Abstract: A method and apparatus for hydraulically actuating a gas exchange valve using a low-pressure, substantially constant flow fluid source applied to at least one actuator cylinder piston coupled to the gas exchange valve. The actuator piston slides within the actuator cylinder upon application of pressure from the fluid for actuating the gas exchange valve. The pressure is continuously variable and builds upon application to the cylinder piston until the valve unseats. A pressure sensor is used to monitor the pressure to provide feedback about the operation of system and to provide variable motion control of the gas exchange valve.

Abstract: The present invention (with reference to FIG.

Abstract: An in-head compressed air start-up system for an internal combustion engine comprises an absolute angular position detector for the crankshaft outputting an electrical signal indicative of the angular position, a computer for storing a table of the firing order of the cylinders and the angular position of the crankshaft at which each piston reaches a desired angular position relative to top dead center (TDC), wherein the computer means compares the signal indicative of angular position of the crankshaft to the firing order table and generates a plurality of signals sequentially open and close solenoid valves to cause rotation of the crankshaft.

Abstract: Engines and methods of controlling an engine may involve one or more fluidically driven actuators associated with engine intake and/or exhaust valves. In some examples, the actuators may be placed in flow communication with high pressure fluid from one source and/or low pressure fluid from another. Timing of valve closing/opening and use of an air supply system may enable engine operation according to a Miller cycle.

Abstract: Actuators, and corresponding methods and systems for controlling such actuators, provide independent lift and timing control with minimum energy consumption. In an exemplary embodiment, an actuation cylinder in a housing defines 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, is moveable along the longitudinal axis. First and second actuation springs bias the actuation piston in the first and second directions, respectively. A first fluid space is defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space is defined by the second end of the actuation cylinder and the second surface of the actuation piston. A fluid bypass short-circuits the first and second fluid spaces when the actuation piston is not substantially proximate to either the first or second end of the actuation cylinder.

Abstract: Hydraulic actuator as an element of a system for controlling an engine valve is presented. The actuator includes a fluidic actuation chamber, defined by an actuation piston that increases chamber volume as the actuation piston is urged away from a neutral. Chamber includes a high pressure fluid inlet and a fluid outlet. A fluidic actuator control chamber, defined by a control piston connected to the actuation piston that increases chamber volume as the actuation piston is urged away from neutral. A control fluid outlet is connected to a fluid control spool valve. The fluid outlet of the actuation chamber is fluidly connected to an inlet of the control valve. There is a valve actuation plunger operably connected to the actuation piston, and a drain outlet to maintain a fluidic backpressure to the actuator control chamber.

Abstract: The present invention provides a method for controlling a closing operation of an exhaust valve (11) in an internal combustion engine. A current position X0 of the exhaust valve (11) and a rotation speed Ne of the internal combustion engine are determined, and on the basis of the current position X0 and rotation speed Ne, a time T0 at which a piston arrives at the current position X0 of the exhaust valve (11) is calculated. The closing operation of the exhaust valve (11) is then started before this arrival time T0. Next, a time T1 at which the gap between the exhaust valve (11) and piston reaches a first predetermined value hc1 is calculated, and when this time T1 arrives, the closing operation of the exhaust valve (11) is stopped temporarily. A time T2 at which the piston arrives at the stopping position X1 of the exhaust valve (11) is then calculated, and the closing operation of the exhaust valve (11) is resumed before this arrival time T2.

Abstract: A shoe housing receives a driving force from a crankshaft and a vane rotor rotates with a camshaft in combination. The vane rotor is received in the shoe housing in such a way as to freely turn. Each of the vanes of the vane rotor partitions each of three receiving chambers into a retard hydraulic chamber and an advance hydraulic chamber. A check valve is disposed in an advance supply passage. The check valve allows a working oil to flow from an oil pump through the advance supply passage to the advance hydraulic chamber and prohibits the working oil from flowing back from the advance hydraulic chamber through the advance supply passage to a drain.

Abstract: Herein disclosed is a combustion cell adapted for an internal combustion engine, comprising i) a hydraulic engine valve actuation portion capable of providing a selection of two different and stable engine valve lift (i.e., open) positions per engine valve or per coupled engine valves and ii) a fuel injection portion capable of providing a selection of comprising i) a hydraulic engine valve actuation portion capable of providing two stable engine valve lift positions and ii) a fuel injection portion capable of providing a selection of one, two or three injection pressure levels for injection fuel. The combustion cell provides more flexibility in control of incoming intake air, outgoing exhaust gas, and/or incoming injection fuel relative to an engine combustion chamber so as to better match engine operating conditions that may change over time.

Abstract: A method of operating an internal combustion engine, including at least one cylinder and a piston slidable in the cylinder, may include supplying a mixture of pressurized air and recirculated exhaust gas from an intake manifold to an air intake port of a combustion chamber in the cylinder, selectively operating an air intake valve to open the air intake port to allow pressurized air to flow between the combustion chamber and the intake manifold substantially during a majority portion of a compression stroke of the piston, and operably controlling a fuel supply system to inject fuel into the combustion chamber after the intake valve is closed.

Abstract: A system and method for controlling a variable valve actuation system for an engine is provided. An engine valve is moved between a first position where the engine valve blocks a flow of fluid and a second position where the engine valve allows a flow of fluid. Fluid is provided to a chamber of a valve actuator adapted to operatively engage the engine valve. A parameter indicative of a viscosity of the fluid provided to the chamber of the valve actuator is sensed. Fluid is trapped within the chamber of the valve actuator to prevent the engine valve from moving to the first position. A response time of the valve actuator is determined based on the viscosity of the fluid provided to the chamber of the valve actuator. The response time indicates the time required to release the fluid from the chamber of the valve actuator to allow the engine valve to move to the first position.

Abstract: The invention relates to a device for electrohydraulic valve lift switching with a hydraulically activatable actuating element for bringing about valve lift switching, which is connected to an oil line, whereby the action of pressurized oil on the actuating element can be controlled by an on/off valve arranged in the oil line and connected to a control device. The invention has an oil pressure metering device arranged in the oil line, which is connected to the control device, and a device for detecting the time period between activation of the on/off valve by the control device and a characteristic change in the measured oil pressure.

Abstract: In a hydraulic actuator comprising a hydraulic piston, a hydraulic cylinder and a hydraulic pressure source wherein said hydraulic piston has a larger area exposed to pressure on the side of the control chamber than on the side of oil supply chamber of said hydraulic cylinder, wherein said hydraulic piston has, in its outer peripheral part, a slot connecting said oil supply chamber side with the control chamber side in the direction of shaft and the cross sectional area of the slot in the direction of said shaft changes according to the displacement of the hydraulic piston in the direction of its shaft, and the control chamber has a pilot valve, the suction and exhaust valve in a variable valve system of the internal combustion engine are opened and closed by said hydraulic actuator through a coupling and springs for the valve, for variably controlling the opening and closing timing, the opening and closing time, and the lift of the valve, whereby it is possible to provide a variable valve system for internal

Abstract: A manifold assembly includes a pressure feed orifice that directly connects an inlet circuit to a control circuit of the manifold. This direct connection between the pressure inlet to the control circuit allows air to be bled out of the manifold assembly. Low pressure fluid in the assembly pushes out air through the orifice out of the assembly, ensuring prompt solenoid response during manifold assembly operation.

Abstract: The present invention relates to engines having multiple hydraulic devices. For instance a multi-cylinder diesel engine might include both an a fuel injector and an engine compression release brake. Traditionally, each of these hydraulic devices has been controlled by an individual actuator control valve. However, engineers have learned that decreasing the number of engine components can increase engine robustness. In addition, engineers have learned that de-coupling fluid pressure to the needle valve member hydraulic surface from fluid pressure lines to other injector components can result in greater control of the injector. Therefore, the present invention utilizes a single actuator control valve to control both hydraulic devices for an engine cylinder and to provide independent control of fluid pressure to the needle valve member closing hydraulic surface.

Abstract: A resin cylinder head cover includes an attaching portion and a sleeve. The attaching portion is formed of resin, and is a portion of the cylinder head cover to which the oil control valve is to be attached. The sleeve is embedded in the attaching portion. The sleeve has an interior space that permits the oil control valve to be accommodated therein and oil holes. Each oil hole is selectively connected to one of ports of the oil control valve accommodated in the interior space of the sleeve. The sleeve is formed of material having higher rigidity than the resin forming the attaching portion. Therefore, the cylinder head cover maintains highly reliable attachment of an oil control valve without a large number of high precision machining steps and prevents deformation of the attaching portion.

Abstract: A hydraulic valve actuator for reciprocating engine includes at least a hydraulic cylinder (3) for opening at least one valve (2) via at least one valve opening selector (11) with at least one hydraulic positive displacement pump (4) whereof the hydraulic fluid supplied at the output can be forced into a high pressure circuit (10) by at least one pump outlet closure (8), the valve (2) capable of being maintained opened by an opening non-return valve (24), then of being reseated by a valve closing selector (25) which directs the hydraulic fluid contained in the hydraulic cylinder (3) in the hydraulic positive displacement pump (4) input by co-operating with a pump input non-return valve (26).

Abstract: First and second attachment portions 6, 8 are formed integrally with a main body 4 and extend along the longitudinal direction of the main body 4. A hydraulic oil supply portion 14 is formed integrally with the main body 4 and extends along the width, or in the direction perpendicular to the axes of the attachment portions 6, 8. In this manner, providing an internal combustion engine with variable valve actuation mechanisms increases the strength of the cylinder head cover 102, while reducing the weight thereof.

Abstract: Actuators, and corresponding methods and systems for controlling such actuators, provide independent lift and timing control with minimum energy consumption, while supplying sufficient supplemental energy to overcome friction. In an exemplary embodiment, an actuation cylinder in a housing defines 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, is moveable along the longitudinal axis. First and second actuation springs bias the actuation piston in the first and second directions, respectively. A first fluid space is defined by the first end of the actuation cylinder and the first surface of the actuation piston, and a second fluid space is defined by the second end of the actuation cylinder and the second surface of the actuation piston.

Abstract: Lost motion systems and methods for providing engine valves with variable valve actuation for engine valve events are disclosed. The system may include a master piston hydraulically linked to a slave piston, and a dedicated cam operatively connected to the master piston. The slave piston may be disposed substantially perpendicular to the master piston in a common housing. The slave piston is adapted to actuate one or more engine valves. The slave piston may incorporate an optional valve seating assembly into its upper end. A trigger valve may be operatively connected to the master-slave hydraulic circuit to selectively release and add hydraulic fluid to the circuit.

Abstract: The invention intends to improve a response by utilizing a rotational variable torque of a cam shaft. Communication paths respectively communicating an advance hydraulic chamber and a retard hydraulic chamber provided in a second rotary member and a hydraulic connecting passage are provided so as to be communicated, at a time when a control member intending to improve a response by moving a phase angle control slider in an axial direction or a rotational direction in correspondence to an operating state such as an advance, a retard or the like so as to intermittently communicate an advance chamber communication path and a retard chamber communication path with a hydraulic chamber connecting groove only in a section in which a cam shaft variable torque in an operating direction is applied, is controlled in a rotating region, and a relative rotation of a third rotary member and the second rotary member stops.

Abstract: A pneumatically actuated valve assembly for use as intake and/or exhaust valves on two- or four-stroke internal combustion engines. The assembly includes a valve (100), valve housing (200), and compressed gas distribution and timing mechanisms (FIGS. 5–8). The valve (100) is comprised of a short light weight hollow cylindrical body with a capped lower end and an opened upper end. The valve is further defined by a plurality of ports (104) adjacent to the lower end and a collar (198) encircling the body adjacent the upper end. The valve housing (200) is hollow and tubular having a larger diameter upper section and a smaller diameter lower section in which the valve (100) slides up to close and down to open. The housing (200) further includes hollow channels which direct compressed gas, managed by the distribution and timing mechanism, alternately towards the areas above and below the valve collar at regular intervals to open and close the valve, respectively.

Abstract: Method and apparatus for providing an internal combustion engine which for each cylinder, with the associated piston, has at least one inlet valve and at least one exhaust valve (10) for controlling the connection between the combustion chamber in the cylinder and an intake system and an exhaust system, respectively. A rotatable camshaft (18) with a cam (22) is designed to interact with a first cam follower (17) and a second cam follower (20) in order to switch between two different operating modes. The cam followers are mounted on a pivotal rocker arm (13), the second cam follower (20) being hydraulically adjustable between two positions by means of a piston (21) located in a hydraulic cylinder. The hydraulic cylinder is connected to a hydraulic fluid source via a hydraulic fluid duct and the piston can be moved from one position to the other by the action of a quantity of hydraulic fluid delivered to the hydraulic cylinder.

Abstract: In an internal combustion engine with variable actuation valves, each variable actuation valve is actuated by an actuator assembly including an actuating piston slidably mounted in a guide bushing. Between the actuating piston and the stem of the respective valve is interposed an auxiliary hydraulic tappet positioned outside the guide bushing of the actuating piston, so that said bushing can be dimensioned with a relatively small diameter, regardless of the outer diameter of the auxiliary hydraulic tappet. The intake valves of a same cylinder are actuated by a single cam, by means of a single pumping piston and by means of a single pressure chamber controlled by a single solenoid valve.

Abstract: A device for controlling gas-exchange valves of an internal combustion engine is provided, which device has hydraulic valve actuators each allocated to one gas-exchange valve. Each valve actuator has an actuating piston acting on the gas-exchange valve, and two hydraulic working chambers delimited by the actuating piston, of which the first working chamber acting upon the gas-exchange valve in the closing direction is constantly filled with fluid under pressure, and the second working chamber acting upon the gas-exchange valve in the opening direction is able to be alternately filled with fluid under pressure and relieved via two electric control valves. For the purpose of cost reduction, provided for each valve-actuator pair is a single first electric control valve that is acted upon with the fluid pressure on the intake side, and is connected on the outlet side to the second working chamber of one valve actuator.

Abstract: The invention is directed to a method and an arrangement for controlling an internal combustion engine (20) which achieve an optimal efficiency in different operating states. An opening time of an inlet valve (5) of a cylinder (1) of the engine (20) is variably adjusted. Depending upon an operating variable, especially the engine speed, two operating states of the engine (20) are distinguished. In a first operating state, during an intake operation, an opening of the inlet valve (5) is delayed. In a second operating state, a closing of the inlet valve is delayed and carried out during a compression operation.

Abstract: Solenoid controlled hydraulic valves in sealed hydraulic circuits are provided with backup actuation without compromise of the hydraulic circuit by provision of an auxiliary, quick fitting solenoid coil case which incorporates manual switches and which may be attached directly to a battery for energization.

Abstract: A valve case includes an attaching portion and a sleeve. The valve case is attached to a cylinder head cover main body formed of resin. The attaching portion is formed of resin and is a portion of the valve case to which an oil control valve is to be attached. The sleeve is embedded in the attaching portion, and has an interior space that permits the oil control valve to be accommodated therein and oil holes. Each oil hole is selectively connected to one of ports of the oil control valve accommodated in the interior space of the sleeve. The sleeve is formed of material having higher rigidity than the resin forming the attaching portion. Therefore, the valve case prevents deformation of the attaching portion.

Abstract: A device for the generation of pressure pulses, includes a cylinder (3), a piston that is displaceably arranged in the cylinder (3), a pressure fluid circuit with an inlet (6) into and an outlet (7) out of the cylinder (3) on one side of the piston (4), a shaft (18) connected to the piston (4), and a liquid-filled chamber (17). The shaft (18) is arranged to be displaced through said chamber (17) in connection to a displacement of the piston (4) in the cylinder (3). The device includes at least one valve member (22, 24, 29, 32) for an occasional interruption of a flow of liquid out of the chamber (17).

Abstract: A device for adjusting a camshaft of an internal combustion engine of a motor vehicle has a stator and a rotor fixedly connected to a camshaft and rotatable relative to the stator. A drive wheel is fixedly connected to the stator and is centered by the camshaft. The stator has a peripheral area provided with a centering element interacting with a counter element provided on the drive wheel for aligning the drive wheel in a rotational direction relative to the stator.

Abstract: Maintenance requirements for hydraulic cylinders used to actuate heavy equipment may be predicted by measuring actual use of the cylinders. Sensors measuring piston position within each cylinder are integrated and the results stored in histograms bins to provide a permanent record of motion. Hydraulic pressure and temperature are also recorded. Data are downloaded periodically and compared with data from laboratory tests and/or from other units in the field.

Abstract: An actuating device for hydraulically securing a camshaft of an engine of a motor vehicle in a start position has a solenoid valve controlling the flow of a pressure medium to a camshaft adjuster with a rotary slide valve that is fixedly connected to the camshaft and moves the camshaft into the required start position according to the pressure medium supplied to it by the solenoid valve.

Abstract: A device for controlling gas exchange valves of an internal combustion engine, which has hydraulic valve positioners, each having a positioning piston acting on the gas exchange valve and two hydraulic working chambers, delimited by the positioning piston, of which the first working chamber, for closing the gas exchange valve, is continuously filled under fluid pressure and the second working chamber, for opening the gas exchange valve, is alternately filled and emptied with pressurized fluid via a first and second electrical control valve. To reduce the number of control valves, which may be necessary, for a valve pair, the filling of the second working chamber of the second valve positioner is performed via the second working chamber of the first valve positioner, which is connected to the first control valve, after a predetermined stroke of the positioning piston of the first valve positioner to open the assigned gas exchange valve.

Abstract: In a valve timing control device, a control means is configured to carry out feeding one of retarding and advancing chambers with a hydraulic pressure upon starting of the engine; actuating one of first and second disengaging mechanisms to cancel the engagement of one of first and second projectable members with the corresponding one of first and second engaging portions; feeding the other of the retarding and advancing chambers with a hydraulic pressure to turn a vane member in a housing within a range determined by each of the first and second engaging portions; and actuating, while the vane member is under the rotational movement within the range, the other of the first and second disengaging mechanisms to cancel the engagement of the other of the first and second projectable members with the corresponding one of the first and second engaging portions.

Abstract: A method of controlling the speed of the valves in an electro-hydraulic actuation unit for the valves of an internal combustion engine in which the pressure of the fluid in the hydraulic actuator of the valve is controlled during the final phase of closure of a valve.

Abstract: An engine valve actuation system is provided that includes an engine valve that is movable between a first position where the engine valve prevents a flow of fluid and a second position where the engine valve allows a flow of fluid. A cam assembly is operatively connected to the engine valve to move the engine valve between the first position and the second position in a predetermined actuation pattern. A valve actuator having a piezo electric device is operable to change the movement of the engine valve from the predetermined actuation pattern. A controller is adapted to control the piezo electric device to achieve a desired valve actuation pattern.

Abstract: A hydraulically actuated, preferably variable, valve drive of an internal-combustion engine is provided, with a slave unit (15), which is embodied as a separate component relative to a master unit. A special characteristic is that the slave unit is provided with a hydraulic backlash compensation element (9), which is connected to a path (12) for feeding hydraulic medium only outside of a stroke phase of a slave piston (5). As a result, on one hand an easy-to-produce valve drive with slave unit (15) is provided. On the other hand, unnecessary “pumping up” of the backlash compensation element (9) during the stroke phases of the slave piston (5) is prevented by the previously mentioned admission of hydraulic medium.

Abstract: An engine valve actuation system is provided. An intake valve is moveable between a first position where the intake valve prevents a flow of fluid relative to the intake valve and a second position where the intake valve allows a flow of fluid relative to the intake valve. A cam assembly is configured to move the intake valve between the first position and the second position. A fluid actuator having a chamber is adapted to selectively prevent the intake valve from moving to the first position. A fluid supply system is adapted to deliver fluid to the chamber of the fluid actuator. A pressure sensor is operatively engaged with the fluid supply system and is adapted to sense the pressure of the fluid within the fluid supply system.

Abstract: An electro-hydraulic lost motion system for variable valve activation including a master piston and an accumulation piston in a first bore, defining a hydraulic pressure chamber therebetween, in response to rotation of an engine cam. A slave piston in the engine head and hydraulically connected to the pressure chamber opens and closes an engine valve. A servo-valve behind the accumulation piston controls the mobility of the accumulation piston via a fluid control chamber. When the control chamber is made hydraulically rigid, the system actuates the engine valve. When the control chamber is vented through the servo-valve, the accumulation piston is movable in lost motion, preventing the engine valve from opening. All intermediate degrees of valve opening are possible. Preferably, the servo-valve, control chamber, accumulation piston, and a control piston are comprehended in a modular subassembly which may be positioned adjacent the master piston or the slave piston.

Abstract: An engine valve actuation system is provided. An intake valve is moveable between a first position to prevent a flow of fluid and a second position to allow a flow of fluid. A cam assembly is connected to move the intake valve between the first position and the second position. A fluid actuator is configured to selectively prevent the intake valve from moving to the first position. A source of fluid is in fluid communication with the fluid actuator. A directional control valve is configured to control a flow of fluid between the source of fluid and the fluid actuator. A control valve is disposed between the source of fluid and the directional control valve. The control valve is moveable between a first position to prevent the flow of fluid between the source of fluid and the directional control valve and a second position to allow the flow of fluid from the source of fluid to the directional control valve.

Abstract: The present invention is directed to a system and method for actuating an engine valve. In one embodiment, the present invention is a system for providing exhaust gas recirculation (EGR) in an engine having at least one engine valve, the system comprising: means for imparting a valve train motion; a first valve actuation subsystem for transferring motion from the motion imparting means to the engine valve, the first valve actuation subsystem capable of providing valve actuation for at least a portion of a main exhaust event during a first engine operating condition, and a full main exhaust event during a second engine operating condition; and a second valve actuation subsystem for transferring motion from the motion imparting means to the engine valve, the second valve actuation subsystem capable of providing valve actuation for an exhaust gas recirculation event during the first engine operating condition.

Abstract: An intake or exhaust valve for an internal combustion engine has a rocker arm with a pivot between its ends, one end of which is engaged by the pushrod, and the other end engages the valve stem. An adjustable stop has two positions for the rocker arm pivot; a rest position where there is no movement of the pivot, and an upper lock position where the pivot moves in response to the pushrod, and there is a reduction in the opening of the valve. A progressive rate spring compresses as the pivot moves towards the upper lock position, thereby modulating valve opening for relatively slow start (or stop) of valve stroke with accelerating (or decelerating stroke), as the progressive rate spring compresses (or expands). Relatively thinner and thicker Belleville springs are used in series to produce a progressive rate spring. The lock position of the pivot elevated above the rest position is determined by a hydraulic block trapping oil in a closed chamber.

Abstract: A system and method for actuating one or more engine valves to produce an engine valve event is disclosed. The system may comprise: a housing; an accumulator disposed in the housing having a first open end and a second open end; a master piston slidably disposed in a first bore formed in the housing; a valve train element(s) for imparting motion to the master piston; and a slave piston slidably disposed in a second bore formed in the housing, the slave piston in fluid communication with the master piston through a high pressure hydraulic passage, wherein the first open end and the second open end of the accumulator are in communication with the high pressure hydraulic passage to selectively modify the imparted motion.

Abstract: The object of the present invention is to provide a camless valve driving device, without having a cam mechanism, which can reduce the valve driving energy and enhances fuel efficiency. According to the one preferred aspect of the present invention, the valve driving device of an internal combustion engine includes a pressure chamber, to which actuating fluid, to drive opening and closing of a main valve serving as an intake valve or as an exhaust valve of the internal combustion engine, is supplied; a first actuating valve for supplying high-pressure (Pc) actuating fluid to the pressure chamber during a prescribed period (tCP1) of the initial valve opening period of the main valve; a second actuating valve for introducing low-pressure (Pf) actuating fluid to the pressure chamber after the prescribed period (tCP1) has elapsed; a third actuating valve for discharging actuating fluid from the pressure chamber when the main valve is closed.

Abstract: An engine valve actuation system is provided. The system includes an engine valve moveable between a closed position and an open position. A spring is operatively connected to the engine valve to bias the engine valve towards the closed position. An actuator is operatively connected to the engine valve and is operable to selectively engage the engine valve to prevent the engine valve from returning to the closed position and to release the engine valve to allow the engine valve to return to the closed position. A sensor is configured to provide information related to the operation of the actuator. A controller is configured to transmit a signal to the actuator to engage the engine valve to prevent the engine valve from returning to the closed position and to release the engine valve to the allow the engine valve to return to the closed position.

Abstract: Methods and systems for retaining hydraulic fluid in a hydraulic valve actuation system adapted to be installed on an internal combustion engine are disclosed. The system may include a hydraulic fluid supply connected by one or more passages to a fluid accumulator and a hydraulic valve actuator. The one or more passages may include a retaining portion elevated above portions of the fluid accumulator and/or the hydraulic valve actuator. The retaining portion may include an air vent and thus prevent back flow of all the fluid in the accumulator and/or hydraulic valve actuator to the fluid supply during periods that the engine is shut off. Retention of hydraulic fluid in the system may be further enhanced during engine shut off by selectively controlling the release of hydraulic fluid from the hydraulic valve actuator during the engine shut off process.

Abstract: A switchable cam follower (1) or a switchable support element of a valve train of an internal combustion engine, said cam follower or support element comprising an outer part (2) which is assembled together with an inner part (4) that is displaceable relative thereto in a direction of cam lift, said inner part (4) comprising, at a parting gap (5) to the outer part (2), two spaced apart or opposing openings (6, 7) for coupling means, each of said openings (6, 7) being aligned, at one cam position, to a further opening (10, 11) for coupling means in the outer part (2), the coupling means being configured and arranged so that, in a coupled state, each coupling means extends beyond the parting gap (5) on one coupling side (12, 13) while simultaneously extending in the opening (10, 6) of the outer and the inner part (2, 4) which in an uncoupled position of the coupling means (14, 15), an axial idle stroke of the coupling means (15) on the one coupling side (12) till coupling is achieved is large and the axial idle

Abstract: In a valve timing control apparatus, hydraulic oil is supplied into retarding and advancing chambers, and first and second hydraulic chambers, when hydraulic pressure is less than a predetermined pressure and when a phase difference between a most advancing target phase and actual phase of a driver-side rotating member relative to a driven-side rotating member is small. Hydraulic pressure is applied from the first and second hydraulic chambers to the stopper pin, so that the stopper piston is restricted from protruding to the engaging ring before the actual phase coincides with the most advancing target phase. Hydraulic oil is drained from the retarding chamber and the first hydraulic chamber, and hydraulic pressure in the second hydraulic chamber is small, so that the stopper pin protrudes and engages with an engaging ring at the most advancing target phase.

Abstract: In an internal combustion engine provided with valves with variable actuation, each variable actuation valve is controlled by a hydraulic actuator unit through a rocker arm.

Abstract: A lost motion engine valve actuation system and method of actuating an engine valve are disclosed. The system may comprise a valve train element, a pivoting lever, a control piston, and a hydraulic circuit. The pivoting lever may include a first end for contacting the control piston, a second end for transmitting motion to a valve stem and a means for contacting a valve train element. The amount of lost motion provided by the system may be selected by varying the position of the control piston relative to the pivoting lever. Variation of the control piston position may be carried out by placing the control piston in hydraulic communication with a control trigger valve and one or more accumulators. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the control piston position. Means for limiting valve seating velocity, filling the hydraulic circuit upon engine start up, and mechanically locking the control piston/lever for a fixed level of valve actuation are also disclosed.