JP2006002720A - Fuel injection device and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide technology of a fuel injection device capable of forming homogeneous liquid film spray and promoting atomization of fuel. <P>SOLUTION: A plurality of injection holes 231 are provided on an injection hole plate 23 of a fuel injection valve injecting fuel. In each injection hole 231, a flow-in opening 231a has an ellipse shape and a flow-out opening 231b has a slit shape, and a flow passage communicating from the flow-in opening 231a to the flow-out opening 231b is formed inside of the injection hole plate 23. Fuel passing through the injection hole 231 and injected from the flow-out opening 231b forms homogeneous liquid film spray and atomization is promoted by the injection hole plate 23 of such structure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection device that injects fuel into an internal combustion engine and a method for manufacturing the same.

  Some fuel injection valves (fuel injection devices) inject fuel in the form of a film in order to atomize the fuel.

  For example, as disclosed in Patent Document 1, two slit-shaped injection holes are provided in parallel on the injection hole plate, so that a liquid film-like spray having a small spray angle when viewed from the side is formed and the fluid is formed. (Fuel) atomization is promoted.

JP-A-8-200197

  In the fuel injection valve of the above-mentioned Patent Document 1, the fuel flowing out from the valve seat forms an outward or inward radial flow on the fuel inflow surface of the nozzle hole plate, and therefore flows into the slit-shaped nozzle hole inlet. However, the fuel distribution in the nozzle hole becomes non-uniform due to the concentration of the flow at both ends of the slit. As a result, there is a problem that the degree of atomization of the fuel injected from the nozzle hole outlet is biased.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a technique of a fuel injection device that can promote atomization of fuel by forming a uniform liquid film spray.

  In order to solve the above-mentioned problem, the invention of claim 1 is a fuel injection device for injecting fuel into an internal combustion engine, and (a) an injection hole for injecting fuel by flowing fuel from an inlet to an outlet And (b) a supply portion for supplying fuel to the inlet, the inlet has a shape line including a substantially elliptical arc or a substantially arc, and the outlet has a belt-like shape.

  According to a ninth aspect of the present invention, there is provided a fuel injection device that includes a plate having an injection hole portion through which fuel flows from an inflow port to an outflow port to inject fuel, and performs fuel injection to an internal combustion engine. The method includes: (a) a step of determining a fuel spray angle from the outlet; and (b) a longitudinal length of the inlet based on the fuel spray angle determined in the step (a). And a step of determining a ratio of the length in the longitudinal direction of the outlet, and (c) a step of manufacturing the plate based on the ratio determined in the step (b). It has a shape line including a substantially elliptical arc or a substantially circular arc, and the outlet has a strip shape.

  According to a tenth aspect of the present invention, there is provided a fuel injection device that includes a plate having an injection hole portion through which fuel flows from an inflow port to an outflow port to inject fuel, and performs fuel injection to an internal combustion engine. A method of (a) determining a fuel spray direction from the outlet, and (b) projecting on the main surface of the plate based on the fuel spray direction determined in the step (a). A step of determining an angle formed by a longitudinal direction of the inflow port and a longitudinal direction of the outflow port, and (c) manufacturing the plate based on the angle determined in the step (b). The inflow port has a shape line including a substantially elliptical arc or a substantially arc shape, and the outflow port has a strip shape.

<Terminology>
The “substantially elliptical arc” in the above-mentioned claims 1, 9 and 10 includes a precise elliptical arc and a substantially elliptical arc that is recognized as an external appearance. Similarly, “substantially circular arc” includes an accurate circular arc and a substantially circular arc that is recognized in appearance.

  According to the first aspect of the present invention, since the fuel flows from the inflow port having a shape line including a substantially elliptical arc or a substantially arc to the outflow port having a strip shape, the fuel is ejected. This can promote fuel atomization.

  According to the invention of claim 9, the longitudinal length of the inlet having a shape line including a substantially elliptical arc or a substantially arc and the longitudinal direction of the outlet having a belt-like shape based on the determined fuel spray angle The ratio with the length of the nozzle is determined, and a plate in which the nozzle hole portion is formed is manufactured based on this ratio. As a result, it is possible to promote atomization of the fuel by forming a uniform liquid film-like spray, and to easily control the fuel spray angle.

  According to the invention of claim 10, the longitudinal direction of the inflow port and the longitudinal direction of the outflow port when projected onto the main surface of the plate in which the nozzle hole portion is formed based on the determined fuel spray direction. Is determined, and the plate is manufactured based on this angle. As a result, a uniform liquid film spray can be formed to promote atomization of the fuel, and the control of the fuel spray direction is facilitated.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing the overall configuration of a fuel injection valve 1 according to Embodiment 1 of the present invention. FIG. 2 is an enlarged cross-sectional view of the lower portion of the fuel injection valve 1 indicated by an imaginary line IL in FIG. In the following description, directions and directions are indicated by appropriately using the XYZ three-dimensional orthogonal coordinate system shown in the drawing.

  The fuel injection valve 1 functions as a fuel injection device that injects fuel into an internal combustion engine. An electromagnetic coil 11, a fixed iron core 12, and two metal plates 13 are disposed in a resin housing 10 and are integrally formed. Has been.

  The electromagnetic coil 11 includes a resin bobbin 11a, a coil 11b wound around the outer periphery of the resin bobbin 11a, and a terminal 11c provided for connection to the outside. It is integrally molded.

  An adjuster 15 for adjusting the load of the compression spring 14 is fixed inside the fixed iron core 12.

  The two metal plates 13 constitute a magnetic circuit, one end of which is fixed by the fixed iron core 12 and the other end is fixed to the magnetic pipe 16 by welding.

  The movable iron core 17 has a needle pipe 18 welded to one end and fixed. One end of the needle pipe 18 on the side of the movable iron core 17 is in contact with the compression spring 14, and the other end is welded and fixed to a ball 21 that functions as a valve.

  The ball 21 is configured to be able to be seated and separated from a valve seat portion 221 of a valve seat 22 disposed inside the magnetic pipe 16. The outer peripheral portion of the ball 21 is processed into a pentagon, and forms a fuel passage together with the guide portion 222 of the valve seat 22 to supply fuel to the inlet 231a (see FIG. 3).

  A cylindrical fuel passage 223 and a fuel cavity 224 communicating with the fuel passage 223 are formed in the valve seat 22. An injection hole plate 23 having an injection hole 231 is attached to the valve seat 22 so as to cover the fuel cavity 224.

  FIG. 3 is a plan view of the nozzle hole plate 23 as viewed from above the Z-axis. 4 is a cross-sectional view seen from the IV-IV position in FIG. 3, and FIG. 5 is a cross-sectional view seen from the V-V position in FIG.

  The nozzle hole plate 23 has ten nozzle holes 231 arranged at equal intervals on the same circumference Co, and these nozzle holes 231 function as nozzle holes for jetting fuel. In each nozzle hole 231, the inflow port 231 a has an elliptical shape, the outflow port 231 b has an elongated rectangular shape (slit shape), and a flow path communicating from the inflow port 231 a to the outflow port 231 b is provided. It is formed inside the nozzle hole plate 23. And the area of the inflow port 231a is larger than the area of the outflow port 231b.

  The outlet 231b of the nozzle hole 231 preferably has a slit width b1 of 0.1 mm or less for good fuel atomization, and the slit length b2 is about 10 times the slit width b1. desirable.

  The number of nozzle holes 231 formed in the nozzle hole plate 23 is determined based on the slit area of the outlet 231b with respect to the fuel flow rate required by the internal combustion engine.

  Further, the center of the inflow port 231a and the center of the outflow port 231b of the injection hole 231 are eccentric by a distance d0 when the injection hole plate 23 is viewed from above (fuel inflow side). As a result, as shown in FIG. 4, the axis 23p of the injection hole 231 from the center of the inflow port 231a toward the center of the outflow port 231b is inclined by an angle θp with respect to the direction of the perpendicular 1p with respect to the main surface of the injection hole plate 23. To do. As a result, the direction of the axis 23p corresponding to the fuel injection direction can be set to a desired direction. Therefore, when two-way injection is performed on an intake two-valve internal combustion engine, or when the injection direction is inclined in one-way injection. It will be possible to respond to.

  Further, by making the ratio of the major axis a2 of the inlet 231a to the slit length b2 of the outlet 231b in the nozzle hole 231 smaller than 1, the spread angle θr of the spray as shown in FIG. 5 can be obtained.

  The operation of the fuel injection valve 1 having the above configuration will be briefly described.

  First, the coil 11b is energized from the outside of the fuel injection valve 1 via the terminal 11c. As a result, a magnetic flux is generated in a magnetic circuit constituted by the fixed iron core 12, the metal plate 13, the magnetic pipe 16 and the movable iron core 17, and the movable iron core 17 is attracted to the fixed iron core 12 by a magnetic attractive force.

  Since the needle pipe 18 is integrally joined to the movable iron core 17, when the movable iron core 17 is attracted to the fixed iron core 12, the ball 21 welded and fixed to the needle pipe 18 moves to the fixed iron core 12 side. To do. As a result, a gap is formed between the valve seat portion 221 of the valve seat 22 and the ball 21 to form a fuel passage, so that fuel is injected from the injection hole 231 of the injection hole plate 23. In this fuel injection, the fuel can be injected as a uniform film-like spray by flowing the fuel from the inlet 231a having the shape shown in FIGS. 3 to 5 to the outlet 231b.

  A method for manufacturing the nozzle hole plate 23 having such a configuration will be described below.

  FIG. 6 is a view for explaining a method of manufacturing the nozzle hole plate 23.

  First, as shown in FIG. 6A, a conductive layer 92 is formed on a substrate 91 configured as a glass substrate, for example. The substrate 91 is not limited to a glass substrate but may be a ceramic substrate.

  Next, after a layer 93 of a photocurable resin that is optically cured when irradiated with a laser beam or the like is formed on the conductive layer 92 in a thin film shape, the laser beam LT is scanned from above to be irradiated with the light beam LT. A portion (mask layer) 93s of the resin layer 93 is cured (see FIG. 6B). Thereby, the mask layer 93s used in the electroplating performed in a later process can be formed with high accuracy.

  Then, by repeating the process shown in FIG. 6B, that is, the process of irradiating the thin film-like resin layer 93 sequentially formed with the light beam LT, the mask layer 93s shown in FIG. 6C is laminated. . Thereafter, by removing the uncured resin layer 93 excluding the mask layer 93s, the mask layer 93s is three-dimensionally generated as shown in FIG. The shape of the mask layer 93 s corresponds to the three-dimensional shape of the nozzle hole 231 of the nozzle hole plate 23 shown in FIGS. 3 to 5, and a complicated shape can be obtained by controlling the irradiation of the light beam LT onto the resin layer 93. The nozzle hole 231 can be formed.

  Next, after the substrate 91 (FIG. 6D) on which the mask layer 93s is formed on the conductive layer 92 is transferred into an electroplating bath (not shown), the conductive layer 92 is electrically connected to FIG. 6E. Through the formation process of the metal layer 94 shown in FIG. 6, the metal layer 94 is formed so as to surround the mask layer 93s (see FIG. 6F).

  Finally, if the mask layer 93s is dissolved and removed, only the metal layer 94 remains, and the metal layer 94 shown in FIG. The metal layer 94 thus manufactured has holes 94 h corresponding to the nozzle holes 231 of the nozzle hole plate 23, and can be used as a part or all of the nozzle hole plate 23.

  By manufacturing the nozzle hole plate 23 by such an electroforming method, the shape of the inlet and the outlet can be freely set.

  For example, the fuel spray angle θr (see FIG. 5) from the inlet 231a is determined, and the long diameter (length in the longitudinal direction) a2 of the inlet 231a and the slit length of the outlet 231b shown in FIG. 3 based on the spray angle θr. The ratio with (length in the longitudinal direction) b2 is determined. Then, by manufacturing the nozzle plate 23 having the nozzle holes 231 having this ratio in the steps shown in FIGS. 6A to 6G, the spray angle θr of the fuel can be controlled.

  In the fuel injection valve 1 described above, since the inlet of the nozzle hole has an elliptical shape, the fuel can flow uniformly and smoothly into the inlet. In addition, since the outlet of the nozzle hole has a belt-like shape, a uniform liquid film spray can be injected from the outlet, and fuel atomization can be promoted. As a result, the combustibility of the internal combustion engine is improved, and performance with reduced fuel consumption and exhaust gas can be realized.

  In the fuel injection valve 1 of the present embodiment, it is not essential to provide the nozzle hole plate 23 having the nozzle holes 231 shown in FIG. 3, and the nozzle hole plates 23A to 23C having the nozzle holes described below are provided. It may be provided.

(1) Injection hole plate 23A
FIG. 7 corresponds to FIG. 3 and is a plan view showing the nozzle hole plate 23A.

  The nozzle hole plate 23A is common to the nozzle hole plate 23 of FIG. 3 in that each nozzle hole 232 has an elliptical inlet and a slit outlet, but only four nozzle holes 232 are provided. Different points are provided. That is, compared with the nozzle hole plate 23 of FIG. 3 in which the centers of the inlets of the nozzle holes 231 are arranged at equal intervals on the same circumference Co, the nozzle hole 23A has four nozzles. The centers of the inlets of the holes 232 are concentrated and biased in a part of the circumference Co.

  The injection hole plate 23A in which the arrangement of the injection holes 232 is biased in this way is effective when the fuel injection direction is restricted according to the shape of the intake pipe in which the fuel injection valve is installed.

(2) Injection hole plate 23B
FIG. 8 corresponds to FIG. 3 and is a plan view showing the nozzle hole plate 23B.

  The nozzle hole plate 23B is common to the nozzle hole plate 23 of FIG. 3 in that it has ten nozzle holes 233 each having an elliptical inlet and a slit outlet. The difference is that the inclination direction is different. That is, in the nozzle hole plate 23B, the inclination direction of the axis of each nozzle hole 233 is changed by changing the direction of the nozzle hole 233 like the angles θa and θb shown in FIG.

  Further, the nozzle hole plate 23B is different from the nozzle hole plate 23 of FIG. 3 in that the distance between the center of the inlet and the center of the outlet is changed. That is, in the nozzle hole plate 23B, the distances d1, d2, and d3 shown in FIG. 8 are compared with the nozzle hole plate 23 in FIG. 3 where the distances d0 between the inlet center and the outlet center of the nozzle hole 231 are all equal. Thus, the distance between the center of the inlet of the nozzle hole 233 and the center of the outlet is changed. Thereby, in each nozzle hole 233, the inclination angle of the axis according to the distance between the center of the inlet and the center of the outlet can be obtained.

  As described above, in the nozzle hole plate 23B, since the directions of the axes (see 23p in FIG. 4) of the ten nozzle holes 233 are different from each other, the fuel flows more smoothly on the inlet side of the nozzle hole 233. And the fuel injection direction can be finely controlled.

(3) Injection hole plate 23C
FIG. 9 corresponds to FIG. 3 and is a plan view showing the nozzle hole plate 23C.

  The nozzle hole plate 23 </ b> C is common to the nozzle hole plate 23 of FIG. 3 in that it has ten nozzle holes 234 having an elliptical inlet and a slit outlet. The difference is that the angle between the major axis of the ellipse at the inlet and the long side of the slit at the outlet is different. That is, in each nozzle hole 234 of the nozzle hole plate 23C, compared to the nozzle hole plate 23 of FIG. 3 in which the major axis direction of the ellipse at the inlet of the nozzle hole 231 and the long side direction of the slit of the outlet are not twisted equally, Like the angle θc shown in FIG. 9, the major axis of the ellipse at the inlet and the long side of the slit at the outlet have a constant twist angle. In the nozzle hole plate 23C, the major axis direction of the inlet of the nozzle hole 234 is arranged along the circumference Co.

  The injection hole plate 23C having the injection holes 234 as described above has a relationship in which the major axis direction of the inlet is orthogonal to the radial flow of fuel in the injection hole plate. Smooth fuel flow can be promoted.

  In addition, by manufacturing the nozzle hole plate 23 </ b> C having such a configuration by the method described with reference to FIG. 6, the twist angle between the outlet and the inlet corresponding to the fuel spraying direction is set at each nozzle hole 234. It can be set freely.

  That is, the spray direction of the fuel from the outlet is determined, and the longitudinal direction of the inlet and the longitudinal direction of the outlet when projected on the main surface of the nozzle hole plate 23C as shown in FIG. An angle (for example, θc in FIG. 9) is determined. And based on the determined angle, the nozzle hole plate 23C is manufactured by the manufacturing method shown in FIG. As a result, the fuel spray direction can be controlled more finely.

Embodiment 2. FIG.
The fuel injection valve 1A according to the second embodiment of the present invention has a configuration similar to that of the fuel injection valve 1 according to the first embodiment shown in FIG. 1, but the injection hole plate is different. The injection hole plate 23D of the fuel injection valve 1A will be described below.

  FIG. 10 is a view for explaining the nozzle hole plate 23D. 10A corresponds to FIG. 3 and is a plan view seen from above, and FIG. 10B is a cross-sectional view seen from the position XX in FIG. 10A.

  As shown in FIG. 10A, the nozzle hole plate 23 </ b> D includes ten nozzle holes 235 arranged on the same circumference Co at substantially equal intervals. In each nozzle hole 235, the inflow port 235a has an elliptical shape, but the outflow port 235b has an arcuate slit shape. The outlet 23g has the same area as the outlet 231b of the nozzle hole 231 in the first embodiment.

  From the injection hole 235 having such a configuration, fuel can be injected with the spread angle suppressed as in the spray G1 shown in FIG.

  In the fuel injection valve 1A having the nozzle hole plate 23D as described above, since the outlet 235b of the nozzle hole 235 has a curved band shape, a fuel flow rate equivalent to that of the fuel injection valve 1 of the first embodiment is ensured. However, it is possible to suppress the spread angle of the spray and prevent the fuel from adhering to the inner wall of the intake pipe.

Embodiment 3 FIG.
The fuel injection valve 1B according to Embodiment 3 of the present invention has a configuration similar to that of the fuel injection valve 1 according to Embodiment 1 shown in FIG. 1, but the injection hole plate is different. The injection hole plate 23E of the fuel injection valve 1B will be described below.

  FIG. 11 is a view for explaining the nozzle hole plate 23E. 11A corresponds to FIG. 3 and is a plan view seen from above, and FIG. 11B is a cross-sectional view seen from the position XI-XI in FIG. 11A.

  As shown in FIG. 11A, the nozzle hole plate 23E has eight nozzle holes 236 arranged on the same circumference Co at almost equal intervals. In each nozzle hole 236, the inlet 236a is divided into three relatively small circular shapes, and these three circular holes communicate smoothly with the outlet 236b of the slit hole inside the nozzle hole plate 23E. (See FIG. 11B). Note that the total area of the three circular holes at the inflow port 236a is equal to the area of the inflow port 231a of the injection hole 231 in the first embodiment.

  From the injection hole 236 having such a configuration, the fuel can be injected with the spread angle largely suppressed as in the spray G2 shown in FIG.

  In the fuel injection valve 1B having the injection hole plate 23E as described above, the inflow port 236b of the injection hole 236 is configured by three circular holes, so that the fuel flow rate equivalent to that of the fuel injection valve 1 of the first embodiment is ensured. However, it is possible to significantly suppress the spread angle of the spray and suppress the fuel from adhering to the inner wall of the intake pipe.

Embodiment 4 FIG.
The fuel injection valve 1C according to the fourth embodiment of the present invention has a configuration similar to that of the fuel injection valve 1 according to the first embodiment, but the lower portion of the fuel injection valve is different. The lower structure of the fuel injection valve 1C will be described below.

  FIG. 12 corresponds to FIG. 2 and is a cross-sectional view showing a lower portion of the fuel injection valve 1C.

  The ball 21A of the fuel injection valve 1C has a structure in which the tip of the ball 21 according to the first embodiment shown in FIG. 2 is removed by cutting along the XY plane, and has a flat tip surface 211.

  In the fuel injection valve 1C, the fuel cavity 224 (FIG. 2) of the first embodiment is omitted from the valve seat 225 of the valve seat 22A.

  In the fuel injection valve 1 </ b> C having such a configuration, the fuel passing through the valve seat 225 has a dominant flow from the outer peripheral portion toward the center on the upper surface of the injection hole plate 23. Therefore, when the fuel flows into the nozzle hole 231, the flow direction is largely changed by the axis 23 p (see FIG. 4) of the nozzle hole 231. Therefore, the fuel spreads in a thin film shape with the energy colliding with the side surface of the nozzle hole. The flow velocity inside the hole 231 increases, and fuel atomization can be further promoted.

Modified example.
-The inlet of the nozzle hole in the above-described first and second embodiments does not necessarily have an exact elliptical shape, and may be recognized as an almost elliptical shape, and may be a perfect circle or a substantially circular shape. But it ’s okay.

  Further, the inlet of the nozzle hole may have a shape line including an elliptical arc or a circular arc such as a semi-elliptical shape or a semi-circular shape. Even in such a case, the fuel can flow into the inlet uniformly and smoothly, and the atomization of the fuel can be promoted.

  -Regarding the outlet of the nozzle hole in the first embodiment, it is not essential that the four corners have a right-angled slit shape, and the four corners may have an arc-shaped slit shape.

  In each of the above embodiments, it is not essential that the shape line of the flow path communicating from the inlet to the outlet of the nozzle hole is a straight line as shown in FIG. 4 or FIG. It may be. Even with such a curved shape, atomization of the fuel spray can be promoted.

  The injection hole plate in each of the above embodiments is not necessarily used for a fuel injection valve, and may be used for a fuel injection device such as a fuel injection nozzle that does not have a valve body.

It is sectional drawing which shows the whole structure of the fuel injection valve 1 which concerns on Embodiment 1 of this invention. It is sectional drawing to which the lower part of the fuel injection valve 1 shown by the imaginary line IL of FIG. 1 was expanded. It is the top view which looked at the nozzle hole plate 23 from upper direction. It is sectional drawing seen from the IV-IV position of FIG. It is sectional drawing seen from the VV position of FIG. FIG. 5 is a view for explaining a method for manufacturing the nozzle hole plate 23. It is a top view which shows the nozzle hole plate 23A. It is a top view which shows the nozzle hole plate 23B. It is a top view which shows the nozzle hole plate 23C. It is a figure for demonstrating nozzle hole plate 23D which concerns on Embodiment 2 of this invention. It is a figure for demonstrating the nozzle hole plate 23E which concerns on Embodiment 3 of this invention. It is sectional drawing which shows the lower part of 1 C of fuel injection valves which concern on Embodiment 4 of this invention.

Explanation of symbols

1, 1A, 1B, 1C Fuel injection valve, 23, 23A-23E Injection hole plate, 23p axis, 231-236 injection hole, 231a, 235a, 236a Inlet, 231b, 235b, 236b Outlet.

Claims (10)

A fuel injection device for injecting fuel into an internal combustion engine,
(a) a nozzle hole for flowing fuel from the inlet to the outlet and ejecting the fuel;
(b) a supply unit for supplying fuel to the inflow port;
With
The inflow port has a shape line including a substantially elliptic arc or a substantially arc,
The fuel injection device according to claim 1, wherein the outlet has a strip shape. The fuel injection device according to claim 1,
The fuel injection device according to claim 1, wherein the inflow port has a substantially elliptical shape or a substantially circular shape. The fuel injection device according to claim 1 or 2,
A plate in which the nozzle hole portion is formed;
Further comprising
The fuel injection device, wherein an axial direction from the center of the inlet to the center of the outlet is inclined with respect to a direction perpendicular to the main surface of the plate. The fuel injection device according to claim 3, wherein
The nozzle hole part comprises a plurality of nozzle holes,
The fuel injection device, wherein the axial directions of the plurality of nozzle holes are different from each other. The fuel injection device according to any one of claims 1 to 3,
The nozzle hole part comprises a plurality of nozzle holes,
The fuel injection device according to claim 1, wherein the center of the inlet of each of the plurality of nozzle holes is arranged eccentrically on a predetermined circle. The fuel injection device according to any one of claims 1 to 5,
The fuel injection device according to claim 1, wherein the outlet has a curved strip shape. The fuel injection device according to any one of claims 1 to 6,
The inflow port has a plurality of circular holes,
The outlet has a slit hole;
The fuel injection device, wherein the plurality of circular holes and the slit holes communicate with each other to form the injection hole portion. The fuel injection device according to any one of claims 1 to 7,
The fuel injection device according to claim 1, wherein the plate in which the injection hole portion is formed is manufactured by an electroforming method. A method of manufacturing a fuel injection device that has a plate in which an injection hole portion for flowing fuel from an inflow port to an outflow port is formed and injects fuel into an internal combustion engine,
(a) determining a fuel spray angle from the outlet;
(b) determining a ratio between a length in the longitudinal direction of the inlet and a length in the longitudinal direction of the outlet based on the spray angle of the fuel determined in the step (a);
(c) producing the plate based on the ratio determined in the step (b);
With
The inflow port has a shape line including a substantially elliptic arc or a substantially arc,
The method for manufacturing a fuel injection device, wherein the outlet has a strip shape. A method of manufacturing a fuel injection device that has a plate in which an injection hole portion for flowing fuel from an inflow port to an outflow port is formed and injects fuel into an internal combustion engine,
(a) determining the spray direction of fuel from the outlet;
(b) Based on the spray direction of the fuel determined in the step (a), an angle formed by the longitudinal direction of the inlet and the longitudinal direction of the outlet when projected onto the main surface of the plate is determined. And a process of
(c) manufacturing the plate based on the angle determined in the step (b);
With
The inflow port has a shape line including a substantially elliptic arc or a substantially arc,
The method for manufacturing a fuel injection device, wherein the outlet has a strip shape.

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