JPH0677863A - Underground data collection device - Google Patents

Abstract

PURPOSE:To collect underground data at a deep part. CONSTITUTION:In this device in which a temperature sensor 11 is imbeded around a tip of a boring rod 10 and underground information sensed by the sensor 11 is converted into an electric signal, and a carrier modulated by the electric signal is given to a transmission coil 16 to allow the boring rod 10 to generate a magnetic signal, a reception coil 31 on the ground detects the magnetism signal and the underground information is demodulated from the detected induction signal, a repeater combined with a reception coil 21, a transmission coil 28 and a time difference reception transmission section 29 having a signal delay circuit 24 delaying tentatively information is provided in an intermediate part of the boring rod 10. As the boring rod 10 gets longer, number of the repeaters is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground data acquisition system using a magnetic material as a signal transmission path.

[0002]

2. Description of the Related Art Conventionally, as this type of underground data collecting device, a sensor is embedded in the tip of a steel boring rod for making a hole in the ground from the surface of the earth, and the ground detected by this sensor is detected. The medium information is converted into an electric signal, and the carrier wave modulated by this electric signal is applied to a solenoid-shaped transmission coil wound around the bowling rod as a magnetic core to generate a magnetic signal in the bowling rod, and then on the ground. A device using electromagnetic induction for detecting a magnetic signal propagating in the bowling rod by a receiving coil wound around the bowling rod as a magnetic core and demodulating underground information from the detected induction signal. Is known, and it is effective in the ground without being affected by the sound of boring rod rotation and pressurizing rod pressurization, the effect of additional rods, and the effects of seawater and rock around the rod. It is possible to collect the information (JP-A-63-160430 JP).

[0003]

Although the method using electromagnetic induction has excellent properties as described above, the propagation range of the magnetic flux is limited by the demagnetizing field in the magnetic material, so that the boring rod has a certain value. With the above length, there is a problem that transmission becomes difficult in terms of SN ratio. The length of this certain value is around 30 meters although it depends on the material of the boring rod. Therefore, it is an object of the present invention to provide an underground data collecting device capable of collecting deep underground data by the method using electromagnetic induction described above.

[0004]

A subsurface data collection apparatus according to the present invention embeds a sensor near the tip of a bowling rod for making a hole in the ground from the surface of the earth, and stores the subsurface information detected by this sensor. The signal is converted into an electric signal, and the carrier wave modulated by the electric signal is applied to a solenoid-shaped first transmission coil wound around the bowling rod as a magnetic core to generate a magnetic signal in the bowling rod. Then, the magnetic signal propagated in the bowling rod is detected by the first receiving coil wound around the bowling rod as a magnetic core, and the underground information is demodulated from the detected induction signal. In the underground data collecting apparatus, when the distance between the first transmitting coil and the first receiving coil is longer than a predetermined distance, the position above the first transmitting coil is not more than the predetermined distance. A second receiving coil in close proximity to each other wound the boring rod as core and a second
Of the transmission coil and a demodulation circuit that receives an induction signal generated in the second reception coil and demodulates the underground information from the induction signal, a signal that temporarily stores the demodulated underground information and outputs it after a predetermined time elapses. A relay device having a delay circuit and a time difference transmitting / receiving unit including a modulating unit that modulates and amplifies the output of the signal delay circuit and outputs the amplified signal to the second transmitting coil is provided, and the second transmitting coil and the first transmitting unit are provided. When the distance between the receiving coils is further longer than a predetermined distance, the next relay device is provided in the upper direction of the second transmitting coil, and the relay device is added if necessary. A medium data acquisition device is obtained.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An underground data collecting device according to the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram schematically showing the structure of an embodiment according to the present invention. According to this example, a steel boring rod 10
A temperature sensor 11 is incorporated at the tip of the, and outputs a DC voltage corresponding to the temperature in the ground. This output is given to the voltage-frequency conversion circuit 12, where it is converted into a signal having a frequency according to the input voltage. The oscillator circuit 13 outputs a high-frequency signal of, for example, 10 kHz for the carrier wave, and the output is given to the modulator circuit 14. The modulation circuit 14 receives the frequency signal from the voltage-frequency conversion circuit 12, and thereby modulates the carrier wave obtained from the oscillation circuit 13. The output of the carrier band obtained from the modulation circuit 14 is the amplification circuit 15
After power amplification at, it is applied to the first transmitter coil 16 for converting electrical signals into magnetism. The first transmission coil 16 is formed by winding the boring rod around the tip of the boring rod 10 as a magnetic core.
A magnetic flux change of the boring rod 10 is given by the driving power from 5.

Although the above magnetic flux change propagates above the boring rod. As mentioned above, the propagation range of the magnetic flux is limited by the demagnetizing field in the magnetic material, so the reaching distance is limited. Therefore, the second receiving coil 21 and the second transmitting coil 28 are provided at a position slightly shorter than this limit distance. An induced voltage is detected from the second receiving coil 21 in the carrier wave band. This detection signal is amplified by the amplification circuit 22, then added to the demodulation circuit 23, and demodulated as a modulation signal. This demodulated signal is the modulation circuit 1
4 has the same information as the signal added to 4, and is guided to the signal delay circuit 24 and held for a predetermined time. Then, the modulation circuit 26 modulates the carrier wave generated by the oscillation circuit 25,
The modulated signal is amplified by the amplifier circuit 27 and applied to the second transmission coil 28. The magnetic signal emitted from the second transmission coil is transmitted through the boring rod 10 and is transmitted to the ground. The six electric circuits from the amplifier circuit 22 to the amplifier circuit 27 are collectively called a time difference transmission / reception unit. A combination of the two coils and the time difference transmission / reception unit may be named a relay device. It should be noted that the above-mentioned predetermined time is a time that is slightly longer than the time that the underground information continues, which prevents simultaneous reception and transmission. First on the ground
The magnetic signal is detected by the receiving circuit 31 and the output is obtained through the amplifying circuit 32 and the demodulating circuit 33.

FIG. 2 shows the second receiving coil 21 and the second receiving coil 21 of FIG.
It is the figure which showed the cross section of the structure of the relay apparatus which combined the transmission coil 28 and the time difference transmission part 29 of this. Numbers 22 to 27 are assigned to the inside of the time difference transmission / reception unit 29 6
Contains two electrical circuits. Further, 41 is a coil cover, and 42 is a supporting member made of stainless steel or an insulator. This relay device is a boring rod 10
Since it requires processing to be attached to the boring rod 10, it is provided near the end of the boring rod 10. Further, although there are solid and tubular boring rods, it is necessary to use tubular ones at least at the portion where the relay device is attached.

If the distance between the second transmitting coil 28 and the first receiving coil 31 is longer than the above-mentioned limit distance, although not shown in the drawing, the receiving coil, the transmitting coil and the time difference transmitting / receiving section are further provided in the middle. A relay device which is a combination may be provided, and the following applies.

[0009]

The device for detecting the underground information of the rod tip portion of the present invention has a required number of relay devices including two coils and a time difference transmitting / receiving means between the rod tip portion in the ground and the ground. By providing the stepped structure, it becomes possible to easily deal with the extension of the signal transmission distance due to the extension of the boring rod, and the effect obtained to improve the reliability and the economical efficiency of the system is great.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an underground data collection device according to the present invention.

FIG. 2 is a view showing a cross section of the relay device in FIG.

[Explanation of symbols]

 10 Bowling Rod 11 Temperature Sensor 12 Voltage-Frequency Conversion Circuit 13 Oscillation Circuit 14 Modulation Circuit 15 Amplification Circuit 21 Second Receiver Coil 22 Amplification Circuit 23 Demodulation Circuit 24 Signal Delay Circuit 25 Oscillation Circuit 26 Modulation Circuit 27 Amplification Circuit 28 Second Transmitting coil 29 Time difference transmitting / receiving unit 31 First receiving circuit 32 Amplifying circuit 33 Demodulating circuit 41 Coil cover 42 Supporting member

Claims (1)

[Claims] 1. A sensor is embedded near the tip of a steel boring rod for drilling a hole from the surface to the ground, and underground information detected by this sensor is converted into an electric signal and modulated by this electric signal. A carrier wave is applied to a solenoid-shaped first transmission coil wound around the bowling rod as a magnetic core to generate a magnetic signal in the bowling rod, and propagated in the bowling rod on the ground. In the underground data collecting device, the magnetic signal is detected by the first receiving coil wound around the bowling rod as a magnetic core, and the underground information is demodulated from the detected induction signal. When the distance between the first transmitting coil and the first receiving coil is longer than a predetermined distance, the boring rod is wound around the boring rod as a magnetic core at a position not above the predetermined distance in the upward direction of the first transmitting coil. Or A second receiving coil and a second transmitting coil that are close to each other, a demodulation circuit that receives an induction signal generated in the second receiving coil and demodulates the underground information from the induction signal, demodulated underground information A relay device having a signal delay circuit for temporarily storing and outputting after a predetermined time elapses, and a time difference transmission / reception unit including a modulation means for modulating and amplifying the output of the signal delay circuit and outputting it to the second transmission coil. When the distance between the second transmission coil and the first reception coil is longer than a predetermined distance, the next relay device is provided above the second transmission coil, and the relay device is provided as necessary. An underground data collection device characterized by comprising a device.