JPH08270022A - Non-contact detector for relative deviation and pipe leak detector using the device - Google Patents

Abstract

PURPOSE: To realize an accurate and simple and inexpensive non-contact detector for a relative deviation generated between two substances without use of exter nal electric sources. CONSTITUTION: A non-contact detector is composed of an ID tag 21 provided with a resonance circuit 31 and stuck on a first substance 11, a conductive piece 22 positioned to contact with the surface of the ID tag 21 and arranged so as to cover the central part of the resonance circuit 31 and also fixed to a second substance 12, and an echo sensor 24 transmitting electromagnetic waves 2 and receiving the echo waves 3 reflected by the ID tag 21 when the waves are reflected. When the echo waves 3 are received, it is detected that a relative deviation has arisen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relative displacement non-contact detection device for detecting a relative displacement generated between two objects in a non-contact manner, and a pipe leak detection device using the same. There is a widespread demand in the general industry for detecting whether or not two objects are in contact with each other and a relative shift is generated between them.

In this case, when these two objects are in direct sight or in direct contact, no special measures are required to detect the relative displacement that occurs between these objects. . However, these 2
When two objects are not in the above environment, that is, when these objects are in the soil (underground) or between the concrete structure groups, the target relative displacement described above is used. Special measures are needed to detect. Of course, in this case, non-contact detection is premised, but it is convenient if the non-contact deviation detection can be realized at extremely low cost.

The present invention describes a relative displacement non-contact detecting device as described above and a pipe leak detecting device using the same. In order to make the explanation easier to understand,
The pipe leak detection device will be described first.

[0004]

2. Description of the Related Art FIG. 12 is a diagram schematically showing an example of a conventional pipe leakage detection technique. This figure schematically shows a conventional general technique for detecting whether or not there is a leak in a water supply pipe. Reference number 1 in the figure is
Represents sub-pipes of water pipes, branch lines, and other pipes buried in the underground E (earth), in which fluid (in this case, water)
Is transported.

Piping leakage is a very serious concern for the water supply business, and the supervisor S (supervisor)
Is regularly monitored by. This also applies to gas pipes in gas utilities that distribute city gas as a fluid. The most common method of this monitoring is that if there is a pipe leak at L (leak) in the figure, a leak sound will be generated from this, so the ground guard S will have a special sound tube P (pick-up). Is to collect the sound using.

[0006]

According to the above-mentioned conventional pipe leakage detection technique, a highly skilled monitor member carefully detects the leakage noise at night when the noise is low, and therefore 1 There is a problem that it is not always satisfactory from the viewpoints of) highly accurate detection of fluid leakage, 2) detection that can be realized at low cost, and 3) detection by simple operation.

In order to solve this problem, the present invention provides a relative displacement non-contact detecting device which will be described in detail later, but no relative displacement non-contact detecting device has been put to practical use in the market. However, in the case of the contact type, it is technically not difficult to realize such a relative displacement detecting device. In other words, if there are two objects embedded in the soil E or between concrete structures and it is necessary to detect the relative displacement between these objects, if it is realized by contact type, a pair of objects will be used. It suffices to fix the electrical detection device (1) in advance. And the detection output from this electrical detection device is a long conductor (lead)
It is pulled out on the ground or on the outer surface of the concrete surface for monitoring. The electrical detection device in this case is, for example, configured as electrodes fixed to both the above-mentioned objects and C (capacitance) coupled between these electrodes to allow high-frequency current to flow. If a shift occurs between the objects, the C-coupling is extremely lowered, so that the high frequency current becomes zero.
Therefore, this zero is detected to detect the deviation.

In the above case, the relative deviation detecting device requires a power source from the outside and is expensive. Therefore, an object of the present invention is to provide a relative deviation non-contact detecting device which can be realized at a low cost with an extremely simple structure without supplying power from the outside, and a pipe leak detecting device using the same.

[0009]

FIG. 1 is a diagram showing the principle configuration of the present invention. In this figure, 11 is a first object, 1
2 is a second object, 21 is an ID (identifier)
ion: identification tag, 22 a conductive piece, 31 a resonance circuit,
Reference numeral 24 is an echo sensor, and 2 and 3 are electromagnetic waves and echo waves transmitted and received by the echo sensor 24. Here, a relative displacement non-contact detection device 10 for non-contactly detecting the relative displacement generated between the first object 11 and the second object 12 is realized. Further details are as follows.

The ID tag 21 is printed with a resonance circuit 31 having a unique resonance frequency therein, and has a first
Affixed to the object 11. The conductive piece 22 is the ID tag 21.
Is arranged so as to be in contact with the surface of the second tag 12 and covers the central portion of the resonance circuit 31 formed in the ID tag 21, and is fixed to the second object 12.

The echo sensor 24 transmits an electromagnetic wave 2 having substantially the same frequency as the above resonance frequency and receives the echo wave 3 reflected from the ID tag 21 when the echo wave 3 is present. Then, when the echo sensor 24 receives the echo wave 3, it is detected that the relative deviation has occurred.
Further, as will be described in detail later with reference to the drawings, the present invention for detecting the leak in a non-contact manner when the fluid leaks from a specific portion of the pipe 1 that conveys a fluid such as tap water or city gas. The piping leak detection device according to the present invention comprises the following components.

That is, the resonance circuit 31 having a unique resonance frequency is printed, and the ID tag 21 attached to the specific portion of the pipe 1 and the surface of the ID tag 21 are in contact with each other, and In order to form a cavity at least around the ID tag 21 and the conductive piece 22, and the conductive piece 22 arranged so as to cover the central portion of the resonance circuit 31 formed in the ID tag 21 and fixed to the support member. A resin cover surrounding the pipe 1 in the specific portion, and a conductive piece provided inside the cover for the ID tag 21 in response to the leakage when the specific portion leaks. There is an echo wave 3 reflected from the ID tag 21, which transmits the electromagnetic wave 2 having a frequency substantially the same as the resonance frequency and a deviation generating mechanism that causes deviation in the support member to which 22 is fixed. It is echo sensor 24 which receives the can.

[0013]

[Action]

(1) In the above relative displacement non-contact detection device, the first
When the relative displacement between the object 11 and the second object 12 occurs, the conductive piece 22 is separated from the central portion of the resonance circuit 31 of the ID tag 21 and is displaced vertically or horizontally. The characteristic is that the echo wave 3 for the electromagnetic wave 2 is returned from the tag 21. In other words, when the conductive piece 22 is in contact with the central part of the resonance circuit 31 of the ID tag 21, the echo wave 3 for the electromagnetic wave 2 is not returned.

(2) In the above-described pipe leakage detection device, the conductive piece 22 placed in the cover causes the leakage from the center portion of the resonance circuit 31 of the ID tag 21 to move vertically or horizontally. The characteristic is that the echo wave 3 with respect to the electromagnetic wave 2 is returned from the ID tag 21 due to the shift in the direction. In other words, when the conductive piece 22 is in contact with the central part of the resonance circuit 31 of the ID tag 21, the echo wave 3 for the electromagnetic wave 2 is not returned.

[0015]

FIG. 2 is an enlarged plan view of the echo sensor 24 shown in FIG. In order to speed up understanding, it is assumed that the second object 12, the conductive piece 22, and the ID tag 21 are all visible. Describing in order from the side closer to the sensor echo sensor 24, the conductive piece 22 is fixed to the second object 12, but here the object 12 is made of, for example, a plastic film.
However, since the second object 12 is an object for detecting relative displacement, it is not known what the object 12 will be, depending on the application.

The conductive piece 22 can be, for example, an aluminum foil printed on the plastic film. Alternatively, it may be coated with copper. The ID tag 21 is also made of, for example, a two-layer plastic film, and the resonance circuit 31 is sandwiched between them by print molding. This resonance circuit 3
The part that looks like a spiral form 1 is a coil (L),
A capacitor (C) is formed below it to form a so-called LC resonance circuit. The resonance frequency can be freely adjusted by adjusting each shape, size, and thickness of the coil (L) and the capacitor (C). I have a resonance frequency of 5 to 50 MHz, which is currently in practical use.
There is a D tag. The ID tag 21 has a size of several cm square.

The ID tag 21 is further attached to the surface of the first object 11. Since this first object 11 is an object for detecting relative displacement, it is unknown what this object 11 will be depending on the application. However, when the first object 11 is made of a conductor, an insulating base material is sandwiched between the object 11 and the ID tag 21 due to the operating principle of the electromagnetic wave type non-contact detection method used in the present invention. It needs to be complicated. Further, the second object 12 must be a non-conductive object due to the operating principle of the electromagnetic wave type non-contact detection method.

FIG. 3 is a sectional view showing an example of use of the relative displacement non-contact detecting device. In the figure, 11 (first object) and 12 (second object) are concrete structures that are vertically adjacent to each other. It is assumed that there is a request to issue a warning when positional displacement occurs between these concrete structures. In response to this request,
The ID tag 21 is previously attached to the first concrete structure (11).
Affix. In addition, the resonance circuit 31 in the ID tag 21
The conductive piece 22 is arranged at a position where it abuts on the central portion of the second concrete structure, and is fixed to the second concrete structure (12) through the supporting member 12 'if necessary.

Concrete structures (1
When the conductive piece 22 shifts vertically or horizontally or in the front-back direction from the central portion of the resonance circuit 31 in the ID tag 21, when the electromagnetic wave 2 is radiated from the echo sensor 24, the ID tag Echo wave 3 is returned from 21. The echo sensor 24 detects this echo wave 3,
The above warning can be issued.

By the way, the above-mentioned operation principle is based on the fact that the present inventor happens to find a very unique phenomenon (characteristic). Hereinafter, this will be described. 4 is a diagram for explaining the operating principle of the present invention (No. 1), FIG. 5 is a diagram for explaining the operating principle of the present invention (No. 2), and FIG. 6 is for explaining the operating principle of the present invention. FIG. 3 (No. 3). The antenna 25 will be specifically described only in FIGS. 4 to 6. For simplicity, the description of the antenna 25 is omitted except for these figures.

(I) First, FIG. 4 is a diagram schematically showing the operation principle of non-contact detection using an ID tag. The operating principle itself of this non-contact detection is well known from old times. First, the electromagnetic wave 2 is transmitted (emitted) from the antenna 25. Then, the ID tag 21 is reached. The above-mentioned LC resonance circuit 31 is printed on the ID tag 21, and when the resonance frequency of the LC resonance circuit 31 and the frequency of the electromagnetic wave 2 match, the LC resonance circuit 31 resonates to generate the echo wave 3. Oscillate. When the echo wave 3 is received by the antenna 25, it is detected by a receiving unit (not shown) in the echo sensor 24, and the presence of the ID tag 21 is detected.

The unique phenomenon (characteristic) described above is explained in the following (II) and (III). (II) FIG. 5 shows a state in which the above-mentioned conductive piece 22 is placed in contact with the central portion of the resonance circuit 31 in the ID tag 21. At this time, even if the electromagnetic wave 2 was radiated from the antenna 25, the echo wave 3 was not returned at all.

(III) FIG. 6 shows a state in which the conductive piece 22 in the state of FIG. 5 is slightly (about 1 mm) lifted from the surface of the ID tag 21. Then, this time, the radiated electromagnetic wave 2
On the other hand, the strong echo wave 3 is returned at the same level as in the case of FIG. The echo wave 3 is restored not only when the conductive piece 22 is floated as described above, but also when the conductive piece 22 is laterally shifted from the central portion (left and right in the drawing).

However, at present, the theoretical reason why the above phenomenon (characteristic) appears has not been accurately grasped. The above-described pipe leak detection device which is another aspect of the present invention also utilizes the above phenomenon (characteristic). FIG. 7 is a diagram showing the basic configuration of the pipe leakage detection device according to the present invention. As shown in this figure, the pipe 1 is buried in the soil E,
A fluid 4 such as city gas or oil is transported at high pressure therein.

The pipe 1 always has a joint and is joined by a joint 5. The joint 5 is a portion where fluid leakage is likely to occur, and is a specific portion suitable for installing the pipe leakage detection device 20 of the present invention. The insulating base material 32 described above is sandwiched in this specific portion (when the joint is metallic), and the ID tag 21 is inserted here.
Affix. The conductive piece 22 contacting above the ID 21 is fixed to the support member 33.

Further, a resin cover 41 is provided around these so as to surround the pipe 11, and at least the ID cover 41 is provided.
A cavity 34 is formed around the tag 21 and the conductive piece 22. The cavity 34 is formed to create a space in which the conductive piece 22 is not crushed by the soil. The fluid leaking into the cavity serves as a shift generation drive source in the shift generation mechanism section described below.

That is, the deviation generating mechanism 51 is provided inside the cover 41, and when a leak occurs in a specific portion (joint 5), the conductive piece 22 is attached to the ID tag 21 in response to the leak. The fixed support member 33 is displaced. Due to this shift, the state shown in FIG. 6 described above is created. When there is no deviation, the state is as shown in FIG. 5 described above, and the echo sensor 24 determines that there is no return of the echo wave 3 even if the electromagnetic wave 2 is radiated into the soil E, and there is no leakage.
If the return of the echo wave 3 is received, the leak is detected.

Note that the observer S follows the design drawings to find the soil E
It can be estimated from the ground where the joint part is located. Therefore, the echo sensor 24 is placed at the corresponding portion to monitor whether or not the echo wave 3 is returned. If the alarm lamp or alarm buzzer is driven in response to the return of the echo wave 3, the leak can be detected without difficulty even during daytime noise. Moreover, since it suffices to place the echo sensor 24 on the relevant portion and check whether or not there is an alarm, no skill is required of the monitor S.

Finally, a specific example of the deviation generating mechanism 51 will be described. There are various possible modes for designing the displacement generating mechanism unit, so only one example is given here. FIG. 8 is a cross-sectional view showing a first example of the deviation generating mechanism section. The shift generation mechanism unit 51 according to the first example is configured to cause the shift of the support member 33 to which the conductive piece 22 is fixed due to the pressure of the leaked fluid 4 itself.

In this figure, the inner cylinder 52 and this cylinder 5
The support member 33 fitted in the hole provided in a part of 2 forms the shift generation mechanism portion 51. When the fluid leaks, the fluid overflows into the inner cylinder 52 with a high pressure and pushes the support member 33 together with the conductive piece 22 in the direction of the arrow in the drawing. Here, the ID tag 21 returns an echo wave 3 to the electromagnetic wave 2 from the echo sensor 24.

FIG. 9 is a sectional view showing a second example of the deviation generating mechanism section. The deviation generating mechanism section 51 according to the second example is configured to cause a deviation in the support member 33 to which the conductive piece 22 is fixed due to buoyancy received from the leaked fluid. However, it is not applicable when the fluid 4 is city gas. In this figure, a gripping body 53 that rotatably grips one end of a supporting member 33 made of styrofoam having a small specific gravity constitutes a deviation generating mechanism section 51. When the fluid 4 leaks and the fluid 4 is filled in the cavity 34, the support member 33 gains buoyancy and rises, and is displaced in the direction of the arrow in the figure.

FIG. 10 is a sectional view showing a third example of the deviation generating mechanism section. The third example includes a swelling member 54 having a property of absorbing the fluid 4 and increasing the volume thereof, and the supporting member 33 to which the conductive piece 22 is fixed by the force of the swelling member 54 increasing the volume of the leaked fluid 4. It is configured to cause a shift in. However, it is not applicable when the fluid 4 is city gas.

The swelling member 5 adhered to the end of the grip body 55.
4 holds the support member 33 so that the conductive piece 22 and the ID tag 21 are just in contact with each other. If leakage occurs, the swelling member 54 absorbs the fluid 4 and expands, moving the conductive piece 22 in the direction of the arrow in the drawing, and forming a gap with the ID tag 21. As a result, the echo sensor 24 receives the echo wave 3 from the ID tag 21.

FIG. 11 is a front view showing an example of the lock mechanism of the present invention. The lock mechanism 61 is for continuing to maintain the displacement when the displacement occurs in the support member 33. The example of this figure shows a case where it is applied to the embodiment of FIG. The lock mechanism 61 includes a permanent magnet 61 a fixed to a part of the outer circumference of the inner cylinder 52 and a thin iron piece 61 b bonded to one end of the support member 33.

When the support member 33 is pushed outward by the fluid 4 that has leaked out together with the conductive piece 22, the iron piece 61b is attracted to the permanent magnet 61a, and one end of the member 33 holds the attracted position as it is, and the conductive piece The piece 22 remains floating from the ID tag 21. The lock mechanism 61 is effective in the following cases. When it is estimated that a leak has occurred somewhere in the soil, the surveillance staff S patrolls with the echo sensor 24 to try to find the leak location. At this time, the valve on the upstream side of the fluid 4 is closed. It is also possible that it will happen.
If the valve is tightened during patrol, the corner angle ID tag 2
The conductive piece 22 separated from No. 1 remains in contact with the ID tag 21 again as the leaked fluid is drawn. In this case, the echo sensor 2
The detection of the leak point by 4 becomes impossible.

Therefore, once the lock mechanism 61 is operated to I
The conductive piece 22 separated from the D tag 21 is prevented from coming into contact with the ID tag 21 again until the leak is repaired. In constructing the above-described pipe leakage detection device 20 according to the present invention, after joining the pipes 1 to each other with the joint 5, after setting the ID tag 21, the conductive piece 22, the deviation generating mechanism 51, etc. at the joint part, 2 The cover 41 divided into pieces (the same applies to the inner cylinder 52) is assembled into a single piece by the set portion.

[0037]

As described above, according to the present invention, 1) the relative displacement of two objects which cannot be seen or touched directly, such as in the soil, from the outside. It can be detected in a non-contact manner without power supply. 2) Moreover, the detection can be performed with high precision without requiring skill. 3) Also, the ID tag used for the detection and the supporting member with the conductive piece are print-molded on the film. Since it can be easily mass-produced by processing, the device can be realized at low cost.

[Brief description of drawings]

FIG. 1 is a diagram showing a principle configuration of the present invention.

FIG. 2 is an enlarged plan view seen from the echo sensor side in FIG.

FIG. 3 is a cross-sectional view showing a usage example of a relative deviation non-contact detecting device.

FIG. 4 is a diagram (No. 1) for explaining the operation principle of the present invention.

FIG. 5 is a diagram (No. 2) for explaining the operation principle of the present invention.

FIG. 6 is a diagram (No. 3) for explaining the operation principle of the present invention.

FIG. 7 is a diagram showing a basic configuration of a pipe leakage detection device according to the present invention.

FIG. 8 is a cross-sectional view showing a first example of a deviation generating mechanism section.

FIG. 9 is a cross-sectional view showing a second example of the deviation generating mechanism section.

FIG. 10 is a cross-sectional view showing a third example of the deviation generating mechanism section.

FIG. 11 is a front view showing an example of the lock mechanism of the present invention.

FIG. 12 is a diagram schematically showing an example of a conventional pipe leak detection technique.

[Explanation of symbols]

 1 ... Piping 2 ... Electromagnetic wave 3 ... Echo wave 4 ... Fluid 5 ... Joint E ... Underground L ... Leakage 10 ... Relative deviation non-contact detection device 11 ... First object 12 ... Second object 20 ... Piping leak detection device 21 ... ID tag 22 ... Conductive piece 24 ... Echo sensor 31 ... Resonance circuit 33 ... Support member 34 ... Cavity 41 ... Cover 51 ... Deviation generating mechanism 52 ... Inner cylinder 53 ... Gripping body 54 ... Swelling member 61 ... Lock mechanism

Claims (6)

[Claims] 1. A first object (11) and a second object (1
In a relative displacement non-contact detecting device for detecting a relative displacement generated between the first object and the second object, a resonance circuit (31) having an inherent resonance frequency is printed. ID attached to 11)
The tag (21) is arranged so as to be in contact with the surface of the ID tag (21) and to cover the central portion of the resonant circuit (31) formed in the ID tag (21), and A conductive piece (22) fixed to the second object (12), transmitting an electromagnetic wave having a frequency substantially the same as the resonance frequency,
An echo sensor (24) for receiving an echo wave reflected from the ID tag (21) when the echo wave is present, and when the echo sensor (24) receives the echo wave,
A relative deviation non-contact detecting device, which detects that the relative deviation has occurred. 2. A pipe leak detecting device for detecting the leak in a non-contact manner when the fluid is leaking from a specific portion of a pipe (1) which conveys the fluid, wherein a resonance circuit having an inherent resonance frequency ( 31) is printed and is attached to the specific portion of the pipe (1), and the ID tag (21) is in contact with the surface of the ID tag (21). Is arranged so as to cover the central portion of the resonance circuit (31) formed in the support member (3).
3) a conductive piece (22) fixed to the at least the ID tag (21) and the conductive piece (2)
2) a resin cover (4) surrounding the pipe (11) in the specific portion to form a cavity around
1) and the ID provided inside the cover (41) in response to the leak when the leak occurs in the specific portion.
A shift generation mechanism section (51) that causes a shift in the support member (33) to which the conductive piece (22) is fixed, and an electromagnetic wave having a frequency substantially the same as the resonance frequency are transmitted to the tag (21).
An echo sensor (24) for receiving an echo wave reflected from the ID tag (21) when the echo wave is present, and when the echo sensor (24) receives the echo wave,
A pipe leakage detection device, which detects that the leakage has occurred. 3. The displacement generating mechanism section (51) causes the conductive piece (22) to operate according to the pressure of the leaked fluid itself.
The pipe leakage detection device according to claim 2, wherein the support member (33) to which is fixed is configured to cause a deviation. 4. The shift generating mechanism section (51) is configured to cause a shift in the support member (33) to which the conductive piece (22) is fixed due to buoyancy received from the leaked fluid. The pipe leak detection device according to 2. 5. A swelling member (54) having a property of absorbing a fluid to increase its volume, wherein the deviation generating mechanism section (51) is caused by the leaked fluid.
4) causes the conductive piece (2
The pipe leakage detection device according to claim 2, wherein the support member (33) to which 2) is fixed is configured to be displaced. 6. The shift generation mechanism section (51) shifts the support member (33) having the conductive piece (22) fixed to the ID tag (21) in response to the leakage. At this time, the pipe leakage detection device according to claim 2, further comprising a lock mechanism (61) that keeps the deviation.