Abstract: An internal combustion engine, such as a direct injection compression ignition diesel engine, includes an engine housing having a plurality of cylinders and a plurality of fuel injectors associated one with each of the cylinders. The fuel injectors each include a first fuel inlet and a second fuel inlet, and an actuator subassembly which is configured to actuate a control valve assembly positioned within the fuel injector. The engine further includes a fuel system having a fuel supply circuit, and a cooling system for the actuator subassembly having a cooling circuit with a segment in common with a segment of the fuel system. The cooling system is configured to pass cooling fuel across a heat exchange interface of the actuator subassembly to exchange heat therewith. The actuator subassembly may include a piezoelectric actuator and a preloading spring, which are each fluidly sealed within a casing of the actuator subassembly.

Abstract: A fuel injector includes a piezoelectric actuator subassembly having a casing and a piezoelectric element disposed within the casing. The piezoelectric element has an operating temperature range and includes a thermally contractive material having a negative thermal expansion coefficient over a second temperature range overlapping with the operating temperature range. A preload control element is coupled with the piezoelectric element and includes a thermally expansive material having a positive thermal expansion coefficient over the second temperature range. The preload control element maintains a constant preload on the piezoelectric element over a wide temperature range to inhibit temperature induced variability in operation, and can axially lengthen in opposition to axial shortening of the piezoelectric element, responsive to a temperature increase.

Abstract: An internal combustion engine, such as a direct injection compression ignition diesel engine, includes an engine housing having a plurality of cylinders and a plurality of fuel injectors associated one with each of the cylinders. The fuel injectors each include a first fuel inlet and a second fuel inlet, and an actuator subassembly which is configured to actuate a control valve assembly positioned within the fuel injector. The engine further includes a fuel system having a fuel supply circuit, and a cooling system for the actuator subassembly having a cooling circuit with a segment in common with a segment of the fuel system. The cooling system is configured to pass cooling fuel across a heat exchange interface of the actuator subassembly to exchange heat therewith. The actuator subassembly may include a piezoelectric actuator and a preloading spring, which are each fluidly sealed within a casing of the actuator subassembly.

Abstract: A fuel injector including a nozzle portion and an electrically actuated valve assembly configured to control a flow of fuel to the nozzle portion. The electrically actuated valve assembly may include a piezoelectric element and a biasing member. The fuel injector also may include a housing with at least a portion of the electrically actuated valve assembly disposed in the housing. The housing may define a cavity between the piezoelectric element and the housing. A thermally conductive material may be disposed at least partially within the cavity and may be configured to transfer heat from the piezoelectric element to the housing.

Abstract: A fuel injector includes a piezoelectric actuator subassembly having a casing and a piezoelectric element disposed within the casing. The piezoelectric element has an operating temperature range and includes a thermally contractive material having a negative thermal expansion coefficient over a second temperature range overlapping with the operating temperature range. A preload control element is coupled with the piezoelectric element and includes a thermally expansive material having a positive thermal expansion coefficient over the second temperature range. The preload control element maintains a constant preload on the piezoelectric element over a wide temperature range to inhibit temperature induced variability in operation, and can axially lengthen in opposition to axial shortening of the piezoelectric element, responsive to a temperature increase.

Abstract: Reducing leakage within fuel injectors is one way in which the efficiency of the overall fuel injection system can be improved. In most fuel injectors that include a direct control needle valve, the needle valve member is still biased toward a closed position by a spring that is located in a spring chamber connected to a low pressure vent. In many instances, the needle valve member is guided in a tight clearance region adjacent the spring chamber. Since the internal plumbing of the fuel injector is connected to a high pressure rail during and between injection events, static leakage across the guide region of the needle valve member can reduce efficiency. Static leakage is reduced in the present invention by connecting the spring chamber to the common rail instead of to a low pressure vent.

Abstract: A valve has a housing defining an interior of the valve. The valve has a first passage in the housing and a second passage in the housing. The valve has a flow limiter movable between a first position at which the first passage is in fluid communication with the second passage and a second position at which the first passage is not in fluid communication with the second passage. The valve has a flow restriction device movable between a first position at which a first flow rate is permitted into the interior of the valve and a second position at which a second flow rate is permitted out of the interior of the valve. The first flow rate is greater than the second flow rate.

Abstract: A fuel system for an internal combustion engine includes at least four fuel injectors for supplying fuel to corresponding combustion chambers of the engine and a pump assembly in fluid communication with the fuel injectors and supplying working fluid to the fuel injectors. The fuel system further includes at least three high pressure rails fluidly connected between the pump assembly and the at least four fuel injectors.

Abstract: Particularly in a relatively large engine that has been inactive for a substantial period of time at a cold temperature, the pressure within a fuel system may decrease. Prior to initiation of engine start-up, fuel pumps that are operably coupled to the engine cannot pressurize and/or circulate fuel within the fuel system. Thus, the time required to supply the high pressure lines with fuel pressure sufficient to start and maintain the engine can be unreasonably delayed. In order to decrease the delay in starting the engine, the present invention includes an electronic control module that includes a priming algorithm. The priming algorithm is operable to activate an electrically powered fuel pump when a fuel system is in an unprimed state. The electronic control module is in communication with at least one sensor that is operable to sense the state of the fuel system.

Abstract: Particularly in a relatively large engine that has been inactive for a substantial period of time at a cold temperature, the pressure within a fuel system may decrease. Prior to initiation of engine start-up, fuel pumps that are operably coupled to the engine cannot pressurize and/or circulate fuel within the fuel system. Thus, the time required to supply the high pressure lines with fuel pressure sufficient to start and maintain the engine can be unreasonably delayed. In order to decrease the delay in starting the engine, the present invention includes an electronic control module that includes a priming algorithm. The priming algorithm is operable to activate an electrically powered fuel pump when a fuel system is in an unprimed state. The electronic control module is in communication with at least one sensor that is operable to sense the state of the fuel system.

Abstract: A fuel system for an internal combustion engine includes at least four fuel injectors for supplying fuel to corresponding combustion chambers of the engine and a pump assembly in fluid communication with the fuel injectors and supplying working fluid to the fuel injectors. The fuel system further includes at least three high pressure rails fluidly connected between the pump assembly and the at least four fuel injectors.

Abstract: Reducing leakage within fuel injectors is one way in which the efficiency of the overall fuel injection system can be improved. In most fuel injectors that include a direct control needle valve, the needle valve member is still biased toward a closed position by a spring that is located in a spring chamber connected to a low pressure vent. In many instances, the needle valve member is guided in a tight clearance region adjacent the spring chamber. Since the internal plumbing of the fuel injector is connected to a high pressure rail during and between injection events, static leakage across the guide region of the needle valve member can reduce efficiency. Static leakage is reduced in the present invention by connecting the spring chamber to the common rail instead of to a low pressure vent.