CN110138271A - A kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design - Google Patents
A kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design Download PDFInfo
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- CN110138271A CN110138271A CN201910403444.2A CN201910403444A CN110138271A CN 110138271 A CN110138271 A CN 110138271A CN 201910403444 A CN201910403444 A CN 201910403444A CN 110138271 A CN110138271 A CN 110138271A
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- 239000000758 substrate Substances 0.000 claims abstract description 56
- 239000000463 material Substances 0.000 claims description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 239000002033 PVDF binder Substances 0.000 claims description 2
- 239000012528 membrane Substances 0.000 claims description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 claims description 2
- 239000002520 smart material Substances 0.000 claims description 2
- 238000000034 method Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 5
- 239000007787 solid Substances 0.000 description 4
- 230000007613 environmental effect Effects 0.000 description 3
- 238000004377 microelectronic Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 230000010355 oscillation Effects 0.000 description 2
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000002689 soil Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N2/00—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction
- H02N2/18—Electric machines in general using piezoelectric effect, electrostriction or magnetostriction producing electrical output from mechanical input, e.g. generators
- H02N2/186—Vibration harvesters
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Abstract
The present invention provides a kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design.Usual energy accumulator can only operate under the big environment of frequency, exported when extraneous frequency is smaller it is extremely low, be unable to satisfy low-frequency vibration place prisoner can needs.Structure of the invention includes spring, the first mass block, the second mass block, the cantilever substrate with cavity, piezoelectric patches, support.This energy accumulator can increase extraneous vibration frequency while guaranteeing to be promoted output voltage, electrical power, and reduce the intrinsic frequency of itself.In ambient enviroment low-frequency vibration, spring mass system resonates by lower intrinsic frequency, and the first mass block impacts the second mass block, achievees the purpose that raising frequency；Second mass block is bonded in cantilever substrate free end, can reduce structural natural frequencies；The setting of cavity is then further substantially reduced the intrinsic frequency of system, so that the present invention being capable of efficient operation under low frequency environments.
Description
Technical field
The present invention relates to generation technologies and renewable and clean energy resource field, and in particular to a kind of raising frequency formula band cavity cantilever slab
The piezoelectric harvester of structure and its prisoner can methods.
Background technique
Energy problem is one of current the problem of paying close attention to the most, and various countries' Scientific Research Workers are all being dedicated to finding and develop
New energy has solved the problems, such as energy shortage.Currently, battery-powered relies on excellent capacitance of storage for most of microelectronic devices
And power good, it is cheap and easy to get the advantages that and be widely used, but since the common batteries service life is low, replacement is troublesome and useless
Used batteries pollute the disadvantages of water and soil, harmful to human, it is therefore desirable to study it is a kind of can be used for a long time, the new energy of environmental protection is supplied
Energy.
Electric energy is converted by the vibrational energy of ambient enviroment using the piezoelectric effect of piezoelectric material, not only the service life is long, environmental protection,
And have many advantages, such as high conversion efficiency, sustainable energy supply.Therefore, this technology becomes the hot spot studied at present.
Conventional piezoelectric harvester intrinsic frequency is higher at present, and ambient environment vibrations frequency is lower, therefore can not make to capture
Energy device reaches resonance, and output power greatly reduces.
Chinese patent application (publication number CN107742994) disclose a kind of collision raising frequency formula bistable state piezoelectric harvester and
It capturees energy method, and the repulsive force by putting magnet on magnet and circular housing on sticking together acts on, and passes through shaft band when human body is swung
Dynamic piezoelectric beam collides with plectrum, produces electricl energy piezoelectric beam high-frequency vibration, improves output power.
Summary of the invention
The purpose of the present invention is aiming at the problem that piezoelectric harvester prisoner energy low efficiency, propose one kind in the environment of low-frequency vibration
It is impacted using resonance and promotes extraneous frequency, and itself intrinsic frequency is reduced by the setting of cavity and improves output voltage, electric work
The efficient energy accumulator of rate and its prisoner can methods.
The technical solution used in the present invention is: a kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design is invented,
Including support (6), cantilever substrate (4), piezoelectric patches (5), the second mass block (3), the first mass block (2) and spring (1)；Spring
(1) it is fixedly connected with the first mass block；First mass block is a cylindrical body, simultaneously with face arranged concentric above and below the second mass block
There are gap 0.5mm；Second mass block is then that rib is long with the wide square of cantilever substrate, and with cantilever substrate free end
End face is concordant with side；And be fixedly connected below the fixing end of cantilever substrate with support, support and substrate are wide, side and fixation
Hold end face alignment；A piece of piezoelectric patches is then pasted above substrate fixing end.Piezoelectric patches length direction it is consistent with substrate length direction and
It is wide, and flushed with substrate fixing end end face and side；Cantilever substrate is provided with a perforative sky at the position close to fixing end
Chamber, cavity is in rectangle along substrate cross section and length direction is consistent with substrate, and cavity thickness must not exceed the 80% of substrate size,
And thickness of two sides cannot be less than thick 10% of substrate to cavity up and down.
Spring (1) and the first mass block (2) constitute first order vibrational system, and as raising frequency system, intrinsic frequency is lower than
Cantilever substrate intrinsic frequency enables to generate resonance under lower extraneous vibration frequency.
In intrinsic frequency problem for reducing second level vibrational system, experimental program of the present invention is cantilever base
The setting of mass block and fixing end cavity is added in plate free end, and cantilever baseplate material is consistent with mass block, is ordinary aluminum plate, empty
Intracavitary is then air；And there are also another advantages for the setting of cavity, it can effectively improve the output voltage and electricity of system
Power.
The present invention investigates system frequency and generated energy in terms of optimizable three and cavity length, cavity are thick
The relationship of degree, empty cavity position.
Firstly, individually influence of the research cavity length to intrinsic frequency and generated energy.Therefore, cavity thickness and position are controlled
It is constant to set variable, only changing cavity length just becomes research method.In COMSOL Multiphysics, using parametrization
The method scanning feature frequency of scanning with cavity length variation, as shown in figure 4, second level vibrational system intrinsic frequency is with cavity
The growth of length lc increases again after reducing before this, and in cavity length lc=7.2mm, intrinsic frequency obtains minimum；For another example Fig. 5
Shown, the intrinsic frequency of the system is 581.5Hz, output voltage 4.3V, electromotive power output 97uW at this time, when with no cavity
Intrinsic frequency 757Hz compared to being greatly reduced, and voltage, electrical power compare before 4V and 76uW there has also been very big
It improves.
Secondly, individually research cavity thickness to thus have the influence of frequency and generated energy.As shown in fig. 6, this system is intrinsic
Frequency increases again after reducing before this with the increase of cavity thickness hc, and minimum (this is obtained in cavity thickness hc=0.27mm
When cavity length be 7.2mm), as also shown in fig. 7, which is 557Hz, output voltage 4.7V at this time, output
Electrical power is 100uW, and with the same lc=7.2mm of cavity length before, cavity thickness hc=0.25mm, which is compared, certain mention
It is high.
Finally, individually influence of the research empty cavity position to intrinsic frequency and generated energy.As shown in figure 8, subsystem is intrinsic
Frequency increases afterwards as the increase of empty cavity position ht first reduces, and then reduces again, finally increases.In empty cavity position ht=
Minimum (lc=7.2mm at this time, hc=0.27mm) is obtained when 0.18mm, as also shown in fig. 9, which is
534Hz, output voltage and electrical power are respectively 5V and 117V, with cavity length lc=7.2mm before, thickness h c=
0.27mm, width are compared for 0.115mm and are improved.
Therefore, can choose out a kind of optimum structure scheme by finite element analysis: i.e. cavity length lc is selected as
7.2mm, cavity thickness hc are selected as 0.27mm, and empty cavity position ht is selected as 0.18mm.At this point, not only by no cavity when intrinsic frequency
It is down to 534hz from 757hz, output voltage and electrical power are also promoted to 5V, 117uW by 4V, 76uW.
Prisoner's energy method of the piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design, specific as follows:
When external environment vibration frequency is lower, external environment directly drives spring (1) and the first mass block (2) same to frequency vibration
Dynamic, spring (1) and the first mass block (2) constitute first order vibrational system, because itself lower intrinsic frequency resonates；
The resonance of first order vibrational system is so that the first mass block Oscillation Amplitude increases, continuous the second mass of impact
Block (3).Therefore, vibrational system vibration frequency in the second level is improved, that is, realizes the purpose of raising frequency；
Second mass block (3) and the cantilever substrate (4) with cavity and piezoelectric patches (5) constitute second level vibrational system, the vibration
Dynamic system significantly reduces solid since the presence of substrate upper plenum not only makes output voltage, electrical power be improved
There is frequency, that is, realizes the purpose of frequency reducing；
The not only effect by outer exciting of second level vibrational system, but also by the impact from the first vibrational system, from
And reach resonance.Piezoelectric patches (5) possesses biggish strain because being pasted onto cantilever substrate fixing end, according to the positive piezoelectricity of itself
Vibrational energy is converted to power output by effect, is worked for microelectronic components such as sensors.
Compared with prior art, the present invention having the advantages that
When environmental frequencies are lower, the first order vibrational system being made of spring with the first mass block resonates, impact
Second mass block of second level vibrational system is allowed to vibration frequency raising, and second level vibrational system is because the setting of cavity reduces
Intrinsic frequency, to ensure that second level vibrational system resonates, and the setting of cavity also improves output voltage, electric work
Rate.Therefore the present invention can not only work under low-frequency vibration environment, but also possess good output performance.
Detailed description of the invention
Fig. 1 is a kind of perspective view of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design of the invention；
Fig. 2 is a kind of front view of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design of the invention；
Fig. 3 is a kind of top view of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design of the invention；
Fig. 4 is the relational graph (cavity thickness that vibrational system intrinsic frequency in the second level changes with cavity length lc in the present invention
Hc=0.25mm, position occupy substrate thickness direction center)；
Output voltage and electrical power change with vibration frequency when Fig. 5 is vibrational system lc=7.2mm in the second level in the present invention
Relational graph；
The relationship that intrinsic frequency changes with cavity thickness hc when Fig. 6 is vibrational system lc=7.2mm in the second level in the present invention
Figure (position occupy substrate thickness direction center)；
Output voltage and electrical power are with vibration when Fig. 7 is second level vibrational system lc=7.2mm, hc=0.27mm in the present invention
The relational graph of dynamic frequency variation；
Intrinsic frequency is (empty with position ht when Fig. 8 is second level vibrational system lc=7.2mm, hc=0.27mm in the present invention
Chamber upper surface is at a distance from upper surface of base plate) variation relational graph；
When Fig. 9 is second level vibrational system lc=8mm, hc=0.27mm, ht=0.18mm in the present invention output voltage with
The relational graph that electrical power changes with vibration frequency；
Figure 10 be when second level vibrational system is without cavity in the present invention output voltage and electrical power with the variation of vibration frequency
Relational graph；
Specific embodiment
It elaborates with reference to the accompanying drawing to the present invention.
Referring to attached drawing 1,2,3, a kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design, including support (6), cantilever
Substrate (4), piezoelectric patches (5), the second mass block (3), the first mass block (2) and spring (1)；Spring (1) and the first mass block are solid
Fixed connection；First mass block is a cylindrical body, with face arranged concentric above and below the second mass block and there are gap 0.5mm；The
Two mass blocks are then a rib length and the wide square of cantilever substrate, and concordant with cantilever substrate free end end face and side；
And be fixedly connected below the fixing end of cantilever substrate with support, support and substrate are wide, and side is aligned with fixing end end face；Substrate
A piece of piezoelectric patches is then pasted above fixing end.Piezoelectric patches length direction is consistent and wide with substrate length direction, and solid with substrate
Fixed end end face and side flush；Cantilever substrate is provided with a perforative cavity at the position close to fixing end, and cavity is along substrate cross
Rectangular in cross-section and length direction is consistent with substrate, cavity thickness must not exceed the 80% of substrate size, and cavity two sides up and down
Thickness cannot be less than thick 10% of substrate.
Quality is block-shaped in this example has selected, but not necessarily in this way, can change under conditions of meeting frequency requirement
Its shape and size.
Spring (1) is consistent with the first mass block (2) selected materials, using structural steel, constitutes first order vibrational system, as
Raising frequency system, intrinsic frequency is determined by the rigidity and the quality of mass block for selecting spring, is enabled in the lower external world
Resonance is generated under vibration frequency.
Cantilever substrate and the second mass block (3) selected materials are consistent, using common aluminum material, are laid with and paste on cantilever substrate
Piezoelectric smart material then use PVDF piezoelectric membrane.
The long 20mm of arm substrate, wide 2mm, thick 0.4mm, cavity length is isometric with piezoelectric patches, is 7mm, and cavity thickness is
0.2mm, apart from substrate fixing end end face 0.5mm.
Prisoner's energy method of the piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design, specific as follows:
When external environment vibration frequency is lower, external environment directly drives spring (1) and the first mass block (2) same to frequency vibration
Dynamic, spring (1) and the first mass block (2) constitute first order vibrational system, because itself lower intrinsic frequency resonates；
The resonance of first order vibrational system is so that the first mass block Oscillation Amplitude increases, continuous the second mass of impact
Block (3).Therefore, vibrational system vibration frequency in the second level is improved, that is, realizes the purpose of raising frequency；
Second mass block (3) and the cantilever substrate (4) with cavity and piezoelectric patches (5) constitute second level vibrational system, the vibration
Dynamic system significantly reduces solid since the presence of substrate upper plenum not only makes output voltage, electrical power be improved
There is frequency, that is, realizes the purpose of frequency reducing；
The not only effect by outer exciting of second level vibrational system, but also by the impact from the first vibrational system, from
And reach resonance.Piezoelectric patches (5) possesses biggish strain because being pasted onto cantilever substrate fixing end, according to the positive piezoelectricity of itself
Vibrational energy is converted to power output by effect, is worked for microelectronic components such as sensors.
Claims (4)
1. a kind of piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design, which is characterized in that including support (6), cantilever substrate
(4), piezoelectric patches (5), the second mass block (3), the first mass block (2) and spring (1)；Spring (1) and the fixed company of the first mass block
It connects；First mass block is a cylindrical body, with face arranged concentric above and below the second mass block and there are gap 0.5mm；Second matter
Gauge block is then a rib length and the wide square of cantilever substrate, and concordant with cantilever substrate free end end face and side；And it hangs
It is fixedly connected below the fixing end of arm substrate with support, support is wide with substrate, and side is aligned with fixing end end face；Substrate is fixed
Then paste a piece of piezoelectric patches in end top；Piezoelectric patches length direction is consistent and wide with substrate length direction, and with substrate fixing end
End face and side flush；Cantilever substrate is provided with a perforative cavity at the position close to fixing end, and cavity is along substrate cross section
In rectangle and length direction it is consistent with substrate, cavity thickness must not exceed the 80% of substrate size, and cavity thickness of two sides up and down
It must not be lower than the 10% of substrate thickness.
2. piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design described in accordance with the claim 1, it is characterised in that spring (1)
First order vibrational system, as raising frequency system are constituted with the first mass block (2), intrinsic frequency is lower than the intrinsic frequency of cantilever substrate
Rate.
3. piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design described in accordance with the claim 1, it is characterised in that cantilever base
Plate and the second mass block (3) be it is integrally formed, using aluminum material, piezoelectric smart material then uses PVDF piezoelectric membrane.
4. piezoelectric harvester of the raising frequency formula with cavity cantilever sheet design described in accordance with the claim 1, it is characterised in that cantilever base
Plate long 20mm, wide 2mm, thick 0.5mm；Cavity length is 7.2mm, and cavity thickness 0.27mm, cavity is apart from upper surface of base plate
0.18mm, apart from substrate fixing end end face 0.5mm.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113791698A (en) * | 2021-09-14 | 2021-12-14 | 哈尔滨工程大学 | Wireless mouse with combined type power generation facility |
| CN114050738A (en) * | 2021-11-26 | 2022-02-15 | 浙江师范大学 | Self-powered positioning and tracking system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010051945A (en) * | 2008-08-29 | 2010-03-11 | Mitsubishi Heavy Ind Ltd | Resonance frequency-adjustable apparatus for collecting piezoelectric vibration energy |
| CN104158440A (en) * | 2014-09-05 | 2014-11-19 | 苏州大学 | Frequency-raising type vibration energy collecting system and collecting method |
| WO2016173151A1 (en) * | 2015-04-28 | 2016-11-03 | 南京航空航天大学 | Piezoelectric oscillator structure for vibration energy recovery |
| CN107147330A (en) * | 2017-06-21 | 2017-09-08 | 北京机械设备研究所 | A kind of non-linear piezoelectricity electromagnetism combined wide-band energy accumulator |
| CN108418470A (en) * | 2018-03-14 | 2018-08-17 | 佛山市顺德区中山大学研究院 | Piezoelectric energy collector |
| CN109067240A (en) * | 2018-07-17 | 2018-12-21 | 同济大学 | A kind of beam type piezoelectric energy collector with cavity |
| CN109428516A (en) * | 2017-08-29 | 2019-03-05 | 三角力量管理株式会社 | Generating element |
-
2019
- 2019-05-15 CN CN201910403444.2A patent/CN110138271A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010051945A (en) * | 2008-08-29 | 2010-03-11 | Mitsubishi Heavy Ind Ltd | Resonance frequency-adjustable apparatus for collecting piezoelectric vibration energy |
| CN104158440A (en) * | 2014-09-05 | 2014-11-19 | 苏州大学 | Frequency-raising type vibration energy collecting system and collecting method |
| WO2016173151A1 (en) * | 2015-04-28 | 2016-11-03 | 南京航空航天大学 | Piezoelectric oscillator structure for vibration energy recovery |
| CN107147330A (en) * | 2017-06-21 | 2017-09-08 | 北京机械设备研究所 | A kind of non-linear piezoelectricity electromagnetism combined wide-band energy accumulator |
| CN109428516A (en) * | 2017-08-29 | 2019-03-05 | 三角力量管理株式会社 | Generating element |
| CN108418470A (en) * | 2018-03-14 | 2018-08-17 | 佛山市顺德区中山大学研究院 | Piezoelectric energy collector |
| CN109067240A (en) * | 2018-07-17 | 2018-12-21 | 同济大学 | A kind of beam type piezoelectric energy collector with cavity |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113791698A (en) * | 2021-09-14 | 2021-12-14 | 哈尔滨工程大学 | Wireless mouse with combined type power generation facility |
| CN114050738A (en) * | 2021-11-26 | 2022-02-15 | 浙江师范大学 | Self-powered positioning and tracking system |
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