JP2525765B2 - Electric blasting device - Google Patents

Description

The present invention relates to an electric blasting device.

[Prior Art] Conventionally, as a blasting system utilizing electromagnetic induction of a magnetic material, for example, Japanese Patent Publication No. Sho 49-22608 as shown in FIG. 5 or a resonance method for improving energy transmission efficiency is used. JP-A-60-86400 (see FIG. 6) and JP-A-57-142499 (details of which will be described later) to be used are known.

In the electric blast device shown in FIG. 5, 1 is a power supply, 2 is a charge / discharge capacitor, 3 is a trigger circuit, 4 is a thyristor,
5 is an oscillating device consisting of these parts 1 to 5, 6 is a loop-shaped bus bar, 7 is a transformer part, 8 is a secondary winding wound around its core 10, and 9 is an electric detonator connected to the secondary winding 8. is there.

Here, a large pulsed current obtained by taking out the electric charge charged in the capacitor 2 by the power source 1 from the thyristor 4 conducted by the trigger circuit 3 is passed through the loop-shaped bus bar 6, and the bus bar 6 serves as a primary circuit. The secondary current is taken out from the transformer section 7 of each of the secondary windings 8 and the pulse current is sent to the electric detonator 9 connected to each of the windings 8.
Thus, the electric detonator 9 is ignited.

Further, in FIG. 6, 11 is a power pulse generator, and 12 is a power pulse generator.
Is a high frequency converter, 13 is a bus configured to have a constant impedance, 14 is a transformer, and 15 is an electric detonator. The power pulse generator 11 includes a DC / DC converter 16 and a charging / discharging capacitor 1
7 and a charge / discharge changeover switch 18. The discharge output pulse is taken out from the terminal 19 and supplied to the high frequency converter 12 via the input terminal 20. Here, the high frequency converter 12 includes tuning coils 21 and 22, a tuning capacitor 23, a high frequency oscillation transistor 24, bias resistors 25 and 26,
A bias capacitor 27 is provided, and a high frequency oscillation output is taken out from its output terminal 28 and supplied to the bus bar 13. The transformer section 14 has a transformer core 29 that is electromagnetically coupled through the bus bar 13 and a loop 30 that is passed through the core 29.
Here, the core 29 is provided with a cut portion for passing the busbar 13 and the loop 30. The electric detonator unit 15 has a detonator 31 connected to the loop 30.

Thus, from the blaster having the power pulse generator 11 and the high frequency converter 12, a high frequency current having a frequency of 100 kHz to 1 MHz is applied to the bus 13 configured to have a constant impedance and electromagnetically coupled to the bus 13. A secondary current is passed through a transformer core 29 having a cut portion to detonate an electric detonator 31.

[Problems to be Solved by the Invention] In the case of electromagnetic induction blasting as shown in FIG. 5, since one pulsed current is passed through the bus bar 6, power is required to detonate the secondary side detonator 9. It is necessary to prepare a loss and to pass a pulsed electric current of a large electric current which cannot be considered in common sense through the bus bar 6. Moreover, since the frequency of the vibration waveform of the pulsed current is several hundreds Hz, the size of the transformer core 10 becomes large, and it becomes difficult to carry it during transportation or handling. Furthermore,
When a large number of electric detonators 9 are required to perform the work of passing the busbar 6 through the transformer core 10, a large number of transformer cores 10 are also required. Therefore, the portion of the transformer core 10 may be entangled with the busbar during the wiring work. Also increases. In order to prevent this, when the busbar 6 is pulled and passed through a large number of transformer cores 10 in sequence, even the leg of the electric detonator 9 may be pulled, which may give a shock to the electric detonator 9, and for safety reasons. It was not practical even when viewed, and it was not preferable.

In the case of FIG. 6, the above-mentioned drawbacks are remedied to some extent, but the problem is that a constant impedance line must be used as the bus bar 13 because the blaster is a self-excited oscillation system with a tuning coil and a tuning capacitor. There is. More specifically, the oscillating frequency of the blaster is determined by the inductance of the tuning coil 21 and the bus 13 and the capacitance of the tuning capacitor 23, so if the inductance of the blasting circuit of the bus 13 changes, the oscillating state also changes, and no firing occurs. Could occur. Therefore, there is no choice but to use a bus with constant impedance.

However, when considering a real blast circuit, it is very difficult to keep the bus bar 13 at a constant impedance. That is, the bus
The impedance on the primary side changes depending on the number of transformer cores 29 and the number of detonators 31 loaded on 13. Even considering only the impedance of the bus bar 13, it changes greatly depending on the distance to the ground, and the oscillation state changes each time,
It may not be possible to perform stable blasting. Therefore, in order to maintain a constant impedance even at least at the busbar 13, it is necessary to use a coaxial cable as the busbar 13,
There was a problem in terms of cost.

Furthermore, in addition, in this case, the frequency is 100kHz ~ 1M
Since it is as high as Hz, there is also a problem that the circuit impedance becomes high and the blasting performance greatly depends on the length of the bus bar 13. If the bus bar length becomes long, it is necessary to use a wire having a large diameter, which causes a problem in workability.

On the other hand, when a single-line auxiliary bus is used, it is easy to install the coupler, but since a high-frequency current is passed through the bus circuit,
Since the impedance changes greatly depending on the wiring conditions,
The blaster output voltage must be high in order to pass a large current on the bus side. In that case, a large radio interference occurs due to the leakage of the electromagnetic waves generated on the bus bar.

Therefore, it is better to use parallel lines to reduce the impedance of the busbars, but when using parallel busbars,
Since the adhesion between the two wires is strong, it is difficult to pull them apart by hand, and the workability is extremely poor.

Alternatively, in order to make it easier to insert the coupler, when the busbar is twisted, it is necessary to twist the parallel single wires, but since such busbar is a consumable item, such twisting is costly. Had a problem.

Further, as a technique for solving the problems in the conventional blasting system as described above, for example, JP-A-57-142499.
There is proposed a blasting system to which a so-called series resonance method is applied, as described in Japanese Patent Publication No. This is a method for efficiently transmitting energy from the blaster to the blast bus, and a plurality of blast field joules (detonators) are provided in the loop-shaped blast bus by electromagnetic induction from the blast bus. Connected via a ferrite ring (core) for giving the blast module, causing series resonance in the series circuit formed by the inductance of the blast bus including the ferrite ring and the capacitance of the capacitor connected in series to the blast bus. , This resonance frequency signal is fed back to the blaster to continue oscillation, and the phenomenon in which the maximum energy flows in the series circuit due to the series resonance is used to transfer the necessary energy from the blaster to the blast bus. It is a thing.

However, the blasting system to which the series resonance method is applied has the following problems. That is, one of the factors that determines the resonance frequency is the inductance of the blast bus. Therefore, as the number of blast modules (detonators) connected to the blast bus via the ferrite ring increases, the inductance of the blast bus (impedance) increases. ) Becomes larger (higher) and the series resonance frequency becomes lower. On the other hand, the hysteresis loss of the ferrite ring that is interposed when connecting the blast module to the blast bus depends on the frequency, and goes out of a predetermined frequency (range) (for example, when the number of the blast modules increases as described above, The energy transfer efficiency falls sharply, and sufficient energy for detonation cannot be transferred to the blast module (detonator).

Therefore, in the blasting system to which the series resonance method is applied, there is a problem that the number of blasting modules that can be connected to the blasting bus is limited.

[Means for Solving the Problems] The inventors of the present invention have made various studies on the conventional electric blasting device having such problems, and as a result, have independent forms independent of the blasting bus (inductance thereof). Of the fixed frequency (within the range of less hysteresis loss of the ferrite ring), the oscillation frequency is 20kHz to 50k.
The present invention has been completed by finding that by setting the frequency to Hz, it is possible to blast sufficiently with a normal blast bus.

Therefore, an object of the present invention is to solve such a problem and to provide an electric blasting device capable of stably performing electromagnetic induction blasting even when a normal blasting bus is used.

Another object of the present invention is to use an auxiliary busbar having a low impedance and to solve the above-mentioned problems to make the work of routing the blasting busbar and mounting the connector quick and easy, and at the same time, electromagnetic induction blasting. It is to provide an electric blasting device capable of efficiently performing a wide range.

In order to achieve such an object, the present invention is a capacitor charging unit, a high-frequency conversion unit that is driven by a discharge current from the charging unit, and outputs a high-frequency current having a fixed frequency within a range of 20 kHz to 50 kHz, A blasting busbar consisting of a twin core busbar and an auxiliary busbar connected to the output of the high-frequency converter, and a loop forming a part of a leg wire connected to the auxiliary busbar and the electric detonator are both inserted into the inside thereof by electromagnetic induction. An electric blast device having a ferrite core for coupling, wherein the high-frequency conversion unit uses a constant voltage generation circuit that obtains a predetermined constant voltage output by using the capacitor charging unit as a power supply, and a constant voltage generation circuit from the constant voltage generation circuit. 20kHz ~ 5 driven by voltage
An oscillator that oscillates a fixed frequency signal within the range of 0 kHz,
It is characterized by comprising a switching unit for extracting a high frequency output by switching based on an oscillation output from the oscillator, and an output unit for deriving the high frequency output from the switching unit to the twin core bus.

Further, the present invention is characterized in that a buffer circuit is provided between the oscillator and the switching unit.

[Operation] In the present invention, in electromagnetically coupling the auxiliary bus bar and the leg wire,
Both are inserted through the ferrite core, and the frequency of the high-frequency current flowing through the auxiliary bus is determined within the range of 20 kHz to 50 kHz.
The circuit impedance of the bus bar can be made as low as possible while maintaining the characteristics of the ferrite core, and as a result, it is possible to blast at a low output voltage without using the normal bus bar or maintaining the bus bar at a constant impedance. It can be performed.

Furthermore, since the high-frequency converter is configured to have an independent fixed-frequency oscillator that does not depend on the blasting bus, even if the blasting bus has a large (high) inductance, there is a direct effect on the oscillation frequency of the oscillator. Do not give.
That is, the fluctuation of the frequency can be suppressed. As a result, even if the number of electric detonators coupled by electromagnetic induction to the blast bus through the ferrite core is larger than that in the blast system that uses the conventional series resonance method, the blast bus does not exceed the range of 20 kHz to 50 kHz. Since a high-frequency current can be stably supplied, there is no sharp drop in energy transfer efficiency due to the hysteresis loss of the ferrite core, and sufficient energy for detonating an all-electric detonator coupled to the blast bus through the ferrite core. Can be blasted to ensure reliable blasting. Furthermore, since the high frequency converter is configured to buffer the oscillator output with a buffer and then supply it to the blast bus,
It is less susceptible to load fluctuations after the blast bus, and as a result, the oscillation state is more stable and blasting can be performed reliably.

Furthermore, since a conductor wire having a mutually related positional relationship is used as the auxiliary bus bar, the circuit impedance of the bus bar is substantially lowered, and even if a large current is passed through this auxiliary bus bar, the electromagnetic wave generated from the auxiliary bus bar is reduced. Do not cancel each other out so that electromagnetic wave leakage does not occur, and therefore radio wave interference does not occur. In addition, since a small ferrite core can sufficiently perform electromagnetic coupling, the core can be easily transported and the workability of routing the auxiliary busbar is excellent.

Moreover, in this case, there is no problem even if the blaster output voltage is increased, but in particular, as described above, it is possible to increase the output voltage in combination with setting the frequency of the high frequency current to 20 kHz to 50 kHz. Electromagnetic induction blasting can be performed stably.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of an electric blasting system for carrying out the present invention. Reference numeral 40 denotes a separately excited oscillation type blaster having a capacitor charging section 41 and a high frequency converting section 42 for exchanging a discharge current from the charging section 41 into a high frequency current, for example, Japanese Patent Application No. 60-124180. Can be the circuit disclosed in. An example of such a circuit is shown in FIG. 2 and will be described later in detail.

In FIG. 2, the charging unit 41 is charged by the DC / DC converter 102 for exchanging the voltage of the battery 101 to a predetermined DC voltage, the charge / discharge switching switch 103, and the DC / DC converter 102 via the switch 103. It is composed of a blasting capacitor 104. The high frequency conversion unit 42 is a constant voltage generation circuit 105 that obtains a predetermined constant voltage output using the capacitor 104 connected via the switch 103 as a power source, and a stable 20 kHz to 50 kHz driven by the constant voltage from the circuit 105. An oscillator 106 such as a CR oscillator that oscillates a fixed frequency signal within the range, a buffer 107 that uses the capacitor 104 as a power supply and buffers the oscillation output of the oscillator 106 with respect to subsequent circuits, and a capacitor 1
With 04 as a power source, a high frequency output is taken out by switching based on the oscillation output from the buffer 107, for example, a switching unit 108 composed of a power MOSFET,
The capacitor 104 serves as a power source, and an output unit 109 for deriving a high frequency output from the switching unit 108 to the bus bar 47. The buffer 107 prevents the influence of the load from the bus circuit from entering the oscillator 106, so that the oscillator 106 can always perform stable oscillation without being affected by the load of the bus circuit, that is, the wiring condition. You can Output unit 109
Can be composed of, for example, a bush-pull output transformer that receives the bush-pull output from the switching unit 108 and a circuit protection discharge resistor that is arranged on the secondary side of the transformer. By using a ferrite core as the core of this transformer, a stable discharge characteristic is exhibited even at a frequency of 20 kHz to 50 kHz, and the output unit 109 can be configured in a smaller size than an air core coil.

With such a circuit arrangement, the oscillation state does not change due to changes in the inductance and impedance of the circuit after the blast bus 47. In other words, the blasting bus 47
Since the oscillation frequency does not change depending on the wiring state of, the high frequency current having the set frequency corresponding to the applied frequency of the ferrite core can be stably supplied to the bus circuit.

Blasting busbars with twin cores at output terminals 43 and 44 of blasting device 40
Connect 47. On the other side of the blast bus 47, two auxiliary buss 48 are connected in a loop. Ie these auxiliary buses
The other side of 48 is connected to each other to form a loop-shaped auxiliary busbar.

Reference numeral 49 denotes a coupler, which is composed of a lower half 50 and an upper half 51 slidable on the half 50, for example, as shown in FIG. , U-shaped groove-shaped and flat-shaped ferrite cores 52 and 53 are embedded. Reference numeral 54 is a cover that protects the exposed portion of the ferrite core 52. It is assumed that the ferrite cores 52 and 53 form a closed magnetic circuit when the upper half portion 51 slides as shown in FIG. 3 (B). When sliding in this way, the cover
54 is connected to the lower half 50 so that it can be pushed by the upper half 51 and bent as shown in FIG.

The leg wire 62 and the auxiliary bus bar 48 connected to the electric detonator 61 are put into the U-shaped groove-shaped core 52 as shown in FIG. 3 (A), and then the upper half as shown in FIG. 3 (B). The part 51 is slid to close the magnetic path between the cores 52 and 53, and the auxiliary bus bar 48 and the leg wire 62 are sandwiched between the cores 52 and 53. Electromagnetically coupled between and. FIG. 1 shows a large number of leg wires 62 connected to the auxiliary bus bar 48 in this way.

FIG. 4 shows another example of an electric blasting system for carrying out the invention, in which instead of using the loop-shaped auxiliary bus 48 shown in FIG. 1 as auxiliary bus, auxiliary buses 71 and 72 are mutually connected. The impedance of the bus bar is reduced as an associated reciprocating conductor, and the conductors 71 and 72 are separated from each other at a place where the coupler 49 is desired to be mounted, so that the coupler 49 can be mounted.

For example, a suitable position between the couplers 49, that is, the couplers.
In the position where it is desired to sandwich 49, the coating of the parallel two wires 71 and 72 to which the coatings are attached to each other is partially separated, and a loop which remains connected at the position 73 is formed, and a coupler is connected to the loop. It may be sandwiched between. The degree of adhesion in this case is preferably weak enough to easily separate the two lines.

Alternatively, the loop can be partially formed by using a reciprocating single wire that is partially fused or adhered, instead of the parallel two-wire auxiliary wire as described above. In this case, it is convenient because it is not necessary to split the parallel lines and separate the two lines when the auxiliary bus bar is rotated.

In the present invention, since the two conductors are arranged in association with each other as described above, low impedance can be realized. However, in order to form such an auxiliary bus, for example, the parallel two auxiliary wires are coated with resin. When heat-sealing with two heat rollers, widen the space between the heat rollers to weaken the degree of heat-sealing of the coating at the place where the above-mentioned loop is to be formed, or do not press the heat roller at all. By 2
Make it easy to form loops between the lines.

The above-mentioned auxiliary busbar has the oscillator 10 even if the inductance changes slightly due to the shape changes of the loops formed in various places.
Since 6 is an independent form fixed-frequency oscillator that does not depend on the blasting bus, it does not hinder the blasting work due to changes in the oscillation state. Furthermore, such an auxiliary bus bar can be easily manufactured, as described above, for example, by weakening the adhesion between the wires during the manufacture of a normal parallel auxiliary wire, so that it is inexpensive. Is.

Next, as the ferrite core used for the coupler,
Usually, a material with high magnetic permeability is used to make it compact and easy to use for improving workability. As the frequency becomes higher, the circuit impedance due to the bus will become higher,
In order to send a large high frequency current to the bus bar on the primary side of the core,
The blaster output voltage must be increased, in which case the above-mentioned radio interference also becomes large.

Therefore, practically, consider the balance between the performance of the ferrite core and the circuit impedance, and set the oscillation frequency to 20 kH.
The best setting is in the range of z to 50kHz. Conversely, the frequency
This is because the performance of the ferrite core is extremely degraded, although the circuit impedance is lowered at 20 kHz or less.
By setting the frequency within the above range, it is possible to perform practical blasting with a low output voltage and little influence by the blasting busbar.

In addition, in the present invention, since the oscillator 106 in the blaster 40 is an independent fixed-frequency oscillator that does not depend on the blasting bus, the oscillation frequency of the oscillator 106 is stable. Therefore, the oscillation frequency of the oscillator 106 may be determined according to the frequency determined from the electromagnetic coupling characteristics of the ferrite core of the coupler 49, and as described above, 20-50 kH
It was confirmed that it was effective when set to z.

 Next, specific examples of the present invention will be shown.

Examples 1 to 4 The cross-sectional area of the twin core bus 47 is 0.75 mm ² , and the length is 100 m or 200.
m, and various types of auxiliary bus 48 with a diameter of 0.6φ and a length of 50 m or 100 m.
= 2500), effective saturation magnetic flux density Bs = 4800 Gauss, size = 15 ×
Coupling with 10 × 15 mm 49 a (TDK manufactured H ₃ S UI-15 type) provided 20, the coupling 49 against five hung and pears as detonator 61, the Ashisen 62 and 1.5 m, exploder 40 As the capacity of 280 V, 400 μF, output voltage of 600 Vp-p, output frequency of 20 kHz, a total of 100 firings were performed, and all the detonators were completely detonated. The results are shown in Table 1 below.

Examples 5 to 7 and Comparative Examples 1 to 4 Blaster 40 under the same conditions as Example 1, coupler 49 (20 pieces) having the same ferrite core, detonator 61 (5 pieces) and 6.
Use 0m leg 62 and double core busbar with cross section 0.75mm ²
With a length of 100 m, the auxiliary busbar is a partially bonded reciprocating single wire with a length of 0.6 mm and a length of 50 m, and the oscillation frequency of the blaster 40 is changed in the range of 10 kHz to 100 kHz to generate 100 simultaneous firing. As a result, the results shown in Table 2 were obtained. From this result, it was a complete explosion when the oscillation frequency was set within the range of 20 kHz to 50 kHz.

EFFECTS OF THE INVENTION As is apparent from the above, according to the present invention, the number of electric detonators coupled to the blast bus can be increased as compared to the conventional blast system to which the series resonance method is applied. Electromagnetic induction blasting can be performed stably even when using the blasting bus of the above, and a stable oscillation output is obtained even with changes in load represented by changes in the wire length and wiring condition of the twin core bus and the auxiliary bus. It can be obtained and the blast can be performed reliably.

Moreover, in the present invention, two parallel lines are used as auxiliary buses.
Since the reciprocating conductors are arranged in a positional relationship that is related to each other, such as a reciprocating single wire or a looped single wire, the impedance of the blasting bus is low, so even if the output voltage of the blaster is increased, radio interference will occur. In addition, there is little possibility that the two reciprocating conductors are separated from each other by providing a loop-shaped portion in which the reciprocating two conductors are separated, or it is easy to separate these two conducting wires. Since it has a structure such as weakly adhering to the connector, workability of attaching the connector, wiring of the auxiliary busbar, and routing is high.

In addition, the auxiliary busbars used in the present invention are used in the process of coating two copper wires at the time of manufacturing a normal parallel busbar,
Since it can be easily realized by weakening the adhesion or fusion partially or not performing the adhesion or fusion, it can be manufactured at the same low cost as the manufacturing cost of the normal parallel busbar, and is therefore a consumable material. It is preferable as a bus bar.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an electric blasting system for carrying out the present invention, FIG. 2 is a block diagram showing an example of the blasting device, and FIGS. 3 (A) and 3 (B) are systems shown in FIG. FIG. 4 is a front view showing an example of the coupler used in FIG. 4, FIG. 4 is a configuration diagram showing another example of the electric blasting system for carrying out the present invention, and FIGS. 5 and 6 show two examples of the conventional electric blasting device. It is a circuit diagram. 1 ... Power supply, 2 ... Capacitor, 3 ... Trigger circuit,
4 ... Silicon controlled rectifier, 5 ... Oscillator, 6 ... Bus, 7 ... Transformer section, 8 ... Secondary winding, 9 ... Electric detonator, 10 ... Transformer core, 11 ... Power pulse generation Division, 12
...... High frequency converter, 13 ...... Bus, 14 ...... Transformer, 15
...... Electric detonator, 16 ...... DC / DC converter, 17 ...... Charging / discharging capacitor, 18 ...... Changeover switch, 19,20,28 ...... Terminal, 21,22 ...... Tuning coil, 23 ...... Tuning capacitor, twenty four
...... Transistors, 25,26 ...... Bias resistors, 27 ......
Bias condenser, 29 …… transformer core, 30 …… loop, 31 …… detonator, 32 …… cut part, 40 …… blaster, 41…
… Charging part, 42 …… High frequency converter, 43,44 …… Output terminals, 4
7 ... Twin core bus, 48 ... Auxiliary bus, 49 ... Coupler, 50 ...
… Lower half, 51 …… Upper half, 52,53 …… Ferrite core, 54 …… Cover, 61 …… Electric detonator, 62 …… Leg wire, 71,7
2 ... Auxiliary busbar, 73 ... Adhesion position, 101 ... Battery, 102 ...
… DC / DC converter, 103 …… Charge / discharge switch, 104 ……
Blasting capacitor, 105 ... Constant voltage generating circuit, 106 ... Oscillator, 107 ... Buffer, 108 ... Switching unit, 109 ...
... Output section.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-57-142499 (JP, A) JP-A-60-86400 (JP, A)

Claims (2)

(57) [Claims] 1. A capacitor charging section, a high frequency converting section that is driven by a discharge current from the charging section and outputs a high frequency current of a fixed frequency within a range of 20 kHz to 50 kHz, and is connected to an output of the high frequency converting section. A blasting busbar consisting of a twin core busbar and an auxiliary busbar, and a ferrite core for connecting by electromagnetic induction by inserting both the auxiliary busbar and a loop forming a part of a leg wire connected to an electric detonator into the inside thereof. In the electric blasting device having, the high-frequency converter is a constant voltage generating circuit that obtains a predetermined constant voltage output by using the capacitor charging unit as a power source, and is driven by a constant voltage from the constant voltage generating circuit to 20 kHz to 50 kHz. An oscillator that oscillates a fixed-frequency signal within the range, a switching unit that extracts a high-frequency output by switching based on the oscillation output from the oscillator, and the switch Electric blasting apparatus according to claim RF output that consists of a output for deriving the twin core bus from parts. 2. The electric blasting device according to claim 1, further comprising a buffer circuit between the oscillator and the switching unit.