U.S. patent application number 11/018218 was filed with the patent office on 2005-05-19 for high flow rate fuel valve and fuel supply pump with the valve.
Invention is credited to Aoki, Nobuo, Ichinose, Takeshi, Kubota, Kazuya, Terada, Takeshi.
Application Number | 20050106035 11/018218 |
Document ID | / |
Family ID | 34577436 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050106035 |
Kind Code |
A1 |
Aoki, Nobuo ; et
al. |
May 19, 2005 |
High flow rate fuel valve and fuel supply pump with the valve
Abstract
A high flow rate fuel valve suitable for an accumulator fuel
injection device by which a large amount of fuel is amplified using
a piston and used and a fuel supply pump using the high flow rate
fuel valve are provided. For this purpose, in a fuel supply pump
with a fuel inlet valve and fuel outlet valve, the fuel inlet valve
has a valve main body, a valve body received in the valve main
body, an inlet chamber provided inside the valve main body, inlet
holes, a seat portion where the valve body and part of valve main
body are in contact with each other. The inlet holes are arranged
in a non-radial pattern relative to the inlet chamber.
Inventors: |
Aoki, Nobuo; (Shiki-shi,
JP) ; Kubota, Kazuya; (Higashimatsuyama-shi, JP)
; Terada, Takeshi; (Tsurugashima-shi, JP) ;
Ichinose, Takeshi; (Kawagoe-shi, JP) |
Correspondence
Address: |
Arthur G. Schaier
Carmody & Torrance LLP
P.O. Box 1110
50 Leavenworth Street
Waterbury
CT
06721-1110
US
|
Family ID: |
34577436 |
Appl. No.: |
11/018218 |
Filed: |
December 21, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11018218 |
Dec 21, 2004 |
|
|
|
PCT/JP03/13687 |
Oct 27, 2003 |
|
|
|
Current U.S.
Class: |
417/279 |
Current CPC
Class: |
F02M 45/00 20130101;
F02M 59/105 20130101; F02M 59/464 20130101; F02M 47/027 20130101;
F02M 57/025 20130101; F02M 63/0225 20130101 |
Class at
Publication: |
417/279 |
International
Class: |
F04B 049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 2002 |
JP |
2002-313763 |
Dec 27, 2002 |
JP |
2002-381008 |
Claims
1. A high flow fuel valve, comprising a valve main body, a valve
body movably installed in the inside of the valve main body, an
inlet chamber installed in the inside of the valve main body, inlet
holes, a seat portion where the valve body and part of the valve
main body are in contact with each other, wherein a plurality of
the inlet holes is formed and arranged in a radial pattern relative
to the inlet chamber.
2. The high flow fuel valve as described in claim 1, wherein a
horizontal cross sectional shape of the inlet chamber is
substantially a circle and the inlet holes are arranged in a
tangential direction of the inlet chamber.
3. The high flow fuel valve as described in claim 1, wherein the
inlet holes are inclined in the vertical direction with respect to
the inlet chamber.
4. The high flow fuel valve as described in claim 1, wherein the
inlet hole has a diameter of 2 to 12 mm.
5. The high flow fuel valve as described in claim 1, wherein a seat
diameter of the valve body is 8 mm or more.
6. The high flow fuel valve as described in claim 1, wherein a
fuel-passing area of the inlet hole is larger than a fuel-passing
area of the seat portion.
7. A fuel supply pump comprising a fuel inlet valve and a fuel out
let valve, wherein the fuel inlet valve is constructed of a valve
main body, a valve body movably installed in the inside of the
valve main body, an inlet chamber installed in the inside of the
valve main body, inlet holes, and a seat portion where the valve
body and part of the valve main body are in contact with each
other, where a plurality of the inlet holes is formed and arranged
in a radial pattern relative to the inlet chamber.
8. The fuel supply pump as described in claim 7, wherein the fuel
supply pump is used in an accumulator fuel injection device for
pressurizing fuel at a flow rate of 500 to 1,500 litters per hour
to a value of 50 MPa or more.
Description
TECHNICAL FIELD
[0001] The present invention relates to a high flow rate fuel valve
and a fuel supply pump with the valve. Particularly, the present
invention relates to a high flow rate fuel valve suitable for a
fuel supply pump used in an accumulator fuel injection device
(APCRS: Amplified Piston Common Rail System) that amplifies the
pressure of a large flow rate of fuel through the use of a pressure
piston, and a fuel supply pump with the valve.
BACKGROUNDS
[0002] Conventionally, various accumulator fuel injection devices
(CRSs: Common Rail Systems) using pressure accumulators (common
rails) have been proposed in order to inject high-pressure fuels
efficiently in diesel engines and so on.
[0003] For instance, as shown in FIG. 20, for switching the
pressures of a pressure accumulator depending on the driving
conditions of an engine, JP 06-93936 A has proposed an accumulator
fuel injection device having a first pressure accumulator 236
responsible for a main injection and a second pressure accumulator
278 responsible for a pilot injection. These pressure accumulators
236, 278 are switched by a switching device 286 to carry out a fuel
injection.
[0004] For obtaining the injection pressure, which is perfect for
engine performance, JP 2885076 B has proposed an accumulator fuel
injection device having a pressure-amplifying piston for amplifying
the pressure of a fuel and a cylinder chamber, located between a
pressure accumulator and a fuel injection valve. More specifically,
as shown in FIG. 21, there is disclosed an accumulator fuel
injection device 380 that comprises a pressure accumulator 395; an
oil supply channel 360 for a fuel; an oil control channel 361; a
switching valve 362 for fuel injection control; a pressure
amplifying piston 378 for elevating the fuel pressure to 70 to 120
MPa (approximately 700 to 1,200 kgf/cm.sup.2); a cylinder chamber
383 for housing the pressure amplifying piston 378; a hydraulic
circuit 363; a piston-work switching valve (three-way solid valve
for amplifier) 364; and a controller (not shown).
[0005] On the other hand, in JP 06-101597 A, as shown in FIG. 22,
there is proposed a fuel injection valve having a fuel spiral
member and the angle formed between a fuel spiral flow channel and
a circular flow channel is restricted. More specifically, the fuel
provided with a revolving force by the fuel spiral member on the
upstream side of a valve sheet flows between the tip portion of a
valve body and the valve sheet toward a fuel injection hole and the
spiral movement of the fuel flow forms a hollow portion in a flow
channel between the tip of the valve body and the fuel injection
hole.
[0006] Similarly, in JP 10-47208 A, as shown in FIG. 23, there is
proposed a fuel injection valve that performs fuel injection by
setting revolving energy to the flow of fuel. More specifically,
there is disclosed a fuel injection valve where the numbers of
periphery portions, flow channel portions, and revolving grooves
are defined as 4 to 8, respectively. Each of the revolving grooves
is eccentric with a predetermined distance from a valve axis. In
addition, the side of the revolving groove far from the valve axis
is tangentially connected to the periphery of a circular groove.
The side surfaces of the respective grooves facing to the revolving
groove are arranged in parallel with each other.
[0007] However, the accumulator fuel injection device disclosed in
JP 06-93936 A needs to be provided with two kinds of the pressure
accumulator, their switching device, and so on. Therefore, there is
a problem in that the accumulator fuel injection device is
complicated and grown in size. In the accumulator fuel injection
device, furthermore, there is an another problem in that a large
amount of fuel cannot be pressurized sufficiently because the fuel
is difficult to flow quickly to the fuel injection valve when the
cam and plunger of the fuel supply pump are driven at high speed.
As the flow rate of fuel is restricted, a large amount of fuel
cannot be pressurized sufficiently.
[0008] For the accumulator fuel injection device disclosed in JP
2885076B, a pressure amplifying piston is placed between the
pressure accumulator and the fuel injection valve to intend to
provide a multi-stage pressure injection. In this case, there is
also proposed a pressure pump for supplying the high-pressure fuel
to the pressure accumulator. However, such a pressure pump is one
of the conventional pressure pumps used for the conventional
accumulator fuel injection devices. Any fuel injection valve
adapted for the pressure pump, which intends to supply a large
amount of high-pressure fuel, is not designed.
[0009] Furthermore, the fuel injection valves disclosed in JP
06-101597 A and JP 10-47208 A are difficult to be used as high flow
fuel valves because their structures differ fundamentally from the
high flow fuel valves in that the proportion of the length of an
injection hole to the diameter of the injection hole is restricted
within a predetermined range, a revolving body is installed, and so
on.
[0010] Therefore, as a result of concentrated study, the present
inventors have found out that, by providing a plurality of inlet
holes and arranging the inlet holes in a non-radical pattern
relative to an inlet chamber, fuel can be allowed to pass through
the inlet holes quickly in a quantitative manner to pressurize a
large amount of fuel sufficiently even in the case of driving a cum
and a plunger at high speed.
[0011] Specifically, for addressing APCRS, an object of the present
invention is to provide a fuel supply pump and a high flow value
suitable for the fuel supply pump, wherein the fuel supply pump
allows fuel to quickly pass through a pressure chamber of a high
pressure pump to pressurize the fuel sufficiently when the cam and
plunger in a fuel supply pump are driven at high speed to discharge
a large amount of the fuel.
DISCLOSURE OF THE INVENTION
[0012] [1] According to the present invention, the above problems
can be solved by providing a high flow fuel valve that comprises a
valve main body, a valve body movably installed in the inside of
the valve main body, an inlet chamber installed in the inside of
the valve main body, inlet holes, and a seat portion where the
valve body and part of the valve main body are in contact with each
other, wherein a plurality of inlet holes is formed and the inlet
holes are arranged in a non-radical pattern relative to the inlet
chamber.
[0013] That is, as constituted above, the fuel can be introduced
into the inlet chamber through a plurality of the inlet holes
arranged in a non-radical pattern without substantially altering
the direction of fuel flow. Even though the streams of fuel are
introduced from plural directions, their mutual collisions in the
inlet chamber can be lessened. Therefore, fuel, even in an
extremely large amount, can be passed quickly and quantitatively
through the high flow fuel valve.
[0014] [2] In addition, for constituting the high flow fuel valve
of the present invention, it is preferable that the horizontal
cross sectional shape of the inlet chamber is substantially a
circle and the inlet holes are arranged in the tangential direction
of the inlet chamber.
[0015] As constituted above, the fuel can be introduced as a
rotational flow in one direction. In addition, even though the fuel
is introduced from plural directions, the mutual collisions in the
inlet chamber are lessened and the streams of fuel can be easily
combined together as rotational flow in one direction, resulting in
smooth flow.
[0016] [3] In addition, for constituting the high flow fuel valve
of the present invention, it is preferable that the inlet holes are
inclined in the vertical direction with respect to the inlet
chamber.
[0017] As constituted above, utilizing the gravity, the fuel can be
introduced as a further controlled rotational flow in one
direction. In addition, the mutual collisions of streams of fuel
flow tangentially from plural directions can be lessened and the
streams of fuel can be easily combined together as rotational flow
in one direction.
[0018] [4] In addition, for constituting the high flow fuel valve
of the present invention, the diameter of the inlet hole is
preferably in the range of 2 to 12 mm.
[0019] As constituted above, for example, fuel at a flow rate of
approximately 500 to 1,500 litters per hour can be easily ensured,
allowing the fuel supply pump to process a large amount of fuel
under high pressure. In addition, it is easy to attain ultra-high
pressure conditions of 180 MPa or more even in an accumulator fuel
injection device used together with a pressure amplifying piston
coupled with the fuel supply pump.
[0020] [5] Furthermore, for constituting the high flow fuel valve
of the present invention, the seat diameter of the valve body is
preferably 8 mm or more.
[0021] As constituted above, for example, fuel at a flow rate of
approximately 500 to 1,500 litters per hours can be easily ensured,
allowing the fuel supply pump to process a large amount of fuel
under high pressure. In addition, it is easy to attain ultra-high
pressure conditions of 180 MPa or more even in an accumulator fuel
injection device used together with a pressure amplifying piston
coupled with the fuel supply pump.
[0022] [6] Furthermore, for constituting the high flow fuel valve
of the present invention, a fuel-passing area of the inlet hole is
larger than a fuel-passing area of the seat portion.
[0023] As constituted above, in the inlet chamber, fuel can be
introduced into an inlet chamber without substantially changing the
direction of fuel flow and the residence time in the inlet chamber
can be shortened. Therefore, the fuel, even in a large amount, can
be allowed to pass quickly through the high flow fuel valve in a
quantitative manner.
[0024] [7] Furthermore, another aspect of the present invention is
a fuel supply pump comprising a fuel inlet valve and a fuel out let
valve, wherein the fuel inlet valve is constructed of: a valve main
body, a valve body movably installed in the inside of the valve
main body, an inlet chamber installed in the inside of the valve
main body, inlet holes, and a seat portion where the valve body and
part of the valve main body are in contact with each other, where a
plurality of the inlet holes is formed and arranged in a radial
pattern relative to the inlet chamber.
[0025] That is, as constituted above, the fuel, even in a large
amount, can be allowed to pass quickly through the high flow fuel
valve in a quantitative manner, allowing the fuel supply pump to
process a large amount of fuel under high pressure. In addition, as
constituted above, it is easy to attain ultra-high pressure
conditions of 180 MPa or more even in an accumulator fuel injection
device used together with a pressure amplifying piston coupled with
the fuel supply pump.
[0026] [8] Furthermore, for constituting the fuel supply pump of
the present invention, the fuel supply pump is used in an
accumulator fuel injection device for pressurizing fuel at a flow
rate of 500 to 1,500 litters per hour to a value of 50 MPa or
more.
[0027] Using such an accumulator fuel injection device, a large
amount of fuel can be easily pressurized. Therefore, the combustion
efficiency in the fuel injection system can be raised. Also, the
generation of erosion can be easily prevented, while the durability
can be increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a diagram that illustrates a high flow valve of
the present invention, where (a) and (b) are cross-sectional views
thereof, respectively.
[0029] FIG. 2 is a cross-sectional view of the high flow fuel valve
of the present invention in an installed state.
[0030] FIG. 3 is a cross-sectional view of another high flow fuel
valve.
[0031] FIG. 4 is a diagram for illustrating a high flow flue valve
equipped with a second valve spring (coil spring).
[0032] FIG. 5 is a diagram for illustrating a high flow valve
equipped with a second valve spring (flat spring).
[0033] FIG. 6 is a diagram for illustrating a high flow valve using
a non-linear spring.
[0034] FIG. 7 is a characteristic diagram that illustrates the
relationship between the lift of the high flow fuel valve and the
flow rate per unit time.
[0035] FIG. 8 is a diagram that illustrates the conventional fuel
valve, where (a) and (b) are cross-sectional views thereof,
respectively.
[0036] FIG. 9 is a diagram that illustrates another conventional
fuel valve, where (a) and (b) are cross-sectional views thereof,
respectively.
[0037] FIG. 10 is a diagram that illustrates the conventional fuel
valve, where (a) and (b) are cross sectional views for illustrating
throttle positions in the fuel valve, respectively.
[0038] FIG. 11 is a diagram that illustrates another conventional
fuel valve, where (a) and (b) are cross sectional views for
illustrating throttle positions in the fuel valve,
respectively.
[0039] FIG. 12 is a diagram that illustrates the fuel valve of the
present invention, where (a) and (b) are cross sectional views for
illustrating throttle positions in the conventional fuel valve,
respectively.
[0040] FIG. 13 is across sectional view of a fuel supply pump
equipped with a high flow valve as a fuel inlet valve or a fuel
outlet valve.
[0041] FIG. 14 is a cross sectional view of an IO valve constructed
of a fuel inlet valve and a fuel outlet valve.
[0042] FIG. 15 is a diagram for illustrating the system of an
accumulator fuel injection device (APCRS: Amplified Piston Common
Rail System) in the form of a pressure amplifying piston
system.
[0043] FIG. 16 is a diagram for illustrating the action of a
proportional control valve (FMU) installed in a fuel supply
pump.
[0044] FIG. 17 is a diagram for illustrating the configuration of
an accumulator fuel injection device (APCRS: Amplified Piston
Common Rail System) in the form of a pressure amplifying piston
system.
[0045] FIG. 18 is a schematic diagram for illustrating a method for
raising the pressure of fuel in the accumulator fuel injection
device (APCRS: Amplified Piston Common Rail System) in the form of
a pressure amplifying piston system.
[0046] FIG. 19 is a diagram for illustrating a timing chart of
high-pressure fuel injection.
[0047] FIG. 20 is a diagram for illustrating the configuration of
the conventional accumulator fuel injection device.
[0048] FIG. 21 is a diagram for illustrating the configuration of
another conventional accumulator fuel injection device.
[0049] FIG. 22 is a diagram for illustrating the configuration of
the conventional fuel injection system.
[0050] FIG. 23 is a diagram for illustrating the configuration of
another conventional fuel injection system.
BEST MODE FOR CARRYING OUT THE INVENTION
[0051] Hereinafter, the high flow fuel valve and the fuel supply
pump provided therewith will be described concretely with proper
references to the drawings.
First Embodiment
[0052] As illustrated in (a) and (b) of FIG. 1, a first embodiment
of the present invention is a high flow fuel valve 73 that
comprises a valve main body 19, a valve body 20 movably installed
in the inside of the valve main body 19, an inlet chamber 19a
formed in the inside of the valve main body 19, inlet holes 19c,
and a seat portion 23 where part of the valve body 20 and part of
the valve main body 19 are contact with each other. The high flow
fuel valve 73 is characterized in that a plurality of inlet holes
19c is formed and these inlet holes 19c are arranged in a
non-radical pattern relative to the inlet chamber 19a.
[0053] Hereinafter, the high flow fuel valve 73 will be described
more concretely by way of individually describing its structural
components.
[0054] 1. Valve Main Body
[0055] A valve main body is not specifically limited to a certain
configuration as far as it retains a valve body and performs a
predetermined movement. Preferably, however, the valve main body
may be in the shape of a cap opened downwardly as shown in FIG.
1(b).
[0056] In addition, as shown in FIG. 1(b), the external shape of
the valve main body 19 is substantially in the form of a cylinder,
while no protrusion, rib, or the like is formed thereon so as to be
substantially flat. In other words, conventionally, for centering,
a rib portion 33 is formed on the upper portion of the valve main
body 19 as shown in FIG. 8(b) and then the rib portion 33 is used
for fixing the valve main body in position with respect to a barrel
or the like. Therefore, there are problems in that the valve main
body is hardly produced and the cost thereof increases. Therefore,
as shown in FIG. 2, The problems in producing the valve main body
can be solved by carrying out the centering by adjusting the inner
diameter of a valve retaining portion 71 and the external diameter
of a valve 73, while no rib portion or the like is formed on the
valve main body.
[0057] Furthermore, as described latter, a valve body is installed
in the valve main body. Preferably, the valve body is movable in
the inside of the valve main body. That is, it is preferable to
constitute a poppet valve structure.
[0058] Here, a method for driving the valve body installed in the
valve main body is, but not specifically limited to, preferably a
mechanical driving method using a valve spring 21 provided above
the valve main body 19. Alternatively, an electro-magnetic driving
method may be preferably applied.
[0059] 2. Valve Body
[0060] Furthermore, it is preferable that the valve body has a
sheet diameter of 8 mm or more. This is because such a
configuration of the valve body leads to secure fuel at a flow rate
of approximately 500 to 1,500 litters per hour and to supply the
fuel to a fuel supply pump to pressurize a large amount of fuel. In
addition, this is also because an ultra-high pressure injection of
180 MPa or more can be easily attained even if the fuel supply pump
is coupled with an accumulator fuel injection device used together
with a pressure amplifying piston.
[0061] However, the high flow fuel valve itself grows in size as
the sheet diameter of the valve body increases too much. Therefore,
it may lead to be difficult in installation of the high flow valve
and high-precision movement of the valve body, or decrease in
durability or mechanical strength of the valve body.
[0062] Therefore, the sheet diameter of the valve body is
preferably in the range of 8 to 15 mm, more preferably in the range
of 8 to 12 mm.
[0063] 3. Inlet Holes
[0064] (1) Number of Inlet Holes
[0065] Furthermore, as shown in FIG. 1(a), the first embodiment is
characterized in that plural of inlet holes 19c are formed. That
is, an extremely large amount fuel can be introduced into an inlet
chamber through a plurality of the inlet holes. Thus, the number of
the inlet holes may be two or more, preferably in the range of
three to five, more preferably three or four.
[0066] (2) Arrangement 1
[0067] Furthermore, as shown in FIG. 1(a), the arrangement of
plural inlet holes is characterized in that the plural inlet holes
19c are arranged so as to be in a non-radical direction with
respect to an inlet chamber 19a. Specifically, the plural inlet
holes 19c are arranged such that the directions of fuel flow from
the respective inlet holes 19c are staggered from the corresponding
phantom lines extending toward the center of an inlet chamber
19a.
[0068] This is because the fuel can be introduced into the inlet
chamber through a plurality of the inlet holes arranged in a
non-radical pattern without substantially altering the direction of
fuel flow. In addition, even though the streams of fuel are
introduced from plural directions, their mutual collisions in the
inlet chamber can be lessened because of their introduction from
the directions in a non-radial pattern.
[0069] Therefore, a high flow fuel valve in which a plurality of
inlet holes is arranged in a non-radial pattern allows fuel to pass
through the inlet holes quickly in a quantitative manner while
keeping the lift of the valve comparatively low even though the
fuel is of an extremely large amount as much as approximately 500
to 1,500 litters per hour.
[0070] Furthermore, as shown in FIG. 1(a), it is preferable that
the inlet chamber 19a substantially have a circular horizontal
cross sectional shape and also the inlet holes 19c are arranged
along the tangential directions of the inlet chamber 19a,
respectively.
[0071] This is because, as the inlet holes are arranged in such a
configuration, the fuel can be introduced as rotational flow in one
direction into the inlet chamber. In addition, this is also
because, the flue is introduced in tangentially directions. Even
though the fuel is introduced from plural directions, the mutual
collisions in the inlet chamber are lessened and the streams of
fuel can be easily combined together as rotational flow in one
direction.
[0072] However, the inlet hole does not necessarily need to be
arranged in the tangential direction. For example, if it is within
the limits of .+-.20 degrees to the tangential direction, it is
tolerance level.
[0073] (3) Arrangement 2
[0074] Furthermore, according the high flow fuel valve of the
present invention, as shown in FIG. 3, it is preferable to arrange
an inlet hole 19c in an oblique direction with respect to an inlet
chamber 19a. That is, the inlet hole is preferably arranged so as
to incline the direction along which fuel is introduced from the
inlet hole at a given angle (.theta.) with respect to a horizontal
plane on which the inlet chamber that receives the fuel is
present.
[0075] This is because further accelerated fuel can be introduced
into the inlet chamber by arranging the inclined inlet holes and
thus a much more amount of fuel can be introduced easily. In
addition, the above arrangement of inclined inlet holes reduces
mutual collisions between the streams of fuel flow from plural
tangential directions to easily bring them together as rotational
flow in one direction.
[0076] Furthermore, when each of the inlet holes 19c is
perpendicularly inclined to the inlet chamber 19a, as shown in FIG.
3, the inlet hole 19c has preferably an inclined angle (.theta.) of
1 to 45 degrees with respect to the horizontal direction.
[0077] This is because the effect of inclined inlet holes may not
be exerted when the inclined angle of inlet hole is less than 1
degree. On the other hand, the inlet flow-ability of fuel into the
inlet chamber may decrease when the inlet hole has an inclined
angle of more than 45 degrees. Therefore, the inclined angle of the
inlet hole is preferably in the range of 5 to 30 degrees, more
preferably in the range of 10 to 25 degrees.
[0078] (4) Diameter
[0079] Furthermore, each of the inlet holes has a diameter of
preferably 2 to 12 mm because of the following reasons. The inlet
holes of less than 2 mm lead to, for example, the difficulty of
ensuring fuel with a flow rate of 500 to 1,500 litters per hour and
thus a large amount of fuel is hardly pressurized in a fuel supply
pump. Therefore, in an accumulator fuel injection device used
together with a pressure amplifying piston coupled with the fuel
supply pump, for example, it is difficult to attain the ultra-high
pressure conditions of 180 MPa or more.
[0080] On the other hand, when the diameter of the inlet hole
exceeds 12 mm, the mechanical strength or durability of the inlet
hole may decrease.
[0081] Therefore, the diameter of the inlet hole is more preferably
in the range of 2.5 to 11.5 mm, further preferably in the range of
3 to 11 mm.
[0082] (5) Area of Inlet Holes
[0083] The area of inlet holes (total area of openings), the
fuel-passing area of plural inlet holes is preferably larger than
the fuel-passing area of a seat portion.
[0084] This is because, as the fuel-passing area of plural inlet
holes is considered as described above, fuel can be introduced into
an inlet chamber without substantially changing the direction of
fuel flow and the residence time in the inlet chamber can be
shortened. Therefore, the fuel, even in a large amount, can be
allowed to pass quickly through the high flow fuel valve in a
quantitative manner.
[0085] More specifically, furthermore, the area (opening area) of
one inlet hole is preferably in the range of 15 to 250
mm.sup.2.
[0086] This is because, if the area of the inlet hole is less than
15 mm.sup.2, for example, the fuel at a flow rate of approximately
500 to 1,500 litters per hour cannot be ensured and thus a large
amount of the fuel is difficult to be pressurized in a fuel supply
pump. Therefore, in an accumulator fuel injection device used
together with a pressure amplifying piston coupled with the fuel
supply pump, for example, it is difficult to attain the ultra-high
pressure conditions of 180 MPa or more.
[0087] On the other hand, the area of the inlet hole exceeds 250
mm.sup.2, the mechanical strength or durability of the inlet hole
may decrease.
[0088] Therefore, the area of the inlet hole is more preferably in
the range of 20 to 200 mm.sup.2, further preferably in the range of
25 to 150 mm.sup.2.
[0089] Here, for plural inlet holes 19c shown in FIG. 1(a), the
term "area of one inlet hole" means the area of one opening portion
19b opened toward the inlet chamber 19a.
[0090] 4. Seat Portion
[0091] As shown in FIG. 1(b), the first embodiment is characterized
in that part of a valve body 20 and part of a valve main body 19
are contact with each other to provide a seat portion 23 as a
fuel-passing portion for correctly controlling the mount of fuel
passed. Specifically, the valve body moves up and down by means of
a valve spring or the like, so that the valve body and valve main
body can be partially contact with each other to form such a seat
portion. Therefore, the fuel, even in a large amount, can be
allowed to pass quickly through the high flow fuel valve in a
quantitative manner.
[0092] In addition, as mentioned above, the seat portion is more
preferably constructed such that the fuel-passing area of the seat
portion is smaller than the area of the inlet hole.
[0093] 5. Valve Spring
[0094] (1) First Valve Spring
[0095] Furthermore, as shown in FIG. 1(b), it is preferable to
provide a valve spring (first spring) for driving a valve body 20
above a valve main body 19.
[0096] As constituted above, the valve body can be moved up and
down by the valve spring to allow the valve main body and valve
body to be easily contact with each other, while absorbing a seat
impact at the time of lifting the valve body.
[0097] (2) Second Valve Spring
[0098] Furthermore, as shown in FIG. 4, a second valve spring 24 is
preferably installed together with the first valve spring (first
spring) 21. That is, the second valve spring 24 is provided such
that it is brought into contact with a valve body 20 from an
initial stage of lifting the valve body 20. It is preferable to
install the second valve spring 24 having a comparatively high
spring constant together with the first spring 21 having a
comparatively low spring constant from the middle stage of the
lifting so as to be brought into contact with the valve body
20.
[0099] As constituted above, the valve body can be easily lifted at
initial valve opening, so that the fuel inlet efficiency to a
plunger can be increased. In addition, as the valve opening
proceeds, an increasing lifting speed is lowered by the second
valve spring to reduce impact force at full lift. Therefore, even
in the case of the high flow fuel valve, reduction in durability
and strength can be prevented and also impact noises at the time of
seating the valve body can be reduced.
[0100] In addition, the second valve spring may be alternatively a
spring 24 as shown in FIG. 4 or a flat spring 25 as shown in FIG.
5(a) to FIG. 5(c).
[0101] (3) Non-Linear Spring
[0102] Furthermore, as an alternative to the use of the first and
second valve springs together, a non-linear spring 26 as shown in
FIG. 6 is preferably used. That is, for example, the spring is
constructed such that the spring has a conical shape gradually
increasing in diameter toward the bottom. Therefore, the spring
constant can be variable and the same effects as those obtained by
installing the first and second valve springs can be obtained
without increasing the number of the valve spring.
[0103] 6. Performance
[0104] (1) Fuel-Passing Amount (Flow Velocity)
[0105] Furthermore, for the fuel-passing amount (flow velocity) in
the high flow fuel valve of the first embodiment, the flow rate of
fuel per unit time when the lift of a valve body is almost 1 mm is
preferably in the range of 500 to 1,500 litters per hour, more
preferably in the range of 800 to 1,300 litters per hour.
[0106] This is because, as constituted above, a small-sized and
low-height high flow fuel valve, which is capable of ensuring a
large flow rate of fuel with a comparatively small lift of the
valve body, can be provided.
[0107] Here, preferably, the high flow fuel valve of the first
embodiment has a performance curve shown in FIG. 7. That is, in
FIG. 7, the lift (relative value) of the valve body is plotted on
the abscissa and the flow rate of fuel per unit of time, i.e., flow
velocity (relative value) is plotted on the ordinate.
[0108] In FIG. 7, the line A corresponds to the conventional fuel
valve. As shown in FIG. 8, this is a fuel valve 32 having a sheet
diameter of 7.6 mm, in which three inlet holes 19c are arranged in
a radial pattern along the periphery of a circular inlet chamber 18
(Type 1).
[0109] Likewise, the line B corresponds to a modified example of
the conventional valve having an enlarged sheet diameter. As shown
in FIG. 9, this is a fuel valve 34 having a sheet diameter of 10
mm, in which three inlet holes 19c are arranged in a radial pattern
along the periphery of a circular inlet chamber 18 (Type 2).
[0110] Furthermore, the line C corresponds to one example of the
high flow fuel valve of the present invention. As shown in FIG. 1,
this is a high flow fuel valve 73 having a sheet diameter of 10 mm,
in which three inlet holes 19c are arranged in a non-radial pattern
along the tangent of a circular inlet chamber 18 (Type 3).
[0111] (2) Throttle and Characteristics
[0112] Furthermore, in FIG. 10(a) and FIG. 10(b) to FIG. 12(a) and
FIG. 12(b), throttle positions decided from the distribution of
fuel velocities in the respective fuel valves (small lift and large
lift) are shown, respectively.
[0113] That is, FIG. 10(a) and FIG. 10(b) illustrate throttle
positions of the conventional fuel valve shown in FIG. 8,
respectively. These figures correspond to the valve of Type 1
described above. In addition, FIG. 11(a) and FIG. 11(b) illustrate
throttle positions of the modified example of the conventional fuel
valve shown in FIG. 9, respectively. These figures correspond to
the valve of Type 2 described above. Furthermore, FIG. 12(a) and
FIG. 12(b) illustrate throttle positions of the high flow fuel
valve shown in FIG. 1, respectively. These figures correspond to
the valve of Type 3 described above.
[0114] As is evident from these figures, in the valve of Type 1, it
is confirmed that the throttle position is located near the seat
position irrespective of the lift. For the flow velocity
characteristics of the valve, it is confirmed that predetermined
flow velocity cannot be attained because of an insufficient sheet
diameter in spite of an increase in valve lift as indicated by the
line A in FIG. 7.
[0115] Furthermore, in the case of the valve of Type 2 having an
enlarged sheet diameter, it is confirmed that the throttle position
moves toward the inlet chamber 18 from the seat portion as the lift
increases. For the flow velocity characteristics of the valve,
however, the flow velocity increases more than that of Type 1 as
indicated by the line B in FIG. 7, but it does not reach to
predetermined flow rate. That is, in the valve of Type 2, the flow
velocity is restricted by the throttle of the inlet chamber even
though the sheet diameter is enlarged.
[0116] On the other hand, in the valve of Type 3, it is confirmed
that inlet holes are tangentially arranged and the sheet diameter
is enlarged, so that the throttle position can be only found on the
seat position irrespective of the lift of the valve and the
throttle of the inlet chamber 18 is improved, even compared with
the valve of Type 2.
[0117] Furthermore, in terms of the flow characteristics of the
valve of Type 3, as indicated by the line C in FIG. 7, it is
confirmed that the predetermined flow velocity can be obtained at a
predetermined lift of the valve as the throttle of the inlet
chamber is improved.
Second Embodiment
[0118] As shown in FIG. 13, a second embodiment of the present
invention is a fuel supply pump 50 having a fuel inlet valve 73 and
a fuel outlet valve 19 and is characterized by the following
configuration. The fuel inlet valve 73 comprises a valve main body
19, a valve body 20 movably installed in the inside of the valve
main body 19, an inlet chamber 19a formed in the inside of the
valve main body 19, inlet holes 19c, a seat portion 23 where part
of the valve body 20 and part of the valve main body 19 are contact
with each other, wherein a plurality of inlet holes 19c is formed
and these inlet holes 19c are arranged in a non-radical
pattern.
[0119] Hereinafter, the fuel supply pump 50 will be described more
concretely by way of individually describing its structural
components.
[0120] 1. Fuel Inlet Valve
[0121] The second embodiment is characterized in that a fuel inlet
valve used is the high flow fuel valve described in the first
embodiment. Thus, it is preferable to design an IO valve 70
constructed of a fuel inlet valve 73 and a fuel outlet valve
60.
[0122] In addition, when the high flow fuel valve of the first
embodiment is used as a fuel inlet valve, even if the flow of fuel
per unit of time is approximately 500 to 1,500 litters per hour,
the fuel can be quantitatively supplied to a fuel supply pump in a
extremely precise manner.
[0123] 2. Fuel Supply Pump
[0124] For example, the configuration of the fuel supply pump is,
but not specifically limited to, preferably one having a fuel
supply pump 50 shown in FIG. 13. That is, the fuel supply pump is
preferably constructed of a pump housing 52, a barrel (cylinder)
53, a plunger 54, a fuel compression chamber 74, a tappet 58, and a
cam 60.
[0125] Furthermore, the plunger 54 slides along the inside of the
barrel 53 in the pump housing 52 to form a fuel compression chamber
74 for pressurizing fuel. The plunger 54 is preferably constructed
so as to perform reciprocal motion in response to the rotary
movement of the cam 60. Therefore, the fuel fed under pressure from
a feed pump 64 is effectively pressurized by the plunger 54 in the
fuel compression chamber 74, resulting in high pressure fuel.
[0126] In this example of the fuel supply pump 50, for example, two
sets of the barrel (cylinder) 53 and the plunger 54 are installed
in the pump housing 52. For pressurizing a much more amount of
fuel, two or more sets are preferably used.
[0127] 3. Amplified Piston Common Rail System (APCRS)
[0128] Furthermore, the fuel supply pump of the second embodiment
is preferably a part of an amplified piston common rail system
using a mechanical pressure amplifying system such as piston.
[0129] That is, as shown in FIG. 15, the fuel supply pump 103 is
preferably constructed of a fuel tank 102, a feed pump (low
pressure pump) 104 for supplying the fuel from the fuel tank 102, a
fuel supply pump (high pressure pump) 103, a common rail 106
provided as a pressure accumulator for pressure-accumulation of the
fuel fed under pressure from the fuel supply pump 103, a piston
amplifier 108, and a fuel injection system 110.
[0130] (1) Fuel Tank
[0131] The capacity and form of a fuel tank 102 exemplified in FIG.
15 are preferably defined in consideration of, for example, the
circulation of fuel at a flow rate of approximately 500 to 1,500
litters per hour.
[0132] (2) Feed Pump and Fuel Supply Pump
[0133] The feed pump 104 is, as shown in FIG. 15, provided for
feeding fuel (diesel oil) in the fuel tank 102 to the fuel supply
pump 103 under pressure. It is preferable that a filter 105 is
placed between the feed pump 104 and the fuel supply pump 103.
Preferably, for example, the feed pump 104 has a gear pump
structure mounted on the end of the cam such that the feed pump 104
can be driven by directly connecting with the axis of the cam or
through an appropriate gear ratio.
[0134] In addition, the fuel supply pump 103 is a device for
pressurizing fuel supplied from the feed pump 104 at high pressure.
The fuel supply pump 103 is constructed such that, after
pressurizing the fuel, the fuel is fed to the common rail 106 under
pressure through a high pressure channel 107.
[0135] Furthermore, the fuel fed under pressure from the feed pump
104 through the filter 105 is preferably supplied to the fuel
supply pump 103 through a proportional control valve (FMU) 120 for
adjusting the amount of fuel injected as shown in FIG. 16.
Preferably, the proportional control valve 120 controls the amount
of current passing through a coil 124 under the control of ECU to
proportionally adjust the position of an anchor 125. That is, the
position of a piston 127 at the tip portion of the anchor 125 is
adjusted in response to the position of the anchor 125, so that the
fuel-passing area between a slit 122 formed in the piston 127 and
the fuel supply portion 129 can be varied to control the fuel
supplied to an inlet valve (not shown) in the fuel supply pump
103.
[0136] Furthermore, as shown in FIG. 16, in addition to feed the
fuel supplied from the feed pump 104 to the proportional control
valve 120 and the fuel supply pump 103 under pressure, it is
preferable to construct that the fuel is returned to the fuel tank
102 through a overflow valve (OFV) 134 installed in parallel with
the proportional control valve 120. Moreover, it is preferable that
part of the fuel is fed under pressure to a bearing (not shown) of
the fuel supply pump 103 and then used as a fuel lubricating oil of
the bearing.
[0137] By the way, the fuel supply pump 103 is a device for
pressurizing the fuel supplied from the feed pump 104 at high
pressure as described above. The fuel supply pump 103 is preferably
constructed such that, after pressurizing the fuel, the fuel is fed
to the common rail 106 under pressure through the high pressure
channel 107.
[0138] (3) One Way Valve
[0139] Furthermore, as shown in FIG. 15, it is preferable to
install a one way valve (not shown) on the outlet of the fuel
supply pump 103, or both of the common rail 106 described below and
the fuel supply pump 103.
[0140] This is because, as constituted above, the fuel can be only
fed from the fuel supply pump 103 to the common rail 106.
Therefore, the adverse current at the time of opening an
electromagnetic control valve can be effectively prevented to
effectively prevent a decrease in pressure in the common rail
106.
[0141] (4) Common Rail
[0142] Furthermore, as shown in FIG. 15, the common rail 106 is
connected to a plurality of injectors (injection valves) 110.
Preferably, the accumulated pressure fuel at high pressure by the
common rail 106 is injected into an internal combustion engine (not
shown) from each of the injectors 110.
[0143] Furthermore, but not shown in the figure, the amount of
discharge from each of these injectors 110 is preferably controlled
through an injector driving unit (IDU). The IDU is connected to an
electrical controlling unit (ECU) provided as a controller
described letter. The IDU is driven by drive signals from the
ECU.
[0144] Moreover, a pressure detector 117 is connected to the side
end of the common rail 106 and a pressure-detection signal obtained
by the pressure detector 117 is preferably sent to the ECU. That
is, it is preferable to control an electromagnetic control valve
(not shown) and also control the drive of IDU in response to the
pressure detected when the ECU receives the pressure-detection
signal from the pressure detector 117.
[0145] (5) Piston Amplifier
[0146] Furthermore, as exemplified in FIG. 17, a piston amplifier
(pressure amplifying piston) is constructed of a cylinder 155, a
mechanical piston 154, a compression chamber 158, an
electromagnetic valve 170, and a circulation pathway 157. It is
preferable that the mechanical piston 154 is equipped with a
pressure-receiving portion 152 having a comparatively large area
and a pressure portion 156 having a comparatively small area.
[0147] That is, the mechanical piston 154 housed in the cylinder
155 is pushed and moved by the fuel having a common rail pressure
at the pressure-receiving portion 152. The common rail pressure of
the compression chamber 158 is preferably adjusted to one that
allows fuel having a pressure of approximately 50 MPa to be
pressurized by the pressure portion 156 having a comparatively
small area to make the pressure of the fuel within the range of 150
to 300 MPa.
[0148] Furthermore, for pressurizing the mechanical piston 154, a
large amount of fuel having the common rail pressure is used. After
pressurization, it is preferable to flow the fuel back to the fuel
tank or the like through an electromagnetic driven overflow valve
170. That is, a major part of the fuel having the common rail
pressure is pressurized by the mechanical piston 154 and then flows
back to the fuel tank or the like together with spilled fuel. Then,
the fuel is preferably used for pressurizing the mechanical piston
154 again.
[0149] On the other hand, the fuel pressurized by the pressure
portion 156 is fed to a fuel injection system (fuel injection
nozzle) 163, effectively injected, and combusted.
[0150] Therefore, providing the piston amplifier as described
above, the mechanical piston can be effectively pushed by the fuel
having a common rail pressure without excessively increasing the
size of the common rail.
[0151] That is, as illustrated in the schematic diagram of FIG. 18,
according to the ARCRS system, a mechanical piston is equipped with
a pressure-receiving portion having a comparatively large area and
a pressure portion having a comparatively small area. While
considering the stroke of the mechanical piston, it is possible to
effectively pressurize e fuel having the common rail pressure to a
desired level with a small pressure.
[0152] More concretely, the fuel from the common rail (pressure:
p1, volume: V1, workload: W1) can be received by a
pressure-receiving portion having a comparatively large area and
then changed to higher-pressure fuel (pressure: p2, volume: V2,
work load: W2) by a mechanical piston equipped with a pressure
portion having a comparatively small area.
[0153] (6) Fuel Injection System
[0154] (i) Basic Configuration
[0155] Furthermore, the configuration of the fuel injection system
(fuel injection nozzle) 110 is, but not specifically limited to,
preferably constructed as follows: As shown in FIG. 17, for
example, the fuel injection system 110 comprises a seat surface 164
on which a needle valve body 162 can be placed on a seat surface
164, an injection hole 165 formed on the downstream side from the
valve body abutting portion of the seat surface 164. Preferably, it
is constructed that the fuel supplied from the upstream side of the
seat surface 164 at the time of lifting a needle valve body 162 is
introduced into the injection hole 165.
[0156] Furthermore, such a fuel injection nozzle system 166 is
preferably of an electromagnetic valve type, in which the needle
valve body 162 is always energized toward the seat surface 164 by
the spring 161 and opens and shuts the needle valve body 162 by
switching energization/no energization of solenoide 180.
[0157] (ii) Injection Timing Sheet
[0158] Furthermore, as to a time chart of high-pressure fuel
injection, it is preferable to indicate a fuel injection chart
having two-staged injection conditions as indicated by the solid
line as exemplified in FIG. 19.
[0159] This is because such a two-stage injection timing chart can
be attained by a combination of the common rail pressure and
amplification with a piston amplifier, and thus the combustion
efficiency of fuel can be raised, while cleaning an exhaust
gas.
[0160] Furthermore, according to the present invention, it is also
preferable to indicate a fuel injection chart as indicated by the
dashed line B in FIG. 19, a combination of the common rail pressure
and amplification with a piston amplifier.
[0161] By the way, when the piston amplifier is not used, the
conventional injection timing chart becomes a single-stage
injection timing chart with a low injection amount as indicated by
the dashed line C in FIG. 19.
[0162] (7) Movement
[0163] Next, the fuel supply pump 103, the actions of the piston
amplifier 108, and the fuel injection valve 110 in the second
embodiment will be described. That is, as shown in FIG. 15, at the
time of operating the fuel injection system (fuel injection nozzle
system) 110, the fuel in the fuel tank 102 is supplied from the
feed pump 104 to the fuel supply pump 103. Then, the high-pressure
fuel is supplied from the fuel supply pump 103 to the high pressure
channel 107 under pressure.
[0164] Subsequently, as shown in FIG. 17, the fuel is subjected to
pressure accumulation at approximately 50 MPa in the common rail
106 and then the fuel is preferably pressurized under ultra-high
pressure conditions of 180 MPa or more as the piston amplifier 108
is provided between the common rail 106 and the fuel injection
valve 110.
[0165] Furthermore, for actuating the piston amplifier 108, a large
amount of fuel is used. Thus, in the case of the example shown in
FIG. 17, the high flow fuel valve (not shown) installed in the fuel
supply pump 103 is functioned effectively.
[0166] That is, the high flow fuel valve, in which a plurality of
inlet holes are formed and arranged in a non-radial pattern
relative to the inlet chamber, is used as a fuel inlet valve of the
fuel supply pump 103. Therefore, for example, the fuel at a flow
rate of approximately 500 to 1,500 litters per hours can be passed
quickly and quantitatively. In addition, a large amount of fuel can
be processed by both the fuel supply pump 103 and the common rail
106.
Industrial Applicability
[0167] According to the high flow fuel valve of the present
invention, a plurality of inlet holes is formed and these inlet
holes are arranged in a non-radical pattern relative to the inlet
chamber. Therefore, for example, even the fuel at a flow rate of
approximately 500 to 1,500 liter per hour can be passed quickly and
quantitatively.
[0168] In addition, according to the high flow fuel of the present
invention, even if the lift of the valve body is comparatively low,
a large amount of fuel at a flow rate of 1,000 litters per hour or
more can be passed. Therefore, the positional change of the valve
body decreases and the impact at the time of seating can be eased
now.
[0169] Furthermore, according to the high flow fuel valve of the
present invention, a large amount of fuel can be allowed to pass
through the inlet holes quickly in a quantitative manner without
excessively enlarging the diameter or cross-sectional area of the
inlet hole. Therefore, the reduction of durability or strength of
the high flow fuel valve itself can be prevented.
[0170] Consequently, the high flow fuel valve of the present
invention can be suitably used as a high flow fuel valve of the
fuel supply pump used in an amplified piston common rail system
(APCRS) that pressurizes a large amount of fuel using a piston.
[0171] In addition, according to the fuel supply pump provided with
the high flow fuel valve of the present invention is equipped with
the high flow valve having a plurality of inlet holes arranged in a
non-radial pattern relative to the inlet chamber. Therefore, for
example, even the fuel at a flow rate of approximately 500 to 1,500
liter per hour can be passed quickly and quantitatively.
* * * * *