Piezoelectric valve

1. A motorized valve, comprising

a hollow case having at least one input tube and at least one output tube;

a saddle connected with said hollow case;

a turn plug having a rod, wherein said turn plug cooperates with said saddle;

a piezoelectric motor, said piezoelectric motor including a piezoelectric generator of radially directed standing acoustic waves, which is fixedly connected with said hollow case and is connectable with a pulse current source, and a rotor operatively connected with said piezoelectric generator and kinematically connected with said rod of said turn plug so as to turn said turn plug when said rotor is actuated by said piezoelectric generator, wherein the length of said kinematic connection between said rotor and said rod is reduced, resulting in said motorized valve having a smaller size and mass and a reduced activation time, and an increased accuracy in angular positioning of said turn plug relative to said saddle;

a control system including a generator of a cycle frequency, a pulse amplifier-interrupter connectable to the pulse current source, to a control output of said generator of the cycle frequency, and to an electric input of said piezoelectric generator;

and a former of modes of operation connected to additional control inputs of said pulse amplifier-interrupter and also connected through a feedback chain to an output of said at least one sensor so as to provide modes consisting of a “start-stop” mode for opening and closing of the valve, and a pseudo-continuous “step-by-step” mode for accurate regulation of a flow rate of a flowing medium which flows through the valve;

wherein the generator provides mechanical oscillations of up to about 1 MHz in the form of radially standing acoustic waves during a transition period between the open and closed positions of said valve, the transition period lasting for not more than 0.5 seconds.

2. A motorized valve as defined in claim 1 , wherein said piezoelectric generator is configured as a ring-shaped piezoelectric generator.

3. A motorized valve as defined in claim 1 ; and further comprising a wave shell which is acoustically tightly connected with said piezoelectric generator and provided with at least one resilient ratchet pusher, said rotor being in a frictional contact with said at least one resilient ratchet pusher, and wherein said wave shell pulsates radially in the same cycle with said acoustic waves of said piezoelectric generator.

4. A motorized valve as defined in claim 3 , wherein said wave shell has a second such resilient ratchet pusher, said pushers being located at substantially equal angular distances from one another.

5. A motorized valve as defined in claim 4 , wherein said pushers provide transmission of torque from said wave shell.

6. A motorized valve as defined in claim 4 , wherein said pushers brake said turn plug during each interruption of operation of said pulse current source.

7. A motorized valve as defined in claim 3 , wherein said wave shell has a shape of a ring-shaped casing and acoustically tightly embraces said piezoelectric generator over its side surface, wherein said at least one resilient ratchet pusher is connected to an external cylindrical surface of said ring-shaped casing.

8. A motorized valve as defined in claim 1 , wherein said rotor is provided with at least one marker of an angular position, while said hollow case is provided with at least one sensor cooperating with said at least one marker.

9. A motorized valve as defined in claim 8 , wherein each of said markers comprises a permanent magnet, while each of said sensors comprises a magneto-electric converter.

10. A motorized valve as defined in claim 1 , further providing torques up to about 100 Nm.

11. A motorized valve as defined in claim 1 , wherein said generator of a cycle frequency is selected within the interval of about 100 KHz to about 1.0 MHz.