JP3705948B2 - Underground drilling rig - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to an underground excavator called a shield machine, and more particularly to an underground excavator equipped with a radar device for obstacle detection at a tip portion.
[0002]
[Prior art]
Conventionally, a shield excavation method is known as a non-cutting method for forming a tunnel in the ground without performing excavation from the ground. Recently, as an ultra-small shield drilling system, a drilling blade with a diameter of about 50 mm to 60 mm was attached to the tip of a flexible long body called a rod, and the base side of this rod was installed on the ground. A method of forming a small-diameter tunnel for laying a pipe in the ground by rotating and propelling with a driving device has been adopted. Such a shield excavation method is referred to as a non-open drilling method.
[0003]
In such a non-open-cut drilling method, the length of the rod is increased by adding a certain length of pipe one after another as the length of the tunnel being formed increases. The pipes need to be added quickly at the work site. For this reason, the pipes are added by forming screw grooves at the ends of the pipes and screwing these screw grooves. In addition, for the purpose of cooling the excavation blade at the tip and softening the soil to be excavated, high pressure water of about 40 atm is fed from the root portion through the rod and discharged from the tip portion into the ground. Things have been done.
[0004]
In the conventional non-open-cut drilling method, prior to the formation of the tunnel, the underground state of the existing equipment such as gas pipes, water pipes, power cables, etc. in the formation target is operated by operating the ground radar device from the ground. A tunnel formation route that can be explored to avoid contact with existing buried objects is determined. However, in reality, a tunnel that is being formed may come into contact with an underground object due to a measurement error or the like. In order to avoid such a situation, it has been considered to perform excavation while attaching a small ground penetrating radar device to the tip of the rod and checking for the presence of obstacles ahead.
[0005]
[Problems to be solved by the invention]
In addition to the problem of how to downsize the ground penetrating radar, the problem of how to transmit the exploration results of the ground penetrating radar apparatus to the ground, and the ground penetrating radar apparatus It is necessary to solve the problem of how to supply operating power. This is because, when an electric cable is used to connect the ground and the underground radar apparatus, it is necessary to add a cable as the pipe is added. However, it is unexpectedly difficult to add the cables quickly at the work site.
[0006]
Therefore, without connecting an electrical cable between the ground and the ground penetrating radar device, the measurement result of the ground penetrating radar device is transmitted from the separately installed communication transmitting antenna device to the ground, and this is transmitted. Wireless systems for receiving with a receiver arranged on the ground have been studied. In this wireless system, the operation power of the ground penetrating radar apparatus is supplied from a storage battery stored at the tip of the rod.
[0007]
However, in this wireless system, the attenuation of the electrical signal transmitted from the ground toward the ground surface is extremely large, so the receiving antenna is placed close to the underground transmission antenna, that is, at the tip of the rod. It is necessary to arrange them close to each other. However, unlike the underground, there are structures such as private houses on the surface of the ground, so it is not always possible to place a receiving antenna near the transmitting antenna. In such a case, it is transmitted from the underground antenna. The received radio wave cannot be received.
[0008]
In addition, the ground penetrating radar needs to transmit a high-power radio wave in order to ensure a certain S / N ratio under a large attenuation of the radio wave in the ground. For this reason, the power consumption of the ground penetrating radar becomes large, and it becomes difficult to install a large-capacity capacitor for covering the large power consumption in the small-diameter rod. As a result, frequent replacement of the storage battery is required, and the efficiency of the entire excavation work is reduced. In addition, in the wireless system, since a communication transmission antenna and a transmission circuit in the preceding stage must be provided, there is a problem that it is difficult to reduce the size and power consumption of the entire apparatus.
[0009]
Accordingly, an object of the present invention is to provide a non-cutting drilling method capable of reliably transmitting electrical signals and power supply between a ground penetrating radar device installed at the tip of a rod and a ground device with an inexpensive structure. It is to provide an underground excavator.
[0010]
[Means for Solving the Problems]
The underground excavation apparatus of the present invention that solves the above-described problems of the prior art has a rotational symmetry around a certain axis, and the rotational symmetry axis coincides with the central axis of each tubular body (pipe), while An electrical signal output from an exploration portion provided at the tip of a long and narrow hollow body (rod) having a connector attached to the threaded portion and constituted by the plurality of tubular bodies is provided on the root side of the hollow body. A transmission line for transmission is provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
According to a preferred embodiment of the present invention, the connector has a configuration capable of bidirectional transmission, and an electrical signal is transmitted also from the base side of the hollow body to the exploration part.
[0012]
According to another preferred embodiment of the present invention, the connector is a non-integral type electromagnetic coupler, for example, a pair of circular pot cores arranged opposite to each other and wound around each of these pot cores. It is composed of a transformer with a shoreline. More preferably, a frequency converter for converting the center frequency of the electric signal to a frequency optimum for the transfer characteristic of the transformer is arranged in front of the transformer.
[0013]
According to a further preferred embodiment of the present invention, the inside of the hollow body is formed with a high-pressure water supply path that is supplied from the base side and discharged from the tip portion into the ground. The connector is resistant to the high pressure water.
[0014]
According to another preferred embodiment of the present invention, the electrical signal transmitted from the base side of the hollow body to the exploration unit includes a power supply component supplied to the exploration unit, Preferably, the power source power component is time-division multiplexed with other signal components and transmitted.
[0015]
According to another preferred embodiment of the present invention, a generator for converting the rotational motion of the hollow body into electric power is built in the distal end portion of the hollow body, or the interior of the hollow body is disposed inside. By incorporating a generator that converts the flow energy of the high-pressure water to be sent into electric power, power supply from the ground is unnecessary.
[0016]
【Example】
FIG. 1 is a schematic diagram showing a configuration of an underground excavation device according to an embodiment of the present invention. This underground excavation apparatus includes a drive device Q installed on the ground, an elongated hollow body (rod) R composed of a plurality of tubular bodies (pipes) Po, P1, P2, P3, P4, and the hollow body R. A drilling blade B and a high-pressure water discharge nozzle N are provided at the tip.
[0017]
An antenna AT of a ground penetrating radar device is attached to the back surface of the excavation blade B at the tip of the hollow body R, and this antenna AT is connected to a ground side device E including a ground exploration portion. The underground side device E and the ground side device D installed on the ground are cables that extend inside the hollow body R while interposing connectors C1, C2, C3, and C4 formed at connection portions of the tubular body. Connected by L.
[0018]
Connectors C1, C2, C3.. Formed at connecting portions of the tubular bodies Po, P1, P2, P3, P4. All C4 have the same structure. 2 and 3 are cross-sectional views representatively showing the configuration of these connectors as a connector C2 formed at a connection portion between the tubular bodies P1 and P2. FIG. 2 is a longitudinal sectional view cut along a plane including the central axis of the tubular bodies P1 and P2, and FIG. 3 is a transverse sectional view cut along a plane orthogonal to the central axes of the tubular bodies P1 and P2. .
[0019]
The connector C2 is a transformer including a pair of circular pot cores 1a and 1b made of ferrite and arranged opposite to each other, and windings 2a and 2b wound around the pot cores 1a and 1b, respectively. This is a non-integral electromagnetic coupler. Each of the circular pot cores 1a and 1b has rotational symmetry, and each of the tubular bodies P1 and P2 has a rotational symmetry axis coincident with each central axis of the tubular bodies P1 and P2 having a circular cross section. It is fixed to the end. In order to perform this fixing, the holders 7a and 7b are fitted to the ends of the tubular bodies P1 and P2, and the pot cores 1a and 1b are held inside the holders 7a and 7b.
[0020]
The pot core 1a held in the holder 7a is pushed forward by springs 6a and 6b, which are also held in the holder 7a, to a position limited by a stopper (not shown), and the front end face thereof is opposed. It is pressed against the front end face of the pot core 1b. A dielectric thin piece 3 of low friction such as tetrafluoroethylene is interposed on the front end face of the pot core 1a, and a smooth rotating operation is ensured between the opposing pot core 1b.
[0021]
Openings 8 a, 8 b, 8 c, 8 d... For flowing high-pressure water of about 40 atm toward the tip of the hollow body R are formed on the outer peripheral portions of the holders 7 a and 7 b. In order to prevent mechanical destruction of the pot core due to the pressure of the high-pressure water and to prevent short-circuiting of the windings 2a and 2b wound around the pot core, the gap portions 4a and 4b inside the pot cores 1a and 1b and the holding The gap portions 5a and 5b of the tools 7a and 7b are filled with resin in advance as shown in the drawing with dots.
[0022]
The connector C2 is formed simultaneously with the screwing of the tubular bodies when the tubular bodies P1 and P2 are screwed together by the thread grooves X formed on the outer peripheral surfaces of the respective end portions. This is made possible by making the rotational symmetry axes of the pot cores 7a and 7b coincide with the central axes of the tubular bodies P1 and P2. Accordingly, workers on site can be unaware of the extension of the cable that is required along with the extension of the tubular body by not only being aware of the presence of the connector, but only being aware of the extension work by screwing the tubular body. Can be done automatically.
[0023]
FIG. 4 is a functional block diagram showing an example of the configuration of the ground side device D and the ground side device E in FIG. The ground side device D includes a signal processing unit D1, a display unit D2, a power feeding unit D3, and a multiplexing / separating unit D4. The underground device E includes an underground exploration unit E1, a frequency conversion unit E2, a rectification / feeding unit E3, and a multiplexing / separation unit E4.
[0024]
As illustrated in the waveform diagram of FIG. 5, the power supply unit in the ground side device D generates burst-like large-amplitude AC power T having a frequency within the passband of the transformer at a constant cycle, and multiplexes this. To the conversion / separation unit D4. The multiplexing / demultiplexing unit D4 is configured by a switch or the like that is switched at a constant cycle, and transfers the large-amplitude constant-period burst AC power T supplied from the power feeding unit D3 onto the cable L over a certain period. At the same time, time-division multiplexing and demultiplexing are performed by transferring a burst-like signal S appearing on the cable L at a timing shifted in the same cycle to the signal processing unit D1 over a certain period.
[0025]
Similarly, a multiplexing / separating unit E4 in the underground side device E transfers a burst-like signal S having a fixed period supplied from the underground exploration unit E1 via the frequency conversion unit E2 onto the cable L. By transferring the large-amplitude burst-like AC power T appearing on the cable L at a timing shifted in the same cycle to the rectifying / feeding unit E3, time division multiplexing and demultiplexing are performed.
[0026]
The rectifying / feeding unit E3 rectifies the burst-like AC power supplied from the multiplexing / separating unit E4 to convert it into DC power having a constant voltage, and converts the DC power into the underground exploration unit E1 and the frequency conversion unit E2. And supplied to the multiplexing / separating unit E4. The multiplexing / separating unit E4 is initially set so as to transfer all electrical signals appearing on the cable L to the rectifying / feeding unit E3 until the DC power supply from the rectifying / feeding unit E3 is started. Has been.
[0027]
The underground exploration section E1 starts operating upon receiving DC power from the rectifying / feeding section E3, radiates pulsed radio waves from the transmitting antenna into the ground at a fixed period, and the reflected waves generated in the ground Is received via the receiving antenna. The underground exploration unit supplies a signal S including information related to the time required from transmission of radio waves to reception of reflected waves to the multiplexing / demultiplexing unit E4 via the frequency conversion unit E2. The frequency conversion unit E2 converts the signal supplied from the underground exploration unit E1 into an optimum frequency with respect to the electrical characteristics such as the pass loss and the band characteristic of the transformer illustrated in FIG. To supply.
[0028]
The signal S is transferred to the ground side device D by the cable L, and is transferred to the signal processing unit D1 through the multiplexing / demultiplexing unit D4. The signal processing unit D1 creates a radar screen by processing the signal transferred from the underground exploration unit E1, and transfers this to the display unit D2. This radar screen is displayed on a display unit D2 including a cathode ray tube, a high-luminance liquid crystal device, or the like. The operator can proceed with excavation work while monitoring obstacles by observing the radar screen being displayed on the display unit D2.
[0029]
As described above, since the signal component and the power component are time-division multiplexed, the distortion of the signal component accompanying the saturation of the magnetic circuit is smaller than in the case of amplitude multiplexing, and the S / N ratio is improved. . Further, compared with the case where the signal component and the power component are frequency-multiplexed, it is possible to reduce the passage loss in the transformer for both components, and the signal component has an improved S / N ratio and the power component is increased. Efficient transmission is possible.
[0030]
FIG. 6 is a cross-sectional view showing another embodiment of the present invention. In this embodiment, a generator is installed in the tubular body Po at the tip. This generator has a central axis Z that is held in the tubular body Po in a state of being coaxial with the tubular body Po and rotates together with the tubular body Po, and a permanent shaft suspended from the central axis Z via a bearing U. A magnet M, four magnetic poles (poles) PL1 to PL4 projecting at equal angular intervals from a yoke Y fitted into the inner peripheral surface of the tubular body Po, and a winding W wound around these magnetic poles are provided. Yes.
[0031]
The permanent magnet M suspended from the central axis Z via the bearing U is rotated by the rotational force transmitted from the ground device to the tubular body Po. Therefore, even if the central axis Z rotates, the permanent magnet M is slipped by its own weight and the bearing U. Keeps stationary. As a result, the four magnetic poles PL1 to PL4 rotating together with the tubular body Po pass one after another directly under the permanent magnet M, and the winding wire wound out of the permanent magnet M and wound around the magnetic pole during this passage. The magnetic flux density intersecting with W changes, and an AC voltage is induced between the terminals w1 and w2. This is rectified to become DC power and supplied as operating power to each part in the underground device.
[0032]
Instead of installing a bearing between the central axis Z and the permanent magnet M, by installing it between the tubular body Po and the central axis, the central axis Z remains in the tubular body even if the tubular body Po rotates. It is also possible to adopt a configuration in which a stationary state is maintained by a bearing installed between po and the weight of the permanent magnet.
[0033]
FIG. 7 is a sectional view showing another embodiment of the present invention. Also in this embodiment, a generator is installed in the tubular body Po at the tip. The generator includes a central axis Z that is held in the tubular body Po in a state of being coaxial with the tubular body Po and rotates together with the tubular body Po, and a rotating body that is rotatably held around the central axis Z. G and a propeller PP that rotates the rotating body G with a water flow of high-pressure water flowing in the tubular body po. On each side of the rotating shaft Z and the rotating body G, a permanent magnet and a shoreline are installed facing each other, and AC power is induced in the shoreline.
[0034]
As described above, by adopting a configuration in which power is generated at the tip of the hollow body R using the rotational force of the hollow body R itself or the flow energy of high-pressure water, there is no need to transmit power from the ground. The system can be simplified.
[0035]
The case where a transformer is used as the connector has been illustrated above. However, a coaxial connector having a structure in which a rod-like pin and a tubular receptacle that accommodates the pin are rotatably fitted while maintaining mechanical contact is arranged with its axis aligned with the axis of the tubular body, etc. The structure of can also be used.
[0036]
【The invention's effect】
As described above in detail, the underground excavation apparatus of the present invention is configured to attach each connector to the threaded portion of the tubular body while aligning the rotational symmetry axis of the connector with the central axis of the tubular body. The operator can quickly and surely extend the tubular body and the cable along with it by noting the presence of the connector but only being aware of the coupling work by screwing the tubular body.
[0037]
According to a preferred embodiment of the present invention, since the connector is a non-integral type electromagnetic coupler, an inexpensive and reliable transmission path can be formed.
[0038]
According to another preferred embodiment of the present invention, since the power is generated at the tip of the hollow body using the rotational energy of the hollow body and the flow energy of high-pressure water, from the ground to the underground device There is an advantage that the power feeding system can be simplified.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of an underground excavation device according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view showing a configuration of connectors C1 to C4 in FIG. 1 represented by a connector C2, which is cut along a plane including the central axes of tubular bodies P1 and P2.
FIG. 3 is a cross-sectional view showing the connector C2 cut along a plane orthogonal to the central axis of the tubular bodies P1 and P2.
4 is a functional block diagram showing an example of a configuration of a ground side device D and a ground side device E in FIG. 1. FIG.
5 is a waveform diagram illustrating a waveform of an electric signal transmitted between the underground device D and the underground device E shown in FIGS. 1 and 4; FIG.
FIG. 6 is a cross-sectional view showing another embodiment of the present invention in which a generator driven by the rotational force of the tubular body is formed inside a pipe at the tip.
FIG. 7 is a cross-sectional view showing still another embodiment of the present invention in which a generator driven by a water flow is formed inside a pipe at the tip.
[Explanation of symbols]
P0 ~ P4 Tubular body (pipe)
R Hollow body (rod)
B drilling blade
N Nozzle for pressure water discharge
Q drive
AT antenna
C1-C4 connector
L cable
D Ground side equipment
E Underground equipment

Claims (10)

An elongated hollow body that is composed of a plurality of tubular bodies that are joined by screwing and is rotated around an axis line and propelled into the ground by a driving device coupled to the root side;
A drilling tool attached to the tip of this hollow body;
Underground exploration part attached to the tip of this hollow body,
A connector having rotational symmetry about a certain axis and being attached to a threaded portion of each tubular body with the rotational symmetry axis being coincident with the central axis of each tubular body, and installed at the tip of the hollow body An underground excavation apparatus comprising: a transmission line that transmits an electrical signal output from the exploration section to the base side of the hollow body. In claim 1,
The connector has a configuration capable of bidirectional transmission, and an underground excavation device is characterized in that an electrical signal is transmitted also from the base side of the hollow body to the exploration part. In each of claims 1 and 2,
The connector is a non-integral electromagnetic coupler, and is an underground excavation device. In claim 3,
The non-integral type electromagnetic coupler comprises a transformer having a pair of circular pot cores arranged opposite to each other and a winding wound around each of the pot cores. . In claim 4,
A ground excavator characterized in that a frequency converter for converting the center frequency of the electric signal to a frequency optimum for the transfer characteristic of the transformer is arranged in a stage preceding the transformer. In each of claims 1 to 5,
Inside the hollow body is formed a water supply path for high-pressure water that is supplied from the root side and discharged from the tip portion into the ground, and the connector has resistance to the high-pressure water. Underground excavator characterized by. In claim 2,
An underground excavation apparatus characterized in that an electrical signal transmitted from the base side of the hollow body to the exploration unit includes a power supply component supplied to the exploration unit. In claim 7,
A power source component of the transmitted electrical signal is time-division multiplexed with other signal components and transmitted. In each of claims 1 to 6,
An underground excavation device characterized in that a generator for converting the rotational motion of the hollow body into electric power is built in the tip of the hollow body. In each of claims 1 to 6,
An underground excavation device characterized in that a generator for converting the flow energy of the high-pressure water fed through the inside of the hollow body into electric power is built in the tip of the hollow body.

Images