Abstract: A hydraulic manifold assembly for variable actuation of engine valves. First and second plates have portions of flow passages integrally molded therein. The plates are formed preferably by injection molding of a suitable polymer, for example, glass-filled PPA, and are joined together as by cementing or preferably by fusion welding along mating surfaces to form the full pattern of flow passages. The assembly further comprises a retainer for retaining a plurality of individual solenoid-actuated valves in sockets formed in the plates. The retainer is similarly formed preferably by injection molding of a suitable polymer and is formed to function simultaneously as a positive crankcase ventilation (PCV) baffle.

Abstract: An improved arrangement for controlling the valve operation of an internal combustion engine wherein the control valves are mounted within perpendicularly extending bores formed in the cylinder head and camshaft bearing cap with the bores being deep enough so that the valves do not project significantly beyond the cylinder head. In addition, one or more of the connecting passages are formed by grooves in the mating surfaces of the cylinder head and bearing cap to avoid the necessity of drillings and particularly of drilling blind bores.

Abstract: Electrohydraulic device for operating an intake or exhaust valve of a combustion engine; the electrohydraulic device comprises a linear hydraulic actuator designed to move the valve axially from a closed position to a maximum opening position, and an electronic control hydraulic distributor designed to regulate the flow of pressurized liquid from and towards the linear hydraulic actuator in order to control movement of the above-mentioned valve between the closed and maximum opening positions; the electronic control hydraulic distributor comprises a slide valve which, by selection, can be set to three positions: a first operating position in which it establishes direct communication between the linear hydraulic actuator and an outlet of the pressurized liquid, a second operating position in which it isolates the linear hydraulic actuator in such a way as to prevent the flow of pressurized liquid from or towards the actuator, and a third operating position which establishes direct communication between the lin

Abstract: A hydraulic manifold assembly for variable actuation of engine valves. First and second plates have portions of flow passages integrally molded therein. The plates are formed preferably by injection molding of a suitable polymer, for example, glass-filled nylon, and are joined together as by cementing or preferably by fusion welding (vibration welding) along mating surfaces to form the full pattern of flow passages. This method of forming the manifold obviates the need for separate fasteners to connect the plates and for internal seals to form the flow passages. The assembly further comprises a retainer for retaining a plurality of individual solenoid-actuated valves in sockets formed in the plates. Preferably, the retainer is formed to function simultaneously as a positive crankcase ventilation (PCV) baffle that attaches to the plates via integrally molded releasable snap tabs.

Abstract: A valve assembly adapted for an internal combustion engine, including a valve housing having a pressure chamber. A piston seperates the pressure chamber into a first subchamber and a second subchamber. A first port is coupled the first subchamber and a second port is coupled to the second subchamber. A valve is coupled to the piston and moveable between an open position and a closed position. The valve is moved from the closed position to the open position by supplying a high pressure working fluid to the first port and coupling the second port to a drain. The valve is moved from the open position to the closed position by supplying the high pressure working fluid to the second port and coupling the first port to the drain.

Abstract: The present invention provides a hydraulic actuator for operating an engine valve, which includes a means for controlling the seating velocity of the valve. The design allows for free, unrestricted movement of the actuator piston during opening of the engine valve, and an unrestricted return of the piston and valve until the valve is within a predetermined distance of the valve seat. Once within this predetermined range, the return velocity of the actuator piston and engine valve are limited by the rate at which a fluid may escape through a restriction. The restriction is calibrated to provide the desired maximum valve seating velocity. The invention also provides for automatic lash adjustment.

Abstract: A valve control system for an internal combustion engine includes a housing comprising a cylinder defining a longitudinal axis, an exhaust port, a piston disposed in the cylinder and an engine valve operably connected to the piston. An exhaust member is disposed in the housing and is variably moveable along a longitudinal path to a desired position between a maximum and minimum lift position. The exhaust member has an exhaust port that is maintained in communication with the housing exhaust port as the exhaust member is selectively, variably moved between the maximum and minimum lift positions. A pressure source selectively applies a pressure to the piston and a control system is operably connected to the exhaust member and selectively, variably moves the exhaust member between the maximum and minimum position. A method for controlling the engine valve is also provided.

Abstract: A hydraulically controllable globe valve having a stem piston to which pressure can be applied by a spring connected to a pressure source, with the stem piston being able to move from a first end position in the direction of a second end position. Pressure control means are provided which maintain a constant pressure of the hydraulic spring means on the stem piston while the latter moves from the first end position in the direction of the second end position by connecting the hydraulic spring means to a pressure source during a variable portion of the valve lift. The valve can be used, for example, as a gas exchange valve in a reciprocating engine.

Abstract: An internal combustion engine comprising at least one intake valve and/or exhaust valve moving axially between a closed position and a position of maximum opening and means for moving the valves adapted to move, on command, this valve between the closed position and the position of maximum opening, the valve movement means comprising an elastic member adapted to maintain this valve in the closed position, a hydraulic actuator selectively adapted to move this valve from the closed position to the position of maximum opening by countering the action of the elastic member, and a hydraulic circuit adapted to supply pressurized fluid to the hydraulic actuator, the hydraulic circuit comprising a delivery duct connected to the hydraulic actuator and pumping means adapted to supply pressurized fluid into the delivery duct, the pumping means comprising the elastic member and the hydraulic actuator.

Abstract: In a Diesel engine with variably actuated valves, the cam controlling each inlet valve is shaped to provoke the opening of the respective inlet valve during the engine's normal exhaust phase and thus realize exhaust gas recirculation within the engine, due to the fact that during the normal exhaust phase, part of the exhaust gas passes from the cylinder into the inlet port, from where it returns to the cylinder during the next induction phase, while part of the exhaust gas that had previously passed into the exhaust port returns to the cylinder during the said induction phase due to the additional opening of the exhaust valve, in consequence of which the exhaust gas charges that return to the cylinder are subjected to further combustion in the next engine cycle.

Abstract: The present invention relates to a method for operating a multi-cylinder internal combustion engine having gas exchange valves which are variably adjustable with respect to the valve opening characteristics either directly electromag-netically or by means of an electrohydraulic valve actuation system which includes several electromagnetic valves. For adaptation of all gas exchange valves to a desired valve opening characteristics, the electromagnetic valves are operated cylinder-selectively in the operation of the internal combustion engine by means of variable actuating voltages and/or actuating currents.

Abstract: In a hydraulically actuated gas exchange valve, the initiation and termination of gas exchange is achieved with a hydraulically driven valve that functions by opening an actuation fluid passage to a high pressure inlet source and a low pressure drain, respectively. The large amount of fluid needed to actuate a gas exchange valve can result in dynamic flow forces around the hydraulically driven valve making closing of the valve with a conventional biasing spring problematic. The small size of the valve limits the size and therefore strength of the biasing springs. Likewise, the need to provide a sufficiently strong spring limits valve designs. The present invention is intended to provide superior control over the timing of gas exchange by employing a hydraulic bias in place of the conventional biasing spring. Hydraulic bias allows both a greater closing force on the valve than could be provided with a spring, and allows for greater versatility in future valve designs.

Abstract: In a direct injection engine which comprises an injector (22) for directly injecting fuel into a combustion chamber (15) and a lean NOx catalyst (36), an ECU (50) changes the air-fuel ratio from that higher than the stoichiometric air-fuel ratio to that substantially equal to or lower than the stoichiometric air-fuel ratio. When the air-fuel ratio has changed from a air-fuel ratio higher than the stoichiometric air-fuel ratio to an air-fuel ratio substantially equal to or lower than the stoichiometric air-fuel ratio, the ECU controls to divisionally execute fuel injection from the injector (22) in at least two injections, i.e., leading injection that starts within the intake stroke period and trailing injection that starts within the compression stroke period.

Abstract: A hydraulically-assisted engine valve actuator and method for assisting in the actuation of an engine valve includes a translatable pilot valve that is operably coupled to and controlled by a pilot valve positioning system. A servo piston is in fluid communication with the pilot valve and is operably coupled to the engine valve. The pilot valve positioning system controls translation of the pilot valve to meter hydraulic fluid under pressure to and from the servo piston. The hydraulic fluid under pressure causes the servo piston to closely follow the translation of the pilot valve to effect a desired profile of translational opening and closing motion of the engine valve.