DE9012031U1 - Perforated cone tail unit - Google Patents

Description

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RHEIHMETALLGHBH "" " Düsseldorf, 20.8.1990

File R 1388 P/Sch

Loehkeqe1Ie \ twerk

The invention relates to a perforated cone tail assembly as characterized by the features of the generic term of claim 1.

Such tail units are known, for example, from DE-PS 27 47 313. Corresponding projectiles are used primarily as practice projectiles. The perforated cone tail unit creates an aerodynamic braking effect, which means that the projectiles have approximately the same flight characteristics as conventional KE balanced projectiles up to the target distance (e.g. 2.5 km), but then fall to the ground much earlier than the latter. The known perforated cone tail units are manufactured by drilling the desired number of axially parallel channels into a cone made of aluminum or steel. This process is extremely labor-intensive and expensive.

The invention is based on the object of specifying a perforated cone tail unit of the type mentioned at the beginning, which can be manufactured in a simple and cost-effective manner.

This object is achieved according to the invention by the features of the characterizing part of claim 1.

Further particularly advantageous embodiments of the invention emerge from the subclaims.

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The invention is therefore based on the idea of producing a perforated cone tail assembly with a conical body made of plastic instead of an aluminum or steel tail assembly. It is particularly advantageous to use a polymer tail assembly. Polymers swell when heat is applied and, after a certain distance, block the holes in the tail assembly due to the frictional heat, which leads to an increase in the drag coefficient of the projectile and thus causes a further reduction in the range of such projectiles.

In the following, further details and advantages of the invention are explained using embodiments and with the help of figures.

Show it:

Fig. 1 shows a projectile with a perforated cone tail assembly according to the invention;

Fig.la a section of the perforated cone tail assembly according to Fig. 1;

Fig. 2 a perforated cone tail unit with an additional heat-absorbing paint layer; and

Fig. 3 a perforated cone tail unit that has deformed due to frictional heat during flight.

In Fig. 1, 1 denotes a projectile which consists of a penetrator 2 and a perforated cone tail assembly 3. The perforated cone tail assembly essentially consists of a cone body 4, which is made of plastic, and an inet allic sleeve 5, via the threaded connection 6

■The penetrator and the perforated cone tail unit are connected to one another. In the cone body 4 there are channels 7, the operation of which is described in detail in the DE-PS 27 47 313 mentioned at the beginning . The sleeve 5 can have space 50 at the rear for a light track set.

The cone body 4 can be manufactured, for example, by casting, injection molding, transfer molding, etc. Such injected perforated cone tail units often cost only a quarter of a corresponding aluminum tail unit.

The frictional connection between the sleeve 5 and the conical body can be produced, for example, by a toothing as indicated in Fig. 1a.

In order to ensure good temperature resistance of the tail unit up to the target distance, it may be advisable to apply a heat-absorbing layer of paint to the surface of the cone body 4, as is known, for example, from DE 28 56 394 Al.

In the case of another embodiment, it has proven to be useful to use a material as the plastic for the cone body 4 in which the surface areas swell up considerably due to the strong heating during flight after reaching the target distance and the channels become blocked. This results in a strong increase in the Cu value, so that the projectile hits the ground more quickly than with a corresponding conventional tail unit made of aluminum. Polyimide materials have proven to be particularly suitable as a material for the cone body, as they are more temperature-resistant in the short term than polyamide materials, for example; later, however, they tend to "bake" or burst.

The heating of the tail assembly by the propellant gases during firing has only a minor effect on the plastic material as long as the projectile is still in the barrel, because due to the low thermal conductivity of the
plastic, a reaction to the hot propellant gases occurs after about 2 s (ie, at a projectile speed of 1500 m/s, the heating occurring during firing only becomes noticeable after 3 km).

RHEINMETALL GMBH File R 1388

Düsseldorf, 20.8.1990 P/Sch

List of reference symbols

1 floor

2 Penetrators

3 hole cone tail unit

4 cone bodies

5 metal sleeve

6 Threaded connection

7 channels

8 Heat absorbing lacquer layer

9 Course of the surface of the channels during heating

Claims (5)

RHZINMETALLGMBH Düsseldorf, 20.8.1990 File R 1388 P/Sch Protection claims 1. Perforated cone tail assembly (3) for projectiles (1) with several channels (7) arranged in the cone body (4) and running essentially parallel to the axis, characterized in that the cone body (4) is arranged on a metallic sleeve (5) and consists of plastic. 2. Perforated cone mixer according to claim 1, characterized in that the cone body (4) is a plastic injection-molded part. 3. Perforated cone tail assembly according to claim 1, characterized in that the cone body (4) is provided with a coating of a heat-absorbing lacquer layer (8). 4. Perforated cone tail unit according to claim 1 or 2, characterized in that the cone body (4) consists of a plastic which, after the projectile has reached the predetermined target distance, swells to such an extent that the channels (7) become blocked. 5. Perforated cone tail unit according to claim 4, characterized in that a polyiraid material is used as the plastic.