Antenna mounting structure, data communication system, and antenna mounting method

Abstract

To increase the degree of freedom to adjust radio wave communication conditions with the outside by an antenna inside an underground facility.SOLUTION: An antenna mounting structure is configured to mount an antenna connected to a communication device installed inside an underground facility on the back surface of a metal lid that closes the upper opening in the shape of a vertical hole of the underground facility. The antenna mounting structure includes a connection portion that electrically connects the antenna to the lid, and a position change portion that allows the installation position of the antenna relative to the connection position between the connection portion and the lid to be changed in a direction horizontal to the back surface of the lid. The position change portion has a guide rail fixed to the back surface of the lid, and a slider that is provided on the antenna and is movable along the guide rail.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technology for attaching an antenna for communication between the inside and outside of an underground facility to the back side of the cover of the underground facility. [Background technology]

[0002] For example, in order to monitor the condition of water supply and sewerage systems in underground facilities, a technology is known in which a sensor and a data transmission device are installed in the underground facility, and data indicating the condition of the monitored object detected by the sensor is transmitted as radio waves from an antenna connected to the data transmission device to various devices above ground. For example, in the technology disclosed in Patent Document 1, in order to improve the communication performance of the antenna, the base of the antenna is attached to the backside of the metal cover of a manhole, which is an underground facility, using a permanent magnet, so that the antenna is in close contact with the cover, and an electromagnetic field is generated not only from the antenna but also from the cover, causing the surface of the cover to function as a virtual antenna. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3234984 Summary of the Invention [Problem to be solved by the invention]

[0004] When an antenna is attached to the underside of a cover for an underground facility, the radiation state of radio waves outside the underground facility changes depending on the position within the underground facility where the antenna emits electromagnetic waves and the position where the electromagnetic waves from the antenna are transmitted to the cover. Therefore, there is a demand for adjusting the radiation state of radio waves appropriately by changing these positions. There is also a demand for adjusting the reception state of radio waves by the antenna appropriately by changing these positions. However, with conventional antenna mounting structures such as those disclosed in Patent Document 1, changing the antenna mounting position also changes the position where the electromagnetic waves from the antenna are transmitted to the cover. This limits the degree of freedom in adjusting communication states, such as the radiation state of radio waves outside the underground facility and the reception state of radio waves inside the underground facility, making it difficult to mount the antenna in a way that maintains good communication states.

[0005] The present invention has been made to solve the above problems, and aims to increase the degree of freedom in adjusting the state of radio wave communication between an antenna inside an underground facility and the outside. [Means for solving the problem]

[0006] The present invention provides an antenna mounting structure for mounting an antenna connected to a communication device installed in an underground facility on the back surface of a metal lid that closes the upper opening of the underground facility in a vertical hole shape, the antenna mounting structure comprising: a connection part that electrically connects the antenna to the lid; and a position change part that allows the installation position of the antenna relative to the connection position between the connection part and the lid to be changed in a direction horizontal to the back surface of the lid. The present invention also provides a data communication system that includes the antenna mounting structure, the communication device, and the antenna that radiates data output from the communication device as radio waves.

[0007] An antenna installation method according to one embodiment of the present invention is an antenna installation method for installing an antenna connected to a communication device installed in a vertical hole-shaped underground facility on the back surface of a metal lid that closes the upper opening of the underground facility, the method comprising: a fixing step in which the antenna is fixed to the back surface of the lid using an antenna installation structure while the back surface of the lid is exposed, and the antenna and the lid are electrically connected by a connection part provided in the antenna installation structure; a radiation step in which radio waves are radiated from the antenna while the upper opening is closed; a display step in which the radio wave strength of the antenna is displayed on a terminal device on the ground; and a change step in which, while the back surface of the lid is exposed, the installation position of the antenna relative to the connection position between the connection part and the lid is changed based on the radio wave strength by a position change part provided in the antenna installation structure. [Effects of the Invention]

[0008] According to the present invention, it is possible to increase the degree of freedom in adjusting the state of radio wave communication between an antenna inside an underground facility and the outside. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of an underground facility and an antenna mounting structure as viewed from the side. [Figure 2] FIG. 10 is a diagram showing the upper opening of the underground facility in an open state (an open state). [Figure 3A] FIG. 10 is an enlarged schematic view showing the vicinity of a connecting portion of the base. [Figure 3B] 10 is a schematic diagram showing a holding portion provided in a connecting portion. FIG. [Figure 4A] FIG. 2 is a bottom view of an example of a base. [Figure 4B] FIG. 10 is a bottom view of another example of the base. [Figure 4C] FIG. 10 is a bottom view of another example of the base. [Figure 4D] FIG. 10 is a bottom view of another example of the base. [Figure 4E] FIG. 10 is a bottom view of another example of the base. [Figure 5A] 10A and 10B are diagrams illustrating a state in which the antenna is not fixed to the position change portion of the base. [Figure 5B] 10A and 10B are diagrams illustrating a state in which the antenna is fixed to the position changing portion of the base. [Figure 5C] 4F is a diagram showing a state in which the antenna is fixed to the guide rail of the base shown in FIG. 4E. FIG. [Figure 6A] FIG. 10 is a schematic side view of an antenna mounting structure using another example of a base. [Figure 6B] FIG. 6B is a view of the base of FIG. 6A as seen from below. [Figure 7A] 10 is a diagram showing a state in which a connecting part that can be expanded and contracted in the depth direction of the underground facility is contracted. FIG. [Figure 7B] 10 is a diagram showing the state in which the extendable connecting part is extended in the depth direction of the underground facility. FIG. [Figure 8A] FIG. 10 is a schematic side view of another example of an antenna mounting structure. [Figure 8B] 8B is an enlarged view of the periphery of the antenna fixing member of FIG. 8A. [Figure 9] 1 is a configuration diagram of a data communication system according to an embodiment of the present invention. [Figure 10A] FIG. 10 is a diagram illustrating an example of information included in data transmitted from a communication device to a server. [Figure 10B] FIG. 2 is a diagram illustrating an example of data stored in a database of a server in a table format. [Figure 10C] FIG. 10 is a diagram illustrating an example of a monitoring screen displayed on a terminal device. [Figure 11] FIG. 2 is a sequence diagram illustrating an operation of a data communication system according to an embodiment of the present invention. [Figure 12A] FIG. 10 is a diagram for explaining an example of a method for attaching an antenna. [Figure 12B] 10A and 10B are diagrams for explaining another example of a method for attaching an antenna. [Figure 12C] 10A and 10B are diagrams for explaining another example of a method for attaching an antenna. [Figure 12D] 10A and 10B are diagrams for explaining another example of a method for attaching an antenna. [Figure 12E] FIG. 10 is a diagram illustrating an example of a measurement screen displayed on a terminal device. [Figure 13]FIG. 10 is a diagram showing a detailed procedure of a modification process. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] 1 is a schematic diagram showing an example of an underground facility 1 and an antenna mounting structure 8 as viewed from the side. The underground facility 1 is a vertical hole-like structure formed underground (below the ground G), such as a manhole, a valve box larger or smaller than a manhole, a valve chest, a meter box, or an electrical wiring box. Inside the underground facility 1, pipes such as water pipes, sewer pipes, or gas pipes, valves installed in the pipes, electrical wiring such as communication cables or electrical cables, and other electrical equipment (not shown) are arranged.

[0012] An upper opening 1a of the underground facility 1 is open to the ground and is closed by a metal lid 3. A metal support frame 4 is provided in the upper opening 1a to support the peripheral edge of the lid 3. The lid 3 and the support frame 4 are connected by a hinge structure 5. In this example, the lid 3 is formed in a disk shape, and the support frame 4 is formed in a circular ring shape when viewed from above, and the lid 3 and the support frame 4 are connected by a single hinge structure 5 (see Figure 2, etc.). The lid 3 and the support frame 4 are made of cast iron.

[0013] A recess is formed on the surface 3b of the lid 3 (the upper surface facing the ground in FIG. 1), and a handle 3t is provided in the recess. When an operator hooks his / her fingers or a jig on the handle 3t and rotates the lid 3 around the axis provided in the hinge structure 5, the upper opening 1a of the underground facility 1 is opened or closed. can be.

[0014] Figure 2 is a diagram showing the upper opening 1a of the underground facility 1 in an open state (open state). Reinforcing ribs 3d are provided in a roughly lattice pattern on the back surface 3a of the lid 3. For convenience, the ribs 3d are not shown in Figure 1. As shown in Figures 1 and 2, a sensor 10, a communication device 11, an antenna 12, a coaxial cable 13, and an antenna mounting structure 8 are provided within the underground facility 1.

[0015] The sensors 10 are attached to pipes, valves, electrical equipment, or the like in the underground facility 1, and detect the state of the monitored object (for example, the flow rate of water flowing in the pipes, water pressure, or the presence or absence of water leaks, the flow rate or composition of gas, the operating state or abnormal state of electrical equipment, etc.). Although only one sensor 10 is shown in FIG. 1, multiple sensors 10 may be provided in the underground facility 1 to obtain the state of different monitored objects.

[0016] The sensor 10 is connected to the communication device 11 by a data line 14, which is an electrical wiring. A detection signal from the sensor 10 is input to the communication device 11 via the data line 14. The communication device 11 is installed at a position different from the antenna 12. For example, as shown in FIG. 1 , the communication device 11 is installed on a fixed base 9 provided below the antenna 12. The fixed base 9 is fixed to the inner circumferential surface of the underground facility 1.

[0017] The communication device 11 and the antenna 12 are connected by a coaxial cable 13. The communication device 11 has a built-in battery as a power source. The communication device 11 generates data indicating the state of the monitored object based on the detection signal output from the sensor 10, and supplies power to the antenna 12 via the coaxial cable 13 to transmit the data from the antenna as radio waves.

[0018] The antenna 12 is installed vertically at an installation position P1 by an antenna installation structure 8 provided on the rear surface 3a of the lid 3. The antenna installation structure 8 includes a metal base 2. The antenna 12 is, for example, a 1 / 4λ wavelength monopole antenna. The ground of the antenna 12 is connected to the base 2 at the installation position P1.

[0019] When the base 2 and the back surface 3a of the lid 3 come into contact at connection position G1, the base 2 functions as the ground line of the antenna 12, and the lid 3 functions as the ground plane of the antenna 12. As a result, the ground of the antenna 12 is electrically connected to the lid 3, the base 2 and the lid 3 are at the same potential, and the surface 3b of the lid 3 functions as a virtual antenna, allowing radio waves radiated from the antenna 12 inside the underground facility 1 to be radiated outside the underground facility 1. In the antenna mounting structure 8, 1 / 4 of the wavelength of the radio waves radiated outside the underground facility 1 is realized by the antenna 12, and the other 1 / 4 is realized by the lid 3.

[0020] 1, in the antenna mounting structure 8, the installation position P1 of the antenna 12 and the connection position G1 at which the ground of the antenna 12 is electrically connected to the lid 3 can be changed individually. In this example, the installation position P1 and the connection position G1 can be changed in a direction parallel to and horizontal to the back surface 3a of the lid 3. This also makes it possible to change the distance from the connection position G1 to the installation position P1 in a direction parallel to and horizontal to the back surface 3a of the lid 3.

[0021] By using the antenna mounting structure 8, the worker can adjust at least one of the installation position P1 of the antenna 12 and the connection position G1 of the lid 3 to which the ground of the antenna 12 is connected, thereby installing the antenna 12 in a position suitable for emitting radio waves from inside the underground facility 1 to the outside and receiving external radio waves inside the underground facility 1.

[0022] The antenna mounting structure 8 includes a base 2, a connection portion fixing member 6, and an antenna fixing member 7. The base 2 is formed by bending a metal plate. The base 2 has a connection portion 2a, a position-changing portion 2b spaced a predetermined distance from the connection portion 2a, and a connecting portion 2c that connects the connection portion 2a and the position-changing portion 2b. The connection portion 2a is fixed to the back surface 3a of the lid 3, which faces downward of the underground facility 1 in Figure 1, by the connection portion fixing member 6. The antenna 12 is fixed to the position-changing portion 2b by the antenna fixing member 7. That is, the antenna 12 is attached to the back surface 3a of the lid 3 via the base 2.

[0023] The connection part fixing member 6 detachably fixes the connection part 2a of the base 20 at an arbitrary position on the rear surface 3a of the lid 3. More specifically, the connection part fixing member 6 includes a first magnet 6a and a second magnet 6b, which are neodymium magnets. The first magnet 6a is attracted to the rear surface 3a of the lid 3. The second magnet 6 b attracts the first magnet 6a, sandwiching the plate-shaped connecting portion 2a between itself and the first magnet 6a.

[0024] When attaching the antenna 12 to the lid 3, for example, a worker attaches the first magnet 6a to any relatively flat position on the back surface 3a of the lid 3 that is free of ribs 3d, places the connection portion 2a of the base 2 against the first magnet 6a, and attaches the second magnet 6b to a position on the connection portion 2a where the first magnet 6a and the second magnet 6b are magnetically attracted to each other. This sandwiches the connection portion 2a between the first magnet 6a and the second magnet 6b, and fixes the base 2 to any position on the back surface 3a of the lid 3. Furthermore, position G1 where the first magnet 6a and the back surface 3a of the lid 3 come into close contact is connection position G1 where the ground of the antenna 12 is electrically connected to the lid 3 via the base 2.

[0025] The connection portion 2a of the base 2 may be fixed by a connection portion fixing member 6 (first magnet 6a and second magnet 6b) to a nearby position within a predetermined range L from the support frame 4 of the underground facility 1. The connection portion 2a may also be fixed by a connection portion fixing member 6 (first magnet 6a and second magnet 6b) to a nearby position within a predetermined range L from the hinge structure 5 that connects the support frame 4 and the lid 3. The predetermined range L is set to a range in which the lid 3 can achieve 1 / 4 wavelength of a specific frequency.

[0026] The antenna mounting structure 8 also includes a coaxial cable 13 that connects the communication device 11 and the antenna 12. The base 2 is provided with a holding portion 2d that is provided at the connecting portion 2c and that holds a midsection of the coaxial cable 13. The midsection of the coaxial cable 13 is held by this holding portion 2d, so that the length of the coaxial cable 13 from the midsection of the coaxial cable 13 to the communication device 11 and the base 2 is kept substantially constant.

[0027] Fig. 3A is an enlarged schematic diagram showing the vicinity of connecting portion 2c of base 2. Fig. 3B is a schematic diagram showing holding portion 2d provided on connecting portion 2c. Fig. 3B shows connecting portion 2c of base 2 as viewed from the left side of Fig. 3A.

[0028] 3A and 3B, the connection portion 2a and the position change portion 2b of the base 2 are formed as parallel plates. The coupling portion 2c is provided with a holding portion 2d, which includes an insertion hole 2e that penetrates parallel to the connection portion 2a and the position change portion 2b and a sleeve 2f that is attached to the insertion hole 2e. The coaxial cable 13 passes through the insertion hole 2e and the sleeve 2f, and its midsection is held by the sleeve 2f.

[0029] As a result, when the antenna 12 is moved to an arbitrary position in the position change unit 2b or when the lid 3 is opened or closed, the coaxial cable 13 is prevented from falling off the base 2, and the weight of the coaxial cable 13 is prevented from concentrating on the connection between the communication device 11 and the coaxial cable 13 and on the connection between the antenna 12 and the coaxial cable 13. Note that the holding unit 2d is not limited to the above configuration, and may be, for example, a hook that anchors the coaxial cable 13 to the base 2.

[0030] 1 and 3A, the coaxial cable 13 is made up of a plurality of coaxial cables 13b, 13c that can be detached between the communication device 11 and the base 2. More specifically, a third fitting 13a provided at the other end of the coaxial cable 13b, one end of which is connected to the antenna 12, is connected to a fourth fitting 13d provided at the other end of the coaxial cable 13c, one end of which is connected to the communication device 11, to form a single coaxial cable 13. In other words, the antenna 12 and the communication device 11 are connected between the communication device 11 and the base 2 by a plurality of coaxial cables 13b, 13c that can be detached.

[0031] In this way, by configuring the coaxial cable 13 with multiple parts, a worker can perform maintenance on the communication device 11 by disconnecting the antenna 12 from the communication device 11, and can also prevent the installation position P1 of the antenna 12 from being accidentally shifted during the maintenance. Note that the number of coaxial cables 13 is not limited to two, and three or more coaxial cables may be strung together to connect the communication device 11 and the antenna 12.

[0032] FIG. 4A is a bottom view of an example of the base 2. As shown in FIG. 4A, the position change portion 2b of the base 2 includes a plurality of guide rails 2b1 formed in an arc shape. As shown in FIGS. 1 and 4A, the guide rails 2b1 are expanded in a direction parallel to the lid 3 and in the circumferential direction of the inner circumferential surface of the underground facility 1 beyond the connection portion 2a. The position change portion 2b has a through hole 2h formed therein, which penetrates in a direction perpendicular to the lid 3. In the following description, the through hole 2h may be referred to as a hole 2h. The through hole 2h shown in FIG. 4A is a slit 2h1 expanded in the circumferential direction of the base 2. The guide rail 2b1 is the peripheral edge of the through hole 2h.

[0033] Fig. 5A is a diagram showing a state in which antenna 12 is not fixed to position change part 2b of base 2. Fig. 5B is a diagram showing a state in which antenna 12 is fixed to position change part 2b of base 2. Figs. 5A and 5B show a cross section AA of position change part 2b of base 2 shown in Fig. 4A.

[0034] As shown in Fig. 5A, the antenna fixing member 7 includes a first metal fitting 7a and a second metal fitting 7b. The first metal fitting 7a is provided at the base 12a of the antenna 12. The first metal fitting 7a is formed in a cylindrical shape, and a first screw portion is formed on the inner circumferential surface. Furthermore, a first terminal is provided at the center of the inside of the first metal fitting 7a.

[0035] The second fitting 7b is provided at one end of the coaxial cable 13. The second fitting 7b is formed in a cylindrical shape, with a second screw-threaded portion 7c formed on its outer circumferential surface and a flange portion 7d formed in the middle of the second screw-threaded portion 7c. For example, the second screw-threaded portion 7c of the second fitting 7b is a male thread, and the first screw-threaded portion of the first fitting 7a is a female thread. A second terminal that fits with the first terminal of the first fitting 7a is provided at the center of the second fitting 7b.

[0036] As shown in Fig. 5A, the worker places antenna 12 and first metal fitting 7a below position change section 2b (the opposite side to connection section 2a in Fig. 3A, etc.), and places coaxial cable 13 and second metal fitting 7b above position change section 2b (the side of connection section 2a in Fig. 3A, etc.). Next, the worker passes second metal fitting 7b through through hole 2h and inserts it inside first metal fitting 7a, as shown in Fig. 5B.

[0037] The worker then screws the first screw-type portion of the first metal fitting 7a into the second screw-type portion 7c of the second metal fitting 7b, clamping the periphery of the through-hole 2h (i.e., the position changeable portion 2b) between the tip end surface of the first metal fitting 7a and the flange portion 7d of the second metal fitting 7b, thereby fixing the antenna 12 to the position changeable portion 2b. This connects the first terminal of the first metal fitting 7a of the antenna 12 to the second terminal of the second metal fitting 7b of the coaxial cable 13, and fixes the antenna 12 to the position changeable portion 2b so that it protrudes downward at an arbitrary installation position P1. The ground of the antenna 12 is also connected to the lid 3 via the first metal fitting 7a, the base 2, and the connection portion fixing member 6.

[0038] The worker also loosens the tip surface of first metal fitting 7a and flange 7d of second metal fitting 7b, and changes the position of antenna 12 along through-hole 2h (slit 2h1). The worker then places antenna 12 in the desired position and tightens first metal fitting 7a and second metal fitting 7b to secure antenna 12 to guide rail 2b1. First metal fitting 7a attached to antenna 12 and second metal fitting 7b attached to coaxial cable 13 function as slider 7e that can move along guide rail 2b1.

[0039] As another example, a plurality of through holes 2h may be formed in the position change portion 2b of the base 2 as shown in FIGS. 4B and 4C.

[0040] In the example shown in FIG. 4B, the position change portion 2b of the base 2 is a circular porous plate 2b2 having a plurality of holes 2h formed therein. The through holes 2h are circular holes 2h2 formed at equal angular intervals along the circumferential direction of the porous plate 2b2. The worker passes a first metal fitting 7a provided on the antenna 12 through a selected circular hole 2h2 from among the circular holes 2h2 of the position change portion 2b (porous plate 2b2), and then passes a second metal fitting 7b provided on the coaxial cable 13 through the selected circular hole 2h2 and inserts it into the first metal fitting 7a. The worker then threads the first screw-engagement portion of the first metal fitting 7a and the second screw-engagement portion 7c of the second metal fitting 7b together, clamping the peripheral edge of the circular hole 2h2 between the tip surface of the first metal fitting 7a and the flange portion 7d of the second metal fitting 7b, thereby fixing the antenna 12 to the porous plate 2b2. In this case, the first metal fitting 7a provided on the antenna 12 and the second metal fitting 7b provided on the coaxial cable 13 function as a first fixing portion 7f that can fix the antenna 12 to a circular hole 2h2 selected by the worker from among the multiple circular holes 2h2.

[0041] In the example shown in FIG. 4C, the position change portion 2b is a disk-shaped porous plate 2b3. The through-hole 2h is an elongated hole 2h3 formed in the porous plate 2b3. The worker passes the first fitting 7a through a selected elongated hole 2h3 from among the multiple elongated holes 2h3 of the position change portion 2b (porous plate 2b3), and then passes the second fitting 7b through and inserts it into the inside of the first fitting 7a. The worker moves the antenna 12 along the elongated hole 2h3 to place it in the desired position. Then, the worker screws the first screw portion of the first fitting 7a into the second screw portion 7c of the second fitting 7b, and inserts the first fitting 7a into the elongated hole 2h3. The peripheral edge of the slot 2h3 is clamped between the flange 7d of the second metal fitting 7b and the antenna 12 to fix it to the slot 2h3. In this case, the first metal fitting 7a provided on the antenna 12 and the second metal fitting 7b provided on the coaxial cable 13 are a slider 7e that can move along the slot 2h3 selected by the worker from among the multiple slots 2h3, and are a first fixing portion 7f that can fix the antenna 12 to the slot 2h3.

[0042] In addition, the underground facility 1 may be formed in a rectangular frame shape when viewed from above ground, and the lid 3 may also be formed in a rectangular shape to match this. In this case, as shown in Fig. 4D, the base 2 and the position change part 2b may also be formed in a rectangular shape (guide rail 2b4), and the through-hole 2h may be a slit 2h4 along each side of the guide rail 2b4.

[0043] As another example, instead of the through-holes 2h, a plurality of semicircular notches 2i may be formed in the position change portion 2b (guide rail 2b5) of the base 2, as shown in Fig. 4E. The plurality of notches 2i are formed at equal angular intervals along the circumferential direction of the guide rail 2b5. The antenna 12 and the coaxial cable 13 are fixed to the periphery of one of the notches 2i.

[0044] Fig. 5C is a diagram showing a state in which antenna 12 is fixed to guide rail 2b5 of base 2 shown in Fig. 4E. Specifically, Fig. 5C shows a BB cross section of guide rail 2b5 of base 2 shown in Fig. 4E. The worker first passes second fitting 7b through one of the notches 2i and inserts it into first fitting 7a. Then, the worker screws together the first screw-engagement portion of first fitting 7a and the second screw-engagement portion 7c of second fitting 7b, clamping the periphery of notch 2i between the tip surface of first fitting 7a and the flange portion 7d of second fitting 7b, thereby fixing antenna 12 to position change unit 2b.

[0045] In the above-described embodiment, an example was shown in which the antenna 12 was fixed to an arbitrary position on the position changer 2b of the base 2, thereby making it possible to change the installation position P1 of the antenna 12 relative to the connection position G1 between the connection portion 2a of the base 2 and the lid 3, but this configuration is not limiting. For example, the position changer 2b of the base 2 may be configured to be movable relative to the connection portion 2a, and after the antenna 12 is fixed to the position changer 2b, the installation position P1 relative to the connection position G1 may be changed by moving the position changer 2b. An embodiment in this case is shown in Figures 6A and 6B.

[0046] FIG. 6A is a schematic side view of an antenna mounting structure 8 using another example of a base 20. FIG. 6B is a schematic bottom view of the base 20 of FIG. 6A. The base 20 shown in FIGS. 6A and 6B has an arm 2j as a position changer 2b. The arm 2j has a connecting portion 2k, a joint 2L, and an antenna mounting portion 2n. As shown in FIG. 6A, the connecting portion 2k is L-shaped when viewed from the side. A connecting portion 2a is connected to the upper portion of the connecting portion 2k. The connecting portion 2a of the base 20 has the same configuration as the connecting portion 2a of the base 2 shown in FIG. 1, etc. That is, one end of the arm 2j is fixed to the rear surface 3a of the lid 3. The antenna mounting portion 2n is connected to the tip of the connecting portion 2k of the arm 2j via the joint 2L. That is, the antenna mounting portion 2n for fixing the antenna 12 is provided at the other end of the arm 2j.

[0047] The joint 2L supports the antenna attachment part 2n rotatably and parallel to the lid 3. More specifically, when a nut 2m included in the joint 2L is loosened, the antenna attachment part 2n becomes rotatable around the joint 2L. When the nut 2m is tightened, the antenna attachment part 2n and the connecting part 2k are fixed together, and the antenna attachment part 2n becomes unable to rotate.

[0048] The antenna 12 and the coaxial cable 13 are fixed to the tip of the antenna mounting portion 2n, for example, by the structure shown in Fig. 5B. After fixing the antenna 12 and the coaxial cable 13 to the tip of the antenna mounting portion 2n, an operator can rotate the antenna mounting portion 2n, thereby changing the installation position P1 of the antenna 12 within the underground facility 1. Note that although there is only one joint 2L in the example shown in Figs. 6A and 6B, multiple joints 2L may be provided on the arm 2j.

[0049] In the above-described embodiment, an example has been shown in which the installation position P1 of the antenna 12 is movable parallel to the lid 3, but the installation position P1 of the antenna 12 may also be movable in the depth direction of the underground facility 1 (i.e., in a direction perpendicular to the lid 3). In this case, for example, a base 21 having a connecting portion 2q that is extendable in the depth direction of the underground facility 1 may be used, as shown in Figures 7A and 7B.

[0050] The base 21 shown in FIG. 7A has a connecting portion 2q in addition to the connecting portion 2a and the position changing portion 2b. The connecting portion 2q is composed of a first connecting portion 2q1 that is perpendicular to the lid 3 and connected to the connection portion 2a, and a second connecting portion 2q2 that is perpendicular to the lid 3 and connected to the position changing portion 2b. The first connecting portion 2q1 and the second connecting portion 2q2 each have a through hole or a notch that penetrates in the thickness direction. A bolt or the like is inserted into the through hole or the notch to fix the first connecting portion 2q1 and the second connecting portion 2q2 together.

[0051] 7A, for example, a worker brings the first connecting portion 2q1 and the second connecting portion 2q2 into close contact with each other and fixes them with connecting portion fixing members 22 such as bolts and nuts. This sets the distance between the connection portion 2a and the position change portion 2b, and also sets the installation position P1 of the antenna 12 in the depth direction of the underground facility 1.

[0052] 7B, for example, the worker slides the second connecting portion 2q2 up and down relative to the first connecting portion 2q1 to adjust the installation position P1 of the antenna 12 fixed to the antenna mounting portion 2n in a direction perpendicular to the lid 3, and then fixes the first connecting portion 2q1 and the second connecting portion 2q2 with the connecting portion fixing member 22. This causes the connecting portion 2q to expand and contract, changing the distance between the connection portion 2a and the position change portion 2b, and also changing the installation position P1 of the antenna 12 in the depth direction of the underground facility 1 (the direction perpendicular to the lid 3). Therefore, the worker can adjust the installation position P1 of the antenna 12 in two directions: horizontal to the lid 3 and perpendicular to the lid 3.

[0053] In the above-described embodiment, an example was shown in which the connection position G1 of the lid 3 at the connection portion 2a of the antenna mounting structure 8 and the installation position P1 of the antenna 12 fixed to the position change portion 2b are electrically connected via the metal pedestals 2, 20, 21, and the pedestals 2, 20, 21 function as the ground line of the antenna 12, but this configuration is not limited to this. Alternatively, for example, the connection position G1 and the installation position P1 may be connected by an electric cable (electrical wiring), and the electric cable may function as the ground line of the antenna 12. An embodiment in this case is shown in FIG. 8A.

[0054] FIG. 8A is a schematic diagram of another example of an antenna mounting structure 8 as viewed from the side. The antenna mounting structure 8 shown in FIG. 8A includes an electrical connection member 2t, an antenna fixing member 2s, and an electrical cable (electrical wiring) 2r. The electrical connection member 2t and the antenna fixing member 2s are separate members (bases). The electrical connection member 2t is fixed to the rear surface 3a of the lid 3 by a first magnet 6a and a second magnet 6b, similar to the connection portion 2a of the base 2 shown in FIG. 1 and other figures. That is, the electrical connection member 2t is the connection portion 2a that connects the ground of the antenna 12 to the lid 3. The antenna fixing member 2s is provided on the base portion 12a of the antenna 12 and detachably fixes the antenna 12 to any position on the rear surface 3a of the lid 3. That is, the antenna fixing member 2s is the position change portion 2b that changes the mounting position of the antenna 12 and is the second fixing portion that fixes the antenna 12.

[0055] As shown in Fig. 8B, the antenna fixing member 2s includes a third magnet 2u, which is a permanent magnet. The third magnet 2u is attached to the rear surface 3a of the lid 3 with an insulating sheet 2v sandwiched therebetween. The antenna 12 is fixed to the rear surface 3a of the lid 3 by the antenna fixing member 2s while being insulated from the lid 3. The antenna fixing member 2s and the electrical connection member 2t are electrically connected by an electrical cable 2r.

[0056] As a result of the above, the antenna 12 is fixed to a desired position on the back surface 3a of the lid 3 via the antenna fixing member 2s and the insulating sheet 2v. In addition, the ground of the antenna 12 is connected to the lid 3 via the antenna fixing member 2s, the electric cable 2r, and the electric connection member 2t. An operator can freely change the installation position P1 of the antenna 12 by fixing the antenna fixing member 2s to a desired position on the back surface 3a of the lid 3, and can freely change the electrical connection position G1 of the antenna 12 with respect to the lid 3 by fixing the electric connection member 2t to a desired position on the back surface 3a.

[0057] FIG. 9 is a configuration diagram of a data communication system 100 according to one embodiment of the present invention. The data communication system 100 includes a sensor 10, a communication device 11, an antenna 12, and the antenna mounting structure 8, all of which are installed inside the underground facility 1, and an above-ground communication device 15, a server 16, and a terminal device 17, all of which are installed outside (above ground) the underground facility 1. The communication device 11 includes a CPU 11a, a memory, and a communication module for wirelessly transmitting and receiving data. The communication device 15 has a CPU 15a, a memory, and a communication module that transmits and receives data wirelessly. The communication device 11 and the ground communication device 15 communicate wirelessly with each other using their respective communication modules. More specifically, the ground communication device 15 receives radio waves emitted by the communication device 11 using an antenna 12. The communication device 11 receives radio waves transmitted by the ground communication device 15 using the antenna 12.

[0058] The ground communication device 15 also communicates with the server 16 and the terminal device 17 via a public network N using a communication module. The network N is, for example, a mobile phone communication network including communication methods such as LTE (Long Term Evolution; registered trademark) and 5G (fifth generation mobile communication system). The ground communication device 15 functions as a wireless base station (or repeater) provided in the mobile phone communication network. The communication module included in the ground communication device 15 may perform wireless communication using at least one of communication methods such as Bluetooth (registered trademark) Low Energy in the Bluetooth (registered trademark) specifications of the IEEE802.15.1 series of communication standards and WiFi (registered trademark) of the IEEE802.11.n series of communication standards.

[0059] The server 16 may be, for example, a stationary computer device installed in a management company that manages the underground facility 1, or may be constructed as a database on a cloud network. The server 16 has a communication unit that communicates with the aboveground communication device 15 and the terminal device 17. The memory unit of the server 16 stores various data transmitted from the communication device 11 in the underground facility 1. That is, the server 16 manages the data D1 detected by the sensor 10.

[0060] The communication device 11 generates data D1 based on a detection signal from the sensor 10 and transmits the data D1 as radio waves (electromagnetic waves) from the antenna 12. The radio waves transmitted from the antenna 12 are received by the ground communication device 15. The ground communication device 15 generates data D1 from the radio waves received from the antenna 12 and transmits the data D1 to the server 16 via the network N. As a result, the server 16 receives the data D1 detected by the sensor 10 periodically or at a predetermined timing and stores the data in a database DB constructed in a storage unit provided in the server 16. The communication device 11, the server 16, and the terminal device 17 can also communicate with each other via a mobile phone communication network or the like.

[0061] FIG. 10A is a diagram showing an example of information included in data D1 transmitted by communication device 11 to server 16. Data D1 includes sender identification information, sensor data type, detection result, and time information. The sender identification information is information for identifying the underground facility 1 in which communication device 11, which is the sender of data D1, is installed. The sensor data type is information indicating the type of data detected by sensor 10. The detection result is information indicating, in numerical form, the state of the monitored object detected by sensor 10. The time information is information indicating the time at which communication device 11 obtained the detection result based on the detection signal from sensor 10. The above information included in data D1 is an example, and information other than the above may also be included in data D1.

[0062] The communication device 11 converts the data D1 from the sensor 10 into an analog electrical signal, outputs the electrical signal to the antenna 12 via a coaxial cable 13, and radiates the signal as radio waves from the antenna 12. An above-ground communication device 15 located outside the underground facility 1 receives the radio waves radiated from the antenna 12 and generates (regenerates) the data D1 from the radio waves. The above-ground communication device 15 then transmits the corresponding data D1 to the server 16. Upon receiving the data D1, the server 16 stores the data D1 in a database DB.

[0063] 10B is a diagram showing, in table format, an example of data D1 stored in database DB of server 16. Data D1 stored in database DB of server 16 includes "source identification information," "sensor data type," "detection result," and "time information."

[0064] The sender identification information includes information for identifying the underground facility 1 in which the communication device 11 is installed, such as "Installation location A." The data type indicates the type of data detected by the sensor 10, such as "flow rate" and "water pressure." The detection result indicates numerical information detected by the sensor 10, such as "flow rate" and "water pressure." The time information indicates information indicating the time when the communication device 11 obtained the detection result. The above information is an example, and information other than the above may be stored in the database DB of the server 16 as the data D1.

[0065] 9 is, for example, any one of a personal computer, a smartphone, a tablet computer, a PDA, etc., and has a display for displaying (outputting) information. The terminal device 17 downloads data D1 stored in the database DB of the server 16 and displays it on the display.

[0066] A user (such as a worker) of the terminal device 17 can refer to D1 displayed on the display to understand the status of the monitored object in the underground facility 1. When the worker performs a predetermined operation on the terminal device 17, the terminal device 17 displays a monitoring screen W1, for example, as shown in Fig. 10C, on the display.

[0067] 10C, the monitoring screen W1 shows in graph form the time series change of the "flow rate" (the flow rate of water flowing through the water pipe per unit time) detected by the sensor 10 at the desired underground facility 1 (installation location A). In addition to this, the terminal device 17 can display in graph or table form the time series change of other data such as the "water pressure" (the pressure of water flowing through the water pipe) on the monitoring screen W1, and can also display the numerical values ​​of the data detected by the sensor 10 at the desired time on the monitoring screen W1.

[0068] 11 is a sequence diagram of the operation of the data communication system 100 according to one embodiment of the present invention. The communication device 11 transmits data D1 indicating the state of the monitoring target detected by the sensor 10 to the server 16 periodically or at a predetermined timing (S1). When the communication device 11 transmits the data D1 periodically, the period may be set to, for example, 10 minutes to 1 hour, but is not limited to this value and may be changed as appropriate. When the server 16 receives the data D1 from the communication device 11, it stores the data D1 in the database DB (S2).

[0069] When an operator performs a predetermined monitoring operation on terminal device 17 (S3), terminal device 17 requests data D1 indicating the state of underground facility 1 to be monitored from server 16 based on the monitoring operation (S4). Server 16 reads out data D1 requested by terminal device 17 from database DB and transmits it to terminal device 17 (S5). Terminal device 17 receives data D1 from server 16 and displays a monitoring screen W1 based on the data D1 (S6).

[0070] The data communication system 100 has a function of measuring and outputting an index for evaluating whether the communication conditions of the communication device 11 and the antenna 12 are good or not. Specifically, the communication device 11 has a function of measuring (calculating) as the index the radio wave intensity D2 when the radio wave (reference signal) transmitted from the ground communication device 15 is received by the antenna 12.

[0071] The radio wave strength D2 can be, for example, RSRP (Reference Signal Received Power), RSSI (Received Signal Strength Examples include Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), etc.

[0072] The worker can visually check the radio wave intensity D2 by acquiring the radio wave intensity D2 measured by the communication device 11 using the terminal device 17 and displaying the radio wave intensity D2 on a display. Based on the visually checked radio wave intensity D2, the worker can determine whether the communication status between the communication device 11 and the ground communication device 15 is good or not, and can also evaluate the communication status in stages.

[0073] The ground communication device 15 transmits a reference signal (radio wave) periodically or at a predetermined timing to the communication device 11. When the communication device 11 receives the reference signal from the ground communication device 15 via the antenna 12, it calculates radio wave intensity D2 based on the reference signal and transmits data indicating the radio wave intensity D2 as radio waves via the antenna 12.

[0074] The ground communication device 15 generates data (electrical signals) indicating the radio wave intensity D2 from the radio waves received from the antenna 12, and transmits the data to the server 16 via the network N. When the server 16 receives the data indicating the radio wave intensity D2, it stores the data in the database DB. Note that the data transmitted by the communication device 11 includes the calculated value of the radio wave intensity D2 as well as the communication The data D1 may also include identification information of the ground communication device 15, time information when the reference signal was received, or identification information of the ground communication device 15 that is the source of the reference signal. The communication device 11 may also include radio wave intensity D2 in the data D1 and transmit it from the antenna 12.

[0075] For example, when an operator performs a predetermined measurement and display operation on the terminal device 17, the terminal device 17 receives data indicating the radio wave intensity D2 stored in the server 16 and displays on the display a measurement screen W2 (FIG. 12E described later) indicating the radio wave intensity D2. The operator adjusts the position of the antenna 12 fixed to the rear surface 3a of the lid 3 while visually checking the radio wave intensity D2 displayed on the measurement screen W2.

[0076] 12A to 12D are diagrams for explaining an example of a method for mounting the antenna 12. Note that, although Fig. 12A to 12D illustrate an example in which the base 2 shown in Fig. 1 etc. is used, the same applies when other examples of the bases 20 and 21 or the antenna mounting structure 8 shown in Fig. 8A etc. are used, as also described above.

[0077] First, as shown in FIG. 12A, the worker lifts the lid 3 to open the upper opening 1a of the underground facility 1, and installs the sensor 10 and the communication device 11 in the underground facility 1 (S10).

[0078] 12B , as a fixing step, the worker attaches the connection part 2a of the base 2 to an arbitrary position on the back surface 3a of the lid 3 using the connection part fixing member 6 with the back surface 3a of the lid 3 exposed (S11). This fixes the connection position G1 between the lid 3 and the base 2. At this time, it is preferable that the connection position G1 between the lid 3 and the base 2 be located near the hinge structure 5. Furthermore, as a fixing step, the worker passes the coaxial cable 13 through the insertion hole 2e of the coupling part 2c of the base 2, and connects the communication device 11 and the antenna 12 with the coaxial cable 13.

[0079] In addition, as a fixing step, the worker fixes the antenna 12 and the coaxial cable 13 to any position on the position change portion 2b of the base 2 (S12). As a result, the antenna 12 is fixed to any installation position P1 on the back surface 3a of the lid 3 by the base 2 (antenna mounting structure 8). At this time, it is preferable that the installation position P1 is located near the connection position G1. The ground of the antenna 12 is electrically connected to the lid 3 at the connection position G1 by the connection portion 2a provided on the base 2 (antenna mounting structure 8).

[0080] Then, the worker activates the communication device 11 and lowers the lid 3 to close the upper opening 1a of the underground facility 1, as shown in FIG. 12C (S13). As a result, the antenna 12 is attached to the rear surface 3a of the lid 3 inside the underground facility 1. After this, as shown in FIG. 12D, the communication device 11 receives the reference signal transmitted from the aboveground communication device 15 via the antenna 12. The communication device 11 then calculates the radio wave intensity D2 of the received reference signal and emits the calculation result as radio waves (electromagnetic waves) from the antenna 12 (S14: radiation step). As a result, with the upper opening 1a closed, the radio waves emitted from the antenna 12 are emitted from the surface 3b of the lid 3 to the outside of the underground facility 1.

[0081] When the ground communication device 15 receives the radio waves radiated from the antenna 12 and the surface 3b of the lid 3, it generates data represented by the radio waves. The generated data includes a calculated value of the radio wave intensity D2 transmitted from the communication device 11. The ground communication device 15 transmits the generated data to the server 16, and the server 16 receives the data and stores it in the database DB. That is, the data stored in the database DB includes the radio wave intensity D2.

[0082] The terminal device 17 acquires the radio wave intensity D2 corresponding to the underground facility 1 specified by the worker from the server 16, and displays the radio wave intensity D2 on the measurement screen W2 (S15: display step). Fig. 12E is a diagram showing an example of the measurement screen displayed on the terminal device 17. On the measurement screen W2, for example, identification information of the communication device 11 (e.g., "Installation location A") and a meter image X1 showing the strength of the radio wave intensity D2 in multiple stages (e.g., five stages) are displayed.

[0083] The worker uses the position changer 2b provided on the base 2 (antenna mounting structure 8) to change the installation position P1 of the antenna 12 relative to the connection position G1 between the connection part 2a and the lid 3 based on the radio wave intensity D2 (changing step).

[0084] For example, the worker adjusts at least one of the connection position G1 and the installation position P1 so that the radio wave intensity D2 is equal to or greater than the threshold value. In order to improve or optimize the communication performance with the terminal device 17, the connection portion 2a of the base 2 is fixed to any position on the back surface 3a of the lid 3, and the antenna 12 is fixed to any position on the position change portion 2b of the base 2, and the connection position G1 and the installation position P1 are adjusted and then confirmed. In this way, after changing the position of at least one of the connection position G1 and the installation position P1, the worker repeatedly visually checks the measurement screen W2 of the terminal device 17 and grasps the radio wave intensity D2, thereby searching for an arrangement where the antenna 12 can more suitably radiate and receive radio waves.

[0085] At the connection position G1 and installation position P1 where the communication performance of the antenna 12 is good or optimal, it is estimated that the state of radiation of radio waves from the antenna 12 to the outside of the underground facility 1, i.e., the transmission performance of the antenna 12, will also be good or optimal. Therefore, according to the above-mentioned installation method of the antenna 12, the communication performance between the antenna 12 in the underground facility 1 and the above-ground device is improved.

[0086] FIG. 13 is a diagram showing detailed steps of the above-mentioned change process. As shown in FIG. 13, the worker visually checks the radio wave intensity D2 on the measurement screen W2 displayed on the terminal device 17 and confirms whether the radio wave intensity D2 is equal to or greater than the first threshold (S16). If the radio wave intensity D2 displayed on the measurement screen W2 is less than the first threshold (S16: NO), the worker lifts the lid 3 to expose the back surface 3a of the lid 3 and changes the attachment position of the connection portion 2a of the base 2 on the back surface 3a of the lid 3 (S17). That is, the worker changes the connection position G1 between the base 2 and the lid 3. Then, the worker lifts the lid 3 to close the upper opening 1a of the underground facility 1, waits until the communication device 11 transmits data indicating the radio wave intensity D2 to the outside, and returns to step S16 of visually checking the measurement screen W2.

[0087] If the radio wave intensity D2 displayed on the measurement screen W2 is equal to or greater than the first threshold (S16: YES), the worker lifts the lid 3 to expose the back surface 3a of the lid 3, and changes the installation position P1 of the antenna 12 and the coaxial cable 13 fixed to the position change portion 2b of the base 2 (S18). Note that it is preferable that the amount of change in the installation position P1 of the antenna 12 in this step be kept within a range that can be achieved by the antenna 12 and the lid 3 to achieve ¼ of the wavelength of the radio waves radiated outside the underground facility 1.

[0088] Next, the worker lifts the lid 3 to close the upper opening 1a of the underground facility 1, and then waits until the communication device 11 transmits radio waves indicating radio wave intensity D2 from the antenna 12 to the outside of the underground facility 1. Then, the worker operates the terminal device 17 to visually confirm the radio wave intensity D2 displayed on the measurement screen W2 and confirm whether the radio wave intensity D2 is equal to or greater than the second threshold (S19). The second threshold may be the same as the first threshold, or may be a value higher than the first threshold.

[0089] If the radio wave intensity D2 displayed on the measurement screen W2 is less than the second threshold (S19: NO), the worker returns to step S 18. If the radio wave intensity D2 displayed on the measurement screen W2 is equal to or greater than the second threshold (S19: YES), the worker confirms the connection position G1 and the installation position P1, and ends the installation work of the antenna 12.

[0090] The procedure of the change process shown in FIG. 13 is an example, and the order in which the positions of the connection position G1 and the installation position P1 are adjusted is not limited to the above description.

[0091] In the above-described method for attaching the antenna 12, an example has been shown in which the installation position P1 is moved manually by an operator. However, the installation position P1 may also be moved automatically using an actuator or the like. Specifically, for example, an actuator such as an electric motor is installed in the joint 2l shown in FIGS. 6A and 6B , and a command indicating a rotation position of the antenna attachment portion 2n is transmitted from the terminal device 17 to the communication device 11. The communication device 11 then receives the command from the terminal device 17 via the antenna 12 and operates the actuator based on the command to rotate the antenna attachment portion 2n and move (change) the installation position P1 of the antenna 12. This allows the operator to change the installation position P1 of the antenna 12 without opening the lid 3, improving work efficiency.

[0092] In the above-described method for mounting the antenna 12, the radio wave intensity D2 of the reference signal received by the communication device 11 from the ground communication device 15 is used as an index for evaluating whether the antenna 12 is installed to improve the communication state. However, another index may be used. For example, the intensity of the electromagnetic wave emitted from the surface 3b of the cover 3 when the antenna 12 transmits radio waves may be used as the index. It may also be used as a marker.

[0093] In this case, in the display process, the worker lifts down the lid 3 with the antenna 12 attached to the back surface 3a to close the upper opening 1a of the underground facility 1, and then uses an electromagnetic wave measuring device such as a spectrum analyzer to measure the strength of the electromagnetic waves from the front surface 3b of the lid 3. The worker visually checks the value indicating the strength of the measured electromagnetic waves and compares the value with a predetermined threshold value to determine whether the installation position P1 and connection position G1 of the antenna 12 are favorable positions for emitting radio waves, and adjusts the position of at least one of the connection position G1 and the installation position P1.

[0094] The embodiments of the present invention provide an antenna mounting structure 8, a data communication system 100, and an antenna mounting method as described in the following items.

[0095] (Item A1) An antenna mounting structure 8 for mounting an antenna 12 connected to a communication device 11 installed in a vertical hole-shaped underground facility 1 on the back surface 3a of a metal lid 3 that closes the upper opening 1a of the underground facility 1, the antenna mounting structure 8 comprising: a connection part 2a that electrically connects the antenna 12 to the lid 3; and a position change part 2b that enables the installation position P1 of the antenna 12 relative to the connection position G1 between the connection part 2a and the lid 3 to be changed in a direction horizontal to the back surface 3a of the lid 3.

[0096] According to the invention related to this item A1, the connection position G1 where the electromagnetic waves radiated from the antenna 12 are transmitted to the lid 3 and the installation position P1 of the antenna 12 where the antenna 12 radiates the electromagnetic waves within the underground facility 1 can be adjusted separately, which increases the degree of freedom in adjusting the radio wave communication state (radiation state, reception state) with the outside by the antenna 12 inside the underground facility 1. As a result, it becomes possible to install the antenna 12 inside the underground facility 1 so as to optimize the radio wave communication state between the inside and outside of the underground facility 1.

[0097] (Item A2) The position change portion 2b has guide rails 2b1, 2b4, 2b5 fixed to the back surface 3a of the lid 3, and a slider 7e (first metal fitting 7a) provided on the antenna 12 and movable along the guide rails 2b1, 2b4, 2b5.

[0098] According to the invention related to this item A2, the worker can easily change the installation position P1 of the antenna 12 along the guide rails 2b1, 2b4, and 2b5. Furthermore, the installation position P1 of the antenna 12 can be easily changed while the connection position G1 relative to the lid 3 is fixed. As a result, the worker can easily compare which installation position P1 of the antenna 12 can best communicate with the outside of the underground facility 1, with respect to the connection position G1 fixed in a predetermined position, thereby improving work efficiency.

[0099] (Item A3) The position change portion 2b is an antenna mounting structure 8 described in Item A1, which has a porous plate 2b2, 2b3 fixed to the back surface 3a of the lid 3 and having a plurality of holes 2h formed therein, and a first fixing portion 7f (first metal fitting 7a) provided on the antenna 12 and capable of fixing the antenna 12 to at least one selected hole 2h out of the plurality of holes 2h.

[0100] According to the invention related to this item A3, the worker can change the installation position P1 of the antenna 12 by changing the hole 2h in which the antenna 12 is fixed. In addition, the position of the installation position P1 of the antenna 12 can be easily adjusted while the connection position G1 relative to the lid 3 is fixed. As a result, the worker can easily compare which installation position P1 of the antenna 12 can best communicate with the outside of the underground facility 1, with respect to the connection position G1 fixed in a predetermined position, thereby improving work efficiency.

[0101] (Item A4) The position change portion 2b is provided with at least one joint 2L, and has an arm 2j having one end fixed to the back surface 3a of the lid 3 and the other end to which the antenna 12 is fixed. The antenna mounting structure 8 described in Item A1.

[0102] According to the invention relating to item A4, the worker can easily change the installation position P1 of the antenna 12 by rotating the arm 2j. Also, the installation position P1 of the antenna 12 can be easily changed without having to detach the antenna 12 after it has been fixed to the antenna mounting structure 8. Also, the installation position P1 of the antenna 12 can be easily adjusted with the connection position G1 relative to the lid 3 fixed. As a result, the worker can It is possible to easily compare which installation position P1 of the antenna 12 provides the most suitable communication with the outside of the underground facility 1 compared to the connection position G1 fixed at a predetermined position, thereby improving work efficiency.

[0103] (Item A5) The antenna mounting structure 8 according to Item A1, wherein the position change portion 2b includes a second fixing portion 2s (antenna fixing member 2s) capable of fixing the antenna 12 to the rear surface 3a of the lid 3 in an insulated state.

[0104] According to the invention related to item A5, the installation position P1 of the antenna 12 can be easily changed while the connection position G1, which is the electrical connection point to the lid 3, is fixed. As a result, the worker can easily compare which installation position P1 of the antenna 12 can best communicate with the outside of the underground facility 1, with respect to the connection position G1 fixed in a predetermined position, thereby improving work efficiency.

[0105] (Item A6) A data communication system 100 including an antenna mounting structure 8 described in any one of items A1 to A5, the communication device 11, and an antenna 12 that emits data D1 output from the communication device 11 as radio waves.

[0106] According to the invention relating to this item A6, data D1 can be transmitted from the communication device 11 in the underground facility 1 via the antenna 12 to the ground device (server 16 or ground communication device 15) in an appropriate communication state.

[0107] (Item A7) A data communication system 100 described in Item A6, which includes a sensor 10 installed in the underground facility 1 and detecting the status of the monitored object, and a server 16 that manages data D1 detected by the sensor, and the communication device 11 transmits the data D1 detected by the sensor 10 to the server 16 via the antenna 12.

[0108] According to the invention relating to item A7, data D1 indicating the status of the monitored object within the underground facility 1 can be transmitted from the communication device 11 via the antenna 12 to a server 16 outside the underground facility 1, and the data D1 can be managed by the server 16.

[0109] (Item A8) A method for mounting an antenna 12 connected to a communication device 11 installed in a vertical hole-shaped underground facility 1 on the back surface 3a of a metal lid 3 that closes the upper opening 1a of the underground facility 1, the method comprising: a fixing step of fixing the antenna 12 to the back surface 3a of the lid 3 using the antenna mounting structure 8 described in any one of Items A1 to A5 while the back surface 3a of the lid 3 is exposed, and electrically connecting the antenna 12 and the lid 3 using a connection portion 2a provided in the antenna mounting structure 8; a radiation step of radiating radio waves from the antenna 12 while the upper opening 1a is closed; a display step of displaying the radio wave intensity D2 of the antenna 12 on a ground terminal device 17; and a change step of changing the installation position P1 of the antenna 12 relative to the connection position G1 between the connection portion 2a and the lid 3 using a position change portion 2b provided in the antenna mounting structure 8 while the back surface 3a of the lid 3 is exposed, based on the radio wave intensity D2.

[0110] According to the invention related to this item A8, while checking the status of communication with the outside performed by the communication device 11 in the underground facility 1, the worker can adjust the connection position G1 where the electromagnetic waves from the antenna 12 are transmitted to the lid 3 and the installation position P1 of the antenna 12 where the antenna 12 radiates the electromagnetic waves within the underground facility 1. This allows the worker to easily determine (position) the connection position G1 and installation position P1 where the communication status is more favorable, improving work efficiency.

[0111] Although the present invention has been described above, the embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0112] 1: Underground equipment 1a: Upper opening 2a: Connection part 2b: Position change section 2b1, 2b4, 2b5: Guide rails 2b2, 2b3: Perforated plate 2h: Through hole (hole) 2j: Arm 2L: Joints 2s: Antenna fixing member (second fixing part) 3: Lid 3a: Back 7e: Slider 7f: 1st fixed part 8: Antenna mounting structure 10: Sensor 11: Communication equipment 12: Antenna 16: Server 17: Terminal device 100: Data communication system D1: Data D2:Radio field strength G1: Connection position P1: Installation position

Claims

1. An antenna mounting structure in which an antenna connected to a communication device installed in an underground facility is mounted on the back surface of a metal cover that closes an upper opening of the underground facility in the form of a vertical hole, a connection portion that electrically connects the antenna to the lid; a position changer that changes the installation position of the antenna relative to the connection position between the connection unit and the lid in a direction parallel to the back surface of the lid; An antenna mounting structure comprising:

2. The position change unit a guide rail fixed to the rear surface of the lid; a slider provided on the antenna and movable along the guide rail; 2. The antenna mounting structure according to claim 1, comprising:

3. The position change unit a perforated plate fixed to the rear surface of the lid and having a plurality of holes formed therein; a first fixing portion provided on the antenna and capable of fixing the antenna to at least one selected hole out of the plurality of holes; 2. The antenna mounting structure according to claim 1, comprising:

4. 2. The antenna mounting structure according to claim 1, wherein the position changing portion has an arm provided with at least one joint, one end of which is fixed to the rear surface of the cover, and the other end of which is fixed to the antenna.

5. The antenna mounting structure according to claim 1 , wherein the position changing portion includes a second fixing portion that can fix the antenna to the rear surface of the lid in an insulated state.

6. The antenna mounting structure according to any one of claims 1 to 5, the communication device; an antenna that radiates data output from the communication device as radio waves; A data communication system including:

7. a sensor installed in the underground facility for detecting a state of an object to be monitored; a server that manages data detected by the sensor; Including, The data communication system according to claim 6 , wherein the communication device transmits data detected by the sensor to the server via the antenna.

8. An antenna mounting method for mounting an antenna connected to a communication device installed in an underground facility on the back surface of a metal cover that closes an upper opening of the underground facility in the form of a vertical hole, a fixing step of fixing the antenna to the back surface of the lid using the antenna mounting structure according to any one of claims 1 to 5 while the back surface of the lid is exposed, and electrically connecting the antenna and the lid using the connection part provided in the antenna mounting structure; a radiation step of radiating radio waves from the antenna with the upper opening closed; a display step of displaying the radio wave intensity of the antenna on a terrestrial terminal device; a changing step of changing an installation position of the antenna relative to a connection position between the connection portion and the lid based on the radio wave intensity by using the position changing portion of the antenna mounting structure while exposing the back surface of the lid; An antenna mounting method comprising:

Images