JP2007163255A - Water leak detection method, water leak detection system and rfid tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water leak detection method, a water leak detection system and an RFID tag capable of detecting a water leak simply, surely and inexpensively by utilizing an existing RFID system without requiring a large-scale device. <P>SOLUTION: A tag 2 operated in some frequency in LF band, MF band, HF band and VHF band (for example, 13.56 MHz band) is installed on a place where a water leak often occurs such as a periphery of a joint of a distributing water pipe, and existence of a water leak is determined based on a change of the communication state between the tag 2 and a reader/writer 7. The tag 2 operated in a short wave band such as the HF band or the VHF band is more inexpensive than a tag operated in another frequency, and a versatile reader/writer 7 can be utilized, and a tag antenna has a structure wherein a lead wire is wound and the antenna shape can be changed freely in accordance with a domain where the water leak is detected. Consequently, the water leak can be detected simply, surely and inexpensively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an RFID (Radio Frequency Identification) system and a method using the system, and more particularly to a water leakage detection method, a water leakage detection system, and an RFID tag that detect water leakage in a water pipe.

  Distribution pipes such as air-conditioning drain pipes installed around various buildings and behind the ceiling are regularly inspected to prevent damage caused by water leaks. This water leakage inspection is performed by a method in which a worker visually checks or palpates the joints of the water pipes one by one in a narrow space where the water pipes are installed. Because it is installed in a dark place with no lighting, such as inside and behind the ceiling, it is not easy to check for water leaks by visual inspection or palpation. There was a risk of oversight. In particular, the surface of a drain pipe of an air conditioner is covered with a heat insulating material. Even if water leaks to the drain pipe, if the water does not ooze out from the heat insulating material, check the water leakage visually or by palpation. It is difficult.

  Therefore, various apparatuses and methods have been proposed in order to automate such work that relies on the skill of the worker. For example, Japanese Patent Laid-Open No. 2004-245618 discloses a vibration sensor that can measure sound generated when water leaks from a water pipe, and a frequency separator that separates a signal obtained by the vibration sensor into a plurality of frequency bands. An inverse conversion device that sums only the frequencies necessary for determination out of the single frequency waveform separated by the frequency separator and returns it to the sound waveform, and a characteristic sound waveform and a determination reference value output by the inverse conversion device And a water leakage detection device including a determination device for determining water leakage is disclosed.

JP-A-2004-245618 (page 3-6, FIG. 5)

  However, the method described in Patent Document 1 requires a large-scale device for comparing the frequency components of water leaking sound leaking from cracks and joints, and costs for water leak inspection. Further, in such a method, when a plurality of water distribution pipes are arranged in a complicated manner, it is difficult to specify in which part the water leakage has occurred.

  The present invention has been made in view of the above problems, and its main purpose is to detect water leakage easily, reliably and inexpensively using an existing RFID system without requiring a large-scale device. Another object of the present invention is to provide a water leakage detection method, a water leakage detection system, and an RFID tag that can be used.

  In order to achieve the above object, the water leakage detection method of the present invention includes one or more RFID tags that are installed in the vicinity of a joint of a water distribution pipe and operate in any frequency band of LF band, MF band, HF band, and VHF band. And a leak detection method using a reader or a reader / writer that communicates with the RFID tag, wherein the leak is detected based on a change in communication state due to leak that flows into the RFID tag from the joint. .

  In the present invention, a water absorbing material is disposed on at least a part of the front surface, back surface or front and back surfaces of the RFID tag, and the water absorbing material causes the water leakage to stay on the front surface, back surface or front and back surfaces of the RFID tag. A guide groove is formed on at least one of the front surface and the back surface of the RFID tag, and the guide groove is used to guide the water leakage to the front surface or the back surface of the RFID tag, or on the water pipe installation surface of the RFID tag. A magnetic material is provided, and the soft magnetic material can be configured to suppress the influence of the constituent material of the water pipe or the water inside the water pipe.

  Further, the water leakage detection system of the present invention includes one or more RFID tags that are installed in the vicinity of a joint of a water distribution pipe and that operate in any frequency band of LF band, MF band, HF band, and VHF band, and the RFID tag A leakage detection system comprising at least a reader or a reader / writer that communicates with the communication device, and further comprising means for detecting a change in communication state due to leakage flowing into the RFID tag from the joint, and the means detects the change in the communication state. A water leakage detection system characterized by enabling detection of the water leakage based on the water leakage.

  In the present invention, a configuration in which a water absorbing material that absorbs and retains the leaked water is disposed on at least a part of the front surface, back surface, or front and back surfaces of the RFID tag, on at least one of the front surface or back surface of the RFID tag, It can be set as the structure provided with the guide groove which guide | induces the said water leak to the surface or back surface of the said RFID tag, or the structure by which the soft-magnetic material is arrange | positioned in the said distribution pipe installation surface of the said RFID tag.

  Further, in the present invention, the water leakage determining means for determining that there is water leakage when the reader or the reader / writer cannot communicate with the RFID tag or when the communication state is worse than a predetermined reference state. It can also be set as the structure provided.

  The RFID tag of the present invention is an RFID tag that is installed in the vicinity of the joint of the water pipe and operates in any one of the LF band, the MF band, the HF band, and the VHF band. At least a part of the front and back surfaces is provided with a water absorbing material that absorbs and retains the leaked water.

  The RFID tag of the present invention is an RFID tag that is installed in the vicinity of the joint of the water distribution pipe and operates in any one of the frequency bands of LF band, MF band, HF band, and VHF band. At least one is provided with a guide groove for guiding the water leakage to the front surface or the back surface of the antenna of the RFID tag.

  In this invention, it can be set as the structure further provided with a soft-magnetic material in the said water pipe installation surface of the said RFID tag.

  As described above, in the present invention, an RFID tag that operates in one of the frequency bands of the LF band, the MF band, the HF band, and the VHF band is installed at a location where water leakage is likely to occur, such as in the vicinity of a joint of a water distribution pipe. Since the presence or absence of water leakage is determined based on the change in the communication status between the device and the reader or reader / writer, water leakage can be detected inexpensively using an existing RFID system without the need for a large-scale device can do. In addition, RFID tag tag antennas that operate in any frequency band of LF, MF, HF, and VHF have a structure in which conductive wires are wound, and the shape of the tag antenna is adjusted to the area where water leakage is detected. Therefore, it is possible to easily and reliably detect water leakage.

  According to the water leakage detection method, the water leakage detection system, and the RFID tag of the present invention, even a slight water leakage can be detected easily, reliably and inexpensively without requiring a large-scale device.

  The reason for this is that RFID tags that operate in one of the frequency bands (for example, 13.56 MHz band) of the LF band, MF band, HF band, and VHF band are located where water leakage is likely to occur, such as in the vicinity of the joint of the water distribution pipe. This is because it is installed and the presence or absence of water leakage is determined based on a change in the communication state between the RFID tag and the reader or reader / writer.

  In addition, an RFID tag that operates in any one of the LF band, MF band, HF band, and VHF band is less expensive than an RFID tag that operates in another frequency band, and has a structure in which a conductive wire is wound. This is because the shape of the tag antenna can be changed according to the area where water leakage is detected, so that water leakage can be detected easily and reliably. In addition, an absorbing material that absorbs and retains leaked water is disposed on at least a part of the front or back surface of the RFID tag, or leaked water is placed on at least one of the front or back surface of the RFID tag. Improve water leak detection accuracy by providing guide grooves on the front or back surface, or by installing spacers or soft magnetic materials on the distribution pipe installation surface of the RFID tag to suppress the influence of water inside the distribution pipe Because it can.

  As described above, conventionally, inspection of water leaks in water distribution pipes has been performed by visual inspection or palpation. However, it is not easy to detect water leaks in water pipes in narrow and dark places. Thus, an apparatus for automatically detecting a water leak is disclosed in Patent Document 1 or the like, but the conventional method has a problem that the apparatus becomes large and the location of the water leak cannot be specified.

  On the other hand, in recent years, an RFID system that performs data communication between a tag including an IC chip and a reader or a reader / writer has been used for various purposes. This RFID system has different communicable distances depending on the frequency band to be used, and operates in a frequency band such as LF band, MF band, HF band or VHF band, or in a high frequency band such as UHF band or SHF band. There are things that work.

  Therefore, the inventor of the present application installed an RFID tag that operates in a high frequency band in a prior application (Japanese Patent Application No. 2005-78524) at a location where water leakage is likely to occur, such as a joint of a water pipe, and the RFID tag and reader Alternatively, a water leakage detection method, a water leakage detection system, and an RFID tag that determine the presence or absence of water leakage based on a change in a communication state with a reader / writer are disclosed. In this prior application, since the high frequency electromagnetic wave used by the RFID tag utilizes the property of being easily absorbed by water, water leakage can be detected with high sensitivity.

  However, RFID tags that operate in high frequency bands are more expensive and less expensive than RFID tags that operate in frequency bands such as the LF band, MF band, HF band, and VHF band that are currently popular. In addition, since short-wave reader / writers having various shapes cannot be used, the cost of the entire system increases. In addition, the tag antenna of an RFID tag that operates in a high frequency band has a linear shape (dipole antenna, monopole antenna, etc.), its detection range is narrow, and it is difficult to freely change the shape of the tag antenna. The installation location of the RFID tag must be determined in consideration of the direction in which water leaking from the water pipe flows, and there are many restrictions on mounting.

  Therefore, the present invention operates in any frequency band (preferably 13.56 MHz band) of the LF band, the MF band, the HF band, and the VHF band that have various shapes and sizes and have few restrictions on mounting. An RFID tag is installed in a place where water leakage is likely to occur, such as a joint of a water distribution pipe, and a change in communication state between the RFID tag and a reader or reader / writer (reduction in communication distance, resonance frequency deviation, communication) It is possible to determine whether there is water leakage based on The specific configuration will be described below with reference to the drawings.

  First, a water leakage detection method, a water leakage detection system, and an RFID tag according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram schematically illustrating a configuration of a water leakage detection system according to the present embodiment, and FIG. 2 is a diagram illustrating a structure of a tag according to the present embodiment. Moreover, FIG. 3 is a figure which shows typically the state which installed the tag of a present Example in the joint of the water distribution pipe, and FIG.4 and FIG.5 is a figure which shows typically the state which the water leak generate | occur | produced. . FIG. 6 is a diagram schematically showing a method of detecting a water leak with a reader or a reader / writer using the tag of this embodiment.

  As shown in FIG. 1, the water leakage detection system 1 according to the present embodiment includes one or more tags that operate in any frequency band (preferably 13.56 MHz band) of the LF band, the MF band, the HF band, and the VHF band. 2 and a reader or reader / writer (hereinafter referred to as reader / writer 7) that communicates data with the tag 2. The tag 2 includes a tag antenna 3 constituting a resonance circuit, a capacitor (not necessarily required when the IC chip 4 has a capacity), and an IC chip 4 for storing information, and a built-in power source or reader / reader / It is driven using the power supplied from the writer 7. The reader / writer 7 includes a reader / writer antenna 8 that communicates with the tag 2, and a control unit 9 such as a communication circuit 9a for converting transmission / reception signals and an arithmetic processing circuit 9b for decoding transmission / reception signals. I have. Note that the tag 2 used in the present embodiment is configured to include the IC chip 4, but if it is not necessary to identify each of the plurality of tags 2, it is not necessary to include the IC chip 4.

  As shown in FIG. 2, the tag 2 includes a tag antenna 3 and an IC chip 4 formed by winding a conductive wire 6 on a base material 5 made of a deformable plastic film or the like. And the IC chip 4 are connected. Moreover, the adhesive material 10 is arrange | positioned by the surface (back surface) on the opposite side to the surface where the tag antenna 3 of the base material 5 is arrange | positioned, and it is comprised so that the tag 2 can be fixed to the detection location of a water leak.

  The structure of FIG. 2 is an example, and the structure, shape, material, and the like of the tag antenna 3 are not particularly limited. For example, the diameter of the conducting wire 6 constituting the tag antenna 3, the number of windings, the winding method, etc. are arbitrary, and the antenna shaft of the tag antenna 3 may be provided with a magnetic core. The tag antenna 3 may be formed by etching a metal film on the base material 5 or may be formed by fixing a conductive wire on the base material 5. In FIG. 2, the tag antenna 3 and the IC chip 4 are exposed, but the entire tag 2 may be protected by a protective material such as a film.

  In FIG. 2, the adhesive material 10 is disposed on the back surface side of the base material 5, but the adhesive material 10 may be disposed on the front surface side, or the adhesive material 10 is disposed on a part of the front surface or the back surface. You may set up. The means for fixing the tag 2 is not limited to the adhesive material 10, and for example, an adhesive material may be provided in advance on the water distribution pipe side, or a fixing jig such as a claw for fitting the tag 2 into the water distribution pipe is used. The ring-shaped tag 2 may be wound around the detection location.

  And the tag 2 of the said structure is installed in the location which is easy to produce the water leak of a water pipe. For example, as shown in FIG. 3, in the case of detecting a water leak in a drain pipe connected to a packaged air conditioner 11 provided on the ceiling 12, the tag 2 has an adhesive 10 in the vicinity of the connection portion between the pipe 13 and the joint 14. And is covered with a heat insulating material 15 made of foamed polyethylene or the like. In addition, the installation location of the tag 2 is arbitrary and may be an upper part or a side part of a water pipe (pipe 13 or joint 14). Moreover, the installation form of the tag 2 is also arbitrary, and may be directly attached to the water pipe, or the tag 2 may be wound around the water pipe or may be installed on the heat insulating material 15. . Further, the number of tags 2 to be installed is arbitrary, and the tags 2 may be installed at a plurality of locations, or a plurality of tags 2 may be installed at each installation location.

  In the above configuration, when water leaks in the drain pipe, water leaks from the joint between the pipe 13 and the joint 14 as shown in FIG. 4, and the leaked water 16 covers at least a part of the tag 2. The tag 2 is deteriorated in communication state by absorbing electromagnetic waves by the leaked water 16 and shortening the communication distance, or by changing the impedance of the tag antenna 3 by the leaked water 16 and shifting the resonance frequency. Or the IC chip 4 is destroyed and communication becomes impossible. In addition, even when the tag 2 is installed on the pipe 13 as shown in FIG. 5, the water 16 leaking from the joint reaches the tag antenna 3 of the tag 2 through the pipe 13. Failure such as communication failure occurs.

  Note that the water leakage state shown in FIGS. 4 and 5 is an example, and if the leaked water 16 spreads over at least part of the front or back surface of the tag antenna 3 of the tag 2, the communication state can be changed sufficiently. Is possible.

  As shown in FIG. 6, detection of water leakage in the drain pipe in which the tag 2 is installed is performed by the inspection operator tagging the reader / writer 7 (preferably a handy type reader / writer that is easy to carry). This is done by holding it over 2. That is, when there is no water leak, data communication is normally performed between the tag 2 and the reader / writer 7, but when water leaks, the tag 2 leaks out. Covering with water 16 causes a change in communication state such as deterioration of communication state or inability to communicate.

  Therefore, based on the change in the communication state between the tag 2 and the reader / writer 7, there is no water leakage if the communication state is normal, and there is water leakage if there is a change in the communication state such as deterioration of communication state or communication failure. Since it can be determined that it has occurred, water leakage can be detected easily and reliably. In particular, when the water distribution pipe is covered with the heat insulating material 15, water leakage can be detected without peeling off the heat insulating material 15, thereby facilitating construction and work related to the heat insulating material 15.

  The operator may determine the presence or absence of water leakage. For example, when the water leakage determining means is provided in the control unit 9 of the reader / writer 7 and communication is impossible or the communication state is worse than a predetermined reference state. A configuration may be adopted in which it is determined that there is water leakage and the inspector is notified by a lamp or the like, or the reader / writer 7 is installed in a place where communication with the tag 2 is possible in advance and the communication state is monitored to detect water leakage. In some cases, a notification may be made using light or sound.

  In addition, when a plurality of tags 2 are installed, each reader / writer 7 can identify each tag 2, so if a table for associating the tag 2 with the installation location is provided in advance, a location where water leakage has occurred Can also be identified. Furthermore, since inspection records such as the inspection date and time and the inspection operator can be stored in the IC chip 4, an inspection history can be secured and the inspection efficiency can be improved.

  As described above, according to the configuration of the present embodiment, the tag 2 that operates in any frequency band of the LF band, the MF band, the HF band, and the VHF band is installed in a place where water leakage is likely to occur, such as a connection portion of the water pipe. In addition, since the presence or absence of water leakage is determined based on a change in communication state between the tag 2 and the reader / writer 7 (deterioration of communication state or communication failure), it is possible to detect water leakage easily and reliably. it can. In particular, when the water distribution pipe is covered with or wrapped around the heat insulating material 15 or the like, it is possible to detect water leakage without removing the heat insulating material 15.

  Next, a water leakage detection method, a water leakage detection system, and an RFID tag according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 10 are diagrams schematically showing the structure of the tag of this embodiment.

  In the first embodiment described above, the tag antenna 3 and the IC chip 4 are disposed on the base material 5 and the tag 2 in which the adhesive material 10 is disposed on the base material 5 as necessary is used. These constituent materials of the tag 2 usually have a property of easily repelling water, so that when the amount of water leakage is small, the leaked water 16 may not stay on the front and back surfaces of the tag antenna 3 and the communication state may not change. is there. In addition, if water leaks occur continuously, it is possible to detect water leaks at any time, but if water leaks occur intermittently, There is a possibility that water leaks cannot be detected even after inspection. Therefore, in this embodiment, the leaked water can be held on the front surface or the back surface of the tag 2 so that even a slight water leak or an intermittent water leak can be reliably detected.

  More specifically, as shown in FIG. 7 (a), the tag 2 of this embodiment has a conducting wire 6 wound on a base material 5 made of a plastic film or the like that can be deformed according to the shape of the water distribution pipe. The tag antenna 3 and the IC chip 4 that operate in any frequency band of the rotated LF band, MF band, HF band, and VHF band are disposed, and water such as sponge is absorbed on the surface of the tag antenna 3 and the IC chip 4. A material (referred to as a water-absorbing material 17) is disposed. And the adhesive material 10 which fixes the tag 2 to an installation location is arrange | positioned at the base material 5 as needed. In the tag 2 provided with such a water absorbing material 17, water leaked from the connecting portion of the water pipe is absorbed and held by the water absorbing material 17, so even a slight water leak or intermittent water leak is ensured. Can be detected.

  The water-absorbing material 17 may be any material as long as it can absorb water and hold it for a certain period of time. For example, the water-absorbing material 17 is formed by a capillary phenomenon such as a filter, paper, or cotton having an appropriately sized hole or gap. A material that can be sucked in or a material that gels by absorbing moisture can be used.

  In FIG. 7, the water absorbing material 17 is disposed on the surface of the tag 2. However, since the communication state changes even when water is present in the lower part of the tag antenna 3, as shown in FIG. It is good also as a structure which arrange | positions the water absorbing material 17 in the (lower layer of the base material 5), and arrange | positions the adhesive material 10 on the back surface of the water absorbing material 17 as needed.

  In FIG. 7, the entire surface of the tag 2 is covered with the water absorbing material 17, but when the tag 2 is not protected by a protective material such as a film, the conductive wire 6 wound as shown in FIG. The water absorbing material 17 may be disposed so as not to cover the IC chip 4 inside, or the water absorbing material 17 is disposed so as to cover the IC chip 4, and the IC chip 4 is destroyed when water leaks. Communication may be disabled. Similarly, the water absorbing material 17 may be disposed on a part of the back surface of the tag 2, or the water absorbing material 17 may be disposed on a part of each of the front surface and the back surface.

  Moreover, in FIG. 7 thru | or FIG. 9, although the water absorbing material 17 was arrange | positioned to one of the surface or the back surface of the tag 2, in order to improve the water absorption effect, as shown in FIG. The water absorbing material 17 may be disposed, or the water absorbing material 17 may be disposed so as to cover the entire tag 2 (for example, the tag 2 is disposed inside the bag-shaped water absorbing material 17).

  As described above, according to the configuration of the present embodiment, the tag 2 that operates in any frequency band of the LF band, the MF band, the HF band, and the VHF band is installed in a place where water leakage is likely to occur, such as a connection portion of the water pipe. In addition, since the water absorbing material 17 is disposed on at least a part of the front or back surface of the tag 2, the leaked water can be retained on the front or back surface of the tag 2, and slight water leakage or intermittent Even if it is a typical water leak, it can detect reliably.

  Next, a water leakage detection method, a water leakage detection system, and an RFID tag according to a third embodiment of the present invention will be described with reference to FIGS. 11 to 13 are diagrams schematically showing the structure of the tag of this embodiment.

  In the first and second embodiments described above, the tag 2 is installed alone or in the water distribution pipe with the water absorbing material 17 disposed. However, depending on the environment of the place where the tag 2 is installed, the tag 2 and the reader / writer 7 are arranged. There is a possibility that the communication state will be changed due to the influence of the communication performed between the two. Therefore, in this embodiment, a structure of the tag 2 for suppressing a factor that changes the communication status is proposed.

  The first is a structure for preventing the communication state from being changed due to the absorption of electromagnetic waves, the shift of the resonance frequency, or the like caused by the water flowing in the water distribution pipe. Specifically, when the thickness of the water distribution pipe is thin, the base material 5 of the tag 2 is thickened, or as shown in FIG. 11A, the base material of the tag 2 having the structure shown in the first embodiment is used. The spacer 18 is disposed on the back surface of the tag 5, and the tag antenna 3 of the tag 2 is separated from the water distribution pipe by the base material 5 and the spacer 18 (preferably about 3 to 5 mm) to suppress the influence of the water flowing inside. Further, as shown in FIGS. 11B to 11D, a spacer 18 is disposed on the back surface of the tag 2 shown in the second embodiment to similarly suppress the influence of water flowing inside.

  The spacer 18 can be formed using an arbitrary material. However, for example, when plastic (dielectric constant 2 to 3) or rubber is used, the dielectric constant of the spacer 18 increases, and as a result, the loss caused by the spacer 18 itself is lost. Therefore, it is preferable to use porous plastics (dielectric constant 1.1 to 1.2) such as urethane foam in which bubbles are mixed, porous rubber, or the like.

  Second, when the water pipe or the like on which the tag 2 is installed is formed of a metal material such as iron or copper, the tag 2 may not operate or the communication distance may be reduced due to an eddy current flowing in the metal material. This is a structure for preventing this. Specifically, as shown in FIG. 12A, a soft magnetic material 19 is disposed on the back surface of the base material 5 of the tag 2 having the structure shown in the first embodiment, and the magnetic flux of the tag 2 is soft magnetic. By allowing the interior of the material 19 to pass, the influence of the metal material forming the water pipe and the like is suppressed. Further, as shown in FIGS. 12 (b) to 12 (d), the influence of a metal material that similarly forms a water distribution pipe or the like by disposing a soft magnetic material 19 on the back surface of the tag 2 shown in the second embodiment. Suppress.

  The soft magnetic material 19 may be a general soft magnetic material or a soft magnetic material manufactured using the method described in the prior application of the present inventor (Japanese Patent Laid-Open No. 2002-215321). However, in order to reduce the loss, it is also possible to use an extremely fine soft magnetic metal powder combined with plastic or rubber.

  In addition, as shown in FIG. 13, you may comprise so that the spacer 18 and the soft-magnetic material 19 may overlap and may be arrange | positioned in the tag 2. As shown in FIG. In this case, the order of superposition of the spacer 18 and the soft magnetic material 19 is arbitrary, and the spacer 18 and the soft magnetic material 19 may be disposed on any of the tags 2 shown in the first and second embodiments.

  As described above, according to the configuration of the present embodiment, the tag 2 that operates in any frequency band of the LF band, the MF band, the HF band, and the VHF band is installed in a place where water leakage is likely to occur, such as a connection portion of the water pipe. And since the spacer 18 is arrange | positioned in the back surface of the tag 2, the influence with respect to communication with the tag 2 and the reader / writer 7 by the water which flows inside a water pipe can be suppressed. Moreover, since the soft magnetic material 19 is arrange | positioned on the back surface of the tag 2, the influence with respect to communication with the tag 2 and the reader / writer 7 by the metal material which comprises the water distribution pipe can be suppressed. That is, it is possible to suppress a factor that changes communication and maintain a state where water leakage can be reliably detected.

  Next, a water leakage detection method, a water leakage detection system, and an RFID tag according to a fourth embodiment of the present invention will be described with reference to FIGS. 14 and 15 are diagrams schematically showing the structure of the tag of this embodiment.

  In the second embodiment described above, the water absorbing material 17 is disposed on at least one of the front surface and the back surface of the tag 2 to retain the leaked water. However, the leaked water leaks to the front or back surface of the tag antenna 3 of the tag 2. For example, as shown in FIG. 14B, a guide groove 20 may be provided on the back surface of the base material 5 as long as the water can be reliably guided. In this structure, the leaked water is guided to the lower part of the tag antenna 3 along the guide groove 20 and stays in the guide groove 20 due to surface tension, so that even a slight water leak can be detected efficiently. Is possible.

  The shape, depth, direction and the like of the guide groove 20 are not particularly limited. For example, the guide groove 20 may be formed along the longitudinal direction of the tag 2 as shown in FIGS. 14 (a) and 14 (b). Alternatively, as shown in FIG. 14C, the adhesive material 10 is disposed on a part of the back surface without specially providing a groove in the base material 5, and the portion where the adhesive material 10 is not disposed is guided into the guide groove 20. It may be used as

  Further, as shown in FIG. 15A, in the case of a structure in which the protective material 21 is formed on the surface of the tag 2, the guide groove 20 may be provided in the protective material 21 on the surface of the tag 2, or the front surface and the back surface. The guide grooves 20 may be provided on both sides. 14 and 15, the guide groove 20 is provided in one direction. However, a lattice-shaped guide groove 20 may be provided, or a guide groove 20 having a curved or bent shape may be provided. Further, the guide groove 20 may be added to the structure shown in the second or third embodiment.

  As described above, according to the configuration of the present embodiment, the tag 2 that operates in any frequency band of the LF band, the MF band, the HF band, and the VHF band is installed in a place where water leakage is likely to occur, such as a connection portion of the water pipe. In addition, since the guide groove 20 is formed on at least one of the front surface and the back surface of the tag 2, the leaked water can be guided to the front surface or the back surface of the tag 2, and slight water leakage or intermittent Even a water leak can be reliably detected.

  In each of the above embodiments, the water distribution pipe has been described as an example. However, the present invention is not limited to the above embodiment, and may be applied to the overall detection of water leakage, for example, detection of water leakage in the apparatus. Can do. In each of the above embodiments, the structure of the tag 2 is characterized. However, in order to efficiently guide the leaked water to the front surface or the back surface of the tag 2, the surface of the water distribution pipe is arranged with the tag 2. You may provide a guide groove on the path | route between the joints of a water pipe.

  The present invention can be applied to any system that utilizes the fact that the communication state changes depending on the presence or absence of water.

It is a figure which shows typically the structure of the water leak detection system which concerns on 1st Example of this invention. It is a figure which shows the structure of the tag which concerns on 1st Example of this invention. It is a figure which shows typically the installation state of the tag which concerns on 1st Example of this invention. It is a figure which shows typically the installation state (at the time of water leakage) of the tag which concerns on 1st Example of this invention. It is a figure which shows the variation of the installation state (at the time of water leakage) of the tag which concerns on 1st Example of this invention. It is a figure which shows typically the detection method of the water leak which concerns on 1st Example of this invention. It is a figure which shows the figure which shows the structure of the tag which concerns on 2nd Example of this invention. It is a figure which shows the variation of the tag which concerns on 2nd Example of this invention. It is a figure which shows the variation of the tag which concerns on 2nd Example of this invention. It is a figure which shows the variation of the tag which concerns on 2nd Example of this invention. It is a figure which shows the structure of the tag which concerns on 3rd Example of this invention. It is a figure which shows the variation of the tag which concerns on the 3rd Example of this invention. It is a figure which shows the variation of the tag which concerns on the 3rd Example of this invention. It is a figure which shows the structure of the tag which concerns on 4th Example for this invention. It is a figure which shows the variation of the tag which concerns on the 4th Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water leak detection system 2 Tag 3 Tag antenna 4 IC chip 5 Base material 6 Conductor 7 Reader / writer 8 Reader / writer antenna 9 Control part 9a Communication circuit 9b Arithmetic processing circuit 10 Adhesive material 11 Package air conditioner 12 Ceiling 13 Pipe 14 Joint 15 Heat insulation Material 16 Leaked water 17 Water absorbing material 18 Spacer 19 Soft magnetic material 20 Guide groove 21 Protective material

Claims (12)

One or more RFID tags that are installed in the vicinity of the joint of the water pipe and operate in any one of the frequency bands of LF band, MF band, HF band, and VHF band, and a reader or reader / writer that communicates with the RFID tag A water leakage detection method using
A water leak detection method, comprising: detecting the water leak based on a change in a communication state due to water leaking into the RFID tag from the joint.   The water-absorbing material is disposed on at least a part of the front surface, the back surface, or the front and back surfaces of the RFID tag, and the leaked water is retained on the front surface, the back surface, or the front and back surfaces of the RFID tag. The water leakage detection method according to 1.   The water leakage detection method according to claim 1, wherein a guide groove is formed on at least one of a front surface and a back surface of the RFID tag, and the water leakage is guided to the front surface or the back surface of the RFID tag by the guide groove.   2. A soft magnetic material is disposed on the surface of the RFID tag to which the water pipe is installed, and the soft magnetic material suppresses the influence of the constituent material of the water pipe or the water inside the water pipe. The water leakage detection method as described in any one of thru | or 3. One or more RFID tags that are installed in the vicinity of the joint of the water pipe and operate in any one of the frequency bands of LF band, MF band, HF band, and VHF band, and a reader or reader / writer that communicates with the RFID tag A leak detection system comprising at least
A water leakage detection system comprising: means for detecting a change in communication state due to water leaking from the joint into the RFID tag, wherein the water leakage can be detected based on the change in the communication state.   6. The water leakage detection system according to claim 5, wherein a water absorbing material that absorbs and retains the water leakage is disposed on at least a part of the front surface, back surface, or front and back surfaces of the RFID tag.   The water leakage detection system according to claim 5, wherein a guide groove for guiding the water leakage to the front surface or the back surface of the RFID tag is formed on at least one of the front surface or the back surface of the RFID tag.   The water leakage detection system according to any one of claims 5 to 7, wherein a soft magnetic material is disposed on the water pipe installation surface of the RFID tag.   The reader or the writer is provided with a water leakage determination unit that determines that there is water leakage when communication with the RFID tag is not possible or when the communication state is worse than a predetermined reference state. Item 9. The water leakage detection system according to any one of Items 5 to 8. An RFID tag that is installed in the vicinity of a joint of a water pipe and operates in any frequency band of LF band, MF band, HF band, and VHF band,
An RFID tag comprising a water absorbing material that absorbs and retains water leaked from the seam on at least a part of its front surface, back surface, or front and back surfaces. An RFID tag that is installed in the vicinity of a joint of a water pipe and operates in any frequency band of LF band, MF band, HF band, and VHF band,
An RFID tag comprising a guide groove for guiding water leakage from the joint to the front or back surface of the RFID tag antenna on at least one of the front surface or the back surface thereof.   The RFID tag according to claim 10 or 11, further comprising a soft magnetic material on a surface of the water distribution pipe of the RFID tag.

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