the extension of the guide region 54 improves the straightness of the fuel jet, and the spray flow is improved. The atomization performance may be deteriorated and / or the penetration of the spray may be increased, and a good fuel spray may not be generated.

  For ease of explanation, FIG. 6 shows a plurality of cross sections including a line segment indicating a location of the minimum thickness (note: the location where the minimum thickness is provided is a “line segment” in the three-dimensional space). It is an explanatory diagram showing the case of the nozzle hole shape, and it happens to be on the same plane, but even if the cross section including the line segment representing the location of the minimum thickness is different for each nozzle hole shape, The case cannot be expressed in the same single figure, and the circumstances to be considered are the same as in the case where a line segment happens to be on the same plane in a plurality of cases.

  The present invention has been made in order to solve such a problem, and the object of the present invention is to prevent the interference with the spray as much as possible by ensuring the minimum thickness of the valve seat plate while ensuring a short guide region. Another object of the present invention is to provide a shape and arrangement method of the diffusion region of the injection hole.

  Hereinafter, means for solving the above-mentioned problems will be described. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

  In order to solve the above-mentioned problems, a fuel injection valve according to the present invention has a plurality of injection holes (112; 212) for injecting fuel into a combustion chamber (22) of an internal combustion engine (1). Guide holes (114; 144; 174; 214) in which each of the holes determines the amount and direction of fuel to be injected through the fuel, and a diffusion region (116; 146; 176; 216), at least one of the plurality of nozzle holes has a central axis (118b; 148b; 178b; 218b) of the diffusion region and a central axis (118a) of the guide region. 148a; 178a; 218a), and eccentrically formed on the side farther from the central axis (120; 150; 180; 220) of the fuel injection valve than the central axis of the guide region; And features.

  Here, if the nozzle hole is characterized in that a countersink is further formed at the outlet end of the diffusion region, the spray injected from the diffusion region is discharged while securing the minimum thickness of the valve seat plate. Interference with the wall at the end can be avoided.

  Further, if the diffusion region has a shape of any one of a circle, an ellipse, and an ellipse when viewed from the fuel injection direction, the spray to be injected interferes with the wall surface at the outlet end of the diffusion region. In order to avoid this, the diffusion region can take various shapes.

  In order to solve the above problems, a fuel injection valve according to the present invention has a plurality of injection holes (312; 342; 412; 442) for injecting fuel into a combustion chamber (22) of an internal combustion engine (1). Each of the plurality of injection holes has a guide region (314; 344; 414; 444) for determining the fuel amount and the injection direction through which the fuel is injected, and a diffusion region for changing the fuel that has passed through the guide region into a spray ( 316; 346; 416; 446), wherein at least one of the plurality of nozzle holes has a center axis (318b; 348b; 418b; 448b) of the diffusion region at the center of the guide region At least a portion of the points on the line segment formed by the portion in the diffusion region of the central axis of the diffusion region that is not parallel to the axis (318a; 348a; 418a; 448a) is an extension of the central axis of the guide region The distance between the central axis (320; 350; 420; 450) of the fuel injection valve and the point on the line segment formed by the portion in the diffusion region or the valve seat plate A diffusion region is formed.

  Here, if the nozzle hole is characterized in that a countersink is further formed at the outlet end of the diffusion region, the spray injected from the diffusion region is discharged while securing the minimum thickness of the valve seat plate. Interference with the wall at the end can be avoided.

In order to solve the above-mentioned problems, a fuel injection valve according to the present invention has a plurality of injection holes for injecting fuel into a combustion chamber (22) of an internal combustion engine (1), and injects fuel through the fuel. In a fuel injection valve (10) having at least one injection hole (812) comprising a guide region (814) for determining the amount and injection direction and a diffusion region (816) for converting the fuel that has passed through the guide region into spray. The diffusion region is defined by the second plane (840) perpendicular to the first plane (830) passing through the center axis (820) of the fuel injection valve and passing through the center of the outlet of the guide region. When divided into a first region far from the central axis of the injection valve and a second region near the central axis, a third region passing through the shallowest part of the outlet end of the diffusion region and parallel to the bottom surface of the diffusion region. In the plane (850), from the second plane of the first region The distance between the distance of the first farthest point also far and (P) to a second plane (d ₁₎ is farthest second farthest point from the second plane of the second region (Q) to a second plane (d ₂ ), Or in a region surrounded by the third plane and the bottom surface of the diffusion region, the volume (V ₁ ) on the first region side is larger than the volume (V ₂ ) on the second region side. .

  By adopting the configuration of the present invention, it is possible to reduce the countersink on the spray side with a relatively small diffusion on the inside and avoid the interference with the spray diffused on the outside, and to secure the thickness of the valve seat plate Become.

  It is possible to avoid increasing the length of the nozzle hole only by limiting the securing of the member thickness.

1 is a longitudinal cross-sectional view showing an example of a main part of an engine in a case of an intake two-valve gasoline engine equipped with a fuel injection valve when fuel is injected during an intake process. FIG. 2 is a schematic perspective view showing a state of an air-fuel mixture in a combustion chamber when fuel is injected during an intake process in the gasoline engine shown in FIG. 1. It is a longitudinal cross-sectional view of the fuel injection valve used for the gasoline engine shown in FIG. It is the longitudinal cross-sectional view which expanded the vicinity of the valve seat plate of FIG. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3. It is a longitudinal cross-sectional view for demonstrating the minimum thickness of the valve seat plate in FIG. It is a longitudinal cross-sectional view of the valve seat plate in which the parallel eccentric type nozzle hole was formed. It is a longitudinal cross-sectional view of the valve seat plate in which the elliptical injection hole was formed. It is sectional drawing of the valve seat plate in which the non-parallel type nozzle hole was formed. It is a longitudinal cross-sectional view explaining the cross-sectional position of the valve seat plate shown in FIG. It is a longitudinal cross-sectional view of the valve seat plate in which the non-parallel type nozzle hole was formed. It is a longitudinal cross-sectional view of the valve seat plate in which the nozzle hole which concerns on the modification of embodiment shown in FIG. 11 was formed. It is a longitudinal cross-sectional view of the valve seat plate which has the nozzle hole in which counterbore was formed in the exit side of a diffusion area | region. It is a figure explaining the shape of the nozzle hole with respect to the central axis of a valve seat plate. It is sectional drawing explaining the shape of the nozzle hole with respect to the central axis of a valve seat plate.

  Embodiments of the present invention will be described below with reference to the drawings.

(Parallel eccentric type)
FIG. 7 is a longitudinal sectional view of the valve seat plate 110 in which the parallel eccentric type nozzle holes 112 are formed. A sack portion 122 for stabilizing the spray is formed at the inner front end of the valve seat plate 110.

  In FIG. 7A, the nozzle hole 112 of the valve seat plate 110 includes a small-diameter guide region 114 formed on the inflow side and a diffusion region 116 formed on the injection side and having a larger diameter than the guide region 114. . The central axis 118a of the guide region 114 is formed parallel to the central axis 120 of the fuel injection valve 10 (FIG. 3), and the central axis 118b of the diffusion region 116 is formed parallel to the central axis 118a of the guide region 114. ing. Further, the central axis 118b of the diffusion region 116 is formed eccentric to the far side from the central axis 120 of the fuel injection valve 10 (FIG. 3) with respect to the central axis 118a of the guide region 114. On the bottom surface of the diffusion region 116, for example, a step portion perpendicular to the central axis 118a of the guide region 114 is formed. The fuel jet flowing from the guide region 114 to the combustion chamber 22 (FIG. 2) through the diffusion region 116 diffuses as fuel spray.

  With such a configuration, since the guide region 114 is not lengthened, there is no change in the penetration of the spray, and the minimum thickness of the valve seat plate 110 is secured near the bottom surface of the diffusion region 116 and the sack portion 122 of the valve seat plate 110. However, it is possible to avoid the spray sprayed from the diffusion region 116 from interfering with the wall surface at the exit end of the diffusion region 116.

(Modification 1 of parallel eccentric type)
In the state where the central axis 148b of the diffusion region 146 maintains a parallel relationship with the central axis 148a of the guide region 144, the central axis 148a of the guide region 144 is aligned with the central axis 150 of the fuel injection valve 10 (FIG. 3). On the other hand, the modification 1 formed by inclining in the direction narrowing in the fuel injection direction is also conceivable (see FIG. 7B). Also in this case, since the guide region 144 is not lengthened, there is no change in the penetration of the spray, and the central axis 148b of the diffusion region 146 parallel to the central axis 148a of the guide region 144 is fuel relative to the central axis 148a of the guide region 144. By decentering away from the central axis 150 of the injection valve 10 (FIG. 3), the spray injected from the diffusion region 146 can avoid interference with the wall surface at the outlet end of the diffusion region 146.

(Modification 2 of parallel eccentric type)
The central axis 178a of the guide region 174 and the central axis 178b of the diffusion region 176 parallel to the central axis 178a may be inclined in an expanding direction with respect to the central axis 180 of the fuel injection valve 10 (FIG. 3) (FIG. 7). (See (3)). In short, the center axis 178b of the diffusion region 176 is eccentric with respect to the center axis 178a of the guide region 174 without increasing the length of the guide region 174, so that the spray injected from the diffusion region 176 is the exit end of the diffusion region 176. In order to avoid interference with the wall surface.

(Oval type)
FIG. 8 is a longitudinal sectional view of the valve seat plate 210 in which an oval injection hole 212 is formed. In this embodiment, the nozzle hole 212 includes a small-diameter guide region 214 and an oval (cornered rectangle) diffusion region 216 having a size including the guide region 214. A central axis 218a of the guide region 214 is formed parallel to the central axis 220 of the fuel injection valve 10 (FIG. 3), and a central axis 218b of the diffusion region 216 is formed parallel to the central axis 218a of the guide region 214. The Further, the central axis 218b of the diffusion region 216 is formed eccentric to the side far from the central axis 220 of the fuel injection valve 10 (FIG. 3) with respect to the central axis 218a of the guide region 214. For example, it is conceivable to align the axis of one of the oval semicircles of the diffusion region 216 with the central axis 218 a of the guide region 214.

  With such a configuration, since the guide region 214 is not lengthened, there is no change in spray penetration, and the minimum thickness of the valve seat plate 210 is secured near the bottom surface of the diffusion region 216 and the sack portion 222 of the valve seat plate 210. However, the spray sprayed from the diffusion region 216 can avoid interference with the wall surface at the exit end of the diffusion region 216.

(Oval-shaped variations 1 and 2)
As a modification of an oval (rounded rectangle), the same effect can be obtained even if the diffusion region 216 is formed in an oval shape without making the guide region 214 long (Modification 1) (not shown). Similarly to the eccentric type modification, the central axis 218a of the guide region 214 may be formed to be inclined with respect to the central axis 220 of the fuel injection valve 10 (FIG. 3) without lengthening the guide region 214. Good (Modification 2) (not shown).

(Non-parallel type)
Next, a valve seat plate in which non-parallel injection holes are formed will be described with reference to FIGS. FIG. 9 is a cross-sectional view of the valve seat plates 310 and 340 in which the non-parallel injection holes 312 and 342 are formed, and FIG. 10 is a longitudinal cross-sectional view for explaining the cross-sectional positions of the valve seat plates 310 and 340 shown in FIG. FIG. In FIG. 9, the nozzle holes 312 and 342 are arranged on the same plane α, with the central axes 318b and 348b of the diffusion regions 316 and 346 and the central axes 318a and 348a of the guide regions 314 and 344 being non-parallel. Has been formed. The plane α is inclined with respect to the central axes 320 and 350 of the fuel injection valve 10 (FIG. 3) as shown in FIG. 10. Here, the plane α in FIG. 10 is the cross-sectional position shown in FIG. 9. Accordingly, the central axes 320 and 350 of the fuel injection valve 10 (FIG. 3) shown in FIG. 9 are not on the cross section shown in FIG. The portion shown on the lower side of the figure is close to the paper surface, and is gradually separated from the paper surface toward the upper side of the drawing.

As shown in FIG. 9 (1), the portion located in the diffusion region 316 of the central axis 318b of the diffusion region 316 is indicated by a line segment S _1. The central axis of the guide area 314 318a, the "line segment formed by the portion in the diffusion region of the extension line of the center axis of the guide region" is indicated by T _1, of which valve the extension line of the center axis of the "guide region A line segment formed by a portion in the seat plate is indicated by U ₁ . Both the central axis 318b of the diffusion region 316 and the central axis 318a of the guide region 314 are inclined in a direction narrowing with respect to the fuel injection direction. In the present embodiment, in FIG. 9 (1), the line segment indicated by a point C ₁ on the S ₁ portion (lowest point of the line segment S ₁₎ is, either on a line T ₁ and line U ₁ of The nozzle hole 312 is formed at a position farther from the central axis 320 of the fuel injection valve 10 (FIG. 3) than the point.

The valve seat plate 340 shown in FIG. 9 (2) is “a line segment formed by a portion in the valve seat plate out of the extension line of the central axis of the guide region” (the portion indicated by U ₁ in FIG. 9 (1)). ) Is different from the valve seat plate 310 shown in FIG. As shown in FIG. 9 (2), the portion located in the diffusion region 346 of the central axis 348b of the diffusion region 346 is indicated by a line segment S _2. The central axis 348a of the guide region 344, "a line segment forming a portion in the diffusion region among the extension line of the center axis of the guide region" is represented by T _2. Both the central axis 348b of the diffusion region 346 and the central axis 348a of the guide region 344 are inclined in a direction narrowing with respect to the fuel injection direction. In the present embodiment, the C ₂ in the portion indicated by a point on the line segment S ₂ in FIG. 9 (2), the central axis than any point on the segment T _2, the fuel injection valve 10 (FIG. 3) An injection hole 342 is formed at a position away from 350.

(Non-parallel type modification 1)
FIG. 11 is a longitudinal sectional view of the valve seat plate 410 in which the nozzle holes 412 of the non-parallel type modified example 1 are formed. In the embodiment shown in FIG. 9, the plane α including the central axes 318b and 348b of the diffusion regions 316 and 346 and the central axes 318a and 348a of the guide regions 314 and 344 has a central axis 320 of the fuel injection valve 10 (FIG. 3). In contrast to the configuration arranged to be inclined with respect to 350, in the first modification, the plane including the central axis 418b of the diffusion region 416 and the central axis 418a of the guide region 414 is the fuel injection valve 10 (FIG. 3). Is different in that it is parallel to the central axis 420 of the.

  In Modification 1 shown in FIG. 11, the nozzle hole 412 includes a guide region 414 having a small diameter and a diffusion region 416 having a larger diameter than the guide region 414. A central axis 418a of the guide region 414 is formed in parallel to the central axis 420 of the fuel injection valve 10 (FIG. 3). On the other hand, the central axis 418b of the diffusion region 416 is formed so as to be inclined in a direction away from the central axis 420 of the fuel injection valve 10 (FIG. 3) toward the fuel injection direction through the center of the outlet of the guide region 414. As a result, the central axis 418b of the diffusion region 416 is not parallel to the central axis 418b of the diffusion region 416 and the central axis 420 of the fuel injection valve 10 (FIG. 3).

  The central axis 418b of the diffusion region 416 is disposed so as to be inclined away from the central axis 420 in the fuel injection direction. The inclination angle of the central axis 418b is determined in consideration of the jet angle of spray sprayed from the diffusion region 416 (FIG. 4). In the embodiment shown in FIG. 11, the spray sprayed from the diffusion region 416 is diffused region 416. The distance from the wall surface at the outlet end is determined to be the same on the side closer to the central axis 420 and on the far side.

  With this configuration, since the guide region 414 is not lengthened, there is no change in the penetration of the spray, and the minimum thickness of the valve seat plate 410 is ensured near the bottom surface of the diffusion region 416 and the sac portion 422 of the valve seat plate 410. However, the spray sprayed from the diffusion region 416 can avoid interference with the wall surface at the exit end of the diffusion region 416.

(Non-parallel type modification 2)
FIG. 12 is a longitudinal sectional view of the valve seat plate 440 in which the injection holes 442 according to the non-parallel type modification 2 are formed. In the second modification, the central axis 448 b of the diffusion region 446 does not pass through the exit center of the guide region 444, and the middle point of the central axis 448 b of the diffusion region 446 is a fuel injection valve with respect to the exit center of the guide region 444. 10 (FIG. 3) is arranged at a position distant from the central axis 450. Since the guide area 444 is not lengthened, there is no change in the penetration of the spray, and the spray area 446 is injected from the diffusion area 446 while ensuring the minimum thickness of the valve seat plate 440 near the bottom surface of the diffusion area 446 and the sack portion 452 of the valve seat plate 440. The spray to be applied can avoid interference with the wall surface at the exit end of the diffusion region 446.

(Non-parallel type modification 3)
In the embodiment shown in FIG. 9, the central axes 318b and 348b of the diffusion regions 316 and 346 and the central axes 318a and 348a of the guide regions 314 and 344 are not parallel but are arranged on the same plane α. However, the present invention is not limited to this, and for example, a configuration in which the central axis of the diffusion region and the central axis of the guide region are arranged at a twisted position (not shown) may be employed.

(Modification example in which the diffusion region has two stages)
13 has nozzle holes 512, 612, and 712 in which countersinks 530, 630, and 730 coaxial with the central axis of the guide regions 514, 614, and 714 are formed on the outlet side of the diffusion regions 516, 616, and 716, respectively. It is a longitudinal cross-sectional view of the valve seat plate 510,610,710. FIG. 13 (1) shows an example in which the countersink 530 is formed on the valve seat plate 510 having the eccentric type injection hole 512 shown in FIG. 7, and FIG. 13 (2) shows the oval injection hole 612 shown in FIG. FIG. 13 (3) shows an example in which the countersink 730 is formed on the valve seat plate 710 having the non-parallel injection hole 712 shown in FIG. Show. In any case, the spray injected from the diffusion regions 516, 616, and 716 can avoid interference with the wall surface at the outlet end portion while ensuring the minimum thickness of the valve seat plates 510, 610, and 710. Note that the countersink further provided for the diffusion region has been described in the present embodiment as being coaxial with the central axis of the guide region, but may be coaxial with the other diffusion region, None of these may be coaxial.

(Shape of the injection hole with respect to the central axis of the fuel injection valve)
14 and 15 are views for explaining the shape of the injection hole 812 with respect to the central axis 820 of the valve seat plate 810 (that is, the fuel injection valve 10 (FIG. 3)) according to the present invention. 14 (1), the first plane 830 is a plane that includes the central axis 820 of the valve seat plate 810 and passes through the outlet center of the guide region 814 (FIG. 15). The second plane 840 is a plane that is perpendicular to the first plane 830 and includes the central axis 818a (FIG. 15) of the guide region 814 (FIG. 15). The fourth plane 860 is a plane that is perpendicular to the second plane 840 and includes the central axis 818b (FIG. 15) of the diffusion region 816 (FIG. 15). FIG. 14 (2) is a view seen from the direction of the line of intersection between the second plane 840 and the fourth plane 860. FIG. 14 (3) is a perspective view of a state in which the valve seat plate 810 is cut along the fourth plane 860.

  15 (1) is a sectional view of the valve seat plate 810 in the fourth plane 860 (see FIG. 15 (2)), and FIG. 15 (2) is relative to the central axis 820 of the fuel injection valve 10 (FIG. 3). It is a figure which shows the positional relationship of the 4th plane 860. FIG. In FIG. 15A, the second plane 840 (FIG. 14) corresponds to the position of the central axis 818a of the guide region 814. The third plane 850 is a plane that passes through a point P (described later) and is parallel to the bottom surface of the diffusion region 816. Since the bottom surface of the diffusion region 816 is perpendicular to the central axis of the diffusion region 816, the third plane 850 is perpendicular to the fourth plane 860. In the embodiment shown in FIG. 15, the central axis 818 a of the guide region 814 is twisted with respect to the central axis 820 of the valve seat plate 810.

The diffusion region 816 is arranged on the second plane 840 (FIG. 14) (that is, the position of the axis 818a of the guide region 814 in FIG. 15) on the side far from the central axis of the fuel injection valve and the side near the central axis. When divided into the second region, the second flat surface 840 of the first region passes through the shallowest part of the exit end of the diffusion region 816 and is parallel to the bottom surface of the diffusion region 816 (FIG. 14). That is, the distance d ₁ from the point P farthest from the axis 818a) to the second plane 840 (FIG. 14) (ie, axis 818a in FIG. 15) is the second plane 840 (FIG. 14) of the second region (ie The distance d ₂ from the point Q farthest from the axis 818a) to the second plane 840 (FIG. 14) is larger by Δd (= d ₁ −d ₂ ). This also applies to the above-described embodiment where the central axis of the guide region and the central axis of the valve seat plate are not in a torsional relationship.

At this time, in the region surrounded by the third plane 850 and the bottom surface of the diffusion region 816, the volume V ₁ on the first region side is larger than the volume V ₂ on the second region side. This also applies to the above-described embodiment in which the central axis of the guide region and the central axis of the valve seat plate are not in a torsional relationship.

  In the above embodiments, the case where the present invention is applied to a side-mount type direct injection engine has been described. However, the present invention is not limited to the case of the side-mount type. It can also be applied to other types of engines.

1: gasoline engine (internal combustion engine), 10: fuel injection valve, 22: combustion chamber,
112; 212; 312; 342; 412; 442; 812: a plurality of nozzle holes;
114; 144; 174; 214; 314; 344; 414; 444; 814: guide region;
116; 146; 176; 216; 316; 346; 416; 446; 816: diffusion region;
118a; 148a; 178a; 218a; 318a; 348a; 418a; 448a: the central axis of the guide region;
118b; 148b; 178b; 218b; 318b; 348b; 418b; 448b: the central axis of the diffusion region;
120; 150; 180; 220; 320; 350; 420; 450; 820: the central axis of the fuel injector;
830: First plane, 840: Second plane, 850: Third plane

Claims (6)

A fuel injection valve having a plurality of injection holes (112; 212) for injecting fuel into a combustion chamber (22) of an internal combustion engine (1),
Each of the plurality of injection holes has a guide region (114; 144; 174; 214) for determining the amount and direction of fuel to be injected through the fuel and a diffusion region for converting the fuel that has passed through the guide region into spray. (116; 146; 176; 216), in a fuel injector (10),
At least one of the plurality of nozzle holes has a central axis (118b; 148b; 178b; 218b) of the diffusion region parallel to a central axis (118a; 148a; 178a; 218a) of the guide region; The fuel injection valve is eccentrically formed on a side farther from the central axis (120; 150; 180; 220) of the fuel injection valve than the central axis of the guide region. The fuel injection valve according to claim 1, wherein
The injection hole is a fuel injection valve in which a countersink is further formed at an outlet end of the diffusion region. The fuel injection valve according to claim 1, wherein
The fuel injection valve, wherein the diffusion region has any one of a circle, an ellipse, and an ellipse as viewed from the fuel injection direction. A fuel injection valve having a plurality of injection holes (312; 342; 412; 442) for injecting fuel into a combustion chamber (22) of an internal combustion engine (1),
Each of the plurality of nozzle holes has a guide region (314; 344; 414; 444) for determining the amount and direction of fuel to be injected through the fuel and a diffusion region for converting the fuel that has passed through the guide region into spray. (316; 346; 416; 446), comprising:
At least one of the plurality of nozzle holes is
The central axis (318b; 348b; 418b; 448b) of the diffusion region is not parallel to the central axis (318a; 348a; 418a; 448a) of the guide region;
At least a part of points on a line segment formed by a portion in the diffusion region of the central axis of the diffusion region is in the diffusion region or a valve seat plate in an extension line of the central axis of the guide region. The diffusion region is formed so as to be farther from the central axis (320; 350; 420; 450) of the fuel injection valve than any point on the line segment formed by the inner portion. , Fuel injection valve. The fuel injection valve according to claim 4, wherein
The injection hole is a fuel injection valve in which a countersink is further formed at an outlet end of the diffusion region. A fuel injection valve having a plurality of injection holes for injecting fuel into the combustion chamber (22) of the internal combustion engine (1), wherein the guide region determines the amount of fuel to be injected and the injection direction (814). A fuel injection valve (10) having at least one injection hole (812) comprising: a diffusion region (816) that converts the fuel that has passed through the guide region into spray;
The diffusion in a second plane (840) perpendicular to the first plane (830) passing through the central axis (820) of the fuel injection valve and passing through the outlet center of the guide area and including the central axis of the guide area When the region is divided into a first region far from the central axis of the fuel injection valve and a second region near the central axis, the region passes through the shallowest part at the outlet end of the diffusion region. In the third plane (850) parallel to the bottom surface of the diffusion region, the distance (d ₁ ) between the first farthest point (P) farthest from the second plane of the first region and the second plane is the first plane. Greater than the distance (d ₂ ) between the second farthest point (Q) farthest from the second plane of the two regions and the second plane, or
The fuel injection valve, wherein a volume (V ₁ ) on the first region side is larger than a volume (V ₂ ) on the second region side in a region surrounded by the third plane and the bottom surface of the diffusion region.