Fuel injection

The method of injecting fuel into a combustion chamber of an internal combustion engine including the steps of:

• reciprocably mounting a pressure-responsive valve member between a pair of chambers;
• communicating pressurized fuel from a first source thereof having a first pressure level into said pair of chambers;
• closing said communication of said pressurized fuel from said first source into one of said pair of chambers in timed relation to said engine;
• sequentially communicating said one chamber to a second source of pressurized fuel having a second pressure level which is less than said first source to shift said valve member to a position communicating fuel into said combustion chamber;
• interrupting said communication of pressurized fuel into the other of said pair of chambers in timed relation to said engine;
• providing a plunger member having a pair of opposed faces, one of said pair of opposed faces communicating with said other chamber;
• communicating pressurized fuel from said first source to the other of said pair of opposed faces to move said plunger member and displace fuel into said combustion chamber past said open valve member;
• opening communication of said other chamber with said second source of pressurized fuel upon a determined movement of said plunger member to interrupt communication of fuel to said combustion chamber;
• and
• providing abutment means cooperating with said valve member and with said plunger member for moving said valve member to a closed position interrupting communication of fuel to said combustion chamber upon said determined movement of said plunger member.

The method of injecting liquid fuel into a combustion chamber of an internal combustion engine, said engine including an injector selectively opening and closing communication of said fuel from a first pressure source thereof to said combustion chamber;

• said injector including a first chamber communicating with said first pressure source, a second chamber communicating with said first pressure source, and a valve member moving in response to a fluid pressure differential between said first chamber and said second chamber to open communication of said fuel into said combustion chamber, said method including the steps of:
• interrupting communication of said second chamber with said first pressure source;
• and communicating said second chamber with a second source of pressurized fuel having a pressure level less than said first pressure source to shift said valve member to an open position communicating fuel into said combustion chamber;
• said injector further including a third chamber communicating with said first pressure source, said third chamber in said open position of said valve member communicating with said combustion chamber, said method including the step of communicating said third chamber with said second source of pressurized fuel to substantially interrupt communication of fuel from said third chamber to said combustion chamber;
• reciprocably mounting a plunger member in said third chamber, said plunger member moving to vary the volume defined within said third chamber;
• moving said plunger member to displace fuel therefrom into said combustion chamber after moving said valve member to said open position;
• communicating said plunger member with said first chamber whereby pressurized fuel from said first pressure source moves said plunger member to displace fuel from the latter into said combustion chamber past said open valve member;
• and forming abutment means for cooperating with said plunger member and said valve member to shift the latter to a closed position upon a predetermined movement of said plunger member.

The method of injecting a pulse of fuel into an internal combustion engine, said method comprising the steps of:

• communicating a first source of pressurized fuel having a first pressure level with a combustion chamber of said engine via a fuel flow path;
• reciprocably disposing a first valve member in said flow path, said first valve member moving between a first position closing communication of fuel to said combustion chamber and a second position opening said communication;
• drivingly coupling said first valve member with a pressure-responsive plunger member reciprocably mounted between a pair of chambers;
• alternately opening and closing communication of one of said pair of chambers with said first pressure source in timed relation with said engine while sequentially communicating the other of said pair of chambers alternately with said first pressure source and with a second source of pressurized fuel having a second pressure level which is less than said first pressure level to move said pressure-responsive valve member to said second position opening said fuel flow path to begin said fuel injection pulse;
• communicating said one chamber with said second source of fuel to substantially end said fuel injection pulse;
• forming a branch of passage in said fuel flow path between said first and said second valve members;
• reciprocably mounting a piston member between a pair of cavities, one of said pair of cavities communicating with said branch passage, the other of said pair of cavities communicating with said first pressure source;
• moving said piston member through a determined distance to displace fuel from said one cavity into said combustion chamber via said branch passage during said fuel injection pulse;
• and
• forming abutment means cooperating with said plunger member and said piston member to move said first valve member to said first position upon said piston member moving through said determined distance, thereby closing said fuel flow path and ending said fuel injection pulse.

Fuel injection apparatus comprising:

• means for increasing the pressure level of fuel from ambient pressure to a determined pressure level;
• means for measuring out a certain quantity of said pressurized fuel at said determined pressure level;
• means for delivering said measured certain quantity of pressurized fuel to an internal combustion engine while maintaining the pressure level thereof substantially at said determined pressure level;
• said injection apparatus including a fuel injector defining an inlet receiving pressurized fuel from said pressure increasing means, a nozzle section opening to a combustion chamber of said engine, and a fuel flow path extending between said inlet and said nozzle section;
• said measuring means comprising said fuel injector defining a bore communicating with said fuel flow path, said bore reciprocably receiving a piston member cooperating with said fuel injector to define a pair of variable-volume cavities, one of said pair of variable-volume cavities communicating with said fuel flow path, and means for moving said piston member to increase the volume of said one variable-volume cavity to measure said certain quantity of pressurized fuel therein;
• said means for moving said piston member including the latter defining a differential area and a pair of opposed faces differing in effective area according to said differential area, the larger of said pair of opposed faces being exposed to said one variable-volume cavity, the smaller of said pair of opposed faces being exposed to the other of said pair of variable-volume cavities and said differential area being exposed to ambient pressure;
• operator-operated variable stop means for cooperating with said piston member to limit the movement thereof in a direction expanding said one variable-volume cavity, whereby pressurized fuel communicating to said larger face of said piston member moves the latter into engagement with said variable stop means to measure said certain quantity of pressurized fuel into said one variable-volume cavity;
• said piston member defining a stem sealingly and movably extending through an end wall of said bore, said stem defining said differential area;
• and
• one of said piston member and stem defining a passage opening communication between said pair of variable-volume cavities upon a predetermined movement of said piston member in a direction contracting said one variable-volume cavity.

Fuel injection apparatus comprising:

• means for increasing the pressure level of fuel from ambient pressure to a determined pressure level;
• means for measuring out a certain quantity of said pressurized fuel at said determined pressure level;
• and
• means for delivering said measured certain quantity of pressurized fuel to an internal combustion engine while maintaining the pressure level thereof substantially at said determined pressure level;
• said injection apparatus including a fuel injector defining an inlet receiving pressurized fuel from said pressure increasing means, a nozzle section opening to a combustion chamber of said engine, and fuel flow path extending between said inlet and said nozzle section;
• said measuring means comprising said fuel injector defining a bore communicating with said fuel flow path, said bore reciprocably receiving a piston member cooperating with said fuel injector to define a pair of variable-volume cavities, one of said pair of variable-volume cavities communicating with said fuel flow path, and means for moving said piston member to increase the volume of said one variable-volume cavity to measure said certain quantity of pressurized fuel therein;
• said means for moving said piston member including the latter defining a differential area and a pair of opposed faces differing in effective area according to said differential area, the larger of said pair of opposed faces being exposed to said one variable-volume cavity, the smaller of said pair of opposed faces being exposed to the other of said pair of variable-volume cavities and said differential area being exposed to ambient pressure;
• operator-operated variable stop means for coooperating with said piston member to limit the movement thereof in a direction expanding said one variable-volume cavity, whereby pressurized fuel communicating to said larger face of said piston member moves the latter into engagement with said variable stop means to measure said certain quantity of pressurized fuel into said one variable-volume cavity;
• said means for delivering said measured certain quantity of pressurized fuel to said combustion chamber including passage means communicating pressurized fuel from said inlet to said other variable-volume cavity, first valve means for closing communication of pressurized fuel from said inlet to said one variable-volume cavity, and second valve means for in an open position thereof opening communication of said measured certain quantity of fuel from said one variable-volume cavity to said combustion chamber, pressurized fuel in said other variable-volume cavity moving said piston member to contract said one variable-volume cavity and displace pressurized fuel therefrom into said combustion chamber;
• said second valve means being drivingly coupled with a pressure-responsive plunger member defining a pair of opposed surfaces exposed to pressurized fuel at said determined pressure level, said first valve member closing communication of pressurized fuel at said determined pressure level to one of said pair of opposed surfaces and sequentially communicating said one surface to a source of comparatively low pressure relative to said determined pressure level to shift said second valve member to said open position;
• and
• cooperating abutment means for cooperating with said plunger member and piston member upon a predetermined movement of the latter contracting said one variable-volume cavity.

Fuel injection apparatus comprising:

• a fuel injector defining an inlet communicable with a first source of pressurized fuel to receive fuel therefrom at a first pressure level, a nozzle section communicable with a combustion chamber of an internal combustion engine, and a fuel flow path extending from said inlet to open on said nozzle section;
• first pressure-responsive valve means reciprocably disposed in said fuel flow path for opening and closing the latter in respective positions of said first valve means, said first valve means defining a pair of opposed faces, one of said pair of opposed faces being exposed to said fuel flow path and the other of said pair of opposed faces being sealingly isolated therefrom, said first valve means in said closed position thereof further defining a differential area exposed to said combustion chamber, said first valve means closing said flow path in response to communication of pressurized fuel at said first pressure level to said other face, said first valve means shifting to said open position in response to communication of said other face to a second source of pressurized fuel having a second pressure level which is less than said first pressure level;
• second pressure-responsive valve means for opening and closing said fuel flow path upstream of said first valve means in respective positions of said second valve means, said second valve means in said open position thereof communicating said other face with said first source of pressurized fuel and in said closed position thereof communicating said other face with said second source of pressurized fuel;
• means for driving said second valve means between said open and closed positions thereof in timed relation with said engine;
• pressure-responsive piston means moving to respectively expand and contract a variable-volume cavity in response to receipt of pressurized fuel at said first pressure level and relief of said pressurized fuel therefrom;
• passage means extending from said variable-volume cavity to said fuel flow path intermediate of said first and second valve means for communicating pressurized fuel therebetween;
• said piston means moving to receive pressurized fuel into said variable-volume cavity when said first and said second valve means are in closed and open positions respectively, said piston means moving to displace said pressurized fuel into said combustion chamber when said first and second valve means reverse positions;
• said first valve means including a valve element sealingly cooperable with said nozzle section to close said fuel flow path, a plunger member defining said pair of opposed faces, and a stem drivingly coupling said plunger member with said valve element, said valve element defining said differential area for said first valve means whereby pressurized fuel at said first pressure level communicating to said other face opposes fluid pressure in said combustion chamber communicating to said differential area thereby to maintain said first valve member in said closed position.

Fuel injection apparatus comprising:

• a fuel injector defining an inlet communicable with a first source of pressurized fuel to receive fuel therefrom at a first pressure level, a nozzle section communicable with a combustion chamber of an internal combustion engine, and a fuel flow path extending from said inlet to open on said nozzle section;
• first pressure-responsive valve means reciprocably disposed in said fuel flow path for opening and closing the latter in respective positions of said first valve means, said first valve means defining a pair of opposed faces, one of said pair of opposed faces being exposed to said fuel flow path and the other of said pair of opposed faces being sealingly isolated therefrom, said first valve means in said closed position thereof further defining a differential area exposed to said combustion chamber, said first valve means closing said flow path in response to communication of pressurized fuel at said first pressure level to said other face, said first valve means shifting to said open position in response to communication of said other face to a second source of pressurized fuel having a second pressure level which is less than said first pressure level;
• second pressure-responsive valve means for opening and closing said fuel flow path upstream of said first valve means in respective positions of said second valve means, said second valve means in said open position thereof communicating said other face with said first source of pressurized fuel and in said closed position thereof communicating said other face with said second source of pressurized fuel;
• means for driving said second valve means between said open and closed positions thereof in timed relation with said engine;
• pressure-responsive piston means moving to respectively expand and contract a variable-volume cavity in response to receipt of pressurized fuel at said first pressure level and relief of said pressurized fuel therefrom;
• passage means extending from said variable-volume cavity to said fuel flow path intermediate of said first and second valve means for communicating pressurized fuel therebetween;
• said piston means moving to receive pressurized fuel into said variable-volume cavity when said first and said second valve means are closed and open positions respectively, said piston means moving to displace said pressurized fuel into said combustion chamber when said first and second valve means reverse positions;
• and
• abutment means for cooperating with said first valve means and with said piston means upon a predetermined movement of the latter contracting said variable-volume cavity, said abutment means moving said first valve means to said closed position thereof.

The method of injecting fuel into an internal combustion engine comprising the steps of:

• increasing the pressure of said fuel to a determined pressure level;
• measuring a certain quantity of said pressurized fuel;
• delivering to said internal combustion engine said measured certain quantity of pressurized fuel while maintaining the pressure level thereof substantially at said determined level;
• expanding and contracting a variable-volume chamber in timed relation to said internal combustion engine to respectively measure said certain quantity of pressurized fuel and to deliver said measured certain quantity of fuel to said internal combustion engine;
• reciprocating a pressure-responsive piston member in timed relation to said internal combustion engine to expand and contract said variable-volume chamber;
• using pressurized fuel having said determined pressure level to reciprocate said pressure-responsive piston member;
• exposing a differential area defined by said pressure-responsive piston member to a first source of comparatively low pressure relative to said determined pressure level;
• communicating pressurized fuel having said determined pressure level to a pair of opposed faces defined by said pressure-responsive piston member, said pair of opposed faces differing in effective are substantially according to said differential area, said pressurized fuel moving said pressure-responsive piston member to expand said variable-volume chamber;
• closing communication of said pressurized fuel having said determined pressure level to the one of said opposed faces of said piston member having the larger area;
• communicating said one face of said piston member to a second source of comparatively low pressure relative to said determined pressure level, pressurized fuel communicating to the other of said opposed faces of said piston member moving said pressure-responsive piston member to contract said variable-volume chamber;
• using said one face of said pressure-responsive piston member to bound said variable-volume chamber;
• forming a fuel flow path leading from a source of pressurized fuel having said determined pressure level to a combustion chamber of said internal combustion engine;
• closing said fuel flow path with a valve element movable to open said flow path;
• drivingly coupling said valve element with a pressure-responsive reciprocable plunger member;
• using pressurized fuel substantially at said determined pressure level to reciprocate said plunger member opening and closing said fuel flow path;
• forming a branch passage leading from said fuel flow path upstream of said valve element to said variable-volume chamber;
• and
• using a valve member reciprocating in timed relation with said engine to open and close said fuel flow path upstream of said branch passage.

The method of injecting fuel into a combustion chamber of internal combustion engine including the steps of:

• reciprocably mounting a pressure-responsive valve member between a pair of chambers;
• communicating pressurized fuel from a first source thereof having a first pressure level into said pair of chambers;
• closing said communication of said pressurized fuel from said first source into one of said pair of chambers in timed relation to said engine;
• sequentially communicating said one chamber to a second source of pressurized fuel having a second pressure level which is less than said first source to shift said valve member to a position communicating fuel into said combustion chamber;
• interrupting said communication of pressurized fuel into the other of said pair of chambers in timed relation to said engine,
• providing a plunger member having a pair of opposed faces, one of said pair of opposed faces communicating with said other chamber;
• communicating pressurized fuel from said first source to the other of said pair of opposed faces to move said plunger member and displace fuel into said combustion chamber past said open valve member;
• and
• using a valve apparatus moving in timed relation with said engine to open and close communication of pressurized fuel from said first source with said other chamber while sequentially communicating said one chamber alternately with said first source and with said second source.

Fuel injection apparatus comprising:

• means for increasing the pressure level of fuel from ambient pressure to a determined pressure level;
• means for measuring out a certain quantity of said pressurized fuel at said determined pressure level;
• and
• means for delivering said measured certain quantity of pressurized fuel to an internal combustion engine while maintaining the pressure level thereof substantially at said determined pressure level;
• said injection apparatus including a fuel injector defining an inlet receiving pressurized fuel from said pressure increasing means, a nozzle section opening to a combustion chamber of said engine, and a fuel flow path extending between said inlet and said nozzle section;
• said measuring means comprising said fuel injector defining a bore communicating with said fuel flow path, said bore reciprocably receiving a piston member cooperating with said fuel injector to define a pair of variable-volume cavities, one of said pair of variable-volume cavities communicating with said fuel flow path, and means for moving said piston member to increase the volume of said one variable-volume cavity to measure said certain quantity of pressurized fuel therein;
• said means for moving said piston member includes the latter defining a differential area and a pair of opposed faces differing in effective area according to said differential area, the larger of said pair of opposed faces being exposed to said one variable-volume cavity, the smaller of said pair of opposed faces being exposed to the other of said pair of variable-volume cavities and said differential are being exposed to ambient pressure;
• operator-operated variable stop means for cooperating with said piston member to limit the movement thereof in a direction expanding said one variable-volume cavity, whereby pressurized fuel communicating to said larger face of said piston member moves the latter into engagement with said variable stop means to measure said certain quantity of pressurized fuel into said one variable-volume cavity;
• said piston member defining a stem sealingly and movably extending through an end wall of said bore, said stem defining said differential area.