RU2568992C2 - Ultrasonic phase vibrator inverter - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: ultrasonic phase vibrator inverter comprises serially connected a driving oscillator, a power amplifier, an emitting converter, an investigated object, a receiving converter, a matching amplifier, meander shapers, a phase detector, the first and second multiplication units, outputs of the driving oscillator and the matching amplifier via meander shapers and the first multiplication unit are connected with the first input of the second multiplication unit, the second input of which is connected to the output of the comparator, the third input - with a clock pulse generator, and the output via an information processing unit is connected to a digital-analogue converter, to the output of the matching amplifier there are the following serially connected components attached - a comparator with three inputs, a source of reference voltage with two outputs, and the output of the comparator is connected to the third input of the second multiplication unit and with serially connected a differentiator, an inverter, with the first input of the third multiplication unit and a unit of vibration signals analysis, the clock pulse generator is connected to the second input of the third multiplication unit, and the second and third inputs of the comparator are connected to the outputs of the source of reference voltages.

EFFECT: expansion of functional capabilities and increased accuracy of measurements of radial vibrations of screw shafts.

2 cl, 1 dwg

Description

The invention relates to measuring technique and may find application in measuring vibration parameters of screw shafts. A measuring device is known that contains a serially connected ultrasonic frequency master oscillator, a radiating transducer, a test object, a transducer, and a phase detector, the first input of which is connected to the output of the master oscillator. The principle of operation of this device is that there is a certain phase shift between the incident object and the acoustic signals reflected from it, which is measured by a phase detector. In the case when the object under study is stationary, the phase difference between the incident (reference) and reflected signals is unchanged. If the object begins to move, the phase difference between the incident and reflected signals begins to change, therefore, the magnitude of the output signal of the phase detector changes. If the phase detector operates in a linear mode, then the magnitude of the signal at its output is proportional to the displacement of the object under study [V. Redchikov Ultrasonic phase method for measuring vibrations. M., MDNTP them. Dzerzhinsky, 1973, p.194-199].

The disadvantage of this device is the narrow dynamic range of measurement of vibrations due to the presence of non-linear distortion of the output signal of the phase detector due to the arbitrary selection of the operating point on the output characteristic of the detector.

This disadvantage is eliminated in a measuring device containing a serially connected ultrasonic frequency master oscillator, an emitting transducer, a test object, a transducer, a phase detector, the second input of which is connected to the output of the transducer, and the first to the output of the ultrasonic frequency generator. The inputs of the phase detector can be interchanged, this will not change its functioning [B. Gordeev. Ultrasonic phase vibration displacement meter, USSR AS No. 823824, class G01B 7/00, 1979]. Although in this measuring device the operating point on the linear portion of the phase characteristic of the detector, but with increasing amplitude of vibration displacements, or with a slow drift of the investigated object, the operating point leaves the linear portion. When measuring stationary vibration processes, this device operates in a linear mode. In practice, an unsteady mode arises much more often in which the measured high-frequency vibration signals interacting with the low-frequency ones create a drift of the operating point of the phase detector, which leads to nonlinear distortions of the output signal.

This disadvantage is eliminated in an ultrasonic phase measuring device containing a serially connected master oscillator, a delay line with controlled inputs, a radiating transducer interacting with the object under study, a receiving transducer, a phase detector, the second input of which is connected to the input of the radiating transducer, an analog-digital transducer, and an information processing unit [Gordeev B.A. Ultrasonic phase meter of vibration displacements, USSR AS, No. 1048330, G01H 1/00; G01B 17/00]. The output of the phase detector is connected to the input of the comparator, the output of which is connected to the input of the switch and the second input of the information processing unit. The outputs of the switch are connected to the control inputs of the controlled delay line.

Ultrasonic phase measuring device operates as follows. The output signal of the master oscillator through the delay line is fed to the emitting transducer. The initial signal delay must satisfy the condition R ₀ = (n / 2 + 1/4) λ, where n is the number of discrete phase changes equal to the number of control inputs of the delay line, λ is the ultrasonic wavelength in this medium. In this case, when the object under study is shifted by an amount not exceeding one eighth of the wavelength, nonlinear distortions do not occur. The measuring device operates in linear mode. The reflected signal from the output of the receiving Converter is fed to the second input of the phase detector, the first input of which receives the reference signal from the delay line. The output signal of the phase detector, which varies in amplitude, is fed to a comparator, to which voltage levels U ¹ and U ² corresponding to the upper and lower thresholds, outside of which the presence of non-linear distortions are visible, are supplied from the reference voltage source. When the output signal of the phase detector is increased by a value corresponding to the displacement of the investigated object by a distance exceeding an eighth of the wavelength of the probing ultrasonic signal, nonlinear distortions begin to appear in this signal. In this case, the output signal of the phase detector in the comparator reaches one of the voltage levels U ¹ or U ² . Then, an impulse appears at the output of the comparator, arriving simultaneously at the switch and the information processing unit. At the second output of the switch, a control signal appears that changes the delay time. The delay time corresponds to a change in the phase of the signal at the second input of the phase detector by an amount equal to one eighth of the period, and the operating point is shifted by one eighth of the wavelength of the ultrasonic signal, which eliminates nonlinear distortion. Similar processes occur if the value of the output signal of the phase detector is reduced to a value of U ² .

However, when measuring the parameters of the radial vibration of the shaft with the screw installed on it, additional difficulties arise, since the surface of the screw is a screw surface, where the height of the spiral of the screw can be of the same order as the diameter of the screw. Then the output signal is saturated with additional harmonics, since the spiral of the screw, falling into the range of the probing acoustic signal, causes the modulation of the reflected signal not only in phase but also in frequency. Therefore, the selection of the information component in phase is associated with increasing errors. Errors increase with increasing angular velocity of rotation of the screw. Also known is an ultrasonic phase vibration transducer comprising a radiating transducer, a phase shifter receiving transducer, a comparator, a reference voltage source, a phase detector, a signal processing unit and a driving generator, the output of which is connected to the input of the radiating transducer, the output of the phase shifter is connected to the input of the phase detector, the output of which is connected to the comparator input, the other input of which is connected to the output of the reference voltage source, the comparator output is connected to the inputs of the I-Not elements and And, and the output of the I-Not element is connected to the information processing unit, the other input of which is connected to the output of the frequency detector, and the input of the frequency detector is connected to the output of the I element [Gordeev B.A., Novozhilov M.V., Karavantsev V.K. ., Korolev V.A. Ultrasonic phase vibration transducer, RF patent No. 1637493 A1, G01H 5/00].

Ultrasonic phase vibration transducer operates as follows.

, где: n - целое число, λ - длина волны ультразвука в воздухе. Отраженный от исследуемого объекта ультразвуковой сигнал принимается приемным преобразователем, сигнал с выхода которого поступает на вход фазовращателя, изменяющего фазу сигнала на постоянную величину, чтобы соблюдалось условие расположения рабочей точки в центре прямолинейного участка выходной характеристики фазового детектора при неподвижном объекте исследования.The signal from the output of the master oscillator is fed to a radiating transducer that emits ultrasonic waves in the direction of the object under study. In this case, the initial distance L must satisfy the condition: $$L=\left(\frac{n}{2}+\frac{\mathrm{one}}{\mathrm{four}}\lambda \right)$$

where: n is an integer, λ is the wavelength of ultrasound in the air. The ultrasonic signal reflected from the object under study is received by the receiving transducer, the output signal of which is fed to the input of the phase shifter, which changes the phase of the signal by a constant value, so that the condition of the location of the operating point in the center of the rectilinear section of the output characteristic of the phase detector with a stationary object of study is observed.

There are two possible cases specific to this converter. In the first case, the oscillations of the studied object do not go beyond the linear portion of the output characteristic of the phase detector. This means that the oscillations of the investigated object occur with small amplitude and frequency. Then the output signal of the phase detector carries all the information about the vibrations of the object under study. The comparator monitors the levels of the output signal of the phase detector. If the levels of this signal do not exceed the permissible ones set in the comparator, then the phase detector operates in the normal mode and its output signal is proportional to vibration displacements. In the event that the value of the output signal of the phase detector goes beyond the permissible levels set in the comparator, the I-He element is triggered, the phase detector is turned off, and through the opened AND element, the signal from the receiving converter passes the phase shifter to the input of the frequency detector. At small frequency modulation indices, when m = 1 or less, the frequency-modulated signal is converted into amplitude-modulated in the frequency detector. Changes in the output signal of the frequency detector correspond to changes in the vibration velocity of the investigated object.

This ultrasonic phase vibration transducer has a significant drawback. It does not allow vibrodiagnostics of such devices as screw conveyors in metal-cutting machines, screw drills in geological exploration, screw mechanisms in road-building machines, etc.

The closest in technical essence to the claimed patent of the Russian Federation.

Gordeev B.A., Kuklina I.G., Golubeva K.V., Gordeev A.B. Ultrasonic phase vibration transducer // Patent for invention. Application No. 20111130282/28, 07.20.2011. Published on 01.10.2013. Bull. No. 1.

The ultrasonic phase vibration transducer contains a serially connected master oscillator, a power amplifier, an emitting transducer, a test object — a shaft with a screw, a receiving transducer, a matching amplifier, meanders, the inputs of which are connected to the outputs of the master generator and matching amplifier, respectively, and the outputs of the formers are connected to the inputs of the first multiplication unit, the output of which is connected to the first input of the second multiplication unit, the second input of which is connected to the output of the generator a clock pulse generator, and the third input, through a sequentially connected code disk, rigidly fixed to the screw shaft, a shaft angle sensor, a rectangular pulse shaper having two stable states, is connected to the output of this shaper, and the output of the second multiplication block is connected through the data processing unit with digital to analog converter.

Ultrasonic phase vibration transducer operates as follows.

First of all, a code disk is fixed on the shaft of the screw mechanism in such a position that, when the shaft rotates, the field of action of the ultrasonic probe signal does not enter the area of the screw protrusion. Otherwise, when the shaft rotates, the probe beam, falling on the screw protrusion, is reflected from it, being filled with uninformative harmonic components. These components significantly complicate signal processing and introduce an error reaching 100% or more.

, где: n - целое число, λ - длина волны ультразвука в воздухе. При вращении вала со шнеком, при условии наличия эксцентриситета, изменяется разность фаз между излученным и отраженным от вала ультразвуковыми сигналами. Изменение фазы линейно связано с изменением расстояния отражающей поверхности вала до излучающего и приемного преобразователей. При повышении частоты вращения вала и при наличии эксцентриситета порядка 1/8 длины волны ультразвука в воздухе начинает проявляться частотная модуляция отраженного ультразвукового сигнала. При этом изменение частоты отраженного сигнала характеризует скорость вращения вала. Для точного определения эксцентриситета вала, являющегося важнейшей причиной возникновения виброперегрузок достаточно угловой скорости его вращения порядка нескольких оборотов в минуту. В данном случае фаза является информативным параметром. С выхода фазовращателя отраженный сигнал поступает на первый вход фазового детектора, на второй вход которого поступает опорный сигнал с выхода генератора.The signal from the output of the master oscillator is fed to the emitting transducer, which emits ultrasonic waves in the direction of the object under investigation - the shaft. The ultrasonic signal reflected from the object under study is received by the receiving transducer, the output of which is fed to the input of the phase shifter, which changes the phase of the signal by a constant value, so that the condition for the location of the operating point in the center of the rectilinear section of the output characteristic of the phase detector when the object is stationary is observed. In this case, the initial distance L must satisfy the condition: $$L=\left(\frac{n}{2}+\frac{\mathrm{one}}{\mathrm{four}}\lambda \right)$$

where: n is an integer, λ is the wavelength of ultrasound in the air. When the shaft with the screw rotates, subject to the presence of eccentricity, the phase difference between the ultrasonic signals radiated and reflected from the shaft changes. The phase change is linearly related to the change in the distance of the reflecting surface of the shaft to the emitting and receiving transducers. With an increase in the shaft rotation frequency and in the presence of an eccentricity of the order of 1/8 of the ultrasound wavelength in air, frequency modulation of the reflected ultrasound signal begins to appear. In this case, a change in the frequency of the reflected signal characterizes the speed of rotation of the shaft. To accurately determine the eccentricity of the shaft, which is the most important cause of vibration overloads, an angular velocity of its rotation of the order of several revolutions per minute is sufficient. In this case, the phase is an informative parameter. From the output of the phase shifter, the reflected signal is fed to the first input of the phase detector, the second input of which receives the reference signal from the output of the generator.

In this case, there are two modes of operation of the vibration transducer.

First, when the field of the probed surface of the shaft is free from the rib of the screw. This is achieved by the fact that the code disk mounted on the shaft corresponds to such a rotation angle of the shaft at which the probing ultrasonic signal falls on the field free from the screw. In this case, the signal from the shaft angle sensor arriving at the first input of the multiplication element “AND” opens it for the signal to pass from the phase detector to the data processing unit. The design of the code disk can be different: either the presence of transparent sections for the passage of optical signals from the sensor, or the presence of reflective sections of the disk surface for the same signals. If the screw shaft has an eccentricity, which is the main cause of vibration, then when the shaft is rotated by some angle, even a small angle, the phase of the reflected ultrasonic signal will change relative to the reference one, which will detect a phase detector. With further rotation of the shaft, the auger rib reaches the field of action of the probe ultrasonic beam. At the same time, the shaft angle sensor gives a prohibiting signal of a logical zero to the first input of the multiplication element “I” and closes it, even before the auger rib enters the zone of operation of the probing ultrasonic beam. After this, the second mode of operation of the ultrasonic phase vibration transducer is valid.

The second mode of operation occurs when the code disk, turning at the appropriate angle, changes the output signal of the shaft angle sensor to polar. For example, when the field of interaction of the probe beam with the shaft surface is free from the screw, the output signal of the sensor corresponds to a logical unit, and when the screw approaches this field, but does not enter the range of the probe ultrasound beam, the output signal of the sensor corresponds to a logical zero. Then the “I-Not” element opens and the ultrasonic signal reflected already from the edge of the screw passes through the “I-Not” element to the frequency detector and then to the data processing unit.

When the probe beam enters the area of the auger, the field of action of the beam is the outer surface of the auger rib. This phenomenon is equivalent to the movement of the reflecting surface towards the incident beam. Therefore, the frequency of the reflected signal will exceed the frequency of the probe beam. So, for example, with a shaft rotation frequency of 10 Hz, a screw rib height of 10 ^-2 m and a distance between the screw ribs along one generatrix of 10 ^-1 m, the equivalent speed of the reflecting surface will be of the same order as the speed of ultrasound in air.

, где: ω₀ - частота падающей волны, при этом отраженную волну теперь можно представить в виде:In this case, due to the double Doppler effect, the frequency of the reflected signal: $$\dot{g}={\omega }_{\mathrm{one}}={\omega }_0\frac{\mathrm{one}-\dot{l}\left(t\right)/c}{\mathrm{one}+\dot{l}\left(t\right)/c}$$

where: ω ₀ is the frequency of the incident wave, while the reflected wave can now be represented in the form:

where: l (t) = L + Δ (t).

If the screw edge is a moving media interface according to the law: Δt = l ₀ sinΩt, then

The last expression can be reduced to the form:

f ₊ = A ₀ [J ₀ (m) cosω ₀ t-2J ₁ (m) sinΩtsinω ₀ t +

+ 2J ₂ (m) cos2Ωtcosω ₀ t-2J ₃ (m) sinω ₀ tcos3Ωt + ...]

Or in a more detailed form

f ₊ = A ₀ cos (ω ₀ t + msinΩt) = A ₀ {J ₀ (m) cosω ₀ t + J ₁ (m) [cos (ω ₀ + Ω) t-cos

(ω ₀ --Ω) t] + J ₂ (m) [cos (ω ₀ + 2Ω) t + cos (ω ₀ -2Ω) t] + J ₃ (m) [cos (ω ₀ + 3Ω) t-

cos (ω ₀ -3Ω) t] + ...},

where: J _n (m) is the nth-order first-order Bessel function of the argument m, m = ω _d / Ω is the frequency modulation index, ω _d is the frequency deviation of the reflected acoustic signal.

Thus, the contribution of various side components to the spectrum of the reflected signal is determined by the value of m.

If m << 1, then the approximate equalities hold

sin (msinΩt) ≈msinΩt, cos (msinΩt) ≈1,

This occurs when the angular velocity of the shaft is negligible.

Thus, with a small frequency deviation of the reflected acoustic signal, only two additional harmonics appear in its spectrum.

For values of the indices m varying in the range from 0.5 to 1, the second pair of lateral frequencies acquires some value, as a result of which the width of the spectrum should be equal to 4Ω. Further, for 1 <m <2, it is necessary to take into account the third and fourth pairs of side frequencies, etc. All these processes are analyzed in a block that performs the functions of a spectrum analyzer.

The ultrasonic phase vibration transducer allows vibration diagnostics of rotating shafts with a complex external surface, the forming of which is not a straight line, by measuring the imbalance of rotors with a complex configuration.

However, this device assumes the presence of a code disk screw on the shaft. This condition is not always possible to put into practice. For example, in construction and road machines, where its presence is associated with additional technical difficulties, since in these machines there is always lateral pressure of soil, snow, and other media on the plane of the screw spiral, and therefore on the code disk. External pressure causes its deformation and, as a result, synchronization errors during measurements. It is not always possible to use code disks in drilling rigs.

The invention relates to measuring technique and can find application in measuring the parameters of radial vibrations of auger shafts in various engineering industries.

The purpose of the invention is the expansion of functionality and improving the accuracy of measurements of radial vibrations of screw shafts. The ultrasonic phase vibration transducer (figure 1) contains a serially connected master oscillator 1, a power amplifier 2, an emitting transducer 3, the object under investigation 4 — a shaft with a screw, a receiving transducer 5, a matching amplifier 6, meanders formers 7, 8, the inputs of which are connected to the outputs master oscillator 1 and matching amplifier 6, respectively, and the outputs of the shapers connected to the inputs of the first block of multiplication 9, the output of which is connected to the first input of the second block of multiplication 14, the second input of which is inen with the output of the comparator 12 and through a series-connected differentiator 15, the inverter 16 and the third multiplication unit 17 is connected to the vibration signal analysis unit 18, the first input of the comparator is connected through the integrator 11 to the output of the matching amplifier 6, the second and third inputs of the comparator are connected to the outputs of the reference source 13 voltages, and the third input of block 14 is connected to the output of the clock generator 10 and to the second input of the third multiplication block 17, the output of which is connected to the vibration analysis block 18.

Ultrasonic phase vibration transducer operates as follows.

The signal of the ultrasonic frequency generator 1 of 100-300 kHz is supplied to a power amplifier 2, and then to the emitting transducer 3. By changing the frequency of the master oscillator 1, the most effective radiation of the ultrasonic signal by the transducer 3 is achieved by tuning it to the electromagnetic resonance frequency. A necessary condition before starting the measurement is the location of the contact spot of the probe ultrasonic beam on the surface of the screw shaft 4, and not on the screw spiral. The ultrasonic beam reflected from the shaft surface through the receiving transducer 5 enters the matching amplifier 6. When the shaft 4 rotates, the phase of the reflected ultrasonic signal changes by a certain amount, which depends on the eccentricity of the shaft, or on the wear of the bearings. If the screw shaft has some eccentricity, then the ultrasonic signal reflected from the shaft surface changes in phase relative to the reference emitted. The phase-modulated ultrasonic signal is fed to a receiving transducer 5 tuned to the frequency of the mechanical resonance. The Converter 5 converts the signal of an acoustic nature into an electromagnetic signal with all the indexes of frequency and phase modulation. Then the electromagnetic signal through the matching amplifier 6 is supplied simultaneously to the integrator 11 and to the meander shaper 8, where from a sinusoidal signal it is converted into a sequence of unipolar rectangular pulses of the same frequency. The output signal (reference) of the master oscillator 1 through the shaper 7 of the rectangular pulses is fed to the first input of the first block 9 of the multiplication, the second input of which receives a sequence of rectangular pulses from the output of the shaper 8. The shaper 7 receives the reference signal from the output of the master generator 1 and its output it takes the form of a meander. The output signal of the shaper 7 having the form of a meander, differs from the output signal of the shaper 8 only in that it may have some mismatch in phase and frequency. The phase change is linearly related to the change in the distance of the reflecting surface of the plane of the spiral of the screw to the emitting and receiving transducers, and the change in frequency characterizes not only the speed of rotation of the shaft, but also the processes caused by the Doppler effect when the contact patch of the probe ultrasonic beam passes to the outer surface of the screw spiral. Since in the presence of even a weak shaft eccentricity, the phase of the reflected ultrasonic signal changes relative to the stable phase of the reference signal from the master oscillator 1, the output signal of the first multiplication unit 9 represents a sequence of rectangular pulses of various durations. This is due to the fact that the output signals of the multiplication block 9 will be greater than zero only when at the same time both inputs of the block 9 will have unipolar signals. Since the phase of the reflected signal does not remain constant, then the pulses from the output of the shaper 8 in the time domain move relative to the pulses of the output signal of the shaper 7. The output signal of the first block 9 multiplication is supplied to the first input of the second block 14 multiplication. The second input of which receives the enable signal from the output of the comparator 12. The purpose of the comparator 12 is that it generates a enable pulse to read information from the output of the first multiplication unit 9. The duration of the resolving pulse corresponds to the time the contact spot of the probing ultrasonic beam is on the shaft surface, without affecting the areas of the screw spiral. The operation of the comparator 12 is as follows. The output signal of the matching amplifier 6 is supplied simultaneously to the shaper 8 and to the integrator 11. The integrator 11 is made according to the scheme of a half-wave rectifier. This corresponds to the fact that with increasing amplitude of the output signal of the amplifier 6, the level of the constant output voltage of the integrator 11 also increases. The output DC voltage of the integrator is supplied to the first input of the comparator 12, the second and third inputs of which receive signals from the source 13 of the reference voltage, which has several stable states. In the case when the signal level at the output of the integrator 11 arriving at the first input of the comparator 12 exceeds the signal level at its second input, a positive rectangular pulse is generated at the output of the comparator, the duration of which is determined by the rise time of the output signal of the integrator 11. When the level of the output signal of the integrator reaches the voltage level supplied to the third input of the comparator 12 from the second output of the reference voltage source 13, the level of the rectangular pulse of the output signal of the comparator children to zero, and a second multiplying block 14 turns off. A necessary condition for the formation of this rectangular pulse is the difference in the levels of the output voltages of the source 13. The voltage level coming from the first output of the source 13 to the second input of the comparator 12 should be of the same order as the output voltage level of the integrator 11 with the auger fixed. The voltage level coming from the second output of the source 13 to the third input of the comparator exceeds the level from its first output at least twice. The maximum excess can be an order of magnitude greater. These conditions are determined by the design of the screw, in particular the shape of its spiral - rectangular, trapezoidal, elliptical, etc.

When the screw shaft rotates, the contact spot of the probe ultrasonic beam, moving along its surface, reaches the area of the screw spiral. The probe ultrasonic beam with a contact spot begins to hit the side surface of the screw. An ultrasonic beam incident on the lateral surface of the screw spiral starts to be reflected at a different angle and the signal power received by the transducer 5 decreases. As a result, the level of the output signal of the integrator 11. If this level is below the threshold of the output voltage from the first output of the source 13, then the output signal of the comparator 12 decreases to zero, the second multiplication circuit 14 stops working and the measurement process stops. But there may be a second option, when the contact spot of the probe ultrasonic beam during rotation of the shaft no longer falls on the lateral, but on the outer surface of the auger rib. Then the reflected beam is saturated with additional harmonics, due to the manifestation of the Doppler effect, and the phase of the reflected signal changes by more than one period of the frequency of the probing signal and the frequency of the reflected signal increases sharply, the energy saturation of the reflected signal also increases. Therefore, the output signal level of the integrator 11 will exceed the level of the signal supplied to the third input of the comparator 12 from the second output of the source 13. Therefore, the output signal of the comparator 12 again takes a zero value. In the case when the second multiplication unit 14 is operating, the phase is an informative parameter. The output signals from the rectangular blocks 7 and 8 are fed to the inputs of the first multiplication block 9, which acts as a phase detector, at the output of which a sequence of rectangular pulses of various durations is formed. The duration of these pulses characterizes the phase change and, consequently, the distance to the object under study, or the displacement of the reflecting surface due to the imbalance of the screw shaft. This sequence of rectangular pulses is fed to the first input of the second multiplication unit 14, the second input of which receives a resolving signal from the output of the comparator 12, which has the form of a rectangular pulse, the duration of which corresponds to the time of finding the contact spot of the probe ultrasonic beam on the surface of the screw shaft, and to the third input of this the block receives clock pulses of high, of the order of 1 GHz, frequency from a generator of 10 clock pulses. The changing number of clock pulses in the output signal of the block 14 corresponds to a phase change between the reflected and reference signals. Block 18 analysis is intended to represent the implementation of the investigated process in the frequency or time domains. The output signal of this block through a digital-to-analog converter (DAC) 19 can be sent to an oscilloscope or directly to a computer, where, depending on the software, the autocorrelation function, spectral composition, and histogram of distributions of informative parameters can be analyzed. In contrast to the prototype, the role of the code disk in the proposed device is performed by the integrator 11, which improves the reliability of its operation when the planes of the screw spiral are subjected to variable loads.

The measurement of the angular velocity of the screw by an ultrasonic phase vibration transducer is carried out as follows.

At the time when the output signal of the comparator 12 takes on a zero value, a differentiated negative pulse is generated at the output of the differentiator 15 connected to the output of the comparator, corresponding in time to the moment the contact spot of the probing ultrasonic beam appears on the outer surface of the screw spiral rib. This pulse through the inverter 16 is supplied to the third block 17 of the multiplication. An inverter can be, for example, an R-S trigger connected to the counter input, so its outputs have only two information signals, zero and one. Suppose a differentiated pulse arriving at its input translated the trigger into a single state. Then the logical unit will be present on the information output of the trigger until the next differentiated pulse of the same polarity transfers it from a single to a zero state. The duration of the generated time interval corresponds to one revolution of the shaft, since negative pulses from the output of the differentiator 15 occur only when a contact spot of an ultrasonic probe beam appears on the outer surface of the auger spiral rib. During the action time of the generated time interval, the pulses of the clock generator 10 received at the second input of the multiplication unit 17 pass to the analysis unit 18. Their number corresponds to one period of rotation of the shaft.

Structurally, the proposed device is as follows. The master oscillator is a standard device, produced commercially, having a frequency range from 20 kilohertz to 1 MHz. This is the operating range of the ultrasonic phase vibration transducer. However, commercially available devices usually have wider frequency ranges, from a few hertz to tens of megahertz. Therefore, depending on the operating conditions of the ultrasonic phase vibration transducer, it is sometimes advisable to produce a master oscillator at one of the frequencies corresponding to the natural frequencies of the emitting and receiving transducers. Moreover, for the most efficient operation, the emitting transducer is tuned to the frequency of electric resonance, and the receiving one to the frequency of mechanical resonance. Radiating and receiving transducers are made by developers, where a sensitive element that converts signals of one physical nature to another is purchased. These are lead zirconate titanate ceramics, TsTS-19. Logical elements - “And”, “And-Not” purchased. The data processing unit is a personal computer with preset programs developed by the authors.

Claims (2)

1. An ultrasonic phase vibration transducer containing a serially connected master oscillator, a power amplifier, an emitting transducer, a test object, a transducer, a matching amplifier, a phase detector, square wave shapers, the first and second multiplication units, the outputs of the master oscillator and matching amplifier through the meanders and the first the multiplication unit is connected to the first input of the second multiplication unit, the second input of which is connected to the output of the clock generator, and the output of Without the information processing unit, it is connected to a digital-to-analog converter, characterized in that it is equipped with a series-connected integrator, a comparator with three inputs, a voltage reference with two outputs, an integrator input connected to the output of a matching amplifier, and the output of the comparator connected to the second input of the second multiplication unit and with a differentiator, an integrator connected in series, the first input of the third multiplication unit and the vibration signal analysis unit, the clock generator is connected to orym input of the third multiplication unit and the third input of the second multiplying unit and the second and third inputs of the comparator are connected to a reference voltage source outputs. 2. The ultrasonic phase vibration transducer according to claim 1, characterized in that the voltage reference source has several stable states.