JP2015012504A - Antenna for manhole cover, and manhole cover with antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manhole cover with an antenna which takes measures to achieve vibration-proof, waterproof and corrosion-proof without degrading antenna properties.SOLUTION: A manhole cover with an antenna comprises: a cover body 13 for closing a ground-side opening of a manhole communicating with a sewer; a radio communication control part for transmitting data measured by a measurement part which measures data required for maintenance management within the sewer; an accommodation recess 20 formed in the cover body 13; an antenna 16 accommodated within the accommodation recess 20; and a protection cover 22 for closing an opening of the accommodation recess. The antenna 16 includes: a case cover formed from a dielectric; a radio wave absorber filling the inside of the antenna 16; and a power supply cable connected with the radio communication control part. Between the case and the accommodation recess 20, a styrene foam material 26 is interposed without gap.

Description

  The present invention relates to an antenna installed on a manhole cover and a manhole cover with an antenna in order to acquire information necessary for maintenance management of a sewer main line or the like in a pipe facility.

  As is well known, water pipes, sewer pipes, gas pipes, power cables, communication cables, etc. are buried underground. In recent years, various data are monitored by monitoring the sewer pipes to detect abnormal conditions such as water leaks in the sewer pipes. Measurement equipment and monitoring equipment are often installed in manholes.

  In order to automatically obtain data when necessary or at regular intervals by a computer device, it is desirable to obtain the data of the measuring device / monitoring device from the ground without entering the tunnel in the manhole.

  In such a situation, a technique has been proposed in which the manhole cover has a communication function in order to acquire data indicating the state of the underground object without opening the manhole cover from the ground. For example, Patent Document 1 is known as a structure for embedding an antenna in a manhole cover.

  If the outline of patent document 1 is demonstrated based on FIG. 11, the antenna 2 is installed in the recessed part formed in the front side of the manhole cover 1. FIG. This antenna 2 includes a disk-shaped antenna substrate 2a, a disk-shaped radiating element conductor 2b deposited on the surface of the antenna substrate 2a, and a disk-shaped ground conductor deposited on the back surface of the antenna substrate 2a. A plate 2c, a cable 2d connected to the ground conductor plate 2c, and a connector 2e at the tip of the cable 2d are provided.

  Each of the plates 2a to 2c is installed in the recess, the ground conductor plate 2c is short-circuited with the manhole cover 1 and integrated with the cover 1, and the surface of the radiating element conductor 2b is coated with a synthetic resin 2f. The cable 2d and the connector 2e are inserted into a through hole formed in the bottom of the recess, and the connector 2e and the wireless water quality measuring device 3 are connected by the cable 4.

JP-A-11-66484

  However, although the manhole cover 1 of Patent Document 1 can be used as a mobile communication base station or the like and for communication of transmission line monitoring information in the manhole, it has the following problems.

(1) Anti-vibration measures Since the manhole cover 1 closes the opening of the manhole, the manhole cover 1 receives vibration when the vehicle travels on the roadway. Certainly, the structure of the antenna 2 is not complicated compared to an electronic device such as a wireless communication control device.

  However, the radio wave boards and the power cables such as the plates 2a to 2c and the connector 2e are easily affected by vibration at the electrical / mechanical connection points, and the antenna 2 is damaged due to the vibration, thereby transmitting data. There is a risk of losing reliability.

(2) Measures for waterproofing and corrosion protection Since the manhole cover 1 is installed on the road outdoors, it must be waterproofed by rainwater. Especially when it is installed in a manhole in the sewer, the humidity inside the manhole is high. It is necessary to consider. This point is not considered at all in Patent Document 1.

(3) Change in antenna characteristics Since the manhole cover 1 is an iron cover, the impedance of the manhole cover 1 is lowered due to the mounting of the antenna 2, which may make it difficult to achieve matching.

  The present invention has been made in order to solve the above-described problems of the prior art, and the anti-vibration measures and waterproofing of the antenna can be achieved without deteriorating the antenna characteristics in the antenna for manhole and the manhole cover with antenna.・ The solution is to take anti-corrosion measures.

  An antenna for a manhole cover according to the present invention includes a housing that is installed on the manhole cover and formed of a dielectric, a radio wave board that is housed in the housing, and a feeder that is connected to a wireless communication device. The housing is filled with a protection material for the radio wave board. The protective material for the radio wave board is preferably made of a radio wave absorber, and is unevenly distributed in a direction other than the direction in which radio waves are transmitted and received. The antenna may be a multiband antenna by installing a plurality of radio wave boards in a housing.

  One aspect of the manhole cover with an antenna according to the present invention includes a lid body that closes an opening on the ground side of a manhole that communicates with the tube, and measurement by a measurement unit that measures data necessary for maintenance in the tube A wireless communication control unit for transmitting data, an antenna storage unit provided on the front side of the lid body, an antenna for a wireless communication control unit stored in the antenna storage unit, and a power supply unit for supplying power to the wireless communication control unit And the antenna includes a housing formed of a dielectric, a radio wave substrate housed in the housing, and a feed line connected to the wireless communication control unit, and the radio wave substrate in the housing A protective material is filled, and a vibration-proof material is interposed between the antenna storage portion and the housing.

  Here, a plurality of single-band antennas may be provided, or a plurality of radio wave boards having different frequencies may be housed in a housing to form a multi-band antenna. The antenna storage portion may be configured by a storage recess formed on the front side of the lid body and a cover for closing the opening of the storage recess, and a cap hole formed in a cap shape on the front side of the lid body. You may comprise.

  Another aspect of the manhole cover with an antenna according to the present invention includes a lid body that closes an opening on the ground side of a manhole that communicates with the tube, and a measurement unit that measures data necessary for maintenance in the tube. A wireless communication control unit that transmits measurement data, a cap hole formed on the front side of the lid body, an antenna for the wireless communication control unit stored in the cap hole, and a power supply unit that supplies power to the wireless communication control unit The antenna includes a housing formed of a dielectric, a radio wave substrate housed in the housing, and a feed line connected to the wireless communication control unit, and the radio wave substrate is protected in the housing It is characterized in that the housing is formed so that it can be fitted into the cap hole. Here, a plurality of cap holes may be formed on the front side of the manhole cover, and each of a plurality of antennas having different frequencies may be stored in each cap hole.

  ADVANTAGE OF THE INVENTION According to this invention, the antenna for manholes and the manhole cover with an antenna by which the anti-vibration countermeasure of the antenna, the waterproofing, and the anticorrosion countermeasure were taken can be provided, without deteriorating antenna characteristics.

Schematic of the manhole to which the manhole cover with an antenna which concerns on embodiment of this invention is applied. The top view of the same manhole cover. The assembly figure of the antenna storage part. AA sectional drawing of FIG. BB sectional drawing of FIG. (A) is a perspective view of the antenna of Example 1, (b) is a cross-sectional view of (a). (A) is a perspective view of the antenna of Example 2, (b) is a cross-sectional view of (a). (A) is a perspective view of the antenna of Example 3, (b) is a cross-sectional view of (a). The figure which shows the half-angle value of an antenna. (A) is a longitudinal cross-sectional view of a cap type | mold antenna, (b) is a top view of (a). The longitudinal cross-sectional view of the manhole cover of patent document 1. FIG.

  Hereinafter, a manhole cover with an antenna according to an embodiment of the present invention will be described. This manhole cover closes the opening on the ground side of the manhole that communicates with the sewer pipe, and enables the construction of a system that measures equipment maintenance information in the pipe just by replacing the manhole cover of the existing structural equipment. ing.

  The overall structure of the manhole cover will be described with reference to FIG. The manhole cover 11 has a unit structure in which a communication device and a power source are incorporated, closes the upper end opening 12 of the manhole M communicating with the sewer pipe P, and receives a receiving frame (not shown) installed in the upper end opening 12. Measurement data (for example, water level data, etc.) of a lid main body 13 that can be freely opened and closed via a hinge 19 and a measurement unit (for example, a water level sensor) 14 that measures data required for maintenance in the tube tub P Wireless communication control unit 15 for transmitting data by wireless communication, antenna 16 for data transmission / reception of wireless communication control unit 15, and power supply unit 17 for supplying power to wireless communication control unit 15. The wireless communication control unit 15 is configured by a wireless communication device (for example, a wireless communication terminal device) that transmits measurement data of the measurement unit 14 to an upper server by wireless communication.

  At this time, considering the communication cost, a mesh network can be constructed by the manhole cover 11 installed in the plurality of manholes M, and a highly reliable information transmission route can be constructed. The power source unit 17 is mainly a lithium primary battery that satisfies both power consumption and dimensions, and the battery capacity may be doubled by connecting two BOXs in series to each other in a rechargeable manner. A power source in combination with a secondary battery or a power generation device may be used.

≪Lid body 13≫
The lid main body 13 is formed in a disc shape, and as shown in FIGS. 2 to 5, an accommodation recess 20 formed on the front side thereof and recessed in a cross-sectional recess for storing the antenna 16, and an O-ring (packing) A plate-shaped protective cover 22 that closes the opening of the storage recess 20 via 21, a foamed polystyrene material 26 interposed between the storage recess 20 and the antenna 16, and a plurality of parallel covers in the vicinity of the storage recess 20 The cap hole 24 formed on the back side and the reinforcing member 25 erected in a lattice shape on the back side, and a space partitioned in a grid shape between the reinforcing members 25 is a storage for storing the parts 15 and 17. A BOX 30 is mounted. In FIG. 1, the reinforcing member 25 and the storage BOX 30 are omitted, and the mounting of the parts 15 and 17 is generally shown. In practice, however, the parts 15 and 17 are stored in the storage BOX 30. Implemented in.

  The lid main body 13 is configured with an antenna storage portion for storing the antenna 16 by the above-described configurations 20 to 22. Here, the lid main body 13 has an antenna storage portion on the front side that is not buffered with the space of each storage BOX 30 arranged on the back side, and this is such that the lid surface has a concave cross section at the antenna mounting position. The hollow of the recess having a concave cross section is formed as a box-shaped storage recess 20 that is open on the front side of the lid body 13.

  The lid body 13 is manufactured in accordance with the standard “Tokyo Metropolitan Sewer Design Standard Manhole Iron Lid (Standard Lid 60cm Metropolitan Type Specification)” regarding the mechanical properties and load bearing strength of the iron lid. It has a load bearing strength equivalent to “manhole iron lid (standard lid) φ600 load classification T-25” compliant with the sewer design standard. Further, it has been confirmed that the lid body 13 satisfies the above-mentioned specifications by performing a load-bearing performance test separately.

  As for the lid body 13, it is required that the antenna 16 attached to the front side is not affected by the communication performance in the long term due to the passage of the vehicle, the weather, or the like as the antenna protection performance. Therefore, tests were performed on various waterproof properties (waterproof against thermal shock, waterproof against repeated loads, waterproof against vehicle loads, etc.) of the antenna housing, and it was confirmed that there was no problem with waterproofness.

  When the protective cover 22 made of polycarbonate was used, a part of the uneven pattern considering the slip resistance disappeared, and therefore the slip resistance was separately tested by a DF tester R85 conforming to ASTM. As a result, it is confirmed that the average of the dynamic friction coefficients of the places passing over the protective cover 22 is larger than the average of the places other than the places where the protective cover 22 is installed, and there is no influence of slip resistance reduction due to the attachment of the protective cover 22. Has been.

  In addition, although the polycarbonate which was excellent in radio wave permeability was adopted as the material of the protective cover 22, it is not limited to this, it has radio wave permeability that allows communication without trouble, and satisfies the standards of the above specifications. Other materials can be selected on the condition.

<< Specifications of antenna 16 >>
As shown in FIG. 3, the antenna 16 mainly uses a dipole antenna of 800 MHz or 2.4 GHz band. Here, the case housing the radio wave board is installed on the bottom wall 20a of the housing recess 20 so as to be parallel to the cover plane.

  In addition, the antenna 16 can be installed in the storage recess 20 on the front side of the lid body 13 and can secure communication performance. The antenna 16 is not limited to the dipole method and can be selected from the monopole method and the diversity method, and the shape is linear or coiled. , Meander, spiral, etc. can be selected. The antenna 16 has the following countermeasures against conventional problems.

(2) Anti-vibration measures, waterproof and anti-corrosion measures The antenna 16 has a case (housing) for housing a radio wave substrate (hereinafter abbreviated as a substrate) filled with a radio wave absorber such as urethane containing carbon. Yes. According to this configuration, vibration can be absorbed by the filled radio wave absorber. Further, since air in the case is excluded (decreased), measures against humidity and condensation are taken, and the waterproofness of the case is improved.

(2) Measures against changes in antenna characteristics The case is made less susceptible to the influence of the lid body (iron lid) 13 by filling the case with a radio wave absorber having a low dielectric constant. Here, when the antenna 16 is mounted in the storage recess 20 of the lid main body 13, the impedance becomes low between the ground, that is, the bottom wall 20 a constituting the storage recess 20. Thus, the alignment can be achieved even under the influence of the lid body 13.

  Also, by filling the gap in the case with a low dielectric constant radio wave absorber, measures against condensation are taken without degrading the antenna characteristics. As a radio wave absorber, low-dielectric-constant foaming urethane is used to bring it closer to the same relationship as air, and countermeasures against deterioration of antenna characteristics are taken. In this sense, the radio wave absorber filled in the case can be said to be a protective material for the radio wave board that has the effects of radio wave absorption, vibration absorption, moisture proofing and dew condensation.

  The antenna 16 may be either a single-band antenna or a multi-band antenna as long as the above specifications are satisfied, and the case shape may be either a rectangular parallelepiped shape or a cap shape. Moreover, the material FR-4 (Frame Regentant Type) which made the flame retardance and low electrical conductivity compatible was used for the material of the board | substrate. For the cases 32 and 42 and the case covers (lids) 33 and 41, polycarbonate having a dielectric constant of 2.9 to 3 was used.

  In addition, although urethane which is a dielectric wave absorbing material was used as the wave absorber, it is not limited to this. For example, a thin wave absorbing sheet that exhibits high absorption performance over a wide band is used to add a loss material to a net-like lightweight foamed polyurethane foam. A coated type, a lightweight foamed polyurethane foam impregnated with carbon, or a resonance type thin / non-combustible / weatherproof electromagnetic wave absorbing sheet in which a urethane rubber sheet is kneaded with carbon may be used. The materials of the substrate, case, case cover, and radio wave absorber are not limited to the above materials, and can be appropriately selected and used according to the use conditions of the antenna.

<< Example of Antenna 16 >>
Hereinafter, an embodiment of the antenna 16 will be described with reference to FIGS. Here, the first and second embodiments show a configuration example of a single-band antenna, and the third embodiment shows a configuration example of a dual-band antenna.

(1) Example 1
FIG. 6 shows an antenna 16 related to a mobile phone band of 800 MHz, which is designed as a small and thin type antenna. Here, as shown in FIGS. 6A and 6B, the antenna 16 is constructed as a pattern antenna having a three-dimensional antenna pattern on the substrate 31, and accommodates it in a case 32 made of polycarbonate. The case 32 is filled with a radio wave absorber (urethane) 36 and the opening of the case 32 is sealed with a case cover 33.

  The case cover 33 is fixed to the four corners of the case 32 by screwing screws 34, and the power supply cable 28 is drawn from the lower portion of the case 32 from the substrate 31. Here, the antenna 16 is configured as a ½λ (wavelength) dipole antenna in which the power supply cable 28 is symmetrically arranged with the substrates (elements) 31, and a ground plane is unnecessary.

  As the radio wave characteristics, the impedance is lowered and the characteristics tend to be deteriorated when the periphery of the antenna 16 is surrounded by the inner wall of the lid body 13, that is, the metal wall. Therefore, the radiation directivity in the 800 MHz band is slightly inclined from the front direction by 0 degrees (the half power angle is taken in the horizontal direction).

  In addition, the antenna 16 is provided with the above-described countermeasures, and the radio wave absorber 36 is combined so that the antenna 16 is hardly affected by the material of the lid body 13. In particular, since the antenna of the 800 MHz band becomes large and is easily affected by the material of the lid main body 13, there is no gap on the bottom wall 20 a side so as to suppress the influence from the lid main body 13 in the radio wave transmission / reception direction. 36 is filled without gaps. In addition, the antenna 16 has a high impedance so that matching can be achieved even if it is affected by the material of the lid body 13, and the gap in the case 22 is filled with a low dielectric constant wave absorber (urethane) 36. The measures against waterproofing and condensation are taken without deteriorating the antenna characteristics.

  The structure of the antenna 16 employs a ½λ (wavelength) dipole antenna from the relationship between the mounting space and the gain, but may employ a ¼λ (wavelength) dipole antenna. In this case, it is necessary to attach a ground plane of ¼λ (wavelength) in a direction perpendicular to the substrate 31.

(2) Example 2
FIG. 7 shows the antenna 16 relating to the 2.4 GHz cellular phone band, and the case 42 is formed in a rectangular parallelepiped shape and is designed to be of a smaller and thinner type. Here again, the antenna 16 has the above-mentioned countermeasures.

  That is, the antenna 16 is constructed as a pattern antenna on the substrate 44 as shown in FIGS. 7A and 7B, and is housed in a polycarbonate case 42, and the case 42 has a radio wave absorber ( Urethane) 48 is filled, and the opening of the case 42 is sealed with a case cover 41.

  At this time, in order to construct a 1 / 4λ (wavelength) dipole antenna, a ground plate is formed on the inner surface of the bottom plate of the case 42 with a conductor 43, and one end of the power supply cable 28 is connected to the substrate 44 with a flat washer 45, a pan screw 46, The power supply cable 28 is pulled out from the lower part of the case 42 by being coupled with the nut 47.

  Here, the approach as the electrical characteristic is the same as that of the first embodiment, and the radiation directivity in the 2.4 GHz band is slightly inclined from the front direction by 0 degree (the half power angle is taken in the horizontal direction). The structure of the antenna 16 employs a ¼λ (wavelength) dipole antenna because of the relationship between mounting space and gain, but a ½λ (wavelength) dipole antenna may be employed. When this 1 / 2λ (wavelength) dipole antenna is used, a ground plane is not required.

(3) Example 3
FIG. 8 shows a dual antenna that handles two waves in the 800 MHz band and the 2.4 GHz band. Here, the dual antenna 16 has a two-frequency antenna, that is, an 800 MHz band antenna 16 a and a 2.4 GHz band antenna 16 b mounted in a limited space.

  In this embodiment, in order to mount the antennas 16a and 16b in a limited space, that is, in the housing recess 20, the antennas 16a and 16b are three-dimensionally arranged up and down, and the depth direction is secured. Here, by using a capacitive coupling type antenna, it is made difficult to be affected by metal and other parts around the antenna.

  At this time, in order to reduce the installation space in the storage recess 20 as much as possible, the dual antennas 16 of the antennas 16a and 16b are accommodated in, for example, a case having a size of 10 cm square. By reducing the installation space in this way, it is possible to mount the multi-frequency (dual band) antenna 16 having two frequencies in the depth direction of the storage recess 20.

  In FIG. 8B, it is assumed that two power feeding cables (coaxial) 28 of 800 MHz band and 2.4 MHz band are arranged. Here, both antennas 16a and 16b are constructed on the ground plate 57. As shown in FIGS. 8 (a) and 8 (b), the antenna 16a is composed of a waveguide 52 and a radiator 53 in the 800 MHz band, and the antenna 16b. Is composed of a 2.4 GHz band director 55 and a radiator 56, and one end of the power feeding cable 28 is coupled to each of the directors 52 and 55.

  Both antennas 16a and 16b are arranged at such a distance that interference is reduced by the spacer 54. Further, by making the planes of polarization of the directors 52 and 55 orthogonal, the antennas are arranged so as not to interfere with each other when using a plurality of frequencies. Although not shown in FIGS. 8A and 8B, the antenna 16 accommodates both antennas 16a and 16b in a polycarbonate case as in the first and second embodiments, and absorbs radio waves in the case. The body (urethane) is filled, and the opening of the case is sealed with a case cover.

<< Example of mounting antenna 16 on lid body 13 >>
An example of mounting the antenna 16 on the lid body 13 will be described with reference to FIGS. First, a foamed polystyrene material 26 having a shape and size that can be stored in the storage recess 20 without any gap is prepared in advance, and the foamed polystyrene material 26 is stored in the storage recess 20 as shown in FIGS. 3 and 5. It is assumed that the foamed polystyrene material 26 is formed in a frame shape having a cavity formed with cases 32 and 42 inside.

  Since the antenna 16 is housed inside the foamed polystyrene 26, the foamed polystyrene material 26 is interposed between the cases 32 and 42 and the housing recess 20. That is, since the foamed polystyrene material 26 is filled between the cases 32 and 42 and the inner wall of the housing recess 20 without a gap, rattling and vibration of the antenna 16 are suppressed. In this case, since the vibration is also absorbed by the urethanes 36 and 48 filled in the cases 32 and 42, the antenna 16 has a strong anti-vibration measure.

  In this state, the protective cover 22 is screwed to the outer edge of the storage recess 20 with the screw 23 via the O-ring 21. At this time, the power feeding cable 28 of the antenna 16 is inserted into the through hole 27 formed in the bottom wall 20 a of the housing recess 20.

  Then, as shown in FIG. 4, the power feeding cable 28 is pulled out from the through hole 27 on the back side of the lid body 13 and fixed to the opposite side of the bottom wall 20 a with a waterproof cable gland 29. Thereafter, the tip connector 28a of the power feeding cable 28 is passed through the mounting hole 30b formed in the side wall 30a of the housing BOX 30 and connected to an antenna terminal (not shown) of the wireless communication control unit 15, and the power feeding cable is connected with the waterproof cable ground 29. The mounting operation of the antenna 16 is completed by tightening 28 on the side wall. As a result, the data measured by the measurement unit 14 can be transmitted to the upper server through the 800 MHZ band or 2.4 GHz band mobile phone communication network.

  Here, since the manhole 11 closes the opening of the manhole M, the manhole 11 is subjected to vibrations when the vehicle is running, but since the strong anti-vibration measures are taken as described above, the substrates 31, 44, It is possible to reduce failures due to vibrations of electrical / mechanical connection points such as the power supply cable 28. As a result, according to the manhole 11, the reliability of the measurement data transmission means can be improved, and the life of the parts can be extended, so that the running cost can be reduced.

  Moreover, since the internal air is eliminated (reduced) by filling the cases 32 and 42 with urethane 36 and 48, measures against humidity and condensation are taken, and the waterproofness of the case is improved. In this respect, corrosion and the like can be suppressed, and it is possible to cope with a poor manhole environment such as high humidity.

  Further, according to the manhole cover 11, the gaps in the cases 32 and 42 are filled with the low dielectric urethane 36 and 48, so that countermeasures against condensation are taken without deteriorating the antenna characteristics. In particular, since the antenna 16 is set to have a high impedance from the beginning so that consistency can be obtained even under the influence of the lid body 13, the reliability of the measurement data transmission means can be improved in this respect as well.

  According to the manhole 11, the antenna 16 is housed in the housing recess 20, and at that time, the housing recess is arranged so that radio waves can be transmitted and received from a depth within about 20 mm from the ground (road surface or the like). The gain in the horizontal direction is increased by setting the distance from the inner wall 20 wide. That is, the sensitivity at the half-power angle indicating the directivity of the antenna can be increased in the horizontal direction. In this case, as shown in FIG. 9, the characteristics of the antenna 16 are taken into consideration so as to reduce the half-power angle.

≪Other examples of antenna 16≫
Although the antenna 16 is housed in the housing recess 20 of the lid body 13 in the above-described embodiment, the housing pattern of the antenna 16 is not limited to this, and is formed in the lid body 13 shown in FIGS. 2 and 3. The cap hole 24 can also be stored. In this case, the cap hole 24 plays a role as an antenna storage portion, and instead of the antenna 16 of the first to third embodiments, a cap-type antenna is prepared separately.

(1) Configuration Example of Cap Type Antenna FIG. 10 shows a 2.4 GHz band cap type antenna 16. As shown in FIGS. 9A and 9B, the antenna 16 has a structure in which a spacer substrate 64 is sandwiched between a radiation substrate 63 and a ground substrate 65 in a case not shown, and a radio wave absorber is contained in the case. It is configured to be filled with urethane.

  Here, the power supply pin 61 is connected to the radiation board 63 to be supplied with power, and the short-circuit pins 62 connect the boards 63 to 65 to the 2.4 GHz band power supply cable (coaxial) 28. An 800 MHz antenna can be mounted with the same structure, and a two-frequency antenna can be mounted as a dual antenna by a deeper method.

(2) Example of mounting cap type antenna 16 on lid body 13 When mounting the cap type antenna 16, a foamed polystyrene material having a shape and size that can be accommodated in the cap hole 24 without any gap as in the first to third embodiments. Prepare and store in cap hole 24. This foamed polystyrene material is also formed in a frame shape having a cavity with a case inside, and the cap-type antenna 16 is accommodated in the foamed polystyrene material. Subsequent wiring of the power supply cable 66 is the same as in the first to third embodiments.

  In this case, the Tokyo Metropolitan Sewerage Bureau uses a cap to clearly indicate the manhole number and pipe installation year on the manhole cover. If a case having the same shape and shape as the cap is manufactured, the cap-type antenna 16 can be fitted into the cap hole 24 without being filled with the expanded polystyrene material.

  According to such a cap-type antenna 16, it is not necessary to form the housing recess 20 in the lid body 13, and in this sense, the change in the manhole appearance can be suppressed. Further, since the opening area of the cap hole 24 is small, it is possible to avoid the load of the vehicle or the like being directly applied to the cap type antenna 16 accommodated therein. As a result, the protective cover 20 is not necessary, and in this respect, the number of parts can be omitted, and the cost can be reduced.

  In addition, this invention is not limited to the said embodiment, It can deform | transform and implement within the range described in each claim. For example, a plurality of single-band antennas 16 having different frequencies may be installed in the housing recess 20 and configured as a multiband. Similarly, if a single-band cap type antenna 16 having a different frequency is accommodated in each cap hole 24 arranged in parallel with the lid body 13, a multiband can be easily constructed.

  Further, when the antenna 16 is housed in the housing recess 20 and the cap hole 24, anti-vibration measures have been taken using a foamed polystyrene material. However, other than foamed polystyrene, the antenna 16 has radio wave permeability and does not affect the transmission and reception of radio waves. Other elastic bodies such as rubber may be used as long as anti-vibration effects can be expected.

11 ... Manhole cover with antenna 13 ... Cover body 15 ... Wireless communication control unit (wireless communication device)
16 ... Antenna (antenna for manhole cover, antenna for wireless communication controller)
17 ... Power supply unit 20 ... Storage recess 22 ... Protective cover (cover)
24 ... Cap 26 ... Styrofoam material (anti-vibration material)
28 ... Electric power supply cable (feed line)
31, 44 ... Board (Radio wave board)
32, 42, 67 ... Case (housing)
36, 48 ... Radio wave absorber (Radio wave board protection material)

Claims (10)

An antenna for a manhole cover that provides an antenna function to the manhole cover that closes the opening on the ground side of the manhole and enables wireless communication devices to communicate,
A housing that is installed on a manhole cover and formed of a dielectric, a radio wave board that is housed in the housing, and a power supply line that is connected to a wireless communication device,
An antenna for a manhole cover, characterized by filling a casing with a protective material for a radio wave board.   The antenna for a manhole cover according to claim 1, wherein the protection member for the radio wave board is made of a radio wave absorber and is unevenly distributed in a direction other than a direction in which radio waves are transmitted and received.   The antenna for a manhole cover according to any one of claims 1 and 2, wherein a plurality of radio wave boards are installed in a casing to form a multiband antenna. A lid body that closes the ground side opening of the manhole communicating with the tube;
A wireless communication control unit that transmits measurement data of a measurement unit that measures data necessary for maintenance in the pipe;
An antenna housing provided on the front side of the lid body;
An antenna for a wireless communication control unit stored in the antenna storage unit;
A power supply unit that supplies power to the wireless communication control unit,
The antenna includes a housing formed of a dielectric, a radio wave substrate housed in the housing, and a feeder line connected to the wireless communication control unit,
A manhole cover with an antenna, wherein a protective material for a radio wave board is filled in the housing, and a vibration isolating material is interposed between the antenna storage portion and the housing.   The manhole cover with an antenna according to claim 4, comprising a plurality of single-band antennas.   5. The manhole cover with an antenna according to claim 4, wherein a plurality of radio wave boards having different frequencies are housed in a casing to form a multiband antenna. The said antenna storage part is equipped with the storage recessed part formed in the front side of the lid | cover main body, and the cover which obstruct | occludes the opening part of a storage recessed part. The antenna with an any one of Claims 4-6 characterized by the above-mentioned. Manhole cover.   The said antenna storage part consists of a cap hole formed in cap shape by the front side of a lid | cover main body, The manhole cover with an antenna of any one of Claims 4-6 characterized by the above-mentioned. A lid body that closes the ground side opening of the manhole communicating with the tube;
A wireless communication control unit that transmits measurement data of a measurement unit that measures data necessary for maintenance in the pipe;
A cap hole formed on the front side of the lid body;
An antenna for a wireless communication control unit stored in the cap hole;
A power supply unit that supplies power to the wireless communication control unit,
The antenna includes a housing formed of a dielectric, a radio wave substrate housed in the housing, and a feeder line connected to the wireless communication control unit,
A manhole cover with an antenna, wherein the casing is filled with a protection material for a radio wave board, and the casing is formed to be fitted into a cap hole. A plurality of cap holes are formed on the front side of the manhole cover,
The manhole cover with an antenna according to claim 9, wherein each of the plurality of antennas having different frequencies is stored in each cap hole.

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