FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]
FUEL INJECTION VALVE;
MITSUBISHI ELECTRIC CORPORATION, A CORPORATION ORGANISED
AND EXISTING UNDER THE LAWS OF JAPAN, WHOSE ADDRESS IS 7-3,
MARUNOUCHI 2-CHOME, CHIYODA-KU, TOKYO 100-8310, JAPAN
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE
INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
2
DESCRIPTION
5 Technical Field
[0001]
The present application relates to a fuel injection valve
used for fuel supply.
10
Background Art
[0002]
In recent years, emission constraints for automobile
15 internal combustion engines have been tightened, there is a
demand for atomization of fuel spray injected from a fuel
injection valve, and various studies have been made regarding
a method for atomizing using a slewing flow.
For example, in Patent Literature 1, a valve body and a
20 valve seat having an opening part through which fuel passes
from the upstream side, and a plate on the downstream side of
the valve seat are provided, a fuel cavity is formed on the
downstream side of the valve seat. The fuel cavity has a
configuration in which the cross-sectional area of the flow
25 channel through which the fuel passes is reduced toward the
outer diameter side in order to suppress a decrease in the
velocity of the fuel flowing into the injection hole, a shape
that generates a slewing flow is introduced as one of the fuel
cavity shapes.
30 Further, in Patent Literature 2, there is a valve seat
having an opening part and a plate provided with a flow
channel for forming a slewing flow as in Patent Literature 1,
a shape that realizes further atomization of the spray by
defining the dimensions of the flow channel including the
35 slewing part is introduced.
At this time, by paying attention to the seat surface
that seals the fuel of the valve seat, all the figures shown
in the Patent Literatures are continuously connected to the
opening part from the seat surface. Further, the intersection
40 of the point where the conical seat surface is extended to the
downstream side and the central axis is located at the valve
seat opening part in Patent Literature 1, further, in Patent
Literature 2, it can be confirmed from the figures that the
plate is located at a point further downstream than the
45 downstream side of the plate flow channel part.
Further, in Patent Literature 3, the fuel flow channel
leading to the injection hole 23 is provided on the valve seat
11 side directly above the injection hole plate 220.
3
[Patent Literature 1] JP 2007-46518 A
[Patent Literature 2] WO 2017/060945 A1
[Patent Literature 3] JP 6342007 B2
5
Disclosure of Invention
Technical Problem
[0003]
10 In Patent Document 1, the fuel flow from the seat
surface collides at the valve seat opening part, and the
collected fuel flow proceeds in the vertical downstream side
direction, after reaching the bottom surface of the plate flow
channel part, the flow suddenly changes in the horizontal
15 direction and is guided to the injection hole part provided on
the outer diameter side along the flow channel.
At this time, when the direction of the fuel flow
changes from the vertical lower side to the horizontal
direction from the valve seat opening part to the plate flow
20 channel part, a fuel exfoliation near the lower end side of
the valve seat opening part occurs.
According to the exfoliation of the fuel, energy loss of
the fluid occurs, the flow velocity just above the injection
hole becomes insufficient, and the atomization of the fuel
25 spray deteriorates, there is a problem that the change in flow
rate characteristics becomes large with respect to changes in
temperature and atmosphere.
Further, in an actual product, the degree of exfoliation
also varies depending on the fuel flow method, the valve seat
30 and plate assembly variation, and the dimensional variation,
which is one of the factors causing the flow rate variation as
a result.
On the other hand, in Patent Document 2, when the fuel
flow from the seat surface passes through the valve seat
35 opening part and reaches the bottom surface of the plate flow
channel, the flow toward the inner diameter side reverses at
the bottom surface and divides with the flow toward the outer
diameter side.
After the collision near the center part, as the fuel
40 flow toward the inner diameter side turns to the flow toward
the outer diameter side, flows along the flow channel, and is
guided to the injection hole, the passage to the injection
hole becomes longer with respect to the flow that reverses at
the bottom surface and goes toward the outer diameter side.
45 Therefore, there is a problem that a fluid energy loss occurs,
and the atomization of the injected fuel is deteriorated.
Further, the volume of the entire fuel cavity surrounded
by the valve body tip end part, the valve seat, and the plate
4
is a factor that greatly affects the flow rate change (dynamic
flow rate) when the atmosphere changes. In other words, at the
time of the injection into the negative pressure atmosphere, a
part of the fuel in the fuel cavity is sucked out from the
5 injection hole into the engine intake pipe by the negative
pressure after the valve closing is completed, and the flow
rate change becomes large.
Since the flow velocity of the fuel sucked out from the
fuel cavity is small, the fuel having a poor particle size is
10 injected immediately after the valve is closed.
Therefore, when considering the shapes of the valve seat
and the plate, one of the important factors to consider is the
fuel cavity volume in order to improve various characteristics
of the fuel injection valve.
15 In addition, in the plate that realizes atomization by
slewing flow, a center part that communicates with the opening
part of the valve seat as a fuel passage, a plurality of flow
channel passages, and a slewing chamber including an injection
hole part are arranged in order to communicate with each other
20 are needed, but the layout is limited by the size of the fuel
injection valve.
Therefore, when arranging each element of the fuel
passage on the plate, it is better to make the valve seat
opening part diameter as small as possible after securing the
25 required passage cross-sectional area, because the layout of
the entire fuel passage is improved, but since there is a
lower limit to the axial length of the opening part due to
processing, the seat surface of the valve seat and the opening
part are continuously connected, when comparing specifications
30 with the same seat angle, which is the angle of the seat
surface, the specification with a smaller opening increases
the cavity volume because the axial height between the seat
and the lower end surface of the valve seat increases.
Further, in recent years, with the tightening of exhaust
35 gas and fuel consumption regulations, the demand for the
amount of fuel valve leakage from the seat part when the
engine is stopped has become stricter.
One of the means for achieving both the reduction of the
fuel cavity volume and the reduction of the valve leakage
40 amount is the reduction of the seat diameter by increasing the
seat angle.
Here, the shapes shown in Patent Literatures 1 and 2 are
commonly connected from the seat surface to the opening part,
when the seat angle is increased, the angle between the seat
45 surface and the opening part becomes large, so that the fuel
exfoliation at the upper end of the opening part increases.
As described above, the increase in fuel exfoliation
causes problems such as deterioration of atomization of spray
5
and large change in flow rate characteristics when temperature
and atmosphere change. Unlike conventional plates, the type of
plate that forms a slewing flow and atomizes has a flow
channel that connects to the slewing chamber, the cross5 sectional area of the flow channel sharply decreases on the
lower end side of the opening part, near the entrance of the
flow channel of the plate. Therefore, the exfoliation of fuel
near the lower end of the opening part is a factor that has a
great influence on the change in flow rate characteristics due
10 to changes in temperature and atmosphere and the atomization
of spray, especially in the type of plate that forms a slewing
flow and atomizes, and it is an issue that should be
suppressed as much as possible.
Further, also in Patent Document 3, it is preferable if
15 the fuel spray can be further atomized.
[0004]
The application discloses the technology made in view of
the above circumstances, and the purpose is to promote the
20 atomization of the fuel.
Solution to Problem
[0005]
25 As the fuel injection valve disclosed in the present
application provides
a valve body that opens and closes the valve seat, and
a plate arranged on the side opposite to the valve body
of the valve seat and having a plate flow channel part through
30 which fuel flows between the valve body and a valve seat part
of the valve seat, and a fuel injection hole at the tip of the
plate flow channel part on the downstream side,
wherein, fuel that has passed between the valve body
and the valve seat part reaches the plate flow channel part
35 through an opening part at the downstream end of the valve
seat part and is ejected from the injection hole,
wherein;
the valve seat part is composed of a conical seat surface
on the upstream side and a conical tapered surface on the
40 downstream side continuously connected to the downstream end
of the seat surface on the upstream side at the connection
part,
when an angle between the seat surface and a central
axis of the valve seat is α, and an angle between the tapered
45 surface and the central axis is β, α > β is satisfied,
further, the tapered surface is formed so that an
intersection Y of an apex of a virtual cone extending the
tapered surface to the downstream side and the central axis is
6
located on the downstream side from the center part of the
opening part of the valve seat,
and further, a center part of the plate that faces the
opening part and communicates with the opening part, a
5 plurality of plate flow channel part that communicate with the
center part of the plate and extend radially outward from the
center part of the plate, and a slewing chamber in which fuel
supplied from the opening part to the center part of the plate
and passing through the plate flow channel is slewed, are
10 formed, on the end face of the plate on the valve seat side,
the injection hole at the bottom surface of each
slewing chamber opens,
the fuel flow from the seat surface of the valve seat
along the tapered surface is done, the fuel supplied from the
15 opening part to the center part of the plate and passing
through the plate flow channel is injected to the outside from
the injection hole (14) while slewing in the slewing chamber
(13c), it is possible to promote atomization of fuel.
20 Advantageous Effects of Invention
[0006]
According to the fuel injection valve disclosed in this
application, the valve seat part is composed of an upstream
conical seat surface and a downstream conical tapered surface
25 continuously connected to the downstream end part of the
upstream seat surface at a connecting part, when the angle
between the seat surface and the central axis of the valve
seat is α and the angle between the tapered surface and the
central axis is β, α> β is satisfied, further, the tapered
30 surface is formed so that the intersection Y of the apex of
the virtual cone extending the tapered surface to the
downstream side and the central axis is located on the
downstream side from the center part of the opening of the
valve seat, it is possible to promote atomization of fuel.
35
Brief Description of Drawings
[0007]
[Fig. 1] Fig. 1 is a view showing a first embodiment of
40 the present application, and is a longitudinal sectional side
view of an example of the whole structure of a fuel injection
valve in a longitudinal section.
[Fig. 2A] Fig. 2A is a view showing the first embodiment
of the present application, and is an enlarged longitudinal
45 section of the valve seat and the plate at the valve body end
tip part in Fig. 1, and is a longitudinal sectional side view
of an example of the fuel flow showed with a long and short
dash line.
7
[Fig. 2B] Fig. 2B is a view showing the first embodiment
of the present application, and is a plan view of a plate
viewed in the direction of an arrow from the line A-A in Fig.
2A, and the slewing flow of fuel is illustrated by a dotted
5 line arrow.
[Fig. 3A] Fig. 3A is a view showing the first embodiment
of the present application, and is a further enlarged
longitudinal section of the left half part of the valve seat
and the plate in Fig. 2A, and is a longitudinal sectional side
10 view of an example of the fuel flow showed with a long and
short dash line.
[Fig. 3B] Fig. 3B is a view showing the first embodiment
of the present application, shows a different example of the
example of Fig. 3A, and is a further enlarged longitudinal
15 section of the left half part of the valve seat and the plate,
and is a longitudinal sectional side view of an example of the
fuel flow showed with a long and short dash line.
[Fig. 4] Fig. 4 is a view showing the second embodiment
of the present application, and is an enlarged longitudinal
20 section of the left half part of the valve seat and the plate
as in Fig. 3A and Fig. 3B, and is a longitudinal sectional
side view of an example of the fuel flow showed with a long
and short dash line.
[Fig. 5] Fig. 5 is a view showing the third embodiment
25 of the present application, and is an enlarged longitudinal
section of the left half part of the valve seat and the plate
as in Fig. 3A and Fig. 3B, and is a longitudinal sectional
side view of an example of the fuel flow showed with a long
and short dash line.
30 [Fig. 6A] Fig. 6A is a view showing the fourth
embodiment of the present application, and is an enlarged
longitudinal section of the left half part of the valve seat
and the plate as in Fig. 3A and Fig. 3B, and is a longitudinal
sectional side view of an example of the fuel flow showed with
35 a long and short dash line.
[Fig. 6B] Fig. 6B is a view showing the fourth
embodiment of the present application, shows a different
example of the example of Fig. 6A, and is an enlarged
longitudinal section of the left half part of the valve seat
40 and the plate as in Fig. 3A and Fig. 3B, and is a longitudinal
sectional side view of an example of the fuel flow showed with
a long and short dash line.
[Fig. 7] Fig. 7 is a view showing the fifth embodiment
of the present application, and is an enlarged longitudinal
45 section of the left half part of the valve seat and the plate
as in Fig. 3A and Fig. 3B, and is a longitudinal sectional
side view of an example of the fuel flow showed with a long
and short dash line.
8
Description of Embodiments
[0008]
5 Hereinafter, while the fuel injection valve of the
present application is applied to a fuel injection valve used
for supplying fuel to an internal combustion engine of an
automobile to promote atomization of fuel spray
characteristics, and ensuring the layout of the plate for
10 forming the slewing flow, while achieving a reduction in valve
leakage and a reduction in fuel cavity volume, various
examples of the fuel injection valve that suppresses
deterioration of fuel atomization and changes in flow rate
characteristics when the temperature and atmosphere change
15 will be described with reference to first to fifth
embodiments. Further, in the first to fifth embodiments, the
downstream side in the fuel flow direction is simply referred
to as "downstream side", and the upstream side in the fuel
flow direction is simply referred to as "upstream side",
20 furthermore, the area of the cross section orthogonal to the
fuel flow in the fuel flow channel is simply referred to as
"flow channel cross-sectional area". Further, in Figs. 1 to 7
illustrating the examples of the first to fifth embodiments,
the same reference numerals indicate the same or corresponding
25 parts.
[0009]
First Embodiment
The first embodiment of the present application will be
30 described below with reference to Fig. 1, Fig. 2A, Fig. 2B,
Fig. 3A and Fig. 3B.
[0010]
Fig. 1 shows an example of the overall structure of the
35 fuel injection valve of the first embodiment in a longitudinal
section.
In Fig. 1, a fuel injection valve 1 is composed of a
solenoid device 4, a housing 5 which is the yoke part of the
magnetic circuit, a core 6 which is the fixed iron core part
40 of the magnetic circuit, a coil 7, an armature 8 which is the
movable iron part of the magnetic circuit and a valve device
9.
The valve device 9 includes a valve body 10, a valve
holder 11, and a valve seat 12.
45 The valve holder 11 is press-fitted into the outer
diameter part of the core 6 and then welded to the outer
diameter part of the core 6.
The armature 8 is press-fitted into the valve body 10
9
and then welded to the valve body 10.
A plate 13 is connected to the downstream side of the
valve seat 12 (downstream side in the fuel flow direction) by
a welding part 50. The valve seat 12 and the plate 13 are
5 connected by the welding part 50 to form an integral
structure.
The integrated valve seat 12 and plate 13 are attached
to the inside of the valve holder 11.
A plurality (four in this example) of plate flow channel
10 parts 13b for generating a slewing flow of fuel are provided
on the plate 13 radially from a center part 13a of the plate
13. A slewing chamber 13c is formed at the tip end part of
each plate flow channel part 13b, and an injection hole 14
penetrating in the plate thickness direction of the plate 13
15 is provided at the center part of each slewing chamber 13c.
The fuel supplied from the top end part of the core 6 of
the fuel injection valve 1 in Fig. 1 passes through the core 6
and the valve body 10, and atomized fuel is sprayed from each
injection hole 14.
20 In other words, in the first embodiment as described
above,
the fuel injection valve provides the valve body 10 that
opens and closes the valve seat 12, and the plate 13 having
the plate flow channel part 13b that is arranged on the side
25 opposite to the valve body 10 of the valve seat 12 and through
which fuel flows between the valve body 10 and a valve seat
part 12a of the valve seat 12, and the fuel injection hole 14
at the tip end part of the plate flow channel 13b on the
downstream side, the fuel injection valve in which fuel that
30 has passed between the valve body 10 and the valve seat part
12a reaches the plate flow channel 13b through an opening part
12d at the downstream end of the valve seat 12 and is ejected
from the injection hole 14,
the valve seat part 12a is composed of a conical seat
35 surface 12b on the upstream side and a conical tapered surface
12c on the downstream side continuously connected to the
downstream end of the seat surface 12b on the upstream side at
the connection part,
when the angle between the seat surface 12b and a
40 central axis ca of the valve seat 12 is α and the angle
between the tapered surface 12c and the central axis ca is β,
α> β is satisfied, further, the tapered surface 12c is formed
so that an intersection Y of the apex of the virtual cone
extending the tapered surface 12c to the downstream side and
45 the central axis ca is located on the downstream side from the
center part of the opening part 12d of the valve seat,
on the end face of the plate 13 on the valve seat 12
side, the center part 13a of the plate 13 that faces the
10
opening part 12d and communicates with the opening part 12d,
and multiple plate flow channels 13b that communicate with the
center part 13a of the plate 13 and extend radially outward
from the center part 13a of the plate 13, are located at each
5 radial tip of the plate flow channel 13b,
the injection hole 14 is open at the bottom of each of
the slewing chambers 13c, and flows from the seat surface 12b
of the valve seat 12 along the tapered surface 12c, the fuel
supplied from the opening 12d of the valve seat 12 to the
10 center part 13a of the plate 13 and flowing evenly dispersed
in each plate flow channel part 13b is injected to the outside
from the injection hole 14 while slewing in each slewing
chamber 13c, as a result, it is possible to promote
atomization fuel.
15
[0011]
Next, the operation will be described.
When an operation signal is sent from the control device
of the internal combustion engine to the drive circuit of the
20 fuel injection valve, a current is applied to the coil 7 of
the fuel injection valve to energize the coil 7, a magnetic
flux is generated in a magnetic circuit composed of the
armature 8, the core 6, the housing 5, and the valve holder
11. When magnetic flux is generated in the magnetic circuit,
25 the armature 8 is sucked toward the core 6, and a ball 15 of
the valve body 10 having an integral structure with the
armature 8 is separated from the valve seat part 12a to form a
gap between the ball 15 and the valve seat part 12a. The fuel
passes through the gap formed between a chamfered part 15a of
30 the ball 15 welded to the tip end part of the valve body 10
and the valve seat part 12a and the ball 15 of the valve body
10, atomized fuel is injected from the injection hole 14 into
the intake port of the internal combustion engine.
Next, when an operation stop signal is sent from the
35 control device of the internal combustion engine to the drive
circuit of the fuel injection valve, the energization of the
current of the coil 7 is stopped, the gap between the valve
body 10 and the valve seat part 12a is closed by a compression
spring 16 that pushes the valve body 10 in the valve closing
40 direction as the magnetic flux in the magnetic circuit
decreases, and the fuel injection ends.
The valve body 10 slides with the guide part of the
valve holder 11 at an armature sliding part 8a, and an
armature upper surface 8b comes into contact with the lower
45 surface of the core 6 in the valve open state.
[0012]
Fig. 2A is an enlarged longitudinal section of the valve
11
seat and the plate at the valve body end tip part in Fig. 1,
and is a longitudinal sectional side view of an example of the
fuel flow showed with a long and short dash line, and is a
plan view of the plate seen in the direction of the arrow from
5 the line A-A in Fig. 2A.
As illustrated in Figs. 2A and 2B, in order to achieve
atomization due to the slewing flow of the fuel, the plate 13
is provided with the center part 13a of the plate 13
communicating with the opening part 12d of the valve seat 12,
10 a plurality of groove-shaped plate flow channel parts 13b, and
the slewing chamber 13c including the injection holes 14 in a
state of communicating with each other.
The fuel that has flowed into the slewing chamber 13c
flows into the injection hole 14 while generating a slewing
15 flow, the fuel that has flowed into the injection hole 14
while generating a slewing flow is retained inside the
injection hole 14, so that the fuel flows into the injection
hole 14, a thin liquid film of fuel is formed along the inner
wall of the injection hole 14, the formed thin liquid film
20 fuel is injected from the injection hole 14 in a hollow
conical shape so that atomization of the fuel is promoted.
[0013]
Fig. 3A is a further enlarged longitudinal section of
25 the left half part of the valve seat 12 and the plate 13 in
Fig. 2A, and is a longitudinal sectional side view of an
example of the fuel flow showed with a long and short dash
line in Fig. 3.
In the case of Fig. 3A, the tapered surface 12c is
30 provided on the downstream side of the seat surface 12b on the
upstream side of the valve seat part 12a of the valve seat 12,
the fluid friction generated by the fuel flowing into the
valve seat part 12a at high speed and flowing along the seat
surface 12b due to contact with the seat surface 12b on the
35 tapered surface 12c is effectively reduced.
Further, since it is configured in order that "an angle
α of the seat surface 12b with respect to the axis of the
valve seat 12> an angle β of the tapered surface 12c", the
effect of suppressing fuel exfoliation at an upper end part 19
40 of the opening part 12d can be obtained.
Further, the intersection Y of the apex of the virtual
cone extending the tapered surface 12c to the downstream side
and the central axis ca of the valve body 10, the valve seat
12, and the plate 13 are configured to be located on the
45 downstream side, lower than an intersection W between the
downstream end surface of the valve seat 12 (upstream side of
the plate 13) and the central axis ca.
12
[0014]
Fig. 3B shows an example of the configuration when the
intersection Y is located on the upstream side of the
intersection W.
5 In the case of Fig. 3B, the main flow of fuel that has
passed through the tapered surface 12c is a channel that
collides with the opening part 12d, passes through the center
part 13a of the plate 13, and reaches the plate flow channel
part 13b.
10 In contrast to Fig. 3B, in Fig. 3A, which is an
embodiment of the present application, the fuel passes through
the tapered surface 12c, after passing through the opening
part 12d, it collides with the center part 13a of the plate 13
and heads toward the plate flow channel part 13b. With such a
15 configuration, focusing on a flow sudden change part 17 of the
opening part 12d, the structure shown in Fig. 3A can be used,
the vertically downward component of the fuel flow from the
opening part 12d to the plate flow channel 13b is suppressed,
the horizontal component of the fuel flow from the center part
20 13a of the plate 13 to the plate flow channel part 13b is
strengthened. As a result, exfoliation at the flow sudden
change part 17 near the lower end part of the opening part is
suppressed, and the effect of shortening the fuel flow channel
from the opening part 12d to the center part 13a of the plate
25 13 can also be obtained.
With the above configuration, the energy loss of the
fluid is suppressed by suppressing the exfoliation in the flow
channel and shortening the channel, by improving the fuel rate
immediately above the injection hole 14, atomization is
30 promoted, and the generation of bubbles due to decompression
boiling in the flow channel is suppressed, changes in flow
rate characteristics due to changes in temperature and
atmosphere are suppressed.
In the actual product, as there are variations in the
35 assembly of the valve seat 12 and the plate 13, the method of
flowing from the opening part 12d to each plate flow channel
13b is different for each, and the degree of exfoliation is
also different.
The flow sudden change part 17 is a place where the
40 cross-sectional area of the flow channel in the flow channel
is rapidly reduced, the variation in the degree of exfoliation
at the same location greatly affects the variation in the
atomization level of the fuel spray and the static flow rate.
Therefore, the suppression of fuel exfoliation at the
45 flow sudden change part 17 also has the effect of reducing
variations in the atomization level of the spray and the
static flow rate.
In addition, the seat surface 12b that seals the fuel is
13
expected to be processed by grinding, when the diameter is
small, the peripheral speed during grinding is small and the
machining time is long, so the productivity is low. Therefore,
as in the present embodiment the tapered surface 12c is
5 provided on the downstream side of the seat surface 12b of the
valve seat 12, the processing range on the upstream side of
the seat surface 12b can be set to a range having a relatively
large diameter, and productivity is also improved.
Further, by defining the angle difference between the
10 angle α of the seat surface 12b and the angle β of the tapered
surface 12c with respect to the central axis to 20 °or less,
the exfoliation of fuel at a connection part 20 between the
seat surface 12b and the tapered surface 12c is further
suppressed. As a result, as described above, the effect of
15 atomizing the fuel spray and suppressing the change in flow
rate characteristics due to changes in temperature and
atmosphere is promoted.
[0015]
20 The technical features of the first embodiment described
above are as follows.
The fuel injection valve has a valve body for opening
and closing the valve seat, by receiving an operation signal
from the control device and operating the valve body, after
25 the fuel passes between the valve body and the valve seat
part, the fuel is injected from a plurality of injection holes
provided in the injection hole plate mounted on the valve seat
opening on the downstream side of the valve seat, it owns
multiple slewing chambers arranged radially outside the valve
30 seat opening on the upstream end face of the plate, a center
part connecting to the valve seat opening, a passage that
guides fuel flow from the center to each slewing chamber,
further, each slewing chamber has an injection hole that opens
and injects fuel to the outside, the valve seat has a conical
35 seat surface whose diameter decreases toward the downstream
and a tapered surface connected to the seat surface on the
downstream side of the seat surface, and has a cylindrical
opening on the downstream side of the tapered surface, the
angle between the seat surface and the central axis of the
40 valve seat is α and the angle between the tapered surface and
the central axis is β, α> β is satisfied, the intersection Y
between the apex of the virtual cone extending the tapered
surface to the downstream side and the central axis is a fuel
injection valve located on the downstream side of the
45 intersection W between the horizontal cross section of the
downstream end surface of the valve seat and the central axis,
further, the valve seat has a structure that satisfies α−β ≦
20°.
14
[0016]
The effects of the first embodiment described above are
as follows.
5 By providing a tapered surface on the downstream side of the
seat surface, the fuel that flows out from the seat at high
speed and flows along the seat surface effectively reduces the
fluid friction generated by the contact with the seat surface.
Further, since the angle of the seat surface with
10 respect to the central axis > the angle of the tapered
surface, the separation of fuel at the upper end of the
opening part is suppressed.
Furthermore, the intersection of the apex of the virtual
cone with the tapered surface extended to the downstream side
15 and the central axis is configured to be located on the
downstream side of the intersection of the horizontal cross
section of the downstream end face of the valve seat and the
central axis, compared to the case where it is located on the
upstream side, the collision position of the main flow passing
20 through the tapered surface is from the valve seat opening
part to the center part of the plate, the vertical component
from the valve seat opening part to the plate flow channel is
suppressed, the horizontal component from the center part of
the plate to the flow channel of the plate is strengthened. As
25 a result, in addition to suppressing the separation of the
flow at the sudden change of the flow from the lower end of
the opening part to each channel, the effect of shortening the
channel from the opening part to the plate channel can also be
obtained.
30 As above, the energy loss of the fluid is suppressed by
suppressing the exfoliation in the flow channel and shortening
the channel, by improving the fuel rate immediately above the
injection hole, atomization is promoted, and the generation of
bubbles due to decompression boiling in the flow channel is
35 suppressed, changes in flow rate characteristics due to
changes in temperature and atmosphere are suppressed.
The suppression of fuel exfoliation at the sudden flow
change part also has the effect of reducing variations in the
atomization level of the spray and the static flow rate.
40 In addition, the seat surface that seals the fuel is
expected to be processed by grinding, when the diameter is
small, the peripheral speed during grinding is small and the
machining time is long, so the productivity becomes low.
Therefore, by providing the tapered part in this shape, the
45 processing range of the seat surface can be limited to a part
having a relatively large diameter, and productivity is also
improved.
Further, by defining the angle difference between the
15
angle of the seat surface and the angle of the tapered surface
with respect to the central axis to 20°or less, the
exfoliation of fuel at the connection between the seat surface
12b and the tapered surface is further suppressed. As a
5 result, as described above, the effect of atomizing the fuel
spray and suppressing the change in flow rate characteristics
due to changes in temperature and atmosphere is promoted.
[0017]
10 Second Embodiment
In the second embodiment, as shown in Fig. 4, when Ｌ≦Ｍ
, where a seat surface length, which is the shortest distance
from the upstream end of the seat surface (12b) to the
upstream end of the tapered surface (12c) is L, and the taper
15 surface length, which is the shortest distance from the
upstream end of the tapered surface (12c) to the opening (12d)
is M, the flow channel cross-sectional area of the valve seat
part 12a is expanded earlier than in the case where the seat
surface length L> a tapered surface length M, the fluid
20 friction generated by the contact with the seat surface 12b on
the upstream side is effectively reduced at the tapered
surface 12c on the downstream side of the connection part 20.
Therefore, a further effect of promoting atomization of fuel
spray can be obtained.
25 According to the early expansion of the flow channel
cross-sectional area, since the speed at which the fuel
reaches the upper end of the opening part (upstream end of the
opening part 12d) 19 is reduced, the speed is reduced, fuel
exfoliation at the same location is more effectively
30 suppressed.
Further, since the ratio of the fuel flow along the
tapered surface 12c is increased, the collision of the fuel at
the center part 13a of the plate 13 is strengthened, a
horizontal direction flow 18 of fuel towards each plate flow
35 channel 13b is enhanced.
Therefore, the exfoliation at the flow sudden change
part 17 (the downstream end part of the opening part 12d) is
suppressed, as described above, the effect of atomizing the
fuel spray and suppressing the change in flow rate
40 characteristics due to changes in temperature and atmosphere
is promoted.
[0018]
The technical features of the second embodiment
45 described above are as follows.
The seat surface length, which is the distance from the
seat part to the upstream end of the tapered surface, and the
tapered surface distance are defined, and the seat surface
16
length ≦ the tapered surface length.
[0019]
The effects of the second embodiment described above are
5 as follows.
According to the technical features of the second
embodiment described above, the fluid passage area after
passing through the seat part will be expanded earlier than in
the case of the seat surface length > the tapered surface
10 length, the fluid friction generated by the contact of the
fuel with the seat surface is further effectively reduced.
Therefore, a further effect of promoting atomization of fuel
spray can be obtained. According to the early expansion of the
fluid passage area, since the speed reached at the upper end
15 of the opening part is reduced, fuel exfoliation at the same
location is more effectively suppressed.
Further, since the ratio of the fuel flow along the
tapered surface is increased, the collision at the center part
is strengthened, the horizontal flow towards each passage is
20 enhanced.
Therefore, the exfoliation at the flow sudden change
part is also suppressed, as described above, the effect of
atomizing the fuel spray and suppressing the change in flow
rate characteristics due to changes in temperature and
25 atmosphere is promoted.
[0020]
Third Embodiment
In the third embodiment, as shown in Fig. 5, when V ≧
30 0.6X, where X is the shortest distance between an intersection
Z of the apex of the virtual cone extending the seat surface
12b on the upstream side to the downstream side and the
central axis ca of the valve seat 12 and the intersection Y,
and V is the amount of overlap in which a groove depth H of
35 the center part 13a of the plate 13 and a shortest distance X
overlap, most of the fuel flow from the tapered surface 12c
collides with each other in the vicinity center part 13a of
the plate 13, and the horizontal direction flow 18 toward each
plate flow channel part 13b (see Fig. 2B) is strengthened.
40 Further, by configuring the relationship between an
overlap amount V and the plate groove depth H so that V ≧
0.8H, in the center part 13a of the plate 13, the fuel flow
component in the downstream direction on the central axis ca
is suppressed, the horizontal direction flow 18 toward each
45 plate flow channel part 13b is further strengthened.
Therefore, the exfoliation of the fuel at the flow sudden
change part is also suppressed, as described above, the effect
of atomizing the fuel spray and suppressing the change in flow
17
rate characteristics due to changes in temperature and
atmosphere is further promoted.
[0021]
5 The technical features of the third embodiment described
above are as follows.
The amount V that overlaps the groove depth H at the
center part of the plate between the intersection Z of the
extension lines of the seat surface on the upstream side and
10 the intersection Y of the extension lines of the tapered
surface is defined. Further, the relationship between the
overlap amount V and the groove depth H at the center part of
the plate is defined.
15 [0022]
The effects of the third embodiment described above are
as follows.
By defining the amount V that overlaps the groove depth
H at the center part of the plate between the intersection Z
20 of the extension lines of the sheet surface on the upstream
side and the intersection Y of the extension lines of the
tapered surface, most of the fuel flow from the tapered
surface collides with each other in the vicinity of the center
part of the plate, and the horizontal flow toward each passage
25 is strengthened. Therefore, the exfoliation at the flow sudden
change part is also suppressed, as described above, the effect
of atomizing the fuel spray and suppressing the change in flow
rate characteristics due to changes in temperature and
atmosphere is promoted.
30 Further, by defining the relationship between the
overlap amount V and the groove depth H at the center part of
the plate, in the center part of the plate, the fuel flow
component in the downstream direction on the central axis ca
is suppressed, the horizontal flow toward each passage is
35 further strengthened. Therefore, the exfoliation at the flow
sudden change part is also suppressed, as described above, the
effect of atomizing the fuel spray and suppressing the change
in flow rate characteristics due to changes in temperature and
atmosphere is promoted.
40
[0023]
Fourth Embodiment
For example, as shown in the case of Fig. 6B, when the
intersection Y is located on the downstream side of the bottom
45 surface 13d of the plate flow channel part 13, which is the
bottom surface of the plate flow channel part 13b, the fuel
passes through the tapered surface 12c and travels in the
inner diameter side along the bottom surface 13d of the plate
18
flow channel part 13b, a flow 18b that turns to the outer
diameter side that collides with the center part 13a of the
plate 13 and turns to the outer diameter side is generated.
On the other hand, as shown in the case of Fig. 6A, by
5 locating the intersection Y within the center part 13a of the
plate 13, the flow 18b that turns to the outer diameter side,
after passing through the tapered surface 12c, the fuel
collides with the center part 13a of the plate 13 and collides
with the fuel, the horizontal direction flow 18 toward each
10 plate flow channel part 13b is strengthened. As a result,
energy loss is reduced by shortening the fluid channel, and
fuel peeling at the flow sudden change part 17 is suppressed.
Therefore, as described above, the effect of atomizing the
fuel spray and suppressing the change in flow rate
15 characteristics due to changes in temperature and atmosphere
is promoted.
[0024]
The technical features of the fourth embodiment
20 described above are as follows.
The intersection of the extension lines of the tapered
surface is defined in the center part of the plate. As a
result, it passes through the tapered surface and proceeds
toward the inner diameter side along the bottom surface of the
25 plate flow channel part, the flow of collision at the center
part of the plate and turning to the outer diameter side is
suppressed, the horizontal flow to each passage is
strengthened by reducing the energy loss by shortening the
fluid passage.
30
[0025]
The effects of the fourth embodiment described above are
as follows.
According to the technical features of the fourth
35 embodiment described above, the exfoliation at the flow sudden
change part is also suppressed, as described above, the effect
of atomizing the fuel spray and suppressing the change in flow
rate characteristics due to changes in temperature and
atmosphere is promoted.
40
[0026]
Fifth embodiment
In the fifth embodiment, as shown in Fig. 7, the
intersection Z is located in the center part 13a of the plate
45 13. As a result, the main fuel flows from the seat surface 12b
and the tapered surface 12c collide substantially within the
center part 13a of the plate 13, and the horizontal direction
flow 18 toward each plate flow channel part 13b is further
19
strengthened. Therefore, the exfoliation at the flow sudden
change part 17 is also suppressed, as described above, the
effect of atomizing the fuel spray and suppressing the change
in flow rate characteristics due to changes in temperature and
5 atmosphere is further promoted.
[0027]
The technical features of the fifth embodiment described
above are as follows.
10 The intersection of the extension lines of the seat
surface is defined in the center part of the plate.
[0028]
The effects of the fifth embodiment described above are
15 as follows.
According to the technical features of the fifth
embodiment described above, the main fuel flows from the seat
surface and the tapered surface collide with each other near
the center part 13a of the plate13, and the horizontal flow
20 toward each passage is further strengthened. Therefore, the
exfoliation at the flow sudden change part is also suppressed,
as described above, the effect of atomizing the fuel spray and
suppressing the change in flow rate characteristics due to
changes in temperature and atmosphere is further promoted.
25
[0029]
Although various exemplary embodiments and examples are
described in this application, the various features, modes,
and functions described in one or more embodiments are not
30 limited to the application of a particular embodiment, but can
be applied to embodiments alone or in various combinations.
Accordingly, countless variations not illustrated are
envisioned within the scope of the art disclosed in this
application. For example, this shall include cases where at
35 least one component is transformed, added or omitted, and even
where at least one component is extracted and combined with
components of other embodiments.
Reference Signs List
40
[0030]
1. Fuel injection valve,
4 Solenoid device,
5 Housing,
45 6 Core,
7 Coil,
8 Armature,
8a Armature sliding part,
20
8b Armature upper surface,
9 Valve device,
10 Valve body,
11 Valve holder,
5 12 Valve seat,
12a Valve seat part,
12b Seat surface,
12c Tapered surface,
12d Opening part,
10 13 Plate,
13a Center part of the plate,
13b Plate flow channel part,
13c Slewing chamber,
13ｄ Bottom surface of the plate flow channel part 13b,
15 14 Injection hole,
15 Ball,
15a Chamfered part,
16 Compression spring,
17 Flow sudden change part,
20 18 Horizontal direction flow,
18b Flow that turns to the outer diameter side,
19 Upper end part of the opening part 12d,
20 Connection part,
50 Welding part,
25 ca Central axis,
H Groove depth of the plate flow channel part 13b,
L Seat surface length,
M Tapered surface length,
V Overlap amount,
30 W Intersection,
X Shortest distance,
Y Intersection,
Z Intersection,
α Angle,
35 β Angle.

21
We Claim :
[Claim 1]
A fuel injection valve comprising;
5 a valve body that opens and closes the valve seat, and
a plate arranged on the side opposite to the valve body
of the valve seat and having a plate flow channel part through
which fuel flows between the valve body and a valve seat part
of the valve seat, and a fuel injection hole at the tip of the
10 plate flow channel part on the downstream side,
wherein, fuel that has passed between the valve body
and the valve seat part reaches the plate flow channel part
through an opening part at the downstream end of the valve
seat part and is ejected from the injection hole,
15 wherein;
the valve seat part is composed of a conical seat surface
on the upstream side and a conical tapered surface on the
downstream side continuously connected to the downstream end
of the seat surface on the upstream side at the connection
20 part,
when an angle between the seat surface and a central
axis of the valve seat is α, and an angle between the tapered
surface and the central axis is β, α > β is satisfied,
further, the tapered surface is formed so that an
25 intersection Y of an apex of a virtual cone extending the
tapered surface to the downstream side and the central axis is
located on the downstream side from the center part of the
opening part of the valve seat,
and further, a center part of the plate that faces the
30 opening part and communicates with the opening part, a
plurality of plate flow channel part that communicate with the
center part of the plate and extend radially outward from the
center part of the plate, and a slewing chamber in which fuel
supplied from the opening part to the center part of the plate
35 and passing through the plate flow channel is slewed, are
formed, on the end face of the plate on the valve seat side,
the injection hole at the bottom surface of each
slewing chamber opens,
the fuel flow from the seat surface of the valve seat
40 along the tapered surface is done, the fuel supplied from the
opening part to the center part of the plate and passing
through the plate flow channel is injected to the outside from
the injection hole while slewing in the slewing chamber.
45 [Claim 2]
The fuel injection valve according to claim 1, wherein,
the relationship between an angle α and an angle β
satisfies α−β ≦ 20 °, and the intersection Y is located
22
downstream of an intersection W with the central axis on the
downstream end surface of the valve seat.
[Claim 3]
5 The fuel injection valve according to claim 1 or 2,
wherein,
When a seat surface length which is a shortest distance
from an upstream end of the seat surface to an upstream end of
the tapered surface is L, and a tapered surface length which
10 is a shortest distance from the upstream end of the tapered
surface to the opening is M, L ≦ M is satisfied.
[Claim 4]
The fuel injection valve according to any one of claims
15 1 to 3, wherein,
a relationship between an overlap amount V and a
shortest distance X satisfies V ≧ 0.6X, where Z is an
intersection of the apex of the virtual cone extending the
seat surface to the downstream side and the central axis, the
20 overlap amount V is the shortest distance between an
intersection Z and the intersection Y is the shortest distance
X, and the amount of overlap between the shortest distance X
at the position of the central axis and a groove depth H of
the plate flow channel part.
25
[Claim 5]
The fuel injection valve according to any one of claims
1 to 4, wherein,
a relationship between an overlap amount V and a groove
30 depth H satisfies V ≧ 0.6X, where Z is an intersection of the
apex of the virtual cone extending the seat surface to the
downstream side and the central axis, the overlap amount V is
the shortest distance between an intersection Z and the
intersection Y is a shortest distance X, and the amount of
35 overlap between the shortest distance X at the position of the
central axis and the groove depth H of the plate flow channel
part.
[Claim 6]
40 The fuel injection valve according to any one of claims
1 to 5, wherein,
the intersection Y is located within a groove depth H of
the plate flow channel part.
45
[Claim 7]
The fuel injection valve according to any one of claims
1 to 6, wherein,
23
an intersection Z of the apex of the virtual cone
extending the seat surface to the downstream side and the
central axis is located within a groove depth H of the plate
flow channel part.