JPH0729085A - Buried pipe marking system - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a buried pipe marking system capable of detecting a pressure change in a pipe. In a buried pipe marking system including an exploration device and a marking device, the marking device transmits and receives electromagnetic waves to and from the exploration device, and an antenna unit including a loop coil 210 for transmission and reception, and a received signal from the antenna unit. The data carrier IC element 250 which operates with the converted DC power and outputs a transmission signal modulated by the buried information of the buried pipe and the identification information indicating the normality of the buried pipe and the identification information indicating the abnormal condition of the buried pipe are also modulated. The antenna is inserted between the data carrier IC element 230 that outputs a transmission signal, the data carrier IC elements 230 and 250, and the antenna section, and the antenna is switched to either the data carrier IC element 230 or 250. Switch 26 connected to
1, and a pressure detector 260 that switches the switch 261 according to the change in the pressure 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 about 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. In the embedded pipe marking system, in which the exploration device receives electromagnetic waves from the marking device and outputs demodulated information, the marking device transmits and receives electromagnetic waves to and from the exploration device, and an antenna unit including a loop coil for transmitting and receiving electromagnetic waves. And a first data communication unit that operates with DC power obtained by converting a reception signal from the antenna unit and outputs a transmission signal that is modulated with the buried information of the buried pipe and the identification information indicating the normality of the buried pipe, and the antenna unit. A second data communication unit which operates with DC power obtained by converting the received signal of, and outputs a transmission signal modulated with the buried information of the buried pipe and the identification information indicating an abnormality of the buried pipe; and a first data A signal unit and the second data communication unit,
A switch that is inserted between the antenna section and connected to the antenna section by switching to either the first data communication section or the second data communication section, and switches according to changes in the pressure inside the buried pipe. And a pressure detector for switching between.

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 for matching impedance between the heating wire and the first data communication section and the second data communication section.

[0012]

With this configuration, the pressure detector of the marking device detects the pressure in the buried pipe and switches the switch.

When the exploration device transmits an electromagnetic wave, the loop coil of the antenna section of the marking device generates a reception signal.

In this case, when the pressure in the buried pipe is normal,
The pressure detector connects the antenna unit to the first data communication unit. As a result, the first data communication unit receives the reception signal from the loop coil via the switch of the pressure detector, and generates DC power from this reception signal. And
This DC power is used to generate a transmission signal modulated with the embedded information and the identification information. The loop coil generates a response electromagnetic wave by this transmission signal.

The exploration device receives the electromagnetic wave from the marking device, demodulates it, and outputs the buried information and the identification information of the first data communication unit.

If the pressure in the buried pipe is abnormal, the pressure detector detects this abnormal pressure and switches the switch to connect the antenna section to the second data communication section. As a result, the marker device transmits the electromagnetic wave modulated by the embedded information and the identification information of the second data communication unit.

The exploration device receives and demodulates the electromagnetic wave from the marking device, and outputs the embedded information and the identification information of the second data communication unit.

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, impedance mismatch may occur between the heating wire and the first data communication section and the second data communication section. For this reason, the transformer is inserted between the heating wire and the first data communication unit and the second data communication unit to match the impedance.

[0020]

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 device 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 that generates a carrier signal and demodulates 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 forms a resonance circuit 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,
The embedded information obtained by amplifying and demodulating this signal is sent to the control circuit 116. 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 main body 110, the control circuit 116 sends the embedded information stored in the memory circuit 115 or the embedded information added to the apparatus main body 110 to the modulation / amplification circuit 114. . Modulation / amplification circuit 11
4 modulates this embedded information and sends it to the antenna 130.

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, capacitors 220 and 240, a data carrier IC (Integrated Circuit) element 230 as a second data communication unit,
Data carrier IC element 2 as first data communication unit
50 and a pressure detector 260.

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.

The pressure detector 260 includes a switch 261, and the switch 26 is activated in response to a change in pressure inside the buried pipe 300.
Switch 1 The switch 261 is switched to
The loop coil 210 is connected to a parallel circuit of the capacitor 220 and the data carrier IC element 230, or the capacitor 240 and the data carrier IC element 25.
The loop coil 210 is connected to the parallel circuit with 0.

An example of the pressure detector 260 is shown in FIG. As shown in FIG. 5A, this pressure detector includes electrodes 263, 264, 265 and a partition 266 inside a cylindrical portion 262 having one end opened and the other end closed. The inside A of the cylindrical portion 262 is partitioned by the partition wall portion 266 and is in a hermetically sealed state. Moreover, the interior A is kept at atmospheric pressure. The partition wall portion 266 is elastically deformable.

The inner electrode portion 264A and the outer electrode portion 264B of the electrode 264 are attached so as to sandwich the partition wall portion 266. Further, the inner electrode portion 264A is attached to the outer electrode portion 264B by the electrode portion 264C while keeping the inside A airtight. Inner electrode portion 264A and outer electrode portion 26
4B is elastically deformable. An electrode 265 is attached separately from the outer electrode portion 264B. The shape of the electrode 265 is a plate shape as shown in FIG. Electrode 263
264 and 265 can be connected to the outside by lead wires 267, 268 and 269. The switch 26 shown in FIG.
1 is composed of these electrodes 263, 264, 265 and lead wires 267, 268, 269.

As shown in FIG. 4, such a pressure detector 260 is attached to the joint portion 310 such that the opening of the cylindrical portion 262 projects from the inside of the joint portion 310. Then, when the pressure in the joint portion 310 is substantially equal to the pressure in the inside A, the electrode 264 contacts the electrode 263 and the lead wire 2
67 and the lead wire 268 are electrically short-circuited. Further, when the pressure inside the joint portion 310 becomes low, the partition wall portion 266 is deformed as shown in FIG.
4 deforms and contacts the electrode 265, and the lead wire 268 and the lead wire 269 are electrically short-circuited.

The capacitors 220 and 240 are for tuning the loop coil 210 to receive the magnetic field component from the prober 100.

The data carrier IC element 230 is connected in parallel to 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 that can read and write information, and retains stored contents even when the DC power from the capacitor 232 is turned off. The memory circuit 234 stores in advance embedded information of the embedded pipe 300 and an ID (Identification) code as identification information indicating an abnormal pressure of the embedded pipe 300.

Upon receiving the carrier signal from the demodulation circuit 233, the control circuit 235 reads the embedded information and the ID code from the memory circuit 234 and sends them to the modulation / amplification circuit 237. The modulation / amplification circuit 237 modulates the high frequency signal oscillated by the oscillation circuit 236 with the embedded information and the ID code from the control circuit 235 to generate a modulation signal. And
This modulated signal is amplified and sent to the loop coil 210 via the switch 238.

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 data carrier IC element 250 has the same structure as the data carrier IC element 230. However, the memory circuit of the data carrier IC element 250 (the memory circuit 2 of the data carrier IC element 230
(Corresponding to 34), the ID code indicating the normal pressure of the buried pipe 300 is stored together with the buried information.

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 data carrier IC elements 230 and 250 of the labeling device 200 include the type of the buried pipe 300,
The burial information such as burial depth, burial date and time, burial position coordinates, burial direction, etc. is stored in advance or at the time of burial work.

When maintenance work of the buried pipe 300 is buried at a later date, the buried pipe 3 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 266 of the pressure detector 260 is elastically deformed, and the electrode 264 contacts the electrode 265. As a result, the lead wire 268 and the lead wire 269 are electrically short-circuited. That is,
The switch 261 (FIG. 3) of the pressure detector 260 connects the loop coil 210 to the parallel circuit of the capacitor 240 and the data carrier IC element 250.

As a result, the carrier signal generated by the loop coil 210 is sent to the data carrier IC element 250. The data carrier IC element 250 starts operation with this carrier signal, and modulates the carrier signal with a signal containing the buried information stored inside and the ID code indicating normal pressure of the buried pipe 300. Occur. The loop coil 210 converts the modulation signal from the data carrier IC element 250 into a modulation wave and transmits it.

Upon receiving the modulated wave, the search device 100 demodulates and displays the embedded information and the ID code. This display allows the worker to know the buried information. At the same time, the operator knows from the ID code from the data carrier IC element 250 that the pressure inside the buried pipe 300 is normal.

If the buried pipe 300 is damaged and the pressure inside the pipe becomes abnormal, the pressure detector 260 detects this abnormality and switches the switch 261. This allows
The switch 261 includes a loop coil 210 in the parallel circuit of the capacitor 220 and the data carrier IC element 230.
Connect. As a result, when the marker device 200 receives the carrier wave from the exploration device 100, it sends an ID code indicating an abnormality in the buried pipe 300 to the exploration device 100 together with the buried information.

The search device 100 is an IC for data carrier.
Since the ID code from the element 230 is displayed, the operator knows that an abnormality has occurred in the buried pipe 300.

When rewriting the embedding information of the marking device 200, the operator performs an operation related 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 250 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 with the information indicated by the ID code.

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.

Furthermore, although the pipe 320 and the joint 310 are separated 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 27 is placed between the terminals 312 and 313.
0 is connected, the tube portion 320 and the tube portion 320 are heat-sealed, and then the power source 270 is removed. Between the terminal 312 and the terminal 313, a parallel circuit of the capacitor 220 and the data carrier IC element 230, a parallel circuit of the capacitor 240 and the data carrier IC element 250, and the pressure detector 2
A circuit consisting of 60 is connected.

These heating wire 311, condenser 22
0,240, data carrier IC elements 230,250
The pressure detector 260 and the pressure detector 260 form 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 transformer 280 is inserted between the points 1 and 2 in the circuit of FIG. At this time, the capacitor 220 and the data carrier IC element 23 are provided on the primary winding 281 side of the transformer 280.
0, the parallel circuit of the capacitor 240 and the data carrier IC element 250, and the pressure detector 260 are connected, and the heating wire 3 is connected to the secondary winding 282 side of the transformer 280.
11 is connected.

The transformer 280 converts the impedance of the heating wire 311 and couples the heating wire 311 to the data carrier IC elements 230 and 250. That is, by the transformer 280, the heating wire 311 and the data carrier IC
Match with the elements 230 and 250. Further, the value of the DC resistance of the secondary winding 282 of the transformer 280 is set to the heating wire 311.
Be smaller than.

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. To this end, the transformer 280 allows the heating wire 3
11 and the data carrier IC elements 230 and 250 are matched.

With such a configuration, the worker can use the power source 27.
Just connect 0 to connect the buried pipe 300 and
Since the heat generation in the secondary winding 282 of the transformer 280 is reduced, the transformer 280 can be protected.

[0060]

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 first data communication unit, so that the marking device is An electromagnetic wave modulated by the embedded information and the identification information of the first data communication unit is transmitted. The exploration device receives and demodulates the electromagnetic wave from the marking device, and outputs the embedded information and the identification information of the first data communication unit. Thereby, it can be displayed that the pressure in the buried pipe is normal.

If the pressure in the buried pipe becomes abnormal, the pressure detector connects the loop coil and the second data communication unit, so that the marking device uses the buried information and the identification information of the second data communication unit. Transmit modulated electromagnetic waves. The exploration device receives the electromagnetic wave from the marking device and outputs the embedded information and the identification information of the second data communication unit. Thereby, the abnormal pressure can be displayed.

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, the heating wire, the first data communication section, the second
When a transformer is inserted between the data communication unit and the heating wire, the impedance of the heating wire can be matched, 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 250 IC Element for Data Carrier 260 Pressure Detector 261 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 exploration device receives the electromagnetic wave from the marking device. In the buried pipe marking system that outputs the demodulated information, the labeling device transmits and receives electromagnetic waves to and from the exploration device, and an antenna unit including a loop coil for transmitting and receiving electromagnetic waves, and a received signal from the antenna unit. A first data communication unit that operates with the converted DC power and outputs a transmission signal that is modulated with the buried information of the buried pipe and identification information that indicates the normality of the buried pipe; and a DC that converted the received signal from the antenna unit. A second data communication unit which operates on electric power and outputs a transmission signal modulated by the buried information of the buried pipe and the identification information indicating abnormality of the buried pipe; and the first data communication. A and the second data communication unit,
A switch that is inserted between the antenna unit and switched to either the first data communication unit or the second data communication unit to connect to the antenna unit is provided, and A pressure detector that switches the switch according to a change, and a buried pipe marking system. 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 embedded pipe marking system according to claim 2, further comprising a transformer for matching impedance between the heating wire and the first data communication unit and the second data communication unit.