CN205136942U - Fluid pressure line fluid pulsation attenuating device based on piezoelectricity reposition of redundant personnel damping technique - Google Patents
Fluid pressure line fluid pulsation attenuating device based on piezoelectricity reposition of redundant personnel damping technique Download PDFInfo
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- CN205136942U CN205136942U CN201520890474.8U CN201520890474U CN205136942U CN 205136942 U CN205136942 U CN 205136942U CN 201520890474 U CN201520890474 U CN 201520890474U CN 205136942 U CN205136942 U CN 205136942U
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Abstract
The utility model discloses a fluid pressure line fluid pulsation attenuating device based on piezoelectricity reposition of redundant personnel damping technique, the middle part of attenuator (31) is a cuboid seal chamber, and both ends have the hydraulic pressure of inflow fluidic import pipe (1) and outflow hydraulic pressure fluidic export pipe (11) respectively about the cavity, and the part of import pipe (1) and export pipe (11) stretches into in the attenuator cavity, the upper portion and the lower part of cavity internal surface are provided with the PVDF piezoelectric membrane respectively, and PVDF piezoelectric membrane overhead has draws forth the outer and outside lead -out wire that forms the electricity and be connected of seal chamber with its two sides. The utility model discloses utilize the pulsation of initiative filter attenuation low frequency, in the passive filter attenuation, the dither, will lead, passive filtering combines, both can keep the original dynamic characteristic of hydraulic system, can improve the pulsation effect that attenuates again in the broad frequency band.
Description
Technical field
The utility model belongs to hydraulic pipe line fluid pulsation control field, is specifically related to a kind of hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology.
Background technique
Because axial piston pump self structure characteristic and huge pressure reduction cause fluid recoil oil return cylinder, make plunger pump there is intrinsic flow pulsation and backwash flow rate pulsation simultaneously, and based on backwash flow rate pulsation.The flow pulsation that pump exports, when flowing through hydraulic tubing, due to the existence of restriction, valve port etc. in pipeline, can produce pressure pulsation.Pressure in pipeline, flow pulsation can bring out pipeline vibration, produce noise, thus reduce the hydraulic element life-span, can cause catastrophic accident time serious.Therefore, the fluid pulsation of control and weakening hydraulic plumbing system has very important realistic meaning.
At present, fluid pulsation decay is divided into Passive Control and ACTIVE CONTROL two-part.Passive Control mainly arranges attenuator in hydraulic system, has successively succeeded in developing polytype pulsation damping device both at home and abroad and has achieved attenuating in various degree in actual applications.But along with hydraulic system is towards high pressure, large discharge, high power density future development, hydraulic fluid pulsations Passive Control also exposes many shortcomings, such as: (1) is in actual hydraulic pressure system, due to the complexity of system, as non-linear, the factor such as distributed parameter and uncertainty, system is made to be easy to be subject to the impact of external interference.And traditional pulsation dampening often belongs to passive type, its structural parameter are immutable, even if variable, are also regulate manually, do not have the ability that self adaption cuts down pulsating wave; (2) usually, pulsation energy mainly concentrates on 200Hz with lower frequency range, and the pulsation decayed in this frequency band is very important.When adopting passive control methods, attenuator centering, dither are cut down relatively good, but to low frequency pulsating, due to bulky, attenuating is not ideal, wherein resistive attenuator energy loss is excessive, and resistance attenuator also respectively has deficiency.
Fluid pulsation ACTIVE CONTROL utilizes special device to produce an additional pressure ripple, makes that it is identical with source pressure pulse wave frequency, amplitude is equal and phase, carrys out the pressure versus flow pulsation in abatement system with this.At present, the method for active filtering mainly contains: (1) directly installs servo actuator additional in the duct, is increased or reduce pipe volume by its to-and-fro motion, produces the pressure pulsation in pressure pulse wave counteracting original hydraulic system; (2) at pipeline outer wall, the intellectual material such as piezoelectric constant or magnetostriction actuator is installed, makes tube wall generation resiliently deformable by the motion of actuator, thus produce pressure pulse wave in pipeline; (3) based on bypass principle of overflow, a bifurcated pipeline is drawn in main line, bifurcated pipeline is installed the active throttle valve, active cancellation valve or the servovalve that are driven by intellectual materials such as piezoelectric constant, by the motion of control valve, reaches the effect suppressing main line pulsation.Along with the development of hydraulic system, the hydraulic fluid pulsations Active Control Method that forefathers study also exposes many shortcomings, be summarized as follows: (1) is when installing servo actuator additional, owing to will produce the secondary pulsating wave of amplitude equal and opposite in direction, phase, this just makes actuator volume larger; Again due in high-pressure hydraulic, actuator will bear very large load, makes its driving voltage or magnetic intensity very large, can cause series of problems such as actuator overheated grade; (2) pipeline rigidity is made to become large because the high-pressure spray in pipeline is known from experience, therefore deform to pipeline, implementation capacity that then will be very large, the distortion of hydraulic system tube wall is utilized mostly to be applied to the hydraulic plumbing system of low pressure to the fluid pulsation ACTIVE CONTROL producing pressure pulse wave, inapplicable for high-pressure hydraulic; (3) although active filtering eliminates the effect of pulsation better, active control system is complicated, cost intensive, is therefore only in laboratory level at present.
Summary of the invention
The purpose of this utility model is to provide a kind of hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology, this device not only compact structure, also achieve the active and passive overall-in-one control schema of fluid pulsation, in conjunction with respective advantage, pulsation in wide band and vibration, noise effectively can be weakened.
The purpose of this utility model is realized by following means.
A kind of hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology, the middle part of attenuator mechanical structure portion 31 is a cuboid seal chamber, the two ends, left and right of cavity have the inflow import pipe 1 of hydraulic fluid and the outlet pipe 11 of efflux hydraulic fluid respectively, and the part of import pipe 1 and outlet pipe 11 stretches in attenuator cavity; The upper and lower of cavity inner surface is respectively arranged with PVDF piezoelectric film, PVDF piezoelectric film is equipped with and its two sides is drawn seal chamber is outer forms with outside the lighting outlet be electrically connected, that is: for the upper lighting outlet (5 and 8) that is connected with controlled inductance type piezoelectric shunt circuit 24 and the lower lighting outlet (18 and 19) for being connected with charge amplifying circuit 27; The sidewall of the import pipe 1 in attenuator cavity, outlet pipe 11 is covered with the uneven micropore of pore size; The internal diameter of attenuator cavity is greater than the internal diameter of import pipe 1 and outlet pipe 11, forms interpolation pipe single chamber expanssion type structure.
Further, as a kind of hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology of the present utility model: when making piezoelectric transducer, in order to improve sensitivity, the PVDF piezoelectric film 17 more than two or two with identical performance is connected in parallel, the aluminium electrode 15 and 16 of film both sides is respectively the aluminium foil that one deck is very thin, very firm, also very pliable and tough with the bonding of PVDF piezoelectric film, very high stress can be born and do significantly flexural strain.Wrap up PVDF piezoelectric film 17 and aluminium electrode thereof with epoxy resin 14, so not only played insulating effect but also can avoid coming in contact with ducted fluid by protective film.
Further, controlled inductance type piezoelectric shunt circuit 24 is composed in series by controlled inductance element 25 and controllable electrical resistance element 26, forms branch circuit piezo-electric damping system.As a kind of hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology of the present utility model: when PVDF piezoelectric film 17 employing is connected in parallel, preamplifier should connect the charge amplifier of high gain and high input impedance, is therefore connected with charge amplifying circuit 27 by the lower lighting outlet (18 and 19) that lower end cap through hole (20 and 21) is drawn.Be only infinitely great in load due to piezoelectric transducer equivalent circuit, inner without electric leakage time, voltage U or the electric charge q of stressed generation could remain unchanged for a long time; If load is not infinitely great, then circuit will exponentially carry out discharging (" piezoelectric transducer and preamplifier connect " that refer to that Li Jintian delivered on " sensor technology " in 2004), and therefore first the measuring circuit of piezoelectric transducer will access the preamplifier of a high input impedance.
The lighting outlet (5 and 8) that attenuator upper end cap through hole (6 and 9) is drawn by the utility model is connected with controlled inductance type piezoelectric shunt circuit 24, this branch circuit piezo-electric damping system is composed in series by controlled inductance element 25 and controllable electrical resistance element 26, wherein the effect of controllable electrical resistance element 26 is the pressure energies dissipated because fluid pulsation causes, and the function of controlled inductance element 25 is store fluid pressure energies.By the value of resistance and inductance in adjustment branch circuit, the resonant frequency of piezoelectric system can be made consistent with fluid pulsation fundamental frequency, thus reach the effect suppressing pressure pulsation.
The import pipe of the utility model attenuator inside cavity and the sidewall of outlet pipe are covered with micropore.The aperture of described micropore (22) and (23) changes between 0.1-0.3mm.Consult domestic pulsation damping device patent, as Chinese patent publication No. CN102226491A, date of publication 2011.10.26, the name of patent of invention is called and disappears arteries and veins denoising device for liquid transport pipeline fluid, this disclosure of the invention is a kind of to be used for liquid transport pipeline fluid and to disappear arteries and veins denoising device, the aperture of the micropore I in device and the aperture of micropore II are 1-3mm, and the bore dia on same microwell plate is identical.The deficiency that this device exists: according to the microperforated panel structure theory of Ma Dayou academician, only have when micropore size is less than 1mm, just easily obtain wide band and absorb (referring to " theory of microperforated panel soundabsorbing construction and design " that Ma Dayou academician delivered in 1975 on " Chinese science "), therefore this contrive equipment attenuate pulsations frequency band is narrower; And the same aperture microwell plate adopted is only effective to single ripple frequency.For these defects, the micropore (22) in a kind of pulsation damping device disclosed in the utility model, (23) aperture be not all more than 0.3mm, and aperture changes between 0.1-0.3mm.Usually, the acoustic resistance of microperforated panel improves greatly along with diminishing of aperture, when reach 0.3mm or less time, its wide band sound absorption is just considerable (referring to " sound absorbing capabilities with transfer matrix method prediction single or multiple lift microwell plate " that Zhang Bin delivered on " applied acoustics " in 2007).The same microwell plate sound absorbing capabilities having multiple different pore size hole has experimental research and result, experiment shows: different pore size microwell plate has the ability expanding wide band sound absorption, have more advantage than same aperture microwell plate, Absorber Bandwidth strengthens, and does not reduce acoustic absorptivity simultaneously.
In sum, a kind of hydraulic pipe line fluid pulsation attenuating device set owner based on Piezoelectric Shunt Damping System technology of the present utility model, Passive Control improve its ability suppressing pulsation.Utilize active filtering attenuate low frequency to pulse, the pulsation of Passive filter decay medium, high frequency, combines active and passive filtering, both can keep the original dynamic response of hydraulic system, can improve attenuate pulsations effect again in broad frequency band.
Accompanying drawing explanation
Fig. 1 is the longitudinal sectional view of a kind of hydraulic pipe line fluid pulsation attenuating device mechanical part based on Piezoelectric Shunt Damping System technology of the present utility model.
Fig. 2 is charge amplifying circuit schematic diagram.
Fig. 3 controlled inductance type piezoelectric shunt circuit schematic diagram.
Fig. 4 is the active and passive integral control system schematic diagram of the utility model embodiment hydraulic pipe line fluid pulsation.
Fig. 5 is controller principle figure.
Embodiment
Below in conjunction with drawings and Examples, the utility model is described in further detail.
The utility model is based on the hydraulic pipe line fluid pulsation attenuating device of Piezoelectric Shunt Damping System technology, and as shown in Figure 1, 2, 3, the part of import pipe 1, outlet pipe 11 stretches in attenuator cavity, and is connected with end cap 3 by helical thread portion 13.Be connected by slotted cheese head screw 4 between attenuator left and right end cap 3 with upper and lower end cap 7; In order to increase the output voltage of charge amplifying circuit 27, PVDF piezoelectric film 17 is connected in parallel, and at PVDF piezoelectric film two-side adhesive aluminium electrode (15 and 16), thus be made into PVDF piezoelectric film sensor; With epoxy resin 14, PVDF piezoelectric film 17 and aluminium electrode are wrapped up, then be bonded on the inwall of upper and lower end cap by 502 tackiness agents 10; Open hole (6,9,20 and 21) at pulsation dampening upper and lower end cap surface, thus the lighting outlet (5,8,18 and 19) on aluminium electrode is drawn.Drawn by upper lighting outlet (5 and 8) and be connected controlled inductance type piezoelectric shunt circuit 24, lower lighting outlet (18 and 19) is drawn and is connected charge amplifying circuit 27; Be positioned at attenuator cavity body import pipe 1, outlet pipe 11 sidewall on be covered with the uneven micropore of pore size (22 and 23).
Control object of the present utility model is basic hydraulic plumbing system, and a typical example as shown in Figure 4, is made up of fuel tank, oil filter, motor, obstruction pump, accumulator, relief valve, hydraulic pipe line and adjustable restrictive valve.Concrete annexation is: the oil suction from fuel tank of driven by motor plunger pump, produces the high-pressure liquid of certain flow, if when oil liquid pressure reaches relief valve set pressure, directly overflow back fuel tank; If when oil liquid pressure does not reach relief valve set pressure, fluid enters in hydraulic pipe line, and install the adjustable restrictive valve as load at hydraulic pipe line end, high-pressure liquid flows through adjustable restrictive valve and gets back to fuel tank; Wherein, bag type accumulator plays the effect of Absorbing Fluctuation and voltage stabilizing, and oil filters the impurity in fluid, and the maximum pressure in hydraulic system set up by relief valve, plays the effect of safety protection.
The utility model is a kind of active and passive integrated control method of hydraulic pipe line fluid pulsation based on Piezoelectric Shunt Damping System technology, comprises following step:
The first step, as shown in Figure 4, utilizes the bag type accumulator that is arranged on pump discharge place to pulse the passive decay carried out to a certain degree to hydraulic line pressure;
Second step, as shown in Figure 4, the active and passive integrated control method of hydraulic pipe line fluid pulsation based on Piezoelectric Shunt Damping System technology adopts PVDF (piezoelectric film) thin-walled cartridge type hydraulic pulsation attenuator as the executive component of the active and passive overall-in-one control schema of fluid pulsation;
3rd step, as shown in Figure 4, pulsation dampening adopts interpolation pipe single chamber expanssion type structure, and this structure belongs to one of structure type of resistance attenuator, the passive decay can carrying out again to the fluid pressure pulse in hydraulic pipe line.With interpolation pipe axis face for symmetry plane, lay upper and lower layer PVDF piezoelectric layer;
4th step, as shown in Figure 4, lower floor's PVDF piezoelectric layer is made piezoelectric film sensor, for detecting the pressure pulsation of hydraulic tubing inside.Utilize the direct piezoelectric effect of PVDF piezoelectric material, Beat is converted into electrical signal, due to the direct electric charge that exported by PVDF piezoelectric film or voltage signal very faint, so only have when PVDF piezoelectric film sensor is connected with the front end circuit matched, a complete segment signal output could be formed.PVDF piezoelectric film sensor is considered as Charge Source, and make it be connected with charge amplifying circuit, charge signal changes into voltage signal through charge amplifying circuit.The voltage signal exported changes into the accessible digital signal of controller by A/D card again, and controller carries out FFT conversion to the pressure pulsation data collected, and obtains pressure vibration frequency spectrum, selects fundamental frequency as the composition that will carry out attenuate pulsations.Adopt adaptive-optimum control algorithm, pressure pulsation amount size after the decay of survey error pressure transducer is as control objectives, the circuit parameter of branch circuit is constantly adjusted, until the pressure pulsation that error pressure transducer measures is minimum, thus realize the ACTIVE CONTROL of fluid pulsation.
Need to do following supplementary notes to the 4th step: (1) contains multiple sinusoidal component due to source pulsating flow, generally high frequency flow pulsation cannot be measured, but can be pulsed by measuring pressure and analyze, and pressure pulsation is again the direct indicator weighing ocsillator strenght just, therefore here by the index of detected pressures pulsation as the vibration of evaluation hydraulic pipe line, and in hydraulic system, the frequency of pressure pulsation is consistent with the frequency of flow pulsation; (2) as shown in Figure 5, adaptive-optimum control algorithm, this algorithm is exactly in the vibration control process of system, dynamically adjusts relevant controlling parameters according to certain Optimality Criteria, with a kind of controlling method making the output of controlled system be in vibration minimum state.This sentences the pressure pulsation amount size after the weakening that error pressure transducer surveys as control objectives, controlled device is pump source system, FFT conversion is carried out to the pressure pulsation data collected, obtain pressure pulsation frequency spectrum, select the Frequency point of its amplitude maximum (i.e. fundamental frequency) to be the composition wanting weakening.Adjustable resistance in branch circuit and adjustable electric inductance value are constantly adjusted, make the resonant frequency of piezoelectric system consistent with certain frequency of pulsating wave, thus the vibratory response of hydraulic control system, until the pressure pulsation that error pressure transducer measures is minimum, thus realize the ACTIVE CONTROL of fluid pulsation.
Claims (5)
1. the hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology, it is characterized in that, the middle part of attenuator (31) is a cuboid seal chamber, the two ends, left and right of cavity have the inflow import pipe (1) of hydraulic fluid and the outlet pipe (11) of efflux hydraulic fluid respectively, and the part of import pipe (1) and outlet pipe (11) stretches in attenuator cavity; The upper and lower of cavity inner surface is respectively arranged with PVDF piezoelectric film, PVDF piezoelectric film is equipped with and its two sides is drawn seal chamber is outer forms with outside the lighting outlet be electrically connected, that is: for the upper lighting outlet (5 and 8) that is connected with controlled inductance type piezoelectric shunt circuit (24) and the lower lighting outlet (18 and 19) for being connected with charge amplifying circuit (27); The sidewall of the import pipe (1) in attenuator cavity, outlet pipe (11) is covered with the uneven micropore of pore size; The internal diameter of attenuator cavity is greater than the internal diameter of import pipe (1) and outlet pipe (11), forms interpolation pipe single chamber expanssion type structure.
2. the hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology according to claim 1; it is characterized in that; described PVDF piezoelectric film adopts the structure of multilayer build-up; multilayer PVDF piezoelectric film is connected in parallel; and at PVDF piezoelectric film two-side adhesive aluminium electrode; PVDF piezoelectric film and aluminium electrode wrap up by epoxy resin (14), play insulating effect and protect PVDF piezoelectric film (17) to avoid and the fluid contact in pipeline.
3. the hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology according to claim 1, it is characterized in that, charge amplifying circuit (27) is made up of operational amplifier (30), charge amplifier feedback electric capacity (28) and feedback resistance (29).
4. the hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology according to claim 1, it is characterized in that, described controlled inductance type piezoelectric shunt circuit (24) is composed in series by controlled inductance element (25) and controllable electrical resistance element (26), forms branch circuit piezo-electric damping system.
5. the hydraulic pipe line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology according to claim 2, is characterized in that, the aperture of described micropore (22 and 23) changes between 0.1-0.3mm.
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| CN201520890474.8U CN205136942U (en) | 2015-11-09 | 2015-11-09 | Fluid pressure line fluid pulsation attenuating device based on piezoelectricity reposition of redundant personnel damping technique |
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| CN201520890474.8U CN205136942U (en) | 2015-11-09 | 2015-11-09 | Fluid pressure line fluid pulsation attenuating device based on piezoelectricity reposition of redundant personnel damping technique |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105257943A (en) * | 2015-11-09 | 2016-01-20 | 西南交通大学 | Hydraulic pipeline fluid pulsation attenuation device based on piezoelectric shunt damping technology |
| CN111237293A (en) * | 2020-01-14 | 2020-06-05 | 北京航空航天大学 | Design method of pressure pulsation attenuator integrated in constant-voltage variable pump |
-
2015
- 2015-11-09 CN CN201520890474.8U patent/CN205136942U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105257943A (en) * | 2015-11-09 | 2016-01-20 | 西南交通大学 | Hydraulic pipeline fluid pulsation attenuation device based on piezoelectric shunt damping technology |
| CN105257943B (en) * | 2015-11-09 | 2017-10-24 | 西南交通大学 | A kind of fluid pressure line fluid pulsation attenuating device based on Piezoelectric Shunt Damping System technology |
| CN111237293A (en) * | 2020-01-14 | 2020-06-05 | 北京航空航天大学 | Design method of pressure pulsation attenuator integrated in constant-voltage variable pump |
| CN111237293B (en) * | 2020-01-14 | 2021-03-09 | 北京航空航天大学 | Design method of pressure pulsation attenuator integrated in constant-voltage variable pump |
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Granted publication date: 20160406 Effective date of abandoning: 20171024 |