JPH0371656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration monitoring device that monitors vibrations of rotating machines, etc., and more specifically, to a vibration monitoring device that has good resolution and is reliable when determining whether a vibration level is abnormal or normal using a computer. The present invention relates to a vibration monitoring device that can obtain highly accurate vibration data.

Conventionally, there was a device of this type as shown in Figure 1. In the figure, 1 is a vibration detector that converts vibration into an electrical signal, and 2 is an amplifier that amplifies the signal until it can be processed or converts the impedance. drawer, 3
4 is a comparator that sets an abnormal vibration value in advance, compares it with the actual vibration level, and issues a signal if that level is exceeded, 4 is a case in which these are all combined into one, and 5 is a case in which an alarm is issued when an abnormality occurs. An abnormality alarm device that displays a display, and 6 a vibration meter that displays a vibration level.

Next, the operation will be explained. The amplification rate of the amplification device 2 is set in advance according to the characteristics of the detector, but this is fixed. Further, since the setting of the abnormality level of the comparator 3 also differs depending on the rotation speed of the target device, etc., the set value is unique to each device, and the set value is fixed.

As shown in FIG. 1, the conventional centralized monitoring system requires a variable amplifier and a comparator for each detection system in order to set its amplification rate detection standard for each detection system. For this reason, in the case of multiple points, the monitoring device becomes large and costly, and the dynamic range of the amplifier is fixed, so the measurement width is held constant and cannot be clipped if the vibration level becomes abnormally high. The drawback was that the true value could not be obtained.

This invention was made to eliminate the drawbacks of the conventional ones as described above, and it enables automatic range by using a scanner controlled by a computer, a variable amplification rate amplifier, and a variable reference value comparator. The purpose is to provide a small, low-cost vibration monitoring device that prevents input signal overflow, diagnoses abnormalities in the detection system, and reduces the need for various setting devices for each channel.

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 2, 1 is a vibration detector, 7 is a preamplifier, 8 is a scanner, 9 is a variable amplifier, 10 is a variable reference comparator, 11 is an analog-to-digital converter, 12 is a control computer, 13 14 is a channel display, 14 is an alarm display, and 15 is a keyboard for setting the amplification rate, comparison reference value, etc. for each channel.

Next, the operation will be explained.

The vibration detector 1 is attached to a rotating machine or the like and converts the vibration into an electrical signal. A preamplifier 7 amplifies this electrical signal to a certain level and converts the impedance. The scanner 8 selects each amplifier 7 according to instructions from the calculator 12. The amplification rate of the selected signal is determined by a variable amplifier whose amplification rate is set in advance by the computer 12. The signal based on this amplification rate is converted into a digital quantity by the A/D converter 11 and becomes an input to the computer 12, and the computer 12 calculates this digital quantity together with the amplification rate, and generates a preset vibration value in the computer. The abnormality level is compared with the level in the case of a failure of the detection system, ie, the detector cable, preamplifier, etc., and if there is an abnormality, the channel is displayed and an alarm is displayed or generated. For the variable reference comparator, when the amplification rate is set at the vibration normal level, the reference value is set slightly smaller than the dynamic range of the amplifier 9 at that amplification rate, and if the vibration level exceeds this value, Since the comparator 10 generates a signal, the computer judges this signal, lowers the amplification rate, and compares again. This is repeated, and if no output is output from the comparator 10, A/D conversion is performed at that amplification rate, and a vibration level that does not overflow can be read. Conversely, if the reference value is set above the normal level, and the vibration level does not reach this value, no signal will be output from comparator 10.
When an output starts from 0, A/D conversion is performed and the level is read, resulting in data with good resolution. Based on the value at this time, it is possible to understand the details of the failure in the detection system. The keyboard is used to set the amplification rate, comparison reference value, abnormal vibration level comparison value, etc. for each channel and store them in the computer.

Further, in the above embodiment, a channel display, an alarm display, etc. are provided, but a graphic display device such as a CRT may be provided instead.

As described above, since the present invention uses a variable amplifier and a variable reference comparator that can be controlled by a computer, there is no need to provide an amplification rate setter or abnormal level comparison setter for each channel, and The detection system for each channel requires only a detector and a preamplifier, and in the case of multiple points, low cost is possible.

In addition, automatic ranging is possible through computer control, which improves measurement resolution and prevents overflow, allowing accurate reading of even large signals. Furthermore, by taking advantage of the high resolution, abnormalities in the detection system can be detected without a special detector.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional multi-point vibration intensive monitoring device, and FIG. 2 is a block diagram of a vibration intensive monitoring device according to an embodiment of the present invention. In the figure, 1 is a vibration detector, 2 is an amplifier, 3 is a comparator, 4 is a case, 5 is an abnormality alarm, 6 is a vibration meter,
7 is a preamplifier, 8 is a scanner, 9 is an amplifier with external gain control, 10 is a variable reference comparator, 11 is an analog-to-digital converter, 12 is a control computer, 13 is a channel indicator, and 14 is an alarm indicator. It is. The same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A plurality of vibration detectors provided in each of the plurality of channels, a scanner that selects a specific vibration detector from among the plurality of vibration detectors based on instructions from a computer, and a specific vibration detection device selected by the scanner. a variable amplifier that varies the amplification rate of the output signal of the amplifier in two directions, a decreasing direction or an increasing direction, based on instructions from the computer; and a variable amplifier that changes an output signal from the variable amplifier based on instructions from the computer. The computer comprises a variable reference comparator for comparing with a set variable reference value, and an A/D converter for A/D converting the output signal from the variable amplifier and outputting it to the computer, and furthermore, the computer includes: Based on the presence or absence of the output of the variable reference comparator corresponding to the direction of variation of the variable amplifier, the output signal of the A/D converter is adopted as vibration data, and the vibration data is set in the computer. A vibration monitoring device characterized by detecting an abnormality by comparing it with a vibration abnormality level or a detection system abnormality level.