JPH0729084A - Buried pipe sign system - Google Patents

Abstract

PURPOSE:To provide a buried pipe sign system capable of detecting pressure change inside a pipe. CONSTITUTION:A locating device transmitting electromagnetic wave and a sign device provided at the buried pipe, which transmits response electromagnetic wave when electromagnetic wave is received are provided. The sign device is provided with an antenna part with transmits/receives electromagnetic wave with the locating device and also has a transmission/reception loop coil 210 and a data carrier IC element 230 which is operated by DC power converted from a reception signal from the antenna part and also transmits a transmission signal modulated by previously stored embedding information to the loop coil. In the buried pipe sign system which demodulates and outputs embedding information at the time of receiving electromagnetic wave from the sign device, the locating device is provided with a switch 241 which is inserted between the loop coil 210 and the data carrier IC element 230 and also provided with a presence detecting equipment 240 opening/closing the switch 240 in accordance with pressure change inside the buried pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a buried pipe marking system for checking the buried position of a buried pipe.

[0002]

2. Description of the Related Art Some buried pipes such as gas pipes, water supply pipes, and sewer pipes buried in the ground are made of thermoplastic synthetic resin. The worker connects the buried pipes to each other and bury them in the ground. For connecting the buried pipe, for example, the tip of the buried pipe is melted by heat and connected.

Although the buried pipe is buried in this way, the buried position may be checked at a later date for construction or the like. For this purpose, for example, a wireless response tag is attached to the buried pipe in advance.

When the radio response tag receives an electromagnetic wave from the reading device, it rectifies the electromagnetic wave to generate DC power,
A transmission signal is generated by this DC power. At this time, the transmission signal is modulated by the buried information of the buried pipe stored in advance. Then, the electromagnetic wave to be sent to the reading device is transmitted by this transmission signal.

When receiving the electromagnetic wave from the wireless response tag, the reading device demodulates the received signal and outputs the embedded information. This reading device and wireless response tag are disclosed in Japanese Patent Laid-Open No. 4-39.
It is shown in Japanese Patent Publication No. 483.

By using such a wireless response tag, it is possible to detect the buried position of the buried pipe and obtain information on the buried pipe.

[0007]

Some buried pipes, such as vacuum type sewer pipes, are used while the inside of the pipe is in a vacuum state. An abnormality occurs in such a buried pipe,
When the pressure inside the pipe changes, the wireless response tag attached to this buried pipe cannot detect this pressure change.

It is an object of the present invention to provide a buried pipe marking system capable of detecting the pressure change in the pipe without the above drawbacks.

[0009]

In order to achieve the object, the present invention comprises an exploration device for transmitting an electromagnetic wave, and a marking device provided in a buried pipe for transmitting a response electromagnetic wave when the electromagnetic wave is received. The marker device operates with direct current power obtained by converting an antenna part that transmits and receives electromagnetic waves to and from the exploration device and has a loop coil for transmission and reception, and a received signal from this antenna part, and modulates with embedded information stored in advance. In the embedded pipe marking system, the exploration device demodulates and outputs embedded information when an electromagnetic wave from the marking device is received, and the data communication unit is provided between the loop coil and the data communication unit. And a pressure detector that opens and closes the switch according to the pressure change in the buried pipe.

Further, according to the present invention, the heating wire for fusion bonding provided in the buried pipe is used as the loop coil.

Further, according to the present invention, there is provided a transformer which is inserted between the heating wire and the data communication section to match the impedance between the heating wire and the data communication section.

[0012]

With this configuration, the switch of the pressure detector is provided between the loop coil of the marking device and the data communication unit. The pressure detector detects the pressure in the buried pipe, opens and closes the switch, and connects the loop coil to the data communication unit when the pressure in the buried pipe is normal. Also, when the pressure is abnormal, this connection is released.

In this state, when the exploration device transmits an electromagnetic wave, the loop coil of the antenna section of the sign device generates a reception signal. When the pressure in the buried pipe is normal, the data communication unit receives the reception signal from the loop coil via the switch of the pressure detector, and generates DC power from the reception signal. Then, using this DC power, a transmission signal modulated with the stored embedded information is generated. The loop coil generates a response electromagnetic wave by this transmission signal.

The exploration device receives and demodulates the electromagnetic wave from the marking device, extracts the embedded information, and outputs it.

If the pressure in the buried pipe is abnormal,
Since the pressure detector disconnects the loop coil from the data communication unit, the received signal from the loop coil is not added to the data communication unit. Therefore, the electromagnetic wave for response is
Not sent from signage.

When a heating wire is used instead of the loop coil, since the heating wire has a loop shape, electromagnetic waves are transmitted and received by this heating wire.

When a heating wire is used instead of the loop coil, an impedance mismatch between the heating wire and the data communication unit may occur. To this end, a transformer is inserted between the heating wire and the data communication section to match the impedance.

[0018]

Embodiments of the present invention will now be described with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of the present invention.
FIG. The buried pipe marking system includes an exploration device 100 for exploring a synthetic resin-made buried pipe 300, and a marking device 200 installed at a joint portion 310 of the buried pipe 300.
With.

When searching for the buried pipe 300, the exploration apparatus 100 transmits the magnetic field component of the electromagnetic wave as a carrier wave. Further, when rewriting the embedded information stored in the marker device 200, a modulated wave (magnetic field component of electromagnetic wave) is transmitted.
On the other hand, when the modulated wave (the magnetic field component of the electromagnetic wave) from the marking device 200 is received, the embedded information of the marking device 200 is demodulated and displayed from this modulated wave.

The exploration device 100 includes a device body 110 for generating a carrier signal and demodulating a modulated signal, and a device body 1.
An antenna 130 that transmits a carrier wave when a carrier signal from 10 is added and generates a modulated signal when a modulated wave is received.

An example of the apparatus main body 110 is shown in FIG. The power supply circuit 112 of the apparatus main body 110 stabilizes the voltage of the battery 111 and supplies it to the circuits 113 to 118. The control circuit 116 follows the control procedure stored in the memory circuit 115 to modulate / amplify circuit 114 or amplify / demodulate circuit 11.
7 control of transmission / reception, control of display of the display circuit 118, control of switching of the switch 119, and the like.
The capacitor 120 constitutes a resonance circuit together with the antenna 130, and selects a magnetic field component from the marking device 200 when receiving.

The modulation / amplification circuit 114 is an oscillation circuit 113.
Amplifies the high-frequency signal oscillated by the antenna 130, passes through the switch 119, and uses the high-frequency signal as a carrier signal for the antenna 130.
Send to. When the amplification / demodulation circuit 117 receives the modulated signal from the antenna 130 via the switch 119,
This signal is amplified and demodulated and embedded information is supplied to the control circuit 11
Send to 6. The control circuit 116 causes the display circuit 118 to display this embedded information.

When an instruction to change the embedded information is added to the apparatus body 110, the control circuit 116 sends the embedded information stored in the memory circuit 115 or the embedded information added to the apparatus body 110 to the modulation / amplification circuit 114. Modulation / amplification circuit 114
Modulates this embedded information and outputs a modulated signal to the antenna 13
Send to 0.

The above is the structure of the exploration apparatus 100.

Next, the marking device 200 will be described.
FIG. 3 is a block diagram showing an example of the marking device 200. The labeling device 200 includes a loop coil 210, a capacitor 220, a data carrier IC (Integrated Circuit) element 230 as a data communication unit, and a pressure detector 240.

The loop coil 210 is an antenna wire formed in a loop and operates as an antenna. As shown in FIG. 4, the loop coil 210 is provided inside the joint portion 310 and in the circumferential direction of the joint portion 310. Since the joint portion 310 is made of synthetic resin, even if the loop coil 210 is provided inside the joint portion 310, it does not affect the transmission and reception of the magnetic field component of the electromagnetic wave. Loop coil 2
A pressure detector 240 is connected to 10 in series.
Further, the parallel circuit of the capacitor 220 and the data carrier IC element 230 is connected to the series circuit of the loop coil 210 and the pressure detector 240.

The pressure detector 240 includes a switch 241, and the switch 24 is activated in response to a change in pressure inside the buried pipe 300.
Open and close 1. An example of the pressure detector 240 is shown in FIG. As shown in FIG. 5A, this pressure detector includes a partition 243 and electrodes 244 and 245 inside a cylindrical part 242 having one end opened and the other end closed.
The inside 246 of the cylindrical portion 242 is partitioned by the partition wall portion 243 and is in a hermetically sealed state. Moreover, the interior 246 is
It is kept at atmospheric pressure. The partition 243 is elastically deformable, and an elastically deformable electrode 244 is attached to the outside thereof. Further, an electrode 245 is attached so as to face the electrode 244. The electrode 245 has a plate shape as shown in FIG. Electrode 24
4, 245 can be connected to the outside by lead wires 247, 248. The switch 241 shown in FIG. 3 is composed of these electrodes 244 and 245 and lead wires 247 and 248.

As shown in FIG. 4, such a pressure detector 240 is attached to the joint portion 310 so that the opening of the cylindrical portion 242 projects from the inside of the joint portion 310. Then, when the pressure in the joint portion 310 becomes low, as shown in FIG.
As shown in FIG. 7, the partition wall portion 243 is deformed, the electrode 244 comes into contact with the electrode 245, and the lead wire 247 and the lead wire 248.
Is electrically short-circuited.

The capacitor 220 is a loop coil 210.
Is for tuning to receive the magnetic field component from the probing device 100.

The data carrier IC element 230 is connected in parallel with the capacitor 220. FIG. 7 shows an example of the data carrier IC element 230. Upon receiving the carrier signal from the loop coil 210 via the switch 238, the rectifying / smoothing circuit 231 of the data carrier IC element 230 rectifies and smoothes the carrier signal to convert it into DC power. The capacitor 232 is a rectifying / smoothing circuit 2
The DC power from 31 is stored. Then, the accumulated DC power is supplied to each of the circuits 233 to 237. The memory circuit 234 is a non-volatile memory capable of reading and writing information, and holds the stored embedded information even when the DC power from the capacitor 232 is turned off.

Upon receiving the carrier signal from the demodulation circuit 233, the control circuit 235 reads the embedded information from the memory circuit 234 and sends it to the modulation / amplification circuit 237. The modulation / amplification circuit 237 outputs the high frequency signal oscillated by the oscillation circuit 236,
Modulation is performed with the embedded information from the control circuit 235 to generate a modulation signal. Then, the modulated signal is amplified and the switch 2
It sends to the loop coil 210 via 38.

The control circuit 235 also includes a demodulation circuit 233.
When the modulated signal is received from the loop coil 210, the embedded information demodulated by the demodulation circuit 233 is stored in the memory circuit 234. When the writing is completed, the control circuit 235
The modulation / amplification circuit 237 is controlled to send a carrier signal to the loop coil 210 to indicate the end of writing.

The above is the structure of the marking device 200.

Next, the operation of the first embodiment will be described.

The marking device 200 is previously provided inside the joint portion 310 of the buried pipe 300. At the time of burying work, the pipe parts 320, 320 of the burying pipe 300 are connected to the arrows a, b.
Inserted into the joint part 310 from the direction of (Fig. 4) respectively, and the synthetic resin pipe parts 320, 320 are heated (not shown).
And heat to fuse. The marking device 200 includes a buried pipe 30.
The burial information such as 0 pipe type, burial depth, burial date and time, burial position coordinates, burial direction, etc. is stored in advance or at the time of burial work.

When the buried pipe 300 that has been buried is to be maintained at a later date, the buried pipe 3 is buried together with the buried information of the buried pipe 300.
When the operator wants to check the state of 00, the worker searches for the exploration device 100.
To transmit a carrier wave for buried pipe exploration.

In the marking device 200 of the buried pipe 300, the loop coil 210 receives the carrier wave. In this case, for example, when the buried pipe 300 is a vacuum sewer pipe, the buried pipe 300
If the internal pressure is normal, as shown in FIG. 6, the partition 243 of the pressure detector 240 is elastically deformed and the electrode 244 comes into contact with the electrode 245. As a result, the lead wire 247 and the lead wire 248 are electrically short-circuited. That is,
The switch 241 (FIG. 3) of the pressure detector 240 is closed. The carrier signal generated by the loop coil 210 is sent to the data carrier IC element 230. The data carrier IC element 230 starts its operation with this carrier signal and generates a modulation signal obtained by modulating the carrier signal with the embedded information stored inside. The loop coil 210 converts the modulated signal from the data carrier IC element 230 into a modulated wave and transmits it.

Upon receiving the modulated wave, the search device 100 demodulates and displays the embedded information. At this time, the operator can know the position of the buried pipe in the state of the modulated wave and can check the buried information on the display. At the same time, the operator knows that the internal pressure of the embedded pipe 300 is normal because the embedded information is displayed.

If the buried pipe 300 is damaged and the pressure inside the pipe becomes abnormal, the pressure detector 240 detects this abnormality and opens the switch 241. As a result, the data carrier IC element 230 cannot receive the carrier signal from the loop coil 210.
Does not output the modulation signal.

The operator transmitted the carrier wave from the exploration device 100, but there was no response from the marking device 200, so that it was possible to know that an abnormality had occurred in the buried pipe 300.

When rewriting the embedding information of the marking device 200, the operator performs an operation relating to the rewriting of the exploration device 100. By this operation, the exploration apparatus 100 transmits the modulated wave modulated by the buried information.

In the marking device 200, the data carrier I
The C element 230 demodulates the embedded information from the modulated signal from the loop coil 210 and newly stores this embedded information.
When the writing is completed, the marking device 200 transmits a carrier wave. The search device 100 displays that the carrier wave has been received. Thereby, the worker knows that the buried information has been updated.

In this way, it becomes possible to check the abnormality of the buried pipe 300 by the presence or absence of the modulated wave for response.

In the first embodiment, the loop coil 210
Is provided inside the joint portion 310, but the present invention is not limited to this. For example, the loop coil 210 may be provided on the inner surface of the joint portion 310.

Further, although the pipe portion 320 and the joint portion 310 are separated from each other in the first embodiment, the present invention is not limited to this. For example, the joint portion 310 may be connected to either pipe portion 3
It may be provided integrally with 20.

[Second Embodiment] FIG. 8 shows a second embodiment of the present invention.
It is a block diagram of the marking device concerning. In the second embodiment, instead of the loop coil 210 of the first embodiment, the joint portion 310 is used.
A loop-shaped heating wire 311 provided in the above is used. For this purpose, the heating wire 311 is provided with terminals 312 and 313. The power supply 25 is placed between the terminals 312 and 313.
0 is connected, the tube portion 320 and the tube portion 320 are heated and fused, and then the power source 250 is removed. A circuit in which a pressure detector 240 is connected in series to a parallel circuit of the capacitor 220 and the data carrier IC element 230 is connected between the terminals 312 and 313.

These heating wire 311, the condenser 22
0, the data carrier IC element 230 and the pressure detector 240 constitute a labeling device.

According to the second embodiment, a dedicated antenna is not required, and the production cost can be reduced when the buried pipe is produced.

[Third Embodiment] FIG. 9 shows a third embodiment of the present invention.
It is a block diagram of the marking device concerning. In the third embodiment, the capacitor 220 and the data carrier IC element 23 of FIG.
A transformer 260 is inserted between the parallel circuit with 0 and the pressure detector 240. At this time, a parallel circuit of the capacitor 220 and the data carrier IC element 230 is connected to the primary winding 261 side of the transformer 260, and the transformer 260 is connected.
On the side of the secondary winding 262 of the heating wire 311 and the pressure detector 24.
Connect a series circuit with 0.

The transformer 260 converts the impedance of the heating wire 311 and couples the heating wire 311 to the data carrier IC element 230. That is, the transformer 260
As a result, the heating wire 311 and the IC element 23 for the data carrier are
Match with 0. Further, the value of the DC resistance of the secondary winding 262 of the transformer 260 is made smaller than that of the heating wire 311.

The heating wire 311 is originally for passing a large current, and when this is used as an antenna,
When transmitting and receiving electromagnetic waves, the efficiency as an antenna becomes poor. For this purpose, the transformer 260 allows the heating wire 3
11 and the data carrier IC element 230 are matched.

With this configuration, the worker can
Just connect 0 to connect the buried pipe 300 and
Since the heat generated in the secondary winding 262 of the transformer 260 is reduced, the transformer 260 can be protected.

[0054]

As described above, according to the present invention, when the pressure in the buried pipe is normal, the pressure detector of the marking device connects the loop coil and the data communication unit, so that the marking device can be used for response. To transmit the electromagnetic waves. The exploration device receives the electromagnetic wave from the marking device and outputs the buried information.
If the pressure in the buried pipe becomes abnormal, the pressure detector of the marking device disconnects the loop coil from the data communication unit, and thus the marking device does not transmit the electromagnetic wave for response. As a result, since the exploration device does not output the buried information, it is possible to inform the abnormal pressure in the buried pipe by the presence or absence of the buried information.

If a heating wire is used instead of the loop coil, the loop coil becomes unnecessary and the production cost of the buried pipe can be reduced.

Further, between the heating wire and the loop coil,
When the transformer is inserted, impedance matching between the heating wire and the loop coil can be achieved, power loss and the like caused by mismatch can be prevented, and the communication distance can be extended.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing an example of a device body.

FIG. 3 is a block diagram showing an example of a labeling device.

FIG. 4 is a cross-sectional view of a buried pipe.

FIG. 5 is a sectional view showing an example of a pressure detector.

FIG. 6 is a diagram for explaining pressure detection by a pressure detector.

FIG. 7 is a block diagram showing an example of a data carrier IC element.

FIG. 8 is a block diagram showing a labeling device according to a second embodiment.

FIG. 9 is a block diagram showing a labeling device according to a third embodiment.

[Explanation of symbols]

 210 loop coil 230 IC element for data carrier 240 pressure detector 241 switch

Claims (3)

[Claims] 1. An exploration device that transmits an electromagnetic wave, and a marking device that is provided in a buried pipe that transmits a response electromagnetic wave when the electromagnetic wave is received, and the labeling device transmits and receives electromagnetic waves to and from the exploration device. An antenna unit having a loop coil for transmission and reception, and a data communication unit that operates with direct current power obtained by converting a reception signal from the antenna unit and sends a transmission signal modulated with embedded information stored in advance to the loop coil. In the embedded pipe labeling system that demodulates and outputs the embedded information when receiving the electromagnetic wave from the labeling device, the exploration device includes a switch inserted between the loop coil and the data communication unit. An embedded pipe marking system comprising a pressure detector that opens and closes the switch according to a pressure change in the embedded pipe. 2. The buried pipe marking system according to claim 1, wherein a heating wire for fusion bonding provided in the buried pipe is used as the loop coil. 3. The transformer according to claim 2, further comprising a transformer that is inserted between the heating wire and the data communication unit to match impedance between the heating wire and the data communication unit. Buried pipe marking system.