EP1685363B1 - Impact part of a projectile - Google Patents

Description

The invention relates to an impact member on a projectile which contains at least one active charge and one activated during impact ignition device, wherein the impact member is formed in the form of a domed cap with a limited of this cavity.

Ignition devices, such as those used in tandem shaped charges, require a defined impact shock for activation (see data sheet PEPZ-05 Piezo Fuze System, PEPZ-05, Zaugg Elektronik AG, CH-4573 Lohn-Ammannsegg). It is therefore notoriously known to design the tips of such projectiles more or less massive in the form of a domed cap in order to transmit the necessary activation energy to the firing device contained in the projectile. By a cambered (rounded) shape of the tip is trying to activate the ignition chain even in an oblique impact of the projectile in the target.

In practice, however, duds, i. E. the projectile is deflected by the target and / or the absorbed impact energy is insufficient to activate the detonating chain. This problem is even more pronounced in tandem hollow charges and multiple warheads, which have independent, autonomous igniters and in which each igniter has its own safety characteristic.

From the EP-A1-595173 which forms a starting point for the preamble of claim 1 is known a projectile with at least one effective charge and with an impact part, wherein the stable jacket coated with a rubber-like support is. This achieves a so-called "erasure effect" at flat angles of impact at the target, ie the projectile is braked to detonate the active charge on the spot. For effective and positive anchoring of the support, inter alia, grooves and the like are provided so that the desired delay results in the target even at low impact angles.

Hard surfaces, for example with ceramic plates coated armor, can not penetrate successfully with this solution. With a shaped charge striking the target at a shallow angle, the forming jet of material can not penetrate the armor; it is released in time, but then distracted along with the impact part.

An anti-tank projectile ( BE -A- 530 433 ) has to prevent the bouncing and slipping of the projectile head at least one mounted on the double hood toothed ring. The toothed ring is made of a very hard material and therefore suitable for hacking on steel plates.

Against modern armor with a variety of outer ceramic plates a patched ring gear is not suitable. The ring is either disengaged from its anchorage and / or breaks. Also single or multiple tiles can jump off, so that the bullet slides off before it can use its only active charge. Another disadvantage is its aerodynamically unfavorable shape, which leads at high speeds to an unstable trajectory of the projectile. In addition, the necessary for the activation of the ignition generator shock wave can not deliberately spread over the shell, so that its use for multiple loads is out of the question.

It is therefore an object of the present invention to provide an impact part, which provides the necessary, to initiate the ignition necessary even at oblique angles in the target incoming projectiles.

The impact part to be created should be suitable in particular for projectiles with shaped charges, which maintain the firing direction even on hard surfaces and at a relatively flat angle of incidence so far that the shaped charge jet penetrates into the target.

Likewise, the impact member should not adversely affect subsequent shaped charge jets and also be able to exert an effective function in active armor (Explosive Reactive Armor = ERA). The aerodynamics of the projectile should not be affected thereby; likewise, the external ballistics should not be changed compared to other, analogous projectiles.

This object is solved by the features of claim 1.

Inventive annular grooves attack the target, even if they hit obliquely and trigger the ignition. Inlaid elastomers maintain the air resistance values compared to smooth impact parts. The thin-walled tip normally does not affect the effective power of the projectile (oblique incidence in the target).

Through the use of successively arranged sharp edges, the impact part hangs in the target or cuts into its surface, so that the projectile is not distracted and remains at the destination.

Optimal are at the target with an angle of 20 ° to 60 ° incident tandem shaped charges. It has been found that in the transmission of the energy required to ignite the charges in this angular range, the tip is damaged in such a way that the hollow charge beam of the precharge has sufficient energy to ignite an ERA box (ie the explosive stored in the target). Due to the surface design of the stored explosive is the outer Metallic protective plate of the armor blasted perpendicular to its base and flies past the projectile, so that the shaped charge jet of the main charge can now unfold its full effect.

The tip can be designed so that in a more or less vertically impinging on the target surface projectile tip absorbs the energy of the first shaped charge jet (the summons) so far and disturbs the structure that an ERA box is not ignited. The second, stronger and now already fully formed beam of the main charge then penetrates the already pierced tip, ignites the ERA box, penetrates their metallic cover and can penetrate into the armor.- The effect of the projectile corresponds in such a case, one of the optimal Distance ignited simple shaped charge.

There remains the phenomenon that the same impact part at its oblique incidence in the target makes the beam of the subpoena effective, and not at a more or less vertical impact at the target. This can be explained by the fact that when vertically hitting the dome of the tip - before breaking - turns inside out and thereby massively disturbs the hollow charge jet still in the construction. Thus, the energy of the beam is not enough to activate the ERA box.

This effect can be achieved if the impact part consists of a sufficiently tough yet ductile steel. For this, uncured tempered steels have proved their worth.

In dependent claims preferred developments of the subject invention are described.

Ring seals according to claim 2 are particularly easy to handle. They can be easily inserted and protect the staff handling the projectile from injuries. Upon impact at the target, the ring seals are forced away and release the sharp edges for engagement.

Commercially available O-rings according to claim 3 are not particularly economical and resistant in a wide temperature range and wear under normal handling.

The discontinuities listed in claim 4 in the profile allow the specification of fractures according to the rules of fracture mechanics.

By an external thread according to claim 5, the assembly of the projectile facilitates; In addition, impact parts with different breakage characteristics can be prepared and adapted to the presumptive target.

The geometric adaptation of the outer shape mentioned in claim 6 allows predetermining the minimum still initiating angle of incidence.

With the inclusion of notch factors, further fracture points can be defined, so that, for example, a targeted fragmentation of the impact part takes place and As a result, the subsequent shaped charge jet can build up unhindered. See claim 8.

As a tempered steel, claim 9, 42 CrMo 4 V (according to DIN 1.72225) has proven very useful due to its high toughness.

Exemplary embodiments of the invention will be discussed with reference to drawings.

Fig. 1

einen Geschosskopf mit Aufschlagspitze, Vorladung und Zündsystem,

Fig. 2

den Grundkörper der vergrössert dargestellte Aufschlagspitze Fig.1,

Fig. 3

die Geschossspitze Fig. 1 beim Auftreffen auf eine schiefwinklige Zielfläche und

Fig. 4

die Strömungsverhältnisse an einem grosskalibrigen Geschosskörper.

Show it:

Fig. 1

a bullet head with impact tip, precharge and ignition system,

Fig. 2

the main body of the enlarged impact tip Fig.1 .

Fig. 3

the bullet point Fig. 1 when hitting an oblique target surface and

Fig. 4

the flow conditions on a large-caliber projectile body.

In FIG. 1 is a head of a projectile of a tandem shaped charge 1. An impact member consists of a tip 2 in dome shape with embedded elastomers, ie with O-rings 3 made of silicone rubber and is placed on a pre-charge with lining 4, explosive 5 and 6 igniter. The comprehensive projectile casing 7 is made slender and has at the end of its cavity a notoriously known, not shown main charge. Between the explosive 5 and the ignition device 6, the projectile casing 7 encloses a cavity 8, which forms the necessary distance to the main charge, not shown.

The sectional view Fig. 2 shows the profile of the impact part Fig.1 , Orthogonal to the axis (= direction of flight). F are annular grooves 20 are inserted, which have sharp edges 21. The very thin-walled tip 2 is designated in its thickness with 22 (wall thickness). At the bottom, di rear side is an external thread 23 proceed, which is screwed in the front end of the projectile casing 7.

The representation in Fig. 3 shows the front of the projectile when hitting a target Z in a direction of flight F with α designated oblique angle.

Here it can be seen that in the target the elastic rings 3 are pushed away, so that the sharp edges 21, Fig. 2 , hook on the surface of the target. As a result, a rebound of the projectile is largely prevented; It creates a sufficiently large impact shock to initiate the ignition systems.

The Fig. 4 shows alternatively a head of an inventive, larger, in itself arbitrary ammunition body with drawn stream threads S. The elastic rings 3 prevent turbulence even at high launching speeds.

The subject invention allows optimal use of projectiles, even in cases where conventional impact parts lead to failure. This also reduces the dud rate considerably.

Claims (9)

1. Impact part of a projectile containing at least one power charge and an igniter activated upon impact, wherein the impact part is shaped like a convex cap with a hollow space enclosed by the same, at least two annular slots (20) concentric to the direction of flight (F) are inserted into the lateral walls, and the annular slots (20) have sharp edges (21), characterized in that the tip (2) of the impact part is thin-walled with respect to the lateral walls and elastomeric materials (3) are inserted in each of these annular slots (20), which fill out and/or overlap the annular slots (20).
2. Impact part according to claim 1, characterized in that the elastomeric material (3) are ring seals.
3. Impact part according to claim 1, characterized in that the ring seals (3) are O-rings made of silicon rubber.
4. Impact part according to claim 1, characterized in that internal shape of the impact part has a profile showing discontinuities.
5. Impact part according to one of the previous claims, characterized in that an external thread (23) is provided, and that the same and the external shape are adapted to the head of the projectile (1).
6. Impact part according to claim 1, characterized in that the external shape and the slots (20) are chosen so that a contact line at the target (Z) encloses an angle (α) of 15° to 90° with the axis of the direction of flight (F).
7. Impact part according to claim 1, characterized in that the tip (2) has a spherical shape and its wall thickness (22) and material are chosen so that after impacting on a hard target (Z) under an angle of 80 to 90 it breaks, at least partially, °.
8. Impact part according to claim 7, characterized in that the tip (2) presents, at least circumferentially, notches and/or abrasions of material.
9. Impact part according to claim 7 or 8, characterized in that the same consists of an unhardened heat-treatable steel.

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