DE102006048841A1 - Rapid action valve opening mechanism has a piezo actuator holding the operating component in a friction grip which, when released, allows a spring to move it and open the valve - Google Patents

Abstract

The rapid action mechanism to open a valve (1) has a spring (3) and an operating component (4) moving between two working positions. The operating component is held in the first position by the tension (F1) of at least one piezo actuator (8) in a friction grip (11). When the grip is released, the spring moves the component into the second position to open the valve.

Description

The The invention relates to a fast-switching release mechanism for a means an energy storage biased and from a first operating position convertible to a second operating position actuator according to the preamble of claim 1. The invention further relates a valve with such a triggering mechanism and a method for using the same.

Fast switching Triggering mechanisms of The genus described above has long been known.

So is out of the DE 30 01 606 A1 a device for emergency actuation of a valve by means of a force accumulator known. In essence, it is proposed that the locking of the energy accumulator, preferably a force storage spring, in the tensioned state by a locking member of a mechanical locking device is effected, which prevents in its locked position, an action of the force accumulator on a valve rod of the valve. In particular, it is proposed that the locking device of the energy accumulator consists of a rotatable under the action of a triggering angle lever which engages with a latch or pawl in an incision of a locking disc which is provided on the valve rod or on a locking sleeve. Certainly, satisfactory emergency actuations of a valve are permitted with this pertinent solution. Regardless, such emergency operation for certain applications is still considered too slow or too cumbersome.

From the DE 38 35 788 C2 Further, a fast-switching ball valve is known, with a two spaces of different pressure separating partition, provided in the partition valve opening whose edge forms a valve seat, serving as a valve body for closing the valve opening ball, and one by an electromagnet in the direction of the Ball transversely to the valve seat drivable actuator. The ball valve is characterized essentially by the fact that upon energization of the electromagnet on the ball, releasing the valve opening, a rolling motion is applied and the backward movement of the ball takes place solely by a passing through the valve opening fluid flow. It is disadvantageous in such a valve to emphasize that the solenoid used no longer fully meets today's requirements for speed and also an undefined closing of the valve is recorded. Finally, this valve is not or only partially used in environments with high electrical and / or magnetic field strength.

Furthermore, with the DE 197 34 845 C1 and the DE 1958 00 257 C1 discloses some of the aforementioned similarly stored solutions, wherein now an actuator in the form of a piezoelectric body is used to achieve high switching times instead of an actuatable with an electromagnet actuating means. The actuation of the valve or the ball takes place directly through said piezoelectric body, which may be a piezo stack. The piezoelectric body or piezo stack allows only very small strokes, whereby only relatively small opening cross-sections served and accordingly relatively small volume flows can be realized. Furthermore, it should be emphasized that a piezoactuator can only do relatively little work per se.

From the DE 37 13 697 A1 Furthermore, a so-called electrically operated, ultra-fast valve with a drive of stacked piezoelectric elements is known to achieve relatively large strokes. Essentially, in the case of the area of the stackable top surface of the piezoelectric elements to the piston surface of a valve stem and a hydraulic space arranged between these elements, an increase of a stroke which can be achieved conventionally by means of piezo stacking is to be achieved. This relatively complicated and complicated solution for actuating a valve is also based on a largely direct actuation of the valve by said piezo stack on the hydraulic chamber in the sense of an energy storage, ie, the energy for opening or closing is provided directly from the piezoelectric actuators.

Finally, out of the EP 1 060 338 B1 a piezoelectric valve with high response known with a piezoelectrically actuated leaf spring as a closure means for the opening of a valve, both ends of the leaf spring attack piezoelectric stack, which in turn are suitable for appropriate control, the leaf spring from a closed position to an open position convict.

Also Here, the piezo stack attacks directly on the closure means and must be in proportion size Accomplish strokes. This is where the invention described below begins.

task The invention is a fast-switching trigger mechanism to create, in turn, with minimal technical effort size to be realized strokes permitted with short switching times. It is also the task of Invention to provide a valve with such a trigger mechanism as well to specify a method of using the same.

Based on a fast-switching trigger mechanism for one by means of an energy Memory biased and from a first operating position into a second operating position operable actuator, wherein the actuating element against the acting biasing force "F ₁ " of at least one actuator in the first operating position fixed but releasably held, the object is first achieved in that the at least an actuator is formed by a Piezoaktuatorik.

Though Are biased by energy storage actuators and piezo actuators, the in turn, directly on the actuating means in the sense of the transfer of the same operate from one operating position to another, each known for themselves, however it has remained unknown, biased by means of energy storage actuating means As well as to combine piezoactuators such that a fast-switching Aulösemechanismus is created, which easily and inexpensively large strokes with short switching times combined.

The Piezoaktuatorik can in this case both by a single piezoelectric element as well as being formed by a piezo element stack.

According to one particularly advantageous first embodiment of the invention is actuator by means of the at least one piezoelectric actuator by friction between the preloaded actuator and at least one attacking and by the Piezoaktuatorik transversely to the potential direction of movement of the actuating element kraftbeaufschlagten Friction held in the first operating position.

It is further provided that the clamping force "F ₂ " generated as a result of frictional engagement between the preloaded actuating element and the at least one friction element is preferably selected to be equal to or greater than the axial preloading force "F ₁ " acting on the actuating element.

In inventive training is further proposed that the actuator a Pull or push rod has, which in turn has a Friction section has, whose outer circumferential surface a first friction surface forms, at which the friction element of the Piezoaktuatorik with a for first friction surface corresponding second friction surface transverse to the potential direction of movement of the actuating element attacks.

in this connection can according to a first advantageous embodiment two or more Piezoaktuatoriken evenly over the circumference of the pull or push rod be distributed and attack at the same.

As well can according to a second advantageous embodiment also two or more piezo actuators in series and one behind the other be arranged axially parallel to the pull or push rod and at the same attack.

As the invention further provides, the actuator can be a train or Push rod, consisting of two or more coaxial one behind the other arranged separate rod sections, wherein the respective aligned section ends of the bar sections interlocking friction lamellar structures have, in turn, form a common disk set and, Achieving a frictional connection, by means of at least one Piezoaktuatorik, preferably by means of both sides of the disk set in a common Opposite working plane arranged piezo actuators transverse to the potential direction of movement of the actuating element are kraftbeaufschlagbar.

in this respect can the respective Piezoaktuatorik via a friction element or directly attack on the top layer of the disk pack.

In be advantageous for the friction partners materials with a high static friction and a chosen low sliding friction coefficient, wherein at least one friction partner may be formed of a ceramic material.

According to one Another advantageous embodiment of the invention is also proposed that the actuator instead of by frictional engagement by means of the at least one Piezoaktuatorik Positive connection between the actuator and at least one of the same engaging in a positive connection recording Positive locking element of the piezoelectric actuator in the first operating position is held.

What As far as the energy store is concerned, it can be replaced by one or more prestressed spring elements, by a pressurized fluid or Gas or by any other suitable known per se energy storage be formed.

henceforth It is envisaged that the Piezoaktuatorik of an electronic Relay is controlled.

The Invention is further characterized by a valve with a fast-switching trigger mechanism of the type described above.

The valve can be designed both fast opening and fast closing and is particularly suitable for use under conditions of high electrical and / or magnetic field strength, for example as Gaseinblasventil to Clearing plasma in fusion reactors.

The with the triggering mechanism according to the invention achieved advantages exist with respect to the prior art essentially in that with very compact design of the trigger mechanism an opening or Close For example, a valve in a very short time, typically ≤ 1 ms after switching signal, with relatively large Strokes respectively Stellwege and with a release or a closure of large flow cross sections and accordingly large mass or volume flows is allowed. Already with relatively little mechanical work, which can perform a piezoelectric actuator, large holding forces can be realized, the in turn, a biased actuator hold in a first operating position to release it when needed. An inventively equipped Valve can be for both Gases as well Liquids, which may be subjected to high pressure, find use. in the Difference to electrodynamically operated valves, such as solenoid valves, is the use of the triggering mechanism in question under conditions strong magnetic fields possible. Thus, already the proof of the functionality of a corresponding equipped valve with piezo actuators up to 7 Tesla magnetic flux density provided.

The The invention will be described below with reference to the drawings illustrated embodiments explained in more detail. It demonstrate:

1 the longitudinal section of a valve equipped with a fast-switching release mechanism in a first operating position (initial position or idle state),

2 the section AA after 1 .

3 the valve after 1 designed as a quick-opening valve,

4 the valve after 1 designed as a fast-closing valve,

5 a special development of the valve after the 1 to 4 , and

6 a circuit arrangement for driving the Piezoaktuatorik the fast-switching release mechanism according to the 1 to 5 ,

After that shows 1 a fast-acting release mechanism on a preferred application example in the form of a valve 1 with a valve housing 2 in which one is by means of an energy storage 3 biased and convertible from a first operating position to a second operating position actuator 4 supported, wherein the actuating element 4 against the acting biasing force "F ₁ " of at least one actuator in the first operating position firmly held but releasably.

The valve 1 is suitable for a flow of a fluid or gas 5 of any kind to release or shut off.

In the present case is the energy storage 3 formed by one or more prestressed spring elements, for example by one or more coil springs, a spring assembly of a plurality of disc springs or the like. More.

In contrast, the energy storage 3 also be formed by a pressurized fluid or gas or any other, for example purely mechanical energy storage (not shown in detail).

The actuator 4 of the valve 1 is in this case by a loaded with the biasing force "F ₁ " pull rod 4a with valve plate 4b formed, which in turn is suitable, in the region of a valve seat 6 a valve opening 7 close tightly.

In the 1 and 3 is initially a fast-opening valve 1 shown, its actuator 4 respectively drawbar 4a with valve plate 4b by means of the energy store 3 biased and by means of at least one actuator, in particular by means of at least one known piezoelectric actuator 8th in a first operating position, which in this case corresponds to a "closed position" ( 1 ) are held.

Every piezoactuator 8th can be formed by a single piezo element or, as shown in more detail here, by a plurality of piezo elements combined to form a piezo element stack, the piezo element stack being located at one end on the valve housing 2 supported and the other end with the actuator 4 , in the present case the drawbar 4a the same can be brought into operative connection.

As a result of applying a voltage to said piezoelectric actuator 8th it causes a sudden expansion of the same, while at the same time the latter contracts again abruptly. By such a piezoelectric actuator 8th Accordingly, a rapid actuation of a trigger mechanism is permitted.

This is preferably the actuating element 4 facing end of the piezoelectric element stack still by means of a solid-state joint 9 , For example, made of plastic and / or metal, on the valve body 2 supported ( 1 ).

How the particular 2 can be seen, it is expedient to, two or more, in the present case four Piezoaktuatoriken 8th evenly over the circumference of the drawbar 4a distributed to provide, on the one hand a uniform force application and on the other functional redundancy in case of failure of individual Piezoaktuatoriken 8th respectively the operational safety and reliability of the valve 1 are guaranteed.

Certainly, it may also be indicated and is accordingly covered by the invention, two or more Piezoaktuatoriken 8th in series one behind the other and paraxial to the drawbar 4a to arrange or provide a combination of both variants (not shown).

The actuator 4 (Pull bar 4a with valve plate 4b ) is in accordance with a particularly preferred embodiment by means of Piezoaktuatoriken 8th in a certain friction section 10 the drawbar 4a of the actuating element 4 held by frictional engagement in the first operating position.

Said friction section 10 is present by a fixed to the drawbar 4a connected, for example glued or otherwise axially fixed sliding bushing 10a educated. Certainly, it is also conceivable, the friction section 10 directly on the lateral surface of the drawbar 4a to be provided and accordingly covered by the invention.

The piezo actuators 8th For this purpose, advantageously each have a transverse to the potential direction of movement of the actuating element 4 / the drawbar 4a force-loaded friction element 11 which, as seen in their combination in cross section form collets ( 2 ).

The outer contour or outer circumferential surface of the sliding bushing 10a the drawbar 4a of the actuating element 4 Thus, it has a first friction surface to which corresponding second and complementary to the first friction surface formed second friction surfaces of the present collet-shaped friction elements 11 to cling or attack (esp. 2 ).

For the expert is certainly easy to understand that due to frictional engagement between the biased actuator 4 and one or more friction elements 11 generated clamping force "F ₂ " preferably equal to or greater than that of the actuator 4 acting axial biasing force "F ₁ " should be selected.

Optionally, however, there is still a certain force on the valve 1 acting and shut off fluid or gas 5 to take into account, which then on the adjusted clamping force "F ₂ " of the friction elements 11 can affect such that it is even further increase, or can also be reduced to below the amount of the axial biasing force "F ₁ ", for example, if the fluid / gas to be shut off 5 applied force with respect to by the friction elements 11 applied clamping force "F ₂ " supporting acts.

The clamping force "F ₂ " is in addition to the number and size of Piezoaktuatoriken 8th especially determined by the friction coefficient between the friction partners. Convenient materials with a high static friction and a low coefficient of sliding friction.

For applications in vacuum or ultrahigh vacuum (UHV) it is known that particularly austenitic steels tend to cold weld, which is the function of components made therefrom, such as valves 1 , would certainly affect. For such applications, ceramic materials offer by at least one of the two friction partners is formed from such a ceramic material.

Through the friction section 10 forming slide bush 10a This circumstance is particularly taken into account by the same is easily and inexpensively adaptable to the prevailing conditions in terms of material selection.

The activation of the piezo actuators 8th is preferably triggered trigger signal via an electronic switch described in more detail below 15 , wherein the piezo actuators 8th in the first operating position of the valve 1 (Closed position or initial position) are in a stretched or stretched state. They are thus permanently under tension.

Should the valve 1 be transferred to the second operating state (open position) is manually or fully electronically, for example, sensor-controlled, a discharge of Piezoaktuatoriken 8th within 50-300 μs causes with the result that the clamping force "F ₂ " is canceled and the actuator 4 be released. The energy storage 3 Applied biasing force "F ₁ " acts and the valve disk 4b becomes from the valve seat at high acceleration 6 lifted, which in turn opens the valve 7 released and a flow for the fluid or gas 5 be allowed ( 3 ).

The size of the acceleration depends essentially on the one hand on the mass of the system to be accelerated, consisting of the actuator 4 and the proportionate mass of the energy storage 3 , and on the other hand of the size the preload force "F ₁ " from.

The embodiment according to 4 differs from the above-described embodiment "only" to the effect that here is a fast-closing valve 1 is shown by an actuator 4 with a push rod 4a is provided, in turn, by means of an energy storage 3 from a first operating position, which in turn represents an open position, in a second operating position or closed position can be transferred.

5 further shows a special development of the valve 1 in the region of the friction section 10 the pull or push rod 4a ,

Thereafter, this consists of two or more coaxially arranged behind each other separate rod sections 12 . 13 wherein a first rod portion 12 at one end on a supporting component of the valve housing 2 is fixed and the each aligned section ends of the rod sections 12 . 13 have interlocking friction-lamellar structures, in turn, a common disk set 14 form. The other not shown in detail free end of the further, present second rod section 13 , is with the valve disc also not shown 4b Mistake.

By means of at least one, preferably by means of both sides of the disk set 14 in a common plane of action opposite arranged piezo actuators 8th The type described above is said disk set 14 in accordance with a multi-plate clutch kraftbeaufschlagbar, which already due to the large number of parallel circuits of contact or friction points by means of small forces exerted by the Piezoaktuatorik / s 8th large holding forces can be realized.

The one or more piezo actuators 8th can, as shown here, via a friction element 11 or directly to the top layer of the disk pack 14 attack.

The above embodiments focus on fast switching triggering mechanisms with piezoactuators 8th from, in turn, frictionally engaged with the actuator 4 are operatively connected.

By the invention, however, are also fast-switching release mechanisms with Piezoaktuatoriken 8th comprising, which by positive engagement between the actuating element 4 and at least one of a positive engagement of the same engaging positive locking element of the piezoelectric actuator 8th are held in the first operating position (not shown in detail).

The interlocking element may be formed, for example, as a bolt or hook, in turn, in a groove or opening of the biased actuating element 4 , an axial movement of the same obstructive, releasably engages.

The quick-switching release mechanism according to the invention, installed in a valve 1 , offers itself due to the very short switching times and the large achievable strokes of the actuator 4 in particular as a gas injection valve for extinguishing plasma in a fusion reactor by means of noble gases, such as argon or neon. In this case, high volume flows must be released in a very short time.

Further it has in this specific application as extremely beneficial proved that the prevailing conditions here are strong magnetic Fields could be mastered without problems.

6 shows the principle of a possible electronic control of Piezoaktuaorik 8th , It is about the entrance 16 an electronic control signal (trigger signal) of an unspecified described per se electronic circuit to the electronic switch 15 given. This signal actuates the electronic switch 15 in the way that in the switch position 15a an electronic energy store 17 , for example, a buffer capacitor is charged. The shown current limiter 18 This serves to protect the electronic energy storage 17 and a constant voltage source 19 , At the same time, by short-circuiting the Piezoaktuatorik 8th take place a charge compensation which in turn causes the stretched state of the Piezoaktuatorik 8th abruptly into an unstretched state. It serves a current limiter 20 the setting of a discharge time constant, which has an influence on the speed of the state change described above, and the protection of the Piezoaktuatorik 8th , In the switching position 15b of the electronic switch 15 becomes the Piezoaktuatorik 8th over the current limiter 20 with the in switch position 15a in the electronic energy storage 17 stored energy is charged. As a result, the stretched state of the Piezoaktuatorik 8th restored.

• • Es müssen auf Grund der Piezoaktuatorik 8 hohe Spannungen verarbeitet werden;
• • Da sich Piezoaktuatorik 8 annähernd wie Kapazitäten verhält, muss im Kurzschlussfall mit sehr hohen Strömen gerechnet werden;
• • Die Forderung einer extrem kurzen Zeit bis zur Ventilöffnung erfordert Schaltzeiten des elektronischen Schalters 15 welche um den Faktor zehn besser sind, als die mechanischen Vorgaben des Ventils 1;
• • Die Elektronik muss unempfindlich gegen ein hohes Magnetfeld sein, sowie im abgeschalteten Zustand für Wartungsarbeiten Temperaturen von 150°C erlauben.

For the aforementioned special application of a gas injection valve for extinguishing plasma in fusion reactors is the electronic switch 15 for quick unloading (branch or switching position 15a ) of the piezoactuator 8th Preferably, IGBT (Insulated Gate Bipolar Transistor) designed to meet the following requirements:

• • It must be due to the Piezoaktuatorik 8th high voltages are processed;
• • Since piezo actuators 8th almost like Kapa behaves in the event of a short circuit, very high currents must be expected;
• • The requirement of an extremely short time to valve opening requires switching times of the electronic switch 15 which are ten times better than the mechanical specifications of the valve 1 ;
• • The electronics must be insensitive to a high magnetic field and allow temperatures of 150 ° C for maintenance during shutdown.

said Insulated Gate Bipolar Transistors (IGBT) are semiconductor devices, which the advantages of Biopolartransistors (good on-state behavior, high reverse voltage) and the advantages of a field effect transistor (almost powerless control) unite. It is also advantageous a certain robustness against Shorts because the IGBT limits the load current. Another advantage of IGBT's is the possibility the direct control of a control electronics, such as by a microcontroller, which then also take over monitoring and communication tasks can highlight.

Of course, in addition to the applications explained in more detail above for the quick-switching trigger mechanism according to the invention, a large number of further applications are conceivable, the enumeration of which would exceed the scope of this application. However, it should be noted that all the applications are included, which realize the basic idea of the invention, namely a separate energy storage 3 for biasing respectively actuating an actuating element 4 , For example, a pull / push rod 4a a valve 1 , with at least one Piezoaktuatorik 8th , which in turn is provided, said biased push / pull rod 4a to hold in a first operating position and release if necessary, to combine.

1

Valve

2

valve housing

3

energy storage

4

actuator

4a

Pull / push rod

4b

valve disc

5

Fluid / gas

6

valve seat

7

valve opening

8th

Piezoaktuatorik

9

Solid joint

10

friction portion

10a

bush

11

friction

12

slug

13

slug

14

disk pack

15

electronic switch

15a

Switching position

15b

Switching position

16

entrance

17

electronic energy storage

18

current limiter

19

Constant voltage source

20

current limiter

"F ₁ "

preload force

"F ₂ "

clamping force

Claims (18)

Fast-acting release mechanism for using an energy storage device ( 3 ) biased and from a first operating position into a second operating position convertible actuator ( 4 ), wherein the actuating element ( 4 ) against the acting biasing force "F ₁ " of at least one actuator in the first operating position is firmly held but releasably, characterized in that the at least one actuator by a Piezoaktuatorik ( 8th ) is formed. Quick-acting release mechanism according to claim 1, characterized in that the piezoactuator ( 8th ) is formed by a piezo element or by a piezo element stack. Quick-acting release mechanism according to claim 1 or 2, characterized in that the actuating element ( 4 ) by means of the at least one piezoactuator ( 8th ) by frictional engagement between the biased actuator ( 4 ) and at least one attacking it and by the Piezoaktuatorik ( 8th ) transversely to the potential direction of movement of the actuating element ( 4 ) force-loaded friction element ( 11 ) is held in the first operating position. Quick-acting release mechanism according to claim 3, characterized in that due to frictional engagement between the prestressed actuating element ( 4 ) and the at least one friction element ( 11 ) generated clamping force "F ₂ " preferably equal to or greater than that of the actuating element ( 4 ) acting axial biasing force "F ₁ " is selected. Quick-acting release mechanism according to claim 3 or 4, characterized in that the actuating element ( 4 ) a pull or push rod ( 4a ), which in turn via a friction section ( 10 ), whose outer lateral surface forms a first friction surface on which the friction element ( 11 ) of the piezoactuator ( 8th ) with a second friction surface corresponding to the first friction surface transversely to the potential direction of movement of the Actuating element ( 4 ) attacks. Quick-acting release mechanism according to claim 5, characterized in that two or more piezo actuators ( 8th ) evenly over the circumference of the pull or push rod ( 4a ) are distributed and attack on the same. Quick-acting release mechanism according to claim 5 or 6, characterized in that two or more piezo actuators ( 8th ) in series one behind the other and paraxial to the pull or push rod ( 4a ) are arranged and attack on the same. Quick-acting release mechanism according to claim 5, characterized in that the actuating element ( 4 ) a pull or push rod ( 4a ), which consists of two or more coaxially arranged behind each other separate rod sections ( 12 . 13 ), wherein the respective mutually aligned section ends of the rod sections ( 12 . 13 ) have intermeshing friction lamellar structures, which in turn have a common lamella packet ( 14 ) and, effecting a frictional connection, by means of at least one Piezoaktuatorik ( 8th ), preferably by means of both sides of the disk set ( 14 ) in a common plane of action of oppositely arranged piezoactuators ( 8th ) transversely to the potential direction of movement of the actuating element ( 4 ) are kraftbeaufschlagbar. Quick-acting release mechanism according to claim 8, characterized in that the piezoactuator ( 8th ) via a friction element ( 11 ) or directly on the top layer of the disk pack ( 14 ) attacks. Fast-acting release mechanism according to one of the claims 3 to 9, characterized in that for the friction partners materials with a high static friction and a low coefficient of sliding friction chosen are. Quick-acting release mechanism according to claim 10, characterized in that at least one friction partner from a ceramic material is formed. Quick-acting release mechanism according to claim 1 or 2, characterized in that the actuating element ( 4 ) by means of the at least one piezoactuator ( 8th ) by a positive connection between the actuating element ( 4 ) and at least one of a positive engagement of the same engaging positive locking element of the piezoelectric actuator ( 8th ) is held in the first operating position. Quick-switching release mechanism according to one of claims 1 to 12, characterized in that the energy store ( 3 ) by one or more prestressed spring elements, by a pressurized fluid or gas or by any other suitable per se known energy storage ( 3 ) is formed. Quick-acting release mechanism according to one of Claims 1 to 13, characterized in that the piezoactuator ( 8th ) is controlled by an electronic switch. Valve ( 1 ) with a fast-switching release mechanism according to one of claims 1 to 14. Valve ( 1 ) according to claim 15, characterized in that the valve ( 1 ) is designed to open quickly or close quickly. Use of the valve ( 1 ) according to claim 15 or 16 under conditions of strong magnetic fields. Use of the valve ( 1 ) according to one of claims 15 to 17 as gas injection valve for extinguishing plasma in fusion reactors.