Abstract:
A combination of a cylinder valve of an internal-combustion engine with an electromagnetic assembly for operating the valve. The electromagnetic assembly includes an electromagnetic actuator having first and second electromagnets supported in a spaced relationship with respect to one another, an armature movable between the first and second electromagnets and connected to the valve for moving it between open and closed positions. The electromagnetic assembly further includes a first control device for energizing the electromagnets to cause a motion of the valve by electromagnetic forces generated by the first and second electromagnets; and first and second pressurizable resetting gas springs operatively coupled to the armature to oppose motions thereof caused by the electromagnetic forces generated by the first and second electromagnets, respectively. A pressure supply device supplies pressure to the first and second resetting gas springs. A second control device controls the pressure supplied to the first and second resetting gas springs.
Abstract:
A method is provided for reducing an impact speed of an armature on a pole face of an electromagnet in an electro-magnetic actuator, in which the armature moves toward the pole face against a restoring spring force when the coil of the electromagnet is charged with current. The method includes limiting a voltage applied to the coil to a predeterminable maximum value as the armature approaches the pole face so that a current flowing through the coil drops for a portion of the time of the voltage limitation.
Abstract:
An electromagnetic actuator, particularly for operating a cylinder valve of an internal-combustion engine, includes an electromagnet for generating an attracting electromagnetic force; an armature movable into contact with and away from the electromagnet; a spring arrangement connected to the armature and opposing the electromagnetic force; and a sound muffling device attached to the electromagnet for reducing sound transmission by body vibration from the electromagnet.
Abstract:
An electromagnetic actuator operating a cylinder valve of an internal-combustion engine includes first and second spaced electromagnets having pole faces oriented toward one another; an armature arranged for reciprocating motion between the pole faces; and a connecting rod having a first rod part being in an abutting contact with a first side of the armature and being a component separate therefrom. The abutting contact is such as to prevent a torque transmission between the first rod part and the armature. The connecting rod has a second rod part which is rigidly affixed to a second side of the armature and extending towards the cylinder valve. There are further provided a first spring situated adjacent the first electromagnet externally thereof and arranged for urging the first rod part into the abutting contact with the armature for urging the armature away from the first pole face towards the second pole face; and a second spring situated adjacent the second electromagnet externally thereof and arranged for urging the armature away from the second pole face towards the first pole face. The first and second springs act oppositely such that in a de-energized state of the first and second electromagnets the armature is held by the first and second springs in an intermediate position between the pole faces of the first and second electromagnets.
Abstract:
An adjustment device for a cam-controlled valve operation in a piston-type internal combustion engine includes a camshaft adapted for actuating intake or exhaust valves of the piston-type internal combustion engine. The camshaft has a camshaft axis and includes an end having a guide surface. A transmission element constituting a magnetic armature is arranged for being moved back and forth in a direction of the camshaft axis. The transmission element includes an inner guide element opposite from and corresponding to the guide surface and a carrier element at a radial distance from the inner guide element that meshes with a corresponding carrier surface on a drive wheel, and is positioned for being twisted coaxially and relative to the camshaft. At least one of the guide surface on the camshaft and the carrier surface on the drive wheel is aligned in a helical shape relative to the camshaft axis. A stationary, switchable magnet has a pole surface facing the transmission element and presents a magnetic force that attracts the transmission element toward the pole surface when the magnet is switched on. A restoring mechanism is arranged along the camshaft and presents a force urging the transmission element away from the pole surface. A limit stop is disposed on the camshaft for holding the transmission element at a short distance from the pole surface of the magnet and counter to the force of the restoring means when the magnet is switched on.
Abstract:
A four-stroke Otto engine. At least two intake valves of the engine have an open position and a closed position, and include a main intake valve and an additional intake valve. A camshaft moves the main intake valve into its open position and into its closed position, and a transmission element transmits a motion of the camshaft to the main intake valve. The transmission element includes a cutoff apparatus actuatable independently of the camshaft for cutting off a transmission of the actuation of the camshaft to the main intake valve for keeping the main intake valve in its closed position in a lower partial load and rpm range of the engine. An operating apparatus connected to the additional intake valve actuates the additional intake valve independently of the actuation of the main intake valve for moving the additional intake valve into its open position in a lower partial load and rpm range of the engine and into its closed position in an upper partial load and rpm range of the engine. The operating apparatus further adjusts at least one of a valve stroke of the additional intake valve, a valve opening time of the additional intake valve and a valve closing time of the additional intake valve as a function of engine load. An intake control device controls the cutoff apparatus and the operating apparatus.