JP2015169172A - fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fuel injection valve capable of injecting fuel in the form of a liquid film and stably atomizing a high flow rate of the fuel with a simple structure.SOLUTION: Four injection holes 16a and four injection holes 16b are arranged on two pitch circles about a hole center of a valve hole 14d of an injection hole plate 15 and having different radii, respectively, the injection hole 16a satisfying a relation of r<(5/4)*(d/h) is present only in one rotation direction if a plane Ph passing through a hole center of the injection holes 16a and including the hole center of the valve hole 14d rotates about the hole center of the valve hole 14d, a plane Ps that includes the hole center of the valve hole 14d and about which the eight injection holes 16a and 16b disposed in the injection hole plate 15 are mirror-image symmetrical is present, and the injection holes 16a and 16b are not disposed on the plane Ps.

Description

  The present invention relates to a fuel injection valve used in an internal combustion engine such as an automobile engine.

  In the fuel injection valve of the engine, the smaller the particle size of the injected fuel, the more the evaporation of fuel is promoted, the amount of fuel adhering to the engine inner wall is reduced, and the amount of unburned fuel is reduced. As a result, the fuel consumption efficiency (fuel consumption) of the engine is improved, and the amount of harmful gas emissions is reduced. Various means have been proposed for atomizing the injected fuel by reducing the thickness of the injected fuel by devising the flow path shape of the fuel injection valve and the arrangement of the injection holes.

  For example, as a means for promoting atomization, there is a method in which a swirling flow is generated inside the nozzle hole and fuel is injected into a liquid film. In the conventional fuel injection valve according to Patent Document 1, by providing a step portion on the nozzle hole plate, the flow of fuel flowing into the nozzle hole is biased, and a swirling flow is generated inside the nozzle hole.

  As other atomization means proposed, there is a method in which the flows in the horizontal direction collide with each other in the upstream portion of the nozzle hole. In the conventional fuel injection valve according to Patent Document 2, by defining the relationship between the nozzle hole diameter and the flow path height, the collision of the fuel at the upstream part of the nozzle hole is effectively performed and atomization is realized. In the conventional fuel injection valve according to Patent Document 2, by defining the nozzle hole arrangement, contrary to Patent Document 1, generation of a swirling flow around the nozzle hole is suppressed, and energy is effectively used for fuel collision. .

  Furthermore, in the conventional fuel injection valve according to Patent Document 3, by defining the relationship between the nozzle hole diameter and the flow path height and the relationship between the nozzle hole diameter and the thickness of the orifice plate, the fuel moves in the centripetal direction directly above the orifice. After colliding, the atomization was realized by changing the flow direction toward the orifice abruptly.

  Further, in the conventional fuel injection valve according to Patent Document 4, the nozzle hole arranged at a position affected by the fuel flow flowing in the radial direction and the position influenced by the fuel flow flowing bidirectionally inside the peripheral wall of the fuel chamber. The injection holes are arranged, and the injection direction of each injection hole is controlled to avoid interference between the fuel sprays, thereby realizing a desired spray shape.

JP 2004-211162 A JP 9-14090 A JP 2003-314411 A JP 2005-264757 A

  However, in patent document 1, the process which provides a level | step difference in a nozzle hole plate was difficult, and there existed a subject which became expensive. In addition, since it is necessary to provide a step in the nozzle hole plate, the number of nozzle holes that can be arranged is limited as compared with the fuel injection valve of the conventional structure, and it is difficult to increase the injection flow rate. The only way to increase the flow rate without increasing the number of nozzle holes is to increase the nozzle hole diameter. When the nozzle hole diameter is increased, it is difficult to control the injection direction.

  In order to atomize the fuel, it is necessary to spread the injected fuel into a thin liquid film. However, the fuel injected from the nozzle hole having a substantially circular cross section is basically in the form of a liquid column and is difficult to atomize. In Patent Document 2 and Patent Document 3, the flow in the horizontal direction is caused to collide with each other in the upstream portion of the nozzle hole. However, in the turbulence generated by the fuel collision in the upstream portion of the nozzle hole, the surface of the fuel injected into the liquid column shape at most In particular, a fuel injection valve that injects fuel at a relatively low pressure, such as an injection fuel pressure of 0.3 MPa to 1 MPa, has a problem that atomization cannot be sufficiently achieved.

  Moreover, in patent document 4, when a nozzle hole arrangement | positioning differs, the particle size of a spray differs for every nozzle hole. In order to promote atomization of a fuel injection valve having a plurality of injection holes, the atomization characteristics are governed by the particle size value of the spray having the worst particle diameter among the sprays injected from the nozzle hole group. However, there is a problem that it is necessary to stably improve the atomization characteristics of all the nozzle holes.

  The present invention has been made in order to solve such problems, and injects fuel in a liquid film with a simple structure, and enables fuel injection that can stably atomize a large amount of fuel. Get a valve.

A fuel injection valve according to the present invention includes a valve seat formed on an inner wall surface forming a fuel passage, a valve seat having a valve hole formed coaxially with the valve seat on the downstream side of the fuel passage, A valve member that has a contact portion that can be seated on the valve seat portion, and that opens or closes the fuel passage when the contact portion is separated or seated on the valve seat; and downstream of the valve hole of the valve seat A plurality of nozzle holes arranged on the pitch circles of n pieces (where n is an integer of 1 or more) having different radii centering on the hole center of the valve hole; And a fuel chamber formed between the valve seat and the injection hole plate and communicating with the fuel passage through the valve hole. When the hole diameter of the nozzle hole is d, the height of the fuel chamber immediately above the nozzle hole is h, and the distance between the hole centers of any two nozzle holes adjacent in the circumferential direction is r. When the surface Ph including the hole center of the valve hole is rotated around the hole center of the valve hole through the hole center of one of the two nozzle holes, only in one rotation direction, There is an injection hole satisfying the relationship of r <(5/4) · (d ² / h), and the hole center of the injection hole on the valve seat side surface of the injection hole plate is mirror-image-symmetric. There is a surface Ps including the hole center of the valve hole, and the nozzle hole is not disposed on the surface Ps.

  According to this invention, even in a fuel injection valve having a plurality of injection holes, the atomization characteristics of all the injection holes can be stably improved, so that atomization of the fuel injection valve can be promoted. .

  In addition, since it is not necessary to provide a step in the nozzle hole plate, the cost can be reduced, the number of nozzle holes can be easily increased, and a fuel injection valve having a large injection flow rate can be realized easily and inexpensively. Furthermore, since a large injection flow rate can be increased without increasing the nozzle hole diameter, the injection direction can be easily controlled.

Furthermore, the fuel, the ^{r <(5/4) · (d} 2 / h) side injection hole satisfying does not exist, the nozzle hole satisfying the ^{r <(5/4) · (d} 2 / h) Since the swirl flow is generated in the injection hole by going around the existing side and flowing into the injection hole, the fuel injection valve that injects the fuel at a relatively low pressure can be sufficiently atomized.

It is a cross-sectional schematic diagram in alignment with the axial direction of the fuel injection valve which concerns on Embodiment 1 of this invention. It is the A section enlarged view of FIG. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. It is a schematic diagram which shows the surroundings of the injection hole of the fuel injection valve which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the surroundings of the injection hole of the fuel injection valve as a comparative example. It is a schematic diagram which shows an example of the shape of the spray liquid film calculated | required by the numerical analysis. It is a figure which shows the relationship between 1 / s and v / v 'in the fuel injection valve which concerns on Embodiment 1 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 2 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 3 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 4 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 5 of this invention. It is principal part sectional drawing which shows the surroundings of the injection hole in the fuel injection valve which concerns on Embodiment 6 of this invention. It is principal part sectional drawing which shows the surroundings of the injection hole in the fuel injection valve which concerns on Embodiment 7 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 8 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 9 of this invention. It is a top view which shows arrangement | positioning of the nozzle hole in the fuel injection valve which concerns on Embodiment 10 of this invention. It is principal part sectional drawing which shows the surroundings of the injection hole in the fuel injection valve which concerns on Embodiment 11 of this invention.

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

Embodiment 1 FIG.
1 is a schematic cross-sectional view along the axial direction of a fuel injection valve according to Embodiment 1 of the present invention.

  In FIG. 1, the fuel injection valve 1 includes a solenoid device 3, a core 4, and a yoke 5 that constitutes a magnetic path disposed inside a resin housing 2, and is integrally formed with the resin housing.

  The solenoid device 3 includes a coil assembly 6 disposed so as to surround one end of the core 4 and a coil 7 wound around the outer periphery thereof. A spring 8 is disposed inside the core 4, and a rod 9 is fixed inside the core 4 so that the weight of the spring 8 can be adjusted. Further, a valve body 10 that is formed in a hollow cylindrical shape and constitutes a magnetic passage is disposed coaxially with the core 4 with a sleeve 11 interposed at one end of the core 4. The sleeve 11 is fixed to the core 4 and the valve body 10 by welding or the like, and is sealed so that internal fuel does not leak. Both ends of the yoke 5 are fixed to the core 4 and the valve body 10 by welding, and the core 4 and the valve body 10 are magnetically coupled.

  An amateur 12 is disposed in the valve body 10 so as to be movable in the central axis direction of the fuel injection valve 1. A valve body 13 that is a valve member is fixed to one end of the armature 12 by welding or the like, and is disposed inside one end side of the valve body 10. The valve seat 14 is fixed inside the one end of the valve body 10. An injection hole plate 15 having injection holes 16 is fixed to the front end portion of the valve seat 14 by welding or the like, and a fuel chamber 15 a is formed between the injection hole plate 15 and the valve seat 14.

  Next, the configuration of the tip portion of the fuel injection valve 1 will be described with reference to FIG. FIG. 2 is an enlarged view of a portion A in FIG. 1, showing the left half of the central axis of the tip portion of the fuel injection valve, and omitting the valve body.

  The valve seat 14 includes a valve seat portion 14a formed in a truncated cone shape with one end tapering on an inner wall surface constituting the fuel passage 14b, a recess portion 14c opened to one end side, and one end of the valve seat portion 14a. And a valve hole 14d that is coaxially formed on the side and communicates with the fuel passage 14b and the recess 14c. The valve body 13 as a valve member has a spherical tip, and a fuel passage 14b that is a space inside the valve seat 14 when an outer peripheral surface 13a as a contact portion contacts or leaves the valve seat portion 14a. Open and close. The nozzle hole plate 15 is fixed to one end surface of the valve seat 14 by welding or the like. As a result, a circular shallow recess 14 c centered on the valve hole 14 d is closed by the injection hole plate 15, and a fuel chamber 15 a is formed between the valve seat 14 and the injection hole plate 15. A plurality of nozzle holes 16 are formed in the nozzle hole plate 15. The fuel chamber 15 a is a space having a minute height for rectifying the flow of fuel from the fuel passage 14 b in a direction along the upper surface of the injection hole plate 15, and is provided around the central axis 18 of the fuel injection valve 1. ing. Note that the hole center (axis) of the valve hole 14 d coincides with the central axis 18 of the fuel injection valve 1.

  Next, the operation of the fuel injection valve 1 configured as described above will be described.

  First, when the coil 7 is energized from the outside, a magnetic flux is generated in a magnetic path formed by the core 4, the yoke 5, the valve body 10, and the armature 12, and a magnetic attractive force that attracts the armature 12 to the core 4 is generated. As a result, the armature 12 moves to the core 4 side against the unbalanced force of the spring 8, and the valve element 13 to which the armature 12 is fixed becomes the valve opening position away from the valve seat portion 14 a of the valve seat 14. Therefore, the fuel supplied from the supply port 17 to the fuel injection valve 1 flows through the core 4 to the valve body 13 side, and the fuel passage 14b and the valve formed between the valve body 13 and the valve seat portion 14a. The fuel is supplied to the fuel chamber 15 a through the hole 14 d and is injected from the injection hole 16 of the injection hole plate 15.

  When the energization of the coil 7 is stopped, the magnetic attractive force that attracts the amateur 12 to the core 4 disappears. As a result, the armature 12 moves to the valve seat 14 side due to the ineffective force of the spring 8, the valve body 13 is brought into a closed position where it contacts the valve seat portion 14a of the valve seat 14, and fuel injection is stopped.

  Next, the arrangement of the nozzle holes 16 in the nozzle hole plate 15 will be described with reference to FIGS. 3 is a cross-sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a schematic view showing the periphery of the injection hole of the fuel injection valve according to Embodiment 1 of the present invention.

  The nozzle holes 16 are arranged on four pitch holes 16a arranged on a pitch circle having a diameter Φ1 with the central axis 18 of the fuel injection valve 1 as a center, and on a pitch circle having a diameter Φ2 (where Φ2> Φ1). It consists of four nozzle holes 16b. The two nozzle holes 16a and 16b are arranged in a line with the hole centers of the nozzle holes 16a and 16b positioned on a straight line passing through the central axis 18 and orthogonal to the central axis 18. The remaining two nozzle holes 16a and 16b are arranged in a row with the hole centers of the nozzle holes 16a and 16b positioned on another straight line that passes through the central axis 18 and is orthogonal to the central axis 18. The nozzle hole diameter of the nozzle holes 16a and 16b is d.

  The plane Ps including the central axis 18 in which the eight nozzle holes 16a and 16b arranged in the nozzle hole plate 15 are mirror-image symmetrical in this way extends in the left and right directions and the up and down direction perpendicular to the paper surface of FIG. There are planes. There is no injection hole 16 on these two surfaces Ps. This means that the nozzle hole 16 does not exist in a place where the flow of fuel is balanced. In this case, as shown in FIG. 4, the fuel flow flowing into the nozzle holes 16a and 16b always has an unbalance that the flow in either direction is fast or the flow rate is large. As a result, a flow of fuel that wraps around the nozzle holes 16a and 16b and reaches the nozzle holes 16a and 16b is generated, and a fuel flow that vortexes around the nozzle holes 16a and 16b is generated. . Thus, a swirl flow is generated in the fuel flow flowing into the nozzle holes 16a and 16b. Due to this swirling flow, fuel is pressed against the inner wall surfaces of the nozzle holes 16a and 16b by the centrifugal force in the nozzle holes 16a and 16b, and the injected fuel is expanded into a liquid film and atomized.

  Here, in order to explain the effect of the first embodiment, the flow of fuel when the injection hole 16b exists on the surface Ps will be described with reference to FIG. FIG. 5 is a schematic view showing the periphery of the injection hole of a fuel injection valve as a comparative example.

In the comparative example, the nozzle hole 16b exists on the surface Ps. Therefore, in FIG. 5, a vertically symmetrical fuel flow with respect to the surface Ps flows into the nozzle hole 16b. Therefore, the fuel flow flowing into the nozzle hole 16b from above and below is vertically symmetric with respect to the plane Ps, so that no fuel flows around the nozzle hole 16b and no swirl flow is generated in the nozzle hole 16b.
On the other hand, in Embodiment 1, since the nozzle holes 16a and 16b do not exist on the surface Ps, a swirl flow is generated in the nozzle holes 16a and 16b, and the fuel is atomized.

In the arrangement of the nozzle holes 16a and 16b according to the first embodiment, when the surface Ph that passes through the center of any two nozzle holes 16a and 16b and includes the central axis 18 is rotated around the central axis 18, In the rotation direction of the nozzles 16a and 16b satisfying the relationship r <(5/4) · (d ² / h), and r <(5/4) · ( There is no nozzle hole 16a, 16b that satisfies the relationship of d ² / h). Here, d is the diameter of the nozzle holes 16a and 16b, h is the height of the fuel chamber 15a immediately above the nozzle holes 16a and 16b, and r is the center of the two nozzle holes 16a and 16b adjacent to each other in the circumferential direction. This is the distance to the hole center.

For example, assuming the arrangement of the nozzle holes 16a and 16b in FIG. 3 as a timepiece, the vertical direction in the figure is the 0: 00-6 o'clock direction. Therefore, when the surface Ph including the central axis 18 passing through the hole centers of the nozzle holes 16a and 16b positioned in the angular direction at about 2 o'clock to 8 o'clock is rotated clockwise about the central axis 18, about 4 o'clock- The nozzle holes 16a and 16b positioned in the 10 o'clock angular direction are nozzle holes that satisfy the relationship r <(5/4) · (d ² / h). Further, when the surface Ph including the central axis 18 passing through the hole centers of the nozzle holes 16a and 16b positioned in the angular direction of about 2 o'clock to 8 o'clock is rotated counterclockwise about the central axis 18, r <( There is no nozzle hole that satisfies the relationship 5/4) · (d ² / h).

  Thereby, the unbalance of the flow rate described above flowing into the nozzle holes 16a and 16b becomes larger, the generation of the swirling flow in the nozzle holes 16a and 16b is promoted, and the atomization characteristics are improved. The reason for this will be described below.

  In the flow field in which two nozzle holes 16 exist, when the distance between the two nozzle holes 16 is sufficiently large, the flow of fuel flowing into the nozzle holes 16 does not affect each other. However, when the two nozzle holes 16 are close to a certain distance or less, the fuel flow existing between the nozzle holes 16 is divided by the two nozzle holes 16, and the fuel flows flowing into the nozzle holes 16 influence each other. Influence each other.

Here, the distance at which the flow of fuel flowing into the nozzle hole 16 affects each other is considered from the viewpoint of flow velocity. When the flow velocity in the nozzle hole 16 is assumed to be v, the flow velocity at a position away from the nozzle hole 16 by the distance r is v ′. If the nozzle hole diameter d, of the fuel chamber 15a height to is h, the flow path cross-sectional area Sd of the injection hole 16, the flow path cross-sectional area Sr at the position of Sd = [pi] d ^2/4, and the distance r is Sr = πrh. Flow rate v 'is, v' since it is = Sd / Sr, v a ^{'= v × (d 2 /} 8rh) next, and arranging the distance r r = (v / v' ) × (d 2 / 8h) .

  Next, the relationship between v / v ′ and the shape of the spray liquid film was evaluated using numerical analysis. FIG. 6 is a schematic diagram showing an example of the shape of the spray liquid film obtained by numerical analysis. FIG. 6 shows a horizontal cross-sectional shape of the spray liquid film at a position 1 mm below the nozzle hole 16 of the fuel injected from the nozzle hole 16.

  Since a swirl flow is generated in the nozzle hole 16, the fuel is usually injected in a hollow conical shape. In the example shown in the first embodiment, the length of the injection hole 16 is short with respect to the turning speed, so that the fuel does not make a round in the injection hole 16 and the hollow cone is cut in half. Is injected. Therefore, the cross section of the liquid film has an approximately C shape. At this time, when the fuel spray spreads thinly to form a liquid film, the spray particles after splitting become smaller. Therefore, the formation of a liquid film of the injected fuel was evaluated by a ratio 1 / s between the minimum value s of the width of the cross-sectional shape and the longitudinal length l of the liquid film. In the numerical analysis, the nozzle hole diameter d was evaluated in the range of 0.1 mm ≦ d ≦ 0.3 mm, and the height h of the fuel chamber 15a was evaluated in the range of 0.1 mm ≦ h ≦ 0.3 mm. FIG. 7 shows the relationship between v / v ′ and 1 / s.

  FIG. 7 shows that l / s changes greatly in the vicinity of v / v ′ = 10, and v / v ′ <10 is sufficient for atomization regardless of the diameter of the nozzle hole and the height of the fuel chamber. It was found that a thin liquid film can be obtained.

Thus, r <(5/4) · (d ² / h) is obtained from v / v ′ <10 and r = (v / v ′) × (d ² / 8h). In other words, if the two injection holes 16 are arranged so as to satisfy r <(5/4) · (d ² / h), the injected fuel becomes fine regardless of the diameter of the injection hole and the height of the fuel chamber. It becomes a thin liquid film that is sufficiently thin. That is, if the two injection holes 16 are arranged so as to satisfy r <(5/4) · (d ² / h), the fuel flows flowing into the injection holes 16 influence each other, and FIG. As shown in FIG. 4, a large imbalance occurs in the fuel flow with respect to the surface Ph. As a result, in the fuel flow around the nozzle hole 16, a fuel flow is generated that wraps around from the side where the nozzle hole 16 exists and reaches the nozzle hole 16, and the swirl flow into the fuel flow flowing into the nozzle hole 16. Will occur. By this swirl flow, fuel is pressed against the inner wall surface of the nozzle hole 16 by centrifugal force in the nozzle hole 16, and the injected fuel spreads as a liquid film, thereby promoting atomization. In addition, since it does not depend only on the diameter of the nozzle hole, if the nozzle hole 16 is arranged so as to satisfy r <(5/4) · (d ² / h), the injection is performed from the nozzle hole 16 even if the flow rate changes. It is assumed that the fuel that is produced turns into a thin liquid film and atomizes after splitting.

According to the first embodiment, there is a plane Ps including the central axis 18 in which the eight nozzle holes 16a and 16b are mirror-image symmetric, and the nozzle holes 16a and 16b are not present on the plane Ps. The holes 16 a and 16 b are arranged in the nozzle hole plate 15. Furthermore, when the surface Ph including the central axis 18 passing through the center of any two nozzle holes 16a and 16b is rotated about the central axis 18, r <(5/4) only in one rotation direction. The nozzle holes 16a and 16b are arranged in the nozzle hole plate 15 so that the nozzle holes 16a and 16b satisfying the relationship (d ² / h) exist.
Therefore, the atomization characteristics of all the nozzle holes 16a and 16b can be stably improved, and atomization of the fuel injection valve 1 can be promoted.

  Further, the arrangement of the nozzle holes 16a and 16b is devised to generate a swirling flow in the nozzle holes 16a and 16b to realize atomization of the injected fuel. Therefore, it is necessary to provide a step in the nozzle hole plate 15. Therefore, the cost can be reduced. Further, since there is no need to provide a step in the nozzle hole plate 15, the number of nozzle holes can be easily increased, and a fuel injection valve having a large injection flow rate can be realized easily and inexpensively. Furthermore, since a large injection flow rate can be increased without increasing the nozzle hole diameter, the injection direction can be easily controlled.

Further, fuel, ^{r <(5/4) · (d} 2 / h) satisfying the nozzle hole 16a, and the side that does not exist 16b is, satisfies ^{r <(5/4) · (d} 2 / h) Since the swirl flow is generated in the nozzle holes 16a and 16b by flowing around the nozzle holes 16a and 16b and flowing into the nozzle holes 16a and 16b, fuel injection for injecting fuel at a relatively low pressure Even the valve can be sufficiently atomized.

Here, even when the nozzle hole 16 and the nozzle hole 16 located on one side of the surface Ph from the nozzle hole 16 are brought close to each other, when another nozzle hole 16 exists at the same position on the opposite side of the surface Ph. The fuel flow will not be unbalanced. Therefore, it is necessary to prevent the injection hole 16 satisfying r <(5/4) · (d ² / h) from the injection hole 16 on the opposite side of the surface Ph. Even if the injection hole 16 is located on the opposite side of the surface Ph, the distance between the injection hole 16 located on the opposite side of the surface Ph and the injection hole 16 is set to be equal to or greater than twice the distance r. The imbalance generated in the flow of the fuel becomes larger and atomization of the injected fuel is promoted.

  Further, it is conceivable that a swirling flow is generated in the flow of fuel flowing into the nozzle hole 16 by an additional member such as a wall. However, the distance between the nozzle hole 16 and the additional member (wall) varies for each nozzle hole 16, and the liquid film shape varies for each nozzle hole 16, which causes generation of poor particles. In the present invention, a swirl flow is generated in the flow of fuel flowing into the nozzle hole 16 due to the proximity of the nozzle hole 16, and the distance between the nozzle holes 16 is the same between the two nozzle holes 16. Each variation can be reduced.

  In order to inject the fuel without impairing the swirling flow generated in the fuel, it is desirable that the thickness t of the nozzle hole plate 15 is t / d <1. However, as described above, if the nozzle hole diameter d is large, that is, if t / d is too small, it becomes difficult to control the injection direction, so it is desirable that t / d> 0.4.

Embodiment 2. FIG.
FIG. 8 is a plan view showing the arrangement of nozzle holes in the fuel injection valve according to Embodiment 2 of the present invention.

  In FIG. 8, four nozzle holes 16a having a nozzle hole diameter da are arranged on a pitch circle having a diameter Φ1 centered on the central axis 18, and four nozzle holes 16b having a nozzle hole diameter db are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. The two nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on a straight line passing through the central axis 18. The remaining two nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on other straight lines passing through the central axis 18. The nozzle hole diameter has a relationship of da> db.

In the second embodiment, the nozzle holes 16a and 16b having two different nozzle diameters are mixed. However, as in the first embodiment, the eight nozzle holes 16a and 16b are mirror-image-symmetry. Two planes Ps including 18 exist, and no nozzle hole exists on the two planes Ps. Further, when the surface Ph including the center axis 18 passing through the center of the arbitrary nozzle hole 16a is rotated around the center axis 18, r <(5/4) · (da ² ) The nozzle hole 16a that satisfies the relationship / h) exists, and the nozzle hole 16a that satisfies the relationship r <(5/4) · (da ² / h) does not exist in the other rotation direction. Further, when the surface Ph including the central axis 18 passing through the center of the arbitrary nozzle hole 16b is rotated around the central axis 18, in one rotation direction, r <(5/4) · (db ² / H) is present, and there is no nozzle hole 16b satisfying the relationship r <(5/4) · (db ² / h) in the other rotational direction.

  Therefore, also in the second embodiment, as in the first embodiment, the fuel flow around the nozzle holes 16a and 16b is unbalanced. Therefore, a fuel flow that wraps around and reaches the nozzle holes 16a and 16b is generated around the nozzle holes 16a and 16b, and a fuel flow that spirals around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of the fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics can be obtained. Furthermore, by combining different nozzle hole diameters, it becomes possible to further change the balance of the flow of fuel and further enhance the swirl flow. Further, since the nozzle hole diameter of the outer diameter side nozzle hole 16b is smaller than the nozzle hole diameter of the inner diameter side nozzle hole 16a, it becomes possible to reduce the fuel in the spray outer portion and suppress the amount of fuel adhering to the inner wall surface of the engine. A spray can be formed.

Embodiment 3 FIG.
FIG. 9 is a plan view showing the arrangement of the injection holes in the fuel injection valve according to Embodiment 3 of the present invention.

  In FIG. 9, four nozzle holes 16a having a nozzle hole diameter da are arranged on a pitch circle having a diameter Φ1 with the central axis 18 as the center, and four nozzle holes 16b having a nozzle hole diameter db are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. The two nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on a straight line passing through the central axis 18. The remaining two nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on other straight lines passing through the central axis 18. The nozzle hole diameter has a relationship of da <db.

In the third embodiment, the nozzle holes 16a and 16b having two different nozzle hole diameters are mixed. However, as in the first embodiment, the eight nozzle holes 16a and 16b are mirror-image-symmetry. Two planes Ps including 18 exist, and no nozzle hole exists on the two planes Ps. Further, when the surface Ph including the center axis 18 passing through the center of the arbitrary nozzle hole 16a is rotated around the center axis 18, r <(5/4) · (da ² ) The nozzle hole 16a that satisfies the relationship / h) exists, and the nozzle hole 16a that satisfies the relationship r <(5/4) · (da ² / h) does not exist in the other rotation direction. Further, when the surface Ph including the central axis 18 passing through the center of the arbitrary nozzle hole 16b is rotated around the central axis 18, in one rotation direction, r <(5/4) · (db ² / H) is present, and there is no nozzle hole 16b satisfying the relationship r <(5/4) · (db ² / h) in the other rotational direction.

  Therefore, also in the third embodiment, as in the first embodiment, the fuel flow around the nozzle holes 16a and 16b is unbalanced. Therefore, a fuel flow that wraps around and reaches the nozzle holes 16a and 16b is generated around the nozzle holes 16a and 16b, and a fuel flow that spirals around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of the fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics can be obtained. Furthermore, by combining different nozzle hole diameters, it becomes possible to further change the balance of the flow of fuel and further enhance the swirl flow. In addition, since the nozzle hole diameter of the inner diameter side nozzle hole 16a is smaller than the nozzle hole diameter of the outer diameter side nozzle hole 16b, it becomes possible to reduce the fuel in the center of the spray and form a spray that promotes mixing with air. Can do.

Embodiment 4 FIG.
FIG. 10 is a plan view showing the arrangement of nozzle holes in the fuel injection valve according to Embodiment 4 of the present invention.

  In FIG. 10, four nozzle holes 16a having a nozzle hole diameter da are arranged on a pitch circle having a diameter Φ1 with the central axis 18 as the center, and four nozzle holes 16b having a nozzle hole diameter db are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. Two nozzle holes 16 a are arranged in a line with the hole centers of the nozzle holes 16 a positioned on a straight line passing through the central axis 18. Two nozzle holes 16b are arranged in a row with the hole center of the nozzle hole 16b positioned on another straight line passing through the central axis 18. Further, the scissor angle of the surface Pha passing through the center of the two injection holes 16a and including the central axis 18 is θ1, and the surface Phb including the central axis 18 passing through the center of the holes of the two injection holes 16b. The scissor angle is θ2. The nozzle hole diameter has a relationship of da> db, and the scissor angle has a relationship of θ1> θ2.

In the fourth embodiment, the nozzle holes 16a and 16b having two different nozzle diameters are mixed, but as in the first embodiment, the eight nozzle holes 16a and 16b are mirror-image-symmetry. Two planes Ps including 18 exist, and no nozzle hole exists on the two planes Ps. Further, when the surface Pha including the central axis 18 passing through the center of the arbitrary nozzle hole 16a is rotated around the central axis 18, in one rotation direction, r <(5/4) · (da ² The nozzle hole 16a that satisfies the relationship / h) exists, and the nozzle hole 16a that satisfies the relationship r <(5/4) · (da ² / h) does not exist in the other rotation direction. Further, when the surface Phb including the center axis 18 passing through the center of the arbitrary nozzle hole 16b is rotated around the center axis 18, in one rotation direction, r <(5/4) · (db ² / H) is present, and there is no nozzle hole 16b satisfying the relationship r <(5/4) · (db ² / h) in the other rotational direction.

In the second embodiment, when the injection hole diameter db of the injection hole 16b is reduced, r that satisfies r <(5/4) · (db ² / h) is reduced. Since the nozzle holes 16a and 16b are arranged in a line on a straight line passing through the central axis 18, the pinching angle θ of the surface Ph including the central axis 18 passing through the hole centers of the nozzle holes 16a and 16b is reduced. There is a need. That is, the nozzle holes 16a and 16b are arranged so as to satisfy r <(5/4) · (db ² / h), and the distance between the nozzle holes 16a becomes excessively small. If the distance between the nozzle holes 16a becomes excessively small, distortions that occur during processing will also affect the adjacent nozzle holes when the nozzle holes are formed, particularly when the nozzle holes are provided by press processing. It causes variation.

In the fourth embodiment, the pinch angle θ1 of the surface Pha passing through the hole center of the nozzle hole 16a and including the central axis 18 and the pinch angle θ2 of the surface Phb passing through the hole center of the nozzle hole 16b and including the central axis 18 are Is different. Therefore, even if the nozzle holes 16a and 16b having different nozzle hole diameters are used, the nozzle hole 16a can be arranged so as to satisfy r <(5/4) · (da ² / h), and the nozzle hole 16b can be arranged as r <(5 / 4) · (db ² / h).

  Therefore, also in the fourth embodiment, an unbalance occurs in the fuel flow around the nozzle holes 16a and 16b. Therefore, a fuel flow that wraps around and reaches the nozzle holes 16a and 16b is generated around the nozzle holes 16a and 16b, and a fuel flow that spirals around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of the fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics can be obtained. Furthermore, by combining different nozzle hole diameters, it becomes possible to further change the balance of the flow of fuel and further enhance the swirl flow. Further, by changing the arrangement of the nozzle holes 16a and 16b, the balance of the fuel flow can be further changed, and the swirling flow can be further strengthened.

Embodiment 5 FIG.
FIG. 11 is a plan view showing the arrangement of nozzle holes in a fuel injection valve according to Embodiment 5 of the present invention.

  In FIG. 11, four nozzle holes 16a having a nozzle hole diameter da are arranged on a pitch circle having a diameter Φ1 with the central axis 18 as a center, and four nozzle holes 16b having a nozzle hole diameter db are arranged on a pitch circle having a diameter Φ2. The four nozzle holes 16c having the nozzle hole diameter dc are arranged on a pitch circle having a diameter Φ3 (where Φ1 <Φ2 <Φ3). Two nozzle holes 16 a are arranged in a line with the hole centers of the nozzle holes 16 a positioned on a straight line passing through the central axis 18. Two nozzle holes 16b are arranged in a row with the hole center of the nozzle hole 16b positioned on another straight line passing through the central axis 18. Two nozzle holes 16c are arranged in a row with the hole center of the nozzle hole 16c positioned on another straight line passing through the central axis 18. Further, the scissor angle of the surface Pha passing through the center of the two injection holes 16a and including the central axis 18 is θ1, and the surface Phb including the central axis 18 passing through the center of the holes of the two injection holes 16b. The scissor angle is θ2, and the scissor angle of the surface Phc that passes through the center of each of the two nozzle holes 16c and includes the central axis 18 is θ3. The nozzle hole diameter has a relationship of da> db> dc, and the scissor angle has a relationship of θ1> θ2> θ3.

In the fifth embodiment, the nozzle holes 16a, 16b, and 16c having three different nozzle hole diameters are mixed, but as in the first embodiment, the twelve nozzle holes 16a, 16b, and 16c are mirror-symmetric. There are two planes Ps including the central axis 18, and no nozzle hole exists on the two planes Ps. Further, when the surface Pha including the central axis 18 passing through the center of the arbitrary nozzle hole 16a is rotated around the central axis 18, in one rotation direction, r <(5/4) · (da ² The nozzle hole 16a that satisfies the relationship / h) exists, and the nozzle hole 16a that satisfies the relationship r <(5/4) · (da ² / h) does not exist in the other rotation direction. Further, when the surface Phb including the center axis 18 passing through the center of the arbitrary nozzle hole 16b is rotated around the center axis 18, in one rotation direction, r <(5/4) · (db ² / H) is present, and there is no nozzle hole 16b satisfying the relationship r <(5/4) · (db ² / h) in the other rotational direction. Further, when the surface Phc including the central axis 18 passing through the center of the arbitrary nozzle hole 16c is rotated around the central axis 18, in one rotation direction, r <(5/4) · (dc ² / H) is present, and there is no nozzle hole 16c that satisfies the relationship r <(5/4) · (dc ² / h) in the other rotational direction.

In the fifth embodiment, the scissor angle θ1 of the surface Ph that passes through the hole center of the nozzle hole 16a and includes the central axis 18, and the scissor angle θ2 of the surface Phb that passes through the hole center of the nozzle hole 16b and includes the central axis 18; The scissor angle θ3 of the surface Phc passing through the hole center of the nozzle hole 16c and including the central axis 18 is different. Therefore, even if the nozzle holes 16a, 16b, and 16c having different nozzle hole diameters are used, the nozzle hole 16a can be arranged so as to satisfy r <(5/4) · (da ² / h), and the nozzle hole 16b is arranged to satisfy r < The nozzle holes 16c can be arranged so as to satisfy (5/4) · (db ² / h), and the nozzle holes 16c can be arranged so as to satisfy r <(5/4) · (dc ² / h).

  Therefore, also in the fifth embodiment, an unbalance occurs in the fuel flow around the nozzle holes 16a, 16b, and 16c. Therefore, a fuel flow that wraps around and reaches the nozzle holes 16a, 16b is generated around the nozzle holes 16a, 16b, 16c, and a fuel that vortexes around the nozzle holes 16a, 16b, 16c. Flow occurs. Thereby, a swirling flow is generated in the flow of fuel flowing into the nozzle holes 16a, 16b, and 16c, and the effect of improving the atomization characteristics can be obtained. Furthermore, by combining different nozzle hole diameters, it becomes possible to further change the balance of the flow of fuel and further enhance the swirl flow. Further, by changing the arrangement of the nozzle holes 16a, 16b, and 16c, the balance of the fuel flow can be further changed, and the swirling flow can be further strengthened. Furthermore, the number of nozzle holes 16 can be increased, and the injection flow rate can be increased while maintaining good atomization characteristics.

Embodiment 6 FIG.
FIG. 12 is a cross-sectional view of the main part showing the periphery of an injection hole in a fuel injection valve according to Embodiment 6 of the present invention.

In FIG. 12, the height h of the fuel chamber 15 a is configured to become lower as the distance from the central axis 18 increases.
Other configurations are the same as those in the second embodiment.

In the second embodiment, since the height h of the fuel chamber 15a directly above the nozzle holes 16a and 16b having different nozzle hole diameters is the same, the atomization characteristics of the nozzle holes 16a and 16b having different nozzle hole diameters are obtained. Variations are likely to occur.
In the sixth embodiment, the height h of the fuel chamber 15a is inclined so as to gradually decrease as the distance from the center axis 18 increases. Therefore, since the heights ha and hb of the fuel chamber 15a directly above the nozzle holes 16a and 16b can be adjusted in accordance with the nozzle diameters of the nozzle holes 16a and 16b, the atomization of the nozzle holes 16a and 16b having different nozzle hole diameters can be performed. Variation in characteristics can be suppressed, and atomization characteristics of the entire spray can be improved.

Embodiment 7 FIG.
FIG. 13 is a cross-sectional view of the main part showing the periphery of an injection hole in a fuel injection valve according to Embodiment 7 of the present invention.

In FIG. 13, the hole centers of the injection holes 16 a and 16 b pass through the hole centers of the injection holes 16 a and 16 b and include the center axis 18, and the hole centers of the injection holes 16 a and 16 b are 10 ° outward from the center axis 18 in the fuel injection direction. The nozzle hole plate 15 is formed to be inclined.
Other configurations are the same as those in the first embodiment.

  In the seventh embodiment, the fuel is injected from the injection holes 16a and 16b toward the center of the injection holes 16a and 16b. Therefore, an arbitrary spray shape can be formed by adjusting the inclination angle of the nozzle holes 16a and 16b with respect to the central axis 18 at the hole center.

Embodiment 8 FIG.
14 is a plan view showing the arrangement of injection holes in a fuel injection valve according to Embodiment 8 of the present invention.

  In FIG. 14, six nozzle holes 16a each having a nozzle hole diameter d are arranged on a pitch circle having a diameter Φ1 with the central axis 18 as the center, and six nozzle holes 16b having a nozzle hole diameter d are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. The nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on a straight line passing through the central axis 18. A group of four nozzle holes 16a and 16b arranged with two rows of nozzle holes 16a and 16b close to the circumferential direction are arranged at a 120 ° pitch in the circumferential direction.

In the eighth embodiment, there are three surfaces Ps including the central axis 18 in which the twelve nozzle holes 16a and 16b are mirror-image-symmetric. However, in the same manner as in the first embodiment, the injection is performed on the three surfaces Ps. There are no holes 16a, 16b. In addition, when a plane Ph including the central axis 18 that passes through the center of any of the injection holes 16a and 16b is rotated around the central axis 18, in one rotation direction, r <(5/4) · ( The nozzle holes 16a and 16b satisfying the relationship d ² / h) exist, and the nozzle holes 16a and 16b satisfying the relationship r <(5/4) · (d ² / h) in the other rotation direction. Does not exist.

  Therefore, also in the eighth embodiment, as in the first embodiment, the fuel flow around the nozzle holes 16a and 16b is unbalanced. As a result, a flow of fuel that wraps around the nozzle holes 16a and 16b and reaches the nozzle holes 16a and 16b is generated, and a fuel flow that vortexes around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics is obtained. Further, the number of nozzle holes 16a and 16b can be increased, and the injection flow rate can be increased while maintaining good atomization characteristics. Further, since the nozzle hole arrangement is uniform in the circumferential direction, it is possible to spray only one spray at the center, instead of spraying one by one on the left and right as in the first embodiment. .

Embodiment 9 FIG.
FIG. 15 is a plan view showing the arrangement of nozzle holes in a fuel injection valve according to Embodiment 9 of the present invention.

  In FIG. 15, eight nozzle holes 16 a having a nozzle hole diameter d are arranged on a pitch circle having a diameter Φ1 centered on the central axis 18, and eight nozzle holes 16 b having a nozzle hole diameter d are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. The nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on a straight line passing through the central axis 18. A nozzle hole group consisting of four nozzle holes 16a and 16b arranged with two rows of nozzle holes 16a and 16b close to the circumferential direction is arranged at a pitch of 90 ° in the circumferential direction.

In the ninth embodiment, there are four planes Ps including the central axis 18 in which the 16 injection holes 16a and 16b are mirror-image-symmetric. However, in the same manner as in the first embodiment, the injection is performed on the four planes Ps. There are no holes 16a, 16b. In addition, when a plane Ph including the central axis 18 that passes through the center of any of the injection holes 16a and 16b is rotated around the central axis 18, in one rotation direction, r <(5/4) · ( The nozzle holes 16a and 16b satisfying the relationship d ² / h) exist, and the nozzle holes 16a and 16b satisfying the relationship r <(5/4) · (d ² / h) in the other rotation direction. Does not exist.

  Therefore, also in the ninth embodiment, as in the first embodiment, the fuel flow around the nozzle holes 16a and 16b is unbalanced. As a result, a flow of fuel that wraps around the nozzle holes 16a and 16b and reaches the nozzle holes 16a and 16b is generated, and a fuel flow that vortexes around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics is obtained. Further, the number of nozzle holes 16a and 16b can be increased, and the injection flow rate can be increased while maintaining good atomization characteristics. Further, since the nozzle hole arrangement is uniform in the circumferential direction, it is possible to spray only one spray at the center, instead of spraying one by one on the left and right as in the first embodiment. .

Embodiment 10 FIG.
FIG. 16 is a plan view showing the arrangement of injection holes in a fuel injection valve according to Embodiment 10 of the present invention.

  In FIG. 16, two nozzle holes 16a having a nozzle hole diameter d are arranged on a pitch circle having a diameter Φ1 with the central axis 18 as the center, and two nozzle holes 16b having a nozzle hole diameter d are Φ2 (where Φ1 <Φ2). Are arranged on the pitch circle. The nozzle holes 16 a and 16 b are arranged in a line with the hole centers of the nozzle holes 16 a and 16 b positioned on a straight line passing through the central axis 18.

In the tenth embodiment, there is one surface Ps including the central axis 18 in which the four nozzle holes 16a and 16b are mirror-image-symmetric. However, as in the first embodiment, the nozzle holes are formed on one surface Ps. 16a and 16b do not exist. In addition, when a plane Ph including the central axis 18 that passes through the center of any of the injection holes 16a and 16b is rotated around the central axis 18, in one rotation direction, r <(5/4) · ( The nozzle holes 16a and 16b satisfying the relationship d ² / h) exist, and the nozzle holes 16a and 16b satisfying the relationship r <(5/4) · (d ² / h) in the other rotation direction. Does not exist.

  Therefore, also in the tenth embodiment, as in the first embodiment, an unbalance occurs in the fuel flow around the nozzle holes 16a and 16b. As a result, a flow of fuel that wraps around the nozzle holes 16a and 16b and reaches the nozzle holes 16a and 16b is generated, and a fuel flow that vortexes around the nozzle holes 16a and 16b is generated. . Thereby, a swirl flow is generated in the flow of fuel flowing into the nozzle holes 16a and 16b, and the effect of improving the atomization characteristics is obtained. Further, the number of nozzle holes 16a and 16b can be reduced, and the injection flow rate can be reduced while maintaining good atomization characteristics. Further, since the nozzle holes 16a and 16b are arranged only on the left side in FIG. 16, the spray is not sprayed one by one on the left and right as in the first embodiment, but only one spray on the left side. It becomes possible to inject. Thereby, the freedom degree of the spray direction to an engine inside improves.

Embodiment 11 FIG.
FIG. 17 is a cross-sectional view of the principal part showing the periphery of the injection hole in the fuel injection valve according to Embodiment 11 of the present invention.

In FIG. 17, the hole centers of the nozzle holes 16 a and 16 b pass through the hole centers of the nozzle holes 16 a and 16 b and include the central axis 18, and the hole centers of the nozzle holes 16 a and 16 b are 10 ° inward in the fuel injection direction. The nozzle hole plate 15 is formed to be inclined.
Other configurations are the same as those in the first embodiment.

  In the eleventh embodiment, fuel is injected from the injection holes 16a and 16b toward the center of the injection holes 16a and 16b. Therefore, it is possible to spray the spray in a direction substantially along the central axis 18 by adjusting the inclination angle of the nozzle holes 16a and 16b with respect to the central axis 18 at the center. Thereby, it is possible to reduce the spray flow rate while maintaining good atomization characteristics, and to form the fuel spray in an arbitrary direction.

  In each of the above-described embodiments, the case where the nozzle hole arranged in the nozzle hole plate has a mirror image symmetry with the plane Ps as the symmetry plane is described, but the nozzle hole arranged in the nozzle hole plate is However, the hole shape does not necessarily have to be mirror-symmetric with respect to the plane Ps, and the center of the nozzle hole on the valve seat side surface of the nozzle plate is mirror-symmetric with the plane Ps as the plane of symmetry. It only has to be.

  The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope described in the claims.

  DESCRIPTION OF SYMBOLS 1 Fuel injection valve, 13 Valve member, 13a Outer peripheral surface (contact part), 14 Valve seat, 14a Valve seat part, 14b Fuel passage, 14d Valve hole, 15 Injection hole plate, 15a Fuel chamber, 16a, 16b, 16c Injection Hole, 18 central axis.

Claims (4)

A valve seat portion formed on the inner wall surface forming the fuel passage, and a valve seat having a valve hole formed coaxially with the valve seat portion on the downstream side of the fuel passage;
A valve member that has a contact portion that can be seated on the valve seat portion, and that opens or closes the fuel passage when the contact portion is separated from or seated on the valve seat;
The valve seat is mounted on the downstream side of the valve hole, and the nozzle holes are arranged on pitch circles of n pieces (where n is an integer of 1 or more) having different radii centering on the hole center of the valve hole. A plurality of nozzle holes,
A fuel chamber formed between the valve seat and the nozzle hole plate and communicating with the fuel passage through the valve hole;
When the hole diameter of the nozzle hole is d, the height of the fuel chamber just above the nozzle hole is h, and the distance between the hole centers of two arbitrary nozzle holes adjacent in the circumferential direction is r, When the surface Ph including the hole center of the valve hole passing through the hole center of one of the two nozzle holes is rotated about the hole center of the valve hole, r < There is a nozzle hole satisfying the relationship of (5/4) · (d ² / h),
There is a surface Ps including the hole center of the valve hole in which the hole center of the nozzle hole on the valve seat side surface of the nozzle hole plate is mirror-image symmetric, and the nozzle hole is on the surface Ps. A fuel injection valve, which is not arranged. A plurality of the nozzle holes are arranged on each of two or more pitch circles having different radii around the hole center of the valve hole,
2. The fuel injection valve according to claim 1, wherein the nozzle hole diameter is different for each of the pitch circles arranged. 3.   The fuel injection valve according to claim 1 or 2, wherein a hole center of the injection hole is inclined with respect to a hole center of the valve hole.   The fuel injection valve according to any one of claims 1 to 3, wherein the height of the fuel chamber decreases as the distance from the center of the valve hole increases.

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