Abstract: A fuel system for an internal combustion engine includes an actuation train having a cam follower, a pushrod, a rocker arm, and a camshaft having a cam lobe rotatable in contact with the cam follower according to an ascending ramp phasing, a peak phasing, and a descending ramp phasing. The fuel system further includes a fuel injector including an electrically actuated spill valve. A fueling control unit is in communication with the spill valve and structured to close the spill valve during the ascending ramp phasing, such that a plunger cavity pressure is increased to oppose a plunger-advancement inertia of the actuation train. Related methodology and control logic is also disclosed.

Abstract: A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.

Abstract: A fuel system is disclosed for use with an engine, including a fuel injector assembly fluidly coupled with a low-pressure fuel conduit, an accumulator, and a cap within an opening in the accumulator. The fuel injector assembly may be structured to draw in low-pressure fuel, pressurize the fuel, and store the pressurized fuel in the accumulator for injection to a combustion chamber. The cap has a pressure sensor and a pressure relief valve therein, and drains fuel leaked past fluid seals between the cap and each of the pressure sensor, the pressure relief valve, and the accumulator by way of a common drain line.

Abstract: A system and a method for actuating intake valves of an internal combustion engine. The system includes a hydraulic circuit including a master cylinder, a control valve, an accumulator, a first one-way valve and a slave cylinder. The slave cylinder accommodates a slave piston, which is coupled to the intake valves. The control valve is disposed upstream of the accumulator for controlling flow from the hydraulic circuit to the accumulator. The first one-way valve is disposed downstream of the accumulator for permitting flow from the accumulator to the hydraulic circuit and for preventing flow from the hydraulic circuit to the accumulator without first passing through the control valve. The control valve has an open position that provides communication between the hydraulic circuit and the accumulator for a Miller cycle or Miller-like cycle operation. The control valve also has a closed position that prevents communication between the hydraulic circuit and the accumulator during Otto cycle operation.

Abstract: A system and a method for actuating intake valves of an internal combustion engine. The system includes a hydraulic circuit including a master cylinder, a control valve, an accumulator, a first one-way valve and a slave cylinder. The slave cylinder accommodates a slave piston, which is coupled to the intake valves. The control valve is disposed upstream of the accumulator for controlling flow from the hydraulic circuit to the accumulator. The first one-way valve is disposed downstream of the accumulator for permitting flow from the accumulator to the hydraulic circuit and for preventing flow from the hydraulic circuit to the accumulator without first passing through the control valve. The control valve has an open position that provides communication between the hydraulic circuit and the accumulator for a Miller cycle or Miller-like cycle operation. The control valve also has a closed position that prevents communication between the hydraulic circuit and the accumulator during Otto cycle operation.

Abstract: A mechanically actuated electronically controlled fuel injector includes a first electrical actuator that controls the position of a spill value, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a nozzle check valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pressurization chamber either to a spill passage or at high pressure out of a nozzle outlet of the fuel injector for an injection event. Pressure in the fuel injector is moderated when the plunger is moving and the nozzle check valve is in a closed position by briefly cracking open the spill valve to relieve some pressure during the dwell between injection events, such as between a large main injection event and a small close coupled post injection event. This strategy allows for longer dwell times between injection events as well as smaller injection quantities in the post-injection.

Abstract: A mechanically actuated electronically controlled fuel injector (MEUI) includes a first electrical actuator that controls the position of a spill valve, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a directly operated needle valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pumping chamber either to a spill passage, or at high pressure out of a nozzle outlet of the fuel injector for an injection event. The minimum controllable fuel injection quantity, especially as it relates to small closely coupled post injections following a large main injection, is accomplished by the inclusion of a variable flow rate valve that restricts fluid flow from a needle control chamber toward a drain, but is relatively unrestricted to high pressure fluid flow toward the needle control chamber.

Abstract: A mechanically actuated electronically controlled fuel injector includes a first electrical actuator that controls the position of a spill value, and a second electrical actuator to control pressure on a closing hydraulic surface associated with a nozzle check valve. The fuel injector is actuated via rotation of a cam to move a plunger to displace fuel from a fuel pressurization chamber either to a spill passage or at high pressure out of a nozzle outlet of the fuel injector for an injection event. Pressure in the fuel injector is moderated when the plunger is moving and the nozzle check valve is in a closed position by briefly cracking open the spill valve to relieve some pressure during the dwell between injection events, such as between a large main injection event and a small close coupled post injection event. This strategy allows for longer dwell times between injection events as well as smaller injection quantities in the post-injection.

Abstract: The present invention broadly applies to any fluid valve made up of a plurality of body components that create sealing lands where the body components are clamped together. The invention is further applicable to any such valves in which pressure differentials within the valve can cause fluid leakage in the region of these sealing lands. Fluid leakage is reduced by locating at least some of these sealing lands within a hollow clamp that holds the valve body components together. This clamping strategy that locates the clamping load where it is needed most is applicable to a wide variety of valves, but is particularly applicable to pressure control valves used in fuel injection systems that experience extremely high pressure differentials during their usage.

Abstract: The present invention broadly applies to any fluid valve made up of a plurality of body components that create sealing lands where the body components are clamped together. The invention is further applicable to any such valves in which pressure differentials within the valve can cause fluid leakage in the region of these sealing lands. Fluid leakage is reduced by locating at least some of these sealing lands within a hollow clamp that holds the valve body components together. This clamping strategy that locates the clamping load where it is needed most is applicable to a wide variety of valves, but is particularly applicable to pressure control valves used in fuel injection systems that experience extremely high pressure differentials during their usage.

Abstract: A reverse flow valve member is positioned within an injector body of a fuel injector and is movable between a closed position and an open position. When the reverse flow valve member is in its closed position, an upper portion of a nozzle supply passage is blocked from fluid communication with a lower portion of the nozzle supply passage. A compressed spring biases the reverse flow valve member to its closed position. When the reverse flow valve member is in its open position, the fuel pressurization chamber is fluidly connected to the lower portion of the nozzle supply passage. The present invention limits gas ingestion due to tip leakage, and allows an injector with trapped gas to prime itself.

Abstract: A reverse flow valve member is positioned within an injector body of a fuel injector and is movable between a closed position and an open position. When the reverse flow valve member is in its closed position, an upper portion of a nozzle supply passage is blocked from fluid communication with a lower portion of the nozzle supply passage. A compressed spring biases the reverse flow valve member to its closed position. When the reverse flow valve member is in its open position, the fuel pressurization chamber is fluidly connected to the lower portion of the nozzle supply passage. The present invention limits gas ingestion due to tip leakage, and allows an injector with trapped gas to prime itself.