JPS6356480B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of detonating a detonator using microwaves and a device used therefor.

As a detonator detonation method (blasting method), a wireless remote detonation method has been put into practical use or has been proposed in place of the generally used wired detonation method. Such wireless remote detonation methods include ultrasonic detonation method (Japanese Unexamined Patent Publication No. 48-20302), electromagnetic induction detonation method (Japanese Patent Publication No. 50-28621), and direct detonation of the detonator using microwaves. method (Japanese Patent Application Laid-Open No. 57-41600, U.S. Patent No.
2672813) is known.

Among these methods, the ultrasonic detonation method has the drawback of having an electric detonator and a power source battery for detonation in the same circuit. In other words, since this method has a built-in power supply battery, there is a possibility of unexpected explosions, and there are also problems such as large battery consumption and lack of operational stability. It could not be said that it was a safe and workable method.

In that respect, electromagnetic induction detonation methods and direct microwave detonation of detonators are improved methods.

As shown in FIG. 1, the electromagnetic induction detonation method uses a detonator comprised of a loop antenna 21 connected to an electromagnetic induction oscillator 20 and an igniter 22. The ignition device 22 consists of a ferrite bar antenna 23 and an ignition circuit 24. The ignition circuit 24 includes an ignition capacitor 25 and an electronic switch 26, and is connected to an electric detonator 27. This device has the advantage of having a charging mechanism in the ignition circuit. However, this method uses an electromagnetic induction oscillator with a low frequency (the typical oscillation frequency is around 550Hz) and high output (the maximum output is usually around 21KW). In order to radiate this electromagnetic wave and cover the blasting area, a huge loop antenna (usually 80m
x 80m) is required. Furthermore, the ignition device is equipped with a large ferrite bar antenna (usually 70 mm in diameter x 700 mm in length) to receive the electromagnetic waves.
degree) is required.

Therefore, the equipment used in this method is large in size, has a complicated structure, and is quite expensive. Furthermore, since a large-sized device is used, it is difficult to load the ignition device into each borehole during blasting work, resulting in a problem of reduced work efficiency.

Next, the method of directly detonating a detonator with microwaves will be explained with reference to the drawings.As shown in FIG.
8 and an igniter 29 are used. The ignition device 29 includes an antenna 30 and an electric detonator 3
Consists of 1. In this method, since the igniter 29 does not have a charging mechanism as in the electromagnetic detonation method described above, the received microwave power must be directly supplied to the electric detonator for detonation. Therefore, the microwave oscillation device needs to be large and have high output (for example, about 2KW), which makes the device expensive. Further, if the ignition device cannot receive sufficient microwave power, there is a problem that sufficient power cannot be supplied to the electric detonator, resulting in a misfire.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, it is an object of the present invention to provide an ignition device equipped with a charging mechanism, a compact detonation method that can reliably respond to microwaves, and a device used therefor.

The outline of the method of the present invention is as follows.

That is, the present invention receives microwaves generated at a point away from the detonation point, tunes to the microwave frequency, generates a microwave current, rectifies it, charges the ignition capacitor, and eliminates the microwave. At the same time, a starting pulse is generated to discharge the ignition capacitor, and the electric detonator is detonated by this discharge.

The device of the present invention used in this method consists of a microwave generator and a specific ignition device, and this specific ignition device includes a tuned circuit that generates a microwave current in tune with the microwave frequency, and a tuning circuit that generates a microwave current in tune with the microwave frequency. a charging circuit that rectifies and charges the ignition capacitor, a starting pulse generation circuit that generates a starting pulse for ignition when the microwave disappears, and an ignition circuit that conducts with the starting pulse and discharges the ignition capacitor. It consists of a circuit and is usually sealed in a plastic container, for example.

Hereinafter, the present invention will be explained based on the drawings.

FIG. 3 is an explanatory diagram showing an example of the method for detonating a detonator using microwaves according to the present invention.

A is a microwave generator, and B is an igniter.

The microwave generator A includes a microwave oscillator 1 that oscillates AC power at a microwave frequency and a microwave radiation antenna 2 that radiates microwaves. As the oscillator 1, for example, a magnetron is used, and as the radiation antenna 2, although its size varies depending on the microwave frequency, for example, an electromagnetic horn type antenna can be used, which is small and has an opening of about 700 mm x 700 mm.

The output of this microwave generator A is usually
The microwave power is about 1 KW, and the usable microwave frequency may be any frequency above about 1 MHz, but is preferably in the range of about 10 MHz to 10 GHz. In the case of high frequencies as described above, the radiation and reception antennas are small, and the coil and tuning capacitor in the tuning circuit described later are also small, which is preferable.

Next, the ignition device B is composed of a tuning circuit C, a charging circuit D, a starting pulse generating circuit E, and an ignition circuit F.

Of these, the tuning circuit C includes a microwave receiving antenna 3 that receives microwaves generated from the microwave generator A, a coil 4 and a tuning capacitor 5 that are tuned to the received microwave frequency. The size of the receiving antenna 3 varies depending on the frequency, but for example, in the case of a half-wavelength dipole type, a small antenna of about 6 cm can be used in the case of a frequency of 2450 MHz.

The charging circuit D includes a rectifier 6 (for example, a diode) connected to the tuning circuit C, and an ignition capacitor 7 that is charged with a positive voltage using a direct current rectified by the action of the rectifier 6.

The starting pulse generating circuit E includes a rectifier 8 (for example, a diode), a starting capacitor 9, a resistor 10, and an FET (field effect transistor) 11. The rectifier 8 has its cathode connected to one side of the tuning circuit C, and its anode connected to one terminal of the starting capacitor 9. The other terminal of the starting capacitor 9 is connected to the other side of the tuning circuit C. The starting capacitor 9 and the resistor 10 are connected in parallel.
The FET 11 has its gate connected to the anode of the rectifier 8, and its drain connected to the cathode of the rectifier 6 of the charging circuit D. In this circuit E, the microwave current is rectified by the rectifier 8 and a direct current is used to charge the starting capacitor 9 with a negative voltage. In addition, the gate of FET 11 is kept at a negative potential by this negative voltage, and when the microwave disappears, it is discharged by the resistor 10 connected in parallel to the starting capacitor 9, lowering the negative voltage at the gate of FET 11. Thyristor 1 connected to ignition capacitor 7
2 to cause conduction and generate a starting pulse.

The ignition circuit F includes a thyristor 1 having a gate connected to the source of the FET 11 of the starting pulse generating circuit E, an anode connected to the cathode of the rectifier 6 of the charging circuit D, and a cathode connected to the electric detonator 13.
2, an ignition capacitor 7 of the charging circuit D, and an electric detonator 13. In this circuit F, a starting pulse is applied to the gate of the thyristor 12 to make the thyristor 12 conductive, thereby discharging the charge and detonating the electric detonator 13.

To detonate a detonator using the above device, oscillate microwave power at a frequency of several GHz, for example, from the microwave oscillator 1 of the microwave generator A.
This is done by emitting microwaves from the microwave radiation antenna 2 toward the ignition device B, and stopping the microwave radiation when the ignition capacitor 7 of the charging circuit D is charged. That is, microwaves radiated from the microwave radiation antenna 2 are received by the microwave receiving antenna 3 of the tuning circuit C, and tuned by the coil 4 and the tuning capacitor 5 to generate microwave current. This current is rectified into a direct current by the rectifier 6 of the charging circuit D, and the large capacity ignition capacitor 7 is charged.
At the same time, the rectifier 8 of the starting pulse generation circuit E rapidly charges the starting capacitor 9 negatively, and FET1
Since the gate of thyristor 1 of ignition circuit F is kept at a negative potential, no current flows through FET 11, and therefore, thyristor 1 of ignition circuit F
No current flows through 2.

When the microwave oscillator 1 is stopped when the ignition capacitor 7 is sufficiently charged, the ignition capacitor 9 is rapidly discharged by the resistor 10, and the negative potential of the gate of the FET 11 decreases, causing the FET
Since FET 11 is conductive and the drain of FET 11 is connected to the positive plate of ignition capacitor 7, a starting voltage is applied to the gate of thyristor 12, and the charge in ignition capacitor 7 is discharged to electric detonator 13 through thyristor 12. , the electric detonator 13 detonates.

The present invention having the configuration as described above,
It has the following features.

That is, compared to the conventional method of directly detonating the detonator using microwaves, the present invention uses a specific ignition device that includes a charging circuit, etc., so the detonator is reliably detonated, and there is no risk of misexplosion. The operation is stable and safe.

Furthermore, compared to conventional electromagnetic induction detonation methods, the present invention uses microwaves, so the transmitting and receiving antennas are smaller, and the ignition device is also smaller, making it easier to load the ignition device into the borehole. The work efficiency is greatly improved. If a frequency on the high frequency side is used even in the microwave band, this effect becomes even greater.

Furthermore, compared to conventional ultrasonic detonation methods, the present invention does not use a power source battery, so there is no unexpected explosion, and multiple loading operations can be carried out safely, even after being left unused for a long time. Since there are no problems such as battery deterioration, it can be started immediately.

Furthermore, the present invention can be detonated at exactly the same time by installing a large number of ignition devices according to the present invention inside the directivity of a microwave radiation antenna, which is extremely useful from the viewpoint of blasting technology. It is something.

Next, the present invention will be specifically explained using examples.

Example 1 Using a circuit device as shown in FIG. 3, specifically, as a microwave generator A, a frequency
We used a microwave oscillator with a 2450MHz, output of 200W, and an electromagnetic horn-type microwave radiation antenna with an opening of 700mm x 700mm.

In the ignition device B, a half-wavelength dipole antenna with an antenna length of 6 cm was used as the microwave receiving antenna 3, and a capacitor with a capacity of 1000 μF was used as the ignition capacitor 7. The dimensions of this igniter are 30mm in diameter
×Length 100mm (excluding antenna and detonator)
It is.

Using this device, an ignition device detonation experiment was conducted. That is, one of the igniters was placed at a distance of 1 m from the axis of the electromagnetic horn in a place without obstacles, and when the microwave was oscillated for 5 seconds and then stopped, it detonated within 1 millisecond.

Example 2 The number of ignition devices is 10, and the distance from the electromagnetic horn is
A detonation test of the detonator was carried out in accordance with Example 1, except that only the receiving antenna section was placed in a borehole drilled in the rock in a plain excavated tunnel with a length of 10 m. However, the microwave oscillation time was 50 seconds. All detonated within 1 millisecond after oscillation stopped.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the device used in the conventional electromagnetic induction detonation method, Fig. 2 is a schematic diagram of the device used in the conventional microwave direct detonation method, and Fig. 3 is the microwave detonation method of the present invention. FIG. 2 is a circuit diagram showing an example of a method and device for detonating a detonator. A...Microwave generator, B...Ignition device,
C...Tuning circuit, D...Charging circuit, E...Starting pulse generation circuit, F...Ignition circuit, 1...Microwave oscillator, 2...Microwave radiation antenna,
3... Microwave receiving antenna, 4... Coil, 5... Tuning capacitor, 6... Rectifier, 7
... Capacitor for ignition, 8 ... Rectifier, 9 ... Capacitor for starting, 10 ... Resistor, 11 ... FET,
12...Thyristor, 13...Electric detonator, 20...
...Electromagnetic induction oscillator, 21...Loop antenna, 2
2... Ignition device, 23... Antenna, 24... Ignition circuit, 25... Ignition capacitor, 26... Electronic switch, 27... Electric detonator, 28... Microwave oscillator, 29... Ignition device, 30...Antenna, 31...Electric detonator.

Claims (1)

[Claims] 1. Receive a microwave, tune to the microwave frequency, generate a microwave current, rectify it, charge an ignition capacitor, and generate a starting pulse when the microwave disappears. A method of detonating a detonator using microwaves, in which the electric detonator is detonated by discharging from the ignition capacitor. 2. A microwave detonator detonator comprising a microwave generator that generates microwaves and an igniter that receives the microwaves and detonates the electric detonator, wherein the igniter includes a microwave that receives the microwaves. A tuning circuit consisting of a wave receiving antenna, a coil and a tuning capacitor that tune to the received microwave and generate a microwave current, a rectifier connected to the tuning circuit to rectify the current, and a rectifier connected to the tuning circuit to rectify the current; Therefore, a charging circuit consisting of an ignition capacitor for charging a positive voltage, another rectifier whose cathode is connected to one of the tuned circuits, one terminal of which is an anode of the other rectifier, and the other terminal of which is connected to one of the tuned circuits. It consists of a starting capacitor connected to each other, a resistor connected in parallel to the starting capacitor, and an FET whose gate is connected to the anode of the other rectifier and the drain is connected to the cathode of the rectifier of the charging circuit, respectively,
a starting pulse generating circuit that generates a starting pulse when the microwave disappears, and a gate connected to the source of the FET of the starting pulse generating circuit, an anode connected to the cathode of the rectifier of the charging circuit, and a cathode connected to the electric detonator, respectively. A detonator comprising a connected thyristor and an ignition capacitor of the charging circuit, and an ignition circuit that detonates the electric detonator by discharging from the ignition capacitor.