FR2629581A1 - Piercing projectile with kinetic effect - Google Patents

Abstract

Piercing projectile with kinetic effect including a shaped elongate body for armour piercing. The shaped body of the projectile contains secondary projectiles such as rods 4 and means such as solid cores 1, 4 associated with a deformable intermediate element 2 to give rise to a radial displacement of the secondary projectiles 4 upon impact of the piercing projectile and as it penetrates into the armour. Application to piercing projectiles with kinetic effect, for increasing the effectiveness thereof at the back of the armour, by widening the zone affected.

Description

 The present invention relates to a kinetic effect piercing projectile.

 Various embodiments of projectiles of the indicated type are known, comprising an elongated profiled body for perforating armor by a simple impact effect, due to the high speed and density of the projectile which is often also endowed with a particularly hard point, to facilitate its penetration into the shielding. Projectiles of this kind are often called '1projectile-needles'.

 To improve the practical effectiveness of such a projectile which is generally not explosive, it is advantageous to seek to widen the zone affected by the impact and the penetration beyond the armor, in order to reach the personnel there. where the equipment that can sty find.

 The object of the invention is to produce a penetrating projectile with kinetic effect such that the area affected by the impact and the penetration of the projectile beyond the shielding is significantly enlarged, as has just been indicated.

 According to the invention, the kinetic effect perforating projectile comprising an elongated profiled body for perforating a shield, is characterized in that the profiled body contains secondary projectiles and means for causing a radial displacement of the secondary projectiles outside the profiled body, during of the impact of the penetrating projectile and during its penetration into the armor.

 The radial displacement of the secondary projectiles out of the profiled body of the perforating projectile gives each secondary projectile an oblique catjectory with respect to that of the perforating projectile. Thus, the trajectories of the secondary projectiles deviate in a relatively open manner with respect to the trajectory of the main projectile, ensuring the widening of the target area.

 8According to a preferred embodiment of the perforating projectile, lws means for causing the radial displacement of the secondary sections outside the profiled body comprise at least one solid core disposed in the body in front of the secondary projectiles; the aforementioned solid core has, opposite the secondary projectiles, a rear face of oblique profile with respect to the longitudinal base of the profiled body, to ensure by inertia an obliquity of the relative trajectory of the secondary projectiles at the moment of the impact of the projectile and of its penetration in the shield.

 At the time of the impact of the penetrating projectile, the solid core placed in front of the secondary projectiles is suddenly slowed down. The secondary projectiles strike it, and are deflected by its rear face which imposes on them a relative trajectory inclined relative to the trajectory of the penetrating projectile.

 Advantageously, the rear face of the solid core has a substantially conical profile co-axial to the profiled body; the tip of the aforementioned conical profile is directed towards the secondary projectiles disposed at the rear of the body.

Preferably, the secondary projectiles are substantially rectilinear elongated elements disposed in the axial direction of the body in a substantially cylindrical compartment thereof. Also preferably, the secondary projectiles are arranged at the periphery of the aforementioned cylindrical compartment, around a solid auxiliary core, having a front face of substantially conical profile directed towards the rear face of conical profile of the front solid core; an element made of deformable material is disposed between the two conical faces of the aforementioned solid cores, to be crushed axially by inertia, and deformed radially by the conical faces at the time of impact and of the penetration of the projectile.

 As explained below, the aforementioned provisions allow efficient industrial production of the piercing projectile according to the invention. We can improve the efficiency of several ways, in particular by preferably giving the solid core before a large mass and high mechanical characteristics, to involve this solid core in the perforation of the shielding.

 To fight by armored vehicles, it is not only a question of obtaining a perforation of the armor, but also of seeking an effective action against the men and the objects protected by the armor. With projectiles acting by their kinetic energy (kinetic perforators) we can generally admit that after the actual perforation (primary effect) there is still sufficient residual energy to obtain a so-called "effect" beyond the perforated shielding. rear "or side effect". The essential problem therefore consists, for this type of projectile, in distributing this residual energy at a relatively large solid angle behind the perforated armor (secondary effect).

 The object of the present invention is to increase the side effect of kinetic piercing projectiles, by mechanical fragmentation of the projectile. This fragmentation is obtained by a series of provisions provided for in the design of the projectile, ensuring rapid fragmentation in the radial direction or the detachment and radial projection of secondary projectiles after the perforation. This principle works for shooting against heavy armor, but also against a goal with thin or light armor compared to the total perforating capacity of the projectile, such as for example a compartmentalized armor of steel, a light alloy armor or other structures of protection: In the case of multi-plate armor, an appropriate design of the projectile makes it possible to obtain the desired side effect, that is to say the fragmentation of the projectile, behind each of the different plates.

 given that the radial fragmentation is certainly more difficult to achieve on a kinetic projectile perforating stabilized by empennage with high perforating power, than on a projectile stabilized by rotation, one will choose such a feathering projectile for the descriptio4 of the peculiarities of the invention, of which efficacy has been confirmed by experimental results.

Other particularities and advantages of the invention will also emerge from the description of some embodiments presented below, by way of nonlimiting examples, with reference to the appended drawings, in which
- Figure 1 shows two schematic views in axial and transverse section, of a first embodiment of the kinetic effect piercing projectile according to the invention;
- Figures 2 and 3, similar to Figure 1, each correspond to an alternative embodiment of the projectile;
FIGS. 4 (a) to 4 (d) represent chemically the arrangement of the test targets used to study in the laboratory the effectiveness of various projectiles in accordance with the invention;
- Figures 5 and 6 are flash x-rays of a test shot of a projectile in accordance with Figure 2 against a target in accordance with Figure 4 (a)
(v = 1364 m / s) for figure 5 and figure 4 (b)
(v = 1364 m / s) for Figure 6;
- Figure 7 is a schematic side view of a massive needle projectile, used for comparison (core material: heavy alloy based on tungsten) for a tube of 20 to 25 mm caliber;
- Figures 8 to II, similar to Figures 5, 6, are flash x-rays of test shots made for comparison with projectiles in accordance with Figure 7, against various targets, in particular in accordance with Figures 4 (b) and 4 (c); to know:
For figure 8:
Steel point needle projectile according to FIG. 7 during the impact (I) and after perforation (II) of a 26.5 mm thick armor plate (f = 1400 N / mm2) under 60C incidence.

Impact speed: 1406 m / s;
Angle at the top of the splinter projection cone: approx. 450.

For figure 9:
Steel point needle projectile according to figure 7 during the perforation of the steel target represented by figure 4b (v = 1353 m / s)
I: at impact II: at impact on the thin plate
intermediate
III: on impact on the back plate in
steel
For figure 19:
Heavy alloy point needle projectile according to figure 7, during the perforation of the steel target represented by figure 4c (v = 1373 m / s)
I: on impact on the 1st plate II: on impact on the 2nd plate
III: on impact on the 3rd plate
For figure 11:
Heavy alloy point needle projectile according to FIG. 7, during the perforation of a multi-plate target in Duralumin (dl = 1 mm, 820 incidence, d2 to d4 = 10 mm).

Impact speed: 1429 m / s.

- Figures 12 to 14, similar to Figures 8 to 11, are flash x-rays of test shots made with projectiles according to the invention (Figure 3), against targets according to Figures 4 (a), 4 (c) and 4 (d); to know:
For figure 12:
Projectile according to figure 2 during the perforation of the target represented by figure 4a (v = 1390 m / s).

For figure 13:
Projectile according to FIG. 2 during the perforation of steel multi-plates represented by FIG. 4c (v = 1375 m / s).

For figure 14:
Projectile according to figure 2 during the perforation of the target represented by figure 4d (v = 1338 m / s).

- Figure 15, similar to Figures 2 and 3, shows another alternative embodiment of the projectile according to the invention, which is, in block diagram, a projectile designed to obtain a maximum side effect;
- Figure 16, similar to Figures 12 to 14, shows a flash X-ray of a shot taken against a multiplaques target of Duralumin according to Figure 4 (d) with a projectile according to the invention (Figure 15) (v = 1393 m / s).

 Figure 1 shows the block diagram of a projectile designed in accordance with the invention to obtain as high a side effect as possible.

The main piercing element of the projectile is a solid anterior core 1 ending in a substantially conical part 1B. This cone is supported, by means of a body 2 of easily deformable material, on another ctne constituting the front of a second solid perforating core 3. Around this second core 3 are arranged in a crown of projectiles secondary 4 which, towards the front, are in contact with the conical face 13 at the rear of the first core 1 and are supported towards the rear on the base 5 of the projectile.

 The secondary projectiles 4 to be projected radially have in this case and in other examples the form of elongated cylindrical bars. In order to make better use of the space available in the projectile section, these bars can also have a prismatic shape so that when brought together in the projectile, their sections form a circular ring. After destruction of the thin cap P, necessary for reasons of external ballistics, upon impact on a target, the first core 1 is braked. Therefore it communicates, via its conical rear part, a radial component to the crown of secondary projectiles 4 so that these perforate the thin envelope 6.This radial projection of the secondary projectiles 4 is found further reinforced by the crushing of the deformable body 2 placed between the core 1 and the core 3 and which pushes the various secondary projectiles 4 outwards.

 The effectiveness of such an organization has been verified with variants of the projectile represented by FIGS. 2 and 3. This differentiation in design makes it possible to highlight the influence of the various elements of the projectile. The projectile of FIG. 3 does not have a body 2 with radial crushing; in this projectile, it is the shell 30 at the rear of the perforating core 31 which separates the secondary projectiles 32. The projectile of FIG. 2 comprises, in addition to the operating device produced in the rear part of the projectile of FIG. 1, a second ring of secondary projectiles 20 with a modified intermediate piece 21, plastically deforming (in the form of a socket in the presented lixfmple), placed in the front part of the projectile. On impact, this plastic deformation sleeve also opens in the radial direction under the action of the cone 22 at the rear part of the first perforating core 23, and the cbne 25 in front of the intermediate core 24, due of the different braking that these nuclei undergo.

 Furthermore, such a distribution makes it possible to assess the effectiveness of the different organizations on the various types of targets (see Figure 4). Thus, FIG. 5 shows the perforation of a homogeneous steel target at 600 incidence (see FIG. 4a) by a projectile designed according to FIG. 3. FIG. 6 shows the perforation by the same projectile of the target of the type represented by Figure 4b under zero incidence. The dimensions of the targets in FIGS. 4i) to 4 (d) are given for information only, as well as those of the experimental projectiles in FIGS. 2, 3 and 7.

 The design of a kinetic perforating project must essentially take into account the forces brought into play at the start of the body. The projectile organizations represented here are designed for accelerations of the order of 100,000 g.

For calibers greater than 100 mm, a launch by self-propulsion could be interesting. In this case, the accelerations would be reduced by a factor of around 102.

As a result, the margin would become much greater for the design of projectiles which the internal organization includes.

a large number of elements for obtaining a significant side effect. This therefore means that in the form of self-propelled projectiles the effectiveness of the invention could be further increased. t
To demonstrate the particular properties of the invention, the performance of a homogeneous needle projectile, having the same energy at impact, has been established for comparison. As shown diagrammatically in FIG. 7, this projectile is a laboratory model comprising a massive perforator provided with a ballistic cap at the front and a stabilization disc at the rear. (The figure also shows the elements required for guidance and the pusher shoe).

 Figure 8 shows (flash X-ray - 1st photograph) the impact of such a heavy alloy tungsten-based projectile (with steel tip), and the cone of splinters projected after perforation of an armor plate ( according to Figure 4a) 26.5 mm thick under 600 (flash x-ray - 2nd photo).

In Figure 9 we show this projectile perforating the double steel target of Figure 4b with a thin intermediate plate.

FIG. 10 represents the projectile of FIG. 7 with a point of heavy alloy during the perforation of the steel multi-plate target of FIG. 4c. Figures 9 and 10 make it clear that the solid perforator is practically not deformed by the passage through the plates of different thickness and that, therefore, the effect of such a projectile in the radial direction remains reduced. In FIG. 11, the projectile of FIG. 7 punctures a multi-plate target made of aluminum alloy (Duralumin), comprising a pre-armor of 1 mm inclined under 820 (see FIG. 4a). The three successive light x-rays show only a slight deformation of the projectile.

 The comparison between FIGS. 5 and 8 shows that the cone of projection of the fragments is much more open (around -600) in the case of a projectile of the type of FIG. 3 than in the case of a solid bar from Figure 7 (approximately 450). Figure 6 clearly shows the process of fragmentation of this projectile: on the three successive light x-rays we recognize the solid core (here made of heavy alloy based on tungsten). On X-ray II, we see on the right the bars (in tungsten) which are still held in part of the envelope. The conical part of the heavy alloy core which is in front of them, spreads.

We can also see the ring of tungsten splinters already projected outwards. In this case the flakes form a cone of 600 to 700 opening, while the flakes torn from the shield are projected into a cone of 900 to 1000.

 Figure 12 shows the projectile of Figure 3 during the perforation of a solid steel target at 600 incidence (see Figure 4a). In FIG. 13 is shown the m & e projectile during the perforation of the steel multi-plate target described by FIG. 4a. FIG. 4 shows the projectile during the perforation of the light alloy target of FIG. 4a, simulating an aerial objective.

 The radiograpMe I of FIG. 12 brings, quite by chance, a confirmation of the effectiveness of the projectile in accordance with the invention. Under the effect of the acceleration which the projectile undergoes at the start of the shot, the rear ring of bars is already subjected to a radial component, under the action of the corresponding conical part. The angle at the top of the splash projection rod again reached around 600, compared to around 450 in the case of Figure 8.

 On the radiograph I of FIG. 13, the projectile only perforated a plate 4.5 mm thick and of relatively low resistance, under zero incidence. But its fragmentation is perfectly engaged in the two zones (secondary tungsten projectiles). On the three successive radiographs, the angle of projection of the fragments is approximately 600.

 On the radiograph I of FIG. 14, the projectile has already perforated the pre-armor of 1 mm in light alloy, at an incidence of 820. In its front part, the radial deformation of the projectile is already in progress and the second ring of secondary projectiles is just starting to open. We distinguish very well on these recordings on the one hand the difference in the deformation process of secondary projectiles according to the material which constitutes them (in this case: ductile steel and tungsten), and on the other hand the difference in behavior of projectiles from - same nature according to their relative position relative to the pre-armor plate. (A differentiation of behavior at the.

deformation can, apart from the choice of material, also be obtained with secondary projectiles of different dimensions). On radiography II the angle of projection of the fragments is approximately 300 and approximately 400 on radiography III.

FIG. 15 shows a projectile design which constitutes an extreme solution of the principle presented in FIG. 3. With the exception of a small core 10 at the front, intended to engage the radial deformation, the projectile consists only of projectiles secondary He contained in an envelope 12 and does not have a properly ditt core
Compared to the homogeneous needle projectile of FIG. 7, the perforating power of this projectile is much weaker, in particular on massive armor. But on multi-plate armor, and in particular on light alloy structures, this type of projectile can have a very spread effect on the surface as shown in the example of figure 16 (target of the kind of figure 4d). again perfectly the differences in projectile deformation depending on the material of which they are made (steel and tungsten).

The technical progress presented by projectiles produced in accordance with the invention resides in the following points
1. An increase in the destructive effect is obtained behind the armor without a noticeable decrease in the perforating power.
2. Fragmentation of the projectile is also possible in the case of light armor, which avoids an over-proportioning perforating power.

 30 No element of the projectile is likely to show deterioration by aging.

 4. By an appropriate choice of secondary projectiles it is possible to quickly adapt the inunition to a new need.

 5. This is a relatively simple projectile design.

 6. The effectiveness of the mode of action is independent of the impact at impact.

 7. In the case of multi-plate armor, the effect is increased behind each plate.

 8. The secondary projectiles can choose to have a large number of small elements, or larger elements, more efficient from a terminal ballistic point of view.

 9. Radially projected secondary projectiles can be designed to have a stable trajectory.

 10. The invention can be applied both to stabilized projectiles by tailplane and to stabilized projectiles by rotation.

 11. With tail stabilized projectiles, the speed of the secondary projectiles is only slightly reduced compared to the speed at impact of the vector projectile.

 Of course, the invention is not limited to the embodiments which have just been described by way of examples, and one can.

bring many variations without departing from the scope of the invention.

Claims (8)

REVENDI CATI ONS  1. Kinetic effect piercing projectile comprising an elongated profiled body for perforating a shield, characterized in that the profiled body contains secondary projectiles and means for causing a radial displacement of the secondary projectiles outside the profiled body, upon impact of the penetrating projectile and during its penetration into the armor.  2. Projectile according to claim 1, characterized in that the means for causing the radial displacement of the secondary projectiles out of the profiled body comprise at least one solid core disposed in the body in front of the secondary projectiles, the solid core having opposite secondary projectiles a rear face of oblique profile with respect to one longitudinal axis of the profiled body, to ensure by inertia an obliquity of the relative trajectory of the secondary projectiles at the time of the impact of the projectile and of its penetration into the armor.  3. Projectile according to claim'2, characterized in that the rear face of the solid core has a substantially conical profile co-axial to the profiled body, the point of the aforementioned conical profile being directed towards the secondary projectiles disposed at the rear from the body.  4th projectile according to claim 3, characterized in that the secondary projectiles are elongated substantially rectilinear elements arranged in the axial direction of the body in a substantially cylindrical compartment thereof.  5. Projectile according to claim 4, characterized in that the secondary projectiles are arranged at the periphery of the aforementioned cylindrical compartment around a solid auxiliary core having a front face of substantially conical profile directed towards the rear face of conical profile of the solid core before, an element of deformable material being disposed between the two opposite conical faces of the aforementioned solid cores, to be crushed axially by inertia and deformed radially by the aforementioned conical faces at the time of the impact and of the penetration of the projectile into the armor.  6. Projectile according to one of claims 2 to 5, characterized in that at least one of the cores has a large mass and high mechanical characteristics, to participate in the perforation of the shielding.  7. Projectile according to one of claims 2 to 6, characterized in that it comprises several solid cores arranged axially in the profiled body.  8. Projectile according to one of claims 1 to 7, characterized in that it comprises several groups of secondary projectiles, the aforementioned groups being arranged in the profiled body successively in the axial direction of the body.  9. Projectile according to one of claims 1 to 8, characterized in that the secondary projectiles include means for stabilizing each on its own trajectory.