JP3653811B2 - Electric detonator and detonator to detonate it - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric detonator useful for confirming the explosion of a detonator or detecting when a detonator is detonated, and a detonator for detonating it. In particular, explosive explosive power detects the explosion (explosion time) of explosives when measuring vibrations in the blasting method for civil engineering work, exploring explosives, and seismic exploration based on ground vibrations caused by detonator explosions. The present invention relates to an electric detonator and a detonator for detonating the detonator.
[0002]
[Prior art]
Conventionally, detection at the time of detonation of this type of detonator or detection at the time of detonation of explosives detonated by a detonator has been performed using the following devices.
[0003]
(1) Explosive sounds of explosives are memorized remotely using a microphone, or an explosion is detected by voice signal or electrical signal communication using a loudspeaker, telephone, wireless communication, or the like.
[0004]
(2) A vibration / sound / light sensor is placed near the explosive, and the vibration, sound, and light associated with the explosion are recorded. An optical fiber is inserted inside the explosive, and light emission due to the explosion phenomenon is detected using the light sensor. Explosion is detected by detecting with a photodetector ["Explosive Handbook", Industrial Explosives Association (1987) Kyoritsu Shuppan Co., Ltd., pages 244-245].
[0005]
(3) Using a normal electric detonator, the moment when the electric detonator is energized or the moment when the resistance wire is broken is regarded as the moment of detonation, and the time of detonation is detected approximately ("Explosives Handbook" edited by the Industrial Explosives Association) (1987) Kyoritsu Shuppan, page 134).
[0006]
(4) Using a power supply that can supply very strong electrical energy of several kV or more and several A or more instantaneously, and a special detonator that initiates the explosion of a resistance wire inside the detonator, the electrical detonator is energized. (Nakakawa et al., “Prototype and performance test of line explosion-type safety electric detonator” Industrial Explosives Vol. 36, No. 3, 1975).
[0007]
[Problems to be solved by the invention]
However, when the conventional apparatus as described above is used, there are the following problems.
[0008]
In the device (1), the farther away, the more difficult it is to distinguish between ambient noise and blasting sound, and the time accuracy is poor. Furthermore, when exploding underground such as in tunnel excavation, the explosion sound does not reach the ground and cannot be detected.
[0009]
The time accuracy is poor in communication using loudspeakers, telephones, voice signals using radio communications, and electrical signals, and there is a limit to improvement.
In the apparatus (2), expensive sensors and measuring devices are required, and the time accuracy is about millisecond accuracy. Moreover, it is necessary to arrange these sensors in the vicinity of the blasting point, which is troublesome, and the sensor may be damaged at the time of blasting.
[0010]
When an optical fiber is inserted into the explosive and light emission due to the explosion is detected by a photodetector using a light sensor, the time accuracy is relatively high, but the expensive optical fiber is consumed every time. Furthermore, due to the attenuation of light within the optical fiber, the optical fiber cannot be made very long, and an expensive photodetector must be placed near the blasting point, and is easily damaged by the blasting.
[0011]
In the apparatus (3), an error of 0.1 to 1 millisecond occurs between the moment when energization is started and the actual detonation due to the ignition delay of the ignition agent, the detonation delay of the detonation, and the detonator. Moreover, the disconnection of the resistance wire is mainly caused by Joule heating due to the blasting current and the combustion heat of the igniting agent, and there is an error of 0.1 to 1 millisecond between the moment of disconnection and the actual initiation.
[0012]
In these cases, for example, in seismic exploration, when measuring the vibration generated by the explosion of a detonator or the explosion of a detonator and explosives being reflected by underground veins and faults, if the vibration wave speed is 4000 m / second, An error of 0.1 to 1 millisecond corresponds to an error of 0.4 to 4 m. For this reason, it is impossible to determine the exact position of the vein or fault.
[0013]
In the apparatus (4), the time accuracy is good, but a very expensive and special power supply and high voltage cable are required. In addition, grounding and shielding are necessary to prevent noise from being induced by other measuring instruments for protecting the handler from electric shock and electric shock.
[0014]
The present invention has been made paying attention to the problems existing in the prior art as described above. An object of the invention is to provide an electric detonator having a simple configuration and having a resistance wire that is disconnected by the initiation of the explosive without causing the resistance wire to be disconnected by the heat generated by the blast current or the combustion heat of the ignition agent. Another object of the present invention is to provide a detonator that can reliably detonate an electric detonator and can detect the detonator at the time of detonation with good time accuracy.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, in the electric detonator according to the first aspect of the present invention, a bottomed cylindrical tubular body, an initiator loaded in the tubular body, and an opening of the tubular body are sealed to provide a sealed space. A pair of conductive wires that extend through the embolus into the sealed space, resistance wires that are connected only to the ends of the two extended wires, and points that are supported on the resistance wires An electric detonator composed of gunpowder , wherein the resistance wire is formed of platinum, a platinum alloy, nichrome or tungsten, has a diameter of 40 to 100 μm, and has a resistance value of 0.1 to 10Ω. Heat is generated by the energized blasting current, and the igniting agent is combusted by the heat, the explosive explodes by the combustion heat, and the explosion breaks.
[0016]
The detonator of the second invention comprises a disconnection detection circuit connected to the conductor of the electric detonator of the first invention and a blasting power supply circuit connected to the disconnection detection circuit, wherein the disconnection detection circuit is the electric A resistor connected in parallel with the resistance wire of the detonator, a resistor connected at one end to the resistor and connected at the other end in parallel with the diode, a capacitor connected between the resistors, and a connection between the capacitor and the resistor It consists of a resistor connected to a point and the other end connected to the blasting power supply terminal, and it conducts a predetermined blasting current through the electrical detonator conductor and detects a break in the blasting current path that conducts the blasting current through the electrical detonator A circuit for generating a signal is provided.
[0017]
Therefore, in the first invention, when a blast current is applied to the electric detonator, the temperature of the resistance wire rises due to the Joule heat generated by the blast current, and the igniting agent ignites and burns. Explosives explode due to the combustion heat of the ignition powder.
[0018]
In this process, the resistance wire is not broken by the Joule heating due to the blasting current or the combustion heat of the igniting agent, but is broken by the destruction effect based on the explosion of the explosive. Therefore, by detecting the disconnection of the resistance wire, it is possible to accurately detect when the detonator is detonated.
[0019]
In the second invention, an electrical detonator, a disconnection detection circuit connected to a conductor of the electrical detonator that detects a disconnection of a blast current passage and generates a signal, and a blasting power supply circuit connected to the disconnection detection circuit are provided. By using the detonator, the resistance wire breakage due to the detonation of the electric detonator is detected. That is, it is possible to detect disconnection in the blast current path, and it is possible to detect the detonation of the electric detonator with good time accuracy based on the detected signal.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0021]
As shown in FIG. 1, the tubular body 11 is formed in a bottomed cylindrical shape from iron, aluminum, copper, or the like. The explosive 12 is loaded on the inner bottom of the tube 11. The initiating agent 12 is a substance that is easily detonated by the combustion of an ignition agent to be described later, and thunder, dinitroazophenol (DDNP), hexogen (RDX) and the like are used. In addition, in order to increase the power, an adjunct is used together with the explosive.
[0022]
The embolus 13 is attached to the open end of the tube 11 and forms a sealed space 14 in the tube 11. A pair of leg wires 15 as lead wires are inserted and supported by the embolus 13, and the tip portion is inserted to the sealed space 14 in the tube body 11. The resistance wire 16 is connected between the ends of both leg wires 15. The ignition agent 17 is supported on the resistance wire 16. When the resistance wire 16 is energized via the leg wire 15, the igniting agent 17 is ignited and burned by Joule heat generated by the resistance wire 16.
[0023]
The resistance wire 16 can ignite the igniting agent 17 by Joule heating by the blasting current, and is not broken by Joule heating by the blasting current and heating by the combustion of the igniting agent 17. Any electrically conductive material can be used as long as it is disconnected by the above.
[0024]
Examples of the resistance wire 16 include electrically conductive substances such as platinum, platinum alloys, nichrome, tungsten, iron, manganin, polyacetylene, and graphite carbon. Of these, platinum, platinum alloys, nichrome, and tungsten are desirable because they have appropriate electrical resistance and strength, have a high melting point, and are easy to manufacture.
[0025]
Further, the shape of the resistance wire 16 has a substantially uniform cross-sectional area and has a length such that the electric resistance is desirably 0.1Ω or more. Most preferably, it is a platinum wire having a diameter of 50 μm and a length of 2 to 3 mm or an alloy wire containing 90% or more of platinum. The reason why the lower limit of the electrical resistance is set to 0.1Ω or more is that if it is too large, the voltage of the blasting power source will be raised and the current cannot be increased extremely. If it is too small, the generated thermal energy will be small. This is because the ignition powder 17 cannot be burned. This electrical resistance is more desirably 0.2Ω or more, and most desirably 0.3Ω or more.
[0026]
On the other hand, the electrical resistance value is desirably 10Ω or less, more desirably 3Ω or less, and most desirably 2Ω or less. This upper limit value is determined from the viewpoint that it becomes difficult to flow a blast current if the electrical resistance becomes too large.
[0027]
Further, the resistance wire 16 needs to be strong enough not to be melted by the heat generated by the blasting current and the combustion heat of the igniting agent 17. In this case, it is advantageous that the heat capacity and specific heat are large, the temperature of itself is not easily raised, the melting point is high, and it is difficult to melt. Therefore, generally, in the main metal wires such as nichrome, platinum, manganin and the like, the resistance to fusing increases as the cross-sectional area increases. That is, the diameter of the resistance wire 16 is preferably 40 μm or more, and more preferably 50 μm or more, in the case of platinum and an alloy containing 90% by weight of platinum. On the other hand, if the diameter is too large, the heat capacity increases, and the temperature at which the igniting agent 17 burns cannot be reached unless a large amount of blasting current is passed.
[0028]
The cross-sectional shape of the resistance wire 16 may be a circle or a polygon such as a square or a hexagon as long as the cross-sectional area is the same as described above.
The method of attaching the resistance wire 16 to the end of the leg wire 15 may be any method as long as it is a mechanically strong method such as a brazing method, a welding method, a crimping method, etc. and does not hinder electrical conduction. Of these, the crimping method is desirable in terms of manufacturability and manufacturing cost.
[0029]
As the constituent elements other than the resistance wire 16, those used in the conventional electric detonator are used, and in this embodiment, those of No. 6 instantaneous electric detonator are used. The details are shown, for example, in “Explosives Handbook” [Industrial Explosives Association (1987) Kyoritsu Shuppan Co., Ltd., pages 130 to 138] as follows.
[0030]
That is, as the igniting agent 17, a substance that is easily ignited by heating, in which a binder such as nitrocellulose is added to a mixture of rhodium lead and potassium chlorate, is used. The ignition powder 17 is supported on the resistance wire 16 in a predetermined shape. The leg wire 15 is a copper wire having a thickness of about 1 mm or less, and an insulating coating such as polyvinyl chloride is applied to the portions other than the ends.
[0031]
As shown in FIGS. 2 and 3, a disconnection detection circuit 20 is connected to the electric detonator 10, and a blasting power supply circuit 30 is connected to the disconnection detection circuit 20.
[0032]
Here, the disconnection detection circuit 20 will be described. The pair of connection terminals 21 are connected to the leg 15 of the electric detonator 10. The resistor 22 is connected in parallel with the resistance wire 16 of the electric detonator 10. One end of the resistor 23 is connected to the resistor 22. The capacitor 24 is connected between the resistors 22 and 23. The diode 25 is connected in parallel with the resistor 23. The output terminal 26 and the ground terminal 27 are connected to both ends of the diode 25. One end of the resistor 28 is connected to the connection point between the capacitor 24 and the resistor 22, and the other end is connected to the blasting power supply terminal 29.
[0033]
Next, the blasting power circuit 30 will be described. The switch 31 has one end connected to the power supply 32 and the other end connected to the blasting power supply terminal 29 of the disconnection detection circuit 20. The other end of the power source 32 is connected to the ground terminal 27 of the disconnection detection circuit 20.
[0034]
The disconnection detection circuit 20 may be any circuit that can detect disconnection.
For example, “a circuit that monitors the change in the blasting current by the current sensor and detects a decrease in the current due to the disconnection”, “the voltage change across the resistor with the blasting circuit inserted in series (by the disconnection) in the comparator (comparison operation circuit) ”A circuit that detects the voltage change across the resistor due to disconnection”, “A combination of a series resistor connected to the blasting circuit and a parallel resistor connected to the electric detonator, and a comparator (comparison operation circuit) that detects the voltage change across the parallel resistor due to disconnection Or, a circuit that detects with a differentiation circuit ”.
[0035]
Of these, a circuit in which a series resistance and a parallel resistance are combined with an electric detonator and a voltage change at both ends of the parallel resistance due to disconnection is detected by a comparator and a differential circuit is desirable from the viewpoint of good response characteristics.
[0036]
In this embodiment, since the number of parts is small, and miniaturization and high reliability are easy, a series resistance is combined with an electric detonator, and a circuit that detects a voltage change at both ends of the parallel resistance due to disconnection is adopted by a differential circuit.
[0037]
The differential circuit includes a series resistor 22 connected in series with the electric detonator 10, a parallel resistor 23 connected in parallel with the electric detonator 10, a capacitor 24 for extracting the voltage across the parallel resistor 23, a resistor 28, an output terminal 26, It is composed of a ground terminal 27, a blasting power supply terminal 29, and an electric detonator connection terminal 21. Further, when the voltage at the output terminal 26 is limited to a constant value, a constant voltage diode 25 can be used in parallel between the output terminal 26 and the ground terminal 27.
[0038]
As the power source 32 of the blasting power supply circuit 30, any device can be used as long as it supplies power necessary for detonation of the electric detonator 10, such as a battery, a storage battery, a charged capacitor, a commercial power source, and a generator. Among these, a battery, a storage battery, and a charged capacitor are preferable because they are easy to handle.
[0039]
Furthermore, a capacitor is most preferable from the viewpoint of easy miniaturization. Any capacitor that can supply power, such as a battery or a DC-DC converter, can be used for charging the capacitor.
[0040]
Next, the operation of the disconnection detection circuit 20 of the resistance line 16 will be described. The current I _O from the blasting power source 32 flows to the blasting power circuit 30 when the switch 31 is closed. The current I _O is a current I _e flowing through the squib 10 at the connection point A, divided into current I _b flowing through the parallel resistor R _22. If the resistance of both the detonator 10 and the leg 15 is R _e Ω, the voltage V _AB between the connection points A and B is expressed by the following equation (1).
[0041]
V _AB = I _O × (R _e ⁻¹ + R ₂₂ ⁻¹ ) ⁻¹ (1)
The current I _O is expressed by the following equation (2), where V _O is the voltage of the blasting power supply 32.
[0042]
I _O = V _O / [(R _e ^-1 + R ₂₂ ^-1 ) ^-1 + R ₂₃ ] (2)
Substituting equation (2) into equation (1) yields the following equation (3).
V _AB = [V _O × (R _e ^-1 + R ₂₂ ^-1 ) ^-1 ] / [(R _e ^-1 + R ₂₂ ^-1 ) ^-1 + R ₂₃ ] (3)
Here, when (R _e ⁻¹ + R ₂₂ ⁻¹ ) ⁻¹ = R _L , the following equation (4) is obtained.
[0043]
V _AB = V _O × R _L / (R _L + R ₂₃ ) (4)
Then, a few Ω to R ₂₃ and R _e, choose the R ₂₂ to be 1 to 10 times of R _e, R _e becomes infinite when the resistance wire 16 of the detonator 10 is disconnected, R _e ^{- 1} is zero. Also, R _L = R ₂₂ and R _L becomes large. Therefore, V _AB increases rapidly. This change in V _AB is shown in FIG. That is, when the switch 31 is turned on at time T ₁ , the voltage V _AB increases, and at time T ₂ when the resistance line 16 is disconnected, the voltage V _AB increases rapidly.
[0044]
The change of the V _AB is differentiated by the capacitor 24, spikes V _AB is the connection point of both ends of R ₂₃ B, taken out a voltage (V _CD) variation between C. The waveform is as shown in FIG. 4B when there is no diode. That is, a large voltage peaks from small voltage peak and time T ₂ at time T ₁ is obtained.
[0045]
Furthermore, by using a general-purpose constant voltage diode (zener diode) as the diode 25 and clipping the plus pulse at the time of disconnection of the resistance wire 16 with the Zener voltage V _Z , a beautiful pulse waveform as shown in FIG. A figure can be obtained. That is, a positive voltage peak from time T ₂ is obtained as a constant Zener voltage V _Z.
[0046]
In this way, the disconnection of the resistance wire 16 can be detected, and the detection when the electric detonator is detonated can be accurately performed.
[0047]
【Example】
(Example 1)
Embodiment 1 of the present invention will be described below.
[0048]
In this example, the electric detonator 10, the disconnection detection circuit 20, and the blasting power circuit 30 described in the above embodiment are used as the electric detonator, the disconnection detection circuit, and the blasting power supply circuit. A capacitor capable of flowing a current of 2 to 10 amperes at least twice as long as the time required for ignition of the electric detonator 10 was used.
[0049]
Then, when the switch 31 was turned on and the blasting voltage V _O was applied from the power source 32, the electric detonator 10 exploded, and the disconnection detection circuit 20 detected the disconnection of the resistance wire 16 and generated a signal.
[0050]
In order to confirm the detection accuracy of this signal, the detonation of the electric detonator 10 is detected in advance by the ion gap method, which is a general-purpose explosion detection method, and compared with the signal of the disconnection detection circuit 20, the electric detonator according to this embodiment is used. In the 10 detonation method, the detonation of the detonator 10 and the detected signal had an error of 5 microseconds or less, and the time accuracy was very good. The ion gap method is a method of detecting the arrival of detonation waves using a microelectrode (ion gap) inserted into the explosive 12 based on the fact that the electrical conductivity of the detonation product is very good. Say.
[0051]
As described above, the resistance wire 16 is not disconnected by the Joule heat generated by the blasting current to the resistance wire 16 or the combustion heat generated by the combustion of the igniting agent 17, and the resistance wire 16 is disconnected by the explosion of the explosive 12 and the non-conductive state is established. Become. Then, by using the electric detonator 10 that opens the blasting current passage (that is, the disconnection state) and the disconnection detection circuit 20 that detects the opening of the blasting current passage, it is possible to detect the disconnection of the blasting current passage. For this reason, the detonation of the electric detonator 10 can be detected with good time accuracy based on the detected signal.
[0052]
Furthermore, in this embodiment, existing equipment such as a blasting bus can be diverted as it is, and equipment such as new measurement cables and devices is not required, and can be carried out easily and at low cost.
[0053]
Therefore, according to the electric detonator 10 of this embodiment, the resistance wire 16 is disconnected by the heat generated by the blast current or the combustion heat of the igniting agent 17 with a simple configuration using only the resistance wire 16 having a predetermined resistance value and strength. It is possible to cause disconnection by the initiation of the explosive 12 without causing the explosion. Moreover, according to the detonator of this embodiment, the electric detonator 10 can be reliably detonated, and detection when the electric detonator 10 is detonated can be performed with good time accuracy.
(Example 2)
A second embodiment embodying the present invention will be described below.
[0054]
In this embodiment, the same configuration as that of the first embodiment is adopted as the electric detonator and the blasting power source, and the circuit shown in FIG. That is, the ignition switch 41 is provided between the connection point A and the connection point E, and supplies the current I _O from the blasting power source 32 to the disconnection detection circuit 40 and applies the voltage V _O.
[0055]
Now, after the switch 31 was turned on, when the ignition switch 41 was turned on and the disconnection detection circuit 40 was energized, the electric detonator 10 was detonated, and the disconnection detection circuit 40 detected a disconnection of the resistance wire 16 and generated a signal. In order to confirm the detection accuracy of this signal, the detonation of the electric detonator 10 was detected in advance by the ion gap method described above and compared with the signal of the disconnection detection circuit 40. As a result, in this embodiment, the error of the detected signal due to the detonation of the electric detonator 10 was very good with a precision of 5 microseconds or less.
[0056]
Then, as shown in FIG. 6 (a), the relationship between the voltage V _AB and the time in this embodiment becomes a step-like graph that changes at time T ₁ and time T ₂ , as shown in FIG. 6 (b). The relationship between the voltage V _CD and time is a graph having a negative voltage peak at time T ₁ and a large positive voltage peak at time T ₂ . Therefore, there is only one positive voltage peak corresponding to the detonation of the electric detonator 10, which makes it easier to discriminate compared with the first embodiment.
[0057]
Further, as shown in FIG. 6C, by using the constant voltage diode 25, the negative voltage portion is cut and the positive voltage portion is cut by the Zener voltage V _Z , so that a very simple pulse waveform is obtained. Can be.
[0058]
In addition, in this embodiment, the initiation operation is performed in two stages, ie, when the switch 31 is turned on and when the ignition switch 41 is turned on, so that the possibility of erroneous operation can be prevented.
(Comparative Example 1)
The electric detonator was detonated by the method described in Example 1 except that a commercially available No. 6 instantaneous electric detonator was used as the electric detonator, and at the same time, detonation was detected in the ion gap.
[0059]
As a result, the detection signal of the initiation by the ion gap and the signal detected by the disconnection detection circuit have an error of about 0.1 to 1 millisecond because the resistance wire is disconnected before the initiation of the explosive by the blast current. there were.
(Comparative Example 2)
The electric detonator was detonated using a commercially available No. 6 instantaneous electric detonator and two types of 100-type condenser-type detonators defined in JIS M 2505 (1994), and at the same time, detonation was detected by the ion gap method. The detection signal of the initiation by this ion gap method was compared with the time accuracy of the initiation detection by the conventionally used detection method.
[0060]
As a result, when the sound accompanying detonation was detected by a microphone at a point 10 m away, there was an error of several milliseconds or more and a time delay of 30 milliseconds or more with respect to the ion gap signal.
[0061]
The configuration of the present invention may be embodied by changing it as follows, for example.
(A) In the embodiment, the length of the resistance wire 16, the amount of the igniting agent 17, or the distance between the igniting agent 17 and the explosive agent 12 is relatively adjusted. Then, the resistance wire 16 should not be disconnected by the blast current that is energized or the combustion heat of the igniting agent 17.
(B) In FIG. 3, the connection location of the capacitor 24 is changed between the connection point B and the connection point D.
(C) In FIG. 3, a coil is used instead of the resistor 22, and a resistor is used instead of the capacitor 24.
[0062]
Further, the technical idea grasped from the embodiment will be described below.
(1) Loading an explosive into a tubular body with a bottom, sealing the opening of the tube with a plug to form a sealed space, and extending a pair of conductors through the plug to the sealed space Then, the ends of both extended wires are connected with resistance wires, the igniting agent is supported on the resistance wires, a blasting current is passed through the resistance wires to generate heat, and the igniting agent is burned with the heat. A method of detonating an electric detonator that explodes the detonator by heat and breaks the resistance wire due to the explosion. By this method, the explosive can be reliably exploded and the resistance wire can be disconnected by the explosion. Therefore, by detecting the disconnection of the resistance wire, it is possible to detect the detonation of the electric detonator with good time accuracy.
(2) The electric detonator according to claim 1, wherein the resistance value of the resistance wire is 0.1 to 10Ω. If comprised in this way, Joule heat will be generated by energizing the blast current to the resistance wire, the igniting agent will be burned by that heat, and the explosive will be exploded without breaking the resistance wire due to the heat of combustion. Can do.
(3) The electric detonator according to claim 1, wherein the resistance wire has a cylindrical shape and a diameter of 40 to 100 µm. According to this configuration, the strength of the resistance wire can be maintained, and the resistance wire can be disconnected by detonation of the explosive without causing the resistance wire to be disconnected by blasting current or burning of the ignition agent.
(4) The electric detonator according to claim 1, wherein the resistance wire is formed of platinum, a platinum alloy, nichrome or tungsten. With this configuration, it is possible to easily obtain a resistance wire having an appropriate electric resistance and strength and a high melting point.
(5) The detonator according to claim 2, wherein the circuit includes a resistance in series and parallel to a resistance wire, and a differential circuit that detects a voltage change at both ends of the parallel resistance. According to this configuration, it is possible to accurately detect the detonation of the electric detonator with a device that has a small number of parts and is small and highly reliable.
[0063]
【The invention's effect】
As described in detail above, according to the electric detonator of the first invention, with a simple configuration, the resistance wire is disconnected by the initiation of the explosive without breaking the heat generated by the blast current or the combustion heat of the ignition agent. be able to.
[0064]
In addition, according to the detonator of the second invention, the electric detonator can be reliably detonated, and the detection at the time of detonation of the electric detonator can be performed with good time accuracy.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an electric detonator according to an embodiment of the invention.
FIG. 2 is an electric circuit diagram showing an electric detonator, a disconnection detection circuit, and a power supply circuit.
FIG. 3 is an electric circuit diagram showing a circuit for detecting disconnection of a blasting current path.
4A is a graph showing the relationship between voltage and time, FIG. 4B is a graph showing time change of voltage, and FIG. 4C is a graph showing time change of voltage after rectification.
FIG. 5 is an electric circuit diagram illustrating a breakage detection circuit of a blasting current path according to the second embodiment.
6A is a graph showing the relationship between voltage and time, FIG. 6B is a graph showing time change of voltage, and FIG. 6C is a graph showing time change of voltage after rectification.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Electric detonator, 11 ... Tube, 12 ... Explosive agent, 13 ... Embolization, 14 ... Sealed space, 15 ... Leg wire as a conducting wire, 16 ... Resistance wire, 17 ... Ignition agent, 20 ... Disconnection detection circuit

Claims (2)

A bottomed tubular tube (11), an initiator (12) loaded in the tube (11), and an opening of the tube (11) are sealed to form a sealed space (14). The embolus (13) to be connected, the pair of conductors (15) extending through the embolus (13) and extending into the sealed space (14), and the ends of both the extended conductors (15) are connected An electrical detonator comprising a resistance wire (16) and an igniter (17) supported on the resistance wire (16) ,
The resistance wire (16) is made of platinum, platinum alloy, nichrome or tungsten, has a diameter of 40 to 100 μm, has a resistance value of 0.1 to 10Ω, and is blasted when the resistance wire (16) is energized. An electric detonator that generates heat by an electric current, burns the igniter (17) with the heat, explodes the explosive (12) due to the heat of combustion, and is disconnected by the explosion. A disconnection detection circuit (20, 40) connected to the conductor (15) of the electric detonator according to claim 1, and a blasting power circuit (30) connected to the disconnection detection circuit (20, 40),
The disconnection detection circuit (20, 40) includes a resistor (22) connected in parallel with the resistance wire (16) of the electric detonator, one end connected to the resistor (22), and the other end connected to a diode (25). A resistor (23) connected in parallel, a capacitor (24) connected between both resistors (22, 23), and a connection point between the capacitor (24) and the resistor (22) and the other end blasted. It consists of a resistor (28) connected to the power supply terminal (29), and conducts a predetermined blast current to the electrical detonator conductor (15) and detects a break in the blast current passage that conducts the blast current to the electrical detonator. A detonator equipped with a circuit that generates a signal.

Images