Abstract: A three-port flow control valve comprising a valve body having two opposite-facing valve seats disposed along a central bore terminating in an exhaust port. A supply port communicates with the first valve seat, and a common port communicates with the second valve seat. A pintle shaft connected to an actuating linear solenoid extends along the central bore. A first valve head actuated by the pintle shaft mates with the first valve seat. A second valve head disposed colinearly with the pintle shaft mates with the second valve seat. Opening of the first valve closes the second valve and vice versa. While the solenoid is de-energized the supply pressure keeps the first valve closed. A spring may be disposed between the second valve head and the exhaust port to urge the second valve head to close with the second valve seat.

Abstract: A pump system for supplying pressurized hydraulic fluid to a hydraulic valve actuation system for operating engine valves of an internal combustion engine comprises a substantially conventional main pump, driven by the engine, which supplies the necessary volume of pressurized hydraulic fluid when the engine is running. The system comprises a booster pump that supplies in conjunction with the main pump the necessary volume of hydraulic fluid during starting/cranking of the engine. The main pump is preferably designed and constructed for operating efficiency during engine operating conditions while the booster pump is preferably designed and constructed for operating efficiency during cranking/starting of the engine.

Abstract: Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

Abstract: A hydraulically operated valve control system includes a hydraulic flow divider including a hydraulic valve adapted to distribute, between two lines feeding respectively to actuators coupled to two inlet or outlet valves of a cylinder, the flow of oil coming either from a source of oil under pressure or from the feeding lines. The oil flow is distributed between the two feeding lines on the basis of the ratio of oil flow-rates in these two lines.

Abstract: A control valve (20) for a device for variably setting the control times of gas exchange valves (110, 111) of an internal combustion engine (100). Two working ports (A, B) and one supply port (24) are formed on an outer casing surface of a valve housing (22) of the control valve (20), the working ports (A, B) are arranged directly adjacent one another, and the supply port adjoins them. Further, two pressure medium ducts (40, 41) are formed on the control piston (30), at least one of the pressure medium ducts (40, 41) is embodied so that it is not rotationally symmetric with respect to a longitudinal axis (36) of the control piston (30).

Abstract: According to the invention, recuperation may be optimised for a hydraulically-operated gas exchange valve by provision of two fluid-filled pressure chambers and a movable regulating piston with two active faces each defining one of the pressure chambers. The pressure chambers are each connected to two hydraulic valves of which the first hydraulic valves may be pressurised from a first pressure reservoir and the second hydraulic valves may be connected to a base pressure reservoir. The first hydraulic valves may furthermore be connected to a second pressure reservoir. A control or regulation device switches the valves, from a rest position in a first accelerating phase and a braking phase.

Abstract: One-way valves (30, 31) are provided in a hydraulic supply passage (28) in an advance chamber (18) and a hydraulic supply passage (29) in a retard chamber (19) respectively for preventing reverse flow of oil from each chamber (18, 19) and drain oil passages (32, 33) bypassing the one-way valves respectively disposed in the hydraulic supply passages (28, 29) of the respective hydraulic chambers (18, 19) are provided to be in parallel therewith. Drain switching valves (34, 35) are disposed in the respective drain oil passages (32, 33). A hydraulic control valve (21) for controlling a hydraulic pressure supplied to the advance chamber (18) and the retard chamber (19) includes integrally a drain switching control function (38) for controlling a hydraulic pressure supplied to the respective drain switching valves (34, 35).

Abstract: A spool valve 10 for a variable camshaft timing (VCT) phaser for an internal combustion engine comprises a spool 11 slidable in a bore 12 in a valve sleeve 13, the spool 11 having spaced apart lands 14-17 dividing the bore 12 into chambers 41, 42, 43 between adjacent lands. The valve sleeve 13 has fluid passages 22-27 including a lock passage 26 communicating with a lock pin 31, a vent passage 27 communicating with a fluid sump 35, and a lock pin oil feed passage 22, with the spool 11 being slidable in the bore 12 to interconnect select passages via particular chambers, wherein the vent passage 27 and the lock pin passage 26 are connectable with different chambers 43 and 42 respectively. The arrangement avoids unnecessary operation of the lock pin 31.

Abstract: An internal combustion engine comprises at least two intake valves per cylinder, each of them provided with respective spring return means which push the valve towards a closed position. The intake valves of each cylinder are controlled by a single cam of an engine camshaft, through a single tappet actuated by said cam and through a hydraulic system. The hydraulic system comprises a master cylinder having a piston positively connected to said tappet and two hydraulic actuators respectively associated to the two intake valves and which are both hydraulically connected to a common pressure chamber of said master cylinder. The return spring means associated to the intake valves of one and the same engine cylinder have predetermined loadS and/or rigidities which are different from each other, in such a way that said intake valves have different lift profiles, so as to cause a swirl motion of the air fed into the engine cylinder, which allows to improve the air-fuel mixing.

Abstract: The invention relates to a valve and suitable hydraulic circuit, especially for camshaft adjusters of an internal combustion engine. The hydraulic circuit comprises a number of check valves or two-way valves operating as check valves, in order to provide a rapid camshaft adjuster with a high regulating quality.

Abstract: A method of controlling an engine with a first group of cylinders having selectively deactivatable cylinders valves and a variable camshaft timing actuator coupled in a hydraulic system is described. In one example, the method includes during a first mode where the first group of cylinders is activated to carry out combustion cycles, adjusting the hydraulic system with a first gain based on cam timing feedback information and/or maintaining a null position of the actuator by adjusting a control signal to the hydraulic system to within a first value range. During a second mode where the first group of cylinders is deactivated, the method includes adjusting the hydraulic system with a second gain based on cam timing feedback information, the second gain higher than the first gain and/or maintaining the null position of the actuator by adjusting the control signal to the hydraulic system to within a second value range.

Abstract: A method and control module includes a control hold duty cycle module generating a control hold duty cycle signal and a voltage correction module generating a voltage correction signal. The control module also includes a correction module generating a corrected proportional correction signal based on a proportional correction signal and the voltage correction signal, and generating a corrected integral correction signal based on an integral correction signal and the voltage correction signal. The control module also includes a force determination module controlling a duty cycle to a phaser operator based upon the control hold signal, the corrected proportional correction signal and the corrected integral correction signal.

Abstract: In a gas exchange valve operating apparatus with at least one overhead camshaft for actuating the gas exchange valves, with a hydraulic medium supply passage extending through the camshaft and with at least one hydraulic switchable support unit cooperating with a lever-like cam follower which is disposed on a switchable support unit and on a gas exchange valve and is furthermore in contact with the overhead camshaft, the support unit is disposed in communication with at least one pressure medium supplied via the hydraulic medium supply passage of the camshaft.

Abstract: A control system and method for a hydraulic system (HS) that controls a fluid supply in an engine includes a timer module determines the response time of the HS to perform at least one of: increasing the pressure of the fluid supply above a predetermined threshold following the state change command and decreasing said pressure of said fluid supply below said predetermined threshold following said state change command. An update module updates the desired time of the HS based on the response time of the HS.

Abstract: A variable tappet includes a tappet body; a variable portion in the tappet body, configured to open and close a valve; and a control portion to maintain the variable portion in either a first state, at which it can open and close the valve, and a second state, at which it cannot open and close the valve.

Abstract: A switchable valvetrain system is provided having a control unit and a pressure regulator valve responsive to control signals from the control unit. A pressurized fluid source is provided in communication with the pressure regulator valve. A switchable valvetrain component having a latching mechanism and lubrication circuit in selective communication with the pressurized fluid source through the pressure regulator valve is also provided. The pressure regulator valve is operable to selectively and variably communicate fluid pressure from the pressurized fluid source to the latching mechanism and the lubrication circuit in response to control signals from the control unit. A method of operating the switchable valvetrain system is also provided.

Abstract: A rotary hydraulic coupling is described for use in an engine having a camshaft, a hydraulic phaser for driving the camshaft, and an oil feed manifold secured to the body of the engine and incorporating oil galleries for supplying oil to the phaser. The rotary coupling, which serves to connect the oil galleries of the oil feed manifold to rotating oil ducts which lead to hydraulic working chambers within the phaser, comprises a cylindrical first element rotatably received within and sealed relative to an annular second element, each of the first and second elements having bores that communicate with annular grooves in a mating surface of at least one of the two elements to establish fluid flow communication between the bores in the two elements, the bores in the first element being connected to axially extending oil passages formed within the first element.

Abstract: A cylinder valve operating system for an internal combustion engine includes a camshaft driving a number of intake and exhaust valve operators which may be selectively disabled through the operation of a valving system including a hydraulic phase shifter integrated with the camshaft and connected between a source of high pressure oil and at least the intake valve operators. The hydraulic phase shifter allows one group of valves, such as the exhaust valves, to be disabled before the other group of valves, typically the intake valves.

Abstract: An internal combustion engine is equipped with a variable actuation system for the intake valves, including a chamber of fluid under pressure interposed between the intake valve and the respective controlling cam, and a solenoid valve whose opening causes the pressure chamber to discharge such as to determine the rapid closure of the valve by effect of the respective biasing spring means, even when the respective cam would tend to keep the valve open. The variable valve operation system is used in combination with the use of cams controlling the intake valves shaped in such a manner as to give rise to an intake valve lift profile including a boot portion at substantially constant lift.

Abstract: With reference to FIG. 1, the present invention provides valve operating system for operating a pair of poppet valves (10, 32) of an internal combustion engine. The system comprises a source of pressurised hydraulic fluid (22), a fluid return (23), a first hydraulic actuator (13) which the first poppet valve (10) and a second hydraulic actuator (13) acts on the second poppet valve (32). A first valve (21) is connected to both the source of pressurised fluid and the fluid return (23). A second valve (20) is connected between the first valve (21) and the first hydraulic actuator (13). A third valve (30) is connected between the first valve (21) and the second hydraulic actuator (31). An electronic controller (40) controls operation of the valves (20, 21, 30) to open and close the pair of poppet valves (10, 32).

Abstract: Apparatus and methods for hydraulic valve actuation of engine valves are disclosed. An exemplary embodiment of the present invention may include a lost motion piston assembly that transfers motion between first and second rocker arms to selectively provide auxiliary engine valve actuation motions to the engine valves for engine operations such as engine braking and exhaust gas recirculation. The lost motion piston assembly may reduce or eliminate transient loads that may otherwise be transmitted to engine valve train elements during the times that lost motions systems are turned on and off for auxiliary valve actuations.

Abstract: A variable valve lift apparatus includes a lift body that contacts a cam and a valve. The lift body has a first hole for receiving hydraulic pressure and a second hole for exhausting the hydraulic pressure. A spring is provided in the lift body. A hydraulic pressure supplying portion supplies the hydraulic pressure to the first hole, and a hydraulic pressure exhausting portion receives the hydraulic pressure from the second hole.

Abstract: A hydraulic unit (5) is provided for a cylinder head (2) of an internal combustion engine with a hydraulically variable valve train (1). In the hydraulic unit, a high-pressure chamber (11), a medium-pressure chamber (12), and a low-pressure chamber (16) used as the hydraulic medium reservoir are formed. The low-pressure chamber communicates via a throttle point (17, 17?, 17?, 17??) with the medium-pressure chamber, and the throttle point is formed by a displaceable valve body (19, 19?, 19?, 19??) and has through-flow cross sections of different sizes according to a position of the valve body.

Abstract: A sleeve allows insertion of an oil control valve, and is used by being inserted to an installation hole provided in a cylinder head cover. An outer surface of a sleeve main body of the sleeve is covered by a rubber-like elastic body layer. The rubber-like elastic body layer has a protrusion provided in the periphery of an oil hole provided in the sleeve main body in such a manner as to surround the oil hole. In accordance with the sleeve, it is possible to install the oil control valve to the cylinder head cover at a high oil tightness.

Abstract: The present invention relates to a mounting module in which an oil control valve for tappet control is mounted in a cylinder deactivation engine. The mounting module of the invention is separately fabricated and coupled to the cylinder head and has various oil passages connecting the oil paths between the oil control valve and the cylinder head with each other and thereby the die structure for molding the cylinder head is simplified. Because of its separately fabricating process it is possible to design the part freely and in a small size and to reduce the cost of die, material, manufacturing and its weight as well. Furthermore, the number of related parts such as steel ball, taker plug, etc. and unnecessary portions in the shape are considerably reduced, thus providing an optimized structure and reducing the manufacturing cost as well as its weight.

Abstract: A method may include commanding operation of an engine in a first lift mode. The engine may include a valve lifter system that selectively operates a valve member in the first lift mode and a second lift mode through engagement with a camshaft. A first duty cycle of a cam phaser oil control valve (OCV) may be determined to maintain a first camshaft position corresponding to the first lift mode. The camshaft position may be maintained by a cam phaser that is coupled to the camshaft and in communication with the cam phaser OCV. Engine operation may be commanded to the second lift mode and a second duty cycle of the cam phaser OCV may be determined to maintain a second camshaft position corresponding to the second lift mode. A valve lifter system failure may be diagnosed based on a difference between the first and second duty cycles.

Abstract: A hydraulic actuator (1) comprising a body (2), in which a control arm (5) and a lift means (6) provided with a piston surface (22) are arranged, which lift means is arranged to follow the reference movement of the control arm (5), and an inlet port (3) and an outlet port (4) for hydraulic medium. The body (2) encloses a pressure chamber (10) delimited by the piston surface (22) of the lift means (6), and the movement of the control arm (5) provides a flow connection between the inlet port (3) and the pressure chamber (10) in order to move the lift means (6), and the movement of the control arm (5) in the opposite direction provides a flow connection between the pressure chamber (10) and the outlet port (4) in order to move the lift means (6) in the opposite direction.

Abstract: Actuators and corresponding methods and systems for controlling such actuators offer efficient, fast, flexible control with large forces. In an exemplary embodiment, an fluid actuator includes a housing having first and second fluid ports, an actuation cylinder in the housing defining a longitudinal axis and having first and second ends in first and second directions, an actuation piston in the cylinder with first and second surfaces moveable along the longitudinal axis, a spring subsystem biasing the actuation piston to a neutral position, a first fluid space defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space defined by the second end of the actuation cylinder and the second surface of the actuation piston. A first flow mechanism controls fluid communication between the first fluid space and the first port, whereas a second flow mechanism controls fluid communication between the second fluid space and the second port.

Abstract: A device for switching activation of a hydraulic valve play equalization element for setting of a maximal stroke or a zero stroke on a valve of an internal combustion engine, has a switching element for locking and unlocking the housing of the valve play equalization element relative to a guide that is axially displaceable therein. The switching element is a switching ring that surrounds the housing, on which a linkage for rotating the switching ring relative to the housing is disposed. The linkage of the switching ring is connected via a guide element with a groove on the circumference of a rotatable adjustment shaft. The groove has a groove section demonstrating an axial incline, and in which the switching ring is rotated, to implement a switching process via the guide element during rotation the adjustment shaft.

Abstract: An improved electro-hydraulic intake and exhaust valve actuator for a “camless” internal combustion reciprocating engine. The present invention integrates an electric motor driven “plug type” rotary control valve and a single acting hydraulic cylinder in one housing for the actuation of an engine valve. The geometry of the hydraulic ports in the rotary control valve may be tailored for desired valve actuation profiles. The electronic control of the rate of rotation and angular position of the rotary control valve are used to infinitely vary the engine valve operating parameters. Thus, engine valve timing, speed, cycle duration and lift may be varied. A rotary control valve permits high speed operation and accommodates a broad range of valve sizes. Availability of a wide range of commercial open frame brushless electric motors and dedicated integrated circuit controllers contribute to the cost effectiveness of the present design.

Abstract: A system for an internal combustion engine of a vehicle is provided. The system comprises a hydraulic pump configured to be powered at least partially by a source other than the engine; an adjustable hydraulic engine actuator configured to be adjusted by hydraulic fluid of the pump; a control system configured to adjust said adjustable hydraulic actuator.

Abstract: An internal-combustion engine for motor vehicles, for example a petrol-fuelled engine or a gas-fuelled engine, is provided with an electronically controlled hydraulic system for variable actuation of the intake valves. The system of variable actuation of the intake valves is governed by an electronic control unit that is programmed for performing at least once, at the start of the life of the engine, an activity of supervision of the functions of self-adaptive control of the air-fuel ratio. The supervision activity is based upon identification of a constant ratio between a delta in the value of the crank angle used by the electronic control unit and the error in the estimation of the air-fuel ratio by the electronic control unit when the system of actuation of the intake valves operates in late-opening mode.

Abstract: Hydraulic valve actuation systems and methods to provide variable lift for one or more engine air valves by way of a variable position hard stop. Various embodiments are disclosed, including embodiments controlling lift by providing a choice of two different fixed stops, three different fixed stops, stops continuously variable throughout a range of lifts, and a fixed stop and stops continuously variable throughout a range of lifts. The valves controlled by a variable position hard stop may be a single engine intake or exhaust valve, or multiple valves of any number, and of either intake or exhaust valves or both, or of one intake or one exhaust valve for one or more cylinders in engines having more than one intake or exhaust valve per cylinder. Dashpot deceleration of engine valve velocity on opening to the hard stop and on engine valve closure is disclosed, as are other aspects and embodiments of the invention.

Abstract: Actuators, and corresponding methods and systems for controlling such actuators, provide independent valve control with a large initial or opening force.

Abstract: A valve actuation mechanism are disclosed, which is capable of controlling the lift of valves of an engine by more than three on/off combinations. In a preferred embodiment of the invention, the valve actuation mechanism is designed to control the opening and closing of engine valves by the use of an uncomplicated structure with minimum solenoid valves and hydraulic lines. By the valve actuation mechanism of the invention, not only the design of hydraulic line as well as that of space mechanism of an engine can be greatly simplified, but also the opening and closing of valves of an engine can be controlled thereby for enabling the engine to provide different valve lifts and thus satisfying different engine requirements, such as output power increasing, combustion efficiency improving, or cylinder deactivation.

Abstract: A supercharged diesel engine is equipped with an electronically controlled hydraulic system for variable actuation of the intake valves of the engine. The cam that controls each intake valve has an additional lobe for causing an additional opening of the intake valve, during the exhaust stroke, so as to provide an exhaust-gas recirculation directly inside the engine. Said additional lobe is shaped in such a way as to give rise to a profile of the additional lift of the valve as the crank angle varies with a boot conformation, including an initial stretch with a gentler slope extending from a point of zero lift corresponding to the expansion stroke in the engine cylinder. The engine is moreover equipped with a duct for exhaust-gas recirculation of the long-route type, which picks up the gases from a point of the exhaust duct set downstream of the catalytic converter and of the particulate trap.

Abstract: A supercharged diesel engine is equipped with an electronically controlled hydraulic system for variable actuation of the intake valves of the engine. The cam that controls each intake valve has an additional lobe for causing an additional opening of the intake valve, during the expansion and exhaust strokes, so as to provide an exhaust-gas recirculation directly inside the engine. The aforesaid additional lobe has its descending stretch radiused to the main lobe with a stretch corresponding to a non-zero lift of the valve in such a way that the profile of the lift of the valve has a portion corresponding to a substantially non-zero value of the lift that radiuses the descending stretch of the profile of the additional lift to the ascending stretch of the profile of the main lift.

Abstract: A gas exchange valve arrangement, especially for an internal combustion engine, with a valve head, which is mounted on a valve body. The valve body can be moved in a straight line in either of two opposite directions by an actuating element, which can be moved in either of the two directions of movement such that, as a result of a movement of the actuating element in at least one direction, the valve body is caused to move in the same direction. The actuating element comprises a piston, which can be moved relative to a space by a fluid medium. The space comprises a feed opening for the fluid medium, and the gas exchange valve arrangement includes a throttle device, which at least temporarily throttles the movement of the actuating element in at least one direction of its movement.

Abstract: Combination of a housing having a fluid passage and one or more solenoid actuated fluid control valves communicated to the fluid passage wherein a permanent magnet is disposed in fluid passage upstream of the fluid control valves to magnetically capture or getter ferrous particles in fluid prior to entry into the fluid control valve.

Abstract: A solenoid valve module includes a first solenoid valve having a first solenoid portion and a first valve body and a second solenoid valve having a second solenoid portion and a second valve body. The first valve body and the second valve body are integrally formed by a solenoid housing. The solenoid valve module is secured to a surface of an engine to provide hydraulic control for an engine component.

Abstract: An engine assembly may include a cylinder head defining an engine coolant reservoir, a pressurized fluid supply, a valve actuation assembly, and a hydraulic fluid reservoir. The valve actuation assembly may be in fluid communication with the pressurized fluid supply and may include a valve member displaceable by a force applied by the pressurized fluid supply. The hydraulic fluid reservoir may be in fluid communication with the valve actuation assembly and in a heat exchange relation to the engine coolant reservoir.

Abstract: A single hydraulic circuit module is provided for controlling valve lift at multiple cylinders in an engine. The single module includes a housing that at least partially forms a supply passage and a control passage. The supply passage is in fluid communication with the fluid supply and the control passage is in fluid communication with the feed passage. At least one solenoid valve is provided and supported by the housing positioned between the supply passage and the control passage. The solenoid valve is controllable to vary fluid flow from the supply passage to the control passage to permit adjustment of hydraulic lift assemblies to vary lift of engine valves in response to control of the solenoid valve.

Abstract: A hydraulic circuit comprises a temperature sensor, an added motion valve system, and a valve. The temperature sensor detects operating temperature of fluid in the hydraulic circuit. The added motion valve system includes a valve body having an actuator fluid volume. The valve adjusts flow rate quantity of fluid to the actuator fluid volume as a function of the operating temperature of the fluid. A method for controlling the hydraulic circuit is also disclosed.

Abstract: Combination of a housing having a fluid passage and one or more solenoid actuated fluid control valves communicated to the fluid passage wherein a permanent magnet is disposed in fluid passage upstream of the fluid control valves to magnetically capture or getter ferrous particles in fluid prior to entry into the fluid control valve.

Abstract: In a multi-cylinder engine provided with a cylinder pausing function, a hydraulically-operated valve-pausing mechanism is capable of selectively suspending operation of at least one intake or exhaust valve of one or more selected cylinders, depending on engine operating conditions, such that the suspended valve is temporarily held in a closed state. A hydraulic-pressure control device, for controlling hydraulic pressure supplied to the valve-pausing mechanism, is disposed on an engine body so as to minimize an amount of protrusion of the hydraulic-pressure control device from the engine body, while situating the hydraulic-pressure control device near the valve-pausing mechanism. A recess portion is formed on an external surface of a cylinder head or a head cover, and the hydraulic-pressure control device is disposed on the engine such that at least part of the hydraulic-pressure control device is accommodated in the recess portion.

Abstract: A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Abstract: Apparatus and methods for hydraulic valve actuation of engine valves are disclosed. An exemplary embodiment of the present invention may include a plurality of slave piston assemblies that impart motion to the engine valves, wherein the motion is operable to open and close the engine valves. A dual diameter master piston assembly may be used to drive the plurality of slave pistons. The dual diameter master piston assembly may be divided into two or more elements with, for example, a spring bias or a button and T-slot assembly to hold the two elements together.

Abstract: An oil circuit for a continuous variable valve timing (CVVT) device includes a main oil passage from a cylinder block toward a cylinder head to feed oil from a main gallery to a cam shaft, and a control oil passage branching off from the main oil passage on a side of the cylinder block and formed so as to feed the oil from the main oil passage to the continuous variable valve timing devices via an intake-side oil control valve and an exhaust-side oil control valve. The oil is fed to the cam shaft, the intake-side CVVT device, the exhaust-side CVVT device and a timing chain tensioner at one time. Thereby, the hydraulic pressure the hydraulic pressure applied to two cam shafts can be equally maintained, and the tension of a belt or a chain can be simultaneously regulated so as to improve the driving force of a crank.

Abstract: A hydraulic control system includes an oil control valve to control oil flow within a valvetrain. The control valve varies the flow rate to actuate an engine component from a first position to a second position based upon fluid pressure from the control valve. Varying the flow rate through the control valve includes increasing the flow rate through the control valve to increase the pressure to a first level to actuate the engine component to the first position. After the engine component is actuated, the flow rate through the control valve is maintained at a level sufficient to maintain the engine component in the first position. To actuate the engine component to the second position the flow rate through the control valve is then decreased. The fluid flow rate through the control valve is then maintained at a level sufficient to maintain the engine component in the second position.

Abstract: A valve actuation system for a combustion engine is provided. The valve actuation system may have an engine valve movable between first and second spaced apart end positions. The valve actuation system may also have a first cam element mechanically coupled to move the engine valve, and a first hydraulic slave piston operatively connected to the engine valve to move the engine valve independent of movement of the first cam element. The valve actuation system may further have a high pressure rail fluidly connected to the first hydraulic piston, and a control valve disposed between the high pressure rail and the first hydraulic piston to regulate movement of the engine valve.