US3651794A

US3651794A - Throttle for gaseous fuels

Info

Publication number: US3651794A
Application number: US46003A
Authority: US
Inventors: Lloyd A Douglas
Original assignee: Victor Equipment Co
Current assignee: Victor Equipment Co
Priority date: 1970-06-15
Filing date: 1970-06-15
Publication date: 1972-03-28
Anticipated expiration: 1989-03-28

Abstract

An accelerator control system for an automobile employing a gaseous fuel in an internal combustion engine, characterized by a dome loaded pressure regulator interposed between a fuel reservoir and an intake manifold; and a fluid sealed signal conveying unit connected with the dome of the pressure regulator and responsive to movement of an accelerator pedal to transmit rapidly acceleration and deceleration signals to the pressure regulator and correspondingly increase or decrease the intake manifold pressure. The engine has a separate air intake manifold but its power; and, hence, r.p.m. at a given load condition; are controlled by the pressure regulator. Also disclosed are preferred embodiments which employ a shut-off valve intermediate the manifold and the fuel source, adjustable flow restrictions in conduits leading to the individual cylinders to obtain even fuel distribution, and trim pressure adjustment on the signal conveying unit for controlling the idling manifold pressure.

Description

States Patent [l5] [451 an,

[72] Inventor:

[52] US. Cl ..l23/l20 [51] Int. Cl ..F02m 21/02 [58] Field oiSearch ..l23/l20, 108,27 GE, 75 B, 123/106; 137/505.42

[56] References Cited UNITED STATES PATENTS 2,352,003 6/1944 Poinsignon 123/120 X 2,896,599 7/1959 Ensign 123/120 3,306,273 2/1967 Dolphin 123/120 X 2,972,988 2/1961 Ranck ..l23/l20 3,540,419 11/1970 Fox 123/120 X 2,652,039 9/1953 Weslake... .....l23/75 B 2,320,886 6/1943 Quiroz..... .137/505.42 2,753,856 7/1956 Rush ..l23/l20 2,780,209 2/1957 Renken ..123/120 X 3,357,687 12/1967 Vanderpoel. .....l23/120 X 2,724,372 l1/1955 Schowalter ..l23/27 GE FOREIGN PATENTS OR APPLICATIONS 806,397 12/1936 France 123/120 Primary Examiner-Mark M. Newman Assistant Examiner-Richard Rothman Attorney-Wofl'ord and Felsman [57] ABSTRACT An accelerator control system for an automobile employing a gaseous fuel in an internal combustion engine, characterized by a dome loaded pressure regulator interposed between a fuel reservoir and an intake manifold; and a fluid sealed signal conveying unit connected with the dome of the pressure regulator and responsive to movement of an accelerator pedal to transmit rapidly acceleration and deceleration signals to the pressure regulator and correspondingly increase or decrease the intake manifold pressure. The engine has a separate air intake manifold but its power; and, hence, r.p.m. at a given load condition; are controlled by the pressure regulator. Also disclosed are preferred embodiments which employ a shut-off valve intermediate the manifold and the fuel source, adjustable flow restrictions in conduits leading to the individual cylinders to obtain even fuel distribution, and trim pressure adjustment on the signal conveying unit for controlling the idling manifold pressure.

6 Claims, 1 Drawing Figure TnaoTTLE FOR GASEOUS FUELS BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to improvements in fuel supply apparatus for internal combustion engines. More particularly, it relates to an improved accelerator control system for an internal combustion engine employing a gaseous fuel.

2. Description of the Prior Art A wide variety of accelerator control structures and systems are known in the prior art for controlling injection of fuel; or in effecting supplemental control in a fuel air mixture wherein fuel enrichment or derichment is effected in response to vacuum pressure detected via an intake manifold. Moreover, it is known to control flow of air and fuel in response to a computer to effect an optimum fuel air ratio in an engine being operated under fairly constant loads such as are encountered on a pipeline. Such prior art systems have not been satisfactory in effecting operation of an internal combustion engine on a gaseous fuel such as natural gas in response to rapid acceleration and deceleration changes such as effected in an ordinary driver driving an automobile in traffic. Moreover, the prior art systems have controlled the fuel air ratio and have not effected satisfactory combustion without controlling the influx of the air, or other oxygen-containing gas for supporting combustion.

BRIEF DESCRIPTION OF THE DRAWING The FIG. is a schematic view, partly in section, illustrating one embodiment of this invention.

DESCRIPTION OF PREFERRED EMBODIMENTS It is an object of this invention to provide an accelerator control system that is operable to control power; and, hence, revolutions per minute (r.p.m.); by controlling only the intake manifold pressure of a gaseous fuel in response to an accelerator pedal means.

It is a specific object of one aspect of this invention to provide an accelerator control system that employs a rapid conveyance, via a pressure wave in a fluid medium, of acceleration and deceleration signals to effect a corresponding and compensated response in the pressure of a gaseous fuel in a fuel intake manifold, regardless of the pressure of a fuel tank containing the gaseous fuel.

Referring to the figure, internal combustion engine 1 1 has a plurality of cylinders 13 for internal combustion of a gaseous fuel to derive power therefrom. As is conventionally employed, a piston, connecting rod, and crank shafts are employed within the internal combustion engine 11 to convert the chemical energy into a useable mechanical form. A firing means; such as, a glow plug or spark plug 15; is connected via suitable conductor 17 with an electrical distribution system for effecting timed ignition of a fuel charge within each cylinder 13. The electrical interconnection of conductors via an appropriate distributor and distribution system to efiect the timed ignition is well known, does not comprise a part of this invention and need not be described herein.

Internal combustion engine 11 also has an oxygen intake means such as air intake manifold 19. Air is drawn in through a suitable filter 21 to remove dust and other destructive particles therefrom. If a conventional engine having a carburetor thereon is employed, it may be converted by simply opening the butterfly valve in the throat of the carburetor. It is not necessary to control the flow of air in this embodiment of this invention. The actual air intake into the cylinder may be effected via intake valves or suitably located ports, depending upon whether internal combustion engine 11 is a two cycle engine or a four cycle engine. The intake porting or valving for either type of engine is well known and need not be described herein.

Internal combustion engine 11 employs, as indicated, a gaseous fuel. The gaseous fuel may be contained in a fuel tank 23 at super atmospheric pressure. For example, fuel tank 23 may contain natural gas at a pressure of up to 2,200 pounds per square inch gauge (p.s.i.g.). Fuel tank 23 may be connected by appropriate pressure conduit 25 with an intake manifold means at the internal combustion engine ill. If desired, a high pressure regulator 27 may be employed to control the pressure in pressure conduit 25 at some relatively high pressure higher than will be desired in the fuel intake manifold means, but lower than the pressure in the fuel tank 23; for example, at a pressure in the range of about 50-100 p.s.i.g.

The fuel intake manifold means may comprise a fuel intake manifold 29 and a plurality of individual flow conduits 31. Each flow conduit 31 is connected with the fuel intake manifold 29 and with a respective one of the cylinders 13. Each flow conduit 31 has interposed in it a check valve 33 and an adjustable flow restricting means such as restriction valve 35. Check valve 33 prevents backflow of high pressure fluid from within cylinder 13 on the compression stroke of the piston therewithin. Individual restriction valves 35 are adjusted to obtain a uniform quantity of fuel through each respective individual flow conduit 31 into each respective cylinder 13 at a given pressure in the fuel intake manifold 29. Thus, uniform power is developed in each respective cylinder regardless of the pressure on fuel intake manifold 29. Preferably, the actual injection passageway 37 and check valve 33 are closely adjacent the internal chamber of cylinder 13 with injection passageway 37 canted so as to deliver a charge of gaseous fuel that, in combination with the entering air, effects a swirling movement so that the fuel is directed toward the center of the cylinder 13. In this way, the richest portion of the fuel air mixture will occur adjacent spark plug 15 so as to always effect ignition of the fuel regardless of how lean the fuel air mixture becomes adjacent the peripheral wall of the cylinder 13.

A fuel cut-off valve that is operable into an open and into a closed position for running and stopping the internal combustion engine 11 is interposed between and in series connection with fuel intake manifold 29 and fuel tank 23. Specifically, solenoid actuated valve 39 is interposed in conduit 41 so as to be electrically operable into an open position for starting the engine and into a closed position for stopping the engine. Its associated solenoid 43 may be a self-latching relay such that when pulsed, as by turning an ignition key on or off, it is energized electrically or mechanically into and remains in a corresponding position until oppositely pulsed; or, it may be maintained energized all the time the ignition key is on to maintain the valve 39 open. While cut-off valve 39 may be interposed at any location intermediate fuel tank 23 and fuel intake manifold 29, it is preferably located downstream of fuel pressure regulator 45 so that a low pressure valve may be employed.

The fuel pressure regulator 45 is interposed in series connection with cut-off valve 39 between fuel intake manifold 29 and fuel tank 23. The fuel pressure regulator 45 is operable to control a downstream pressure that is substantially the same as the pressure in the fuel intake manifold. Normally, the pressure in the fuel intake manifold runs from an idling pressure of only a few inches of water to a maximum running pressure of several or even many p.s.i.g. Preferably, the pressure regulator 45 has a biasing element such as spring 47 and a pressure responsive element such as diaphram 49. Spring 47 is preset to effect a predetermined downstream pressure at atmospheric pressure on diaphram 49. The compressive force on spring 47 may be effected by a suitable screw passed through a threaded aperture. The screw is thus pre-set at the factory, although it may be altered by removing a portion of the dome and; for example, screwing inwardly to increase the pressure. As illustrated, however, dome 51 is dome loaded. That is, it is sealingly connected with diaphram 49 and not vented to the atmosphere. Thus, the dome pressure acting on diaphram 49 may be altered to increase or decrease the downstream pressure. Fuel pressure regulator 45 may be of the single stage compensated type such as described in copending application Ser. No. 827,711, by Ray R. Zimmer entitled Single Stage,

Compensated Pressure Regulator, and assigned to the assignee of the present invention, or it may be a two stage compensated regulator. The compensation is preferably employed to obtain accurate and predictable response in effecting a desired manifold pressure regardless of the pressure in fuel tank 23. Such compensation becomes less critical if a high pressure regulator 27 is employed although it is still desirable if the fuel pressure in fuel tank 23 becomes less than the pressure for which the high pressure regulator 27 is set.

An accelerator pedal means is disposed in the interior of the automobile for imparting relatively rapid acceleration and deceleration signals to the internal combustion engine 11.

' Specifically, a foot accelerator pedal 53 is pivotally mounted on mounting 55. Foot accelerator pedal 53 is depressed to signal an acceleration signal and is allowed to spring upwardly to signal a deceleration signal to the fuel pressure regulator 45. Fuel pressure regulator 45, in turn, controls the pressure in the fuel intake manifold 29 and, consequently, the power output from the internal combustion engine 11.

A fluid sealed signal conveying means is disposed intermediate the accelerator pedal means and the fuel pressure regulator for signaling the fuel pressure regulator to increase or decrease the fuel intake manifold pressure in response to the respective acceleration or deceleration signal from the accelerator pedal means. The fluid sealed signal conveying means 57 comprises a conduit means 59 and a pressure generating unit 61. The conduit means 59 is connected with dome 51 of the fuel pressure regulator 45 so as to alter the manifold pressure as a predetermined function of the pressure in the signal conveying means 57. The pressure generating unit 61 is connected with the other end of the conduit means and positioned adjacent and operably responsive to the accelerator pedal means illustrated as foot accelerator pedal 53. As illustrated, dome 51 is sealingly connected with the conduit means 59 such that any pressure generated by pressure generating unit 61 is transmitted directly to diaphram 49 and a predetermined and corresponding change in downstream pressure thereby effected. Thus, an acceleration signal, denoted by depression of foot accelerator pedal 53, is conducted with the speed of the pressure wave via conduit means 59 to diaphram 47 to signal the fuel pressure regulator 45 to increase the downstream pressure, or fuel intake manifold pressure, Conversely, releasing foot accelerator pedal 53 signals a decrease in fuel intake manifold pressure via the same route.

The pressure generating unit 61 has a centrally disposed diaphram member 63 that is disposed adjacent and responsive to shaft 65, which is, in turn, responsive to movement of foot accelerator pedal 53. Shaft 65 may be connected with diaphram member 63 as by a nut; and with foot accelerator pedal 53 as by a pivot pin; or otherwise held as by being compressively disposed therebetween. Spring 67 beneath diaphram member 63 biases diaphram member in the opposite direction to decrease the pressure in the pressure generating unit 61 when the foot accelerator pedal 53 is released. Expressed otherwise, diaphram member 63 is depressed to increase the pressure by downward movement of accelerator pedal 53 and is moved in the opposite direction of decrease the pressure in the dome 51 by the spring 67.

The signal conveying unit may be filled with either a gas or a liquid. A gas such as air affords a convenience in loading and is economical. On the other hand, a liquid has less compressibility and effects a more rapid response to the acceleration or deceleration signals.

A trim pressure adjustment means is provided for effecting a predetermined pressure in the dome 51 at a given setting of the accelerator pedal for controlling the manifold pressure at the idling speed of the engine. Specifically, a screw 69 is sealingly inserted in a threaded aperture 71 in pressure generating unit 61 such that the diaphram member 63 may be positioned at any point to effect a given quantity of the fluid in the signal conveying means 57. Screw 69 is thereafter inserted to trap the fluid therein and effect the predetermined pressure. in addition, the pressure may be adjusted precisely by increasing or decreasing the volume minutely, as by screwing screw 69, respectively, outwardly or inwardly.

In operation, a given quantity of fluid is entrapped in signal conveying means 57 and the foot accelerator pedal 53 allowed to rest at a desired position. Once set, little further adjustment need be made. The ignition key may be turned on to open solenoid valve 39 and connect the fuel intake manifold 29 with the fuel pressure regulator 45 for starting the engine. The engine is started in the conventional manner. Upon a signal to accelerate, fuel pressure regulator 45 increases the pressure in the fuel intake manifold 29 from a few inches of water to several p.s.i.g., depending upon the degree of acceleration signalled by the driver.

Within the individual cylinders, air is taken in at a relatively constant rate if there is no adjustable butterfly or obstruction. On the intake, when the pressure in the cylinder gets below the pressure in the fuel intake manifold, the gaseous fuel flows through check valve 33 and through canted passageway 37 into the interior of cylinder 13. If internal combustion engine 11 is a two cycle engine this fuel flow occurs on every stroke. Alternatively, if it is a four cycle engine the fuel flow may occur on every stroke if desired to sweep out the exhaust gases; or it may be valved such that the fuel gas is taken into the cylinder only on the compression stroke. In any event, the gaseous fuel is admixed with the air; although not necessarily uniformly, since it is preferably richer in the central portion adjacent the spark plug, or the glow plug. At the proper time, as determined by a distributor, the fuel is ignited and burned in cylinder 13 for delivering power during the expansion stroke. if it is desired to decelerate, the foot is removed from the foot accelerator pedal and the diaphram member 63 moves backwardly, or upwardly, decreasing the pressure in dome 51 and on diaphram 49. This effects a decreased downstream pressure and a decreased pressure in the fuel intake manifold 29. Consequently, less fuel is delivered to the cylinder 13 and lower power is realized from the engine. There is a concomitant slowing of the automobile. lf acceleration is again signalled by depression of the foot accelerator pedal, diaphram 49 senses the increased pressure and increases the fuel pressure in the fuel intake manifold 29. Consequently, a greater amount of fuel enters the cylinder 13 to deliver a greater amount of power.

When it is desired to kill the engine, cut-off valve 39 is closed to cut off the flow of fuel thereto.

A preferred embodiment has been described hereinbefore in which a fluid filled signal conveying means is employed intermediate a foot accelerator pedal and a fuel pressure regulator for controlling the pressure of the fuel in a fuel intake manifold. If desired, other embodiments, such as, a mechanical connection between the foot accelerator pedal and a spring balanced diaphram in the fuel pressure regulator; could be employed to control the fuel pressure in the fuel intake manifold. Such embodiments may have, however, aspects that are not as advantageous as the preferred embodiment described hereinbefore.

One of the advantages of this invention is that no exotic new materials are required but those materials ordinarily employed in manufacturing pressure regulating elements, valves and engine parts, may be employed herein. One advantage that has been found with this operation, in which the richest fuel air mixture is adjacent the glow plug 15, is that, if desired, the electrical charge to the glow plug 15 can be reduced after the engine has been warmed up and still effect satisfactory combustion.

It can be seen from the foregoing descriptive matter that this invention provides an accelerator control system that obviates the disadvantages of the prior art devices and controls the power; and, hence, rpm at a given load; by controlling only the intake manifold pressure for a gaseous fuel in response to an accelerator pedal operation. It also can be seen that this invention provides an accelerator control system that employs a fast response in one aspect, via a pressure wave in a confined fluid medium, to convey the acceleration and deceleration signals to a pressure regulator that correspondingly and responsively controls pressure of a fuel intake manifold to regulate the power provided by an internal combustion engine.

Although the invention has been described with a certain degree of particularity, it is understood that the present disclosure is made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention.

What is claimed is:

1. An accelerator control system for an automobile employing a gaseous fuel in the cylinders of its internal combustion engine, comprising:

a. oxygen intake means connected with said cylinders for intake of a combustionsupporting gas; said oxygen intake means being set at a predetermined setting independent of movement of an accelerator pedal means in a gas flow system controlling the flow of the gaseous fuel;

. a source of gaseous fuel at super atmospheric pressure;

c. fuel intake manifold means comprising a fuel manifold connected with said source of gaseous fuel, and a plurality of flow conduits; each flow conduit being connected with said manifold and with a respective one of said cylinders and having a check valve means connected therewith for preventing back flow of fluid from said cylinder to said fuel manifold;

d. a fuel cut-off valve that is operable into an open and into a closed position for running and for stopping said engine;

e. a fuel pressure regulator that is operable to control a downstream pressure that is substantially the same as the pressure in said manifold from an idling pressure of a few inches of water to a maximum running pressure of many pounds per square inch gauge in response to a biasing element and a pressure responsive element associated therewith; said flow pressure regulator and said fuel cutoff valve being interposed in series connection between and connected with said source of gaseous fuel and said fuel intake manifold means;

accelerator pedal means disposed in the interior of said automobile for imparting relatively rapid acceleration and deceleration signals to said fuel pressure regulator; and g. fluid sealed signal conveying means disposed intermediate said accelerator pedal means and said fuel pressure regulator for signalling said fuel pressure regulator to increase or decrease the fuel manifold pressure in response respectively to the accelerate or decelerate signal from said accelerator pedal means; said fluid sealed signal conveying means comprising a conduit means connected at one end with said fuel pressure regulator so as to alter the manifold pressure as a predetermined function of the pressure in said signal conveying means; and a pressure generating unit sealingly connected with the other end of said conduit means and positioned adjacent and operably responsive to said accelerator pedal means.

2. The accelerator control system of claim 1 wherein said fuel pressure regulator is a compensated, preset, dome loaded pressure regulator, the dome of which is sealingly connected with said conduit means of said signal conveyor means, said dome being also sealingly connected with a diaphram serving as said pressure responsive element of said fuel pressure regulator.

3. The accelerator control system of claim I wherein said flow conduits contain respective adjustable flow restricting means for effecting equal flow of the gaseous fuel to all cylinders.

4. The accelerator control system of claim 1 wherein said signal conveying means contains a trim pressure adjustment means for effecting a predetermined pressure therein for controlling the manifold pressure and, consequently, the speed of said engine when idling.

5. An accelerator control system for an automobile employing a gaseous fuel in the cylinders of its internal combustion engine, comprising:

b. a source of gaseous fuel at super atmospheric pressure;

0. fuel intake manifold means comprising a fuel manifold connected with said source of gaseous fuel, and a plurality of flow conduits; each flow conduit being connected with said manifold and with a respective one of said cylinders;

. a fuel cut-off valve that is operable into an open and into a closed position for running and stopping said engine;

e. a fuel pressure regulator that is operable to control a downstream pressure that is substantially the same as the pressure in said manifold from an idling pressure of a few inches of water to a maximum running pressure of many pounds per square inch gauge; said flow pressure regulator and said fuel cut-off valve being interposed in series connection between and connected with said source of gaseous fuel and said fuel intake manifold means;

f. accelerator pedal means disposed in the interior of said automobile for imparting acceleration and deceleration signals to said fuel pressure regulator; and

g. signal conveying means disposed intermediate said accelerator pedal means and said fuel pressure regulator for signalling said fuel pressure regulator to increase or decrease the fuel manifold pressure in response respectively to the accelerate or decelerate signal from said accelerator pedal means; said signal conveying means being connected with said fuel pressure regulator so as to alter the manifold pressure as a predetermined function of movement of said accelerator pedal means.

6. The accelerator control system of claim 5 wherein a high pressure regulator is emplaced intermediate said source of gaseous fuel and said fuel pressure regulator to control the pressure therebetween at a pressure intermediate the super atmospheric pressure of said source of gaseous fuel and the fuel manifold pressure; and wherein a check valve means is interposed between each said respective cylinder and each said flow conduit in association with a canted injection passageway which injects the gaseous fuel into said cylinder at an angle so as to effect a swirling motion within said cylinder and emplace the richest part of the fuel air mixture adjacent a firing means in said cylinder.

i i X i lnunn A.

Claims

1. An accelerator control system for an automobile employing a gaseous fuel in the cylinders of its internal combustion engine, comprising: a. oxygen intake means connected with said cylinders for intake of a combustion-supporting gas; said oxygen intake means being set at a predetermined setting independent of movement of an accelerator pedal means in a gas flow system controlling the flow of the gaseous fuel; b. a source of gaseous fuel at super atmospheric pressure; c. fuel intake manifold means comprising a fuel manifold connected with said source of gaseous fuel, and a plurality of flow conduits; each flow conduit being connected with said manifold and with a respective one of said cylinders and having a check valve means connected Therewith for preventing back flow of fluid from said cylinder to said fuel manifold; d. a fuel cut-off valve that is operable into an open and into a closed position for running and for stopping said engine; e. a fuel pressure regulator that is operable to control a downstream pressure that is substantially the same as the pressure in said manifold from an idling pressure of a few inches of water to a maximum running pressure of many pounds per square inch gauge in response to a biasing element and a pressure responsive element associated therewith; said flow pressure regulator and said fuel cut-off valve being interposed in series connection between and connected with said source of gaseous fuel and said fuel intake manifold means; f. accelerator pedal means disposed in the interior of said automobile for imparting relatively rapid acceleration and deceleration signals to said fuel pressure regulator; and g. fluid sealed signal conveying means disposed intermediate said accelerator pedal means and said fuel pressure regulator for signalling said fuel pressure regulator to increase or decrease the fuel manifold pressure in response respectively to the accelerate or decelerate signal from said accelerator pedal means; said fluid sealed signal conveying means comprising a conduit means connected at one end with said fuel pressure regulator so as to alter the manifold pressure as a predetermined function of the pressure in said signal conveying means; and a pressure generating unit sealingly connected with the other end of said conduit means and positioned adjacent and operably responsive to said accelerator pedal means.

2. The accelerator control system of claim l wherein said fuel pressure regulator is a compensated, preset, dome loaded pressure regulator, the dome of which is sealingly connected with said conduit means of said signal conveyor means, said dome being also sealingly connected with a diaphram serving as said pressure responsive element of said fuel pressure regulator.

3. The accelerator control system of claim 1 wherein said flow conduits contain respective adjustable flow restricting means for effecting equal flow of the gaseous fuel to all cylinders.

5. An accelerator control system for an automobile employing a gaseous fuel in the cylinders of its internal combustion engine, comprising: a. oxygen intake means connected with said cylinders for intake of a combustion-supporting gas; said oxygen intake means being set at a predetermined setting independent of movement of an accelerator pedal means in a gas flow system controlling the flow of the gaseous fuel; b. a source of gaseous fuel at super atmospheric pressure; c. fuel intake manifold means comprising a fuel manifold connected with said source of gaseous fuel, and a plurality of flow conduits; each flow conduit being connected with said manifold and with a respective one of said cylinders; d. a fuel cut-off valve that is operable into an open and into a closed position for running and stopping said engine; e. a fuel pressure regulator that is operable to control a downstream pressure that is substantially the same as the pressure in said manifold from an idling pressure of a few inches of water to a maximum running pressure of many pounds per square inch gauge; said flow pressure regulator and said fuel cut-off valve being interposed in series connection between and connected with said source of gaseous fuel and said fuel intake manifold means; f. accelerator pedal means disposed in the interior of said automobile for imparting acceleration and deceleration signals to said fuel pressure regulator; and g. signal conveying means disposed intermediate said accelerator pedal mEans and said fuel pressure regulator for signalling said fuel pressure regulator to increase or decrease the fuel manifold pressure in response respectively to the accelerate or decelerate signal from said accelerator pedal means; said signal conveying means being connected with said fuel pressure regulator so as to alter the manifold pressure as a predetermined function of movement of said accelerator pedal means.