METHOD AND APPARATUS FOR CONTROLLING A HIGH-PRESSURE VALVE
A system and a method are described for converting a small motion from a piezoelectric actuator to a larger motion in a valve mechanism. A piezoelectric actuator is connected in series to a mechanical amplifier, and, optionally, a mechanical temperature compensation element and a mechanical fine tuning element, all acting in the same effective direction as the piezoelectric actuator.
1 . An actuator-controlled high pressure valve having a valve inlet and a valve outlet, comprising:
a piezoelectric actuator;
a mechanical amplification element; and
a valve mechanism acting on a valve seat;
wherein the actuator, the mechanical amplifier element, and the valve mechanism are arranged along a common axis, wherein the actuator is arranged to generate a motion for controlling the valve mechanism, and the mechanical amplifier element is arranged to amplify the motion of the actuator to a closing or opening motion of the valve mechanism.
2 . The high pressure valve of claim 1 , wherein the valve is arranged in a tube with a valve inlet and a valve outlet.
3 . The high pressure valve of claim 1 , wherein a first flow resistance element is arranged between the valve seat and the valve outlet.
4 . The high pressure valve of claim 3 , wherein a differential pressure gauge is connected upstream and downstream of the flow resistance element respectively.
5 . The high pressure valve of claim 3 , wherein a second flow resistance element is arranged downstream of the first flow resistance element.
6 . The high pressure valve of claim 3 , wherein the first flow resistance element has a shape of a cylindrical tube or a cone.
7 . The high pressure valve of claim 3 , wherein a flow channel downstream of the outside of the first flow resistance element decreases in width.
8 . The high pressure valve of claim 1 , wherein a thermal expansion element is connected in series to the actuator.
9 . The high pressure valve of claim 1 , wherein at least one mechanical fine tuning element is connected in series to the actuator.
10 . The high pressure valve of claim 1 , wherein two seals are arranged between the actuator and the mechanical amplification element, and wherein a ventilation channel is arranged between the two seals.
11 . A method for controlling a high pressure valve where all included components are connected in series along a common axis, said method comprising the valve being controlled by a piezoelectric actuator with a stroke length which is amplified by a mechanical amplifier element to a valve mechanism acting on a valve seat, and wherein said method comprises generating a motion with the actuator, transmitting the motion to the mechanical amplifier element, and controlling the valve mechanism with the amplified motion to a closing or opening motion in the valve mechanism.
12 . The method of claim 11 , further comprising fine tuning the valve with a mechanical fine tuning element.
13 . The method of claim 11 , further comprising temperature compensating the motion with a thermal expansion element.