U.S. patent number 3,568,652 [Application Number 04/795,947] was granted by the patent office on 1971-03-09 for valve mechanisms.
This patent grant is currently assigned to S.R.M. Hydromekanik AB. Invention is credited to Karl Gustav Ahlen.
United States Patent |
3,568,652 |
Ahlen |
March 9, 1971 |
VALVE MECHANISMS
Abstract
An apparatus for regulating fuel consumption of an internal
combustion engine. A valve mechanism forms a part of the connecting
linkage between the throttle pedal and a fuel consumption
regulating mechanism. Fluid impulses are provided by opening and
closing passages through the valve mechanism in response to
movement of the throttle pedal and the throttle linkage. Such a
valve mechanism may include first and second valve passages, a
valve means for placing each of these passages in an open condition
or closed condition wherein a biasing force is exerted on the valve
means for placing the passages in one of said conditions and an
actuating member is provided for displacing the valve means against
the biasing force such that in a first position of the actuating
member, the first passage is open and the second passage is closed
and in a second position of the actuating member the first and
second passages are closed and in a third position of the actuating
member the second passage is open and the first passage is closed.
The elements are arranged such that the force required to displace
the actuating member from the second position to the third position
is greater than the force required to displace the actuating member
from the first position to the second position.
Inventors: |
Ahlen; Karl Gustav (Stockholm,
SW) |
Assignee: |
S.R.M. Hydromekanik AB
(Stockholm-Vallingby, SW)
|
Family
ID: |
9807734 |
Appl.
No.: |
04/795,947 |
Filed: |
February 3, 1969 |
Foreign Application Priority Data
Current U.S.
Class: |
123/378; 477/141;
137/625.69 |
Current CPC
Class: |
F02D
29/00 (20130101); Y10T 477/693675 (20150115); Y10T
137/8671 (20150401); F02D 2700/07 (20130101) |
Current International
Class: |
F02D
29/00 (20060101); F02m 039/00 (); F17d 001/10 ();
F02d 001/00 () |
Field of
Search: |
;123/139.68,(Inquired)
;137/595,596,625.69,(Inquired) ;74/843,(Inquired) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McKeon; Arthur T.
Claims
I claim:
1. In combination, a combustion engine, a regulating mechanism for
regulating the fuel consumption of the engine, a throttle pedal, a
connecting linkage connecting the throttle pedal to the regulating
mechanism to operate the same to regulate the fuel consumption of
the engine, and a valve mechanism, fluid passages through the valve
mechanism for passing fluid for producing fluid impulses, said
passages being opened and closed in response to movement of the
throttle pedal and the connecting linkage, said valve mechanism
forming a part of said connecting linkage between the throttle
pedal and the regulating mechanism for movement therewith.
2. The invention of claim 1, including a hydraulic transmission
means operatively connected to the engine, said valve mechanism
being operatively connected to the said transmission to operate the
transmission by said impulses.
3. The invention of claim 1, wherein said passages include first
and second valve passages, valve means for placing each of said
passages in an open condition or a closed condition, means for
exerting a biasing force on the valve means for placing the
passages in one of said conditions and an actuating member for
displacing said valve means against said biasing force so that, in
a first position of the actuating member the first valve passage is
open and the second valve passage is closed, in a second position
of the actuating member the first and second valve passages are
closed and in a third position of the actuating member the second
valve passage is open and the first valve passage is closed, the
force required to displace the actuating member from the second
position to the third position being greater than the force
required to displace the actuating member from the first position
to the second position.
4. A combination according to claim 3 wherein the valve means is
enclosed in a casing and wherein the displaceable actuating member
is connected to one part of the connecting linkage and said casing
is connected to another part of said linkage.
5. A combination according to claim 3 wherein the first position of
the actuating member corresponds to zero throttle and the first
valve passage is then open to provide a fluid impulse, and wherein
initial displacement of the actuating member closes said first
valve passage without influencing the said engine regulating
mechanism.
6. A combination according to claim 3 wherein a lost-motion device
is included in the connection between the actuating member and the
valve means.
7. A combination according to claim 3 including a transmission
operatively connected to said engine, and wherein movement of the
throttle linkage effects the setting of said transmission by means
of fluid impulses which causes air to be supplied to or vented from
said transmission through said first and second passages.
8. A combination according to claim 3 wherein the movement of the
throttle linkage comprises an initial movement changing the
position of the first valve passage, a second movement during which
the valve means transfers said movement of the throttle linkage to
the said regulating mechanism without changing the position of the
first or second valve passages and a final movement wherein the
force in the linkage exceeds a predetermined value and changes the
position of the second valve passage.
9. A combination according to claim 3 wherein the valve means
comprises separate valve members operated individually by the said
actuating member.
10. A combination according to claim 9 including a casing, first
and second chambers in said casing, first and second passages
leading from the first and second chambers, respectively, to a
source of pressure fluid, one of said valve members in each
chamber, a spring means urging each valve member to close its
respective passage and also to open an aperture from its respective
chamber to atmosphere, and said actuating member being operable
during its first and third positions to move the valve members of
the first and second chambers, respectively, to open the first and
second passages, respectively.
11. A combination according to claim 3 wherein the valve means
comprises axially spaced parts of a common piston type valve member
having sections of different diameter for opening and closing the
said passages.
12. A combination according to claim 11 wherein the casing
surrounding the said valve member is formed with channels for the
passage of air, separated by O-rings of elastic material, said
channels being arranged to intercommunicate by axial displacement
of the piston type valve member, and said channels including said
first and second passages, a pressure fluid supply channel and a
vent channel.
13. A combination according to claim 12, including a transmission
operatively connected to said engine, and wherein movement of the
throttle linkage effects the setting of said transmission by means
of said impulses which causes air to be supplied to or vented from
said transmission through said first and second passages, and
wherein intercommunication of the supply channel and the first
channel leads pressure air to one member of the transmission and
intercommunication of the supply channel and the third channel
leads pressure air to another member of the transmission.
14. A combination according to claim 13 including a servovalve
interposed in each path of flow of pressure air from the valve
member to the respective transmission member, said servovalves
forming large flow areas, whereby immediate setting of said
transmission members is obtained.
15. A combination according to claim 11 including a relatively weak
spring urging the valve member to the first position, and wherein
the actuating member is operatively connected to the valve member
by a lost-motion device and wherein the actuating member moves, on
actuation of the throttle pedal, against the force of said weak
spring to change the position of the first valve passage and
subsequently move as a unit with the valve casing to actuate the
regulating mechanism of the engine.
16. A combination according to claim 15 including an additional
spring, stronger than said relatively weak spring, and wherein the
actuating member, on reaching the end position of the regulating
mechanism, is movable further against said additional spring
pressure to change the position of the second valve passage.
17. A combination according to claim 3 wherein the actuating member
is supported in an external casing by roller bearings.
18. A combination according to claim 3 wherein the movement into
the third position of the actuating member to open the second valve
passage takes place under a higher pressure than that necessary to
move the said regulating mechanism to its maximum limiting position
and corresponds to kickdown position of the said throttle.
19. A combination according to claim 3 having connections for flow
of pressure fluid to and from the valve mechanism, said connections
comprising U-shaped flexible pipes having the legs of the U-shaped
flexible pipes having the legs of the U extending substantially
parallel to the direction of displacement of the actuating
member.
20. A valve mechanism having fluid passages, means for producing
fluid impulses through the passages, said valve mechanism
comprising first and second valve passages, a valve means for
placing each of said passages in an open condition or a closed
position, means for exerting a biasing force on the valve means for
placing the passages in one of said conditions and an actuating
member for displacing said valve means against said biasing force
so that, in a first position of the actuating member the first
valve passage is open and the second valve passage is closed, in a
second position of the actuating member the first and second valve
passages are closed and in a third position of the actuating member
the second valve passage is open and the first valve passage is
closed, the force required to displace the actuating member from
the second position to the third position being greater than the
force required to displace the actuating member from the first
position to the second position.
21. A valve mechanism according to claim 20, wherein a lost-motion
device is included in the connection between the actuating member
and the valve means.
22. A valve mechanism according to claim 20, wherein the valve
means comprises separate valve members operated individually by the
said actuating member.
23. A valve mechanism according to claim 22, including a casing,
first and second chambers in said casing, first and second passages
leading from the first and second chambers, respectively, to a
source of pressure fluid, one of said valve members in each
chamber, a spring means urging each valve member to close its
respective passage and also to open an aperture from its respective
chamber to atmosphere, and said actuating member being operable
during its first and third positions to move the valve members of
the first and second chambers, respectively, to open the first and
second passages respectively.
24. A valve mechanism according to claim 20, wherein the valve
means comprises axially spaced parts of a common piston type valve
member having sections of different diameters for opening and
closing the said passages.
25. A valve mechanism according to claim 24, wherein the casing
surrounding the said valve member is formed with channels for the
passage of air, separated by O-rings of elastic material, said
channels being arranged to intercommunicate by axial displacement
of the piston type valve member, and said channels including said
first and second passages, a pressure fluid supply channel and a
vent channel.
26. A valve mechanism according to claim 20, wherein the movement
into the third position of the actuating member to open the second
valve passage takes place under a higher pressure than that
necessary to move the said regulating mechanism to its maximum
limiting position and corresponds to kickdown position of the said
throttle.
Description
This invention relates to valve mechanisms. A valve mechanism in
accordance with this invention may be used to provide an output
impulse or other signal for controlling the operation of additional
equipment and particularly for controlling mechanical and
hydromechanical transmissions for motor vehicles.
For many years there has been a need for indicating the zero
throttle position and the so called kickdown throttle position,
that is the position in which the throttle is fully depressed.
Hitherto electrical contacts and valves have been used for
providing impulses or signals in the zero throttle and kickdown
positions. Known valves have been connected with the throttle
pedal, the carburetor or the fuel injection pump depending upon the
form of engine regulator mechanism used. Where such valves have
been used for heavy vehicles, the valves have always been dependent
for their operation upon a very high external force and this force
has been reflected in the force necessary to depress the throttle
pedal from zero to maximum positions. In an attempt to reduce the
force necessary to depress the throttle and operate the known
valves, it was proposed to use a manually operable device for
providing the necessary impulses.
It is an object of the present invention to appreciably reduce the
force required to operate a valve system and produce the necessary
impulses by operation of the throttle pedal without subjecting the
driver of a vehicle to unnecessary strain.
According to one feature of the invention a valve mechanism for
producing impulses responsive to the movement of an engine throttle
pedal forms a part of a connecting linkage between the throttle
pedal and a regulating mechanism of the engine.
According to a further feature of the invention the valve mechanism
comprises first and second valves each having a valve member
movable between open and closed positions against a force urging
the member into one of the said positions, and an actuating member
displaceable against a biasing force so that, in a first position
of the actuating member the first valve is open and the second
valve is closed, in a second position of the actuating member the
first and second valves are closed and in a third position of the
actuating member the second valve is open and the first valve is
closed, the force required to displace the actuating member from
the second position to the third position being greater than the
force required to displace the actuating member from the first
position to the second position.
Several forms of valve mechanism in accordance with the invention
will now be described by way of example with reference to the
accompanying drawings in which:
FIG. 1 shows diagrammatically a layout of an automatic transmission
employing a valve mechanism in accordance with the invention;
FIG. 2 shows a longitudinal section through a valve mechanism of
the invention;
FIG. 3 is a section taken on line 3-3 of FIG. 2;
FIG. 4 shows a longitudinal section through a modified valve
mechanism;
FIG. 5 is a section on the line V-V of FIG. 4;
FIG. 6 is an end elevation of the device shown in FIG. 4;
FIG. 7 shows a longitudinal axial section through a further
modified valve mechanism; and
FIG. 8 is a section on the line VIII-VIII of FIG. 7.
In FIG. 1 a hydraulic transmission 2 is mounted on an engine having
a fuel injection pump 6 and a connecting linkage generally
indicated at 8 to a throttle pedal (not shown). A valve mechanism
10 according to the invention is mounted as shown to form part of
the throttle pedal connecting linkage. A pressure air line 12
serves to connect the valve mechanism to the pressure air system of
the vehicle and additional pressure connections 14 and 16 serve to
transmit impulses from the valve mechanism in dependence on the
position of the throttle pedal.
In the particular case described the transmission is a SRM DS
transmission and the pipe 14 carries pressure air when the throttle
pedal is released thereby giving an impulse in the transmission and
releasing the guide vane for free rotation this position in such
transmissions being termed "positive neutral." This means that if
reverse gear is also released the transmission is freely rotatable.
It also means that should reverse gear be engaged there is no
torque multiplication through the transmission and consequently
there is no tendency for a creeping condition to be realized. Such
a creeping condition is otherwise very great since the transmission
in question has a 9:1 torque ratio. When the throttle pedal is
fully depressed into its bottom position which generally speaking
is beyond the position of full throttle or maximum fuel injection,
the valve mechanism as shown in FIG. 2 conveys pressure air through
pipe 16 to control the transmission in such a way that in a
particular field direct drive is released enabling maximum tractive
effort to be obtained at the expense of a slight fall in fuel
economy. This last mentioned position is, as previously indicated,
referred to as the kickdown throttle position.
Reference was made earlier to a reduction in the force necessary to
operate a valve mechanism in accordance with this invention and
this is due to the fact that a return spring 18 (FIG. 1) placed on
the connecting rod on the fuel injection pump side of the valve
mechanism 10 provides the return force. No other spring force is
required and it is not necessary for the spring 18 to be any
stronger than a normal fuel injection pump return spring because
the only additional forces with which the return spring has to
contend are those arising from the connection of the U-shaped and
flexible pressure lines 12, 14 and 16 and such forces are
minimal.
Referring to FIGS. 2 and 3 which show the valve mechanism in detail
an actuating member 30 having a threaded end 30A for mounting in
the linkage leading to the throttle pedal, is slidable in a casing
32. A threaded bore 32A in the casing provides for the connection
of the casing in the throttle pedal linkage to the fuel injection
pump or throttle. Located between the actuating member 30 and the
casing 32 are two helical springs 34 and 36. The spring 34 acts
against a flange 38 carried by the actuating member 30 and the
spring 36 acts against a ring 40 slidable within the casing 32. The
position of the ring 40 in a direction to the right as viewed in
FIG. 2 is limited by a stop ring 31A carried by the casing 32.
The spring 34 serves to retain the member 32 in its extended
position wherein a valve 42 is maintained open under the influence
of a projection 44 carried by the actuating member 30. The
projection 44 cooperates with a pin 46 carried by a valve plate 48
tending under normal conditions to close a bore 52 under the
influence of a spring 50. Pressure air from the vehicle pressure
air system enters the valve mechanism through inlet 54 and when the
bore is open passes through the bore 52 into a passage 56 and
thence to pipe 14 (FIG. 1).
The valve plate 48 comprises a metal ring carrying a disc made from
rubber or other flexible material and when the bore 52 is open, the
valve 42 closes an outlet 59 from chamber 60. Since the spring 34
is weaker than the return spring 18 very little, if any, additional
force is required to depress the throttle and cause actuation of
the valve assembly 46, 48, 50.
When a driver depresses the throttle pedal, initial movement of the
pedal will compress the spring 34 and the flange 38 will abut
against the ring 40 normally retained in a position by spring 36 to
maintain the valves 42 and 58 closed. In this position the valve
actuating mechanism transmits a force from the primary side (pedal)
to the secondary side (pump arm) and serves only to vary the
position of the arm of the fuel injection pump until the return
spring 18 is in its maximum compressed position and the fuel
injection pump regulating arm is consequently in the maximum fuel
injection position. In this position the casing 32 is prevented
from further axial movement. Additional pressure on the throttle
pedal will then cause the spring 36 to be compressed which results
in valve 58 being opened and pressure air conveyed (in the same way
as for valve 42) but to the pipe 16 thereby transmitting the
required impulse to the transmission. This impulse disconnects
direct drive as soon as higher tractive effort is obtainable from
the hydraulic transmission.
The force of the spring 36 may be chosen to be independent of the
spring 18 and is sufficiently strong to enable a driver to feel a
distinct difference between maximum fuel injection and kickdown
positions.
The pipes 12, 14 and 16 are as mentioned above flexible and these
assume a U-shape i.e. bent through 180.degree. between the valve
mechanism 10 and a stationary abutment on the engine. This
arrangement means that the transverse dimension measured between
the generally parallel sides of the U-shaped pipes remains
substantially constant during actual movement of the valve
mechanism 10 and little or no additional force is applied to the
valve mechanism 10 by the pipe connections.
A valve mechanism in accordance with the invention has the
advantage that it is independent of any movement of the vehicle
cabin or any changes in dimensions of the throttle connecting
linkage. The valve mechanism may be assembled into the throttle
pedal linkage before delivery of the transmission enabling testing
in situ and setting of the valve mechanism to be carried out prior
to delivery which apart from the features already mentioned
concerning the reduction of force required to operate the throttle
pedal by the driver offers considerable improvement over known
devices.
A modification of the valve mechanism 10 is shown in FIGS. 4 to 6.
In this construction a casing 61 carries within the same a slidable
actuating member 62, the casing 61 and member 62 being connected in
the throttle pedal linkage, depression of the pedal moving the
member 62 in the direction of the arrow P. Disposed between casing
61 and member 62 are two compression springs 64, 65, the inner
weaker spring 64 acting between an abutment 66 held by stops 67 on
the casing 61 and a movable ring 74 slidable on the member 62 and
limited as to its inward movement by a stop 68 secured to the
member 62. The outer spring 65 acts between the abutment 66 and a
ring 69 slidable on the casing 61 and limited as to its inward
movement by a shoulder 70 on the casing.
Arranged at the opposite end of the casing 61 is an axially
slidable valve 71 of the piston type having sections of different
diameters for opening and closing passages across a plurality of 0
rings 72 mounted in a valve casing 73. Formed in the casing 73 are
a number of radial passages three of which communicate respectively
with the openings to which the pressure pipes 14, 54, 16 are
connected through bores 75, 76, 77 respectively. The valve 71 is
connected to the movable member 62 by a coupling disc which allows
lost motion between the members 62 and 71. The member 62 is
supported in the casing 61 by bearings 63.
As shown in FIG. 5 the casing 61 and the valve casing 73 are
interconnected by a number of bolts 79. The casing 61 is lubricated
and is maintained oil tight by a flexible sealing ring 80 of rubber
or the like.
In operation in the case of zero throttle with the member 62 held
in its left-hand position as shown in FIGS. 4 and 5 by the spring
64, the position of the valve 71 is such that pressure air entering
through connection 54 and bore 76 is directed through bore 75 and
pipe 14 for the connection of the positive neutral of the
transmission. Depression of the throttle pedal moves member 62 to
the right relative to casing 61 compressing spring 64, while the
valve 71 at first remains stationary due to the lost motion
connection with member 62. Continued movement of member 62 then
moves valve 71 to the right, thereby breaking the communication
between bores 76 and 75 and venting bore 75 to atmosphere through
the valve. The spring 64 is so weak that the compression thereof
does not produce a force between the members 61 and 62 sufficient
to move the regulating arm of the injection pump.
Further movement of the members 62 and 71 to the right causes the
movable ring 74 on the member 62 to contact the ring 69, the member
62 moving the arm of the injection pump to full throttle position
and then compressing spring 65 moving further to kickdown position
at which point the valve member 71 has moved to the right
sufficiently to provide communication between the bores 76 and 77
so that pressure air passes from the supply opening 54 to the pipe
16 and effects the kickdown at the transmission.
The provision of the lost motion connection between the member 62
and the valve 71 enables the position of the throttle or regulating
arm of the injection pump to remain steady in the case where the
driver, due to bad road conditions or the like, cannot hold the
throttle pedal steady, so that "hunting" will not arise.
FIGS. 7 and 8 show a modification of the valve mechanism of FIGS. 4
to 6 which is particularly adapted for heavy off-the-road vehicles.
In this case the operating mechanism 61, 62 of the control valve 71
is the same as that described with reference to FIGS. 4 and 5. The
operation of the valve 71 is however such that pressure air passing
through the valve is not led directly to the transmission to
provide the necessary impulse but through servovalves 82, 92 shown
in FIG. 8. This has the advantage that the setting for positive
neutral or for kickdown is effected practically immediately through
large areas when the respective servovalve is actuated for the
setting.
The servovalves 82, 92 are of the piston type having sections of
differing diameters for opening and closing passages across a
plurality of O-rings 83 and 84 respectively. The servo valve 82 has
in its casing apertures which communicate under control of the
control valve 71 at 85 with the pressure air supply at 86 with the
positive neutral of the transmission through pipe 14 and at 87 with
the atmosphere. Similarly the casing of the servo valve 92 is
provided with apertures 88, 89, 90 communicating respectively with
the pressure air supply, with the kickdown of the transmission
through pipe 16 and with the atmosphere.
The valve assembly is mounted in the linkage of the throttle pedal
so that, on depression of the pedal, the member 62 moves to the
right as shown by the arrow R in FIG. 8. In the neutral position of
the pedal the elements of the control valve and servovalves will be
in the positions shown in FIG. 8. At this time pressure air is
conveyed from the air supply through 54 through the passage 76,
valve 71 and opening 75 to the left-hand end face of the servovalve
82 thereby pressing the servovalve 82 to the right against the
force of a spring 91. In this position of the piston 82, a passage
having a large area leads pressure air from aperture 85 to aperture
86, thus causing connection of the positive neutral of the
transmission through pipe 14.
When the throttle pedal is depressed, the valve member 71 is moved
to the right closing the connection between the passage 76 and the
opening 75 and venting the latter to the atmosphere at 94 thus
causing air at the left hand end face of the piston 82 to vent to
atmosphere. Thus the spring 91 presses the piston 82 to the left
thereby venting air through 86 from the neutral and disconnecting
positive neutral. Initial movement of the valve member 71 and
compression of the spring 64 is stopped by abutment against the
prestressed spring 65.
Further depression of the throttle pedal merely moves the arm of
the fuel injection pump to increase the speed of the engine. When
the said arm reaches its end position compression of the two
springs 64 and 65 will move the valve member 71 further to the
right allowing pressure air to pass from 54 to the opening 77 and
then to the left hand end face of the servovalve 92 thereby
displacing the piston 92 to the right against the force of a spring
93. This movement of the piston 92 allows air to pass through a
large area from the opening 77 to the aperture 89 thereby effecting
connection of kickdown in the transmission through the pipe 16.
When the throttle pedal is released, the whole sequence of
operation will follow in the reverse order. In this embodiment
also, lost motion is provided between the member 62 and the control
valve 71, to avoid hunting.
* * * * *