Information
-
Patent Grant
-
6405946
-
Patent Number
6,405,946
-
Date Filed
Tuesday, August 1, 200024 years ago
-
Date Issued
Tuesday, June 18, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
A fuel injector has a chamber between a valve body and a plate in which a plurality of through holes are formed. The chamber has a diameter larger than that of an opening of the valve body. The through holes are opened at an outer chamber area shaded by the valve body are distanced from an outer wall of the chamber more than a diameter of the through hole. Fuel flowing along an inner inclined surface of the valve body turns to the through holes and flows into the through hole from all directions and collides with each other at inlets of the through hole. Therefore, injected fuel has a lot of turbulences and is finely atomized.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application is based on Japanese Patent Application No. Hei 11-224141 filed on Aug. 6, 1999, the content of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fluid injection nozzle having a plate in which a fluid injection hole is formed. For instance, the present invention applies to a fuel injection valve for supplying fuel to an internal combustion engine (engine).
2. Description of Related Art
DE 19636396A1 discloses fuel injector having a plate in which a plurality of through holes are formed as fuel injection orifices. Such a plate type injectors are effective to generate a plurality of fuel jets. In this arrangement, fuel flows along an inclined surface formed by a valve seat. However, some of the through holes are opened on an imaginary line where a surface of the plate crosses an extended line of the inclined surface. Therefore, fuel flowing along the inclined surface directly flows into the through holes. Therefore, fuel is insufficiently atomized.
U.S. Pat. No. 4,907,748, U.S. Pat. No. 5,762,272 and WO 98/34026 disclose the fuel injectors having flat chambers just upstream the through holes. Such a chamber provides a compound fuel flow just upstream the through hole and is effective to atomize fuel. However, there is a possibility to spoil an atomization by a collision of injected fuel columns at just after the through holes. Here, the fuel column is a shape of fuel before fuel is atomized by collision with air. Further, a shape of a wall defining the chamber is important to define a fuel flow at an inlet of the through hole, since the fuel atomization is affected by the fuel flow flowing along the plate. However, WO 98/34026 does not provide a surface having a sufficient flatness and a size to atomize fuel.
SUMMARY OF THE INVENTION
The present invention addresses these drawbacks by providing an improved fluid injection nozzle arrangement.
It is therefore an object of this invention to improve an atomization of fluid.
It is a further object of this invention to provide a fluid injection nozzle in which a collision of injected fluid columns is avoided.
According to a first aspect of the present invention, the fluid injection nozzle has a chamber for controlling a fluid flow to a through hole formed on a plate. Fluid flowing along an inner surface of a valve body is inclined to meet and collide at a center region of the plate. Therefore, fluid turns its direction and flows along the plate. Specifically, the chamber is flat and is extended more than a diameter of the through hole at an outside of the through hole. Therefore, fluid flows along the chamber for a sufficient distance and reaches the through hole from all directions and collides at an inlet of the through hole. As a result, fluid injected from the through hole has a lot of turbulences and is finely atomized. Further, an inlet of the through hole opens at an outer area of a projected area which is defined by projecting a downstream end opening of the inner surface of the valve body. Therefore, the through holes are separately arranged to avoid a collision of columns of fluid injected from the through holes.
According to another aspect of the present invention, a plate has an inner through hole and an outer through hole located both side of an imaginary line. Here, the imaginary line is defined by crossing a surface of the plate and a line extended along the inner surface of the valve body. Therefore, the inner through hole and the outer through hole are mainly influenced by fluid flows having different directions. As a result, columns of injected fluid are directed in different directions and a collision of the columns is avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features and advantages of the present invention will be appreciated, as well as methods of operation and the function of the related parts, from a study of the following detailed description, the appended claims, and the drawings, all of which form a part of this application. In the drawings:
FIG. 1
is a partial sectional view of a nozzle portion of a fuel injector according to a first embodiment of the present invention;
FIG. 2
is a bottom view of a plate according to the first embodiment of the present invention;
FIG. 3
is a sectional view of the fuel injector according to the first embodiment of the present invention;
FIG. 4
is a partial sectional view of a nozzle portion of a fuel injector according to a second embodiment of the present invention;
FIG. 5
is a bottom view of a plate according to the second embodiment of the present invention;
FIG. 6
is a partial sectional view of a nozzle portion of a fuel injector according to a third embodiment of the present invention;
FIG. 7
is a partial sectional view of a nozzle portion of a fuel injector according to a fourth embodiment of the present invention;
FIG. 8
is a bottom view of a plate according to the fourth embodiment of the present invention;
FIG. 9
is a bottom view of a plate according to a fifth embodiment of the present invention;
FIG. 10
is a bottom view of a plate according to a sixth embodiment of the present invention; and
FIG. 11
is a bottom view of a plate according to a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be explained with reference to the drawings.
FIG.
1
through
FIG. 3
shows a first embodiment of the present invention. In this embodiment, the present invention applies to a fuel injector for supplying fuel to an internal combustion engine such as a gasoline engine.
Referring to
FIG. 3
, the fuel injector
1
has a cylindrical stator core
30
for providing a fuel passage therein. The stator core
30
is connected to a first pipe
32
made of nonmagnetic material by a laser welding. The first pipe
32
is connected to a second pipe
12
made of magnetic material by a laser welding. The second pipe
12
is connected to a valve body
13
by a laser welding. An electromagnetic coil having a spool
40
and a coil
41
is disposed on an outside of the stator core
30
, and the first and second pipes
32
and
12
. The coil
41
has a pair of terminals that are connected to connector pins
42
respectively. The coil
41
and the stator core
30
are covered with a resin
11
forming an outer body and a connector housing.
A movable valve member is disposed between the stator core
30
and the valve body
13
. The movable valve member has a needle
20
and an armature core
31
made of a magnetic material. The armature core
31
is connected to an upper end of the needle
20
and is guided on an inner surface of the first pipe
32
in a slidable manner. A spring
35
is disposed between the armature core
31
and an adjust pipe
34
adjustably fixed on an inner surface of the stator core
30
. The needle
20
has an annular contact portion
21
and a flat end surface
20
a
on its bottom end and is guided on an inner surface of the valve body
13
. The annular contact portion
21
contacts with a valve seat
14
a
formed on an inner surface
14
of the valve body
13
.
Referring to FIG.
1
and
FIG. 2
, the inner surface
14
provides a funnel-shaped fuel passage
50
of which a cross section decreases toward a downstream side. The inner surface
14
defines an opening
14
b
at a downstream end. A diameter of the opening
14
b
is smaller than that of the annular contact portion
21
. The valve body
13
has a shallow and circular shaped depression on its bottom surface. The depression
15
has a diameter
201
larger than that of the opening
14
b
. A cylindrical outer wall and a flat bottom surface
15
a
surrounding the opening
14
b
define the depression
15
.
A circular plate
25
is fixed on a bottom surface
13
a
of the valve body
13
by a laser welding. The plate
25
covers the depression
15
and defines a chamber
51
between the plate
25
and the valve body
13
. The chamber
51
is thin, circular-shaped, and extended parallel with the plate
25
. The plate
25
provides an approximately flat wall defining a downstream wall of the chamber
51
. The plate
25
provides the flat wall extending throughout the chamber
51
. The chamber
51
is divided into an inner chamber
52
and an outer chamber
53
by a projected line
200
. The projected line
200
is defined by projecting the opening
14
a
on the plate
25
in an axial direction.
The plate
25
has a plurality of through holes
25
a
,
25
b
,
25
c
, and
25
d
as fuel orifices for defining a flow rate of fuel.
The through holes
25
a
to
25
d
have the same diameter d
1
and are arranged on a circle having a larger diameter than that of the contact portion
21
and the projected line
200
. Each of the through holes is inclined to apart from an axis
26
of the plate
25
and the injector
1
. The through holes
25
a
and
25
b
are inclined at the same angle α and the through holes
25
c
and
25
d
are inclined at the same angle α in an opposite direction. Therefore, the injector
1
provides two directional fuel injections. In this embodiment, the inclined angle α is set within 2° to 40° (2°≦α≦40°).
Each of the through holes
25
a
to
25
d
has an inlet opened between the projected line
200
and an outer line
201
. Therefore, the inlets of the through holes
25
a
to
25
d
faces the bottom surface
15
a
of the valve body
13
and are shaded in an axial direction. Each of the through holes
25
a
to
25
d
has an outlet opened between the projected line
200
and the outer line
201
. The inlet of each of through holes
25
a
to
25
d
is spaced by a distance d
2
, which is greater than or equal to the diameter d
1
of the through holes (d
2
≧d
1
), from the outer line
201
. In this embodiment, a significant distance d
2
. is provided in an inclining direction of the each through hole and in a radial direction. Therefore, the chamber
51
is extended a distance that is greater than the diameter d
1
radially beyond the through holes.
When the coil
41
is not energized, the spring
35
pushes the needle
20
toward the seat
14
a
, the seat
14
a
and the contact portion
21
closes the fuel passage
50
.
When the coil
41
is energized, the coil
41
generates an electromagnetic force between the stator core
30
and the armature core
31
and attracts the armature
31
and the needle
20
to lift up the needle
20
. Therefore, the fuel passage
50
is opened to inject fuel.
Fuel flowing into the chamber
51
is divided into a first flow toward a center of the chamber
51
and a second flow toward radial outside of the chamber
51
. The first flow meets and collides at a center of the plate
25
and turns into the radial outside. As a result, the first flow has a lot of turbulences. A part of the second flow and the turned first flow reaches to the inlets of the through holes after flowing along the plate
25
. A remaining part of the second flow and the turned first flow passes between the inlets of the through holes and reaches to the outer end of the chamber
51
. After that, the remaining part of the second flow changes its direction and reaches to the inlets of the through holes. Here, a distance d
2
is wider than the diameter of the through holes to provide a passage on an outer side which is sufficient to provide a counter flow flowing radially from an outside to an inside. Therefore, fuel guided along the plate
25
flows into the inlets from all directions evenly. Fuel collides at just above the inlets and makes a lot of turbulences in the column of the injected fuel. Therefore, each of the columns of the injected fuel from the through holes
25
a
to
25
d
are atomized finely. Additionally, the columns of the injected fuel don't collide each other, since four through holes are separately arranged.
FIGS. 4 and 5
show a second embodiment of the present invention. Hereinafter, the same or equivalent component as the above-mentioned embodiment is indicated by the same reference numerals and characterizing portions of each embodiment will be explained.
In this embodiment, a depression is formed on an upper surface of the plate
60
to provide the chamber
51
. The through holes
60
a
to
60
d
are similar to the through holes
25
a
to
25
d
of the first embodiment.
FIG. 6
shows a third embodiment of the present invention. In this embodiment, a plate
70
and a plate
75
are fixed on the bottom surface
13
a
of the valve body
13
. The plate
70
has a depression and through holes which are similar to the second embodiment. The plate
75
is disposed between the valve body
13
and the plate
70
for providing an opening
75
a
having the same diameter as the opening
14
b
. The plate
70
has the through holes
70
a
to
70
d
similar to the thorough holes
25
a
to
25
d
of the first embodiment. In this embodiment, fuel guided by the inner surface
14
a
reaches more inner side of the chamber
51
, and changes a flow direction. Further, it is possible to form the chamber precisely.
FIG. 7 and 8
show a fourth embodiment of the present invention. In this embodiment, the plate has four through holes
80
a
,
80
b
,
80
c
and
80
d
. The through holes
80
a
and
80
b
are arranged inside of an imaginary line
202
on an upper surface of the plate
80
and form inner through holes. The through holes
80
c
and
80
d
are arranged outside of the imaginary line
202
and form outer through holes. Here, the imaginary line
202
is defined as a circular line where a line extended along the inner surface
14
crosses the upper surface of the plate
80
. The imaginary line
202
also indicates a portion where fuel flowing along the inner surface
14
directly collides with the plate
80
. Therefore, the imaginary line
202
appears inside of the projected line
200
. The through hole
80
a
of the inner holes and the through hole
80
c
of the outer holes are inclined toward a left side. The through hole
80
b
of the inner holes and the through hole
80
d
of the outer holes are inclined toward a right side.
In this embodiment, fuel flowing along the inner surface
14
is divided into a first flow toward the inner holes
80
a
and
80
b
and a second flow toward the outer holes
80
c
and
80
d
. Here, each of a paired through holes
80
a
and
80
c
mainly receives opposed flows. Therefore, fuel jet formed by the thorough hole
80
a
is influenced by the first flow so that the jet inclines inside from an axis
82
of the hole
80
a
. On the other hand, fuel jet formed by the thorough hole
80
c
is influenced by the second flow so that the jet inclines outside from an axis
82
of the hole
80
c
. As a result, a pair of jets injected from a pair of holes
80
a
and
80
c
are separated to avoid a collision of the fuel jets. In the through holes
80
b
and
80
d
, the same function is achieved.
FIG. 9
shows a fifth embodiment of the present invention. In this embodiment, a plate
95
has ten through holes
95
a
to
95
95
j
. The through holes
95
a
to
95
d
form inner through holes. The through holes
95
e
to
95
j
form outer through holes. The through holes
95
a
,
95
b
,
95
e
,
95
f
and
95
g
form a group of through holes directed in a left side. The through holes
95
c
,
95
d
,
95
h
,
95
i
and
95
j
form a group of through holes directed in a right side. In this embodiment, inner through holes and outer through holes being member of one group are distanced at least L
1
. The outer through holes being member of one group are distanced at least L
3
which is wider than the distance L
1
. Therefore, a collision of the jets injected from the outer through holes is avoided even the second flow is influenced on both of the adjacent outer through holes.
FIG. 10
shows a sixth embodiment of the present invention. In this embodiment, a plate
100
has twelve through holes
100
a
to
100
k
and
100
m
. The through holes
100
a
to
100
d
form inner through holes. The through holes
100
e
to
100
k
and
100
m
form outer through holes. The through holes
100
a
,
100
b
,
100
e
,
100
f
,
100
g
and
100
h
form a group of through holes directed in a left side. The through holes
100
c
,
100
d
,
100
i
,
100
j
,
100
k
and
100
m
form a group of through holes directed in a right side. In this embodiment, the inner through holes being member of one group are distanced at least L
2
which is wider than L
1
. Therefore, a collision of the jets injected from the inner through holes is avoided even the first flow is influenced on both of the adjacent inner through holes.
FIG. 11
shows a seventh embodiment of the present invention. In this embodiment, the needle is indicated by a reference
110
. The contact portion in indicated by a reference
111
. The needle
111
additionally has a protrusion
112
thereon. The protrusion
112
decreases a capacity of the inner chamber
52
and provides a flat wall facing the inlets of the inner through holes
80
a
and
80
b
. It is possible to reduce a remaining fuel in the chamber and improve an accuracy of a fuel measurement. Such a protrusion may be used for the above-mentioned embodiments.
Although the present invention has been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of the present invention as defined in the appended claims.
Claims
- 1. A fluid injection nozzle having a plate with orifices comprising:a valve body providing a valve seat on an inner surface, said inner surface defining a fluid passage; a valve member for cooperating with said valve seat to open and close said fluid passage; and a plate disposed on a downstream side of said fluid passage, said plate having at least four through holes as orifices for injecting fluid and for defining a shape of injected fluid, said plate providing a chamber just above said through holes, wherein said chamber being defined by an approximately flat surface of said plate and being extended substantially in parallel with said plate, and wherein said chamber is larger than a downstream end opening of said inner surface of said valve body, and wherein at least two of said through holes have inlets opened at an area outside a projected area of said downstream end opening in an axial direction, and are inclined away from an axis of said nozzle at a downstream side, and wherein said chamber is extended outwardly beyond said through holes by a distance d2 more than a diameter d1 of said through holes.
- 2. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said valve body has a depression on its downstream end for defining said chamber, and said inlets opened at said outside area face a bottom surface of said depression.
- 3. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said plate has a depression on its upstream side for defining said chamber, and said inlets opened at said outside area face a bottom surface of said valve body or another plate disposed between said plate and said valve body.
- 4. The fluid injection nozzle having a plate with orifices according to claim 1, wherein all of said through holes are inclined at a predetermined angle away from an axis of said nozzle at a downstream side.
- 5. The fluid injection nozzle having a plate with orifices according to claim 4, wherein said predetermined angle is set between 2° and 40°.
- 6. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said valve member has a protrusion protruding into said chamber.
- 7. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said valve member has a flat surface facing said chamber.
- 8. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said fluid passage has a funnel-shaped surface having a cross sectional area that decreases toward a downstream side, and wherein said funnel-shaped surface and said plate are arranged so that fluid flowing on said funnel-shaped surface flows directly onto an upper surface of said plate.
- 9. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said inner surface of said valve body has a surface part defining an acute angle with a surface defining an upside wall of said chamber.
- 10. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said chamber is a circular shape.
- 11. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said plate is a circular disc shape.
- 12. The fluid injection nozzle having a plate with orifices according to claim 1, wherein said plate is fixed in place by a welding.
- 13. The fluid injection nozzle having a plate with orifices according to claim 12, wherein said chamber is a circular shape.
- 14. The fluid injection nozzle having a plate with orifices according to claim 13, wherein said through holes define a plurality of groups in accordance with inclined directions, each group including at least two of said through holes.
- 15. The fluid injection nozzle having a plate with orifices according to claim 14, wherein each group includes at least two of said through holes that have said inlets opened at said outside area.
- 16. The fluid injection nozzle having a plate with orifices according to claim 14, wherein each group includes at least one through hole that has an inlet opened inside of said projected area.
- 17. The fluid injection nozzle having a plate with orifices according to claim 13, wherein all of said through holes are circular holes inclined away from said axis of said nozzle, and have inlets that are wider in a radial direction than circumferentially with respect to the axis of the nozzle.
- 18. The fluid injection nozzle having a plate with orifices according to claim 1, wherein at least two of said through holes have inlets opened at an area inside said projected area of said downstream end opening, and are inclined away from an axis of said nozzle at a downstream side.
- 19. The fluid injection nozzle having a plate with orifices according to claim 1, wherein the inlets located in the outside area are located close to a circle diametrically corresponding to the valve seat or are located on an outside of the circle.
- 20. A fluid injection nozzle having a plate with orifices comprising:a valve body which has a fluid passage therein, the fluid passage defining a valve seat and an opening at a downstream end thereon, the fluid passage further defining a funnel-shaped portion of which a cross sectional area decreases in a downstream direction; a valve member for cooperating with the valve seat to open and close the fluid passage; and a circular plate disposed on an end of the valve body by a welding, the plate defining a thin, flat and circular chamber between the opening of the fluid passage and an upper surface thereon, the chamber having a diameter larger than that of the opening of the valve body, the plate having at least four circular through holes as orifices for injecting fluid and for defining a shape of injected fluid, the through holes having inlets located on an upper surface of the plate and outlets located on a bottom surface of the plate, at least two of the inlets being located in an area outside a projected area of the opening of the valve body in an axial direction, wherein the through holes are outwardly inclined from an axis of the nozzle in a flow direction, and the inlets located in the outside area are located close to a circle diametrically corresponding to the valve seat or are located on an outside of the circle.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-224141 |
Aug 1999 |
JP |
|
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Number |
Name |
Date |
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A |
4925111 |
Foertsch et al. |
May 1990 |
A |
5762272 |
Tani et al. |
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A |
5921474 |
Zimmermann et al. |
Jul 1999 |
A |
6170763 |
Fuchs et al. |
Jan 2001 |
B1 |
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Number |
Date |
Country |
19636396 |
Mar 1998 |
DE |
11-200998 |
Jul 1999 |
JP |
9834026 |
Aug 1998 |
WO |