CN203241188U - Inductance differential pressure sensor - Google Patents
Inductance differential pressure sensor Download PDFInfo
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- CN203241188U CN203241188U CN 201320121589 CN201320121589U CN203241188U CN 203241188 U CN203241188 U CN 203241188U CN 201320121589 CN201320121589 CN 201320121589 CN 201320121589 U CN201320121589 U CN 201320121589U CN 203241188 U CN203241188 U CN 203241188U
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- differential pressure
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- inductance
- core assembly
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Abstract
The utility model discloses an inductance differential pressure sensor, including a sensor housing, and a detection circuit and a sensor body mounted in the housing. The sensor body is composed of two butting connected housings. The butting surface of the two housings is symmetrically provided with mounting grooves and air inlet channels communicated with the mounting groove. Each mounting groove is fixedly connected with a group of coil magnetic core assemblies. The leading end of the coil magnetic core assemblies is electrically connected with the detection circuit. A flexible metal diaphragm is arranged between the butting surface of the two housings. Sealing rings for sealing and isolating the mounting grooves and the air inlet channels are symmetrically disposed between both sides of flexible metal diaphragm and the butting surface of the two housings. The coil magnetic core assemblies form a closed magnetic circuit after power on through the flexible metal diaphragm, and have gaps between the flexible metal diaphragm. The inductance differential pressure sensor is high in sensitivity, small in size, high in pressure, small in range, and suitable for a high-precision air-tight detector with small scale, high accuracy and high pressure resistance.
Description
Technical field
The utility model relates to a kind of pressure detection technical field, particularly a kind of inductance type differential pressure pick-up.
Background technology
At present, the variation with straight line or angular displacement that is made of iron core and coil is converted to the sensor that winding inductance quantity changes, and claims again inductive displacement transducer.The coil turn of this sensor and material magnetic capacity all are certain, and the variation of its inductance value is to cause owing to the displacement input quantity causes the magnetic flux change of coil magnetic circuit.When coil being accessed metering circuit and connecting excitation power supply, just can obtain to be proportional to voltage or the electric current output of displacement input quantity.The characteristics of inductance type transducer are: high without armature contact, fiduciary level, the life-span is long; Resolution is high; Highly sensitive; Linearity height, good reproducibility etc.Inductance type transducer is mainly used in displacement measurement and can converts the mechanical quantity of change in displacement such as the measurement of pressure, thickness, liquid level and torque etc. to.At present, inductance pressure transducer commonly used mostly is the helix tube type inductance sensor and becomes the GAP TYPE inductance sensor.The helix tube type inductance sensor mainly is comprised of a magnetic plug and a cylinder-shaped iron core, during working sensor, because of the variation of iron core built-in length in coil, causes the variation of magnetic plug self-induction value.When encouraging with constant current source, then the output voltage of coil is relevant with the displacement that the iron core pressurized produces, thereby calculate the size and Orientation of force value, helix tube type pressure inductance sensor has assembling manufacturing simply and the characteristics of the wide ranges of measuring, but its sensitivity is lower, is unsuitable for precision measurement; Become the GAP TYPE inductance sensor, relative sensitivity is high, and it is comprised of coil, iron core and armature three parts, between iron core and armature air gap is arranged, air gap thickness is δ, the motion parts of sensor links to each other with armature, and when armature moved, air gap thickness δ changed, cause magnetic resistance change rate in the magnetic circuit, thereby cause the inductance value of telefault to change, as long as the variation that therefore can measure this inductance value just can be determined the size and Orientation of the displacement that the armature pressurized produces.The change GAP TYPE inductive pressure transducer of at present common measurement air pressure is by bellows, iron core, the composition such as armature and coil, the upper end of armature and bellows connects together, when the gas of certain pressure intensity enters bellows, the top of bellows produces the displacement that is directly proportional with atmospheric pressure P size under the effect of atmospheric pressure P, so armature also is moved, thereby air gap is changed, corresponding variation also occurs in the electric current that flows through coil, above-mentioned change GAP TYPE inductive pressure transducer, its sensitivity is higher, but sensitivity and non-linearly all reduce with the increase of air gap, be unsuitable for measuring the gas of high pressure, simultaneously because range ratio is larger, maximum error when causing measuring can increase hundreds of even thousands of times, and sensor body is larger because the bellows volume ratio is set, and is not suitable for being applied in the measuring accuracy height, on the withstand voltage high high precision airtight detecting apparatus.
Summary of the invention
The utility model for solve the technical matters that exists in the known technology provide a kind of highly sensitive, volume is little, can detect gases at high pressure and the little a kind of inductance type differential pressure pick-up of range.
The technical scheme that the utility model is taked for the technical matters that exists in the solution known technology is: a kind of inductance type differential pressure pick-up, comprise sensor outer housing, in the enclosure testing circuit and sensor body are installed, described sensor body is comprised of the housing that two docking connect, the inlet channel that is arranged with mounting groove on the interface of described two housings and is communicated with mounting groove, be fixedly connected with one group of coil core assembly in each described mounting groove, the exit of described coil core assembly is electrically connected with described testing circuit, be provided with the elastic metallic diaphragm between the interface of described two housings, between the interface of the two sides of described elastic metallic diaphragm and described two housings, be arranged with the O-ring seal of the described mounting groove of seal isolation and described inlet channel, consist of closed magnetic loop by described elastic metallic diaphragm after the energising of described coil core assembly, and and described elastic metallic diaphragm between air gap is arranged.
The utility model can also adopt following technical scheme:
Described coil core assembly comprises E shape magnetic core.
The magnetic core of described coil core assembly is the permalloy magnetic core.
Described coil core assembly is fixedly connected in the described mounting groove by cementing agent or screw.
Described air gap thickness is 0.10mm-0.40mm.
Described O-ring seal is O type circle.
Advantage and the good effect that the utlity model has are: adopt the differential pressure type detection method, two inlet channels pass into respectively and detect gas and canonical reference gas, elastic metallic diaphragm induction by the pressure differential between measuring pressure and the normal pressure, form the gas cavity volume between metallic membrane and two docking housings, reduced bellows, so that sensor construction is simple, volume is little, physical dimension can be 55 ㎜ * 36 ㎜ * 70 ㎜; And the referenced normal pressure of detected pressures that acts on the elastic metallic diaphragm offsets, and air gap changes little, and it is highly sensitive, can reach 0.8 * 10-5ml/Pa; Can detect the gas of elevated pressures, solved from negative pressure, minute-pressure, low pressure, the sealing propertytest problem of other high precision of each grade of pressure, high stability, simultaneously because of the always significantly reduction of range, thereby improve absolute resolution and measuring accuracy, its resolution is high, can reach 1Pa, and the detected pressures scope is large, its withstand voltage height, the highest one-sided withstand voltage 5MPa that reaches; The utility model is fit to be applied in that range is little, precision is high, on the airtight detector of withstand voltage high high precision, simultaneously the utility model compact conformation, volume are little, and low cost of manufacture can be widely used in the fields such as automobile, medical treatment, combustion gas, chemical industry, national defence, military project.
Description of drawings
Fig. 1 is structural representation of the present utility model;
Fig. 2 is coil core assembly structure of the present utility model and fundamental diagram.
Among the figure: 1, shell; 2, testing circuit; 3, housing; 4, coil core assembly; 5, elastic metallic diaphragm; 6, O-ring seal; 7, inlet channel; 8, magnetic core; 9, coil.
Embodiment
For further understanding summary of the invention of the present utility model, Characteristic, hereby exemplify following examples, and cooperate accompanying drawing to be described in detail as follows:
See also Fig. 1, a kind of inductance type differential pressure pick-up, comprise sensor outer housing 1, in the enclosure testing circuit 2 and sensor body are installed, described sensor body is comprised of the housing 3 that two docking connect, the inlet channel 7 that is arranged with mounting groove on the interface of described two housings 3 and is communicated with mounting groove, be fixedly connected with one group of coil core assembly 4 in each described mounting groove, the exit of described coil core assembly 4 is electrically connected with described testing circuit 2, be provided with elastic metallic diaphragm 5 between described two housing 3 interfaces, between the interface of the two sides of described elastic metallic diaphragm 5 and described two housings 3, be arranged with the O-ring seal 6 of the described mounting groove of seal isolation and described inlet channel 7, consist of closed magnetic loop by described elastic metallic diaphragm 5 after 4 energisings of described coil core assembly, and and described elastic metallic diaphragm 5 between air gap is arranged.
Elastic metallic diaphragm 5 in the middle of the housing 3 of two docking is clamped connects fastening with screw.Link together with the circuit board of screw with sensor body, shell and testing circuit, make encapsulation process when the exit of described coil core assembly 4 is drawn, make mounting groove keep sealing.
Wherein: described coil core assembly can use the magnetic core that comprises the forms such as E shape magnetic core, and magnetic core can be selected the permalloy magnetic core, and described coil core assembly can be fixedly connected in the described mounting groove by cementing agent or screw.
Air gap thickness between described coil core assembly and the described elastic metallic diaphragm can be 0.10mm-0.40mm, preferred 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm.
Described O-ring seal 6 can be O type circle.
Principle of work of the present utility model:
Please refer to Fig. 2, the type of this sensor belongs to inductance type transducer, namely utilize electromagnetic induction principle tested non electrical quantity to be converted to the variation of coil inductance value, be converted to again the variable quantity output of voltage or electric current by metering circuit, this device is called inductance type transducer, the coil 9 of the both sides band magnetic core 8 of elastic metallic diaphragm 5 forms differential pressure transducer, when telefault 9 energisings produce magnetic field, and by the closed magnetic loop of elastic metallic diaphragm 5 formations, 0.1 millimeter-0.5 millimeter air gap is arranged between magnetic core 8 and the elastic metallic diaphragm 5, without pressure differential the time, elastic metallic diaphragm 5 mediates, and the two ends inductance equates, when having pressure differential, 5 one pressurizeds of elastic metallic diaphragm, elastic metallic diaphragm 5 deforms, and the air gap of a protruding back gauge magnetic core reduces, the recessed heart one end increases apart from the air gap of magnetic core, the difference that consists of inductance changes, and then becomes the alternating voltage exporting change by electric bridge, and this variable quantity is to become corresponding relation with tested pressure differential.
Computing formula according to inductance value:
Wherein: L is coil inductance, and N is coil turn, and S is that magnetic flux cross section is long-pending, μ
0Be the magnetic permeability of magnetic conductor, δ is air gap thickness.
After the material of telefault, iron core and structure are determined, number of turn N, sectional area S and magnetic permeability μ
0Just can determine that then coil inductance value L is the single-valued function of air gap thickness δ.
Workflow of the present utility model:
The alternating voltage of certain frequency is applied in the coil of sensor, according to the law of electromagnetic induction, makes two coils in the body can produce equivalent inductance;
Respectively be filled with respectively detection gas and the canonical reference gas of certain pressure intensity to two inlet channels 7 because gas moment can be full of the cavity volume that forms between metallic membrane 5 and the housing 3, this moment elastic metallic diaphragm 5 in the centre position, elastic metallic diaphragm 5 keeps balances;
When the pressure that detects gas reduces (there is leakage in loading line), the pressure meeting out of trim on elastic metallic diaphragm 5 both sides, the gaseous tension that is filled with the cavity volume that detects gas is less than the gaseous tension of the cavity volume that is filled with canonical reference gas, under the effect of this pressure differential, elastic metallic diaphragm 5 can be recessed to a side of pressure decreased, so that the air gap thickness δ of 8 of elastic metallic diaphragm 5 and iron cores changes;
Because inductance is the single-valued function of air gap thickness, air gap thickness is directly proportional with the Pressure Drop of both sides cavity volume, so inductance also is the relation that is directly proportional with Pressure Drop, this has just guaranteed the linearity between inductance and the Pressure Drop;
Because inductance L and air gap thickness δ are the inverse proportion funtcional relationships, δ changes very little, the L value is very large, δ is caused by Pressure Drop, be that Pressure Drop is when having very little variation, inductance value alters a great deal, and passes through amplification and the conversion of testing circuit 2 again, can accurately measure the pressure reduction that detects gas and canonical reference gas.
Claims (6)
1. inductance type differential pressure pick-up, it is characterized in that, comprise sensor outer housing, in the enclosure testing circuit and sensor body are installed, described sensor body is comprised of the housing that two docking connect, the inlet channel that is arranged with mounting groove on the interface of described two housings and is communicated with mounting groove, be fixedly connected with one group of coil core assembly in each described mounting groove, the exit of described coil core assembly is electrically connected with described testing circuit, be provided with the elastic metallic diaphragm between the interface of described two housings, between the interface of the two sides of described elastic metallic diaphragm and described two housings, be arranged with the O-ring seal of the described mounting groove of seal isolation and described inlet channel, consist of closed magnetic loop by described elastic metallic diaphragm after the energising of described coil core assembly, and and described elastic metallic diaphragm between air gap is arranged.
2. inductance type differential pressure pick-up according to claim 1 is characterized in that, described coil core assembly comprises E shape magnetic core.
3. inductance type differential pressure pick-up according to claim 1 is characterized in that, the magnetic core of described coil core assembly is the permalloy magnetic core.
4. inductance type differential pressure pick-up according to claim 1 is characterized in that, described coil core assembly is fixedly connected in the described mounting groove by cementing agent or screw.
5. inductance type differential pressure pick-up according to claim 1 is characterized in that, described air gap thickness is 0.10mm-0.40mm.
6. according to claim 1 to 5 arbitrary described inductance type differential pressure pick-ups, it is characterized in that described O-ring seal is O type circle.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320121589 CN203241188U (en) | 2013-03-18 | 2013-03-18 | Inductance differential pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320121589 CN203241188U (en) | 2013-03-18 | 2013-03-18 | Inductance differential pressure sensor |
Publications (1)
| Publication Number | Publication Date |
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| CN203241188U true CN203241188U (en) | 2013-10-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320121589 Expired - Fee Related CN203241188U (en) | 2013-03-18 | 2013-03-18 | Inductance differential pressure sensor |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103196620A (en) * | 2013-03-18 | 2013-07-10 | 天津俞昌科技有限公司 | Inductance type differential pressure transducer |
| CN104198109A (en) * | 2014-09-11 | 2014-12-10 | 北京交通大学 | Magnetic-liquid micropressure differential sensor with branch tube |
| RU2620450C1 (en) * | 2016-07-29 | 2017-05-25 | Акционерное общество "Научно-исследовательский институт теплоэнергетического приборостроения" АО "НИИТеплоприбор" | Pressure sensor |
-
2013
- 2013-03-18 CN CN 201320121589 patent/CN203241188U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103196620A (en) * | 2013-03-18 | 2013-07-10 | 天津俞昌科技有限公司 | Inductance type differential pressure transducer |
| CN104198109A (en) * | 2014-09-11 | 2014-12-10 | 北京交通大学 | Magnetic-liquid micropressure differential sensor with branch tube |
| RU2620450C1 (en) * | 2016-07-29 | 2017-05-25 | Акционерное общество "Научно-исследовательский институт теплоэнергетического приборостроения" АО "НИИТеплоприбор" | Pressure sensor |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131016 Termination date: 20190318 |
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| CF01 | Termination of patent right due to non-payment of annual fee |