U.S. patent number 3,791,366 [Application Number 05/206,656] was granted by the patent office on 1974-02-12 for fail-safe throttle control.
Invention is credited to Charles W. MacMillan.
United States Patent |
3,791,366 |
MacMillan |
* February 12, 1974 |
FAIL-SAFE THROTTLE CONTROL
Abstract
The invention relates to a fail-safe throttle control mechanism
which is positioned between an accelerator pedal of a motor vehicle
engine incorporating a fuel injection system and includes a linkage
assembly which extends from the accelerator pedal to the fuel
injection control system and has combined therewith a sensing
mechanism for disengaging the accelerator pedal from the fuel
injection control system so that the engine of the motor vehicle
can instantly return to an idle condition irrespective of any
impairment in the control linkage or blockage of the accelerator
pedal. There are disclosed various embodiments for achieving this
fail-safe operation of fuel injection control mechanisms.
Inventors: |
MacMillan; Charles W. (Rock
Island, IL) |
[*] Notice: |
The portion of the term of this patent
subsequent to December 28, 1988 has been disclaimed. |
Family
ID: |
27375962 |
Appl.
No.: |
05/206,656 |
Filed: |
December 10, 1971 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
88450 |
Nov 10, 1970 |
3626919 |
|
|
|
153330 |
Jun 15, 1971 |
3731667 |
|
|
|
Current U.S.
Class: |
123/198DB;
123/337; 180/282; 123/445; 477/183 |
Current CPC
Class: |
B60K
26/04 (20130101); F02D 17/04 (20130101); B60K
28/00 (20130101); F02D 9/02 (20130101); F01L
1/00 (20130101); F02D 9/00 (20130101); F02D
2700/023 (20130101); Y10T 477/81 (20150115); F01L
2710/006 (20130101); F02B 1/04 (20130101); F02D
2009/0277 (20130101); F02B 3/06 (20130101); F02D
2009/0264 (20130101); F02D 2009/0271 (20130101) |
Current International
Class: |
B60K
26/00 (20060101); B60K 26/04 (20060101); B60K
28/00 (20060101); F02D 9/02 (20060101); F02D
17/00 (20060101); F02D 17/04 (20060101); F01L
1/00 (20060101); F02D 9/00 (20060101); F02B
3/00 (20060101); F02B 1/04 (20060101); F02B
1/00 (20060101); F02B 3/06 (20060101); F02b
077/08 (); F02b 011/04 (); B60k 027/08 () |
Field of
Search: |
;74/512,513
;123/198R,198D,198DB,98,108 ;180/82,82.1,82.7,103,105
;192/3T,3R |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Al Lawrence
Attorney, Agent or Firm: Greigg; Edwin E.
Parent Case Text
This application is a continuation-in-part of my earlier
applications Ser. No. 88,450, filed Nov. 10, 1970, now U.S. Pat.
No. 3,626,919, entitled "Fail-Safe Throttle Control," and Ser. No.
153,330, filed June 15, 1971, now U.S. Pat. No. 3,731,667, also
entitled "Fail-Safe Throttle Control."
Claims
That which is claimed is:
1. A fail safe apparatus for controlling the speed of an engine
comprising:
an engine speed control means,
a means for actuating said speed control means,
an accelerator pedal and
means operatively connecting said accelerator pedal and said
actuator means, said connecting means including
means for sensing failure of the accelerator pedal to return to a
normal condition upon an attempt to decelerate,
means responsive to said sensing means for returning said actuating
means to a position in which said engine speed control means causes
said engine to run at idling speed, and
means effective to transmit force from said responsive means to
said actuator means but ineffective to transmit force from said
actuating means to said responsive means.
2. An apparatus as claimed in claim 1, wherein the force
transmitted by the means which transmits force in one direction
only is a tension force.
3. An apparatus as claimed in claim 2, wherein said means effective
to transmit force in one direction only comprises an elongated
flexible member.
4. An apparatus as claimed in claim 1, wherein said engine is an
internal combustion engine of the fuel injection type and said
speed control means includes rack and pinion means controlling the
position of injector pistons.
5. A fail safe apparatus for controlling the speed of an engine
comprising:
an engine speed control means,
a means for actuating said speed control means,
an accelerator pedal and
means operatively connecting said accelerator pedal and said
actuator means, said connecting means including
means for sensing failure of the accelerator pedal to return to a
normal condition upon an attempt to decelerate, and
means responsive to said sensing means for returning said actuating
means to a position in which said engine speed control means causes
said engine to run at idling speed,
said responsive means comprising a valve responsive to said sensing
means, said valve controlling the application of vacuum to a
cylinder and piston means.
6. An apparatus as claimed in claim 5 comprising means effective to
transmit force from said responsive means to said actuator means
but ineffective to transmit force from said actuating means to said
responsive means.
7. An apparatus as claimed in claim 6 wherein the force transmitted
by the means which transmits force in one direction only is a
tension force.
8. An apparatus as claimed in claim 7, wherein said means effective
to transmit force in one direction only comprises an elongated
flexible member.
9. An apparatus as claimed in claim 8, wherein said engine is an
internal combustion engine of the fuel injection type and speed
control means includes rack and pinion means controlling the
position of injector pistons.
Description
In the earlier application Ser. No. 88,450 there are disclosed
multiple species of systems which teach the concept of how to
de-activate or return to idle the engine of a motor vehicle which
is controlled by a carburetor when the accelerator linkage becomes
impaired, thus preventing proper operation because of jamming or
freezing of the linkage, disconnection of parts, failure of the
accelerator linkage return spring, as well as most other forms of
such difficulties.
As was disclosed in the earlier application Ser. No. 88,450 and was
also true in application Ser. No. 153,330, it is of particular
concern that the engine speed of the motor vehicle be returned to
an idle condition when some impairment to the linkage operation
occurs, for it is vitally essential that the continued operation of
the engine in present motor vehicles be maintained, since many of
these vehicles depend upon power accessories, such as brakes and
steering, that operate off the power of the engine or vacuum of the
manifold and which would otherwise be practically useless without
the engine running.
As mentioned in the previous applications, the fail-safe throttle
control is indeed applicable to fuel injection racks of Diesel
engines and, quite obviously, therefore the control mechanisms of
all fuel injected engines whether Diesel or spark ignited. This
application is intended to show application of the species of this
invention to various fuel injection control units as used in Diesel
or gasoline powered engines.
Fuel injectors in most cases inject fuel under high pressure
directly into the cylinder at the correct time during the
compression stroke to cause proper ignition in the Diesel or in
time to be ignited in the spark ignition engine. Timing of
injection is commonly controlled by a cam shaft in the same manner
as valve timing, as is well known in the art, and normally does not
control the speed or load characteristics of the engine. In the
fuel injected engine the speed is dependent upon the quantity of
fuel injected and the amount of load applied, so that more fuel is
needed when the load increases just to maintain the same speed
(otherwise the speed will drop) or to increase the speed under a
uniform load. The injector system therefore requires a metering
system to provide precisely the right amount of fuel for the load
conditions presented.
Various methods and combinations have been devised to meter and to
distribute the fuel to each cylinder of an engine. There are three
basic systems in use: the individual pump system in which the fuel
injector in each cylinder is the metering device and the high
pressure pump, the distributor system in which a single pump
provides the metering of the fuel and the high injection pressure,
the fuel being routed through a distributor to the proper cylinder,
and the common rail system wherein high pressure fuel is supplied
from a single pump to all of the fuel injectors, the individual
injector metering the quantity of fuel during injection.
All of the basic systems have a metering device which, in its most
common form, is a helically grooved plunger within a housing with
fixed inlet ports, which is axially moved a fixed distance by a cam
which is gear driven from the crankshaft, and which meters the fuel
by the angular relationship between the plunger and the housing.
This angular relationship is most commonly achieved by utilizing a
pinion gear attached to the plunger, this element engaging a "rack"
gear which is slidably fitted within the housing, so that when the
rack is pushed or pulled, it changes the angular relationship
between the plunger and housing and therefore the quantity of fuel
metered. This rack is called a control rack or control rod. When
multiple metering units are used, all of the racks are connected
together, holding each plunger in precisely the same angular
position, so that upon actuation each plunger meters exactly the
same amount of fuel to its respective cylinder. Thus, it will be
understood that when the rack is at one end of its stroke, the
metering plunger is adjusted to provide maximum fuel allowing
maximum speed, while when the rack is at the other end of its
stroke, the plunger is adjusted to deliver no fuel, thus stopping
the engine. Accordingly, it will be appreciated that by
reciprocation of the rack between these extreme positions, the
amount of fuel supplied is varied to provide speeds from idle to
full speed. With the system disclosed herein and considered in its
simplest form, with the accelerator linkage attached to the end of
the control rod, control of the engine can be achieved in the same
manner as in a gasoline engine which utilizes a carburetor.
As will be understood from a careful study of this application, it
is not necessary, however, to have a direct mechanical connection
to the control rack. Daimler Benz AG of Stuttgart-Unterturkheim,
Germany, use, on their Mercedes Benz automobile, a vacuum-operated
governor between the manifold and the control rod and place a
throttle plate within the intake manifold to control the amount of
air fed to the engine, and thus vary the vacuum within the intake
manifold, which, in turn, controls the position of the rack through
a spring-loaded diaphragm. This provides not only the necessary
movement of the control rod, but constant speed governing as
well.
Accordingly, the principal object of this invention is to
incorporate, into the linkage system extending from the accelerator
pedal of an internal combustion engine to the control rod or rack
of a fuel injection system, a trigger mechanism which is capable of
sensing an operator's act of deceleration of a motor vehicle and
compensation for any unknown impairment in the linkage by instantly
returning the control rack to idle position.
Another object of this invention is to provide for operation of the
trigger mechanism by either mechanical, electrical and/or pneumatic
means.
Still another object of this invention is to provide a fuel
injection throttle control linkage system for use in motor vehicles
which has incorporated therein a second trigger mechanism.
A still further object of this invention is to include in the
electrical system for actuating the fuel injection control rod an
electrical switch or a pneumatic valve arranged to be operated by
the accelerator pedal.
Yet another object of this invention is to incorporate into the
linkage system and electrical elements combined therewith a
solenoid member that is arranged to operate the trigger means
either by a pull or push operation thereof.
Further objects and advantages will become apparent from a reading
of the following specification taken in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a and 1b generally are side elevational views of the
preferred embodiment of the invention showing the manner of
connecting a fuel injection control rack to an accelerator pedal
which includes dual pivot points;
FIG. 2 is an end elevational view of the trigger mechanism as
viewed in the direction of the arrow adjacent to the line A--A in
FIG. 1a;
FIG. 3 is a schematic side elevational view of a fuel injected
engine showing one injector in a cylinder and one system of moving
the control rack by rotation of a shaft which extends parallel to
the axis of the engine;
FIG. 4 is a schematic side elevational view of a four-cylinder fuel
injected engine showing the means of connecting the shaft which
actuates the control rack to the fail-safe throttle control;
FIG. 5 is a schematic side elevational view of the preferred
embodiment of the fail-safe throttle control in association with a
pneumatic governor control; and
FIG. 6 is a schematic side elevational view of the invention
utilizing a vacuum cylinder and a valve in place of the switch and
solenoid of FIGS. 1a and 1b.
Turning first to the view in FIG. 1b there is shown a typical
head-mounted fuel injector 150 commonly used on Diesel engines, and
used on some spark ignition engines. Extending horizontally and
outwardly towards the firewall of the vehicle is a control rack 151
engaging a gear 152, which when moved axially, rotates said gear
and a housing 153. The injector piston 154 moves slidably in a
fixed housing 155 upward and downward, being axially keyed and
slidably fitted to the top of the rotatable housing 153 so that
said piston turns with the housing 153 and can be angularly
adjusted by said housing and therefore by the control rack 151. The
injector piston 154 is pushed downward, through a fixed stroke
determined by accelerator position, by a rocker arm, activated by a
push rod and cam in exactly the same manner as the valves in an
automobile engine, none of which is shown, since it is very well
known to the art. The amount of fuel injected through an injection
port 160 is controlled by a helix 156. The injection pressure,
built up in a cavity 157 by injector piston 154 as it moves
downward, is relieved when said helix passes a port 158. It should
be obvious from the drawing that the angular position of injector
piston 154 thus determines the volume of fuel injected. As the
injector piston is rotated counterclockwise, the stroke becomes
shorter before the helix intersects the port 158 and the fuel
volume is small. When a slot 159 aligns with the port 158, no
pressure can be built up, since port 158 is always open, and
therefore no fuel is delivered. Accordingly, with such a condition,
the engine will stop. The control rack 151 therefore controls the
angular position of injector piston 154 and the volume of fuel
injected, and, as discussed earlier, it therefore controls the
speed of the engine.
The end of the control rack 151 is flattened and perforated to
receive a pivot pin 161 to which is attached a clevis 162, which is
rigidly attached to a push rod 163, the other end of which also
terminates in a clevis. The rod 163 is pivotally attached to an
upwardly extending ear 164 of a pivotal lever 165, which, in my
previous applications, was referred to as the throttle lever
18.
As is shown in FIG. 2, which generally corresponds to FIG. 2 in my
copending application discussed hereinafter, the pivotal lever 165
includes integral, oppositely-offstanding flange portions, one of
which is screw-headed and provided with a slow idle adjusting screw
20.
In a different way from my previous application the connecting
linkage between 28 and solenoid 94 has been changed to include a
new, non-rigid pull link 191 in place of rigid links 108 and 104.
Should solenoid 94 have a tendency to stick, the use of non-rigid
pull link 191 would prevent the throttle from being held open. The
possibility of such a failure was anticipated in my previous
application Ser. No. 153,330, filed June 15, 1971, wherein FIG. 5
shows a resilient spring mechanism inserted into linkage 108 for
just such purposes; however, the present construction is a greatly
simplified and inexpensive form of achieving the same result.
The remainder of the mechanism shown in FIGS. 1a and 2 is identical
in construction and operation to that of FIG. 1 of my previous
application Ser. No. 153,330, filed June 15, 1971, wherein pivotal
lever 165 assumes the identical function of the throttle lever of
that application.
As described in my previous application Ser. No. 153,330, it should
be clear that during normal operation of the motor vehicle the
fail-safe system remains in a passive non-influential condition
with the accelerator pedal serving to accelerate and decelerate the
vehicle, by means of the elements described, to maintain the
electrical contacts 88 and 90 of FIG. 1 out of contact, and the
non-rigid pull link 191 and latch 22, best shown in FIG. 1, moving
unrestrained with the linkage.
However, should various types of failure appear in the mechanism,
which is required for normal operation of the vehicle, the
electrical contacts are brought into engagement, as shown in FIG. 4
of my earlier application, this operation serving to retract the
plunger of the solenoid into its housing, causing the non-rigid
link 191 to pull the pin 30 forwardly, thereby rotating body 28
against spring 32 to withdraw the latch 22 from lever 26 so that
the pivotal lever 165 will instantly push the control rack to
idle.
Referring now to FIG. 3 there is shown injector 150 mounted in
cylinder head 166 so that control rack 151 moves horizontally and
perpendicularly to the axis of the engine 167 and crankshaft 168
(shown in FIG. 4). At one end of said control rack is fitted a
pivot pin 168', which is slidably fitted into slot 169 of lever
170, which, in turn, is rigidly mounted on shaft 171. Shaft 171 is
disposed parallel to the axis of engine 167, pivotally mounted to
supports (not shown) and rigidly affixed to a cylinder head 166, so
that, as shaft 171 is rotated, control rack 151 is moved to the
right or left. At one end of shaft 171 is rigidly mounted a control
lever 172 having a pivot ball 173 extending horizontally therefrom.
Pivotally mounted on pivot ball 173 is a socket 174 and a shaft
175, as is commonly used in modern day automotive carburetor
linkages.
As shown in FIG. 4, shaft 175 extends downwardly terminating in a
second ball socket 176 and pivotally attached to a ball 177, which
is rigidly attached to a lever extension 178 which has been added
to the pivotal lever 165.
Shown more clearly in FIG. 4, the shaft 171 which extends forwardly
along the upper side of the engine 167 past each of the fuel
injectors 150, and at each of which are provided levers 170 to move
the control rack 151 in precise alignment with all of the others,
thus assuring the identical volume of fuel to each cylinder at its
given speed setting.
It should be obvious that by rotating pivotal lever 165 clockwise,
shaft 175 will push lever 172 upwardly, thereby rotating shaft 171
in such a manner as to move control rack 151 to the right, thus
increasing the fuel volume and therefore the speed of the
engine.
It should be obvious to those skilled in the art that the fail-safe
system will operate, as in previous applications, by forcing lever
165 to return the control rack to idle, should the accelerator
linkage become inoperative.
Referring at this time to FIG. 5, there is shown the Robert Bosch
GMBH fuel injection system which includes an intake manifold 179
and within which is pivotally supported the throttle plate lever
181 by means of a shaft 182. The shaft 182 in this view performs
the equivalent function of shaft 16 and to which is attached the
oscillatable lever 26 as disclosed in my copending application Ser.
No. 153,330. In such a construction a vacuum line 183 communicates
with the chamber 184 in the housing 185. This chamber is sealed
with a diaphragm 186 and is arranged to abut the end of the rack
151, a spring 187 being interposed between the diaphragm 186 and
the inside right end wall of the housing 185. As shown, the chamber
188 to the left of vacuum diaphragm 186 communicates with
atmosphere through opening 189.
It is believed to be apparent from the foregoing to those skilled
in the art that this construction describes the well-known vacuum
actuator.
At idle, the throttle plate is closed and the vacuum within the
venturi 180 is high, therefore the vacuum within chamber 184 is
high, causing diaphragm 186 to pull control rack 151 to the right
against the force of spring 187, thereby reducing the fuel flow to
the engine. At other load and speed conditions the control rack
position varies, depending upon the difference in pressure between
chambers 184 and 188. At high engine load, the throttle plate is
wide open and the vacuum is low, allowing spring 187 to urge
diaphragm 186, and thus control rack 151, to the left, providing
maximum fuel flow. It can be seen that the control rack position is
entirely controlled without a direct mechanical link to the
accelerator pedal 52, and that throttle plate 181 performs in the
same manner as throttle plate 14 of the conventional carburetor,
thus the fail-safe throttle system would operate equally well when
connected to throttle plate 181, in the same manner as in a
conventional carburetor.
Pneumatic means may be substituted for the electrical means of
actuating the safety trigger in the embodiments described in this
and my previous application wherein a valve may be substituted for
switch contacts 88 and 90 and a vacuum actuator for solenoid
94.
Referring now to FIG. 6, there is shown the dual pivot acceleration
mounting arrangement of my previous application with face 76
bearing against one end of rod 192 which is slidably fitted within
guide 193 which is affixed to the firewall of the vehicle; the
other end of rod 192 bearing against the face 194 of one arm of
right angle lever 195 which is pivotally mounted through pin 196 to
support 197 which is rigidly affixed to the body of the vehicle.
The second arm of right angle lever 195 extends to the left and is
urged downwardly by compression spring 198 which is disposed
between its upper surface 199 and support surface 200 which is
rigidly affixed to the body of the vehicle. The lower surface of
the right angle lever arm bears against the actuating button 202 of
a normally closed vacuum valve 203. One vacuum connection 204 of
vacuum valve 203 communicates with the engine manifold vacuum and
the other side of vacuum valve 203 communicates through tube 205
with vacuum actuator 206, the output shaft 207 being firmly
connected to non-rigid pull link 191.
It will thus be apparent that the function of this arrangement of
elements replaces the functions of solenoid 94 and contacts 88 and
90 and their immediately associated elements. During normal
operation of the vehicle the pull on cable 42 and/or the pedal
pressure on pedal 52 force rod 192 against lever 195 urging spring
198 against its support and allows actuating pin 202 to extend from
the valve body 203 thus closing off the vacuum from the manifold to
the vacuum actuator 206. Should the pull force in cable 42 be
relaxed, however, due to the linkage sticking and the operator
removes his foot from the pedal 52, the force against rod 192 is
removed and spring 198 urges lever 195 and actuating pin 202
downward opening vacuum valve 203 causing vacuum to be applied to
the vacuum actuator 206 pulling on the non-rigid pull link 191,
thereby returning the throttle to idle as previously described.
In all Diesel applications a stop control is required to move the
control rack to the stop position, where no fuel is delivered. This
has not been shown in any of the schematic illustrations since it
does not affect the basic operation of the fail-safe throttle
control and can be accomplished in many ways that are well known to
the art of Diesel control.
It should also be clear from the foregoing discussion that all of
the other embodiments of my previous applications are applicable to
fuel injection systems, as is the preferred embodiment, and that
the embodiments described in this application are applicable to
carburetor controlled gasoline engines.
* * * * *