Closed throttle tip-in circuit

Claim 2

In combination with an internal combustion engine fuel control system, having a source of electrical power, an electronic fuel control generating signals indicative of the engine''s fuel requirements, fuel delivery means for delivering fuel to the engine in response to the signals generated by said fuel control computer and a throttle moveable intermediate a closed and a full open position to control the air delivery to the engine, an improvement comprising: means for generating a closed throttle signal only when the throttle is in the closed position and for terminating said closed throttle signal when said throttle is intermediate said open and closed position; input circuit portion means responsive to the termination of said closed throttle signals for generating a pulse width control signal each time said closed throttle signal is terminated; and output circuit portion means including at least one output transistor switch for generating a fuel enrichment pulse signal in response to a pulse width control signal.

Claim 3

The improvement of claim 1 wherein said input circuit portion means comprises: first circuit means generating a first signal in response to the closed throttle signal and a second signal in the absence of a closed throttle signal; and second circuit means for generating said pulse width control signal in response to said second signal, said pulse width control signal persisting a predetermined time after the occurrence of said second signal.

Claim 4

The improvement of claim 2 wherein said second circuit means further includes sensor means responsive to an engine operating parameter for controlling the length of the predetermined time said pulse width signal persists after the occurrence of said second signal as a function of said engine operating parameter.

Claim 5

The improvement of claim 3 wherein said sensor means is a temperature sensor responsive to the temperature of the engine and the length of said pulse width signal is an inverse function of the engine''s temperature.

Claim 6

The improvement as claimed in claim 2 wherein said means for generating a closed throttle signal is an electrical switch mechanically linked to the throttle and said closed throttle signal is a ground potential signal, said first curcuit means comprises: a transistor switch having an emitter, collector, and base wherein the electrical potential applied to said base controls the current flow from said collector to said emitter; a first resistance connected between the source of electrical power and said base; a diode connected between said base and said electrical switch; a second resistance connected between said source of electrical power and said collector; and a second diode connected between said emitter and ground.

Claim 7

The improvement as claimed in claim 5 wherein said second circuit means includes: a capacitor having one end connected to said input transistor for storing an electrical charge in response to said first signal and to discharge in response to said second signal; and a resistance connected between the source of electrical power and the other side of said capacitance to recharge said capacitance to its original value at a predetermined rate after being discharged by said second signal, wherein the charge on said capacitance is said pulse width control signal.

Claim 8

The improvement as claimed in claim 6 wherein said output circuit means includes: said output transistor switch having an emitter, collector and base wherein the electric potential applied to said base controls the current flow from said collector to said emitter; a diode connecting the base of said output transistor switch to the other end of said capacitance; a resistance connecting the collector of said output transistor switch with said source of electrical power and means connecting the emitter of said transistor switch to ground wherein said tip-in fuel enrichment pulse signal is generated at the collector of said output transistor switch when the charge on said capacitance is below a predetermined value.

Claim 9

The improvement as claimed in claim 7 wherein the fuel delivery means includes gate means having a plurality of input gates receiving the signals generated by the electronic fuel control computer, said gate means further includes an input gate for receiving said tip-in fuel enrichment pulse signals from said tip-in fuel enrichment circuit.

Claim 10

In combination with an internal combustion electronic fuel control system having a source of electrical power, an electronic fuel control computer for generating signals indicative of the engine''s fuel requirements, at least one electrically actuated fuel injector valve for delivering fuel to the engine in response to the signals generated by the computer and a throttle controlling the air delivery to the engine wherein said fuel control system further includes an acceleration enrichment switch mechanically linked to said throttle for generating acceleration fuel enrichment pulses, and wherein said acceleration enrichment switch further includes a closed throttle position switch generating a closed throttle signal indicative that the throttle is in the closed position, a closed throttle tip-in circuit for generating a fuel enrichment pulse signal activating said fuel delivery means to deliVer a predetermined quantity of fuel to the engine each time the closed throttle signal is terminated comprising: input circuit means for generating a first signal in response to said closed throttle signal and a second signal in response to the absence of the closed throttle signal; a capacitance and resistance forming an RC network, said capacitance being charged to a predetermined value by said first signal and discharged by said second signal and said resistance recharging said capacitance from its discharged state to its initial charged value at a predetermined rate; and output circuit means responsive to the charge on said capacitance for generating said tip-in fuel enrichment signal when the charge on said capacitance is below a predetermined value.

Claim 11

In combination with an internal combustion electronic fuel control system having a source of electrical power, an electronic fuel control computer for generating signals indicative of the engine''s fuel requirements, at least one electrically actuated fuel injector valve for delivering fuel to the engine in response to the signals generated by the computer and a throttle controlling the air delivery to the engine wherein said fuel control system further includes an acceleration enrichment switch mechanically linked to said throttle for generating acceleration fuel enrichment pulses, and wherein said acceleration enrichment switch further includes a closed throttle position switch generating a closed throttle signal indicative that the throttle is in the closed position, a closed throttle tip-in circuit for generating a fuel enrichment pulse signal activating said fuel delivery means to deliVer a predetermined quantity of fuel to the engine each time the closed throttle signal is terminated comprising: input circuit means for generating a first signal in response to said closed throttle signal and a second signal in response to the absence of the closed throttle signal; a capacitance and resistance forming an RC network, said capacitance being charged to a predetermined value by said first signal and discharged by said second signal and said resistance recharging said capacitance from its discharged state to its initial charged value at a predetermined rate; and output circuit means responsive to the charge on said capacitance for generating said tip-in fuel enrichment signal when the charge on said capacitance is below a predetermined value.

Claim 12

The enrichment tip-in circuit as claimed in claim 9 wherein said acceleration enrichment switch further includes a drag switch terminating said closed throttle signal prior to the opening of said closed throttle position switch, said input circuit means generates said second signal in response to the termination of said closed throttle signal by said drag switch.

Claim 13

In combination with an acceleration enrichment switch mechanically linked to the throttle of an internal combustion engine, said acceleration enrichment switch having a two position drag switch, said two position drag switch operative to be in a first position when the throttle is moved in a direction tending to open the throttle providing electrical continuity through the acceleration switch with the acceleration pulse forming elements, and operative to be in a second position breaking electrical continuity with the acceleration pulse forming elements when the throttle is moved in a direction tending to close the throttle, further when the throttle is in the closed position the drag switch in the second position provides electrical continuity to a closed throttle switch, and generates a closed throttle signal, the drag switch operative to move from said second position to said first position prior to the opening of said closed throttle switch and the generation of said first acceleration enrichment pulse, a circuit for generating a tip-in fuel enrichment pulse with the throttle in the closed position in response to the drag switch switching from its first position to its second position comprising: input circuit means for generating a first signal in response to the closed throttle signal generated by the acceleration switch with the throttle in the closed position and the drag switch in the second position, and for generating a second signal in response to the termination of the closed throttle signal generated by the acceleration switch with the throttle in the closed position and the drag switch in the second position; a capacitance and a current source forming an R.C. network, said capacitance being charged to a predetermined value by said first signal, and discharged by said second signal, and said current source recharging said capacitance from its discharged state to its initial value at a predetermined rate; and output circuit means responsive to the charge on said capacitance for generating said tip-in fuel enrichment signal when the charge on said capacitance is below a predetermined value.

Claim 14

In combination with an acceleration enrichment switch mechanically linked to the throttle of an internal combustion engine, said acceleration enrichment switch having a two position drag switch, said two position drag switch operative to be in a first position when the throttle is moved in a direction tending to open the throttle providing electrical continuity through the acceleration switch with the acceleration pulse forming elements, and operative to be in a second position breaking electrical continuity with the acceleration pulse forming elements when the throttle is moved in a direction tending to close the throttle, further when the throttle is in the closed position the drag switch in the second position provides electrical continuity to a closed throttle switch, and generates a closed throttle signal, the drag switch operative to move from said second position to said first position prior to the opening of said closed throttle switch and the generation of said first acceleration enrichment pulse, a circuit for generating a tip-in fuel enrichment pulse with the throttle in the closed position in response to the drag switch switching from its first position to its second position comprising: input circuit means for generating a first signal in response to the closed throttle signal generated by the acceleration switch with the throttle in the closed position and the drag switch in the second position, and for generating a second signal in response to the termination of the closed throttle signal generated by the acceleration switch with the throttle in the closed position and the drag switch in the second position; a capacitance and a current source forming an R.C. network, said capacitance being charged to a predetermined value by said first signal, and discharged by said second signal, and said current source recharging said capacitance from its discharged state to its initial value at a predetermined rate; and output circuit means responsive to the charge on said capacitance for generating said tip-in fuel enrichment signal when the charge on said capacitance is below a predetermined value.

Claim 15

The combination of claim 11 wherein said acceleration switch has a base fixedly attached to the stationary throttle body and is mechanically linked to the moveable throttle shaft biased in the closed position, said drag switch comprises: a drag rotor pivotally mounted to the moveable throttle shaft; means disposed between said drag rotor and the switch base for generating a frictional force retarding movement of the drag rotor relative to the base; two upstanding contact posts separated from each other by a first predeterminable separation distance and radially disposed from the center of the throttle shaft, a first predetermined radial distance; an upstanding spring post, angularly disposed bEtween said contact posts and radially disposed a second radial distance from the center of the throttle shaft, said second radial distance being substantially less than said first radial distance; means for making electrical contact to said two contact posts and said spring post individually; a driven rotor, fixedly attached to said throttle shaft and adapted to rotate therewith, said driven rotor having two parallel arms stradling said spring post, said parallel arms being separated by a distance slightly greater than the distance between said contact posts, and having a radial length less than said first radial distance and greater than said second radial distance; a pickup bar pivotally attached to said spring post and disposed between said two arms of the driven rotor and said two contact posts, said pickup bar radially extending slightly beyond said contact posts and having a width less than the distance between said two contact posts permitting said pickup bar to freely pivot about said spring post through a predetermined angle defined by said two contact posts; a hair pin spring in continuous electrical contact with said spring post, said hair pin being disposed over said pickup arm and rotatable therewith, said hair pin spring further having two free ended prongs extending radially outward from said spring post a short distance beyond said contact posts, and said prongs further being separated by a distance greater than the width of said pickup bar; and a keeper fixedly disposed at the end of said pickup bar beyond said contact posts, said keeper having a rectangular slot biasing the free ends of said prongs towards each other so that the separation of said prongs proximate said contact posts is slightly less than the distance between said contact posts; wherein the spring bias on the throttle shaft in the closed throttle position causes one arm of the driven rotor to bias the pickup bar against one of the contact posts placing one prong of the hair pin spring in electrical contact with said one contact post and the initial rotation of the throttle shaft against the spring bias causes the other arm of the driven rotor to move the pickup bar away from said one contact post removing said prong away from said one contact post breaking said electrical contact prior to said pickup bar engaging the other contact post and rotating said drag rotor with said driven rotor.

Claim 16

The combination of claim 12 wherein said input circuit means includes an input transistor switch having a first state in response to the closed throttle signal and a second state in the absence of said closed throttle signal, said transistor switch in said first state generates said first signal, and in said second state generates said second signal; and wherein said output circuit means includes at least one output transistor switch, said at least one output transistor switch generating said tip-in enrichment signal when the charge on said capacitance is below a predetermined value.

Claim 17

The combination of claim 12 wherein said current source includes sensor means responsive to the temperature of the internal combustion engine for controlling said predetermined rate at which said capacitance recharges.