JPS61186278A - Electrical delay primer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electrical delay detonator that is safe against stray currents.

[Prior art] Detonators are used to detonate dynamite, slurry explosives, etc., and use the detonation force to crush rocks, coal, etc. for mining. This is called blasting. These detonators include industrial detonators that are ignited by a fuse and electric detonators that are ignited electrically. Currently, electric detonators are mainly used.

Normally, for blasting, there are some sites where a small number of electric detonators are used, such as in limestone and quarrying, and others where dozens of electric detonators are used at a time, such as tunnels, mines, and coal mines. There are some places.

Conventionally, there are power lines, electric light lines, and other wiring near the blasting site, and electric machines such as motors are in operation.When electricity leaks from these lines, stray current flows into the blasting circuit, and when the electricity is not in use, There was a risk of igniting the detonator. For example, it has been found that conventional electric detonators can ignite at low voltages of 5 to 20 V and low currents of 0.3 to 0.6 A.

In order to solve these drawbacks, as electrical delay detonators, Japanese Patent Publication No. 5B-28228 and Japanese Patent Application Laid-Open No. 54-43454 were developed.
No., JP-A-57-142496, JP-A-57-142
No. 498.

Japanese Unexamined Patent Publication No. 58-83200 has been proposed.

To explain the configuration of these electrical delay detonators with reference to FIG. 3, for example, a timer 5 is connected between energy supply terminals 1 and 2, and the output of the timer 5 causes a switching element 6 to conduct and an ignition resistor. i7 Which series circuit is connected between terminals 1 and 2, and also between terminals 1 and 2 an energy storage capacitor 3 which supplies power to timer 5 and ignition resistance wire 7. A time delay circuit 4 is configured by the timer 5 and the switching element 6.

Electrical energy is supplied via terminals l and 2 from a blaster (not shown) and stored in capacitor 3. Next, the timer 5 is activated by the signal, and when the set time of the timer 5 has elapsed, a timer output appears, and the timer output is inputted to the switching element 6 as a trigger signal. As a result, the switching element 6 becomes conductive and the capacitor 3
This can cause the substance to accumulate and cause a fire.

[Problem to be solved] As mentioned above, since the electrical delay detonator has the energy storage capacitor 3 inside, if input terminals 1 and 2 are opened, in that case, the detonator will not receive any energy from the outside. Stray current flows through the input line to the energy storage capacitor 3.
gradually accumulates.

When the amount of stored energy increases, the stored energy activates the delay circuit 4, and a trigger signal is input to the switching element 6, causing the condenser to generate heat and causing the detonator to ignite.

The amount of energy stored differs depending on whether the stray current energization state yE is pulse energization (one time or repeated energization) or continuous energization. IOV, a stray current of about 2 mA leads to ignition in several seconds to tens of seconds. Also,
These electrical delay detonators also have the disadvantage that their continuity cannot be checked or measured.

[Means and effects for solving the problem] Therefore, an object of the present invention is to provide an electric delay detonator that solves the drawbacks of the conventional electric delay detonator regarding stray current and the problem of continuity check. be.

To achieve this objective, the present invention connects a resistor in parallel to the input terminal of the electrical delay detonator to shunt stray currents to the capacitor.

As a result of conducting various tests against stray current regarding the electrical delay detonator of the present invention, it was found that the resistance value of such a resistor was It has been found that if the resistance is set to 10 to 100 Ω, it is possible to prevent the electrical delay detonator from igniting and at the same time, it becomes possible to check continuity.

[Implementation Example 1] Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows an analog embodiment of the electrical delay detonator of the present invention, in which the timer 5 is connected to the delay resistor 10.
and a time constant circuit 8 consisting of a time delay capacitor 11, adjustment resistors 12 and 13 connected in series, and the connection point between these resistors is connected to the gate, and the connection point between the resistor 10 and the capacitor 11 is connected to the anode. It has a trigger circuit 9 consisting of a programmable tljT (PtlT) 14 whose cathode is connected to a thyristor as a switching element 6.

In parallel with the capacitor 3, that is, between the energy supply terminals 1 and 2, there is a resistor 15 for stray current that bypasses the stray current.
Connect.

In the specific example, an aluminum electrolytic capacitor (10 JtF) was used as the energy storage capacitor 3.

The time delay capacitor 11 is 0.17 tF, and the time delay resistor 10 is 2. OMΩ, and the adjustment resistors 12 and 13 of the trigger circuit 9 are set to 1. The resistor 15 for stray current was set to 20Ω.

Although a DC voltage of 20 V and a current of 0.3 A were continuously applied as a stray current through input terminals 1 and 2 of the electrical delay detonator of the present invention, no ignition occurred. On the other hand, in the case of a conventional electrical delay detonator in which the stray current resistor 15 is removed from the circuit of FIG. 1, when a stray current is supplied under the same conditions,
It ignited in 2-3 seconds.

Embodiment 2 FIG. 2 shows an embodiment of the electrical delay detonator of the present invention having a digital time delay circuit. Here, terminals 1 and 2
A bridge-connected diode is used as a wrap-around prevention circuit 16 between the capacitor 3 and the capacitor 3, and its output is supplied to both ends of the capacitor 3. A constant current power supply field effect transistor 17 and a planar type constant voltage diode 18 are connected to one end (+ side) of the capacitor 3. A time limit circuit 19 such as a C-NOS timer IC is connected to the gate of the electric field transistor 17. 20 and 21 respectively indicate this timer IC 19.
These are a time delay capacitor and a time delay resistor that are externally connected to the 22 and 23 are a reset capacitor and a diode, respectively, which are connected to the timer IC 19. The timer output from the timer IC+9 is supplied to the gate of the thyristor as the switching element 6 via the buffer resistor 24. Also in this example, a stray current resistor 15 is connected between terminals 1 and 2.

Here, as a specific example, the energy storage capacitor 3 was determined to be an aluminum electrolytic capacitor 470, F, and the time delay capacitor 20 was determined to be 200 pF. Time delay resistor 2
1 to 100Ω, reset capacitor 22 to 0.02
2JLF, buffer resistor 24 5. IKΩ, the capacitor 25 for noise absorption was set to 0.022 gF, and the resistor 15 for stray current was set to 20Ω.

Although a DC voltage of 20 V and a current of 0.3 A were continuously applied as a stray current through the input terminals 1 and 2 of the electrical delay detonator of the present invention, no ignition occurred. On the other hand, in the case of a conventional electrical delay detonator in which the stray current resistor 15 is removed from the circuit shown in FIG. 2, when a stray current is supplied under the same conditions, 2
It ignited in ~3 seconds.

[Effects of the Invention] As can be seen from 1-1 below, according to the present invention, by inserting a resistor in parallel to the input section to the electrical delay detonator, low voltage (20 V or less) and low current (0, The detonator can be configured safely against stray currents (3A or less).

Moreover, this resistor also has the advantage of making it easy to check the continuity of the electrical delay detonator.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the electrical delay detonator of the present invention, Fig. 2 is a circuit diagram showing another embodiment of the invention, and Fig. 3 is a circuit diagram of a conventional electrical delay detonator. It is a block diagram. 1.2... Energy supply terminal, 3... Energy storage capacitor, 4... Time delay circuit, 5... Timer, 8... Time constant circuit, 9... Trigger circuit, 10...・Resistance for time delay, 11... Capacitor for time delay, 12.13... Resistor for adjustment, 14... PUT, 15... Resistor for stray current, 16... Circuit to prevent wraparound, 17...・Field effect transistor for constant current power supply, 18...Brain type constant voltage diode, 18...C
-MOS timer IC1 20... Capacitor for time delay, 21... Resistor for delay, 22... Capacitor for reset, 23... Diode for reset, 24... Resistor for buffer, 25... Noise absorption capacitor.

Claims (1)

[Scope of Claims] First and second input lines; energy storage means connected to the first and second input lines; energy storage means connected to the first and second input lines; An electrical delay detonator having time delay means for producing an output when energy stored in the means reaches a predetermined value, and means for igniting in response to the output, between the first and second input lines. An electrical delay detonator characterized in that a resistor is connected to the detonator.