JP6188153B2 - Manhole cover and IC tag for cover - Google Patents

Description

  The present invention relates to an IC tag built-in manhole cover for enabling individual identification of a manhole cover using the built-in IC tag, and an IC tag for the cover.

  Conventionally, individual identification work of a metal manhole cover has been performed by an operator visually confirming identification characters and identification numbers formed on the manhole surface. However, in this method, it is difficult to visually confirm the identification character or the like due to the dirt on the surface of the manhole cover or thinning of the wear, so that a human error may occur. Therefore, an IC tag-embedded manhole cover that can be directly identified from above the manhole cover using electromagnetic waves (radio waves) is developed so that mechanical reading (communication) work other than visual inspection is possible. became.

  As such a manhole cover with a built-in IC tag, for example, a cover (rubber plug) for preventing intrusion of earth and sand and dust is provided in an opening / closing recess for inserting an operation tool into the manhole cover. A technique for enclosing a tag is known (see, for example, Patent Document 1).

There is also known a technique in which a screw-like mounting rod with an IC tag attached to the front surface side is created, this mounting rod is passed through a through-hole formed in a manhole cover, and is detachably attached from the front and back with a screw ( For example, see Patent Document 2).

  Further, an IC tag is embedded in a hole or recess formed on the surface of the iron lid, and the coil antenna surface inside the IC tag is arranged so as to face the wall of the metal hole or recess. ing. As a result, the induced electromagnetic wave is positively guided to the outside of the hole or the recess so as to bend from the wall surface (see, for example, Patent Document 3).

JP 2009-127395 A JP 2008-150903 A JP 09-33279 A

  However, in the technique of Patent Document 1 described above, when a car passes over the manhole cover, the impact may cause the cover to jump out of the recess and drop off. Further, when using the operation tool, the cover must be removed from the recess of the manhole cover. Therefore, if it cannot be ensured that the cover that has popped out or has been removed is attached to the same manhole cover again, the integrity of the IC tag and the manhole cover cannot be guaranteed, and there is a possibility that an error may occur in the individual identification information. Similarly, in the technique of Patent Document 2, since the mounting rod is detachable, there is a problem in the integrity of the individual identification information. In addition, providing the through hole in the manhole cover causes another problem that the strength of the cover is impaired. Further, in the structure in which the IC tag is attached to the surface side of the attachment rod, the IC tag may drop from the manhole cover itself when aged wear due to long-term use occurs.

  Furthermore, in the technique of Patent Document 3, when the operating electromagnetic wave emitted from the reader hits the metal surface of the manhole cover, an eddy current is generated on the surface so as to cancel the electromagnetic wave. Therefore, the emitted electromagnetic wave is weakened by the eddy current on the metal surface, and it is difficult to reach the IC tag embedded in the metal of the manhole cover. In particular, according to electromagnetism, it is known that the higher the frequency of the applied electromagnetic wave (for example, electromagnetic waves in the HF and UHF bands), the stronger the generation of this eddy current. For this reason, there is also a technique that uses the low frequency (LF) electromagnetic wave of 125 KHz to suppress the generation of eddy currents and to utilize the feature that the effect of eddy currents is practically insignificant. However, in the future, it is preferable to perform communication at a high frequency of the world standard MHz band (UHF). However, in the case of a high frequency such as LF or HF, there is a problem that communication cannot be performed due to generation of a strong eddy current. Note that HF and UHF are electromagnetic waves used in IC tags, HF is 13.56 MHz, and UHF includes a band from 860 to 960 MHz.

  On the other hand, in an electromagnetic induction reader / writer (hereinafter referred to as a reader) for reading an IC tag, the electromagnetic wave weakens in inverse proportion to the square or the third power of the distance from the IC tag installed on the manhole cover to the reader. . In addition, the metal manhole cover installed on the road surface is reduced in thickness due to aged wear (thickness reduction of about 3 mm is expected after 15 years of use). For this reason, the IC tag to be embedded needs to satisfy the condition of being incorporated in a tag recess provided about 5 mm inside the metal surface.

  The present invention has been made in view of any of the above-described circumstances, and the purpose of the present invention is to prevent the IC tag portion from easily falling off even with wear over time, and to prevent electromagnetic waves in the high frequency band of UHF. An object of the present invention is to provide an IC tag built-in manhole cover that can detect individual identification information of an IC tag even if it is used. Further, the present invention provides a lid IC tag that can detect individual identification information even when electromagnetic waves in a high frequency band of UHF are used.

  In order to solve any of the above-described problems, the present invention has an uneven portion formed on a metal surface for preventing slipping or designing a wheel or a shoe, and an IC tag for individual identification is attached to the uneven portion. In the IC tag built-in manhole cover, the IC tag is attached by screwing or fitting at a position deeper than a predetermined depth (or length) that is an allowable value of wear thinning on the road surface in the concave portion of the uneven portion. When a high-frequency electromagnetic wave in the UHF 920 MHz band, for example, is applied to the metal surface, an uneven portion is formed on the metal surface in the vicinity of the IC tag so that a standing-wave high-frequency current different from the eddy current flows. The coil antenna is arranged close to the central portion of the standing wave so that the electromagnetic coupling relationship between the primary current and the secondary current of the transformer is established by the high-frequency current. (Hereafter, the standing wave current on the manhole cover surface will be called the primary current, and the current flowing in the coil antenna inside the IC tag will be called the secondary current.)

  Further, the outside of the IC tag is covered with a main body portion formed of a dielectric resin material, the main body portion is formed in a columnar shape, and a male screw portion in which a male screw is processed on the outer peripheral surface of the columnar shape is formed, A counterbored screw hole that does not penetrate to the back surface of the manhole cover may be formed on the recess side, and the male screw part may be screwed into the screw hole to fix the IC tag.

  Furthermore, a part of the entire circumference of the screw hole can be lost to block the eddy current flow path.

  Furthermore, the first protrusion and the second protrusion are formed in the recess so as to protrude from two adjacent protrusions of the uneven portion, and the first protrusion and the second protrusion face each other. A screw hole into which the male screw part of the IC tag is screwed is formed so that the diameter of the screw hole is larger than the width dimension of the first protrusion and the second protrusion. Some can be lost.

  Further, the plane of the coil antenna of the IC tag is attached in a manner substantially orthogonal to the surface of the manhole cover, and is opposed to the direction in which the screw holes formed in the first and second protrusions are missing. Can be placed in

  On the other hand, the outside of the IC tag is covered with a main body portion formed of a dielectric resin material, the main body portion is formed in a long shape, and does not penetrate to the back side of the manhole cover on the concave side. A long hole that matches the long shape of the IC tag is formed so that it can be inserted, and a drop prevention recess that is recessed toward the side is formed at a position deeper than the predetermined length of the long hole, thereby preventing the drop. The IC tag can be fixed by filling the recess with a resin material.

  Moreover, a part of the entire circumference of the long hole can be lost to block the eddy current flow path.

  Furthermore, the plane of the coil antenna of the IC tag can be arranged so as to be substantially orthogonal to the longitudinal direction of the IC tag.

  Further, the present invention provides a manhole cover IC tag that is attached to a manhole cover and generates an electromagnetic wave for individual identification of the manhole cover. The main body has a dielectric main body that is assembled in a long hole formed on the surface of the main body and has an elongated shape corresponding to the shape of the long hole. A coil antenna that generates electromagnetic waves is flat inside the main body. The IC tag substrate arranged in a shape is embedded, and the coil antenna is arranged so that the plane of the coil antenna is substantially orthogonal to the longitudinal direction of the main body.

  In the IC tag built-in manhole cover according to the present invention, the IC tag is attached by screwing or fitting to a position deeper than a predetermined length, which is an allowable value of wear thinning on the road surface, in the concave portion of the uneven portion. The concave and convex portions are formed such that a standing-wave high-frequency current different from an eddy current flows on the metal surface in the vicinity of the IC tag when a high-frequency electromagnetic wave in the MHz band is applied to the metal surface. Since the coil antenna in the tag is arranged close to the central portion of the standing wave so that the electromagnetic coupling relationship between the primary current and the secondary current of the transformer is established by the high-frequency current, A large secondary current can be generated. Therefore, the magnetic field lines generated from the coil antenna can be strengthened, and the induced electromagnetic wave that reaches the hand (several centimeters) (the electromagnetic wave that is in inverse proportion to the square or the third power of the distance, and that the sensitivity rapidly decreases as the distance increases. ) In addition to radiated electromagnetic waves that reach up to several meters, for example, by standing waves (electromagnetic waves that are inversely proportional to the first power of distance and do not suddenly decrease in sensitivity even at long distances) Can do. As a result, even an IC tag using UHF can allow, for example, communication up to a practical flight distance of several centimeters or the height of the operator's waist without causing misreading. Thereby, even if there is wear over time, the IC tag portion does not easily fall off, and the individual identification information of the IC tag can be detected even when electromagnetic waves in the high frequency band of UHF are used.

  In the IC tag for manhole cover according to the present invention, since the plane of the coil antenna is arranged so as to be substantially orthogonal to the longitudinal direction of the main body, strong electromagnetic waves are generated along the longitudinal direction of the main body having a dielectric. Can be generated. Therefore, the electromagnetic wave reaches a high position from the surface of the manhole cover, and the individual identification information of the IC tag can be detected even when the electromagnetic wave in the high frequency band of UHF is used.

It is a perspective view showing the outline | summary of the electromagnetic induction type IC tag built-in manhole cover based on 1st Embodiment of this invention. It is AA sectional drawing of FIG. It is a perspective view of the IC tag incorporated in a manhole cover incorporating an IC tag. It is sectional drawing of the IC tag shown in FIG. FIG. 3 is an enlarged view of a portion B in FIG. 2 and shows a state in which an IC tag is incorporated between an edge portion and a marking portion. It is the perspective view which looked at FIG. 5 from diagonally upper side. It is a schematic diagram explaining the operation | movement of electromagnetic radiation. It is CC sectional drawing of FIG. 1, Comprising: The state which integrated the IC tag in the vicinity of a post | mailbox is shown. It is an enlarged view of the D section of FIG. FIG. 6 is a top view of a modification of the first embodiment in which an IC tag is incorporated in a rectangular manhole cover. It is a top view of the radiation wave type IC tag built-in manhole cover concerning a 2nd embodiment of the present invention. It is EE sectional drawing of FIG. It is the F section enlarged view of FIG. It is a schematic diagram explaining a radiation | emission radio wave type | mold operation | movement. It is a perspective view of the IC tag used for the electromagnetic induction type IC tag built-in manhole cover according to the third embodiment of the present invention. It is a perspective view which expands and shows the tag insertion long hole of a manhole cover. FIG. 17 is a perspective view showing a state in which an IC tag is assembled in the tag insertion slot shown in FIG. 16 and corresponds to FIG. 6 of the first embodiment. It is GG sectional drawing of FIG. It is a top view of the whole manhole cover which concerns on 3rd Embodiment of this invention. It is sectional drawing of the radiation wave type | mold IC tag built-in manhole cover which concerns on 4th Embodiment of this invention, Comprising: It corresponds to FIG. 14 of 2nd Embodiment.

(First embodiment)
Hereinafter, an electromagnetic induction IC tag built-in manhole cover 1 (hereinafter referred to as a manhole cover 1) according to a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an outline of a manhole cover 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA in FIG. In the following description, the front side in FIG. 1 (upper side in FIG. 2) is referred to as the upper side (the surface side of the manhole cover), and the rear side in FIG. This is called the side (back side).

  As shown in FIG. 1, the manhole cover 1 is formed in a disk shape having a thickness, and an uneven portion 2 is formed on the surface 1 </ b> A of the manhole cover 1. There are various shapes of the concavo-convex portion 2 depending on the size and application (for example, for sewage and gas) of the manhole cover 1, and the concavo-convex shape shown in FIG. 1 is shown as an example.

  As shown in FIG. 1, the concavo-convex portion 2 includes an edge portion 2A continuous along the outer circumference of the manhole cover 1, a marking portion 2B and a post 2C formed on the inner side surrounded by the edge portion 2A, and these The edge portion 2A, the marking portion 2B, and the recessed portion 2D formed to be lower than the post 2C. For example, a mark or character of a city to be used is displayed on the marking unit 2B. Further, a plurality of posts 2C are provided on the inner side surrounded by the edge 2A in order to prevent the surface 1A of the manhole cover 1 from being worn. Further, the concave portion 2D of the concave and convex portion 2 is filled with a resin material 3 to be described later in detail, and the surface of the resin material 3 is substantially flush with the surfaces of the edge portion 2A, the marking portion 2B, and the post 2C. Finished to a state.

  The depth dimension of the concave portion 2D of the concave-convex portion 2 is formed to a predetermined length X (for example, 5 mm) so that the manhole cover 1 can accept a value (about 3 mm in 15 years) that is reduced by thinning due to aging. (See FIG. 2). Note that the IC tag 10, which will be described in detail later, is embedded at a position deeper than the predetermined length X, and the IC tag 10 is not exposed from the manhole cover 1 even if aged wear occurs.

  Further, as shown in FIG. 2, the back surface 1B of the manhole cover 1 is formed with a recess 4 having a shape recessed from the back surface 1B toward the front surface 1A.

  FIG. 3 is a perspective view of the IC tag 10, and FIG. 4 is a cross-sectional view of the IC tag 10. The IC tag 10 includes a main body portion 11 formed of a resin material having dielectric properties and an IC tag substrate 12 embedded in the main body portion 11 so as to be covered with the main body portion 11. The main body portion 11 is formed in a substantially cylindrical shape, and a male screw portion 11A is formed on the outer peripheral surface thereof. The male screw portion 11A is screwed into a screw hole 7 (details will be described later) formed in the manhole cover 1, so that the IC tag 10 is fixed to the manhole cover 1. Further, two screw holes 11B and 11B for rotating the main body part 11 for screwing the IC tag 10 into the screw hole 7 are formed in the upper part of the main body part 11.

  A typical example of the external dimensions of the main body portion 11 of the IC tag 10 has a diameter of 8 mm (M8 screw) and a height dimension H of 4 mm, and is very small. The reason why the downsizing is necessary is due to the strength of the manhole cover 1. That is, in order to attach an IC tag having a large external shape, a larger drilling process (or grooving process) must be performed on the metal portion of the manhole cover 1, resulting in a decrease in strength. Since the manhole cover 1 is to be stepped on by heavy heavy trucks and trailers, the manhole cover 1 must have a high strength, and the strength must be ensured over a long period of time. Therefore, it is necessary to ensure sufficient strength even in anticipation of wear thinning. Therefore, it is desired to make the processing for attaching the IC tag 10 as small as possible.

  The IC tag substrate 12 is formed in a substantially rectangular flat plate shape. As shown in FIG. 4, an IC chip 13 and a coil antenna 14 for the IC tag are arranged on the flat plate surface. Has been. The plane of the IC tag substrate 12 is embedded in the main body 11 so as to be substantially parallel to the center line S of the main body 11 of the IC tag 10. As described above, the IC tag 10 is further miniaturized by embedding the coil antenna 14 inside the main body 11 and not providing it outside the main body 11.

  FIG. 5 is an enlarged view of a portion B in FIG. 2 and shows a state in which the IC tag 10 is incorporated in the recess 2D between the edge portion 2A and the marking portion 2B. FIG. 6 shows a perspective view of FIG. 5 as viewed obliquely from above. As shown in FIG. 6, the IC tag 10 is attached to a recess 2D between the marking portion 2B and the edge 2A. More specifically, the recess 2D has a first protrusion 5A protruding from the side of the marking portion 2B toward the edge 2A, and a second protrusion protruding from the side of the edge 2A toward the marking portion 2B. 5B is formed, and screw holes 7 are formed in the surfaces of the first protrusion 5A and the second protrusion 5B facing each other so that the male screw portion 11A of the main body portion 11 is screwed together. Yes. Moreover, as shown in FIG. 1, the recessed part 2D is extended in the right and left of the 1st protrusion part 5A and the 2nd protrusion part 5B.

  As a method of forming the first protrusion 5A and the second protrusion 5B, a connecting portion that connects the marking portion 2B and the edge portion 2A in the state of the material of the manhole cover 1 is formed. It is formed by drilling a hole from the upper side of the central part. For example, the diameter (M8) of 8 mm of the hole formed by this drill is larger than the width L of the first protrusion 5A and the second protrusion 5B (the width dimension of the connecting portion; about 6 mm). The part 5A and the second projecting part 5B are configured in such a manner that the edge part 2A side and the marking part 2B side are completely divided by this drill hole (with the side part of the connecting part missing). . Then, the screw hole 7 is formed by tapping the hole drilled. Although it is possible to form holes from the beginning with a mold, etc., in order to make it easier to understand, the explanation was given by drilling in trial production or small-scale production. It goes without saying that the formation of the defect part may be performed by mass production, for example, by pouring molten metal into a mold or by other rational methods.

  The IC tag 10 is attached to the manhole cover 1 such that the center line S of the IC tag 10 is directed in the vertical direction by screwing the male screw portion 11A into the screw hole 7. That is, the plane of the IC tag substrate 12 inside the IC tag 10 is attached in a manner that is substantially orthogonal to the surface 1A of the manhole cover 1. Note that “substantially orthogonal” means that it is allowed to deviate at a certain angle, and it is not limited to being strictly orthogonal. Further, the IC tag 10 is arranged so that the surface of the coil antenna 14 of the IC tag substrate 12 inside the IC tag 10 faces the direction in which the screw holes 7 formed in the first protrusion 5A and the second protrusion 5B are missing. Align the rotational position of the screw. That is, the screw rotation position is set so that the metal of the screw portion 7 does not interfere with the lines of magnetic force Φ passing through the surface of the coil antenna 14.

  As shown in FIGS. 5 and 6, the depth of the screw hole 7 is a dimension (X + H) obtained by adding the height dimension H (4 mm) of the IC tag 10 to the predetermined length X (5 mm) of the recess 2D described above. It is formed with. That is, in a state where the IC tag 10 is completely screwed down to the lower side of the screw hole 7, the head portion 10A of the IC tag 10 is positioned below the predetermined length X. Thereby, even if the surface 1A of the manhole cover 1 is reduced in thickness due to aging, the IC tag 10 is not likely to be exposed from the manhole cover 1.

  Further, as shown in FIG. 5, the screw hole 7 does not penetrate to the depression 4 on the back surface 1 </ b> B side of the manhole cover 1 and is formed in a counterbore shape having a bottom. Therefore, the IC tag 10 does not fall down from the back surface 1B side. Moreover, since it is not a through hole, it can be manufactured without weakening the rigidity of the manhole cover 1. Furthermore, since it is not a through hole, for example, when the manhole cover 1 is used for sewerage, even if the back surface 1B side is immersed by overflowing sewage, there is no possibility that the IC tag 10 gets wet.

  Moreover, as shown in FIG. 6, the inclined groove part 8 of the aspect which dug down the bottom face of the recessed part 2D further downward is formed in the right-and-left both sides of the 1st protrusion part 5A and the 2nd protrusion part 5B. The inclined groove portion 8 is such that the side portion (the male screw portion 11A) of the IC tag 10 extends from the side surfaces of the first protrusion portion 5A and the second protrusion portion 5B in a state where the IC tag 10 is completely screwed down to the lower side of the screw hole 7. It is formed to be exposed. In other words, the inclined groove 8 is formed so that the first protrusion 5A and the second protrusion 5B are completely separated at the side of the IC tag 10 in a state where the IC tag 10 is completely screwed. Has been.

  As described above, the structure in which the first protrusion 5A and the second protrusion 5B are separated from each other is that when an electromagnetic wave is applied to the surface 1A of the manhole cover 1, the IC tag is applied to the surface 1A of the manhole cover 1. This is to prevent an eddy current centering around 10 from being generated. That is, by adopting a structure in which the first protrusion 5A and the second protrusion 5B are completely separated, the first protrusion 5A passes through the surface of the manhole cover 1 to the second protrusion 5B (second The flow path of the eddy current flowing from the protrusion 5B to the first protrusion 5A can be interrupted, thereby preventing the generation of eddy current.

  The resin material 3 filled in the concave portion 2D of the concave and convex portion 2 covers the upper side of the IC tag 10 in the injected state. Thereby, the resin material 3 protects the IC tag 10 from dropping from the manhole cover 1. In addition, if a resin material 3 having no adhesive action or a weak material is used, even if the resin material 3 is peeled off from the recess 2D, the resin material 3 may be dropped together with the IC tag 10. It does not apply a strong force (prevention of infection peeling).

  The resin material 3 also plays a role of notifying the replacement life of the manhole cover 1. That is, since the resin material 3 is injected so as to fill the predetermined length X, when the resin material 3 is worn by the predetermined length X and the metal surface of the recess 2D is exposed, It can be known that the wear limit of the manhole cover 1 has been reached.

  As the resin material 3, a material that allows electromagnetic waves to freely pass therethrough is used. The resin material 3 is formed by mixing a radio wave medium such as a dielectric or magnetic powder, or a mixture of dielectric and magnetic powder in order to improve the flow of the magnetic path. There may be. The resin material 3 may be made of variously colored materials according to the type of the manhole cover 1. Furthermore, the resin material 3 can have an anti-slip effect, or can have a waterproof and rust-proof effect.

  Further, as shown in FIGS. 1, 2, 5, and 6, an IC tag enclosing mark 6 is provided in the vicinity of the portion where the IC tag 10 is embedded so that the embedded portion can be visually recognized. For example, as shown in FIG. 5, the IC tag enclosing mark 6 has a counterbored hole 6A formed from the surface 1A side to the back side of the manhole cover 1, and a colored resin material 6B is injected into the counterbored hole 6A. Has been. This coloring uses a color different from that of the resin material 3 injected into the recess 2D described above so that the operator can recognize the mark.

  In the manhole cover 1 having the above-described structure, even when a high frequency electromagnetic wave in the MHz band is applied from above the manhole cover 1, as described above, the first protrusion 5A to which the IC tag 10 is fixed and the first protrusion 5A are fixed. No eddy current is generated on the surface of the two protrusions 5B. Instead, the high frequency current IA flows along the surface of the metal of the manhole cover 1. This principle will be described with reference to FIG.

  FIG. 7 is a schematic diagram for explaining the operation of electromagnetic radiation. In FIG. 7, for convenience of explanation, the resin material 3 as a dielectric and the main body 11 of the IC tag 10 are omitted. FIG. 7 schematically shows the current flowing along the cross section of FIG. As described above, the high-frequency current IA flows along the metal surface of the manhole cover 1. In addition, this metal surface means all the surfaces of the uneven | corrugated | grooved part 2 formed in the surface 1A of the manhole cover 1, and the surface of the resin material 3 is not included.

  That is, the high-frequency current (primary current) IA is, for example, the upper surface of the marking portion 2B that is a metal surface → the upper surface of the first protrusion 5A → the screw portion of the screw hole 7 of the first protrusion 5A → the screw hole 7. It flows in the path of the bottom surface → the threaded portion of the screw hole 7 of the second protrusion 5B → the upper surface of the second protrusion 5B → the upper surface of the edge 2A (traveling wave). On the other hand, the current IA is reflected by a discontinuous portion such as an end portion of the manhole cover 1 and flows while following a path opposite to the above-described path (reflected wave). At this time, a standing wave of a current in which two currents of a traveling wave and a reflected wave interfere with each other is formed. As is well known in electromagnetism and the like, standing waves are generated in the current path in a number of ways, resulting in a plurality of knot CFs. From standing waves, radiated electromagnetic waves that reach far away, such as waist height, are emitted. The distance between the CF and CF of the standing wave is the path length of the high-frequency current IA and corresponds to half the wavelength. In other words, the distance between CF and CF can be determined from the wavelength of the high-frequency current IA induced by electromagnetic waves. In addition, the said discontinuous part refers to the site | part where the surface changes suddenly from a flat part in the metal surface like the manhole cover 1. FIG. Examples of the discontinuous portion where the surface is interrupted include an outer edge and an end portion of the edge portion 2A. As a discontinuous portion where the surface changes abruptly although it is not a place where it is interrupted, there are, for example, a portion where the metal surface of the concavo-convex portion 2 suddenly rises and a corner portion where it suddenly falls.

  That is, the direction of the standing wave is switched at a distance of λ / 2 with respect to the wavelength λ of the electromagnetic wave. Further, the maximum wave height of the standing wave is the central portion of one standing wave. Based on these, the center portion of the wavelength of the standing wave is configured to come to the bottom surface 7A of the screw hole 7. Further, the coil antenna 14 of the IC tag 10 is arranged so as to be close to the central portion of the standing wave.

  On the other hand, the secondary current IB amplified by using the high frequency current IA as the primary current of the transformer flows through the coil antenna 14 on the IC tag substrate 12. On the surface 1A side of the manhole cover 1, a high-frequency magnetic field line Φ induced by the secondary current IB is generated.

  As shown in FIG. 7, when the magnetic field lines Φ form a closed loop and start from the center of the coil antenna 14, the surface extends from the surface 1A of the manhole cover 1 to the external space, and again the surface of the manhole cover 1 A closed loop is formed from 1A to the center of the coil antenna 14 as an end point. The loop of the magnetic lines of force Φ is formed so as to be surely closed according to electromagnetics. Also, the loop path of the magnetic lines of force Φ passes through a lossless medium (dielectric or magnetic material) such as vacuum, air, or an insulator, and does not pass through a conductor such as a metal through which a current flows. Therefore, recesses 2D are formed on the left and right sides of the first protrusion 5A and the second protrusion 5B so that there is no disturbing metal in the loop path of the lines of magnetic force Φ.

  On the other hand, the IC tag 10 can be incorporated into the recess 2D near the post 2C, for example, other than the recess 2D between the edge 2A and the marking portion 2B. FIG. 8 is a cross-sectional view taken along the line CC of FIG. 1 and shows the IC tag 10 incorporated in the recess 2D near the post 2C. FIG. 9 is an enlarged view of a portion D in FIG.

  The IC tag 10 shown in FIGS. 8 and 9 is embedded in a recess 2D located between two posts 2C and 2C. This attachment structure is the same as the structure attached between the edge 2A and the marking portion 2B described above, and the first protrusion 5A and the second protrusion 5B are provided so as to face each other, and the screw hole between them. The IC tag 10 is screwed onto 7. The structure in which the IC tag 10 is attached below the predetermined length X is also the same. Further, it goes without saying that the structure of the recess 2D is devised to remove interference such as an inclined portion 8 as shown in FIG. 6 so that there is no interfering metal in the closed magnetic field line loop path passing through the IC tag substrate 12. Yes.

  In the structure shown in FIGS. 8 and 9, the IC tag enclosing mark 6 is provided on one of the posts 2C. As a result, the operator can visually confirm the position of the IC tag 10.

  Further, the first protrusion 5A and the second protrusion 5B include not only the above-described recess 2D between the marking portion 2B and the edge 2A and the recess 2D between the two posts 2C and 2C, but also, for example, an edge The IC tag 10 can be attached by forming the recess 2D between the portion 2A and the post 2C or the recess 2D between the marking portion 2B and the post 2C. In other words, the concave portion 2D located between two adjacent convex portions (any two of the edge portion 2A, the marking portion 2B, and the post 2C) of the concave-convex portion 2 protrudes toward the respective convex portions. One protrusion 5A and second protrusion 5B can be formed.

  That is, when the IC tag incorporated in the metal substrate of the manhole cover 1 is an electromagnetic induction type using the coil antenna 14, it is incorporated so that the coil surface of the coil antenna 14 stands upright with respect to the metal surface to be installed. The structure is such that electromagnetic waves radiated from the laser beam are not directly incident on the surrounding metal surface, and the high-frequency current flowing in the coil antenna 14 inside the IC tag and the high-frequency current induced on the nearest metal surface are stronger electromagnetic waves. For example, installation is performed by induction so as to perform strong electromagnetic coupling that is a relationship between a primary current and a secondary current of a transformer, for example. With these contrivances, even if the IC tag information detection electromagnetic wave from the reader reaches the surface 1A of the manhole cover 1 even if the IC tag operates with UHF, which is a radiation electromagnetic wave that arrives in inverse proportion to the detection distance, A high frequency current IA that flows along the surface of the groove flows. This can be regarded as a strong electromagnetic coupling of the transformer in which the surface current is the primary current IA and the current flowing through the coil antenna 14 in the IC tag is the secondary current IB. From such an operation, the manhole cover 1 was buried in a deeper part than the metal surface of the manhole cover 1, that is, in a predetermined recess 2D or a depression having a depth X which is considered to be consumed due to wear or thinning, for example, a depth X of 5 mm or more. For example, a small-diameter (20 cm in diameter) lid can be normally detected from 5 cm above without erroneously detecting an adjacent manhole lid.

  Further, in the case of the IC tag 10 that operates by induced electromagnetic waves such as UHF and microwaves, even if it is disposed at a depth that does not cause impact or wear on the metal surface of the manhole cover 1, the external space of the manhole cover 1 is practical. It is possible to operate at a height of the waist of the worker due to radiated electromagnetic waves from a short distance, for example, a practical distance that does not cause misreading, and a distance of several centimeters of the worker's hand.

  According to the electromagnetic induction IC tag built-in manhole cover 1 according to the first embodiment of the present invention, it is within the concave portion 2D of the concave and convex portion 2 and is longer than a predetermined length X that is an allowable value for wear thinning on the road surface. When the IC tag 10 is attached to a deep position by screwing and a high frequency electromagnetic wave in the MHz band is applied to the metal surface, a standing wave high frequency current IA different from the eddy current flows on the metal surface in the vicinity of the IC tag 10. The uneven portion 2 is formed as described above, and the coil antenna 14 in the IC tag 10 is brought close to the center portion of the standing wave so that the electromagnetic coupling relationship between the primary current and the secondary current of the transformer is established by the high-frequency current IA. Therefore, a large secondary current can be generated by the coil antenna 14. Therefore, the magnetic force line Φ generated from the coil antenna 14 can be strengthened. That is, it is possible to generate a radiated electromagnetic wave reaching several meters in addition to the induced electromagnetic wave reaching the hand (several centimeters). As a result, even with the IC tag 10 using UHF, for example, communication up to the waist level of the worker can be permitted.

  In addition, since the IC tag 10 is attached by screwing at a position deeper than the predetermined length X, which is an allowable value for wear thinning on the road surface, the IC tag 10 is detached from the manhole cover 1 even if aged wear occurs. You can avoid it. In addition, by screwing into such a deep position with a screw, the structure is such that the operator does not attach and detach the IC tag 10 as necessary, so that the integrity of the IC tag 10 and the manhole cover 1 is ensured, and the individual There is no risk of errors in the identification information.

  Further, the outer side of the IC tag 10 is covered with a main body portion 11 formed of a dielectric resin material, the main body portion 11 is formed in a columnar shape, and a male screw portion whose male screw processing is applied to the outer peripheral surface of the columnar shape. 11A is formed, a counterbored screw hole 7 not penetrating to the back surface 1B of the manhole cover 1 is formed on the recess 2D side, and the male screw portion 11A is screwed into the screw hole 7 to fix the IC tag 10 Therefore, once the IC tag 10 is attached, it can be prevented from falling off. Thereby, the integrity of the IC tag 10 and the manhole cover 1 is ensured, and there is no possibility that an error occurs in the individual identification information.

  Further, since the outside of the IC tag 10 is configured by the main body 11 and no other antennas are configured outside, the IC tag 10 itself can be configured in a small size. As a result, the IC tag 10 can be attached without unnecessarily large processing on the manhole cover 1, so that the rigidity of the manhole cover 1 is not lowered more than necessary.

  Furthermore, since a part of the entire circumference of the screw hole 7 is lost and the flow path of the eddy current is blocked, the generation of eddy current can be suppressed by simpler processing.

  Further, the concave portion 2D includes a first protruding portion 5A and a first protruding portion protruding from two adjacent protruding portions (any two of the edge portion 2A, the marking portion 2B, and the post 2C) of the uneven portion 2 respectively. Two protrusions 5B are formed, and screw holes 7 into which the male screw portions 11A of the IC tag 10 are screwed are formed on the mutually opposing surfaces of the first protrusion 5A and the second protrusion 5B. Since the diameter of the screw hole 7 is formed to be larger than the width dimension L of the two protrusions 5B and a part of the entire circumference of the screw hole 7 is lost, the first protrusion 5A and the second protrusion The part 5B can be configured to be separated (deleted) by the screw hole 7. As a result, even if an electromagnetic wave in the UHF band is applied to the metal surface, the flow path of the eddy current centering on the IC tag 10 is cut off, so that eddy current can be prevented from being generated.

  Furthermore, the coil antenna 14 of the IC tag 10 is attached in a manner substantially orthogonal to the surface of the manhole cover 1, and the screw holes 7 formed in the first protrusion 5A and the second protrusion 5B are missing. Since they are arranged so as to face each other, the secondary current IA that flows through the bottom of the screw hole 7 and the secondary current IB that flows through the coil antenna 14 can be arranged close to each other. As a result, the high-frequency magnetic field lines Φ induced by the secondary current IB can be made stronger.

  The electromagnetic induction type IC tag built-in manhole cover 1 according to the first embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various types can be made based on the technical idea of the present invention. Variations and changes are possible.

  For example, in this embodiment, the secondary current IB is electromagnetically induced using the high-frequency current IA flowing along the bottom surface 7A (metal surface) of the screw hole 7, but the screw hole 7 is processed by a drill or the like. The bottom surface 7A does not necessarily become a flat surface, and is processed into a concave shape in a mountain shape similar to the tip shape of a general drill. In this case, the distance between the primary current IA flowing along the bottom surface recessed in the mountain shape and the secondary current IB flowing through the coil antenna 14 is increased, which is not suitable for electromagnetic induction. Therefore, the primary current IA flows in parallel with the coil antenna 14 along the metal plate so that a conductive metal plate such as aluminum is attached to the bottom surface of the main body 11 of the IC tag 10. It can also be devised. According to this, it becomes possible to obtain electromagnetic waves with more stable intensity.

  In the present embodiment, the outer shape of the manhole cover 1 has been described as a circular shape (disc shape), but is not limited thereto. For example, as shown in FIG. 10, the present invention can be similarly applied to a small and square manhole cover 50 that is often seen as a cover of a water meter or the like. A plurality of lattice ribs 51 are formed on the surface of the manhole cover 50, and the resin material 3 is injected into the recesses between the lattice ribs 51. The IC tag 10 can be attached to any one of the recesses below the resin material 3. Further, the IC tag enclosing mark 6 can be provided in the vicinity of the IC tag 10.

  Furthermore, in this embodiment, the communication distance is increased by electromagnetic induction. However, if the distance over which the radio wave reaches is longer than necessary, the communication distance may be adjusted by the reader software. For example, when the installation positions of the adjacent manhole covers 1 are close, it is conceivable that the individual identification information of the adjacent manhole cover 1 is detected if the communication distance is long. Therefore, such erroneous detection can be prevented by adjusting the communication distance to be short.

  Further, in the present embodiment, external thread processing is performed on the outside of the main body portion 11 of the IC tag 10, the screw hole 7 is formed on the concave portion 2D side, and these are fixed by screwing, but the present invention is not limited to this. . For example, you may make it fix the main-body part 11 by fitting to the screw hole 7 (however, threading is unnecessary). As a result, the IC tag 10 is not easily detached from the recess 2D, so that the integrity of the IC tag 10 and the manhole cover 1 can be ensured, and there is no possibility of errors in the individual identification information.

(Second Embodiment)
Hereinafter, a radiation wave type IC tag built-in manhole cover 101 (hereinafter referred to as a manhole cover 101) according to a second embodiment of the present invention will be described. FIG. 11 is a top view of a manhole cover incorporating a radiated radio wave type IC tag according to the second embodiment of the present invention. 12 is a cross-sectional view taken along line EE in FIG. 11, and FIG. 13 is an enlarged view of a portion F in FIG. Furthermore, FIG. 14 is a schematic diagram for explaining the operation of the radiated radio wave type.

  The manhole cover 101 is obtained by changing the shape of the uneven portion 102 on the surface 1A of the manhole cover 1 used in the first embodiment, and the IC tag and its mounting structure. Hereinafter, differences from the manhole cover 1 will be described, and the same structure will be denoted by the same reference numerals and detailed description thereof will be omitted.

  As shown in FIG. 11, the uneven portion 102 of the manhole cover 101 includes an edge portion 102 </ b> A continuous along the outer peripheral circle of the manhole cover 101, and a marking portion formed at substantially the center of the range surrounded by the edge portion 2 </ b> A. 102B, a post 102C erected between the edge portion 102A and the marking portion 102B, and a concave portion 102D formed lower than the edge portion 102A, the marking portion 102B and the post 102C. Yes.

  The IC tag 110 is a metal-compatible IC tag, and as shown in FIGS. 12 and 13, the outside is covered with a metal box. This outer metal box serves as an antenna for the IC tag. Further, the IC tag 110 includes the IC tag 10 described in the first embodiment and the structures of the first protrusion 5A and the second protrusion 5B that support the IC tag 10 as they are. . Therefore, as described in the first embodiment, in this IC tag 110, generation of eddy current is suppressed by itself, and electromagnetic waves are not canceled by this eddy current.

  As shown in FIGS. 12 and 13, the IC tag 110 is placed and attached in a groove 109 that is recessed further toward the back surface 1 </ b> B than the recess 102 </ b> D. The depth of the groove 109 is formed deeper than the height H of the IC tag 110. As a result, the head of the IC tag 110 is positioned below the recess 102D, and the IC tag 110 does not fall off even if wear thinning proceeds beyond the predetermined length X of the recess 102D. Yes. A mounting base 108 is attached below the IC tag 110 and between the IC tag 110 and the metal surface of the manhole cover 101, and is integrated so as not to drop off. For example, the integration method is welding or screwing although not shown in the figure.

  The resin material 3 is injected into the recess 102D with the IC tag 110 attached to the groove 109. With this resin material 3, the IC tag 110 is fixed at a predetermined position.

  Next, operation of radiated radio waves using the IC tag 110 will be described with reference to FIG. When an electromagnetic wave in the MHz band is emitted toward the IC tag 110, a high-frequency current IF flows on the top of the IC tag 110 in a direction from the paper surface to the back side as shown in FIG. Due to the current IF, the lines of magnetic force φ are generated in a loop according to the right-handed screw law. When there is no metal surface that prevents this magnetic field line Φ on the loop path, the magnetic field line Φ is transmitted to the outside space as a radiated radio wave. In FIG. 14, the radiated electromagnetic wave is shown by cutting off a part of the state in which the loop of the magnetic lines of force Φ is continuous above the manhole cover 101. Incidentally, a set of magnetic field lines Φ having different directions corresponds to one wavelength λ.

  According to the radiated radio wave type IC tag built-in manhole cover 101 according to the second embodiment of the present invention, the IC tag is a radiated radio wave type, sufficiently small in size, and the depression of the manhole cover 1 on which the IC tag is installed can also ensure mechanical strength. In some cases, the IC tag incorporated into the manhole cover 1 from the beginning can be a radiated radio wave type. Radiated radio wave type IC tags are considered to be electromagnetic induction type because a mechanism to strongly combine the electromagnetic coupling strength between the primary current flowing on the metal surface and the secondary current flowing inside the IC tag from the beginning is completed. In addition, it is not necessary to consider a close arrangement for causing strong electromagnetic coupling between the primary current and the secondary current. For this reason, with UHF radio waves, a flight distance of several tens of centimeters or more can be secured even if the depth of incorporation is 5 mm or more. Thereby, the manhole identification work burden is greatly reduced. The radiated radio wave type has a relatively large flight distance. Therefore, if the manhole cover has a small diameter, the possibility of erroneous detection up to the adjacent cover increases. Therefore, a large-diameter lid is suitable.

  In addition, by using a manhole cover with a built-in IC tag for radiated radio wave operation, identification work on the road can be performed at the height of the operator's waist, reducing the work burden. As a result, road closure time can be shortened, underground information acquisition and maintenance management human errors can be reduced, information accuracy can be improved, and safety can be improved.

  As described above, the radiation wave type IC tag built-in manhole cover 101 according to the second embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various types can be made based on the technical idea of the present invention. Variations and changes are possible.

  For example, in the present embodiment, the outer shape of the manhole cover 1 has been described as a circular shape (disc shape), but is not limited thereto. That is, as shown in FIG. 10 described in the modification of the first embodiment, the present invention can be similarly applied to a small and square manhole cover 50 that is often seen as a cover of a water meter or the like.

  Furthermore, in this embodiment, as described in the modification of the first embodiment, when the distance that radio waves reach is longer than necessary, the communication distance can be adjusted to be short by the reader software. Good.

(Third embodiment)
Hereinafter, an electromagnetic induction IC tag built-in manhole cover 201 (hereinafter referred to as a manhole cover 201) and a manhole cover IC tag 210 according to a third embodiment of the present invention will be described. FIG. 15 is a perspective view showing the IC tag 210 as a single unit. FIG. 16 is an enlarged perspective view showing the tag insertion slot 207 of the manhole cover 201. Further, FIG. 17 is a perspective view (corresponding to FIG. 6) showing a state in which the IC tag 210 is assembled in the tag insertion slot 207, and FIG. 18 is a cross-sectional view taken along line GG in FIG.

  A manhole cover 201 according to the third embodiment of the present invention is obtained by changing the shape of the uneven portion 2 of the manhole cover 1 described in the first embodiment, the shape of the IC tag 10 to be attached, and the attachment structure of the IC tag 10. is there. In the following description, different points from the manhole cover 1 will be described, and the same structure will be denoted by the same reference numerals and detailed description thereof will be omitted.

  As shown in FIG. 15, the IC tag 210 is long in the M direction (a direction substantially orthogonal to the plane of the IC tag substrate 12) and is formed in a substantially rectangular parallelepiped shape. Note that the substantially rectangular parallelepiped shape is merely an example, and may be another rectangular shape. The IC tag substrate 12 is embedded in the main body 211 formed of a resin material having dielectric properties. Moreover, the height dimension H of the main-body part 211 is formed in the same dimension as the main-body part 11 shown in 1st Embodiment. Although the length of the IC tag 210 in the longitudinal direction will be described in detail later, the lines of magnetic force Φ emitted perpendicularly from the plane of the IC tag substrate 12 (plane of the coil antenna 14 of the IC tag 12) (see FIG. 7) The length of the magnetic path can be secured.

  On the other hand, between the first protrusion 205A and the second protrusion 205B of the manhole cover 201, a tag insertion slot 207 and a bottom 207B are formed as shown in FIG. The shape of the side wall surface of the tag insertion elongated hole 207 is the same as the shape of the outer surface of the IC tag 210 or is formed to have a slight gap, and the IC tag 210 is inserted into the tag insertion hole 207 from the surface 1A side ( To the bottom portion 207B (see FIG. 17). Further, the side wall surface of the tag insertion slot 207 has a function of contacting the outer surface of the IC tag 210 and guiding it in the insertion direction when the IC tag 210 is inserted into the tag insertion slot 207. The bottom portion 207B is formed with a concave portion on the bottom surface of the concave portion 2D so that the above-described IC tag 210 can be attached and fixed to the manhole cover 201 to match the substantially rectangular parallelepiped shape of the IC tag 210.

  As shown in FIG. 16, the tag insertion slot 207 is formed so that its longitudinal direction is directed to the recess 2D (a direction substantially orthogonal to the protruding directions of the first protrusion 205A and the second protrusion 205B). Has been. Thus, when the IC tag 210 is inserted into the tag insertion slot 207, the orientation of the IC tag 210 is constant, and the orientation of the IC tag substrate 12 embedded in the IC tag 210 is always constant. More specifically, the plane of the IC tag substrate 12 is substantially perpendicular to the surface 1A of the manhole cover 201 and substantially perpendicular to the direction toward the recess 2D (the first protrusion 205A and the second protrusion 205B). It is attached in a protruding direction (a direction parallel to the opposing direction). As a result, the magnetic lines of force Φ draw a closed loop toward the recess 2D (see FIG. 7).

  Separation grooves 209 extending to both side portions (recessed portions 2D) of the first protrusion 205A and the second protrusion 205B are formed at both ends in the longitudinal direction of the tag insertion slot 207, respectively. The separation groove 209 and the tag insertion hole 207 completely separate the first protrusion 205A and the second protrusion 205B in the protrusion direction (part of the entire circumference of the tag insertion long hole 207 is lost). An eddy current is not generated on the surface 1A of the protrusion 205A and the second protrusion 205B.

  As shown in FIG. 18, the depth of the tag insertion slot 207 is formed by a dimension (X + H) obtained by adding a height dimension H of the IC tag 210 to a predetermined length X of the recess 2D. Is attached to the bottom 207B so as to be pushed down below a predetermined length X. Further, a drop-off preventing recess 207A is formed on both sides of the IC tag 210 attached to the bottom 207B (on both sides in the protruding direction of the first protrusion 205A and the second protrusion 205B).

  The drop-off preventing recess 207 </ b> A is formed over the entire length of the tag insertion slot 207 in the longitudinal direction. As shown in FIG. 18, when the recess 2D is filled with the resin material 3 after the IC tag 210 is attached, the resin material 3 is dropped along the recess 2D. It flows into the bottom part 207B. The side surface of the resin material 3 covering the recess 2D is caught by the resin material 3 flowing (filled) into the drop prevention recess 207A to prevent the resin material 3 filled in the tag insertion slot 207 from being peeled off. Deviation of the tag 210 can be prevented.

  FIG. 19 is a plan view of the entire manhole cover 201 according to the third embodiment of the present invention. The IC tag 210 is inserted into the above-described tag insertion slot 207 (formed long in the left-right direction, with a separation groove 209) at the upper right side (indicated by reference numeral K) in FIG. With the configuration of the K portion, a stronger electromagnetic wave can reach a position higher than the surface 1A of the manhole cover 201.

On the other hand, in order to prevent erroneous detection with electromagnetic waves generated from other adjacent manhole covers, it may be desired to weaken the electromagnetic waves (so that they do not reach a high position). At that time, as shown in the upper left part of FIG. 10 (indicated by reference numeral M), the separation groove 209 is not provided in the longitudinal direction end of the tag insertion slot 207 (covers the entire outer periphery of the IC tag 210). by doing,
The electromagnetic wave can be prevented from reaching a high position.

  The IC tag 210 can be attached to either one or both of the above-described K part and M part. As described above, by selecting and attaching the IC tag 210 to the K part and the M part depending on the type of the manhole cover, the installation position, and the like, the individual identification information can be acquired according to the situation.

  The orientations in the longitudinal direction of the K part and the M part shown in FIG. 19 are merely examples, and can be configured to be arbitrarily oriented vertically and horizontally in accordance with the shape of the recess 2D. Further, the manhole cover 201 does not necessarily have to be provided with one each of the K part and the M part shown in FIG. 19, and may be a manhole cover provided with only the K part or only the M part.

  According to the electromagnetic induction type IC tag built-in manhole cover 201 according to the third embodiment of the present invention, the outside of the IC tag 210 is covered by the main body 211 formed of a dielectric resin material, and the main body 211 is long. A tag insertion length that is formed in a substantially rectangular parallelepiped shape and does not penetrate the back surface 1B of the manhole cover 201 on the side of the recess 2D so that the IC tag 210 can be inserted. A hole 207 is formed, and a drop-off preventing recess 207A that is recessed toward the side is formed at a position deeper than a predetermined length X of the tag insertion slot 207, and the resin material 3 is filled into the drop-off preventing recess 207A. Thus, since the IC tag 210 is fixed, it is not necessary to form the IC tag 20 in a screw shape and screw it together as in the first embodiment. For this reason, the IC tag 210 can be easily assembled.

  Further, the resin material 3 filled in the drop-off preventing recess 207A becomes resistant to the force to peel the resin material 3 upward, and has a function of increasing the strength of preventing the resin material 3 from peeling.

  Furthermore, by forming the IC tag 210 to be long, it is not necessary to provide the inclined groove portion 8 (see FIG. 6) provided in the first embodiment. More specifically, the inclined groove portion 8 is formed in order to secure a magnetic path of the magnetic lines of force Φ (see FIG. 7) emitted from the plane of the IC tag substrate 12 in the vertical direction. Thus, it is necessary to form the inclined groove portion 8 in the concave portion 2D by forming the IC tag 210 in a long shape so that a magnetic path can be secured in the length direction (M direction in FIG. 15). Absent. Therefore, the shape of the uneven portion 2 of the manhole cover 201 can be configured more simply.

  Further, by forming the IC tag 210 and the tag insertion elongated hole 207 to be long, the mounting direction of the IC tag 210 is determined to be one. Therefore, the orientation of the plane of the IC tag substrate 12 embedded in the IC tag 210 can always be attached in a certain direction (direction toward the recess 2D) simply by attaching the IC tag 210. Therefore, it is not necessary to adjust the orientation of the plane of the IC tag substrate 12 when the IC tag 10 is fixed by screwing as in the first embodiment, and the assembling work of the IC tag 210 can be easily performed.

  On the other hand, the IC tag 210 is assembled in a tag insertion slot 207 formed on the surface of the manhole cover 201, and has a dielectric main body 211 formed in a long shape according to the shape of the tag insertion slot 207. The IC tag substrate 12 in which the coil antenna 14 for generating electromagnetic waves is arranged in a planar shape is embedded inside the main body 211, and the plane of the coil antenna 14 is substantially orthogonal to the longitudinal direction of the main body 211. Therefore, a strong electromagnetic wave can be generated along the longitudinal direction of the main body 211 formed of a dielectric. Therefore, the electromagnetic wave reaches a high position from the surface 1A of the manhole cover 201, and the individual identification information of the IC tag 210 can be detected even when the electromagnetic wave in the high frequency band of UHF is used.

  In the third embodiment, the first protrusion 205A and the second protrusion 205B are completely separated by the tag insertion slot 207 and the separation groove 209 (a part of the entire circumference of the tag insertion slot 207 is lost). However, it is also possible to provide the tag insertion slot 207 continuously up to both side portions (recess 2D) of the first protrusion 205A and the second protrusion 205B without providing the separation groove 209. That is, the separation groove 209 may not be provided, and the separation may be completely performed only by the tag insertion hole 207.

  In this embodiment, the IC tag 210 is configured in a long and substantially rectangular parallelepiped shape, and the tag insertion long hole 207 is formed in a shape matching the IC tag 210. However, the present invention is not limited to a substantially rectangular parallelepiped shape. That is, when the IC tag 210 is attached to the tag insertion slot 207, if the orientation of the IC tag 210 is always constant (the direction of the plane of the IC tag substrate 12 toward the recess 2D), an elliptical shape, other It may be a polygonal shape.

(Fourth embodiment)
Hereinafter, a radiation wave type IC tag built-in manhole cover 301 (hereinafter referred to as a manhole cover 301) according to a fourth embodiment of the present invention will be described. FIG. 20 is a cross-sectional view of a radiation wave type IC tag built-in manhole cover according to the fourth embodiment of the present invention, and corresponds to FIG.

  The manhole cover 301 according to the fourth embodiment is obtained by changing the shape of the uneven portion 102 of the manhole cover 101 described in the second embodiment and the mounting structure of the IC tag 110. In the following description, differences from the manhole cover 101 will be described, and the same structure will be denoted by the same reference numerals and detailed description thereof will be omitted.

  As shown in FIG. 20, the IC tag 110 is placed and attached in a groove 309 that is further recessed toward the back surface 1B side than the recess 302D. The depth of the groove 309 is formed deeper than the height H of the IC tag 110. As a result, the head of the IC tag 110 is positioned below the recess 302D, and the IC tag 110 does not fall off even if the wear reduction progresses beyond the predetermined length X of the recess 302D. Yes. A mounting base 108 is attached below the IC tag 110 and between the IC tag 110 and the metal surface of the manhole cover 301 so as not to drop off. For example, the integration method is welding or screwing although not shown in the figure.

  Further, as shown in FIG. 20, a drop-off preventing recess 331 is formed on both sides of the attached IC tag 210, respectively. The dimension in the height direction of the drop-off preventing recess 331 is formed to be larger than the height dimension of the mounting base 108 of the IC tag 210. Further, the drop-off preventing concave portion 331 is formed over the entire length of the groove portion 309 in the longitudinal direction. As shown in FIG. 20, when the resin material 3 is filled in the recess 2 </ b> D after the IC tag 110 is placed and disposed in the drop-off prevention recess 331, the resin material 3 flows along the recess 302 </ b> D. . The IC tag 210 is pressed from the side by the resin material 3 flowing (filled) into the drop-off preventing recess 331 and is fixed at the bottom of the groove 309.

  In addition, the resin material 3 filled in the drop-off prevention recess 331 becomes resistant to the force that peels the resin material 3 upward, and has a function of increasing the strength of preventing the resin material 3 from peeling. Thereby, it is possible to prevent the IC tag 110 from being detached together with the peeling of the resin material 3.

1, 50, 201 IC tag built-in manhole cover (manhole cover)
1A surface
1B back
2, 102, 202 Concavity and convexity
2A, 102A edge
2B, 102B Marking part
2C, 102C post
2D, 102D recess
3 Resin materials
4 depressions
5A, 205A first protrusion
5B, 205B 2nd protrusion
6 IC tag inclusion mark
6A counterbored hole
6B resin material
7 Screw holes
7A Bottom of screw hole
8 Inclined groove
10 IC tag 10A IC tag surface
11 Body
11A Male thread
11B Screw hole
12 IC tag board
13 IC chip
14 Coil antenna
51 lattice ribs
101, 301 Manhole cover with built-in radiation type IC tag (manhole cover)
108 Mounting base
109, 309 Groove
110 IC tag 207 Tag insertion slot 207A Fall-off prevention recess 207B Bottom 209 Separation groove 210 IC tag (IC tag for lid)
211 Body 331 Fall-off prevention recess IA High-frequency current (primary current)
IB secondary current
IF high frequency current
CF standing wave milestone
L Width of the first and second protrusions
H IC tag height
S IC tag center line
X Predetermined length (predetermined depth)
Φ Magnetic field lines

Claims (2)

In a manhole cover on which a concavo-convex part is formed on the metal surface and an IC tag for identifying an individual can be attached to the concavo-convex part.
The IC tag can be attached by screwing or fitting in a position deeper than a predetermined length that is an allowable value of wear thinning on the road surface, in the concave portion of the concave and convex portions ,
When irradiated with high-frequency electromagnetic waves in the UHF band to the metal surface, the form the uneven portion to flow differently standing wave frequency current and an eddy current on the metal surface in the vicinity of the IC tag <br/> A manhole cover characterized by that. A lid IC that generates an electromagnetic wave for individual identification of a metal lid having a concavo-convex portion formed so that a standing-wave high-frequency current different from an eddy current flows when a high-frequency electromagnetic wave in the UHF band is applied. In the tag,
A body portion assembled in a recess in the uneven portion on the surface of the lid, and having a dielectric property;
An IC tag substrate embedded in the main body, and having a coil antenna for generating the electromagnetic wave disposed in a plane,
When the high-frequency current is applied in the state of being assembled in the concave portion, the relationship between the current flowing through the bottom surface of the concave and convex portion of the lid and the current flowing through the coil antenna is as follows. An IC tag for a lid, which has an electromagnetic coupling relationship .

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