Compact high performance fuel system with accumulator

An electronically controllable, fail safe, high pressure fuel pump assembly for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising

• (a) pump means for pressurizing fuel above the predetermined pressure, said pump means including plural positive displacement pump elements having variable displacement capability,
• (b) an accumulator means for accumulating and temporarily storing fuel at high pressure received from said pump means, said accumulator including at least one accumulator chamber arranged to receive fuel from all said positive displacement pump elements,
• (c) a fuel distributor means for enabling sequential periodic fluidic communication between said accumulator chamber and the engine cylinders,
• (d) at least a pair of associated solenoid operated pump control valves for controlling the effective displacement of said pump elements to cause said pump elements to share the pumping load necessary to maintain a desired pressure of fuel in said accumulator chamber,
• (e) a first solenoid operated injection control valve for normally controlling the timing of one portion of the quantity of fuel injected into each engine cylinder during each injection event, and
• (f) electronic control means for controlling the operation of said pump control valves to allow substantially normal engine operation should one of said pump control valves become disabled by causing the associated pump control valve to take over the function of the disabled pump control valve.

A compact, high pressure fuel pump assembly for supplying fuel to a multi-cylinder internal combustion engine, comprising

• a pump housing having minimal extent in mutually perpendicular lateral, radial and axial directions, said pump housing containing at least one pump cavity having a first pump axis extending in the radial direction and a drive shaft cavity adjacent one end of said pump cavity having a drive axis extending in the axial direction;
• a drive shaft mounted within said drive shaft cavity for rotation about said drive axis;
• a pump plunger mounted within said pump cavity for reciprocatory motion along said first pump axis in response to rotational movement of said drive shaft;
• and
• an accumulator housing containing at least one elongated accumulator chamber for accumulating and temporarily storing fuel at high pressure, said accumulator housing being mounted on said pump housing adjacent the other end of said pump cavity with the central axis of said elongated accumulator chamber being arranged parallel to said drive axis.

An ultra high pressure fuel pump assembly for supplying fuel through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine having a predetermined operating range and having reciprocating pistons associated with the respective cylinders, comprising:

• pump means for supplying fuel at a pressure above a predetermined operating pressure;
• a high pressure accumulator means fluidically connected with said pump means for accumulating a predetermined volume of fuel at said predetermined operating pressure;
• a fuel distribution means for providing sequential periodic fluidic communication between said accumulator means and the engine cylinders through the fuel injection lines associated with the corresponding engine cylinders for causing periodic injection of fuel into the corresponding engine cylinder in timed synchronism with the movement of the piston in the corresponding engine cylinder;
• wherein said high pressure accumulator means includes a high strength, compact accumulator housing containing a fluidically interconnected labyrinth of accumulator chambers having a total volume sufficient to allow controlled quantities of fuel at the said operating pressure to be delivered to each engine cylinder at appropriate times throughout the entire operating range of the engine as determined by said fuel distribution means.

A fuel pump assembly for supplying fuel to a multi-cylinder internal combustion engine above a predetermined high pressure, comprising

• a compact pump housing having minimal dimensions in mutually perpendicular lateral, radial and axial directions, said pump housing containing at least one pump cavity having a first pump axis extending in the radial direction;
• pumping means mounted within said pump cavity for pressurizing fuel above the predetermined high pressure;
• an accumulator housing containing at least one accumulator chamber for accumulating and temporarily storing fuel at high pressure, said accumulator housing being mounted on said pump housing adjacent one end of said pump chamber, at least one of said axial extent and said lateral extent of said accumulator housing being greater than the corresponding extent of said pump housing thereby creating a cantilevered overhang of said accumulator housing relative to said pump housing;
• and
• pump control valve means connected with said overhang of said accumulator housing adjacent said pump housing for controlling the amount of fuel pumped into said accumulator chamber.

A high pressure fuel pump assembly for periodic injection of fuel through plural fuel injection lines into corresponding engine cylinders of a plural cylinder internal combustion engine having a predetermined operating range and a plurality of reciprocating pistons associated with the corresponding cylinders, comprising:

• a compact pump housing having minimal dimensions in mutually perpendicular lateral, radial and axial directions, said pump housing containing at least one pump cavity having a first central axis extending in the radial direction;
• a pump plunger mounted within said pump cavity for reciprocatory motion along said first central axis;
• an accumulator housing containing at least one accumulator chamber for accumulating and temporarily storing fuel at high pressure, said accumulator housing being mounted on said pump housing adjacent one end of said pump chamber, at least one of said axial extent and said lateral extent of said accumulator housing being greater than the corresponding extent of said pump housing thereby creating a cantilevered overhang of said accumulator housing relative to said pump housing;
• and
• a fuel distributor means for providing sequential periodic fluidic communication between said accumulator means and the engine cylinders through the corresponding fuel injection lines associated with the corresponding engine cylinders for causing periodic injection of fuel into the corresponding engine cylinder in timed synchronism with the movement of the pistons in the corresponding cylinders, said fuel distribution means including a distributor body cantilever mounted on said pump housing in parallel, generally spaced apart relationship with respect to said overhang of said accumulator housing.

A fuel pump assembly, comprising

• a pump housing containing an outwardly opening pump cavity,
• a drive shaft rotatably mounted in the pump housing,
• a pump head mountable on the pump housing to close the outwardly opening pump cavity, said pump head containing a pump unit recess positioned to communicate with the pump cavity, and
• a replaceable pump unit including a pump barrel containing a pump chamber and a pump plunger adapted to be mounted for reciprocal movement within said pump chamber in response to rotation of said drive shaft, said replaceable pump unit including retaining means for mounting said pump unit within said pump unit recess of said pump head in a position to extend at least partially into said pump cavity in spaced apart non-contacting relationship with said pump housing.

A unitized fuel pump assembly for sequential periodic injection of fuel through plural fuel injection lines into corresponding engine cylinders of a plural cylinder internal combustion engine having a predetermined operating range and a plurality of reciprocating pistons associated with the corresponding cylinders, comprising:

• pump means for pressurizing fuel, said pump means including a pump housing and a drive shaft mounted within said housing for rotation about a rotational axis, said pump housing containing a plurality of pump cavities positioned along said rotational axis, said pump cavities being aligned along said rotational axis in a single radial direction;
• accumulator means for accumulating and temporarily storing fuel under pressure received from said pump means, said accumulator means including an accumulator housing mounted on said pump housing in a position which is separated from said drive shaft cavity by said pump cavities;
• a fuel distributor means for providing sequential periodic fluidic communication between said accumulator means and each of the engine cylinders through the corresponding fuel injection lines associated with the corresponding engine cylinders for causing periodic injection of fuel into the corresponding engine cylinder, said fuel distribution means including a distributor housing mounted on said pump housing adjacent one end of said drive shaft cavity, and
• injection control valve means for controlling the timing and quantity of fuel injected into each cylinder in response to engine operating conditions, said injection control valve means including a solenoid operator mounted on said distributor housing oriented generally in the same radial direction as said pump cavities relative to said rotational axis of said drive shaft.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a pump means for pressurizing fuel above the predetermined pressure;
• an accumulator means for accumulating and temporarily storing fuel at high pressure received from said pump means;
• a fuel distributor means fluidically connected with said accumulator means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• a solenoid operated injection control valve positioned within said fuel transfer circuit between said accumulator means and said fuel distributor means for controlling the fuel injected into each engine cylinder during each of the sequential periods of communication enabled by said fuel distributor means to thereby define sequential injection events, said solenoid operated injection control valve movable between an open position permitting fuel flow from said accumulator means to said fuel distributor means and a closed position blocking fuel flow from said accumulator means to said fuel distributor means;
• and
• a rate shaping control means positioned within said fuel transfer circuit between said accumulator means and said fuel distributor means for producing a predetermined time varying change in the pressure of fuel during each injection event occurring sequentially at each engine cylinder to effect injection.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a pump means for pressurizing fuel above the predetermined pressure, said pump means including plural pump chambers and plural pump plungers mounted for reciprocal movement in said pump chambers;
• a constant volume high pressure accumulator means for accumulating and temporarily storing fuel at high pressure received from said pump means;
• a fuel distributor means fluidically connected with said constant volume high pressure accumulator means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• an injection control valve means for controlling the fuel injected into each engine cylinder during each of the sequential periods of communication enabled by said fuel distributor means to thereby define sequential injection events;
• and
• a rate shaping control means positioned within said fuel transfer circuit between said constant volume high pressure accumulator means and said fuel distributor means for producing a predetermined time varying change in the rate of fuel injected into each engine cylinder during said sequential injection events.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a pump means for pressurizing fuel from said fuel supply means above the predetermined pressure;
• a fuel distributor means fluidically connected with said pump means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• an injection control means for controlling the fuel injected into each engine cylinder during each of the sequential periods of communication enabled by said fuel distributor means to thereby define sequential injection events;
• and
• a rate shaping control means positioned within said fuel transfer circuit between said pump means and said fuel distributor means for producing a predetermined time varying change in the rate of fuel injected into each engine cylinder during said sequential injection events, wherein said rate shaping control means includes a flow limiting means positioned within said fuel transfer circuit between said pump means and said fuel distributor means for limiting the flow of fuel from said pump means to said fuel distributor means during each of said sequential injection events, a by-pass passage for directing fuel flow around said flow limiting means and a rate shaping by-pass valve positioned within said by-pass passage.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a pump means for pressurizing fuel above the predetermined pressure;
• an accumulator means for accumulating and temporarily storing fuel at high pressure received from said pump means;
• a fuel distributor means fluidically connected with said accumulator means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• an solenoid operated injection control valve positioned within said fuel transfer circuit between said accumulator means and said fuel distributor means for controlling the fuel injected into each engine cylinder during each sequential periods of communication enabled by said fuel distributor means;
• a cavitation control means for minimizing cavitation in said fuel transfer circuit between said cavitation control means and the cylinders, said cavitation control means including a reverse flow restrictor valve positioned within said fuel transfer circuit between said injection control valve and said fuel distributor means for allowing substantially unimpeded forward flow of fuel toward each engine cylinder while substantially restricting reverse flow.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a drain passage for connection to said fuel transfer circuit;
• a high pressure pump means for pressurizing fuel above the predetermined pressure;
• a fuel distributor means fluidically connected with said high pressure pump means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• an injection control valve positioned within said fuel transfer circuit between said high pressure pump means and said fuel distributor means for controlling the fuel injected into each engine cylinder during each of the sequential periods of communication enabled by said fuel distributor means to thereby define sequential injection events, said injection control valve is movable between an open position allowing fuel flow from said high pressure pump means to said fuel distributor means and a closed position blocking flow from said high pressure pump means while fluidically connecting said drain passage to said fuel transfer circuit downstream of said injection control valve;
• a cavitation control means for minimizing cavitation in said fuel transfer circuit and the fuel injection lines between said injection control valve and the engine cylinders, said cavitation control means operable to maintain fuel in said fuel transfer circuit downstream of said fuel distributor means, said cavitation control means including an auxiliary fuel supply connected to said drain passage for supplying pressurized fuel at an auxiliary supply pressure to said fuel transfer circuit downstream of said injection control valve when said injection control valve is in said closed position, wherein said auxiliary supply pressure is high enough to minimize the effects of cavitation while low enough to cause no fuel injection.

A high pressure fuel system for supplying fuel at a predetermined pressure through plural fuel injection lines to the corresponding cylinders of a multi-cylinder internal combustion engine, comprising:

• a fuel supply means for supplying fuel for delivery to the internal combustion engine, said fuel supply means including a fuel transfer circuit;
• a drain passage for connection to said fuel transfer circuit;
• a high pressure pump means for pressurizing fuel above the predetermined pressure;
• a fuel distributor means fluidically connected with said high pressure pump means through said fuel transfer circuit for enabling sequential periodic fluidic communication with the engine cylinders through the corresponding fuel injection lines;
• an injection control valve positioned within said fuel transfer circuit between said high pressure pump means and said fuel distributor means for controlling the fuel injected into each engine cylinder during each of the sequential periods of communication enabled by said fuel distributor means, wherein said injection control valve is movable between an open position allowing fuel flow to said fuel distributor means and a closed position blocking flow from said accumulator means while fluidically connecting said drain passage to said fuel transfer circuit downstream of said injection control valve, wherein movement of said injection control valve from said open position to said closed position and from said closed position to said open position defines a draining event and movement of said injection control valve from said closed position to said open position and from said open position to said closed position defines an injection event;
• a cavitation control means for minimizing cavitation in said fuel transfer circuit and the fuel injection lines between said injection control valve and the engine cylinders, said cavitation control means including a pressure regulating means positioned in said drain passage for maintaining fuel in said fuel transfer circuit downstream of said injection control valve and in the fuel injection lines at a regulated pressure during said draining event.

A fuel pump assembly, comprising

• a pump housing containing an outwardly opening pump cavity,
• a pump head mountable on the pump housing to close the outwardly opening pump cavity, said pump head containing a pump unit recess positioned to communicate with the pump cavity,
• a pump unit mounted within said pump unit recess, said pump unit including a pump barrel containing a pump chamber and a pump plunger adapted to be mounted for reciprocal movement within said pump chamber, said pump barrel containing a valve cavity, and
• a variable displacement pump control valve means mounted in said valve cavity for varying the effective displacement of said pump unit in response to a variable displacement control signal.

A fuel pump assembly, comprising

• a pump housing containing an outwardly opening pump cavity,
• a pump head mountable on the pump housing to close the outwardly opening pump cavity, said pump head containing a pump unit recess positioned to communicate with the pump cavity and a valve cavity having a central axis aligned with a central axis of said pump unit recess,
• a pump unit mounted within said pump unit recess, said pump unit including a pump barrel containing a pump chamber and a pump plunger adapted to be mounted for reciprocal movement within said pump chamber, and
• a variable displacement control valve means mounted in said valve cavity for varying the effective displacement of said pump unit in response to a variable displacement control signal.

A fuel pump assembly for supplying fuel to a multi-cylinder engine above a predetermined high pressure, comprising:

• a pump housing containing an outwardly opening pump cavity,
• a drive shaft rotatably mounted in the pump housing,
• a single piece, integral pump head mountable on said pump housing to close said outwardly opening pump cavity, said integral pump head containing a pump chamber and at least one accumulator chamber for temporarily storing fuel under pressure received from said pump chamber;
• a pump plunger adapted to be mounted for reciprocal movement within said pump chamber in response to rotation of said drive shaft;
• and
• distributor means for sequentially distributing fuel to said engine cylinders from said at least one accumulator chamber.