EP4027098B1 - Device for controlling the stationing of a projectile in the tube of a weapon and control method implementing such a device - Google Patents

Description

The technical field of the invention is that of devices making it possible to control the placement of a projectile in the barrel of a weapon.

In large caliber weapon systems (caliber greater than 75mm), the projectile is generally separated from its propellant charge.

When loading, the projectile is first introduced into a chamber of the weapon and pushed to a so-called forcing cone which is an area where the diameter of the chamber is reduced to the diameter of the tube. The projectile is pushed until it is stuck at the level of the forcing cone by its belt or a rim of its body and it then seals the weapon tube at this area.

This sealing guarantees, on the one hand, a rise in nominal pressure of the propellant firing gases behind the projectile, and on the other hand the immobilization of the projectile in the weapon before firing.

It is known from the patent DE19737078 a device for monitoring the presence of a projectile in a weapon, device which comprises sonic sensors coupled to a sound source and which determines by comparison with a reference sound signature whether the weapon is loaded or not.

The device as described by this patent does not, however, detect whether the projectile is correctly loaded, that is to say correctly stuck or hooked in the forcing cone of the weapon.

However, it is essential to be able to check the quality of the attachment of the projectile in the forcing cone before triggering the shot.

Indeed, if the projectile becomes detached from the forcing cone, it will fall towards the chamber of the weapon, and this is even more so when the weapon is pointed at a positive angle.

This risks causing the projectile to fall out of the weapon if the breech is open, or to fall onto the propelling charge elements.

Even if the projectile does not detach but if the quality of the placement is insufficient, leaks of propellant gases are to be feared due to a lack of sealing between the projectile and the tube.

All of these events are highly detrimental to the safety of surrounding property and people.

The invention proposes to resolve this security problem by ensuring quality control of the positioning of the projectile in the forcing cone of the weapon.

The subject of the invention is thus a device for controlling the placement of a projectile in a tube of a weapon comprising a forcing cone intended to radially trap a projectile, device comprising at least one sensor intended to be placed in position placed against the tube of the weapon, sensor connected to a computer intended for processing a signal coming from the sensor(s), device characterized in that the sensor comprises a set of piezoelectric elements generating ultrasonic waves, sensor intended to be arranged so as to diffuse at least one ultrasonic wave front which is directed radially towards the longitudinal axis of the weapon and which is centered longitudinally facing the forcing cone, the sensor being chosen such that the wave front can extend inside the weapon tube over a width greater than the width of the forcing cone, the sensor also being able to receive at minus a reflection echo of the emitted wavefront and to transmit this echo in the form of an electrical signal to the computer.

Advantageously, the device comprises at least two sensors each oriented in radial directions to the weapon tube and which are perpendicular to each other.

• le capteur émet au moins un front d'onde et reçoit au moins un écho en retour ;
• le capteur transmet un signal représentatif de l'écho au calculateur ;
• le calculateur analyse l'écho par rapport à un écho de référence puis fournit une information relative à la mise à poste conforme ou non conforme du projectile.

The invention also relates to a method for controlling the placement of a projectile in the barrel of a weapon, a method implementing a device according to one of the preceding characteristics and characterized in that:

• the sensor emits at least one wavefront and receives at least one echo in return;
• the sensor transmits a signal representative of the echo to the computer;
• the computer analyzes the echo in relation to a reference echo then provides information relating to the compliant or non-compliant placement of the projectile.

Advantageously, the process can be activated following information about projectile placement.

Advantageously, the process can be deactivated after the shot, thus making it possible to verify that the projectile has left, or after unloading the projectile.

• [Fig. 1] montre une vue en coupe longitudinale d'un dispositif selon un mode de réalisation de l'invention.
• [Fig. 2] montre une vue en coupe transversale d'un dispositif selon une variante de réalisation l'invention.

The invention will be better understood on reading the following description, description made in light of the appended drawings, drawings in which:

• [ Fig. 1 ] shows a longitudinal sectional view of a device according to one embodiment of the invention.
• [ Fig. 2 ] shows a cross-sectional view of a device according to a variant embodiment of the invention.

According to figure 1 , a device 1 for securing the loading of a weapon is fixed to a weapon tube 10 of a caliber greater than 75 mm.

The weapon tube 10 comprises a bore 11 which is separated into two parts, on the one hand a chamber 12 intended to receive a projectile 100 and a propellant charge 101 and on the other hand a rifled part 13 intended to impart a gyroscopic movement to the projectile 100 fired by this tube 10.

The chamber 12 has an internal diameter D2 greater than the internal diameter D1 of the striped part 13. The progressive connection of the two diameters D1 and D2 between the chamber 12 and the striped part 13 takes place in a zone called forcing cone 14.

This forcing cone 14 allows a belt 102 of the projectile 100, located between a base 103 and a warhead 104, to ensure sealing against the propellant gases coming from the initiation of the charge 101.

The belt 102 consists for example of a malleable metal alloy capable of conforming by creep to the profile of the tube, in particular by occupying the stripes of the striped part 13.

If the projectile does not have a belt, it may include one or more beads having satisfactory dimensional and material characteristics to ensure a seal between the forcing cone and the projectile 100.

The device 1 according to one embodiment of the invention comprises at least one sensor 2 of a particular type, called an electro-magneto-acoustic sensor, as described below.

This type of sensor which is commercially available is capable of initially emitting an ultrasonic wave front 20 (arrows at the figure 2 ) in a support (here the weapon tube) on which it is fixed. Secondly, it can receive and transform the waves reflected in echo 21 by the support into an electrical signal which can be analyzed by processing electronics (such as a calculator 200). It comprises a set of piezoelectric elements 2b (generally several dozen) which are capable of generating ultrasonic waves 20 when they are controlled by an electrical signal and which can also conversely generate another electrical signal following their request by incident ultrasonic waves.

In this case, the sensor 2 is fixed on the tube 10 facing the forcing cone 14. A sound coupling medium 2a conducive to the propagation of ultrasonic waves 20, such as grease for example, is placed between the tube 10 and sensor 2 to ensure a perfect acoustic connection. The area of the tube 10 in which the wave fronts 20 and echo fronts 21 move is shown figures 1 And 2 by a gray area 2c.

The sensor 2 is arranged in such a way that the waves 20 that it generates travel radially through the material of the tube 10 and that of the belt 102 if a projectile 100 is placed in position, that is to say stuck in the forcing cone 14 .

It should be noted that the greater the contact pressure between the projectile belt and the tube, the better the propagation of waves between the two elements.

In the case where the projectile 100 is not placed in position, or when the jamming is not locally tight, an air blade is present between the forcing cone 114 and the belt 102. This blade hinders the passage ultrasound 20 and in return modifies the echo 21 which is perceived by the sensor 2.

The sensor 2 is electrically connected to a computer 200 to which it transmits a signal representative of the echo 21 perceived by the sensor.

The calculator 200 is able to interpret the nature of the echoes collected by the sensor 2. The calculator 200 thus compares the echo received with reference echoes which have been determined by experiment. It is then possible to provide a user with information regarding the conformity of the posting. via an interface (interface not shown), such as a screen or indicator lights.

The positioning will be compliant if the seal is satisfactory (no air gap or presence of an air gap whose thickness is below a predefined threshold).

It will be non-compliant (sealing fault) if the echo corresponds to the presence of an air gap whose thickness is above the predefined threshold.

It will also be non-compliant if the projectile is released or if the echo corresponds to a lack of belt.

Device 1 will ensure continuous monitoring of the state of the station. This monitoring will start with information about the positioning of the projectile 100, given for example by a firing control of the weapon or by the system controlling the loading of the projectile.

It can stop after the shot, thus making it possible to verify that the projectile has fired, or else it can be stopped after the possible unloading of the projectile 100 at the level of the chamber.

The detection of a non-compliant positioning may also, in addition to the display of the non-compliance information, order the prohibition of firing.

The sensor 2 will be chosen so that the wave fronts 20 that it emits and the echoes 21 that it receives cover an area of width L1 greater than the width L2 of the forcing cone 14 and up to twice the width L2 of cone 14.

This extended coverage makes it possible to take into account the dispersion of longitudinal positioning of the projectile 100 in the tube 10. This dispersion can come from wear of the forcing cone 14, from a variation in the force of placing the projectile 100 into position. or dimensional variations of the belt 102.

These sources of dispersion can obviously be combined, hence the importance of monitoring an area of the tube larger than the forcing cone 14 but remaining centered on the forcing cone 14.

For even greater security, it is preferable to use several sensors 2 oriented in radial directions to the tube 10 of the weapon and which are perpendicular to each other and perpendicular to the longitudinal axis X of the tube 10.

The signals from the two sensors will be combined at the level of the computer 200, the correct positioning being confirmed only if the two sensors provide correct positioning information.

It will be noted that the device according to the invention is non-intrusive with respect to the weapon since the sensors are placed against the tube 10 without any machining being necessary. The invention therefore allows adaptation to existing equipment without major modifications.

Claims (5)

1. - A device (1) for controlling the positioning of a projectile (100) in a tube (10) of a weapon including a forcing cone (14) intended to wedge a projectile (100) radially, the device (1) including at least one sensor (2) intended to be placed against the tube (10) of the weapon, which sensor (2) is connected to a computer (200) intended to process a signal originating from the sensor(s) (2), the device being characterized in that the sensor (2) includes a set of piezoelectric elements (2b) generating ultrasound waves (20), which sensor (2) is intended to be arranged so as to deliver at least one ultrasound wavefront (20) that is directed radially toward the longitudinal axis (X) of the weapon and that is centered longitudinally opposite the forcing cone (14), the sensor (2) being chosen such that the wavefront (20) can extend inside the tube of the weapon (10) over a width (L1) greater than the width (L2) of the forcing cone (14), the sensor (2) also being able to receive at least one reflection echo (21) of the emitted wavefront (20) and to transmit this echo to the computer (200) as an electric signal.
2. - The device (1) according to claim 1, characterised in that it includes at least two sensors (2) each oriented along directions radial to the tube (10) of the weapon and which are perpendicular to one another.
3. - A method for controlling the positioning of a projectile (10) in the tube of a weapon, which method implements a device (1) according to one of the preceding claims and characterised in that:

   - the sensor (2) emits at least one wavefront (20) and receives at least one echo (21) in return;

   - the sensor (2) transmits a signal representative of the echo to the computer (200);

   - the computer (200) analyzes the echo (21) relative to a reference echo (21), then supplies information relative to the compliant or noncompliant positioning of the projectile (10).
4. - The control method according to claim 3, characterised in that it is activated following an information that the projectile (10) has been positioned.
5. - The control method according to claim 4, characterised in that it is deactivated after firing, thus allowing verification that the projectile (10) has been fired, or else after unloading of the projectile (10).

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