| 摘要 |
<p>A solenoid valve for an irrigation control unit comprises a cut-off element (7) movable inside a respective seat (25, 26) between a closed position and an open position; the cut-off element (7) defines inside the seat (25, 26) a chamber (26) in constant communication with the inlet (2) of the solenoid valve, so that the pressure exerted on the cut-off element (7) by the water present at the inlet of the solenoid valve is balanced by the pressure exerted on the cut-off element (7) by the water present in the chamber (26), the cut-off element (7) is provided with a passing conduit (12) that can be opened so that the chamber (26) can be put in communication with the outlet (3) of the solenoid valve so that, since the pressure exerted on the cut-off element (7) by the water present at the inlet of the solenoid valve is no longer balanced by the pressure exerted on the cut-off element (7) by the water present in the chamber (26), the cut-off element (7) is displaced by the thrust of the water present at the inlet of the solenoid valve in said open position; the solenoid valve also comprises a bistable electromagnetic device (14-22) comprising an electromagnetically-operated valve suitable for determining alternatively the closing and the opening of said passing conduit (12) as a result of the generation of an electrical control impulse and up to the generation of an opposite electrical impulse. <IMAGE></p> |
