DE19921660A1 - Micro valve assembly has micro valve fixed on housing by valve support which defines fluid duct system for valve and uncouples micro valve from mechanical and thermal influences of housing - Google Patents

Abstract

The micro valve assembly has a housing (2) containing a micro valve (8) which is fixed on the housing by a valve support (15) which on one hand defines a fluid duct system (16) interacting with the micro valve, and on the other uncouples the micro valve from the mechanical and/or thermal influences acting on the housing. The valve support can be fitted with micro valves on opposite sides and several valves can be linked by the fluid duct system so that with a corresponding control one overall valve functional unit is provided lying above that of the individual valves.

Description

The invention relates to a microvalve arrangement, which has at least one microvalve through which a fluid flow control is controllable.

A microvalve arrangement is known from WO 92/20942, which has a central block on one side several micro valves are assigned. In the central block there is a fluid channel system made by a fluid can be flowed through, the fluid flow through the Micro valves is controlled.

The known microvalve arrangement is especially for that Field of application of gas chromatography conceived. On the other hand this well-known valve concept is insufficient for Applications in industrial fluid technology and thereby ins especially in the industrial pneumatics sector. The right there inhospitable environmental conditions which inevitably cause malfunctions and the Le severely affect the life of the microvalve arrangement.

It is therefore an object of the present invention to provide a Mi to create kroventilanordnung, which is also under unfavorable  reliable in environmental conditions with a long service life can operate.

This task is solved by a micro valve arrangement, which has a housing in which at least one microvalve is arranged, with the interposition of a Ventilträ Gers is fixed to the housing, the valve carrier on the one hand a fluid channel cooperating with the microvalve system and on the other hand the micro valve from to Mechanical mechanical and / or thermal action rivers decoupled.

In this way, there is a microvalve arrangement, the Micro valves are shielded from the environment by the housing and, moreover, by interposing the valve carrier, are decoupled from the housing so that the Ge mechanical and / or thermal load acting on the housing to a large extent. It can by the design of the valve carrier and in particular by appropriate choice of materials a specific adaptation to the more common in industrial use of the microvalve arrangement wise environmental influences occur. Here comes for the valve carrier in particular a material with high me mechanical strength, low coefficient of thermal expansion, high thermal conductivity and electrical insulation in question. A material whose elasticity is advantageous modulus greater than or equal to the elastic modulus of the basic body pers of the micro valves arranged on the valve carrier. Kera Mikmaterial, especially aluminum oxide, has proven to be special  recommended for the construction of the valve carrier sen.

Advantageous developments of the invention go from the Un claims.

The valve carrier expediently has a plat ten-shaped structure and can simultaneously with several micro valves. A particularly practical version tion form provides that on the valve carrier two micro-valves le are attached on opposite sides of the valve carrier.

With a multiple arrangement of micro valves, there is advantageous possibility, building on a micro valves low-value functionality through appropriate linkage a total of about the fluid channel system of the valve carrier to realize higher-quality valve functionality tap the corresponding connections of the microvalve arrangement leaves. For example, there is the option of starting of two 2/2 micro valves, one of which is in the "nor sometimes closed "and their other design "normally open" is a microvalve arrangement with a 3/2-valve functionality.

The microvalves are attached to the valve carrier expediently by an adhesive process, the adhesive for example in the screen printing process or with a dispenser is applied to the valve carrier. Electrically conductive Surfaces or conductor tracks made of conductive paste, which are used for the electri  control of the individual micro valves are required, can also be screen printed onto the valve carrier be applied.

To manufacture the fluid channel system of the valve carrier too simplify, the fluid channels can at least partially in Form groove-like surface depressions, which are inserted in the valve carrier and from each micro valve are covered.

The valve carrier can be secured using suitable fastening measures be fixed in the housing of the microvalve arrangement. Here Centering means are also expediently used, which the exact position of the valve carrier with respect to the housing give.

In order to optimally decouple the micro valves from the surrounding one To get housing, the arrangement is conveniently so met that the microvalves exclusively with the Ven tilträger are in contact and no direct contact points with the housing.

The communication of the micro valves with external fluid lines gene takes place via the fluid channel system and expediently several connecting channels passing through the housing, which with are connected to the fluid channel system. A sealed fluid can be transferred here in particular by interposing a suitable sealing element take place that at the same time Lich all fluid transfer positions the sealing function takes over.  

The microvalves used can in particular have a micromechanically structured structure, one Manufacture in etching technology or impression technology is possible. Valve designs that use pie zoelectric or magnetostrictive principle of operation ren, or on a memory metal functional principle.

The valve electronics used to control the micro valves tronics is also conveniently located inside of the housing.

In a particularly advantageous embodiment of the microven til the housing is at least partially as a MID Body ("Molded Interconnect Device") running, where it directly with an electrical contact to the Ven tilelectronic components and / or the at least one microven tils serving conductor structure is provided. Compared to a conventional planar circuit board technology, such as it is described, for example, in US Pat. No. 5,640,995 This way, they are much more complex and, if necessary, also three-dimensional conductor structures can be realized, too are part of the housing so that it can be used a small number of components compact electrical Ver let ties be realized.

The ladder structure can be found on the inside of the outer wall extension of the housing and / or on one or more, in Ge located inside the partition walls of the housing  the. The MID technology used allows this a very variable realization of needs-based shaping.

The invention based on the accompanying drawing tion explained in more detail. In this show:

FIG. 1 kroventilanordnung a preferred design of the Mi invention, the housing only partially depicted example, to visualize the be inside the case-sensitive components,

Fig. 2 shows the housing used in the micro-valve arrangement according to FIG. 1 and again shown only in partial view in individual representation,

Fig. 3, the housing of FIG. 2, in addition to instal profiled valve electronics and sealing measures for the fluid connection to the valve carrier,

Fig. 4 is a side view of the micro valve assembly looking in the direction according to arrow IV of FIG. 1 on the terminal side of the assembly,

Fig. 5 the valve carrier used in the microvalve arrangement according to FIGS. 1 to 4 in a perspective individual representation, with dash-dotted lines the micro valves seated on it are indicated and

Fig. 6 shows an alternative design of the valve carrier.

The microvalve arrangement 1 of the embodiment has a housing 2 with a preferably cuboid and in particular re cube-like outer contour. In the drawing, the outer wall 3 of the housing 2 , which normally forms a coherent hollow body that defines an interior 4 , only partially in order to improve the clarity. Visible is a bottom wall 5 and a side wall 6 oriented to the connection side of the microvalve arrangement 1 and at right angles to the bottom wall 5 .

The housing 2 has a further dividing the interior space 4 intermediate wall. 7 It is firmly connected to the outer wall 3 , preferably an integral construction is provided.

In the exemplary embodiment the intermediate wall 7, both the bottom wall 5 connected as well as one piece with the side wall ver. 6

Adjacent to the intermediate wall 7 , two micro valves 8 , 8 ′, which are only indicated schematically, are accommodated in the interior 4 . You are in the embodiment in a first ( 12 ) of the two by the intermediate wall 7 abge divided partitions 12 , 13 of the interior 4th

The two microvalves 8 , 8 'have a one-part or multi-part base body 14 , for example in a layered construction, each of which contains at least one valve member (not shown in more detail) and an associated actuator system. It can be, for example, piezo valves or Ven tiles whose activation is caused by magnetostriction or on the basis of the so-called memory metal effect. The valve member can be designed, for example, as a bending element or as a membrane element, an electrostatic actuation being conceivable as well. The processes known from microsystem technology are used in particular for production, for example using a silicon etching technique or a plastic molding process.

The microvalves 8 , 8 'are not placed directly on the housing 2 , the housing-fixed fixation takes place rather only with telbar with the interposition of an intermediate body designated as valve carrier 15 be. The microvalves 8 , 8 'are fastened to the valve carrier 15 , which in turn is fixed on the housing 2 . Between the micro valves 8 , 8 'and the Ge housing 2 there is expediently an all-round distance, which can be very small and is therefore not shown in detail in the drawing.

The valve carrier 15 contains a fluid channel system 16 composed of a plurality of fluid channels, which is also clearly visible from FIGS . 5 and 6. It opens with connection openings 17 , 17 'to two outer mounting surfaces 18 , 18 ' of the Ven tilträger 15 , on which the two micro valves 8 , 8 'fi xed. Via the connection openings 17 , 17 ', the fluid channel system 16 communicates with valve channels of the microvalves 8 , 8 ', which are not shown in detail.

For optimal use of the available installation space, the valve carrier 15 is designed in the manner of a plate, the ones in the assembly surfaces 18 , 18 'being located on the two larger plate surfaces oriented opposite one another. This results in a sandwich-like structure, the two micro-valves 8 , 8 'enclosing the valve carrier 15 between them.

The arrangement is expediently such that the plane of expansion of the valve carrier 15 extends parallel to the plane of expansion of the intermediate wall 7 .

The fluid channel system 16 has further connection openings 22 , which represent the interface of the fluid channel system 16 to the surroundings of the microvalve arrangement 1 . They are located on an outer surface of the valve carrier 15 and in the present case on the narrow side of the valve carrier 15 facing the inner surface of the side wall 6 .

If the housing 2 in the region of the further calculations Verbindungsöff 22 have appropriate recesses, which further connection openings 22 could be used directly for the connection of continuing fluid lines or fluid conduits. In the exemplary embodiment, however, it is provided that the outer wall 3 of the housing 2 is penetrated by connecting channels 23 , which on the one hand open out via connection openings 24 on the outer surface of the outer wall 3 and on the other hand open out on the other side of the further connecting openings 22 in such a manner that they lie opposite on the inner surface of the side wall 6 that there is a connection to the fluid channel system 16 . The fluidic interface between the valve carrier 15 and the housing 2 is sealed, which is done in the exemplary embodiment by interposing a sealing element 25 consisting of a suitable sealing material. This has a mask-like structure with a number of holes corresponding to the number of channel transitions, so that it serves for simultaneous sealing of all channel transitions. In this way, a number of individual seals are saved.

The valve carrier 15 is fixed to the housing 2 by suitable fastening measures. In the exemplary embodiment, it engages with an edge-side holding section 26 in a form-fitting manner in egg ne on the inner surface of the outer wall 3 recessed holding recess 27 , which contributes to the exact positioning or centering. In addition, the Ventilträ ger 15 is firmly bonded to the housing 2 by gluing. But other, for example non-positive and / or positive connections, for example by screwing or pinning, are also conceivable. In any case, the two micro valves 8 , 8 'are advantageously not directly influenced by the chosen fastening measures.

The valve carrier 15 thus has a multiple function. In addition to the provision of the supply and discharge of the fluid channel system 16 to be controlled by the micro-valves to be controlled, it has the function of a decoupling body, which has the micro-valves 8 , 8 ′ attached to it from mechanical and / or thermal influences acting externally on the housing 2 decoupled. In this way it is prevented that the environmental influences acting on the microvalve arrangement 1 during operation - for example temperature fluctuations, shocks or vibrations - are transmitted to the microvalves 8 , 8 'to a harmful extent.

The valve carrier 15 essentially fulfills these requirements by choosing a material that is matched to the structure of the microvalves 8 , 8 ′. In the exemplary embodiment, it consists of ceramic material, alumina material having proven particularly expedient. Material of this type is characterized by high mechanical strength, low thermal expansion coefficient, high thermal conductivity and electrically insulating properties. The modulus of elasticity (E-modulus) of the valve wearer 15 is preferably equal to or greater than the elastic modulus of the base body 14 of the carrier to the valve 15 attached micro-valves 8, 8 '.

The micro valves 8 , 8 'are expediently glued to the valve carrier 15 . The adhesive can move here in Siebdruckver or be brought onto valve carrier 15 with a dispenser. Also in the screen printing process, electrically conductive surfaces or conductor tracks made of conductive paste can be applied to the valve carrier 15 in order to obtain electrical conductors 28 , 28 'which are used for connection to the electrically actuated actuators of the micro valves 8 , 8 '.

The actuation of the microvalves 8 , 8 'as required takes place through the intermediation of valve electronics 32 , which is conveniently placed in the interior 4 of the housing 2 . Ver different components 33 of the valve electronics are exemplified in FIGS . 1 and 3. In connection with the Mikroven valves 8 , 8 'formed in the exemplary embodiment as piezo valves, the valve electronics 32 expediently includes an auxiliary voltage module, a DC / DC converter and a discharger module. The central element is the DC / DC converter, through which the voltage conversion of the regularly available input voltage of 24 volts to the required actuator drive voltage takes place. The auxiliary voltage module connected upstream of this converter serves to reduce the input voltage to a constant supply voltage of approximately 10 to 11 volts in order to prevent negative effects of tolerance-related fluctuations in the input voltage. The unloader module has the task of switching off the DC / DC converter when the input voltage is switched off and discharging the actuator formed by a piezo bender, which has a capacitive effect here. For this purpose, the input voltage is continuously measured by the discharger module and a transistor circuit is activated when the voltage falls below 15 volts, which triggers this discharge and switch-off process (not shown).

The necessary electrical circuit is convenient in partial functions or completely in an ASIC on one Silicon chip summarized.

The valve electronic components 33 are seated on an electrically conductive conductor structure 34 , which can be clearly seen in FIG. 2 and which also serves for contacting the microvalves 8 , 8 'by being connected to the electrical conductors 28 of the valve carrier 15 .

A great advantage of the exemplary microvalve arrangement 1 now consists in the fact that the entire conductor structure 34 is provided directly on the housing 2 of the microvalve arrangement 1 , which in this case is embodied as a MID body, at least in the region of the conductor structure 34 , wherein "MID "stands for" Molded Interconnect Device ", in other words for a regularly injection molded part with a structured conductor pattern.

The MID technology makes it possible to carry out the conductor structure 34 more than two-dimensionally than in the conventional planar circuit-board technology, and in particular to implement three-dimensional solutions such as are shown in the drawing. This makes it much easier to implement the required conductor structures in the smallest of spaces, with virtually unlimited design freedom. Since the housing 2 itself forms the MID body, it is also possible to dispense with separate conductor structure carriers, which results in further savings potential in terms of manufacturing and material costs.

In the exemplary embodiment, the conductor structure 34 extends both over the intermediate wall 7 and also over the inner surface of the outer wall 3 , it expediently running on both opposite wall surfaces of the intermediate wall 7 . However, it goes without saying that, depending on the design of the housing 2, any components of the same can act as a carrier for the conductor structure 34 . It is also possible in particular a multi-part housing structure in such a way that a part comprising the conductor structure 34 as an MID body and the other components are designed in conventional housing technology.

The valve electronics components are expediently in their entirety on the intermediate wall 7 , whereby they are distributed over the two wall surfaces in order to obtain optimal space utilization.

As is apparent from Fig. 2, some conductors of the conductor structure 34 extend on the inner surface of the side wall 6 and in the first connecting sections 35 , which are connected to second connecting sections 36 of the electrical conductors 28 of the valve carrier 15, in order in this way the Ven electronics electronics 32 to link the actuation of the micro valves 8 , 8 'control technology.

Finally, electrical connection means 37 are also provided on the outer surface of the side wall 6 , which are also connected to the conductor structure 34 of the housing 2 and which enable the connection of an external control device and / or power supply device.

Various methods can be used in the manufacture of the MID housing 2 . For example, two-component injection molding processes, hot stamping processes, laser direct structuring or 3D mask exposure are possible. When applying a two-component injection molding process, for example, the procedure is such that first a body made of metalizable plastic is injected, which forms the structures for the later conductor tracks. In an intermediate step, this pre-molded part is pickled and activated with palladium seeds. After this chemical treatment, a non-metallizable plastic is injected around the first mold in a white injection process, which fills the gaps between the pre-molded parts and produces the final shape of the MID body. In the subsequent chemical metallization, no metal is deposited on the non-germinated surface of the second spraying process, so that conductor tracks are only formed on the exposed surface of the first spraying process, which can be galvanically reinforced in a further step and which form the conductor structure 34 .

The two microvalves 8 , 8 'present in the exemplary embodiment are designed as 2/2-way valves, in one case it is a design of the "normally closed" type and in the other case it is a "normally open" design . These two microvalves 8 , 8 'are now controllable by the valve electronics 32 such that, in conjunction with a corresponding fluidic connection by means of the fluid channel system 16 at the outer connection openings 24, a 3/2-valve function can be performed. Building on two identical valves with a simple, low functionality, a microvalve arrangement with higher valve functionality can be realized in this way. As a rule, this enables a simpler and more cost-effective construction than a comparative solution in which only a single microvalve is installed, which already includes a 3/2-valve function.

Regarding the valve carrier 15, it should also be noted that the fluid channel system 16 can also be realized at least partially in the form of groove-like surface depressions 38 of the valve carrier 15 , as is exemplified in FIG. 6. The surface depressions 38 are covered here by the respectively placed microvalve 8 , 8 'to form fluid channels.

Claims (22)

1. Micro valve arrangement, with a housing ( 2 ) in which at least one micro valve ( 8 , 8 ') is arranged, which is fixed with the interposition of a valve carrier ( 15 ) on the housing ( 2 ), the valve carrier ( 15 ) for one defines a fluid channel system ( 16 ) cooperating with the microvalve ( 8 , 8 ') and secondly decouples the microvalve ( 8 , 8 ') from mechanical and / or thermal influences acting on the housing ( 2 ). 2. Microvalve arrangement according to claim 1, characterized by a valve carrier ( 15 ) equipped simultaneously with a plurality of microvalves ( 8 , 8 '). 3. Micro valve assembly according to claim 2, characterized in that the valve carrier ( 15 ) on opposite sides of each other is equipped with at least one micro valve ( 8 , 8 '). 4. Microvalve arrangement according to claim 2 or 3, characterized in that a plurality of microvalves ( 8 , 8 ') are linked via the fluid channel system ( 16 ) in such a way that, when actuated accordingly, overall a valve functionality results which exceeds that of the individual microvalves ( 8 , 8 '). 5. Microvalve arrangement according to one of claims 2 to 4, characterized in that several and preferably all existing microvalves ( 8 , 8 ') are built as 2/2-way valves. 6. Microvalve arrangement according to claim 5, characterized by connecting two 2/2-way Micro valves received 3/2-way valve functionality. 7. Microvalve arrangement according to one of claims 1 to 6, characterized in that the modulus of elasticity (modulus of elasticity) of the valve carrier ( 15 ) is equal to or preferably greater than that of the base body ( 14 ) of the at least one microvalve ( 8 , 8 ') attached to it. is. 8. Microvalve arrangement according to one of claims 1 to 7, characterized in that the valve carrier ( 15 ) consists of Kera mic material, preferably of aluminum oxide material. 9. Micro valve arrangement according to one of claims 1 to 8, characterized in that the at least one micro valve ( 8 , 8 ') is glued to the valve carrier ( 15 ). 10. Microvalve arrangement according to one of claims 1 to 9, characterized in that the valve carrier ( 15 ) on its with a microvalve ( 8 , 8 ') equipped assembly area ( 18 , 18 ') via at least one groove-like belonging to the fluid channel system ( 16 ) Surface recess ( 38 ) has. 11. Microvalve arrangement according to one of claims 1 to 10, characterized by a positive and / or non-positive and / or integral fastening of the valve carrier ( 15 ) on the housing ( 2 ). 12. Microvalve arrangement according to one of claims 1 to 11, characterized in that the at least one microvalve is placed at all sides from the housing ( 2 ). 13. Micro valve arrangement according to one of claims 1 to 12, characterized by in the housing ( 2 ) extending connecting channels ( 23 ) which communicate with the fluid channel system ( 16 ) of the Ventilträ gers ( 15 ), wherein at the fluidic interface between the valve carrier ( 15 ) and the housing ( 2 ) a sealing element ( 25 ) sealing all channel transitions at the same time is provided. 14. Micro valve arrangement according to one of claims 1 to 13, characterized by a micromechanically structured structure of at least one micro valve s ( 8 , 8 '). 15. Microvalve arrangement according to one of claims 1 to 14, characterized in that at least one microvalve ( 8 , 8 ') is based on a piezoelectric and / or a magnetostrictive functional principle and / or on a memory metal functional principle. 16. Microvalve arrangement according to one of claims 1 to 15, characterized in that the housing contains a valve electronics ( 32 ) assigned to the at least one microvalve ( 8 , 8 '). 17. Microvalve arrangement according to claim 16, characterized in that the housing ( 2 ) is at least partially designed as an MID body ("Molded Interconnect Device"), it directly with one for electrical contacting of the valve electronic components ( 33 ) and / or at least one microstructure ( 8 , 8 ') serving conductor structure ( 34 ) is provided. 18. Microvalve arrangement according to claim 17, characterized in that the conductor structure ( 34 ) has a three-dimensional expansion. 19. Microvalve arrangement according to claim 17 or 18, characterized in that the housing ( 2 ) has at least one intermediate wall ( 7 ) inside, which carries at least part of the conductor structure ( 34 ). 20. Microvalve arrangement according to claim 19, characterized in that the conductor structure ( 34 ) on both of the opposite wall surfaces of an intermediate wall ( 7 ) it stretches. 21. Microvalve arrangement according to claim 19 or 20, characterized in that the valve electronic components ( 33 ) are provided at least partially and preferably in their entirety on an intermediate wall ( 7 ). 22. Micro valve arrangement according to one of claims 17 to 21, characterized in that the housing ( 2 ) has an outer wall ( 3 ) which is provided on the inner surface with at least one part of the conductor structure ( 34 ).