초록 ▼

A solenoid valve, particularly of the type to be used for controlling a hydraulic system for variable actuation of the valves of an internal-combustion engine, has a valve element co-operating with a valve seat and a pusher element, separate from the valve element, which is pushed against the valve

A solenoid valve, particularly of the type to be used for controlling a hydraulic system for variable actuation of the valves of an internal-combustion engine, has a valve element co-operating with a valve seat and a pusher element, separate from the valve element, which is pushed against the valve element by the movable core of the solenoid valve when the solenoid of the solenoid valve is energized in order to bring the valve element into contact with the valve seat. After de-energization of the solenoid, the time necessary for bringing back the pusher element into the resting condition in contact with the valve element is reduced thanks to the application of a braking current to the solenoid of the solenoid valve during the stage in which the movable core and the pusher element associated thereto displace in the direction opposite to the direction of the movement generated by the magnetic field of the solenoid, following upon de-energization of the solenoid valve.

대표청구항 ▼

What is claimed is: 1. A system for controlling a solenoid valve, in which the solenoid valve comprises:a valve seat;a valve element normally kept by first spring means in a condition set at a distance from the valve seat, corresponding to an open condition of the solenoid valve, against a stop elem

What is claimed is: 1. A system for controlling a solenoid valve, in which the solenoid valve comprises:a valve seat;a valve element normally kept by first spring means in a condition set at a distance from the valve seat, corresponding to an open condition of the solenoid valve, against a stop element;a solenoid, which can be activated for pushing a movable core and a pusher element associated thereto against said valve element in order to bring it, against the action of said first spring means, into a condition of contact with said valve seat, corresponding to a closed condition of the solenoid valve; andsecond spring means for normally holding the movable core and the pusher element associated thereto in the position corresponding to contact of the pusher element with said valve element; andin which said system further comprises electronic means for controlling supply of said solenoid,said system being characterized in that said electronic means are programmed for supplying a braking current to the solenoid following upon de-energization of the solenoid, which causes passage of the solenoid valve from its closed condition to its open condition, and for interrupting said braking current before another energization of the solenoid, which causes passage of the solenoid valve from its open condition to its closed condition, in order to brake the movement of the movable core and of the pusher element following upon said de-energization so as to reduce the time required for bringing the pusher element back into contact with the valve element after said de-energization.