Abstract: 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.

Abstract: A fuel injector with a direct control needle valve has a closing hydraulic surface exposed to a control fluid, and an opening hydraulic surface exposed to fuel. The control fluid is different from the fuel. A vented annulus is positioned around the needle valve member between the control fluid chamber and the fuel chamber. An o-ring is positioned in a lower pressure region between the annulus and the control fluid chamber.

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: In some hydraulically actuated fuel injectors, a pressure communication passage extends from a pilot valve to the underside of a spool valve to control movement of the same. For the spool valve to move, a substantial amount of fluid flow past the pilot valve is required due to the relatively large amount of fluid that must be displaced by movement of the spool valve member. However, during cold start, when the oil in the pressure communication passage is relatively viscous, it is difficult to move enough fluid past the relatively small flow area through the pilot valve to allow the spool valve to advance to its upper position. Therefore, the fuel injector of the present invention includes a pressure communication passage that is connected to the underside of the spool valve to be separated from the branch that passes through the pilot valve.

Abstract: A nozzle insert that is capable of being irreversibly attached to a needle valve tube such that the resulting needle valve member can be used in a nested needle valve configuration for a dual mode fuel injector.

Abstract: In some hydraulically actuated fuel injectors, a pressure communication passage extends from a pilot valve to the underside of a spool valve to control movement of the same. For the spool valve to move, a substantial amount of fluid flow past the pilot valve is required due to the relatively large amount of fluid that must be displaced by movement of the spool valve member. However, during cold start, when the oil in the pressure communication passage is relatively viscous, it is difficult to move enough fluid past the relatively small flow area through the pilot valve to allow the spool valve to advance to its upper position. Therefore, the fuel injector of the present invention includes a pressure communication passage that is connected to the underside of the spool valve to be separated from the branch that passes through the pilot valve.

Abstract: A linear control valve is disclosed regulating the flow of fluid to hydraulically activated devices, preferably a fuel injector and an engine compression release brake. The valve includes a valve member that is moveable between a first position in which the fuel injector is, at least partially, activated, a second position in which neither the fuel injector nor the engine compression release brake is activated, and a third position in which the engine compression release brake is activated. An electrical actuator providing two permanent magnets and two oppositely wound solenoid coils moves the valve member between its three positions. The polarity of the permanent magnets are oriented such that when the solenoids are energized, one solenoid coil pulls the valve member while the other solenoid coil pushes the valve member in the same direction.

Abstract: The present invention relates to hydraulic systems including hydraulically actuated fuel injectors that have a pilot operated spool valve assembly. One class of hydraulically actuated fuel injectors includes a solenoid driven pilot valve that controls the initiation of the injection event. However, during cold start conditions, hydraulic fluid, typically engine lubricating oil, is particularly viscous and is often difficult to displace through the relatively small drain path that is defined past the pilot valve member. Because the spool valve typically responds slower than expected during cold start due to the difficulty in displacing the relatively viscous oil, accurate start of injection timing can be difficult to achieve. There also exists a greater difficulty in reaching the higher end of the cold operating speed range. Therefore, the present invention utilizes a fluid evacuation valve to aid in displacement of the relatively viscous oil during cold start conditions.

Abstract: A fuel injector nozzle assembly comprises a nozzle defining a guide bore, a fuel pressurization chamber, a seat, and a nozzle orifice. A check valve member has an impact area and a guide portion. The guide portion slides within the guide bore to allow the check valve member to slide between an open position and a closed position. In the open position the fuel pressurization chamber is in fluid communication with the nozzle orifice. In the closed position the impact area of the check valve member is pressing against the seat of the nozzle, and the check valve member is blocking fluid communication between the fuel pressurization chamber and the nozzle orifice. The check valve member comprises a ceramic material having a coefficient of thermal expansion &agr;>8×10−6/° C. when averaged over a temperature range of 0° C. to 300° C.

Abstract: An engine including a crankshaft having a crankshaft pump portion including at least one cam lobe for operably engaging a pump integral to the engine block of the engine, such that the pump is actuated directly by the crankshaft pump portion, thereby eliminating the typical drive train so as to reduce weight of the pump and engine combination while enhancing the reliability thereof and improving pump efficiency.

Abstract: A fuel injector includes an injector body with a plunger bore, a nozzle chamber, and a nozzle outlet that opens to the nozzle chamber. A plunger is positioned to reciprocate in the plunger bore between an advanced position and a retracted position. A portion of the plunger and a portion of the plunger bore define a fuel pressurization chamber. At least one of the injector body and the plunger define a main passage extending between the fuel pressurization chamber and the nozzle chamber. At least one of the injector body and the plunger define a restricted passage extending between the fuel pressurization chamber and the nozzle chamber. The restricted passage restricts flow of fuel to the nozzle chamber over the beginning portion of each injection event. The main passage is substantially closed over a portion of the plunger's movement between its retracted position and its advanced position.

Abstract: A check valve assembly is disposed in a flow path of a high pressure hydraulic actuating system between a source of pressurized fluid and a pressure responsive mechanism to limit flow to a single direction therebetween. A valve housing defines a fluid passage therethrough with a first axis therealong. The fluid passage has an annular first seat surface normal to the axis. A fitting is fixed to the valve housing and has a post directed toward fluid flow from the source of pressurized fluid. A check valve assembly slidably translates on the post between a closed position abutting the first seat surface which restricts flow toward the pressure source, and an open position spaced from the first seat surface which permits flow toward the pressure responsive mechanism. A spring disposed between the fitting and the check biases the check to the closed position.

Abstract: A fuel injection system for diesel engines provides precision metering of the amount of fuel admitted to each cylinder under very high pressure throughout the speed and load range.

Abstract: The present invention is an apparatus 10 for hydraulically slowing a member (12), preferably an engine poppet valve, to an acceptable impact seating velocity as the valve (12) is moved from open to closed. The poppet valve (12) has a stem (16) having a first portion (18) connected through a stepped portion (20) to a second portion (22) having a greater cross-sectional area than the first portion (18). The valve (12) rides within a guide body (28) having an opening (34) in an end wall (32) thereof through which the first portion (18) of the stem (16) extends. A hydraulic fluid space (50) is formed by the guide body (28) and the valve (12). As the valve (12) closes, fluid is forced out of the space (50) through a first fluid exit opening (66). As the valve (12) nears its seat (44), the fluid still in the space (50) is forced out through a second fluid exit opening (68) through which the rate of flow is less than the rate of flow through the first fluid exit opening (66).

Abstract: An edge filter for use with a variable-displacement pump control is disclosed. The edge filter comprises a first portion disposed between a source of hydraulic actuating fluid and an orifice having a first flow area. The first portion has an outer circumference defining a radial gap within a bore. The gap has a predetermined gap width less than a diameter of the orifice.

Abstract: A pressure control system for controlling output pressure of a variable-displacement hydraulic pump used with a hydraulically-actuated electronically-controlled injector fuel system and method of operation is disclosed. The control system comprises a variable-displacement hydraulic pump with a control element adjustable to a range of positions which controls an output of the pump. The control system additionally includes positioning means for positioning the control element responsive to pressure differences between the fluid reference chamber and the output port. Electronic valve means regulates a pressure of hydraulic actuating fluid in the fluid reference chamber. The electronic valve means is electronically connected with the electronic control means to receive the output signal.

Abstract: Adjacent an axially displaceable engine poppet valve (12) is a fluid pathway (36). Within the fluid pathway (36) is a snubbing valve (14) including a snubber (48) movable between first and second locations within the pathway (36) and a snubbing passage (54). When the poppet valve (12) is open, the snubber (48) is at its first location and there is fluid in the fluid pathway (36) between the snubber (48) and poppet valve (12). During a first portion of displacement of the poppet valve (12) as it closes, the snubber (48) is displaced to its second location. During the second portion of displacement of the poppet valve (12) as it closes, fluid in the fluid pathway (36) is snubbed through the snubbing passage (54), thereby increasing the pressure in the fluid in the pathway (36), thereby providing a resistive force against movement of the poppet valve (12), thereby slowing the poppet valve (12) to an acceptable impact seating velocity.

Abstract: The service life of conventional glow plugs is extremely short when they are continuously energized at an elevated temperature during engine operation in order to assist ignition of non-autoignitable fuels. Such glow plugs typically fail due to thermal stresses and/or oxidation and corrosion.Herein is disclosed an improved heating element assembly adapted for incorporation in a glow plug. The heating element assembly includes a monolithic sheath having a relatively-thin and generally annular wall defining a blind bore. The heating element assembly further includes a heating device positioned in the blind bore and adapted to emit heat, and a heat transfer device adapted to transfer heat from the heating means to the sheath. The heating device includes a heating filament and a ceramic insulator. THe heating filament is protected against oxidation by being encapsulated in the insulator. The insulator is protected against corrosion by being encapsulated in the sheath.

Abstract: An improved mechanical joint structure is provided and adapted for positively retaining a heating element within a bore of a body of a glow plug. The glow plug includes a body, a heating element and a ferrule. The ferrule is sealingly positioned radially between an internal surface of the body bore and a peripheral surface of the heating element. The glow plug further includes a compressing structure for positively compressing an internal surface of the ferrule against the peripheral surface of the heating element in response to the heating element being forced into the body bore by, for example, the gas pressure developed in an operating engine combustion chamber.Unlike conventional brazed or interference joints used in typical glow plugs, the present invention provides a normal force (F.sub.n), for sealing the heating element, and an axially-directed frictional force (F.sub.f), for retaining the heating element, which both increase as the heating element is forced deeper into the body bore.

Abstract: The service life of conventional glow plugs is extremely short when they are continuously energized at an elevated temperature during engine operation in order to assist ignition of non-autoignitable fuels. Such glow plugs typically fail due to thermal stresses and/or oxidation and corrosion. Herein is disclosed an improved heating element assembly adapted for incorporation in a glow plug. The heating element assembly includes a monolithic sheath having a relatively-thin and generally annular wall defining a blind bore. The heating element assembly further includes a heating device positioned in the blind bore and adapted to emit heat, and a heat transfer device adapted to transfer heat from the heating means to the sheath. The heating device is protected by the sheath formed of a preselected material which is chosen and configured so as to minimize failure of the heating element assembly caused by thermal stresses, oxidation and/or corrosion.