Firing circuit and explosive device

Abstract

The present invention relates to an ignition circuit (100) comprising a storage device (110) for storing electrical energy; an ignition device (120); a switching device (130); a plurality of electrical resistors (140); and at least one discharge tube (150); wherein the switching device (130), the plurality of electrical resistors (140), and the at least one discharge tube (150) are arranged such that, in an open state of the switching device (130), no electrical energy flows from the storage device (110) through the discharge tube (150) to the ignition device (120), and in a closed state of the switching device (130), electrical energy flows from the storage device (110) through the discharge tube (150) to the ignition device (120). The present invention further relates to an explosive device.

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to an ignition circuit and an explosive device. BACKGROUND OF THE INVENTION

[0002] Various types of detonators are used to detonate explosive devices, some of which require a high current pulse with a very rapid current rise time. The energy required for this is typically stored in an ignition capacitor, which is charged to a high voltage before receiving an ignition signal. To achieve the necessary current rise time and current magnitude to detonate the EFI detonator, the ignition capacitor must discharge very quickly and with low inductance. This requires a suitable ignition switch.

[0003] To achieve this ignition, components are currently used which are sometimes very expensive and difficult to obtain or are irreversibly destroyed even after a single use.

[0004] Document DE 11 26 980 B describes an electrical ignition device operating with a capacitor for firing detonator chains of high ignition pulse energy, in which a number of series-connected discharge tubes are connected in series with the capacitor supplying the ignition pulse and the detonator chain. SUMMARY OF THE INVENTION

[0005] Accordingly, the object of the present invention is to provide an ignition circuit which can be realized as cost-effectively as possible and can advantageously be used multiple times.

[0006] This object is achieved by an ignition circuit having the features of patent claim 1 and an explosive device having the features of patent claim 10.

[0007] Accordingly, an ignition circuit is provided with a storage device for storing electrical energy, an ignition device, a switching device, a plurality of electrical resistors, and at least one discharge tube. The switching device, the plurality of electrical resistors, and the at least one discharge tube are arranged such that, when the switching device is open, no electrical energy flows from the storage device through the discharge tube to the ignition device, and, when the switching device is closed, electrical energy flows from the storage device through the discharge tube to the ignition device. The at least one discharge tube has two discharge tubes connected in parallel.

[0008] Furthermore, an explosive device with an ignition circuit according to the invention is provided.

[0009] One idea underlying the invention is the use of discharge tubes, in particular gas discharge tubes, to provide the ignition current. Discharge tubes have a particularly advantageous current conduction method for this purpose, since no current can flow through them at an applied voltage below the ignition voltage of the discharge tube. However, as soon as an applied voltage exceeds the ignition voltage, the electrical resistance of the discharge tube immediately drops to almost zero. This allows the desired behavior of a high current flowing through the discharge tube, and thus also through the ignition device, with a high rise rate to be achieved using relatively inexpensive components.

[0010] According to one embodiment of the ignition circuit, the storage device comprises at least one capacitor. This is a particularly simple and cost-effective way to store the electrical energy required for ignition.

[0011] According to a further development of the ignition circuit, the storage device has two capacitors connected in parallel. This allows the current flow through the at least one discharge tube to be advantageously controlled, particularly if more than one discharge tube is provided.

[0012] According to one embodiment of the ignition circuit, the ignition device comprises a bridge igniter, a foil igniter, or a slapper igniter. These types of igniters particularly benefit from the properties provided by the ignition circuit according to the invention.

[0013] According to one embodiment of the ignition circuit, the switching device has a control element with which the switching device can be controlled, in particular via radio. Such control of the switching device, in particular via radio, expands the potential areas of application of the ignition circuit according to the invention.

[0014] According to one embodiment of the ignition circuit, the at least one discharge tube is designed as a 3-pin discharge tube. This allows the desired behavior to be advantageously realized with just one discharge tube, as explained in more detail below with reference to the figures.

[0015] According to a further development of the ignition circuit, the switching device, the plurality of electrical resistors, and the 3-pin discharge tube are arranged such that, in the open state of the switching device, half of the voltage provided by the storage device is applied between each two pins of the 3-pin discharge tube, and in the closed state of the switching device, the entire voltage provided by the storage device is applied between two specific pins of the 3-pin discharge tube. This allows the ignition behavior of the ignition circuit to be regulated particularly advantageously.

[0016] According to one embodiment of the ignition circuit, the at least one discharge tube comprises two 2-pin discharge tubes connected in series. This is an implementation of the ignition circuit according to the invention with particularly advantageously simple, and therefore cost-effective, components.

[0017] According to a further development of the ignition circuit, the switching device, the plurality of electrical resistors, and the two series-connected 2-pin discharge tubes are arranged such that, in the open state of the switching device, half of the voltage provided by the storage device is applied to each of the two 2-pin discharge tubes, and in the closed state of the switching device, the entire voltage provided by the storage device is applied to one of the two 2-pin discharge tubes. This allows the ignition behavior of the ignition circuit to be regulated particularly advantageously.

[0018] According to the invention, the at least one discharge tube comprises two discharge tubes connected in parallel. This advantageously increases the service life of the individual discharge tubes, as explained in more detail below with reference to the figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention is explained below with reference to the figures of the drawings. The figures show: Fig. 1 is a schematic representation of an explosive device according to an embodiment not according to the invention; Fig. 2 is a schematic circuit diagram of a firing circuit according to an embodiment not according to the invention; Fig. 3a is a schematic circuit diagram of a firing circuit according to an embodiment of the present invention; Fig. 3b is a schematic circuit diagram of a firing circuit according to an embodiment of the present invention; Fig. 3c is a schematic circuit diagram of a firing circuit according to an embodiment of the present invention; Fig. 4a is a schematic circuit diagram of a firing circuit according to an embodiment of the present invention; and Fig. 4b is a schematic circuit diagram of a firing circuit according to an embodiment of the present invention.

[0020] In the figures, the same reference symbols denote identical or functionally identical components, unless otherwise stated. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0021] Fig. 1 shows a schematic representation of an explosive device 10.

[0022] The explosive device 10 comprises an ignition circuit 100. For reasons of clarity, the illustration of further components of the explosive device 10, in particular an explosive charge, is omitted here.

[0023] The ignition circuit 100 comprises a storage device 110 for storing electrical energy, an ignition device 120, a switching device 130, a plurality of electrical resistors 140, and two discharge tubes 150, which in the present embodiment are embodied as 2-pin discharge tubes. The storage device 110 comprises a capacitor 111 and a resistor. The switching device 130 comprises a control element 131.

[0024] The storage device 110, in particular the capacitor 111, is charged to an ignition voltage by a DC voltage source (not shown). To regulate the charging of the capacitor 111, the resistance of the storage device and two of the plurality of electrical resistors 140 are used, which form an electrical circuit independent of the switching device. These resistors also ensure safe discharge of the capacitor 111, for example, in the event that the DC voltage source is switched off in the event of an ignition failure. These resistors are designed with high resistance to keep the losses of the ignition circuit and the demands on the DC voltage source low.

[0025] The charge of the storage device 110 is set such that the voltage applied to the capacitor is greater than the respective ignition voltage of the two discharge tubes 150 but less than the sum of the ignition voltages of the two discharge tubes 150. Two of the plurality of electrical resistors 140 are each connected in parallel to each of the two discharge tubes 150 and configured such that, when the switching device is open, a voltage is applied to each of the two discharge tubes 150 which is less than the ignition voltage of the respective discharge tube 150. Accordingly, no current flows through the ignition device 120, which is connected in series with the two discharge tubes 150, in this state.

[0026] If both discharge tubes 150 have the same ignition voltage, it may be advantageous to adjust the resistors 140 so that half of the voltage provided by the storage device 110 is applied to each of the two discharge tubes 150. However, asymmetrical designs of the ignition voltages of the discharge tubes 150 and the corresponding resistors 140 are also conceivable.

[0027] If the control device 131 receives an ignition signal, the switching device 130 is closed. In this case, another of the plurality of electrical resistors 140 is connected in parallel to one of the two discharge tubes 150. A higher voltage, which is greater than the ignition voltage of the discharge tube 150, is then applied to the other discharge tube 150. This discharge tube 150 then ignites, as a result of which only a much lower voltage is applied to it and the majority of the voltage provided by the storage device 110 is applied to the first of the two discharge tubes 150, as a result of which this too is ignited and a current now flows through the ignition device 120, as a result of which the explosive charge (not shown) of the explosive device 10 is ignited.

[0028] Fig. 2 shows another schematic diagram of an ignition circuit 100.

[0029] The Fig. 2 The ignition circuit 100 shown differs from that shown in Fig. 1 shown by the fact that instead of two 2-pin discharge tubes in Fig. 2 only one discharge tube 150 is provided, which is designed as a 3-pin discharge tube.

[0030] The mode of action of the Fig. 2 The ignition circuit 100 shown essentially corresponds to that shown in Fig. 1 The plurality of electrical resistors 140 serves in the exemplary embodiment of the Fig. 2 not the regulation of the voltage on several discharge tubes but the regulation of the voltage between the electrodes of the 3-pin discharge tube shown.

[0031] Fig. 3a bis 3c each show a schematic circuit diagram of an ignition circuit 100 according to an embodiment of the present invention.

[0032] The ignition circuits 100 of the Fig. 3a bis 3c The embodiments shown differ from the embodiments already described by the parallel connection of additional discharge tubes 150.

[0033] In Fig. 3a A total of four discharge tubes 150, in this case 2-pin discharge tubes, are provided, two of which are connected in parallel.

[0034] In Fig. 3b A total of two discharge tubes 150, in this case 3-pin discharge tubes, are provided, which are connected in parallel.

[0035] In Fig. 3c A total of three discharge tubes 150 are provided, in this case two 2-pin discharge tubes and one 3-pin discharge tube, with the 3-pin discharge tube being connected in parallel to the 2-pin discharge tubes connected in series.

[0036] By connecting the discharge tubes 150 in parallel, the current which, compared to the embodiments of the Fig. 1 and 2flowing through each of the discharge tubes 150 is reduced, thereby increasing their service life.

[0037] Fig. 4a und 4b each show a schematic circuit diagram of an ignition circuit 100 according to an embodiment of the present invention.

[0038] The Fig. 4a und 4b The ignition circuits 100 shown correspond to those shown in the Fig. 3a und 3b shown ignition circuits 100. In the Fig. 4a und 4b In the embodiments shown, the memory device 110 comprises a second capacitor 112 and an associated resistor.

[0039] In the embodiment of the Fig. 4a A first series-connected pair of discharge tubes 150 is supplied with voltage by the first capacitor 111, and a second series-connected pair of discharge tubes 150 is supplied with voltage by the second capacitor 112. In this case, the discharge tubes 150 are designed as 2-pin discharge tubes, and the first pair of discharge tubes is connected in parallel to the second pair of discharge tubes.

[0040] In the embodiment of the Fig. 4b A first discharge tube 150 is supplied with voltage by the first capacitor 111, and a second discharge tube 150 is supplied with voltage by the second capacitor 112. The discharge tubes 150 are designed as 3-pin discharge tubes and connected in parallel.

[0041] By using multiple capacitors 111 and 112, it is possible to better control how much current flows through which discharge tube 150, thereby further optimizing the lifetime of the individual discharge tubes 150. LIST OF REFERENCE SYMBOLS

[0042] 10Explosive device 100Ignition circuit 110Storage device 111Capacitor 112Capacitor 120Ignition device 130Switching device 131Control element 140Electrical resistor 150Discharge tube

Claims

1. Firing circuit (100) having a storage device (110) for storing electrical energy; a firing device (120), a switching device (130), a plurality of electrical resistors (140); and at least one discharge tube (150); wherein the switching device (130), the plurality of electrical resistors (140) and the at least one discharge tube (150) are arranged in such a way that no electrical energy flows from the storage device (110) through the discharge tubes (150) to the firing device (120) in an open state of the switching device (130) and electrical energy flows from the storage device (110) through the discharge tubes (150) to the firing device (120) in a closed state of the switching device (130); characterised in that the at least one discharge tube (150) has two discharge tubes (150) connected in parallel.

2. Firing circuit (100) according to claim 1, wherein the storage device (110) has at least one capacitor (11).

3. Firing circuit (100) according to claim 2, wherein the storage device (110) has two capacitors (111; 112) connected in parallel.

4. Firing circuit (100) according to one of the preceding claims, wherein the firing device (120) has a bridge wire initiator, an exploding foil initiator or a slapper detonator.

5. Firing circuit (100) according to one of the preceding claims, wherein the switching device (130) has a control element (131), which can be used to control the switching device (130), in particular by radio.

6. Firing circuit (100) according to one of the preceding claims, wherein the at least one discharge tube (150) is designed as a 3-pin discharge tube.

7. Firing circuit (100) according to claim 6, wherein the switching device (130), the plurality of electrical resistors (140) and the 3-pin discharge tubes are arranged in such a way that half of the voltage provided by the storage device (110) is applied respectively between two pins of the 3-pin discharge tubes in the open state of the switching device (130) and all the voltage provided by the storage device (110) is applied between two specific pins of the 3-pin discharge tubes in the closed state of the switching device (130).

8. Firing circuit (100) according to one of the preceding claims, wherein the at least one discharge tube (150) comprises two 2-pin discharge tubes connected in series.

9. Firing circuit (100) according to claim 8, wherein the switching device (130), the plurality of electrical resistors (140) and the two 2-pin discharge tubes connected in series are arranged in such a way that half of the voltage provided by the storage device (110) is applied respectively to one of the two 2-pin discharge tubes in the open state of the switching device (130) and all the voltage provided by the storage device (110) is applied to one of the 2-pin discharge tubes in the closed state of the switching device (130).

10. Explosive device (10) having a firing circuit (100) according to one of the preceding claims.

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