RU2551666C2 - High-voltage generator and method of its manufacture - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: invention relates to piezoelectronics. Essence of the invention: the working body of the high-voltage generator is formed by inertial mass and a package of the plates of polarised composite ferroelectric materials with high values of piezoelectric voltage coefficient and compressive strength pre-set for each plate. The distances between the conducting surfaces applied on the plates is set such that their values multiplied by values of mechanical stress and piezoelectric stress coefficient be identical to each plate in the package. The method comprises the manufacture of each batch of the plates polarised composite ferroelectric materials by consecutive execution of the following operations: preparation of moulding powder of the synthesised material, preparation of mix of moulding powder of the synthesised material and pore agent, moulding from mix of work-pieces and their high-temperature processing by an agglomeration method, machining, metallisation, polarisation and measurement of parameters. The pre-set compressive strength for each batch of plates is achieved by a porosity variation due to change of concentration of pore agent in the plate.

EFFECT: conversion of mechanical compression stress to electric energy without explosive, reduction of time of formation and increase of occurring electric charge in unit of volume of the working body at high values of potential difference.

2 cl, 2 dwg, 2 ex

Description

The invention relates to electronic equipment, and more specifically: to piezoelectronics, converters of mechanical energy into electrical energy, to sources of high voltage electric charge based on piezoceramics.

Piezoelectric devices are known - converters of mechanical energy into electrical energy. Energy conversion due to deformation of a piezoelectric ceramic element consisting of polarized ferroelectric ceramics occurs in piezoelectric sensors (VV Yanchich. Piezoelectric vibration transducers. Rostov-on-Don, Publishing House "SFU", 2010), and in household appliances - piezo lighters a high voltage discharge is formed. With a longitudinal, relative to the residual polarization vector, compression-tension strain of the piezoelectric ceramic element under the action of a force applied normally to the planes of the electrodes, according to the definition of the piezoelectric effect, a charge arises on the electrodes.

Explosive generators for meteorological applications are known that convert the mechanical energy of a shock wave propagating in a working medium into high-voltage electric energy (Prishchepenko AB, Tretyakov DV, Shchelkachev MV Energy balance of an explosive piezoelectric frequency generator. Conference proceedings “ Mega-house and mega-ampere technology of application ”, Sarov, VNIIEF, 1997, pp. 954 ÷ 958). The main element of such generators is a working fluid made as a package of n plates of polarized ferroelectric material with conductive surfaces deposited on them. The shock wave in the working fluid is formed by a special explosive charge. The advantages of the considered devices are compactness and complete autonomy from external energy sources.

An explosive shock wave has a high intensity, and the dominant process in the conversion of the mechanical energy of the shock wave to electrical energy is the transition of the ferroelectric state to the paraelectric state.

The source current i _E and the resulting charge Q, assuming the linearity of the properties of the material of the working fluid, can be estimated by the formulas:

where: n is the number of plates of a ferroelectric material coated with conductive surfaces;

ΔР is the polarization jump at the front of the shock wave;

u _e - the velocity of the front of the shock wave, u _e equate to the speed of sound in the working fluid;

S _E - the area of the contact surfaces of the ferroelectric working fluid;

δ = nh is the path of the shock wave along the ferroelectric working fluid;

h is the distance between the contact surfaces of the ferroelectric plates;

t = δ / u _e is the current flow time.

Known explosive piezoelectric generator (RF patent No. 2154888, prototype) contains a shock wave generator, a piezoelectric transducer of shock wave energy into electrical energy, made in the form of a single piezoelectric plate with electrodes on two opposite sides parallel to the direction of propagation of the shock wave.

The disadvantages of these designs of a high-voltage generator include:

- the presence in explosive generators of explosive and the accompanying initialization system to create a shock wave;

- the presence of a source of electrical energy (battery, battery) and electronic filling for the formation of high voltage;

- relatively small values of the emerging charge in a unit volume of the working fluid when it is necessary to create high values of the potential difference between the conductive surfaces deposited on the plates.

The problem to which this invention is directed, is, while maintaining the advantages (compactness and complete autonomy), achieving a technical result, which consists in:

- in the creation of a high-voltage generator, eliminating the presence of explosives, converting the work of mechanical shock into high-voltage electric energy using the working fluid of a piezoelectric high-voltage generator under the influence of a shock wave, for example, in the volume of a shot such as VOG-25 grenade launcher type GP-25;

- to reduce the formation time and increase the value of the emerging electric charge per unit volume of the working fluid at high potential differences between the conductive surfaces deposited on the plates.

The problem is solved in a piezoelectric high-voltage generator, consisting of an inertial mass and a package of plates of polarized composite ferroelectric materials with high values of the piezoelectric stress coefficient and the compressive strength specified for each plate, mechanically connected in series so that the mechanical stresses arising in the plates upon impact are summed, and electrically connected in parallel so that the electrical charges arising in the plates are summed pounds with the same potential difference, for which the distances between the conductive surfaces deposited on the plates are set such that their values multiplied by the values of the mechanical stress and the piezoelectric voltage coefficient are the same for each plate in the stack, and the working fluid is exposed to the shock wave; and placed, for example, in the volume of a shot such as VOG-25 grenade launcher type GP-25.

The inventive high voltage generator and the properties of its constituent elements are illustrated in FIG. 1 and 2, tab. one.

FIG. 1a - Mechanical diagram of a piezoelectric high voltage generator.

FIG. 16 - Electrical diagram of a piezoelectric high voltage generator.

FIG. 1c - Overall dimensions of the VOG-25 shot.

M ₀ - inertial mass.

и заданной для каждой - k-й пластины прочностью на сжатие

1 ÷ 6 - plates with a density ρ _{k of} polarized composite ferroelectric materials with increased values of the piezoelectric voltage coefficient

and specified for each - k-th plate compressive strength

7 - electrodes,

8 - mounting tape made of silver,

9 - embedded parts - electrodes of current collectors,

10 - the body of a porous polymeric material,

11 is the direction of polarization of each plate,

- направление движения генератора при уларе,

- the direction of movement of the generator with ular,

- направление сил сжатия (инерции) при ударе.

- direction of compression forces (inertia) upon impact.

FIG. 2 Dependences of the properties of piezoceramics with closed porosity (3-0 connectivity) on porosity.

FIG. 2a. Dependence of piezoelectric modules d on porosity P of piezoelectric ceramics with closed porosity.

d ₃₃ is a longitudinal piezoelectric module;

d _v - volumetric piezoelectric module;

d ₃₁ - transverse piezoelectric module.

от пористости Р пьзокерамики с закрытой пористостью.FIG. 2b. Dielectric constant $${\epsilon }_{33}^T$$

from porosity P of piezoceramics with closed porosity.

FIG. 2c. Dependence of compressive strength T _SJ on porosity P of piezoelectric ceramics with closed porosity.

Table 1. Characteristics of the properties of the piezoelectric plates of the working fluid of a high-voltage generator.

Table 2. Characteristics of the properties of the plates of the working fluid made of polarized ferroelectric material.

k is the serial number of the plate;

P _k is the porosity of the k-th plate,%;

ρ _k is the density of the k-th plate, kg / m ³ ;

- механические напряжения, возникающие в k-й пластине, 10⁸ Па; $$T_{33}^k$$

- mechanical stresses arising in the k-th plate, 10 ⁸ Pa;

- диэлектрическая проницаемость k-й пластины; $${\epsilon }_{33}^{T_k}$$

- dielectric constant of the k-th plate;

- пьезоэлектрический коэффициент напряжения k-й пластины, В·м/Н; $$g_{33}^k$$

- piezoelectric voltage coefficient of the k-th plate, V · m / N;

h _k is the distance between the conductive surfaces of the k-th plate, m;

Q _k is the charge arising in the k-th plate, C;

U _k is the potential difference of the charges on the conductive surfaces of the k-th plate;

и прочность на сжатие Т_СЖ уменьшаются, как это приведено на Фиг. 2а), 26) и 2в) причем в диапазоне 0≤Р≤30% изменения ε₃₃ (Р), g₃₃ (Р) и Т_СЖ (Р) определены экспериментально и описываются формулами:X _k is the concentration of the introduced blowing agent for the k-th plate with a given compressive strength, wt. % In polarized composite ferroelectric materials, 3-0 connectivity, which corresponds to ceramic with closed porosity, with an increase in its porosity P from ≈0 to ≈50%, the piezoelectric module d ₃₃ practically does not change, and the dielectric constant $${\epsilon }_{33}^T$$

and compressive strength T _{SJ are} reduced, as shown in FIG. 2a), 26) and 2c) and in the range 0≤P≤30%, the changes in ε ₃₃ (P), g ₃₃ (P) and T _SJ (P) are determined experimentally and are described by the formulas:

, $$g_{33}^1$$

, $$T_{СЖ}^1$$

- характеристики «беспористой» керамики, которая соответствует спеченным без порообразователя образцам.Where $${\epsilon }_{33}^{T_{\mathrm{one}}}$$

, $$g_{33}^{\mathrm{one}}$$

, $$T_{\mathrm{FROM}F}^{\mathrm{one}}$$

- Characteristics of "non-porous" ceramics, which corresponds to samples sintered without a blowing agent.

The characteristics of the “non-porous” ceramic corresponding to the samples sintered without a blowing agent are shown in row 1 of Table 1 and are shown in FIG. 2.

и заданной для каждой - k-й пластины прочностью на сжатие $$T_{СЖ}^k$$

, причем механически пластины соединены последовательно так, что возникающие в пластинах при ударе со скоростью V механические напряжения $$T_{33}^k$$

суммируются, а электрически соединены параллельно так, что суммируются возникающие в пластинах электрические заряды с одинаковой разностью потенциалов U_k, для чего расстояния h_k между нанесенными на пластины токопроводящими поверхностями площадью S_k устанавливают такими, чтобы их значения h_k, умноженные на значения механического напряжения $$T_{33}^k$$

и пьезоэлектрического коэффициента напряжения $$g_{33}^k$$

, были одинаковы

для каждой пластины рабочего тела.In the proposed design of a high-voltage generator (Fig. 1a), placed, for example, in the volume of a shot of the VOG-25 type (Fig. 1c), the working fluid is an inertial mass M ₀ and a package of n plates of polarized composite ferroelectric materials (Fig. 1b) density ρ _k with high values of the piezoelectric voltage coefficient

and specified for each - k-th plate compressive strength $$T_{\mathrm{FROM}F}^k$$

moreover, the plates are mechanically connected in series so that mechanical stresses arising in the plates upon impact with a speed V $$T_{33}^k$$

are summed up and electrically connected in parallel so that the electric charges arising in the plates with the same potential difference U _k are summed, for which the distances h _k between the conductive surfaces of area S _k applied to the plates are set such that their values of h _k multiplied by the values of mechanical stress $$T_{33}^k$$

and piezoelectric voltage coefficient $$g_{33}^k$$

were the same

for each plate of the working fluid.

The characteristics of the k-th plate of the high-voltage generator according to the identified and previously presented experimental laws and constants are described by the following formulas

в k-й пластине при ударе генератора параллельны направлению поляризации, и их максимальные значения в пластинах составляют:The plates in the bag are connected mechanically in series so that mechanical stresses $$T_{33}^k$$

in the k-th plate, upon impact of the generator, they are parallel to the direction of polarization, and their maximum values in the plates are:

- for the “upper”, nth plate (k = n)

- for the k-th plate

where a is the acceleration of the high-voltage generator upon impact;

S _n is the contact surface area of the “upper”, nth plate.

значению прочности на сжатие $$T_{СЖ}^k$$

, по зависимостям характеристик поляризованных композиционных сегнетоэлектрических материалов от пористости P_k, приведенным в формулах (3) (4) и (5), определяют требуемую пористость P_k композита и соответствующие этой пористости значения диэлектрической проницаемости $${\epsilon }_{33}^{T_k}$$

.Equating the value for the kth plate $$T_{33}^k$$

compressive strength $$T_{\mathrm{FROM}F}^k$$

, from the dependences of the characteristics of the polarized composite ferroelectric materials on the porosity P _k given in formulas (3) (4) and (5), the required porosity P _{k of the} composite and the dielectric constant corresponding to this porosity are determined $${\epsilon }_{33}^{T_k}$$

.

для чего величины расстояния h_k определяют из условия постоянства произведения

для каждой пластины.The plates are electrically connected in parallel so that the resulting electric charges with the same potential difference are summed

why the distance h _k is determined from the condition of constancy of the product

for each plate.

The maximum time of occurrence of charges with the same potential difference U _k can be estimated as the time of passage of a shock wave (compression wave) through a plate with a maximum value of h _k , which is significantly less than the time of passage of a compression wave in series across all plates.

With the values of the acceleration causing the excess of compressive strength, the process of converting the mechanical compression energy into electrical energy occurs simultaneously in all plates of the working fluid and is accompanied by a jump in polarization at the front of the compression wave upon transition of the ferroelectric state to the paraelectric state.

An increase in the value of the electric charge arising in a unit volume of the working fluid at high values of the potential difference between the conductive surfaces deposited on the plates follows from the dependences in FIG. 2a) and 2b).

с увеличением пористости увеличивается.In FIG. 2a) schematically shows the dependences of the piezoelectric modules d ₃₃ , and d ₃₁ and d _v on the porosity P. If the values of the transverse piezomodule d ₃₁ decrease with increasing porosity, the volume piezomodule d _v grows, then the longitudinal piezomodule d ₃₃ , which determines the charge, remains practically unchanged , and the value of the voltage coefficient proportional to the ratio

with increasing porosity increases.

Thus, a distinguishing feature of a high-voltage generator that converts the energy of a shock wave of mechanical compression into electrical energy is a working fluid exposed to a shock wave, for example, in the volume of a shot of the VOG-25 type of a grenade launcher of the GP-25 type, which is an inertial mass and a packet of plates of polarized composite ferroelectric materials with high values of the piezoelectric voltage coefficient and the compressive strength specified for each plate, mechan connected in series so that the mechanical stresses arising in the plates upon impact are summed up, and electrically connected in parallel so that the electric charges arising in the plates are combined with the same potential difference, for which the distances between the conductive surfaces deposited on the plates are set so that their values multiplied The values of mechanical stress and piezoelectric stress coefficient were the same for each plate in the package.

The specified set of distinctive features of the invention allows to achieve a technical result, consisting in:

- creating a piezoelectric high-voltage charge generator, for example, in the volume of a VOG-25 type shot of a GP-25 type under-barrel grenade launcher, which converts the work of the mechanical compression stress arising upon impact of the generator into electrical energy and eliminates the presence of explosive;

- reducing the time of formation and increasing the value of the arising electric charge per unit volume of the working fluid at high values of the potential difference between the conductive surfaces deposited on the plates.

The formation of an electric charge occurs simultaneously in all plates and can be estimated from the time the compression wave propagates through the plate with the largest distance between the conductive surfaces. The potential differences of the charges on the conductive surfaces of the plates are the same and equal

A method of manufacturing the inventive high voltage generator. The manufacturing process of high-voltage generators includes the manufacture of:

- plates of polarized composite ferroelectric materials with high values of the piezoelectric voltage coefficient and the compressive strength specified for each plate;

- packages of plates mechanically connected in series (in a column) so that the mechanical stresses arising in the plates during acceleration are added up, and electrically connected in parallel so that the electric charges arising in the plates are summed;

- assembly of a high-voltage generator in a housing made of porous polymeric material, including assembly of a working fluid from an inertial mass and a package of plates, as well as current collectors, in a housing made of porous polymeric material.

The process of manufacturing plates of porous piezoceramics for generators begins with the preparation of batches of mixtures of press powder of synthesized material and powder of a pore former, for example, corn starch or methyl cellulose. Press powder of the synthesized material, for example, ZTS-46, is made from a powder of synthesized material having a total specific surface area of (1 ± 0.1) m ² / g according to the PSX-4 instrument, and the grain size of the organic blowing agent powders, for example, from methyl cellulose , Ø = 6 ± 1 μm. For each plate, a batch of the mixture is prepared separately in the vortex layer mixing apparatus (ABC), where the random movement of magnetic working bodies, for example steel needles for gramophones, is determined by the rotating magnetic field of the stator of a three-phase electric motor. The volumetric content of the blowing agent in the mixture is laid during loading and is controlled by the bulk density of the mixture.

Pressing batches of powder mixtures is carried out in molds, the dimensions of which take into account shrinkage during sintering up to 45% and the necessary allowances for machining.

Sintering of the preforms is carried out in a lead-containing backfill according to a special temperature-time regime, which provides for a temperature rise at a rate of 25 ± 3 ° C / h, exposure at a temperature of 450 ± 10 ° C for 2.0 ± 0.1 hours to burn the binder and blowing agent powder; sintering is carried out at a temperature of 980 ± 10 ° C for 3 hours.

Sintered blanks are ground in diameter and, as clean as in a plane, with an allowance of up to 5 mm in height.

On polished billets, density is determined geometrically as the ratio of mass to volume (weighing on a scale with an error of not more than 0.1%, sizing with a caliper with a division value of 0.01 mm. The final error in determining the density is estimated as not exceeding 1.0%. Of polished samples are sampled, up to 10% of each batch, samplers are made, electrophysical parameters are determined and subjected to compression by a hydraulic press, determining the compressive strength.

Billets of batches with different densities (porosity) are ground to a height size determined on the probes in accordance with the calculated values.

The metallization of the flat surfaces of porous preforms is carried out in the traditional way, by applying a silver-containing paste through a silk-screen with edges and by burning silver-containing paste with a porosity value of up to 25%, when the porosity is closed. On billets with open (through) porosity (more than 25%), only contact pads are metallized by burning silver, and then silver is sprayed through a mask with edges on all flat surfaces.

The polarization of the blanks is carried out according to the modes selected on the probes, for example, at a temperature of 120 ± 3 ° C and a field strength of 2.0 ± 0.1 kV / mm for an hour.

The described method uses well-known technologies, but does not provide the manufacture of plates with the required set of parameters.

The problem to which this invention is directed, is to achieve a technical result, which consists

in providing technological capabilities for manufacturing plates of polarized composite ferroelectric materials with high values of the piezoelectric stress coefficient and the compressive strength specified for each plate with such distances between the conductive surfaces deposited on the plates so that their values multiplied by the values of mechanical stress and piezoelectric voltage coefficient are the same for each batch of plates.

The problem is solved when using the method of manufacturing piezoelectric high-voltage generators, consisting of a body of porous polymeric material with embedded electrodes of current collectors and a working fluid, including an inertial mass and a package of plates of polarized composite ferroelectric materials with high values of the piezoelectric voltage coefficient and the specified strength for each plate compression, and the manufacture of each batch of polarized composite plates ferroelectric materials with a given compressive strength include operations: - preparation of a press powder of synthesized material, preparation of a mixture of press powder of synthesized material and a blowing agent, pressing from a mixture of billets and their high-temperature processing (sintering), machining, metallization, polarization and measurement of parameters, characterized in that:

и пористостью P_K содержит порообразователь в концентрации Х_K, мас. %;- a batch of a mixture of press powder with a blowing agent for the k-th plate with a given compressive strength $$T_{\mathrm{FROM}F}^k$$

and porosity P _K contains a blowing agent in a concentration of X _K , wt. %;

- коэффициент объемной усадки пьезокерамического материала $${К}_{ус}^{об}=\mathrm{1,455}$$

;Where $${\mathrm{TO}}_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

- coefficient of volumetric shrinkage of a piezoceramic material $${\mathrm{TO}}_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}=\mathrm{1,455}$$

;

ρ _{n / rev} - pore former density, ρ _{n / rev} = 1.2 g / cm ³ ;

ρ _rg is the x-ray density of the piezoceramic material, ρ _rg = 8.02 g / cm ³ ;

ρ _CR - the density of the compact, ρ _CR = 5.2 g / cm ³ ;

a P _{k is} calculated from the dependence

- прочность на сжатие «беспористой» керамики первой, наиболее удаленной от инерционной массы, пластины, $$T_{СЖ}^1\approx 6\cdot {10}^8Па$$

;Where $$T_{\mathrm{FROM}F}^{\mathrm{one}}$$

- the compressive strength of the "non-porous" ceramics of the first plate most remote from the inertial mass, $$T_{\mathrm{FROM}F}^{\mathrm{one}}\approx 6\cdot {10}^{8}P\mathrm{but}$$

;

a - acceleration upon impact a = (1.3 ÷ 1.5) · 10 ⁶ m / s ² ;

ρ ₁ — density of the “non-porous” ceramic of the first plate farthest from the inertial mass, ρ ₁ = 7.8 · 10 ³ kg / m ³ ;

ρ _k - density of the k-th plate ρ _k = ρ _rg · (1-P _k / 100),

h _k is the distance between the conductive surfaces deposited on the plate,

- U _K is the potential difference of the charges on the conductive surfaces of the plates U _k ≈10 ⁵ V;

and all the data is summarized in a working Table 1, the values of the parameters in which are checked on probes;

for the first plate farthest from the inertial mass of the plate, the parameter values are given in the first row of Table 1, and the inertial mass parameters are determined from the formulas:

; M₀=ρ₀S_nh₀ следовательно $$F=T_{33}^n\cdot S_n={\mathrm{<figure-callout\; id="0"\; label="M"\; filenames="00000099.png"\; state="\{\{state\}\}">M</figure-callout>}}_0\cdot a$$

; M ₀ = ρ ₀ S _n h ₀ therefore

и h₀=M₀/(P₀S_n) $${\mathrm{<figure-callout\; id="0"\; label="M"\; filenames="00000099.png"\; state="\{\{state\}\}">M</figure-callout>}}_0=T_{33}^n\cdot S_n/a$$

and h ₀ = M ₀ / (P ₀ S _n )

where: ρ ₀ is the density of the inertial mass,

h ₀ - the height of the inertial mass,

- прочность на сжатие верхней пластины, прилегающей к инерционной массе (k=n=6); $$T_{33}^n$$

- compressive strength of the upper plate adjacent to the inertial mass (k = n = 6);

S _n is the contact surface area of the “upper”, nth plate.

Examples of calculations in the manufacture of piezoelectric high-voltage generators.

The acceleration a arising in the plates upon impact of a high-voltage generator is estimated as a = (1.2 ÷ 1.5) 10 ⁶ m / s ² (~ 10 ⁵ g).

Example 1. A piezoelectric high-voltage generator for converting mechanical impact energy into electrical energy, in which the working fluid is an inertial mass M ₀ and a packet of plates of polarized composite ferroelectric materials, each plate having its own values of density, compressive strength, and dielectric constant.

A piezoelectric high-voltage generator converts the work of the mechanical compression stress arising upon impact of the generator with acceleration a = 1.282 · 10 ⁶ m / s ² into electrical energy with the potential difference of the charges on the conductive surfaces of the plates U _k = 10 ⁵ V.

Acceleration a = 1.282 · 10 ⁶ m / s ² corresponds to a change in the generator speed from 70 m / s to zero at a distance L = 1.9 · 10 ^-3 m in 5.46 · 10 ^-5 s.

Overall dimensions of the device: diameter D = 38 mm, height h <65 mm.

These overall dimensions satisfy the landing dimensions of a shot of the VOG-25 type under-barrel grenade launcher of the GP-25 type (Fig. 1c).

Characteristics of a polarized composite “non-porous” ferroelectric material with a porosity value of P ₁ ≈0-2.7%:

.ultimate compressive strength $$T_{\mathrm{FROM}F}^{\mathrm{one}}=6\cdot {10}^{8}P\mathrm{but}$$

.

The values of compressive strength and permittivity of each of the plates of polarized composite ferroelectric materials with porosity values P _k in the range 0≤P _k ≤30% are determined by formulas (3), (4) and (5).

The mechanical stresses arising in the plates during acceleration a are added up, and their maximum values in the plates are:

- for the “upper”, nth plate (k = n)

- for the k-th plate

for the first bottom plate

, и характеристики композиционного «беспористого» сегнетоэлектрического материала соответствуют приведенным выше значениям при пористости Р≈0-2,7%:At the same time, for the first plate, the maximum value $$T_{33}^{\mathrm{one}}=T_{\mathrm{FROM}F}$$

, and the characteristics of the composite “non-porous” ferroelectric material correspond to the above values at a porosity of P≈0-2.7%:

To obtain the potential difference U _k = 10 ⁵ V in the first plate, with a porosity of P ₁ ≈0-2.7%, the distance h ₁ between the conductive surfaces will be:

Charge

For the second plate

This value of the compressive strength, in accordance with formula (5), characterizes a composite with a porosity of P ₂ = 8.2%, for which the main parameters, in accordance with formula (3), are defined as:

d ₃₃ = 500 · 10 ^-12 C / N;

To obtain the potential difference of the charges on the conductive surfaces of the plates U _k = 10 ⁵ V, the distance h ₂ between the conductive surfaces of the second plate of a polarized composite material with a porosity of P ₂ ≈ 8.2% will be equal to

Charge

For the third and subsequent plates, the calculations are carried out similarly, their results are shown in Table 1.

The number of plates in the device is limited to 6, since the porosity of plate No. 7 will be more than 30% and goes beyond the action of formulas (3), (4) and (5).

The mechanical stress acting on the surface of the 6th plate, equal to 3.56 · 10 ⁸ Pa, corresponds to the inertial mass M ₀ = 0.315 kg, which can create a layer of material with a height of 35.6 mm at a density of 7800 kg / m ³ .

The total height of the device in question, excluding the thickness of the electrodes, is 64.4 mm, which corresponds to the set conditions.

In FIG. 1 shows a diagram of the device according to example 1.

- направление векторов скорости и механического напряжения.

- direction of the vectors of speed and mechanical stress.

Example 2. A piezoelectric device for converting mechanical energy into electrical energy, characterized in that its working fluid is an inertial mass M _{0 and a} packet of wafers of a “non-porous” polarized ferroelectric material.

A piezoelectric device converts the work of the mechanical compression stress arising upon acceleration of the device a = 1.282 · 10 ⁶ m / s ² into electrical energy with a potential difference of charges on the conductive surfaces of the plates U _k = 10 ⁵ V.

The characteristics of the polarized ferroelectric material are the same for all plates of the device:

d ₃₃ = 500 · 10 ^-12 C / N;

; $${\epsilon }_{33}^T=2000$$

;

ρ = 7.8 · 10 ³ kg / m ³ ;

ultimate compressive strength T _SJ ≥6 · 10 ⁸ Pa

Overall dimensions of the device: diameter D = 38 mm, height h <65 mm.

Just as in the first example, mechanical stresses arising in the plates during acceleration a are added up, and their maximum values in the plates are:

- for the “upper”, nth plate

- for the k-th plate

for the first bottom plate

и расстояние h₁ между токопроводящими поверхностями, которое соответствует разности потенциалов U_k=10⁵ В, определяется какFor the first plate $$T_{33}^{\mathrm{one}}=T_{\mathrm{FROM}F}^{\mathrm{one}}$$

and the distance h ₁ between the conductive surfaces, which corresponds to the potential difference U _k = 10 ⁵ V, is defined as

Charge

For the second plate

Since the other parameters of the second plate are identical to the parameters of the first plate, the distance h ₂ required for the potential difference U ₂ = 10 ⁵ B is defined as

Charge for the second plate

, h_k и Q_k для пластин с k=3, 4, 5 и 6; эти значения сведены в Таблице 2. Значения параметров для пластины с k=7Similarly defined $$T_{33}^k$$

, h _k and Q _k for plates with k = 3, 4, 5 and 6; these values are summarized in Table 2. The parameter values for the plate with k = 7

(h ₇ = 0.157 m) exceed the overall dimensions of the device.

The mechanical stress acting on the surface of the 6th plate, equal to 0.23 · 10 ⁸ Pa, corresponds to the inertial mass M ₀ = 0.02 kg, which can create a layer of material 2.3 mm high at a density of 7800 kg / m ³ .

The total height of the device in question, excluding the thickness of the electrodes, <60.1 mm, which corresponds to the set conditions.

In the device described in Example 1 (with composite material), the values of the electric charge arising in a unit of the total volume of the working fluid are 1.13 greater than in the device described in Example 2 (without composite material). If we compare the volumes of ferroelectric materials, then the advantage of the device in the first example will be 2.28 times.

Preparation method

The manufacturing process of a high-voltage generator includes three stages.

1.) 1) The first stage is the manufacture of plates of polarized composite ferroelectric materials with increased values of the piezoelectric voltage coefficient and the compressive strength specified for each plate,

2) The second stage is the manufacture of a package of plates mechanically connected in series so that the mechanical stresses arising in the plates during acceleration are added up, and electrically connected in parallel so that the electric charges arising in the plates are summed

3) The third stage is the manufacture of the generator in the housing from a porous polymeric material, including the assembly of the working fluid from the inertial mass and the package of plates, as well as current collectors in the housing.

1) The first stage is the manufacture of plates of polarized composite ferroelectric materials

The process of manufacturing plates of porous piezoceramics includes

1.1. preparation of a powder of synthesized material, for example, TsTS-46, having a total specific surface area in the range of 1.0 ± 0.1 m ² / g according to the PSX-4 device;

1.2. preparation of a press powder from a powder of synthesized material;

1.3. calculation of the concentration of the blowing agent according to the formula:

- коэффициент объемной усадки пьезокерамического материала $$K_{ус}^{об}$$

=1,455;Where $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

- coefficient of volumetric shrinkage of a piezoceramic material $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

= 1.455;

P _{n / rev} is the density of the blowing agent, P _{n / rev} = 1.2 g / cm ³ ;

P _rg is the x-ray density of the piezoceramic material, P _rg = 8.02 g / cm ³ ;

P _np is the density of the compact, P _np = 5.2 g / cm ³ ;

and P _k - porosity is set for each batch according to the values of column 2 of Table 1 to provide the necessary parameters of the batch of piezoelectric elements.

1.4. Preparation of batches of a mixture of the powder of the synthesized material and the blowing agent in the devices of the vortex layer (ABC), where the chaotic movement of magnetic working bodies, such as steel needles for gramophones, is determined by the rotating magnetic field of the stator of a three-phase electric motor.

1.5. Pressing batches of powder mixtures is carried out in molds, the dimensions of which take into account shrinkage during sintering up to 20-45% and the necessary allowances for machining.

1.6. Sintering of the preforms is carried out in a lead-containing backfill according to a special temperature-time regime, which provides for a temperature rise at a rate of 25 ± 3 ° C / h, exposure at a temperature of 450 ± 10 ° C for 2.0 ± 0.1 hours to burn the binder and blowing agent powder; sintering at a temperature of 980 ± 10 ° C for 3 hours.

1.7. Grinding the sintered billets in diameter to a size of _38-0.1 mm and, as cleanly in the plane, with an allowance in height of up to 5 mm.

1.8. Determination of the density of each batch of workpieces geometrically as the ratio of mass to volume (weighing on a scale with an accuracy of not more than 0.1%, determining the size with a caliper with a division price of 0.01 mm.)

1.9. Production of probes for each batch, determination of electrophysical parameters, compression on a hydraulic press and determination of compressive strength.

1.10. Grinding of batch blanks with different densities (porosity) into a height dimension determined on probes, in accordance with the values of column 7 of table 1,

1.11. Metallization of the flat surfaces of porous preforms in the traditional way, with the application of silver-containing paste through a silk-screen with edges and with the burning of silver-containing paste with a porosity value of up to 25%, when the porosity is closed. On billets with open (through) porosity (more than 25%), only contact pads are metallized by burning silver, and then silver is sprayed through a mask with edges on all flat surfaces.

1.12. Polarization of the blanks according to the modes selected on the probes, for example, at a temperature of 120 ± 3 ° C and a field strength of 2 ± 0.1 kV / mm for an hour.

Thus, the hallmark of the method of manufacturing piezoelectric high-voltage generators, consisting of a body made of a porous polymer material with embedded electrodes of current collectors and a working fluid, including an inertial mass and a package of plates of polarized composite ferroelectric materials with high values of the piezoelectric voltage coefficient and the strength specified for each plate compression, and the manufacture of each batch of plates of polarized composite ferroeoe of electric materials with a given compressive strength includes operations: - preparation of a press powder of synthesized material, preparation of a mixture of press powder of synthesized material and a pore former, pressing from a mixture of billets and their high-temperature processing (sintering), machining, metallization, polarization and measurement of parameters, characterized in that:

и пористостью Р_К содержит порообразователь в концентрации Х_k, мас. %;- a batch of a mixture of press powder with a blowing agent for the k-th plate with a given compressive strength $$T_{\mathrm{FROM}F}^k$$

and porosity R _K contains a pore former in a concentration of X _k , wt. %;

- коэффициент объемной усадки пьезокерамического материала $$K_{ус}^{об}$$

=1,455;Where $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

- coefficient of volumetric shrinkage of a piezoceramic material $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

= 1.455;

P _{n / rev} — pore former density, P _{n / rev} = 1.2 g / cm ³ ;

P _rg is the x-ray density of the piezoceramic material, R _pg = 8.02 g / cm ³ ;

ρ _np is the density of the compact, ρ _np = 5.2 g / cm ³ ;

a P _{k is} calculated from the dependence

- прочность на сжатие «беспористой» керамики первой, наиболее удаленной от инерционной массы, пластины,

Where $$T_{\mathrm{FROM}F}^{\mathrm{one}}$$

- the compressive strength of the "non-porous" ceramics of the first plate most remote from the inertial mass,

a - acceleration upon impact a = (1.3 ÷ 1.5) · 10 ⁶ m / s ² ,

ρ ₁ is the density of the “non-porous” ceramic of the first plate farthest from the inertial mass, ρ ₁ is 7.8 · 10 ³ kg / m ³ ;

ρ _k is the density of the kth plate, ρ _k = ρ _rg · (1-P _K / 100);

h _k is the distance between the conductive surfaces deposited on the k-th plate,

- U _K is the potential difference between the conductive surfaces deposited on the plates U _K ≈10 ⁵ V;

and all the data is reduced to a worksheet such as table 1, the parameter values in which are checked on probes; and the inertial mass parameters are determined from the formulas:

where ρ ₀ is the density of the inertial mass;

h ₀ is the height of the inertial mass;

- прочность на сжатие верхней пластины, прилегающей к инерционной массе (k=n=6); $$T_{33}^n$$

- compressive strength of the upper plate adjacent to the inertial mass (k = n = 6);

S _n is the contact surface area of the “upper”, nth plate.

For the first plate farthest from the inertial mass of the plate, the parameter values are given in the first row of Table 1.

Claims (2)

1. A high-voltage generator with a working fluid consisting of polarized ferroelectric material, characterized in that the housing of the generator is made of a porous polymer material with embedded electrodes of current collectors, and the working fluid additionally contains an inertial mass, while the ferroelectric material is a package of plates of polarized composite ferroelectric materials with high values of the piezoelectric voltage coefficient and the strength set for each plate compression, so that
- for the “upper”, nth plate (k = n)

- for the k-th plate

Where $$T_{\mathrm{FROM}F}^n$$

and $$T_{\mathrm{FROM}F}^k$$

- compressive strength of the nth plate and the kth plate;
$$T_{\mathrm{FROM}F}^n$$

and $$T_{33}^k$$

- mechanical stresses arising in the nth plate and the kth plate upon impact with acceleration of an inertial mass M ₀ ;
S _n is the contact surface area of the “upper”, nth plate;
ρ and h are the density of the plate and the distance between the contact surfaces of the plate, respectively,
mechanically connected in series so that the mechanical stresses arising in the plates upon impact are summed up, and electrically connected in parallel so that the electric charges arising in the plates are summed with the same potential difference, for which the distances between the conductive surfaces deposited on the plates are set so that their values multiplied The values of mechanical stress and piezoelectric stress coefficient were the same for each plate in the package. 2. A method of manufacturing piezoelectric high-voltage generators, consisting of a body of a porous polymeric material with embedded electrodes of current collectors and a working fluid, including an inertial mass and a package of plates of polarized composite ferroelectric materials with increased values of the piezoelectric voltage coefficient and the compressive strength specified for each plate, containing the manufacture of each batch of plates of polarized composite ferroelectric materials with a given compressive strength, including operations: preparation of a synthesized material press powder, preparation of a synthesized material press powder mixture and a pore former, pressing of a mixture of preforms and their high-temperature sintering, machining, metallization, polarization and parameter measurement, characterized in that The manufacturing process of a high-voltage generator includes three stages:
the first stage is the manufacture of plates of polarized composite ferroelectric materials with increased values of the piezoelectric voltage coefficient and the compressive strength specified for each plate;
the second stage is the manufacture of a package of plates mechanically connected in series so that the mechanical stresses arising in the plates during acceleration are added up, and electrically connected in parallel so that the electric charges arising in the plates are summed;
the third stage - the manufacture of the generator in the housing of a porous polymeric material, including the assembly of the working fluid from the inertial mass and the package of plates, as well as current collectors in the housing,
wherein the batch of the mixture of fresh powder with a blowing agent for the k-th plate with a given compressive strength $$T_{\mathrm{FROM}F}^k$$

and porosity P _k contains a blowing agent in a concentration of X _k , wt. %

Where $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}$$

- coefficient of volumetric shrinkage of a piezoceramic material $$K_{\mathrm{at}\mathrm{from}}^{\mathrm{about}b}=\mathrm{1,455}$$

;
ρ _{n / rev} - pore former density, ρ _{n / rev} = 1.2 g / cm ³ ;
ρ _rg is the x-ray density of the piezoceramic material, ρ _rg = 8.02 g / cm ³ ;
ρ _np is the density of the compact, ρ _np = 5.2 g / cm ³ ;
a P _{k is} calculated from the dependence

Where $$T_{\mathrm{FROM}F}^{\mathrm{one}}$$

- compressive strength of the non-porous ceramics of the first plate farthest from the inertial mass, $$T_{\mathrm{FROM}F}^{\mathrm{one}}\approx 6\cdot {10}^{8}P\mathrm{but}$$

,
a - acceleration upon impact a = (1.3 ÷ 1.5) · 10 ⁶ m / s ² ,
ρ ₁ — density of the “non-porous” ceramic of the first plate farthest from the inertial mass, ρ ₁ = 7.8 · 10 ³ kg / m ³ ;
ρ _k is the density of the kth plate,

h _k is the distance between the conductive surfaces deposited on the plate,

U _k is the potential difference between the conductive surfaces deposited on the plates U _K ≈10 ⁵ V;

and all the data is reduced to a worksheet, the parameter values in which are checked on probes,
moreover, the parameters of the inertial mass - its mass M ₀ and height h _{0 are} determined

where ρ ₀ is the density of the inertial mass,
h ₀ - the height of the inertial mass,
$$T_{33}^n$$

- compressive strength of the upper plate adjacent to the inertial mass (k = n = 6),
S _n is the contact surface area of the “upper”, nth plate.

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