SU741077A1

SU741077A1 - Pressure sensor

Info

Publication number: SU741077A1
Application number: SU742084701A
Authority: SU
Inventors: Владимир Рубенович Варданян; Сергей Зармович Мамян
Original assignee: Ереванский политехнический институт им. К.Маркса
Priority date: 1974-12-18
Filing date: 1974-12-18
Publication date: 1980-06-15

Description

Изобретение относится к области контрольно-измерительной техники, в частности к датчикам давления.The invention relates to the field of instrumentation, in particular to pressure sensors.

Известны датчики давления, содержащие ' корпус , мембрану и пьезоэлемен· ты [1]. Недостатком датчиков является большая погрешность при регистрации медленно протекающих процессов.Known pressure sensors containing a housing, a membrane and piezoelectric elements [1]. The disadvantage of the sensors is a large error in the registration of slowly proceeding processes.

Известны также датчики давления, содержащие корпус, силопередающую систему в виде мембраны с жестким центром, выполненного за одно целое с ним толкателя и полки, а также электромеханические преобразователи деформации в электрический сигнал, зажатые между корпусом и полкой с обеих ее сторон и выполненные в виде упругих цилиндров с тенэорезисторами [2]. Эти датчики являются аналоговыми преобразователями и не обеспечивают высокой точности. Из-за низкой. собственной частоты упругих цилиндров быстродействие датчиков недостаточно.There are also known pressure sensors containing a housing, a power-transmitting system in the form of a membrane with a rigid center, made in one piece with a pusher and a shelf, as well as electromechanical converters of deformation into an electrical signal, sandwiched between the housing and the shelf on both sides and made in the form of elastic cylinders with teneoresistors [2]. These sensors are analog converters and do not provide high accuracy. Due to low. the natural frequency of elastic cylinders; the performance of the sensors is not enough.

В предлагаемом датчике с целью повышения точности измерений и быстродействия электромеханические преобразователи деформации в электрический сигнал выполнены в виде пьеэоре- 30 зона.торных преобразователей, а полка жестко соединена с толкателем. Кроме того, полка может быть выполнена за одно целое с толкателем. Пьезорезона5 торные преобразователи выполнены в виде пьезопластин, распределенных¹на пары, в каждой из которых они расположены с противоположных сторон полки и контактируют узкими гранями Ю с упорными стойками, размещенными на полке. Одна из пьезопластин, каждой пары включена во времязадающую цепь автогенератора, а другая — последовательно с выходом автогенера15 тора. С целью повышения чувствительности с одной из сторон полки между пьезопластинами и корпусом закреплена дополнительная полка и пара пьезопластин, контактирующая с дополнительной полкой и корпусом противоположными узкими гранями. Кроме того, пьезорезонаторные преобразователи выполнены в виде размещенных с обеих сторон полки пар упругих кольцевых 25 элементов с закрепленными внутри в диаметральной плоскости пьезорезонаторами, причем в каждой паре плоскость одного из пьезорезонаторов параллельна а плоскость другого перпендикулярна плоскости мембраны.In the proposed sensor, in order to improve the accuracy of measurements and speed, the electromechanical converters of deformation into an electric signal are made in the form of a pyeoreore 30 zone converters, and the shelf is rigidly connected to the pusher. In addition, the shelf can be made in one piece with the pusher. Piezon resonator 5 transducers are made in the form of piezoelectric plates distributed ¹ into pairs, in each of which they are located on opposite sides of the shelf and come in contact with narrow faces Yu with thrust posts placed on the shelf. One of the piezoelectric plates of each pair is connected to the oscillating circuit of the oscillator, and the other is connected in series with the output of the oscillator15. In order to increase the sensitivity on one side of the shelf between the piezoelectric plates and the body, an additional shelf and a pair of piezo plates are fixed, which are in contact with the opposite narrow edges in contact with the additional shelf and the body. In addition, piezoresonating transducers are made in the form of pairs of elastic annular 25 elements placed on both sides of the shelf with piezoresonators fixed inside in the diametrical plane, and in each pair the plane of one of the piezoresonators is parallel and the plane of the other is perpendicular to the membrane plane.

На фиг. 1 представлен датчик давления в разрезе; на фиг. 2 и 3 приведены схемы включения пьеэорезонаторов в радиотехническую схему; на фиг. 4 — вариант датчика повышенной чувствительности; на фиг» 5 — вариант датчика с электромеханическими преобразователями в виде упругих кольцевых элементов, содержащих пьезорезонаторы.In FIG. 1 shows a sectional pressure sensor; in FIG. Figures 2 and 3 show the connection diagrams of piezoresonators in a radio circuit; in FIG. 4 - version of the sensor increased sensitivity; in Fig. 5 is a variant of the sensor with electromechanical transducers in the form of elastic ring elements containing piezoresonators.

Датчик содержит корпус 1 и силопередающую систему в виде мембраны 2 с жестким центром, выполненным за одно целое с толкателем 3, и полкиThe sensor contains a housing 1 and a power transmitting system in the form of a membrane 2 with a rigid center, made in one piece with the pusher 3, and shelves

4. Полка 4 жестко соединена с толкателем 3 и может быть выполнена за одно целое с ним.4. The shelf 4 is rigidly connected to the pusher 3 and can be made in one piece with it.

Между корпусом 1 и полкой 4 с обеих её сторон с помощью шайбы 5 и втулки 6 зажаты электромеханические преобразователи деформации в электрический сигнал, выполненные в виде пьезорезонаторных преобразователей. Пьезорезонаторные преобразователи могут представлять собой пластины, распределенные на пары 7,. 8 и 9, 10, в каждой из которых они расположены с противоположных сторон полки и контактируют узкими противоплож ными гранями с полкой и корпусом. Плоскости пластин, разделенных пол-кой, перпендикулярны. На полке 4 с обеих ее сторон размещены пары упорных стоек 11, одна из которых выполнена с винтом 12. Пластины контактируют со стойками другими узкими гранями. Между стойками 11 и пластиной 8 установлены изоляторы 13. К корпусу прикреплена плата 14 с радиотехнической схемой, размещенная в экране.Between the housing 1 and the shelf 4 on both sides with the washer 5 and the sleeve 6 are clamped electromechanical strain transducers into an electrical signal, made in the form of piezoresonating transducers. Piezoresonant transducers can be plates distributed on pairs 7 ,. 8 and 9, 10, in each of which they are located on opposite sides of the shelf and in contact with narrow opposing faces with the shelf and the body. The planes of the plates separated by a half are perpendicular. On the shelf 4, on both sides of it there are pairs of thrust posts 11, one of which is made with a screw 12. The plates are in contact with the posts with other narrow faces. Between the racks 11 and the plate 8, insulators 13 are installed. A board 14 with a radio circuit located on the screen is attached to the housing.

В варианте включения на фиг. 2 одна из пластин каждой пары 7 и 9 присоединена к время задающим цепям автогенераторов 15, 16 соответственно, а другие-8 и 10 включены последовательно с выходами автогенераторов в цепи пьезоэлектрических фильтров с резисторами 17, 18. Выходы фильтров 19 и 20 соединены с балансным усилителем 21 и регистратором 22.In the embodiment of FIG. 2, one of the plates of each pair of 7 and 9 is connected to the time of the driving circuits of the oscillators 15, 16, respectively, and the other 8 and 10 are connected in series with the outputs of the oscillators in the piezoelectric filter circuit with resistors 17, 18. The outputs of the filters 19 and 20 are connected to a balanced amplifier 21 and registrar 22.

Пьезорезонаторные преобразователи имеют подстроечные конденсаторы С, —СЦ.Piezoresonator converters have tuning capacitors C, - SC.

В варианте включения на фиг. 3 пластины включены в схемы автогенераторов 23-26, выходы которых.попарно соединены со смесителями 27, 28. Смесители 27, 28 включены на вход оконечного смесителя 29, соединенного с Частотным дискриминатором 30 и регистратором 31.In the embodiment of FIG. 3 plates are included in the schemes of oscillators 23-26, the outputs of which are paired with mixers 27, 28. Mixers 27, 28 are connected to the input of the terminal mixer 29 connected to the Frequency discriminator 30 and the recorder 31.

В варианте датчика повышенной чувствительности на фиг. 4 между пьезопластинами 8, 10 и шайбой 5 закреплена дополнительная полка 32 и пара пьезопластин 33, 34, Пьезопластины включены в систему измерений по дифференциальной схеме.In an embodiment of the hypersensitivity sensor in FIG. 4 between the piezoelectric plates 8, 10 and the washer 5 an additional shelf 32 is fixed and a pair of piezoelectric plates 33, 34, the piezoelectric plates are included in the differential measurement system.

В варианте датчика на фиг. 5 пьезореэонаторные преобразователи выпол йены в виде пар упругих кольцевых элементов 35, 36 и 37, 38 с закрепленными внутри в диаметральной плоскости пьезорезонаторами 39, 40 и 41, 42 соответственно. В каждой паре плоскость одного из пьезорезонаторов параллельна, а плоскость другого перпендикулярна плоскости, мембраны 2.In the embodiment of the sensor in FIG. 5 piezoelectric transducers are made in the form of pairs of elastic ring elements 35, 36 and 37, 38 with piezoresonators 39, 40 and 41, 42 fixed respectively in the diametrical plane. In each pair, the plane of one of the piezoresonators is parallel, and the plane of the other is perpendicular to the plane of the membrane 2.

Датчик давления работает следующим образом.The pressure sensor operates as follows.

С помощью винтов 12 производят настройку частоты пьезорезонаторов. При действии давления мембрана 2 через толкатель и полку вызывает деформации противоположного знака у пьезорезонаторов каждой пары, в результате чего изменяются их собственные частоты. В датчике, включенном по схеме на фиг. 2, сигналы автогенераторов 15, 16 с зависящей от величины давления, частотой модулируются по амплитуде при прохождении через пьезоэлектрические фильтры, детектируются с помощью детекторов, усиливаются в балансном усилителе 21 и фиксируются регистратором 22.Using screws 12 adjust the frequency of the piezoresonators. Under the action of pressure, the membrane 2 through the pusher and the shelf causes deformations of the opposite sign in the piezoresonators of each pair, as a result of which their natural frequencies change. In the sensor included in the circuit of FIG. 2, the signals of the oscillators 15, 16 with a pressure-dependent frequency are modulated in amplitude when passing through piezoelectric filters, detected by detectors, amplified in a balanced amplifier 21 and recorded by a recorder 22.

В датчике, включенном по схеме на фиг. 3, изменения частоты пьезорезонаторов суммируются при помощи смесителей 27—29, преобразуются в частотном дискриминаторе 30 и регистрируются прибором 31.In the sensor included in the circuit of FIG. 3, changes in the frequency of piezoresonators are summarized using mixers 27–29, converted into a frequency discriminator 30, and recorded by the device 31.

Датчик обеспечивает высокую чувствительность, которую можно регулировать изменением числа пьезорезонаторов.The sensor provides high sensitivity, which can be adjusted by changing the number of piezoresonators.

Повышению быстродействия способствует непосредственная передача действующей нагрузки от силопередакцией системы к пьезорезонатору без промежуточных звеньев и жесткая конструкция силопередающей системы. Выполнение пьезорезонаторов с упругими кольцевыми элементами упрощает сборку и настройку датчика.Improving performance is facilitated by the direct transfer of the current load from the power transmission system to the piezoelectric resonator without intermediate links and the rigid structure of the power transmission system. The implementation of piezoresonators with elastic ring elements simplifies the assembly and configuration of the sensor.

Claims

The invention relates to the field of instrumentation technology, in particular to pressure sensors. Pressure sensors are known that include a housing, a membrane, and piezoelectric elements 1. A disadvantage of the sensors is a large error in the registration of slow-moving processes. Pressure sensors are also known, comprising a housing, a force-transmitting system in the form of a membrane with a rigid center, a pusher and shelves integral with it, as well as electromechanical transducers of deformation into an electrical signal, clamped between the housing and the shelf on both its sides and made in the form of elastic cylinders with strain gauges 2. These sensors are analog converters and do not provide high accuracy. Due to a low, natural frequency of elastic cylinders, the speed of the sensors is not enough. In the proposed sensor, in order to improve measurement accuracy and speed, electromechanical transducers of deformation into an electrical signal are made in the form of piezoresonator transducers, and the shelf is rigidly connected to the pusher. In addition, the shelf can be made in one piece with the pusher. The piezoresonator transducers are made in the form of piezoplates, which are divided into pairs, in each of which they are located on opposite sides of the shelf and come into contact with narrow faces with stop posts placed on the shelf. One of piezoplastin. each pair is turned on during the master oscillator circuit of the autogenerator, and the other - in series with the output of the autogenerator. In order to increase the sensitivity, from one side of the shelf between the piezoplates and the body an additional shelf is fixed and a pair of piezoplates, in contact with the additional shelf and the body with opposite narrow edges. In addition, piezoresonator transducers are made in the form of pairs of elastic ring elements placed on both sides of the shelf with piezoresonators mounted inside in the diametral plane, with each pair of flat one of the zoner blades parallel to the plane of the other perpendicular to the membrane plane. FIG. 1 shows a sectional pressure sensor; in fig. 2 and 3 are diagrams for the incorporation of pieoreresonators into a radio engineering circuit; in fig. 4 - variant of the sensor sensitivity; in fig. 5 shows a variant of a sensor with electromechanical converters in the form of elastic annular elements containing piezoresonators. The sensor includes a housing 1 and a power transmission system in the form of a membrane 2 with a rigid center, made in one piece with the pusher 3, and shelves 4. Shelf 4 is rigidly connected to the pusher 3 and can be made in one piece with it. Between case 1 and shelf 4, on both of its sides, washers 5 and bushings 6 clamp electromechanical transducers of deformation into an electrical signal, made in the form of piezoresonator transducers. Piezoresonator transducers can be plates with their own, divided into pairs 7, 8 and 9, 10, in each of which they are located on opposite sides of the shelf and come into contact with narrow opposite faces with the shelf and housing. The planes of the plates, separated by a shelf, are perpendicular. On the shelf 4 on both sides there are pairs of support posts 11, one of which is made with screw 12. The plates are in contact with the posts of other narrow edges. Insulators 13 are installed between the pillars 11 and the plate 8. A board 14 is attached to the case with a radio engineering circuit placed in a screen. In the embodiment shown in FIG. 2 one of the plates of each pair 7 and 9 is connected to the time setting circuits of the autogenerators 15, 16, respectively, and the others 8 and 10 are connected in series with the outputs of the autogenerators in the circuit of piezoelectric filters with resistors 17, 18. The outputs of the filters 19 and 20 are connected with balanced amplifier 21 and recorder 2. Piezorezonator converters have trimming capacitors C, -C. In the embodiment shown in FIG. 3 plates are included in the circuits of the autogenerators 23-26, the outputs of which are connected in pairs with the mixers 27, 28. The connectors 27, 28 are connected to the input of the window mixer 29 connected to the frequency discriminator 30 and the recorder 31. In the sensor variant increased sensitivity in FIG. 4 between the piezo plates 8, 10 and the washer 5 is fixed on the additional shelf 32 and a pair of piezoplates 33, 34. The piezoplates are included in the measurement system according to a differential scheme. In the embodiment of the sensor in FIG. 5, piezoresonator transducers are made in the form of pairs of elastic annular elements 35, 36 and 37, 38 with piezoresonators 39, 40 and 41, 42 fixed inside in the diametral plane, respectively. In each pair, the plane of one of the piezoresonators is paraillary, and the plane of the other is perpendicular to the plane of membrane 2. The pressure sensor works as follows. Using screws 12, the frequency of the piezoresonators is adjusted. Under the action of pressure, the membrane 2 through the plunger and the flange causes deformations of the opposite sign in the piezoresonators of each pair, as a result of which their own frequencies change. In the sensor included in the circuit in FIG. 2, the signals of the autogenerators 15, 16, depending on the pressure value, are frequency modulated in amplitude as they pass through the piezoelectric filters, detected with the help of detectors, amplified in a balanced amplifier 21 and recorded by the recorder 22. In the sensor connected as shown in FIG. 3, the frequency changes of the piezoresonators are summed with the help of mixers 27-29-, converted into frequency discriminator 30, and recorded by instrument 31. The sensor provides high sensitivity, which can be adjusted by changing the number of piezoresonators. The increase in speed is facilitated by the direct transfer of the actual load from the system power switches to the piezoresonator without intermediate links and the rigid construction of the power transmission system. The implementation of piezoresonator with elastic ring elements simplifies the assembly and adjustment of the sensor. Claim 1. Pressure transducer comprising a body, a force-transmitting system in the form of a membrane With a rigid center, a pusher and a shelf integral with it, as well as electromechanical transducers of deformation into an electrical signal, clamped between the body and the shelf on both its sides, characterized by that, in order to improve the measurement accuracy and speed of the sensor, electromechanical transducers of deformation into an electrical signal are made in the form of piezoresonator transducers, and the shelf is rigidly connected to Lkatel. 2. A sensor according to claim 1, characterized in that the shelf B is integral with the pusher. 3. A pop sensor, 1, characterized in that the Piezoresonator transducers: 9 are made in the form of pyeoplastins, arranged in pairs in each of which they are located on opposite sides of the shelf and come into contact with narrow faces with the supporting struts placed on the shelf. 4. The sensor according to claim 3, characterized in that one of the piezoplates of each pair is turned on during the oscillator circuit of the autogenerator, and the other in series with the output of the autogenerator. 5. The sensor according to claim 3, characterized in that, in order to increase sensitivity, an additional shelf and a pair of piezoplates, in contact with the additional shelf and body with opposite narrow edges, are fixed on one side of the shelf between the piezoplates and the body 6. Sensor Claim 1, characterized in that the piezoresonator transducers are made in the form of pairs of elastic annular elements placed on both sides of the shelf with piezoresonators mounted inside in the diametral plane, and in each pair the plane of one of the piezo resonators parallel, and the plane of the other perpendicular to the membrane plane. Sources of information taken into account in the examination 1.Ageykin DM and others. Sensors of control and regulation. M. Machine Building, 1965, p. 619.

2.Agaykin DI and others. Sensors of control and regulation. M., Machine Building, 1965, p. 65-66 (prototype).

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