DE69902704T2 - Mine, in particular for fighting tanks or vehicles, with means for confirming the presence of a target - Google Patents

Description

The technical subject matter of the present invention is mines, in particular anti-tank mines or mines for combating vehicles.

Current anti-tank mines contain at least one explosive charge designed to be detonated by an ignition device, e.g. a detonator.

The explosive charge is generally a flat charge or a core-forming charge in which the explosive is given a metal covering.

The firing process is usually initiated by an electronic module or circuit connected in some way to one or more target sensors (magnetic, acoustic or seismic technology).

The patent FR2475716 describes such an anti-tank mine.

Although electronic modules have now become sufficiently complex to be able to detect a given target from a distance, the risk remains that a mine will react in an undesirable way to rough handling.

For example, mines used to combat vehicles pose a danger to infantry that should not be underestimated, both during military missions when clearing mines and when disposing of former combat zones.

The aim of the invention is to propose an anti-tank mine whose efficiency is not limited compared to vehicles but has an increased level of safety compared to the troops on foot and the civilian population.

The mine according to the invention therefore requires not only an initial identification of the target object in order to be detonated, but also confirmation that the identified object is a vehicle.

Furthermore, this confirmation must only take a very short time interval, which corresponds to the time required to trigger the mine. The mine should go into the neutral state very quickly.

Thus, the object of the invention is a mine, in particular for combating tanks or other vehicles, which contains at least one explosive charge, the ignition of which is an electronic circuit connected to the target detection sensors is triggered, the mine being characterized in that it has at least one means for confirming the presence of a target, means comprising at least one confirmation sensor which is projected towards the target by means of a projection member when the sensors report the approach of the target object.

Advantageously, the confirmation sensor is integrated with a control box, the projection device consisting of a pyrotechnic charge.

The mine's control box can be connected to the mine by means of a sufficiently strong holding cord to limit the throwing distance.

The confirmation sensor can be equipped with an accelerometer and/or a magnetic or electromagnetic sensor.

The confirmation sensor may include an electrical contact.

It would be advantageous to equip the mine with at least two confirmation sensors of different nature.

According to a preferred embodiment, the control box contains the electronic circuit.

The control box may contain an electrical energy source.

The mine can be equipped with an electrical connection cable, which is connected to the control box by means of a removable plug connection.

According to a variant of the implementation, the length and the mechanical resistance of the electrical connection cable and/or the connector can be such that the electrical connection is interrupted if the control box is ejected beyond a maximum height.

The control box can contain a remote control receiver.

According to another feature of the invention, the control box releases a latch when it is ejected, which holds a slider in the safety position to interrupt the pyrotechnic chain.

Advantageously, the slider for interrupting the pyrotechnic chain after the bolt has been released could be moved from its original safety position to a second armed position and to a third neutralisation position by the action of motor forces, in which latter position it interrupts the pyrotechnic chain.

The mine may contain means to ensure irreversible locking of the slide when it is in the neutralisation position.

The invention will be better understood by reading the following description of the various embodiments, with the help of the attached drawings in which:

- Fig. 1 is a partial longitudinal section in elevation of a first embodiment of an anti-tank mine according to the invention;

- Figures 2a, 2b and 2c show three stages of the use of a mine according to the invention;

- Fig. 3 is a logic diagram of the sequence of stages of a mine according to the invention;

- Fig. 4 is a detailed view of a second embodiment of a valve for interrupting the pyrotechnic chain in use in the mine according to the invention, the valve here being in the safety position for storage;

- Fig. 5a shows the same slider in the safety position, Fig. 5b in the mine armed position and Fig. 5c in the mine neutralized position;

- Fig. 6 represents a second embodiment of a mine for combating tanks according to the invention;

- Figures 7a and 7b show, in two positions, a vertical sensor in use in this second type of implementation of the mine;

- Figures 8a and 8b show the safety latch for storage in this implementation, respectively in active and inactive position;

- Figures 9a and 9b are partial cross-sections of the control box 17 in the plane AA of Figure 1, Figure 9c is a view of the extremity of the second bar;

- Fig. 10 is a detailed view of the mobile relay in use in the variant of Fig. 6.

Referring to Figure 1, a mine 1 according to the invention for combating tanks or other vehicles has a body 2, made for example of plastic, inside which the explosive charge 3 is placed, which is covered by a noticeably conical metal cover 4.

At the rear end, the body 2 is closed by a cover 16.

The explosive charge is designed to be ignited by a detonation relay 5, which in turn is triggered by a detonator 6 with electrical excitation.

Relay and ignition capsule are in solidarity with a device for securing the arming 7 which here is equipped with a slide 8 mounted slidingly in a support to interrupt the pyrotechnic chain.

The device for securing the arming is located in the middle of a protective plastic cover 58. This device is shown here in its storage securing position, in which the slide 8 is located between the ignition capsule 6 and the relay 5.

The slide 8 is pushed into its armed position by means of force 9 (here a spring). It is advantageous to provide delay means that allow the slide to be given a stroke with well-defined characteristics in terms of speed and duration. For example, an escapement plate (clockwork) could be used in which one of the gears engages the teeth of a rack carried by the slide 8.

The slider is held in place by a first latch 10, a radial rod whose one end 10a presses on the slider. held in the safety position. The other end, 10b, of the rod is extended and held by means of a tube 11 (shown here in dashed lines), which belongs to a launching system of the mine. An ejection spring 12 lies compressed between the body 2 and the end 10b of the rod, in a depression 13 of the body 2.

The function of this spring 12 is to eject the locking rod 10 from the mine when it is scattered on the field and thus to release one of the locking mechanisms of the safety device for arming 7.

Such a general structure of the anti-tank mine is known, in particular through the patents FR2475716 and US4252062, which can be used specifically to describe the mine body and the radial bolt.

The slide 8 has an opening 14 which is intended to establish the connection between the detonator 6 and the relay 5 when the slide is in the "armed" position.

The slider has the option of moving beyond the "armed" position, so that it once again interrupts the pyrotechnic chain (Fig. 2c). It then reaches the so-called neutral position, in which known devices (not shown here), such as spring blades, hold it in this neutral position and prevent the slider from returning to the "armed" position.

A second bolt 15, in the form of a rod inserted lengthwise, penetrates the safety device 7 and the opening 14 of the slide 8. This bolt ensures that the slide is held in the safety position, even after the first bolt 10 has been removed.

The second bolt 15 passes through the explosive charge 3 and the ceiling 4 and enters the control box 17, which, of noticeably cylindrical shape, lies on the ceiling 4 of the explosive charge.

Box 17 contains one or more means for confirming the presence of a target object. Two means are indicated schematically here: a Accelerometer 18 and a coil 19 of a magnetic detector.

The box 17 also contains an integrated electronic circuit 20 for processing the signals and an energy source 21, such as a lithium battery, intended to supply both the electronic circuit 20 and the detonator 6 with energy.

The box also contains a glow plug 22 and a gas generating composition 23 (e.g. a composition of aluminum/copper oxide [AlCuO]).

A multi-core electrical connection cable 24 allows the detonator 6 to be connected to the electronic circuit 20. The same cable also connects the electronic circuit 20 to a target detection coil 25 located around the safety device 7. Likewise, the cable connects the electronic circuit 20 to a circuit breaker (not shown here) which is activated by the ejection of the rod of the bolt 10, which energizes the electronic circuit when the mine is scattered in the field.

The electrical connection between the cable 24 and the circuit 20 is made via a removable plug 26.

A sufficient length of the cable 24 must be provided and accommodated on the ceiling 4 so that the cable 24 does not hinder the throw of the control box 17 as described in more detail below.

Advantageously, the box 17 is held on the ceiling by a connecting means, such as a thin plastic cover 27, easily fastened by clamps in the mine body 2. This cover can also prevent the penetration of moisture into the mine body and will protect the electrical connecting cable 24.

A trace of adhesive may also be provided between the ceiling and the box 17 to reinforce the joint, or another connecting means, such as the control box is held in place by a bracket that is solidly attached to the ceiling.

The lower part of the box 17 has a cylindrical part 28 of smaller diameter around which a retaining cord 29 is wound. One of the ends of the cord is fixed to the box and the other end is solid with the center of the ceiling 4, e.g. by means of a screw, in order to maintain the possibility of dismantling the box.

The end of the second bolt 15 is made solid with the box 17 by means of a releasable connecting means.

This connector is shown in more detail in Figures 9a and 9b.

The box 17 has a transverse groove 30, inside which a releasable connecting means 31 is stored. This connecting means consists of two spring blades of rectangular cross-section 32a, 32b, made of spring steel, the extremities of which are in solidarity with two cast-in buttons 33a and 33b.

The rod 15 of the second latch (Fig. 9c) has a rounded end 15a and an annular groove 34 into which the spring slats 32a and 32b engage.

When the box 17 is inserted into the mine, the rod of the second bolt 15 penetrates into the box 17 and its rounded end 15a spreads the spring leaves 32a, 32b.

These take up their original position in the groove 34 and ensure the solidarity of the second bar 15 with the box 17.

If it is desired to remove the box 17 (e.g. to neutralize the mine or replace the battery 21), the box and the second latch 15 can be separated from each other by pressing the keys 33a, 33b in the direction of F1 and F2.

This action has the effect of deforming the spring slats 32a, 32b (see Fig. 9b) and thus releasing the rod of the second latch 15.

The function of the mine according to the invention will now be described with the aid of the organizational chart in Figure 3 and Figures 2a, 2b and 2c.

First, the mine is laid in the field in the conventional way (either by hand or by scattering). The laying has first led to the ejection of the first bolt 10 and the mine is now awaiting a target object or in readiness E1 (Fig. 3).

In this state, the electronic circuit 20 processes the information sent to it by the detector coil 25 in a conventional manner. The changes in the magnetic field are therefore measured and compared with the reference values present in the memories or registers of the electronic circuit.

When a target object 35 whose magnetic characteristics match one of the stored values is detected (test T1), the electronic circuit 20 does not command the ignition of the explosive charge as in the case of mines of earlier design, but the ignition of the glow plug 22, which sets the gas-forming composition 23 on fire.

The box 17 then breaks the thin lid 27 and is ejected vertically upwards towards the target object 35 (stage E2), pulling the electrical cable 24 and the retaining cord 29 (Fig. 2b) with it.

This ejection has two consequences:

- on the one hand, the second bolt 15 is taken away from the box 17. The slide 8 of the safety device is released (stage E3) and is pushed by the action of the force means 9 from its "safety" position to the "arming" position (stage 4), in which the detonator 6 is aligned with the relay 5;

- on the other hand, the control box 17 approaches the target object 35 in direction F and strikes the target (the floor assembly of the vehicle) at a distance from the mine of the order of 0.5 m to 0.8 m.

The ejection of the box also allows the clearing of the soil in front of the mine if it is a buried mine.

The approach between box 17 and the target results in the emission of signals from the detector contained in the box.

The magnetic detector 19 detects a change in the magnetic field, which allows the magnetic mass of the target object to be confirmed. The output signal is compared with the stored signals to confirm the magnetic characteristics of the target object.

When impacting the target object, the accelerometer 18 registers a deceleration which allows the hardness of the vehicle's floor assembly to be evaluated; this signal is also compared with the stored values.

The electronic circuit 20 processes the values supplied by the confirmation detectors and carries out a confirmation test (test T2).

It states that the presence of a target object is confirmed if the deceleration signal and the magnetic signal are also correct.

In this case, the order to arm is given to detonator 6 (stage E6).

If the slider is still in the "sharpen" position (test T3), the mine is armed (stage E8).

If the slider is no longer in the "arming" position but has taken the "neutralization" position (stage E5), the arming of the detonator has no effect on the mine (stage E9).

If during test T2 only one of the two signals is correct, or if neither of the signals is correct, the detonator is not armed (stage E7). In the meantime, the slider moves to the "neutralization" position (stage E5) and the mine remains in the field in a perfectly secured state, since the safety device is in the "neutralization" position.

The mine is therefore only dangerous in the relatively short time interval during which the slider is in the sharpened position. The power means must be designed in such a way that the mine is only in the sharpened state for 20 to 40 milliseconds. Such a design is easy to implement, for example by using a suitable escapement plate or by using a miniature motor that drives the slider via a pinion/rack combination via the electronic circuit 20.

Furthermore, during this short period of time the mine can only be armed if the presence of a well-defined target object is confirmed by the target detectors contained in Box 17.

Therefore, if clumsy handling, e.g. when recovering the mines, causes the box 17 to be ejected, it will not hit a target and will separate from the mine (Fig. 2c) without causing it to explode. It is then easy to distinguish the neutralized mines from the others.

Furthermore, if the ejection of the box is triggered by a person, the impact of the box on the person results in a deceleration value that is in no way proportional to that of an impact on the underbody of a vehicle. The mine is therefore not activated. On the other hand, it should be noted that the mass of a confirmation box according to the invention does not exceed 50 g, it is ejected at a speed of about 30 m/sec, the corresponding kinetic energy is 22.5 joules, which has little effect on a person.

The retaining cord 29 prevents the box 17 from moving vertically more than approximately one meter. This limits the risk of the box hitting a person near the mine.

It is advantageous to dimension the electrical connecting cable 24 so that it breaks if the box 17 moves more than 0.8 m away from the mine.

This creates a physical separation between the body of the mine and the explosive charge, the detector electronics and the energy source which are located in box 17. This increases safety because on the one hand the slider is set to neutralization in the explosive part of the mine, and on the other hand the control electronics are separated from the mine.

Different variants are possible without leaving the scope of the invention.

It is therefore possible to vary the number of confirmation detectors in the box: a single detector, two or more. The greater the number of detectors, the greater the security provided by the system.

The nature of the confirmation detectors can also vary: magnetic field sensors, inductive sensors, isolating switches, piezoelectric capsules.

The load for ejecting the box can be replaced by a telescopic rod.

The box can also contain other electronic components, e.g. a remote control receiver that allows you to change the mine's operating algorithms remotely or to remotely control the mine's activation or deactivation.

It is also possible to use a sharpening device with a different concept.

Thus, Fig. 4 shows a safety device 7 for arming the mine, in which the slide 8 is designed to rotate about an axis 36. Here too, the slide is held in the safety position by a first bolt 10 and a second bolt 15. The slide 8 [let us now call it rotor 8] is set in rotation by means of delayed drive means such as an escapement plate 37 of known design.

The rotor has a circular arc-shaped opening 38 (see Fig. 5a, 5b, 5c). It also has two notches, 39 and 40 on its circumference, designed to cooperate with the spring blades 41 and 42, which are in solidarity with the safety device 7.

During storage of the mine and while awaiting a target object, the rotor remains in the position shown in Fig. 5a.

After the bolts 10 and 15 are withdrawn, the escapement plate rotates the rotor 8 around its axis in the direction of the arrow Z.

One millisecond after the release of the second bolt 15, the rotor goes into the armed position, the detonator 6 is then located opposite the relay 5 (Fig. 5b).

30 to 50 milliseconds after the release of the second latch 15, the rotor goes into the "neutralization" position (Fig. 5c). In this position, the rotor becomes a barrier that separates the detonator 6 from the relay. The spring leaf 41 cooperates with the notch 40 and prohibits the rotor from returning to the armed position. The spring leaf 42 cooperates with the notch 39 to prevent any further rotation that could lead to the armed position again.

The rotor is therefore completely immobilized from rotating relative to the safety. The mine is therefore neutralized and no arming of the system is possible without disassembly.

Figure 6 shows another possibility of implementation according to the invention.

This type of implementation differs fundamentally from the previous one in that it is designed on two sides, i.e. it consists of two charge covers 4a, 4b, each cover over an explosive mass 3a, 3b.

The assembly of such a mine is facilitated by the fact that the body of the mine consists of two shells 2a and 2b.

A double-ended mine is easier to deploy in the field because it is able to function correctly no matter what position it occupies on the ground.

The patent US 4252062 describes such a double-sided mine and it is recommended to use this patent, especially for the special structure of the Arming means that allow the mine to function with just one electric glow plug 6.

The means for arming consist of two ignition relays 43a and 43b, each near one of the covers, intended to cooperate with a mobile relay 44 which slides with play in an axial tube 45. This relay is shown in detail in Fig. 10. It consists of two small relay charges 59a, 59b, each at one end of the relay tube 44 and connected to each other by means of a connecting cord 60 glued to a generatrix of the tube. The hole 62 visible in Fig. 10 allows the rod of the first bolt 10 to pass through.

In the safety position for storage, the mobile relay is in the central position shown in Fig. 6. In this position, it is immobilized by the first bolt 10 which passes radially through it in the hole 62 in order to also immobilize the isolating slide 8 of the pyrotechnic chain.

When the mine is deployed, the first bolt 10 is radially projected by its spring 12 and the mobile relay slides under the influence of gravity to a position where it rests on the cover of the explosive mass facing the ground.

In this position, one of the relay charges 59a or 59b is opposite the detonator 6 and the other relay charge is opposite one of the ignition relays 43a or 43b.

The ignition of the detonator 6 results in the arming of one of the relays 59a, 59b, which arms the ignition relay 43a or 43b via the connecting cord 60, as well as the other relay 59a or 59b.

Thus, whatever the ground position, the explosive charge of the mine is armed by the relay closest to the ground, which triggers the movement of the ceiling lying towards the target object.

According to the invention, this mine is equipped with two control boxes, 17a and 17b, each containing the means for confirming the presence of a target object.

Each box rests on the cover of an explosive charge (4a, 4b) as described above with reference to Fig. 1.

Each box encloses an electronic circuit 20, a power source 21 and one or more confirmation detectors (such as accelerometer 18 and coil 19) as described above.

Each box is also provided with a glow plug 22 and a gas generating composition 23.

Each box is connected by an electric cable 24a, 24b to the detonator 6, the detector coil 25 and to electric isolators (not shown) which are activated when the first bolt 10 is ejected and cause each control box to be energized. Thus, each switch can independently identify a target object and cause the mine to be armed.

In addition to this common structure, which corresponds to the implementation shown in Fig. 1, each control box also contains a verticality sensor 46.

A special type of implementation of such a sensor is shown in Fig. 7a and 7b. The sensor is formed from a circuit breaker, known as a "reed switch". Such a circuit breaker consists of two magnetizable contacts 47a, 47b enclosed in a glass capsule 48 and a ring-shaped magnet 49 placed around the glass capsule and sliding along it.

A plastic guide tube 50 facilitates the sliding of the magnet and guides it with respect to the glass capsule. This unit is enclosed in a housing 51 which is fixed to the base 52 which carries the contacts 53a, 53b of the isolating switch.

Depending on the position of this circuit breaker in relation to the vertical, the magnet assumes one or other of the positions shown in Figs. 7a and 7b. In one of the positions of the magnet, the contacts 47a and 47b are separated from each other (Fig. 7a) or they touch each other (Fig. 7b).

By equipping each electronic circuit 20 with such a vertical detector, it is given the opportunity to know its position relative to the ground.

The electronic circuits are designed by the specialist in such a way that only the electronic circuit 20, which is connected to the box 17 and is located on the ceiling that is to be set in motion by the mine, is effectively activated.

In the same way as described above, each box 17a, 17b carries a rod 15a, 15b forming the second latch for the slider/rotor 8. The structure of these latches is clear from Figs. 8a and 8b.

The rotor 8 is provided with a safety device 7 for arming, similar to that described in connection with Figures 4 and 5a to 5c. The rotor has a flat 54 which cooperates with a bolt 55 to prevent the rotor from rotating. The bolt 55 is cylindrical and has a pin 56a, 56b at each end which penetrates into the bore 57a, 57b of a rod 15a, 15b.

The diameters of the pins 56a, 56b are approximately 1 mm smaller than the diameters of the holes 57a, 57b that they accommodate.

The structure of the various parts is such that the two rods 15a, 15b of the axis YY' are coaxial and the wood, displaced from this axis, rests against the holes 57a, 57b, at the level of the generatrix of the tenons 56a, 56b (Fig. 8a).

When one of the two rods 15a or 15b is pulled out in the vertical direction D, following the ejection of the confirmation box 17 associated with it (Fig. 8b), the bolt 55 is no longer held. It tilts in the direction of the arrow K and the rotor can rotate in the direction Z under the influence of its escapement plate.

The clearance between the pins 56a, 56b and the bores 57a, 57b, as well as the length of the pins, will be designed so that the rotor 8 can rotate without being hindered by the bolt 55.

The confirmation circuits used in this implementation are identical, which is advantageous for the modularity of the production.

Of course, it would be possible to design a mine in which the functions were divided between the control boxes 17a and 17b. For example, one could provide only one electronic circuit 20, only one power source and/or only one vertical sensor for the two boxes. These would exchange information between themselves via the electrical connecting cables 24a, 24b. However, it is essential to have confirmation detectors in each box.

Various variants are possible without departing from the scope of the invention.

For example, the electronic circuit and the power source could be located outside the box, at about the level of the safety device for arming, leaving only the confirmation detectors and the ejection means in the boxes.

However, one of the advantages of the implementation methods described above is that it is possible to store the confirmation boxes and the mines separately.

This makes maintenance operations easier (replacing batteries), updating (changing detection algorithms) and increases the modularity and safety of the mines. In fact, different confirmation boxes can be defined, containing a greater or lesser number of detectors, and can be assigned to the mines in stock depending on operational needs.

Claims (15)

1. Mine (1), in particular for combating tanks or other vehicles, which contains at least one explosive charge (3) whose ignition is triggered by an electronic circuit connected to the sensors for target detection, mine characterized in that it has at least one means for confirming the presence of a target, means which contains at least one confirmation sensor (18, 19) which is projected towards the target by means of a projection device when the sensors report the approach of the target object. 2. Mine according to claim 1, characterized in that the confirmation sensor is in solidarity with a control box (17), the projection element consisting of a pyrotechnic charge (23). 3. Mine according to claim 2, characterized in that the control box (17) is connected to the mine (1) by means of a sufficiently strong holding cord (29) to limit the throwing distance. 4. Mine according to one of claims 1 to 3, characterized in that the confirmation sensor is equipped with an accelerometer. 5. Mine according to one of claims 1 to 4, characterized in that the confirmation sensor is equipped with a magnetic or electromagnetic sensor. 6. Mine according to one of claims 1 to 5, characterized in that the confirmation sensor contains an electrical contact. 7. Mine according to one of claims 1 to 6, characterized in that it is equipped with at least two confirmation sensors of different nature. 8. Mine according to one of claims 2 to 7, characterized in that the control box (17) contains the electronic circuit (20). 9. Mine according to one of claims 2 to 8, characterized in that the switch box (17) contains an electrical energy source (21). 10. Mine according to one of claims 2 to 9, characterized in that it is equipped with an electrical connecting cable (24) which is connected to the switch box (17) by means of a removable plug connection (26). 11. Mine according to claim 10, characterized in that the length and the mechanical resistance of the electrical connection cable (24) and/or the plug connection (26) are dimensioned such that the electrical connection is interrupted when the control box (17) is ejected beyond a maximum height. 12. Mine according to one of claims 2 to 11, characterized in that the control box (17) contains a receiver for remote control. 13. Mine according to one of claims 2 to 12, characterized in that the control box (17) releases a latch (15) when it is ejected, which holds a slide (8) in the safety position for interrupting the pyrotechnic chain. 14. Mine according to claim 13, characterized in that the slide (8) for interrupting the pyrotechnic chain after the release of the bolt (15), by the action of motor forces (9, 37), is brought from its original safety position into a second armed position and into a third neutralization position, wherein in the latter position it interrupts the pyrotechnic chain. 15. Mine according to claim 14, characterized in that it comprises means (39, 40, 41, 42) ensuring the irreversible locking of the slide (8) when it is in the neutralization position.