摘要:
A cyclic high pressure fluid seal for a fuel injector includes an injector body that defines a cyclic high pressure space connected to a low pressure space by a bore. A member with a pressure face end and a side surface is mounted to reciprocate in the bore between a retracted position and an advanced position. An O-ring is positioned in contact with the side surface of the member and the injector body within the bore. A portion of the member and the bore define a pressure accumulation volume positioned between the O-ring and the pressure face end. The pressure accumulation volume is positioned such that fluid pressure in the pressure accumulation volume changes with that of the cyclic high pressure space.
摘要:
Because of the relatively high pressures experienced within fuel injectors, several internal components can undergo substantial deformation each time fuel is pressurized to injection levels. In some instances, such as when a solenoid operated control valve is positioned near a distortion region, the internal distortion can cause a fuel injector to behave with less predictability, and can undermine consistency from one fuel injector to another, since distortion levels and affects therefrom are likely to vary substantially from one injector to another. In order to desensitize fuel injector performance to this internal distortion, a deflection cavity is disposed within the fuel injector between the distortion region and the needle valve of the fuel injector. This strategy finds particular applicability to needle control valves disposed deep within fuel injectors in order to control fluid pressure on a closing hydraulic surface of a direct control needle valve, which opens and closes the nozzle outlets.
摘要:
The present invention relates to high speed control valves which are especially applicable for use in fuel injection systems. Producing a valve with a quick response time within acceptable packaging constraints and with a structure that allows the valve to be mass produced with consistent performance between valves is extremely problematic. By moving flow restrictions within the valve away from the valve seats, flow forces on the valve member can be reduced, while possibly also permitting a reduction in the necessary travel distance of the valve member to improve response time and other performance characteristics. The valve is particularly applicable in controlling hydraulic pressure applied to the closing hydraulic surface of a direct control needle valve in a fuel injector.
摘要:
A common rail fuel injection system addresses three basic issues involving all common rail fuel injection systems. These include high performance, low variability and high efficiency. These issues are addressed by combining pressure intensification with a three way needle control valve, which exhibits substantial leakage only durring a brief instant when the valve is moving between seats. A quick acting needle control valve tightly coupled to a responsive direct control needle valve, as modified by relative timing with a flow control valve, can produce a wide variety of fuel injection rate shapes, including up to five or more discrete injections per engine cycle.
摘要:
A hydraulically actuated fuel injector includes an injector body defining an actuation fluid chamber that opens to an actuation fluid drain, an actuation fluid inlet and a piston bore, and further defining a nozzle chamber that opens to a plunger bore and a nozzle outlet. A control valve, positioned in the injector body, has a first position that opens the actuation fluid inlet and closes the actuation fluid drain, and a second position that closes the actuation fluid inlet and opens the actuation fluid drain. A piston, positioned in the piston bore. A plunger, positioned in the plunger bore, is moveable between an upper position and a lower position. A needle valve member, positioned in the nozzle chamber, is moveable between an open position in which the nozzle outlet is open and a closed position in which the nozzle outlet is blocked. A portion of the plunger bore and the plunger define a fuel pressurization chamber that opens to the nozzle chamber. A variable rate return spring biases the piston and plunger toward their retracted positions. The variable rate return spring has a relatively low spring rate when the piston is a first distance away from its retracted position and has a relatively high spring rate when the piston is at a second distance away from its retracted position.
摘要:
A hydraulically actuated fuel injection system includes an actuation fluid supply pipe having a flange. A hydraulically actuated fuel injector has a centerline, at least two different clamping surfaces and a side surface with an actuation fluid inlet. The clamping surfaces are positioned on opposite sides of the centerline. A clamp is attached to the flange of the actuation fluid supply pipe around the centerline of the injector while bearing against the at least two different clamping surfaces. The clamp allows for reliable sealing in a small space while minimizing internal distortion to injector components.
摘要:
A fuel injector includes an injector body with a plunger bore that opens to a nozzle outlet. A plunger having a pressure face and a side surface is positioned to reciprocate in the plunger bore between an advanced position and a retracted position. A portion of the plunger bore and the plunger define a fuel pressurization chamber that opens to the nozzle outlet. A needle valve is positioned in the injector body adjacent the nozzle outlet and is moveable between an open position which opens the nozzle outlet and a closed position in which the nozzle outlet is closed to the fuel pressurization chamber. An O-ring is in contact with the side surface of the plunger and the plunger bore on the injector body and serves to seal against fuel leakage past the plunger. Pressure acting on the O-ring is attenuated by providing either a pressure accumulation volume between the pressure face end of the plunger and the O-ring and/or a pressure release passage that opens the plunger bore to a low pressure return line below the O-ring.
摘要:
A machine includes a machine body and a dual fuel compression ignition engine attached to the machine body. A dual fuel system is operably coupled to supply the engine with liquid diesel fuel and natural gas fuel directly into respective cylinders of the engine. The fuel system includes an insulated tank for storing the natural gas fuel, a pressure sensor positioned to measure fluid pressure within the tank, and a pump for drawing the natural gas fuel from the tank. An electronic controller is in communication with the pressure sensor and has a cryogenic system diagnostics algorithm executable thereon that is configured to receive a pressure signal from the pressure sensor, detect a cryogenic system fault based on the signal, and generate a notification signal based on the fault.
摘要:
A pumping element for pressurizing a fluid within a fluid pump includes a plunger reciprocally disposed within a bore defined in a barrel. The plunger and barrel at least partially define a pressurization chamber into which fluid is pressurized. A flow path is defined between the plunger and the bore, the flow path permitting fluid to pass from the pressurization chamber during pressurization of fluid disposed therein. A collection chamber is formed between the plunger and the bore, the collection chamber being disposed adjacent to the bore and being part of a cooling circuit for the pumping element. A plurality of weep openings is defined in the barrel and is fluidly connected to the collection chamber. A reduced diameter portion of the barrel forms an annular reservoir that receives fluid from the weep openings.
摘要:
A fuel system for an engine including a cylinder head having a first bore and a second bore intersecting the first bore is disclosed. The fuel system includes a common rail and a fuel injector coupled to the cylinder head and at least partially received within the first bore. The fuel system also includes a one-piece hollow tube, extending linearly from the common rail to the fuel injector through the second bore. The one-piece hollow tube is configured to communicate high pressure fuel from the common rail to the fuel injector.