U.S. patent number 3,578,116 [Application Number 04/775,239] was granted by the patent office on 1971-05-11 for device for selective combustion in a multicylinder engine.
This patent grant is currently assigned to Nissan Jidsha Kabrishiki Kaisha. Invention is credited to Yoshimasa Hayashi, Yasuo Nakajima.
United States Patent |
3,578,116 |
Nakajima , et al. |
May 11, 1971 |
DEVICE FOR SELECTIVE COMBUSTION IN A MULTICYLINDER ENGINE
Abstract
A device for saving fuel and cleansing exhaust gas in a
multicylinder automobile engine, by interrupting fuel supply to
selected cylinders of the engine during deceleration and coasting
of the automobile. The device comprises valves mounted in the
selected cylinders of the engine, a pressure-sensing means to sense
the negative pressure at the intake manifold of the engine, and a
connecting means to operatively connect said pressure-sensing means
to said valves. The valves are closed by the pressure-sensing means
when the negative pressure at the engine intake manifold exceeds a
certain predetermined level due to deceleration or slow running of
the automobile.
Inventors: |
Nakajima; Yasuo (Yokohama,
JA), Hayashi; Yoshimasa (Yokohama, JA) |
Assignee: |
Nissan Jidsha Kabrishiki Kaisha
(Yokohama City, JA)
|
Family
ID: |
11572333 |
Appl.
No.: |
04/775,239 |
Filed: |
November 13, 1968 |
Foreign Application Priority Data
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Jan 25, 1968 [JA] |
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43/3986 |
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Current U.S.
Class: |
477/90; 123/321;
123/198F |
Current CPC
Class: |
F02M
3/04 (20130101); F02D 17/04 (20130101); Y10T
477/6433 (20150115); F02B 1/04 (20130101) |
Current International
Class: |
F02M
3/04 (20060101); F02D 17/00 (20060101); F02D
17/04 (20060101); F02M 3/00 (20060101); F02B
1/04 (20060101); F02B 1/00 (20060101); F16d
021/04 (); F02d 009/00 () |
Field of
Search: |
;123/198 (F)/ ;123/97
(B)/ ;192/.062 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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771,649 |
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Mar 1957 |
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GB |
|
651,837 |
|
Nov 1962 |
|
CA |
|
653,400 |
|
Dec 1962 |
|
CA |
|
Primary Examiner: Burns; Wendell E.
Claims
We claim:
1. A device for saving fuel and cleansing the exhaust gas in a
multicylinder automobile engine having at least one intake manifold
and a carburetor means communicating therewith, and a plurality of
branch passages communicating said intake manifold with the engine
cylinder inlets, said apparatus comprising, a plurality of
butterfly valves mounted in selected branch passages for isolating
the engine cylinders connected thereto from said intake manifold, a
first spring means biasing said butterfly valves to an open
position, a first piston and cylinder assembly for closing said
butterfly valves, connecting means connecting said butterfly valves
with said first piston, a conduit means having one end thereof
communicating with said intake manifold between said carburetor
means and said butterfly valves and the other end thereof in
communication with said first piston and cylinder assembly on that
side of said first piston opposite said connecting means to
communicate negative pressure from said intake manifold to said
first piston to close said butterfly valve, the second piston and
cylinder assembly connected in said conduit means, said second
cylinder having a port therein communicating with the ambient
atmosphere, said second piston having a first position for
communicating said conduit with said first cylinder and a second
position for blocking said conduit and connecting said port with
said first cylinder, and a second spring means for biasing said
second piston to said second position, and sensing means responding
to a coasting condition of the vehicle for moving said second
piston to said first position, whereby, when the vehicle is
coasting and the intake manifold vacuum is sufficient to overcome
the biasing force of said second spring means, said conduit is
communicated with said first piston and cylinder assembly to
actuate said first piston and positively close said butterfly
valves to prevent the selected engine cylinders from receiving a
fuel mixture supply.
2. A device for saving fuel and cleansing the exhaust gases of a
multicylinder engine as claimed in claim 1 further comprising, an
opening in said selected branches of said intake manifold for
communicating said selected cylinders with the ambient atmosphere,
said opening positioned in said selected branches between the
butterfly valves and the engine cylinder inlets, and a valve means
having a first position for blocking said openings and a second
position for allowing the ambient air to enter said openings, said
valve means normally biased to said first position and being
controlled by said connecting means to open said opening when said
first piston is actuated.
3. Apparatus claimed in claim 1 wherein one end surface of said
second piston is communicated with said conduit and the other end
surface of said second piston being open to communicate with
atmospheric pressure, whereby said second piston is urged to said
first position by the pressure difference at both end surfaces
prevailing at a coasting condition of the vehicle.
4. Apparatus for saving fuel and cleansing exhaust gas in a
multicylinder vehicle engine having at least one intake manifold
with a carburetor means and a plurality of branches communicating
engine cylinder inlets with the manifold, said apparatus
comprising,
a. a plurality of valves mounted in selected branches and operable
to isolate selected engine cylinders from said manifold, first
spring means biasing said valves to an open position, a first
piston and cylinder assembly, connecting means connected between
said valves and said first piston for operating said valves, said
first cylinder slidably accommodating said first piston, and
conduit means connected between said manifold and said first
cylinder to communicate negative pressure to one end surface of
said first piston means to close said valves,
b. a second cylinder communicating with said conduit means and
having a port communicating with said first cylinder, a second
piston slidably accommodated in said second cylinder and adapted to
establish communication between said first cylinder and said
conduit in one position and to interrupt said communication in a
second position, and second spring means biasing said second piston
to said second position,
c. a solenoid valve means connected to said second cylinder means
and operably connected to said second piston to urge said second
piston to said one position when said solenoid valve is
actuated,
d. sensing means responding to a coasting condition of the vehicle
for actuating said solenoid valve, whereby said selected engine
cylinders receive decreased fuel mixture supply to improve
combustion when the vehicle is coasting.
5. Apparatus as claimed in claim 4 wherein said sensing means
comprises a negative manifold pressure sensing means including a
vacuum switch connected to said solenoid valve and operably
connected to said intake manifold for energizing said solenoid
valve when said vehicle is coasting.
6. Apparatus as claimed in claim 4, wherein said sensing means
comprises, a clutch pedal actuated switch, said switch being closed
when a clutch pedal of said vehicle is in the clutch-engaging
position, an accelerator actuated switch, said switch being closed
when an accelerator pedal of said vehicle is in the engine idle
position, and a transmission gearshift neutral switch, said neutral
switch being closed when a transmission of said vehicle is in a
driving gear position, said clutch pedal switch, said accelerator
pedal switch and said transmission gear switch being connected in
series with said solenoid valve to actuate said solenoid when said
switches are closed simultaneously.
7. Apparatus as claimed in claim 6 further comprising, a manual
switch shunting said clutch switch, accelerator switch and gear
neutral switch.
Description
The present invention relates to an apparatus for saving fuel and
cleansing the exhaust gas in a multicylinder vehicle engine having
at least one intake manifold with a carburetor means and a
plurality of branches communicating engine cylinder inlets with the
manifold.
Generally speaking, when a vehicle having a gasoline engine is
coasting, the mixture of fuel and air fed to the engine does not
burn completely in the combustion chamber, resulting in a discharge
of a large amount of hydrocarbons from the engine exhaust to the
atmosphere, and the increase in the hydrocarbon discharge causes
air contamination.
The reason for incomplete combustion of the supply gas mixture in
the combustion chamber during coasting is due to the fact that the
intake amount of air in the supply gas mixture decreases and a
large amount of residual gas stays in the combustion chamber during
the coasting, so that either ignition fails or the barely ignited
combustion dies out without spreading through the combustion
chamber. This is one of the problems related to the fundamental
structure of internal combustion engines, and the only way to
effectively burn the supply gas mixture in the combustion chamber
under such conditions is to increase the intake amount of the
supply gas mixture to the combustion chamber.
A known method of preventing air contamination is to retard the
spark advance during idling, and to keep the engine-revolving speed
at a comparatively high level, so as to improve the fuel combustion
in the combustion chamber as far as possible. With a high revolving
speed, the idling throttle valve opening is increased to allow a
large intake amount of the supply gas mixture during the
deceleration. However, such method has a disadvantage in that the
throttle valve cannot be opened widely due to the danger of
overheating and the occurrence of run-on phenomenon.
An object of the present invention is to obviate the aforesaid
difficulties of the known air contamination preventing devices, by
providing an improved device for effectively preventing the air
contamination and at the same time reducing the fuel consumption.
The operative principles of the device according to the present
invention are as follows.
When the degree of throttle valve opening of an automobile engine
is kept constant during idling, then the intake amount of the
supply gas mixture during coasting of the automobile becomes
constant. Under such conditions, if the intake of the supply gas
mixture to one half of the cylinders of the automobile engine is
interrupted by providing suitable valves in those cylinders, while
the supply gas mixture is burnt in the remaining half of the
cylinders, then, such remaining cylinders receive an amount of the
supply gas mixture twice as much in volume as in the case of
feeding the mixture to all the cylinders, so that the combustion in
the remaining half of the cylinders is improved. For instance, with
an engine adapted to burn the supply gas mixture at a speed up to
1,500 r.p.m. during deceleration, that is in coasting condition, it
is possible to burn the supply gas mixture in the engine at a speed
up to 3,000 r.p.m. by limiting the fuel supply to only one half of
the cylinders.
Another object of the present invention is to fulfill the function
of preventing air contamination without sacrificing the
effectiveness of the engine-braking action, as experienced in the
case of known device controlling the negative pressure at the
intake manifold, and without causing any mechanical shocks as
experienced with a known device limiting fuel shut off.
For a better understanding of the invention, reference is made to
the accompanying drawings, in which:
FIG. 1 is a partial sectional plan view of the inlet pipe of a
four-cylinder-type engine with a device according to the present
invention, shown with a carburetor removed therefrom;
FIG. 2 is a schematic composite vertical sectional view, prepared
by combining a section at the line II-II and another section at the
line II'-II' of FIG. 1;
FIG. 3 is a sectional view of another embodiment of the present
invention, having an electric control circuit;
FIG. 4 is a diagrammatic illustration of another embodiment of the
invention; and
FIG. 5 is a schematic sectional view of an electric switch usable
in the embodiment of FIG. 4.
Same parts and members are designated by same numerals and symbols
throughout the drawings.
Referring to FIGS. 1 and 2, a carburetor 1, having venturies 2 and
throttle valves 3, is connected to an intake manifold 4 with
branches 5, 6, 7, and 8. FIG. 1 illustrates an engine with four
cylinders, but the number of cylinders is not limited to four, but
any other number of plural cylinders can be used. The dash-dot
lines 9 of FIG. 2 represent a cylinder head.
In the device according to the present invention, butterfly valves
10 are mounted on branches 6 and 7, in such a manner that the
butterfly valves are rotatable around the shafts 11 secured to the
intake manifold across the branches. An arm 12 is secured to the
shaft 11. In the particular embodiment of the device of the present
invention, as depicted in FIGS. 1 and 2, one end of a pipe 13 is
connected to open in the wall of the intake manifold 4 at a
position of upstream of the butterfly valves 10, and the opposite
end of the pipe 13 is communicated with a cylinder 15 having a
piston 14 slidably fitted therein. The piston 14 has a hollow
chamber 14a formed inside thereof and communicated with the pipe
13, through-holes 14b communicating the hollow chamber 14a to the
outside of the piston 14, and an annular recess 14c formed on the
outer periphery of the piston 14. The cylinder 15 has an annular
recess 15a formed on the inner peripheral surface thereof. A port
16 is bored at the bottom of the annular recess 15a so as to
communicate the inside of the cylinder 15 with another cylinder 20
to be described later. The cylinder 15 has an additional opening 17
bored in the proximity of the annular recess 15a, a stop ring 18
fitted on the inner surface of the cylinder 15 at the right-hand
end thereof for stopping the piston 14, and a spring 19 fitted
between the left-hand end of the cylinder 15 and the left-hand end
of the piston 14, as shown in FIG. 2.
The cylinder 20 is connected to the aforesaid cylinder 15 in such a
manner that the port 16 communicates with the two cylinders 15 and
20. A piston 21 slidably fitted in said other cylinder 20 has a
piston rod 22, which is connected to the free end of said arm
through a link 23. A spring 24 is engaged with the arm 12 to force
the arm 12 to a counterclockwise direction and the link 23
downwards, as seen in FIG. 2.
The branches 6, 7 have holes 25 bored thereon at positions between
the respective butterfly valves 10 and the cylinder head 9. The
holes 25 of the branches 6 and 7 are communicated with each other
through a tube 26. A short open tube 27 is connected to the tube 26
so as to communicate the inside of the tube 16 with the atmosphere.
A valve lever 28 is pivotally supported by the branch passage
portion 7 by means of a pin 29, to selectively close and open the
upper end opening of the open tube 27. A projection 30 is secured
to the piston rod 22 in such a manner that when the butterfly valve
10 is closed, the projection 30 raises the free end of the valve
lever 28 to open the upper end opening of the tube 27. A packing 31
is mounted on that portion of the valve lever 28 where the hole 27
engages the valve lever 28, and a spring 32 engages the valve lever
28 so as to bias the valve lever 28 toward the lowered position, as
seen in FIG. 2, for keeping the open tube 27 closed.
The operation of the device of the present invention, having the
aforesaid construction, will now be described. The solid lines in
FIGS. 1 and 2 illustrate the device under the conditions when the
automobile is neither decelerating nor coasting.
In other words, when the automobile is in conditions other than
deceleration and coasting, the negative pressure at the engine
intake manifold, which acts on the piston 14 through the pipe 13,
is so low that the elasticity of the spring 19 surpasses the
negative pressure, and hence, the piston 14 assumes the position as
illustrated in FIG. 2. Thus, the space A in the cylinder 20 above
the piston 21 communicates with the atmosphere through the port 16
and the hole 17. Accordingly, the link 23 is kept at the lower
position by the spring 24 and the butterfly valve 10 remains
open.
Then, let it be assumed that the throttle valves 3 of the
carburetor 1 are closed. The negative pressure at the intake
manifold now increases and forces the piston 14 leftwards against
the elasticity of the spring 19, as seen in FIG. 2. When the piston
14 has moved to the left-hand position, the communication between
the opening 17 and the port 16 of the cylinder 15 is interrupted by
closing the opening 17 with the nonrecessed surface of the piston
14, and at the same time, the through-holes 14b of the piston 14
becomes to face the annular recess 15a formed on the inner surface
of the cylinder 15, and hence, the hollow chamber 14a of the piston
14 communicates with the space A above the piston 21 through the
holes 14b, the annular recess 15a, and the port 16. Accordingly,
the thus increased negative pressure at the intake manifold is
delivered to the space A, so as to pull up the piston 21. As a
result of it, the arm 12 rotates clockwise, as shown by the arrow B
in FIG. 2, through the piston rod 22 and the link 23, so as to
close the butterfly valves 10, as shown by dash-dot lines. Thus,
the supply gas mixture is absorbed only by the cylinder branches 5
and 8 having no butterfly valves 10, so that the amount of the
supply gas mixture to the branches 5 and 8 is considerably
increased and the combustion conditions in the engine is greatly
improved.
In the embodiment, as shown in FIGS. 1 and 2, the downstream side
space of the butterfly valves 10 is communicatable with the
atmosphere through the holes 25, the tube 26, and the short open
tube 26 blockable by the valve lever 28. The projection 30 secured
to the piston rod 22 connected to the piston 21 engages the free
end of the valve lever 28 upon the closure of the butterfly valve
10, so that the valve lever 28 turns clockwise against the
elasticity of the spring 32, as seen in FIG. 2, to deblock the
short tube 27. As a result of it, the atmospheric pressure enters
into the back of the butterfly valves 10 through the short tube 27,
the tube 26, and the holes 25. Thus, the pressure at the back of
the butterfly valves 10 increases to insure the complete
interruption of the supply gas mixture by stopping the leakage
through fine gaps around outer periphery of the butterfly valves
10. Furthermore, the air delivered to the back of the butterfly
valves 10 through the holes 25 proceeds to the exhaust tube and
acts to oxidize the incompletely burnt hydrocarbons contained in
the exhaust gas to convert them into harmless carbon dioxide gas.
Thereby, the cleansing effect of the exhaust gas is further
improved.
FIG. 3 shows another embodiment of the device according to the
present invention, in which an electric control means is
incorporated. The electric control means comprises a vacuum switch
33 to sense the negative pressure at the intake manifold of an
automobile engine, a solenoid valve 34 whose solenoid is connected
in series with said vacuum switch 33, power source batteries BT
connected in series with the series-connected vacuum switch 33 and
the solenoid valve 34, and a manual switch 35 connected across the
vacuum switch 33. The performance characteristics of the vacuum
switch 33 is such that when the automobile is decelerated to reduce
the negative pressure at the engine intake manifold, a diaphragm 36
is deflected downwards against the elasticity of a spring 37, as
seen in FIG. 3, and accordingly, an actuating rod 38 is pulled
downwards to close a contact 39. Thereby a circuit is completed,
which traces from one terminal of the batteries BT, through the
thus closed contact 39 of the vacuum switch 33 and a solenoid 40 of
the solenoid valve 34, and back to the opposite end of the
batteries BT.
As a result of it, a current flows through the solenoid 40, to pull
an armature 41 rightwards against the elasticity of a spring 42, as
seen in FIG. 3. Thus, the solenoid valve 34 is opened and the space
A above a piston 21 is communicated with the branch 7 through the
thus opened solenoid valve 34, so that a butterfly valve (FIGS. 1
and 2) can be closed in the same manner as described in detail in
the foregoing, referring to FIGS. 1 and 2. A packing 43 is secured
to the left-hand end surface of the armature 41, so as to establish
airtight contact between the end of pipe 13 and the armature 41 for
interrupting the communication through the solenoid valve 34 when
it is deenergized.
In the last-mentioned embodiment, the operation of the solenoid
valve 34 is controlled by the vacuum switch 33, but the actuator of
the solenoid valve in the device of the invention is not limited to
only such vacuum switch. For instance, an accelerator switch, a
clutch switch, and a gear neutral switch can be connected in
series, so that the solenoid valve can be actuated only when i.e.
accelerator is not stepped down while connecting the clutch with
the gear at any position other than neutral position.
In the preceding embodiment, a vacuum switch 33 is used to actuate
a solenoid valve 34, but the present invention is not limited to
the use of such vacuum switch, and any other means capable of
detecting the coasting condition of automobiles can be also used
for actuating the solenoid valve 34. FIG. 4 shows another
embodiment of the present invention, using three electric switches,
i.e. a clutch switch 46, an accelerator switch 47, and a gear
neutral switch 48, for the purpose of detecting the coasting
operation of an automobile. FIG. 5 shows an electric switch usable
in the embodiment of FIG. 4, which comprises brushes 49, 52, a push
rod 51 made of electric insulating material, an electric conductor
member 50 secured to the push rod 51, a bias spring 54, and
terminals B and C. When the push rod 51 is raised against the
elasticity of the spring 54, as shown by solid lines in FIG. 5, a
circuit between the terminals B and C is completed through the
electric conductor member 50. On the other hand, when the rod 51 is
lowered by the spring 54, the circuit between the terminals B and C
is interrupted.
Referring to FIG. 5, during coasting of an automobile, neither a
clutch pedal nor an accelerator pedal is stepped down, and the push
rods 51 of the clutch switch 46 and the accelerator switch 47 are
so arranged that the push rods 51 are raised by the engagement
between the lower end 53 of the rod and such pedal unless the
clutch pedal and the accelerator pedal are stepped down. During
coasting, the transmission gear occupies an operative position
other than its neutral, and the relation of the neutral gear switch
48 to the transmission gear is such that the push rod 51 of the
gear neutral switch 48 is lowered only when the transmission gear
is at the neutral position, so that the circuit through the gear
neutral switch 48 is closed during coasting. Thus, all three
switches 46, 47, and 48 are closed during coasting. Therefore, by
connecting those three switches in series, the coasting operation
of the engine can be detected, and the solenoid valve can be
actuated through such switches. More particularly, in FIG. 4, when
an automobile runs in coasting mode, a circuit is completed, which
traces from one terminal of the power source BT through switches
46, 47, 48, and the solenoid valve 34, and back to the opposite
terminal of the power source BT. Upon the actuation, the solenoid
40 acts to pull an armature 41 rightwards against the elasticity of
a spring 42 to communicate a pipe 13 to the space A above a piston
21, in the same manner as the preceding embodiment described
hereinbefore referring to FIG. 3. At the same time, the right-hand
end 44 of the armature 41 blocks an opening 45 communicating the
inside of the solenoid valve to the outside atmosphere.
When the current through the solenoid valve is interrupted, the
armature 41 is pushed back leftwards by the spring 42, so as to
interrupt delivery of the engine manifold negative pressure to the
space A above the piston 21. Thus, the space A communicates with
the atmosphere and the piston 21 moves downwards, as seen in FIG.
4.
The manual switch 35 in the circuit of FIG. 3 or FIG. 4 can be
closed to improve the fuel consumption in a multicylinder engine
during low speed running by actuating only a part of the
multicylinders. More particularly, with the switch 35 thus closed,
the supply gas mixture delivered to nonvalved cylinders burns well,
while those valved cylinders do not receive any supply gas mixture
at all, and hence, the overall fuel combustion rate is improved.
Thus, the fuel consumption can be improved.
In FIG. 1, if it is assumed that the firing sequence of the four
cylinders are in the order of the first, third, fourth, and second,
as counted from the uppermost cylinder, then it is preferable to
interrupt the intake of supply gas mixture to those cylinders which
are not fired in succession, i.e. second and third, when the
negative pressure at the intake manifold is high. Thereby, the
intervals between explosions become uniform. In other words, the
first and the fourth cylinders explode with uniform intervals, and
the engine can be balanced. Similarly, in the case of a
six-cylinder engine with a firing sequence of first, fifth, third,
sixth, second, and fourth cylinders, a perfect balance of engine
can be maintained by interrupting the intake of the supply gas
mixture to the fourth, fifth, and sixth cylinders.
However, the extent of the interrupting of the intake of the supply
gas mixture is not limited to one half of all the cylinders of an
engine. If the balance does not present any serious problems to a
particular engine, any number of cylinders of the engine may be
clocked against the supply of the mixture during deceleration and
coasting.
As described in the foregoing, according to the present invention,
the fuel supply mechanism to a multicylinder engine is so
constructed that during deceleration, the intake of the supply gas
mixture is interrupted to some of the engine cylinders, so that the
amount of the supply gas mixture delivered to each of the remaining
cylinders is increased as compared with the corresponding amount
for the case of delivering the mixture to all the cylinders. As a
result of it, the compression pressure is increased accordingly,
for instance when the mixture supply to two cylinders of a
four-cylinder engine is interrupted, the compression pressure in
the remaining cylinders is roughly doubled. Thus, the compression
pressure exceeds the combustion limit pressure, and accordingly,
perfect explosion takes place in the cylinders which is receiving
the supply gas mixture. Therefore, the amount of raw hydrocarbons
exhausted without burning can be greatly reduced, as compared with
the corresponding amount of known engines.
Furthermore, similar interruption of the intake of the supply gas
mixture to selected cylinders can be applied during slow driving or
coasting, so that the heat efficiency in the cylinders provided
with the mixture is improved, and the fuel cost is remarkably
improved. Moreover, by the proper use of the manual switch 35, the
fuel cost can be further improved.
* * * * *