JP2001330400A - Antenna for remote wireless detonation system - Google Patents

Abstract

[57] [Problem] To provide reliable communication for transmitting and receiving control signals and return signals with all of the radio detonators mounted on the entire face, thereby improving the reliability and safety of detonation. . SOLUTION: An antenna for transmitting and receiving a control signal and a return signal is fixed to the ground by using a member or the like installed on a cave wall and electrically grounded, thereby making the rock ground into an infinite ground plane with a quarter wavelength. The monopole antenna has a characteristic equivalent to a half-wave dipole antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna for a remote wireless detonation system used for a blasting method in tunnel excavation or the like.

[0002]

2. Description of the Related Art A conventional blasting excavation method in tunnel excavation or the like involves loading explosives and a detonator for detonation into blast holes drilled in appropriate quantities throughout the excavation face. After performing the connection work, the blast was finally performed. The wire connection operation, which is one of the blasting operations, is difficult to automate because flexible legs and a squib are connected, and even now, the operator has to perform it manually. There is a risk of personal injury due to rock fall or rock fall near the face of the site where the connection work is performed, and there remains a safety problem.

[0003] Particularly, in a severe work environment such as unstable scaffolding due to exposed rocks, burial of legs and a squib due to spring water and landslides, and insufficient illuminance at hand, several tens to 100 or more primers are surely provided. It takes a lot of effort and time to connect to, and there has been a longing for streamlining the blasting operation. As described above, entry into the vicinity of the face in the blasting work of tunnels and underground spaces is completed as quickly as possible due to the high risk of rock collapse and rock fall as described above, or as primary reconstruction to avoid entry It has been determined that it is desirable to perform charging and connection work remotely from a place at least 2 m or more away from the face face where rock bolts, support steel, shotcrete, etc. are applied.

[0004] To meet such a demand, as disclosed in Japanese Patent Publication No. 50-28621, the ignition energy is transmitted by electromagnetic induction between a transmitting coil and a receiving coil built in a detonator by applying electromagnetic induction. However, there has been proposed a wireless detonation system which eliminates the need for a wire connection operation in which the deactivation command is to eliminate the magnetic field generated by the transmission coil.

[0005]

In the remote detonation technique disclosed in Japanese Patent Publication No. 50-28621, there is no means for remotely confirming and controlling the ignition energy accumulation status of the wireless detonator, and the conventional technique has been proposed. For example, there is no means for detecting an abnormality in the detonator, which is equivalent to a continuity check after charging with an electric detonator, and the technology for simply transmitting the ignition energy by electromagnetic induction between the transmitting coil and the receiving coil is not enough for the reliability and safety of the detonation. However, there was a problem that it was not possible to secure the property.

The present invention has been made in order to solve such a problem, and all of the individual radio detonators mounted on the entire face of the face, control signals from the operating device side, and return signals from the radio detonator are provided. It is an object of the present invention to provide an antenna for a remote wireless detonation system capable of performing communication with sufficient reliability for transmitting and receiving a signal and improving reliability and safety of detonation.

[0007]

In order to achieve the above object, an antenna for a remote wireless detonation system according to a first aspect of the present invention provides a remote wireless detonator which is capable of remotely detonating a wireless detonator mounted on a face. In the detonation system,
An antenna for transmitting or receiving to or from the wireless detonator is fixed and installed on the ground such as a cave floor, a cave side wall, a cave ceiling or the like.

According to a second aspect of the present invention, there is provided a remote wireless detonation system antenna according to the first aspect, wherein the antenna is fixed to a member fixed and installed on the ground. The member fixedly installed on the ground refers to a rock bolt or a supporting steel installed on a cave wall used as a supporting material for underground excavation. An antenna for a remote wireless detonation system according to a third aspect is the first aspect.
Or 2) characterized by being fixed to the ground and electrically grounded. By grounding the ground such as a cave wall or the like, the quarter-wave monopole antenna as a conductor plate or an infinite ground plate extending infinitely over the rock ground has characteristics equivalent to a half-wavelength dipole antenna.

According to a fourth aspect of the present invention, there is provided a remote wireless detonation system antenna according to the first, second, or third aspect, wherein the antenna is installed close to a face. The vicinity of the face refers to a proximity of 30 m or less from the face, preferably 10 m.
Hereinafter, more preferably, it is close to 6 m or less. The installation work of the antenna is much safer and easier than the connection of the detonator, and therefore, the installation position of the antenna may be 0 m.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the following, an embodiment of the present invention in which an operation device receives a return signal from a radio detonator mounted on a face in a tunnel blasting of an antenna for a remote radio detonation system of the present invention. An example will be described with reference to the drawings. FIG. 1 shows a remote wireless detonation system using an antenna for a remote wireless detonation system according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes an operation device 1 including main circuits such as an operation console, a transmission circuit, a power amplifier, and a reception circuit (both are not shown). Not for example face face 14-10
It is installed at an ignition place or the like where safety measures have been taken at a distance of about 0 to 200 m. The power cable 2 is connected to the power amplifier,
The other end of the power cable 2 is connected to the loop-shaped transmission coil 3 installed near the face 14, and current from the transmission circuit of the operating device 1 is supplied to the transmission coil 3 through the power cable 2 and is applied to the face. To generate AC magnetic field energy.

An operation instruction according to the blasting procedure is transmitted as a control signal to a transmission circuit of the operating device 1. The transmission circuit generates an AC sine wave signal having a constant amplitude and a constant frequency when there is no control signal input, and when the control signal is input,
The frequency phase or amplitude of the output AC sine wave signal is changed according to the control signal, and the AC magnetic field generated by the transmission coil 3 is modulated by the control signal, and is applied to all of the radio detonators 10 mounted on the entire face face. Sent.

A radio detonator 10 to be described later modulates a return signal according to a control signal and radiates radio waves from the leg antenna 29 as a high-frequency current. The electric wave is received by the demodulation circuit in the demodulation circuit box 6 via the signal cable 5 from the remote wireless detonation system antenna 4 of the present invention installed near the face, and the output of the demodulation circuit is received in the operation device 1. Transmitted to the circuit. The operation device 1 interprets the received content and proceeds to the next operation. Note that the antenna 4 for the remote wireless detonation system of the present invention can also be used when transmitting the control signal from the operating device 1 using radio waves.

FIG. 2 shows a state where the wireless detonator 10 is loaded in the charging hole 9, and FIG. 3 shows a circuit block diagram of the wireless detonator 10. As shown in FIG. 2, the radio detonator 10 has a drilling length of 10 cm to 3 depending on the rock condition.
m, and the radio detonator 10 and the explosive 11 are applied to a large number of charging holes 9 drilled in appropriate quantities throughout the excavation face section in the same manner as in the conventional tunnel blasting excavation method. The charge 12 is loaded in each charge hole 9 in the same manner. As shown in FIG. 3, the receiving coil 19 of the wireless detonator 10 and the core 18 made of a high-permeability material inserted into the coil receive the AC magnetic field energy transmitted from the transmitting coil 3, and Generate electricity.

A resonance circuit 20 including a capacitor is connected to the reception coil 19, and an electromotive force generated in the reception coil 19 is efficiently extracted as electric power. The alternating current generated in the resonance circuit 20 is rectified into direct current by a diode in the rectifying and charging circuit 21 and charged in a capacitor in the circuit.
By the electric energy stored in this capacitor,
The overall control CPU 24, the demodulation circuit 27, and the modulation circuit 28 are driven.

A demodulation circuit 27 receives a modulated AC signal, and the demodulation circuit 27 demodulates the modulated AC signal into a control signal and outputs the control signal to the overall control CPU 24. The overall control CPU 24 interprets the control signal output from the demodulation circuit 27, controls the entire ignition detonation, and finally detonates the electric detonator 26 with the electric energy of the detonation charging circuit 23. When the control signal output from the demodulation circuit 27 to the overall control CPU 24 is a content requesting the return of a predetermined signal from the wireless detonator 10, the overall control CPU 24 modifies the content of the response according to the control signal to the modulation circuit 28. Output to The modulation circuit 28 outputs the high-frequency current modulated according to the content of the reply to the leg antenna 29, and radiates a radio wave from the leg antenna 29.

The radio wave used as a means of transmission and reception from the radio detonator 10 to the operating device 1 is limited to a weak radio wave or an antenna power regulation value stipulated in the Radio Law Enforcement Regulations for Specified Low Power Radio Stations and requires a license. It is desirable to use within the range that does not. Also, a radio detonator 10 loaded on the entire face
Of these, those loaded near the bottom row are particularly buried in collapsed earth and sand, or under severe environmental conditions submerged by spring water from the face, etc. The radio wave with the longest possible wavelength can reduce the absorption loss by the rock, but if the frequency is too small, the leg-like antenna 29 of the radio detonator 10 with a length of about 3 m, which is easy to handle, can improve the radiation efficiency. Is undesirably reduced. Depending on the selection of the frequency band, a relatively large-scale antenna of several meters is required for the half-wave dipole antenna on the operating device 1 side. Furthermore, high-power radio waves cannot be used to drive electronic circuits generated in the receiving coil of the radio detonator 10 or to communicate by radio waves using a limited electromotive force other than the electric detonator detonation energy. Absorption loss due to rock and leg antenna 29
Considering the radiation efficiency, antenna scale and power consumption of
Communication using weak radio waves is preferable. Radio frequency is 10MHz ~ 6
0 MHz is preferable, and 40 MHz to 30 MHz is more preferable.

Here, when communicating using weak radio waves,
The antenna must be installed as close to the face as possible because it is susceptible to the harsh environment and noise as described above, and damage to the antenna due to blasting stones is inevitable. Half-wave dipole antennas and loop antennas It is not economical to use an element with many elements such as a Yagi antenna like disposable. FIG. 6 is a schematic diagram in which the current distribution and directivity of the antenna 4 for a remote wireless detonation system of the present invention are symbolically written.

An antenna that connects both terminals of a high-frequency source to an antenna conductor, such as a half-wave dipole antenna, is called an ungrounded antenna, whereas the antenna 4 for a remote wireless detonation system of the present invention is a feeder. Is connected to the ground through a member installed on the cave wall, for example, the lock bolt 7 or the shoring 13, and thus can be said to be a ground antenna. If the tip of the feeder is replaced with a high-frequency source and is symbolically written as shown in Fig. 6, high-frequency power is applied between the ground and the antenna conductor, and a quarter-wave monopole antenna is equivalent to a half-wave dipole antenna. It is possible to have such characteristics.

As described above, even in communication using weak radio waves,
Communication with sufficient reliability can be performed with all of the radio detonators 10 mounted on the entire face, and a relatively inexpensive leg-shaped quarter-wavelength monopole antenna can be used. Even if the antenna is damaged by stepping stones or the like, it is possible to provide the antenna 4 for the remote wireless detonation system, which does not cause a problem economically. Next, a method of installing the antenna 4 for the remote wireless detonation system of the present invention will be described in more detail through an actual use example.

N, which is often used as a tunnel excavation method
In the ATM construction method, the lock bolt 7 shown in FIG. 5 is fixed to the bearing material 16 such as mortar or resin, the bearing plate 16 and the nut 15 at regular intervals radially from the cross section of the tunnel excavation after the construction of the shotcrete 17 and radially from the tunnel excavation section. It is fixed to the inner wall of the tunnel. Further, the arch-shaped supporter 13 is one of support members for maintaining the stability of the tunnel together with the shotcrete 17 and the lock bolt 7, and the like.
The construction interval will be determined to withstand the expected load.

The method for installing the antenna 4 for a remote wireless detonation system of the present invention on the lock bolt 7 is, for example, as shown in FIGS. The coil fixing nut 8 is screwed into the lock bolt 7 near the top so as to be hung down. It is also possible to extend not only one antenna but also two or more antennas at appropriate positions above both ends of the tunnel, or to extend in the lateral direction across the both ends so as to cross, or in the tunnel traveling length direction. In order to extend an antenna fixed so as to hang it, it is also possible to simply suspend the weight and use an antenna having a role of loading with a coil or capacitor inserted at the top of the antenna as the weight.

If the electrical connection between the lock bolt 7 and the antenna / transmitting coil fixing nut 8 is poor, grease or a fastener containing a conductive component is applied. Further, as shown in FIG. 4, if the cable fixing hook is attached, the transmission coil 3 and the signal cable 5 can be simultaneously installed close to the face face 14, and the installation work efficiency can be further improved. The material of the antenna 4 is a metal conductor such as aluminum, copper, iron, or nichrome, and is a material suitable for the antenna 4 through which a high-frequency current can flow, such as an electric wire or a stranded wire. Inexpensive electric wires may be used.

The antenna 4 and the signal cable 5 are connected by a signal cable connection terminal 30 and are made of a material capable of characteristic impedance matching, such as a coaxial cable, a parallel two-wire feeder, a relatively inexpensive feeder for television reception, or the like.
By fixing the signal cable 5 along the fixed hook of the transmission coil 3 fixed close to the tunnel cavity wall, an effect of favorably preventing damage due to blasting stones or the like can be obtained. Also, when impedance matching between the remote wireless detonation system antenna 4 and the signal cable 5 is required,
It is also possible to provide an adjustment box on the nut 8 for fixing the antenna and the transmission coil, and to incorporate necessary electronic components such as a coil and a capacitor.

On the other hand, when it is installed on the shoring 13, it is desirable to lay connection terminals in advance so that good electrical connection can be secured.

[0025]

According to the present invention, since the remote radio detonation system antenna 4 is fixedly installed on the ground, protection means against blasting stones can be easily provided.
The effect is obtained that damage to the antenna and the signal cable can be effectively prevented. In addition, the antenna 4 for the remote wireless detonation system is fixed to the cave wall using members often provided on the cave wall, such as the lock bolt 7 and the shoring 13, so that the antenna 4 is fixedly laid on the ground. The effect that work can be performed easily and reliably is obtained.

Further, by grounding the antenna 4 for the remote wireless detonation system of the present invention to the ground of the cave wall through the lock bolts 7 and the shoring 13, etc., a conductor plate which extends infinitely over the rock ground, 1 / A four-wavelength monopole antenna has characteristics equivalent to a half-wavelength dipole antenna,
Even in communication using weak radio waves that does not violate the regulations of the Radio Law, communication with sufficient reliability can be performed with all of the radio detonators 10 loaded on the entire face, and the reliability and safety of detonation can be improved. The effect that it can be obtained is obtained.

Further, by arranging the antenna 4 for the remote wireless detonation system of the present invention close to the facet 14, the effect of further improving the reliability of communication by weak radio waves can be obtained, and the leg-shaped relatively inexpensive. Since a simple quarter-wave monopole antenna is sufficient, even if the antenna 4 is damaged by blasting stones or the like, there is no economical problem.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram for explaining a remote wireless detonation system using a remote wireless detonation system antenna 4 which is an example of an embodiment of the present invention, and is a schematic perspective view in which an inner wall of a tunnel is cut by a hatched portion. is there.

FIG. 2 is a cross-sectional view showing a state where a wireless detonator 10 and an explosive 11 are loaded into a charge hole 9 cut into a face 14;

FIG. 3 is a circuit block diagram of a wireless detonator 10;

FIG. 4 is a plan view of a nut for fixing an antenna and a transmission coil.

FIG. 5 is a cross-sectional view showing a state in which a nut for fixing an antenna and a transmission coil is attached to a lock bolt 7 constructed on the inner wall of the tunnel.

FIG. 6 is a schematic diagram in which the current distribution and directivity of a grounded antenna are symbolically written.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Operating device 2 ... Power cable 3 ... Transmission coil 4 ... Antenna 5 ... Signal cable 6 ... Demodulation circuit box 7 ... Lock bolt 8 ... Nut for fixing antenna and transmission coil 9 ... Charging hole 10 ... Wireless detonator 11 ... Explosive DESCRIPTION OF SYMBOLS 12 ... Inclusion 13 ... Shoring 14 ... Face face 15 ... Nut 16 ... Bearing plate 17 ... Shotcrete 18 ... Core 19 ... Receiving coil 20 ... Resonance circuit 21 ... Rectification charging circuit 22 ... Constant voltage circuit 23 ... Explosion charging circuit 24: Overall control CPU 25: Switch circuit 26: Electric detonator 27 ... Demodulation circuit 28: Modulation circuit 29: Leg antenna 30: Signal cable connection terminal

Claims (4)

[Claims] 1. A remote radio detonation system for detonating a radio detonator mounted on a face by remote control, comprising an antenna for transmitting or receiving to and from the radio detonator, a cave bed, a cave side wall, An antenna for a remote wireless detonation system, which is fixedly installed on the ground such as a cave ceiling. 2. The antenna for a remote wireless detonation system according to claim 1, wherein the antenna is fixed to a member fixedly installed on the ground. 3. The antenna according to claim 1, wherein the antenna is fixed to the ground and electrically grounded. 4. The remote wireless detonation system antenna according to claim 1, wherein the antenna is disposed close to a face.