Fuel injection system

Claim 2

In a fuel injection system: a. a fuel tank; b. at least one fuel injector; c. a fuel supply system for communicating fuel from said tank to said at least one injector at flow rates greater than the volume rate of injection of fuel into an engine by said at least one fuel injector; d. said fuel supply system comprising a fuel pump; e. a fuel return system including an excess fuel manifold communicating with said injector and an excess fuel passage communicating said manifold with said fuel tank for returning excess fuel supplied to said injector to said tank; f. fuel flow control means between said fuel pump and said injector for modulating the flow of fuel to said injector in response to fuel pressure in said return passage to prevent injection of excessive amounts of fuel into an engine as a result of blockage of the fuel return system, saId control means comprising: g. a fuel flow control valve including a valve member movable for continuously variably restricting fuel flow to said injector in response to a pressure force applied to said valve member; h. a pressure-transmitting passage communicating fuel pressure in said excess fuel manifold to said valve member, said valve member moving to restrict fuel flow to said injector when the pressure force applied thereto by fuel pressure in said excess fuel manifold increases above a predetermined level; and, i. said valve member including pressure-balancing surfaces exposed to fuel in said supply system for preventing application of substantial unbalanced pressure forces on said valve member by fuel in said supply system.

Claim 3

The system claimed in claim 1 including a plurality of injectors, said injectors communicating with said fuel return manifold, said pressure-transmitting passage opening into said fuel return manifold.

Claim 4

The system claimed in claim 1 wherein said valve member includes a pressure reaction surface defining a movable wall of an expansible chamber, said pressure-transmitting passage opening into said chamber for maintaining the pressure in said chamber equal to the pressure in said fuel return manifold.

Claim 5

The system claimed in claim 1 wherein said valve member is movable between a first limit position enabling relatively unrestricted fuel flow to said injector and a second limit position providing for a maximum fuel flow restriction, and further including biasing means urging said valve member toward one of said positions.

Claim 6

The system claimed in claim 4 wherein said valve member includes a pressure reaction surface against which said pressure force acts, said surface oriented so that said pressure force acts in opposition to the biasing force of said spring means to move said valve member toward its second position.

Claim 7

The system claimed in claim 1 wherein the extent of movement of said valve member from a first position affording minimum restriction of fuel flow to said injector is a function of the fuel pressure in said fuel manifold, and said valve member moves to a position for restricting fuel flow to said injector at which the pressure in said manifold does not exceed a predetermined maximum level.

Claim 8

The system as claimed in claim 1 wherein said fuel flow control valve is integral with said fuel pump.

Claim 9

In combination: a. an internal combustion engine; b. a fuel supply tank; c. a fuel supply system between said tank and said engine including a fuel injection pump and a plurality of fuel injectors; d. said pump normally supplying a volume rate of fuel flow to said fuel injectors which is in excess of the volume rate of injection of fuel into said engine to insure injection of adequately large fuel charges into said engine; e. a fuel return system for returning excess fuel from said fuel injectors to said tank; f. fuel control means for modulating the flow of fuel to said injectors in response to fuel pressure in said fuel return system, said control means comprising: i. a fuel-flow-controlling valve connected between said pump and said fuel injectors, said valve defined by a housing and a valve member movable in said housing, said valve member having a normal position enabling said pump to provide said normal fuel supply; ii. said valve member including a pressure reaction surface forming a movable wall of an expansible chamber defined by said surface and said housing and opposed surfaces exposed to fuel flowing to said injectors whereby the pressure of fuel flowing to said injectors is substantially ineffective to move said valve member; and, iii. a pressure-transmitting passage communicating fuel pressure in said fuel return system to said chamber, fuel pressure greater than a predetermined pressure in said fuel return system communicated to said chamber through said pressure-transmitting passage for applying a force to said reaction surface for moving said valve member from said normal position to variably restrict fuel flow to said injectors to maintain a predetermined limit between pump output pressure, and therefore fuel delivery, and return line pressure at any given engine speed and thereby enable continued substantially normal operation of the engine under load without oversupply of fuel.

Claim 10

In combination: a. an internal combustion engine; b. a fuel supply tank; c. a fuel supply system between said tank and said engine including a fuel injection pump and a plurality of fuel injectors; d. said pump normally supplying a volume rate of fuel flow to said fuel injectors which is in excess of the volume rate of injection of fuel into said engine to insure injection of adequately large fuel charges into said engine; e. a fuel return system for returning excess fuel from said fuel injectors to said tank; f. fuel control means for modulating the flow of fuel to said injectors in response to fuel pressure in said fuel return system, said control means comprising: i. a fuel-flow-controlling valve connected between said pump and said fuel injectors, said valve defined by a housing and a valve member movable in said housing, said valve member having a normal position enabling said pump to provide said normal fuel supply; ii. said valve member including a pressure reaction surface forming a movable wall of an expansible chamber defined by said surface and said housing and opposed surfaces exposed to fuel flowing to said injectors whereby the pressure of fuel flowing to said injectors is substantially ineffective to move said valve member; and, iii. a pressure-transmitting passage communicating fuel pressure in said fuel return system to said chamber, fuel pressure greater than a predetermined pressure in said fuel return system communicated to said chamber through said pressure-transmitting passage for applying a force to said reaction surface for moving said valve member from said normal position to variably restrict fuel flow to said injectors to maintain a predetermined limit between pump output pressure, and therefore fuel delivery, and return line pressure at any given engine speed and thereby enable continued substantially normal operation of the engine under load without oversupply of fuel.

Claim 11

In combination: a. an internal combustion engine; b. a fuel supply tank; c. a fuel supply system between said tank and said engine including a fuel injection pump and a plurality of fuel injectors; d. said pump normally supplying a volume rate of fuel flow to said fuel injectors which is in excess of the volume rate of injection of fuel into said engine to insure injection of adequately large fuel charges into said engine; e. an excess fuel manifold communicating with said injectors; f. a fuel control valve for continuously varying the quantity of fuel supplied to said injectors by said pump in response to fuel pressure in said excess fuel manifold; i. said valve including a valve member movable in relation to fuel pressure in said excess fuel manifold, said valve member moving from a position wherein fuel flow to said injectors is relatively unrestricted in response to increases in pressure in said excess fuel manifold; ii. pressure-balancing surfaces on said valve member preventing application of substantial unbalanced pressure forces to said valve member by fuel in said fuel supply system; and, iii. means cooperating with said valve member for creating a force acting on said valve member to tend to move said valve member to said position; and, g. a static-pressure-transmitting conduit communicating the static fuel pressure from said excess fuel manifold to said valve member whereby said valve member moves from said position in response to increases in static pressure of fuel in said excess fuel manifold above a predetermined level to maintain a predetermined limit between pump output pressure, and therefore fuel delivery, and the pressure in said excess fuel manifold at any given engine speed and thereby enable continued substantially normal operation of said engine under load without oversupply of fuel.

Claim 12

In combination: a. an internal combustion engine; b. a fuel supply tank; c. a fuel supply system between said tank and said engine including a fuel injection pump and a plurality of fuel injectors; d. said pump normally supplying a volume rate of fuel flow to said fuel injectors which is in excess of the volume rate of injection of fuel into said engine to insure injection of adequately large fuel charges into said engine; e. an excess fuel manifold communicating with said injectors; f. a fuel control valve for continuously varying the quantity of fuel supplied to said injectors by said pump in response to fuel pressure in said excess fuel manifold; i. said valve including a valve member movable in relation to fuel pressure in said excess fuel manifold, said valve member moving from a position wherein fuel flow to said injectors is relatively unrestricted in response to increases in pressure in said excess fuel manifold; ii. pressure-balancing surfaces on said valve member preventing application of substantial unbalanced pressure forces to said valve member by fuel in said fuel supply system; and, iii. means cooperating with said valve member for creating a force acting on said valve member to tend to move said valve member to said position; and, g. a static-pressure-transmitting conduit communicating the static fuel pressure from said excess fuel manifold to said valve member whereby said valve member moves from said position in response to increases in static pressure of fuel in said excess fuel manifold above a predetermined level to maintain a predetermined limit between pump output pressure, and therefore fuel delivery, and the pressure in said excess fuel manifold at any given engine speed and thereby enable continued substantially normal operation of said engine under load without oversupply of fuel.