摘要:
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. Such a fuel injector could find potential application in any directly controlled fuel injection system, but is particularly applicable in common rail systems in which the fuel injector remains fully pressurized between injection events.
摘要:
A pump has a housing defining at least one pumping chamber, and a plunger slidably disposed within the at least one pumping chamber. The plunger is movable between a first and second spaced apart end positions to pressurize a fluid. The pump also has a driver operatively engaged with the plunger to move the plunger between the first end position and the second end position. The pump further has a high-pressure outlet in fluid communication with the at least one pumping chamber. The high pressure outlet passes pressurized fluid during movement of the plunger between the first end position and the second end position. The passing of pressurized fluid through the high-pressure outlet terminates before the plunger completes movement from the first end position to the second end position.
摘要:
A hydraulic system comprises a pump, low pressure drain, high pressure rail, fuel injector, a gas exchange valve actuator, and a timing valve. The high pressure rail is connected to the pump with a supply line. A method of operating an engine comprises the steps of opening a gas exchange valve by connecting it with the outlet of the pump at a first chosen time, supplying pressurized fluid to a high pressure rail by connecting it with the outlet of the pump after the first time, and injecting fuel by supplying fluid from the high pressure rail to a fuel injector at a second chosen time. An engine comprises an engine casing that defines a plurality of cylinders. A fuel injector, gas exchange valve actuator, pump, supply line, and timing valve is provided for each of the cylinders. A low pressure drain and a high pressure rail are also provided.
摘要:
A fuel injector is provided which has an injector body with a metallic tip having an outer surface. A non-metallic insulator, such as a ceramic, is attached to the tip and covers a portion of the outer surface. Injector tip overheating can be a problem, especially during sustained two-cycle boosted engine compression release braking. In addition, injector tip overheating can be a problem when an engine is experiencing simultaneous engine compression release braking and exhaust braking.
摘要:
A valve system having a valve operated by a piezoelectric device to control the flow of fluid through the valve system. Movement of the valve is controlled by a pre-stressed bender actuator that changes its shape by deforming in opposite axial directions in response to a control signal applied by an actuator control system. The valve system may comprise a common rail fuel injector, electrohydraulic actuator system, electronically-controlled fuel injector, gasoline port injector, fluid metering valve, relief valve, reducing valve, direct valve or direct-injection gasoline injector.
摘要:
A valve system having a valve operated by a piezoelectric device to control the flow of fluid through the valve system. Movement of the valve is controlled by a pre-stressed bender actuator that changes its shape by deforming in opposite axial directions in response to a control signal applied by an actuator control system. The valve system may comprise a common rail fuel injector, electrohydraulic actuator system, electronically-controlled fuel injector, gasoline port injector, fluid metering valve, relief valve, reducing valve, direct valve or direct-injection gasoline injector.
摘要:
A fuel injector includes an injector body that defines a nozzle outlet. A needle valve member is mounted in the injector body and moveable a lift distance between an open position in which the nozzle outlet is open, and a closed position in which the nozzle outlet is blocked. A piezoelectric actuator is mounted in the injector body and is moveable a piezo distance between an off position and an on position. A coupling linkage interconnects the needle valve member to the piezoelectric actuator such that a movement of the piezoelectric actuator is multiplied into a larger movement of the needle valve member.
摘要:
A jumper tube with improved misalignment capability comprising a cylindrically shaped receiver portion having a central bore that receives an electronically controlled hydraulically actuated unit fuel injector, an annular groove disposed adjacent each end of the bore, a resilient seal ring disposed in each annular groove, forming a seal between the injector and the bore and providing three degrees of freedom between the injector and bore, a tubular portion having an elongated passage in fluid communication with the bore and a conduit in fluid communication with an actuating fluid manifold and the elongated passage and a bolt extending through the tubular portion, the conduit portion and a portion of the actuating fluid manifold removably attaching the jumper tube to a head of an internal combustion engine.
摘要:
An improved hydraulically-actuated fluid injector system comprises a hydraulically-actuated fuel pressurization member, a fluid storage chamber, and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulically unbalancing the check. Fluid injection ends by hydraulically balancing the check to allow a biasing device to close the check. Preferably, actuating fluid that is spilled from the fuel pressurization member (to end fuel injection) is communicated to a hydraulic motor which drives a source of pressurized hydraulically-actuating fluid. The present invention provides improved control of several fluid injection parameters, including higher peak fluid injection capability and less fluid injection pressure drop at the end of injection, resulting in improved engine performance and lower emissions, noise, and wear. The present invention also improves efficiency of operation due to the above hydraulic energy recovery feature.
摘要:
An improved electronically-controlled fluid injector system comprises a fluid storage chamber and a direct-operated check. Pressurization of fluid in the storage chamber begins before the start of fluid injection. Fluid injection begins by hydraulically unbalancing the check. Fluid injection sharply ends by hydraulically balancing the check to allow a biasing device to close the check. A fluid, such as fuel, can be injected as a purely vapor phase to improve mixing with combustion air.The present invention provides improved control of several fluid injection parameters, including higher peak fluid injection capability and less fluid injection pressure drop at the end of injection, resulting in improved engine performance and lower emissions, noise, and wear.