Abstract: The present disclosure provide a driving device for a composite engine valve of a dedicated driving cam. The driving device includes a valve bridge, a dedicated driving cam, a driver, and a driving oil circuit. The driving oil circuit is configured to be intermittently in communication with a main piston hole and an auxiliary piston hole through a closure and disconnection of the driving oil circuit. The driver is fixedly mounted on a rocker arm shaft, which is simple in structure and low in cost. No motion friction between the driver and the rocker arm shaft, and the dedicated driving cam separating from the main piston when the driver is not in operation effectively reduce wear and noise between the dedicated driving cam and the main piston and improve engine power utilization. When the driver is in operation, the dedicated driving cam automatically adjusts a driving valve through a hydraulic gap, and a driving lift is not affected by an initial gap setting.

Abstract: The embodiments of the present disclosure provide a valve actuator for a specialized stationary two-piston hydraulic engine, including a specialized drive cam, an actuator, an oil drive line, and a control valve. A hydraulic linkage is maintained between a primary piston and a secondary piston when the control valve is open, and the oil drive line is drained through the control valve when the control valve is closed. In the present disclosure, by integrating the primary piston and the secondary piston in a specialized actuator, oil consumption is reduced, and with a design of the specialized drive cam, an optimized design of the valve actuator that operates independently of a positive valve mechanism is realized, thus reducing interference and influence of the valve actuator on an operation of the positive valve mechanism.

Abstract: Provided is a valve timing adjustment device that suppresses slippage of an assist spring, prevents disengagement, and facilitates assembly of the assist spring. A valve timing adjustment device adjusts an opening timing and closing timing of an intake valve or an exhaust valve of an internal combustion engine. In the assist spring, the inner peripheral end portion is formed in a non-bent shape, the outermost periphery is in contact with the rib, a second winding is in contact with the inner peripheral end portion, and there is no contact between windings from the second winding to the outermost periphery.

Abstract: A compression release engine in-cylinder braking system, comprising a valve mechanism, an oil cylinder device, an oil pump device, and an oil supply device. The oil cylinder device and the oil pump device of each air cylinder communicate with each other through a pressure transmission oil circuit, which communicates with the oil supply device through a low-pressure relief valve. An air release valve is arranged at the high end of an oil circuit system. During in-cylinder braking, the air release valve is closed, an electromagnetic reversing valve is energized, engine oil having a pressure of P1 is supplied to the pressure transmission oil circuit, and a cam abuts against and pushes the oil pump device to pump high-pressure oil to the oil cylinder device, so as to push a rocker arm to open a valve, thereby achieving in-cylinder braking.

Abstract: Valve bridge systems include constraints and guides for managing bridge jump and other uncontrolled valve bridge motion during engine operation. Constraints may include an e-foot collar, an extended portion on the bridge, and a bridge brake pin. Guides may include valve stem tip lead-in chamfers surrounding the valve bridge valve pockets as well as a deflection surface on the bridge extended portion. Methods of configuring valve bridges may include configuring the valve step tip lead-in chamfers based on worst-case positions of the valve bridge defined by one or more or a combination of the constraints provided by the e-foot collar, extended portion and brake pin.

Abstract: A valve actuation system comprises a valve actuation motion source configured to provide main and auxiliary valve actuation motions for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in a valve bridge and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism is arranged in a rocker arm and configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is parallel with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

Abstract: A valve actuation system comprises a valve actuation motion source configured to provide a main valve actuation motion and an auxiliary valve actuation motion for actuating at least one engine valve via a valve actuation load path. A lost motion subtracting mechanism is arranged in the valve actuation load path and configured, in a first default operating state, to convey at least the main valve actuation motion and configured, in a first activated state, to lose the main valve actuation motion and the auxiliary valve actuation motion. Additionally, a lost motion adding mechanism configured, in a second default operating state, to lose the auxiliary valve actuation motion and configured, in a second activated state, to convey the auxiliary valve actuation motion, wherein the lost motion adding mechanism is in series with the lost motion subtracting mechanism in the valve actuation load path at least during the second activated state.

Abstract: A control device and a control method for variable valve timing mechanism according to the present invention obtains a first measurement of a rotational phase based on a rotational angle of the motor, obtains a second measurement of the rotational phase based on a relative relationship between a rotational angle of the crankshaft and a rotational angle of the camshaft, calibrates the first measurement based on the second measurement, obtains a derivative term proportional to a rate of change in a deviation between the first measurement and a target value, reduces change in derivative term when calibrating the first measurement based on the second measurement, and controls the motor based on a manipulated variable including the derivative term.

Abstract: A compact, modular, lost motion variable valve actuation assembly includes a dry start hydraulic circuit to enable quick priming of a lost motion master-slave circuit from a dry start reservoir to the master piston chamber during engine start. Motion of the master piston on engine startup may draw in fluid from the dry start hydraulic circuit. The dry start components may be integrated into a compact modular rocker shaft pedestal package suitable for retrofit on existing engine head assemblies. The master piston may include a push tube interface that includes a deep push tube cavity and lubrication capabilities in the master piston that provides for improved wear, stability, easy installation and alignment. The slave piston may be provided with a valve catch to reduce valve closing velocity during cycles involving lost-motion.

Abstract: Methods and systems are provided for variable valve actuation assembly. In one example, the variable valve actuation assembly may include a first pressure reservoir with a first pressure fluidly coupled to valve actuators and positioned below an engine valve. A second pressure reservoir with a second pressure is arranged directly below the first pressure reservoir and a hydraulic medium flows between the first and second pressure reservoirs.

Abstract: Systems and methods for controlling valves in valve actuation systems in internal combustion engines systems may be particularly suitable for sequencing valve motion in engine environments that combine cylinder deactivation and high-power density (HPD) engine braking. A main event motion system is configured to produce main event motion in one or more valve sets. An engine braking system produces engine braking motion and a cylinder deactivation system selectively deactivates main event motion of the intake and exhaust valves the valve set. A blocking system selectively prevents the cylinder deactivation system from deactivating main event motion of at least one intake valve during the engine braking operation. Thus, main event intake valve motions may be available for braking operations, such as HPD braking where main event intake valve motion may be used to enhance CR braking. One actuator can control deactivation of paired intake and exhaust main event motion.

Abstract: An efficient engine combustion system with multiple combustion modes, includes a valve actuating mechanism, a pre-combustion chamber, and a main combustion chamber. The valve actuating mechanism is a fully variable valve mechanism; an intake valve and an exhaust valve are driven by high-pressure oil; ignition is implemented by means of an ignition apparatus of the pre-combustion chamber; and a spark plug and a single-hole fuel injector are mounted in the pre-combustion chamber, a bottom end of which is provided with a flame jet hole. The continuous variable of valve timing and real-time adjustment of valve lift are realized by the control of a three-position four-way servo valve, driven by the high-pressure oil and monitored by a displacement sensor. The efficient engine combustion system with multiple combustion modes employs different combustion modes under different engine conditions, so as to ensure optimal thermal efficiency under different operating condition regions.

Abstract: A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is supported by a vehicle body frame. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A part of the vehicle body frame is arranged between the oil control valve unit and the heat exchanger in a front and rear direction.

Abstract: Methods and systems are provided for oil flow for hydraulic lash adjusters of a vehicle engine. In one example, an engine cylinder bank includes a plurality of deactivatable hydraulic lash adjusters and a plurality of non-deactivatable hydraulic lash adjusters. A first linear oil supply passage and a second linear oil supply passage are formed within the cylinder bank and extend linearly through the cylinder bank without bends or curvature to the deactivatable and non-deactivatable hydraulic lash adjusters, with the deactivatable and non-deactivatable hydraulic lash adjusters having a same length.

Abstract: The disclosure relates 10 a device which is used to adjust the valve stroke of internal combustion engines and has an actuation element for the valve stem. The actuation element is actuated by the camshaft and has a receiving space for a pressure medium. The receiving space is fluidically connected to a reservoir space of an adjustment reservoir. The volume of the reservoir space can be adjusted by means of a reservoir piston. The reservoir piston is loaded toward the reservoir space with a force that is greater than the force applied by the pressure medium and that is less than the restoring force acting on the piston.

Abstract: A hydraulic valve assembly includes an algorithm stored in an internal memory of the hydraulic valve assembly that determines a spool correction command based on a flow demand which is calculated for obtaining a target single port pressure or a target delta pressure using one or more port pressure measurements. The spool correction command is sent to an upper level controller of the hydraulic valve assembly, and the upper level controller uses the spool correction command to obtain an optimal displacement of a spool inside the valve assembly.

Abstract: A valve train for the variable actuation of an inlet valve and an outlet valve of a combustion chamber of an internal combustion engine, having a first operative connection between a valve actuating device and the inlet valve and a second operative connection between the valve actuating device and the outlet valve. The first operative connection and the second operative connection are assigned an interrupting element which is set up to temporarily interrupt the operative connections. The first operative connection and the second operative connection are connected to the same interrupting element in such a way that the first operative connection and the second operative connection can be interrupted temporarily by way of the interrupting element.

Abstract: Various methods and systems are provided for skip-firing an engine. As one embodiment, a method for an engine includes firing all cylinders of the engine and not altering the closing timing of the intake valves when fueling demands are greater than a threshold. The method further includes skip-firing the engine when fueling demands are less than a threshold, and holding open the intake valves of skipped cylinders for a greater duration than intake valves of firing cylinders.

Abstract: A method of providing a rocker arm set for a valvetrain includes providing a first rocker arm configured as a switching rocker arm for a first intake valve, and providing a second rocker arm configured as a fixed rocker arm for a second intake valve, the second rocker arm operating in a normal Otto cycle mode. The first rocker arm operates in a late intake valve closing (LIVC) mode where the first rocker arm is configured to close the first intake valve later than the second intake valve.

Abstract: For a given cylinder in the engine having two intake valves and two exhaust valves, one of the intake valves is driven by a bucket tappet, while the other intake valve is actuated via a roller finger follower. Similarly, one of the exhaust valves is driven by a bucket tappet, while the other exhaust valve is actuated via a roller finger follower. The intake valves read inputs form an intake camshaft, and the exhaust valves read inputs from an exhaust camshaft.

Abstract: A controller sets a target hydraulic pressure from a required hydraulic pressure of a hydraulically operated device according to an operating condition of an engine. The controller causes an oil control valve to perform feedback control of the discharge amount of an oil pump in such a manner that an actual hydraulic pressure detected by a hydraulic pressure sensor coincides with the target hydraulic pressure. The controller executes feedback control after executing fixed duty control of setting a duty ratio of the oil control valve to a fixed duty ratio for a predetermined period of time from start of the engine.

Abstract: A regenerative valve hydraulic actuator includes a high-pressure accumulator fed by a high-pressure feed hydraulic pump, an actuator defining an actuator hydraulic chamber for actuating—by way of a progressive lever arm ratio lever—a valve provided with a valve return device, a valve lifter hydraulic valve placed between the high-pressure accumulator and the actuator hydraulic chamber, a lifter check valve which connects a low-pressure accumulator to the actuator hydraulic chamber, a valve closure hydraulic valve placed between the chamber and a closure and regeneration hydraulic motor which recovers energy previously invested to open the valve.

Abstract: There is provided a mounting structure of an oil control valve unit configured to control a hydraulic pressure to a variable valve timing device of an engine. The engine is provided with a transmission. A heat exchanger is mounted in front of the engine. The oil control valve unit is mounted at a side of the engine. A transmission cover configured to cover the transmission from a side bulges from a side surface of the engine and the oil control valve unit is mounted above the transmission cover.

Abstract: Aspects of the present disclosure are directed to an internal combustion engine having a valve actuation device and at least one first exhaust valve and one second exhaust valve per cylinder. The first and second exhaust valves may be actuated together in at least one operating area of the internal combustion engine, via an exhaust valve bridge and a first valve lifter, by a first cam lobe of a first exhaust cam arranged on a camshaft. The camshaft having a second exhaust cam with at least one additional cam lobe and at least one second cam lobe A transmission device being arranged in the functional path between the second exhaust cam and the second exhaust valve, the transmission device allowing an idle stroke to be activated or deactivated. The first exhaust cam and the second exhaust cam are configured and arranged to be rotatable relative to one another.

Abstract: A camshaft phaser includes an input member connectable to the crankshaft of an engine; an output member connectable to a camshaft of the engine and defining an advance chamber and a retard chamber with the input member. A valve spool is moveable between an advance position and a retard position and includes a valve spool bore extending thereinto. An insert within the valve spool bore and carries a check valve. The check valve includes a check valve member which moves between a seated position and an unseated position. The check valve also includes a check valve positioning member which is held in compression against an inner periphery of the valve spool bore such that compression of the check valve positioning member holds the check valve in contact with the insert.

Abstract: In an internal combustion engine, a linkage is provided between an auxiliary motion source and a main motion load path, such that motions received by the linkage from the auxiliary motion source result in provision of a first force to at least one engine valve and a second force to the main motion load path in a direction toward a main motion source. Where an automatic lash adjuster is associated with the main motion load path, the second force may be selected to aid in the control of lash adjustments made by the automatic lash adjuster. In various embodiments, the linkage may be embodied in an mechanical linkage, whereas in other embodiments, an hydraulic linkage may be employed. The linkage may be incorporated into, or otherwise cooperate, a valve bridge or a rocker arm.

Abstract: A camshaft phaser includes an input member connectable to the crankshaft of an engine; an output member connectable to a camshaft of the engine and defining an advance chamber and a retard chamber with the input member. A valve spool is moveable between an advance position and a retard position and includes a valve spool bore extending thereinto. An insert within the valve spool bore and carries a check valve. The check valve includes a check valve member which moves between a seated position and an unseated position. The check valve also includes a check valve positioning member which is held in compression against an inner periphery of the valve spool bore such that compression of the check valve positioning member holds the check valve in contact with the insert.

Abstract: A variable valve lift (VVL) system for an internal combustion engine is provided that utilizes hydraulic fluid supply pressure feedback to provide noise free operation. The VVL system includes a high pressure pump, a solenoid valve, a pressure translating device, a one-way valve, and a hydraulic fluid pressure sensor. The high pressure pump is fluidly connected to the solenoid valve and pressure translating device by at least one fluid gallery that forms a high pressure chamber. The solenoid valve selectively fluidly connects the high pressure chamber to a middle pressure chamber formed by at least one fluid gallery that fluidly connects the one-way valve to the solenoid valve. The hydraulic fluid pressure sensor is arranged to detect a hydraulic fluid supply pressure of the one-way valve and provides feedback to an electronic controller that determines a proper fluid intake opening timing of the solenoid valve.

Abstract: A variable camshaft timing device that adjusts phase between a camshaft and a crankshaft includes a planetary gear assembly that changes an angular position of the camshaft relative to an angular position of the crankshaft; a sun gear configured to receive an output shaft of an electric motor that rotates at least a portion of the planetary gear assembly and controls phase adjustment between the camshaft and crankshaft by angularly displacing the camshaft with respect to the crankshaft; and a hydraulic lock (82) that releasably engages a portion of the variable camshaft timing device (10) in response to force applied by pressurized fluid thereby selectively preventing rotation of the camshaft relative to the crankshaft.

Abstract: An exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode can include a rocker shaft and a rocker arm. The rocker shaft can define a pressurized oil supply conduit. The rocker arm can receive the rocker shaft and is configured to rotate around the rocker shaft. The rocker arm can have an oil supply passage defined therein. A valve bridge can engage a first exhaust valve and a second exhaust valve. An accumulator assembly can be disposed in the rocker arm and includes an accumulator piston that translates within the accumulator piston housing between closed and open positions. A predetermined amount of oil is stored in the accumulator assembly.

Abstract: A system for actuating engine valve comprises a main valve actuation motion source configured to supply main valve actuation motions to the at least one engine valve via a main motion load path, and an auxiliary valve actuation motion source separate from the main valve actuation motion source and configured to supply complementary auxiliary valve actuation motions to the at least one engine valve via an auxiliary motion load path. A lost motion component is configured, in one state, to maintain lash between the auxiliary valve actuation motion source and the auxiliary motion load path or within the auxiliary motion load path and, in another state, to take up this lash. The auxiliary valve actuation motion source is further configured to supply at least one lash-prevention valve actuation motion that substantially matches at least one of the main valve actuation motions.

Abstract: A valve assembly includes a valve body with an interior cavity and one or more supply ports, a control port, and an exhaust port each fluidly connected to the interior cavity. An armature assembly is movable within the interior cavity from a first position to a second position in response to the coil being energized. In some configurations, a regulator body, which is connected to the valve body, has an exhaust passage fluidly connected to the exhaust port. A regulator valve in the regulator body prevents fluid flow out of the exhaust passage when fluid pressure on the regulator valve is at or below a pilot pressure. The regulator valve permits fluid flow out of the exhaust passage when fluid pressure on the regulator valve is greater than the pilot pressure. The valve body is configured to provide fluid from the supply port/ports to the control port.

Abstract: A floating module for modular solar panel platforms having two separate components mounted, a structural component that is a rigid component and a buoyancy component that is a flexible component allowing for a more compact and simple solution all-around. The floating module allows for a technologically more advanced floating component, easier to produce, transport and deploy than most currently available solutions.

Abstract: Provided is a method for flaw inspection of a stem joint of a valve including: an internal flaw inspection step including causing a flaw detection probe to be disposed so as to face upward in water in a tank in an ultrasonic inspection chamber, holding a valve in such fashion as to cause the tip to face the flaw detection probe, and inspecting for a flaw at the interior of the stem joint; and a surface flaw inspection step including causing a flaw detection probe to be disposed horizontally in an eddy-current inspection chamber, holding a valve in such fashion as to cause the side face of a stem of the valve to be close to and facing the flaw detection probe, inspecting for a flaw on the surface of the stem joint while the flaw detection probe and the valve are made to engage in mutual rotation.

Abstract: Methods and systems are provided for an engine oil system of a cylinder head. In one example, an engine oil system may include a first oil gallery and a second oil gallery fluidly coupled to each other via a plurality of oil chambers. Each oil chamber includes a plug, and one or more of the plugs may include a slot shaped to direct a flow of engine oil from a solenoid valve to the second oil gallery.

Abstract: An actuator for axial displacement of a gas exchange valve of a combustion engine is configured to be connected to a pressure fluid source and a pressure fluid sink, respectively, and to be driven by a gaseous pressure fluid and includes an actuator piston including an actuator piston disc and an actuator piston rod projecting therefrom in the axial direction, a cylinder volume, the disc separating the cylinder volume into a first part and a second part and being displaceable back and forth in the axial direction in the cylinder volume between an inactive position and an active position, the first part being configured for controllable fluid communication with the pressure fluid source and the pressure fluid sink, respectively, and a hydraulic circuit includes a chamber, the free end of the rod being arranged therein, wherein the rod is displaceable back and forth in the axial direction in a channel.

Abstract: The invention relates to a method (3) for determining (33) a state characteristic value (28) of a electric device (4) controlled by a temporally variable control signal (17). The at least one state characteristic value (28) is determined using the frequency of the temporally variable control signal (17) and/or the switching characteristics of the temporally variable control signal (17).

Abstract: Embodiments disclosed herein relate to internal combustion engines, combustion systems that include such internal combustion engines, and controls for controlling operation of the combustion engine. The internal combustion engine may include one or more mechanisms for injecting fuel, air, fuel-air mixture, or combinations thereof directly into one or more cylinders, and controls may operate or direct operation of such mechanisms.

Abstract: An engine brake device is provided for attenuating compression. The device is able to brake engine by attenuating a pressure increase in a cylinder by temporarily opening an exhaust valve at the end of a compression stroke of the engine, using an eccentric assembly eccentrically coupled to a pivot center of an exhaust rocker arm and an actuator for pushing up the eccentric assembly.

Abstract: A variable valve train module selectively controls the opening and closing of a valve of an engine. The variable valve train module includes a drive element configured to be driven by a cam which rotates on a camshaft, a pump which is driven by the drive element, and a hydraulic control unit. The hydraulic control unit is configured to control the engine valve. The hydraulic control unit has a high pressure chamber containing hydraulic fluid which is selectively pressurized by the pump. The hydraulic control unit also has a control valve which is configured to depressurize the high pressure chamber, and a damper which is configured to increase an effective volume of the high pressure chamber when a pressure in the high pressure chamber exceeds a threshold value.

Abstract: The invention relates to an electromagnetically actuable intake valve for a high-pressure pump of a fuel injection system, in particular of a common-rail injection system, comprising a reciprocating valve closure element (2) that engages with a valve seat (1) and is loaded in the closing direction by the spring force of a valve spring (3) which is supported on a spring plate (4) connected to the valve closure element (2), further comprising a reciprocating armature (6) that engages with an electromagnet (5) and is loaded in the direction of the valve closure element (2) by the spring force of an armature spring (7) which is larger than that of the valve spring (3). According to the invention, the spring plate (4) has a first abutment face (9) for limiting the opening travel of the valve closure element (2) and a second abutment face (10) for mechanically coupling to the armature (6). The invention also relates to a high-pressure pump having such an intake valve.

Abstract: The present invention provides a camshaft capable of suppressing an increase in the number of parts and the number of places to be processed, preventing scratching on a sliding surface that is a part of an outer peripheral surface of an outer shaft and on which an inner cam is rotated, and preventing occurrence of deformation in the entire camshaft after final assembly. A camshaft includes an inner cam that is attached from a radial direction of an outer shaft and that is fixed to an inner shaft with a pin inserted into the inner cam from the radial direction of the outer shaft in a cam surface of the inner cam.

Abstract: A valve opening and closing timing control apparatus includes a driving-side rotating body, a driven-side rotating body fixed to a camshaft by a bolt, a fluid pressure chamber, an intermediate lock mechanism, a lock flow passage bringing the working fluid to the intermediate lock mechanism, and an electromagnetic valve including a spool which is arranged at an inner portion of the bolt, the lock flow passage including a first flow passage which is arranged between the spool and a supply flow passage in a radial direction and which is connected to the supply flow passage, the lock flow passage including a second flow passage which is provided at the inner portion of the bolt in a penetrating manner in the radial direction and which brings the working fluid to flow between the spool and the intermediate lock mechanism.

Abstract: A central valve for a camshaft adjuster, and to an internal combustion engine, which includes a camshaft, a camshaft-adjusting device, and a central valve. The central valve includes a shaped part as a valve housing (3), including a control piston (4) guided coaxially within the valve housing (3) in such a way that the control piston can move axially and including a stop, which limits the mobility of the control piston in an axial direction (piston stop). The piston stop is a piston stop washer (5), wherein the piston stop washer and the valve housing (3) are joined.

Abstract: A drive unit, in particular an internal combustion engine, has a fluid line arrangement, wherein the fluid line arrangement has a cavity accessible for a fluid via a bore in a first wall element. A spacer element for the fluid line arrangement has a resilient clamping sleeve which can be introduced through the bore. The clamping sleeve has a first longitudinal section which is provided so as to remain in the bore in contact with the bore wall and a second longitudinal section which is set back from the first longitudinal section by way of at least one notch which runs transversely with respect to a longitudinal axis of the clamping sleeve. The second longitudinal section is configured as an axially slotted tube which serves as the spacer element, the borders of the slot being bent radially outwards.

Abstract: A valve train system that eliminates the inefficiencies of current spring biased systems. The system uses teeter beams that are manipulated by cams that are driven by cam shafts to control and operate the valve system more efficiently and dependably.

Abstract: A spool 220 is provided with a second land section 224 that blocks a portion between the spool 220 and the valve sleeve 210 at a position between the output port P21 and the lead-in port P22 when the spool 220 is located in a position for connecting the channel for input T1 and the channel for output T2 via the input port P10 and the output port P21 and blocking a channel leading from the channel for output T2 to the channel for discharge T3, and when the spool 220 is located in a position for connecting the channel for output T2 and the channel for discharge T3 via the lead-in port P22 and the discharge port P30 and blocking a channel leading from the channel for input T1 to the channel for output T2.

Abstract: A hydraulic valve brake for a hydraulic valve drive of an internal combustion engine is provided. The valve brake includes a housing with a housing wall and with a housing base, and includes a piston which moves axially in the housing and one end side of which, together with the housing wall and the housing base, delimits a hydraulic pressure chamber and the other end side of which actuates a gas exchange valve. The housing wall is perforated in the region of the pressure chamber by one or more overflow openings, the opening cross sections of which are controlled by a control edge, which delimits the end side at the pressure chamber side, of the piston. In this case, it is the intention for the axial distance (h) between the control edge of the piston, when the latter is fully retracted into the housing, and the housing base to be set by a spacer of predetermined thickness (d).

Abstract: Described herein is a system for variable actuation of an engine valve of an internal-combustion engine, where the system is able to actuate the engine valves, selectively, in a four-stroke operating mode and in a two-stroke operating mode, on the basis of the operating conditions of the engine.