US3106196A

US3106196A - Fuel supply system

Info

Publication number: US3106196A
Application number: US622618A
Authority: US
Inventors: Stephen G Woodward; Curtis A Hartman
Original assignee: Bendix Corp
Current assignee: Bendix Corp
Priority date: 1956-11-16
Filing date: 1956-11-16
Publication date: 1963-10-08
Anticipated expiration: 1980-10-08
Also published as: GB858964A; FR1196936A

Description

Oct. 8, 1963 Filed Nov. 16, 1956 s. G. wooDwARD ETAL 3,106,196

FUEL SUPPLY SYSTEM 3 Sheets-Sheet 1 .52 4g N0 40 Z6 57 34 P 7 4 I o f V 4 46 1a 56 1- 1 A EI- 5e 44 l 52 v 50 exam 5:5: I?

[Z5 10 I6 20 ENGMIIE -16 TEMPERATURE COMPENSATDR l4 Z6 ELECTRON/c 4 CONTROL.

i I r [I] 1 1| I INVENTORS STEPHEN G. Wooowmo CUR IS A. HARTMAN B 1963 s. G. WOODWARD ETAL 3,

FUEL SUPPLY SYSTEM Filed Nov. 16, 1956 3 Sheets-Sheet 2 I76 i I66 /60 I64 I62 I70 =-l72 2/2 155 152 FF? 4- I76 150 IN VENTOR5 ATTOEN E Y S. G. WOODWARD ETAL Oct. 8, 1963 FUEL SUPPLY SYSTEM 3 Sheets-Sheet 3 Filed Nov. 16, 1956 INVENTORJ STEPHEN G. Woovwmu CURT A XH RTMAN BY m ATTORNEY United States Patent 3,106,196 FUEL SUPPLY SYSTEM Stephen G. Woodward and Curtis A. Hartman, Eimira,

N.Y., assiguors to The Bendix Corporation, a corporation of Delaware Filed Nov. 16, 1956, Ser. i o. 622,618 11 Claims. (Q1. 123-li19) The present invention relates generally to fuel supply systems wherein the quantity of fuel is varied by electrical means and more particularly for an acceleration control for such a system.

In some engines having such a fuel supply system when the accelerator pedal is depressed there is produced a hesitation or fiat-spot in the response of the engine. In order to eliminate or reduce the hesitation of the engine to respond to an acceleration signal, an acceleration control is proposed to temporarily increase the quantity of fuel supplied by the system. To be effective such a control must respond rapidly to the accelerating signal and must accurately deliver a metered increased quantity of fuel over a controlled time duration.

It is accordingly an object of the invention to provide a quick responding acceleration control of simple, reliable construction which will deliver a metered quantity of fuel over a controlled time duration.

Other objects and advantages will be readily apparent from the following detailed description taken in connection with the appended drawings in which:

FIGURE 1 is a schematic view of an injector embodying our invention;

FIGURE 2 is a schematic view of a portion of our acceleration control;

FIGURE 3 is a circuit diagram of the electrical control; and

FIGURE 4 is a schematic view of another embodiment of our acceleration control.

Referring now to the drawings and more particularly to FIGURE 1, numeral 1i) designates a source of fuel, 12 an engine with a cylinder or combustion chamber 1-4, a spark plug .16, an intake valve 18, an induction passage 20 and a fuel injector 22 mounted thereon. The numbers of injectors 22 conveniently corresponds with a number of combustion chambers 14 although the proportion of injectors to combustion chambers may be increased or decreased as desired.

The injectors 22 are arranged to be actuated by an electronic control 24 which is triggered by and connected to an appropriate injector 22 by trigger-distributor 26. Unit 26 triggers or energizes the electronic control 24 which remains energized for a controlled time duration. The output of the control 24 is connected to an appropriate injector 22 through unit 26 whereby the injector discharges fuel for the time duration that the electronic control remains energized.

The time that electronic control 24 remains energized is regulated by various sensory elements including engine temperature compensator 223, altitude compensator 30, induction passage pressure responsive element 32, ambient air temperature compensator 34 and low air flow control 36.

The air how to the induction passage 20 is regulated by a throttle body unit 38 which is provided with a pair of

air flow passages

46 and 42 in which are respectively mounted on a shaft 44

throttle valves

46 and 48. The throttle valves are actuated by a conventional accelerator pedal 50 through a link 52 and a throttle lever 54 secured to shaft 44. A temperature control unit 56 is mounted on throttle body 38 and arranged to position a fast idle cam 57 in the path of throttle lever 54 to pre- 3,165,196 Fatented Get. 8, 1963 vent the throttle valves from fully closing when the control 56 is cold.

Also mounted on the throttle body unit 38 is an acceleration control 58 which, as best seen in FIGURE 2, comprises a housing 60 which is secured to body 38 by appropriate bolts '62. A diaphragm 64 is marginally clamped between said housing 60 and body 38 to separate the interior of housing 60 into twochambers designated respectively 66 and 68. Diaphragm 64 is formed with a bleed or restricted opening 70 to provide limited communication between chambers 66 and 68. An electrical contact 72 is centrally clamped to diaphragm 64 and is urged into engagement with stationary contact 74 by means of a spring 76' located in chamber 66. Chamber 68 is connected to the induction passage 29 on the downstream side of the throttle valves by means of conduits 78. The construction of accelerator control '58 is such that the

electrical contacts

72 and 74 are normally in engagement so as to complete a shunt circuit to be described. Whenever there is a rise in the induction passage absolute pressure sufiicient to overcome the force of spring 76 the

contacts

72 and 74 will be moved out of en agement and the shunt circuit opened. The

contacts

72 and 74 will remain open until the pressure in chamber 66 as communicated thereto from chamber 68 through bleed 70 has risen to a value which together with the force of spring 76 is sufiicient to overcome the pressure in chamber 68. The time duration that contacts 72 and 74 remain open is a function of the amount of change in pressure in the induction passage, the size of bleed 76, the rate of spring 76 and the relative volumes of chambers 63 and 66. The

contacts

72 and 74 are adapted for connection into the circuit of FIGURE 3 which will now be described.

Referring now to FIGURE 3, E designates a source of electrical energy connected through a switch 80 and conductor 82 with a switch 84 located in injector-distributor unit 26. Switch 84 is mounted for actuation by shaft 86 which is adapted to be driven as a function of engine speed and when actuated produces -a series of pulses which are transformed by condenser 88 and rectiher '90 into a series of negative voltage spikes which are eiiective to trigger a normally non-conducting transistor 92 in multi-vibrator unit 94. The multi-vibrator 94 produces a pulse in conductor 96, the width of which is a function of the time constant of a circuit to be described.

In our invention alternative circuits are provided to determine the time constant of the multi-vibrator 94. In describing the circuitry of the time constant in a specific embodiment a resistive-capacitive combination is used. It is to be understood however that the circuit may be inductive-resistive or combinations thereof and that while the resistive elements are described as variable that the inductive or capacitive elements could equally as well be varied.

The first of the circuits includes source E, conductor 82, multi-vibrator 94 and a power amplifier 98. The time constant of this first circuit is determined by condensor C and variable resistors or

potentiometers

160, 192, 104, 106 and 108 which are respectively variable by altitude compensator 30, manually, induction passage pressure responsive element 32, ambient compensator 34 and engine temperature compensator 28. The time constant in the first circuit is also controlled by the acceleration unit 58 which provides a normally closed shunt path around a resistor. or impedance 110 which is connected in series with the aforementioned variable potentiometer. The shunt path includes leads 112, switch 114 and lead 116. When switch 114 is closed the acceleration control 58 has substantially no effect on the time constant in the firstcircu-it. However, when switch C3 114 is open resistor is effectively placed in the circuit whereby the time constant is increase The second of these circuits includes source E, conductor 82, switch 84-, multi-vibrator 94- and power ampliher 93. in the second circuit the time constant includes condensor C, variable resistors or potentiometers 105), 162, 118, and 168. Potentiometer 113 is manually variable. A switch lid in low air flow control 36 opcratively connected to throttle shaft 44 is adapted to alternatively select one of the two circuits to control the time constant of the electronic control 24. The first circuit is adapted to control the time constant during normal operation and is sometimes referred to as the normal circuit. The second circuit is adapted to control the time constant during low air fiow conditions.

The pulse of electrical energy produced in conductor 96 by the multi-vibrator 94 has a width or time duration which is controllahe as a function of an engine operating condition such as are introduced by various sensory elements into either the first or second circuit above described. The pulse or energy in conductor 96 is emplitied by the amplifier section 98 which increases the amplitude of the pulse without change in width or time duration. The output from amplifier 98 is connected through lead 122 to a conductor ring 124 formed in the distributor portion 126 of trigger-distributor unit 26. Arm 128 secured to shaft 86 is adapted to successively connect the ring 1.4 to spaced contact segments 13%, each of which is connected to a solenoid 132. The solenoids 132 are located in injectors 22 for actuation of the fuel valve (not shown) located therein. The fuel valve and injector construction is claimed and more fully disclosed in U.S. application Serial No. 637,852, filed February 4, 1957, now Patent No. 2,980,090, issued Apr. 18, 1961, and assigned to the assignee of the present invention.

in FIGURE 4 there is disclosed another embodiment of our invention wherein the acceleration control 158 is actuated by positive pressure produced by throttle actuated piston. As shown diagrammatically in FIGURE 4 acceleration control 153 comprises a housing 160 secured to the throttle body 33 by appropriate bolts 162. A diaphragm 164 is marginally clamped between the housing and throttle units and divides the interior of the housing into two chambers designated respectively 166 and 168. The diaphragm 164 is perforated as at 170 to provide limited communication between

chambers

166 and 168. An electrical contact 172 is centrally clamped to diaphragm 164 and is adapted for engagement with a stationary electrical contact 174.

Contacts

172 and 174 form a switch designated generally by numeral 214. Contact 172 is urged into engagement with contact 174 by a spring 176 mounted in chamber 166 whereby switch 214, comprising

contacts

172 and 174, is normally closed. Chamber 163 is connected by means of a conduit 178 with a cylinder 130 in which is reciprocably mounted a piston 182 having an operative connection with throttle shaft 44.

In operation when the throttle valves are open, piston 18?. travels in cylinder 180 to increase the pressure in chamber 163 whereby switch 214 is opened. The switch 214 will remain open until the pressures in

chamber

168 and 166 through the communication of bleed 170 approach a balanced condition whereby the force of spring 176 is sufficient to again close the switch 214. The acceleration control 153 is adapted for connection in the circuit shown in FIGURE 3 by means of leads 212 and 216 in the same manner as control 58 is connected. The operation of the control 158 in the circuit of FIGURE 3 is the same as described above in connection with the control 58.

While only two embodiments of our invention have been described it will be readily apparent to those skilled in the art that various changes and arrangements can be made to change the objects of the invention without departing from the spirit thereof.

We claim:

1. In a fuel supply system for an internal combustion engine, an electrically actuated fuel valve for supplying fuel to said engine, an electrical pulse generating means operatively connected to said valve for controlling the time duration of valve opening, impedance means operatively connected to said pulse generating means for controlling the time duration of the pulses generated by said means, and a device operatively connected to said impedance means for increasing said impedance means and said time duration of said pulses in response to a change in an engine operating condition indicative of acceleration of the engine.

2. in a fuel supply system for an internal combustion engine having an induction passage and an electrically ctuated fuel valve mounted thereon, an electrical pulse generating means operatively connected to said valve to open said valve for the time duration of a pulse, and means operativcly connected to said pulse generating means and responsive to an increase in induction passage pressure for temporarily increasing the time duration of said pulse.

3. An acceleration control for a fuel supply system for an internal combustion engine having an induction passage comprising a fuel valve mounted on said induction passage, means for periodically opening said valve, means operatively connected to said first mentioned means for varying the time duration that said valve remains open, and means operatively connected to said last mentioned means and responsive to an increase in induction passage pressure for temporarily increasing the time duration that said valve remains open.

4. An acceleration control for a fuel supply system for an engine having an induction passage and an electrically actuated fuel valve mounted thereon and a circuit including impedance means having a time constant for opening said valve for a controlled time duration comprising an impedance in said circuit and forming at least a part of said time constant, a switch in said circuit adapted to control the effectiveness of said impedance in said circuit to vary said time constant, and means operatively conneeted to said switch and responsive to an increase in induction passage pressure for moving said switch to render said impedance effective to vary said time constant.

5. An acceleration control for a fuel supply system for an engine having an induction passage and an electrically actuated fuel valve mounted thereon and a circuit including impedance means having a time constant for opening said valve for a controlled time duration comprising an impedance in said circuit and forming at least a part of said time constant, a hous ng, a movable wall in said housing defining a pair of chambers therein, means connecting one of said chambers to the induction passage, means defining a restricted flow path between said chambers, a switch in said circuit adapted for actuation by said wall for controlling the effectiveness of the impedance of said circuit to vary the time constant therein in response to changes in induction passage pressure.

6. An acceleration control for a fuel supply system for an engine having an induction passage and an electrical circuit including impedance means having a time constant, comprising a housing, a movable wall in said housing separating the interior thereof into two chambers, means connecting one of said chambers to the induction passage, means defining a restricted flow path between said chambers, an impedance in said circuit forming at least part of said time constant, a shunt around said impedance, :1 switch in said shunt, and means connecting said switch to said movable wall whereby said switch is opened to vary said time constant upon increase in induction passage pressure.

7. An acceleration control for a fuel supply system for an engine having a throttle and electrical circuit including impedance means having a time constant comprising a throttle actuated pressure creating means, a housing, a movable wall in said housing separating the interior thereof into two chambers, means connecting one of said chambers with said pressure creating means, an impedance in said circuit forming at least part of said time constant and means operatively connected to said movable wall for controlling the efiectiveness of said impedance in said circuit.

8. An acceleration control for a fuel supply system for an engine having a throttle and an electrical circuit including impedance means having a time constant comprising a throttle actuated pressure creating means, a housing, a movable Wall in said housing separating the interior thereof into two chamber, means connecting one of said chambers with said pressure creating means, means defining a restricted flow path between said chambers, an impedance in said circuit forming at least part of said time constant, a switch movable by said wall to one position wherein said impedance is shunted in said circuit and to another position where said impedance is effective to vary said time constant, and resilient means in said housing urging said switch toward said one position.

9. In a fuel injection system for a combustion device of the type including injection valve means to supply a fuel under pressure to said device, control means comprising actuating means adapted to open said valve means by and for the duration of an electric current pulse applied thereto, monostable pulse forming means comprising a first amplifier, a second amplifier, load resistance means for each said amplifiers, direct coupling means between the output of said first amplifier and the input of said second amplifier, a resistance-capacity coupling network between the output of said second amplifier and the input of said first amplifier, to normally pass an output current through said first amplifier and to normally bias said second amplifier to output current cut-off, whereby to render said first amplifier temporarily non-conductive during a period determined by the time constant of said network upon the application of a triggering pulse to said second amplifier, to produce output current pulses of said first amplifier, means to energize said actuating means by said output current pulses, and further means to vary the time constant of said network, whereby to control the fuel injection time of said valve means.

10. In a fuel injection system as claimed in claim 9, including means to control said last-mentioned means in dependence upon at least one varying operating condition of said device affecting the fuel-air ratio in the combustion chamber thereof, to substantially maintain the fuelair ratio of a predetermined value.

11. In a fuel injection system as claimed in claim 9 for use in the internal combustion engine of an automotive vehicle, including triggering pulse generating means for said second amplifier synchronized with said engine, and means to control the resistance of said network in dependence upon at least one operating condition of said engine affecting the fuel-air ratio in the combustion chamber thereof, whereby to substantially maintain said fuel-air ratio at a constant value within a predetermined range of variation of the engine operating conditions.

References Cited in the file of this patent UNITED STATES PATENTS 2,482,254 Fairchild Sept. 20, 1949 2,521,244 Moore Sept. 5, 1950 2,859,738 Campbell Nov. 11, 1958 2,911,966 Pribble Nov. 10, 1959 2,967,953 Pribble Jan. 10, 1961

Claims

1. IN A FUEL SUPPLY SYSTEM FOR AN INTERNAL COMBUSTION ENGINE, AN ELECTRICALLY ACTUATED FUEL VALVE FOR SUPPLYING FUEL TO SAID ENGINE, AN ELECTRICAL PULSE GENERATING MEANS OPERATIVELY CONNECTED TO SAID VALVE FOR CONTROLLING THE TIME DURATION OF VALVE OPENING, IMPEDANCE MEANS OPERTIVELY CONNECTED TO SAID PULSE GENERATING MEANS FOR CONTROLLING THE TIME DURATION OF THE PULSES GENERATED BY SAID MEANS, AND A DEVICE OPERATIVELY CONNECTED TO SAID IMPEDANCE MEANS FOR INCREASING SAID IMPEDANCE MEANS AND SAID TIME DURATION OF SAID PULSES IN RESPONSE TO A CHANGE IN AN ENGINE OPERATING CONDITION INDICATIVE OF ACCELERATION OF THE ENGINE.