JP5812050B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve.

  Conventionally, a fuel injection valve provided with an injection hole plate is known (see, for example, Patent Document 1). The nozzle hole plate has a plurality of nozzle holes penetrating in the plate thickness direction. The nozzle hole is formed so as to gradually increase in cross-sectional area from the fuel inlet opening on one side of the nozzle hole plate to the elliptical fuel outlet opening on the other side of the nozzle hole plate. Yes.

  In the cross section along the short axis of the fuel outlet including the axis of the nozzle hole, the nozzle hole extends along the first angle formed by the inner wall surface of the nozzle hole and the long axis of the fuel outlet including the axis of the nozzle hole. The cross section has a second angle formed by the inner wall surface of the nozzle hole. The nozzle hole is formed so that the second angle is larger than the first angle.

  Therefore, the fuel injection valve described above can promote fuel atomization by expanding the fuel injected outside through the nozzle holes of the nozzle hole plate in the long axis direction of the fuel outlet.

JP 2013-87757 A

  Since the fuel injection valve described above can atomize the fuel injected from the nozzle hole to the outside, adhesion of fuel to the inner wall surface of the intake port of the engine to which the fuel injection valve is mounted is reduced, and the intake valve When opened, the introduction of fuel into the combustion chamber is facilitated. Thereby, the above-described fuel injection valve can suppress the HC emission amount (HC content in the exhaust gas) when the engine is cold-started.

  However, when the fuel injected from the nozzle hole is too fine, the fuel injection valve described above is vaporized before the fuel reaches the combustion chamber, and the volume efficiency is reduced by the amount of fuel vaporized. There is a concern that the engine output will decrease.

  Therefore, the present invention has been made to solve the above-described problems, and can reduce the HC emission amount at the time of cold start of the engine and improve the engine output as compared with the conventional one. It aims at providing a fuel injection valve.

In order to achieve the above object, a fuel injection valve according to the present invention includes (1) a valve body having a valve hole, a valve body provided inside the valve body so as to open and close the valve hole, and the valve hole A fuel injection valve having a first injection hole penetrating in the thickness direction of the plate and a second injection hole formed in the injection hole plate. The hole and the second nozzle hole have an inlet-side opening end that opens toward the valve body and an outlet-side opening end that opens toward the opposite side of the valve body, and the first nozzle hole The second nozzle hole is formed on the radially outer side of the nozzle hole plate with respect to the first nozzle hole, and the first nozzle hole and the second nozzle hole are formed on the center side of the nozzle hole plate. In the plan view with respect to the nozzle hole plate, the hole has an oval shape in which the opening end on the entry side has a major axis and a minor axis. Made, the first injection hole and the second injection hole, the channel cross-section is formed so as to spread toward the exit opening end portion from the entry side opening end portion, said first injection hole, the first injection In the cross section along the long axis of the inlet side opening end of the first injection hole including the axis of the hole, the inner wall surfaces facing each other of the first injection hole form a first injection hole long axis angle with each other, and In a cross section along the minor axis of the inlet side opening end of the first nozzle hole including the axis of the nozzle hole, the inner wall surfaces facing each other of the first nozzle hole form a first nozzle minor axis angle, and the second In the cross section along the long axis of the inlet side opening end portion of the second nozzle hole including the axis of the second nozzle hole, the inner wall surfaces facing each other of the second nozzle hole are mutually connected to the second nozzle hole long axis. with angled in cross-section along the minor axis of the ingress opening end portion of the second injection hole including the axis of the second injection hole, the second injection An inner wall surface facing the forms the second injection hole short axis angle to each other, wherein the injection hole plate, the first injection hole short axis angle is greater than the first injection hole major axis angle, and the second injection hole short An axial angle is configured to be larger than the second nozzle hole major axis angle, the first nozzle hole minor axis angle is smaller than the second nozzle hole minor axis angle , and the first nozzle hole major axis is configured. The angle and the second nozzle hole major axis angle are substantially equal .

  In the fuel injection valve of the present invention, the first nozzle hole short axis angle formed by the inner wall surface portion of the first nozzle hole of the nozzle hole plate is the second nozzle hole short axis angle formed by the inner wall surface portion of the second nozzle hole of the nozzle hole plate. Is smaller than For this reason, in the fuel injection valve of the present invention, the particle size of the fuel injected from the first injection hole is relatively larger than the particle size of the fuel injected from the second injection hole to the outside. That is, in the fuel injection valve of the present invention, the kinetic energy of the fuel injected from the first nozzle hole is relatively larger than the kinetic energy of the fuel injected from the second nozzle hole to the outside.

  Thereby, in the fuel injection valve of the present invention, the particle size of the fuel injected from the second nozzle hole to the outside is relatively smaller than the particle size of the fuel injected from the first nozzle hole to the outside. Therefore, the fuel injection valve of the present invention can reduce the HC emission amount at the time of cold start of the engine. In the fuel injection valve according to the present invention, the penetration force of the fuel injected from the first injection hole is relatively larger than the penetration force of the fuel injected from the miniaturization promoting nozzle. . Therefore, the fuel injection valve of the present invention does not vaporize before the fuel reaches the combustion chamber, and can improve the engine output.

  In order to achieve the above object, the fuel injection valve according to the present invention includes (2) a valve body having a valve hole, a valve body provided inside the valve body to open and close the valve hole, A fuel injection valve comprising a nozzle hole plate provided in a valve body so as to cover the valve hole, wherein a first nozzle hole and a second nozzle hole penetrating in the plate thickness direction are formed in the nozzle hole plate; The first nozzle hole and the second nozzle hole each have an inlet opening end that opens toward the valve body and an outlet opening end that opens toward the opposite side of the valve body. The hole is drilled on the center side of the nozzle hole plate, and the second nozzle hole is drilled on the radially outer side of the nozzle hole plate with respect to the first nozzle hole, and the first nozzle hole and the first nozzle hole The two nozzle holes are an over-the-side opening end portion having a major axis and a minor axis in a plan view with respect to the nozzle hole plate. The first nozzle hole and the second nozzle hole are formed such that a cross section of the flow channel extends from the inlet opening end toward the outlet opening end, and the first nozzle hole includes the first nozzle hole. In the cross section along the long axis of the inlet side opening end of the first nozzle hole including the axis of the first nozzle hole, the inner wall surfaces facing each other form the first nozzle long axis angle, In a cross section along the minor axis of the inlet side opening end of the first nozzle hole including the axis of the first nozzle hole, the inner wall surfaces facing each other form the first nozzle minor axis angle, The second nozzle hole has a cross section along the major axis of the inlet opening end of the second nozzle hole including the axis of the second nozzle hole, and the inner wall surfaces facing each other of the second nozzle holes are mutually connected to the second nozzle hole. In a cross section along the short axis of the inlet side opening end portion of the second nozzle hole including a long axis angle and including the axis of the second nozzle hole, The inner wall surfaces of the two nozzle holes facing each other form a second nozzle hole short axis angle, and the nozzle hole plate has the first nozzle hole short axis angle larger than the first nozzle hole long axis angle and the second nozzle hole axis. The short axis angle of the nozzle hole is configured to be larger than the long axis angle of the second nozzle hole, and the short axis angle of the first nozzle hole is configured to be smaller than the short axis angle of the second nozzle hole. .

  In the fuel injection valve of the present invention, the first nozzle hole minor axis angle of the first nozzle hole of the nozzle hole plate is larger than the first nozzle hole major axis angle. For this reason, the fuel injection valve of the present invention is such that the fuel liquid film in the major axis direction of the inlet side opening end portion becomes thin and the fuel liquid film enters the fuel injected from the first injection hole to the outside. It expands sufficiently in the short axis direction of the side opening end, and can promote fuel atomization.

  In the fuel injection valve of the present invention, the second nozzle hole short axis angle in the second nozzle hole of the nozzle hole plate is larger than the second nozzle hole long axis angle. For this reason, in the fuel injection valve of the present invention, the thickness of the fuel liquid film in the major axis direction of the inlet opening end is reduced and the fuel liquid film enters the fuel injected from the second nozzle hole to the outside. It expands sufficiently in the short axis direction of the side opening end, and can promote fuel atomization.

  Further, in the fuel injection valve of the present invention, the first nozzle hole short axis angle in the first nozzle hole of the nozzle hole plate is smaller than the second nozzle hole short axis angle in the second nozzle hole of the nozzle hole plate. . For this reason, in the fuel injection valve of the present invention, the particle size of the fuel injected from the first injection hole is relatively larger than the particle size of the fuel injected from the second injection hole to the outside. That is, in the fuel injection valve of the present invention, the kinetic energy of the fuel injected from the first nozzle hole is relatively larger than the kinetic energy of the fuel injected from the second nozzle hole to the outside.

  Thereby, in the fuel injection valve of the present invention, the particle size of the fuel injected from the second nozzle hole to the outside is relatively smaller than the particle size of the fuel injected from the first nozzle hole to the outside. Therefore, the fuel injection valve of the present invention can reduce the HC emission amount at the time of cold start of the engine. In the fuel injection valve of the present invention, the penetration force of the fuel injected from the first nozzle hole is relatively larger than the penetration force of the fuel injected from the second nozzle hole to the outside. Therefore, the fuel injection valve of the present invention does not vaporize before the fuel reaches the combustion chamber, and can improve the engine output.

  In the fuel injection valve according to the above (1) or (2), (3) the injection hole plate has a flow passage cross-sectional area of an inlet side opening end portion of the first injection hole that is in the second injection hole. It is comprised so that it may become larger than the flow-path cross-sectional area of a side opening edge part.

  In the fuel injection valve of the present invention, the flow path cross-sectional area of the inlet side opening end of the first nozzle hole is larger than the channel cross-sectional area of the inlet side opening end of the second nozzle hole. Therefore, in the fuel injection valve, the fuel liquid film inside the first injection hole is relatively thicker than the fuel liquid film inside the second injection hole, and the fuel injected from the first injection hole to the outside Is relatively larger than the particle size of the fuel injected from the second nozzle hole to the outside. That is, in the fuel injection valve of the present invention, the kinetic energy of the fuel injected from the first nozzle hole is relatively larger than the kinetic energy of the fuel injected from the second nozzle hole to the outside.

  Thereby, in the fuel injection valve of the present invention, the particle size of the fuel injected from the second nozzle hole to the outside is relatively smaller than the particle size of the fuel injected from the first nozzle hole to the outside. Therefore, the fuel injection valve of the present invention can reduce the HC emission amount at the time of cold start of the engine. In the fuel injection valve of the present invention, the penetration force of the fuel injected from the first nozzle hole is relatively larger than the penetration force of the fuel injected from the second nozzle hole to the outside. Therefore, the fuel injection valve of the present invention does not vaporize before the fuel reaches the combustion chamber, and can improve the engine output.

  (4) In the fuel injection valve according to (1) or (2), (4) the nozzle hole plate is injected from the first nozzle hole in a penetrating direction of the first nozzle hole and the second nozzle hole. The fuel spray range is configured so that the fuel spray range injected from the second nozzle hole does not overlap.

  In the fuel injection valve of the present invention, the first nozzle hole and the second nozzle hole are penetrated in the direction in which the spray range of fuel injected from the first nozzle hole and the spray range of fuel injected from the second nozzle hole overlap. It is supposed not to be. For this reason, in the fuel injection valve of the present invention, due to the viscosity of the air, the flow of the fuel injected from the second injection hole is drawn into the flow of the fuel injected from the first injection hole to the outside. A phenomenon occurs.

  Thereby, in the fuel injection valve of the present invention, the particle size of the fuel injected from the second nozzle hole to the outside is relatively smaller than the particle size of the fuel injected from the first nozzle hole to the outside. Therefore, the fuel injection valve of the present invention can reduce the HC emission amount at the time of cold start of the engine. In the fuel injection valve of the present invention, the penetration force of the fuel injected from the first nozzle hole is relatively larger than the penetration force of the fuel injected from the second nozzle hole to the outside. Therefore, the fuel injection valve of the present invention does not vaporize before the fuel reaches the combustion chamber, and can improve the engine output.

  According to the present invention, it is possible to provide a fuel injection valve capable of reducing the amount of HC emission during cold start of the engine and improving the engine output as compared with the conventional one.

It is a schematic diagram which shows the structure of the fuel injection valve which concerns on embodiment of this invention, Fig.1 (a) is a longitudinal cross-sectional view of the front-end | tip part of a fuel injection valve, FIG.1 (b) is A1- of Fig.1 (a). A1 sectional drawing and FIG.1 (c) are A2-A2 sectional drawings of Fig.1 (a). It is a bottom view of the nozzle hole plate in the fuel injection valve concerning the embodiment of the present invention. It is a schematic diagram which shows the fuel spray range of the fuel injection valve which concerns on embodiment of this invention, Fig.3 (a) is a front view of the front-end | tip part of a fuel injection valve, FIG.3 (b) is the front-end | tip part of a fuel injection valve FIG. 3C is a side view taken along the line BB in FIG. It is a graph which contrasts the average particle diameter distribution of the fuel in the fuel injection valve which concerns on embodiment of this invention, and the fuel injection valve of a comparative example. It is a graph which compares the average particle diameter of the fuel in the outer edge part of the fuel spray range in the fuel injection valve which concerns on embodiment of this invention, and the fuel injection valve of a comparative example. It is a graph which contrasts the spray length of the fuel in the fuel injection valve which concerns on embodiment of this invention, and the fuel injection valve of a comparative example.

  Hereinafter, embodiments of a fuel injection valve according to the present invention will be described with reference to the drawings.

  The fuel injection valve 1 according to the present embodiment includes a valve body 10, a valve body 20, and an injection hole plate 30, as shown in FIGS. 1 (a), 1 (b), and 1 (c).

  The valve body 10 is a hollow structure, and has a fuel supply passage 11 that extends vertically in the figure and a valve hole 12 that communicates with the lower end of the fuel supply passage 11 and opens downward. A fuel pressurized by a pump (not shown) is supplied to the fuel supply passage 11. The inner peripheral surface portion of the valve hole 12 is formed so that the inner diameter thereof decreases in a tapered shape toward the lower side, and serves as a valve seat 13.

  The valve body 20 is a rod-like body extending in the vertical direction, and is disposed coaxially inside the valve body 10. The lower end portion of the valve body 20 is formed so that the outer diameter decreases in a tapered shape downward. The entire circumference of the tapered portion where the outer diameter is the largest is in contact with the valve seat 13 of the valve body 10 as a seal portion 21 having a larger diameter than the minimum inner diameter of the valve seat 13.

  The valve body 20 is moved up and down by a valve driving device including a spring and a solenoid coil (not shown) and closes the valve hole 12 of the valve body 10 when the seal portion 21 contacts the valve seat 13. It is supposed to be.

  The spring presses the valve body 20 downward against the valve body 10. That is, when the solenoid coil is not excited, the valve body 20 is pressed downward by the restoring force of the spring, and the seal portion 21 is in contact with the valve seat 13 of the valve body 10. The communication between the valve 11 and the valve hole 12 is cut off.

  The solenoid coil pulls up the valve body 20 against the restoring force of the spring. That is, when the solenoid coil is excited, the valve body 20 is pulled up by the magnetic attractive force, and the seal portion 21 is separated from the valve seat 13 of the valve body 10, so that the fuel supply passage 11 and the valve hole 12 Will communicate.

  As shown in FIG. 2, the nozzle hole plate 30 has a first nozzle hole 31 and a second nozzle hole 32 that penetrate in the plate thickness direction, and is welded to the lower end portion of the valve body 10 so as to cover the valve hole 12. It is attached.

  The first injection hole 31 has an inlet side opening end portion 31 a that opens toward the valve body 10 and an outlet side opening end portion 31 b that opens toward the opposite side of the valve body 10. The second injection hole 32 has an inlet side opening end portion 32 a that opens toward the valve body 10 and an outlet side opening end portion 32 b that opens toward the opposite side of the valve body 10. Two first nozzle holes 31 are drilled on the center side of the nozzle hole plate 30, and eight second nozzle holes 32 are drilled on the radially outer side of the nozzle hole plate 30 relative to the first nozzle holes 31. (See FIG. 2).

  The first injection hole 31 is formed in an oval shape having an input side opening end portion 31a having a long axis X1 and a short axis Y1 in a plan view with respect to the injection hole plate 30, and an output side opening end portion 31b is set to a long axis X2. And is formed in an oval shape having a short axis Y2. The first injection hole 31 is configured such that the center of the outlet opening end 31b is located on the radially outer side of the nozzle hole plate 30 with respect to the center of the inlet opening end 31a.

  In the fuel injection valve 1 according to the present embodiment, the shape of the inlet side opening end portion 31a and the outlet side opening end portion 31b of the first injection hole 31 in plan view of the injection hole plate 30 is an oval that is an example of an oval shape. It is said. Here, the oval shape is not limited to a closed curve that is axisymmetric about at least one axis, such as an ellipse, an oval, or an oval, and includes a closed curve that is not axisymmetric. .

  The first injection hole 31 has a major axis X1 of the inlet opening end 31a extending radially outward from the center of the nozzle hole plate 30, and a minor axis Y2 of the outlet opening end 31b is the nozzle hole plate. 30 extends from the center side toward the radially outward side. The first nozzle hole 31 is formed such that the cross-section of the flow path extends in a tapered shape from the inlet side opening end part 31a toward the outlet side opening end part 31b, and a first angle (first nozzle hole major axis angle). It has (theta) 1 and 2nd angle (theta) 2 (1st nozzle hole short axis angle) (refer Fig.1 (a) and FIG.1 (b)).

  The first angle θ1 means that the inner wall surface portion of the first injection hole 31 facing in the cross section along the axis Z1 of the first injection hole 31 and the long axis X1 of the entrance side opening end 31a of the first injection hole 31 is It is an angle to make. The second angle θ2 means that the inner wall surface portion of the first injection hole 31 that faces the first injection hole 31 in the cross section along the axis Z1 of the first injection hole 31 and the short axis Y1 of the entrance side opening end 31a of the first injection hole 31 is defined. It is an angle to make.

  The second nozzle hole 32 is formed in an oval shape having an input side opening end 32a having a major axis X3 and a minor axis Y3, and an outlet side opening end 32b is a major axis X4 in a plan view with respect to the nozzle hole plate 30. And is formed in an oval shape having a short axis Y4. Further, the second injection hole 32 is configured such that the center of the outlet opening end 32b is located on the radially outer side of the nozzle hole plate 30 with respect to the center of the inlet opening end 32a.

  In the fuel injection valve 1 according to the present embodiment, the shape of the inlet side opening end portion 32a and the outlet side opening end portion 32b of the second nozzle hole 32 in a plan view of the nozzle hole plate 30 is an oval that is an example of an oval shape. It is said. Here, the oval shape is not limited to a closed curve that is axisymmetric about at least one axis, such as an ellipse, an oval, or an oval, and includes a closed curve that is not axisymmetric. .

  In the second nozzle hole 32, the long axis X3 of the inlet opening end 32a extends from the center side of the nozzle hole plate 30 toward the radially outer side, and the minor axis Y4 of the outlet opening end 32b is the nozzle hole plate. 30 extends from the center side toward the radially outward side. The second nozzle hole 32 is formed such that the cross section of the flow path extends in a taper shape from the inlet side opening end part 32a toward the outlet side opening end part 32b, and has a third angle θ3 (second nozzle hole major axis angle). ) And a fourth angle θ4 (second nozzle hole short axis angle) (see FIGS. 1A and 1C).

  The third angle θ3 means that the inner wall surface portion of the second injection hole 32 facing the cross section along the axis Z2 of the second injection hole 32 and the long axis X3 of the entrance side opening end 32a of the second injection hole 32 is It is an angle to make. The fourth angle θ4 means that the inner wall surface portion of the second injection hole 32 is opposite to the axis Z2 of the second injection hole 32 and the cross section along the minor axis Y3 of the entrance side opening end 32a of the second injection hole 32. It is an angle to make.

  In the nozzle hole plate 30, the second angle θ2 in the first nozzle hole 31 is larger than the first angle θ1, and the fourth angle θ4 in the second nozzle hole 32 is larger than the third angle θ3. It is configured. Further, the nozzle hole plate 30 is configured such that the second angle θ <b> 2 in the first nozzle hole 31 is smaller than the fourth angle θ <b> 4 in the second nozzle hole 32. The nozzle hole plate 30 is configured to be substantially equal to the first angle θ1 in the first nozzle hole 31 and the third angle θ3 in the second nozzle hole 32.

  The nozzle hole plate 30 is configured such that the flow passage cross-sectional area of the inlet side opening end portion 31 a of the first nozzle hole 31 is larger than the flow passage cross-sectional area of the inlet side opening end portion 32 a of the second nozzle hole 32. . Further, the nozzle hole plate 30 has a spray range F1 of fuel injected from the first nozzle holes 31 and a second nozzle hole 32, as shown in FIGS. 3 (a), 3 (b), and 3 (c). The spray range F2 of the fuel injected from is not overlapped in plan view. This can be achieved by appropriately setting the penetration direction of the first nozzle hole 31 and the second nozzle hole 32.

  Next, the operation of the fuel injection valve 1 according to this embodiment will be described.

  The fuel injection valve 1 is assembled to a gasoline intake port, and injects fuel into a fuel supply passage 11 of the valve body 10 while fuel is being supplied from a pump (not shown). Yes.

  In the fuel injection valve 1, when the valve body 20 is pulled up by a valve drive device (not shown), the fuel in the fuel supply passage 11 flows into the gap between the valve seat 13 and the outer peripheral surface portion of the lower end portion of the valve body 20, and the valve hole 12 flows into the first nozzle hole 31 and the second nozzle hole 32. Thus, the fuel injection valve 1 injects fuel from the first injection hole 31 and the second injection hole 32 toward the intake port.

  When the valve body 20 is pushed down by a valve drive device (not shown), the fuel injection valve 1 blocks communication between the fuel supply passage 11 and the valve hole 12. Thereby, the fuel injection valve 1 interrupts the injection of the eye fuel to the intake port.

  In the fuel injection valve 1, the second angle θ2 in the first injection hole 31 of the injection hole plate 30 is larger than the first angle θ1. For this reason, the fuel injection valve 1 reduces the thickness of the fuel liquid film in the major axis X1 direction of the inlet side opening end 31a for the fuel injected from the first injection hole 31 and the fuel liquid film. It spreads in the direction of the minor axis Y1 of the inlet side opening end 31a, and fuel atomization can be promoted.

  Further, in the fuel injection valve 1, the fourth angle θ4 in the second injection hole 32 of the injection hole plate 30 is larger than the third angle θ3. For this reason, the fuel injection valve 1 reduces the thickness of the fuel liquid film in the major axis X3 direction of the inlet side opening end 32a for the fuel injected from the second injection hole 32, and the fuel liquid film It spreads in the direction of the minor axis Y3 of the inlet side opening end 32a, and fuel atomization can be promoted.

  Further, in the fuel injection valve 1, the second angle θ2 in the first nozzle hole 31 of the nozzle hole plate 30 is larger than the fourth angle θ4 in the second nozzle hole 32 of the nozzle hole plate 30. For this reason, in the fuel injection valve 1, the particle size of the fuel injected from the first injection hole 31 to the outside is relatively larger than the particle size of the fuel injected from the second injection hole 32 to the outside. That is, in the fuel injection valve 1, the kinetic energy of the fuel injected from the first injection hole 31 to the outside is relatively larger than the kinetic energy of the fuel injected from the second injection hole 32 to the outside.

  Thereby, in the fuel injection valve 1, the penetration force of the fuel injected from the first injection hole 31 to the outside is relatively larger than the penetration force of the fuel injected from the second injection hole 32 to the outside. Further, in the fuel injection valve 1, the particle size of the fuel injected from the second injection hole 32 to the outside is relatively smaller than the particle size of the fuel injected from the first injection hole 31 to the outside.

  Further, in the fuel injection valve 1, the flow passage cross-sectional area of the inlet side opening end portion 31 a of the first injection hole 31 is larger than the flow passage cross-sectional area of the inlet side opening end portion 32 a of the second injection hole 32. . Therefore, in the fuel injection valve 1, the fuel liquid film inside the first injection hole 31 becomes relatively thicker than the fuel liquid film inside the second injection hole 32, and the fuel injection film 1 goes from the first injection hole 31 to the outside. The particle size of the injected fuel is relatively larger than the particle size of the fuel injected from the second injection hole 32 to the outside. That is, in the fuel injection valve 1, the kinetic energy of the fuel injected from the first injection hole 31 to the outside is relatively larger than the kinetic energy of the fuel injected from the second injection hole 32 to the outside.

  Thereby, in the fuel injection valve 1, the penetration force of the fuel injected from the first injection hole 31 to the outside is relatively larger than the penetration force of the fuel injected from the second injection hole 32 to the outside. Further, in the fuel injection valve 1, the particle size of the fuel injected from the second injection hole 32 to the outside is relatively smaller than the particle size of the fuel injected from the first injection hole 31 to the outside.

  In the fuel injection valve 1, the center of the outlet side opening end portion 31b of the first injection hole 31 is located on the radially outer side of the injection hole plate 30 with respect to the center of the inlet side opening end portion 31a. For this reason, in the fuel injection valve 1, the diffusion range of the fuel sprayed to the outside from the first injection hole 31 is expanded. Further, in the fuel injection valve 1, the center of the outlet side opening end portion 32b of the second injection hole 32 is located on the radially outer side of the nozzle hole plate 30 with respect to the center of the inlet side opening end portion 32a. For this reason, in the fuel injection valve 1, the diffusion range of the fuel sprayed to the outside from the second injection hole 32 is expanded.

  In the fuel injection valve 1, the first injection hole 31 and the second injection hole 32 penetrate the injection hole plate 30 in the direction in which the fuel is sprayed from the first injection hole 31 and the second injection hole 32. The fuel spray range F2 does not overlap. For this reason, in the fuel injection valve 1, due to the viscosity of air, the flow of fuel injected from the second injection hole 32 to the outside is drawn into the flow of fuel injected from the first injection hole 31 to the outside. A phenomenon occurs.

  Thereby, in the fuel injection valve 1, the penetration force of the fuel injected from the first injection hole 31 to the outside is relatively larger than the penetration force of the fuel injected from the second injection hole 32 to the outside. Further, in the fuel injection valve 1, the particle size of the fuel injected from the second injection hole 32 to the outside is relatively smaller than the particle size of the fuel injected from the first injection hole 31 to the outside.

  The inventor compared the fuel injection valve 1 according to the present embodiment with the fuel injection valve of the comparative example, and obtained the following knowledge. Here, the fuel injection valve of the comparative example has a configuration in which only the second injection holes 32 are formed in the injection hole plate 30 and the first injection holes 31 are omitted. The conditions are the same as those of the fuel injection valve 1 according to the embodiment.

  In FIG. 4, the solid line represents the average particle size distribution of the fuel injected from the fuel injection valve 1 according to this embodiment, and the broken line represents the average particle size distribution of the fuel injected from the fuel injection valve of the comparative example. . Since the fuel injection valve 1 according to the present embodiment has the first injection holes 31 formed in the injection hole plate 30, the average particle size of the fuel in the central portion of the fuel spray region compared to the fuel injection valve of the comparative example. The diameter increases. Thereby, the fuel injection valve 1 according to the present embodiment has a greater penetration force of the injected fuel than the fuel injection valve of the comparative example.

  In addition, since the fuel injection valve 1 according to the present embodiment has the same fuel flow rate as that of the fuel injection valve of the comparative example, the flow passage cross-sectional area of the second injection hole 32 is the same as that of the first injection hole 31. The amount obtained by subtracting the area is smaller than the flow path cross-sectional area of the second injection hole of the fuel injection valve of the comparative example. Therefore, in the fuel injection valve 1 according to the present embodiment, the particle size of the fuel injected from the second injection hole 32 to the outside is the particle size of the fuel injected from the second injection hole of the fuel injection valve of the comparative example. It becomes relatively smaller than the diameter.

  5 and 6 are based on actual measurement results using the fuel injection valve 1 according to this embodiment and the fuel injection valve of the comparative example. As shown in FIG. 5, the fuel injection valve 1 according to the present embodiment has an average particle size of fuel at the outer edge portion of the fuel spray region that is substantially the same as the fuel injection valve of the comparative example. Further, in the fuel injection valve 1 according to the present embodiment, the fuel penetration length is increased by the first injection holes 31 formed in the injection hole plate 30, so that the fuel spray length is the fuel injection valve of the comparative example. Longer than.

  Thus, in the fuel injection valve 1 according to the present embodiment, the particle size of the fuel injected from the second injection hole 32 to the outside is larger than the particle size of the fuel injected from the first injection hole 31 to the outside. Relatively small. That is, the fuel injection valve 1 according to the present embodiment can atomize the fuel injected to the outside from the second injection hole 32, so that the adhesion of fuel to the inner wall surface of the intake port is reduced and the intake valve is opened. The introduction of fuel into the combustion chamber is promoted. Therefore, the amount of HC emission when the engine is cold started can be suppressed.

  Further, in the fuel injection valve 1 according to the present embodiment, the penetration force of the fuel injected from the first injection hole 31 to the outside is relative to the penetration force of the fuel injected from the second injection hole 32 to the outside. Become bigger. That is, the fuel injection valve 1 according to the present embodiment does not vaporize before the fuel reaches the combustion chamber, and can improve the engine output.

  It should be noted that the technical scope of the fuel injection valve according to the present invention is not limited to the above-described embodiment, and various components of the constituent elements described in the claims can be made without departing from the scope of the present invention. Includes changes.

  As described above, the fuel injection valve according to the present invention has an effect of reducing the HC emission amount at the time of cold start of the engine and improving the engine output, and is applied to a gasoline engine adopting a port injection system. Useful.

  DESCRIPTION OF SYMBOLS 1 ... Fuel injection valve, 10 ... Valve body, 12 ... Valve hole, 20 ... Valve body, 30 ... Injection hole plate, 31 ... 1st injection hole, 31a ... Inlet side opening edge part (inlet side opening of 1st injection hole) End), 31b ... exit opening end (exit opening end of the first injection hole), 32 ... second injection hole, 32a ... input opening end (input opening end of the second injection hole) 32b: Outlet opening end (outlet opening end of the second nozzle hole), F1: Spray range (spray range of fuel injected from the first nozzle hole), F2 ... Spray range (from the second nozzle hole) Spray range of fuel to be injected), X1... Long axis (long axis of the inlet side opening end of the first injection hole), X3... Long axis (long axis of the inlet side opening end of the second injection hole), Y1 ... Short axis (short axis of the inlet side opening end of the first nozzle hole), Y3 ... Short axis (short axis of the inlet side opening end of the second nozzle hole), Z1 ... Axis (axis of the first nozzle hole) , Z2 ... axis (axis of the second nozzle hole), θ1 ... first angle ( 1 nozzle hole major axis angle, θ2 ... second angle (first nozzle hole minor axis angle), θ3 ... third angle (second nozzle hole major axis angle), θ4 ... fourth angle (second jet) Hole short axis angle)

Claims (3)

A valve body with a valve hole;
A valve body provided inside the valve body to open and close the valve hole;
An injection hole plate provided in the valve body so as to cover the valve hole,
A fuel injection valve in which a first injection hole and a second injection hole penetrating in the plate thickness direction are formed in the injection hole plate,
The first nozzle hole and the second nozzle hole have an inlet-side opening end that opens toward the valve body and an outlet-side opening end that opens toward the opposite side of the valve body,
The first nozzle hole is drilled on the center side of the nozzle hole plate, and the second nozzle hole is drilled on the radially outer side of the nozzle hole plate with respect to the first nozzle hole,
The first nozzle hole and the second nozzle hole are formed in an oval shape having an entrance side opening end portion having a major axis and a minor axis in a plan view with respect to the nozzle hole plate,
The first nozzle hole and the second nozzle hole are formed such that a cross section of the flow path extends from the inlet opening end toward the outlet opening end,
In the first nozzle hole, in the cross section along the long axis of the inlet side opening end portion of the first nozzle hole including the axis of the first nozzle hole, the inner wall surfaces facing each other of the first nozzle holes are mutually connected to the first nozzle hole. In the cross section along the short axis of the inlet opening end portion of the first nozzle hole including the long axis angle of the first nozzle hole and including the axis of the first nozzle hole, the inner wall surfaces facing each other of the first nozzle hole are first to each other. The nozzle has a short axis angle,
In the second nozzle hole, in the cross section along the long axis of the inlet side opening end portion of the second nozzle hole including the axis of the second nozzle hole, the inner wall surfaces facing each other of the second nozzle holes are mutually connected to the second nozzle hole. In the cross section along the minor axis of the inlet side opening end portion of the second nozzle hole that includes the axis of the second nozzle hole and includes the axis of the second nozzle hole, the inner wall surfaces facing the second nozzle hole are second to each other. The nozzle has a short axis angle,
In the nozzle hole plate, the first nozzle hole short axis angle is larger than the first nozzle hole long axis angle, and the second nozzle hole short axis angle is larger than the second nozzle hole long axis angle. The first nozzle hole minor axis angle is smaller than the second nozzle hole minor axis angle , and the first nozzle hole major axis angle is substantially equal to the second nozzle hole major axis angle. A fuel injection valve characterized by comprising. The nozzle hole plate is configured such that the flow path cross-sectional area of the inlet side opening end of the first nozzle hole is larger than the flow path cross-sectional area of the inlet side opening end of the second nozzle hole. The fuel injection valve according to claim 1 . In the nozzle hole plate, a penetrating direction of the first nozzle hole and the second nozzle hole has a spray range of fuel injected from the first nozzle hole and a spray range of fuel injected from the second nozzle hole. the fuel injection valve according to claim 1 or claim 2, characterized in that it is configured to do not overlap.

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