FR2615610A1 - METHOD FOR INCREASING THE SENSITIVITY TO THE IMPACT OF A PROJECTILE HAVING A PERCUTABLE ROCKET - Google Patents

Abstract

THE TECHNICAL SECTOR OF THE PRESENT INVENTION IS THAT OF MEDIUM-CALIBER AMMUNITION, INCLUDING A POWERFUL ROCKET 3, IN PARTICULAR BASE, AND A BALLISTIC WARG 6. THE PROCESS ACCORDING TO THE INVENTION CONSISTS OF INTEGRATING INTO THE PROJECTILE MEANS ALLOWING TO REALIZE A IMPACT ON A TARGET, A DEFORMATION OF THE WARGIVE 6 OF A KIND TO SLOW THE PENETRATION OF THE PROJECTILE INTO THE TARGET, THUS ALLOWING TO INCREASE THE DRIVING FORCE OF THE POWERFUL MOBILE MASS OF THE ROCKET AND TO INCREASE THE SPECIFIC SENSITIVITY OF THE MUNITION . APPLICATION TO MEDIUM-CALIBER EXPLOSIVE AMMUNITION.

Description

2 615610

  PROCESS FOR INCREASING SENSITIVITY

  The present invention applies to medium-caliber explosive ordnance and relates to a method for increasing the impact sensitivity of a projectile carrying a percussion rocket, as well as to the impact of a projectile carrying a percussion fuse. that the devices for implementing such a method. The current area of use of medium caliber ammunition is such that it covers all forms of combat. As such, they can be directed against a wide variety of

  including light vehicles or aircraft.

  For projectiles equipped with percussion fuzes, in particular base fuses, this type of target, consisting of thin t8les easy to perforate, requires from said rockets, high sensitivity. However, these same projectiles must be able to be fired without damage through natural obstacles such as foliage or tropical rain; it is conceivable under these conditions that the setting of the

  sensitivity of a rocket is delicate.

  Each type of rocket having its own sensitivity, in adequacy with the projectile for which it is intended; this projectile having itself certain characteristics (mass, initial speed, etc ...), one is in the presence of a "couple" hardly separable and having a specific sensitivity. Also, there are few cases of absolute interchangeability outside families of ammunition

  having common features or otherwise very similar.

  The adaptation of a known rocket to a new or different projectile then presupposes a redefinition of all or part of the parameters acting on the sensitivity of the rocket and which are: - adjustment of the percussive mobile mass - stroke of the mobile percussive mass - sensitivity of the primer - possibly, modification of the equilibrium point of self-destruction. In practice, these modifications have implications for the design of the rocket itself, but sometimes also for the projectile; the duration and cost of studies and developments and make

  delicate if not prohibitive of such modifications.

  The object of the present invention is to propose a simple solution for adjusting the specific sensitivity of a projectile, without intervention on the rocket, but by increasing the driving force of the percussive mobile mass of this rocket by increasing the

  deceleration when puncturing a thin target.

  The present invention may also allow a time adjustment of

  delayed operation of the projectile to which it is applied.

  The method according to the invention is intended for a medium-caliber projectile comprising a percussion fuse and a ballistic ogive and characterized in that the projectile is integrated with means making it possible, following the impact on a target, to deform warhead likely to slow the penetration of the

projectile in the target.

  According to another characteristic, the means making it possible to carry out the method consist of at least one rupture primer.

practiced on the warhead.

  According to a particular embodiment of the invention, the one or more rupture primers result from internal and coaxial chamberings.

to the warhead.

  According to other embodiments: - the one or more rupture primers result from a sudden change in the thickness of the ogive - the warhead comprises at least two break primers made according to internal or external generatrices - an intermediate piece is disposed inside the warhead - the intermediate piece has a peripheral zone in contact with the warhead and having a profile of such a nature to shear said warhead on impact - the intermediate piece has at least one cylindrical hole - the intermediate piece is integral with the ogive - the intermediate piece is constituted by a composition

compressed pyrotechnics.

  The invention will be better understood in view of the description which will

  follow, made with reference to the accompanying drawings and in which: - Figure 1 is a simplified representation of a medium caliber rocket ammunition - Figure 2 shows the behavior of a customary warhead after an impact on a thin target FIGS. 3 and 4 refer to an ogive having a fracture primer resulting from a recess, warhead shown before and after impact; FIG. 5 shows a nose whose nose is solid, thus creating a variation in thickness; FIGS. 6 and 7 describe an ogive carrying four failure primers made at 90, along internal generatrices, before and after impact; FIG. 8 is an ogive according to the invention, provided with an intermediate piece having an axial bore; 9 represents a warhead and an intermediate piece carrying a sharp peripheral zone that can shear said warhead at impact.

  - The ogive and the intermediate piece of Figure 10 are integral.

  The projectile represented in FIG. 1 comprises a body 1 carrying a belt 2 and, at the rear, a percussive base rocket 3 comprising, in known manner, a percussive moving mass and responsible for initiating a generally explosive pyrotechnic charge4. , by means of a primer 5. The aerodynamic profiling of this projectile is obtained by the addition of a ballistic warhead 6. This warhead, usually of light alloy (other materials may nevertheless be suitable, such as plastics ) has a tendency, following an impact on a thin target, to slide on the body of the projectile, as shown in Figure 2, without significant modification of its profile. The target is easily perforated and it follows that the slowdown following the impact risks being

  insufficient to ensure the operation of the base rocket 3.

  A first example of an ogive according to the invention is shown in FIG. 3. A rupture primer 8 is provoked inside the warhead 6 by means of a cylindrical recess 7, other shapes that can be given to FIG. this chamber, for example conical. At impact, the ogive thus weakened at the level of the rupture primer 8, is sheared and the front part is embedded in the recess 7, as shown in Figure 4, very substantially modifying the profile of the projectile which then becomes very unfavorable to a good perforation, o o a strong deceleration allowing a better exploitation of the inertia of the percussive mobile mass of the rocket 3. It is possible to vary the sensitivity and the delay of operation by modifying the diameter and / or the position of the recess 7 (dimensions D and X in FIG. 3) as well as the internal conicities. The multiplication of chambers can

  also be a way to adjust the sensitivity.

  The beginning of rupture 8 may result from a sudden change in the thickness of the ogive as in the case of a nose full ogive,

  for ballistic reasons, shown in Figure 5.

  Figures 6 and 7 show an ogive in which four primers have been practiced repetition 8 to 90, following-internal generatrices. The resulting embrittlement causes, on impact, the crash of the warhead as shown in Figure 7, and a strong deceleration that can be modulated by changing the number

  and the section of the rupture primers 8.

  It is also possible to increase the specific sensitivity of the projectile by interposing, inside the warhead, an intermediate piece 9 on which the nose of said warhead is crashed, and giving an additional energy to the mobile percussive mass. This piece may be solid or have one (FIG 8) or several holes 10 made axially or radially. In the case of axial holes the nose of the warhead will be embedded in the holes on impact. The adjustment of the sensitivity will relate to the diameter and / or the height of the intermediate part 9 or the number, the diameter and the position of any holes 10. Moreover the increase in mass consecutive to the presence of the part 9 can have a favorable influence on the

ballistic projectile.

  It is possible to design the intermediate part 9 so that it has, in contact with the warhead, a profile allowing

shear the warhead at impact.

  FIG. 9 is an illustration of such a device, in which the intermediate part 9 behaves like a punch, through a sharp peripheral zone 11. The sensitivity will depend on the section to be sheared, said section being determined by the diameter of the peripheral zone 11 and the thickness of the warhead at

view of said area 11.

  Moreover, it is conceivable to secure the ogive 6 and the intermediate piece 9, for example by making an ogive by molding or injection. In this case, it is possible to group together the various sensitivity adjustment possibilities permitted by the presence of rupture primers 8, an intermediate part 9 and holes 10,

as shown in Figure 10.

  It is often interesting to reinforce the end effects of ammunition by adding, when changing pyrotechnic substances with particular properties (incendiaries, blowing effect ....). It is therefore perfectly conceivable to produce the intermediate part 9 in highly compressed pyrotechnic composition, while retaining the adjustment possibilities.

  of sensitivity specific to this configuration.

Claims (8)

  1 - Process for increasing the impact sensitivity of a projectile comprising a percussion fuse (3) and a ballistic ogive (6), characterized in that the projectile is integrated with means making it possible to perform, consecutively to the impact on a target, a deformation of the warhead (6) likely to slow down the   penetration of the projectile into the target.   2 - Device for implementing the method according to claim 1, characterized in that the means are constituted   by at least one rupture primer (8) made on the warhead (6).   3 - Device according to claim 2, characterized in that the or the rupture primers (8) result from internal chamberings (7) and coaxial with the warhead (6).   4 - Device according to claim 2, characterized in that the or the rupture primers (8) result from a sudden variation thickness of the warhead (6).   - Device according to claim 2, characterized in that it comprises at least two break primers (8) practiced   following generatrices internal or external of the ogive (6).   6 - Device according to claims 2 to 5, characterized in   an intermediate piece (9) is arranged inside the the warhead (6).   7 - Device according to claim 6, characterized in that the intermediate piece (9) comprises a peripheral zone (11) in contact with the ogive (6) and having a profile of shear nature said warhead at impact.   8 - Device according to claims 6 or 7, characterized in   the intermediate piece (9) has at least one hole cylindrical (10).   9 - Device according to claims 6 to 8, characterized in   that the intermediate piece (9) is integral with the ogive (6).   - Device according to claims 6 to 8, characterized in   the intermediate piece (9) consists of a composition compressed pyrotechnics.