A continuously variable valve duration apparatus may include: a camshaft; a cam unit on which a cam is formed, and the camshaft inserted to the cam; an inner wheel for transmitting rotation of the camshaft to the cam unit; a wheel housing into which the inner wheel is rotatably inserted and movable perpendicular to the camshaft; a guide shaft on which a guide screw thread is formed and disposed perpendicular to the camshaft; a worm wheel formed with an inner screw thread for engaging with the guide screw thread, and the worm wheel disposed within the wheel housing; and a control shaft on which a control worm for engaging with the worm wheel is formed.

A continuous variable valve duration apparatus may include a camshaft, a plurality of wheels mounted to the camshaft, of which a wheel key is formed thereto respectively, a plurality of cam portions of which a cam and a cam key are formed thereto respectively, of which the camshaft is inserted thereto, of which relative phase angle with respect to the camshaft is variable, a plurality of inner brackets connected with the each wheel key and the each cam key, a plurality of a slider housings of which the each inner bracket is rotatably inserted thereto respectively, and rotatably configured around a hinge hole formed a side of a cam cap and a control portion selectively moving the slider housings to change relative position of a rotation center of the inner brackets.

A variable system of an internal combustion engine spaces a closing timing IVC of an intake valve apart from an intake bottom dead center BDC by a variable actuation valve mechanism and also increases a mechanical expansion ratio E by a variable compression ratio mechanism when an engine torque increases to around a maximum engine torque. The variable system sets the closing timing IVC of the intake valve to a closing timing IVCd spaced apart from the intake bottom dead center BDC around the maximum engine torque. Due to this control, the variable system can reduce an effective compression ratio to enhance a knocking resistance capability, and, further, achieve improvement of thermal efficiency and also reduce a temperature of exhaust gas to prevent or reduce thermal damage on an exhaust-system component by increasing the mechanical expansion ratio.

A continuous variable valve duration apparatus may include: a camshaft; a cam unit on which a cam is formed, and the camshaft inserted to the cam; an inner wheel for transmitting rotation of the camshaft to the cam unit; a wheel housing into which the inner wheel is rotatably inserted and movable perpendicular to the camshaft; a guide shaft on which a guide screw thread is formed and disposed perpendicular to the camshaft; a worm wheel formed with an inner screw thread for engaging with the guide screw thread, and the worm wheel disposed within the wheel housing; and a control shaft on which a control worm for engaging with the worm wheel is formed.

A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing in which the first and the second inner brackets are rotatably inserted; first and second guiding portions formed on the slider housing; a control shaft parallel to the camshaft; a control rod eccentrically formed on the control shaft; a positioning protrusion connected to the control shaft; a guide head on which a head guiding portion and a head hole are formed; a cam cap supporting rotations of the first and the second cam portions and guiding movement of the slider housing, a control portion selectively rotating the control shaft; and a stopper unit limiting movement of the positioning protrusion.

A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing in which the first and the second inner brackets are rotatably inserted; first and second guiding portions formed on the slider housing; a cam cap on which a cam cap guide contacting the second guiding portion is formed; a control shaft parallel to the camshaft; a control rod eccentrically formed on the control shaft; a guide head on which a head guiding portion and a head hole are formed; a control portion selectively rotating the control shaft; and a stopper limiting movement of the guide head. The head guiding portion is connected to the first guiding portion, and the control rod is inserted into the head hole.

A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing in which the first and the second inner brackets are rotatably inserted; first and second guiding portions formed on the slider housing; a control shaft parallel to the camshaft; a control rod eccentrically formed on the control shaft; a guide head on which a head guiding portion and a head hole are formed; a cam cap supporting the control shaft; a cam cap guiding portion mounted to the cam cap; and a control portion selectively rotating the control shaft such that the slider housing is moved along the cam cap guiding portion.

A continuous variable valve duration apparatus may include a camshaft, a cam unit on which a cam is formed, of which the camshaft is inserted thereto and of which a relative phase angle with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the cam unit, a wheel housing in which the inner bracket is rotatably inserted, on which a guide groove parallel to the camshaft is formed, and on which a guide hole vertical to the camshaft is formed, a guide portion including a guide shaft inserted into the guide hole for guiding movement of the wheel housing and a control portion including a control shaft disposed parallel to the camshaft and inserted into the guide groove, and the control portion selectively rotating the control shaft for the relative position of the wheel housing with respect to the camshaft to be changed.

A device for adjusting a camshaft of an internal combustion engine, comprising a lifting profile assembly (10) which is provided in a rotationally fixed manner on or at an axially movably mounted camshaft, and which forms a control groove (12), having a groove depth that varies along a direction of rotation, and comprising actuating means (FIG. 4) which are designed to cause an axial movement by controlled engaging in the control groove, and which have an electromagnetically drivable tappet unit (P1, P2), wherein the tappet unit cooperates with the control groove in such a way that, when rotating, same can exert a reset- or driver effect on the tappet unit in a predetermined groove section, characterized in that the tappet unit has at least two neighbouring and preferably axially parallel individual tappets (P1, P2), said tappets being independently drivable, the control groove, designed to engage using a first of the individual tappets (P2), forms a radially peripheral wall at least along a peripheral groove side in such a way that a neighbouring second of the individual tappets (P1) is positioned outside the control groove during rotation, and outside the control groove (12), and the lifting profile assembly is provided with a radially height-variable and/or ramp section (20) for cooperating with the second individual tappet, in such a way that a resetting and/or driving of the second individual tappet (P1) is caused when the first individual tappet (P2) is reset or driven against a tappet drive direction using the control groove.

A control method using a continuous variable valve duration apparatus implements a continuous variable valve duration apparatus which includes a wheel mounted on a camshaft and having a wheel key so as to control duration of an intake valve of an engine, a cam unit having a cam and a cam key, adapted such that the camshaft is inserted thereinto, and being disposed so as to vary relative phase of the cam with respect to the camshaft, an inner bracket connected with the wheel key and the cam key, a slider housing being adapted such that the inner bracket is rotatably inserted thereinto and disposed so as to move vertically with respect to the engine, a controller varying a position of the slider housing so as to adjust rotation center of the inner bracket, and a guide unit guiding motion of the sliding housing. The control method includes calculating a required air amount for maintaining idle rotation speed of the engine by the controller when the engine is an idle state; mapping a supplied air amount in accordance with duration of the intake valve or the exhaust valve by the controller; setting a target valve duration for supplying the required air amount of the engine by the controller; and controlling duration of the intake valve or exhaust valve according to the set target valve duration by the controller.