Fuel injection system for internal combustion engines

Claim 2

In an internal combustion engine of the type having a fuel injection valve for each cylinder and a common feed rail for feeding fuel to said fuel injection valves, a system for varying the pressure of the fuel in accordance with a desired engine parameter comprising: means for generating a first voltage having an amplitude representative of the fuel pressure in said common fuel rail, means for generating a second voltage having an amplitude representative of said desired engine parameter, means for raising said second voltage to the nth power, where n is an adjustable index whose value is established by a desired engine tuning to provide a third voltage representative of a desired fuel pressure, means for comparing said first voltage and said third voltage to establish their difference and which is the larger, and means responsive to the output of said means for comparing to change the pressure of the fuel in said common feed rail at a rate determined by said difference until said fuel pressure attains the value determined by said third voltage.

Claim 3

In an internal combustion engine as recited in claim 1 wherein said means for generating a second voltage having an amplitude representative of a desired engine parameter comprises tachometer means for generating a voltage representative of engine speed.

Claim 4

In an internal combustion engine as recited in claim 1 wherein said means for generating a second voltage having an amplitude representative of a desired engine parameter comprises transducer means for generating a voltage representative of the pressure differential of the air mass flowing to the engine through a venturi.

Claim 5

In an internal combustion engine as recited in claim 1 wherein said means responsive to the output of said means for comparing to change the pressure of the fuel in said common feed rail at a rate determined by said difference until said fuel pressure attains the value determined by said third voltage includes: electromechanical pump means to which fuel from said feed rail is applied for increasing the pressure of said fuel, control valve means to which the fuel at an increased pressure output of said electromechanical pump is applied to control the rate at which fuel in said common feed rail is permitted to circulate whereby its pressure may be controlled.

Claim 6

In an internal combustion engine of the type having a fuel injection valve for each cylinder and a common feed rail for feeding fuel to said fuel injectors, fuel being circulated by means of a pump from said common feed rail to a fuel bowl and then to a pump which pumps said fuel into said common feed rail, the improvement comprising: means for generating a first voltage representative of engine speed, means for generating a second voltage representative of the Fuel pressure in said common rail, means for raising said first voltage to the power n to produce a third voltage, wherein n is an adjustable index whose value is established by a desired engine tuning; means for comparing said second and third voltages to produce a first output when said second voltage exceeds said third voltage and a second output when said third voltage exceeds said second voltage, and control valve means connecting said common feed rail to said fuel bowl for increasing fuel flow whereby fuel pressure is reduced responsive to said first output and for decreasing fuel flow responsive to said second output whereby fuel pressure is increased.

Claim 7

In an internal combustion engine of the type having a fuel injection valve for each cylinder and a common feed rail for feeding fuel to said fuel injectors, fuel being circulated by means of a pump from said common feed rail to a fuel bowl and then to a pump which pumps said fuel into said common feed rail, the improvement comprising: means for generating a first voltage representative of engine speed, means for generating a second voltage representative of the Fuel pressure in said common rail, means for raising said first voltage to the power n to produce a third voltage, wherein n is an adjustable index whose value is established by a desired engine tuning; means for comparing said second and third voltages to produce a first output when said second voltage exceeds said third voltage and a second output when said third voltage exceeds said second voltage, and control valve means connecting said common feed rail to said fuel bowl for increasing fuel flow whereby fuel pressure is reduced responsive to said first output and for decreasing fuel flow responsive to said second output whereby fuel pressure is increased.

Claim 8

In an internal combustion engine as recited in claim 5 wherein there is included a means for subtracting said second voltage from said third voltage to establish a difference voltage: voltage controlled oscillator means to generate a pulse train whose frequency is determined by said difference voltage, gate means rendered inoperative responsive to said first output and operative responsive to said second output to pass the pulse train from said voltage controlled oscillator, and electromechanical actuator means connected to said gate means for controlling said control valve means responsive to said pulse train.

Claim 9

In an internal combustion engine of the type having a fuel injection valve for each cylinder and a common feed rail for feeding fuel to said fuel injectors, fuel being circulated by means of a pump from said common feed rail to a fuel bowl and then to a pump which pumps said fuel into said common feed rail, the improvement comprising: means for generating a first voltage representative of (air mass flow rate) into the engine, means for generating a second voltage representative of the fuel pressure across a fuel injection valve, means for raising said first voltage to the power n to produce a third voltage, where n is an adjustable index whose value is established by a desired engine tuning, means for comparing said second and third voltage to produce a first output when said second voltage exceeds said third voltage and a second voltage when said third voltage exceeds said second voltage, and control valve means connecting said common feed rail to said fuel bowl for increasing fuel flow whereby fuel pressure is reduced responsive to said first output and for decreasing fuel flow responsive to said second signal whereby fuel pressure is increased.

Claim 10

In an internal combustion engine of the type having a fuel injection valve for each cylinder and a common feed rail for feeding fuel to said fuel injectors, fuel being circulated by means of a pump from said common feed rail to a fuel bowl and then to a pump which pumps said fuel into said common feed rail, the improvement comprising: means for generating a first voltage representative of (air mass flow rate) into the engine, means for generating a second voltage representative of the fuel pressure across a fuel injection valve, means for raising said first voltage to the power n to produce a third voltage, where n is an adjustable index whose value is established by a desired engine tuning, means for comparing said second and third voltage to produce a first output when said second voltage exceeds said third voltage and a second voltage when said third voltage exceeds said second voltage, and control valve means connecting said common feed rail to said fuel bowl for increasing fuel flow whereby fuel pressure is reduced responsive to said first output and for decreasing fuel flow responsive to said second signal whereby fuel pressure is increased.

Claim 11

In an internal combustion engine as recited in claim 7 wherein there is included a means for subtracting said second voltage from said third voltage to establish a difference voltage, voltage controlled oscillator means to generate a pulse train whose frequency is determined by said difference voltage, gate means rendered inoperative responsive to said first output and operative responsive to said second output to pass the pulse train from said voltage controlled oscillator, and electromechanical actuator means connected to said gate means for controlling said control valve means responsive to said pulse train.