WO1982001041A1 - Electropneumatic converter - Google Patents
Electropneumatic converter Download PDFInfo
- Publication number
- WO1982001041A1 WO1982001041A1 PCT/CH1981/000101 CH8100101W WO8201041A1 WO 1982001041 A1 WO1982001041 A1 WO 1982001041A1 CH 8100101 W CH8100101 W CH 8100101W WO 8201041 A1 WO8201041 A1 WO 8201041A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- capillary tube
- pneumatic
- pressure
- electrical converter
- converter according
- Prior art date
- Legal status (The legal status 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 status listed.)
- Ceased
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L13/00—Devices or apparatus for measuring differences of two or more fluid pressure values
- G01L13/04—Devices or apparatus for measuring differences of two or more fluid pressure values using floats or liquids as sensing elements
Definitions
- the present invention relates to a pneumatic-electrical converter with a control part which can be connected to a pneumatic circuit and which responds to pressure differences in the pneumatic circuit and with an electrical signal part which can be excited by the control part.
- Converters of this type are summarized in "Taschenbuch Maschinenbau” l / II 1980, VEB Verlagtechnik, Berlin / pages 979 and 930 and are used to solve a large number of control problems in the most varied areas of technology, for example the transmission of signals over a long time Distances or, for example, as a converter for pneumatic-electrical control systems for level control of liquid or gaseous media, for overpressure display etc.
- An essential component of such known pneumatic-electrical converters is a double diaphragm relay that can be connected to the pressure lines of the pneumatic circuit and that connects directly to the electrical signal part with a contact set or with an electromagnet interacts.
- transducers are structurally very complex, in particular with regard to the clamping technology on the membranes, and are therefore relatively expensive.
- the service life of such transducers is also limited in particular due to signs of fatigue on the membranes.
- the detection sensitivity is relatively low and the switching sequence is relatively slow. Additional means are also required for reversible signals.
- the pressure-differential control part comprises a capillary tube arrangement which is at least partially filled with a liquid which can be set under the pressure of the gaseous medium in the pneumatic circuit; and that the elek trical signal part comprises at least one capacitive or inductive or optoelectric measuring cell, the measuring zone can be enforced by the liquid column in the capillary tube arrangement.
- Such a converter which can be referred to as a capillary pressure differential switch
- Rapid pressure changes so-called pressure jumps, on the other hand, can be critical if the liquid column thrown up under the pressure jump partially penetrates the pressure line in question, which can result in considerable disturbances in the pressure-differential control part, in particular if the part of the liquid column penetrating the pressure line is separated from the rest Part separates. In itself, this can be countered by appropriate lengths of the capillary tube legs, but this should generally lead to nonsensical sizes.
- the pneumatic-electrical converter according to the invention is therefore expediently designed such that an expansion chamber arrangement extends between the pneumatic circuit and the capillary tube.
- each capillary tube leg opening into its own expansion chamber into which one of the pressure lines of the pneumatic circuit opens at a distance from and above the relevant capillary tube opening.
- the configuration is further made such that baffles are located in the flow path of the expansion chamber between the capillary tube mouth and the mouth of the pressure line in question. It is useful if part of the ski kanen flow dividers and another part of the baffles are barriers forming traps.
- baffles expediently have cutting edges directed against the capillary tube mouths.
- expansion combs expand laterally and vertically from the capillary tube mouths to the mouth of the pressure lines, which allows a further reduction in the construction volume.
- the capillary tube arrangement and the expansion chambers together with their baffles are molded in a housing, preferably a plastic housing.
- the converter is supplemented by the electrical signal part in such a way that in the area of the capillary tube arrangement, above the level of the liquid in equilibrium columns in the capillary tube legs extends the measuring zone of the electrical signal part, the electrical signal part is expediently a proximity switch.
- This arrangement then allows reversible signaling. It is of course also possible for only one capillary tube leg to be located in, or both, each in a separate measuring field of the electrical signal part.
- FIG. 1 is a schematic diagram of the pneumatic-electrical converter according to the invention.
- FIG. 2 shows a plan view of a practical embodiment of a pneumatic-electrical converter, along the section line II - II in FIG. 3;
- FIG. 3 shows a section through the arrangement according to FIG. 2 along the section line III-III in FIG. 2.
- the pneumatic-electrical converter shown schematically in FIG. 1 comprises a pressure-differential control part 10, which responds to pressure differences in a pneumatic working circuit indicated by pressure lines 4 and 5 and which cooperates here with an opto-electrical signal part 20, which can also be capacitive or inductive.
- the pressure-differential control part 10 is essentially formed by a capillary tube arrangement, which is formed here from a U-shaped capillary tube with the capillary tube 12 and 13.
- This capillary tube which is of course essentially vertical in use, is up to level 30 with a control liquid 11, for example water, distilled water or the like. filled, with the two liquid columns in the capillary tube legs 12 and 13 are in the equilibrium state of the device under the same pressure of the medium of the connected pneumatic working group.
- This working group or its pressure lines 4 and 5 are each connected to the end of the capillary tube legs 12 and 13 via suitable coupling means 6.
- the optoelectric signal part 20, which interacts with the pressure-differentiated control part 10, comprises a light emitter diode 21, which emits its emitted light pulses to a photocell 22, at which a recordable output signal 23 appears.
- the measuring zone of the measuring cell 21, 22 formed in this way is penetrated here by the capillary tube leg 13, the measuring zone being directly above the equilibrium level 30.
- a pressure drop in the pressure line 4 or a pressure increase in the pressure line 5 now causes an increase in the liquid column in the capillary tube leg 13 beyond the level 30, which part of the liquid column now passes through the measuring zone of the measuring cell 21, 22 and a signal change at the output of the photocell 22 causes.
- a further measuring cell 21, 22 can also be arranged in the area of the other capillary tube leg 12 for reversible signaling. Furthermore, it is easily possible for both capillary tube branches 12 and 13 to pass through the measuring zone of the measuring cell 21, 22 together.
- FIGS. 2 and 3 A practical embodiment of the pneumatic-electrical converter according to the invention can now be seen from FIGS. 2 and 3.
- the pressure-differential control 10 is surrounded by a housing 35, preferably made of at least partially transparent plastic, in the lower region of which the U-shaped capillary tube with the capillary tube legs 12 and 13 is molded in again.
- control part 20 which cooperates with the pressure-differential control part 10, is arranged with its measuring zones directly above the equilibrium level 30 of the liquid columns in the capillary tube legs 12 and 13.
- This control part 20 is a conventional capacitive proximity switch with a supply circuit 24 and a conductor 25 on which the output signal 23 appears.
- the capillary tube legs 12 and 13 open out at points 16 and 17 into an expansion chamber 14 and 15, which chambers are also molded in the housing 35.
- the expansion chambers 14 and 15 each open into a pressure line 4 and 5, which are flanged to the housing 35 again by means of suitable coupling means 6, substantially distant from the capillary tube openings 16 and 17.
- the expansion chambers 14 and 15 widen laterally from the capillary tube mouths 16 and 17 to the mouth 44 and 55 of the pressure line 4 and 5 in question, and also, as FIG. 3 clearly shows, also in height .
- FIG. 2 also shows that sieves 18 and 19 are located in the flow path of the expansion chambers 14 and 15 between the capillary tube mouths 16 and 17 and the mouths 44 and 55 of the pressure lines in question.
- the baffles 18 form Flow dividers, whereas the baffles are 19 barriers that form traps.
- the baffles 18 and 19 have cutting edges 18 'and 19' directed against the capillary tube mouths 16 and 17, respectively, which serve to "break open" bubbles that are forming.
- the pneumatic-electrical converter according to the invention is not limited to the above-described embodiments.
- any configuration of the expansion chambers and the type and arrangement of the baffles are located in the expansion chambers.
- an expansion chamber with preferably baffles between the capillary tube mouth and the pressure line mouth is arranged for the lowest overall height of the transducer and in particular the capillary tube arrangement without the risk of a part of the liquid column pushed up under a pressure jump being thrown into one of the pressure lines.
- a pneu results from the above Matic-electrical converter, which is suitable to meet all conditions to be placed on such converters.
- this results in a converter of high sensitivity and optimal detection sensitivity with a robust, simple, space-saving and practically maintenance-free design.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
Le convertisseur electro-pneumatique comporte une partie de commande (10) sensible a une difference de pression, pouvant etre reliee aux conduites (4, 5) d'un circuit pneumatique et presentant un dispositif a tubes capillaires (12, 13) dispose dans un boitier (35) et partiellement rempli d'un liquide (11) soumis a la pression du circuit pneumatique. Le dispositif a tubes capillaires (12, 13) coopere avec un commutateur de proximite (20), dont la zone de mesure se trouve au-dessus du niveau d'equilibre (30) du liquide (11) present dans ce dispositif a tubes capillaires (12, 13). Entre chacune des embouchures (16, 17) des tubes capillaires et l'embouchure (44, 45) de la conduite correspondante (4, 5) est situee une chambre d'expansion (14, 15) comportant des chicanes (18, 19). Ce convertisseur est de construction simple, ne necessite pas d'entretien, a une duree de vie pratiquement illimitee et presente une fiabilite absolue et une meilleure sensibilite.The electro-pneumatic converter comprises a control part (10) sensitive to a pressure difference, which can be connected to the lines (4, 5) of a pneumatic circuit and having a capillary tube device (12, 13) arranged in a housing (35) and partially filled with a liquid (11) subjected to the pressure of the pneumatic circuit. The capillary tube device (12, 13) cooperates with a proximity switch (20), the measurement area of which is above the equilibrium level (30) of the liquid (11) present in this capillary tube device (12, 13). Between each of the mouths (16, 17) of the capillary tubes and the mouth (44, 45) of the corresponding pipe (4, 5) is located an expansion chamber (14, 15) comprising baffles (18, 19) . This converter is of simple construction, does not require maintenance, has a practically unlimited lifespan and presents an absolute reliability and a better sensitivity.
Description
Pneumatiach-elektrischer Wandler Pneumatic-electrical converter
Die vorliegende Erfindung betrifft einen pneumatisch- elektrischen Wandler mit einem an einen pneumatischen Kreis anschliessbaren, auf Druckdifferenzen im pneumatischen Kreis ansprechenden Steuerteil und mit einem, vom Steuerteil erregbaren elektrischen Signalteil.The present invention relates to a pneumatic-electrical converter with a control part which can be connected to a pneumatic circuit and which responds to pressure differences in the pneumatic circuit and with an electrical signal part which can be excited by the control part.
Wandler dieser Art sind im "Taschenbuch Maschinenbau" l/II 1980, VEB Verlag Technik, Berlin / Seiten 979 und 930 zusammenfassend dargestellt und dienen der Lösung einer grossen Anzahl Steuerprobleme in den verschiedensten Bereichen der Technik, beispielsweise der Uebertra- gung von Signalen über lange Entfernungen oder beispielsweise als Umformer für pneumatisch-elektrische Steuersysteme zur Niveauregulierung von flüssigen oder gasförmigen Medien, zur Ueberdruckanzeige etc.Converters of this type are summarized in "Taschenbuch Maschinenbau" l / II 1980, VEB Verlag Technik, Berlin / pages 979 and 930 and are used to solve a large number of control problems in the most varied areas of technology, for example the transmission of signals over a long time Distances or, for example, as a converter for pneumatic-electrical control systems for level control of liquid or gaseous media, for overpressure display etc.
Wesentlicher Bestandteil von solchen bekannten pneumatisch-elektrischen Wandlern ist ein an die Druckleitungen des pneumatischen Kreises anschliessbares Doppelmembranrelais, welches direkt mit einem Kontaktsatz oder mit einem Elektromagneten des elektrischen Signalteiles zu sammenwirkt.An essential component of such known pneumatic-electrical converters is a double diaphragm relay that can be connected to the pressure lines of the pneumatic circuit and that connects directly to the electrical signal part with a contact set or with an electromagnet interacts.
Solche Wandler sind allerdings konstruktiv sehr aufwendig, insbesondere, was die Einspanntechnik an den Membranen anbetrifft, und somit relativ teuer. Die Funktionsdauer solcher Wandler ist zudem insbesondere wegen Ermüdungserscheinungen an den Membranen beschrankt. Ferner ist die Nachweisempfindlichkeit relativ niedrig und die Schaltsequenz relativ trage. Zudem sind für reversible Signale zusätzliche Mittel notwendig.However, such transducers are structurally very complex, in particular with regard to the clamping technology on the membranes, and are therefore relatively expensive. The service life of such transducers is also limited in particular due to signs of fatigue on the membranes. Furthermore, the detection sensitivity is relatively low and the switching sequence is relatively slow. Additional means are also required for reversible signals.
Es ist deshalb Aufgabe der Erfindung, einen pneumatischelektrischen Wandler der vorgenannten Art zu schaffen, welcher von einfachster Bauart, wartungsfrei, von praktisch unbegrenzter Lebensdauer und absolut funktionssicher bei einer höchsten Nachweisempfindlichkeit und optimal hoher Ansprechgeschwindigkeit ist.It is therefore an object of the invention to provide a pneumatic-electrical converter of the aforementioned type, which is of the simplest type, maintenance-free, of practically unlimited service life and absolutely reliable with a high detection sensitivity and an optimally high response speed.
Dies wird nun erfindungsgemass dadurch erreicht, dass der druckdifferente Steuerteil eine Kapillarrohranordnung umfasst, die wenigstens teilweise mit einer, unter den Druck des gasförmigen Mediums im pneumatischen Kreis stellbaren Flüssigkeit gefüllt ist; und dass der elek trische Signalteil mindestens eine kapazitive oder induktive oder optoelektrische Messzelle umfasst, deren Messzone von der Flüssigkeitssäule in der Kapillarrohr anordnung durchsetzbar ist.This is now achieved according to the invention in that the pressure-differential control part comprises a capillary tube arrangement which is at least partially filled with a liquid which can be set under the pressure of the gaseous medium in the pneumatic circuit; and that the elek trical signal part comprises at least one capacitive or inductive or optoelectric measuring cell, the measuring zone can be enforced by the liquid column in the capillary tube arrangement.
Aus der Physik ist bekannt, dass die Flüssigkeitssäule im Kapillarrohr auf die geringsten Druckänderungen reagiert, was eine höchste Nachweisempfindlichkeit und optimalste Ansprechgeschwindigkeit garantiert. Zudem ist die Kapillarrohranordnung einfach herzustellen, absolut funktionssicher und wartungsfrei.It is known from physics that the liquid column in the capillary tube reacts to the slightest pressure changes, which guarantees the highest detection sensitivity and the best possible response speed. In addition, the capillary tube arrangement is easy to manufacture, absolutely reliable and maintenance-free.
Allerdings ist ein solcher, als kapillarer Druckdifferenzschalter bezeichenbarer Wandler vorzugsweise nur in Steuersysteme einsetzbar, in denen relativ langsame Druckänderungen erfolgen. Schnelle Druckänderungen, sogenannte Drucksprünge, können hingegen dann kritisch sein, wenn die unter dem Drucksprung hochgeschleuderte Flüssigkeitssäule teilweise in die betreffende Druckleitung eindringt, woraus sich erhebliche Störungen im druckdifferenten Steuerteil ergeben können, insbesondere, wenn sich der in die Druckleitung eindringende Teil der Flüssigkeitssäule vom übrigen Teil trennt. An sich kann dem durch entsprechende Längen der Kapillarrohrschenkel begegnet werden, was aber in der Regel zu unsinnigen Baugrössen führen dürfte.However, such a converter, which can be referred to as a capillary pressure differential switch, can preferably only be used in control systems in which relatively slow pressure changes occur. Rapid pressure changes, so-called pressure jumps, on the other hand, can be critical if the liquid column thrown up under the pressure jump partially penetrates the pressure line in question, which can result in considerable disturbances in the pressure-differential control part, in particular if the part of the liquid column penetrating the pressure line is separated from the rest Part separates. In itself, this can be countered by appropriate lengths of the capillary tube legs, but this should generally lead to nonsensical sizes.
Zweckmässig wird deshalb der erfindungsgemässe pneumatisch-elektrische Wandler so ausgestaltet, dass sich zwischen dem pneumatischen Kreis und dem Kapillarrohr eine Expansionskammeranordnung erstreckt.The pneumatic-electrical converter according to the invention is therefore expediently designed such that an expansion chamber arrangement extends between the pneumatic circuit and the capillary tube.
Hierbei ist die Ausgestaltung zweckmässig derart, dass das Kapillarrohr U-förmig ausgebildet ist, wobei jeder Kapillarrohrschenkel in eine, eigene Expansionskammer ausmündet, in welche, distanziert von und oberhalb der betreffenden Kapillarrohrmündung eine der Druckleitungen des pneumatischen Kreises einmündet.The design is expediently such that the capillary tube is U-shaped, each capillary tube leg opening into its own expansion chamber into which one of the pressure lines of the pneumatic circuit opens at a distance from and above the relevant capillary tube opening.
Um dabei das Bauvolumen nicht nur der Kapillarrohranordnung, sondern auch der Expansionskammern möglichst auf ein Minimum zu halten, wird die Ausgestaltung ferner so getroffen, dass sich im Strömungsweg der Expansionskammer zwischen der Kapillarrohrmundung und der Mündung der betreffenden Druckleitung Schikanen befinden. Zweckmässig ist es dann, wenn ein Teil der Schi kanen Strömungsteiler und ein anderer Teil der Schikanen Fangräume bildende Sperren sind.In order to keep the construction volume not only of the capillary tube arrangement but also of the expansion chambers to a minimum, the configuration is further made such that baffles are located in the flow path of the expansion chamber between the capillary tube mouth and the mouth of the pressure line in question. It is useful if part of the ski kanen flow dividers and another part of the baffles are barriers forming traps.
Es ist bekannt, dass bei der Expansion einer Flüssigkeit unter Druck diese schäumt und Blasen bildet. Um wenigstens einen Teil dieser Blasen zu zerstören, weisen die Schikanen zweckmässig gegen die Kapillarrohrmündungen gerichtete Schneiden auf.It is known that when a liquid expands under pressure, it foams and forms bubbles. In order to destroy at least some of these bubbles, the baffles expediently have cutting edges directed against the capillary tube mouths.
Ferner ist es von Vorteil, wenn sich die Expansions kammsrn von den Kapillarrohrmündungen her zur Mündung der Druckleitungen hin sowohl seitlich als auch in der Höhe erweitern, was eine weitere Verringerung des Bauvolumens gestattet.It is also advantageous if the expansion combs expand laterally and vertically from the capillary tube mouths to the mouth of the pressure lines, which allows a further reduction in the construction volume.
Für eine optimale Herstellung des druckdifferenten Steuerteils ist es von Vorteil, wenn die Kapillarrohranordnung sowie die Expansionskammern samt deren Schikanen in einem Gehäuse, vorzugsweise Kunststoffgshäuse eingeformt sind. Hierbei wird der Wandler durch den elektrischen Signalteil derart ergänzt, dass sich im Bereich der Kapillarrohranordnung, oberhalb des Niveaus der sich im Gleichgewicht befindlichen Flüssigkeits säulen in den Kapillarrohrschenkeln die Messzone des elektrischen Signalteiles erstreckt, wobei der elektrische Signalteil zweckmässig ein Annäherungsschalter ist. Diese Anordnung gestattet dann eine reversible Signalgabe. Dabei ist es natürlich auch möglich, dass nur ein Kapillarrohrschenkel im oder aber beide je in einem eigenen Messfeld des elektrischen Signalteiles liegen.For an optimal production of the pressure-differential control part, it is advantageous if the capillary tube arrangement and the expansion chambers together with their baffles are molded in a housing, preferably a plastic housing. Here, the converter is supplemented by the electrical signal part in such a way that in the area of the capillary tube arrangement, above the level of the liquid in equilibrium columns in the capillary tube legs extends the measuring zone of the electrical signal part, the electrical signal part is expediently a proximity switch. This arrangement then allows reversible signaling. It is of course also possible for only one capillary tube leg to be located in, or both, each in a separate measuring field of the electrical signal part.
Durch diese Massnahmen ist es nunmehr möglich, einen pneumatisch-elektrischen Wandler von sehr einfacher, kompakter und absolut funktionssicherer Bauweise zu konzipieren, der sich universell einsetzen lässt und der sich durch eine bisher nicht erreichte hohe Nachweis- und Ansprechempfindlichkeit auszeichnet.These measures now make it possible to design a pneumatic-electrical converter of very simple, compact and absolutely reliable design that can be used universally and is characterized by a previously unattainable level of detection and response sensitivity.
Beispielsweise Ausführungsformen des Erfindungsgegenstandes sind nachfolgend anhand der Zeichnung näher erläutert.. Es zeigen:For example, embodiments of the subject matter of the invention are explained in more detail below with reference to the drawing.
Fig. 1 eine Prinzipskizze des erfindungsgemässen pneumatisch-elektrischen Wandlers; Fig. 2 eine Draufsicht auf eine praktische Ausführungsform eines pneumatisch-elektrischen Wandlers, entlang der Schnittlinie II - II in Fig. 3; undFigure 1 is a schematic diagram of the pneumatic-electrical converter according to the invention. FIG. 2 shows a plan view of a practical embodiment of a pneumatic-electrical converter, along the section line II - II in FIG. 3; and
Fig. 3 einen Schnitt durch die Anordnung gemäss Fig. 2 entlang der Schnittlinie III - III in Fig. 2.3 shows a section through the arrangement according to FIG. 2 along the section line III-III in FIG. 2.
Der in Fig. 1 schematisch dargestellte pneumatisch-elektrische Wandler umfasst einen, auf Druckdifferenzen in einen durch Druckleitungen 4 und 5 angedeuteten pneumatischen Arbeitskrais ansprechenden druckdifferenten Steuerteil 10, welcher hier mit einem optoelektrischen Signalteil 20, der auch kapazitiv oder induktiv sein kann, zusammenwirkt.The pneumatic-electrical converter shown schematically in FIG. 1 comprises a pressure-differential control part 10, which responds to pressure differences in a pneumatic working circuit indicated by pressure lines 4 and 5 and which cooperates here with an opto-electrical signal part 20, which can also be capacitive or inductive.
Der druckdifferente Steuerteil 10 wird im wesentlichen von einer Kapillarrohranordnung gebildet, die hier aus einem U-förmigen Kapillarrohr mit den Kapillarrohr schenkeln 12 und 13 gebildet ist. Dieses Kapillarrohr, das im Gebrauch natürlich im wesentlichen senkrecht steht, ist bis zum Niveau 30 mit einer Steuerflüssigkeit 11, beispielsweise Wasser, destilliertes Wasser o.dgl. gefüllt, wobei die beiden Flüssigkeitssäulen in den Kapillarrohrschenkeln 12 und 13 im Gleichgewichtszustand der Einrichtung unter dem gleichen Druck des Mediums des angeschlossenen pneumatischen Arbeitskreises stehen. Dieser Arbeitskreis bzw. dessen Druckleitungen 4 und 5 sind über geeignete Kupplungsmittel 6 jeweils mit dem Ende der Kapillarrohrschenkel 12 bzw. 13 verbunden.The pressure-differential control part 10 is essentially formed by a capillary tube arrangement, which is formed here from a U-shaped capillary tube with the capillary tube 12 and 13. This capillary tube, which is of course essentially vertical in use, is up to level 30 with a control liquid 11, for example water, distilled water or the like. filled, with the two liquid columns in the capillary tube legs 12 and 13 are in the equilibrium state of the device under the same pressure of the medium of the connected pneumatic working group. This working group or its pressure lines 4 and 5 are each connected to the end of the capillary tube legs 12 and 13 via suitable coupling means 6.
Der mit dem druckdifferenten Steuerteil 10 zusammenwirkende optoelektrische Signalteil 20 umfasst eine Lichtemitter-Diode 21, welche ihre emittierten Lichtimpulse an eine Photozelle 22 abgibt, an welcher ein registrierbares Ausgangssignal 23 erscheint. Die Messzone der so gebildeten Messzelle 21,22 wird hier vom Kapillarrohr schenkel 13 durchsetzt, wobei sich die Messzone unmittelbar über dem Gleichgewichtsniveau 30 befindet.The optoelectric signal part 20, which interacts with the pressure-differentiated control part 10, comprises a light emitter diode 21, which emits its emitted light pulses to a photocell 22, at which a recordable output signal 23 appears. The measuring zone of the measuring cell 21, 22 formed in this way is penetrated here by the capillary tube leg 13, the measuring zone being directly above the equilibrium level 30.
Ein Druckabfall in der Druckleitung 4 bzw. ein Druckanstieg in der Druckleitung 5 bewirkt nun eine Erhöhung der Flüssigkeitssäule im Kapillarrohrschenkel 13 über das Niveau 30 hinaus, welcher Teil der Flüssigkeits säule nun die Messzone der Messzelle 21,22 durchsetzt und eine Signaländerung am Ausgang der Photozelle 22 bewirkt. An dieser Stelle sei üemerkt, daas für eine reversible Signalgebung eine weitere Messzelle 21,22 auch im Bereich des anderen Kapillarrohrschenkels 12 angeordnet sein kann. Weiter ist es ohne weiteres möglich, dass beide Kapillarrohrscbenkel 12 und 13 gemeinsam die Messzone der Messzelle 21,22 durchsetzen.A pressure drop in the pressure line 4 or a pressure increase in the pressure line 5 now causes an increase in the liquid column in the capillary tube leg 13 beyond the level 30, which part of the liquid column now passes through the measuring zone of the measuring cell 21, 22 and a signal change at the output of the photocell 22 causes. At this point it should be noted that a further measuring cell 21, 22 can also be arranged in the area of the other capillary tube leg 12 for reversible signaling. Furthermore, it is easily possible for both capillary tube branches 12 and 13 to pass through the measuring zone of the measuring cell 21, 22 together.
Aus den Figuren 2 und 3 ist nun eine praktische Ausführungsform des erfindungsgemassen pneumatisch-elektrischen Wandlers erkennbar.A practical embodiment of the pneumatic-electrical converter according to the invention can now be seen from FIGS. 2 and 3.
Bei diesem Wandler wird der druckdifferente Steuerten 10 von einem Gehäuse 35, vorzugsweise aus wenigstens teilweise transparentem Kunststoff umgeben, in dessen unterem Bereich wieder das U-förmige Kapillarrohr mit den Kapillarrohrschenkeln 12 und 13 hier eingeformt ist.In this converter, the pressure-differential control 10 is surrounded by a housing 35, preferably made of at least partially transparent plastic, in the lower region of which the U-shaped capillary tube with the capillary tube legs 12 and 13 is molded in again.
Auch hier ist der mit dem druckdifferenten Steuerteil 10 zusammenwirkende Steuerteil 20 mit seiner Messzαne unmittelbar über dem Gleichgewichtsniveau 30 der Flüssigkeitssäulen in den Kapillarrohrschenkeln 12 und 13 angeordnet. Dieser Steuerteil 20 ist hier ein üblicher kapazitiver Annäherungsschalter mit einem Speisekreis 24 und einem Leiter 25, an dem das Ausgangssignal 23 erscheint.Here too, the control part 20, which cooperates with the pressure-differential control part 10, is arranged with its measuring zones directly above the equilibrium level 30 of the liquid columns in the capillary tube legs 12 and 13. This control part 20 is a conventional capacitive proximity switch with a supply circuit 24 and a conductor 25 on which the output signal 23 appears.
Wie nun insbesondere Fig. 2 erkennen lässt, münden die Kapillarrohrschenkel 12 und 13 an den Stellen 16 bzw. 17 in eine Expansionskammer 14 bzw. 15 ein, welche Kammern ebenfalls im Gehäuse 35 eingeformt sind. Wesentlich distanziert von den Kapillarrohrmündungen 16 und 17 münden dann die Expansionskammern 14 bzw. 15 je in eine Druckleitung 4 bzw. 5 aus, die wieder über geeignete Kupplungsmittel 6 am Gehäuse 35 angeflanscht sind.As can now be seen in particular in FIG. 2, the capillary tube legs 12 and 13 open out at points 16 and 17 into an expansion chamber 14 and 15, which chambers are also molded in the housing 35. The expansion chambers 14 and 15 each open into a pressure line 4 and 5, which are flanged to the housing 35 again by means of suitable coupling means 6, substantially distant from the capillary tube openings 16 and 17.
Wie Fig. 2 zeigt, erweitern sich die Expansionskammern 14 und 15 von den Kapillarrohrmundungen 16 bzw. 17 her zur Mündung 44 bzw. 55 der betreffenden Druckleitung 4 bzw. 5 hin seitlich und zudem, wie Fig. 3 deutlich zeigt, auch in der Höhe.As FIG. 2 shows, the expansion chambers 14 and 15 widen laterally from the capillary tube mouths 16 and 17 to the mouth 44 and 55 of the pressure line 4 and 5 in question, and also, as FIG. 3 clearly shows, also in height .
Weiter lässt Fig. 2 auch erkennen, dass sieb im Strömungsweg der Expansionskammern 14 und 15 zwischen den Kapillarrohrmundungen 16 bzw. 17 und den Mündungen 44 bzw. 55 der betreffenden Druckleitungen 4 bzw. 5 Schikanen 18 und 19 befinden. Die Schikanen 18 bilden dabei Strömungsteiler, wogegen die Schikanen 19 Fangräume bildende Sperren sind. Wie deutlich aus Fig. 2 erkennbar, weisen die Schikanen 18 und 19 gegen die Kapillarrohrmundungen 16 bzw. 17 gerichtete Schneiden 18' bzw. 19' auf, welche dem "Aufbrechen" von sich bildenden Blasen dienen.Furthermore, FIG. 2 also shows that sieves 18 and 19 are located in the flow path of the expansion chambers 14 and 15 between the capillary tube mouths 16 and 17 and the mouths 44 and 55 of the pressure lines in question. The baffles 18 form Flow dividers, whereas the baffles are 19 barriers that form traps. As can be clearly seen from FIG. 2, the baffles 18 and 19 have cutting edges 18 'and 19' directed against the capillary tube mouths 16 and 17, respectively, which serve to "break open" bubbles that are forming.
Selbstverständlich beschränkt sich der erfindungsgemässe pneumatisch-elektrische Wandler nicht auf die vorbeschriebenen Ausführungsformen. Beispielsweise liegt ohne weiteres im Rahmen des Erfindungsgedankens jede beliebige Ausgestaltung der Expansionskammern sowie die Art und Anordnung der Schikanen in den Expansionskammern.Of course, the pneumatic-electrical converter according to the invention is not limited to the above-described embodiments. For example, within the scope of the inventive concept, any configuration of the expansion chambers and the type and arrangement of the baffles are located in the expansion chambers.
Wesentlich ist, dass für eine geringste Bauhöhe des Wandlers und insbesondere der Kapillarrohranordnung ohne die Gefahr eines Hineinschleuderns eines Teiles der unter einem Drucksprung hochgedrückten Flüssigkeitssäule in eine der Druckleitungen eine Expansiαnskammer mit vorzugsweise Schikanen zwischen Kapillarrohrmundung und Druckleitungsmündung angeordnet wird.It is essential that an expansion chamber with preferably baffles between the capillary tube mouth and the pressure line mouth is arranged for the lowest overall height of the transducer and in particular the capillary tube arrangement without the risk of a part of the liquid column pushed up under a pressure jump being thrown into one of the pressure lines.
Aus dem Vorbeschriebenen ergibt sich somit ein pneu matisch-elektrischer Wandler, welcher geeignet ist, alle an solche Wandler zu stellenden Bedingungen zu erfüllen. Insbesondere ergibt sich ein Wandler von hoher Ansprechempfindlichkeit und optimalster Nachweisempfindlichkeit bei insgesamt einer robusten, einfachen, raumsparenden und praktisch wartungsfreien Konzeption. A pneu results from the above Matic-electrical converter, which is suitable to meet all conditions to be placed on such converters. In particular, this results in a converter of high sensitivity and optimal detection sensitivity with a robust, simple, space-saving and practically maintenance-free design.
Claims
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU75354/81A AU7535481A (en) | 1980-09-22 | 1981-09-08 | Electropneumatic converter |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH7076/80800922 | 1980-09-22 | ||
| CH707680A CH642453A5 (en) | 1980-09-22 | 1980-09-22 | Pneumatic-electrical transformer. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1982001041A1 true WO1982001041A1 (en) | 1982-04-01 |
Family
ID=4319556
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CH1981/000101 Ceased WO1982001041A1 (en) | 1980-09-22 | 1981-09-08 | Electropneumatic converter |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0060260A1 (en) |
| CH (1) | CH642453A5 (en) |
| WO (1) | WO1982001041A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107543638A (en) * | 2016-06-28 | 2018-01-05 | 深圳长城开发科技股份有限公司 | Stannum plaster scribing knife pressure test device and its detection method based on foil gauge |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6274975B1 (en) | 1999-04-01 | 2001-08-14 | Thomson Licensing S.A. | Color picture tube having a tension mask attached to a frame |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB901210A (en) * | 1959-10-06 | 1962-07-18 | Ass Elect Ind | Manometers or tilt gauges for deriving electrical quantities dependent on liquid levels |
| GB1023042A (en) * | 1962-05-07 | 1966-03-16 | Wayne Kerr Lab Ltd | Improvements in or relating to pressure responsive apparatus |
| US3745348A (en) * | 1968-04-26 | 1973-07-10 | Mtu Muenchen Gmbh | Electric differential pressure converter for the control of probes in the direction of flow |
-
1980
- 1980-09-22 CH CH707680A patent/CH642453A5/en not_active IP Right Cessation
-
1981
- 1981-09-08 WO PCT/CH1981/000101 patent/WO1982001041A1/en not_active Ceased
- 1981-09-08 EP EP19810902480 patent/EP0060260A1/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB901210A (en) * | 1959-10-06 | 1962-07-18 | Ass Elect Ind | Manometers or tilt gauges for deriving electrical quantities dependent on liquid levels |
| GB1023042A (en) * | 1962-05-07 | 1966-03-16 | Wayne Kerr Lab Ltd | Improvements in or relating to pressure responsive apparatus |
| US3745348A (en) * | 1968-04-26 | 1973-07-10 | Mtu Muenchen Gmbh | Electric differential pressure converter for the control of probes in the direction of flow |
Non-Patent Citations (3)
| Title |
|---|
| ATM Archiv fur Technisches Messen, page J132-6, published in October 1971, A. GUYH "Eine Automatische Digitale Vielfach-Druckmessvorrichtung Teil I" pages 209-212, see page 212, 3.5. Scanning Devices * |
| ATM Messtechnische Praxiz, issued 474/475 (July/August 1975) "Hochgenause Druckmessergerat mit nur 0.005 % Fehlergrenze" see page R119 * |
| IBM Technical Disclosure Bulletin, Volume 20, Nr. 10, published in March 1975 (New York, US) F. HENDRIKS u.a. "Electrical Micromanometer" see the whole article * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107543638A (en) * | 2016-06-28 | 2018-01-05 | 深圳长城开发科技股份有限公司 | Stannum plaster scribing knife pressure test device and its detection method based on foil gauge |
| CN107543638B (en) * | 2016-06-28 | 2023-10-13 | 深圳长城开发科技股份有限公司 | Solder paste scraper pressure testing device based on strain gauge and detection method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CH642453A5 (en) | 1984-04-13 |
| EP0060260A1 (en) | 1982-09-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE1619899A1 (en) | Device for separating the gas and liquid components in a flow | |
| DE1962804A1 (en) | Differential pressure measuring device | |
| DE2652405A1 (en) | PROCEDURE AND FILTER FOR FILTERING A LIQUID | |
| EP0416146A1 (en) | Device for the separation of solid particles and fluids with an elevated density from fluids having a lower density | |
| DE2510762C3 (en) | Device for measuring the flow | |
| EP0060260A1 (en) | Electropneumatic converter | |
| DE1148771B (en) | Gas and liquid flow meter with variable aperture | |
| DE19916953A1 (en) | Device for displaying and / or checking fluids | |
| EP0049756B1 (en) | Device for measuring differential pressure | |
| DE1536852C (en) | ||
| DE2359839A1 (en) | SPINDLE NOZZLE CONSTRUCTION WITH FILTRATION CAVITY | |
| DE1655404C3 (en) | Refill container for a hydraulically operated two-circuit brake system, in particular for motor vehicles | |
| DE20307912U1 (en) | Leakage indicator for a filter element of a filter press | |
| DE2419350A1 (en) | VALVE | |
| DE2207664C2 (en) | Jet pipe of a steam jet condenser | |
| DE2542025B2 (en) | Electronic heat meter | |
| DE2452181A1 (en) | Flow monitor esp. for cooling circuit - gives clear indication of flow stoppage due to blockages etc. | |
| DE102022203627A1 (en) | Microfluidic device | |
| DE382969C (en) | Device for displaying the liquid level | |
| DE2759390C3 (en) | Filling and control device for a battery | |
| DE823461C (en) | Arrangement for influencing electrical components in LF or HF devices | |
| DE2749907A1 (en) | PRESSURE DISPLAY DEVICE | |
| DE1942145A1 (en) | Fluid powered storage device | |
| DE363845C (en) | Contact column consisting of a metal tube with insulated inserted contact pins for measuring devices with electrical display or measurement, in particular for differential manometers | |
| DE484290C (en) | Device for rocking mercury scales with liquid level indicators. like |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Designated state(s): AU BR DK JP NO SU US |
|
| AL | Designated countries for regional patents |
Designated state(s): AT DE FR GB LU NL SE |