JPH0522171B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a water leakage system for automatically discovering the leakage point when a water distribution pipe is damaged and water leaks from the damaged location. Regarding a detection device.

[Technical background and problems of the invention]

For example, Japanese Patent Application Laid-Open No. 56-10226
The one in Publication No. 1 is known. As shown in Fig. 3, this device detects the sound generated in the water pipe 1 with a sound detector.
The sound is collected by the sound-to-current converter 3, converted into an electrical signal, and sent to the waveform converter 5 via the transmission line 4, which combines the normal signal set by the waveform setting device 6 and the signal output from the waveform converter 5. are compared by a waveform comparator 7, and if the deviation exceeds a permissible value, a discriminator 8 issues an alarm.

With the above configuration, when a water pipe is damaged and water leaks from the damaged location, the leakage sound generated by the water gushing out from the leakage location is collected and compared with the normal sound. to determine whether there is a water leak. However, in general, there is a considerable amount of the water leakage sound and the powdery noise. For example, if there is a water supply outlet nearby that branches off from a water pipe, the sound of water coming from the water supply outlet will also be collected. Therefore, you have to wait until late at night when other noises will be less.
If it is late at night, the difference between the noise and the water leakage sound will be large, making it easier to distinguish. However, depending on the location, there are places where there is constant noise caused by traffic such as cars. This trend has been increasing in recent years, and it is becoming difficult to distinguish them even at night.

[Purpose of the invention]

An object of the present invention is to provide a reliable water leak detection device that prevents malfunctions due to noise.

[Summary of the invention]

The water leakage detection device according to the present invention has means for removing noise, as shown in FIG. In general, it is thought that noise entering from the outside, such as noise associated with traffic such as automobiles, becomes louder when it passes by, and disappears after it passes. Also,
Noises such as fluid sounds emitted from nearby discharge ports,
It is a temporary phenomenon that disappears when the release stops. In other words, it is thought that temporary changes are repeated. Therefore, by removing transient inputs from the collected sound input, it is attempted to eliminate the influence of noise.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 11 is a water pipe, and 12 is a sensor attached to the water pipe, which is made of a piezoelectric element or the like that detects sound or vibration as an electric signal. 1
3 is an amplifier that amplifies the electrical signal output from the sensor 12. 14 is a storage means, and an amplifier 13
The electrical signals output from the device are stored in chronological order. 1
Reference numeral 5 denotes data selection means for removing noise data from the data stored in the storage means 14. Reference numeral 16 denotes a comparison alarm means that compares the data during normal conditions (no water leakage) with the detected data, and outputs an alarm display if there is an abnormality (water leakage).

In the above configuration, sounds and vibrations generated in the water pipe 11 are detected by the sensor 12 and converted into electrical signals. This electrical signal is amplified by an amplifier 13 to a level of several volts. There are various types of sounds and vibrations generated in the water pipe 11 in addition to the water leakage sound to be detected. Water supply inlet (faucet) branched from the water pipe
The sound of water being emitted from water pipes, as well as noise and vibrations from cars driving near water pipes, etc., also enter the system. The waveform of the electrical signal due to sound and vibration including these is as shown in FIG. That is, mixed with the lowest level waveform, short-term, high-level waveforms enter as noise here and there. Figure 2a shows a case where there is no water leakage, but when water leakage occurs, the minimum level increases and becomes as shown in Figure 2b. The peak values of these signals are taken out and subjected to waveform conversion as shown in FIG. The stored data is extracted and the data selection means 15 removes noise data. That is, data for a certain period of time (for example, one hour) are compared, and the lowest level data is selected.
Since the lowest level data is considered to have noise removed, the lowest level will show a constant value throughout the day. If a water leak were to occur here, the lowest level throughout the day would increase,
The comparison alarm means 16 compares it with a previously set normal value, and if the difference exceeds a certain value, an alarm is output. Here, storage means 14, data selection means 1
5 and the comparison/alarm means 16 can of course be implemented using a microcomputer.

Note that the normal value, which is a reference value, is not shown, but a push button switch input is given to the comparison alarm means 16, and the data detected during normal operation is stored.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to constantly monitor the sounds or vibrations generated in water pipes, detect abnormal sounds, and discover water leaks at an early stage without malfunctions due to noise.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the water leakage detection device according to the present invention, Fig. 2 is a waveform diagram of sound or vibration detected in Fig. 1, and Fig. 3 shows an example of a conventional water leakage detection device. FIG. 11...Water pipe, 12...Sensor, 13...
Amplifier, 14...Storage means, 15...Data selection means, 16...Comparison alarm means.

Claims (1)

[Claims] 1. A sensor for detecting sound or vibration occurring in a water pipe, and means for amplifying the signal of this sensor;
means for storing the amplified signal; data selection means for removing transient signal data from the stored signal data; and signal data at the lowest level after removing the transient signal data. A water leakage detection device comprising means for comparing signal data stored in advance during normal times and determining that there is a water leak and issuing an alarm if the lowest level signal data is greater than the normal signal data by a certain value or more.