SU993063A1

SU993063A1 - Frequency pickup of pressure

Info

Publication number: SU993063A1
Application number: SU813282620A
Authority: SU
Inventors: Юрий Михайлович Биянов; Виктор Петрович Лавров; Геннадий Александрович Панкратов
Original assignee: Предприятие П/Я В-2827
Priority date: 1981-05-14
Filing date: 1981-05-14
Publication date: 1983-01-30

Description

Изобретение относитс к контроль-нр-иэмерительной технике, в частности к частотным датчикам давлени , предназначенным дл измерени давлени в устройствах автоматического контрол и управлени .The invention relates to a control-and-measuring technique, in particular to frequency pressure sensors for measuring pressure in automatic control and monitoring devices.

Известны частотные датчики давлени , содержагдае в качестве резонатора анероидную коробку, образованную двум плоскими мембранами на кольцевых основани х, герметично скрепленных между собой. В корпусе датчика размещены системы возбуждени и съема колебаний Cl3.Frequency pressure sensors are known to contain, as a resonator, an aneroid box formed by two flat membranes on annular bases, tightly fastened together. In the sensor housing are located the systems of excitation and removal of Cl3 vibrations.

Основным недостатком таких датчиков вл етс их чувствительность к линейным ускорени м, к изменени м температуры, плотности и влажности газа.The main disadvantage of such sensors is their sensitivity to linear accelerations, to changes in temperature, density and gas humidity.

Известны также частотные датчики давлени ,. содержа1цие расположенный в корпусе упругий чувствительный элемент и дополнительный упругий элементу каждый из которых снабжен самосто тельными системами возбуждени и съема колебаний, включенных на смеситель частот 2 .Frequency pressure sensors are also known,. Contains a resilient sensing element located in a housing and an additional elastic element each of which is equipped with self-contained systems for exciting and picking up oscillations connected to frequency mixer 2.

Такие датчики защищены от вли ни линейных ускорений и других внешних вли ний. Однако вследствиеSuch sensors are protected from the effects of linear accelerations and other external influences. However, due to

того, что из полезного частотного сигнала вычитаетс , практически посто нный сигнал с дополнительного упругого , элемента, результирующа характеристика датчика обладает небольшой крутизной и, следовательно, невысокой чувствительностью и точностью.the fact that a practically constant signal from an additional elastic element is subtracted from the useful frequency signal, the resulting characteristic of the sensor has a small steepness and, consequently, low sensitivity and accuracy.

Цель изобретени - повышение чувствительности и точности.The purpose of the invention is to increase the sensitivity and accuracy.

10ten

Указанна цель достигаетс тем, что в частотном датчике давлени , содержащем упругий чувствительный элемент и дополнительный упругий элемент, снабженные системами возбуж15 дени и съема колебаний, включенных на смеситель частот, упом нутые упругие элементы выполнены в виде мембранных коробок, у одной из которых 20 образующие ее мембраны выполнены с предварительным прогибом внутрь, а у другой - наружу на величину, превышаюпою рабочий ход.This goal is achieved by the fact that in a frequency pressure sensor containing an elastic sensing element and an additional elastic element equipped with excitation and vibration pickup systems connected to the frequency mixer, said elastic elements are made in the form of membrane boxes, one of which has 20 membranes are made with a preliminary deflection inward, and the other - outward by an amount greater than the working stroke.

На фиг.1 показан предлагаемый частотный датчик давлени , обцщй вид, Figure 1 shows the proposed frequency pressure sensor, with a general view,

25 на фиг.2 - графическа зависимость частоты (f)OT давлени (Р).25 in Fig. 2 is a graphical dependence of the frequency (f) OT pressure (P).

Датчик состоит из корпуса 1, в котором размещены мембранные коробки 2 и 3, выполненные в виде анероидных The sensor consists of a housing 1 in which membrane boxes 2 and 3 are placed, made in the form of aneroid

Claims

30 boxes, while the aneroid box 2o & is developed from pre-bent inside membranes having a rigid base around the perimeter, and the box 3 is made from membranes having a preliminary deflection to the outside, with the amount of deflection of the membrane 3 of the box longer than normal. Membrane aneroid boxes are made by welding or soldering along the contour of two identical membrane membranes with rigid bases. Flat elastic suspensions 4 in the form of rings, which are attached to two brackets 5, for example, welding, are made together with aneroid boxes. In the brackets there are fixed systems of excitation 6 and removal of 7 oscillations, which are electromagnets. The crowns of the mattes have grooves 8 filled with a rubber-like mass tightly attached to the suspensions 4. Nylon boxes 2 and 3, brackets 5 with exciters b and receivers 7 are installed c. the housing 1 by means of the suspension 9 made, for example, in the form of gaskets of rubber-like mass. To bring the measured pressure inside the sensor, housing 1 has fitting 10. The sensor works as follows. The oscillations of the aneroid boxes 2 and 3 are excited by two autogenerators containing excitation systems b and picking up 7 oscillations with amplifiers 11. The frequency signal from the two autogenerators goes to the mixer 12, from the output of which the difference frequency is taken. In the absence of pressure in the housing, there is a certain frequency response at the output of the sensor. With increasing pressure, the natural frequency of oscillations f of the aneroid box 2 with concave membranes increases and the natural frequency f2 of the aneroid box 3 with convex membranes decreases (Fig. 2). . A signal equal to the difference between these frequencies is removed from the sensor output. In this case, the change in the resulting frequency at the same pressure values will be significantly greater. To reduce the acoustic communication between the excitation and pickup systems and the aneroid boxes, the latter are connected to brackets, in which electromagnetic exciters and vibration receivers are fixed with elastic rings made in one piece with the aneroid boxes, and acoustic isolation from the case is performed by fastening of oscillatory units with systems of excitation and removal of oscillations through an elastic gasket. Such an embodiment of the sensor allows, in addition to reducing the errors caused by the influence of external mechanical and climatic effects, to increase sensitivity and accuracy. The invention includes a frequency pressure sensor containing an elastic sensing element and an additional elastic element located in a housing, each of which is equipped with excitation and pickup systems connected to a frequency mixer, which also differs with an increase circuit in sensitivity and accuracy. and additional elastic elements in the form of membrane boxes, in one of which the membranes forming it are made with a preliminary deflection inward, and in the other - outward by an amount exceeding the working stroke. Sources of information taken into account during the examination 1. USSR author's certificate No. 263231, cl. G 01 L 11/00, 1967.

2. USSR author's certificate number 666450, cl. G 01 L 7/06, 1977 (prototype)

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