CN202903411U - Pressure sensor - Google Patents
Pressure sensor Download PDFInfo
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- CN202903411U CN202903411U CN 201220536446 CN201220536446U CN202903411U CN 202903411 U CN202903411 U CN 202903411U CN 201220536446 CN201220536446 CN 201220536446 CN 201220536446 U CN201220536446 U CN 201220536446U CN 202903411 U CN202903411 U CN 202903411U
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- output terminal
- frequency
- housing
- memory
- circuit board
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- Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
Abstract
The utility model relates to a pressure sensor which is small in measurement error. The pressure sensor is characterized in that an elastic diaphragm (3) is fixed at the combination position of a gas cover and a shell, an iron core (4) is arranged in the center of the elastic diaphragm, and an inductance coil (5) is wound on a frame of the shell; a circuit board (7) is arranged below the shell, a memory device (71) is arranged on the circuit board, and a frequency signal output terminal (8) and a memory signal input/output terminal (9) are fixed on the shell; one end (81) of the frequency signal output terminal and one end (91) of the memory signal input/output terminal output signals outwards, the middle part (82) of the frequency signal output terminal and the middle part (92) of the memory signal input/output terminal are fixed with the shell, and the other end (83) of the frequency signal output terminal and the other end (93) of the memory signal input/output terminal are connected with the circuit board; and frequency values outputted and obtained via the frequency output terminal under different pressure values are stored in the memory device. The pressure sensor of the utility model is suitable for being used as a water level pressure sensor.
Description
Technical field
The utility model relates to a kind of pressure transducer, and particularly a kind of being installed on the home appliances such as washing machine, dish-washing machine is for detection of the pressure transducer of the water level of the equipment such as washing machine, dish-washing machine when the work.
Background technology
Using at present maximum water level sensor for home appliance is to use following principle: water pressure is delivered to the sensor air chamber by tracheae, produce air pressure, the bounce that sensor membrane is subjected to the effect of air pressure to overcome spring drives ferrite iron core and moves to coil direction, iron core is when section moves in coil, the corresponding variation that is approximately linear with the displacement of iron core of the inductance of coil (L), the displacement of iron core is then corresponding with level pressure, the iron core displacement is converted to level pressure, and the relation between level pressure and the outputting inductance as shown in Figure 1.
The pressure transducer of Chinese utility model patent ZL200820059885.2 comprises the upper cover body with the connector slot, lower cover and coil with the pressure introducing port consist of, described upper cover body is contained on the circuit board by the connector slot, described coil is arranged in the upper cover body, between coil and lower cover, be provided with the barrier film of being made by encapsulant and the metal leaf spring with certain elasticity coefficient, the middle body of metal leaf spring one side is equipped with magnetic, this magnetic and described coil relatively move, be provided with some gaps on the described metal leaf spring, the metal leaf spring is arranged in the described lower cover and with described pressure introducing port by described barrier film and is communicated with; By barrier film and metal leaf spring are set, offer the gap at the metal leaf spring, both kept the hardness of metal material, increased its deformational displacement amount, be not subjected to the impact of environment temperature, mounting position, the magnetic that is arranged on simultaneously the metal leaf spring can freely be adjusted with respect to the initial position of coil.But because the elasticity coefficient deviation of leaf spring is larger, cause the output frequency deviation between the different pressure transducers larger.
Summary of the invention
It is large that the utility model will solve present inductive type pressure transducer output frequency deviation, and the problem that causes sensor accuracy to descend provides a kind of pressure transducer of the present utility model for this reason, and this pressure transducer measuring accuracy is high.
For addressing the above problem, the technical solution adopted in the utility model is to comprise gas lid and housing, housing has the skeleton of winding telefault, gas lid and housing are mutually fixing removably, the junction of gas lid and housing is fixed with flexible sheet, the flexible sheet center is provided with iron core, iron core can move axially in described skeleton with described flexible sheet, be wound with telefault on the skeleton of described housing, spring one is housed between iron core and the housing, be provided with circuit board below the described housing of its special character, be provided with memory storage on this circuit board, be fixed with frequency signal lead-out terminal and memory signal input and output terminal on the described housing, described frequency signal lead-out terminal one end and memory signal input and output terminal one end are to external output signal, it is fixing that frequency signal lead-out terminal pars intermedia and memory signal input and output terminal pars intermedia and housing keep, the frequency signal lead-out terminal other end is connected with described circuit board with the memory signal input and output terminal other end, the wire wrap terminal of described telefault is connected with described circuit board, stores the frequency values that obtains by the output of frequency output terminal under the different pressures in the described memory storage.
The utility model can be provided with spring two on described flexible sheet, between described iron core and the spring one iron core bracket is housed.
Memory storage described in the utility model is erasable reservoir chip.
Set memory storage on the circuit board of pressure transducer of the present utility model can record the benchmark output data of pressure transducer, conveniently calls in use, with each sensor of exact matching.
Its circuit of circuit board in the utility model can be divided into two functional modules:
The one, the LC oscillating circuit take 4069 phase inverters as core; Its effect is the frequency values of output level sensor, and its structure can be traditional LC formula level sensor oscillating circuit.
The 2nd, the data accumulating device circuit; It can be E2ROM (BR24L08) the standard connection circuit of I2C bus, also can be that other are with erasable storage chip, such as the flash chip.
Description of drawings
Fig. 1 is the graph of a relation of level pressure and outputting inductance;
Fig. 2 is the stereographic map of the utility model pressure transducer;
Fig. 3 is the structural representation of the utility model pressure transducer;
Fig. 4 is the explosive view of the utility model pressure transducer;
Fig. 5 is the circuit board figure of the utility model pressure transducer;
Fig. 6 is the utility model pressure transducer and current stress sensor water stage measurement error synoptic diagram;
Fig. 7 is the double-spring structure explosive view of the utility model pressure transducer;
Fig. 8 is the circuit structure schematic diagram of the utility model embodiment;
Fig. 9 is that the utility model is assemblied in washing machine complete machine use software flow pattern;
Figure 10 is that the utility model is assemblied in water level of washing machine-frequency inverted program flow diagram.
Be labeled as among the figure: 1 gas lid, 2 housings, 3 flexible sheets, 4 iron cores, 5 telefaults, 6 springs one, 7 circuit boards, 71 memory storages, 8 frequency signal lead-out terminals, 81 frequency signal lead-out terminals, one end, 82 frequency signal lead-out terminal pars intermedias, the 83 frequency signal lead-out terminal other ends, 9 memory signal input and output terminals, 91 memory signal input and output terminals, one end, 92 memory signal input and output terminal pars intermedias, the 93 memory signal lead-out terminal other ends, 10 iron core brackets, 11 springs two.
Embodiment
Embodiment one
The pressure transducer of present embodiment, comprise gas lid 1 and housing 2, housing has the skeleton of winding coil, but gas lid and housing interfix by the buckle of the set folding of side face, the junction of gas lid and housing is fixed with flexible sheet 3, the embedding of flexible sheet center is connected with iron core 4, iron core can move axially in described skeleton with described flexible sheet, be wound with telefault 5 on the skeleton of described housing, between the framework inner cavity bottom surface of iron core lower end and housing spring 1 is installed, housing below be connected with circuit board 7, circuit board is provided with memory storage 71, be fixed with frequency signal lead-out terminal 8 and memory signal input and output terminal 9 on the housing, one end 91 of frequency signal lead-out terminal one end 81 and memory signal input and output terminal is to external output signal, the pars intermedia 92 of frequency information lead-out terminal pars intermedia 82 and memory signal input and output terminal keeps fixing with housing, the frequency information lead-out terminal other end 83 is connected with the memory signal input and output terminal other end and is connected with described circuit board, the wire wrap terminal of described telefault is connected with described circuit board, is storing the frequency values that obtains by the output of frequency signal lead-out terminal under the different water level corresponding pressures in the described memory storage.
Circuit on the circuit board 7 is divided into two functional modules:
The one, the LC oscillating circuit take 4069 phase inverters as core; Its effect is the frequency values of output level sensor, and its structure is traditional LC formula level sensor oscillating circuit.
The 2nd, the data accumulating device circuit; It is E2ROM (BR24L08) the standard connection circuit take I2C as bus, and it also can be that other are with erasable storage chip, such as the flash chip.
In the sensor production manufacture process, from the 0mm water column pressure, (L is step-length every a step-length L, together lower), 10mm water column pressure for example, exert pressure to sensor, record the frequency Output rusults by the frequency signal lead-out terminal, and this result according to the pressure of correspondence by from low to high sequential storage in memory storage.
When washing machine is judged height of water level at the working pressure sensor, generally be the frequency values that the target setting water level is corresponding in program (target frequency), when system moves, the target frequency of setting in the frequency of current pressure sensor output and the program is compared, when both are consistent, judge that namely water level arrives object height.But because between the different sensors, output frequency has a little deviation, causes actual water level and target water level that certain deviation is arranged.
When using this sensor, the MCU on the circuit board converses the memory location D of corresponding water level/frequency in the memory storage according to required height of water level H, D=H/L, and the result rounds.Reading the frequency values f of memory storage D position, namely is required target frequency F.When H can't be divided exactly by L, get its merchant D remainder t, read D and corresponding frequency f and the f ' in D+1 position in the memory storage; Target frequency F=f+ (f '-f) * t/L, as long as step-length L is enough little, just can think to be similar to pressure-frequency relation between f and f ' and to satisfy linear relationship.
In addition because MCU crystal oscillator deviation, or environment temperature is when changing, the sensor output frequency can deviation occur with the 0 water level frequency that writes in the sensor memory storage during 0 water level that washing machine MCU obtains, so when 0 water level the actual frequency F1 that records of MCU is deducted the 0 water level frequency F0 that stores in the memory storage and obtains frequency modified value Δ F.And after the target frequency F of conversion gained added upper frequency modified value Δ F, the frequency values that uses as reality.
Because each sensor has recorded its output frequency curve separately when dispatching from the factory, can eliminate because the problem of the precise decreasing that deviation causes between the different sensors.The step-length of setting in process of production is less, and the data that are stored in memory storage are more, and the precision of pressure transducer is higher.
Because may need several water level point in actual use.So when using this sensor, the user only need to be when program initialization converts out with the frequency values of required water level point in the lump, can compare with the same frequency values that directly calls of software originally in ensuing program, is highly susceptible to switching.
Fig. 9, Figure 10 are respectively the utility model and are assemblied in washing machine complete machine use software flow pattern and water level-frequency inverted program flow diagram.
One, complete machine uses the software flow explanation:
When using this sensor, washing machine software strategy proposed steps is as follows:
1 boot system initialization;
The output frequency of this sensor when 2MCU lives and to have leisure barrel;
3MCU obtains the target water level table;
4MCU is converted to the target frequency table by " water level-frequency inverted program " with the target water level table;
5 is tactful identical with washing machine operation originally, and the method for usage comparison sensor output frequency and target frequency determines whether the arrival target water level.
Two, water level-frequency inverted program circuit explanation:
1 read MCU live empty bucket frequency value F 0;
The empty bucket frequency value F 1 of preserving in the 2 read sensor memory storages;
3 obtain the empty bucket of sensor offset Δ F=F0-F1;
4 read first aim water level H;
5 preserve step-length L with target water level H divided by sensor frequency obtains t more than merchant D and the remainder t H/L=D;
If 6 t=0 then D data f1 of reading and saving, otherwise read D and two data f1 of D+1 f2;
If 7 t=0 then standard target frequency f=f1, otherwise standard target frequency f=f2+ (f1-f2) * t/L
8 output realistic objective frequency F=f+ Δ F;
9 read next target water level H ' jumped to for the 5th step, if all converted then move program for washing.
See Fig. 6 the utility model pressure transducer and current stress sensor water stage measurement error ratio:
Horizontal ordinate represents actual height of water level among the figure, ordinate represent determination of pressure sensor with the actual water level absolute value of the bias.Among the figure, the corresponding the utility model pressure transducer of "●", " ▲ " corresponding current stress sensor.When height of water level was 100mm, the current stress sensor was determined as 107.7mm, and the utility model determination of pressure sensor is 102mm; When height of water level was 500mm, the current stress sensor was determined as 527mm, and the utility model determination of pressure sensor is 501mm.The water level value of the utility model determination of pressure sensor and actual water level absolute value of the bias are below 2mm, and this deviation much bigger (in the test site, this deviation average is about 17mm) that the current stress sensor is measured.
Embodiment two
Present embodiment pressure transducer, referring to Fig. 4, Fig. 7, be provided with spring 2 11 above the described flexible sheet, can make sensor the starting in just begin recording curve, between described iron core 4 and the spring 1 iron core bracket 10 is housed.Other constructed embodiment one identical.
Claims (3)
1. pressure transducer, comprise gas lid (1) and housing (2), housing has the skeleton of winding telefault, gas lid and housing are mutually fixing removably, the junction of gas lid and housing is fixed with flexible sheet (3), the flexible sheet center is provided with iron core (4), iron core can move axially in described skeleton with described flexible sheet, be wound with telefault (5) on the skeleton of described housing, spring one (6) is housed between iron core and the housing, it is characterized in that described housing below be provided with circuit board (7), be provided with memory storage (71) on this circuit board, be fixed with frequency signal lead-out terminal (8) and memory signal input and output terminal (9) on the described housing, described frequency signal lead-out terminal one end (81) and memory signal input and output terminal one end (91) are to external output signal, frequency signal lead-out terminal pars intermedia (82) and memory signal input and output terminal pars intermedia (92) keep fixing with housing, the frequency signal lead-out terminal other end (83) is connected 93 with the memory signal input and output terminal other end) be connected with described circuit board, the wire wrap terminal of described telefault is connected with described circuit board, stores the frequency values that obtains by the output of frequency output terminal under the different pressures in the described memory storage.
2. pressure transducer as claimed in claim 1 is characterized in that being provided with above the described flexible sheet spring two (11), between described iron core (4) and the spring one (6) iron core bracket (10) is housed.
3. pressure transducer as claimed in claim 1 or 2 is characterized in that described memory storage is erasable reservoir chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220536446 CN202903411U (en) | 2012-10-19 | 2012-10-19 | Pressure sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220536446 CN202903411U (en) | 2012-10-19 | 2012-10-19 | Pressure sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202903411U true CN202903411U (en) | 2013-04-24 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220536446 Expired - Lifetime CN202903411U (en) | 2012-10-19 | 2012-10-19 | Pressure sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202903411U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102937498A (en) * | 2012-10-19 | 2013-02-20 | 杭州神林电子有限公司 | Pressure sensor |
| CN110186534A (en) * | 2019-06-27 | 2019-08-30 | 芜湖乐佳电器有限公司 | A kind of chip-shaped fluid sensor |
-
2012
- 2012-10-19 CN CN 201220536446 patent/CN202903411U/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102937498A (en) * | 2012-10-19 | 2013-02-20 | 杭州神林电子有限公司 | Pressure sensor |
| CN110186534A (en) * | 2019-06-27 | 2019-08-30 | 芜湖乐佳电器有限公司 | A kind of chip-shaped fluid sensor |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130424 |