CN202149011U - Driving-sensing integrated piezoelectric chip pump - Google Patents

Abstract

The utility model relates to a driving-sensing integrated piezoelectric chip pump, which at least comprises a chip type piezoelectric vibrator (formed by adhesive bonding of a piezoelectric chip and a metal substrate), a pump body, a pump cover, a group of check valve used for controlling fluid motion direction and a control source. The driving-sensing integrated piezoelectric chip pump is characterized in that an electrode on the surface of the piezoelectric chip in the piezoelectric vibrator is separated into a driving unit and a sensing unit, when the driving unit bends and deforms due to external voltage, piezoelectric ceramics of the sensing unit also bend and deform and generate electric energy, voltage signals produced by the sensing unit are used for representing output pressure and flow of a piezoelectric pump after being converted and processed. The driving-sensing integrated piezoelectric chip pump has the advantages of adopting the same chip type piezoelectric vibrator to achieve a driving function and a sensing monitoring function, being capable of achieving online monitoring of output performance of the piezoelectric pump without an extra pressure and flow measuring device, and being apt to obtain accurate output flow and pressure.

Description

Driving-sensing integrated piezoelectric chip pump

Technical field

The utility model belongs to the small accurate piezoelectric pump of microfluid transmission and the application of control field, is specifically related to a kind of driving-sensing integrated piezoelectric chip pump.

Background technique

An important branch as piezoelectric actuator; Many advantages such as the piezoelectric chip pump is simple in structure with it, volume is little, reaction is fast, no electromagnetic interference, easy operating, flow/pressure controllability are good; All have wide practical use at aspects such as the fuel supply of medical treatment, chemical analysis, Aero-Space, motor car engine and fuel cell, micro electronmechanical liquid systems, its development enjoys countries in the world scholar's extensive concern.For satisfying the application demand of different field, people have proposed the piezoelectric chip pump of multiple structural type.Although the structural type and the performance difference of the piezoelectric pump that proposes are bigger, all be that the bending deflection that utilizes chip type piezoelectric vibrator (by substrate and piezoelectric chip is bonding form) under electric field action, to produce realizes fluid-operated.The fluid of exporting because of each work cycle of piezoelectric chip pump is the volume-variation amount that piezoelectric vibrator is out of shape caused pump chamber; So can realize the accurate control of flow and pressure, be particularly useful for medicine controlled release (like Chinese patent 200610016573.9,200610030183.7), chemical reagent proportioning aspects such as (like Chinese patents 200810050550.9).Yet the output flow of piezoelectric chip pump and pressure receive the influence of operating conditions bigger in real work, and except that driving voltage and frequency, variations such as fluid viscosity (temperature) and delivery pressure also all can influence the amount of deformation (being the flow of piezoelectric pump) of piezoelectric vibrator.Therefore; Merely adopt the method for regulating driving voltage and frequency still can't obtain higher output accuracy; Require flow and the accurate higher occasion of pressure control also need adopt flow and pressure-measuring instrument to monitor in real time at medicine controlled release, chemical analysis and fuel cell etc.; This has not only increased user cost, has also increased volume, weight and the complexity of system, has seriously hindered piezoelectric chip pump applying in MEMS and portable series products.

Summary of the invention

Be output accuracy and the controllability that improves the piezoelectric chip pump, the volume and weight that reduces cost, reduces overall system; The utility model proposes a kind of driving-sensing integrated piezoelectric chip pump; Utilize same chip type piezoelectric vibrator to realize fluid drives and two kinds of functions of sensor monitoring, need not extra pressure and flowrate measuring tool.

The driving of the utility model-sensing integrated piezoelectric chip pump comprises an one-way valve and the control power supply by piezoelectric chip and the bonding chip type piezoelectric vibrator that forms of metal substrate, a pump housing, a pump cover, one group of control fluid moving direction at least.Said chip type piezoelectric vibrator is installed on pump housing inside and is clamped by pump cover, and the said pump housing adopts screw to be connected with pump cover and clamps piezoelectric vibrators through two seal rings, and inlet valve and outlet valve are installed on the said pump housing; Said terminal valve, the pump housing, seal ring and piezoelectric vibrator constitute pump chamber jointly, and said piezoelectric vibrator links to each other with the control power supply through lead.The utility model is characterised in that the surface electrode of piezoelectric chip is divided into two-part in the said piezoelectric vibrator, and what a part of area was bigger is driver element, and what another part area was less is sensing unit; When the driver element of piezoelectric vibrator received the applied voltage effect to produce bending deflection, said sensing unit also received to compel crooked and produces electric energy; Its characteristic is that also the voltage signal that sensing unit generates is used to characterize the delivery pressure and the flow of piezoelectric pump after conversion treatment.

When said control electric power starting and when getting into steady operation, the driver element of piezoelectric chip receives voltage (input voltage-V ₀→ 0 → V ₀) effect makes piezoelectric vibrator crooked in pump chamber, makes said pump chamber reduce that (hydrodynamic pressure increases), inlet valve are closed, outlet valve is opened, the interior fluid of said pump chamber is discharged through outlet valve, and this is the fluid discharge process; In said fluid discharge process, the sensing unit of piezoelectric chip also with piezoelectric vibrator to the pump chamber interior curve, and the output voltage that is produced progressively increases (V _g→ 0 → V _g).(V after the output voltage switching-over of control power supply ₀→ 0 →-V ₀), the driver element of piezoelectric chip makes the outer bend of piezoelectric vibrator to pump chamber, causes said pump chamber increase, inlet valve unlatching, outlet valve to be closed, and fluid gets into pump chamber by inlet valve, and this is a suction process; In suction process, the stress of the sensing unit of piezoelectric chip is also corresponding to change, and makes output voltage begin the (V that descends _g→ 0 →-V _g).

As everyone knows; When frequency and driving voltage are confirmed; Be better linearity relation between piezoelectric pump output flow and the delivery pressure: piezoelectric vibrator amount of deformation (pump chamber variable quantity or flow) maximum when delivery pressure is zero, the voltage of the corresponding sensing unit output of institute is maximum also; On the contrary, when delivery pressure is maximum, piezoelectric vibrator amount of deformation (pump chamber variable quantity or flow) minimum, the voltage of pairing sensing unit output is also minimum.Therefore, the utility model adopts the output voltage of piezoelectric chip sensing unit to characterize the delivery pressure and the flow of piezoelectric pump.For given input voltage V ₀And frequency f, the delivery pressure P of piezoelectric pump and flow Q are by the output voltage V of piezoelectric chip sensing unit in the utility model _gExpression, that is:

$P=\frac{{2\mathrm{\η}}_P{h}_p}{{3R}^2}[\frac{{6d}_{31}\mathrm{\α\λ}(1+\mathrm{\α})E_p}{(1-v_p)(1+\mathrm{\α\λ})}{V}_0-\frac{3{(1-{\mathrm{\α}}^2\mathrm{\λ})}^2-4(1+\mathrm{\α\λ})(1+{\mathrm{\α}}^3\mathrm{\λ})}{\mathrm{\α\λ}(1+\mathrm{\α})g_{31}}{V}_g]$

$Q=\frac{{\mathrm{\&eta;}}_{Q}f{\mathrm{\&pi;<figure-callout\; id="4"\; label="R"\; filenames="DEST\_PATH\_HSB00000671408300011.png"\; state="\{\{state\}\}">R</figure-callout>}}^4}{{12h}_p^2}[\frac{(1+\mathrm{\&alpha;\&lambda;})(1-v_p)(7+v_p)}{\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})g_{31}{E}_p}{V}_g-\frac{{6d}_{31}\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})(1+v_p)}{3{(1-{\mathrm{\&alpha;}}^2\mathrm{\&lambda;})}^2-4(1+\mathrm{\&alpha;\&lambda;})(1+{\mathrm{\&alpha;}}^3\mathrm{\&lambda;})}{V}_0]$

Wherein, R is the pump chamber radius, α=h _m/ h _p, h _m, h _pBe respectively the thickness of substrate and pottery, d ₃₁, g ₃₁Be piezoelectric crystal,

E _m, E _pBe respectively the Young's modulus of metal and piezoceramic material, v _m, v _pBe respectively the Poisson's ratio of metal and stupalith, η _P, η _QBe respectively the transducer calibration coefficient of corresponding delivery pressure and flow.

The utility model characteristics and advantage are: utilize same chip type piezoelectric vibrator to realize driving and two kinds of functions of sensor monitoring; Need not extra pressure and flowrate measuring tool and can realize the on-line monitoring of piezoelectric pump output performance, be easy to obtain accurate output flow and pressure.

Description of drawings

Fig. 1 drives in preferred embodiment of the utility model-sensing integrated piezoelectric chip pump structure and generalized section thereof;

Fig. 2 a is that two laminated piezoelectricity oscillator dividing electrodes reach and the Placement schematic representation of controlling power supply in preferred embodiment of the utility model;

Fig. 2 b is the left view of Fig. 2 a;

Fig. 3 a is the scheduling structural representation of driving-sensing integrated piezoelectric chip pump in preferred embodiment of the utility model;

Fig. 3 b is the suction journey structural representation of driving-sensing integrated piezoelectric chip pump in preferred embodiment of the utility model;

Fig. 4 a is piezoelectric vibrator driver element input voltage waveform figure in preferred embodiment of the utility model;

Fig. 4 b is a piezoelectric vibrator sensing unit output voltage waveform in preferred embodiment of the utility model.

Embodiment

As shown in Figure 1, chip type piezoelectric vibrator 1 is installed on the inside of the pump housing 2, and clamps through pump cover 3; The said pump housing 2 is connected through screw 4 with pump cover 3, and the pump housing 2 clamps piezoelectric vibrator with pump cover 3 through seal ring 5; Inlet valve 7 and outlet valve 8 are installed on the said pump housing 2; Piezoelectric vibrator 1, the pump housing 2, seal ring 5, inlet valve 7 and outlet valve 8 common formation pump chambers 6.

Shown in Fig. 1, Fig. 2 a and Fig. 2 b, chip type piezoelectric vibrator 1 is by piezoelectric chip 10 and metal substrate 11 bonding forming; The electrode on said piezoelectric chip 10 surfaces is divided into driver element 101 and sensing unit 102, and said driver element 101 links to each other with control power supply 9 with lead group 91 through lead group 92 respectively with sensing unit 102.

Shown in Fig. 3 a, Fig. 3 b, Fig. 4 a and Fig. 4 b, when said control power supply 9 was opened and got into steady operation, the driver element 101 of piezoelectric chip 10 received voltage (input voltage-V ₀→ 0 → V ₀) effect makes the interior bending of piezoelectric vibrator 1 to pump chamber 6, and then the volume of said pump chamber 6 is reduced, and (hydrodynamic pressure increases), inlet valve 7 are closed, outlet valve 8 is opened, the fluids in the said pump chamber 6 are through outlet valve 8 discharges, and this is the fluid discharge process; In said fluid discharge process, the sensing unit 102 of piezoelectric chip 10 also in company with piezoelectric vibrator 1 to pump chamber 6 interior curve, and its output voltage progressively increases (V _g→ 0 → V _g).(V after the output voltage switching-over of control power supply 9 ₀→ 0 →-V ₀), the driver element 101 of piezoelectric chip 10 makes the outer bend of piezoelectric vibrator 1 to pump chamber 6, causes said pump chamber 6 volumes increase, inlet valve 7 unlatchings, outlet valve 8 to be closed, and fluid is got into by inlet valve 7, and this is a suction process; After getting into suction process, the stress of the sensing unit 102 of piezoelectric chip 10 changes, and makes output voltage begin the (V that descends _g→ 0 →-V _g).

In the scheduling and suction journey of the foregoing description piezoelectric pump, the output voltage of the instantaneous delivery pressure of piezoelectric pump, flow and sensing unit 102 all is determined by the bending deflection state of piezoelectric vibrator 1.In addition; When the output frequency of driving power 9 and driving voltage are confirmed; Be the better linearity relation between piezoelectric pump output flow and the delivery pressure: when the delivery pressure of pump is zero; The amount of deformation of piezoelectric vibrator 1 (that is, pump chamber variable quantity or flow) maximum, the voltage of corresponding sensing unit 102 outputs also maximum; On the contrary, when the delivery pressure of pump was maximum, the amount of deformation of piezoelectric vibrator 1 was minimum, and is also minimum with the voltage that the sensing unit 102 of correspondence is exported.Therefore, the utility model adopts the output voltage of sensing unit 102 to characterize the delivery pressure and the flow of piezoelectric pump.For given input voltage V ₀And frequency f, the delivery pressure P of piezoelectric pump and flow Q are by the output voltage V of the sensing unit 102 of piezoelectric vibrator 1 in the utility model _gExpression, that is:

$P=\frac{{2\mathrm{\&eta;}}_P{h}_p}{{3R}^2}[\frac{{6d}_{31}\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})E_p}{(1-v_p)(1+\mathrm{\&alpha;\&lambda;})}{V}_0-\frac{3{(1-{\mathrm{\&alpha;}}^2\mathrm{\&lambda;})}^2-4(1+\mathrm{\&alpha;\&lambda;})(1+{\mathrm{\&alpha;}}^3\mathrm{\&lambda;})}{\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})g_{31}}{V}_g]$

$Q=\frac{{\mathrm{\&eta;}}_{Q}f{\mathrm{\&pi;<figure-callout\; id="4"\; label="R"\; filenames="DEST\_PATH\_HSB00000671408300011.png"\; state="\{\{state\}\}">R</figure-callout>}}^4}{{12h}_p^2}[\frac{(1+\mathrm{\&alpha;\&lambda;})(1-v_p)(7+v_p)}{\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})g_{31}{E}_p}{V}_g-\frac{{6d}_{31}\mathrm{\&alpha;\&lambda;}(1+\mathrm{\&alpha;})(1+v_p)}{3{(1-{\mathrm{\&alpha;}}^2\mathrm{\&lambda;})}^2-4(1+\mathrm{\&alpha;\&lambda;})(1+{\mathrm{\&alpha;}}^3\mathrm{\&lambda;})}{V}_0]$

Wherein, R is the pump chamber radius, α=h _m/ h _p, h _m, h _pBe respectively the thickness of substrate and pottery, d ₃₁, g ₃₁Be piezoelectric crystal,

E _m, E _pBe respectively the Young's modulus of metal and piezoceramic material, v _m, v _pBe respectively the Poisson's ratio of metal and stupalith, η _P, η _QBe respectively the transducer calibration coefficient of corresponding delivery pressure and flow.

Claims (2)

1. driving-sensing integrated piezoelectric chip pump comprises an one-way valve and the control power supply by piezoelectric chip and the bonding chip type piezoelectric vibrator that forms of metal substrate, a pump housing, a pump cover, one group of control fluid moving direction at least; It is characterized in that; The electrode on piezoelectric chip surface is divided into driver element and sensing unit two-part in the said piezoelectric vibrator; When the driver element of said piezoelectric vibrator was occured bending and deformation by the applied voltage effect, said sensing unit piezoelectric constant also occured bending and deformation and produces electric energy; Its characteristic is that also the voltage signal that sensing unit generates is used to characterize the delivery pressure and the flow of piezoelectric pump after conversion treatment.

2. driving according to claim 1-sensing integrated piezoelectric chip pump is characterized in that the delivery pressure P of piezoelectric pump and flow Q are by the output voltage V of the sensing unit of piezoelectric vibrator _gExpression, that is:

Wherein, R is the pump chamber radius, α=h _m/ h _p, h _m, h _pBe respectively the thickness of substrate and pottery, d ₃₁, g ₃₁Be piezoelectric crystal,

E _m, E _pBe respectively the Young's modulus of metal and piezoceramic material, v _m, v _pBe respectively the Poisson's ratio of metal and stupalith, η _P, η _QBe respectively the transducer calibration coefficient of corresponding delivery pressure and flow.

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