U.S. patent number 3,656,464 [Application Number 05/023,572] was granted by the patent office on 1972-04-18 for fuel injection nozzle and system.
This patent grant is currently assigned to Fuel Injection Engineering Company. Invention is credited to Stuart G. Hilborn.
United States Patent |
3,656,464 |
Hilborn |
April 18, 1972 |
FUEL INJECTION NOZZLE AND SYSTEM
Abstract
A fuel injection nozzle having a passage extending therethrough
and terminating at one end in an outlet. An atomizing device is
positioned in the passage adjacent the outlet. The nozzle is
preferably mounted on an intake manifold of an engine at such an
angle that it directs the fuel into the manifold in the same
direction as the air flowing through the manifold. The nozzle
controls the shape of the spray pattern so that the cross sectional
configuration of the spray pattern generally conforms to the cross
sectional configuration of the manifold.
Inventors: |
Hilborn; Stuart G. (Laguna
Niguel, CA) |
Assignee: |
Fuel Injection Engineering
Company (South Laguna, CA)
|
Family
ID: |
21815927 |
Appl.
No.: |
05/023,572 |
Filed: |
March 30, 1970 |
Current U.S.
Class: |
123/470;
261/DIG.82; 239/DIG.22; 239/462 |
Current CPC
Class: |
F02M
69/04 (20130101); F02M 69/047 (20130101); Y10S
239/22 (20130101); Y10S 261/82 (20130101) |
Current International
Class: |
F02M
69/04 (20060101); F02m 045/12 () |
Field of
Search: |
;123/119,139,139.15,139.17,139.18,140.2,140.3,141
;239/295,317,314,318,366,368,369,370,372,406,425.5,462 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Goodridge; Laurence M.
Claims
I claim:
1. A fuel injection system for supplying fuel to an engine
comprising:
an intake manifold for supplying fuel and air to the engine, a
predetermined region of the manifold adjacent the engine being of a
predetermined cross sectional configuration;
a fuel injection nozzle mounted on said intake manifold adjacent
said region;
means for supplying fuel under pressure to the fuel injection
nozzle;
a valve means for controlling the supply of fuel under pressure to
the fuel injection nozzle;
a throttle valve for controlling air flow through the manifold;
said nozzle having a fuel passage therethrough, said passage
including an outlet and first and second contiguous portions with
said first portion including said outlet, said outlet being adapted
to direct fuel into said region and toward the engine generally in
the same direction as the direction of air flow through said region
of said manifold;
said nozzle having means including at least two strand-like
elements adjacent the outlet and spaced from said second portion
for atomizing the fuel supplied therethrough to the manifold;
the cross sectional area of said first portion immediately adjacent
the strand-like elements being larger than the cross sectional area
of said second portion at the juncture of said portions; and
said nozzle including means for directing the atomized fuel into
the engine in a predetermined pattern which is substantially
coaxial with said region and which is of a cross sectional size to
substantially avoid wetting of the manifold walls with the atomized
fuel, the cross sectional shape of said pattern being similar to
said predetermined cross sectional configuration of said region
whereby wetting of the manifold walls with the atomized fuel is
minimized.
2. A fuel injection system for supplying fuel to an air intake
manifold of an engine comprising:
a fuel injection nozzle connectible to the intake manifold of the
engine, said nozzle having a passage therethrough for supplying
fuel to the engine;
means for supplying fuel under pressure to the fuel injection
nozzle;
valve means for controlling the supply of fuel under pressure to
the fuel injection nozzle;
said passage terminating in an outlet;
at least two elongated elements;
means for mounting said elongated elements on said fuel injection
nozzle closely adjacent said outlet, said strandlike elements
extending into the path of fuel flow and generally transverse to
said path; and
said elongated elements defining a plurality of impingement
surfaces adjacent said outlet whereby impingement of the fuel on
said elongated elements causes atomization of the fuel.
3. A fuel injection system as defined in claim 2 including a
plurality of said elongated elements in addition to said two
elongated elements, said elongated elements defining a screen
adjacent said outlet.
4. A fuel injection system as defined in claim 2 wherein said
passage has first and second contiguous portions with the first
portion containing sad outlet, said first portion having a region
extending from the juncture of said portions toward said outlet,
the cross sectional area of said region of said first portion being
greater than the cross sectional area of the second portion at the
juncture of said portions, said elongated elements being in said
region of said first portion.
5. A fuel injection system as defined in claim 4 wherein said
elements are spaced from said juncture of said portions.
6. A fuel injection system as defined in claim 4 wherein said
second portion is substantially longer than said first portion of
said passage.
7. A fuel injection system as defined in claim 4 wherein the cross
sectional area of said outlet is at least as large as the cross
sectional area of the first portion at the juncture of said
portions.
8. A fuel injection system as defined in claim 2 wherein the intake
manifold supplies air to the engine with the air travelling along a
predetermined path in said manifold to the engine, the axis of said
passage of said nozzle extending in the same general direction as
said path at the location of said outlet.
9. A fuel injection system as defined in claim 1 wherein said
predetermined cross sectional configuration is generally
circular.
10. A fuel injection system as defined in claim 1 wherein said
means for atomizing includes a screen adjacent said outlet against
which the fuel can impinge.
11. A fuel injection nozzle for directing fuel and air into an
engine comprising:
body means having a passage therethrough, said passage including an
inlet section connectible to a source of fuel under pressure, an
intermediate section and an outlet section, said outlet section
having an outlet for directing fuel into the engine;
said body means having means for conducting air to the intermediate
section whereby the fuel and air in said intermediate section can
flow through the outlet section to the outlet;
said outlet section having a downstream portion and an upstream
portion, said downstream portion defining said outlet, said
portions of said outlet section being contiguous;
an atomizing member mounted on said body means, said atomizing
member including at least two generally transversely extending
elongated atomizing elements against which the fuel stream can
impinge, each of said two elements extending at least partially
across the downstream portion at a location spaced from said
juncture; and
the cross sectional area of said downstream portion at said
location being greater than the cross sectional area of said
upstream portion at the juncture of said portions.
12. A nozzle as defined in claim 11 wherein said atomizing member
includes a screen extending at least substantially across said
downstream portion at said location.
13. A fuel injection nozzle as defined in claim 12 wherein said
outlet section is elongated, said means for conducting includes at
least one aperture in said body means providing communication
between the intermediate section and the exterior of the body
means, said inlet and outlet sections being of lesser cross
sectional area than the intermediate section at their respective
junctures with the intermediate section.
14. A fuel injection nozzle as defined in claim 11 wherein said
location is within said downstream portion.
15. A fuel injection nozzle for supplying fuel to an engine
comprising:
body means having a passage therethrough, said passage including an
inlet section, an outlet section and an intermediate section, said
outlet section terminating in an outlet and said inlet section
being connectible to a source of fuel, said passage being adapted
to conduct fuel therethrough;
said outlet section having a first portion and a second portion
with said first portion including said outlet, said portions being
contiguous;
said second portion being elongated;
means for directing a stream of fuel across at least a portion of
said intermediate section and into said outlet section, said stream
of fuel being of lesser cross sectional area than said intermediate
section;
an atomizing screen;
means for mounting said atomizing screen on said body means in the
path of fuel flow, said atomizing screen being adjacent said outlet
and spaced from said second portion;
the cross sectional area of said first portion immediately adjacent
the atomizing device being larger than the cross sectional area of
said second portion at the juncture of said portions; and
said second portion of said passage being adapted to direct a
stream of fuel against said atomizing screen whereby said atomizing
screen atomizes the fuel directed thereagainst to produce a spray
pattern with the cross sectional area of the spray pattern being a
function of the distance between the atomizing screen and the
adjacent end of said second portion.
16. A fuel injection nozzle as defined in claim 15 wherein said
atomizing screen is mounted within said first portion axially
inwardly of said outlet whereby said atomizing screen is protected
by said body means.
17. A fuel injection nozzle as defined in claim 15 wherein said
outlet section includes a bore and a counterbore defining said
first and second portions, respectively, said body means defining a
shoulder at the juncture of said first and second portions, said
atomizing screen lying axially intermediate said shoulder and said
outlet.
18. A fuel injection nozzle as defined in claim 15 wherein said
body means includes an annular retainer defining said outlet and
clamping said atomizing device against another portion of said body
means.
19. A fuel injection nozzle as defined in claim 15 wherein said
intermediate section is of larger cross sectional area than said
outlet section, said second portion being longer axially than said
first portion, said second portion being of lesser cross sectional
area throughout the full length thereof than said first portion.
Description
BACKGROUND OF THE INVENTION
Fuel injection nozzles and systems are used extensively with high
performance engines such as in race cars although their use need
not be so limited. One fuel injection system includes a fuel pump
for supplying fuel under pressure to several fuel injection
nozzles. The rate of fuel supply through the nozzles is controlled
by a metering valve and one or more fuel bypasses.
One function of the fuel injection nozzle is to atomize the fuel
supplied thereto and discharge the atomized fuel into the engine.
Improved or finer atomization results in better mixing of the fuel
and air, more complete combustion of the fuel, increased fuel
economy and a greater cooling effect from the latent heat of
vaporization of the fuel. One problem with fuel injection nozzles
is how to improve the degree of atomization obtainable
therefrom.
SUMMARY OF THE INVENTION
The present invention provides a fuel injection nozzle in which
fuel atomization is substantially improved. This is accomplished by
an atomizing device which includes one or more transversely
extending strand-like elements in the path of the fuel stream
through the nozzle. Preferably the atomizing device is a screen
composed of numerous relatively fine wires. A screen provides
optimum atomization and is easier and less expensive to make than
an apertured disc. Another advantage of a screen over an apertured
disc is that a screen can provide a greater number of impingement
surfaces and a greater number of orifices.
The atomizing device is preferably located near the outlet of the
nozzle. The fuel is preferably substantially prevented from
atomizing upstream of the atomizing device because atomized fuel
would be more difficult to force through the nozzle. Accordingly a
substantially nonatomized fuel stream impinges against the
atomizing device and substantially all atomization occurs at the
atomizing device.
The passage through the nozzle has an inlet section, an
intermediate section and an outlet section. The inlet section is
connected to a supply of fuel under pressure and the outlet section
terminates in an outlet which discharges the fuel into the inlet
manifold of an engine. The atomizing device is provided in the
outlet section adjacent the outlet.
One preferred way for preventing fuel from atomizing upstream of
the atomizing device is to maintain the cross sectional area of the
outlet section of the passage relatively small. Also, a tube may be
provided in the intermediate section spaced from the outlet section
by a gap for shooting a stream or needle of fuel across the gap
into the outlet section.
When a screen is used as the atomizing device, a number of small
orifices are provided through which the fuel must pass. If the
screen were provided in the small cross sectional area outlet
section, only a few of the orifices would be exposed to the fuel
stream. Accordingly, to increase the number of orifices and the
number and length of wires exposed to the fuel stream, the present
invention teaches enlarging the cross sectional area of a
downstream portion of the outlet section and locating the atomizing
device in such downstream portion. The atomizing device is spaced
from the juncture of the downstream portion of the passage with the
upstream portion of the passage to thereby expose more and greater
lengths of wires. Another advantage of exposing a greater number of
orifices of the atomizing device is that the likelihood of complete
clogging of the atomizing device is reduced.
When the screen is used as the atomizing device, the degree of
atomization can be controlled, to some extent, by the size and
number of the orifices and wires. For improved atomization, it is
preferred to utilize a large number of small diameter wires for the
screen.
The nozzle of the present invention is adapted to be mounted on the
intake manifold to discharge fuel therein. The present invention
recognizes that it is desirable for the nozzle to distribute the
atomized fuel substantially throughout the manifold without
excessively wetting the walls of the manifold. The present
invention is also based, to some degree, on the discovery that
engine horsepower can be increased somewhat by directing fuel flow
into the air stream in the manifold generally coaxial therewith and
in a pattern, the cross section of which is generally similar to
the cross sectional configuration of the surrounding portion of the
intake manifold. The spray pattern should be controlled so as to
avoid wetting of the walls of the manifold with fuel.
With the present invention, the shape of the outlet of the nozzle
controls the shape of the spray pattern. For example, a circular
outlet provides a conical spray pattern. The direction of the spray
pattern is controlled by the angle at which the nozzle is mounted
on the manifold. The rate at which the pattern diverges can be
controlled by controlling the area of the nozzle outlet and the
distances from the atomizing device to the nozzle outlet and to the
juncture of the upstream and downstream portions of the outlet
section.
The invention, both to its organization and method of operation
together with further features and advantages thereof, may best be
understood by reference to the following description taken in
connection with the accompanying illustrative drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a partially schematic view of a fuel injection system
constructed in accordance with the teachings of this invention. In
FIG. 1, an engine intake manifold is illustrated in axial cross
section and a fuel injection nozzle constructed in accordance with
the teachings of this invention is shown in side elevation.
FIG. 2 is an axial sectional view through the fuel injection
nozzle.
FIG. 3 is an enlarged fragmentary side elevational view partially
in section of the nozzle tip.
FIG. 4 is an end elevational view of the nozzle tip.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings and in particular to FIG. 1, reference
numeral 11 designates a fuel injection system constructed in
accordance with the teachings of this invention. The fuel injection
system 11 includes a fuel supply tank 13, a fuel pump 15, a
metering valve 17 and a plurality of fuel injection nozzles 19
(only one being shown in FIG. 1). Although any number of the
nozzles 19 may be utilized depending upon the number of engine
cylinders, only one of these nozzles is described herein in detail,
it being understood that the other nozzles may be of similar or
identical construction. The fuel pump 15 supplies fuel under
pressure through a fuel supply conduit 21 and the metering valve 17
to the nozzle 19. The metering valve 17 controls the rate of fuel
flow to the nozzle 19 and the metering valve may itself be
controlled, for example, by the throttle linkage (not shown).
To provide additional control over the rate of fuel supply to the
nozzle 19, the system 11 also preferably includes at least one fuel
bypass which, in the embodiment illustrated, is a primary bypass
23. The primary bypass 23 leads from the pump 15 back to the tank
13 and includes a selector valve 25 and a plurality (three being
illustrated) of parallel passages 27. The primary bypass 23
receives fuel under pressure from the pump 15 and returns it
through one of the passages 27 which has been selected by the valve
25 to the tank 13. Each of the passages 27 contains a restriction
29 which may be, for example, a metering orifice with each of the
orifices providing a different restriction to the flow of fuel
therethrough. The selector valve 25 is manually adjustable to
provide a return path through any one of the passages 27.
Accordingly, by selecting the appropriate passage 27 for the return
of bypassed fuel to the tank 13, the degree of restriction, and
hence, the rate of fuel flow through the primary bypass can be
adjusted. The primary bypass 23 can be used, for example, to permit
the driver to adjust the fuel-air ratio supplied to the engine, and
this is particularly useful when switching from one fuel to
another.
The nozzle 19 is mounted on an intake manifold 31 of an engine (not
shown) of a vehicle such as a racing car. The intake manifold 31
includes a manifold wall 33 defining a main manifold passage 35 for
supplying air to the engine. A throttle valve or butterfly valve 37
is suitably pivotally mounted within the main manifold passage 35
for controlling the flow of air to the engine. The throttle valve
37 is illustrated in FIG. 1 as being in the closed position and it
is preferably controlled by the same linkage as the metering valve
17 so that fuel and air will be supplied to the engine in the
proper proportions. Air is supplied to the main manifold passage 35
upstream of the throttle valve 37 by a supercharger (not shown);
however, the present invention is applicable to systems not
employing a supercharger.
The manifold wall 33 also defines an auxiliary manifold passage 39
which provides communication between the main manifold passage 35
upstream of the throttle valve 37 and the nozzle 19. In the
embodiment illustrated, the nozzle 19 is mounted on the intake
manifold 31 downstream of the throttle valve 37, and accordingly,
the auxiliary manifold passage 39 forms a bypass around the
throttle valve 37. The manifold passage 39 is preferably formed by
the manifold wall rather than by a separate tube or other member
attached to the manifold 31.
The manifold wall 33 has an inclined mounting portion 41 having an
aperture 43 extending therethrough. The manifold wall 33 also has a
threaded opening 45 coaxial with the opening 43. The nozzle 19 has
an externally threaded portion 47 mounted within the opening 45 and
a nut 49 which bears on the outer surface of the mounting portion
41 to thereby securely mount the nozzle 19 on the manifold 31.
It will be readily appreciated that the size and configuration of
an intake manifold can vary widely and the intake manifold 31 is
illustrated merely by way of example. In the embodiment
illustrated, the main manifold passage 35 is circular in transverse
cross section. Specifically, the upper portion of the passageway 35
is generally cylindrical and the lower portion of the passageway 35
curves slightly. Air is supplied from above the throttle valve 37
and flows along a path which extends in the same general direction
as the axis of the main manifold passage 35.
With reference to FIG. 2, the nozzle 19 includes a body member 51
and a nozzle tip 53 mounted within the body member 51 to define
body means for the nozzle. The nozzle 19 has an axial passage 55
extending therethrough. The passage 55 includes an inlet section
57, a first intermediate section 59, a second intermediate section
or chamber 61 and an outlet section 63, all of which are coaxial.
The section 57, 59 and 61 are cylindrical and of progressively
increasing diameter. The inlet section 55 may be connected to the
conduit 21 by a suitable connector (not shown) which may utilize
external threads 65 which surround the inlet section. The outlet
section 63 includes a frusto conical flared portion 67, an upstream
portion 69 and a downstream portion 71 with the downstream portion
71 terminating in an outlet 73. In the embodiment illustrated, the
portions 69 and 71 are cylindrical and coaxial.
A tubular member 75 is suitably mounted within the chamber 61. The
tubular member 75 has a block portion 77 of substantially the same
cross sectional area and configuration as the chamber 61 and a
coaxial tube portion 79 of substantially smaller diameter than the
block portion and spaced radially inwardly from the peripheral wall
of the chamber 61. The tubular member 75 has a relatively small
diameter passageway 81 extending axially therethrough and coaxial
with the chamber 61. The inlet end of the passage 81 has a flared
portion 83 and the outlet of the passage 81 terminates in coaxial
spaced relationship to the outlet section 63. Preferably the
diameter of the passage 81 is smaller than the diameter of the
upstream portion 69 of the outlet section 63.
A fuel filter may be provided in the passage 59 if desired so long
as it does not atomize the fuel.
A plurality of radially extending ports 85 provide communication
between the chamber 61 and the exterior of the nozzle 19. The
tubular member 75 and the nozzle tip 53 may be mounted on the body
member 51 in any suitable manner such as by soldering.
The details of the nozzle tip can best be seen in FIGS. 3 and 4.
The nozzle tip 53 includes a body section 87 having an annular end
face 89. In the embodiment illustrated, the body section 87 defines
the flared portion 67, the upstream portion 69, and a portion of
the downstream portion 71 of the passage 55.
An atomizing device in the form of a screen 91 is clamped against
the end face 89 by an annular retainer 93. The retainer 93 may be
removably affixed to the body section 87 as by screw threads but it
is preferably permanently attached to the body section as by
soldering. The retainer 93 forms the remainder of the downstream
portion 71 of the passage 55 and also defines the outlet 73.
The screen 91 is spaced downstream from a shoulder 95 which defines
the juncture between the passage portions 69 and 71. The screen 91
is spaced upstream from the outlet 73. The screen 91 extends
transverse to the axis of the outlet section 63 and, in the
embodiment illustrated, is perpendicular to the axis of the outlet
section.
The screen 91 includes a plurality of fine wires or strand-like
elements 97 and 99 (FIG. 4) which define a plurality of small
orifices 101 (FIG. 4). In the embodiment illustrated, the wires 97
are in spaced parallel relationship and extend generally
transversely to the wires 99. Similarly, the wires 99 are in spaced
parallel relationship, it being understood that the orientation of
the wires 97 and 99 can be varied. Accordingly, the orifices 101
are generally square. The function of the screen 91 is to finely
divide and atomize the fuel stream which impinges thereagainst.
Although the present invention is not limited to any particular
size or arrangement of wires for accomplishing this atomizing
result, optimum results can be obtained if numerous small diameter
slightly spaced wires are utilized.
In operation of the fuel injection system 11, the fuel pump 15
supplies fuel under pressure to the nozzle 19 with the quantity of
fuel supplied being controlled by the metering valve 17 and the
bypass 23. Simultaneously, air is supplied through the main
manifold passage 35 at a rate which is dependent upon the position
of the throttle valve 37 and other factors. Air is also supplied to
the nozzle 19 through the auxiliary manifold passage 39, such air
entering the ports 85 which are exposed within the passage 39.
Thus, the air supplied to the ports 85 of the nozzle 19 is
independent of the position of the throttle valve 37.
The fuel under pressure travels through the inlet section 57 and
the intermediate section 59 to the passageway 81 without atomizing.
The passageway 81 is of smaller diameter than the intermediate
section 59, and accordingly, the velocity of the fuel is increased
in the passageway 81. This permits the tubular member 75 to shoot a
high velocity, small diameter stream or needle of fuel across the
gap between the tube 79 and the nozzle tip 53. Such stream of fuel
enters the outlet passage 63 and travels therethrough substantially
to the screen 91 without atomizing. Simultaneously, the air from
the manifold passage 39 enters the ports 85 and surrounds the fuel
stream. This air is drawn into the outlet passage 63 in a tubular
column which surrounds the fuel stream within the outlet section 63
but substantially no atomization of the fuel stream occurs upstream
of the screen 91.
When the high velocity needle of fuel and the surrounding tubular
column of air impinge against the wires 97 and 99, such wires are
operative to finely atomize or divide the fuel stream into minute
particles while the orifices 101 are operative to permit passage of
such finely divided particles therethrough to the outlet 73 and
into the main manifold passage 35.
As the screen 91 is spaced downstream from the shoulder 95 (FIG. 3)
a larger area of the screen 91 is exposed to the fuel stream than
if the screen were clamped directly against the shoulder 95. In
addition, more of the orifices 101 are exposed to the fuel stream
thereby making complete clogging of the orifices 101 much less
likely.
The cross sectional configuration of the fuel pattern sprayed into
the manifold passage 35 is a function of the cross sectional
configuration of the outlet 73. In the embodiment illustrated, the
outlet 73 is circular and this produces a conical spray pattern.
The rate of divergence of the cone can be decreased by decreasing
the diameter of the outlet 73 or by increasing the distance between
the screen 91 and the outlet 73. The degree of atomization is
effected by varying the distance between the screen 91 and the
shoulder 95 and by the number, diameter and spacing of the wires 97
and 99. It is preferred to have the screen 91 spaced from but
closely adjacent the screen 95. The spacing between the screen 91
and the shoulder 95 should be sufficient to allow the fuel stream
to take advantage of the greater cross sectional area of the screen
which is exposed to the fuel in the passage portion 71. For
convenience in manufacturing, it is preferred that the downstream
portion 71 be a cylindrical bore in which event the outer diameter
of the shoulder 95 would be the same as the diameter as the outlet
73.
Another feature of the present invention is the mounting of the
nozzle 19 in such a relationship to the manifold passage 35 that
the fuel injected by the nozzle flows in substantially the same
direction as the air flow through the manifold passage 35.
Specifically the fuel preferably forms a spray pattern 103, the
axis of which generally follows the axis of the surrounding portion
of the manifold. In addition, the shape of the spray pattern 103 is
adjusted so that wetting of the wall of the manifold passage 35 by
the atomized fuel is substantially eliminated.
Thus, as shown in FIG. 1, the fuel particles in the spray pattern
103 flow in generally the same direction as the fuel flowing
through that particular region of the manifold passage 35. The
cross sectional configuration of the pattern 103 is generally
similar to cross section configuration of the surrounding regions
of the manifold passage 35. In addition, the rate of divergence of
the conical spray pattern 103 is adjusted so that substantially all
of the fuel particles have been picked up and are travelling with
the airstream prior to the time that the spray pattern diverges
sufficiently to wet the walls of the manifold passage 35. By this
arrangement, it has been found that engine horsepower can be
increased. Although the spray pattern 103 is shown as being
conical, in actual practice of the invention the air flowing
through the manifold passage 35 would affect the shape of the spray
pattern.
The concepts of this invention are equally applicable to a fuel
injection system having no auxiliary manifold passage 39 and in
which the ports 85 are eliminated. Similarly, the shape of the fuel
pattern 103 can be tailored to meet the requirements of manifold
passages of different cross sectional configurations.
Although an exemplary embodiment of the invention has been shown
and described, many changes, modifications and substitutions may be
made by one having ordinary skill in the art without necessarily
departing from the spirit and scope of this invention.
* * * * *