Patent Description:
A wireless detonation system used in blasting work at a tunnel excavation site, etc. has a wireless detonator and a blasting operation device. <CIT> discloses a state of the art wireless detonation system. The wireless detonator is loaded with explosives into a plurality of blast holes drilled in the excavation direction through the blasting face. For example, the blast hole has a diameter of several centimeters and a depth of several meters. The blasting operation device is disposed at a remote location away from the blasting face. The wireless detonator and the blasting operation device each has a transmitting-receiving antenna.

For example, <CIT> describes a wireless detonation system may have an antenna on a blasting operation device side, which is disposed in the vicinity of the blasting face. The antenna on the blasting operation device side is disposed, for example, at a position about <NUM> meter away from the blasting face. The antenna may be formed in a loop-shape having a size such that it surrounds a plurality of blast holes on the blasting face. The antenna on the blasting operation device side wirelessly transmits control signals, including energy for driving the wireless detonator, and detonation signals to the wireless detonator. An explosive-side antenna receives energy for driving and receives control signals from the blasting operation device. The energy for driving is accumulated in a storage element of the wireless detonator. The wireless detonator uses radio waves to transmit a response signal, including its own operating state, based on the control signal via the explosive-side antenna. The radio wave is received by the blasting operation device via an antenna. The blasting operation device recognizes that charging of the wireless detonator has been completed based on the response signal. Then, the blasting operation device transmits a detonation signal to the wireless detonator, which detonates the explosive.

The antenna on the blasting operation device side transmits energy for driving from outside the blasting face to the explosive-side antenna in the blast hole. The wireless detonation systems disclosed in <CIT> and <CIT> have a large antenna on the blasting operation device side, which is disposed in the vicinity of the blasting face. The wireless detonation system disclosed in <CIT> includes a large antenna on the blasting operation device side at the ignition location. Therefore, it was troublesome to dispose a large antenna on the blasting operation device side. In addition, there are restrictions on the place where the antenna on the blasting operation device side can be disposed, and there are cases where the workability is not good.

The antenna on the blasting operation device side transmits energizing energy and control signals to the explosive-side antenna through a bedrock. The antennas on the blasting operation device side disclosed in <CIT>, <CIT>, and <CIT> transmit energizing energy and control signals using a relatively large power (for example, exceeding several Watts) and at a low frequency of, for example, <NUM> to <NUM>, which easily penetrates the bedrock. Therefore, in some cases, countermeasures, such as electromagnetic wave shielding, are required to prevent electromagnetic waves from leaking out of the tunnel.

For example, <CIT> discloses a wireless detonation system may have an auxiliary antenna drawn out from a wireless detonator to be positioned outside a blast hole. Thereby, the antenna on the blasting operation device side and the explosive-side antenna can transmit and receive electromagnetic transmissions at high frequencies of, for example, <NUM> to <NUM>, which are difficult to pass through the bedrock. However, using this method, it is necessary to pull out an auxiliary antenna for each wireless detonator, which complicates the loading operation of the wireless detonator. Therefore, there is a need for a wireless detonation system which allows for efficient placement of communication equipment between the antenna on the blasting operation device side and the antenna on the explosives side. Furthermore, there is a need for preventing the signals transmitted and received by the antenna on the blasting operation device side and the antenna on the explosives side from leaking to the surroundings.

According to the invention there is provided a wireless detonation system according to the independent claim <NUM>, a relay device according to independent claim <NUM> and a detonating method according to independent claim <NUM>.

Therefore, the relay device and the detonator communicate wirelessly at the second frequency, which is a relatively low frequency. The relay device and the detonator may communicate wirelessly at a low frequency that penetrates, for example, a bedrock constituting a blasting target. Since both of the relay device and the detonator are placed in the holes formed in the blasting face, they are positioned close to each other. Therefore, the relay device and the detonator can wirelessly communicate with each other using signals with a small power of, for example, less than or equal to <NUM> W. On the other hand, the relay device and the blasting operation device communicate wirelessly using a first frequency, which is a relatively high frequency. Therefore, it is possible to prevent signals from leaking to the surroundings, such as outside the tunnel, of a blasting target.

According to another aspect of the present disclosure, the detonator includes an explosive-side transmitting antenna to wirelessly transmit a second upstream signal at the second frequency. The relay device includes a second transmitting antenna to wirelessly transmit a second upstream signal, a relay processor that processes to wirelessly receive the second upstream signal and processes to wirelessly transmit the first upstream signal at the first frequency, and a first transmitting antenna to wirelessly transmit the first upstream signal. The blasting operation device is configured to wirelessly receive the first upstream signal. Therefore, the above-mentioned effect can be wirelessly obtained not only with the downstream signal transmitted from the blasting operation device to the detonator via the relay device, but also with the upstream signal in the opposite direction.

According to another aspect of the present disclosure, the explosive-side receiving antenna and the explosive-side transmitting antenna are a common antenna. The first receiving antenna and the first transmitting antenna are a common antenna. The second receiving antenna and the second transmitting antenna are a common antenna. Therefore, the number of parts of the entire wireless detonation system can be reduced.

According to another aspect of the present disclosure, the relay device has a housing which is partially or entirely inserted into the insertion hole. The first receiving antenna, the second transmitting antenna, and the relay processor are integrally provided in the housing. Alternatively, the relay device may include a plurality of housings which may be inserted into the insertion holes. The first receiving antenna may be provided to any of the plurality of housings. The second transmitting antenna may be provided to any of the plurality of housings. The relay processor may be provided to any of the plurality of housings. Therefore, the relay device is supported by the blasting target via the housing. This allows the relay device to be easily inserted into and supported by the blasting target.

According to another aspect of the present disclosure, the housing includes a rear end provided at the rear side of the insertion hole. The second transmitting-receiving antenna is provided at the rear end. The first receiving antenna is provided at the front end of the housing opposite to the rear end. Therefore, the second transmitting antenna is positioned at a location close to the detonator, which has been loaded in the rear side of the blast hole. Therefore, the relay device and the detonator can communicate with each other using low power signals. On the other hand, the first receiving antenna is positioned at a location close to the opening of the insertion hole. Therefore, the first receiving antenna can wirelessly communicate with the blasting operation device using signals that are not substantially interrupted by a bedrock, etc. constituting a blasting target.

According to another aspect of the present disclosure, the first receiving antenna is disposed in the front end of the housing, with the first receiving antenna projecting through the insertion hole and/or beyond the blasting face. Therefore, the relay device and the blasting operation device can wirelessly communicate with each other using signals that are not substantially interrupted by the bedrock, etc. constituting the blasting target. Further, the first receiving antenna projects from the blasting target using the housing held at the blasting target. The first receiving antenna is thus supported by the blasting target using a simple structure.

According to another aspect of the present disclosure, the second frequency may be within the range of <NUM> to <NUM>, which is a frequency range that penetrates the bedrock. The first frequency may be within the range of <NUM> to <NUM>. Therefore, the relay device and the detonator can communicate well wirelessly within the bedrock. Further, the frequency bands of the first frequency and the second frequency are separated from each other. Interference between signals at the first frequency and signals at the second frequency can thus be reduced, thereby further preventing erroneous communication.

According to another aspect of the present disclosure, a detonator loading unit is provided to load the detonator into the blast hole. The detonator loading unit includes a loading-unit-side communication device capable of communicating with the explosive-side receiving antenna of the detonator. This communication may occur before the detonator is loaded into the blast hole and using radio signals at the second frequency. Therefore, a process to allow for communication between the detonator and the loading-unit-side communication device and a process to load the detonator into the blast hole can be efficiently performed in a series of flows. Further, the explosive-side receiving antenna receiving from the loading-unit-side communication device and the explosive-side receiving antenna receiving from the relay device can be used in common. It is thus possible to reduce the number of parts of the detonator.

According to another aspect of the present disclosure, the detonator includes a receiving coil to receive energy for driving the detonator and a capacitor to accumulate the energy for driving. The detonator loading unit includes a power supplying coil that feeds energy to the receiving coil of the detonator to drive the detonator before it is loaded into the blast hole. The capacitor of the detonator can thus maintain a state in which the energy necessary for driving the detonator is not accumulated or is low until immediately before the detonator is loaded in the blast hole. Therefore, when transporting the detonator to the blasting target, it can be transported in a stable state without having detonatable energy. The power is supplied to the detonator immediately before being loaded into the blast hole. It is thus possible to use a relatively small capacity capacitor. As a result, the cost of the detonator can be reduced. It is also possible to shorten the amount of time needed to supply power to the capacitor, which allows work to be done more efficiently.

According to another aspect of the present disclosure, the relay device includes a receiving coil to receive energy for driving the relay device from the power supplying coil of the detonator loading unit and includes a capacitor to store the energy for driving. Therefore, electric power can also be supplied to the relay device using the power supplying coil as the one that feeds the electric power to the detonator. It is thus possible to reduce the number of parts of the entire system. Further, the electric power is stored in the capacitor immediately before inserting the relay device into the insertion hole. The storage capacity of the capacitor can thus be reduced to the minimum amount required for communication.

According to another aspect of the present disclosure, the detonator loading unit is provided to an explosive delivery unit, which is configured to deliver explosives to be loaded in the blast holes. Therefore, a process to load the detonators into the blast holes and a process to load the explosives in a further front side of the blast holes than the detonators can be efficiently performed in a series of flows.

According to another aspect of the present disclosure, the relay device for the wireless detonation system includes the first receiving antenna, the relay processor, and the second transmitting antenna. The first receiving antenna wirelessly receives a first downstream signal at the first frequency from the blasting operation device disposed distanced from the blasting target. The relay processor processes to wirelessly receive the first downstream signal and processes to wirelessly transmit a second downstream signal at the second frequency lower than the first frequency. The second transmitting antenna wirelessly transmits a second downstream signal to the explosive-side receiving antenna of the detonator, which has been loaded in the blast hole of the blasting target. The first receiving antenna, the relay processor, and the second transmitting antenna are attached to the housing. The housing is loaded in an insertion hole of the blasting target aligned with the blast hole.

Therefore, the relay device and the detonator can communicate wirelessly with each other at the second frequency, which is a relatively low frequency. For example, the relay device and the detonator communicate wirelessly at a low frequency that penetrates a bedrock, etc. constituting a blasting target. Since both the relay device and the detonator are placed in the holes formed in the blasting target, they are positioned close to each other. Therefore, the relay device and the detonator can wirelessly communicate with each other using signals with a small power of, for example, less than or equal to <NUM> W. On the other hand, the relay device and the blasting operation device communicate wirelessly with a first frequency, which is a relatively high frequency. Therefore, it is possible to prevent signals from leaking to the surroundings, such as outside the tunnel, of a blasting target.

According to another aspect of the present disclosure, the relay device for the wireless detonation system includes a second receiving antenna, a relay processor, and a first transmitting antenna. The second receiving antenna wirelessly receives a second upstream signal transmitted from the detonator at the second frequency. The relay processor processes to wirelessly receive the second upstream signal and processes to wirelessly transmit the first upstream signal at the first frequency. The first transmitting antenna wirelessly transmits the first upstream signal. The second receiving antenna, the relay processor, and the first transmitting antenna are attached to the housing. Therefore, the above-mentioned effect can be wirelessly obtained not only with the downstream signal transmitted from the blasting operation device to the detonator via the relay device, but also with the upstream signal in the opposite direction.

According to another aspect of the present disclosure, the first receiving antenna and the first transmitting antenna are a common antenna. The second receiving antenna and the second transmitting antenna are a common antenna. Therefore, the number of parts of the entire wireless detonation system can be reduced.

According to another aspect of the present disclosure, the second transmitting antenna is provided at a rear end of the housing disposed at the rear side of the insertion hole. The first receiving antenna is provided at a front end of the housing opposite to the rear end. Therefore, the second transmitting antenna is positioned at a location close to the detonator loaded in the rear side of the blast hole. Therefore, the relay device and the detonator can communicate with each other using signals with smaller power. On the other hand, the first receiving antenna is positioned at a location close to the opening of the insertion hole. Therefore, the first receiving antenna can wirelessly communicate with the blasting operation device using signals relatively that are not substantially interrupted by a bedrock, etc. constituting a blasting target.

According to another aspect of the present disclosure, the front end of the housing and the first receiving antenna pass through the insertion hole and project from the blasting target. Therefore, the relay device and the blasting operation device can wirelessly communicate with each other using signals that are not substantially interrupted by the bedrock, etc. constituting the blasting target. Further, the first receiving antenna projects from the blasting target using the housing held by the blasting target. The first receiving antenna is thus supported to the blasting target with a simple structure.

According to another aspect of the present disclosure, the second frequency is within a frequency range of <NUM> to <NUM>, which penetrates the bedrock. The first frequency is within a frequency range of <NUM> to <NUM>. Therefore, the relay device and the detonator can communicate well wirelessly through the bedrock. Further, the frequency bands at the first frequency and the second frequency are separated from each other. Interference between signals at the first frequency and signals at the second frequency can thus be reduced and erroneous communication can be prevented.

Another aspect of the present disclosure relates to a wireless detonation method using the wireless detonation system. The blasting operation device is disposed in a position distanced from the blasting target. The relay device is disposed within the insertion hole of the blasting target. The blasting operation device and the first antenna of the relay device wirelessly communicate with each other using signals at the first frequency within the range of <NUM> to <NUM>. The detonator is disposed within the blast hole of the blasting target. The detonator and the second antenna of the relay device wirelessly communicate with each other using signals at the second frequency within the range of <NUM> to <NUM>. The relay processor of the relay device processes to receive the first frequency signals and processes to transmit the second frequency signals. Further, the relay processor of the relay device processes to receive the second frequency signals and processes to transmit the first frequency signals.

Since the relay device and the detonator wirelessly communicate with each other using signals within the range of, for example, <NUM> to <NUM>, their signals are able to penetrate the bedrock, etc. constituting the blasting target. Since both the relay device and the detonator are disposed in the holes formed in the blasting target, they are positioned at locations close to each other. Therefore, the relay device and the detonator can wirelessly communicate with each other using signals with a small power of, for example, less than or equal to <NUM> W. On the other hand, the relay device and the blasting operation device wirelessly communicate using signals within a relatively high range of, for example, <NUM> to <NUM>. Therefore, it is possible to prevent signals from leaking to the surroundings, such as outside the tunnel, of a blasting target.

According to another aspect of the present disclosure, the blasting operation device wirelessly transmits the first downstream signal at the first frequency to the relay device. The relay processor of the relay device processes to wirelessly receive the first downstream signal and processes to wirelessly transmit the second downstream signal at the second frequency. The relay device wirelessly transmits the second downstream signal to the detonator. Therefore, the downstream signal at the first frequency, which is to be wirelessly transmitted from the blasting operation device to the relay device, is prevented from leaking to the surroundings, such as outside the tunnel, of a blasting target. The downstream signal at the second frequency, which is to be wirelessly transmitted from the relay device to the detonator, penetrates the bedrock, etc. constituting the blasting target. Therefore, the downstream signal can be favorably wirelessly transmitted from the blasting operation device to the detonator via the relay device.

According to another aspect of the present disclosure, the detonator wirelessly transmits the second upstream signal to the relay device at the second frequency. The relay processor of the relay device processes to wirelessly receive the second upstream signal and processes to wirelessly transmit the first upstream signal at the first frequency. The relay device wirelessly transmits the first upstream signal to the blasting operation device. Therefore, the above-mentioned effect can be wirelessly obtained not only with the downstream signal transmitted from the blasting operation device to the detonator via the relay device, but also with the upstream signal in the opposite direction.

According to another aspect of the present disclosure, a detonator loading unit wirelessly feeds electric power to the detonator and the relay device while in the vicinity of the blasting target. The detonator loading unit loads the energized detonator into the blast hole of the blasting target. The detonator loading unit loads the energized relay device into the insertion hole of the blasting target. Therefore, a process to charge the detonator and to load the detonator into the blast hole and/or a process to charge the relay device and to load the relay device into the insertion hole can be efficiently performed in the vicinity of the blasting face in a series of flows. The power is supplied to the detonator immediately before the detonator is loaded into the blast hole and/or to the relay device immediately before the relay device loaded into the insertion hole. It is thus possible to use energy storage circuits such as a capacitor having a relatively small capacity. As a result, the cost of the detonator and the relay device can be reduced.

Preferred embodiments of the present disclosure are described in detail below with reference to the figures. The same reference numbers in the description denote similar elements with similar functions, so as to avoid redundant description. An embodiment of the present disclosure will be described with reference to <FIG>. A wireless detonation system <NUM> is used to detonate explosives to excavate or demolish structures, such as tunnels, sea floors, rocks, buildings, etc. In the present embodiment, as shown in <FIG>, an excavation site of a tunnel <NUM> will be described as an example. The tunnel <NUM> has a blasting surface <NUM> at its inner end. A plurality of blast holes <NUM> are drilled in the blasting surface <NUM> at desired intervals in the vertical and horizontal directions. The blast hole <NUM> extends in the depth direction of the tunnel <NUM>. As shown in <FIG>, each blast hole <NUM> is loaded with a detonator <NUM> and a plurality of explosives <NUM>. The entrance of the blast hole <NUM> in front of the explosive <NUM> is sealed with a sealing member <NUM>, such as clay.

As shown in <FIG>, the blasting surface <NUM> is drilled with one or more insertion holes <NUM> for disposing the relay device <NUM>. The insertion holes <NUM> are positioned at desired intervals in the vertical and horizontal directions with respect to the plurality of blast holes <NUM>, into which the explosives <NUM> are loaded. The insertion hole <NUM> extends in the depth direction of the tunnel <NUM> and is substantially parallel to the plurality of blast holes <NUM>. The relay device <NUM> is inserted into the insertion hole <NUM>. A portion of a housing <NUM> of the relay device <NUM> protrudes from the entrance of the insertion hole <NUM>. The relay device <NUM> wirelessly communicates with each of the multiple detonators <NUM> in the various blast holes <NUM>.

As shown in <FIG>, the wireless detonation system <NUM> has a blasting operation device <NUM> disposed on the floor of the tunnel <NUM> or outside the tunnel <NUM>. The blasting operation device <NUM> is disposed at a position away from the blasting face <NUM> by a distance L1. The distance L1 is set to, for example, <NUM> to <NUM>. The blasting operation device <NUM> has a transmitting-receiving antenna <NUM> capable of communicating with the relay device <NUM> in a wireless manner. Therefore, the blasting operation device <NUM> can wirelessly communicate with each of the plurality of detonators <NUM> in the blast holes <NUM> via the relay device <NUM>.

As shown in <FIG>, the detonator <NUM> and the explosive <NUM> are loaded into each blast hole <NUM> using a detonator loading unit <NUM>. The detonator loading unit <NUM> is provided, for example, to a vehicle-type explosive delivery unit <NUM>. A power supply device <NUM> for charging the detonator <NUM> is attached to the detonator loading unit <NUM>. The power supply device <NUM> supplies power to the detonator <NUM> immediately before the detonator <NUM> is loaded into the blast hole <NUM>. Alternatively, the power supply device <NUM> may be provided separately from the detonator loading unit <NUM> and may be of a portable type.

Now, the detonator <NUM> will be described in detail with reference to <FIG> and <FIG>. The detonator <NUM> has a detonator body <NUM> which is in substantially cylindrical in shape. A receiving coil <NUM> is annularly wound around the approximate center of the outer peripheral surface of the detonator body <NUM>. The number of turns of the receiving coil <NUM> is one turn or more, for example, <NUM> turns or more. The receiving coil <NUM> generates a current with a specific frequency and amplitude when exposed to an electromagnetic field. The current is used as an electric power source for controlling and detonating the detonator <NUM>. The receiving coil <NUM> also serves as a transmitting-receiving antenna for transmitting/receiving various signals of a specific frequency. The receiving coil <NUM> transmits specific signals when a current with a specific frequency and amplitude flows. The receiving coil <NUM> receives various signals of a specific frequency and amplitude when exposed to a specific electromagnetic field. The frequency of the electromagnetic waves is within the range of, for example, <NUM> to <NUM>, and preferably more than <NUM>, e.g., <NUM>, so as to have good permeability through soil or rock.

As shown in <FIG>, the detonator <NUM> has a detonator ignition part <NUM> protruding from one end surface of the detonator body <NUM>. The detonator ignition part <NUM> extends along the longitudinal direction of the detonator body <NUM>. The detonator ignition part <NUM> is inserted into a parent die 2a, which is positioned in one of the explosives <NUM>.

As shown in <FIG>, the detonator <NUM> has a tuning circuit <NUM>, which is electrically connected to the receiving coil <NUM>, a rectification element <NUM>, and a storage circuit <NUM>. The tuning circuit <NUM> tunes to the receiving frequency of the electric current generated when the receiving coil <NUM> receives electric power. The rectification element <NUM> rectifies the electric current input from the tuning circuit <NUM> to direct current. The storage circuit <NUM> may be, for example, a capacitor and stores the power rectified by the rectification element <NUM>. The storage circuit <NUM> stores the electric power to operate electronic components of the detonator <NUM> and the electric power used for igniting the detonator ignition part <NUM>.

As shown in <FIG>, the detonator <NUM> has a detonator modem <NUM>, which uses the receiving coil <NUM> as an antenna. The detonator modem <NUM> has a reception circuit (a demodulation circuit) 24a and a transmission circuit (a modulation circuit) 24b. The reception circuit 24a and the transmission circuit 24b are connected to both the receiving coil <NUM> and a control circuit (CPU) <NUM>. When the receiving coil <NUM> receives a signal, a current is generated. The reception circuit 24a converts (demodulates) the analog signal into a digital signal based on the change in current. The transmission circuit 24b converts (modulates) a digital signal transmitted from the control circuit <NUM> into an analog signal. A current based on the signal modulated by the transmission circuit 24b flows through the receiving coil <NUM>. The detonator <NUM> has a memory <NUM> connected to the control circuit <NUM>. An ID number (a serial number) unique to the detonator <NUM> and an algorithm are recorded in advance in the memory <NUM>. The memory <NUM> records an initiation delay time based on a signal for setting the initiation delay time, which may be demodulated by the reception circuit 24a, for example.

As shown in <FIG>, the detonator <NUM> has a detonating switch <NUM> and a resistance measurement circuit <NUM>, both of which are connected to the control circuit <NUM>. The detonating switch <NUM> switches the storage circuit <NUM> and the detonator ignition part <NUM> between the electrically connected and electrically disconnected states. The detonating switch <NUM> maintains the storage circuit <NUM> and the detonator ignition part <NUM> in a shutdown state when no ON signal is output from the control circuit <NUM>. The detonating switch <NUM> puts the storage circuit <NUM> and the detonator ignition part <NUM> in a connected state when an ON signal is output from the control circuit <NUM>. The resistance measurement circuit <NUM> measures the electrical resistance of the detonator ignition part <NUM> based on the output from the control circuit <NUM>. This may be done in order to determine whether the detonator ignition part <NUM> is functioning normally.

As shown in <FIG>, the relay device <NUM> has a housing <NUM> with a cylindrical shape. The housing <NUM> has a front end 31a at one end and a rear end 31b at the other end. The front end 31a is disposed at a position protruding from the entrance of the insertion hole <NUM>. The rear end 31b is disposed at a far end of the insertion hole <NUM>, which is positioned far from the entrance of the insertion hole <NUM>. The relay device <NUM> has a first transmitting-receiving antenna <NUM> at its front end 31a. The relay device <NUM> has a second transmitting-receiving antenna <NUM> at its rear end 31b.

As shown in <FIG>, the relay device <NUM> has a control circuit (CPU) <NUM>. The control circuit <NUM> includes a relay processor. The relay processor receives and processes an input signal. The relay processor then processes and transmits a signal with a different frequency. For example, the relay processor may receive signals within the <NUM> to <NUM> range and may transmit signals at a frequency within the range of <NUM> to <NUM>. Alternatively, the relay processor may receive a signal within a frequency range of, for example, <NUM> to <NUM>, and may transmit a signal within a frequency range of <NUM> to <NUM>. The relay device <NUM> includes a power source <NUM> that supplies power to the control circuit <NUM> and a memory <NUM>. The control circuit <NUM> is configured to record information in the memory <NUM> based on commands, read out data stored in the memory <NUM>, and/or perform calculations based on algorithms stored in the memory <NUM>.

As shown in <FIG>, the relay device <NUM> has a first modem <NUM> and a second modem <NUM>. The first modem <NUM> has a first-antenna-side reception circuit 36a and a first-antenna-side transmission circuit 36b. The first-antenna-side reception circuit 36a and the first-antenna-side transmission circuit 36b are connected to both the first transmitting-receiving antenna <NUM> and the control circuit <NUM>. The first-antenna-side reception circuit 36a demodulates an analog signal received by the first transmitting-receiving antenna <NUM> into a digital signal. The first-antenna-side transmission circuit 36b modulates a digital signal transmitted from the control circuit <NUM> into an analog signal. The first transmitting-receiving antenna <NUM> transmits and/or receives radio waves in the frequency range of, for example, <NUM> to <NUM>. It is difficult for these frequencies to pass through soil and bedrock. The first transmitting-receiving antenna <NUM> preferably transmits and/or receives radio waves in the frequency range of <NUM> or higher, for example, <NUM>.

As shown in <FIG>, the second modem <NUM> has a second-antenna-side reception circuit 38a and a second-antenna-side transmission circuit 38b. The second-antenna-side reception circuit 38a and the second-antenna-side transmission circuit 38b are connected to both the second transmitting-receiving antenna <NUM> and the control circuit <NUM>. The second-antenna-side reception circuit 38a demodulates an analog signal received by the second transmitting-receiving antenna <NUM> into a digital signal. The first-antenna-side transmission circuit 36b modulates a digital signal transmitted from the control circuit <NUM> into an analog signal. The second transmitting-receiving antenna <NUM> transmits and/or receives radio waves in the frequency range of, for example, <NUM> to <NUM>. The second transmitting-receiving antenna <NUM> preferably transmits and/or receives radio waves with a frequency of approximately <NUM>, which has good penetration through soil and bedrock.

As shown in <FIG>, the blasting operation device <NUM> has a control circuit (CPU) <NUM>, an input unit <NUM>, and a display unit <NUM>. The control circuit <NUM> outputs an electric signal to each electric part based on the electric signal input from each electric part of the blasting operation device <NUM>. The input unit <NUM> includes, for example, a keyboard, switches, and a touch panel. The display unit <NUM> includes, for example, a display and a lamp that turns on and off. An operator operates the input unit <NUM> while confirming the information displayed on the display unit <NUM>. The input unit <NUM> and the display unit <NUM> are electrically connected to the control circuit <NUM>. The blasting operation device <NUM> has a power source <NUM> that supplies power to the control circuit <NUM> and has a memory <NUM>. The control circuit <NUM> records information, such as the ID number of the detonator <NUM>, in the memory <NUM> based on the commands, reads out data stored in the memory <NUM>, and/or performs calculations based on algorithms stored in the memory <NUM>.

As shown in <FIG>, the blasting operation device <NUM> has the transmitting-receiving antenna <NUM> and an operating unit modem <NUM>. The operating unit modem <NUM> has a reception circuit 46a and a transmission circuit 46b. The reception circuit 46a and the transmission circuit 46b are connected to both the transmitting-receiving antenna <NUM> and the control circuit <NUM>. The reception circuit 46a demodulates an analog signal received by the transmitting-receiving antenna <NUM> into a digital signal. The transmission circuit 46b modulates a digital signal transmitted from the control circuit <NUM> into an analog signal. The transmitting-receiving antenna <NUM> transmits and/or receives radio waves in the frequency range of <NUM> to <NUM>, for example.

As shown in <FIG>, the wireless detonation system <NUM> has an explosive delivery unit <NUM> that delivers the detonator <NUM> and the explosive <NUM> into each blast hole <NUM>. The explosive delivery unit <NUM> has a boom 50b mounted on a vehicle 50a. The boom 50b is extendably and/or tiltably supported by the vehicle 50a. The detonator loading unit <NUM> is provided at the end of the boom 50b. The detonator loading unit <NUM> is moved into the blast hole <NUM> by extension/retraction and/or tilting of the boom 50b. The detonator loading unit <NUM> holds and then releases the detonator <NUM>. The detonator <NUM> is loaded into the blast hole <NUM> by moving the detonator loading unit <NUM> into the blast hole <NUM>.

As shown in <FIG>, the detonator loading unit <NUM> has a power feeder <NUM> that feeds energy for driving to the receiving coil <NUM> of the detonator <NUM>. The detonator <NUM> may be energized before it is charged into the blast hole <NUM>. The power feeder <NUM> has a cylindrical body 52a that has a tubular-shape open on each side. The cylindrical body 52a has a power-supplying coil (an antenna) <NUM> wound in an annular shape. The power-supplying coil <NUM> is wound along the outer peripheral surface of the cylindrical body 52a. The number of turns of the power-supplying coil <NUM> is one turn or more, for example, <NUM> turns or more. The opening 52b of the cylindrical body 52a has an inner diameter larger than the outer diameter of the receiving coil <NUM>, which is wound around the outer peripheral surface of the detonator body <NUM>.

As shown in <FIG>, the power-supplying coil <NUM> generates an electric field or magnetic field around the power-supplying coil <NUM> when a current with a specific frequency, amplitude, and wavelength flows. The power-supplying coil <NUM> may transmit a specific electromagnetic wave. The power-supplying coil <NUM> receives various signals having specific frequencies and amplitudes by being exposed to the specific electromagnetic fields. The power-supplying coil <NUM> communicates with the receiving coil <NUM> at a frequency within a frequency range of, for example, <NUM> to <NUM>, preferably at <NUM>.

As shown in <FIG>, the detonator loading unit <NUM> has a loading-unit-side communication device <NUM>, which is capable of communicating with the receiving coil <NUM> of the detonator <NUM> before the detonator <NUM> is loaded into the blast hole <NUM>. The loading-unit-side communication device <NUM> has a control circuit (CPU) <NUM>, an input unit <NUM>, and a display unit <NUM>. The control circuit <NUM> outputs an electric signal to each electric component based on the electric signals input from each electric component of the loading-unit-side communication device <NUM>. The input unit <NUM> includes, for example, a keyboard, switches, and a touch panel. The display unit <NUM> includes, for example, a display and a lamp that can be turned on and off. The operator operates the input unit <NUM> while confirming the information displayed on the display unit <NUM>. The input unit <NUM> and the display unit <NUM> are electrically connected to the control circuit <NUM>.

As shown in <FIG>, the loading-unit-side communication device <NUM> has a power source <NUM> that supplies power to the control circuit <NUM>, a memory <NUM>, and a power-supplying circuit <NUM>. For example, the control circuit <NUM> records information, such as the ID number of the detonator <NUM>, in the memory <NUM>, and/or reads data stored in the memory <NUM>, and/or performs calculations based on algorithms stored in the memory <NUM> based on commands. The power-supplying circuit <NUM> is electrically connected to the power source <NUM> and the power-supplying coil <NUM>. The control circuit <NUM> outputs a current from the power supply <NUM> to the power-supplying coil <NUM> via the power-supplying circuit <NUM>. This is done based on a command.

As shown in <FIG>, the loading-unit-side communication device <NUM> has a loading unit modem <NUM> connected to the power-supplying coil <NUM> and the control circuit <NUM>. The loading unit modem <NUM> has a reception circuit 62a and a transmission circuit 62b. The reception circuit 62a and the transmission circuit 62b are connected to the power-supplying coil <NUM> and the control circuit <NUM>, respectively. The reception circuit 62a demodulates the analog signal received by power-supplying coil <NUM> into a digital signal. The transmission circuit 62b modulates the digital signal transmitted from the control circuit <NUM> into an analog signal. The transmission circuit 62b outputs to the power-supplying coil <NUM> a current having a specific code signal and a specific frequency of <NUM> to <NUM> related to, for example, a signal for setting the initiation delay time.

The flow of the wireless detonation method for blasting and excavating the blasting face <NUM> using the wireless detonation system <NUM> will be described according to <FIG>. As shown in <FIG>, an operator first drills a plurality of blast holes <NUM> and one or more insertion hole <NUM> into the blasting face <NUM> (Step S1 in <FIG>). This is done in preparation for blasting. The blast hole <NUM> and the insertion hole <NUM> are drilled to have a diameter of about <NUM> and a depth of about <NUM>, for example. As shown in <FIG>, the detonator body <NUM> of the detonator <NUM> is inserted into the cylindrical body 52a of the power feeder <NUM> along the longitudinal direction (Step S2). The receiving coil <NUM> is moved to be disposed radially inward of the power power-supplying coil <NUM>. The operator then operates the input unit <NUM> (see <FIG>) to start electrically charging the detonator <NUM> (Step S3).

As shown in <FIG>, the control circuit <NUM> of the loading-unit-side communication device <NUM> receives an input signal from the input unit <NUM> and outputs a current to the power-supplying coil <NUM> via the power-supplying circuit <NUM> (Step S11 in <FIG>). The power-supplying coil <NUM> generates a magnetic field with a frequency within the range of, for example, <NUM> to <NUM> (Step S12). The receiving coil <NUM> of the detonator <NUM> receives the magnetic field and generates a current (Step S13). The tuning circuit <NUM> tunes to the frequency of the current generated by the receiving coil <NUM> (Step S14). The rectification element <NUM> rectifies the received current into a direct current (Step S15).

As shown in <FIG>, the storage circuit <NUM> stores electric power due to being supplied with the direct current (Step S16). Note that the voltage of the storage circuit <NUM> is <NUM> V before the current is generated in the receiving coil <NUM>. If the voltage of the storage circuit <NUM> is less than a predetermined value, no response will be made to a transmission of an ID number inquiry signal from the loading-unit-side communication device <NUM> (Step S17). If the storage circuit <NUM> responds, an amount of electric power to be used for controlling the detonator <NUM> and for igniting the detonator ignition part <NUM> will have been sufficiently accumulated in the storage circuit <NUM>. When the receiving coil <NUM> receives an ID number inquiry signal (Step S18), the reception circuit 24a demodulates the inquiry signal (Step S19). The control circuit <NUM> then transmits the ID number of detonator <NUM> to the transmission circuit 24b (Step S20). The transmission circuit 24b modulates the signal (Step S21), and then transmits it to the receiving coil <NUM>. The receiving coil <NUM> transmits the modulated signal using a radio wave within the range of, for example, <NUM> to <NUM> (Step S22).

As shown in <FIG>, the power-supplying coil <NUM> is configured to receive a signal (Step S23). The reception circuit 62a demodulates this signal (Step S24), and then transmits it to the control circuit <NUM>. The control circuit <NUM> checks the ID number of the detonator <NUM> (Step S25), and then records the ID number in the memory <NUM>. The control circuit <NUM> transmits the signal for setting the initiation delay time, which may correspond to the ID number of the detonator <NUM>, to the transmission circuit 62b (Step S26). The transmission circuit 62b modulates the signal (Step S27), and then the power-supplying coil <NUM> generates a magnetic field with a frequency within the range of, for example, <NUM> to <NUM>. The transmission circuit 62b also transmits a signal for setting the initiation delay time (Step S28).

As shown in <FIG>, the receiving coil <NUM> receives a signal (Step S29), which the reception circuit 24a then demodulates (Step S30). The memory <NUM> records the initiation delay time based on a command from the control circuit <NUM> (Step S31). The control circuit <NUM> then transmits a signal indicating completion of the setting of the initiation delay time to the transmission circuit 24b (Step S32). The transmission circuit 24b modulates the signal (Step S33), and then transmits it to the receiving coil <NUM>. The receiving coil <NUM> transmits the modulated signal using radio waves within the range of, for example, <NUM> to <NUM> (Step S34).

As shown in <FIG>, the power-supplying coil <NUM> receives a signal (Step S35), which the reception circuit 62a then demodulates (Step S36). The demodulated signal is then transmitted to the control circuit <NUM>. The control circuit <NUM> confirms completion of the setting of the initiation delay time of the detonator <NUM> (Step S37). The display unit <NUM> displays that the charging processing (preparation) for the detonator <NUM> has been completed.

As shown in <FIG>, the power supply device <NUM> is provided at the end of the boom 50b of the detonator loading unit <NUM>. Alternatively, the power supply device <NUM> may be provided at a location different from the boom 50b. For example, the power supply device <NUM> may be provided separately from the detonator loading unit <NUM>. In such a case, as shown in <FIG>, the operator pulls out the fully charged detonator <NUM> from the cylindrical body 52a of the power supply device <NUM> (Step S4 in <FIG>). The operator then sets the charged detonator <NUM> in the explosive delivery unit <NUM>. As shown in <FIG>, the detonator <NUM> and the explosive <NUM> are loaded into the blast hole <NUM> using the detonator loading unit <NUM> (Step S5). The detonator <NUM> is loaded with the parent die 2a facing forward. The parent die 2a is connected to the detonator ignition part <NUM>. A plurality of additional dies 2b are loaded on the front side of each of the parent dies 2a. The entrance of the blast hole <NUM> is then sealed off with a sealing member <NUM>. The operator inserts the relay device <NUM> into the insertion hole <NUM> (Step S6). The rear end 31b, which has the second transmitting-receiving antenna <NUM>, is disposed in the end of the insertion hole <NUM>, where is far from the entrance. The front end 31a, which has the first transmitting-receiving antenna <NUM>, protrudes from the entrance of the insertion hole <NUM>. The first transmitting-receiving antenna <NUM> is supported by the housing <NUM>.

Referring to <FIG>, an operator disposes the blasting operation device <NUM> at a remote location at a certain distance from the blasting face <NUM> (Step S7). This is done after all detonators <NUM>, explosives <NUM>, and relay devices <NUM> have been loaded. The explosive delivery unit <NUM>, which has the detonator loading unit <NUM> (see <FIG>), is evacuated to a remote location a certain distance from the blasting face <NUM>. The operator operates the input unit <NUM> to start a blast preparation process of the detonators <NUM> (Step S8).

Referring to <FIG>, the control circuit <NUM> of the blasting operation device <NUM> receives signals from the input unit <NUM> and transmits signals for blast preparation, which may be used to confirm the soundness of the detonator ignition part <NUM>, to the transmission circuit 46b (Step S41 in <FIG>). The transmission circuit 46b converts the signals (Step S42) and the transmitting-receiving antenna <NUM> transmit downstream signals with radio waves in the range of, for example, <NUM> to <NUM> (Step S43).

Referring to <FIG>, the first transmitting-receiving antenna <NUM> of the relay device <NUM> receives downstream signals (Step S44) and the first antenna-side reception circuit <NUM> demodulates the signals (Step S45). A rely processor of the control circuit <NUM> processes the received high frequency signals having a frequency within the range of, for example, <NUM> to <NUM> (Step S46). A second antenna-side transmission circuit 38b modulates signals (Step S47) and a second transmitting-receiving antenna <NUM> transmits downstream signals with radio waves having a frequency within the range of, for example, <NUM> to <NUM> (Step S48).

Referring to <FIG>, the receiving coil <NUM> receives downstream signals (Step S49) and the reception circuit 24a demodulates the signals (Step S50). A resistance measurement circuit <NUM> serves to measure the electrical resistance of the detonator ignition part <NUM> based on the output from the control circuit <NUM> (Step S51). The control circuit <NUM> determines the soundness (conductivity) of the detonator ignition part <NUM> from the measured resistance value (Step S52). The control circuit <NUM> transmits signals corresponding to the soundness of the detonator ignition part <NUM> to the transmission circuit 24b (Step S53). The transmission circuit <NUM> modulates the signals (Step S54) and the receiving coil <NUM> (e.g. transmitting-receiving antenna) transmits upstream signals using radio waves within the range of, for example, <NUM> to <NUM> (Step S55).

Referring to <FIG>, the second transmitting-receiving antenna <NUM> receives upstream signals (Step S56) and the second antenna-side reception circuit 38a demodulates the signals (Step S57). The relay processor of the control circuit <NUM> processes the received low frequency signals having a frequency within the range of, for example, <NUM> to <NUM>, and processes to transmit high frequency signals having a frequency within the range of, for example, <NUM> to <NUM> (Step S58). The first antenna-side transmission circuit 36b modulates signals (Step S59) and the first transmitting-receiving antenna <NUM> transmits upstream signals with radio waves having a frequency within the range of, for example <NUM> to <NUM> (Step S60).

Referring to <FIG>, the transmitting-receiving antenna <NUM> receives upstream signals (Step S61), and the reception circuit 46a modulates (e.g. demodulates) the signals (Step S62). When the soundness of the detonator ignition part <NUM> is determined to be sufficient by the control circuit <NUM> (Step S63), the control circuit <NUM> allows the display unit <NUM> to display that the blast preparation of the detonator <NUM> has been completed (Step S64). When the soundness of the detonator ignition part <NUM> of the detonator <NUM> with a certain ID number is determined to be insufficient (Step S63), the control circuit <NUM> allows the display unit <NUM> to display the ID number of the detonator <NUM> and the detonator ignition part <NUM> that has insufficient soundness. After the blast preparation process has been completed, the operator may operate the input unit <NUM> to start a blast process of the detonators <NUM> (Step S9 in <FIG>).

Referring to <FIG>, when the operator operates the input unit <NUM> of the blasting operation device <NUM>, the control circuit <NUM> receives signals from the input unit <NUM> and transmits detonation initiation signals to the transmission circuit 46b (Step S71 in <FIG>). The transmission circuit 46b modulates the signals (Step S72) and the transmitting-receiving antenna <NUM> transmits the downstream signals with radio waves having a frequency within the range of, for example, <NUM> to <NUM> (Step S73). The first transmitting-receiving antenna <NUM> of the relay device <NUM> receives the downstream signals (Step S74) and the first antenna-side reception circuit 36a demodulates the signals (Step S75). The rely processor of the control circuit <NUM> processes to receive high frequency signals having a frequency within the range of, for example, <NUM> to <NUM> (Step S76). The second antenna-side transmission circuit 38b modulates signals (Step S77) and the second transmitting-receiving antenna <NUM> transmits downstream signals with radio waves having a frequency within the range of, for example, <NUM> to <NUM> (Step S78).

Referring to <FIG>, the receiving coil <NUM> receives downstream signals (Step S79) and the reception circuit 24a demodulates the signals (Step S80). The control circuit <NUM> activates an internal timer upon receiving the detonation initiation signals. It is then determined whether or not the time counted by the timer has reached the blast initiation delay time recorded in the memory <NUM> (Step S81). This determination will be repeated until the count time of the timer reaches the blast initiation delay time. When the count time of the timer has reached the blast initiation delay time, the control circuit <NUM> outputs an ON signal to a detonating switch <NUM> (Step S82). The detonating switch <NUM> is turned ON and connected (Step S83), which allows the storage circuit <NUM> to transmit power to the detonator ignition part <NUM> via the detonating switch <NUM> (Step S84). The detonator ignition part <NUM> is then ignited (Step S85), such that the explosives <NUM> (see <FIG>) are detonated.

According to the wireless detonation system <NUM> described-above, as shown in <FIG>, the wireless detonation system <NUM> includes a blasting operation device <NUM>, a detonator <NUM>, and a relay device <NUM>. The blasting operation device <NUM> is disposed at a distance from the blasting face <NUM> and is configured to wirelessly transmit a first downstream signal at a first frequency. The first detonator <NUM>, which has been loaded in the blast hole <NUM> of the blasting face <NUM>, includes a receiving coil <NUM> configured to wirelessly receive a second downstream signal at a second frequency lower than the first frequency. The relay device <NUM> includes a first transmitting-receiving antenna <NUM> for receiving the first downstream signal. The relay device <NUM> further includes a relay processor for the control circuit <NUM> configured to be used to process the wirelessly received first downstream signal and to transmit the second downstream signal at the second frequency. The relay device <NUM> further includes a second transmitting-receiving antenna <NUM> configured to be used to wirelessly transmit the second downstream signal. The second transmitting-receiving antenna <NUM> is loaded in an insertion hole <NUM> of the blasting face <NUM>, the insertion hole <NUM> being aligned with the blast hole <NUM>.

Therefore, the relay device <NUM> and the detonator <NUM> are configured to communicate wirelessly with each other at the second frequency, which is relatively low frequency. For example, the relay device <NUM> and the detonator <NUM> communicate wirelessly at a low enough frequency that can penetrate a bedrock constituting a blasting target. Since the relay device <NUM> and the detonator <NUM> are placed in either the blast holes <NUM> or the insertion holes <NUM> formed in the blasting face <NUM>, they can be positioned close to each other. Therefore, the relay device <NUM> and the detonator <NUM> can wirelessly communicate with each other using signals with a small power of, for example, less than or equal to <NUM> W. On the other hand, the relay device <NUM> and the blasting operation device <NUM> communicate wirelessly using the first frequency, which is a relatively high frequency. Therefore, it is possible to prevent signals from leaking to the surroundings, such as outside the tunnel <NUM>, of the blasting target.

As shown in <FIG>, the detonator <NUM> includes a receiving coil <NUM> for wirelessly transmitting a second upstream signal at the second frequency. The relay device <NUM> includes the second transmitting-receiving antenna <NUM> for wirelessly receiving the second upstream signal. The relay device <NUM> further includes a relay processor of the control circuit <NUM>. The relay processor is configured to process the wirelessly received second upstream signal and to wirelessly transmit using the first upstream signal at the first frequency. The relay device <NUM> also includes a first transmitting-receiving antenna <NUM> for wirelessly transmitting the first upstream signal. The blasting operation device <NUM> wirelessly receives the first upstream signal. Therefore, the above-mentioned effect can be wirelessly obtained not only with the downstream signal transmitted from the blasting operation device <NUM> to the detonator <NUM> via the relay device <NUM>, but also with the upstream signal in the opposite direction.

As shown in <FIG>, an explosive-side receiving antenna and an explosive-side transmitting antenna are a common receiving coil <NUM>. A first receiving antenna and a first transmitting antenna are a common first transmitting-receiving antenna <NUM>. A second receiving antenna and a second transmitting antenna are a common second transmitting-receiving antenna <NUM>. Therefore, the number of parts of the entire wireless detonation system <NUM> can be reduced.

As shown in <FIG>, the relay device <NUM> includes a housing which is partially or entirely inserted into the insertion hole <NUM>. The first transmitting-receiving antenna <NUM>, the second transmitting-receiving antenna <NUM>, and the control circuit <NUM> having the relay processor are integrally provided in the housing <NUM>. Therefore, the relay device <NUM> is supported by the blasting target via the housing <NUM>. This allows the relay device <NUM> to be easily inserted into and supported by the blasting target.

As shown in <FIG>, the housing <NUM> includes a rear end 31b disposed in the rear side of the insertion hole <NUM>. The second transmitting-receiving antenna <NUM> is provided at the rear end. The first transmitting-receiving antenna <NUM> is provided at the front end of the housing <NUM> opposite to the rear end. Therefore, the second transmitting-receiving antenna <NUM> is positioned at the location close to the detonator <NUM>, which is also loaded in the rear side of the blast hole <NUM>. Therefore, the relay device <NUM> and the detonator <NUM> can communicate with each other using low power signals, for example, less than or equal to <NUM> W. On the other hand, the first transmitting-receiving antenna <NUM> is positioned at a location close to the opening of the insertion hole <NUM>. Therefore, the first transmitting-receiving antenna <NUM> can wirelessly communicate with the blasting operation device <NUM> using signals that have not been interrupted by a bedrock constituting a blasting target.

As shown in <FIG>, the front end 31a of the housing <NUM> is disposed with the first transmitting-receiving antenna <NUM> projecting from the insertion hole <NUM> and beyond the blasting face <NUM>. Therefore, the relay device <NUM> and the blasting operation device <NUM> can wirelessly communicate with each other using signals that would normally be interrupted by the bedrock, etc. constituting the blasting target. Further, the first transmitting-receiving antenna <NUM> projects from the blasting face <NUM> using the housing <NUM> held by the blasting target. The first transmitting-receiving antenna <NUM> is thus supported by the blasting target using a simple structure.

As shown in <FIG>, the second frequency is within a range of <NUM> to <NUM>, which typically penetrates bedrock. The first frequency is within the range of <NUM> to <NUM>. Therefore, the relay device <NUM> and the detonator <NUM> can easily communicate with each other wirelessly within the bedrock. Further, the frequency bands at the first frequency and the second frequency are separated from each other. Thus, interference between signals at the first frequency and signals at the second frequency can be reduced, thereby preventing erroneous communication.

As shown in <FIG>, a detonator loading unit <NUM> is provided to load the detonator <NUM> into the blast hole <NUM>. The detonator loading unit <NUM> includes a loading-unit-side communication device <NUM> capable of communicating with the receiving coil <NUM> of the detonator <NUM>. This communication may occur before the detonator <NUM> is loaded into the blast hole <NUM> using radio signals at the second frequency. Therefore, a process to allow for communication between the detonator <NUM> and the loading-unit side communication device <NUM> and a process to load the detonator <NUM> into the blast hole <NUM> can be efficiently performed in a series of flows. Further, the same receiving coil <NUM> can be used for receiving signals from the loading-unit-side communication device <NUM> and for receiving signals from the relay device <NUM>. It is thus possible to reduce the number of parts of the detonator <NUM>.

As shown in <FIG>, the detonator <NUM> includes a receiving coil <NUM> to receive energy for driving the circuit and includes a storage circuit <NUM> to store the energy used for driving the detonation. The detonator loading unit <NUM> includes a power supplying coil <NUM> that feeds energy for driving to the receiving coil <NUM> of the detonator <NUM> before it is charged into the blast hole <NUM>. The storage circuit <NUM> can thus maintain a state in which the energy used for driving the detonation is not sufficiently accumulated within the detonator until immediately before the detonator <NUM> is loaded in the blast hole <NUM>. Therefore, when transporting the detonator <NUM> to the blasting face <NUM>, the detonator <NUM> can be transported in a low-energy, stable state. The power is supplied to the detonator <NUM> immediately before being loaded into the blast hole <NUM>. It is thus possible to use, for example, a capacitor having a relatively small capacity in the storage circuit <NUM>. As a result, the cost of the detonator <NUM> can be reduced. Since it is also possible to shorten the power supply time, the work can be done efficiently.

As shown in <FIG>, the detonator loading unit <NUM> is provided to the explosive delivery unit <NUM>, which is configured to deliver explosives to be loaded in the blast holes <NUM>. Therefore, a process to load the detonators <NUM> into the blast holes <NUM> and a process to load the explosives on a further front side than the detonators <NUM>, which have been loaded in the blast holes <NUM>, can be efficiently performed in a series of flows.

As shown in <FIG>, the relay device <NUM> includes a second transmitting-receiving antenna <NUM>, a control circuit <NUM> having the relay processor, and a first transmitting-receiving antenna <NUM>. The second transmitting-receiving antenna <NUM> wirelessly receives second upstream signals transmitted by the detonator <NUM> at the second frequency. The relay processor processes the wirelessly received second upstream signal and processes to wirelessly transmit the first upstream signal at the first frequency. The first transmitting-receiving antenna <NUM> wirelessly transmits the first upstream signal. The second transmitting-receiving antenna <NUM>, the relay processor, and the first transmitting-receiving antenna <NUM> are attached to the housing <NUM>. Therefore, the above-mentioned effect can be wirelessly obtained not only with the downstream signal transmitted from the blasting operation device <NUM> to the detonator <NUM> via the relay device <NUM>, but also with the upstream signal in the opposite direction.

As shown in <FIG>, the blasting operation device <NUM> is disposed at a position distanced from the blasting target. The relay device <NUM> is disposed within the insertion hole <NUM> of the blasting target. The blasting operation device <NUM> and the first transmitting-receiving antenna <NUM> of the rely device <NUM> wirelessly communicate with each other using signals at the first frequency within the range of, for example, <NUM> to <NUM>. The detonator <NUM> is disposed within the blast hole <NUM> of the blasting target. The detonator <NUM> and the second transmitting-receiving antenna <NUM> of the relay device <NUM> wirelessly communicate with each other using signals at the second frequency within the range of, for example, <NUM> to <NUM>. The relay processor of the relay device <NUM> processes the received first frequency signals and processes to transmit the second frequency signals. Further, the relay processor of the relay device <NUM> processes the received second frequency signals and processes to transmit the first frequency signals.

Therefore, the relay device <NUM> and the detonator <NUM> wirelessly communicate with each other using signals having a frequency within the range of, for example, <NUM> to <NUM>, which penetrates the bedrock, etc. constituting the blasting target. Since both the relay device <NUM> and the detonator <NUM> are disposed in either the blast hole <NUM> or the insertion hole <NUM>, they are positioned in locations close to each other. Therefore, the relay device <NUM> and the detonator <NUM> can wirelessly communicate with each other using low power signals of, for example, less than or equal to <NUM> W. On the other hand, the relay device <NUM> and the blasting operation device <NUM> wirelessly communicate using signals at a frequency having a relatively high frequency, for example within the range of <NUM> to <NUM>. Therefore, it is possible to prevent signals from leaking to the surroundings such as outside a tunnel <NUM>, which is a blasting target.

As shown in <FIG>, the blasting operation device <NUM> wirelessly transmits the first downstream signal at the first frequency to the relay device <NUM>. The relay processor of the relay device <NUM> processes the wirelessly received first downstream signal and processes to wirelessly transmit the second downstream signal at the second frequency. The relay device <NUM> wirelessly transmits the second downstream signal to the detonator <NUM>. Therefore, the downstream signal, which is wirelessly transmitted at the first frequency, is transmitted from the blasting operation device <NUM> to the relay device <NUM> while being prevented from leaking to the surroundings outside of the blasting target, such as outside the tunnel <NUM>. The downstream signal, which is wirelessly transmitted at the second frequency, is transmitted from the relay device <NUM> to the detonator <NUM> by penetrating the bedrock, etc. constituting the blasting target. Therefore, the downstream signal can be favorably wirelessly transmitted from the blasting operation device <NUM> to the detonator <NUM> via the relay device <NUM>.

Another embodiment of the present disclosure will be described with reference to <FIG> and <FIG>. The wireless detonation system <NUM> according to the second embodiment includes a relay device <NUM> shown in <FIG>, instead of the relay device <NUM> of the wireless detonation system <NUM> shown in <FIG>. The relay device <NUM> includes a receiving coil <NUM> wound annularly around an outer circumferential surface of the substantially cylindrical housing <NUM>, instead of the second transmitting-receiving antenna <NUM> (see <FIG>). The number of turns of the receiving coil <NUM> is more than or equal to one turn, for example, more than or equal to <NUM> turns. When the receiving coil <NUM> is exposed to an electromagnetic field to generate electric current, the electric current can be used as electric power for driving the relay device <NUM>. The receiving coil <NUM> also serves as the second transmitting-receiving antenna for wirelessly transmitting and receiving signals within a frequency range of, for example, <NUM> to <NUM>.

As shown in <FIG>, the relay device <NUM> includes a tuning circuit <NUM>, a rectification element <NUM>, and a storage circuit <NUM> electrically connected to the receiving coil <NUM>, instead of the power source <NUM> (see <FIG>). The tuning circuit <NUM> tunes to the receiving frequency of the electric current generated when the receiving coil <NUM> receives electric power. The rectification element <NUM> serves to rectify the electric current input from the tuning circuit <NUM> to direct current. The storage circuit <NUM> may be, for example, a capacitor. The storage circuit <NUM> stores the electric power rectified by the rectification element <NUM>, which can then be used as the electric power to operate each electronic component of the relay device <NUM>.

The flow of processes to charge the storage circuit <NUM> of the relay device <NUM> will be described according to <FIG>. The charging processes of the relay device <NUM> can be performed between Step S5 and Step S6 shown in <FIG>. First, referring to <FIG>, the control circuit <NUM> of the loading-unit-side communication device <NUM> receives input signals from the input unit <NUM> and outputs electric current to the power-supplying coil <NUM> via the power-supplying circuit <NUM> (Step S101 in <FIG>). The power-supplying coil <NUM> generates a magnetic field with a frequency within the range of, for example, <NUM> to <NUM> (Step S102). The receiving coil <NUM> of the relay device <NUM> receives the magnetic field and generates electric current (Step S103). The tuning circuit <NUM> tunes to the frequency of the electric current generated by the receiving coil <NUM> (Step S104). The rectification element <NUM> rectifies the received electric current into a direct current (Step S105).

As shown in <FIG>, the storage circuit <NUM> stores electric power by being supplied with direct current (Step S106). If the voltage of the storage circuit <NUM> is less than a predetermined value, no response is made to the transmission of the ID number inquiry signal from the loading-unit-side communication device <NUM> (Step S107). If it responds, the electric power for driving the rely device <NUM> has sufficiently accumulated within the storage circuit <NUM>. Accordingly, the receiving coil <NUM> receives the ID number inquiry signal (Step S108), and then the second antenna-side reception circuit 38a demodulates the signal (Step S109). The control circuit <NUM> transmits the ID number of storage circuit <NUM> to the second antenna-side transmission circuit 38b (Step S110). The second antenna-side transmission circuit 38b modulates the signal (Step S111), and then the receiving coil <NUM> transmits the modulated signal by radio waves within the range of, for example, <NUM> to <NUM> (Step S112).

As shown in <FIG>, the power-supplying coil <NUM> receives the signals (Step S113). The reception circuit 62a demodulates the signals (Step S114), then transmits them to the control circuit <NUM>. The control circuit <NUM> checks the response of the ID number of the relay device <NUM> (Step S115) and confirms that charging has been completed (Step S115). The control circuit <NUM> also allows the display unit <NUM> to display that the charging processing of the relay device <NUM> has been completed.

According to the above-described wireless detonation system <NUM>, as shown in <FIG>, the relay device <NUM> includes a receiving coil <NUM> for receiving energy for driving from the power supplying coil <NUM> of the detonator loading unit <NUM>. The relay device <NUM> also includes a storage circuit <NUM> for storing the energy for driving. Therefore, electric power can be supplied to the relay device <NUM> using the power supplying coil <NUM>, which also feeds the electric power to the detonator <NUM> (see <FIG>). It is thus possible to reduce the number of parts of the entire wireless detonation system <NUM>. Further, the electric power is stored in a storage circuit <NUM> immediately before inserting the relay device <NUM> into the insertion hole <NUM>. The storage capacity of the storage circuit <NUM> can thus be reduced to the minimum amount required for communication.

As shown in <FIG>, the detonator loading unit <NUM> wirelessly feeds electric power to the detonator <NUM> (see <FIG>) and to the relay device <NUM> while they are in the vicinity of the blasting target. The detonator loading unit <NUM> loads the electrically charged detonator <NUM> into the blast hole <NUM> (see <FIG>) of the blasting target. The detonator loading unit <NUM> loads the electrically charged relay device <NUM> into the insertion hole <NUM> (see <FIG>) of the blasting target. Therefore, a process for loading the detonators <NUM> into the blast holes <NUM> and/or a process for charging the relay device <NUM> and then loading it into the insertion hole <NUM> can be efficiently performed in the vicinity of the blasting face <NUM> in a series of flows. The power is supplied to the detonator <NUM> immediately before it is loaded into the blast hole <NUM> or to the relay device <NUM> immediately before being loaded into the insertion hole <NUM>. It is thus possible to use a capacitor having a relatively small capacity as part of the storage circuits <NUM>, <NUM>. As a result, the cost of the detonator <NUM> and the relay device <NUM> can be reduced.

As shown in <FIG>, the power supply device <NUM> is provided at the detonator loading unit <NUM>. In this case, the detonator <NUM> is delivered to the detonator loading unit <NUM> using the explosive delivery unit <NUM>. The detonator <NUM> is inserted into the cylindrical body 52a through an entrance of the cylindrical body 52a of the power supply device <NUM>. The detonator <NUM> is charged by the power supply device <NUM>. The detonator <NUM> then exits through an exit of the cylindrical body 52a by the detonator loading unit <NUM>. As a result, the detonator <NUM> moves linearly and penetrates the cylindrical body <NUM> so as to be loaded into the blast hole <NUM>.

Another embodiment of the present disclosure will be described according to <FIG>. A wireless detonation system <NUM> according to the third embodiment includes a relay device <NUM> shown in <FIG>, instead of the relay device <NUM> of the wireless detonation system <NUM> shown in <FIG>. The relay device <NUM> includes a cylindrical housing <NUM> having a front end 92a at one end and a rear end 92b at the other end. The rear end 92b is disposed at an inner end of the insertion hole <NUM>, so as to have substantially the same depth as the detonator <NUM>, when the detonator <NUM> is inserted into the blast hole <NUM>. The front end 92a is accommodated within an interior of the insertion hole <NUM> and disposed in front of the rear end 92b.

As show in <FIG>, the relay device <NUM> includes a first transmitting-receiving antenna <NUM> at the front end 92a, and includes a second transmitting-receiving antenna <NUM> at the rear end 92b. The first transmitting-receiving antenna <NUM> extends to the front side of the insertion hole <NUM> and projects beyond the entrance of the insertion hole <NUM>. The first transmitting-receiving antenna <NUM> transmits and/or receives radio waves within the frequency range of, for example, <NUM> to <NUM>. It is typically difficult for frequencies within this range to penetrate soil and bedrock. The first transmitting-receiving antenna <NUM> preferably transmits and/or receives radio waves with a frequency of <NUM> or higher, for example <NUM>. The second transmitting-receiving antenna <NUM> transmits and/or receives radio waves within a frequency range of, for example, <NUM> to <NUM>. It is typically easy for frequencies within this range to penetrate soil and bedrock. The second transmitting-receiving antenna <NUM> preferably transmits and/or receives radio waves with a frequency of, for example, <NUM>.

As shown in <FIG>, the relay device <NUM> includes a first modem <NUM> disposed at a front end 92a side and a second modem <NUM> disposed at a rear end 92b side. A relay processor <NUM> and a power source (not shown) are provided between the first modem <NUM> and the second modem <NUM>. The relay processor <NUM> processes received input signals and processes to transmit signals at a different frequency than the frequency of the received signals. The first modem <NUM> demodulates analog signals received by the first transmitting-receiving antenna <NUM> into digital signals. The first modem <NUM> modulates digital signals transmitted from the second modem <NUM> via the relay processor <NUM> into analog signals. The second modem <NUM> demodulates analog signals received by the second transmitting-receiving antenna <NUM> into digital signals. The second modem <NUM> modulates digital signals transmitted from the first modem via the relay processor <NUM> into analog signals.

According to the above-described wireless detonation system <NUM>, as shown in <FIG>, the front end 92a of the housing <NUM> is accommodated and disposed within the interior of the insertion hole <NUM>. The first transmitting-receiving antenna <NUM> extends from the front end 92a to the entrance of the insertion hole <NUM>, so as to project beyond the entrance of the insertion hole <NUM>. Therefore, it is possible to transmit and/or receive signals with the first frequency within a range of, for example, <NUM> to <NUM>, between the relay device <NUM> disposed at the rear side of the insertion hole <NUM> and the blasting operation device <NUM> outside the insertion hole <NUM>. It is typically difficult for frequencies within this range to penetrate soil and bedrock. In addition, the housing <NUM> can be made more compact with respect to the insertion hole <NUM>. This makes it easier to insert and dispose the relay device <NUM> within the insertion hole <NUM>.

Another embodiment of the present disclosure will be described according to <FIG>. The wireless detonation system <NUM> of the fourth embodiment includes the relay device <NUM> shown in <FIG>, instead of the relay device <NUM> of the wireless detonation system <NUM> shown in <FIG>. Further, the wireless detonation system <NUM> includes a second relay device <NUM>. The relay device <NUM> is configured similarly to the relay device <NUM> shown in <FIG>. The rear end 102b of the housing <NUM> of the relay device <NUM> is disposed in the inner end of the insertion hole <NUM>. The front end 102a of the housing <NUM> is accommodated within the interior of the insertion hole <NUM> and is disposed in front of the rear end 102b. A first transmitting-receiving antenna <NUM>, which is configured to transmit and receive radio waves within the frequency range of, for example, <NUM> to <NUM>, preferably <NUM> or higher, for example <NUM>, is provided at the front end 102a. A second transmitting-receiving antenna <NUM>, which is configured to transmit and receive radio waves within the frequency range of, for example, <NUM> to <NUM>, preferably, for example, <NUM>, is provided at the rear end 102b.

As shown in <FIG>, the relay device <NUM> includes a first modem <NUM> disposed at a front end 102a side, a second modem <NUM> disposed at a rear end 102b side, a relay processor <NUM> disposed therebetween, and a power source (not shown). The relay processor <NUM> processes received input signals and processes to transmit signals having a different frequency than that received. The first modem <NUM> and the second modem <NUM> demodulate analog signals received by the first transmitting-receiving antenna <NUM> and the second transmitting-receiving antenna <NUM>, respectively, into digital signals. The first modem <NUM> and the second modem <NUM> modulate digital signals transmitted from the second modem <NUM> and the first modem <NUM>, respectively, via the relay processor <NUM> into analog signals.

As shown in <FIG>, the second relay device <NUM> is disposed at the entrance of the insertion hole <NUM>. The second relay device <NUM> has a cylindrical housing <NUM>. The housing <NUM> includes a front end 109a disposed at a location projecting from the entrance of the insertion hole <NUM> and a rear end 109b disposed at the rear side of the entrance of the insertion hole <NUM>. The first transmitting-receiving antenna <NUM> is provided at the front end 109a and the second transmitting-receiving antenna <NUM> is provided at the rear end 109b. The first transmitting-receiving antenna <NUM> and the front end 109a project from the entrance of the insertion hole <NUM>. The first transmitting-receiving antenna <NUM> and the second transmitting-receiving antenna <NUM> transmit and/or receive radio waves at frequencies that do not easily penetrate soil and bedrock, of for example, frequencies within the range of <NUM> to <NUM>, preferably, <NUM> or higher, for example <NUM>.

As shown in <FIG>, the second relay device <NUM> includes a modem <NUM>, a relay processor <NUM>, and a power source (not shown). The modem <NUM> demodulates analog signals received by the first transmitting-receiving antenna <NUM> and/or the second transmitting-receiving antenna <NUM> into digital signals. The relay processor <NUM> processes the signals input by the modem <NUM> and regenerates signals at the same frequency band to be transmitted. The modem <NUM> modulates digital signals transmitted from the relay processor <NUM> into analog signals. The modulated signals are transmitted from the first transmitting-receiving antenna <NUM> and/or the second transmitting-receiving antenna <NUM>.

According to the above-described wireless detonation system <NUM>, as shown in <FIG>, the front end 102a of the housing <NUM> is accommodated and disposed within the interior of the insertion hole <NUM>. The second relay device <NUM> is disposed at the entrance of the insertion hole <NUM>. The housing <NUM> of the second relay device <NUM> has its front end 109a projecting from the entrance of the insertion hole <NUM> and its rear end 109b accommodated within the interior of the insertion hole <NUM>. Therefore, it is possible to more easily transmit and/or receive signals having the first frequency, which is a frequency that does not easily penetrate soil and bedrock, between the relay device <NUM> disposed at the rear side of the insertion hole <NUM> and the blasting operation device <NUM> positioned outside the insertion hole <NUM>. In addition, the housing <NUM> can be made compact with respect to the insertion hole <NUM>. This makes it easier to insert the relay device <NUM> into the insertion hole <NUM> so as to be positioned at a rear side thereof.

Although one embodiment has been described with reference to the above structure, it is obvious to those skilled in the art that various replacements, improvements, and/or variations can be made without departing from the object of one embodiment of the present disclosure. Therefore, one embodiment of the present disclosure may include all replacements, improvements, and variations without departing from the gist and the object of attached claims. For example, one embodiment of the present disclosure shall not limited to the specific structure, and may instead be modified, examples of which will be described below.

For example, the wireless detonation systems <NUM>, <NUM> may be used for tunnel <NUM> excavation work, as described above. Alternatively, they may be applied, for example, to demolition of structures, such as buildings, or excavation of the seabed. The detonator <NUM> according to the above-described embodiments include a receiving coil <NUM> that also serves as a transmitting-receiving antenna. Alternatively, the detonator <NUM> may include a transmitting-receiving antenna different from the receiving coil <NUM> or a receiving antenna and a transmitting antenna different from the receiving coil <NUM>. The receiving antenna and a transmitting antenna may be separated from each other. Similarly, the relay device <NUM> may include first and second receiving antennas and first and second transmitting antennas, which are separated from each other alternative to the first transmitting-receiving antenna <NUM> and the second transmitting-receiving antenna <NUM>. The blasting operation device <NUM> may include a receiving antenna and a transmitting antenna, which are separated from each other alternative to the transmitting-receiving antenna <NUM>.

The loading-unit-side communication device <NUM> according to the above-described embodiments may include a power supplying coil <NUM>, which may also serve as a transmitting-receiving antenna. Alternatively, the loading-unit-side communication device <NUM> may also include an antenna different from the power supplying coil <NUM> or a receiving antenna and a transmitting antenna different from the power supplying coil <NUM>. The receiving antenna and transmitting antenna may be separated from each other. Similarly, the relay device <NUM> may include, for example, a second transmitting-receiving antenna different from the receiving coil <NUM>, or include a second receiving antenna and a second transmitting antenna, which are separated from each other alternative to the receiving coil <NUM>.

The relay device <NUM> according to the above-described embodiments include a housing <NUM> in which the first transmitting-receiving antenna <NUM>, the second transmitting-receiving antenna <NUM>, and the control circuit <NUM> having the relay processor are integrally provided within the housing <NUM>. Alternatively, the relay device <NUM> may be configured to have, for example, three housings. Each of the first transmitting-receiving antenna <NUM>, the second transmitting-receiving antenna <NUM>, and the control circuit <NUM> may be provided to any of the three housings.

The loading-unit-side communication device <NUM> according to the above-described embodiments is attached to the detonator loading unit <NUM>. Alternatively, the loading-unit-side communication device <NUM> may be, for example, a handy-type separated from the detonator loading unit <NUM>. The detonator loading unit <NUM> may also include a plurality of loading-unit-side communication devices <NUM>. The detonator loading unit <NUM> and the explosive delivery unit <NUM> may be separate. An operator may also perform the work of charging and loading the detonator <NUM> into the blast hole nearby by operating the detonator loading unit <NUM>. Alternatively, this work may perform automatically in accordance with programs that are prepared in advance.

Claim 1:
A wireless detonation system (<NUM>), comprising:
a blasting operation device (<NUM>) disposed at a distanced from a blasting target (<NUM>), the blasting operation device being configured to wirelessly transmit a first downstream signal at a first frequency;
a detonator (<NUM>) loaded in a blast hole (<NUM>) of the blasting target, characterised in that, the detonator including an explosive-side receiving antenna (<NUM>) configured to wirelessly receive a second downstream signal at a second frequency lower than the first frequency; and
a relay device (<NUM>) including a first receiving antenna (<NUM>) configured to wirelessly receive the first downstream signal, a relay processor configured to process the wirelessly received first downstream signal and configured to process the second downstream signal to be wirelessly transmitted at the second frequency, and a second transmitting antenna (<NUM>) configured to wirelessly transmit the second downstream signal,
wherein the second transmitting antenna is positioned within an insertion hole (<NUM>) of the blasting target, the insertion hole being aligned with the blast hole (<NUM>).