Abstract: A variable valve timing apparatus rotatably receives a rotor in a housing. The rotor can rotate within a predetermined angular range. In some cases, the rotor is locked by a lock pin at an intermediate position within the angular range. In this manner, it is possible to realize a suitable valve timing even when an engine is restarted after it is stopped. In some case, the rotor is prevented from moving to the largest delay angle position by a restricting pin. In this manner, it is possible to prevent the rotor from reaching the largest delay angle position before the engine is stopped. On the other hand, while the engine is operated, it is possible to rotate the rotor to the largest delay angle position and to realize a valve timing responsive to the state of operation.

Abstract: A valve operating device for an internal combustion engine enabling both valve timing and valve lift characteristic to be varied depending on engine operating conditions includes intake and exhaust camshafts, an eccentric cam fixed to a first one of the intake and exhaust camshafts so that an axis of the eccentric cam is eccentric to an axis of the first camshaft. A rockable cam is supported on the first camshaft so that the rockable cam rotates or oscillates about the axis of the first camshaft. A rocker arm is oscillatingly supported on an outer periphery of the eccentric cam so that a center of an oscillating motion of the rocker arm revolves around the axis of the first camshaft. Also provided is a control shaft variably controlling the center of the oscillating motion of the rocker arm.

Abstract: A desmodromic drive (30) for imparting reciprocal translation to a valve (32) has a cam ring (52) that rotates about an axis (42), a follower (50) that reciprocates with axial motion as the ring rotates, an endless cam track (69) on the ring, and rollers (76, 78) on the follower that ride along the cam track as the ring rotates. A follower guide (48) guides the follower for axial. Rollers (60, 62) constrain the follower against rotation on the follower guide.

Abstract: A process for operating an electromagnetic actuator is provided, in particular to actuate a gas exchange lift valve of an internal combustion engine, with an armature, which is moved oscillatingly between two electromagnetic coils against the force of at least one return spring via an alternating supply of current to the electromagnetic coils. Whereby, during the so-called catch process as the armature approaches the coil that is subjected first to a current flow, the voltage applied to the coil catching the armature is reduced. To avoid unnecessary losses, a voltage curve is chosen with which an eddy current, calculated with a mathematical model, is minimized in the armature.

Abstract: A variable valve operating system of an internal combustion engine comprises a first variable mechanism 1 capable of variably controlling a lift characteristic of an intake valve 12, and a second variable mechanism 2 capable of variably controlling a valve-open and/or valve-close timing characteristic of the intake valve. The first variable mechanism varies an oscillating position of an oscillating cam 17 via a transmission mechanism 18 by controlling a rotational position of a control shaft 32 by an electric motor 34. On the other hand, the second variable mechanism is constructed to change a phase by axially moving a ring gear 43 by way of hydraulic-pressure supply or release to and from first and second hydraulic pressure chambers 49 and 50 so as to produce relative rotation between a timing sprocket 40 and a drive shaft 13. At the initial state of engine starting, the system operates to drive only the first variable mechanism.

Abstract: The invention proposes a lever-type cam follower (1) which, for mounting a pin (7) for a cam roller, comprises bores (5, 6) in the region of its side walls (2, 3). The diameter of the bore (5) is larger than the diameter of the bore (6). Corresponding ends (8, 9) of the pin (7) are configured so that when mounted, the pin (7) is fixed in the bores (5, 6) by a press fit. Thus, the pin (7) can be inserted with its second end (8) at first through the larger bore (5) without causing damage to its raceway (8a) during assembly. At the same time, the press fit guarantees an excellent fixture of the pin (7) in the cam follower (1) with an all-round contact.