Piezoelectric shock pick-up
SUBSTANCE: shock pick-up includes piezoelectric working medium and recording system. The working medium is made of piezoceramics with cohesion of 3-0 with maximum values of voltage index g33. At that the pick-up has an additional a resonating piezoelectric cell for calibration, which surface is coupled to the working medium surface.
EFFECT: increasing sensitivity of the piezoelectric pick-up at minimum weight, potential calibration and functional check in zero gravity conditions.
4 cl, 3 dwg, 1 tbl
The invention relates to electronic devices, and more particularly to piezoelectronic, the transducers of mechanical energy into electrical energy, the sensors kick and other
Well-known application of the piezoelectric elements uses the fact that during the deformation of the piezoelectric element in it is the charge transfer is a direct piezoelectric effect. On the other hand, the piezoelectric elements are also to purposefully influence the detail, in particular to deform it, when the piezoelectric element, on the contrary, serves voltage and use the resulting deformation of the reverse piezoelectric effect.
Known piezoelectric sensor is a Converter of mechanical energy into electrical energy due to the deformation of the piezoceramic element mechanical effects (impacts).
Known piezoelectric actuator Converter applied thereto electrical signals into mechanical force.
It is widely known application of piezoelectric sensors in the diagnostic systems of the car and the car alarm systems.
Mechanical impact of the piston on the housing in an internal combustion engine cause mechanical vibrations of the engine block, which in the working body of the knock sensor is a piezoelectric element is converted by a direct piezoeffect is in electrical signal. Piezoelectric sensors are used for registration of stroke and actuation of safety systems in cars.
The disadvantages of these structures are weak sensitivity to small mechanical stress, a lot of weight and the inability to estimate the magnitude of the impact.
Occurs when a mechanical impact on the piezosensor charge Q is determined by the formula
where F is force,
dij- the value of piezomodulus.
For piezoceramic sensors connectivity 3-0, representing a porous piezoelectric ceramics with closed pores or cavities filled with a second phase, the determining factor is the longitudinal piezomodulus therefore, dij=d33.
When measuring the recorded quantity is the potential difference U that occur at the electrodes of the working fluid sensor
where C is the capacity of the working fluid sensor, and
where k is a factor determined by the geometry of the working fluid sensor, the properties of the measuring circuits;
g33is the piezoelectric stress coefficient of the piezoelectric material of the working fluid (piezocrystals).
Minimum detectable value of the force F is determined by the minimum values of the measured value U, depending on many factors, so a one-to-one correspondence between the measured value U and the force F is determined experimentally. This process is called calibration (calibration, scaling). As a specific influencing quantities use, for example, the impulse of the impact of a solid body (ball) of a certain mass, which they throw on the sensor with a known speed (from a height) and construct a calibration graph of U from mV, where m is the mass of the ball, V is the velocity at impact.
The multifactorial nature of the dependence of the recorded acting force F from the measured piezoelectric sensor potential difference U leads to the conclusion that to achieve high precision measurements of the piezoelectric shock sensor should be its calibration prior to the each dimension.
Disclosure of inventions
The problem to which this invention is directed, is the achievement of the technical result consists in creating a shock sensor with high piezocrystals with minimum weight, with the possibility of calibration and verification of the operability of the sensor even in the absence of gravity.
The problem is solved by the presence of piezoelectric shock sensor of the working fluid, is made of a piezoelectric composite connectivity 3-0-based piezoelectric ceramics with a maximum value of piezocrystals g33and the surface of the working body are mechanically connected to a surface of a piezoelectric resonator for calibration; another distinguishing feature is that the resonator for calibration is made in the form of a multilayer piezoelectric element.
The most important characteristic of the piezoelectric elements is piezocrystals g33
Significantly improve piezocrystals allows the transition to composite materials due to the significant decrease in the dielectric constant of the piezoelectric material the material of the working fluid sensor ε 33compared to dense magnetoactive material.
Use as a working body sensor piezoelectric composite connectivity 3-0-based piezoelectric ceramics with a maximum value of piezocrystals g33(currently, according to the OST 110444-87 the highest value of g33the material sjpc-36) provides the maximum sensitivity of the sensor at the minimum, due to the porosity, the weight while maintaining sufficient for the manufacture of a working body of the sensor mechanical q-factor. Depending on the porosity characteristics of the piezoelectric composite connectivity 3-0-based piezoceramics shown in Fig.1. Longitudinal piezoelectric module d33with increasing porosity up to 40% almost unchanged (Fig.1A), and the relative dielectric constant of
Use as a working body sensor piezoelectric composite connectivity 3-0-based piezoelectric ceramics also provides increased attenuation of the undesirable transverse vibrations in the working body of the sensor, since the magnitude of the transverse piezomodulus d31when the porosity decreases (Fig.1A).
When the application to the piezoelectric-resonator potential difference there is a rearrangement of the domain structure and the increase in the size N of the piezoelectric element by the value of ΔN (elongation of the piezoelectric element). The center of gravity of the piezoelectric element is moved by the value L=ΔH/2 during the reconstruction of the domain structure, buying at the end of the movement velocity V and momentum mV, which is transmitted to the piezoelectric working body of the sensor (Fig.2).
For piezoelement resonator is constructed of the calibration dependence of the momentum mV from the applied potential difference.
Calibration of the piezoelectric sensor is carried out by the changes applied to the piezoelectric-resonator is mechanically connected with the working surface of the sensors, the difference of potentials, using the previously obtained calibration dependence.
The expansion of the range of reliable measurements of the piezoelectric sensor is directly related to the prob is gnosti of the piezoelectric resonator to the extension.
Use for calibration multi-layer piezoelectric element dramatically increases the range of variation of the dimensions of the piezoelectric element by applying to the electrodes a potential difference U, which is illustrated by the following examples.
The elongation of the piezoelectric element δ [n] for the case of monolithic piezoelectric resonator (Fig.3A) is determined by the formula
ΔN=N·E·d33=0.01 m·104I/m·400·10-12m/=4·10-8m=0,04 µm,
where H=0.01 m is the length of the piezoelectric element,
E=U/H=104B/m, the electric field in the piezoelectric element,
U=100 V - potential difference,
d33=400·10-12m/b is the longitudinal piezomodulus.
Multilayer piezo-resonator (IPE) consists of layers of piezoelectric ceramics with a thickness h=5 0 μm=50·10-6m between the metal electrodes to a thickness of 3-5 μm, the layers are mechanically connected in series and electrically in parallel, as the capacitor (Fig.3b). When the supply voltage is 100 V field strength in the ceramic layers of IPE up to 2 kV/mm, and the thickness of each layer is to increase ΔN length of the piezoelectric element N.
The elongation of the piezoelectric element δ [n] for the case of multilayer piezoelectric resonator (Fig.3b) is determined by the formula
ΔN=N·E·d33=0.01 m·2·106I/m·400·1012m/=8·10-6 m=8 μm,
where N is the length of the piezoelectric element,
E=U/h=1·106/M - e tension is aktionscode field in the piezoelectric element,
U=100 V - potential difference,
h - the thickness of the layer of piezoelectric ceramics,
d33=400·10-12m/b is the longitudinal piezomodulus.
Thus, the use for calibration multi-layer piezoelectric element increases the range of variation of the dimensions of the piezoelectric element by applying to the electrodes a potential difference U is more than two orders of magnitude (200 times).
Theoretical calculations of the stresses arising from the application to the piezoelectric-resonator voltage Up,equal to 100 V and 1 V for the working fluid 30×25×1 mm composite 3-0-based material sjpc-36P, and the piezoelectric resonator 50 layer monolithic piezoelectric element, are shown in Table 1.
Resulting voltage 427 and 4,27 differ In 100 times and can be measured.
Thus, the distinctive features of the invention are: the presence in the piezoelectric shock sensor of the working fluid, is made of a piezoelectric composite, connectivity 3-0-based piezoelectric ceramics with a maximum value of the stress ratio g33and mechanically connected to the surface of the working body of the piezoelectric resonator for calibration; another distinguishing feature is that the resonator for calibration is made in the form of a multilayer piezoelectric element.
The embodiments of the invention are explained using the accompanying drawings Phi is .1-3, Table 1.
Fig.1A. The dependence of pesumably d from the porosity p of ceramics with closed porosity.
d33- longitudinal piezomodulus;
d31- cross piezomodulus.
Fig.1B. The dependence of relative permittivity of
Fig.1B. The dependence of piezocrystals g33from the porosity p of ceramics with closed porosity.
Fig.2. The inventive piezoelectric shock sensor, where:
1 - working body of the sensor is made of a piezoelectric composite, connectivity 3-0-based piezoelectric ceramics with a maximum value of the stress ratio g33,
2 - the working surface of the piezoelectric working body of the sensor,
3 - piezo-resonator for calibration,
4 - move the center of gravity of the piezoelectric element when applying a potential difference (voltage),
5 is a pulse that occurs when moving, and the recoil impulse.
Fig.3. The design of the piezoelectric resonator for calibration: (a) monolithic piezo-resonator, b) multilayer piezo-resonator.
Table 1. Theoretical calculations of the stresses arising in applied and the piezoelectric-resonator voltage U pequal to 100 V and 1 V for the working fluid 30×25×1 mm composite 3-0-based material sjpc-36P, and the piezoelectric resonator 50 layer monolithic piezoelectric element.
The implementation of the invention.
The choice of materials and Assembly on a concrete example.
From piezoceramic materials included in the OST 11 0444-87, the maximum value of piezocrystals characterized piezoelectric ceramic CTS-36
g33=d33/ε33=221·10-12CL/N/(700 cent to 8.85 10-12F/m)=357·10-4In·m/N
Piezoelectric composite connectivity 3-0-based piezoelectric ceramics CTS-36 is marked as porous piezoceramics CTS-36P, and is characterized less by 23% density and higher value of stress ratio
g33=d33/ε33=176·10-12CL/N/a(462 cent to 8.85 10-12F/m)==540·10-4In·m/N (the values of d33and ε33experimentally obtained and is close to the values given on the website of JSC "NII ELPA" [http://www.elpapiezo.ru/porous.shtml]).
The working body of the sensor is made of porous piezoceramics CTS-36P, in the form of a piezoelectric-plate size 30-0,2× 25-0,2× 1,0-0,01mm, with continuous metallization planes 30-0,2× 25-0,2mm and polarization in the direction perpendicular to the planes.
Multilayer piezo-resonator for calibration is made on the technology with the use of laid down the nogo casting, when powder of piezoelectric ceramics with a solution of an organic ligaments prepare a slurry, which through the die plate, pour on a moving surface, dried, and get a flexible, thin raw film of powder of piezoelectric ceramics and organic ligament thickness 60 μm; the "raw" film is cut into blanks, each cover through sectretary metal-containing paste; procurement quantity 50 pieces stacked on each other in the package, and the bottom and top of the package are 2-4 non-plated layer of the film; the package is pressed and cut into a layered raw blanks, each of which size 7,2 x 7,2×3.2 mm is of the 50 layers of raw ceramic film with a metal-containing paste, heat treatment transforms the raw blanks sintered in a 50-layer monolith dimensions 6 x 6 x 2.5 mm of alternating layers of ceramic with a thickness of 50 μm and the internal electrodes to a thickness of 3-5 μm, odd and even layers which extend on the opposite side of the surface, where they connect the outer electrodes so that the sintered 50 layer monolith is a capacitor with gaskets made of ceramics; application to the side electrodes of a DC electric field voltage 100-120 V at a temperature of 100°C ceramics polarize; 50 is formed g-layer monolithic piezo with insulating layers on the ends of the top and reduce the. This multilayer piezo grind the ends and connected, for example glued, preferably close to the center, to the surface of the working body of the shock sensor.
Piezoelectric shock sensor can be manufactured on standard equipment manufactured piezoelectric ceramics.
|The formulas and parameters||Values for Up=100||Values for Uo=1B|
|The parameters of the piezoelectric resonator|
|The number of piezoelectric elements n||n=50||n=50|
|The thickness of the layer of piezoelectric ceramics h||50·10-6m||50·10-6m|
|Side resonator and||6·10-3m||6·10-3m||The height of the resonator N||2,5·10-3m||2,5·10-3m|
|The voltage on the resonator Up||100||1B|
|E=Up/h||100B/0.05 m=2·103/M||1B/0.05 m=2·101/M|
|ΔN=N·E·d33||2,5·10-3m·2·103V/m 400·10-12CL/N=2·10-6m||2,5·10-3m·2·101V/m 400·10-12CL/N=2·10-8m|
|The speed of sound in the resonator With||≈3·103m/s||≈3·103m/s|
|Time "polarization" τ=h/C||50·10-6m/3·103m/s≈17·10-9||50·10-6/3·103m/s≈17·10-9|
|The velocity V of the center of gravity at the end of the motion V=andτ||≈6,92·109m/c2·17·10-9C=117,6·m/s||=6,92·107m/s2·17·10-9C=1,176 m/s|
|The momentum p=mV||p=720·10-6kg·of 117.6 m/s=84,67·10-3kg·m/c||P=720·10-6kg·1,176 m/c=84,67·10-5kg·m/c|
|Force F=ma||720·10-6kg·6,92·109m/c2=4982,4·103m/s2=≈4982,4·103N||≈720·10-6kg 6,92 107m/s2=49824 10-12kg m/s2=49,82·103N|
|The parameters of the working fluid|
|The density ρ, ·103kg/m3||5,85||5,85|
|The thickness of the piezoelectric element h, 1·10-6m||1||1|
|Mass m=(a×a×h) p=(30×25×1) 5,85·10-6kg||=30*25*1*5.85·10-9·103kg=4,39·10-3kg||-30*25*1*5.85·10-9kg =4,39·10-3kg|
|The container, F. (experiment)||3500·10-12||3500·10-12|
|The resulting charge Q=F·d33||4982,4·103N·300·10-12CL/H=1494·10-6CL||49,8·103H·400·10-12CL/H=14,94·10-6CL|
|The voltage U=Q/S||=1494·10-6CL/3500·10-12F≈0.427·103In||=14,94·10-6CL/3500·10-12F≈4.27 B|
1. Piezoelectric shock sensor comprising a piezoelectric actuating and registration system, characterized in that the working body made of piezoelectric ceramics connectivity 3-0 with a maximum value of the stress ratio g33moreover , the sensor further comprises a piezo-resonator for calibration, the surface of which is connected to the surface of the working body.
2. Piezoelectric shock sensor under item 1, characterized in that h is of the piezo-resonator for calibration is made in the form of a multilayer piezoelectric element.
3. Piezoelectric shock sensor under item 1, characterized in that the surface of the piezo-resonator for calibration and the surface of the working body are connected by bonding.
4. Piezoelectric shock sensor under item 1, characterized in that the surface of the piezo-resonator for calibration and the surface of the working body are connected mechanically.
SUBSTANCE: invention relates to making magnetoelectric converters used as a base for magnetic field sensors, microwave electronic devices, for magnetoelectric information recording technology and for electromagnetic energy and vibration energy storages. The method involves forming a stack of alternating magnetostrictor and piezoceramic layers. Said stack is formed in three steps: first, electroconductive contacts are deposited on the entire surface of magnetostrictors; all surfaces of magnetostrictors and piezoceramic, except end surfaces, are coated with a layer of electroconductive epoxy adhesive, after which a stack of alternating magnetostrictor and piezoceramic layers is formed. The layers are joined by pressing at temperature of 60-100°C and excess pressure of (1.3-2.6)·105 Pa. The multilayer ceramic heterostructure contains 9-11 magnetostrictor and piezoceramic layers. The piezoeceramic layer has thickness of 0.10-0.13 mm and the magnetostrictor layer has thickness of 0.25-0.30 mm.
EFFECT: low power consumption and high sensitivity.
2 cl, 2 tbl, 4 dwg
SUBSTANCE: piezoelectric multilayer component has a stack (1) of piezoceramic layers (2) and electrode layers (3) arranged one above the other. At least one piezoceramic layer is printed with a layer (4) structured according to a predefined configuration in a piezoelectrically inactive zone of the stack. The structured layer has at least one connecting element (4a) by which piezoceramic layers which are adjacent in the stacking direction are mechanically connected to each other with a first strength. The structured layer has interspaces (4b) filled at least in part with piezoceramic material of the adjacent piezoceramic layers. The adjacent piezoceramic layers in the interspaces are mechanically connected to each other with a second strength, which is less than the first strength.
EFFECT: longer extension and period of operation.
15 cl, 1 tbl, 4 dwg
SUBSTANCE: acoustic line is made in form of a rectangular prism. Further, optically antireflecting coatings are deposited via vacuum deposition onto the faces of the rectangular prism. A first adhesive layer is then deposited on one of the faces of the rectangular prism by vacuum deposition. Using vacuum deposition, a first gold layer is deposited on said first adhesive layer. Further, a first indium layer is deposited on said first gold layer by vacuum deposition. Also, using vacuum deposition, a second adhesive layer is deposited on one of the larger faces of each of two plates made from lithium niobate of the (Y+36°)-section. Using vacuum deposition, a second gold layer is then deposited on said second adhesive layer. Using vacuum deposition, a second indium layer is deposited on said second gold layer. The acoustic line is the joined with the lithium niobate plates by pressing the lithium niobate plates with the pressure of each lithium niobate plate of the second indium layer to the corresponding first indium layer. Each of the lithium niobate plates is then ground off to the required thickness which corresponds to the operating frequency band. Using vacuum deposition, a third adhesive layer is deposited on each free large face of each lithium niobate plate. A third gold layer is then deposited on said third adhesive layer via vacuum deposition. The method is characterised by that the acoustic line material used is a TeO2 monocrystal, wherein the faces of the rectangular prism are directed perpendicular to the crystallographic direction , , , and deposition of optically antireflecting coatings is carried out on faces of the rectangular prism which are perpendicular to the the crystallographic direction ; when joining the lithium niobate plates to the acoustic line, the projections of polar axes of the lithium niobate plates are directed onto the same plates in opposite sides; the first adhesive layer is deposited on one of the faces of the rectangular prism (001); the first, second and third adhesive layers are made from chromium; said pressure lies in the range of 50-100 kg/cm2, during at least part of the time when the lithium niobate plates are pressed to acoustic line; voltage of 10-50 V is applied across each lithium niobate plate at antiresonance longitudinal vibrations of the corresponding lithium niobate plate for 1-3 minutes; the resulting workpiece, which is in form of an acoustic line with antireflection coatings, first adhesive layer, first gold layer and first indium layer lying successively on the acoustic line, and successively lying second indium layer, second gold layer, second adhesive layer of one of the lithium niobate plates and the lithium niobate plate itself, as well as the nearby successively lying second indium layer, second gold layer, second adhesive layer of another lithium niobate plate and the lithium niobate plate itself, as well as the third adhesive layer and third gold layer lying on each of said lithium niobate plates, is cut into separate elements in parallel to planes (110) of the TeO2 monocrystal.
EFFECT: high efficiency of the device while simultaneously increasing efficiency of the manufacturing process.
1 cl, 3 dwg
SUBSTANCE: piezoelectric device consists of a number of stacked layers of piezoceramic material. Each layer has two flat inner electrodes with engagement factor less than 100%; they contact in sequence with either left or right external electrodes which are located at side wall of the device. The device also contains additional uniformly distributed layers of material with high thermal conductivity, for example, aluminium nitride (AlN), beryllium oxide (BeO) or silicon carbide (SiC) or similar materials. Thickness of additional layers is not less than thickness of piezoceramic layers. Number of additional layers is determined by ratio for product of thickness, number of layers and thermal conductivity of main and additional layers.
EFFECT: reduction of inner temperature gradients, improvement of reliability and operating life.
2 cl, 1 dwg
SUBSTANCE: piezoelectric drive with 3D packet piezoelement for installation on basic structure has at least one surface of packet piezoelement, which is exposed to 2D or 3D profiling perpendicularly to layers of packet, and this at least one profiled surface is fit to circuit of basic structure, at which drive should be installed.
EFFECT: invention provides for high capacity of piezoelement and piezoelectric drive with simultaneous elimination of piezoelement damage risk in process of installation onto part.
17 cl, 12 dwg
SUBSTANCE: radiator of plane ultrasonic wave represents coaxial construction containing the set of piezoelements in the form of plane rings, which is enveloped on two sides with parts made in the form of bushes. In holes of piezoelements and bushes, along the construction axis there arranged is resonant waveguide acoustic transformer. This transformer serves as tie bar as well. At that, projection of connection of tie bar and the second bush to radiator axis includes the point belonging to the plane of equal amplitudes of coupled vibrations of itself and the construction tied with it if it can be assumed solid and when there is no that connection. Radiator can include several sets of piezoelements alternating with bushes and tied with common tie bar, which increases mechanical radiation power proportionally to the number of those sets.
EFFECT: increasing efficiency owing to decreasing energy losses in mechanical connections of its vibrating system.
1 tbl, 4 dwg
FIELD: piezoelectric drives.
SUBSTANCE: proposed piezoelectric drive characterized in high economic efficiency has housing accommodating thin-walled piezoelectric cylinder, electrodes exciting resonance-tuned bending vibrations, and at least two multilayer cylinders shielded by wear-resistant flexible shells within housing. Multilayer cylinders are assembled by inserting one into other for alternate vibration in convexo-concave manner relative to one another thereby varying cylinder-to-cylinder space filled with material in the form of liquid or air. This material in the form of liquid or air brought to water hammer condition in conjunction with hydraulic ram or supersonic air speed creates superfluidity of material in the form of liquid or air. In addition, proposed device is distinguished by high mechanical endurance at system resonance ensuring superconductivity; the latter and multilayer cylinders jointly provide for minimal voltage requirement for exciting and passing maximal current.
EFFECT: enhanced economic efficiency, ability of handling considerable forces and displacements.
2 cl, 2 dwg
FIELD: flaw inspection of rolling stock and tubes.
SUBSTANCE: ultrasonic transducer lattice has base, piezoids, grounded and pulse electrodes for connection to respective probing-pulse generators; it can be assembled, for instance, of plurality of equal-size piezoids fully insulated from one another; base is made in the form of one- or two-sided organic glass prism whose surfaces are stepped; each piezoid is glued to step parallel to other step partially overlapping the latter; idle parts of piezoids are depolarized; lattice is potted in compound; installation and overall dimensions of piezoids meet following equations: a = 1.2b to 100b, where a is piezoid length; b is piezoid thickness; d > (1 to 10)p, where d is distance between axes of piezoid effective parts; p is length of piezoid effective part; d = 0.2 to 10 mm.
EFFECT: simplified design of ultrasonic transducer lattice.
1 cl, 1 dwg
FIELD: piezoelectric electromechanical drives or packaged sensory components.
SUBSTANCE: proposed drive or sensory component has several piezoelectric ceramic layers. Electrode layer and electrical connector protruding outside are disposed between two layers whose surfaces are facing one another and directly abutting against one another. At least one of two piezoceramic layer surfaces facing one another is provided with groove to receive at least part of electrical connector.
EFFECT: enhanced precision under impact of high temperatures and heavy steady state and transient loads.
15 cl, 7 dwg
SUBSTANCE: proposed converter designed for operation as actuating device in adaptive optical systems has multilayer stack of plates electrically connected in parallel with double-layer ferroelectric ceramic plate with diffused phase transition. One layer of double-layer plate has slot of depth equal to thickness of this layer. Axes of slots in adjacent double-layer plates are disposed in relatively perpendicular planes.
EFFECT: elongated travel distance of operating element, enhanced time and temperature stability.
1 cl, 2 dwg
FIELD: measuring instrumentation.
SUBSTANCE: invention refers to measuring instrumentation, particularly to mechanical vibration parameter measurement in a wide frequency range. Invention can be applied for measurement of mechanical vibration wave parameters in various objects in construction, mechanical engineering, acoustics, etc. Proposed method of mechanical vibration detection and transformation is implemented with 3D detector in the form of triangular pyramid with sides equi-inclined against the pyramid base at a given φ angles, while removable detection units (vibration blocks) are positioned in the centre of each side in a definite point of symmetry axis, allowing for spatial, physical and electrical superposition of information on vector components in the measurement point and for reliable measurement of mechanical vibration vector.
EFFECT: method and 3D detector for highly reliable detection and simultaneous tensor transformation of components of measured mechanical vibrations in the whole range of diagnostic parameters of an object.
2 cl, 2 dwg
FIELD: measuring equipment.
SUBSTANCE: invention belongs to measuring equipment, in particular to equipment of measurement of parameters of blow at stands and can be used at research of shock interaction of bodies. The device for measurement of duration of a blow, contains a case, a switching element, a generator and an indication block, is supplied with a converter of duration of impulses of the generator in a digital code, a scheme, which carries out a momentum transfer from the generator on the counter of impulses at short circuit of contacts of the conductor, a pulse counter, a pulse converter into a digital code and a computing block, the case is executed as a cylindrical plug, in which a spring-loaded rod in the axial direction with a striker with possibility of its shock interaction with the collided body located on the metal base, thus on the free end of a rod the conductor connected to one of inputs of the scheme, carrying out a momentum transfer from the generator on the counter of impulses, is fixed, on the metal base there is a conductor connected to other input of the scheme, carrying out a momentum transfer from the generator on the counter of impulses. The electric pulse signal produced from strike blow arrives in the electronic block, is transformed into a digital code, and duration of the blow is determined, as the product of the quantity of impulses and the total time of impulses, which is shown on the digital indicator of the block of indication.
EFFECT: increased accuracy of determination of duration of blow and definition of development of accelerations, forces at any moment of development of a short-term shock process with precision.
4 cl, 1 dwg
FIELD: measurement equipment.
SUBSTANCE: piezoelectric sensor of impact acceleration includes a housing, in the inner cavity of which there fixed is a support having projections in middle part, which are located at equal distance from the housing sides, on each of which a piezoelement and inertia mass are fixed by means of an intermediate adhesive coat and inertia mass. Adhesive layer includes bonding material, rubber and calibrated conducting particles, and geometrical centre of support coincides with geometrical centre of the housing. Into the adhesive layer there added is graphite, the content of which does not exceed 10%, and calibrated particles have the size of 20-80 mcm; at that, rubber content in adhesive layer is at least 60%.
EFFECT: increasing conversion coefficient and damping properties of a sensor.
FIELD: instrument making.
SUBSTANCE: accelerometer comprises a metering cell in the form of a rectangular parallelepiped, a porous sphere, inside of which there is a sealed bellows with additional weights. In the lower part of the cell there is an additional bellows fixed, an electromagnet coil, a core, and also three pairs of piezoelements (emitters and receivers in pairs).
EFFECT: invention makes it possible to simplify design and to increase accuracy of measurements.
2 cl, 2 dwg
SUBSTANCE: disclosed apparatus for measuring vibration acceleration has a housing 1, in which there is a sensitive element in form of a cantilever bar made from an elastic plate 2, on which there is a load which can be displaced and fixed on the surface of the bar. Displacement of the load 3 is shown by horizontal arrows. A flat mirror 4 is rigidly mounted at the end of the cantilever bar 2. On the side surface of the housing 1 there is an opening accommodating the end of a fibre-optic information transducer 5, which is in form of bundle of an emitting 6 and receiving 7 light guide, grouped according to a mosaic optical arrangement. The mirror surface of the flat mirror lies on the side of the end face of the fibre-optic transducer 5, perpendicular to the mirror surface of the flat mirror 4. The apparatus is mounted on the surface of the test article 8.
EFFECT: high sensitivity and wider range of measuring vibration acceleration without complicating the design.
2 cl, 2 dwg
SUBSTANCE: frequency transducere contains a frame body (1) which is fixed to the foundation (8). An inertial mass (2), a core resonator (4), a system for signal excitation and pick-up are positioned in the central hole of the frame body (1). The inertial mass (2) is fixed to the frame body (1) via plan-parallel springs (3). The core resonator (4), on one side, is connected to the inertial mass (2), on the other side - to the frame body (1). The foundation (8) having a projection (15) is fixed to an object (16). In the foundation (8) grooves (9) are made filled with a damping material and forming flat springs (11), (12).
EFFECT: flat springs ensure reliable isolation of the core resonator fixture points from the points of the foundation fixture to the object increasing quality factor of the core resonator oscillations.
2 cl, 3 dwg
SUBSTANCE: at the first stage of manufacture preparation of component parts and assemblies takes place that is manufacture of an armour ring of spring steel, of a ring nozzle with a conic external facet of a tungsten alloy, a titanium hexagonal foundation and a cup-type body with a coaxial connector or a cable. The second stage involves fixation of the assembly in the vertical axial fixture of the electroerosion wire-cutting machine-tool, making three vertical grooves in fixed positions, mounting sensor elements, press-fitting or hot shrink fit of the armour ring on the ring nozzle with piezoelectric elements, making horizontal radial sections under the armour ring for an inertial mass formation and installation and fixation of the body and connection to the outlet of the preliminary amplifier of the connector.
EFFECT: invention allows to use in the transducer various materials for the foundation and inertial masses which enables to deliver small-scale sizes combined with high sensitivity and self frequency due to addition of a preliminary amplifier to the transducer design which amplifier is connected to the sensor elements while the manufacture method proper involves a minimum quantity of operations.
SUBSTANCE: vibration-frequency micromechanical accelerometer has a substrate (1) made from dielectric material, an inertial mass (2) with a centre hole (3), support element (4) and an additional support element (5), mounted on the substrate (1) and placed in the centre hole (3). The inertial mass (2) is linked to the support element (4) through elastic members (6). A resonator (7) is mounted on one side to the inertial mass (2) and on the other side to the additional support element (5), is a movable electrode and, together with fixed electrodes (8), is an oscillation exciting-pick up system.
EFFECT: accelerometer enables to measure the value of the current linear acceleration in the direction of axis X with high accuracy owing to a frequency-domain output signal and high Q-factor of oscillations of the resonator.
2 cl, 2 dwg
SUBSTANCE: accelerometer has an elastically deformable element 1 made from piezoelectric material, attached on one side to a holder 2, and on the other side to an inertial mass 3. The elastically deformable element 1 has on both sides identical cuts 4 and 5, over which low-temperature glass soldering is used to symmetrically attach ends of plates 6 and 7 of measuring piezoelectric elements with SAW or VAW - structures with possibility of their longitudinal compression-stretching. The holder 2 and the inertial mass 3 may be made from material of the elastically deformable element - piezoelectric material, and their crystallographic axes are aligned identically with crystallographic axes of the elastically deformable element 1 and plates 6 and 7. The material of the elastically deformable element 1 may be a metal alloy with constant modulus of elasticity in the working temperature range, and plates 6 and 7 are attached by their ends using glue or glass-to-metal soldering. The material of the elastically deformable element 1 may be a composite material on which there is a metal layer. Plates 6 and 7 are attached by their ends by soldering and their electrodes are made by etching the metal layer of the elastically deformable element. The inertial mass 3 may be an elongated section of the elastically deformable element 1. Plates 6 and 7 may be attached by their ends in rectangular cuts 4 and 5 flush with surfaces of the elastically deformable element and with a gap to the bottom of these cuts.
EFFECT: reduced measurement error, high accuracy and sensitivity of the device.
16 cl, 3 dwg
FIELD: machine building.
SUBSTANCE: procedure consists in lightning object with optical radiation, in conversion of reflected signal into autodyne signal and in recording its power. Further the signal is digitised and analysed. Value of object acceleration is determined by solving an inverse problem defining minimum of functional: where a is linear acceleration of an object, Pexsp are experimental values of the autodyne signal, Ptheor are theoretical values of the autodyne signal, θ is phase incursion of the autodyne signal, t is time interval of the autodyne signal. The exact value of global minimum is found by the method of descent along sought-for parametres θ and a.
EFFECT: measurement of acceleration at micro-shifts in wide dynamic range of accelerations and upgraded accuracy of absolute acceleration measurement within limits meeting modern precision devices.
FIELD: measurement technology.
SUBSTANCE: device can be used for measuring accelerations of objects. Liquid accelerometer has channel filled with working fluid. Two hydrostatic pressure frequency converter detectors are disposed at ends of accelerometer. Frequency converter is made in form of fiber interferometer, which has coherent light source matched optically with two fiber coils and photoreceiver connected with frequency meter through amplifier. To determining sign of acceleration the special electronic circuit is introduced into accelerometer additionally.
EFFECT: optical output signal at output of accelerometer.
3 cl, 3 dwg