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Publication numberUS3766897 A
Publication typeGrant
Publication dateOct 23, 1973
Filing dateAug 23, 1971
Priority dateAug 23, 1971
Publication numberUS 3766897 A, US 3766897A, US-A-3766897, US3766897 A, US3766897A
InventorsR Husted
Original AssigneeAutomatic Switch Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fluidic control apparatus for fuel injection systems
US 3766897 A
Abstract
A fluidic controlled fuel injection system for internal combustion engines comprises an engine speed sensor and a sensor for monitoring the mass flow of air into the intake manifold. The sensors provide digitized fluidic inputs to fluidic logic circuits for deriving phased fluidic load signals utilized to control various fuel injection valves.
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Description  (OCR text may contain errors)

United States Patent mi Husted Oct. 23, 1973 [54] FLUlDlC CONTROL APPARATUS FOR 3,6l6,782 ll/l97l Matsui et al. 123/119 R FUEL-INJECTION SYSTEMS 3,672,339 6/1972 Lazar l23/DlG. 10

[75] inventor: Royce H. Husted, Wheaton, ill. [73] Assignee: Automatic Switch 0)., Florham Primary Bums Attorney-Breitenfeld & Levine Park, NJ.

[22] Filed: Aug. 23, 1971 [21] Appl. No.: 173,870 ABSTRACT 123/119 123/103 123/139 A fluidic controlled fuel injection system for internal l l0 combustion engines comprises an engine speed sensor F02! FOZm 39/00 and a sensor for monitoring the mass flow of air into Field of Search 139 the intake manifold. The sensors provide digitized flu- 123/119 103 103 B idic inputs to fluidic logic circuits for deriving phased fluidic load signals utilized to control various fuel in- [56] References Cited j tion valves.

UNITED STATES PATENTS 3,556,063 1/197-1 Tuzson 123/103 R 19 Claims, 2 Drawing Figures 54 r" g fl w m w L fl s m 1 l i M 82 ENGINE 5a tggg- I smear) e0 SENSDR 62 ea 1 FLUIDIC LOGIC 79 fh FUEL 68 7e 7 1p pumn 7e FLUlDlC r i i l MASS LOGIC 1 96/94 INTERNAL 9 99] AIR COBLBJEEON FLOW 8 10 7 E SENSOR FLUIDIC LOGIC FLUIDIC CONTROL APPARATUS FOR FUEL INJECTION SYSTEMS BACKGROUND OF THE INVENTION The present invention relates to fuel injection systems for internal. combustion engines, and more particularly to a novel approach for controlling fuel injection systems.

Improper carburetion is a significant factor contributing to air pollution by internal combustion engines. Improper fuel-air mixtures produce inefficient operation and, in many cases, an incomplete or total absence of combustion with'the resulting discharge of uncombusted fuel into the atmosphere.

The carburetor is most widely used for controlling the fuel-air mixture in internal combustion engines. Despite their wide use, carburetors are not capable of precise control of the fuelair mixture or ratio'for all engine operating conditions. Thus, matching carburetion to engine speed is largely a matter of compromise. Moreover, carburetors, in time, fall out of adjustment and are easily fouled.

Fuel injection systems are well known and are capable of more accurately and reliably controlling the fuelair mixture. However such systems are considerably more expensive than carburetors and thus their use has been limited to large engines or high performance, special purposeengines where the additional expense can be justified. A significant portion of the expense of fuel injection systems resides in the apparatus for controlling the fuel injection valves. 7

It is accordingly an object of the present invention to provide an improved fuel injection system for internal combustion engines.

An additional object is to provide a fluidic control for fuel injection systems.

Still another object is to provide a fluidic control of the above character, which is efficient and reliable in operation, and yet is inexpensive to manufacture.

Other objects of the invention will in part be obvious and in part appear hereinafter.

SUMMARY OF THE INVENTION Further in accordance with the invention, the engine speed sensor synchronizes the timing of the load signal pulses relative to each engine cycle such that the fuel is injected at the proper time.

For multi-cylinderinternal combustion engines, the sensor outputs are applied to plural fluidic logic circuits to derive discrete fluidic load signals to separate fuel injection valves associated with the various engine cylinders. To accommodate the fact that the reciprocations of the pistons in the various cylinders are relatively phased, the fluidic output signals of the engine speed sensor supplied to the various fluidic logic circuits are correspondingly time phased.- As a consequence, the resulting load signal pulses are also appropriately phased in time, in order that fuel injection for a particular cylinder is initiated at the proper time during the reciprocation cycle of the piston therein, as well These digitized fluidic output signals are processed in fluidic logic circuitry to derive a fluidic signal proportional to engine load for controlling a fuel injection valve to admit a determined amount of fuel.

More specifically, the digitized sensor output signals are processed by the fluidic logic to, in effect, enter a theoretically optimum load curve for the internal combustion engine on the basis of the prevailing engine speed and prevailing mass air flow into the intake manifold, pursuant to deriving the appropriate load signal. The informational aspect of the load signal is, in accordance with the present invention, its pulse duration which is utilized to control the duration the fuel injection valve is opened and thus the amount of fuel injected.

as for the appropriate time duration.

The invention accordingly comprises the features of construction, combination of elements and arrangements of parts which will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of thenature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a block-diagram of a fluidic controlled fuel injection system illustrating the principles of the present invention; and I FIG. 2 is a detailed fluidic logic and schematic diagram illustrating a specific embodiment of the invention.

Like reference numerals refer to corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION The apparatus of the invention is generally illustrated in FIG. 1 as including anengine speed sensor, generally indicated at 50, which is mechanically linked to an internal combustion engine 52, asrepresented by the dash line 54, to monitor engine RPM. The internal combustion engine is assumed to be a four cylinder engine, however, it will be apparent from the description to follow that the apparatus of the present invention can readily be adapted to control a fuel injection system for an engine having any number of cylinders.

The engine speed sensor 50 develops fluidic outputs, indicative of engine speed, which are supplied via fluidic connections 56, 58, 60 and 62 to separate, but identically constructed, fluidic logic circuits 64, 66, 68 and 70. As will be seen, sensor 50 may also be considered as a crank angle sensor. A sensor 72 is coupled by a fluid connection 74 to the throat of a venturi section 76, included in'the input end of an intake manifold 78 for the internal combustion engine, to monitor the mass flow, i.e., velocity, of air into the intake manifold, as

- controlled by throttle 79. This mass air flow sensor provides a fluidic output, representative of mass air flow, for application over fluidic connection 80 to each of the fluidic logic circuits 64, 66, 68 and 70. The fluidic outputs from sensors 50 and 72 are processed by the various fluidic logic circuits to derive separate load signals, indicative of the engine load, which are supplied over individual fluidic connections 82, 84, 86 and 88 to control respective fuel injection valves 90, 92, 94 and 96. These injection valves admit a determined amount of fuel supplied thereto under constant pressure by a fuel pump 98 via a fluid connection 100.

As is well known,thc reciprocation cycles of the pistons in a four cylinder engine are phased 90 apart, and thus the load signals derived by the four fluidic logic circuits must be correspondingly time phased, such that fuel is injected at the appropriate time in the reciprocation cycle of each piston. As will be seen from FIG. 2, appropriate phasing of the load signals is controlled by the engine speedsensor 50, which is effectively synchronized to the operating cycles of the various pistons. It will be appreciated that the invention is applicable to internal combustion engines having any number of cylinders. 7

As will be seen more clearly from FIG. 2, the fluidic outputs from the engine speed sensor 50 and from the mass air flow sensor 72 consist of plural, digitized fluidic output signals which are processed by the various fluidic logic circuits to effectively enter a theoretically optimum load curve for the particular internal combustion engine on the basis of the prevailing engine speed and the prevailing mass air flow into the intake manifold, pursuant to deriving phased fluidic load signals for controlling the various fuel injection valves. Specifically, the load signals are in the form of fluidic signal pulses which are properly timed relative to engine speed and are of appropriate durations to control the open time interval for the various fuel injection valves, thus determining the amounts of fuel injected.

Now turning to FIG. 2, the engine speed sensor 50 comprises, in the illustrated embodiment of the invention, an annular ring, schematically indicated at 102, for mounting a circular array of appropriately spaced fluidic sensors, schematically indicated at 104 and numbered 1 through 28 around the mounting ring. A semi-circular disc 106 is rotated coaxially with ring 102 in synchronism with the internal combustion engine via mechanical linkage 54 (FIG. 1). In practice, the disc 106 may be linked to the engine cam shaft and thus is rotated at one-half the engine speed.

The fluidic sensors 104 may take a variety of forms, so long as they have the capability of developing digitized fluidic output signals depending upon whether or not the periphery of disc 106 is in opposed relation thereto. Suitable fluidic sensors for use in the engine speed sensor 50 are back pressure sensors, such as shown in US. Pat. No. 3,545,256. In the application of these specific fluidic sensors to the engine speed sensor 50, they operate to develop relatively high fluidic pressure or logical ONE output signals as long as the periphery of disc 106 is in contiguous, opposed relation to their discharge orifices. On the other hand, when the periphery of disc 106 is not in opposed relation to their discharge orifices, they develop relatively low fluidic pressure or logical ZERO fluidic output signals.

The fluidic output signal developed by fluidic sensor No. 28 (also designated by the letter A), together with the fluidic output signals developed by fluidic sensors Nos. 1 through 12 are supplied over separate fluidic connections to fluidic logic 64. Although not specifically shown, it will be understood that the fluidic output signals generated by fluidic sensors Nos. 7 through 12 are also supplied to fluidic logic 66 (FIG. 1), together with the fluidic output signals generated by fluidic sensors Nos. 13 through 19. The fluidic output signals developed by fluidic sensors Nos. 14 through 19 are also supplied to the fluidic logic circuitry 68, to-

gether with the fluid output signals developed by fluidic sensors Nos. 20 through 26. Finally, the fluidic output signals developed by fluidic sensors 21 through 28 and 1 through 5 are also supplied to fluidic logic 70.

As will be seen, the fluidic output signal developed by fluidic sensor No. 28 (letter A) constitutes a synchronizing signal which is supplied as an input to a pair of NOR gates 110 and 112, included in the fluidic logic circuitry 64 detailed in FIG. 2. The output of fluidic NOR gate 112 is connected through a fluidic delay line 113 as a second input to fluidic NOR gate 110, such that these two gates function as a monostable multivibrator ofone-shot circuit 11 1. The fluidic output signals developed by fluidic sensors Nos. 1 through 12 are respectively connected as one input to each of a plurality of two input fluidic NOR gates, commonly indicated at 114 and numbered 1a through 12a, also included in logic circuitry 64.

It will be understood that the fluidic output signal generated by fluidic sensor No. 7 (letter B) is supplied as a synchronizing signal to fluidic logic circuitry 66, while the fluidic output signal from fluidic sensor No. 14 (letter C) is supplied as a synchronizing signal to fluidic logic circuitry 68 and the fluidic output signal developed by fluidic sensor No. 21 (letter D) is supplied as a synchronizing signal to fluidic logic circuitry 70. It will be noted that these fluidic sensors Nos. 28, 7, l4 and 21, also designated A through'D, are spaced 90 apart, and thus the synchronizing signals generated by these fluidic sensors can conveniently be utilized to achieve the appropriate 90 phasing between the fluid load signals generated by the four, identically constructed, fluidic logic circuits.

The mass air flow sensor 72, illustrated schematically in FIG. 2, comprises an annular member 120 for mounting a spaced array of fluidic sensors, indicated at 122 and numbered lb through 12b. These fluidic sensors may be of the same type used in the engine speed sensor 50. A semi-circular disc 124 is mechanically linked, as diagrammatically indicated at 126, to a vacuum meter movement 128, which is coupled by fluid connection 72 to respond to the pressure at the throat of venturi section 76 included in the input end of the intake manifold 78. The response of the vacuum meter movement 128 is effective to selectively angularly position disc 124, such that its periphery is in contiguous, opposed relation to the discharge orifices of an appropriate number of fluidic sensors 122. As the mass air flow through venturi section 72 is increased by throttle 79, the pressure at the venturi throat decreases and the vacuum meter movement 128 responds by rotating disc 124 in the clockwise direction to increase the number of fluidic sensors 122 opposed by the disc periphery. The fluidic output signals developed by fluidic sensors Nos. 1b through 12b are separately connected as the second input to each of the NOR gates Nos. 1a through 12a. Thus, the fluidic output signal from fluidic sensor No. 1 of the engine speed sensor is gated with the fluidic output signal from fluidic sensor No. 1b of the mass air flow sensor in NOR gate No. 1a, and so on.

The outputs of NOR gates Nos. la through 40 are gated together in a four input NOR gate 130, while the outputs of NOR gate Nos. 5a through 8a are gated together in a NOR gate 132 and the outputs NOR gates Nos. 9a through 12a are gated together in a NOR gate 134. The outputs of NOR gates 130, 132 and 134 are complemented by NOR gates 136, 138 and 140 and supplied as separate inputs to a three input NOR gate 142, The output of this NOR gate is complemented in a NOR gate 144 and supplied as one input to a three input NOR gate 146.

The output of NOR gate 110, of monostable multivibrator 111 is'gated with the output of NOR gate 146 in a two input NOR gate 148. The output of this NOR gate is'supplied directly as a second input to NOR gate 146 and is alsocomplemented in a NOR gate 150 and coupled through a fluidic delay line 152 as the third input to NOR gate 146. In addition, the output of NOR gate 148 is complemented in NOR gate 154 and supplied to a fluidic power amplifier 156, whose output constitutes the fluidic load signal supplied over fluidic connection 82 to control fuel injection valve 90. This valve may be any suitable type of conventional airoperated valve which opens when a pulse of air is applied to it and closes when the air pulse terminates. As will be seen, the fluidic load signal is in the form of a pulse, whose pulse interval determines the length of time the valve element 90a of the fuel injection valve must be open in order to inject the proper amount of fuel for mixture with air in the intake manifold 78, which miitture is then admitted through intake valve 158 into cylinder 160 during the suction stroke of piston 162 operating therein. Fluidic NOR gates are well know in the art and may take a variety of forms. Package structures are available which include a plurality of NOR logic elements, each having a four input capability. Such structures are shown in U.S. Pat. Nos. 3,512,558 and 3,495,608. Fluidic power amplifier 156 simply amplifies the pulse output from NOR gate 154 in order that the load signals at its output has sufficient drive'capability. A suitable fluidic power amplifier is shown in US. Pat. No. 3,507,295. I i

The operation of the fluid logic circuits in conjunction with the two sensors 50 and 72 will now be described. Assume that disc 106 of the engine speed sensor 50 is rotated in the clockwise direction'and that its trailing edge is about to pass the discharge orifice of fluid sensor No. 28, which has as one of its functions the generation of the synchronizing signalfor fluidic logic circuit 64.Until the trailing edgeof disc 106 passes fluid sensor No. 28, its fluidic output signal is a logical ONE, which is effective to disable NOR gate 110 such that its output is held to a logical ZERO. Similarly this logical ONE input is complemented by NOR gate 112 to a logical ZERO which is supplied through fluidic delay line element 113 as an enabling input to NOR gate 110. Since the discharge orifices of fluidic sensors Nos. 1 through 12 are blocked by the periphery of disc 106, their resulting logical ONE outputs are effective to disable each of the NOR gates 114. The resulting logical ZERO outputs of these NOR gates fully qualify each of the NOR gates 130, 132 and 134, whose logical ONE outputs are complemented by NOR gates 136, 138 and 140 to fully qualify NOR gate 142. its logical ONE output is complemented to a logical ZERO by NOR gate 144 to enable NOR gate 146. However,

NOR gate 146, which operates in conjunction with NOR gates 148, 150 and 154 as a variable length, fluidic pulse generatorl55. It will be understood that the provision of intermediate coincident NOR gates 130, 132, 134 and 144 is necessitated solely by the fact that the particular fluidic NOR gates contemplated for use in the illustrated embodiment of the invention are limited to a maximum of four inputs. Thus, the number of gates required to perform the requisite logic function on the outputs of the twelve NOR gates 114 is determined by the input number capabilities of the particular fluidic logic elements employed. It will also be appreciated that the number of NOR gates 114 employed in each fluidic logic circuit is a matter of choice, depending upon the pulse length resolution or variability desired of the load signal pulses. That is, by employing twelve fluidic snesors in each of the sensor 51) and 72, to supply the fluidic inputs to each fluidic logic circuit, as illustrated herein, the load signal may be varied over twelve different pulse lengths.

It will further be assumed that disc 124 of mass air flow sensor 72 is angularly oriented in response to the mass flow of air into the intake manifold 78, as regulated by the throttle 79, such that the discharge orifices of the first five fluidic sensors 122, Nos. 1b through 512, are blocked by the disc periphery, as illustrated in FIG. 2. Thus the fluidic output signals of these first five fluidic sensors are logical ONES, effective to disable the first five NOR gates, Nos. 1a through 5a of the NOR gate array 114. Since the discharge orifices of the remaining seven fluidic sensors 122 are not blocked by the periphery of disc 124, their fluidic outputs signals are logical ZEROES to qualify NOR gates Nos. 6a through 12a of the NOR gate array 114. it is understood that if the throttle 79 is open wider to increase the mass flow of air into the intake manifold 7%, disc 124 is rotated in the clockwise direction to a new angular position, such that an additional number of the NOR gates 114 are disabled. Conversely, if the throttle 79 is closed, disc 124 is rotated in a counterclockwise direction to decrease the numberof NOR gates 114 which are disabled by the fluidic output signals developed by fluidic sensors 122. j i

As the trailing edge of disc 106 in the engine speed sensor passes fluidic sensor No. 28, its fluidic output 6 signal goes from a logical ONE to a logical ZERO. The

since the output of NOR gate 148 normally sits at a logical ONE, the output of NOR gate 146, by virtue of the cross-coupling, is a logical ZERO to qualify the former for response to the output from multivibrator circuit 111.

It is seen that the outputs of the twelve NOR gates 114 are effectively all gated together in order to control output of NOR gate 1 10 thus goes from a logical ZERO to a logical ONE. The output of NOR gate 148 then goes from a logical ONE to a logical ZERO and is complemented to a logical ONE by NOR gate 154 to define the leading edge of the fluid load signal pulse, which is amplified in fluidic power amplifier 156 to drive the .fuel injection valve to its open position. The injection of fuel into the intake manifold 78 is thus initiated. With continued rotation of disc 106 in the engine speed sensor 50, its trailing edge passes in sequence the fluidic sensors 104. The fluidic output signals of these fluidic sensors successively go from a logical ONE to a logical ZERO to, in effect, sample or scan the NOR gate array 114 to determine the lowest numbered NOR gate qualified by the fluidic output signals generated by the mass air flow sensor 72. While this sampling is being carried out at a rate synchronized to the engine RPM, the fluidic load signal pulse continues at a logical ONE to maintain the fuel injection valve open and thus sustain the injection of fuel into the intake manifold.

Shortly after NOR gate 110 was fully enabled by the transition of the fluidic output signal from fluidic sensor No. 28 to a logical ZERO, the resulting logical ONE fluidic output from NOR gate 112, delayed by fluidic delay element 113 for approximately 3 milliseconds, disables NOR gate 110. Thus the output of the monostable multivibrator 111 returns to its normal or stable state with its logical ZERO output serving to qualify NOR gate 148. However, by virtue of the cross coupling'between NOR gates 148 and 146, the initial transition of the output of the former from a logical ONE to a logical ZERO, thereby defining the leading edge of the load signal pulse,.was effective to fully enable NOR gate 146 and its resulting logical ONE output maintains NOR gate 148 disabled to sustain the load signal pulse.

When the trailing edge of disc 106 passes fluidic sensor No. 6 in the engine speed sensor 50, the transition of its output signal from a logical ONE to a logical ZERO finds that NOR gate No. 6 in the NOR gate array 114 is the lowest numbered gate which has been qualified by the mass air flow sensor 72. Since the first five NOR gates were disqualified by the mass air flow sensor, the preceding transitions of the fluidic output signals from fluidic sensors Nos. 1 through 5 from logical ONES to logical ZEROES had no effect on their fluidic output signals. However, when NOR gate No. 6 is sampled, both of its inputs are logical ZEROES and its output goes to a logical ONE. NOR gate 132 is disabled, and its logical ZERO output, as complemented by NOR gate 138, is effective to disable NOR gate 142. The output of this gate goes to a logical ZERO and is complemented to'a logical ONE by NOR gate 144 to disable NOR gate 146. The fluidic output of NOR gate 146 returns to its normal, logical ZERO level which is effective to fully enable NOR gate 148. The output of this NOR gate goes from a logical ZERO to a logical ONE, thereby terminating the load signal pulse and effecting closure of fuel injection valve 90.

If for some reason none of the NOR gates 114 were enabled so as to terminate the fluidic load signal pulse, it is automatically terminated after a predetermined length ofitime, for example, milliseconds, by the output of NOR gate 150 supplied through fluidic delay line element 152 to the input of NOR gate 146. Specifically, on the leading edge of the fluidic load signal pulse, the output of NOR gate 150 goes from a logical ZERO to a logical ONE. The application of this logical ONE fluidic signal to NOR gate 146 is delayed for 20 milliseconds by fluidic delay line element 152. Thus, if the fluidic load signal pulse is not terminated by a'logical ONE input from NOR gate 144, it is terminated after 20 milliseconds by the output from NOR gate 150. Thus, the maximum pulse length of the load signal pulse is 20 milliseconds-in the illustrated embodiment of the invention.

From the foregoing description, it is seen that for an engine speed of, for example 900 RPM, if the positions of consecutive fluidic sensors 104 in the engine speed sensor 50 are 2.4 milliseconds apart and fluidic sensor No. 6b of the mass air flow sensor 72 is the lowest numbered fluidic' sensor providing an enabling, logical ZERO input to the NOR gate array 114, the pulse length of the load signal is 6 X 2.4 milliseconds or 14.4 milliseconds.

' It is understood that when the trailing edge of disc 106 in the engine speed sensor passes fluidic sensor No. 7, the transition of its fluidic output signal from a logical ONE to a logical ZERO is used not only to sample NOR gate No. 7a in fluidic logic circuitry 64 but also to trigger the multivibrator 111 in fluidic logic circuitry 66 to define the leading edge of the load signal pulse derived to control the fuel injection valve associated with the cylinder or cylinders out of phase with the cylinder or cylinders handled by fluidic logic circuitry 64. Similarly, fluidic sensor No. 14, away from fluidic sensor No. 28, delivers its logical ONE to logical ZERO fluidic output signal transition to the NOR gate array 114 of fluidic logic circuitry 66 and also triggers the multivibrator 111 in fluidic logic 68 to define the leading edge of the load signal pulse developed thereby. Also, the fluidic output signal from fluidic sensor No. 21 is used to sample the NOR gate array 114 in fluidic logic circuitry 68 and also to trigger the multivibrator ll 1 in the fluidic logic 70, thereby defining the leading edge of the load signal pulse developed thereby. Finally, the fluidic output signal of fluidic sensor No. 28 is also used to sample the NOR gate array 114 in fluidic logic circuitry 70, as well as to trigger multivibrator 111 in fluidic logic 64.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Having described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for controlling a fuel injection valve-in a fuel injection system-for an internal combustion engine, said apparatus comprising, in combination:

A. an engine speed sensor for deriving a first fluidic output indicative of engine speed;

B. a mass air flow sensor for deriving a second fluidic output indicative of the mass of air flow into the intake manifold of the engine, said second fluidic output comprising a plurality of discrete digitized second fluidic output signals, each of said digitized output signals corresponding to a different rate of mass of air flow into the intake manifold of the engine; and v C. fluidic circuitry for processing said first and second fluidic outputs to derive a fluidic load signal for controlling the injection valve to admit a determined amount of fuel for mixture with air and ultimate combustion in a cylinder of the engine.

2. The system defined in claim 1, wherein said engine speed sensor includes means for generating said first fluidic output as a succession of first fluidic output signals at rate proportional to engine speed.

3. The apparatus defined in claim 1, wherein said load signal is in the form of a pulse to effect the opening of the injection valve to admit fuel for the duration of the pulse interval, said fluidic circuitry including first means for processing said first fluidic output to synchronize the leading edge of said load signal pulse to the operating cycle of the engine and second means for processing said first fluidic output in conjunction with said second fluidic output to terminate said load signal pulse on the basis of the instantaneous engine load.

4. The apparatus defined in claim 1, wherein said engine speed sensor includes means for generating said first fluidic output as a synchronizing output signal followed by a succession of first digitized output signals generated at a rate proportional to engine speed, and said fluidic circuitry includes first logic means responsive to said synchronizing output signal for synchroniz ing the leading edge of said load signal to the engine operating cycle and second logic. means responsive to said first digitized output signals and said second digitized output signals to terminate said load signal, whereby said load signal is in the form of a pulse of a pulse length proportional to engine load for effecting the opening of the injection valve to admit fuel for the duration of said pulse.

The apparatus defined in claim 4, wherein said first logic means includes a fluidic pulse generator for generating said load signal pulse, said pulse generator being triggered on in response to said synchronizing output signal, and said second logic means includes an array of fluidic coincident gating elements, each connected to receive a different one of said second digitized output signals and connected to be sampled in predetermined sequence by said succession of said first digitized output signals, the first of said elements sampled in sequence by said first digitized output signals found to be qualified by one of said second digitized output signals deriving a fluidic output signal for triggering said pulse generator off, thereby to define said fluidic load signal pulse interval.

6. The apparatus defined in claim 5, wherein said pulse generator includes means for automatically triggering itself off after a predetermined time interval in the event it is not triggered off by said fluidic output derived from one of said gating elements.

7. The apparatus defined in claim 5, wherein said pulse generator includes a first fluidic gating element having a first input connected to respond to said synchronizing output signal, a second input and an output on which said load signal pulse appears; a second flu idic gating element having a first input connected to the output of said first gating element, a second input connected to receive said output signal derived by said coincident gating element array, a third input, and an output connected to said second input of said first gating element; a third fluidic gating element for complementing the output of said firstgating element; and a fluidic delay lineelement connecting said third gatingelement to said third input of said second gating element.

8. The apparatus defined in claim 7, wherein said fluidic circuitry further includes a fluidic monostable multivibrator circuit connected to be triggered to generate a fluidic pulse of fixed length by said synchronizing output signal, said fluidic pulse being coupled to said first input of said first gating element.

9. The apparatus defined in claim 5, wherein said engine speed sensor comprises an array of first fluidic sen- I sors and means operating in synchronism with the engine to actuate said first fluidic sensors in sequence to generate said synchronizing output signal and said succession of first digitized output signals.

10. The apparatus definedin claim 9, wherein said mass air flow sensor comprises an array of second fluidic sensors and means positionable in accordance with the mass of air flow into the intake manifold to actuate a selected number of said second. fluidic sensors, whereby to generate said second digitized output signals.

llll. Apparatus for contolling the various fuel injection valves in a fuel injection system fora multicylinder internal combustion engine, said apparatus comprising, in combination:

A. an engine speed sensor for deriving a plurality of phased first fluidic outputs, each indicative of engine speed;

B. a mass air flow sensor for deriving a second fluidic output indicative of the mass of air flow into the intake manifold of the engine, said second fluidic output comprising a plurality of discrete digitized second fluidic output signals, each of said digitized output signals corresponding to a differentrate of mass of air flow into the intake manifold of the engine; and

C. plural fluidic circuits for processing different ones of said first fluidic outputs in conjunction with said second fluidic output to derive phased fluidic load signals for separately controlling the various fuel injection valves.

12. The apparatus defined in claim ll, wherein said load signals are each in the form of a pulse to effect the opening of different ones of the injection valves to admit fuel for the durations of the various load signal pulse intervals, said fluidic circuits each including first means for processing a different one of said first fluidic outputs to synchronize the leading edge. of a different one of said load signal pulses to the operating cycle of the engine and second means for processing said one first fluidic output in conjunction with said second fluidic output to terminate said one load signal pulse on the basis of the instantaneous engine load.

I 13. The apparatus defined in claim 11, wherein said engine speed sensor includes means for generating each of said first fluidic outputs as a synchronizing output signal followed by a succession of first digitized output signals generated at a rate proportional to engine speed, said synchronizing output signals being phased relative to each other, and each said fluidic circuit includes first logic means responsive to a different one of said synchronizing output signals for synchronizing the leading edge of a different one of said load signals to the engine operating cycle and second logic means responsive to the succession of first digitized output signals succeeding said one synchronizing output signal and said second digitized output. signals to terminate said one load signal, whereby each of said load signals is in the form of a pulse of apulse length proportional to engine load for effecting the opening of the various injection valves to admit fuel for the durations of said load signal pulses.

14. The apparatus defined in claim 13, wherein said first logic means of each said fluidic circuit includes a fluidic pulse generator for generating one of said load signals, said pulse generator of each said fluidic circuit being triggered on in response to a different one of said synchronizing output signals to define the leading edge of a different one of said load signal pulses, and said second logic means of each said fluidic circuit includes an array of fluidic coincident'gating elements, each connected to receive a different one of said second digitized output signals and connected to be sampled in predetermined sequence by the succession of said first digitized output signals immediately succeeding said one synchronizing output signal, the first of said elements sampled in sequence by said first digitized output signals found to be qualified by one of said second digitized output signals deriving a fluidic output signal for triggering said pulse generator off, thereby to define the pulse interval of said one fluidic load signal pulse.

15. The apparatus defined in claim 14, wherein each said pulse generator includes means for automatically triggering itself off to terminate said one load signal pulse in the event it is not triggered off by said fluidic output derived from one of said gating elements.

16. The apparatus defined in claim 14, wherein said engine speed sensor comprises an array of first fluidic sensors and means operating in synchronism with the engine speed to actuate said first fluidic sensors in sequence to generate said relative phased synchronizing output signals and said successions of first digitized output signals.

17. The apparatus defined in claim 16, wherein certain ones of said first fluidic sensors are connected to supply said synchronizing output signal to one of said fiuidic circuits and a first digitized output signal to a nals.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3556063 *Jun 25, 1969Jan 19, 1971Borg WarnerFuel system
US3616782 *Dec 23, 1969Nov 2, 1971Nippon Denso CoFuel supply device for internal combustion engines
US3672339 *Feb 24, 1970Jun 27, 1972Honeywell IncFuel injection apparatus
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3937195 *Aug 26, 1974Feb 10, 1976The United States Of America As Represented By The Secretary Of The ArmyConstant mass air-fuel ratio fluidic fuel-injection system
US3938486 *Apr 18, 1974Feb 17, 1976Borg-Warner CorporationPneumatically controlled fuel injection system
US3967596 *Apr 9, 1974Jul 6, 1976The Lucas Electrical Company LimitedEngine control systems
US4125090 *Nov 22, 1976Nov 14, 1978Toyota Jidosha Kogyo Kabushiki KaishaEfficient operation of internal combustion engines by adjusting ratios of air and gaseous fuel
Classifications
U.S. Classification123/444, 123/DIG.100, 123/445
International ClassificationF15C1/00
Cooperative ClassificationF15C1/002, Y10S123/10
European ClassificationF15C1/00C