SU1710463A1 - Method of determining technical condition of roller supports of belt conveyer - Google Patents

Description

ABOUT

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A vibration sensor 1 is installed under one of the roller carriages, which are in good condition, which we call fixed, when the conveyor is in operation, it perceives vibration from the rollers, the belt, the load, and various interferences. In order to isolate the vibrating signal emitted by the rollers, i.e. rebuild from extraneous signals; informative frequencies are preliminarily determined by calculation or experimentally. By measuring the vibration of the conveyor at idle and highlighting the obtained informative frequencies with the aid of microcomputer 7, a signal is generated that is generated simultaneously by a number of rollers. To receive a signal from each roller carriage separately, you need to skip a portion of the load through the conveyor, and the registration of signals starts at the moment of transfer by the load to the fixed roller carres. When this load passes through each roller, the vibration signal changes its size and character with respect to the signal at idle. In order to be able to carry out, the Invention relates to the field of automated control of the operation of technological equipment, namely the roller conveyor roller, and can be used in the mining industry and in crushing and screening complexes.

The technical condition of the roller carriers is mainly determined by the serviceability of the rollers.

Methods are known for detecting the fixed rollers of a belt conveyor by detecting changes in the level of a vibroacoustic signal relative to its reference value.

The closest to that proposed by the technical entity is the method of detecting stationary rollers of a belt conveyor, including the registration of a change in the spectrum of a vibroacoustic signal emitted by the conveyor stand portions.

A disadvantage of the known method is the lack of control over the change in the belt speed and conveyor loading, since when the transport speed changes, the vibroacoustic signal (its particular amplitude) and the center of gravity of the flat figure formed by the spectral envelope change, which makes it impossible to correctly analyze

Zirovat signals from each subsequent roller, strobe them. At the same time, a series of selected vibration signals (strobe) from a number of corresponding roller bearings is obtained. The resulting gated vibration signal is subjected to narrowband filtering or spectral analysis in order to determine the informative frequencies characterizing the state of the rollers of the roller supports. From these signals subtract the signal informative frequency at idle, receive an increment (modulo). The degree of malfunction of the roller carriages can be determined by the change in the amplitude increment of the informative frequency signal over the signal of the same frequency at idle compared to the signal amplitude increment from the fixed roller coaxial signal over the signal of the same frequency at idling. For this, the signal increment from each roller support is compared with the signal increment from the fixed roller support. 1 il.

the reason for deviation of the center of the body. When changing the load and tension of the conveyor belt, the belt is more or less attached to the rollers;

the traffic flow on the roller carrier, which leads to a similar error and the reliability of the detection of defective rollers is reduced.

In addition, according to a known method, only the area where the stationary roller is located is determined, and according to the proposed method, the number of the roller supports.

The aim of the invention is to improve the reliability and accuracy of the detection of defective rollers.

This goal is achieved by registering changes in the signal emitted by the reference section of the conveyor butt, as compared to the tested one, and measure the vibration of the conveyor stand at idle.

the conveyor and during the transportation of the control portion of the cargo, the registration of the signals begins at the moment of transition by the load of the reference rollers, gates the Bvt6po signal, select the sections corresponding

In time for the load to pass through each successive roller carriage, spectral analysis of the vibrosignal is performed, informational frequencies are taken from the frequency spectrum, which characterize the transition of the test carriage through the roller carrier, the amplitude of oscillations of this frequency is determined. which will characterize the signal of the fixed roller, find the increment of the amplitude of the informative frequency of the section of the fixed roller, over the amplitude of the same frequency at idle, the resulting increment is taken as the standard, compare the amplitudes of the informative frequencies of the subsequent roller, with the amplitude of the same frequency at idle, increment its decrease with attenuation depending on the distance from the fixed roller supports and compared with the standard, the value obtained assoglasovani compared with the permissible value and in case of exceeding modulo conclude faults, with the fault number corresponds to the number of analyzed roller strobyrovannogo site. The amplitude of oscillations of a given frequency is determined by the proposed method A (G) AO where AO is the amplitude of oscillation of the reference beam from the effect of the control portion of the load. Ao 2xst Sin, hbt, where fin is the dynamic coefficient, is xst the static deflection of the longitudinal beam or the vertical displacement of the rack of the roller cooper when passing the test portion of the load; y is the absorption coefficient of vibrations in the metal; I is the distance from the point of origin of the oscillations to the control roller. The gated vibration signal sections are compared when the control portion of the cargo is transported with the informative frequency signal at idle, the difference obtained is compared with the reference difference, i.e. between the signal from the fixed roller and the idling, the attenuation of the signal is taken into account depending on the distance from the reference roller on the speed of the conveyor belt, the wave propagation speed in the center Ci {G-p-V 2 where G is the shear modulus; p is the density of the material (steel) ;. G 0.5E (1+ / 4) where E is Young's modulus; fi - Poisson's ratio. Accounting for changes in transport and transport is done by gating the vibrogram at regular intervals equal to the time it takes for the load to pass from one roller to another. Monitoring the change in the transport speed ensures precise determination of the signal location from the interaction of the load with the roller support relative to the sensor installation site, and hence the identification of the number of damaged roller supports, since even a change in speed due to technical reasons (change in network voltage, engine characteristics, etc.). ) after 15–20, the roller support will shift the characteristic signal by one roller support. This makes it possible to increase the reliability of diagnosing faulty rollers. The application of the proposed method will improve the reliability and durability of the mechanical equipment of the conveyor, the supporting structures and the belt, since with timely replacement and repair of malfunctioning rollers adjacent roller supports are not overloaded, additional vibrations do not occur, i.e. improved operating conditions. Due to the timely detection of faulty rollers, the downtime for repair is reduced. The proposed method is carried out as follows. Under one of the rollers that are in serviceable grade (reference), we install a vibration sensor. During the work of the conveyor, it will perceive vibration from rollers, tape, cargo, various interferences. In order to isolate the vibrating signal emitted by the rollers, i.e. to clear up from all other signals, it is first necessary to determine informative frequencies by calculation or experimentally. By measuring the vibration of the conveyor at idle and highlighting the obtained informative frequencies, we obtain a signal generated simultaneously by a number of rollers. In order to receive a signal from each roller carriage separately, you need to skip a portion of the load through the conveyor, and the registration of signals begins at the time of the transfer of the reference roller carousel. When this load passes through each roller, the vibration signal will change its size and character with respect to the signal at idle. To analyze the signals from each subsequent roller, it is necessary to distinguish them in time from the total vibration. This operation is called gating. At the same time, we obtain a sequential series of selected wybrosignals (strobe) from a series of corresponding roller bearings. The resulting gated vibration signal is subjected to narrowband filtering or spectral analysis in order to determine the informative frequencies characterizing the state of the rollers of the roller supports. From these signals we subtract the informative frequency signal by

idle and get increment (modulo). The degree of malfunction of the roller carriage can be determined by the change in the amplitude increment, the informative frequency signal above the signal at the same frequency at idle compared to the signal amplitude increment from the reference roller cone above the signal at the same frequency at idling. For this, the signal increment from each roller support is compared with the signal increment from the reference roller support.

But since the vibration sensor is only under one roller. then, as the load portion moves away from the vibration sensor installation site, the vibrosignal from subsequent rollers stops out. The attenuation value is determined by the well-known formula, by means of which a certain increment of the amplitude of the informative gated signal leads to the same scale, which makes it possible to compare the increment values with the increment on the reference roller support.

The drawing shows a block diagram of the device.

The device consists of a vibration sensor 1 and a strain gauge 2 mounted on a fixed roller support. the comparator 3, the tape speed sensor 4, the matching unit 5 with the USO object, which is intended to match the output signals of the sensors with the input of the analog-digital converter (ADC) 6 and consists of matching amplifiers with galvanic isolation and switch signals, the ADC is connected to microcomputer 7 connected to block 8 of indications 1 / 1I.

A device that implements the method of determining the technical condition of the roller conveyor belt operates as follows.

In order to diagnose the condition of the roller, the conveyor is released from the load and idling. From the vibration sensor 1, the vibration converted into an electrical signal enters the USO 5, in which the signal from the microcomputer 7 amplifies the signal and connects it to the input of the ADC 6. At the same time, the signal from the microcomputer 7 ADC converts this signal to digital a form that is perceived by the microcomputer 7, the latter performs spectral analysis of the idle vibration signal of the conveyor and highlights the informative no-load frequencies of the conveyor, the amplitudes of which are memorized.

Then on the empty tape load control portion of the load, equal to the linear mass. When the load passes over the fixed roller support, the strain gauge 2 takes the load, the value of which is converted into an electrical signal and fed to the comparator 3, which is triggered when this signal is received and outputs a logical unit to USO 5 (which corresponds to the passage of the load portion). The signal from microcomputer 7 in USO 5 connects it to the ADC 6, where this

0, the signal from the signal from microEV and 7 is digitized and entered into microcomputer 7.

From the 4 speed sensor, the tape speed value converted to electrical

5, the signal enters the USO 5, in which the signal from the microcomputer 7 amplifies the signal and connects it to the A / D converter 6, where it is converted into a digital form, which is perceived by the microcomputer.

0 The appearance of the signal from the strain gauge 2 is for microcomputers 7 the starting point required for organizing gating. The speed signal is required to determine strobe intervals 5. The determination of gating intervals allows the connection of the Vibration Sensor 1 using USO 5 at time intervals of gating, which allows you to enter a signal into the microcomputer 7 into

0 the moment of finding the load Nbd next to be diagnosed roller.

When the signal from the strain gauge 2 appears, the first gating pulse appears, which is the control signal

5 USO 5 and ADC b for input to the microcomputer 7 of the signal from vibration sensor 1, which will correspond to the fixed roller support,

In this case, microcomputer 7 occurs

0 spectral analysis of the incoming signal, selection of the amplitudes of the informative frequencies, comparison of the obtained amplitudes of the informative frequencies with the amplitudes of the informative frequencies at idle and determining the increment (modulo), the value of which is taken as the standard. The second gating pulse appears when the load passes over the roller support following the fixed one, which

0 is the control signal of the USO 5 and the A / D converter 6 for inputting the microcomputer 7 signal from the vibration sensor 1.

At the same time, the spectral analysis of the incoming signal, the selection of the amplitudes of the informative frequencies, the comparison of the amplitudes of the informative frequencies with the amplitudes of the informative frequencies at idle and the determination of the increment, the correction of the increment

diagnosed roller on the value

vibration damping depending on the distance from the fixed roller, comparing the standard with the corrected increment and determining the increment difference, comparing the increment difference with the specified value. If the increment difference does not exceed the specified value, the computer 7 generates the message Norm on the display unit. Otherwise, a message is generated. The roller support is faulty and the number of the gating pulse is indicated, which corresponds to the number of the faulty roller bearing with respect to the fixed one.

Starting from the second gating pulse, the device performs the operations according to the described algorithm.

The downtime of the rotor complexes, caused by the failure of the roller, amounts to 8.1% of the total downtime (up to 80 hours). Reliable diagnosis of malfunctioning rollers with an indication of the malfunction and the number of the malfunctioning roller supports reduces the time for visual detection of breakdowns and, thus, reduces the time for eliminating failures and results in performance savings. Saving (in thousand rubles) from the introduction of the proposed method in comparison with the known is

E 0 -At -Kg, 57, where Q - the performance of the complex;

At - save time, h;

Kg - availability factor;

C - the cost of 1 m overburden.

Claims (1)

The invention of the method for determining the technical condition of the roller conveyor, including registering a vibration signal, the checked conveyor section, setting the reference vibration signal and the permissible error value, comparing the value of the vibration signal emitted by the tested section of the conveyor belt with the reference signal value, and comparing the obtained error value with an acceptable error value that differs from the purpose of increasing the reliability and accuracy of detecting faulty rollers, the vibration signal emitted by a conveyor belt is recorded first at idle After moving the control portion of the load, starting from the moment of passage through the fixed roller support, gates the vibration signal at the sections corresponding to the load transfer through each subsequent roller support, the informative frequencies characterizing the load transfer through the roller support are determined the amplitudes of the vibrational signals of the informative frequencies, determine the increment of the amplitude of the informative frequency of the section of the fixed roller support when transporting the control portion of the load to the amplitude of the same frequency at idle, the increment obtained is taken as the reference signal, the increments of the amplitudes of the informative frequencies of the subsequent roller supports are determined in the same way, the value of the specified increments for subsequent roller supports increase in proportion to the attenuation of the vibrating signal as each subsequent roller stops from the fixed one and compared with the reference signal .