JPH09257560A - Vibration detecting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To intensively control outputs of plural acceleration sensors, and obviate laying of a cable by detecting a signal corresponding to acceleration of vibration of an inspection object body, judging a level of its signal, and wirelessly transmitting a judging result to a centralized control room. SOLUTION: Detecting output of a piezoelectric acceleration sensor 2 installed on a bearing 1 being a vibration source, is supplied to a level judging unit 3, and an output signal of the sensor 2 is amplified (7) by the judging unit 3, and is compared with a reference value preset in a comparator 9. When vibration of the bearing is put in a normal condition, a detecting signal level becomes smaller than the reference value, and a low level signal is outputted from the comparator 9, and the bearing 1 is degraded by abrasion, and when vibration becomes large, since the detecting signal level becomes larger than the reference value, a high level signal is outputted. Output of the comparator 9 is sent out to a vibration analyzer through a receiver of a centralized control room by a transmitter 200 built in a vibration detecting device 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for detecting vibrations of, for example, a bearing of a rotating machine, and more particularly to transmission of a detection signal thereof.

[0002]

2. Description of the Related Art A bearing or the like of a rotating machine is worn and deteriorates due to its continued use, and depending on the progress of wear, the rotating machine may be stopped or damaged, resulting in a serious accident. For this reason, it is necessary to grasp the degree of wear of bearings of rotating machines. For example, in the case of a bearing of a rotating machine, vibration increases as wear progresses. Therefore, conventionally, a sensor for detecting this vibration, such as an acceleration sensor, is regularly attached to the bearing of the rotating machine, and a signal detected by this sensor is transmitted. It is analyzed by a vibration analyzer, or is disclosed in Japanese Patent Laid-Open No. 63-
As proposed in Japanese Patent No. 42427, vibration is analyzed by a vibration detection device in which a vibration sensor and a display portion of a vibration level are integrated, and the presence or absence of wear deterioration of a bearing of a rotating machine or the progress of wear deterioration. Was judged and, if necessary, measures such as bearing replacement were taken.

[0003]

There are many places such as bearings that require vibration detection even in one factory. Therefore, it is necessary to use a vibration analysis device arranged in a central control room for monitoring. However, there has been a problem that cables have to be laid from each acceleration sensor to the vibration analysis device, resulting in a huge cost. Further, the vibration detecting device proposed in Japanese Patent Laid-Open No. 63-42427 does not require the above-mentioned cable, but it is necessary to go to the installation location and inspect it, and the inspection work is complicated. There was a problem that was.

The present invention has been made in order to solve such a problem, it is possible to intensively monitor the outputs of a plurality of acceleration sensors, and the above-mentioned cable laying is unnecessary. The purpose of the present invention is to provide a vibration detection system.

[0005]

SUMMARY OF THE INVENTION A vibration detecting system according to one aspect of the present invention is an acceleration detecting means for detecting a signal corresponding to an acceleration of vibration of an object to be inspected, and a level of a detection signal of the acceleration detecting means. Level determination means for determining
And a transmitting means for wirelessly transmitting the determination result of the level determining means. A vibration detection system according to another aspect of the present invention includes an acceleration detection unit that detects a signal corresponding to an acceleration of vibration of an object to be inspected, a level determination unit that determines a level of a detection signal of the acceleration detection unit, and And a transmission means for wirelessly transmitting the determination result of the level determination means together with a signal for identifying the main body device. In the vibration detection system according to another aspect of the present invention, the transmission unit transmits the determination result of the level determination unit every predetermined time. In a vibration detection system according to another aspect of the present invention, a vibrating body vibrates due to vibration of an object to be inspected, a piezoelectric element installed on the vibrating body, and a DC converter for converting AC charges of the piezoelectric element into a DC voltage. The power supply generating means further supplies the DC voltage to at least the level determining means.

[0006]

DETAILED DESCRIPTION OF THE INVENTION

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a vibration detection system according to Embodiment 1 of the present invention. As shown in the figure, this vibration detection system is provided with a plurality of vibration detection devices 100 each mounted on a bearing of a rotating machine and having a built-in transmission device. Signals wirelessly transmitted from the vibration detection devices 100 are stored in a central control room. The signal is received by the receiving apparatus 300 arranged in.

FIG. 2 is a block diagram showing details of the vibration detecting device 100 of FIG. In FIG. 2, 1 is a bearing of a rotating machine which is a vibration source, 2 is a piezoelectric acceleration sensor, and 3 is a level determiner. The level determiner 3 includes an amplifier 7
And a comparator 9. Reference numeral 5 is a piezoelectric element power supply generator, 6 is a DC converter, and 200 is a transmitter.

In FIG. 2, the piezoelectric acceleration sensor 2 is
It is attached to the bearing 1 which is a vibration source, and its detection output is supplied to the level discriminator 3. The level determiner 3 outputs a high level signal when the output level of the piezoelectric acceleration sensor 2 becomes larger than a preset reference value. The piezoelectric element power supply generation unit 5, like the piezoelectric acceleration sensor 2,
An AC charge is generated by the vibration of the bearing 1, the generated AC charge is converted into a DC voltage by the DC converter 6, and this DC voltage is supplied as a power consumption of the level determiner 3. Further, since the vibration acceleration due to the rotation of the bearing is about 1 to 2 G, the total amount of power consumption of the vibration detection device 100 and the transmission device 200 can be sufficiently covered by the amount of electric charge generated by the piezoelectric element power generation unit 5 in this case. it can.

As described above, the level determiner 3 includes the amplifier 7 and the comparator 9. The amplifier 7 amplifies the output signal of the piezoelectric acceleration sensor 2 corresponding to the vibration acceleration of the bearing, and one of the comparator 9 Input to the input terminal of. A preset reference value is given to the other input terminal of the comparator 9, and this reference value and the amplifier 7
Of the signal values of the two are compared to determine the magnitude relationship between the signal values of the both. Then, when the bearing vibration is in a normal state, that is, when the output of the acceleration sensor 2 is small, the reference value is set to be larger than the output of the amplifier 7, so that the output of the comparator 9 is at a low level. Become. When the bearing wears and deteriorates and the vibration increases, the output of the amplifier 7 becomes larger than the reference value, so that the output of the comparator 9 becomes a high level. The output of the comparator 9 is sent to the built-in transmitter 200.

FIG. 3 is a diagram showing the configuration of the piezoelectric element power source generating section 5 of FIG. In this piezoelectric element power supply generation unit 5, a rectangular plate-shaped piezoelectric element 1 having electrodes formed on both surfaces is formed.
1, 12 are bonded to a metal plate 13 to form a bimorph structure, one end of which is fixed to a frame 16 with an adhesive 14 such as an epoxy resin for insulation, and the other end of the adhesive is also an adhesive such as epoxy resin for insulation. A weight 17 made of metal is attached at 15. When vibration is applied in the vertical direction via the frame 16 with such a configuration, the piezoelectric elements 11 and 12 generate electric charges by bending vibration as indicated by the broken line. The generated charges are taken out by the lead wires 18 and 19, and the DC converter 6
Supplied to

Here, in the case of the bimorph structure shown in FIG. 3, when one of the plate-shaped piezoelectric elements 11 and 12 is stretched by bending vibration, the other is compressed and deformed in the opposite directions to generate electric charges. Since it is generated, the electric charge is generated twice as much as that in the case of one piezoelectric element. Further, by providing the metal plate 13 between the two piezoelectric elements 11 and 12, the piezoelectric element can be easily attached and the mechanical strength is increased. In addition, this plate-shaped piezoelectric element (vibration element) 1
The larger the deflection amplitude, the larger the amount of electric charge generated, and therefore the weights of the weights 17 attached to the other ends of the cantilever-supported vibrating elements are so as to obtain the largest deflection amplitude by vibration. Is adjusted so that the vibrating element resonates in a normal vibration frequency band (about 10 to 100 Hz) such as a bearing. When the vibration frequency band to be detected is wide and cannot be covered by the resonance band of one piezoelectric element power supply generation unit 5, a plurality of piezoelectric element power supplies having different resonance bands such as for low band and high band. A generator may be provided and the charges generated from these may be added. Further, the configuration of the piezoelectric element is not limited to that shown in FIG. 3, and may have an arbitrary configuration such as a U-shape, a C-shape, and a spiral shape.

FIG. 4 is a circuit diagram of the DC converter 6 of FIG. The DC converter 6 includes four full-wave rectifying diodes D1 to D4 and smoothing and storage capacitors C, and converts the input AC voltage into a DC voltage and outputs the DC voltage. Then, this DC output voltage is supplied to the level determiner 3 (amplifier 7, comparator 9) and the transmission device 200.

FIG. 5 is a block diagram showing the configuration of the transmitting device 200 of FIG. The transmitter 200 includes a microprocessor 50, a memory 51, a modulator 52, a PLL circuit 53, a low pass filter 54, a voltage controlled oscillator 55, a band pass filter 56, a high frequency amplifier 57 and an antenna 58.
It is composed of The memory 51 may be a memory built in the microprocessor 50, but an external one is used here, and the address signals “000 to 99” for the vibration detection device 100 are used.
9 "(one of the above signals is selected) and channel data" 0-9 "defining the carrier frequency (also 1
Two signals are selected) are stored.

The microprocessor 50 is activated at regular intervals, sequentially fetches the output signal of the level determiner 3, reads the address signal of the signal from the memory 51, and detects the address signal and the detection signal (normal or abnormal). Then, a signal pattern as shown in FIG. 6 is generated and output to the modulator 52. This signal pattern is composed of a signal group including a bit synchronization signal (30 bits), a frame synchronization signal (31 bits), an identification signal (12 bits) .... When the signal pattern of FIG. 6 is input from the microprocessor 50, the modulator 52 converts the signal “0” into an MSK (Minimum Shift Keying) signal in which 1800 Hz and “1” are 1200 Hz, and the voltage control oscillator 55. Output to.

The PLL circuit 53 is the microprocessor 5
The set frequency based on the channel data from 0 is compared with the frequency of the transmission signal transmitted from the antenna 58,
PLL so that the frequency of the transmission signal is always the set frequency
The controlled output signal is output to the low pass filter 54. The output of the low-pass filter 54 is supplied as a control voltage to the voltage control oscillator 55 together with the output from the modulator 52. The voltage control oscillator 55 uses the FSK (Frequency Shif) based on the above-mentioned output (MSK signal) from the modulator 52.
1 is output from the antenna 58 via the band pass filter 56 and the high frequency amplifier 57. The receiving device 3 of FIG.
00 is wirelessly transmitted.

The receiving device 300 of FIG. 1 has a plurality of lamps 301 respectively corresponding to the vibration detecting device 100, and when receiving the transmission signals from the transmitting device 200, the address signal and the detection signal included in the identification signal. Based on (normal / abnormal), the corresponding lamp is turned on or off. In this way, by displaying the detection signal from the vibration detection device 100, it is possible to grasp not only the presence or absence of abnormality of the inspection object but also whether or not the vibration detection device 100 itself is operating normally. can do.

As described above, in the present embodiment,
Piezoelectric element power source generator 5 that spontaneously occurs in the vibration detection device
Can fully cover the total power consumption of the vibration detection device, and it is not necessary to consider the life of the power source of the battery, etc., and the state of bearings etc. of continuously operating equipment is constantly monitored to detect abnormal vibrations reliably. be able to. Further, the detection signals of a plurality of vibration detection devices can be intensively and continuously monitored in the reception device, and wear deterioration can be detected at an early stage, so inspection work is less than in the past. With improved productivity, no inspection costs
Production costs are reduced.

(Embodiment 2) FIG. 7 is a perspective view showing another embodiment of the piezoelectric element power source generator 5. In this embodiment, the piezoelectric ceramic 40 is adhered to the disc-shaped metal plate 41, and the weight 42 is adhered to the central portion of the metal plate 4.
The structure which supported a part of 1 or the periphery is employ | adopted.

(Embodiment 3) By the way, in the above-mentioned embodiment, the reference value (generally called a threshold value) for the comparator 9 of the level determiner 3 to compare with the vibration detection level to detect an abnormality is: Since it can be set arbitrarily, if a reference value is set so that it can detect the initial stage when the bearing is worn and abnormal vibration starts to occur, the abnormality of bearing wear deterioration can be found at the initial stage, It is possible to prevent a serious failure from developing due to the progress of wear deterioration.

Further, in the above-described embodiment, FIG.
An example of detecting the presence / absence of an abnormality in the level determiner 3 has been described. For example, a plurality of comparators are installed to detect the degree of abnormality, and the abnormality is transmitted to the receiving device 300 via the transmitting unit 200. May be. For example, if two reference values having different values and two comparators are provided and the respective levels are individually judged, it is possible to judge three states of normal, caution, and abnormal. In this case, the detection signal of the identification signal of FIG. 6 occupies at least 2 bits.

Further, in the above-mentioned embodiment, the embodiment in which the piezoelectric element power source generating section 5 is used has been described, but a battery may be used.

Further, in the above-described embodiment, an example in which the transmission device 200 cyclically transmits the detection signal of the vibration detection device 100 at a constant cycle regardless of whether or not there is an abnormality has been described. When the output signal of No. 3 becomes high level, the transmitting device 200 may be made to perform the above-mentioned processing, or only the vibration detecting device 100 which has detected the abnormality may be made to wirelessly transmit the identification signal. May be.

Further, a plurality of vibration detecting devices 100 respectively installed over a wide area are divided into groups, and the receiving device 3
For 00, install the number of antennas corresponding to the group toward the installation area of the group,
A configuration may be adopted in which signals are received and signal processing is performed with each group as a unit. For example, No.1 to No.50
The signal from the group of the vibration detection devices 100 up to
Received by the antennas of No. 51 and No. 51
Signals from the group of vibration detectors 100 up to 00 are received by the second antenna.

[0024]

EXAMPLE Next, an example of the piezoelectric element power source generating section 5 will be described. As the piezoelectric elements 11 and 12 of FIG.
mm, a length of 17.5 mm, and a thickness of 0.22 mm are used, and the two plate-shaped piezoelectric elements have a thickness of 0.1 mm.
To a bimorph structure, one end of which was fixed to the frame 16 and a brass weight 17 was attached to the other end to form the piezoelectric element power generation unit 5. When the characteristics of the piezoelectric element power supply generating section 5 were examined, the electrostatic capacity was 12.
A charge sensitivity of 5 μF and a charge sensitivity of 100 nC (nano Coulomb) / G was obtained. When this is vibrated at a frequency of 60 Hz and a vibration acceleration of 1 G, and the output of this piezoelectric element power supply generation unit 5 is connected to the input terminal (INPUT) of the DC conversion unit 6 of FIG. 4, nothing is connected to the output terminal (OUTPUT). DC under no load
8 V was obtained, and a current of about 20 μA flowed with the output terminal (OUTPUT) short-circuited. In addition, the output terminal (O
If a 25 KΩ resistor is connected to (UTPUT), the voltage across the resistor will be DC3V, and the resistance will be 12μ continuously.
A current flowed. From these data obtained, it was confirmed that the piezoelectric element power supply generation unit 5 and the DC conversion unit 6 shown in FIGS. 3 and 4 can be used as a power supply of DC 3V, 12 μA.

[0025]

As described above, according to the present invention, the acceleration of vibration is detected, the magnitude thereof is judged, and the judgment result is wirelessly transmitted. It enables centralized monitoring and eliminates the need for cable laying.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vibration detection system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing details of the vibration detection device of FIG.

FIG. 3 is a diagram showing a configuration of a piezoelectric element power supply generation unit in FIG.

FIG. 4 is a circuit diagram of a DC converter of FIG.

5 is a block diagram showing a configuration of the transmission device of FIG.

6 is an explanatory diagram of a signal pattern supplied from a microprocessor of FIG. 5 to a modulator.

FIG. 7 is a perspective view showing another embodiment of the piezoelectric element power source generating unit of FIG.

[Explanation of reference numerals] 1 bearing 2 piezoelectric type acceleration sensor 3 level determiner 5 piezoelectric element power source generation section 6 DC conversion section 7 amplifier 9 comparator 100 vibration detection apparatus 200 transmission apparatus 300 reception apparatus

Claims (4)

[Claims] 1. An acceleration detecting means for detecting a signal corresponding to an acceleration of vibration of an object to be inspected, a level judging means for judging a level of a detection signal of the acceleration detecting means, and a judgment result of the level judging means by radio. A vibration detecting system, comprising: a transmitting unit for transmitting. 2. An acceleration detecting means for detecting a signal corresponding to an acceleration of vibration of an object to be inspected, a level judging means for judging a level of a detection signal of the acceleration detecting means, and a judgment result of the level judging means. A vibration detecting system, comprising: a transmitting unit that wirelessly transmits together with a signal for specifying a main body device. 3. The vibration detecting system according to claim 1, wherein the transmitting unit transmits the determination result of the level determining unit at every predetermined time. 4. A vibrating body which vibrates due to the vibration of the inspection object,
The piezoelectric device further comprises a piezoelectric element installed on the vibrating body, and a direct current converter configured to convert an alternating current charge of the piezoelectric element into a direct current voltage, and at least the direct current voltage generated by the power source generating means is The vibration detection system according to claim 1, 2 or 3, characterized in that the vibration detection system is supplied to a level determination means.