CN1198118C

CN1198118C - Gas flow sensor

Info

Publication number: CN1198118C
Application number: CN 03138705
Authority: CN
Inventors: 刘冬
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-24
Filing date: 2003-06-24
Publication date: 2005-04-20
Anticipated expiration: 2023-06-24
Also published as: CN1470851A

Abstract

The present invention relates to a gas flow sensor which comprises a tubular outer shell, a tubular inner shell is inserted into the inner cavity of the outer shell, a tubular inner film is inserted into the inner cavity of the inner shell, a vibration cavity and a vibration transmitting passage communicated with the vibration cavity are arranged on the inner shell, the vibration cavity is arranged along the inner circular surface of the inner shell, and an induction film piece for blocking the vibration transmitting passage is arranged on the inner shell, and is connected with a metal column. The gas flow sensor has the advantages of simple structure, low cost, low pressure loss of measured gas and high measuring accuracy.

Description

Gas flow sensor

Technical field

The present invention relates to a kind of gas flow sensor.

Background technology

Gas meter is the device of measurement gas flow, and its critical component is a sensor.General gas meter can be divided into four kinds of vane type, toll bar Scroll-tupe, hot-wire and hot diaphragm types basically.The sensor of this gas meter of four types, its common drawback is complex structure, cost height, and the pressure loss is big, and sensitivity is low, measuring accuracy is poor.It as the patent No. 92204506.2 gas meter, in the disclosed technical scheme, its Sensor section is included in to be provided with in the passage of gas by the gas that flows and promotes rotation and have the impeller of big and small blade, be fixed with the permanent-magnet steel body on the impeller, on the circumference corresponding, be fixed with electromagnetic sensor with impeller, when the gas that flows promotes the impeller rotation, the permanent-magnet steel body that is fixed on the impeller also rotates thereupon, the permanent-magnet steel body is every through electromagnetic sensor once, the duty of electromagnetic sensor just takes place once to change, and produces electric signal output.The sensor of the described gas meter of this patent, owing in the passage of gas, be provided with impeller and the big and small blade that hinders gas flow, thereby the pressure loss of tested gas is big, complex structure.The patent No. is 97220720.1 displacement-type gas flow sensor, comprise upper chamber and lower chamber, upper chamber and lower chamber are separated by by rubber diaphragm movably, upper chamber is communicated with air intake opening, lower chamber is communicated with the gas outlet, when air intake opening and gas outlet produce pressure reduction, when flow in the gas outlet, rubber diaphragm produces displacement to gas under the promotion of this pressure reduction from air intake opening, thereby make the photoelectric reflection plate that links to each other with rubber diaphragm produce displacement accordingly, this displacement makes photoelectrical coupler export corresponding electric signal.The described displacement-type gas flow sensor of this patent have baroque drawback equally, and sensitivity is low, and measuring accuracy is poor.

Summary of the invention

The purpose of this invention is to provide a kind of simple in structure, the pressure loss is little and measuring accuracy is high gas flow sensor.

In order to realize above-mentioned purpose, this gas flow sensor, comprise shell in a tubular form, its design feature is the inner casing that is plugged with in the inner chamber of this shell in a tubular form, is plugged with inner membrance in a tubular form in the inner chamber of this inner casing, inner casing is provided with vibration cavity and the biography that is communicated with vibration cavity is shaken passage, wherein vibration cavity is along the inner headed face setting of inner casing, the biography passage that shakes extends in the shell, is equipped with on inner casing the shake reaction diaphragm of carrier frequency channel break of biography, is connected to metal column on the reaction diaphragm.

Working environment, the flow range of gas and the accuracy requirement of measurement according to the gas meter of adapted, the quantity of above-mentioned vibration cavity is 1 or 2-3, because the pressure of tested gas, the isoparametric variation of temperature meeting produce different influences to the work of difform vibration cavity, in order to eliminate deviation, improve measuring accuracy, vibration cavity can be annular, semi-circular or circular arc, by the variation of the corresponding relation that vibrates between the different vibration cavity, get rid of the influence that other parameter beyond the flow changes.

According to the working environment of the gas meter of adapted and the accuracy requirement of measurement, above-mentioned reaction diaphragm comprises rheostat diaphragm, piezoelectric type diaphragm and condenser type diaphragm.

For the ease of making and installing, the reaction diaphragm potting is on the periphery of inner casing.

During use, gas flow sensor of the present invention is serially connected in flange in the pipeline of tested gas, metal column is connected with the signal input part of gas meter by lead.

The principle of work of gas flow sensor of the present invention is: when measured gas flows through from the inner membrance of tubulose, endocardial wall can produce vibration, particularly be positioned at the position of vibration cavity, its vibration is more obvious, this vibration enters through vibration cavity and passes the passage that shakes, make the generation vibration of reaction diaphragm correspondence, type according to selected reaction diaphragm, the sense film sector-meeting is transformed into electric signal with this vibration, be delivered to gas meter through metal column and lead, material when each parts of sensor, after size and dimension is determined, the frequency of its vibration, parameter such as waveform and amplitude just constitutes corresponding relation with the flow velocity of gas, and the frequency of vibration, the isoparametric change of waveform and amplitude, can on reaction diaphragm, produce corresponding electric signal, this electric signal is input to the cpu chip of gas meter, carries out data processing, can obtain the gas flow in certain period by cpu chip.

Gas flow sensor of the present invention, its beneficial effect is: 1, only used shell, inner casing, inner membrance and reaction diaphragm, geometric configuration is standard again, thereby structure is simple especially, and cost is low; 2, the barrier barrier gas of no impeller blade one class flows in the inner chamber of inner membrance, and the pressure loss of tested gas is little; 3, the heat conduction time that does not need heat conduction formula sensor, reaction diaphragm is fast to the variation response speed of vibration, the induction sensitivity height; 4, because discernible parameter is many, cpu chip can in time be proofreaied and correct according to the comprehensive parameters of gas in the gas meter, thereby the measuring accuracy height.

Description of drawings

The embodiment of gas flow sensor of the present invention is illustrated in conjunction with the accompanying drawings, wherein:

Fig. 1 is that the quantity of vibration cavity is the structural representation of 1 gas flow sensor;

Fig. 2 is the A-A cut-open view of Fig. 1;

Fig. 3 is that the quantity of vibration cavity is the structural representation of 2 gas flow sensor;

Fig. 4 is the structural representation of rheostat diaphragm;

Fig. 5 is the schematic diagram of rheostat diaphragm;

Fig. 6 is the structural representation of piezoelectric type diaphragm;

Fig. 7 is the schematic diagram of piezoelectric type diaphragm;

Fig. 8 is the structural representation of condenser type diaphragm;

Fig. 9 is the schematic diagram of condenser type diaphragm.

Embodiment

With reference to accompanying drawing, gas flow sensor of the present invention, comprise plastic casing 4 in a tubular form, in the inner chamber of this shell 4, be plugged with plastic inner shell 2 in a tubular form, in the inner chamber of this inner casing 2, be plugged with inner metallic membrane 1 in a tubular form, inner casing 2 is provided with 1-3 vibration cavity 5 and the biography that is communicated with each vibration cavity 5 is respectively shaken passage 6, wherein each vibration cavity 5 is along the inner headed face setting of inner casing 2, the reaction diaphragm 3 of passage 6 blocking-up of respectively each biography being shaken is housed on inner casing 2, be connected to metal column 9 on every reaction diaphragm 3, vibration cavity 5 can be an annular, semi-circular or circular arc, reaction diaphragm 3 comprises the rheostat diaphragm, piezoelectric type diaphragm and condenser type diaphragm according to needing, also can be selected the reaction diaphragm of other types for use, reaction diaphragm 3 best pottings pass the passage 6 that shakes and extend in the shell 4 on the periphery of inner casing 2.

When reaction diaphragm 3 is selected the rheostat diaphragm for use, the vibration of rheostat diaphragm, change attached to the resistance correspondence of the strain resistor on the silica gel sheet 78, utilize the principle of resistance bridge, determine the contact position 10 of metal column 9 and silica gel sheet 7, rheostat diaphragm resistance R 1, R2, R3 and R4 resistance when static state are equated, at the input end energized V of this electric bridge _B, when vibration, resistance R 1, R2, R3 and R4 resistance are unequal, and the output terminal of electric bridge has voltage V _OOutput.When reaction diaphragm 3 is selected the piezoelectric type diaphragm for use, piezoelectric element 13 is when vibration, just at the reed generation voltage V between electrode 11 and the battery lead plate 12 that holds concurrently _OOutput.When reaction diaphragm 3 is selected the condenser type diaphragm for use, reed hold concurrently the vibration change of electrode 11 and the electric capacity between the battery lead plate 12 make output voltage V by discharging and recharging of electric capacity _OChange.

Claims

1, a kind of gas flow sensor, comprise shell (4) in a tubular form, it is characterized in that in the inner chamber of this shell (4), being plugged with inner casing (2) in a tubular form, in the inner chamber of this inner casing (2), be plugged with inner membrance (1) in a tubular form, inner casing (2) is provided with vibration cavity (5) and the biography that is communicated with vibration cavity (5) is shaken passage (6), wherein vibration cavity (5) is along the inner headed face setting of inner casing (2), the biography passage (6) that shakes extends in the shell (4), on inner casing (2), be equipped with the shake reaction diaphragm (3) of passage (6) blocking-up of biography, be connected to metal column (9) on the reaction diaphragm (3).

2, gas flow sensor according to claim 1, the quantity that it is characterized in that vibration cavity (5) is 1.

3, gas flow sensor according to claim 1, the quantity that it is characterized in that vibration cavity (5) are 2-3.

4,, it is characterized in that vibration cavity (5) is annular, semi-circular or circular arc according to claim 2 or 3 described gas flow sensors.

5, gas flow sensor according to claim 1 is characterized in that reaction diaphragm (3) comprises rheostat diaphragm, piezoelectric type diaphragm and condenser type diaphragm.

6, gas flow sensor according to claim 1 or 5 is characterized in that reaction diaphragm (3) potting is on the periphery of inner casing (2).