摘要 |
The valve is arranged to control the pressure of a hydraulic fluid by discharging a proportion of its flow, and comprises a mobile valve element arranged to control the opening of a discharge port of a first chamber and kept normally closed by the action of a spring, a piston element rigid with said valve element and arranged to define a second chamber which is in hydraulic communication with the first by way of a first bore of predetermined size, and a third chamber in hydraulic communication both with the preceding by way of a second bore also of predetermined size, and with the discharge outlet by way of a discharge port the opening of which is controlled by an interception member operated by an electromagnet; the pressure of said fluid is controlled by varying the discharge port controlled by said interception member and consequently the rate of a flow of control fluid passing through said first bore, second chamber, second bore and third chamber. |