Electronic fuel injection control devices for internal combustion motors

Claim 2

In an electronic fuel-injection system of the type for a motor energized by a starter circuit means including a switch contact which is actuated for a time to produce a starting signal to operate a means for starting the motor, said fuel injection system including injection means for supplying fuel to the motor and computer means for controlling the duration of normal injections supplied by said injection means during the turning of the motor, the improvement comprising first control circuit means responsive to the starting signal for operating said injection means to supply a pre-injection of fuel of a predetermined duration to the motor prior to its starting and the application of the normal injections, and second control circuit means responsive to the starting signal for operating said injection means to supply supplementary injections of fuel to the motor in a predetermined time relationship with the normal injections for a duration not to exceed the production of the starting signal.

Claim 3

The system of claim 1 wherein said second control circuit means operates for a period of time substantially equal to that for which the starting signal is produced.

Claim 4

The system of claim 1 wherein said first control circuit means operates said injection means to supply the pre-injection of fuel to the motor substantially coincident with the production of the starting signal and prior to the operation of said means for starting the motor.

Claim 5

The system of claim 1 wherein said first control circuit means operates said injection means to supply the pre-injection of fuel to the motor a predetermined time after the starting signal is produced.

Claim 6

A system as in claim 1 further comprising means connected to said first control circuit means and responsive to the temperature of the motor to control the duration of the fuel pre-injection.

Claim 7

A system as in claim 1 further comprising means responsive to the temperature of the motor and connected to said second control circuit means to vary the duration of the supplementary fuel injections.

Claim 8

A system as in claim 1 wherein said first and second control circuit means includes means for controlling said injection means to produce a supplementary fuel injection immediately following a pre-injection.

Claim 9

A system as in claim 1 wherein said first control circuit means includes means for disabling said first control circuit means for a predetermined time to prevent a pre-injection of fuel during a subsequent operation of the starter switch contact.

Claim 10

A system as in claim 1 wherein said first control circuit means includes an input for receiving said starting signal, first transistor means having an output electrode at which the control signal for causing the pre-injection is produced and a control electrode, controllable transistor means having a control electrode, an anode and a cathode, circuit means for producing a control potential for said control electrode, a capacitor connected to the anode of said controllable transistor means, charging circuit means for supplying a potential to said capacitor to establish the anode potential with respect to the control electrode potential of said cOntrollable transistor means, output means connected to said controllable transistor for supplying a control signal to said control electrode of said first transistor means, said controllable transistor means becoming conductive in response to a potential on said capacitor which exceeds the potential at the control electrode by a certain value, said controllable transistor means when conductive producing a control signal across said output means which operates said first transistor means to terminate the production of the pre-injection control signal.

Claim 11

A system as in claim 9 wherein said circuit means for producing the control potential for said controllable transistor means includes means responsive to the temperature of the motor for determining the control potential of the uni-junction transistor means.

Claim 12

A system as in claim 9 wherein said charging circuit means for said capacitor includes a voltage divider means having a first impedance means in parallel with a portion thereof and being connected to the voltage divider by a diode, the capacitor charging up to the voltage determined by the voltage divider in a rapid manner at a slower rate through the said first impedance means which is isolated from the voltage divider by said diode.

Claim 13

A system as in claim 9 further comprising second transistor means connected to said capacitor to discharge the same, a second capacitor connected in the control electrode circuit of said second transistor and responsive to the starting signal produced by the first closing of the starter switch contact to operate said second transistor means to discharge said first capacitor, said second capacitor preventing the operation of said second transistor means to discharge said first capacitor for a predetermined time.

Claim 14

A system as in claim 1 wherein said second control circuit means comprises a first input for receiving the starting signal and a second input for receiving a normal fuel injection signal from said computing means and means responsive to the occurrence of said starting signal and a normal fuel injection signal for producing a supplementary fuel injection signal.

Claim 15

A system as in claim 13 wherein said second control signal means also includes a third input for receiving a pre-injection signal from said first control circuit means and produces a supplementary fuel injection signal in response to the pre-injection signal and the starting signal.

Claim 16

A system as in claim 13 wherein said second control circuit means includes first transistor means including an output electrode at which said supplementary fuel injection control signal is produced and a control electrode, and timing means responsive to the normal injection signals from said computing means for periodically operating said first transistor means to produce the supplementary fuel injection control signals.

Claim 17

A system as in claim 15 wherein said timing means includes capacitor means, charging circuit means for charging said capacitor means to a first voltage level which operates said first transistor means to terminate the production of a said supplementary fuel injection control signal.

Claim 18

A system as in claim 16 wherein said timing means also includes means responsive to the temperature of the motor for controlling the charging time of said first capacitor means to said first voltage level.

Claim 19

The system of claim 1 wherein said first control circuit means operates said injection means to supply the pre-injection of fuel to the motor during the operation of the means for starting the motor.