JPS6157558B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a detonator detonated by microwaves.

Conventional technology The commonly used blasting method is wired electric blasting, in which an electric blaster and an electric detonator are connected by a blasting bus, and the electric energy of the blaster is supplied to the electric detonator through the blasting bus, causing ignition and explosion. It was a method.

However, in the case of tunnel blasting, etc., which requires detonating a large number of electric detonators at the same time, for example, in the case of a railway single-track tunnel (approximately 30 m ² ), the number of electric detonators required is about 100 to 150. It is extremely time-consuming to electrically connect such a large number of detonators one by one in series or parallel on a site with poor footing, and furthermore, the ignition current generated by grounding the connection part (bare wire part) is extremely troublesome. In order to prevent leakage and failure of the electric detonator to explode, it was necessary to suspend the wire connections in the air or seal them with insulating tape, which reduced work efficiency.

Furthermore, because the terminals of the leg wires of conventional electric detonators are exposed, there is a risk of explosions due to leakage current or inflow of static electricity, and great care must be taken in handling them for safety.

In addition, ultrasonic detonation and electromagnetic induction detonation have been proposed as wireless remote detonation methods, but the electric detonator used in ultrasonic detonation is closed by a battery and an ultrasonic signal. It consists of a switch, a capacitor that is charged from the battery when this switch is opened, and another switch that is closed by another ultrasonic signal and leads the charge in this capacitor to an electric detonator to detonate it. The electric detonator, which is equipped with a detonator and is used in the electromagnetic induction detonation method, is a tuned circuit that generates an alternating current voltage in tune with a control electromagnetic field, that is, a tuned circuit consisting of an antenna coil and a capacitor for the tuned circuit, and a detonator. The frequency on the oscillator side is high frequency, that is, 3 to 30MHz.
In addition to the above-mentioned tuning circuit, there is also an ignition capacitor for storing the electromotive force induced in the antenna coil after rectifying it into direct current, and a detonator to store the charged charge of this capacitor. The oscillator is equipped with a detonating element consisting of a switch and the like for guiding the oscillator to the oscillator and detonating it, and the frequency of the oscillator side is several kilohertz (Japanese Patent Publication No. 28621/1983).

Problems to be Solved by the Invention The electric detonator used in the ultrasonic detonation method has a built-in power battery, so there is a possibility of an unexpected explosion, and it is not inherently safe. In addition, even though it is a consumable item for each explosion,
It had the disadvantage of being structurally complex and large.

On the other hand, the electric detonator used in electromagnetic induction detonation is safe because it does not contain a built-in power supply battery, but the tuned circuit connected to the detonator is far away from the control electromagnetic field generator, especially the loop coil. In this case, an ignition capacitor charging circuit and a switch circuit are required, resulting in a complicated structure and large size. In addition, when it is necessary to install a tuning circuit near the loop coil, especially when the detonator is used for tunnel blasting as shown in Figure 5, the conductor from the high-frequency oscillator to the loop coil becomes long, making it difficult to use the conventional blasting bus line. The problem was that the loop coils had to be placed near each detonator in a narrow space with poor footing, making the work extremely difficult. .

When electric detonators became larger, there was also the problem that work efficiency decreased because it was difficult to load the detonators into each borehole during blasting work.

The object of the present invention is to provide a wireless electric detonator, which
Another object of the present invention is to provide a safe and compact detonator that does not use a loop coil, that is, detonates using a completely new method other than the conventional electromagnetic induction method.

Means for Solving the Problems The detonator that is detonated by microwaves of the present invention includes both the additive and the detonator loaded in the tube, or the detonator, the igniter disposed near the detonator, and the detonator. In an electric detonator consisting of a heating element disposed in contact with the igniter and a leg wire connected to the heating element at one end and led out of the tube, the heating element is a group consisting of a conductor, a semiconductor, and a dielectric. It is characterized in that the leg wire is a coaxial cable, and the other end of the coaxial cable is connected to one type selected from the group consisting of a hoarded antenna, a loop antenna, and a whip antenna.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

1 to 3 are schematic diagrams, partially in cross section, showing examples of detonators that are detonated by microwaves according to the present invention.

FIG. 1 shows an example of an instantaneous detonator, and the detonator 1 of the present invention, which is detonated by microwaves, has a tube body 2 with
An additive charge 3 and a detonator 4 are sequentially loaded from the bottom side, and then a powdered ignition charge 6 is loaded separated by an inner tube 5, and a heating element 7 is placed inside the ignition charge 6.
is arranged so as to be in contact with the ignition powder 6. This heating element 7 is connected to one end of a coaxial cable 13 that is fixed by an embolus 9 and led out of the tube body 2 . Here, coupling means electrical coupling (the same applies hereinafter).

The other end of the coaxial cable 13 is coupled to the antenna 12. The antenna 12 in this case is a hoarded antenna.

FIG. 2 shows an example of a delayed-fire detonator, in which the detonator 1' which is detonated by microwaves according to the present invention is placed in a tube body 2 in which the additive 3 is sequentially placed from the bottom side as in FIG.
and a detonator 4 is loaded. A time delay medicine 8 is then loaded, in this case separated by the inner tube 5;
In a space 10 between the time-prolonging medicine 8 and the embolus 9 at the tip of the tube body 2, an ignition ball 11 in which the ignition powder 6 is hardened is arranged around the heating element 7. This heating element 7
As in FIG. 1, is coupled to one end of the coaxial cable 13 led out of the tubular body 2, and the other end of the coaxial cable is coupled to the antenna 12, in this case a loop antenna.

Fig. 3 shows an example of an instantaneous detonator, but the difference from the detonator shown in Fig. 1 is that no additive is provided and a whip antenna is used as the antenna 12. . The other parts are the same as those shown in FIG.

Note that the component parts 2 to 7 or 2 to 11 of the detonator shown in FIGS. 1 to 3 constitute the so-called detonator body, and the arrangement of these components and other configurations that should function as the detonator are Since the conditions and the like are known, detailed explanation thereof will be omitted, and the present invention is not limited to the illustrated configuration example.

The antenna used in the detonator of the present invention is
This is an antenna of a form that effectively receives microwaves, as shown in FIGS. 1 to 3.

In addition, this antenna and heating element are tuned circuits,
For example, the antenna coil and the antenna are directly coupled by a coaxial cable without going through a capacitor.

The reason for using a coaxial cable is that when using the detonator of the present invention for tunnel blasting as shown in Figure 5, even if there is a conductor such as water in the hole, the microwave current induced in the antenna can be effectively absorbed. This is so that the detonator can be guided to the heating element, and to prevent rocks etc. scattered by the blasting of the former stage from cutting off the antenna of the rear stage detonator and the heating element. This is because if the detonator in the latter stage were to be cut off, it would result in unexploded residual charges, posing a major safety problem.

The heating element used in the detonator of the present invention is a material that generates heat by microwave current, such as platinum wire, platinum and iridium, or other conductive material used in conventional igniters, or a material that generates heat at low frequencies. It is a conductor that generates heat at frequencies in the microwave region, or a dielectric that generates heat due to its dielectric loss.

Figures 4A to 4C show the coaxial cable 13 and the heating element 7.
Examples of electrical connection methods are shown below.
For example, in the case of a heating element 7 made by mixing and solidifying a semiconductive chemical substance, such as carbon, with ignition powder, the end of the coaxial cable 13 is connected to the heating element 7, as shown in FIG. 4A. If the electrical contact is made, it is sufficient to achieve the purpose, and if a heating element 7 such as platinum wire is used, as shown in Figure 4B, a coaxial cable can be electrically connected to both ends of the heating element 7, as shown in Figure 4B. Furthermore, if a dielectric material such as phenolic resin is used as the heating element 7, it is sufficient to connect it as shown in Fig. 4C.
The heating element 7 may be electrically connected to the end of the coaxial cable 13 as shown in FIG.

The detonator of the present invention can be assembled as follows.

That is, although the detonator shown in FIGS. 1 to 3 shows the antenna 2, coaxial cable 13, and detonator part as an integrated structure, the antenna 12 and , coaxial cable 13
It is also possible to configure the heating element 7 and the heating element 7 as separate parts and assemble them into the detonator part at the work site, or alternatively, the combination of the antenna 12 and the coaxial cable 13 can be assembled into the heating element 7 of the detonator part. Alternatively, only the antenna 12 may be connected to the coaxial cable 13.
It may be configured to be detachable so that it can be connected to.

Effect Next, the operation of the detonator of the present invention will be explained.

FIG. 5 is a schematic diagram showing the situation when tunnel blasting is performed using the detonator of the present invention.

First, a predetermined amount of explosives 17 are loaded into a plurality of blast holes 16 drilled in the face 15 of the tunnel 14, and then a detonator cartridge 25 equipped with a detonator 1 that is detonated by microwaves according to the present invention is loaded. Blasting hole 16
The antenna 12 is installed so as to protrude from the hole. 26 is a filler such as sand or clay.

On the other hand, an arbitrary suitable microwave emitting device 20 is installed opposite to the face 15 at a distance that does not cause damage due to blasting. This microwave emitting device 20 includes a microwave oscillator 21 such as a magnetron, an electromagnetic horn 22 for emitting microwaves with directivity, and a power source 2.
3, and the microwave emitting device 20 from this power source 23
The switch 24 may be configured to control the power transmission to the switch 24.

First, it is confirmed that the detonator is inserted and installed in each blast hole as specified and that the surrounding area is safe, and then the electric field generated by the microwave from the electromagnetic horn 22 is adjusted so that it is concentrated on the face 15. Next, when the switch 24 is closed by remote control at the site or at a point further away, microwaves are emitted from the microwave emitting device 20 and the electric field is transmitted to the antenna 1.
Each of these antennas 12 receives the microwaves, which induces a microwave current that flows through the heating element through the coaxial cable, causing the heating element to generate heat and ignite the ignition powder or igniter. The explosive charge can be detonated by causing the explosive charge 17 to explode.

The reason why the detonator of the present invention is detonated only by microwaves is because the wavelength of conventional high frequencies or frequencies of several KHz is longer than that of microwaves, which requires a significantly longer antenna. This is because loading work becomes difficult. Moreover, when used for tunnel blasting, the micro is excellent in its ability to go straight even in a narrow space.

Further, the frequency of the microwave emitted to the detonator of the present invention is 1000 MHz or more, but the frequency normally used is about 2500 MHz due to the Radio Law and the like.

In addition, for safety reasons, unused detonators may be stored in a handling or processing area away from the blasting site, covered with wire mesh, etc., or stored in a metal box to further increase safety. Therefore, a wire mesh or other means for absorbing microwaves may be provided between the microwave emitting device and the handling or processing facility. Still another method is to cover the antenna of the unused detonator with a metallic (for example, tin foil) cap that is not tuned to microwaves. Further, in the case where the detonator and the antenna described above are formed separately, the antenna and the like may not be attached to the detonator.

Example The face of the tunnel has a small cross-sectional area of 1.5 m x 2.0 m, and the microwave-detonated detonator of the present invention is installed in 5
A microwave oscillator with an output of 2 kW and a frequency of 2500 MHz was installed at a distance of 10 m from the face. When the electromagnetic horn was pointed at the antenna and microwaves were emitted for 2/1000 seconds, all five detonators were completely detonated.

Effects of the Invention The microwave-detonated detonator of the present invention does not require a loop coil to be placed near the detonator, unlike electric detonators used in conventional electromagnetic induction detonation methods, so It is extremely easy to load the detonator into the blast hole even in a confined space with poor footing, and the detonator that is detonated by microwaves of the present invention can be used in place of the electric detonator used in the conventional electromagnetic induction detonation method. As it does not require a special tuning circuit, nor does it require any detonating elements such as ignition capacitors or switches, it can be made very compact, making it extremely easy to load the detonator into the blast hole. It is.

Furthermore, the microwave-initiated detonator of the present invention operates only by microwaves and does not need to be connected to a blasting bus bar, etc., so there is no risk of explosion accidents due to leakage current or inflow of static electricity. It is also very safe as it does not have a built-in power supply battery.

[Brief explanation of the drawing]

Figures 1 to 3 are schematic diagrams, partially in cross section, showing examples of detonators that are detonated by microwaves according to the present invention. FIG. 5 is a schematic diagram showing a situation when tunnel blasting is performed using the detonator of the present invention. 1, 1', 1''... detonator, 2... tube body, 3... additive, 4... explosive, 5... inner tube, 6... igniter, 7... heating element, 8... ...Deferred medicine, 9...Embolism,
10...Space, 11...Ignition ball, 12...Antenna, 13...Coaxial cable.

Claims (1)

[Scope of Claims] 1. Both the additive and the priming agent loaded in the tube, or the priming agent, the igniter placed in the vicinity of the igniter, and the heating element placed in contact with the igniter. and an electric detonator consisting of a leg wire connected to the heating element at one end and led out of the tube body, wherein the heating element is one type selected from the group consisting of an electric conductor, a semiconductor, and a dielectric material, and the leg wire is 1. A detonator detonated by microwaves, which is a coaxial cable, and the other end of the coaxial cable is coupled to one type selected from the group consisting of a hoarded antenna, a loop antenna, and a whip antenna.