| 摘要 |
A proportional valve (10) is described that is configured to be used inside a fluid-treatment machine, comprising a main body (12) provided with a first connection element (14) to the hydraulic circuit of the machine, configured for entering a fluid into the proportional valve (10), and with a second connection element (16) to the hydraulic circuit of the machine, configured for the ejection of the fluid from the proportional valve (10). Inside of the main body (12) there are at least an inlet duct (18) of the fluid, operatively connected to the first connection element (14), and at least one outlet duct (20) of the fluid, operatively connected both to the inlet duct (18), and to the second connection element (16). Inside of the main body (12), in an inner chamber (22) forming the intersection point between the inlet duct (18) and the outlet duct (20), there being further inserted an actuation piston (24), movable according to reciprocating motion, which is capable of selectively putting in communication the inlet duct (18) with the outlet duct (20). The actuation piston (24) is operatively connected to an actuation mechanism that comprises at least one elastic actuation member (30) made of a shape-memory alloy and an electric current generating device (32), operatively connected to the elastic actuation member (30) in order to modify, in a progressive and modulable manner, the value of the elastic force applied on the actuation piston (24) through a temperature variation caused by the passage of electric current inside the elastic actuation member (30). |
