WO2009000284A1 - Microvalve - Google Patents

Microvalve Download PDF

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Publication number
WO2009000284A1
WO2009000284A1 PCT/EP2007/005535 EP2007005535W WO2009000284A1 WO 2009000284 A1 WO2009000284 A1 WO 2009000284A1 EP 2007005535 W EP2007005535 W EP 2007005535W WO 2009000284 A1 WO2009000284 A1 WO 2009000284A1
Authority
WO
WIPO (PCT)
Prior art keywords
flow
channel
transducers
transducer
duct
Prior art date
Application number
PCT/EP2007/005535
Other languages
German (de)
French (fr)
Inventor
Kurt Dirk Bettenhausen
Wolfgang Ens
Herbert Grieb
Peter Hauptmann
Original Assignee
Siemens Aktiengesellschaft
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Aktiengesellschaft filed Critical Siemens Aktiengesellschaft
Priority to PCT/EP2007/005535 priority Critical patent/WO2009000284A1/en
Publication of WO2009000284A1 publication Critical patent/WO2009000284A1/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K99/0001Microvalves
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K99/0001Microvalves
    • F16K99/0003Constructional types of microvalves; Details of the cutting-off member
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K99/0001Microvalves
    • F16K99/0034Operating means specially adapted for microvalves
    • F16K99/0042Electric operating means therefor
    • F16K99/0048Electric operating means therefor using piezoelectric means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K99/0001Microvalves
    • F16K99/0034Operating means specially adapted for microvalves
    • F16K99/0042Electric operating means therefor
    • F16K99/0051Electric operating means therefor using electrostatic means
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K2099/0082Microvalves adapted for a particular use
    • F16K2099/0084Chemistry or biology, e.g. "lab-on-a-chip" technology
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K99/00Subject matter not provided for in other groups of this subclass
    • F16K2099/0082Microvalves adapted for a particular use
    • F16K2099/009Fluid power devices

Abstract

The invention relates to a microvalve (1) for adjusting the volume flow rate of a fluid through a duct (2). A field of electromechanical transducers (5...8), which are adjacent to one another, is provided in a duct wall (4), by means of which electromechanical transducers (5...8) in each case the flow cross section of the duct (2) can be varied. By means of an activation device (9), the transducers (5...8) are excited so as to perform alternating movements, wherein adjacent transducers move counter to one another. Here, turbulence is generated in the duct (2), which turbulence increases the flow resistance in the duct (2) according to the frequency of the excitement. The new valve has the advantage that it is continuously controllable and has good endurance properties.

Description

description

microvalve

The invention relates to a micro valve for a volumetric flow of a fluid through a channel setting according to the preamble of claim 1.

Microvalves may generally be used in pneumatics and fluidics in the control of gas or liquid flows, so fluid flows. Such valve may either have the function of a pilot valve, for example in electro-pneumatic positioners, or it may directly the control of a volume flow and pressure in a piston or serve the like, or it is used in micro-process technology devices or analyzers.

For example, from DE 197 35 156 Cl a piezoelectrically actuated micro-valve is known, comprising the following components: a body having a passage opening, a plunger, a suspension device by which the plunger is so guided in relation to the basic body that the passage opening by can be closed by the plunger or, free-, and a piezoelectric actuator for actuating the tappet, the extent of which is variable in the longitudinal direction by applying an electrical voltage. For regulating a volume flow through the valve, the known micro-valve can be continuously adjusted or supplied with a pulse-width modulation principle either. A continuous adjustment of this case has the disadvantage that the valve position required to achieve the desired flow rate can change with time. Reasons for this can deposit on the closing body, an abrasion from the flowing

his medium on the closing body or relaxation. takes place in a pulsed mode, in which the control with PuIs- width modulated signal for fully opening and closing of the microvalve, there occurs an increased wear, as the closing body continuously moves against a hard stop. With long-term persistence of the moving parts in an end position, it is possible also that they attach themselves and thus the valve fails.

The disadvantages mentioned above are also in most other known valve types before, for example in valves with a ball valve, a slide, a combination of a nozzle and flapper valves with a magnetically driven actuator, a needle valve, etc .. In valves, in which parts, for example, rub against each other for actuating the closure body, also may occur the so-called stick-slip phenomenon in which the mutually moving parts, a sequence of movements from adhering, clamping, cutting and sliding exercise until the next adhering. This effect leads to vibrations and can adversely affect the accuracy of the setting of the closing body and therefore on the accuracy of the setting of the air flowing through the microvalve volume also.

The invention has for its object to provide a micro-valve, with which a volume flow is continuously adjustable and which is distinguished by good long-term characteristics.

To achieve this object, the new micro-valve of the type mentioned in the feature stated in the characterizing part of claim 1. In the dependent claims, advantageous refinements of the invention are described.

By electromechanical transducer active structures through which the free flow cross section in the channel is changed are formed in at least one channel wall. Due to the overall targeted alternating excitation adjacent active elements in push-pull and / or, if more than one active channel wall is provided by alternating excitation of opposed active elements in unison a standing wave in the near field with the active structures can be produced. Adjacent thereto transducers are driven in push-pull, that is, during a transducer moves in the direction of a cross-sectional constriction, the movement of the or the neighboring transducer is exactly the opposite, namely, in the direction of a cross-sectional widening. The movement of the active patterns thus influences the flow resistance in the channel on the one hand with a static component due to variation of the flow cross-section and on the other by a dynamic component due to the increased flow-loss due to turbulence in the area of ​​the electromechanical transducer, and due to an increase in the eddy viscosity by the selective excitation of the electro-mechanical transducer.

Advantageously, the above-mentioned disadvantages of conventional Mikroven- be largely avoided tile roventil in the novel micro-. In addition, micro-valve according to the invention has the advantage that it is falling safety is characterized by an increased off, since a plurality of electromechanical transducers is provided as a variable flow obstacles which may be designed partially redundant also. Due to the alternating movement of the electromechanical transducer is a self occurs in an advantageous manner, a cleaning effect because of moving parts deposits form to a lesser extent than at fixed. As can be adjusted very accurately with the inventive micro-valve a predetermined volume flow, it is particularly well suited for use as an actuator in a control circuit for the regulation-of the flow rate used.

If the field is formed one-dimensionally of adjacent electromechanical transducers, that is, the transducers are arranged in a substantially linear array, and if the number of the transducers is substantially parallel to the flow direction of the fluid, this has the advantage that by the above- movement of the transducer described, a standing wave is generated, the wave height decreases the remaining free flow cross section of the channel. Here, the wave height, and thus the flow rate can be influenced by varying the amplitude of the transducer movements.

In addition, in an advantageous manner, a fine control is possible by the frequency of the alternating change in the flow cross-section is changed by the driving means. Through selective excitation, the fluid can also be vibrated, whereby the Strömungswi- changed resistor. The laminar flow is disturbed and the eddy viscosity increased. Thus, with the frequency of the eddy viscosity and the flow rate increases through the channel is reduced.

The electromechanical transducer may be formed as a capacitive or piezoelectric micromachined ultrasonic transducers manufactured. This has the advantage that it can be made to an already proven technology for the realization of such transducers. Such transducers are often called capacitive micromachined ultrasonic transducer (cMUT) or piezoelektric micromachined ultrasonic transducer (pMUT), respectively.

Referring to the drawings in which an embodiment of the invention is illustrated in the following, the invention and its embodiments and advantages will be explained in more detail.

Show it:

1 shows a control circuit with a micro valve for setting a predetermined flow rate,

Figures 2 and 3 are schematic diagrams showing for explaining the dynamic effects and

Figures 4, 5 and 6, flow diagrams for explaining the Ver - whirl. According to Figure 1, a micro-valve 1 for a volume flow of a fluid setting through a channel 2, whose direction is indicated by an arrow 3, four on a wall channel 4 in a direction parallel to the flow direction series of arranged electromechanical transducer 5, 6, 7, and 8, which are connected to a drive apparatus. 9 At least one channel wall is formed as described. With appropriate control the electromechanical transducer 5 ... 8 perform a movement perpendicular to the flow direction of the medium, so that the flow cross section of the channel 2 can be varied. By appropriate control of the converter 5 ... 8, the volume flow of the fluid can be adjusted to a desired value corresponding to the driving device 9 via an input 10 from the outside, for example via a communication link from a master controller, predetermined. With a flow sensor 11, the measurement signal 12 is guided e- benfalls on the drive apparatus 9, which respectively currently prevailing volume flow is detected. In the presence control device 9, the current flow is compared as an actual value with the predetermined flow rate as a target value ... 8 and changes the control of the converter 5 at any deviations such that the deviations are corrected. Since the micro-valve allows a precise fine adjustment of the flow rate, the predetermined value of the volume flow can be maintained very accurately.

In order to illustrate the operating principle of the micro-valve are shown in Figures 2 and 3 different motion states of electromechanical transducers 20 ... 27, which are installed in a wall 28 of a channel 29, is shown. Identical parts are provided in both figures with the same reference numerals. Perpendicular arrows indicate the respective movement direction of the transducer 20 ... 27th Since the wall 28 and the fastening of the transducer 20 ... may be formed in any desired manner in principle 27 cause its effective lower sides can perform the movements, the wall is merely indicated 28 in Figures 2 and 3 with broken lines. The converters 20 ... 27 perform by appropriate control with a in Figures 2 and 3 for clarity's sake not shown driving device up and down movements for the alternating change in the Strömungsquer- section. If a plurality of walls provided with active elements, opposite active elements are driven in unison. This reinforces the effect. The movements of adjacent transducers are in push-pull. In the embodiment shown in Figure 2 movement of the transducers 20, 22, 24 and 26 are moved downward, while the transducers 21, 23, 25 and 27 move upward. located in front of the bottom of the converter 20, 22, 24 and 26, medium is displaced during this movement and displaced in the resultant under the transducers 21, 23, 25 and 27 space. This Volumenverschie- environment of the fluid is indicated by curved arrows in the channel 29th A movement in exactly the reverse direction is shown in FIG 3. On both figures 2 and 3 it is clear that ... in the vicinity thereof vortices in alternating movement of the converter 20 27, which restrict the free flow cross section in the channel 29th The movement of the transducer 20 ... 27 changes the volume flow in the channel 29 on the one hand due to the actual change in the flow cross-section and on the other due to the eddy generated in the channel 29th Depending on the amplitude and frequency of the movements, a fine adjustment of the volume flow is thus enabled.

Based on the flow patterns in the figures 4 to 6, this should again be clarified. Figures 4 to 6 show flow lines resulting in a horizontally extending passage with a flow of a fluid from left to right. An electromechanical transducer 40 urges the flow according to Figure 4 only a little into the flow channel. Turbulence takes place here and there is hardly a largely laminar flow front. The free flow cross section of the channel is not changed.

In contrast, in Figure 5 an electromechanical transducer 50 projects static far into the duct and reduces the free channel cross-section substantially. In the vicinity of the transducer 50 caused turbulence being formed behind the converter 50, a large vortex 51 in the direction of flow. The volume flow is limited to a small range above the fluidized.

The transducer 60 shown in Figure 6 performs an alternating movement in the vertical direction. Although he similarly far protrudes in the middle in the channel as the transducer 50 shown in Figure 5, a substantially stronger vortex formation is obtained by the movement according to FIG. 6 The size of the turbulence leads to a further reduction of the residual volume flow in channel. It depends partly on the amplitude of the transducer movement and on the other by its frequency.

On the basis of Figures 5 and 6 is particularly clear that the dynamic movement of the transducer 60 has a considerable influence on the flow resistance of the channel and that thus an adjustment of the volume flow can be effected by changes in the dynamics in an advantageous manner.

Claims

claims
1. micro-valve for a volumetric flow of a fluid setting through a channel (2), characterized in that in at least one channel wall (4) is provided an array of at least two adjacent electromechanical transducers (8 5 ...), which are each formed in such a way are that through it the flow cross section of the channel (2) variable, and in that a drive device (9) for the converter (5 ... 8) is provided, by which mutually adjacent in the field transducer to an alternating variation of the flow cross-section in the are push-pull controllable.
2. Micro-valve according to claim 1, characterized in that the field-dimensional and substantially parallel to
The direction of flow (3) is aligned.
3. A microvalve according to claim 1 or 2, characterized in that the frequency of the alternating change in the flow cross section through the driving device (9) is variable.
4. A microvalve according to one of the preceding claims, characterized in that the electromechanical transducer (5 ... 8) are formed as capacitive or piezo-electric, micro-mechanical ultrasonic transducer.
PCT/EP2007/005535 2007-06-22 2007-06-22 Microvalve WO2009000284A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/EP2007/005535 WO2009000284A1 (en) 2007-06-22 2007-06-22 Microvalve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/EP2007/005535 WO2009000284A1 (en) 2007-06-22 2007-06-22 Microvalve

Publications (1)

Publication Number Publication Date
WO2009000284A1 true WO2009000284A1 (en) 2008-12-31

Family

ID=38573454

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2007/005535 WO2009000284A1 (en) 2007-06-22 2007-06-22 Microvalve

Country Status (1)

Country Link
WO (1) WO2009000284A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19735156C1 (en) * 1996-11-25 1999-04-29 Fraunhofer Ges Forschung Piezoelectric actuated microvalve
EP1215426A2 (en) * 2000-12-12 2002-06-19 Eastman Kodak Company Electrostrictive valve for modulating a fluid flow
US20030215342A1 (en) * 2002-03-27 2003-11-20 Kusunoki Higashino Fluid transferring system and micropump suitable therefor
US20040253123A1 (en) * 2003-01-15 2004-12-16 California Institute Of Technology Integrated electrostatic peristaltic pump method and apparatus
WO2005060593A2 (en) * 2003-12-10 2005-07-07 Purdue Research Foundation Micropump for electronics cooling
US20060145110A1 (en) * 2005-01-06 2006-07-06 Tzu-Yu Wang Microfluidic modulating valve

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19735156C1 (en) * 1996-11-25 1999-04-29 Fraunhofer Ges Forschung Piezoelectric actuated microvalve
EP1215426A2 (en) * 2000-12-12 2002-06-19 Eastman Kodak Company Electrostrictive valve for modulating a fluid flow
US20030215342A1 (en) * 2002-03-27 2003-11-20 Kusunoki Higashino Fluid transferring system and micropump suitable therefor
US20040253123A1 (en) * 2003-01-15 2004-12-16 California Institute Of Technology Integrated electrostatic peristaltic pump method and apparatus
WO2005060593A2 (en) * 2003-12-10 2005-07-07 Purdue Research Foundation Micropump for electronics cooling
US20060145110A1 (en) * 2005-01-06 2006-07-06 Tzu-Yu Wang Microfluidic modulating valve

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