DESCRIPTION
TITLE OF THE INVENTION Fuel Injection Valve
FIELD OF THE INVENTION
[0001] ...... . ..- -
This invention relates to a fuel injection valve, and more particularly, relates to a fuel injection valve which is used for supplying fuel to an internal combustion engine.
BACKGROUND OF THE INVENTION
[0002]
In an internal combustion engine for an automobile and the like, a fuel injection
, valve is used to control the feed rate of the fuel. In recent years, exhaust gas _ '
, -regulations on the internal combustion engine have been strengthened, and the ■ • _■ -;'i.
1 - ' . . . . ■ ■ . ■ . - ■
atomization of the fuel spray which is injected from a fuel injection valve has been . :.
■ . , called for. In the known techniques shown in Patent Documents 1 and 2, forming a • '
_. .' circulating flow in a fuel injection valve is examined, in order to achieve the
atomization of fuel. " ■ ' -,"- • •"
..- ■.■ .-"' [0003] ■'.. -"■*.; - ■* ■•■■_ .v ' -,-"',.
,': "7 ' The fuel injection valve according to Patent Document 1 is equipped with a valve _ " —
. ■ casing which is symmetrically formed with respect to a longitudinal axis line. Inside .. -" • --.. ■
■ *;-,. '■ the valve casing, a valve closing component which conducts a cooperative move with a '•".-£■ l ;'-, -.
*"*"' valve seat surface is arranged. A central opening is disposed in the lower stream of the * '
' ;> .' . valve seat surface, and at least two tangential direction passages have extended from -. ' _
■i '' the central opening to a radial direction. Each of the tangential direction passages >
■includes an opening which is opened to a respective swirl room along a tangential ■■ 7 '
■ " ■ ■ " direction. The constant flow openings for the fuel, respectively, lead from the center of - •
a swirl room to the exterior, > ■ *L
[0004] - . \. ' '■" . . .;-■--'... '■:■
■ . As to fuel which is straightened in flow and accelerated.by a guidance passage, the ■: ■,
"■ - -liquid flows into the swirl room. The fuel is formed into a circulating flow at the swirl ■*. \pi
t,'.", room, and after that, is injected from the exit of an injection hole plate, while "- _ "."-.:■/,,
* •' ' .'■'■*'-'
-;.- - _ circulating inside of an injection hole. Sprayed materials are in the form of injection - .„ "^ '-

mist with a hollow conical shape and the atomization of the fuel is said to be promoted. In such a constitution, fuel flows into the swirl room only from a single direction, and then, the swirl flow becomes non-uniform. Fuel liquid films formed on the inner wall of the injection hole produce deviation in film thickness, and then, the degree of the atomization after the injection is far from a high enough level. [0005]
In the fuel injection valve according to Patent Document 2, there is provided a single injection hole which is arranged keeping a distance of a radial direction with respect to a valve opening. The fuel injection valve has been constructed in such a manner that two arc-like eddying flow formation passages, which are mutually arranged with a mirror imaged symmetric manner, are guided to an eddying flow formation room with the single injection hole. In such a constitution, there are two passages which are guided to a swirl room. Accordingly, circulating flow becomes better in homogeneity, and the atomization of the fuel is improved. It is true that formation of multi injection holes is desirable for attaining further atomization of the fuel, but the two passages are constraint in layout nature and make it difficult to form multi injection holes.
CITATION LIST
[PATENT LITERATURE] [0006]
[ Patent Document 1 ] JP 1989 - 271656 A
[ Patent Document 2 ] WO 2013 - 023838 A
SUMMARY OF THE INVENTION
[TECHNICAL PROBLEM]
[0007]
A system which has' employed two opposing flow channels to a swirl room can attain good homogeneity in the swirl flow, to be sure. However, in the system there are two passages which lead to the low layout nature, and then, the atomization by the formation of multi injection holes was difficult to achieve. Therefore, a structurer which can attain the high layout nature and further can produce a homogeneous swirl flow is desired. [0008]

It is an object of the present invention to solve the above mentioned issues. The present invention aims at attaining further atomization of the fuel, maintaining the homogeneity of the flow of fuel, in the fuel injection valve which is equipped with a valve driven by a solenoid device and a valve seat which is arranged at a lower stream side of this plunger.
[SOLUTION TO PROBLEM]
[0009]
A fuel injection valve in accordance with the present invention contains ; a plunger
which is driven by a solenoid device, a valve seat which is arranged at a lower stream
side of the plunger and has an opening part, and an injection hole plate which includes
a radially shaped hollow formed at an upper stream side, the hollow having a branch
*■■■ part, a lead in part, a cylinder part, and a swirl part, and has an injection hole opened *
at a lower stream side of the cylinder part, wherein the lead in part includes one end which is connected to the branch part, and the other end which is connected to the cylinder part and the swirl part, the swirl part is closed at a termination face which is circumscribed to the cylinder part, after surrounding a part of the cylinder part, the termination face of the swirl part is tilted at Angle 0 to a central axis of the lead in part, Angle 6 is in a range from 0 degree or more to 45 degrees or less, and moreover Ratio W2 / Wl , where W2 denotes a width of the swirl part and Wl denotes a width of the lead in part, is in a range from 0.3 or more to 0.7 or less. [ADVANTAGEOUS EFFECTS OF INVENTION] [0010]
The fuel injection valve according to the present invention includes a cylinder part of a cylinder-like shape and a swirl part which is provided at the outer periphery side of the cylinder part. Injection holes are opened at the center of the cylinder part. A termination part of the swirl part is referred to as a termination face L of the outer periphery part of the cylinder part. Angle 8 which is formed between the termination face L and the central axis of the lead in part is made to fall in the relation of 0 degree < — 6 < = 45 degrees. Thereby, Flow A which directly flows in from the lead in part will oppose in the cylinder part with Flow B which flows into the cylinder part via the swirl part. Moreover, both Flows will become roughly equal in strength, by setting W2 / Wl in the range of 0.3 < = W2 / Wl < = 0.7, where Wl denotes a width of the lead in part and W2 denotes a width of the swirl part. [0011]
As mentioned above, in the fuel injection valve according to the present invention the swirl flow will become more homogeneous, compared with the case where a swirl

flow is formed by streams from a single direction. As a result, fuel liquid films formed on the inner wall of an injection hole become uniform in thickness, and then, the level of the atomization will be in a good condition. Furthermore, the fuel injection valve can attain the similar atomization effect, and in addition, is compact in the configuration, as compared with the case where two independent and opposing channels are provided to a swirl room. Thereby, the formation of multi injection holes becomes easy to attain, and then, the injection flow volume per injection hole is deceased in the fuel injection valve. Fuel liquid films formed after the injection are in the state of finer thicknesses, and thereby, the further atomization of the fuel can be attained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] .....
FIG. 1 is a sectional view for showing the whole configuration of a fuel injection valve in accordance with Embodiments.
FIG. 2Ais a sectional view for showing a tip part of the fuel injection valve and FIG. 2B is a plan view for showing an injection hole plate of the fuel injection valve.
FIG. 3 is a plan view for showing a hollow which is formed in the injection hole plate.
FIG. 4 is an enlarged view for showing a lead in part and a cylinder part and a swirl part which are formed in the injection hole plate.
FIG. 5 is a drawing for showing a relation among Angle 6, Wl and W2, where Wl is a width of the lead in part and W2 is a width of the swirl part.
FIG. 6 is a drawing for showing two fuel streams which are produced in the cylinder part and the swirl part.
FIG. 7 is a drawing for showing the correlation between the level of the atomization and Angle6, where the angle is formed between a termination face L and a central axis of the lead in part.
FIG. 8 is a drawing for showing the correlation between the level of the atomization and the ratio of Wl to W2, where Wl is a width of the lead in part and W2 is a width of the swirl part.
FIG. 9 is a drawing for explaining the relation between Wl and Dl, where Wl denotes a width of the lead in part and Dl denotes a diameter of the cylinder part.
FIG. 10 is a drawing for showing two fuel streams in the fuel injection valve according to Embodiment 2.
FIG. 11A is a plan view drawing for illustrating a hollow in accordance with Embodiment 3. FIG. 11B is a sectional view drawing for illustrating a hollow in

accordance with Embodiment 3.
FIG. 12 is a drawing for showing two fuel streams in the fuel injection valve according to Embodiment 3.
FIG. 13 is a plan view for showing a hollow which is formed in the injection hole plate according to Embodiment 4.
DESCRIPTION OF EMBODIMENTS
[0013]
Hereinafter, a fuel injection valve according to the embodiments of the present invention will be described with reference to drawings. Incidentally, the same reference numerals are given to those identical or similar to constitutional portions in respective drawings and the size and/or the scale size of-the corresponding respective constitutional portions are respectively independent. For example, when the identical constitutional portions, which are not changed, are shown, the size and/or the scale size of the identical constitutional portions may different among sectional views in which a part of the configuration is changed. Furthermore, although the configurations of the fuel injection valve are further actually provided with a plurality of members, for ease of explanation, only portions necessary for explanation will be described and other portions are omitted. [0014] Embodiment 1 .
Figure 1 shows a cross section of a fuel injection valve in accordance with the embodiments of the present invention. In the fuel injection valve 100, fuel which is introduced from a fuel feed opening is atomized in the form of spraying mist and discharged out from a fuel spray opening. The fuel injection valve 100 consists of a drive circuit 1, a solenoid device 4, a housing 5, a core 6, an armature 8, a plunger 9, a valve main body 11, a valve seat 12, an injection hole plate 13 and others. Actuating signals and stop signals are sent to the drive circuit 1 of the fuel injection valve 100 from the control device of an engine. According to these signals, the drive circuit 1 supplies driving current to the solenoid device 4, and drives the plunger 9. The driving current generates magnetic fluxes in a magnetic circuit which is made up of the armature 8, the core 6, the housing 5, and the valve main body 11. The valve seat 12 is arranged at the lower stream side of the plunger 9. [0015]
The housing 5 corresponds to a yoke portion of a magnetic circuit. The core 6 corresponds to a fixed iron core portion of the magnetic circuit. The armature 8

corresponds to a movable iron core portion of the magnetic circuit. The solenoid device 4 is equipped with a coil 7 and a compression spring 16. The plunger 9 is composed of a valve body 10 and a ball 15. The valve main body 11 was press fitted into the outside diameter part of the core 6, and then, welded there. The armature 8 was press fitted into the valve body 10, and then, welded there. The injection hole plate 13 is combined with the valve seat 12. In the injection hole plate 13, arranged are a plurality of injection holes 14 which penetrate in a through thickness direction. The plunger 9 includes a ball 15 which is formed of a plurality of chamfered parts. [0016]
Figure 2A is a drawing which enlarges a fuel spray opening (tip part of the valve body ) of the fuel injection valve 100. On the same drawing, a ball 15, a valve seat 12, and an injection hole plate 13 are depicted. The valve seat 12 and the injection hole plate 13 are combined with a welding bead 13b. The valve seat 12 includes a valve seat opening part 12b which is arranged in the central part. When the fuel injection valve 100 is in a closed state, the ball 15 of the plunger 9 pushes with pressures against the valve seat sheet part 12a. In the injection hole plate 13, arranged are a plurality of injection holes 14 which penetrate in a through thickness direction. A part of the injection hole plate 13 is depressed to form a hollow 13a in the upper stream side of the plate. Figure 2B is a plan view for showing the configuration of the hollow 13a which is formed in the injection hole plate 13. The injection hole plate 13 includes a radially hollow 13a which is formed in the upper stream side. A plurality of injection holes 14 are connected with the hollow 13a. Fuel is introduced into the hollow 13a and then injected in the form of spraying mist from a plurality of injection holes 14, after passing through the valve seat opening part 12b. [0017]
In the next place, the movement of the fuel injection valve 100 will be explained. When an actuating signal is sent to the drive circuit 1 of the fuel injection valve 100 from a control device of the engine, electric current will be applied to the coil 7 of the solenoid device 4, and magnetic flux will be produced in a magnetic circuit which is made up of the armature 8, the core 6, the housing 5, and the valve main body 11. The armature 8 will be attracted to a core side, and the valve body 10 which has a solid construction with the armature 8 will separate from the valve seat sheet part 12a to form a gap. Fuel is injected from a plurality injection holes 14 to an engine air intake passage, after proceeding, from the chamfered part 15a of the ball 15 which is welded to the tip part of the valve body 10, through the gap between the valve seat sheet part 12a and the valve body 10.

[0018]
At the next step, when a stop signal of the operation is sent to the drive circuit 1 of the fuel injection valve 100 from the control device of the engine, the driving current which is applied to the coil 7 of the solenoid device 4 will be turned off. Magnetic flux in the magnetic circuit will decrease, due to the reduction in coil current. With the help of a compression spring 16 which pushes the valve body 10 toward a valve closing direction, the gap between the ball 15 and the valve body 10 and the valve seat sheet part 12a will be in a closed state, and then, the fuel injection will come to an end. The armature 8 and the valve body 10 perform sliding motions at the guide part 11a of the valve main body 11, and the upper side surface 8a of the armature 8 makes contact with the lower side surface of the core 6 in a valve open state. [0019]
The detailed configuration of the hollow 13a which is formed in the upper stream side of the injection hole plate 13 will be explained with reference to Figure 3. The hollow 13a consists of a branch part 2, a lead in part 18, and a fuel room 17. The fuel room 17 sits in around the injection hole 14. The lead in part 18 introduces fuel from the valve seat opening part 12b to the fuel room 17. From the branch part 2, a plurality of lead in parts 18 are branched off. The injection hole 14 is formed in the fuel room 17. Fuel proceeds into the lead in part 18 via the branch part 2 from the valve seat opening part 12b which is formed in the valve seat sheet part 12a. The central axis of the lead in part 18 extends radiantly from the center of a valve seat. The branch part 2 is contained in the valve seat opening part 12b. [0020]
Figure 4 shows in detail a configuration of the fuel room 17. The fuel room 17 is made up of a cylinder part 19 which has a cylinder type shape, and a swirl part 20 which surrounds roughly halfway around the outer periphery of the cylinder part 19. The injection hole 14 is opened at the center of the cylinder part 19. The lead in part 18 leads to both of the cylinder part 19 and the swirl part 20. A termination face L of the swirl part 20 is circumscribed to the outer periphery of the cylinder part 19, and serves as a termination part of the swirl part 20. The lead in part 18 has a central axis 3. The lead in part 18 includes one end which is connected with the branch part 2, and the other end which is connected to the cylinder part 19 and the swirl part 20. Therefore, the injection hole plate 13 includes a radially hollow 13a which has the branch part 2, the lead in part 18, the cylinder part 19, and the swirl part 20, and is formed at the upper stream side thereof. An injection hole 14 is opened at the lower stream side of the cylinder part 19. The swirl part 20 surrounds the cylinder part 19 in part, and then,

is closed at a termination face which is circumscribed to the cylinder part 19. [0021]
In the next place, the fuel room 17 and the lead in part 18 will be explained about
their sizes, with reference to Figure 5. The lead in part 18 has a width Wl. The swirl
part 20 has a width W2. Angle 9 denotes an angle which is formed between the
termination face L of the swirl part 20 and the central axis 3 of the lead in part 18. The
swirl part 20 communicates directly with the lead in part 18, because the outer
periphery part thereof is in contact with the inner wall of the lead in part 18. The
termination part of the swirl part 20 serves as the termination face L of the outer
periphery part of the cylinder part 19. In the fuel injection valve 100 in accordance
with the present embodiment, Ratio W2 / Wl falls into a relation of 0.3 < = W2 / Wl < =
0.7. Angle 6 satisfies a relation of 0 degree < = 9 < = 45 degrees.
[0022] * ; - ■>■
Figure 6 shows the direction of the fuel flows which are produced in the hollow 13a
that is formed in the injection hole plate 13. Two typical routes of the fuel which flows '
into the cylinder part 19 and the swirl part 20 from the "lead in part 18 are shown in ■.«
the drawing, Flow 21 denotes a stream which proceeds directly into the cylinder.part'
19: from the.lead in part 18. On the other hand, Flow .22._denotes a stream which"-,
proceeds via the swirl part.20 from the lead in part 18.: ■
[0023] '*rY:: - '-•-'/??';L-- .■-'- ■*■ - ■'■<:*.*_;
■ In thefuel injection valve 100 according to the present embodiment, Flow 21', which,"' proceedsndirectly into the cylinder part 19 from the lead in part 18, and Flow 22,-:.whicE.".
.proceeds from the lead in part 18 via the swirl part 20, face each other and flow into the .cylinder part 19. Flow 21 which proceeds directly into the cylinder part 19 from the
:lead,in p!aft. 18 flows into the cylinder part 19, while being drawn to the direction of an,.;^
injection hole. Here, it is important to make two flows encounter each other completely, ,.
in order to make a homogeneous circulating flow. ■ , . ,,
J0024] ." ■ - - - '
. Figure 7 is a drawing for showing a correlation between Angle 9, which is formed between the termination face L and the central axis 3 of the lead in part 18, and atomization of the fuel. The drawing shows results "which were obtained by measuring diameters of fuel particles after injection, with respect to Specification A and Specification B. By adjusting the magnitude of Angle 9 which is formed between the termination face L and the central axis of the lead in part 18; and then, by changing a flow-in angle to the cylinder part 19 for Flow 22 which proceeds via the swirl part 20, two flows are allowed to completely encounter each other. It is true that the optimal-"

value of Angle 6 which is formed between the termination face L and the central axis of the lead in part 18 depends on the diameter of the cylinder part 19, the width of the swirl part 20 W2, the width of the lead in part 18 Wl, and others. Anyway as shown in the drawing, both specifications showed good results in the atomization of fuel spraying, if AngleO falls inside the range of 0 degree < = 8 < = 45 degrees. [0025]
Figure 8 is a drawing which illustrates the correlation between the atomization level and Ratio W2 / Wl, where Wl denotes a width of the lead in part 18 and W2 denotes a width of the swirl part 20. The two flows which encounter each other are desired to be equal in the strength to some extent. The strength of the flow which proceeds via the swirl part 20 changes according to Ration W2 / Wl, where W2 denotes the ratio of the width of the swirl part 20 and Wl denotes the width Wl of the lead in part 18. As shown in the drawing, by setting Ratio in the range of 0.3 < = W2 / Wl < = 0.7, the two flows can keep a good balance in the strength and the high atomization in the fuel spraying was attained. [0026]
The two opposing flows of the fuel, which flowed into the cylinder part 19, proceed to the injection hole 14. By creating thin liquid films with uniform thicknesses along the inner wall of an injection hole, the fuel injection valve 100 injects fuel particles which are good in the level of the atomization, and moreover small in the variation of the atomization level. As mentioned above, by creating a circulating flow through the streams from two opposing directions, a swirling flow which is high in homogeneity is produced. Accordingly, liquid films along the inner wall of the injection hole become also homogeneous in thickness. Therefore, the level of the atomization is improved, as compared with the system which makes out a circulating flow by the streams from a single direction, because the reduction in the atomization due to the variation in the thickness of fuel liquid films can be canceled. [0027]
Moreover, while an equivalent atomization effect can be acquired, the configuration of the fuel room is simply constructed, and the layout nature is improved, compared with the system which provides two independent and opposing channels to a swirl room. These factors make the formation of multi injection holes easier. Thereby, an injection feed rate assigned to an injection hole can be reduced, with respect to the flow rate which an engine requires. Thickness of the liquid films which are formed along the inner wall of an injection hole becomes smaller due to the decrease of the injection feed rate per injection hole. Accordingly, the atomization of the fuel particles which are

to be injected will be in a further higher level. [0028]
In other words, the fuel injection valve in accordance with the present embodiment, is a fuel injection valve, which has a valve body for opening and closing a valve seat, wherein, by operating the valve body in response to an actuating signal from a control device, fuel is injected from a plurality of injection holes arranged in an injection hole plate which is prepared in the valve seat opening part of a valve seat lower stream side, after passing through a gap between the valve body and a valve seat sheet part. A plurality of fuel rooms and lead in parts which introduce fuel from a valve seat opening part to the fuel rooms are formed, in such a manner that the upper stream side end face of the injection hole plate is depressed. The fuel room consists of a cylinder-shaped cylinder part and a swirl part, and the injection holes are opened at the center of the cylinder part. [0029]
The swirl part surrounds roughly halfway around the outer periphery of the cylinder part, and Ratio W2 / Wl falls in a relation of 0.3 < = W2 / Wl < = 0.7, where Wl denotes a width of the lead in part and W2 denotes a width of the swirl part. Moreover, the swirl part communicates with the lead in part, due to the fact that the outer periphery thereof is in contact with the inner wall of the lead in part, and the termination face L of the outer periphery part of the cylinder part serves as a termination part of the swirl part. Angle 6 which is formed between the termination face L and the central axis of the lead in part has a feature in that it falls in a relation of 0 degree < = 6 < = 45 degrees. [0030] Embodiment 2 .
Figure 9 shows a hollow 13a, in the fuel injection valve 100 in accordance with Embodiment 2. The cylinder part 19 has a diameter Dl. In order to produce a homogeneous circulating flow, it is desired that Flow 21 which directly proceeds from the lead in part 18 to the cylinder part 19 and Flow 22 which proceeds via the swirl part 20 from the lead in part 18 will flow into the cylinder part 19 smoothly, without colliding with circulating flows which are formed in the cylinder part 19. In other words, it is necessary to make the flow-in domain to the cylinder part 19 of each Flow smaller than a radius of the cylinder part, Dl / 2. [0031]
In the fuel injection valve 100 in accordance with the present embodiment, as shown in Figure 10, a domain where a stream proceeds directly into the cylinder part

19 from the lead in part 18 has a width, Wl - W2; and a domain where a stream proceeding via the swirl part 20 flows into the cylinder part 19 has a width, W2. If each of the flow-in domains is made to be smaller than Dl / 2, a radius of the cylinder part 19, each flow will flow into the cylinder part 19, without colliding with circulating flows which are formed in the cylinder part 19. [0032]
Therefore, by setting Wl - W2 < = Dl / 2, and W2 < = Dl / 2, where Dl denotes a diameter of the cylinder part 19, Wl denotes a width of the lead in part 18, and W2 denotes a width of the swirl part 20, each flow can produce circulating flows in the cylinder part 19 smoothly, without colliding with circulating flows which are formed in the cylinder part. Thereby, the degree of homogeneity in the circulating flow is improved. Accordingly, fuel particles which are to be injected can attain better
j * • . *
homogeneity in the level of the atomization.
[0033]
Embodiment 3 .
Figure 11A shows a plan view of a hollow 13a in the fuel injection valve in accordance with Embodiment 3. Figure 11B shows a sectional view of the hollow 13a in the fuel injection valve in accordance with Embodiment 3. In the configurations according to Embodiments 1 and 2, streams which flow into the cylinder part proceed directly into the injection hole 14. Accordingly, fuel may be injected in a state of insufficient swirl, and the thin film formation of liquid films may not fully be performed. Therefore, in Embodiment 3, the bottom of the cylinder part 19 is made deeper than the bottoms of the lead in part 18 and the swirl part 20. Thereby, Flow 21 which proceeds directly into the cylinder part 19 from the lead in part 18 and Flow 22 which proceeds via the swirl part 20 from the lead in part 18 go to the bottom of the cylinder part after they flowed into the cylinder part. Accordingly, a flow which is drawn to the direction of the injection hole will be relieved. [0034]
Figure 12 illustrates fuel flows which are produced in the hollow 13a in accordance with the present embodiment. The drawing shows two routes of the fuel which flows, from the lead in part 18, into the cylinder part 19 and the swirl part 20. As shown in the drawing, fuel flows into an injection hole after making out sufficient circulating flows at the cylinder part 19 with the help of two streams. Accordingly, thin film formation of the fuel liquid films which are formed on the inner wall of the injection hole is further accelerated and fuel particles which are to be injected will be in a higher atomization level.

[0035] Embodiment 4 .
In Embodiments 1-3, the lead in part 18 is in a radially straight line shape where the basis point is at the center of a valve seat. Even if the lead in part 18 is changed into a curved form within the range which does not deviate from the scope of the invention, the same effect can be attained. For example, in order to extend a lead in part for the purpose of straightening the flow, a lead in part in the form of a refracted shape will also produce the same effect. To be more precise, the lead in part 18 has a refraction part 18a, as shown in Figure 13. [0036]
It is to be noted that each embodiment of the present invention may be freely combined, or appropriately modified or omitted within the spirit and scope of the invention.
[EXPLANATION OF NUMERALS AND SYMBOLS]
[0037]
1 Drive Circuit ; 2 Branch Part ', 3 Central Axis ', 4 Solenoid Device ; 5 Housing ; 6
Core ; 7 Coil ; 8 Armature ; 9 Plunger ; 10 Valve Body ; 11 Valve Main Body ; 12 Valve
Seat ; 12a Valve Seat Sheet Part', 13 Injection Hole Plate ; 14 Injection Hole ," 15 Ball!
16 Compression Spring ; 17 Fuel Room ," 18 Lead In Part ; 19 Cylinder Part ; 20 Swirl
Part; 21 Flow ; 22 Flow ; 100 Fuel Injection Valve

CLAIMS
What is claimed is:
[Claim 1]
A fuel injection valve comprising ',
a plunger which is driven by a solenoid device,
a valve seat which is arranged at a lower stream side of the plunger and has an opening part, and
an injection hole plate which includes a radially shaped hollow formed at an upper stream side thereof, the hollow having a branch part, a lead in part, a cylinder part, • and a swirl part, and has an injection hole opened at a lower stream side of the cylinder part,
characterized in that the lead in part includes one end which is connected to the branch part, and the other end which is connected to the cylinder part and the swirl part,
the swirl part is closed at a termination face which is circumscribed to the cylinder part, after surrounding a part of the cylinder part,
the termination face of the swirl part is tilted at Angle 6 to a central axis of the lead in part,
Angle 6 is in a range from 0 degree or more to 45 degrees or less, and moreover
Ratio W2 / Wl , where W2 denotes a width of the swirl part and Wl denotes a width of the lead in part, is in a range from 0.3 or more to 0.7 or less. [Claim 2]
The fuel injection valve as set forth in Claim 1,
characterized in that a radius of the cylinder part is equal to or larger than the difference between the width of the lead in part Wl and the width of the swirl part W2 , and moreover, is equal to or larger than the width of the swirl part W2. [Claim 3]
The fuel injection valve as set forth in Claim 1 or 2,
characterized in that a depth of the cylinder part is larger than a depth of the lead in part and a depth of the swirl part. [Claim 4]
The fuel injection valve as set forth in any one of Claims 1 to 3,
characterized in that the lead in part is in a straight line shape.

[Claim 5]
The fuel injection valve as set forth in any one of Claims 1 to 3, characterized in that the lead in part has a refraction part.