FR2882816A1 - INTERFACE DEVICE FOR DETONATORS - Google Patents

Abstract

The present invention relates to an interface device (24) for a detonator (1), comprising two lines (29a, 29b) each capable of electrically connecting an electrical conductor (4a, 4b) of a control surface circuit (3). to an electrical input of a detonator (1). According to the invention, the device comprises means for short-circuiting (27) the two lines (29a, 29b) controlled by a control signal. Application to the field of pyrotechnic shots.

Description

The present invention relates to an interface device for

  detonators as well as a connection device and a pyrotechnic fire installation with a plurality of detonators. Finally, it relates to a tracking method.

  Detonators are used in large numbers for the mining of rocks in the field of mines and quarries. Generally, a large amount of drilling is carried out in the rock that is to be extracted so as to introduce, in each borehole, at least one detonator incorporating an explosive material. Means are used to carry out the explosion according to a defined firing program. In particular, electronic detonators with a programmable and extremely accurate internal delay device are often used. Each of these detonators is an independent unit which contains a microprocessor, means of communication with the outside and energy storage means generally in the form of a capacitor.

  The detonators are interconnected by a wired network, one end of which is connected to equipment forming a central unit that successively allows the programming of each detonator (in particular the assignment of an order to each of them and a delay on ignition), a test procedure, the charge of the capacitors able to provide the energy necessary for the ignition of the explosive and the firing.

  Pyrotechnic installations commonly use several tens or even hundreds of detonators. The effectiveness of the wired, programming and testing stages of the detonators is crucial to ensure a good execution of the shot. By programming is meant in particular the operation of assigning a delay to a particular detonator. This operation can be carried out either individually (in this case each detonator is programmed individually) or centrally (in this case, a device transmits by the wired network the delay to each detonator). The term "test" refers in particular to the connection checking of the detonators with one another, the verification of the programmed delays or the verification of the state of charge of the energy storage unit at the level of the capacitor of each detonator.

  In general, a pyrotechnic fireworks installation comprises a surface circuit capable of controlling the detonators and constituted by a wired network at the beginning of which is placed a central unit fulfilling the functions of the equipment indicated above (programming, test, charging capacitors, firing).

  Several surface circuit configurations are currently used.

  According to a first possibility, the detonators are connected in series along the control surface circuit.

  According to another possibility, the detonators are connected in parallel to said circuit which then comprises two substantially parallel electrical conductors to which each detonator is connected wire to wire.

  It is readily understood that the proper electrical connection of the detonators to the control surface circuit is crucial for proper operation of the entire installation. Indeed, a single faulty connection can disturb the expected result for the predetermined firing plan.

  Document AU-A4-2002 100821 discloses an installation of pyrotechnic shots employing a plurality of electronic detonators with a surface network able to control both in energy and in instructions a plurality of detonators placed at the end of a line of descent in drill holes. This invention describes an intermediate electronic device adapted to be connected to the surface line and to constitute an electrical isolation member between the surface line and the line of descent towards the detonator.

  This document provides a buffer function and transports the electronics usually embedded in the detonator, at the intermediate device. This creates a complex intermediate device for limited security enhancement. No detection of the position of the detonator is allowed by this intermediate unit.

  The present invention overcomes all or some of the disadvantages of the systems known hitherto and has for this purpose a new interface device for detonators, a connection device, a pyrotechnic fire installation and a method for identifying a particularly advantageous interface device.

  Typically, the interface device presented here comprises two lines for the parallel connection of the control surface circuit to an electrical input of a detonator. In addition, the device comprises means for short-circuiting the two lines controlled by a control signal.

  A first advantage of the short-circuiting means is, according to a first possibility of operation, that they make it possible to operate a brief short-circuiting of the electrical path comprised between a central unit of head-end, the drivers of the control surface circuit and the electrical circuit portion of the interface device upstream of the short-circuiting means. During this phase, it is possible to locate the position of the device on the electrical chain, in particular relative to other identical interface devices.

  In addition, the short-circuiting means make it possible to maintain the two electrical input terminals of the detonator at the same potential, thus avoiding any unwanted capacitor load within the detonator which could cause an accidental explosion. In this way, it is guaranteed that the detonators are inert during all the phases prior to the explosion, especially during assembly and testing. It is impossible for them to store enough energy to be able to ignite the pyrotechnic head.

  According to an advantageous embodiment, the interface device further comprises a switch means on one of the lines activatable by a control signal. This switch is advantageously naturally in the open position and isolates the detonator connected in parallel to the control surface circuit. The switch means thus closes only on an order conveyed by the control surface circuit and interpreted by the interface device. By placing, at the same time, the shorting means in the active position (short-circuiting), the two input son of the detonator are set to the same potential. The detonator can never operate, which could happen, without the device of the invention, if damaged wires were in contact with the ground or with other son of the detonator network establishing then an electrical circuit to through the ground (for example by leakage of current, leakage).

  Another advantage of the invention is, according to a preferred variant, to allow a test of the proper operation and good electrical connection of the interface device, the connection device and the detonator to the control surface circuit.

  Other objects and advantages will become apparent from the following description which presents a preferred embodiment of the invention, however not being limiting.

  As previously indicated, the present invention relates to a detonator interface device, comprising two lines each adapted to electrically connect an electrical conductor of a control surface circuit to an electrical input of a detonator. This interface device is such that it comprises means for shorting the two lines controlled by a control signal.

  According to preferred embodiments, this device is such that: - it comprises a switch means on one of the lines, activatable by a control signal, - the switch means is upstream of the short-circuiting means, - the means short circuit are configured to be active by default and the switch means is configured to be open by default; - it comprises a control module of the short-circuiting means and the switch means; control comprises means for: - addressing a request for identification to a head-end central unit of the control surface circuit, receiving a response containing identification data of the interface device, - the control module comprises means for producing an error signal if the response to the identification request is not received, - the error signal is audible or visual, - the control module comprises means for: addressing an inactivation control signal to the short-circuiting means; - send a closing control signal to the switch means; transmitting an identification message received from a central unit of the control surface circuit to the detonator; receiving an acknowledgment of receipt of the identification message from the detonator; - Address an opening control signal of the switch means; io - addressing an activation control signal of the short-circuiting means, - the control module comprises means for producing an error signal if the acknowledgment of receipt is not received, - the signal of error is sound or visual, the control module comprises means for: receiving a registering order; - address, if necessary, an activation control signal to the short-circuiting means; addressing a closing control signal by means of a switch; and, after a determined delay, - send an opening control signal of the switch means; so as to form a temporary short-circuit in the control surface circuit and the interface device to allow the measurement of an electrical quantity as a function of the length of the electrical conductors separating a head-end central unit from the surface circuit and the interface device, - it comprises at least one button for triggering the operation of the control module, - the control module is formed on an integrated circuit card.

  The invention also relates to a detonator connection device, between a control surface circuit comprising two electrical conductors and a detonator connection circuit, said connection device comprising at least two connecting members each connectable to an electrical conductor. This connection device is such that it integrates an interface device according to the invention, each line is in electrical continuity with a connection member.

  The invention also relates to an installation of pyrotechnic shots having a plurality of detonators connected by a connecting circuit to a control surface circuit having two conductors. This installation comprises at least one device according to the invention between the surface circuit and a connecting circuit.

  The invention also relates to a method for detecting the position of a detonator in a pyrotechnic fire installation having a plurality of detonators connected in parallel with a control surface circuit provided with two electrical conductors. This method is such that the following marking operations are carried out: use of an interface device according to the invention for electrically connecting the detonator to be located at the surface circuit; control of the means for short-circuiting the interface device to activate them, measurement of the value of an electrical quantity as a function of the length of the electrical conductors separating a central head-end unit from the surface circuit, and the interface device.

  According to preferred embodiments, this method is such that the electrical quantity is the impedance of the electrical circuit formed between the central unit of the head-end, the electrical conductors and the part of the interface device upstream of the control means. short circuiting, - the electrical quantity is the intensity of the current flowing in the electrical circuit formed between the central unit of the head-end, the electrical conductors and the part of the interface device upstream of the means for putting into short- circuit.

  - Repeating operations are repeated for several detonators, - we assign an order to the detonators according to the measured value associated with them.

  The accompanying drawings are given by way of example and are not limiting of the invention. They represent only one embodiment of the invention and will make it easy to understand.

  Figure 1 schematically illustrates the formation of an installation of 5 pyrotechnic shots with a series connection configuration detonators.

  Figure 2 illustrates a configuration alternative with parallel connection of the detonators.

  Figure 3 schematizes the implementation of the connection devices of the invention in a pyrotechnic fireworks installation.

  Figure 4 is a side view of the connection device of the invention and Figure 5 shows a sectional view along a transverse plane with a variant of the inner contour of the wings.

  Figure 6 shows more particularly some means of the present interface device, according to the example on a connection device.

  Figures 7 and 8 respectively show a side view and a top view (in the open position) of the connection device incorporating the interface device, according to another embodiment.

  In order to understand the various existing installation configurations, FIG. 1 shows the case of a series connection of the detonators. In this situation, the control surface circuit 3 comprises, at the head end, a central head-end unit 5 capable of providing the programming functions of the detonators 1, of testing, of charging the capacitors (or other means of storage of energy present in detonators 1) as well as firing. In this case, each detonator 1 placed in a borehole 2 is connected in series to the control surface circuit 3 with a down line comprising a forward portion and a return portion. The location of the detonators 1 may in certain cases be operated by their position in the electrical chain thus formed.

  A parallel configuration is illustrated in FIG. 2 in which we find the formation of a control surface circuit 3 comprising two substantially parallel conductors 4a, 4b connected at the head end to a central unit of the head-end 5. The detonators 1 housed in drilling holes 2 are connected to the surface circuit 3 via a connecting circuit 6 connected to the leads 4a, 4b to form a parallel connection.

  Note that, in this context, the identification of detonators 1 must be done individually because there is no way to differentiate the detonators 1 from each other in the electrical chain, each detonator 1 having a relative position identical to the others on this plan.

  The interface device incorporated in the connection device 7 whose implantation is shown in Figure 3 overcomes all or part of these disadvantages. It can be positioned intermediately between the surface circuit 3 and a connecting circuit 6 connected in part terminal to a detonator 1. It can also be an input stage of the detonator itself.

  In a first phase of the description which follows, a possibility of structural and electrical realization of the connection device 7 is described.

  A first variant embodiment is presented with reference to FIGS. 4 to 6 and a second variant is described with reference to the illustrations of FIGS. 7 and 8. Next, the means incorporated in the interface device 24 itself are described more precisely.

  Referring to FIGS. 4 to 6, an example of a connection device 7 is shown comprising a pair of connection members 8, 9 disposed on either side of an insulating wall 12, for example made of very plastic material. weakly conductive.

  In the case shown, the connecting members 8, 9 are insulating displacement fork connectors allowing, when a conductor 4a, 4b is inserted, to cut the sheath 11a, 11b of the conductor 4a, 4b and 4b. come into contact with the conductive core 10a, 10b.

  The fork connectors are U-shaped in the center of which the driver is inserted. The width of the U is adapted to cut the sheath and to make electrical contact with the driver's core.

  An insertion start phase of the conductors 4a, 4b is shown in FIG. 4 and a position of cooperation in electrical continuity is shown in FIG.

  In the case illustrated, the connecting device 7 has a substantially mushroom cross section with a trunk 13 whose base 14 constitutes an electrical connection zone of the circuit 6 and having a head 21 at which the insulating wall 12 is constituted.

  More specifically, the head 21 cooperates with two flanges 18, 19 folded towards the trunk 13 advantageously in the direction of the base 14 thereof so as to define two cavities 20a, 20b marked in FIG.

  Advantageously, the mouth 23a, 23b of the wings 18, 19 defines a rounded periphery of entry into the cavity 20a, 20b facilitating the insertion of the conductors 4a, 4b. Connection members are formed at the bottom of the cavities 20a, 20b.

  Also advantageously, a retention boss 22a, 22b is formed on the inner wall of the flanges 18, 19, slightly below the connecting members 8, 9 so as to constitute a retaining surface of the conductors 4a, 4b in each connecting members 8, 9.

  The function of the retention bosses 22a, 22b can be combined with a certain mechanical elasticity of the wings 18, 19. More specifically, during the insertion of the conductors 4a, 4b, the wings 18, 19 are slightly spaced from the surface of the trunk 13 so as to easily accommodate the conductors 4a, 4b within the cavities 20a, 20b to the connecting members 8, 9. By releasing the spreading force of the wings 18, 19, when the insertion is complete, the return to position of the wings 18, 19 ensures optimum retention of the conductors in the connection device 7 avoiding untimely release.

  According to the variant of Figure 5, the retention boss 22a, 22b is more pronounced in Figure 4. In this way, the retention can be accentuated.

  In addition, the smaller the space between the boss 22a, 22b, the more the conductor 4a, 4b housed in the connection member 8, 9 is protected against external aggressions such as dirt, sludge, water, etc.

  In a variant not shown, in the rest position, the wings 18, 19 are applied on the trunk 13 at the boss 22a, 22b.

  Note that the trunk 13 shown in the figures is substantially cylindrical but that this physiognomy is not limiting. In particular, it may have a relief opposite each boss 22a, 22b.

  As shown in FIG. 5, each connection member 8, 9 is connected by a wire, respectively 17, 16, to an interface device 24 providing an electrical and / or electronic interface to connection connection means. link circuit 6.

  Referring now to FIGS. 7 and 8, another example of formation of a connection device 7 is shown in which a housing 30 of substantially rectangular parallelepiped shape and delimiting an interior receiving volume of an interface device 24 as well as that connecting means in the form of forks 31a, 31b is presented. The housing 30 includes a base portion receiving the various means set forth above and a hingedly hinged cover portion and foldable over the base portion so as to close the assembly.

  The forks 31a, 31b are of current design and each receive one of the electrical conductors 4a, 4b as illustrated in Figures 7 and 8.

  Each fork 31a, 31b is electrically connected to the interface device 24. At the output of the device 24, a link circuit 6 is connected to the input of the detonator 1. It will be noted that the link circuit 6 could be replaced by any other type of electrical connection. For example, the detonator 1 can be attached directly to one of the faces of the connection device 7.

  Both in the case of the embodiment illustrated in FIGS. 4 to 6 and in that shown in FIGS. 7 and 8, the interface device 24 comprises lines 29a, 29b, for example, shown in FIGS. 6 and 8, capable of electrically connecting a conductor. 4a, 4b electric to an electrical input of a detonator 1, for example via a connecting circuit 6 as in the illustrated case but not limiting. Each line 29a, 29b may for example simply consist of a conductor type electric wire copper core and sheathed.

  The term electrical connection here refers to the capacity of the lines 29a, 29b to put in electrical continuity the conductors 4a, 4b of the control surface circuit 3 and the detonator 1. Any physical embodiment is within the scope of the present invention.

  Still with reference to FIGS. 6 and 8, short-circuiting means 27 are presented between lines 29a and 29b. In the illustrated case, a controlled switch is shown. However, the short-circuiting means 27 can be made by any suitable electrical or electronic arrangement. In particular, a transistor system can be used to perform the function of opening and closing the short-circuiting means 27.

  Also shown in Figures 6 and 8 an interface device 24 having a switch means 28 at one of the lines 29b. Through this switch means 28, for which any electrical or electronic variant falls within the scope of the present invention as for the short-circuiting means 27, the electric input of the detonator 1 can be completely isolated from the circuit control surface 3.

  As indicated above, both the short-circuiting means 27 and the switch means 28 are controlled by a control signal enabling their configuration to be modified between an active or inactive position and an open and closed position. The control signal is generally an electrical signal carrying a binary activation or deactivation information. The control signal can be produced at the interface device 24 itself by a control module or transmitted by the device 24 from an element outside said device 24, for example by the central unit of the head 5 .

  The control module may, according to a first possibility, comprise a microprocessor coupled to a memory containing program instruction data for controlling the switch means 28 and the short-circuiting means 27 by itself or in cooperation with the central unit 5 (in this case, the control module locally interprets instruction data addressed by the central unit 5).

  Advantageously, the control module further comprises an electronic circuit. The assembly is powered by the surface circuit 3.

  According to another possibility, the control module essentially consists of a wired logic circuit (including gates or, and or other conditions) able to be configured according to the signals received from the surface circuit 3 so as to produce the desired commands.

  An example of operation of the interface device 24 in which the device 24 fulfills at the same time the functions of locating, testing and isolating the detonator 1 for security reasons is described below.

  The switch means 28 is in this default setting in the open position and isolates the detonator 1 connected in parallel to the surface circuit 3. The switch means 28 closes only on an order (control signal) carried on the circuit 3 from the central unit 5 and interpreted and transmitted by the interface device 24.

  The short-circuiting means 27 is in turn in the active (closed) position at rest. It then bypasses the two input wires of the detonator 1 putting them at the same potential. It is easy to understand that the detonator 1 can not, in this case, be put into operation, which could happen if wires were damaged and in contact with the ground or with other wires of the detonator network thus establishing an electrical circuit. through the ground by leakage or leakage. This security is offered regardless of the position of the switch means 28.

  To ensure communication between the surface circuit and the detonator, the short-circuiting means 27 are switched in open mode by a control signal advantageously transmitted from the central unit 5 by the surface circuit 3 and this before the switch means 28 is actuated in closing to ensure communication between the surface circuit 3 and the detonator 1.

  After mounting the connection device on the surface circuit 3 and the detonator 1 connected to the other end of the connection device 7, the support on the member 25 triggers a test procedure at the control module generating instructions from a computer program for triggering a connection test function on the surface circuit 3. The control module of the interface device 24 then sends a signal to the central unit of line 5 which responds to it in communicating an identification message including an identifier to the connection device 7. Then, the control module of the interface device 24 performs the tilting cycle of the short-circuiting means 27 and the switch means 28 for a time short enough not to allow sufficient energy to be supplied to detonator 1 to trigger firing. In this time interval, the central unit of line 5 interrogates the detonator 1 and communicates a network identifier. This operation makes it possible to check the good connection of the detonator 1 to the connection device 7 and the integrity of the wires necessary for the electrical connection up to this point.

  Advantageously, an indicator 26 present on the interface device 24 informs the user responsible for mounting that the electrical connections are correct and that the operation is normal.

  Another function of the short-circuiting means 27 is to short circuit the electric circuit formed between the central unit 5, the surface circuit 3 and the connection device 7 for a short time so as to measure the distance separating the central unit of line head 5 to the connection device 7 considered. More specifically, the central unit of line 5 sends an encoded command with an identifier to the interface device 24. The latter, through the control module, closes a short time (of the order of a few milliseconds ) the short-circuiting means 27 and the switch means 28 thus bypassing the surface circuit 3 and allowing the central unit 5 to measure an electrical quantity characteristic of the length of the circuit thus formed in short circuit. It can be the impedance of the electrical conduction assembly thus formed or the intensity value of the current. The measurement of this electrical quantity makes it possible to determine either a relative positioning of the interface device 24 with respect to other devices in the same pyrotechnic installation or to determine an absolute value of distance between the central unit 5 and the device. interface 24 considered.

  Note that in the illustrated embodiment, the assembly is greatly simplified for the user. Indeed, the electrical connection is very convenient because of the configuration of the connection device 7 itself. In addition, the test of the correct operation and the location of the interfacing device 24 in the electrical circuit (and consequently the positioning of the positioning of the detonator 1) is effected by a simple manipulation (pressure on a member 25 of the button type). at the level of the interfacing device 24 which, in the illustrated case, is very accessible since close to the surface. This configuration is therefore more advantageous than integrally forming the detonator 1 and the interface device 24 although this solution is within the scope of the present invention.

  For preference, the interface device 24 is an integrated circuit card integrating the control module and the shortcircuiting means and the switch means described above. The set is thus small and inexpensive, allowing production in large numbers.

REFERENCES

  1. Detonator 2. Hole 3. Surface circuit 4a, 4b. Electrical conductors 5. Head-end central unit 6. Connecting circuit 7. Connecting device to 8. Connecting body 9. Connecting body 10a, 10b. Soul 11a, 11b. Sheath 12. Insulating wall 13. Trunk 14. Base 15. Means of connection 16. Wire 17. Wire 18. Wing 19. Wing 20a, 20b. Cavity 21. Head 22a, 22b. Boss 23a, 23b. Mouthpiece 24. Interface device 25. Trigger member 26. Indicator 27. Means for short-circuiting 28. Switching means 29a, 29b. Line 30. Housing 31a, 31b. forks

Claims (20)

  An interface device (24) for detonator (1), comprising two lines (29a, 29b) each adapted to electrically connect an electrical conductor (4a, 4b) of a control surface circuit (3) to a electrical input of a detonator (1), characterized in that it comprises means for short-circuiting (27) the two lines (29a, 29b) controlled by a control signal.   2. Device according to claim 1, comprising a switch means (28) on one of the lines (29a, 29b), activatable by a control signal.   3. Device according to claim 2, wherein the switch means (28) is upstream of the short-circuiting means (27).   The apparatus of claim 3, wherein the shorting means (27) is configured to be active by default and the switch means (28) is configured to be open by default.   5. Device according to claim 4 comprising a control module of the short-circuiting means (27) and the switch means (28).   6. Device according to claim 5, in which the control module comprises means for: addressing a request for identification to a central head-end unit (5) of the control surface circuit (3); response containing identification data of the interface device (24).   7. Device according to claim 6 wherein the control module comprises means for producing an error signal if the response to the identification request is not received.   8. Device according to claim 7 wherein the error signal is audible or visual.   9. Device according to any one of claims 5 to 8 wherein the control module comprises means for: - addressing an inactivation control signal to the short-circuiting means (27); sending a closing control signal to the switch means (28); transmitting an identification message received from a head end unit (5) of the control surface circuit (3) to the detonator (1); - receive an acknowledgment of the identification message from the detonator (1); - Addressing an opening control signal of the switch means (28); - Address an activation control signal of the short-circuiting means (27).   10. Device according to claim 9 wherein the control module comprises means for producing an error signal if the acknowledgment of receipt is not received.   11. Device according to claim 10 wherein the error signal is sound or visual.   12. Device according to any one of claims 5 to 11 wherein the control module comprises means for: - receiving a registration order; - address, if necessary, an activation control signal to the short-circuiting means (27); - send a closing command signal to the! switch means (28); and, after a determined delay, - addressing an opening control signal of the switch means (28); so as to form a temporary short circuit in the control surface circuit (3) and the interface device (24) to allow the measurement of an electrical magnitude dependent on the length of the electrical conductors separating a head central unit line (5) of the surface circuit (3) and the interface device (24).   13. Device according to any one of claims 5 to 12 comprising at least one button (25) for triggering the operation of the control module.   14. Device according to any one of claims 5 to 13 wherein the control module is formed on an integrated circuit card.   15. Connecting device (7) for detonator (1), between a control surface circuit (3) comprising two electrical conductors (4a, 4b) and a connecting circuit (6) to a detonator (1), said device connecting device (7) comprising two connecting members (8, 9) each connectable to an electrical conductor (4a, 4b), characterized in that it integrates an interface device (24) according to any one of the claims 1 to 14, each line (29a, 29b) is in electrical continuity with a connection member (8, 9).   16. Installation of pyrotechnic shots with a plurality of detonators (1) connected by a connecting circuit (6) to a control surface circuit (3) comprising two conductors (4a, 4b) characterized in that it comprises at least one device (7) according to claim 15 between the surface circuit (3) and a connecting circuit (6).   17. A method of detecting the position of a detonator (1) in a pyrotechnic fire installation having a plurality of detonators (1) connected in parallel with a control surface circuit (3) provided with two electrical conductors ( 4a, 4b), characterized in that the following marking operations are carried out: -use of an interface device (24) according to any one of claims 1 to 14 for electrically connecting the detonator (1) to locate at the surface circuit (3); control of the short-circuiting means (27) of the interface device (24) for activating them; measurement of the value of an electrical quantity as a function of the length of the electrical conductors (4a, 4b) separating a head end unit (5) of the surface circuit (3) and the interface device (24).   18. The method of claim 17 wherein the electrical quantity is the impedance of the electrical circuit formed between the central unit of head-end (5), the electrical conductors (4a, 4b) and the part of the interface device ( 24) upstream of the short-circuiting means (27).   19. The method of claim 17 wherein the electrical magnitude is the intensity of the current flowing in the electrical circuit formed between the central unit of the head (5), the electrical conductors (4a, 4b) and the portion of the device. interface (24) upstream of the short-circuiting means (27).   20. A method according to any one of claims 17 to 19 wherein: - the tracking operations for several detonators (1) are repeated, an order is assigned to the detonators (1) according to the measured value associated with them.