JP2005320877A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish a shape and homogeneity of a spray injected in a direction oblique to the axial line of a solenoid type fuel injection valve main element by changing the inlet shape of an orifice. <P>SOLUTION: A seat surface is a roughly 90° cone shape surface on which a valve element abuts on. The part downstream thereof is a secondary cone surface less than 90°, and the second cone surface is unsymmetrical in relation to the axial line of the solenoid type fuel injection valve main element and a deflection side of the orifice is short. The orifice is positioned downstream of the second cone surface and is symmetrical in relation to a deflection axis and is substantially of the same length. Also, the orifice is unsymmetrical in relation to the deflection axis, and the deflection side is made long or short. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection valve, and more particularly, to an electromagnetic fuel injection valve that determines a fuel spray shape and a spray shape based on a seat surface, a second conical surface, and an inlet shape of an orifice.

  Conventionally, Patent Document 1 discloses an object that improves the homogeneity of spray sprayed in a deflection direction with respect to the axis of the electromagnetic fuel injection valve (the penetration length is substantially uniform).

  This is formed in the inner hemisphere of the fuel injection chamber that is opened and closed by the needle valve, and the injection hole is formed in an oblique direction. In order to suppress the deviation of the flow velocity distribution in the axial direction of the injection hole of the fuel flowing into the injection hole, the position of the injection hole is swirled from the inclination direction of the injection hole with respect to the center of the bottom surface of the fuel injection chamber. Shift in the direction rotated 90 ° in the direction.

  According to this, when the injection hole is formed in the center of the bottom surface of the fuel injection chamber, the axial flow velocity is minimum at 90 ° and maximum at 270 °. The amount by which the injection hole is displaced is set within a range in which the connecting portion between the inner peripheral surface of the fuel injection chamber and the inlet portion of the injection hole is not stepped. Further, the entire circumference of the injection hole is formed in an R shape (circular curved surface), and the inner peripheral surface of the fuel injection chamber and the inlet part of the injection hole are connected by a continuous curved surface.

  On the other hand, as a method of changing the spray reach distances L1 and L2 to make the spray non-uniform (lengthening the penetration on the deflection side of the orifice), there is Patent Document 2 described above.

  Fuel swirling means for imparting swirl force upstream of the valve seat to fuel passing around the valve body, and a nozzle for injecting swirl fuel are provided. The fuel spray injected from the nozzle injection port is deflected in one direction with reference to the fuel injection valve body axis C, and the spray arrival distance L1 on the deflection side is large, and the spray arrival distance L2 on the opposite side to the deflection side. The spray shape is set to be small.

The means is as follows.
(1) Since the orifice is deflected, the outlet portion of the orifice is cut obliquely so that the length of the injection port becomes non-axisymmetric.
(2) The length from the sheet position to the outlet of the orifice is made non-axisymmetric.
(3) In FIG. 13, the tendency of the spray distribution is strengthened or weakened by offsetting the injection port inlet with respect to the turning center C.
(4) The reach distance of L1 and L2 is changed by making the outlet shape of the orifice non-axisymmetric.

Japanese Patent Laid-Open No. 10-18496 JP-A-11-159421

  In the technique described in Japanese Patent Application Laid-Open No. 10-18496, it is necessary to offset the injection hole with respect to the axis. For example, when the injection hole is processed by press work with excellent productivity, the position offset from the center of the curved surface is set. Since it is pressed, bending stress is applied to the punch, causing breakage. Moreover, it is necessary to make the injection hole inlet a smooth curved surface, which increases the number of processing steps and processing facilities such as electric discharge machining and lapping.

  The technique described in Japanese Patent Application Laid-Open No. 11-159421 is intended to change the spray reach distances L1 and L2, and in order to change L1 and L2 with the deflected injection port, the outlet part of the injection port is cut obliquely and injected. Mouth length is non-axisymmetric. For this reason, it is necessary to match the direction of the injection port and the direction of the inclined surface, and the number of processing steps increases, for example, alignment is required by machining.

Further, by offsetting the injection port inlet with respect to the turning center C, the shape of the injection port inlet is changed, and the tendency of uneven distribution of the spray distribution is increased or decreased to obtain a desired spray shape, flow velocity, and flow rate distribution. . However, there is no mention of homogeneous spraying, the use of a ball valve, and the relatively long aspect of the jet port length (L) and jet port diameter (d) of 0.3 <L / d <1.3. It is considered that an orifice with a short ratio cannot achieve homogeneity such that the penetration length is the same all around. Moreover, the length ratio between L1 and L2 cannot be reversed.

  An object of the present invention is to obtain a highly homogeneous spray even with an orifice deflected with respect to the axis of an electromagnetic fuel injection valve.

  Another object is to change the homogeneity of the orifice deflected with respect to the axis of the electromagnetic fuel injection valve by changing the shape of the second conical surface and the orifice.

  One of the above objects is to form a swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and a swirl fuel at the bottom of the fuel injection chamber In an electromagnetic fuel injection valve for an in-cylinder injection engine having an orifice that injects in an oblique direction, the seat surface has a conical shape with a surface in contact with the valve body of about 90 °, and the downstream side is smaller than 90 °. A conical surface, the second conical surface is asymmetrical with respect to the axis of the electromagnetic fuel injection valve body, and the deflection side of the orifice is short; the orifice is located downstream of the second conical surface and is relative to the deflection axis; This is achieved by making the axes symmetrical and approximately the same length.

  Preferably, according to the present invention, the inlet portion of the orifice connected to the second conical surface is formed in an edge shape.

  Preferably, in the present invention, the relationship between the length L of the orifice and the orifice diameter d is L / d ≧ 1.5, the outlet surface of the orifice is spherical, and the orifice located in the spherical surface is curved toward the outlet side. This is achieved by slightly increasing the diameter.

  Another object of the present invention is to form a swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and a swirl fuel at the bottom of the fuel injection chamber. In the electromagnetic fuel injection valve for an in-cylinder injection type engine having an orifice for injecting the nozzle in an oblique direction, the seat surface has a conical shape with a surface in contact with the valve body of about 90 °, and the downstream side is smaller than 90 °. The second conical surface is symmetric with respect to the axis of the electromagnetic fuel injection valve body, and the orifice is located downstream of the second conical surface and is asymmetric with respect to the deflection axis, This is achieved by shortening slightly.

  One of the above objects is to form a swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and a swirl fuel at the bottom of the fuel injection chamber. In an electromagnetic fuel injection valve for an in-cylinder injection engine having an orifice that injects in an oblique direction, the seat surface has a conical shape with a surface in contact with the valve body of about 90 °, and the downstream side is smaller than 90 °. A conical surface, the second conical surface is asymmetrical with respect to the axis of the electromagnetic fuel injection valve body, and the deflection side of the orifice is short; the orifice is located downstream of the second conical surface and is relative to the deflection axis; Asymmetric and achieved by lengthening the deflection side.

  One of the above objects is to form a swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and a swirl fuel at the bottom of the fuel injection chamber. In an electromagnetic fuel injection valve for an in-cylinder injection engine having an orifice that injects in an oblique direction, the seat surface has a conical shape with a surface in contact with the valve body of about 90 °, and the downstream side is smaller than 90 °. A conical surface, the second conical surface is asymmetrical with respect to the axis of the electromagnetic fuel injector body, and the deflection side of the orifice is long; the orifice is located downstream of the second conical surface and is relative to the deflection axis; Asymmetric and achieved by shortening the deflection side.

  Preferably, according to the present invention, the inlet portion of the orifice connected to the second conical surface is formed in an edge shape.

  Preferably, in the present invention, the relationship between the length L of the orifice and the orifice diameter d is L / d ≧ 1.5, the outlet surface of the orifice is spherical, and the orifice located in the spherical surface is curved toward the outlet side. This is achieved by slightly increasing the diameter.

  According to the present invention, by optimizing the shape of the second conical surface located on the downstream side of the seat surface and the deflected orifice following the second conical surface, a highly homogeneous spray or Therefore, it is possible to easily obtain a spray having arbitrarily changed homogeneity. For this reason, the spray shape which can respond to various engines can be provided only by changing the shape of the deflected orifice following the second conical surface and the second conical surface.

  Further, the number of processing steps of the orifice plate is small, and the orifice can be easily produced by a processing method having excellent productivity such as press working.

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

  FIG. 1 is a longitudinal sectional view showing the overall configuration of an electromagnetic fuel injection valve according to an embodiment of the present invention.

  The electromagnetic fuel injection valve body 1 includes a magnetic circuit including a core 2, a yoke 3, a housing 4, and a mover 5, a coil 6 for exciting the magnetic circuit, and a terminal bobbin 7 for energizing the coil 6. A seal ring 8 is coupled between the core 2 and the housing 4 to prevent fuel from flowing into the coil 6.

  Valve parts are housed inside the housing 4, and a movable element 5, a nozzle 9, and a ring 10 that adjusts the stroke amount of the movable element 5 are arranged. The movable element 5 is obtained by connecting the valve body 11 and the movable core 12 with a joint 13, and suppresses the bounce when the movable element 5 is closed in cooperation with the pipe 18 between the movable core 12 and the joint 13. A plate 14 is provided.

  The housing 4 and the nozzle 9 constituting the jacket member cover the periphery of the movable element 5. The nozzle 9 includes the orifice plate 15 having a sheet surface 15 a and an orifice 15 b at the tip, and the guide plate 16 and the movable element 5. A swirler 17 is provided that slidably guides and applies a turning force to the fuel.

  A spring 19 that presses the valve element 11 against the seat surface 15a via the pipe 18 and the plate 14, an adjuster 20 that adjusts the pressing load of the spring 19, and a filter 21 that prevents entry of contamination from the outside are disposed inside the core 2. Has been.

  The operation of the electromagnetic fuel injection valve body 1 configured as described above will be described. When the coil 6 is energized, the mover 5 is attracted in the direction of the core 2 against the urging force of the spring 19, and a gap is formed between the valve seat portion 11a at the tip of the mover 5 and the seat surface 15a (opening). Valve state). The pressurized fuel first enters the nozzle 9 from the core 2, the adjuster 20, and the pipe 18 through the fuel passage 13 a in the mover 5. Next, the fuel passage 16 a of the guide plate 16 and the passage 9 a of the nozzle enter the passages 17 a and 17 b of the swirler 17, and a turning force is given by the turning groove 17 c of the swirler 17. The fuel given the turning force is injected through the orifice 15b from the gap between the valve seat portion 11a and the seat surface 15a.

  On the other hand, when the current of the coil 6 is interrupted, the valve seat portion 11a of the mover 5 is brought into contact with the seat surface 15a by the force of the spring 19, and the valve is closed.

  In the fuel injection valve body 1 configured as described above, the orifice plate 15, the second conical valve 15c, and the orifice 15b determine the spray shape, and the details thereof will be described below.

  FIG. 2 is a partially enlarged view of the tip of FIG. 1 and shows the periphery of the valve that forms a homogeneous spray in which the penetration lengths L1 and L2 are substantially equal.

The orifice plate 15 has a spherical shape (spherical surface 15f) on the outlet side of the orifice 15b, and has a seat surface 15a of about 90 ° and a second conical surface 15c of about 70 ° that open and close with the valve seat portion 11a from the upstream side. The inlet portion 15d of the orifice 15b and the outlet portion 15e having a curved outlet. Here, the second conical surface 15c is on the downstream side from the position where the valve seat portion 11a and the seat surface 15a are opened and closed, and the upstream side has a two-stage conical surface shape. The second conical surface 15c and the inlet 15d of the orifice 15b are connected in an edge shape. The orifice 15b has a diameter of about 0.6 mm and a length of about 1.2 mm, and the deflection angle of the orifice 15b may be 5 ° to 20 °. In this case, it is set to 12.5 °.

  The seat surface 15 a is symmetric with respect to the axis A of the electromagnetic fuel injection valve body 1. The second conical surface 15c is on the axis A, but the deflection side of the orifice 15b is shortened. The orifice 15b is axisymmetric with respect to the deflection axis B passing through the intersection of the axes A and C in the second conical surface 15c, and the inlet portion 15d is substantially perpendicular to the deflection axis B. That is, the inlet portion 15d of the orifice 15b connected to the second conical surface 15c is set to about 90 ° with respect to the deflection axis B.

  As a result of the experiment, if the setting is made as described above, the flow of fuel given the turning force in the turning groove 17c reaches the second conical surface while turning in the gap between the valve seat portion 11a and the seat surface 15a, and then turns. However, since the inlet portion 15d is inclined, it flows into the orifice 15b sequentially from the deflection side of the orifice 15b, and is injected into the cylinder of the engine from the outlet portion 15e. The spray shape at this time is an isosceles triangle-shaped homogeneous spray in which penetration lengths L1 and L2 which are substantially symmetrical with respect to the deflection axis B are substantially equal, and has a shape like the spray 30.

  FIG. 3 is a partially enlarged view of the tip of FIG. 1 and shows the periphery of a valve that forms a spray with a penetration length of L1> L2.

  The orifice plate 15 has a spherical shape (spherical surface 15f) on the outlet side of the orifice 15b, and has a seat surface 15a of about 90 ° and a second conical surface 15c of about 70 ° that open and close with the valve seat portion 11a from the upstream side. The inlet portion 15d of the orifice 15b and the outlet portion 15e having a curved outlet. Here, the second conical surface 15c is on the downstream side from the position where the valve seat portion 11a and the seat surface 15a are opened and closed, and the upstream side has a two-stage conical surface shape. The second conical surface 15c and the inlet portion 15d of the orifice 15b are connected in an edge shape. The orifice 15b has a diameter of about 0.6 mm and a length of about 1.2 mm, and the deflection angle of the orifice 15b may be 5 ° to 20 °. In this case, it is set to 12.5 °.

  The seat surface 15a and the second conical surface 15c are symmetric with respect to the axis A of the electromagnetic fuel injection valve body 1. The orifice 15b is on the deflection axis B passing through the intersection of the axis A and the C line at the inlet 15d of the orifice 15b, but the deflection side is slightly short and non-axisymmetric, and the inlet 15d is substantially perpendicular to the axis A. It has become. That is, the inlet portion 15d of the orifice 15b connected from the second conical surface 15a is set to about 90 ° with respect to the axis A.

  As a result of the experiment, when the setting is made as described above, the flow of fuel given the turning force in the turning groove 17c reaches the second conical surface 15c while turning in the gap between the valve seat portion 11a and the seat surface 15a, and then turns. However, it flows into the orifice 15b simultaneously from the entire circumference and is injected into the cylinder of the engine from the outlet 15e. The spray shape at this time is longer on the deflection side with respect to the deflection axis B, becomes a heterogeneous spray having a penetration length of L1> L2, and has a shape like the spray 31.

  FIG. 4 is a partially enlarged view of the tip of FIG. 1 and shows the periphery of a valve that forms a spray with a penetration length L1 <L2.

  The orifice plate 15 has a spherical shape (spherical surface 15f) on the outlet side of the orifice 15b, and has a seat surface 15a of about 90 ° and a second conical surface 15c of about 70 ° that open and close with the valve seat portion 11a from the upstream side. The inlet portion 15d of the orifice 15b and the outlet portion 15e having a curved outlet. Here, the second conical surface 15c is on the downstream side from the position where the valve seat portion 11a and the seat surface 15a are opened and closed, and the upstream side has a two-stage conical surface shape. The second conical surface 15c and the inlet portion 15d of the orifice 15b are connected in an edge shape. The orifice 15b has a diameter of about 0.6 mm and a length of about 1.2 mm, and the deflection angle of the orifice 15b may be 5 ° to 20 °. In this case, it is set to 12.5 °.

The seat surface 15 a is symmetric with respect to the axis A of the electromagnetic fuel injection valve body 1. The second conical surface 15c is on the axis A, but the deflection side of the orifice 15b is shortened. The orifice 15b is on the deflection axis B passing through the intersection of the axes A and C in the second conical surface 15c, but the deflection side is long, and the inlet portion 15d is inclined downward to the right with respect to the deflection axis B. It has become. That is, the inlet portion 15d of the orifice 15b connected to the second conical surface 15c is more inclined to the right with respect to FIG. As a result of the experiment, when set as described above, the flow of the fuel given the turning force in the turning groove 17c reaches the second conical surface 15c while turning around the gap between the valve seat portion 11a and the seat surface 15a, and then Since the inlet portion 15d is tilted while turning, it flows into the orifice 15b sequentially from the deflection side of the orifice 15b, and is injected into the cylinder of the engine from the outlet portion 15e. The spray shape at this time is a non-homogeneous spray in which the deflection side is shorter than the deflection axis B, and the penetration length is L1 <L2, resulting in a spray-like shape.

  FIG. 5 is a partially enlarged view of the tip of FIG. 1 and shows the periphery of a valve that forms a spray with a penetration length of L1> L2.

The orifice plate 15 has a spherical shape (spherical surface 15f) on the outlet side of the orifice 15b, and has a seat surface 15a of about 90 ° and a second conical surface 15c of about 70 ° that opens and closes with the valve seat portion 11a from the upstream side. The inlet portion 15d of the orifice 15b and the outlet portion 15e having a curved outlet. Here, the second conical surface 15c is on the downstream side from the position where the valve seat portion 11a and the seat surface 15a are opened and closed, and the upstream side has a two-stage conical surface shape. The second conical surface 15c and the inlet portion 15d of the orifice 15b are connected in an edge shape. The orifice 15b has a diameter of about 0.6 mm and a length of about 1.2 mm, and the deflection angle of the orifice 15b may be 5 ° to 20 °. In this case, it is set to 12.5 °.

  The seat surface 15 a is symmetric with respect to the axis A of the electromagnetic fuel injection valve body 1. The second conical surface 15c is on the axis A, but the deflection side of the orifice 15b is long. The orifice 15b is on the deflection axis B passing through the intersection of the axis A and the C line in the orifice 15b, but the deflection side is shortened, and the inlet portion 15d is inclined upward to the deflection axis B. That is, the inlet portion 15d of the orifice 15b connected to the second conical surface 15c is inclined to the right with respect to FIG.

  As a result of the experiment, when set as described above, the flow of the fuel given the turning force in the turning groove 17c reaches the second conical surface 15c while turning around the gap between the valve seat portion 11a and the seat surface 15a, and then Since the inlet portion 15d is inclined while turning, it flows into the orifice 15b sequentially from the side opposite to the deflection side of the orifice 15b, and is injected into the cylinder of the engine from the outlet portion 15e. The spray shape at this time becomes a heterogeneous spray in which the deflection side is longer than the deflection axis B, and the penetration length is L1> L2, and is shaped like a spray 33.

  As described above in the first to fourth embodiments, the shape of the spray can be arbitrarily changed by changing the shape of the inlet portion 15d of the orifice 15b from the second conical surface 15c. That is, the spray shape can be changed only by changing the position of the intersection of the axis B of the orifice 15b and the axis A of the electromagnetic fuel injection valve body 1.

  FIG. 6 is a view of the electromagnetic fuel injection valve body 1 as viewed from the outlet side. The orifice 15b is on the X-axis, and is not offset with respect to the X-axis as disclosed in JP-A-10-18496.

  Although not shown, the orifice plate 15 is processed by processing the outer shape of the orifice plate 15 and the spherical surface 15f by cutting or the like, and processing the orifice 15b from the spherical surface 15f side into a half-cut shape by pressing. Next, the second conical surface 15c is processed by cutting or the like to open the orifice 15b. Further, after quenching, the sheet surface 15a is finished by grinding or the like. Here, by changing the position on the X-ray in FIG. 6 when the orifice 15b is pressed, the shape of the second conical surface 15c and the inlet portion 15d of the orifice 15b can be changed to the desired shape.

  The present invention can be applied to an electromagnetic fuel injection valve for an in-cylinder injection engine that directly injects gasoline into the cylinder of the engine, and contributes to improvement of fuel consumption and reduction of harmful components of exhaust gas.

1 is a longitudinal sectional view showing the overall configuration of an electromagnetic fuel injection valve showing a first embodiment of the present invention. The longitudinal cross-sectional view which shows the expansion of the front-end | tip part of the electromagnetic fuel injection valve main body which shows 1st Example of this invention. The longitudinal cross-sectional view which shows the expansion of the front-end | tip part of the electromagnetic fuel injection valve main body which shows 2nd Example of this invention. The longitudinal cross-sectional view which shows the expansion of the front-end | tip part of the electromagnetic fuel injection valve main body which shows 3rd Example of this invention. The longitudinal cross-sectional view which shows the expansion of the front-end | tip part of the electromagnetic fuel injection valve main body which shows 4th Example of this invention. The general-view figure which shows the exit part of the electromagnetic fuel injection valve of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electromagnetic fuel injection valve main body, 15 ... Orifice plate, 15a ... Seat surface, 15b ... Orifice, 15c ... 2nd conical surface, 15d ... Inlet part, 15e ... Outlet part.

Claims (10)

A swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body and a fuel injection chamber that is opened and closed by the valve body are formed, and swirl fuel is injected obliquely into the bottom of the fuel injection chamber. A fuel injection valve with an orifice,
The seat surface is a conical shape having a surface in contact with the valve body of about 90 °, and the downstream side of the seat surface is a second conical surface smaller than 90 °, and the second conical surface is an axis of the fuel injection valve body. The fuel injection is characterized in that it is asymmetrical, the deflection side of the orifice is short, the orifice is located downstream of the second conical surface, is axially symmetric with respect to the deflection axis and has substantially the same length valve.   2. The electromagnetic fuel injection valve according to claim 1, wherein an inlet portion of the orifice connected to the second conical surface has an edge shape. In Claim 1, the relationship between the length L of the orifice and the previous orifice diameter d is L / d ≧
1.5. The electromagnetic fuel injection valve according to 1.5, wherein the outlet surface of the orifice is spherical, and the orifice located in the spherical portion has a curved surface with a diameter increasing toward the outlet side. A swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and an orifice that injects swirl fuel in an oblique direction at the bottom of the fuel injection chamber. A fuel injection valve provided,
The seat surface is a conical shape having a surface in contact with the valve body of about 90 °, and the downstream side of the seat surface is a second conical surface smaller than 90 °, and the second conical surface is an axis of the fuel injection valve body. A fuel injection valve characterized by being symmetrical with respect to each other, wherein the orifice is disposed downstream of the second conical surface, is asymmetric with respect to a deflection axis, and has a short deflection side. A swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and an orifice that injects swirl fuel in an oblique direction at the bottom of the fuel injection chamber. A fuel injection valve provided,
The seat surface is a conical shape with a surface of about 90 ° in contact with the valve body, and a downstream side thereof is a second conical surface smaller than 90 °, and the second conical surface is asymmetric with respect to the axis of the fuel injection valve body. A fuel injection valve characterized in that the deflection side of the orifice is short, the orifice is located downstream of the second conical surface, is asymmetric with respect to the deflection axis, and has a long deflection side. A swirler that applies a swirl force upstream of the seat surface to the fuel that passes around the valve body, a fuel injection chamber that is opened and closed by the valve body, and an orifice that injects swirl fuel in an oblique direction at the bottom of the fuel injection chamber. A fuel injection valve provided,
The seat surface is a conical shape with a surface of about 90 ° in contact with the valve body, and a downstream side thereof is a second conical surface smaller than 90 °, and the second conical surface is asymmetric with respect to the axis of the fuel injection valve body. A fuel injection valve characterized in that the deflection side of the orifice is long, the orifice is located downstream of the second conical surface, is asymmetric with respect to the deflection axis, and has a short deflection side.   7. The fuel injection valve according to claim 4, wherein an inlet portion of the orifice connected to the second conical surface has an edge shape.   The relationship between the orifice length L and the previous orifice diameter d is L / d ≧ 1.5, the outlet surface of the orifice is spherical, and the orifice located in the spherical portion is A fuel injection valve characterized in that its diameter slightly increases in a curved shape toward the outlet side. In any one of Claims 1 thru | or 8,
The fuel injection valve is an electromagnetic fuel injection valve that injects a predetermined amount of fuel by operating a valve body by energizing and shutting off a built-in coil. In claim 9,
The fuel injection valve is applied to an in-cylinder injection engine that obtains power by directly spraying fuel into a combustion chamber of the engine.

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