JPS61213647A - Detector for water leakage - Google Patents

Abstract

PURPOSE:To reduce a difference in the ability to detect water leak by providing a decision part which decides leakage of water from the time integral value of a water leak signal and a decision part which makes a decision from the ratio of a time integral value based upon a dark noise signal when there is no leakage of water. CONSTITUTION:A sensor 1, a waveform shaping circuit 2, a signal continuance integration circuit 3, a water leak decision circuit 5, etc., are provided. Then, oscillation caused by a water leaking sound, noise, etc., detected by the sensor 1 is converted into an electric signal, which is inputted to the circuit 2. The circuit 2 amplifies the electric signal from the sensor 1 and performs waveform shaping so that a signal significant as a water leak signal has a high level and an insignificant signal has a low level. The circuit 3 integrates the time when the input signal has the high level and outputs a time integral value T. Further, the circuit 5 stores the time integral value when there is no water leakage and outputs a decision signal indicating a leakage of water only when the ratio of the integral value T to the time integral value or the integral value T is larger than a set decision reference value.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides a water leakage detection bag wL for detecting water leakage from water pipes.
Regarding 4th.

[Technical background of the invention and its problems]

The amount of water leaking from the water distribution pipes and water supply pipes on the way from the water treatment plant or water distribution reservoir to the v141 homes is currently 10all of the total amount of water distributed, and the loss due to this is calculated as follows: :If converted, if the water cost per 1-IrLa is 100 yen, it will amount to about 2,0001 yen per year.
＝Requires a large amount of funds. Therefore, it is urgent to know the occurrence of water leakage as soon as possible and to control the amount of water leakage.
Most leaks occur underground and are difficult to detect from above ground.

Traditionally, conventional underground water leakage detection methods have been provided (
There is a method using sound rod C; This can be done by applying a sound rod to the ground where the V-way is buried, or directly contacting the buried pipe (= this) through a bored hole, or by directly contacting the buried pipe (= this) with the part exposed above the ground such as a fire hydrant or water meter. This is a method of determining the presence or absence of water leaks by bringing the sound rod into contact with the sound rod, mechanically or mechanically amplifying the sound, and having the investigator listen to it through headphones. but,
This method requires skilled techniques to distinguish between water leak sounds and other noises, and requires a huge amount of labor and time as surveyors with this technique patrol the entire city area. There are problems such as slow progress in discovery.

For this reason, a correlated water leak detection device, which has recently been put into trial use, has been developed with the aim of automating water leak detection. This is 2
The water leak location is determined by cross-correlating the signals from the vibrating sensors installed at the fire extinguisher at the 1 tl location. However, this 1: has the following drawbacks.

First, the data on the branching of the electric circuit, pipe material, and pipe length in the survey section must be known accurately.
2. If there is a branch of the pipe between two senna locations, the branch f
Thirdly, there is a need to investigate separately.
Although it does not require any specialized skills, it requires patrolling the city for inspections, which limits the ability of samurai to detect water leaks early.

Currently, approximately 90 of the water leaks occur in the water supply pipes leading to customers, including branch points from the distribution pipes, so it is necessary to permanently install a water leak detection device at each customer's water supply. Therefore, water leakage around the customer can be detected early.

A water leakage detection device such as this has been developed through research conducted by the inventors. In other words, once a water leak occurs, unless it is repaired, it will continue to occur and will never recover naturally.

On the other hand, it is clear that water consumption from tap water, which is a line sound source, generates noise only when water is used, and it is extremely rare for other external noise sources to occur continuously. This difference in basic phenomena is used to distinguish between water leaks and signals caused by causes other than water leaks.

As this type of device, for example, Japanese Patent Application Laid-Open No. 59-1951
Publication No. 39 is known. This device uses water leakage sounds and noises detected by the senna, or vibrations and noises caused by water leakage (=vibrations caused by water leakage) to be converted into electrical signals and input to the waveform shaping circuit.The waveform shaping circuit amplifies the electrical signals from the senna. , filtering by frequency a, and wave height 11
Discrimination based on [1-] is performed, and a signal significant as a water leakage signal is waveformed to a high level (; and an insignificant signal is waveformed to a low level.

The signal duration integration circuit integrates the time during which the input signal is at a high level and outputs a time-integrated signal. The water leak determination circuit is a circuit that outputs a water leak measurement determination signal only when the time integrated by the signal duration integration circuit exceeds a preset determination criterion.

However, the noise signal level depends on the location! = Since the difference is large, individual differences occur in the time-integrated signal when there is no water leakage. In other words, it is necessary to set a high judgment standard for a water leak detection device installed in a place where the noise signal level is high, and a low judgment standard for a device installed in a place where the noise signal level is low. For a constant 11i[,
Water leakage signal level that can be detected by reaching a location (= making a difference).

[Purpose of the invention]

The present invention was made in view of these problems.
It is an object of the present invention to provide a water leakage detection device that can reduce differences in water leakage detection ability depending on location.

[Summary of the invention]

The present invention includes a first determining section that makes a determination based on the magnitude of a time integral value, and a second determining section that makes a determination based on the -magnitude of the ratio or difference between the background noise signal in a state where there is no water leakage (= the time integral value). Therefore, it is possible to always detect water leaks of a constant size, regardless of the level of background noise at the installation location.

That is, the present invention includes a sensor that detects sound pressure fluctuations and vibrations of pipe walls caused by water pipes and associated equipment, and a sensor that inputs the output of this sensor and shapes it into a predetermined peak value signal. A signal duration integration circuit that integrates the signal duration of the output of the waveform shaping circuit for a predetermined period of time, and compares the magnitude of the integrated value with a set judgment reference value to detect noise and water leakage. This is a water leak detection device consisting of a water leak determination circuit that distinguishes between sounds.

[Embodiments of the invention]

Next, examples of the present invention will be described. Figure 1P11 and Figure 6 show a water leakage detection device consisting of the following components.

(b) A sensor that detects sound pressure fluctuations or pipe wall vibrations caused by water leakage from water pipes or equipment attached to the water pipes and converts them into electrical signals. Predetermined peak value signal 25a
an amplification circuit 6 that amplifies the peak value signal 25a;
A band-pass filter passes the earth component of the filter. Then, the negative signal of the intercurrent 4-air signal 26a that has passed through the band-pass filter is converted into a positive signal (=absolute 1-direction amplification circuit w!r2
7, and a comparison circuit W 8 which compares the converted signals outputted from the absolute value amplification circuit n with a predetermined 9 judgment reference pressure Er and outputs only the converted signal ' which is equal to or higher than the judgment reference pressure Er. A waveform shaping circuit 2 consisting of (c) a circuit 41 that digitizes the duration of the output of the waveform shaping circuit 2, a kakunta 43 that counts the digitized output panosis sequence for a predetermined period of nine hours, and a preset time. Integration start signal INI, integration end (F1
Signal IB continuation time integration circuit (→ time integration 11T measured by signal continuation time integration circuit 3 and preset A step 52 of comparing and determining the result with the nine constant 01 and outputting a judgment signal DI, a step 57 of adding the number of measurements Nb (;1) indicating that there is a water leak, and adding the time integral value T to the cumulative time integral memory B of the presence of a water leak. Step edict and cumulative time integral memory B are measured N
The water leakage determination circuit 5 comprises a step 59 of updating the time integral value llIb in the state of water leakage by dividing by b. Water leak sound and noise detected in 1.

Or the vibration and noise caused by water leakage; the vibration caused by it is a signal 4; it is converted into a waveform! It is input to type 1 circuit 2.

In waveform round $2, the signal from sensor 1 is amplified, filtered by frequency a4, and discriminated by wave height 1. For example, a significant signal as a water leakage signal is set to a high level (=, an insignificant signal is The low Be/E/C waveform is square-shaped.The signal duration integral 43 integrates the time when the input signal is at a high level and outputs the time integral value T.Usually, a built-in clock circuit Time period when noise is low (measured 2181 times. Improved water leak detection image I!5
Store the time integral value T when there is no water leakage,
This is a circuit that outputs a water leak determination signal only when the ratio of the time integral value T to the time integral value T, or the time integral value T is larger than a respective set determination reference value.

The following (=Details about these configurations≦2 series.St.
Reference numeral 1 denotes a converter that converts an acoustic signal or vibration, speed, acceleration, etc. into an electrical signal.

FIG. 2 is a configuration diagram of an embodiment of the waveform shaping circuit 2. In FIG. The amplifier circuit δ amplifies the signal from the sensor 1, for example, the low frequency! The generated signal is passed through a band-pass filter 26 having M frequencies of kHz and a high cutoff frequency of 10 k.

This alternating current signal is converted into an absolute value amplification circuit 971i; therefore, a negative signal is converted into a positive signal and inputted to the comparison circuit 28. The comparator circuit converts only input signals that are equal to or greater than the judgment criterion-ratio+Er into a constant pressure signal and outputs the signal.

Figures II & 3 are the signal duration integration circuit 3 in Figures 1/&1.
This shows an example of this. The frequency of the pulse oscillation circuit Kiku is several times higher than the high-frequency cutoff frequency of the waveform shaping circuit 2 (= the included filter) to ensure resolution. Timing circuits 11 & 4 contain timers δ and are set. 9 time C: Integration starts Signal INI, integration end signal INO.

Judgment execution signal DIO, reset signal R8 of counter 43
It has the function of generating a series of command signals such as. These signals are normally generated on a daily basis, and are set, for example, so that the integration start signal INI is output at midnight and the integration end signal INO is output at 4 a.m.

The storage circuit 6 stores integration start signal INI to integration end signal IN.
The state of logic 11'' is maintained until O, and the AND gate 41 (=therefore, logical product with the pulse], AND7-)
42 pulses are supplied. The AND gate 42 digitizes the output signal duration of the waveform shaping circuit 2 by performing the logical product of the output pulse of the AND gate 41 and the output signal of the waveform shaping circuit 2. The counter 43 counts the output pulse train of the AND gate 42 (=Therefore, it performs time integration of the waveform shaping circuit output signal from the generation of the integration start signal INI until the generation of the integration end signal INO.

FIG. 4 is a chart showing the operation 70 of the water leakage determination circuit 5.

Upon receiving the determination execution signal DIO from the signal duration integration circuit 3, it is determined whether there is a water leak or not in accordance with the following procedure.

In step 51, if the time integral value T measured this time is larger than the preset constant 01, it is determined that there is a water leak, and a determination signal DI is output.

In step 52, if the number of measurements without water leakage is aN, = 00 (CN at the start of use, WO-, so at the first measurement time, the value of the time integral value T when there is no water leakage is Since it is unknown, step 53 is skipped.

In the step group, time integral [T,
+If the ratio of the currently measured time integral value T to one is larger than the preset constant C2 (T/T, >02)
Then, it is determined that there is water leakage 9, and a determination signal D2 is output.

In step 54, the number of measurements without water leakage (N-21) is added.

In step 55, the nine-hour integral value Tt4 measured this time is
Add to cumulative time integral memo IJA without water.

In step 56, the cumulative time integral memory A obtained in step 2 is divided by the number of measurements N, to update the time integral 11T in a state where there is no water leakage.

In step 5742, 1 is added to the number of measurements Nb indicating water leakage.

In step 5B, the time integral value T measured this time is added to the cumulative time integral memo IjB (==of leakage).

Step 59C: The cumulative time integral memo yB obtained in step 5 is divided by the number of measurements Nb to update the time integral tTb in the state where there is water leakage.

The above judgment signal D1 indicates that the water leakage failure is gradually (=growing) and the time integral signal is gradually increasing.C means that the time integral value is T.

Since the value gradually increases, there is a risk that the determination in step 53 will miss the value (= must be approved).

The circuit that fulfills the above functions is a microcomputer and ROM.
g = Therefore, it can be easily realized.

In addition, instead of the determination criterion T/T, >C2 in step 53, the determination criterion 62T-T, >C2 may be used.

The number of measurements N- and Nb are reset by an external reset signal R8T after this device is installed. Improved water leakage determination circuit 5
By using a microcomputer, the timing circuit 44 stores the number of times the determination signals Di, D2 are issued; the timing circuit 44 stores the date read from the built-in timer in association with the determination signals DI, D2. In addition, it is easy to memorize the installation date of this device, and to continue to store these stored contents. The output terminal P is used to output the successively outputted contents to a display device or to the voice communication gland through a transmission circuit.

5a is an example of the output signal waveform of the bandpass filter,
b is an example of the output signal waveform of the absolute value amplification circuit, and C is the output signal waveform of the comparator circuit that becomes high level when the signal is larger than the determination reference voltage +Er, and is the output signal of the waveform shaping circuit 2.

d is the output pulse train of the AND gate 42, and the output signal period of the waveform shaping circuit 2 is proportional to the number of pulses. ・ is the integration start signal INI, and f is the integration end signal lN01g is the output signal of the memory circuit 45. Integration period signal indicating the state of compression@bi, h is the judgment execution signal DIO and the integration end signal I
It is issued after NO and is used to operate the water leakage determination circuit 5. The reset signal R8 is further outputted by ζ≦2, and the counter 43 is initialized.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to always detect water leaks of a constant size, regardless of the magnitude of background noise or lit vibration at the location where the water leak detection device is installed. Also,
It is also possible to detect water leakage that gradually increases as corrosion and cracks grow.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a water leakage detection device according to an embodiment of the present invention, Fig. 2 is a block diagram of a waveform shaping circuit, Fig. 3 is a block diagram of a signal time integration circuit, and Fig. 4 is a water leakage determination circuit. FIG. 5 is a flow explanatory diagram showing the operation of the present invention, and FIG. 5 is a waveform explanatory diagram of the configuration 6s showing the operation of the present invention. 1...Sensor 2...Waveform shaping circuit 3...
・Signal duration integration circuit 5...Water leakage determination circuit agent Patent attorney Nori Chika m 6 (and 1 other person) No.
1 Figure 2 Figure 3 Figure 4 Timetable Figure 5

Claims (1)

[Claims] A water leakage detection device comprising the following components. (b) A detector that detects sound pressure fluctuations or pipe wall vibrations caused by water leakage from water pipes or equipment attached to water pipes and converts them into electrical signals. (b) The electrical signals of this detector are converted into electrical signals. an amplification circuit that amplifies the peak value signal, a bandpass filter that passes the main component of the amplified peak value signal, and a negative signal of the AC electrical signal that has passed through this bandpass filter that converts into a positive signal. and a comparison circuit that compares the converted signals output from the absolute value amplified circuit with a predetermined judgment reference voltage and outputs only converted signals that are equal to or higher than this judgment reference voltage. Circuit (c) A circuit that digitizes the signal duration of the output of this waveform shaping circuit, a counting circuit that counts this digitized output pulse train for a predetermined time, and an integration start signal and an integration circuit at a predetermined time. a signal duration integration circuit comprising a timing circuit that outputs an end signal, a determination execution signal, and a return signal for the counting circuit; (d) a time integral value measured by this signal duration integration circuit and a preset constant; a determination circuit that compares and determines and outputs a determination signal; a first addition circuit that adds 1 to the number of times water leakage has been measured; and a second addition circuit that adds the time integral value to a water leakage cumulative time integral memory. and an update circuit that divides this cumulative time integral memory by the number of measurements to update the time integral value in a state where there is a water leak.