JPH0273499A - Monitoring method for abnormality of machine - Google Patents

Abstract

PURPOSE:To monitor the abnormality of many parts at a high speed and with high accuracy by amplifying the signal obtained with each detector by an exclusive amplifier, inputting the output levels of those amplified signals to a decider to monitor them continuously, and deciding the parts having the abnormality via a monitor part based on the specific frequency generated by a transmitter for each parts. CONSTITUTION:The sensors 2a-2d are added to the bearings 1a-1d of a rotary machine. The bearings 1a-1d are continuously monitored and the temperatures or vibrations of these bearings are detected and outputted to the exclusive amplifiers 3a-3d. The outputs of the amplifiers 3a-3d are inputted to the level deciders 4a-4d, and the outputs of the deciders are continuously monitored. When the signal level exceeds the prescribed value, a built-in relay is turned on and the abnormality signals are outputted to the transmitters 5a and 5b. Then the transmitters 5a and 5b send the different frequency signals to a common cable 6 based on a case where the abnormal voltage signals received from the deciders 4a-4d are received from the sensor 2a or a case where those abnormal voltage signals are received from the sensors 2b-2d respectively. Then the abnormality signals are outputted from an alarm signal transmitter 7 via the cable 6 for each of parts corresponding to different frequencies.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for continuously monitoring abnormalities in so-called industrial machinery and equipment such as electric motors, pumps, blowers, etc., which rotate several times, and hydraulic lubrication systems. be.

[Conventional technology] There are various methods for monitoring the quality of equipment. For example, there is a method of cyclically measuring vibrations, temperature, etc. caused by abnormalities, and diagnosing quality in batches based on the level (Japan Plant Engineers Association 1st Equipment diagnosis symposium 5ESSION
A-3 May 1980), as shown in Fig. 4, for example, a vibration sensor or a temperature sensor 2 is permanently installed in the bearing part 1 of a rotating machine, and these signals are sent to each dedicated terminal via a cable network 11. A method in which the signal is transmitted to the amplifier 12, the AD conversion multiplexer 13 and the personal computer 14 determine whether the signal is good or bad based on the size of the signal, and in the event of an abnormality, an alarm is issued from the alarm 15 (Japan Plant Engineers Association 8th Equipment Diagnosis Symposium 5ESSION A-4 May 1986) Furthermore, as a method of automatically determining pass/fail, a level judge 17 is installed in the amplifier 16 shown in Fig. 5 (a), and when a specified level is exceeded, an alarm is sent or the equipment is automatically stopped. how to,
Furthermore, as shown in Fig. 5(b), in order to efficiently discriminate multiple points, there is a method in which a personal computer 19 is connected to the A/D multiplexer 18 and each point is scanned and determined (Japan Iron and Steel Institute Equipment Diagnosis Handbook, 1985). ) are used for each pole.

[Problem to be solved by the invention] However, these methods had the following drawbacks.

First of all, in the case of batch-type diagnosis in which humans make rounds, it is natural that if the diagnosis cycle is long, abnormalities will be overlooked, and a large amount of manpower will be wasted on problems and diagnosis work that can lead to accidents or breakdowns.

In addition, in the case of continuous monitoring shown in Figures 4 and 5 (b), the machine where the sensor is installed and the monitoring location are different, so the number of cables required for transmission to the monitoring location is large.
The equipment becomes very expensive. Furthermore, since analog signals are transmitted, there are drawbacks such as vulnerability to electrical noise.

It is an object of the present invention to overcome these drawbacks of the prior art and to provide an inexpensive monitoring method that is capable of highly accurate and rapid abnormality monitoring and is not affected by electrical noise.

[Means for Solving the Problems] The configuration of the present invention for achieving the above object is as follows.

(1) In a method of detecting temperature or vibration by placing a detector at a predetermined location of rotating machinery equipment and monitoring abnormalities in the equipment from the detected signal level, the signals obtained by each detector are sent to a dedicated amplifier. The output of the amplifier is input to a level judger and continuously monitored, and when the signal level (absolute value or rate of change in level) exceeds a specified value, an abnormality is sent to the transmitter, and the transmitter detects the A method for monitoring an abnormality in a machine, characterized in that a signal is transmitted to a signal monitoring section for each component via a common cable at a specific frequency, and the monitoring section determines a component in which an abnormality has occurred based on the frequency.

(2) The signal emitted from the transmitter varies depending on the degree of abnormality.
The first aspect of the invention is characterized in that the transmission voltage level is changed.
Method for monitoring machine abnormalities as described in section.

(3) The method for monitoring an abnormality in a machine according to item 1 or 2 above, characterized in that a triangular wave or a rectangular wave is used as the transmission signal from the transmitter.

[Operation] As described above, the present invention determines pass/fail based on the signal level (absolute value or rate of change in level) of the sensor that detects temperature, vibration, etc., and if it is defective, the frequency is 100 Hz for equipment A, 150 Hz for equipment B, and 150 Hz for equipment C. Then, a vibration frequency specific to the part, such as 200Hz, is transmitted, and a remote monitoring unit monitors whether the transmitted signal is acceptable or not. If a signal is detected, the frequency is determined by F/V conversion or simply frequency analysis, and the abnormal part is identified. It is something. Since the transmission from the transmitter uses one common cable, the status of a large number of monitoring equipment can be transmitted using a minimum number of cables.

Furthermore, since the signal transmits frequency information, unlike analog information, it is a highly reliable monitoring method with less influence of attenuation and the like. In addition, by adding a transmission voltage depending on the degree of abnormality (caution, danger), it is possible to quickly grasp which equipment is in what state, and it is possible to quickly take appropriate measures.

Furthermore, by using a triangular wave or a rectangular wave for the transmitted signal, it is easy to distinguish it from noise and no false detection occurs.

[Example] The configuration and effects of the present invention will be described below with reference to the drawings of the example.

In Fig. 1, ■a to 1d are bearings of a rotating machine that are continuously monitored, and 28 to 2d are sensors placed on the bearings 1a to 1d to detect temperature or vibration, and a dedicated amplifier 38
~ Output to 3d. 48-4d are dedicated amplifiers 3a-3d
Continuously monitors the output of the
00 tlz, 2 b When 15011z
, 2110Hz when 2c, 250H when 2d
It is an oscillator that emits a frequency specified for each component, such as z. Reference numeral 6 denotes a common cable connecting a large number of transmitters 5a, 5b, . . . and a remote monitoring unit; 7 an alarm signal transmission monitor connected to the transmitter 5 through the common cable 6 and composed of a relay; When there is a transmission signal from 5, an alarm signal is generated and output to the alarm 8, and the part indicator 9
Also output to. The part indicator 9 is preferably a frequency analyzer or an F/V converter that converts a frequency signal into a voltage signal.Since the received frequency is determined and displayed, it is possible to quickly find out whether an abnormality has occurred in the part of the sea. Ru.

Figure 2 shows that from the signal level detected by the sensor,
1 in Figure 1 shows a means to change the transmission voltage level when transmitting from the transmitter 5 depending on the degree of abnormality occurrence (caution, danger, etc.)
0 is a transmission voltage variable device.

FIG. 3(a) shows the concept of the signal transmitted by the transmitter 5, where the horizontal axis is time and the vertical axis is the signal magnitude.When an abnormality occurs, either a rectangular wave or a triangular wave is transmitted. Figure 3 (b
) shows the result of frequency analysis of the signal, with the horizontal axis being the frequency and the vertical axis being the signal size.Since rectangular waves and triangular waves are used, Subactor appears up to higher frequencies, and depending on the presence or absence of this result, the signal It is also possible to check the noise characteristics of

For example, the present invention may be carried out using the above-mentioned apparatus, or
The specific configuration of the device can be changed as desired within the scope of achieving the object of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, (1) By changing the oscillation frequency for each monitoring component, it is easy to identify the location where an abnormality occurs in the monitoring section.

(By determining the degree of abnormality (caution level, danger level) and changing the transmission voltage, it is possible to take prompt and appropriate measures.

■By using triangular waves and rectangular waves, it is easy to check the noise of the signal and there is no risk of misidentification.

(4) Since the detection part and the monitoring part are connected using a common cable,
It is possible to centrally monitor a large number of equipment for abnormalities,
It can be configured as an inexpensive monitoring device.

Excellent industrial effects such as these can be obtained.

[Brief explanation of the drawing]

1 and 2 show examples of apparatus suitable for carrying out the present invention,
FIG. 1 is an explanatory diagram showing the overall configuration of the device, and FIG. 2 is an explanatory diagram showing means for changing the transmission voltage level. FIG. 3 is an explanatory diagram showing the concepts of rectangular waves and triangular waves and the results of frequency analysis. FIG. 4 is an explanatory diagram showing a conventional monitoring method, and FIG. 5 is an explanatory diagram showing a pass/fail determination method using the conventional method. l...bearing, 2...sensor, 3...dedicated amplifier. 4.17... Level judger, 5... Transmitter, 6...
・Common cable, 7...Alarm signal transmission monitor, 8
゜15...Alarm, 9...Part indicator, 10...
Transmission voltage variable device, 11... cable network, 12...
Dedicated amplifier, 13゜18...AD conversion multiplexer-114, 19...PC, 16...amplifier.

Claims (1)

[Claims] 1. In a method for detecting temperature or vibration by placing a detector at a predetermined location of rotating mechanical equipment and monitoring abnormalities in the equipment from the detected signal level, The signal is sent to a dedicated amplifier, and the output of the amplifier is input to a level judger for continuous monitoring, and when the signal level (absolute value or rate of change in level) exceeds a specified value, an abnormality is sent to the transmitter. Then, in the transmitter, each component transmits a signal at a specific frequency to a signal monitoring unit via a common cable,
A method for monitoring an abnormality in a machine, characterized in that the monitoring unit determines a component in which an abnormality has occurred based on a frequency. 2. Claim 1, characterized in that the signal emitted from the transmitter changes the emitted voltage level depending on the degree of abnormality.
Method for monitoring machine abnormalities as described in section. 3. The machine abnormality monitoring method according to claim 1 or 2, wherein a triangular wave or a rectangular wave is used for the transmission signal from the transmitter.