CH247026A - Pressure transducer with at least one prestressed piezo-electric crystal. - Google Patents
Pressure transducer with at least one prestressed piezo-electric crystal.Info
- Publication number
- CH247026A CH247026A CH247026DA CH247026A CH 247026 A CH247026 A CH 247026A CH 247026D A CH247026D A CH 247026DA CH 247026 A CH247026 A CH 247026A
- Authority
- CH
- Switzerland
- Prior art keywords
- dependent
- pressure transducer
- pressure
- piezo
- transducer according
- Prior art date
Links
- 239000013078 crystal Substances 0.000 title claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 239000011888 foil Substances 0.000 claims description 5
- 238000005070 sampling Methods 0.000 claims description 5
- 238000002485 combustion reaction Methods 0.000 claims description 4
- 229910052709 silver Inorganic materials 0.000 claims description 4
- 239000004332 silver Substances 0.000 claims description 4
- 239000004020 conductor Substances 0.000 claims description 3
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 3
- 229910052737 gold Inorganic materials 0.000 claims description 3
- 239000010931 gold Substances 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims 6
- 238000000605 extraction Methods 0.000 claims 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 230000036316 preload Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910000906 Bronze Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- 238000005034 decoration Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L23/00—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid
- G01L23/08—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically
- G01L23/10—Devices or apparatus for measuring or indicating or recording rapid changes, such as oscillations, in the pressure of steam, gas, or liquid; Indicators for determining work or energy of steam, internal-combustion, or other fluid-pressure engines from the condition of the working fluid operated electrically by pressure-sensitive members of the piezoelectric type
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Description
Druckaufnehmer mit mindestens einem vorgespannten piezo-elektrischen Kristall.
Die Erfindung bezieht sich auf einen Druckaufnehmer mit mindestens einem vorgespannten piezo-elektrischen Eristall, der besonders vorteilhaft anwendbar ist bei Ver brennungsmotoren.
Bei bekannten Druckaufnehmern dieser Art werden die Entnahmeelektroden häufig auf chemischem Wege, z. B. durch Reduzie- rung einer Metallverbindung auf den elektrisch wirksamen Eristalloberflächen angebracht. Durch diese Weise des Anbringens eines Metallbelages wird, wie aus der keramischen Dekorationstechnik und der Kondensatorherstellung bekannt ist, eine besonders haltbare Verbindung ohne Luftein schlüsse und dergl. zwischen Unterlage und Belag erhalten. Solch ein guter Eontakt zwischen Kristall und Elektrode ist im vorliegenden Fall von Wichtigkeit, um einen grösstmöglichen Teil der bei Druck auf der wirksamen Eristalloberfläche auftretenden elektrischen Ladung ausnutzen zu können.
Die Erfindung hat den Zweck, einen Druckaufnehmer zu schaffen, bei dem die Entnahmeelektrode auf besonders einfache Weise am Kristall angebracht ist. Der Druckaufnehmer gemäss der Erfindung zeichnet sich dadurch aus, dass die elektrisch wirksamen Kristalloberflächen so genau geschlif- fen worden sind, dal3 sich keine für das blouse Auge wahrnehmbaren Eratzer zeigen und dass die zugehörigen Entnahmeelektroden je aus einem Belag bestehen, der zunächst lose auf die geschliffene Oberfläche gelegt worden ist und der durch die Vorspannungsmittel gegen diese Oberfläche gedrückt wird.
Überraschenderweise wird bei Ausfüh- rungsformen dieses Druckaufnehmers und bei Anwendung einer Vorspannung von etwa 50 kg/cm2 eine gleich groRe Ladungsände- rung bei Änderung der Eristallbelasttmg er- halten wie bei den erwähnten, bekannten Eristall-Druckaufnehmern bei hoheren Vor spannungen sogar eine annähernd l, 5mal so grosse Ladungsänderung.
Es sei dabei ausdrücklich bemerkt, daB bei mit ungenügender Genauigkeit geschliffe- ner Oberfläche und/oder beim Nichtvorhan- densein der Vorspannung kein praktisch brauchbarer"gontakt"zwischen gristall und Entnahmeelektrode erhalten wird.
Um zu verhindern, dass der Kristall zerbricht, wenn er unter Vorspannung gebracht wird, und im Einblick auf die Empfindlichkeit, hat es sich als vorteilhaft erwiesen, wenn der Belag aus einem Metall besteht, dessen Härte wesentlich geringer als die des Eristalles ist.
Ferner soll das Belagmetall, insbesondere bei verhÏltnismÏ?ig hohen Temperaturen (von 150 bis500 C)auszusetzendenDruck- aufnehmern, wie beispielsweise f r Verbrennungsmotoren, kein die elektrische Leitung stark verschlechterndes Oxyd ergeben. Brauchbar sind Zink, Kadmium, Zinn, Wolfram.
MolybdÏn, Eisen, Silber, Gold. Es ist dabei zu bemerken, dass trotz des Schliffes und der Vorspannung eine Oxydationstattfinden, kann.
Es ergab sich, dass im Zusammenhang mit den beiden letztgenannten Anforderungen bei einem Quarzkristall insbesondere Silber und Gold sich gut bewahrten ; beide Metalle sind genügend temperaturbeständig und ergeben gutleitende Oxyde. Als Belag wird vorzugsweise eine Metallfolie mit einer Stärke von 45-55 Mikron angewendet. Vorzugsweise wird der Belag mit Hilfe einer Druckvertei- lungsplatte an den Kristall gedrückt, so da? eine gleichmässige Oberflächenbelastung der Elektrode erhalten werden, während dabei die Druckverteilungsplatte au?erdem als An schlussstelle für den mit der Elektrode zu verbindenden Anschlussleiter dienen kann.
In der beiliegenden Zeichnungisteinebeispielsweise Ausführungsform des Druckauf- nehmers gemÏ? der Erfindung dargestellt.
Der Druckaufnehmer 1 weist die beiden genannten gegeneinandergeschalteten Kri- stalle 2, 3 auf, deren Arbeitspunkt in an sich bekannter Weise durch die von einer als Hülse 4 ausgebildeten Vorspannungsfeder herr hrende Vorspannung. eingestellt ist.
Diese Vorspannung wird ausserdem dazu benutzt, um die zunächst lose auf die Kristalloberflächen gelegten Silberfolien 5 mit einer Stärke von 30 Mikron mittels Druckvertei lungsplatten 6 an die elektrisch wirksamen EjistaJIoberfläcbenzudrücken, die so gut geschliffen sind, dass von blossem Auge keine Gratter wahrnehmbar sind. Die Abnahmeelektroden 5 der Kristalle sind durch Ver mittlung der Druckverteilungsstücke 6 mit der äMasse" bezw. mit einem Anschlussleiter 7 verbunden. Die Vorspannungshülse 4, die am einen Ende mittels einer Membran 8 abgeschlossen ist, ist in einem Halter 9 untergebracht, der in eine Zylinderwand eingeschraubt werden kann.
Zum Schutz der Mem- bran 8 gegen übermässig hohe Temperaturen ist eine im Haltef befestigte, durchlochte Kühlplatte 10 aus Aluminiumbronze vorgesehen.
Pressure transducer with at least one prestressed piezo-electric crystal.
The invention relates to a pressure transducer with at least one preloaded piezo-electric Eristall, which is particularly advantageously applicable to internal combustion engines.
In known pressure transducers of this type, the sampling electrodes are often chemically, e.g. B. by reducing a metal connection attached to the electrically effective Eristalloberflächen. This way of attaching a metal coating, as is known from ceramic decoration technology and capacitor manufacture, a particularly durable connection without air inclusions and the like. Between the base and the coating. Such a good contact between crystal and electrode is important in the present case in order to be able to utilize the largest possible part of the electrical charge that occurs when pressure is applied to the active surface of the eristal.
The aim of the invention is to create a pressure sensor in which the sampling electrode is attached to the crystal in a particularly simple manner. The pressure transducer according to the invention is characterized in that the electrically active crystal surfaces have been ground so precisely that there are no visible scratches that can be seen by the naked eye and that the associated sampling electrodes each consist of a coating that is initially loosely applied to the ground Surface has been laid and which is pressed against this surface by the biasing means.
Surprisingly, with embodiments of this pressure transducer and when a preload of about 50 kg / cm2 is used, a charge change of the same size as the known Eristall pressure transducers mentioned above is obtained with a change in the preload. 5 times the change in charge.
It should be expressly noted here that if the surface is ground with insufficient accuracy and / or if there is no preload, no practically useful "contact" is obtained between the crystal and the sampling electrode.
In order to prevent the crystal from breaking when it is brought under tension, and in view of the sensitivity, it has proven to be advantageous if the coating consists of a metal whose hardness is significantly lower than that of the crystal.
Furthermore, the covering metal should not result in an oxide that would severely deteriorate the electrical conduction, especially at relatively high temperatures (from 150 to 500 C) to be exposed to pressure transducers, such as for internal combustion engines. Zinc, cadmium, tin, tungsten can be used.
Molybdenum, iron, silver, gold. It should be noted that, despite the grinding and the pretensioning, oxidation can take place.
It was found that in connection with the last two requirements mentioned above, silver and gold in particular performed well in a quartz crystal; both metals are sufficiently temperature resistant and result in highly conductive oxides. A metal foil with a thickness of 45-55 microns is preferably used as the covering. The covering is preferably pressed against the crystal with the aid of a pressure distribution plate so that? a uniform surface loading of the electrode can be obtained, while the pressure distribution plate can also serve as a connection point for the connection conductor to be connected to the electrode.
In the accompanying drawing, for example, an embodiment of the pressure transducer according to of the invention shown.
The pressure sensor 1 has the two mentioned crystals 2, 3 connected against one another, the working point of which is known per se by the prestressing resulting from a prestressing spring designed as a sleeve 4. is set.
This bias is also used to press the silver foils 5 with a thickness of 30 microns, which are initially loosely placed on the crystal surfaces, by means of pressure distribution plates 6 against the electrically effective EjistaJIoberfläcben, which are so well ground that no burrs can be seen with the naked eye. The pick-up electrodes 5 of the crystals are connected to the "ground" or to a connection conductor 7 through the intermediary of the pressure distribution pieces 6 can be screwed in.
In order to protect the membrane 8 against excessively high temperatures, a perforated cooling plate 10 made of aluminum bronze and fastened in the holder is provided.
Claims (1)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL247026X | 1943-04-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CH247026A true CH247026A (en) | 1947-02-15 |
Family
ID=19780891
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CH247026D CH247026A (en) | 1943-04-06 | 1944-04-04 | Pressure transducer with at least one prestressed piezo-electric crystal. |
Country Status (1)
| Country | Link |
|---|---|
| CH (1) | CH247026A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE834763C (en) * | 1948-08-06 | 1952-03-24 | Schweizerische Lokomotiv | Piezoelectric pressure indicator |
| DE1236827B (en) * | 1963-04-05 | 1967-03-16 | Kistler Instrumente Ag | Piezoelectric pressure transducer and method and device for its assembly |
| DE1245171B (en) * | 1963-04-05 | 1967-07-20 | Kistler Instrumente Ag | Piezoelectric pressure transducer |
| DE3330411A1 (en) * | 1983-08-23 | 1985-03-14 | Siemens AG, 1000 Berlin und 8000 München | Piezoelectric transducer |
| DE19602048A1 (en) * | 1996-01-20 | 1997-07-24 | Karlsruhe Forschzent | Pressure wave sensor |
-
1944
- 1944-04-04 CH CH247026D patent/CH247026A/en unknown
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE834763C (en) * | 1948-08-06 | 1952-03-24 | Schweizerische Lokomotiv | Piezoelectric pressure indicator |
| DE1236827B (en) * | 1963-04-05 | 1967-03-16 | Kistler Instrumente Ag | Piezoelectric pressure transducer and method and device for its assembly |
| DE1245171B (en) * | 1963-04-05 | 1967-07-20 | Kistler Instrumente Ag | Piezoelectric pressure transducer |
| DE1236827C2 (en) * | 1963-04-05 | 1973-02-08 | Kistler Instrumente Ag | Piezoelectric pressure transducer and method and device for its assembly |
| DE3330411A1 (en) * | 1983-08-23 | 1985-03-14 | Siemens AG, 1000 Berlin und 8000 München | Piezoelectric transducer |
| DE19602048A1 (en) * | 1996-01-20 | 1997-07-24 | Karlsruhe Forschzent | Pressure wave sensor |
| DE19602048C2 (en) * | 1996-01-20 | 1999-07-01 | Karlsruhe Forschzent | Pressure wave sensor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE3811311C1 (en) | ||
| DE3036676C2 (en) | Piezoelectric vibration sensor | |
| DE1416028B2 (en) | Process for the production of a transducer acting as a thickness shear transducer | |
| EP2011170B1 (en) | Method for the production of a piezo actuator | |
| DE3423590A1 (en) | OXYGEN PROBE | |
| CH630459A5 (en) | ELECTRIC LIGHTER. | |
| EP0016858A1 (en) | Piezoelectric transducer for mounting in pressure, force or acceleration sensing devices | |
| DE2830778C2 (en) | Electrochemical measuring sensor with improved adhesive strength of the electrode system on the solid electrolyte | |
| DE2617731C3 (en) | Miniature pressure transducer | |
| EP0173800A2 (en) | Electrochemical measuring cell with a complementary electrode | |
| DE1285575B (en) | Process for the production of a multilayer piezo element | |
| DE3702412A1 (en) | PRESSURE SENSOR WITH A SILICONE BODY | |
| DE19834461A1 (en) | Multi-layer piezo actuator | |
| CH247026A (en) | Pressure transducer with at least one prestressed piezo-electric crystal. | |
| EP0226742A2 (en) | Pressure transducer for measuring pressures at high temperatures | |
| DE102014117911A1 (en) | Pressure measuring cell | |
| DE1646795C3 (en) | Carrier body for a semiconductor body of a semiconductor arrangement and method for its production | |
| DE2520622A1 (en) | SPARK PLUG FOR COMBUSTION MACHINERY | |
| DE2022652A1 (en) | Semiconductor converters that respond to mechanical stress | |
| DE1039434B (en) | Spark generator for igniting explosive bodies and process for its manufacture | |
| EP0180071A1 (en) | Measuring probe | |
| DE2361643C2 (en) | Method and device for fastening a fitting on a non-metallic part | |
| DE2445805C3 (en) | Process for the production of a button to be actuated with a properly directed pressure force exerted by the finger | |
| DE3208456C2 (en) | Piezoelectric oscillating system | |
| DE2730416A1 (en) | DEVICE FOR IGNITION VOLTAGE DISTRIBUTION IN IGNITION SYSTEMS OF COMBUSTION MACHINERY |