A valve opening and closing apparatus is disclosed having one or a plurality of rocker arms in contact with the cam, such that each of the rocker arms causes a valve to be opened and closed using the rotation of a cam. An eccentricity-creating unit is disposed on the rocker arm, and changes an eccentric position using rotation of a rotary shaft extending through the plurality of rocker arms. A driving unit is connected to the rotary shaft of the eccentricity-creating unit to rotate the rotary shaft.

A valve opening and closing apparatus includes a rocker arm which is in contact with a cam and causes a valve to be opened and closed using rotation of the cam. In particular, the valve opening and closing apparatus includes an eccentricity-creating unit which is disposed on the rocker arm and changes an eccentric position using rotation. A contact-maintaining unit of the valve opening and closing apparatus is disposed between the rocker arm and the eccentricity-creating unit so as to maintain the contact between the cam and the rocker arm when the cam is rotating.

A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively, to which the camshaft is inserted and of which relative phase angles with respect to the camshaft are variable; first and second inner brackets transmitting rotation of the camshaft to the first and second cam portions respectively; a slider housing unit in which the first and second inner brackets are rotatably inserted and of which a relative positions with respect to the camshaft is variable; a control shaft parallel to the camshaft; a control rod eccentrically formed on the control shaft; a lifter on which a lifter hole and a rotation hole are formed; and a control portion selectively rotating the control shaft so as to controlling a position of the slider housing unit.

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, a first and second cam portions on which a cam is formed respectively, of which the camshaft is inserted thereto and of which relative phase angles with respect to the camshaft are variable, a 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 second inner brackets are rotatably inserted, of which a relative position with respect to the camshaft is variable, and on which a control slot is formed, a cam cap rotatably supporting the first and the second cam portions and to which the slider housing is slidably mounted, a control shaft parallel to the camshaft and on which a control rod is eccentrically formed, an eccentric plate rotatably connected to the control rod and rotatably inserted into the control slot, a separation prevention pin disposed to inhibit the eccentric plate from being separated from the slider housing and a control portion selectively rotating the control shaft so as to controlling a position of the slider housing.

A continuous variable valve duration apparatus may include: a camshaft; first and second cam portions on which a cam is formed respectively, to which the camshaft is inserted and of which relative phase angles with respect to the camshaft are variable; 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 second inner brackets are rotatably inserted, and on which a control slot is formed; a cam cap rotatably supporting the first and the second cam portions and to which the slider housing is slidably mounted; a control shaft which is parallel to the camshaft and on which a control rod is eccentrically formed; an eccentric plate rotatably connected to the control rod and rotatably inserted into the control slot; and a control portion selectively rotating the control shaft.

A continuous variable valve duration system may include a camshaft, a first cam portion including a first cam, of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing on which a control slot is formed, the slider housing being rotatable around a pivot shaft, a first rocker arm including a first end contacting the first cam and a second end connected to a first valve, a rocker shaft to which the first rocker arm is rotatably connected, and onto which an eccentric shaft inserted into the control slot is formed, a duration controller configured to rotate the rocker shaft for the slider housing to move with respect to the camshaft, and an operation mode controller configured to change a position of the pivot shaft.

A variable valve duration system may include a camshaft, a first cam portion including a first cam, into which the camshaft is inserted and of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing into which the inner bracket is rotatably inserted, a first rocker arm having a first end contacting the first cam and a second end connected to a first valve, a rocker shaft to which the first rocker arm is rotatably connected, a solenoid valve to selectively supply hydraulic pressure, and a position controller to selectively change a position of the slider housing according to the selective supplying of the hydraulic pressure from the solenoid valve.

A variable valve duration/variable valve lift system may include a camshaft, a first cam portion including a first cam, into which the camshaft is inserted and of which a relative phase angle of the first cam with respect to the camshaft is variable, an inner bracket transmitting rotation of the camshaft to the first cam portion, a slider housing into which the inner bracket is rotatably inserted, a first rocker arm having a first end contacting the first cam, a rocker shaft to which the first rocker arm is rotatably connected, a solenoid valve configured to selectively supply hydraulic pressure, a position controller configured to selectively change a position of the slider housing, a first bridge connected to a second end of the first rocker arm and to which a first valve is connected, and a valve lift disposed within the first bridge.

A control method using a continuous variable valve duration apparatus may use a continuous variable valve duration apparatus including a wheel being mounted on a camshaft and having a wheel key to control duration of an intake valve of an engine, a cam device having a cam and a cam key, being adapted that the camshaft is inserted thereinto, and being disposed to can vary relative phase of the cam with respect to the camshaft, an inner bracket being connected with the wheel key and the cam key, a slider housing being adapted that the inner bracket is rotatably inserted thereinto and being disposed to can move vertically with respect to the engine, a controller varying a position of the slider housing to adjust rotation center of the inner bracket, and guide device guiding motion of the sliding housing.