JPH1166484A - Manhole cover antenna equipment and communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manhole cover antenna capable of providing an antenna function for a manhole cover without deteriorating cover strength only by simply machining the manhole cover. SOLUTION: The surface of the manhole cover 1 is slightly cut to form a through hole 1b for putting a power feed line through in a center of the cut and recessed part 1a to install a substrate antenna 2 in the part 1a. A base conductor plate 2c on the rear surface of the antenna 2 is brought into contact with the cover 1 to short-circuit. Through the use of the thin substrate antenna 2 as an antenna element, the machining work of the part 1a for arranging the antenna element is minimized and as only the hole 1b for inserting a cable 2d and a connector 2e is provided, the strength of the cover 1 is not deteriorated much.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole cover antenna device in which an antenna is installed on a manhole cover for performing wireless communication between the ground and the inside of a manhole, and a communication system using the same.

[0002]

2. Description of the Related Art Water pipes, sewer pipes, gas pipes, power cables, communication cables, and the like are buried underground.
Measure various data values to detect water leaks in water pipes, poor water flow in sewer pipes, gas leaks in gas pipes, leaks in power cables, disconnections in communication cables, etc. It is necessary to monitor the condition of these underground objects. Therefore, measuring equipment and monitoring equipment are often installed in manholes, and when acquiring data required by those measuring equipment and monitoring equipment, an observer enters the manhole and obtains these data. It is troublesome, and it is desirable to obtain these data from the ground.

Under such circumstances, development of a system capable of acquiring data indicating the state of an underground buried object from the ground without opening the manhole cover is being promoted. Hereinafter, a conventional example of such a system will be described.

Japanese Unexamined Patent Publication No. 55-30050 discloses a conventional example in which a transceiver is mounted on the back side of a manhole cover made of an insulating material, and a transmitting antenna is mounted in a manner embedded in the manhole cover. Further, Japanese Patent Application Laid-Open No. Hei 3-227073
Japanese Patent Application Laid-Open Publication No. H11-157210 discloses a technique in which a part of a manhole cover is made into a dielectric material and a transmitting antenna is installed in the dielectric material. Japanese Utility Model Laid-Open No. 5-83053 discloses a configuration in which an antenna element is sandwiched between a pair of dielectric films in a frame made of cast iron. Further, Japanese Patent Application Laid-Open No. H7-143631 discloses a technique in which a manhole cover has a double cover structure and an inner cover has an antenna function.

[0005]

SUMMARY OF THE INVENTION As described above, an object of the present invention is to form a wireless communication network by combining an underground communication means for transmitting a result of monitoring the condition of an underground object with an antenna attached to a manhole cover. As
The embedding of the antenna element in the manhole cover is being studied. However, in the conventional example, the reduction in the strength of the manhole cover due to the processing is not taken into consideration, and if this is taken into account, there is a problem that a special processing to the manhole cover or a significant change in the structure of the manhole cover is required. There is also a problem that the method of processing and using the manhole cover and the method of adjusting and installing the antenna are not sufficiently considered.

[0006] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a manhole cover antenna device capable of providing a manhole cover with an antenna function without lowering the cover strength.

It is another object of the present invention to provide a manhole cover antenna device which can rotate an antenna in an arbitrary direction and can set the direction to an optimum direction.

Still another object of the present invention is to provide a communication system capable of selecting between a configuration in which power is directly supplied from an underground radio and a configuration in which a relay antenna is combined with another paired antenna. Is to do.

Still another object of the present invention is to provide a communication system which enables wide area communication by wireless public line connection and facilitates remote management in a manhole.

[0010]

A manhole cover antenna device according to the present invention is an antenna device in which an antenna having a ground conductor and a feeder line is attached to a manhole cover, and a concave portion is provided on the surface thereof. A cover for a manhole provided with a through hole from the concave portion, and a planar substrate antenna disposed in the concave portion, the ground conductor portion of which is in contact with the lid, and the feed line of which is passed through the through hole. It is characterized by the following.

In the manhole cover antenna device of the present invention,
A part of the surface of the manhole cover is slightly shaved or thinly cast, a through hole is formed in the center of the part (recess) for passing a feeder line, and the planar substrate antenna is installed in the recess. At this time, the ground conductor plate on the back surface of the planar substrate antenna is brought into contact with the manhole cover to cause a short circuit. By using a thin planar substrate antenna as an antenna element in this way, processing of the concave portion for disposing the antenna element is minimized, and
Since only a through-hole into which the power supply line can be inserted is provided, the strength of the manhole cover does not significantly deteriorate. Furthermore,
By short-circuiting to the manhole cover, a ground conductor plate having a sufficient area can be formed.

A manhole cover antenna device according to the present invention is characterized in that, in addition to the above-described configuration, the concave portion and the planar substrate antenna have a circular or regular polygonal shape in plan view.

By making the substrate of the planar substrate antenna circular or regular polygonal, the planar substrate antenna can be installed at an appropriate rotation angle. When the planar substrate antenna is installed, the planar substrate antenna can be rotated in any direction about the feed line, and the planar substrate antenna can be directed in an optimal direction with respect to a ground base station. Further, the antenna orientation can be rotated at an appropriate pitch angle, and the rotation angle does not shift when the flat substrate antenna is fixed, so that the flat substrate antenna can be easily installed.

[0014] A communication system according to the present invention includes the above-described manhole cover antenna device and an underground transmission / reception radio device connected to the power supply line via a cable.

If a cable is connected between the feeder of the flat board antenna and the radio transceiver in the basement, the manhole cover antenna device functions as an external antenna of the radio transceiver.

A communication system according to the present invention includes the above-described manhole cover antenna device, another antenna connected to the power supply line, and a radio transmitter / receiver in the underground that wirelessly communicates with the antenna. Features.

If another pair of antenna elements is connected to the feed line of the planar substrate antenna, the manhole cover antenna device functions as a relay antenna.

[0018] The communication system according to the present invention is characterized in that the underground transmission / reception radio device uses an automobile telephone system.

By using a car telephone system as a radio transceiver in the basement, communication over a wide area using a public line becomes possible, and easy remote management in a manhole can be realized.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described with reference to the drawings showing the embodiments. Hereinafter, a case will be described as an example in which the present invention is applied to a communication system that transmits measurement data obtained by a measuring device installed in a fire hydrant to a base station on the ground.

(First Embodiment) FIG. 1 is a schematic diagram showing a state in which a manhole cover antenna device according to a first embodiment of the present invention is applied to the communication system, and FIGS.
3B is a diagram showing the mounting of the board antenna to the manhole cover in the manhole cover antenna device of the first embodiment, and FIGS. 3A and 3B are a side view and a front view of the board antenna.

In FIG. 1, reference numeral 10 denotes a water distribution pipe buried underground, and a branch pipe 11 of the water distribution pipe 10 passes through a manhole 12. A water storage tank 13 is connected to the tip of the branch pipe 11, and a wireless water quality measuring device 14 for measuring the pressure, quality, flow rate and the like of the water inside the water storage tank 13 is attached to the water storage tank 13. The configuration of the wireless water quality measuring device 14 will be described later.

On top of the manhole 12, a circular manhole cover 1 (hereinafter simply referred to as cover 1) is placed. The thickness of the lid 1 is about 20 mm. Reference numeral 31 denotes a base station provided on the ground, and the base station 31 includes a ground antenna 32 for the base station. Radio waves can be transmitted and received between the ground antenna 32 and the board antenna 2 provided on the lid 1. The base station 31 is connected by a telephone line to a management unit 33 that manages the internal state of the fire hydrant.
Is capable of managing the internal state of the fire hydrant with a computer or the like provided based on the transmitted measurement data.

As shown in FIG. 2A, a circular concave portion 1a having a depth of about 3 to 5 mm is provided in the center of the surface of the lid 1 on the ground side. The lid 1 is formed with a through hole 1b having a diameter of about 10 to 20 mm which is continuous with the center of the concave portion 1a. The depth of the concave portion 1a is such that the pattern on the surface of the lid 1 is shaved, and the diameter of the through hole 1b may be large enough to insert a cable and connector of the board antenna 2 described later.
These can be formed only by performing simple processing on existing manhole covers. Since the processing is minute, the strength of the lid 1 does not significantly deteriorate. In the examples shown in FIGS. 1 and 2, the cover 1 is provided with a reinforcing rib 1c so that the substrate antenna is not damaged when the cover 1 is opened and closed. Recess 1a
Are formed at positions avoiding the reinforcing ribs 1c. The depth of the concave portion 1a to be formed is sufficiently smaller than the thickness of the lid 1, and the periphery of the concave portion 1a is reinforced by ribs 1c, so that the strength of the lid 1 does not deteriorate.

The substrate antenna 2 installed on the lid 1
As shown in FIGS. 3A and 3B, for example, a disk-shaped antenna substrate 2a made of glass epoxy resin and an antenna substrate 2a attached to the surface of the antenna substrate 2a and having a smaller area and a smaller thickness than the antenna substrate 2a A radiating element conductor 2b having a disc shape, a ground conductor plate 2c formed on the back surface of the antenna board 2a and having a thin disc shape having the same area as the antenna board 2a, and a cable 2d connected to the ground conductor plate 2c And the connector 2e provided at the end of the cable 2d
It is composed of As shown in FIG. 3B, the feeding point of the board antenna 2 coincides with the center of the antenna board 2a, but the radiating element conductor 2b and the antenna board 2a are not concentric, and the radiating element conductor 2b Are unevenly distributed.

Then, the substrate antenna 2 having such a configuration
As shown in FIG. 2 (b), is installed in the concave portion 1a and the through hole 1b of the lid 1 in the following manner. Radiating element conductor 2
b, the laminated body of the antenna substrate 2a and the ground conductor plate 2c is set in the concave portion 1a of the lid 1, and the cable 2d and the connector 2e are connected to the through hole 1b.
Is inserted into. The ground conductor plate 2 c is short-circuited with the lid 1 and integrated with the lid 1. The antenna substrate 2a is fixed with cement, synthetic resin, or the like. The cable 2d and the connector 2e inserted into the through hole 1b are fixed on the back surface of the lid 1. Further, in order to prevent the radiating element conductor 2b of the board antenna 2 from external pressure or water, its surface is coated with a synthetic resin 2f for protection.

When the board antenna 2 is installed on the cover 1, the radiating element can be rotated in an arbitrary direction around the cable 2d (through hole 1b) so that the directivity to the fixed base station 31 is good. The direction of the conductor 2b is determined.

The connector 2e of the board antenna 2 and the wireless water quality measuring device 14 are connected by a cable 16. FIG.
FIG. 2 is a block diagram showing a configuration of a wireless water quality measuring device 14. The wireless water quality measuring device 14 includes a sensor unit 21 and a logger unit 22.
And a communication unit 23. The sensor unit 21 has various sensors for measuring water pressure, flow rate, pH, etc., and the logger unit 22 has a CPU 24 for controlling the entire operation, a memory 25 for storing measurement data and the like, and a power supply 26. Communication unit 23
Is a modem that converts the format of measurement data and communication data
Mobile phone 28 as a communication device for transmitting and receiving communication data with 27
And a power supply circuit 29.

In the above-described configuration, the pressure, flow rate, pH, etc. of the water in the fire hydrant are measured by the respective sensors of the sensor unit 21, and a signal radio wave including the measured data is transmitted to the cable.
16, radiated to the ground via the board antenna 2 and received by the base station 31 installed on the ground, and presents measurement data to the observer. Also, the measurement data is sent from the base station 31 to the management unit 33 via a telephone line, and the internal state of the fire hydrant is managed by a computer.

As described above, in the board antenna 2 of the first embodiment, the connector 2e is connected to the wireless transceiver (mobile phone 28) in the manhole 12 by the cable 16, so that the wireless transceiver Functions as an external antenna. When wireless communication within the manhole is difficult, a direct power supply system using such a cable connection can be selected. In addition, the propagation efficiency is higher than that of wireless communication.

(Second Embodiment) FIG. 5 is a schematic diagram showing a state in which a manhole cover antenna device according to a second embodiment of the present invention is applied to the communication system. In FIG. 5, the same reference numerals as those in FIGS. 1 to 3 denote the same or corresponding parts. The illustration of water supply facilities is omitted.

In FIG. 5, reference numeral 3 denotes a relay antenna connected to the board antenna 2 by a connector. FIG. 6 (a),
2B is a side view and a front view of the relay antenna 3. FIG. As shown in FIGS. 6A and 6B, the relay antenna 3 includes an antenna substrate 3a having a rectangular plate shape, and an antenna substrate 3a.
A radiation conductor plate 3b having a rectangular plate shape with a smaller area than 3a, a ground conductor plate 3c attached to the antenna substrate 3a and having a rectangular plate shape having the same area as the antenna substrate 3a, and a cable connected to the ground conductor plate 3c. 3d and a connector 3e provided at the end of the cable 3d
And a spacer 3f for maintaining a distance between the antenna substrate 3a and the radiation conductor plate 3b. As shown in FIG. 6B, the feed point of the relay antenna 3 coincides with the center of the antenna substrate 3a, but the radiation conductor plate 3b and the antenna substrate 3a are not concentric, and the center of the radiation conductor plate 3b is Are ubiquitous.

FIGS. 7 (a), 7 (b) and 7 (c) are views showing the mounting of the board antenna 2 and the relay antenna 3 on the lid 1 in the manhole cover antenna device of the second embodiment. First, as in the first embodiment, the board antenna 2 is placed in the recess 1a and the through hole 1b of the lid 1 (FIG. 7).
(A))) Then, from the back side of the lid 1, the relay antenna 3
Is connected to the connector 2e of the board antenna 2 (FIGS. 7B and 7C).

The communication section 23 of the wireless water quality measuring apparatus 14 is provided with an antenna 41 connected to a mobile phone instead of the cable 16 in the first embodiment. Wireless transmission / reception with the relay antenna 3 is enabled. Further, on the inner wall surface of the manhole 12, a radio wave absorber 42 such as ferrite for absorbing radio waves is provided.

In the configuration described above, similarly to the first embodiment, the water pressure, flow rate, pH, etc. are measured by each sensor of the sensor section 21, and a signal radio wave including the measured data is transmitted to the relay antenna. 3 and the board antenna 2 are relayed and radiated to the terrestrial space. The base station 31 installed on the ground receives this and presents measurement data to the observer. Also, the measurement data is sent from the base station 31 to the management unit 33 via a telephone line, and the internal state of the fire hydrant is managed by a computer.

As described above, in the board antenna 2 of the second embodiment, by connecting the pair of relay antennas 3 to the connector 2e of the board antenna 2, the manhole 12
It functions as an external antenna for the wireless transceiver (mobile phone 28) inside. By providing such a relay antenna function, antenna cable connection is not required, and there is no problem such as cable disconnection, and durability is improved.

Since the inner wall surface of the manhole 12 is covered with the radio wave absorber 42, the reflection of the radio wave on the inner wall surface can be suppressed.
Deterioration of radio wave propagation characteristics due to reflected radio waves can be prevented.
Also, unlike the board antenna 2, the relay antenna 3 can be provided without performing any special processing on the lid 1, so that the thickness of the relay antenna 3 must be as thin as the board antenna 2. Can be set relatively freely for no reason. Therefore, the distance between the relay antenna 3 and the lid 1 is adjusted so that an optimum gain is obtained. Further, from the viewpoint of reducing transmission loss, it is better to bring the relay antenna 3 closer to the antenna 41.

In the example described above, the relay antenna 3
Although the antenna having the same configuration as that of the substrate antenna 2 was used, the installation space of the relay antenna 3 is not restricted as compared with the substrate antenna 2, so that the dipole antenna,
It is also possible to use a loop antenna or the like as the relay antenna 3.

Hereinafter, another embodiment which can be applied to the above-described first and second embodiments will be described.

(Third Embodiment) In the above embodiment, a single-layer board antenna (see FIG. 3) is used as the board antenna 2 to be attached to the lid 1, but a multi-layer board antenna is used. You may. FIG. 8 is a side view of this multilayer substrate antenna, in which two antenna substrates 2a exist, and a radiating element conductor 2b exists between the two antenna substrates 2a and 2a. Other configurations are the same as those of the single-layer substrate antenna shown in FIG.

When the multilayered board antenna having such a configuration is used as the board antenna 2, the radiating element conductor is provided on the surface.
2b is not exposed, so that deterioration of radiating element conductor 2b can be prevented.

(Fourth Embodiment) In the above-described embodiment, one board antenna 2 is provided and the board antenna 2 is provided with a function for both transmission and reception. A dedicated substrate antenna may be provided separately. With this configuration, radio wave propagation can be performed efficiently by using two antenna elements tuned to independent frequencies in accordance with the transmission and reception frequencies.

(Fifth Embodiment) In the above embodiment, the substrate antenna 2 having a circular shape in plan view was used, but the plan view shape is shown in FIGS. 9 (a) and 9 (b). Regular polygons such as regular hexagons and regular octagons may be used. However, also in this case, the center of the radiating element conductor 2b is deviated from the center of the antenna substrate 2a (coincident with the feed point corresponding to the through hole 1b of the lid 1). By setting such a regular polygonal shape, the rotation angle of the radiating element conductor 2b can be easily recognized when setting the optimum angle with respect to the base station 31, and the pitch angle during the rotation can be easily adjusted. It can be set, and the rotation angle does not shift at the time of setting.

In the system as described above, it is possible to remotely monitor the water quality and amount of water in the fire hydrant from the ground, and by centrally managing the entire water pipe network,
Water treatment can be performed efficiently.

The present invention can be applied not only to additional processing on an existing manhole cover, but also to a case where a new manhole cover is cast.

Further, the present invention is not limited to a water supply pipe system including such a fire hydrant,
Of course, the present invention can be applied to other underground objects such as gas pipe facilities and power cable facilities.

[0047]

As described above, in the manhole cover antenna device of the present invention, the flat board antenna is installed in the recess of the manhole cover so that the ground conductor portion is short-circuited to the manhole cover, and the feed line is connected to the recess. Since the manhole cover is inserted into the through hole, the manhole cover can have an antenna function without lowering the strength of the manhole cover, and a desired radiation pattern can be obtained. Since the antenna can be attached to the manhole cover with a simple processing, the antenna can be applied to an existing manhole cover without newly manufacturing a manhole cover.

In the manhole cover antenna device of the present invention,
Because the board shape of the flat board antenna is circular or regular polygonal, the flat board antenna can be rotated in consideration of the radiation pattern of the antenna when installing the antenna, and the antenna direction is set to the optimal direction with excellent directivity it can.

The communication system of the present invention can be configured to connect a cable between the feeder line of the flat board antenna and the radio transceiver in the underground and to provide another pair of antenna elements. The configuration that functions as an external antenna and the configuration that functions as a relay antenna can be freely selected in accordance with.

In the communication system of the present invention, since the underground wireless transceiver is an automobile telephone system, a wide area communication is possible by wireless public line connection, and remote management in a manhole can be easily performed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an application example of a manhole cover antenna device according to a first embodiment.

FIG. 2 is a diagram illustrating attachment of a board antenna to a manhole cover in the manhole cover antenna device according to the first embodiment;

FIG. 3 is a side view and a front view of the board antenna.

FIG. 4 is a block diagram illustrating a configuration of a wireless water quality measurement device.

FIG. 5 is a schematic diagram showing an application example of the manhole cover antenna device of the second embodiment.

FIG. 6 is a side view and a front view of the relay antenna.

FIG. 7 is a diagram illustrating attachment of a board antenna and a relay antenna to a manhole cover in the manhole cover antenna device according to the second embodiment;

FIG. 8 is a side view of a modified example of the board antenna.

FIG. 9 is a front view of another modification of the board antenna.

[Explanation of symbols]

 1 manhole cover 1a recess 1b through hole 2 board antenna 2a antenna board 2b radiating element conductor 2c ground conductor plate 2d cable 2e connector 3 relay antenna 12 manhole 28 mobile phone

Claims (5)

[Claims] 1. An antenna device comprising an antenna having a ground conductor and a feeder line attached to a manhole cover, wherein a recess is provided on a surface thereof, and a manhole cover provided with a through hole from the recess. A manhole cover antenna device, comprising: a planar substrate antenna that is disposed in the concave portion, a ground conductor thereof contacts the cover, and a feeder line passes through the through hole. 2. The manhole cover antenna device according to claim 1, wherein the concave portion and the planar substrate antenna have a circular or regular polygonal shape in plan view. 3. A communication system comprising: the manhole cover antenna device according to claim 1 or 2; and an underground transmitting / receiving radio device connected to the power supply line via a cable. 4. A manhole cover antenna device according to claim 1, further comprising: another antenna connected to the feeder line; and a radio device for transmitting and receiving in the basement that wirelessly communicates with the antenna. Communication system. 5. The communication system according to claim 3, wherein the underground transceiver radio uses an automobile telephone system.