U.S. patent number 3,601,108 [Application Number 04/848,637] was granted by the patent office on 1971-08-24 for intake manifold for automotive fuel injection system.
This patent grant is currently assigned to Nissan Motor Company. Invention is credited to Shuya Nambu.
United States Patent |
3,601,108 |
Nambu |
August 24, 1971 |
INTAKE MANIFOLD FOR AUTOMOTIVE FUEL INJECTION SYSTEM
Abstract
An intake manifold for fuel injection system of an internal
combustion engine having a main throttle valve, and an auxiliary
throttle valve each communicating with the atmosphere. The suction
inertia effect (ram effect) of the intake manifold contributes to
the improvement of the engine torque by operating the auxiliary
throttle valve in relation to the opening of the main throttle
valve and engine speed.
Inventors: |
Nambu; Shuya (N/A, JA) |
Assignee: |
Company; Nissan Motor
(JA)
|
Family
ID: |
25303866 |
Appl.
No.: |
04/848,637 |
Filed: |
August 8, 1969 |
Current U.S.
Class: |
123/364; 123/365;
123/505; 123/184.38 |
Current CPC
Class: |
F02D
9/00 (20130101); F02D 2700/0243 (20130101) |
Current International
Class: |
F02D
9/00 (20060101); F02M 039/00 (); F02B 003/00 ();
F02M 023/04 () |
Field of
Search: |
;123/140.32,139.17,52M,52MV,119d,124,139.18 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Burns; Wendell E.
Claims
I claim:
1. An intake manifold of a fuel injection system of an internal
combustion engine comprising a main throttle valve chamber open to
the atmosphere, a main throttle valve mounted in said main throttle
valve chamber and operated by an accelerator pedal, an air chamber
communicating with said main throttle valve chamber downstream of
said throttle valve, a plurality of branches leading from said air
chamber to respective cylinders of the engine, an auxiliary
throttle valve chamber open to the atmosphere and communicating
with said air chamber at a position spaced from said main throttle
valve chamber, an auxiliary throttle valve mounted in said
auxiliary throttle valve chamber, means responsive to the speed of
the engine and auxiliary-throttle-valve-actuating means connected
with said main throttle valve and with said speed responsive means
for opening said auxiliary throttle valve only when said main
throttle valve is open not less than a selected amount and when the
engine speed exceeds a selected value.
2. An intake manifold according to claim 1, wherein the value of
engine speed above which said auxiliary throttle valve is opened by
said actuating means is the value at which the engine torque with
said auxiliary valve closed reaches a maximum value.
3. An intake manifold according to claim 1, wherein said actuating
means operates to open said auxiliary throttle valve fully when
said main throttle valve is open not less than said selected amount
and the engine speed reaches said selected value.
4. An intake manifold according to claim 1, wherein said actuating
means operates to open said auxiliary throttle valve progressively
when said main throttle valve is open not less than a selected
amount and the engine speed goes above said selected value.
5. An intake manifold according to claim 1, wherein one said
throttle valve chamber communicates with said air chamber at one
end thereof and the other said throttle valve chamber communicates
with said air chamber intermediate its ends.
6. An intake manifold as set forth in claim 1, wherein said air
chamber is connected with the main throttle valve chamber at one
end thereof and said auxiliary throttle valve chamber is connected
with the other end thereof.
7. An intake manifold as set forth in claim 1, wherein said
branches are formed straight whereby the intake air tends to be
accelerated by the intake vacuum in the cylinder and then tends to
enter the cylinder abruptly.
8. An intake manifold as set forth in claim 1, wherein said
actuating means is a control device for mechanically opening and
closing the auxiliary throttle valve and including an angled lever
pivotally connected to the vehicle body and having two arms one of
which is connected with said main throttle valve to cause said
lever to be interconnected with the main throttle valve, a first
lever pivotally connected with the vehicle body at one end and
connected at an intermediate point with the other arm of said
angled lever to cause the first lever to be interconnected with the
angled lever and a roller mounted at the other end of said first
lever, a centrifugal governor driven by the engine and having a
plurality of weights, a plurality of angled levers each connected
at one end with the weight, a first rod having a disc fixed at one
end thereof and engaged at one surface with the other ends of the
angled levers and inserted at the other through a first hole formed
in the vehicle body, a spring so disposed between the disc of the
rod and the vehicle body as to press the disc against the
centrifugal force of the weights applied to the other surface of
the disc, a second lever supported at an intermediate point by the
vehicle body and interconnected with the auxiliary throttle valve
at one end, a second rod slidably inserted into a second hole
formed in the vehicle body and connected at one end with the other
end of the second lever, a third lever pivotally supported at an
intermediate portion by said roller on the first lever and
connected at one end with the other end of the second rod and with
a second spring which is fixed at one end to the vehicle body for
biasing the second lever and engaged with the end of the first rod
at the other end, said intermediate portion of said third lever
being so formed with a recess as to move the auxiliary throttle
valve in response to the movement of the main throttle valve and
engine speed, and a stop for limiting the movement of the third
lever.
9. An air intake manifold as set forth in claim 1, wherein said
actuating means comprises a control device for electrically opening
and closing the auxiliary throttle valve and including an
accelerator switch connected with the accelerator pedal
interconnected with the main throttle valve to operate to open or
close its contact in response to the opening of the main throttle
valve so that when the main throttle valve fully opens or
substantially opens the contact of the switch closes, a generator
for generating a voltage proportional to the engine speed, a
control relay, a voltage control device for energizing said relay
when the engine speed reaches a predetermined speed so that the
generator generates a voltage corresponding to the predetermined
engine speed and accordingly the contact of the relay closes by the
energization of the voltage control device, a solenoid connected
with the auxiliary throttle valve and energized when the main
throttle valve fully opens or substantially opens, and an electric
power source for energizing the solenoid through said switch and
relay.
Description
This invention relates to an intake manifold for fuel injection
system of an internal combustion engine more particularly to such
manifold employing in addition to a main throttle valve an
auxiliary throttle valve.
There generally exist two types of intake manifold for fuel
injection system of an internal combustion engine; one
single-throttle valve type and the other plural-throttle valve type
which has a plurality of throttle valves. In practice, the
single-throttle valve type is mostly utilized because it is less
expensive, easy to operate its accelerator pedal and also easy to
meter the amount of intake air.
In the conventional air intake manifold for fuel injection system
of an internal combustion engine, an air chamber is provided
posteriorly of the throttle valve so that the air is introduced
through individual air branches or passages to the respective
cylinders or combustion chambers of the engine so as to reduce the
suction resistance of the intake air and also to improve the
performance of the engine by utilizing the suction inertia of the
air.
In such a conventional intake manifold for fuel injection system
such as, for example, the intake manifold for four-cycle
four-cylinder engine in which the firing order is from the first,
then third, fourth to second cylinders, the air intake operation is
achieved in this order at the interval of crank angle of
180.degree. so that there exists overlap in air intaking operations
between the first and third, between the third and fourth, between
the fourth and second, and between the second and first cylinders
excepting between the first and fourth, and between the second and
third cylinders.
Though the interference of intake air of the adjacent cylinders
does not occur even if the period of air intaking operations
between the adjacent cylinders is overlapped in case the volume of
the air chamber is large enough, it is impossible to provide such a
large air chamber in the actual engine with the result that the
interference of intake air of the adjacent cylinders cannot be
avoided because the normal volume of the conventional air chamber
is approximately half that of the engine cylinder volume.
This interference of the intake air of the adjacent cylinders
introduces at low engine speed maximum torque in the engine
operation due to the effect of the apparent suction inertia and at
intermediate and high speeds a lower torque due to the disturbance
of the true suction inertia corresponding to the length of the air
branches.
This invention contemplates eliminating the aforementioned
disadvantages of the conventional intake manifold for fuel
injection system and provides an air intake manifold for fuel
injection system of an internal combustion engine which has in
addition to the main throttle valve an auxiliary throttle valve
communicating with the atmosphere for removing the suction
interference, and in which the suction inertia effect of the intake
manifold contributes to the improvement of the engine torque by
operating the auxiliary throttle valve in relation to the opening
of the main throttle valve and engine speed.
The features and advantages of the present invention will become
apparent from the following description taken in conjunction with
the accompanying drawings, in which:
FIG. 1 is a schematic diagram of an arrangement of intake manifold
with its related parts as one example of the present invention;
FIGS. 2, 3 and 4 are graphical representations of the relationship
between the engine speed and torque when the intake manifold of the
present invention is used;
FIG. 5 is a plan view of the intake manifold of another example of
the present invention;
FIG. 6 is a sectional view of the intake manifold taken along the
line VI-VI shown in FIG. 5;
FIG. 7 is a schematic view of a control device for mechanically
opening and closing the auxiliary throttle valve in accordance with
the present invention;
FIG. 8 is a schematic view of another control device for
mechanically opening and closing the auxiliary throttle valve
according to the present invention;
FIG. 9 is an operational graph showing the opening of the auxiliary
throttle valve in relation to the engine speed shown in FIG. 8;
FIG. 10 is a schematic view of an electric control device for
opening and closing the auxiliary throttle valve in accordance with
the present invention;
FIG. 11 is a schematic view of another example of an electric
control device shown in FIG. 10;
FIG. 12 is an operational graph showing the opening of the
auxiliary throttle valve in relation to the engine speed shown in
FIG. 11;
FIGS. 13A and 13B are graphs showing the relationship between the
air pressure wave forms and time of the conventional air intake
manifold; and
FIGS. 13C and 13D are graphs showing the relationship between the
air pressure wave forms and time of the air intake manifold
constructed in accordance with the present invention.
In FIG. 1, the arrangement of the intake manifold with its related
parts as one embodiment of the present invention for an internal
combustion engine 10 having a fuel injection pump 11 driven at half
of engine speed for injecting the fuel from a plurality of nozzles
12 into an intake hole 13 of a cylinder 14 by being controlled or
measured in response to the opening of a main throttle valve 15 for
controlling the amount of intake air and the engine speed, is shown
as comprising an air cleaner 16 for admitting and filtering
atmospheric air, a throttle valve chamber 17 connected with the air
cleaner 16 and having the throttle valve 15 connected with an
accelerator pedal 18, an air chamber 19 connected with the throttle
valve chamber 17 at one end, and a plurality of individual branches
or passages 20, 21, 22 and 23 each connecting the air chamber 19
with a cylinder 14 of the engine 10. The intake manifold further
comprises an auxiliary throttle valve chamber 24 connected with the
other end thereof and having an auxiliary throttle valve 25, and an
air cleaner 26 connected with the auxiliary throttle valve chamber
24 for venting admitting and filtering atmospheric air to be fed to
the air chamber 19 through the auxiliary throttle valve chamber 24.
In this arrangement thus constructed, the air branches 20, 21, 22
and 23 are straight so that suction inertia, that is, the action
that the weight of the intake air tends to be accelerated by the
intake vacuum in the cylinder in the air branches and then tends to
enter the intake valve abruptly, is provided, and the air branches
20, 21, 22 and 23 are connected anteriorly thereof with the air
chamber 19 connected with the throttle valve chamber 17 having the
throttle valve 15, and are connected posteriorly thereof with the
intake port for a suction valve (not shown).
In consideration again of the conventional arrangement of the air
intake manifold with reference to FIG. 13A, the air chamber is
common to the respective cylinder for supplying the suction inertia
and cannot actually be enlarged to a sufficient size with the
result that there occurs pressure fluctuation therein so that this
fluctuation is added to the suction inertia to cause the apparent
inertia to be increased while this apparent inertia is reduced at
the desired engine speed. It means that as seen in FIG. 13A, since
the pressure p of the intake port when the intake valve of the
first cylinder closes at low engine speed corresponds with the
crest of the inner pressure q within the air chamber produced due
to the effect of the suction interference of the third cylinder
adjacent to the first cylinder in the firing order, the pressure p
increases at low engine speed. On the other hand, as shown in FIG.
13B at intermediate and high engine speed since the time when the
intake valve closes corresponds with the valley of the pressure q,
the pressure p is decreased so much that as illustrated by the
solid line in the graph shown in FIG. 2 the torque is lowered due
to the reduction of the volumetric efficiency, because the pressure
wave form is delayed with respect to the time of the opening of
intake valve with increasing engine speed due to the inertia of the
air. In other words, the intake valve opens earlier with respect to
the pressure wave form with the result that a negative effect
occurs. However, the intake manifold of the present invention
comprises the auxiliary throttle valve chamber 24 connected with
the other end thereof with respect to the main throttle valve
chamber 17 and having the auxiliary throttle valve 25, and the air
cleaner 26 connected with the auxiliary throttle valve chamber 23
for admitting and filtering the atmospheric air to be fed to the
air chamber 19 through the auxiliary throttle valve chamber 14
wherein the engine performance is improved by the control of the
auxiliary throttle valve 15 in accordance with the invention.
If the auxiliary throttle valve 25 is substantially closed during
the full load or substantially full load operation of the engine,
the torque of the engine is as shown by a solid line in FIG. 2, as
previously described the maximum torque is produced in the engine
due to the positive effect of the suction interference at low
engine speed while at intermediate and high engine speed the torque
of the engine decreases due to the negative effect of the suction
interference. However, if the auxiliary throttle valve 25 is fully
opened so that the air chamber 19 communicates with the atmosphere
through the auxiliary throttle valve 25 in the auxiliary throttle
valve chamber 24 and air cleaner 26, as seen in FIGS. 13C and 13D
the pressure within the air chamber does not substantially change
and accordingly the suction interference is removed with the result
that though the torque of the engine decreases at low engine speed,
the true suction inertia is effected to a maximum extent so that
the torque of the engine becomes as shown by a broken line in FIG.
2 and accordingly the torque of the engine is improved at
intermediate and high engine speed.
Referring now to FIG. 3, which shows a graphical representation of
the relationship between the torque and the engine speed in case of
using the intake manifold of the present invention, the engine
speed when the torque of the curve 27 is maximum as the auxiliary
throttle valve 25 is fully closed is designated by n.sub.1 and the
engine speed when the torque of the curve 28 is maximum as the
auxiliary throttle valve 25 is fully open is designated by n.sub.2,
and if the auxiliary throttle valve 25 is gradually opened from
fully closed state to fully open state between the engine speeds
n.sub.1 and n.sub.2, the combination of the suction interference
and the suction inertia effects introduces the torque curve
designated by 29 in FIG. 3. Accordingly, if the auxiliary throttle
valve 25 is fully closed until the engine speed becomes n.sub.1,
then the auxiliary throttle valve 25 is gradually opened from fully
closed to fully opened with the engine speed being increased from
n.sub.1 to n.sub.2, and then the auxiliary throttle valve 25 is
kept fully opened, the torque curve is improved by the shaded area
designated by 30.
In this case, if the air branches 20, 21, 22 and 23 are shortened
and the torque characteristics of the engine when the auxiliary
throttle valve 25 is fully opened is of high-speed type, the torque
and maximum power of the engine is further improved in intermediate
and high speeds.
Referring now to FIG. 4, which shows graphical representation of
the relationship between the torque and the engine speed in case of
using the intake manifold of the present invention, if the engine
speed corresponding to the cross point between the torque curve 31
when the auxiliary throttle valve 25 is fully closed and the torque
curve 32 when the auxiliary throttle valve 25 is fully opened is
designated by n and the auxiliary throttle valve 25 is abruptly
opened to full position from fully closed position at this engine
speed n, the engine torque becomes as designated by the torque
curve 31 when the auxiliary throttle valve 25 is fully closed until
the engine speed n and the engine torque becomes as designated by
the torque curve 32 when the auxiliary throttle valve 25 is fully
opened over the engine speed n, the engine torque is improved by
the area designated by 33.
In this case, if the manifold branches 20, 21, 22 and 23 are
shortened and the torque characteristics of the engine when the
auxiliary throttle valve 25 is fully opened is of intermediate
speed type, the torque of the intermediate speed is further
improved.
Referring now to FIGS. 5 and 6, which show another embodiment of
the intake manifold of the present invention, the auxiliary
throttle valve chamber 25 may be mounted on an intermediate portion
of the intake manifold 19.
In the embodiment of FIGS. 5 and 6, the locations of the main
throttle and the auxiliary throttle may be interchanged, the
auxiliary throttle being located at one end of the intake manifold
and the main throttle being at an intermediate position.
The embodiment shown in FIGS. 5 and 6 may cause the same effect as
the first embodiment shown in FIG. 1.
The operation of the auxiliary throttle valve 25 may be
mechanically or electrically controlled by detecting the engine
speed by means of a centrifugal governor, the amount of the suction
air, the voltage generated by the generator, lubrication oil
pressure or coolant pressure when the main throttle valve 15 opens
over a predetermined degree. Two embodiments of the control of the
auxiliary throttle valve 25 will hereinafter be described.
Reference is now made to FIG. 7, which shows a control device for
mechanically opening and closing the auxiliary throttle valve in
accordance with the present invention. The control device comprises
a link 18a pivotally connected at one end with the accelerator 18,
an angled lever 18b fixedly connected with the throttle valve and
having one arm pivotally connected with the other end of the link
18a, and another link 18c pivotally connected with the other arm of
the angled lever 18b, a lever 18d fixedly connected with the
auxiliary throttle valve 25 and pivotally connected with the other
end of the other link 18c.
Referring now to FIG. 8, which shows a control device for
mechanically opening and closing the auxiliary throttle valve in
accordance with the present invention, the mechanical control
device 40 comprises an angled lever 41 pivotally connected to the
vehicle body 42 and having two arms 43 and 44. One arm 43 is
connected with the main throttle valve 15 by a link 43a to cause
the one arm 43 to be interlocked with the main throttle valve 15. A
first lever 45 is pivotally connected with the vehicle body 42 at
one end and is connected at an intermediate point with the other
arm 44 of the angled lever 41 by a link 44a to cause the lever 45
to be interlocked with the angled lever 41. The lever 45 also has a
roll support 46 rotatable mounted at the other end thereof. A
centrifugal governor 47 driven by the engine has a plurality of
weights 48, a plurality of angled levers 49 each connected at one
end with the weight 48, a first rod 50 having a disc 51 fixed at
one end thereof and engaged at one surface with the other ends of
the angled levers 49 and inserted at the other end through a first
hole 52 formed in the vehicle body 42. A spring 53 is so disposed
between the disc 51 of the rod 50 and the vehicle body as to press
the disc 51 against the centrifugal force of the weight applied to
the other surface of the disc from the surface applied by the
tension of the spring 53 supported on the vehicle body 42. A second
lever 54 supported at an intermediate point by the vehicle body 42
is interlocked with the auxiliary throttle valve 25 at one end by a
link 54a. A second rod is slidably inserted into a second hole 56
formed in the vehicle body 42 and is connected at one end with the
other end of the lever 54. A third lever 57 is supported at an
intermediate position by the roll support 46 rotatably mounted on
the first lever 45 and is connected at one end with the other end
of the rod 55 and with a second spring 58 which is fixed at one end
to the vehicle body 42 for pressing the lever 57 rightwardly in the
drawing. The other end of the lever 57 is engaged with the end of
the rod 50 of the governor. The third lever 57 is formed with a cam
recess 57a as to move the auxiliary throttle valve 25 in response
to the movement of the main throttle valve 15 and engine speed. A
stop 59 is provided for limiting the movement of the third lever
57.
In operation of the device thus constructed, the main throttle
valve 15 is interlocked with the lever 45 through the angled lever
41 so that when the main throttle valve 15 is fully opened or
substantially opened the lever 57 is contacting with the roller 46
of the lever 45 but when the main throttle valve 15 is not fully
opened nor substantially opened the lever 57 is not contacting with
the roller 46. If the main throttle valve 15 is fully opened or
substantially opened, when the engine speed increases, the rod 50
moves rightwardly in the drawing by the operation of the
centrifugal governor 47 so that when the engine speed reaches
n.sub.1 the rod 50 contacts with the lever 57 at one end and
accordingly the other end of the lever 57 is rocked around the roll
support 46 at the center of the lever 57 to cause the other end of
the lever 57 to move leftwardly in the drawing against the tension
of the spring 58 and accordingly the auxiliary throttle valve 25 is
gradually opened through the rod 56 connected with the other end of
the lever 57 and the lever 54 connected at one end with the other
end of the rod 55 and interlocked at the other end with the
throttle valve 25. In this case, the tension of the spring 53 in
the centrifugal governor 47 is so determined as to fully open the
auxiliary throttle valve 25 when the engine speed reaches n.sub.2
and the stop 59 is so disposed as to stop the lever 57 at one end
when the engine speed exceeds the speed n.sub.2. Thus, the area
designated by 30 in graph shown in FIG. 3 is improved by the
opening operation of the auxiliary throttle valve 25. The opening
of the auxiliary throttle valve 25 is shown in the graph
illustrated in FIG. 9.
Referring now to FIG. 10, which shows a control device for
electrically opening and closing the auxiliary throttle valve in
accordance with the present invention, the electrical control
device 60 comprises an accelerator switch 61 connected with the
accelerator pedal 18 interlocking with the main throttle valve 15
to operate to open or close its contact in response to the opening
of the main throttle valve 15 so that when the main throttle valve
15 fully opens or substantially opens the contact of the switch 61
closes while when the main throttle valve 15 does not fully open
nor substantially open the contact of the switch 61 opens. The
output of a generator 62 for generating a voltage proportional to
the engine speed to detect the engine speed is connected to a
voltage control device 63 for energizing a relay 64. When the
engine speed reaches a valve n so that the generator 62 generates a
voltage V corresponding to the engine speed n, the contact of the
relay 64 closes by the energization of the voltage control device
63. A solenoid valve 65 connected with the auxiliary throttle valve
25 is energized from an electric power source 66 when the main
throttle valve 15 fully opens or substantially opens, and the
engine speed has reached a valve n so that the relay 64 is
closed.
In operation of the device thus constructed, when the main throttle
valve 15 fully opens or substantially opens by the depression of
the accelerator pedal 18, the contact of the switch 61 is closed
and when the engine speed reaches the speed n so that the relay 64
is energized by the voltage generated at the generator 62 through
the voltage control device 63 to cause the contact of the relay 64
to be closed with the result that the solenoid valve 65 is
energized from the source 66 through the contact of the switch 61
and the contact of the relay 64 and accordingly the auxiliary
throttle valve 25 is abruptly opened as shown in the graph in FIG.
12. Thus, the area designated by 32 in graph shown in FIG. 4 is
improved thereby in the opening operation of the auxiliary throttle
valve 25.
Referring now to FIG. 11, the electrical control device 60 may
comprise the accelerator switch 61 connected with the accelerator
pedal 18 interlocking with the main throttle valve 15 to operate to
open or close its control its contact in response to the opening of
the main throttle valve 15, a relay 64 having a relay coil 64a
electrically connected between the accelerator switch 61 and the
ground and a contact 64b to be contacted when the relay coil 64a is
energized by the accelerator switch 61 the solenoid valve 65
electrically connected with the contact 64b of the relay 64 and to
be energized to let the auxiliary throttle valve 25 to fully open
when the relay 64 is energized by the accelerator switch 61 wherein
when the main throttle valve 15 is fully opened the accelerator
switch 61 becomes ON.
In the thus constructed control device 61, when the main throttle
valve 15 fully opens, the auxiliary throttle valve 25 is always
opened with the result that the torque curve designated by a broken
line in FIG. 2 is obtained. It means that while the main throttle
valve 15 fully opens the auxiliary throttle valve 25 fully opens in
all range of the engine speed.
The main throttle valve 15 may be directly connected mechanically
with the auxiliary throttle valve 25 wherein the amount of the
intaken air is controlled by both the main and auxiliary throttle
valves 15 and 25 so that both the valves 15 and 25 may be fully
opened. Thus, the torque curve designated by the broken line in
FIG. 2 may also be obtained.
* * * * *