WO2019216329A1

WO2019216329A1 - Fuel injection device

Info

Publication number: WO2019216329A1
Application number: PCT/JP2019/018325
Authority: WO
Inventors: 渡辺　正浩; 岡本　明浩; 靖英田口
Original assignee: 株式会社デンソー
Priority date: 2018-05-11
Filing date: 2019-05-08
Publication date: 2019-11-14
Also published as: JP2019196750A; JP6844583B2

Abstract

A fuel injection device (1) is provided with a seat section (10), a hollow cylindrical valve body (20) which has a fuel outlet (24) having a smaller diameter than the seat section (10), a valve member (50) which controls the injection of fuel and the stop thereof by opening and closing the seat section (10), a nozzle plate (30) which is disposed downstream of the fuel outlet (24) and which has a nozzle hole (32) for injecting the fuel to form spray, and a nozzle holder (40) which is affixed to the valve body (20) and which holds the nozzle plate (30). The nozzle plate (30) is disposed at a distance from the valve body (20). The nozzle hole (32) is formed radially outside the fuel outlet (24). A diametrically enlarged fluid chamber (55) which is enlarged radially outward from the fuel outlet (24) toward the nozzle hole (32) is formed between the nozzle plate (30) and the valve body (20).

Description

Fuel injection device

Cross-reference of related applications

This application is based on Patent Application No. 2018-91838 filed on May 11, 2018, the contents of which are incorporated herein by reference.

The present disclosure relates to a fuel injection device.

Conventionally, a fuel injection device having a plurality of injection holes and including an injector plate joined to an outer end surface of a valve seat member is known. In the fuel injection device disclosed in Patent Document 1, the injector plate forms an annular flat portion joined to the valve seat member and a protruding portion that protrudes in the opposite direction to the valve seat member inside the annular flat portion. ing. The inner diameter of the protrusion is larger than the valve hole at the center of the valve seat member. A fuel passage is formed between the valve seat member and the injector plate to communicate the valve hole and the injection hole.

Japanese Patent Laying-Open No. 2005-54656

In Patent Document 1, an injector plate is manufactured by press drawing from a single plate having a uniform thickness in order to form a concave shape that defines a fuel passage. In order to perform such drawing processing, it is necessary to select a soft material. Therefore, there is a concern that the fatigue strength of the injector plate will decrease.

The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide a fuel injection device capable of improving the fatigue strength of a plate in which nozzle holes are formed.

The fuel injection device of the present disclosure includes a seat portion, a valve body, a valve member, a nozzle plate, and a nozzle holder. The valve body is cylindrical and has a fuel outlet having a smaller diameter than the seat portion. The valve member controls fuel injection and stop by opening and closing the seat portion. The nozzle plate is disposed downstream of the fuel outlet and has injection holes that inject fuel and form spray. The nozzle holder is fixed to the valve body and holds the nozzle plate.

The nozzle plate is thinner than the nozzle holder and is spaced apart from the valve body. The nozzle hole is formed radially outward from the fuel outlet. A diameter expansion fluid chamber is formed between the nozzle plate and the valve body so as to extend radially outward from the fuel outlet toward the injection hole.

This eliminates the need to set the drawing process by pressing. Further, it is not necessary to select a soft material considering the drawability as the material of the nozzle plate, and the fatigue strength can be improved by selecting a hard material. Further, since it is not necessary to form a concave shape for the enlarged fluid chamber in the valve body, it is possible to share the specification with no enlarged fluid chamber and the valve body.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is a cross-sectional view of the fuel injection device according to the first embodiment. FIG. 2 is an enlarged view of part II in FIG. FIG. 3 is an enlarged view of part III in FIG. FIG. 4 is a view corresponding to FIG. 3 and illustrating the flow of fuel. FIG. 5 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the second embodiment, FIG. 6 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the third embodiment, FIG. 7 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the fourth embodiment, FIG. 8 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the fifth embodiment, FIG. 9 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the sixth embodiment, FIG. 10 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the seventh embodiment, FIG. 11 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the eighth embodiment, FIG. 12 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the ninth embodiment, FIG. 13 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the tenth embodiment, FIG. 14 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the eleventh embodiment, FIG. 15 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the twelfth embodiment, FIG. 16 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the thirteenth embodiment, FIG. 17 is an enlarged view showing the periphery of the nozzle plate of the fuel injection device according to the fourteenth embodiment.

Hereinafter, a plurality of embodiments of the fuel injection device will be described with reference to the drawings. In the embodiments, substantially the same components are denoted by the same reference numerals and description thereof is omitted.

[First Embodiment]
The fuel injection device according to the first embodiment is shown in FIGS. The fuel injection device 1 includes a cylindrical member 12, a valve body 20, a nozzle plate 30, a needle 50, a movable core 60, a fixed core 70, a spring 80, a coil 90, and the like.

The cylindrical member 12 is formed in a cylindrical shape, and has a first magnetic portion 13, a nonmagnetic portion 14, and a second magnetic portion 15 in order from the lower valve body 20 side in FIG. The first magnetic part 13 and the second magnetic part 15 are made of a magnetic material. The nonmagnetic portion 14 is made of a nonmagnetic material. The first magnetic part 13 and the nonmagnetic part 14, and the nonmagnetic part 14 and the second magnetic part 15 are coupled by, for example, laser welding. The nonmagnetic part 14 prevents the magnetic flux from being short-circuited between the first magnetic part 13 and the second magnetic part 15. The tubular member 12 houses a fuel filter 18 at one end on the second magnetic part 15 side.

The valve body 20 is formed in a cylindrical shape and is fixed to the other end portion of the cylindrical member 12. The valve body 20 has a fuel passage 21 through which fuel flows toward the nozzle plate 30. An end of the valve body 20 opposite to the tubular member 12 forms an annular protrusion 23 that protrudes radially inward. On the inner wall of the annular protrusion 23, an inclined surface valve seat 22 having an inner diameter that decreases toward the nozzle plate 30 is formed. A fuel outlet 24 that is an outlet of the fuel passage 21 is formed inside the annular protrusion 23.

The nozzle plate 30 has a plurality of injection holes 32 communicating with the fuel passage 21. The detailed configuration of the nozzle plate 30 will be described later.

The needle 50 as a “valve member” is formed in a bottomed cylindrical shape and is accommodated coaxially with the inside of the first magnetic part 13 and the valve body 20. The needle 50 is guided by the inner peripheral portion 25 of the valve body 20 and can reciprocate in the axial direction. The needle 50 has a plurality of fuel holes 52 communicating from the inner wall surface of the cylindrical wall to the outer wall surface. The needle 50 forms a contact portion 51 on the bottom wall located on the valve body 20 side. The contact portion 51 can be seated on the valve seat 22. The fuel passage 21 is closed when the contact portion 51 contacts the valve seat 22. The fuel passage 21 is opened when the contact portion 51 is separated from the valve seat 22. The contact portion 51 and the valve seat 22 constitute the seat portion 10. The fuel outlet 24 is an opening having a smaller diameter than the seat portion 10.

The movable core 60 is formed in a cylindrical shape from a magnetic material, and is fixed to an end portion of the needle 50 in the direction opposite to the contact portion 51. The movable core 60 is integrated with the needle 50 and can reciprocate.

The fixed core 70 is formed in a cylindrical shape from a magnetic material, and is fixed to the inner peripheral walls of the nonmagnetic portion 14 and the second magnetic portion 15. The fixed core 70 is provided to face the movable core 60 in the direction opposite to the needle 50 of the movable core 60.

The spring 80 has one end locked to the movable core 60 and the other end locked to the adjusting pipe 81. The adjusting pipe 81 is press-fitted into the inner peripheral wall of the fixed core 70. The biasing force of the spring 80 is adjusted by adjusting the press-fitting amount of the adjusting pipe 81 into the fixed core 70. The spring 80 applies a restoring force generated by elastic deformation to the movable core 60. Accordingly, the spring 80 biases the needle 50 in the direction in which the needle 50 is seated on the valve seat 22.

The spool 91 around which the coil 90 is wound is fixed to the outer peripheral wall of the cylindrical member 12. Outside the coil 90,

magnetic members

94 and 95 are provided which are made of a magnetic material and are magnetically connected to each other. The magnetic member 94 is magnetically connected to the first magnetic part 13. The magnetic member 95 is magnetically connected to the second magnetic part 15. The housing 75 covers the outer peripheral side of the cylindrical member 12 and the

magnetic members

94 and 95. The movable core 60, the first magnetic part 13, the

magnetic members

94 and 95, the second magnetic part 15 and the fixed core 70 constitute a magnetic circuit.

The housing 75 has a connector portion 76. A terminal 92 provided at the opening of the connector portion 76 is electrically connected to the coil 90. A drive current is supplied to the coil 90 through the terminal 92.

Pressurized fuel flowing from one end of the cylindrical member 12 passes through the fuel passage in the fixed core 70, the fuel passage in the movable core 60, the fuel passage in the needle 50, and the fuel hole 52, and enters the valve body 20. The fuel passage 21 is reached. The fuel that has reached the fuel passage 21 is injected from the injection hole 32 through the gap formed between the contact portion 51 and the valve seat 22 when the contact portion 51 is separated from the valve seat 22. A spray is formed.

In the fuel injection device 1, when energization of the coil 90 is turned off, no magnetic attractive force is generated between the movable core 60 and the fixed core 70. At this time, the needle 50 moves in the direction of the valve seat 22 by the restoring force of the spring 80. When the contact portion 51 is seated on the valve seat 22, the fuel passage 21 is closed and fuel injection from the injection hole 32 is stopped.

When energization of the coil 90 is turned on, magnetic flux flows through a magnetic circuit composed of the movable core 60, the first magnetic part 13, the

magnetic members

94 and 95, the second magnetic part 15, and the fixed core 70, and the fixed core 70 and the movable core A magnetic attraction force is generated between As a result, the movable core 60 is attracted toward the fixed core 70, and the needle 50 moves in the direction of the fixed core 70 against the restoring force of the spring 80 together with the movable core 60. When the contact portion 51 is separated from the valve seat 22, the fuel passage 21 is opened and fuel is injected from the injection hole 32. Thereafter, when the power supply to the coil 90 is turned off, the magnetic flux flowing through the magnetic circuit disappears, the magnetic attractive force between the fixed core 70 and the movable core 60 disappears, and the contact portion 51 is seated on the valve seat 22. Thus, one fuel injection operation is completed. The needle 50 controls fuel injection and stop by opening and closing the seat portion 10.

Next, the configuration of the nozzle plate 30 and its peripheral parts will be described. As shown in FIGS. 2 and 3, the fuel injection device 1 further includes a nozzle holder 40. The nozzle holder 40 is fixed to the valve body 20 and holds the nozzle plate 30. The nozzle holder 40 is plate-shaped and annular, and has a through hole 42 penetrating the center. The nozzle holder 40 is welded to the outer end surface of the nozzle holder 40 (that is, the end surface where the fuel outlet 24 is open), and is fixed to the nozzle holder 40 by a welded portion 46 that penetrates the nozzle holder 40 in the plate thickness direction. ing.

The nozzle plate 30 has a plate shape and is thinner than the nozzle holder 40. The nozzle plate 30 is fitted in the through hole 42 in a state where the plate thickness direction substantially coincides with the valve body 20. The nozzle plate 30 is disposed away from the valve body 20. The outer peripheral portion (that is, the fitting portion) of the nozzle plate 30 is welded to the inner peripheral portion of the nozzle holder 40 (that is, the inner wall of the through hole 42), and is fixed to the nozzle holder 40 by the welded portion 36. In the first embodiment, the plate thickness of the nozzle plate 30 is uniform. If the portion of the nozzle plate 30 that is fixed to the nozzle holder 40 is a plate fixing portion 38, the plate fixing portion 38 does not protrude from the inlet of the injection hole 32 toward the valve body 20. The inlet of the injection hole 32 has the same axial position as the surface of the plate fixing portion 38 on the valve body 20 side. Further, the nozzle plate 30 and the nozzle holder 40 are arranged such that surfaces opposite to the valve body 20 are aligned in the axial direction.

The nozzle hole 32 is drilled by pressing. The material of the nozzle plate 30 is selected from austenite-based material such as SUS304 in consideration of the use environment and press workability. In the first embodiment, the tempered material SUS304-1 / 2H is selected. The Vickers hardness of this material is 250 Hv or more.

The nozzle plate 30 is disposed downstream of the fuel outlet 24. The nozzle hole 32 is formed on the radially outer side than the fuel outlet 24. Between the nozzle plate 30 and the valve body 20, a diameter expansion fluid chamber 55 is formed that extends radially outward from the fuel outlet 24 toward the injection hole 32.

As shown by the arrows in FIG. 4, the fuel that has passed through the seat portion 10 once flows radially inward and toward the fuel outlet 24. Then, the fuel that has passed through the fuel outlet 24 flows through the diameter expansion fluid chamber 55 radially outward and is injected from the injection hole 32. Thus, by forming a flow in the radially outward direction toward the nozzle hole 32, the spray can be atomized and diffused.

(effect)
Conventionally, the plate in which the nozzle hole is formed is composed of one part including a portion fixed to the valve body. In order to form a concave shape that defines an enlarged fuel passage corresponding to the enlarged fluid chamber 55 of the present application, the plate having such a form has been manufactured by press drawing from a single plate having a uniform thickness. . In order to perform such drawing processing, it is necessary to select a soft material. For this reason, there has been concern about a decrease in the fatigue strength of the plate.

On the other hand, it is conceivable to form a concave shape in the valve body that partitions the expanded fuel passage. However, if the concave shape is formed on the valve body, it is not possible to share the valve body with the specification without the enlarged fuel passage.

In contrast, in the first embodiment, the nozzle plate 30 having the nozzle holes 32 and the nozzle holder 40 that holds the nozzle plate 30 and is fixed to the valve body 20 are provided, and these two parts form a concave shape. Yes. The nozzle plate 30 is thinner than the nozzle holder 40 and is arranged away from the valve body 20. The nozzle hole 32 is formed on the radially outer side than the fuel outlet 24. Between the nozzle plate 30 and the valve body 20, a diameter expansion fluid chamber 55 is formed that extends radially outward from the fuel outlet 24 toward the injection hole 32.

This eliminates the need to set the drawing process by pressing. Further, it is not necessary to select a soft material considering the drawability as the material of the nozzle plate 30, and the fatigue strength can be improved by selecting a hard material. Further, since it is not necessary to form a concave shape for the enlarged diameter fluid chamber 55 in the valve body 20, it is possible to share the specification without the enlarged diameter fluid chamber 55 with the valve body 20.

In the first embodiment, the Vickers hardness of the material of the nozzle plate 30 is 250 Hv or more. Conventionally, it has been necessary to select, for example, SUS304 as a non-refining agent as a material having a Vickers hardness of 200 Hv or less in consideration of drawability. However, the fatigue strength can be improved by selecting a hard material as the material of the nozzle plate 30 by forming a concave shape with the two parts of the nozzle plate 30 and the nozzle holder 40 as described above.

In the first embodiment, the nozzle plate 30 is arranged so that the plate thickness direction coincides with the axial direction of the valve body 20. The inlet of the injection hole 32 has the same axial position as the surface of the plate fixing portion 38 on the valve body 20 side. That is, the surface of the nozzle plate 30 where the nozzle holes 32 are drilled protrudes from the surface layer portion. More specifically, the nozzle plate 30 has a concave shape and only the injection holes 32 are perforated. Conventionally, since the nozzle hole was opened in the concave bottom surface of the plate, it was difficult to remove the burr at the nozzle hole opening by tape polishing or the like. On the other hand, in the first embodiment, after the injection holes 32 are processed, it is easy to remove burrs from the openings of the injection holes 32 by tape polishing or the like.

[Second Embodiment]
In the second embodiment, as shown in FIG. 5, the nozzle hole 322 of the nozzle plate 302 has a tapered shape. The taper shape includes not only a conical surface but also a shape in which the inner diameter gradually increases or decreases. Thereby, the effect of thinning the liquid film of the fuel flowing in the nozzle hole 322 is obtained. Therefore, atomization of the spray injected from the nozzle hole 322 is promoted, and the engine performance is improved. In the second embodiment, the configuration other than the above is the same as that of the first embodiment, and the same effect as that of the first embodiment is achieved.

[Third Embodiment]
In the third embodiment, as shown in FIG. 6, a step is formed on the outer side of the nozzle plate 303 on the valve body 20 side. The nozzle plate 303 is welded to the nozzle holder 403 in a state in which the stepped surface 343 lowered by one step is in contact with the nozzle holder 403 in the axial direction. The outer peripheral portion of the nozzle plate 303, that is, the plate fixing portion 383 is fixed to the nozzle holder 403 by a welding portion 363 that penetrates the plate fixing portion 383.

The inlet of the nozzle hole 32 is located on the valve body 20 side in the axial direction from the plate fixing portion 383. That is, the surface of the nozzle plate 303 in which the nozzle holes 32 are formed protrudes from the surface layer portion. Therefore, it is easy to remove burrs from the opening of the injection hole 32 by tape polishing after the injection hole 32 is processed. In the third embodiment, the configuration other than the above is the same as that of the second embodiment, and the same effect as that of the second embodiment is achieved.

[Fourth Embodiment]
In the fourth embodiment, as shown in FIG. 7, the plate fixing portion 384 on the outer peripheral portion of the nozzle plate 304 is press-fitted into the inner peripheral portion of the nozzle holder 404 (that is, the inner wall of the through hole 42). Thereby, the distortion of the nozzle hole 32 by welding with the nozzle plate 304 and the nozzle holder 404 can be eliminated, and the stable spray performance can be ensured. The fourth embodiment has the same configuration as the first embodiment except for the above, and has the same effect as the first embodiment.

[Fifth Embodiment]
In the fifth embodiment, as shown in FIG. 8, the nozzle holder 405 has a cup shape having a cylindrical portion 485 that is fitted to the valve body 20. The cylindrical portion 485 is welded to the valve body 20 and is fixed to the valve body 20 with a welded portion 465. By disposing the welding position between the nozzle holder 405 and the valve body 20 away from the nozzle plate 30, distortion of the nozzle hole 32 due to welding can be reduced. In the fifth embodiment, the configuration other than the above is the same as that of the first embodiment, and the same effects as those of the first embodiment are achieved.

[Sixth Embodiment]
In the sixth embodiment, as shown in FIG. 9, the nozzle holder 406 has a cup shape having a cylindrical portion 486 that fits into the valve body 20. The cylinder portion 486 is press-fitted into the valve body 20. When welding so as to penetrate the nozzle holder 406 having a plate thickness that is thicker than that of the nozzle plate 30, relatively large welding energy is required, which causes distortion of the nozzle plate 30. However, by press-fitting the nozzle holder 406 into the valve body 20, distortion of the nozzle plate 30 and the nozzle hole 32 due to welding can be eliminated. The sixth embodiment has the same configuration as the first embodiment except for the above, and has the same effect as the first embodiment.

[Seventh Embodiment]
In the seventh embodiment, as shown in FIG. 10, the nozzle holder 407 has a stepped hole 427 having a large diameter on the side opposite to the valve body 20 at the center. The nozzle plate 307 is welded to the inner wall of the large diameter portion of the stepped hole 427 in a state in which the nozzle plate 307 is in contact with the stepped surface 447 of the stepped hole 427 in the axial direction. An outer peripheral portion of the nozzle plate 307, that is, a plate fixing portion 387 is fixed to the nozzle holder 407 by a welding portion 367. Therefore, the position in the axial direction of the nozzle plate 307 can be set by the step height of the stepped hole 427, and positional accuracy can be easily ensured during assembly. The seventh embodiment has the same configuration as the first embodiment except for the above, and has the same effect as the first embodiment.

[Eighth Embodiment]
In the eighth embodiment, as shown in FIG. 11, the plate fixing portion 388 of the nozzle plate 308 is in contact with the stepped surface 447 of the stepped hole 427 of the nozzle holder 408 in the axial direction. It is press-fitted into the inner wall of the large diameter part. Therefore, the position in the axial direction of the nozzle plate 308 can be set by the step height of the stepped hole 427, and positional accuracy can be easily ensured during assembly. Further, the distortion of the nozzle hole 32 due to welding between the nozzle plate 308 and the nozzle holder 408 can be eliminated. Further, the configuration of the eighth embodiment is the same as that of the first embodiment except for the above, and has the same effects as those of the first embodiment.

[Ninth Embodiment]
In the ninth embodiment, as shown in FIG. 12, the plate fixing portion 389 of the nozzle plate 309 is in contact with the stepped surface 447 of the stepped hole 427 of the nozzle holder 409 in the axial direction. It is welded to the small diameter part. The nozzle plate 309 and the nozzle holder 409 are fixed to the valve body 20 by a welded portion 369 penetrating them. Therefore, the position in the axial direction of the nozzle plate 309 can be set by the step height of the stepped hole 427, and positional accuracy can be easily ensured during assembly. Further, by fixing the nozzle plate 309 and the nozzle holder 409 to the valve body 20 by the common welded portion 369, the assembly man-hour can be reduced. In the ninth embodiment, the configuration other than the above is the same as that of the first embodiment, and the same effects as those of the first embodiment are achieved.

[Tenth embodiment]
In the tenth embodiment, as shown in FIG. 13, the nozzle holder 410 has a through hole 42 at the center. A plate fixing portion 390 that is an outer peripheral portion of the nozzle plate 310 is welded to the inner wall of the through hole 42 and is fixed to the nozzle holder 410 by the welding portion 370. Thereby, the height of the diameter expansion fluid chamber 55 can be easily adjusted by changing the axial fixing position of the nozzle plate 310, and the influence on the spray performance can be easily adjusted.

The surface 450 of the nozzle holder 410 opposite to the valve body 20 protrudes on the opposite side of the valve body 20 from the outlet of the nozzle hole 32. Thereby, it can suppress that the exit of the nozzle hole 32 collides with other components and is damaged at the time of the assembly | attachment of the fuel injection apparatus 1. FIG. Further, it is not necessary to set a sleeve for protecting the injection hole 32, and the injection hole 32 can be protected without increasing the number of parts. In the tenth embodiment, the configuration other than the above is the same as that of the first embodiment, and the same effects as those of the first embodiment are achieved.

[Eleventh embodiment]
In the eleventh embodiment, as shown in FIG. 14, the plate fixing portion 391 that is the outer peripheral portion of the nozzle plate 311 is press-fitted into the inner wall of the through hole 42 of the nozzle holder 411. Thereby, the height of the diameter expansion fluid chamber 55 can be easily adjusted by changing the axial fixing position of the nozzle plate 311, and the influence on the spray performance can be easily adjusted. Further, the configuration of the eleventh embodiment is the same as that of the tenth embodiment except for the above, and has the same effect as the tenth embodiment.

[Twelfth embodiment]
In the twelfth embodiment, as shown in FIG. 15, the surface 452 of the nozzle holder 412 opposite to the valve body 20 protrudes on the opposite side of the valve body 20 from the outlet of the injection hole 32. Thereby, it can suppress that the exit of the nozzle hole 32 collides with other components and is damaged at the time of the assembly | attachment of the fuel injection apparatus 1. FIG. The configuration of the twelfth embodiment is the same as that of the ninth embodiment except for the above, and has the same effects as those of the ninth embodiment.

[Thirteenth embodiment]
In the thirteenth embodiment, as shown in FIG. 16, the plate fixing portion 393, which is the outer peripheral portion of the nozzle plate 313, is welded while being in axial contact with the bottom portion 493 of the cup-shaped nozzle holder 413. The nozzle plate 313 and the nozzle holder 413 are fixed to the valve body 20 by a welded portion 373 penetrating them. Therefore, by fixing the nozzle plate 313 and the nozzle holder 413 to the valve body 20 with the common welded portion 373, the assembly man-hour can be reduced. In the thirteenth embodiment, the configuration other than the above is the same as that of the fifth embodiment, and the same effects as those of the fifth embodiment are achieved.

[Fourteenth embodiment]
In the fourteenth embodiment, as shown in FIG. 17, the nozzle plate 314 is formed in a cup shape and is fitted to the nozzle holder 414 and the valve body 20. A plate fixing portion 394 which is an outer peripheral portion of the bottom portion of the nozzle plate 314 is welded in a state of being in contact with an annular plate nozzle holder 414 in the axial direction. The nozzle plate 314 and the nozzle holder 414 are fixed to the valve body 20 by a welded portion 374 penetrating them. Therefore, by fixing the nozzle plate 314 and the nozzle holder 414 to the valve body 20 with the common welded portion 374, the assembly man-hour can be reduced. In addition, the configuration of the fourteenth embodiment is the same as that of the thirteenth embodiment except for the above, and has the same effects as the thirteenth embodiment.

[Other Embodiments]
In another embodiment, the nozzle hole is not limited to press working, and may be drilled by other methods such as laser processing. In other embodiments, the material of the nozzle plate is not limited to SUS304, and other materials may be selected.

In the thirteenth embodiment, the nozzle holder 413 has a cup shape. On the other hand, in other embodiments, the nozzle holder may be plate-shaped. Further, the nozzle plate may be fixed by welding or the like in a state where the nozzle plate is overlapped in the axial direction with respect to the plate-like nozzle holder.

This disclosure has been described based on embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also includes various modifications and modifications within the equivalent scope. Also, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

A seat (10);
A valve body (20) which is tubular and has a fuel outlet (24) having a smaller diameter than the seat portion;
A valve member (50) for controlling fuel injection and stopping by opening and closing the seat part;
Nozzle plates (30, 302, 303, 304, 307, 308, 309, 310, 311 and 313) disposed on the downstream side of the fuel outlet and having injection holes (32, 322) for injecting fuel to form spray. 314) and
A nozzle holder (40, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414) fixed to the valve body and holding the nozzle plate;
With
The nozzle plate is disposed away from the valve body,
The nozzle hole is formed radially outside the fuel outlet,
A fuel injection device in which a diameter-enlarged fluid chamber (55) is formed between the nozzle plate and the valve body so as to extend radially outward from the fuel outlet toward the nozzle hole.
The fuel injection device according to claim 1, wherein the nozzle plate material has a Vickers hardness of 250 Hv or more.
The nozzle plate is arranged so that the plate thickness direction coincides with the axial direction of the valve body,
When the portion of the nozzle plate that is fixed to the nozzle holder is a plate fixing portion (38, 383, 384, 387, 388, 389, 390, 391, 393, 394),
The inlet of the nozzle hole has the same axial position as the valve body side surface of the plate fixing part, or is located on the valve body side of the plate fixing part. The fuel injection device described in 1.
The fuel injection device according to any one of claims 1 to 3, wherein the nozzle hole (322) has a tapered shape.
The nozzle holder (40, 403, 404, 405, 407, 408, 409, 410, 411, 412, 413) is welded to the valve body,
The fuel injection device according to any one of claims 1 to 4, wherein the nozzle plate is welded or press-fitted to the nozzle holder.
The nozzle holder (405, 406, 413) has a cup shape having a cylindrical portion (485, 486) fitted to the valve body,
The cylindrical portion is welded or press-fitted to the valve body,
The fuel injection device according to any one of claims 1 to 4, wherein the nozzle plate (30, 313) is welded or press-fitted to the nozzle holder.
The nozzle holder (407, 408, 409, 412) has a stepped hole (427) having a large diameter on the opposite side to the valve body at the center,
The fuel injection device according to any one of claims 1 to 6, wherein the nozzle plate (307, 308, 309) is in axial contact with the step surface (447) of the stepped hole.
The nozzle plate (309, 313, 314) and the nozzle holder (409, 412, 413, 414) are fixed to the valve body by welds (369, 373, 374) passing therethrough. 8. The fuel injection device according to any one of 1 to 7.
The nozzle holder has a through hole (42) in the center,
The fuel injection device according to any one of claims 1 to 6, wherein an outer peripheral portion of the nozzle plate (30, 302, 304, 310, 311) is welded or press-fitted to an inner wall of the through hole.
The fuel injection device according to any one of claims 1 to 9, wherein a surface (450, 452) opposite to the valve body of the nozzle holder protrudes from an outlet of the nozzle hole.