JP4390625B2 - Water leakage monitoring device - Google Patents

Description

The present invention relates to a water leakage monitoring equipment attached to the water pipes or water meter.

Conventionally, various types of water leakage monitoring devices that detect water leakage by detecting vibration transmitted to a water pipe due to water leakage have been proposed (Patent Documents 1 and 2).
Such a conventional water leakage monitoring device is a type that determines “with water leakage” or “without water leakage” based on vibration or sound pressure transmitted to the water pipe detected by the vibration sensor, and displays only the result. The leak criteria were already determined by the equipment.
JP-A-9-196798 JP 2000-352542 A

The proposed water leakage monitoring device can easily determine whether there is water leakage and can be used permanently. However, the criteria for determining whether there is water leakage is determined in advance, and the measured value is used to determine whether there is a water leakage. If it is above the standard, it is determined that there is a water leak regardless of the strength of the vibration. Therefore, there is a problem that a plurality of water leakage monitoring devices in the vicinity of the leaked location detect the presence of water leak and cannot easily identify the water leak location.
In addition, in order to finally identify the water leakage point, it is necessary to conduct a sound survey by an expert based on the measurement results of each device to find the water leakage point.

With reference to FIG. 7, the water leak location detection method at the time of using the conventional water leak monitoring apparatus is demonstrated.
In this figure, 31 is a water distribution pipe, 32 is a water supply pipe branched from the water distribution pipe 31, 33 is a water meter connected to the water supply pipe 32 via a stopcock (not shown), and 34 is a vibration of the water supply pipe 32. It is a water leakage monitoring device installed corresponding to each water meter 33 so that it can be seen. As shown in the figure, there are eight water meters 33 indicated by A to H in the target area, and a water leakage monitoring device 34 is attached to each of them.
Here, water leakage has occurred at the points indicated by crosses in the figure. Among the water leakage monitoring devices 34, the water leakage monitoring device 34 attached to the A, B, C, E, F and G water meters. It is assumed that a “with water leak” reaction is displayed (black circle in the figure), and a “no water leak” reaction is displayed with D and H (white circle in the figure).
At this time, there were 6 places where “leakage occurred”, and since all of these 6 places were “leakage”, it was difficult to estimate the leak point, and A, B, C , E, F and G had to be heard in a range 35 including all the points, and the leak point had to be found.

The present invention aims to provide a water leakage monitoring equipment which is able to identify efficient leakage points.

In order to achieve the above object, a water leakage monitoring apparatus of the present invention is a water leakage monitoring apparatus that can be attached to a water pipe or a water meter, and includes a vibration sensor that converts vibrations of the water pipe into an electrical signal, and the vibration sensor. a filter for passing the frequency band of the signal of the leak noise of the signal output, a rectifier circuit for rectifying the signal outputted from the filter, a / D converting the output signal from the rectifying circuit into digital data The level of the converter, the lowest measurement value output from the A / D converter during the measurement time, the reference value for determining the presence or absence of water leakage, and the state of water leakage are divided into a plurality of stages. by comparing the leakage detection level reference value defining the size of vibration level as a threshold, vibration determines the measured value belongs to which level of the leakage detection level of the plurality of stages And level processing means, the magnitude of the vibration level as a threshold for Placement the state of the reference value and the leakage there for determining the presence or absence of the leakage in a plurality of stages, are respectively shifted by a predetermined amount Storage means for storing a plurality of types of leakage detection level reference values that are set as values, and the vibration level processing means is selected from the plurality of types of leakage detection level reference values stored in the storage means. The water leak detection level corresponding to the measured value is determined using the selected water leak detection level reference value .

Moreover, the lowest measured value is one that is the lowest value among moving average values of the measured measurement values during the measurement time.
In addition, the leakage detection level reference value with the reference value determining whether a nearest leakage to a value obtained by multiplying a predetermined constant to the lowest value among moving average values for a predetermined period measured measurement value, the leakage detection It is designed to be used for level determination.

The water pipe connected to the water meter is almost always a short distance from the water pipe to the household water meter. The water meter closest to the leaking water pipe (the leaking water pipe) In a directly connected water meter, an output value of a water leakage sound is generated that is greater than the vibration sensor of a water leakage monitoring device attached to another nearby water meter.
Therefore, according to the water leakage monitoring equipment of the present invention, since the measurement value of the leak noise can be Placement by the size of the vibration level, even when leakage of a plurality of water leakage monitoring device is detected, the vibration level By comparing these, it is possible to specify the range in which the hearing survey is to be performed in a narrower range, and it is possible to efficiently and easily specify the location of water leakage.
In addition, by providing multiple leak detection level reference values for determining the leak detection level and using the leak detection level reference value selected according to the location of the leak monitoring device, etc. Even so, it is possible to accurately detect water leakage.

FIG. 1 is a block diagram showing a circuit configuration of an embodiment of a water leakage monitoring apparatus of the present invention. This water leakage monitoring device is attached to a water meter or a water supply pipe (water pipe).
In this figure, reference numeral 1 denotes a vibration sensor that converts vibration of a water meter or a water supply pipe into an electric signal. Reference numeral 2 denotes an amplification circuit that amplifies the output signal of the vibration sensor 1, and 3 denotes a frequency filter (band) that passes a signal in the frequency band (about 100 Hz to 2000 Hz) of the leaking sound among the signals output from the amplification circuit 2. (Pass filter) 4 is a rectifier circuit for rectifying a signal output from the frequency filter 3, and an analog circuit unit 5 is constituted by the amplifier circuit 2, the frequency filter 3 and the rectifier circuit 4. The frequency filter 3 is not limited to a band-pass filter, and may be a low-pass filter that removes a noise signal having a frequency higher than the frequency band of water leakage sound.

  6 is an analog / digital converter (A / D converter) that converts the output signal from the rectifier circuit 4 into digital data, and 7 is the lowest measured value output from the A / D converter 6 during the measurement time. (Minimum value) is compared with the data of the water leak detection level reference value stored in the storage circuit 8 to be described later, and the vibration of the water pipe measured by the vibration sensor 1 indicates which of the plurality of water leak detection levels. A vibration level processing means 8 for determining whether the sound belongs to a level, 8 stores a plurality of water leak detection level reference values, and a memory such as a flash memory for storing a result of water leak detection level determination by the vibration level processing means 7 Circuit. These A / D converter 6, vibration level processing means 7 and storage circuit 8 constitute a digital circuit section 9. The digital circuit unit 9 can be configured by a one-chip microcomputer, for example. In this case, the vibration level processing means 7 is realized by a program executed by the one-chip microcomputer.

Reference numeral 10 denotes a clock circuit for performing time management such as a measurement time and a measurement cycle of water leakage sound vibration, and is always supplied with power, and supplies power to the analog circuit unit 5 and the digital circuit unit 9 for a predetermined period at a predetermined cycle. Supply voltage. For example, a time period with the least noise in a day (for example, every day between 2 am and 5 am) is set as a measurement time, and a predetermined cycle (for example, every 2 minutes for 2 seconds every measurement cycle) Then, a power supply voltage is supplied to the digital circuit unit 9 and the analog circuit unit 5 to measure the leakage sound vibration.
An operation unit 11 is connected to the digital circuit unit 9 and includes a switch, a reed switch, an optical sensor, and the like. Reference numeral 12 denotes a display unit such as a liquid crystal display element or LED connected to the digital circuit unit 9.
The user inputs a command to the digital circuit unit 9 using the operation unit 11 to display the determination result of the water leakage detection level stored in the storage circuit 8 on the display unit 12, Processing such as selection of a water leakage detection level reference value used for water leakage detection level determination in the vibration level processing means 7 can be performed from a plurality of water leakage detection level reference values stored in the storage circuit 8.

The water leakage detection level reference value will be described with reference to FIG. As described above, the storage circuit 8 stores a plurality of water leakage detection level reference values. In this figure, two types of water leakage detection level reference values of group 1 and group 2 are shown.
The leakage detection level reference value includes a vibration level that serves as a reference value for determining the presence / absence of water leakage, and a vibration level that serves as a threshold for dividing the state of water leakage into a plurality of levels. It is included.
As shown in the figure, the water leak detection level reference value of group 1 is (1) 1 × 10 ⁽⁻⁴⁾ (1E-04) [m / s ² ], which is a reference value for determining the presence / absence of the water leak. (2) 5 × 10 ⁽⁻⁴⁾ (5E-04) [m / s ² ], (3) 1 × 10 ⁽⁻³⁾ (1E-03) [m / s ² ], ( 4) 5 × 10 ⁽⁻³⁾ (5E-03) [m / s ² ] and (5) 1 × 10 ⁽⁻²⁾ (1E-02) [m / s ² ] have four threshold values. It is defined to classify a given state into five levels. Therefore, when the minimum value of the output of the A / D converter 6 during the measurement time is less than the value corresponding to (1) 1 × 10 ⁽⁻⁴⁾ (1E-04) [m / s ² ], “None” is determined, and when the value corresponds to (1) or more and less than (2), “Level 1”, and when the value corresponds to (2) or more and less than (3), “Level 2” or (3) or more When the value corresponds to less than (4), it is determined as “level 3”, when the value corresponds to (4) or more and less than (5), it is determined as “level 4”, and when it is equal to or more than (5), it is determined as “level 5”. The

In group 2, each threshold value in group 1 is shifted to the higher vibration level by “a1”, that is, a value obtained by adding + a1 to each threshold value in group 1 is set in each group 2. It is a threshold value.
Although only the group 1 and the group 2 are shown in this figure, more groups of water leakage detection level reference values having different shift amounts are defined and stored in the storage circuit 8.
Here, when a plurality of leak detection level reference values are stored in the storage circuit 8, the leak detection level reference values of the group 1 are stored as reference data used in various parts of the country, and data of other groups is stored. As such, only the shift amount with respect to the water leakage detection level reference value of the group 1 may be stored.
In the example shown in the figure, four threshold values for each level are set and divided into five levels. However, the number may be more or less than this. Further, although the interval between the thresholds is set at an equal interval, it may be set at a different interval.
As will be described later, an accurate leak detection result can be obtained by selecting and using a leak detection level reference value suitable for the place where the leak monitoring apparatus is installed.

  In the water leakage monitoring apparatus of the present invention configured as described above, when the measurement time set by the clock circuit 10 is reached, the operation of the analog circuit unit 5 and the digital circuit unit 9 is started, and the water leakage transmitted through the water pipe Sound vibration is converted into an electrical signal by the vibration sensor 1. The leakage sound vibration converted by the vibration sensor 1 is very weak and is amplified by the amplifier circuit 2. Next, since the frequency band of the leaking sound is about 100 Hz to 2000 Hz, the frequency filter 3 removes unnecessary frequency components, and the signal waveform obtained by alternating current is rectified by the rectifier circuit 4 to facilitate level analysis. And a DC voltage level signal. The water leakage sound vibration converted into a DC voltage level signal by the rectifier circuit 4 is converted into a digital numerical value by the A / D converter 6.

The vibration level processing means 7 detects the lowest measured value (minimum value) among the measured values output from the A / D converter 6 during the measurement time, and detects water leakage stored in the storage circuit 8. Compared with the level reference value, level processing is performed to determine to which level of the plurality of stages of water leakage detection levels the measured value belongs. For example, during the measurement time from 2:00 am to 5:00 am, the minimum value of the measurement value output from the A / D converter 6 every measurement cycle is obtained, and the minimum value of the measurement value is stored in the storage circuit 8. The leakage detection level is determined by comparing with a selected leakage detection level reference value among the plurality of stored leakage detection level reference values.
At this time, a moving average of the output of the A / D converter 6 for a predetermined period may be obtained, and the minimum value of the moving average may be compared with the leakage detection level reference value.
In this way, the level determination result by the vibration level processing means 7 is stored in the storage unit such as the storage circuit 8.
In the above description, the measurement is performed at a predetermined period during the measurement time (2 am to 5 am). However, the measurement may be performed continuously during the measurement time.

When a result display is requested by an input signal of the operation unit 11 by a user operation or the like, the digital circuit unit 9 reads the determination result from the storage circuit 8 and displays it on the display unit 12.
The display unit 12 is composed of a liquid crystal display element or LED, and displays and outputs the level of the measurement result stored in the storage circuit 8 by numerical display, bar graph display, LED blinking display, or the like.
FIG. 3 is a diagram illustrating an example of a display method of the water leakage detection level on the display unit 12. In this figure, 12a shows an example of a display unit that displays a numerical value representing a water leak detection level using a 7-segment display, 12b shows an example of a display unit that displays the water leak detection level by a bar graph display, and 12c shows an indicator light. The example of the display part which displays a water leak detection level using is shown. Here, in 12c, a green LED and a red LED are used, “no water leakage” is indicated by lighting of the green LED, and a water leakage detection level is displayed by the number of lighting times of the red LED. For example, when level 3 is displayed, the numerical value “3” is displayed in 12a, three elements are lit in 12b, and the red LED is blinked three times in 12c.

Next, selection of the water leak detection level reference value stored in the storage circuit 8 will be described.
FIG. 4 is a diagram showing a graph of the vibration level measured during the measurement time by the water leakage monitoring device. Here, (a) shows a case where there is no continuous noise source in the vicinity, and (b) shows a case where there is a continuous noise source in the vicinity.
In the figure, the measurement level within the measurement time changes in magnitude, but this is due to the influence of disturbances other than leakage noise vibration, such as the running sound of automobiles and the sound of water passing through the use of water. By processing the vibration level that is less affected by the disturbance, that is, the minimum value of the measurement level measured during the measurement time, as the water leakage sound vibration level, it is possible to capture the water leakage sound vibration with less disturbance noise.

Even if the water leakage monitoring device is a pipe without water leakage, the vibration level varies depending on the installation location. For example, transformer sounds emitted from pole transformers, operation sounds of vending machines, sewage sounds, etc., are continuously transmitted to the pipes even at midnight, and are detected by the water leakage monitoring device even in the absence of water leakage. The level will be different.
FIG. 4A shows an example of a measurement result in a water leakage monitoring apparatus installed in a place with little noise. In this case, level processing is performed using the water leak detection level reference value of group 1, and since the minimum value of the measured value is smaller than the reference value 1E-04, it is determined that there is no water leak.
(B) of FIG. 4 has shown the measurement result in the water leak monitoring apparatus installed in the place with much noise. Compared with the measured value in FIG. 4A, the level of the measured value is generally increased due to continuous noise. If this is determined using the same water leak detection level reference value of group 1 as in FIG. 4A, it will be determined as “level 1” even if there is no water leak.
Therefore, for the water leakage monitoring apparatus installed in the vicinity of a noise source such as a columnar transformer or a vending machine, the water leakage detection level reference value of group 2 is used as shown in FIG. Thereby, as shown in the figure, it is possible to prevent erroneous determination due to the influence of noise or the like.

For example, by measuring vibrations of water pipes without water leakage in advance, taking the moving average of the measured values, taking the lowest measured value as the reference value for “no water leakage” and multiplying that reference value by a predetermined constant The group having the judgment reference value closest to the presence / absence of water leakage is determined as the water leakage detection level reference value used in the water leakage monitoring apparatus.
Alternatively, once the "leakage" determination was made by the water leakage monitoring device, but as a result of the hearing survey, it was found that it was caused by noise due to a columnar transformer or the like, by an operation from the operation unit 11, etc. You may make it change the group of the water leak detection level used for level determination.

Such water leakage points detected how using the water leakage monitoring device of the present invention will be described. Figure 5 is a diagram for explaining a water leakage location detection method described above, FIG. 6 is a diagram showing an example of a measurement result in water leakage monitoring device for each measurement point shown in FIG.
In FIG. 5, 21 is a water distribution pipe, 22 is a water supply pipe, 23 (A to H) is a water meter, 24 is each water meter 23 or the water leakage monitoring device of the present invention attached to the water pipe. As in the case of FIG. 7, there are eight water meters 23 indicated by A to H in this target area, and the water leakage monitoring device 24 responds to vibrations of the water meter or the water pipe corresponding to each. It is installed to catch.
FIG. 6 is an example of actual measurement data and level determination at each measurement location (A to H water meters) illustrated in FIG. However, in order to avoid complication, illustration of E, G, and H is omitted.

Here, it is assumed that water leaks at the crosses in FIG. In this case, it is assumed that, for example, a measurement result as shown in FIG. That is, “level 2” for the water leakage monitoring device attached to the water meter “A”, “level 5” for the water leakage monitoring device B, “level 1” for C, “no water leakage” for D, “level 1” for E It is assumed that the determination result is “level 3” for F, “level 2” for G, and “no water leakage” for H.
In this case, since the water leakage monitoring device attached to the water meter of B shows the highest water leakage detection level, the acoustic survey for identifying the water leakage point is performed on the water pipe connected to the water meter of B. What is necessary is to perform only in the vicinity range 25.
On the other hand, in the case of FIG. 7 described above, the “leakage” reaction is displayed on the leakage monitoring devices A, B, C, E, F, and G, and the “no leakage” reaction is displayed on D and H. Therefore, it was necessary to conduct a sound survey in a wide range 35 including all points A, B, C, E, F, and G to find a water leak point.
As described above, according to the present invention, the intensity of the leaked sound vibration is displayed at each of the points A, B, C, E, F, and G “with water leak”, so that the point B is one. It can be easily estimated that it is close to the water leakage point. As a result, it is possible to find a water leak point by conducting a sound survey conducted at six locations in the past, and to improve the efficiency of the work of investigating the water leak point.

It is a block diagram which shows the circuit structure of one Embodiment of the water leak monitoring apparatus of this invention. It is a figure for demonstrating a water leak detection level reference value. It is a figure which shows the example of the display method of the water leak detection level in a display part. It is a figure which shows an example of the measurement result of a vibration level, (a) is the case where there is no continuous noise generation source in the vicinity, (b) is the vibration level when there is a continuous noise generation source in the vicinity. It is a figure which shows an example of a measurement result. It is a diagram for explaining a water leakage location detection method using the water leakage monitoring device of the present invention. It is a figure which shows the example of the measurement result of the vibration level in each measurement location. It is a figure for demonstrating the water leak location identification method at the time of using the conventional water leak monitoring apparatus.

Explanation of symbols

  1: vibration sensor, 2: amplification circuit, 3: frequency filter, 4: rectification circuit, 5: analog circuit section, 6: A / D converter, 7: vibration level processing means, 8: storage circuit, 9: digital circuit 10, 10: Clock circuit, 11: Operation unit, 12, 12a, 12b, 12c: Display unit, 21: Water distribution pipe, 22: Water supply pipe, 23: Water meter, 24: Water leakage monitoring device, 25: Audition survey range

Claims (3)

A water leakage monitoring device that can be attached to a water pipe or a water meter,
A vibration sensor that converts vibrations in water pipes into electrical signals;
A filter that passes a signal in a frequency band of water leakage sound among signals output from the vibration sensor ;
A rectifier circuit for rectifying a signal output from the filter;
An A / D converter for converting an output signal from the rectifier circuit into digital data ;
The lowest measured value output from the A / D converter during the measurement time, the reference value for determining the presence or absence of water leakage, and the threshold value for dividing the state with water leakage into a plurality of stages. A vibration level processing means for comparing with a water leakage detection level reference value that defines the magnitude of the vibration level, and determining which of the plurality of stages of water leakage detection levels the measurement value belongs to ;
The reference value for determining the presence or absence of water leakage and the magnitude of the vibration level serving as a threshold value for dividing the state of water leakage into a plurality of stages are values each shifted by a predetermined amount. Storage means for storing a plurality of types of the water leakage detection level reference value,
The vibration level processing means determines a leakage detection level corresponding to the measurement value using a leakage detection level reference value selected from a plurality of types of leakage detection level reference values stored in the storage means. A water leakage monitoring device characterized by that. The lowest measured value, leakage monitoring device according to claim 1, characterized in that the lowest value of the moving average of the measured measurement values during the measurement time. Determination of the leakage detection level is a leakage detection level reference value having a reference value for determining the presence or absence of leakage closest to a value obtained by multiplying the lowest value among the moving average values of the measured values measured for a predetermined period by a predetermined constant. The water leakage monitoring device according to claim 1 or 2 , wherein the water leakage monitoring device is used for the water leakage.

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