An actuation apparatus for actuating a component of a switchable valve train device of an internal combustion engine includes: a support body for mounting on a cylinder head cover of the internal combustion engine; an actuation lever mounted to the support body for pivotal movement of the actuation lever between a first position for actuation of the component and a second position for allowing de-actuation of the component; and a biasing means for urging the actuation lever from the second position towards the first position. In use, the biasing means becomes biased when an actuation source causes the actuation lever to pivot to the second position. When the actuation source attempts to actuate the component when the component is non-actuatable, the biasing means causes the actuation lever to pivot from the second position to the first position, thereby to actuate the component when the component becomes actuatable again.

A dual body rocker arm for a valve train assembly of an internal combustion engine includes: an outer body having a protrusion; an inner body connected to the outer body and arranged for pivotal movement relative to the outer body about an axis between a first position and a second position; and a torsional biasing element supported by the protrusion and arranged to bias the inner body relative to the outer body towards one of the first position and the second position. The protrusion is formed integrally with the outer body.

A method for controlling intake and exhaust valves of an engine includes: controlling, by an intake continuous variable valve timing (CVVT) device and an exhaust CVVT device, opening and closing timings of the intake valve and exhaust valves; determining, by a controller, a target opening duration of the intake and exhaust valves based on an engine load and an engine speed; modifying, by an intake continuous variable valve duration (CVVD) device and by an exhaust two-stage variable valve duration device, current opening and closing timings of the intake valve and exhaust valve based on the target opening durations. In particular, the exhaust two-stage VVD device switches a current opening duration of the exhaust valve to a first exhaust opening duration or a second exhaust opening duration which is shorter than the first opening duration based on the target opening duration of the exhaust valve.

A continuous variable valve duration apparatus may include a camshaft, a cam unit on which a cam is formed, wherein the camshaft is inserted into the cam unit, a guide bracket having an upper guide boss formed thereon, an internal wheel transmitting rotation of the camshaft to the cam unit, a wheel housing in which the internal wheel is rotatable inserted, wherein the wheel housing includes a guide shaft on which a guide screw thread is formed and the guide shaft is inserted into the upper guide boss to be movable, a worm wheel to which an internal screw thread engaging with the guide screw thread is formed therewithin, and to which an external screw thread is formed thereon, and a control shaft on which a control worm engaging with the external screw thread is formed.

A continuous variable valve duration apparatus may include a camshaft, a cam unit on which a cam is formed, wherein the camshaft is inserted into the cam unit, a guide bracket having an upper guide boss formed thereon, an internal wheel transmitting rotation of the camshaft to the cam unit, a wheel housing in which the internal wheel is rotatable inserted, wherein the wheel housing includes a guide shaft on which a guide screw thread is formed and the guide shaft is inserted into the upper guide boss to be movable, a worm wheel to which an internal screw thread engaging with the guide screw thread is formed therewithin, and to which an external screw thread is formed thereon, and a control shaft on which a control worm engaging with the external screw thread is formed.

A variable valve apparatus includes: a swing body mounted to rotate to open and close a valve; an inner body driven by a cam and mounted in the swing body so as to switch a relatively-rotatable state and a latched state with respect to the swing body; a latching pin slidably mounted in the swing body so as to switch the latched state and the relatively-rotatable state of the inner body with respect to the swing body; and a control mechanism pressing the latching pin to make the inner body be latched to the swing body.

An actuator arrangement for controlling a latching arrangement of a dual body rocker arm of an internal combustion engine, the dual body rocker arm comprising a first body, a second body, and the latching arrangement, the latching arrangement being controllable to latch and unlatch the first body and the second body. The actuator arrangement includes: an actuation source; a shaft including a cam for controlling the latching arrangement; and a gear mechanism for translating a continuous rotation of the actuation source into an intermittent rotation of the shaft in steps of a predefined degree. In use, a continuous rotation of the actuation source causes, via the gear mechanism, the shaft to rotate in steps of a predefined degree, thereby to change an orientation of the cam relative to the latching arrangement by a predefined amount, so as to control the latching arrangement.

A valvetrain for an internal combustion engine has a camshaft that can be rotated in a direction of rotation around an axis of rotation, at least two cam pieces arranged on the camshaft which each have at least two cams for actuating a respective gas exchange valve and which are rotationally fixedly connected to the camshaft, and an actuator via which the cam pieces can be shifted in the axial direction of the camshaft. A first of the cam pieces has a first rib protruding outwardly from a first base body of the first cam piece in the radial direction of the camshaft and the second cam piece has a second rib protruding outwardly from a second base body of the second cam piece in the radial direction of the camshaft.

A method for diagnosing an engine system including a continuous variable valve duration (CVVD) apparatus, a driving unit of the CVVD apparatus including a first driving unit and a second driving unit, a CVVD position detector configured to detect a position of the CVVD apparatus, a camshaft position detector configured to detect a position of a camshaft, a front lambda detector configured to detect a lambda value at front of intake valve, and a controller may include the steps of starting the engine, detecting measured values of the front lambda detector during combustion of first to fourth cylinders (first to fourth lambda values), determining whether CVVD driving unit is misaligned according to the detected first to fourth lambda values, and generating a warning notification when the CVVD driving unit is determined to be misaligned.

An actuation arrangement for actuating a plurality of latching arrangements of a respective plurality of dual body rocker arms of a valve train assembly of an internal combustion engine includes: a first shaft comprising one or more first selector cam for controlling the latching arrangements of a first group of one or more of the dual body rocker arms; and a second shaft comprising one or more second selector cams for controlling the latching arrangements of a second group of one or more of the dual body rocker arms. At least a portion of the first shaft is received in the second shaft, and the first shaft and the second shaft are controllable to rotate independently of one another, thereby to allow control of the latching arrangements of the dual body rocker arms on a per group basis.