U.S. patent number 3,777,727 [Application Number 05/275,050] was granted by the patent office on 1973-12-11 for fuel feed regulating device.
This patent grant is currently assigned to Kugelfischer Georg Schafer & Co.. Invention is credited to Gerhard Braune, Willi Kirchner.
United States Patent |
3,777,727 |
Kirchner , et al. |
December 11, 1973 |
FUEL FEED REGULATING DEVICE
Abstract
An apparatus for regulating the feed of fuel to a
mixture-compressing internal combustion engine having a throttle
valve and a normally closed sensor flap located within the air
intake line. A channel connects the air intake line between the
throttle valve and sensor flap to the atmosphere, this channel
being opened and closed by a closure flap which is coupled to the
sensor flap and a vacuum capsule responsive to the vacuum in the
air intake line between the engine and the throttle valve.
Regardless of the adjustment of the throttle valve upon the
starting of the engine, the apparatus feeds only the necessary
amount of fuel to the engine so that errors on the part of the
driver during starting do not have an effect on the regulating
device permitting the engine to start reliably.
Inventors: |
Kirchner; Willi (Schwebheim,
DT), Braune; Gerhard (Euerbach, DT) |
Assignee: |
Kugelfischer Georg Schafer &
Co. (Schweinfurt, DT)
|
Family
ID: |
5815549 |
Appl.
No.: |
05/275,050 |
Filed: |
July 25, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Aug 2, 1971 [DT] |
|
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P 21 38 623.2 |
|
Current U.S.
Class: |
123/587;
123/179.16; 123/590; 261/39.3; 261/50.2 |
Current CPC
Class: |
F02M
69/22 (20130101); F02M 69/48 (20130101); F02M
69/20 (20130101); F02M 69/32 (20130101) |
Current International
Class: |
F02M
69/32 (20060101); F02M 69/46 (20060101); F02M
69/22 (20060101); F02M 69/48 (20060101); F02M
69/16 (20060101); F02M 69/20 (20060101); F02M
69/30 (20060101); F02m 009/06 (); F02m 059/20 ();
F02m 063/02 () |
Field of
Search: |
;123/179G,119DB,119D,119R,119F,139AW ;261/5A,39B |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Al Lawrence
Assistant Examiner: Rutledge, Jr; W. H.
Claims
What is claimed is:
1. In an apparatus for regulating the feed of fuel to a
mixture-compressing internal combustion engine having an air intake
line; a sensor flap; a first spring means coupled to said sensor
flap for urging said sensor flap into its closed position; a
throttle valve positioned within said air intake line, said
throttle valve being interposed between the internal combustion
engine and said sensor flap; and metering means coupled to said
sensor flap for metering the quantity of fuel to be fed to each
chamber of the internal combustion engine in order to obtain an
optimum fuel air mixture for each operating condition for the
internal combustion chamber; the improvement comprising
a. a closure flap positioned in a channel in the wall of said air
intake line for opening and closing said channel, said channel
having one end connected to the atmosphere and the other end
discharging into said air intake line between said sensor flap and
said throttle valve,
b. second spring means,
c. first linkage means coupling said second spring means to said
closure flap and said sensor flap, said linkage and second spring
means closing said sensor flap when said closure flap is open and
closing said closure flap when said sensor flap is moved out of its
closed position, said sensor flap being held during starting of the
internal combustion engine in its closed position by said first and
second spring means,
d. first vacuum means responsive to the vacuum in said air intake
line between the internal combustion engine and said throttle
valve, and
e. second linkage means coupling said first vacuum means to said
closure flap and to said first linkage means, said closure flap
being closed by operation of said first vacuum means through said
second linkage means upon the reaching of a given vacuum in said
air intake line and said sensor flap being disengaged from said
second spring means by the operation of said first vacuum means
through said first and second linkage means.
2. An apparatus as defined by claim 1 wherein said second linkage
means comprises a shaft coupled to said first vacuum means and an
arm displaceably mounted on said shaft, said arm being capable of
displacement on said shaft when said sensor flap is moved out of
the closed position.
3. An apparatus as defined by claim 2 wherein said first vacuum
means comprises a capsule having a diaphragm secured to the shaft
of said second linkage and wherein said shaft has an end stop for
limiting the displacement of the arm of said second linkage, the
shaft and arm of said second linkage means having a total length
such that when the diaphragm of said capsule is curved away from
said closure flap, said closure flap is closed.
4. An apparatus as defined by claim 1 wherein a one-way throttle is
provided in a line coupling said first vacuum means to said air
intake line between the internal combustion engine and said
throttle valve, said one-way throttle throttling in the direction
toward said first vacuum means.
5. An apparatus as defined by claim 1 wherein said first linkage
means comprises a roller coupled to said sensor flap; a swingable
curved cam piece on which said roller travels coupled to said
closure flap and said second spring means, the travel path of the
curved cam piece when the closure flap is closed extending
concentrically to the pivot axis of said sensor flap, said cam
piece being pressed against said roller by said second spring means
when said closure flap is open.
6. An apparatus as defined by claim 1 wherein said sensor flap is
pivotally mounted on a shaft and which further comprises a pulley
mounted coaxial with said shaft and a cable passing over said
pulley connecting said sensor flap to said first spring means.
7. An apparatus as defined by claim 1 which further comprises a
second vacuum means responsive to the vacuum in said air intake
line between the internal combustion engine and said throttle valve
and wherein said metering means is coupled to said sensor flap by a
swingable double-armed lever having a pivot shaft coupled to said
second vacuum means, said lever swinging around the point of
connection with said sensor flap to bring said metering means into
position for zero delivery.
8. An apparatus as defined by claim 1 which further comprises a
sensor arm movable around the pivot axis of said sensor flap and
coupled to said metering means, and a bimetallic element positioned
between said sensor flap and said sensor arm, said bimetallic
element compensating for the temperature of the air drawn into said
air intake line.
9. An apparatus as defined by claim 1 which further comprises third
vacuum means responsive to the vacuum in said air intake line
between said sensor flap and said throttle valve coupled to said
first spring means, the initial tension of said first spring means
being variable as a function of the vacuum in said air intake line
between said sensor flap and said throttle valve.
10. An apparatus as defined by claim 1 wherein the inner
cross-section of said air intake line in the region of swing of
said sensor flap is so developed that upon the swinging of the said
sensor flap out of the closed position there is no initial change
in the free cross-sectional area, thereafter said free
cross-sectional area increasing in proportion to the angular
displacement of said sensor flap.
11. An apparatus as defined by claim 1 which further comprises an
elastically resilient stop, said sensor flap in its closed position
resting against said stop.
Description
BACKGROUND OF THE INVENTION
The present invention relates to means for regulating the feed of
fuel in mixture-compressing internal combustion engines, in which a
throttle valve which can be actuated at will is arranged in the air
intake line and an idle air bypass is provided between the throttle
valve and the internal combustion engine. There is furthermore
provided in the air intake line on the side of the throttle valve
facing away from the internal combustion engine an eccentrically
supported sensor flap. The sensor flap is urged into closed
position by a spring and is swingable against the action of the
spring in the direction of the flow of the intake air, the sensor
flap responding to the difference in pressure in the air intake
line in front of and behind the sensor flap and controlling a
device for metering the quantity of fuel to be fed to each internal
combustion engine chamber in order to obtain an optimum fuel/air
ratio for every operating condition of the internal combustion
engine.
Means having such a sensor flap are known, control of the manner of
operation of the sensor flap upon the starting of the internal
combustion engine being either electromagnetic or pneumatic in
order to permit an enriched fuel/air mixture to arrive at the
individual internal combustion engine chambers upon starting.
SUMMARY OF THE INVENTION
An object of the present invention is to create a regulating device
of the aforementioned type which, regardless of the adjustment of
the throttle valve upon the starting of the internal combustion
engine, provides assurance that the engine will be fed only the
amount of fuel necessary so that errors on the part of the driver
of a vehicle upon starting are without effect on the proper
functioning of the regulating device and the latter therefore at
all times permits the engine to start reliably.
This object is achieved in accordance with the invention by
providing a channel connected on the one end with the outside air
and discharging at the other end into the air intake line between
the sensor flap and the throttle valve. The channel has at the
place of discharge a closure flap which is urged by a spring into
the open position and cooperates, via a first linkage means
including a rod, with the sensor flap. When the closure flap is
open, the sensor flap is in the closed position; when the sensor
flap is moved out of the closed position, the closure flap is in
the closed position, the sensor flap being held in closed position
during the starting of the internal combustion engine by the
sensor-flap closure spring and in addition by the closure-flap
opening spring. Upon starting the engine with the throttle valve
open, the sensor flap is movable against the action of the sensor
flap and closure-flap springs from the closed position without
opening of the air intake conduit but rather by closing the closure
flap and adjusting the fuel quantity metering device for larger
delivery. Furthermore, the closure flap, after starting of the
internal combustion engine and upon the obtaining of a given vacuum
in the air intake line between the internal combustion engine and
the throttle valve, is swingable into closed position by a vacuum
capsule acting through a second linkage means with displacement of
the mechanism for the release of the sensor flap from the closure
flap opening spring.
In this way, dependable starting of the internal combustion engine
is assured in all cases, i.e., both with the throttle valve duly
closed and with it open.
In the former case the air (which is necessary for the combustion
of the fuel supplied by the fuel quantity metering device present
in idling position in the engine chambers) is drawn in through the
idle-air bypass by the internal combustion engine driven by the
starter. The internal combustion engine starts and idles with the
throttle valve still closed and the drawing in of the necessary
combustion air through the idle air bypass. When a given vacuum is
reached in the air intake line between the throttle valve and the
internal combustion engine, the closure flap is moved into the
closed position and the sensor flap is freed from the additional
load by the closure flap opening spring so that it can carry out
its normal control function.
In the second case, the required combustion air is drawn in by the
internal combustion engine driven by the starter through the
channel which bypasses the sensor flap which is held closed by the
sensor flap closure spring and in addition by the closure flap
opening spring. The two springs prevent displacement of the sensor
flap out of the closed position and thus also the displacement of
the fuel quantity metering device out of the idling position. The
internal combustion engine starts up and when a given vacuum is
reached in the air intake line between the throttle valve and the
internal combustion engine, the closure flap moves into the closed
position, while at the same time the sensor flap is freed from the
additional load by the closure flap opening spring, so that it can
fulfill its normal control function.
As a rule, the throttle valve is opened by the driver upon starting
when the internal combustion engine, after repeated or lengthy
startings with the throttle valve closed, has not started. A
relatively large amount of fuel has then accumulated in the
internal combustion engine chambers. If the internal combustion
engine fires in this condition with the throttle valve open, it
then races until the accumulated fuel has been consumed. In this
connection, a vacuum is produced in the air intake line on the side
of the closed sensor flap facing the internal combustion engine
such that the sensor flap swings against the action of the sensor
flap closure spring and the closure flap opening spring swings out
of the closed position, so that the closure flap closes and the
fuel quantity metering device is adjusted to a larger delivery. In
this connection, the sensor flap does not open the air intake
line.
Thus, the fuel/air mixture which passes into the engine chambers is
prevented, because of the large quantity of air as compared with
the quantity of fuel supplied by the fuel quantity metering device
in the idle position thereof, which air passes through the channel
bypassing the closed sensor flap into the air intake line, from
being so impoverished after combustion of the fuel collected in the
engine chambers that the internal combustion engine comes to a
stop. Rather, the engine continued to operate. If the throttle
valve is now closed, the engine idles, and the necessary combustion
air is drawn in through the idle air bypass and the sensor flap is
again in closed position, while the closure flap is again open.
When a given vacuum is reached in the air intake line between
throttle valve and engine, the closure flap is moved into closed
position and the sensor flap is freed of the additional load by the
closure flap opening spring, so that it can carry out its normal
control function.
The closure flap is preferably connected via a lag mechanism with
the vacuum capsule connected to the air intake line between engine
and throttle valve, the lag mechanism being capable of being pushed
together upon the starting of the engine with an open throttle
valve by the sensor flap moving out of the closed position. In this
connection, the lag mechanism between the closure flap and the
vacuum capsule can advantageously consist of an arm acting on the
closure flap or a lever arm thereof and a shaft, the arm being
displaceably seated at the end remote from the flap on the shaft
which is connected with the diaphragm of the capsule andhas an end
stop. The arm and shaft have a total length such that when the
diaphragm is arched away from the closure flap, the closure flap is
closed.
The lag mechanism also prevents the closure flap from being urged
in the opening direction upon a sudden opening of the throttle
valve in the air intake line during the operation of the engine,
the vacuum collapsing between the engine and throttle valve. The
same purpose is served by the arrangement in accordance with the
invention of a one-way choke which throttles in the direction
towards the vacuum capsule in the line between the vacuum capsule
and the air intake line.
The closure flap is preferably connected with a swingable curved
cam piece on which a roller on the sensor flap travels. The travel
surface of the cam piece when the closure flap is closed extends
concentrically from the axis of swing of the sensor flap, and the
cam piece when the closure flap is open is pressed against the
roller by the spring which urges the closure flap into open
position.
The sensor flap is advantageously connected via a cable with the
tension spring for urging into the closed position, the cable
extending over a pulley which is coaxial with the axis of swing of
the sensor flap. In this way there is assured a linear dependence
between the position of swing of the sensor flap and the spring
loading thereof.
If the sensor flap cooperates via a swingable double-armed lever
with the fuel quantity metering device, then, as an advantageous
further development of the invention, the axis of swing of the
lever is movable by means of a vacuum capsule which is connected to
the air intake line between throttle valve and engine in such a
manner that the lever swings around the point of connection with
the sensor flap and brings the metering device into the
zero-delivery position. In this manner, the conditions upon engine
braking are taken into consideration. A considerable vacuum is then
produced in the direction of flow of the intake air behind the
throttle valve. When it reaches a given value, for instance a 7 m
water column, the vacuum capsule swings the double-armed lever in
such a manner that the fuel metering device does not feed any fuel
to the internal combustion engine chambers.
In order to take the temperature of the intake air into account, a
bimetallic element may be arranged between the sensor flap and an
arm movable around its pivot, which arm is connected with the fuel
metering device.
It has also proven advantageous for the initial tension of the
spring which urges the sensor flap into closed position to be
variable as a function of the vacuum in the air intake line between
the throttle valve and the sensor flap.
The inner cross-section of the air intake line is preferably so
developed in the region of swing of the sensor flap that upon the
swinging of the sensor flap from the closed position, at first no
change in the free cross-sectional area takes place, after which
this free cross-sectional area increases in proportion to the angle
of swing.
In accordance with a final characteristic feature of the invention,
the sensor flap can rest in its closed position against an
elastically resilient stop. In this way damage to the apparatus is
avoided in case of a sudden increase in pressure in the air intake
line between the throttle valve and the sensor flap.
BRIEF DESCRIPTION OF THE DRAWINGS
Two embodiments of the arrangement of the invention are described
below by way of example with reference to the accompanying drawings
in which:
FIG. 1 is a longitudinal section through that part of the air
intake line of a mixture-compressing internal combustion engine in
which the throttle valve and the device in accordance with the
invention are provided;
FIG. 2 is a side view partially in axial section, corresponding to
FIG. 1;
FIG. 3 is a part of the side view of FIG. 2, in which the control
device is in a different position;
FIG. 4 shows a part of the longitudinal section of FIG. 1 through
another embodiment of the invention;
FIG. 5 is a view of the section along the line V--V of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the air intake line 1 in which air can flow in the direction
indicated by the arrow 2 from an air filter (not shown) to a
mixture-compressing internal combustion engine (also not shown),
there is provided a throttle valve 4 which is swingable about a
horizontal pin 3 and can be adjusted as desired by the operator,
this being generally done by means of a foot-actuated, so-called
gas pedal. Between the throttle valve 4 and the internal combustion
engine (not shown), there is provided the ordinary idle air bypass
4' via which the required quantity of combustion air passes into
the air intake line 1 when the engine is idling, the throttle valve
4 being closed.
Furthermore, within the air intake line 1, in the direction
indicated by the arrow 2, in front of the throttle valve 4, there
is arranged a sensor flap 5 which is fastened to a shaft 6
rotatably supported inthe air intake line 1. On the shaft 6 there
is keyed, outside the air intake line 1, a pulley 7 to which there
is fastened at 8 a cable 9 which acts on a tension spring 10.
The end of the tension spring10 facing away spring 10 the cable 9
is fastened to the diaphragm of a vacuum capsule 11 which is
connected via a line 12 with the air intake line 1 between the
throttle valve 4 and the sensor flap 5. The initial tension of the
tension spring 10 is in this way variable as a function of the
vacuum in the air intake line 1 between the throttle valve 4 and
the sensor flap 5.
The sensor flap 5 is swingable in the air intake line 1 around the
longitudinal axis of the shaft 6 between the two positions shown in
solid and in dashed line respectively in FIG. 1, namely in the
direction of the arrow 2 against the action of the tension spring
10 as the result of a higher pressure in front of the sensor flap 5
and a lower pressure behind the sensor flap 5, the angle of swing
of the sensor flap 5 from the position shown in solid line in FIG.
1 being proportional to the force exerted by the spring 10 on the
sensor flap 5, and thus on the amound of said difference in
pressure. This linear dependence is assured by the pulley 7 and the
cable 9 between sensor flap 5 and spring 10.
In the wall of the air intake line 1 there is provided a channel 13
one end of which is in communication with the atmosphere, while the
other end is provided at the place of discharge thereof into the
air intake line between the sensor flap 5 and the throttle valve 4
with a closure flap 14. The latter is fastened to a shaft 15
rotatably supported in the air intake line 1 and can be swung
between the position shown in solid line in FIG. 1 and the closed
position shown in dashed line, in cooperation with the sensor flap
5 in such a manner that the sensor flap 5 is in closed position
when the closure flap 14 is open and, conversely, the closure flap
14 is closed when the sensor flap 5 is moved out of the closed
position, as shown in FIG. 1. In this connection the closure valve
14 is connected with a vacuum capsule 17 connected to the air
intake line 1 via a line 16 behind the throttle valve 4, as seen in
the direction of the arrow 2, the vacuum capsule serving to close
the closure flap 14 and to release the sensor flap 5 from an
additional load which is still to be described when the closure
valve 14 is open, in case a given vacuum is reached in the air
intake line 1 behind the throttle valve 4, as seen in the direction
of flow.
As is particularly clear from FIGS. 2 and 3, a double-armed lever
18 is fastened to the shaft 15 outside the air intake line 1. A
tension spring 19 fastened at 20 to the air intake line acts on the
end of one of the lever arms. The spring 19 urges the closure flap
14 via the lever 18 and the shaft 15 into the open position shown
in solid line in FIG. 1.
To the end of the other arm of lever 18 there is pivoted an arm 21
which is seated displaceably at the end remote from the flap on a
shaft 24 which is connected with the diaphragm 22 of the vacuum
capsule 17 and has an end stop 23. In this connection there is
provided in the line 16 between the vacuum capsule 17 and the air
intake line 1 a one-way throttle 25 which throttles in direction
towards the vacuum capsule 17 and which, in accordance with FIG. 2,
comprises a movable piston 26 which together with an opening in the
throttle housing forms an annular throttle slot 27 the size of
which can be varied by a setscrew 28 on which a pin-shaped
extension of the piston 26 rests.
Between spring 19 and shaft 15 there is pivoted to the lever 18 a
rod 29 which is pivotally connected at the other end to a curved
cam piece 30. The cam piece 30 has a travel path 31 curved in the
shape of a circular arc and is swingably supported around a shaft
32 on the outside of the air intake line 1.
With the cam piece 30 there cooperates a roller 33 moving on the
cam path 31. The roller 33 is rotatably supported on the free end
of an arm 34 which is fastened on the shaft 6 of the sensor flap 5
outside the air intake line 1. In the closed position of the sensor
flap 5 shown in solid line in FIG. 1 the arm 34 assumes the
position shown in FIG. 2, the roller 33 being pressed against a
stop 35 which is swingable around a shaft 36 outside of the air
intake line 1 and is pressed against a screw 39 by a tension spring
38 acting at 37 on the outside against the air intake line 1. The
screw 39 can be turned in a lug 40 on the outside of the air
suction line 1 to adjust the stop 35.
With the shaft 6 of the sensor flap 5 there is connected a cam disk
41 by means of which a device for metering the quantity of fuel to
be fed to each chamber of the internal combustion engine (not
shown) in order to obtain an optimum fuel/air mixture for every
condition of operation of the internal combustion engine is
controlled. For example, this device may be a rotary distributor
for distributing the fuel, fed with constant pressure, to the
individual chambers of a mixture-compressing injection internal
combustion engine which has a cylindrical distributor rotor with an
approximately triangular distribution groove in the cylindrical
surface and a distributor stator which are displaceable axially
with respect to each other in order to adjust the duration of the
emergence of fuel at the individual places of delivery.
The cam disk 41 in the closed position of the sensor flap 5 which
is shown in solid line in FIG. 1, the roller 33 being pressed
against the stop 35, assumes the idle position shown in FIG. 2.
Over the cam edge 44 of the cam 41 there moves a roller 45 arranged
on one end of a double-armed lever 46 the other end of which acts
on the setting member 47 of the aforementioned fuel metering
device, which is not shown in detail.
The double-armed lever 46 is pivoted, swingable around a shaft 48,
to another double-armed lever 49. The lever 49 is supported for
rotation around a shaft 50 on the outside of the air intake line 1
and its second arm is connected via a rod 51 to a vacuum capsule
52. The latter is connected via a line 53 with the air intake line
1 between throttle valve 4 and the internal combustion engine (not
shown). The pivot pin 48 of the lever 46 is movable by means of the
vacuum capsule 52 in the manner that the lever 46 swings around the
point of connection with the sensor flap 5, i.e., in the present
case around the roller 45, and displaces the member 47.
The regulating device of the invention operates in the following
manner. Before the start of the internal combustion engine (not
shown in the drawings), the device is in the position shown in
FIGS. 1 and 2. The sensor flap 5 is in this case held in closed
position by the tension spring 10, the roller 33 of the sensor flap
5 resting against the stop 35. The curved cam piece 30 is swung by
the spring 19 via the lever 18 and the rod 29 upwards so that the
roller 33, and thus the sensor flap 5, are urged also by the spring
19 into closed position. The closure flap 14 is held open by the
lever 18. The roller 45 of the double-armed lever 46 is pressed by
a compression spring 54 against the cam edge 44 of the cam 41
connected with sensor flap 5, so that the adjustment member 47 is
in idle position, and the internal combustion engine can be fed the
quantity of fuel necessary for starting. The vacuum capsules 11, 17
and 52 are in neutral position since not acted on by any
vacuum.
If the internal combustion engine is now started with the throttle
valve 4 closed, as shown in solid lines in FIGS. 1 and 2, it then
draws in the necessary quantity of combustion air via the idle air
bypass 4' and after firing continues to idle with the throttle
valve 4 closed. As soon as a given vacuum is reached in the air
intake line 1 behind the throttle valve 4, as seen in the direction
of the arrow 2, the vacuum capsule 17 becomes active and closes the
closure flap 14, the cam curve 30 at the same time being swung into
the position shown in FIG. 3 in which its cam path 31 is concentric
to the pivot shaft 6 of the sensor flap 5 and the sensor flap 5 and
its roller 33 are freed from the additional load by the spring 19,
so that the sensor flap 5 is acted on only by the spring 10 and can
exert the normal control function.
If instead of this the internal combustion engine is started with
the throttle valve 4 open, as shown in dashed lines in FIGS. 1 and
2, then air flows into the air intake line 1 through the channel 13
which bypasses the closed sensor flap 5 and is opened by the
closure flap 14. The sensor flap 5 remains held in closed position
by spring 10 and in addition by the spring 19 via the cam curve 30,
so that also the cam disk 41 remains in the position shown in FIG.
2 and furthermore the displacement member 47 remains in the idle
position shown in FIG. 2.
As soon as there is reached in the air intake line 1 behind the
throttle valve 4, as seen in the direction of the arrow 2, a given
vacuum which acts via the line 16 with one-way throttle 25 on the
vacuum capsule 17, the capsule via the shaft 24 with end stop 23
and via the arm 21 pulls the double-arm lever 18 against the action
of the spring 19 into the position shown in FIG. 3, so that the
closure flap 14 assumes the closed position shown in dashed line in
FIG. 1 and the channel 13 is closed. Arm 21 and shaft 24 have such
a total length that with the diaphragm 22 of the vacuum capsule 17
arched away from the closure flap 14, flap 14 is closed.
Furthermore, as can be noted from FIG. 3, the cam curve 30 is so
swung via the rod 29 by lever 18 that the travel path 31 extends
concentrically to the shaft 6 of the sensor flap 5. The additional
loading of the roller 33 and thus of the sensor flap 5 by the
spring 19 is therefore eliminated, and the sensor flap 5 can assume
its normal control function, i.e., swing against the action alone
of the tension spring 10 between the two positions shown in
straight and dashed lines in FIG. 1, due to the difference
resulting, upon operation of the internal combustion engine,
between the originally static pressures and then dynamic pressures
in front of and behind the sensor flap 5, the instantaneous
position of swing of the sensor flap 5 being proportional to the
instantaneous value of the pressure difference. The sensor flap 5
displaces the cam disk 41 in corresponding manner, so that the
displacement member 47 of the fuel metering device (not shown in
detail) is displaced via the double-arm lever 46. This can be noted
from FIGS. 2 and 3 in which the position of the displacement member
47 is indicated in dot-dash lines in FIGS. 2 and 3.
As already mentioned, the arm 21 is displaceably guided on the
shaft 24. In this way the following results are obtained. If upon
repeated or lengthy unsuccessful attempts to start the internal
combustion engine with the throttle valve closed, a certain supply
of fuel collects in the internal combustion engine chambers and
starting with open throttle valve is now attempted by the driver,
the vehicle after firing races due to the supply of fuel and the
air entering in ample quantity through the channel 13. In this way
there is produced behind the feeler flap 5, as seen in the
direction of the arrow 2, a vacuum which is sufficient to swing the
sensor flap 5 in opposition to the action of the two springs 10 and
19 out of the closed position shown in solid line in FIG. 1. The
cam curve 30, the rod 29 and the lever 18 are swung by the roller
33 of the arm 34 out of the position shown in FIG. 2 into the
position shown in FIG. 3, so that the closure flap 14 assumes the
closed position shown in dashed line in FIG. 1, and therefore no
air can pass any longer through the channel 13 into the air intake
line 1, and so that the displacement member 47 is set to a larger
delivery of the metering device (not shown). In this way the
fuel/air mixture fed to the internal combustion engine chambers
after consumption of the supply of fuel in them cannot become so
lean that the vehicle comes to a stop. Upon the swinging of the
sensor flap 5, the latter does not release the air intake line 1,
as will be explained below.
Furthermore, in case of an abrupt opening of the throttle valve
during the operation of the internal combustion engine in
connection with which all vacuum disappears behind the throttle
valve 4, as seen in the direction of flow, and the diaphragm 22 of
the vacuum capsule 17 moves from the position shown in FIG. 3 into
the position shown in FIG. 2, the lag mechanism 21, 24 prevents the
arm 21 from being carried along and the lever 18 from being swung,
which would lead to an opening of the closure flap 14 and an
actuation of the arm 34 with roller 33 via the cam curve 30. The
desired behavior is supported by the one-way throttle 25 in the
line 16 to the vacuum capsule 17 which in the case described
provides assurance that the vacuum present previously in the vacuum
capsule 17 will be only slowly destroyed and the diaphragm 22 moves
correspondingly slowly from the position shown in FIG. 3 into the
position shown in FIG. 2.
As explained above, the pivot pin 48 of the double-armed lever 46
is movable. Upon push operation of the internal combustion engine
provided with the arrangement in accordance with FIGS. 1 to 3,
i.e., upon downhill travel of the corresponding motor vehicle, for
instance, the throttle flap 4 is closed, as shown in FIGS. 1 and 2.
The internal combustion engine is driven from the vehicle and
produces a relatively strong vacuum behind the throttle valve 4 in
the direction of flow of the intake air. As soon as the vacuum
assumes a given value, for instance exceeds 7 m water column, the
vacuum capsule 52 responds and pulls the arm 51. The double-armed
lever 49 swings around the shaft 50, so that the lever 46 swings to
the right around the roller 45 resting against the cam disk 41 out
of the position shown in FIG. 2 and brings the adjustment member 47
from the idle position into the zero-delivery position in which all
feed of fuel to the internal combustion engine is interrupted by
the fuel metering device (not shown).
The inner cross-section of the air intake line 1 is developed
rectangularly in the region of swing of the sensor flap 5, as can
be noted from FIG. 5. The shape of the sensor flap 5 is
correspondingly rectangular so that in the closed position shown in
solid line in FIG. 1 the inner cross-section of the air intake line
1 is closed. The rectangular inner cross-section of the air intake
line 1 is furthermore so developed in the region of swing of the
sensor flap 5 that upon swinging of the sensor flap 5 from the
closed position at first no change in the free cross-sectional area
takes place, whereafter this free cross-sectional area increases
with an increase of swing of the sensor flap 5. This can be noted
from FIG. 1. During a swinging of the sensor flap 5 from the
position shown in solid line into the position 55 shown in dash-dot
line, there is no change in the slow between the lower edge of the
sensor flap 5 and the adjacent surface of the inner cross-section
of the air intake line 1. Only after this does the slot increase
with further swinging of the sensor flap 5 in such a manner that at
every angle of swing of the sensor flap 5, the free area of the
slot is proportional thereto.
The embodiment in accordance with FIGS. 4 and 5 corresponds in
structure and operation to that of FIGS. 1 to 3, aside from the
fact that in order to take into consideration the temperature of
the air which is drawn in upon the displacement of the adjustment
member 47 by the lever 46 and the cam disk 41, special measures are
taken, namely a coil-spring-like bimetallic element 57 is inserted
between the sensor flap 5 and a sensor arm 56 movable around the
pivot axis thereof, the arm 56 being connected with the fuel
metering device.
The shaft 6 on the sensor flap 5 on which the pulley 7 is keyed
outside the air intake line 1 has within the air intake line 1 a
larger outside diameter and a longitudinal bore 58. In said bore
there is rotatably supported a shaft 59 to which the movable arm 56
is fastened. The shaft 59 extends out of the air intake line 1 and
has at its free end the cam disk which is keyed on in fixed
position. Pin 6 and shaft 59 are rotatably supported in the air
intake line 1 and in addition turnable with respect to each other.
The pin 6 therefore does not extend completely transversely through
the air intake line 1, as can be noted particularly clearly from
FIG. 5.
The bimetallic element 57 between the sensor flap 5 and the movable
arm 56 expands to a greater or lesser extent depending on the
temperature of the air drawn in so that the movable arm 56 is swung
to a greater or lesser extent with respect to the sensor flap 5.
The instantaneous position of rotation of the cam disk 41 thus
corresponds at the same time to the instantaneous angular position
of the sensor flap 5 in the air intake line 1 and the instantaneous
angular position of the movable arm 56 with respect to the sensor
flap 5.
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