ES2232795T3 - PROJECT WITH AN EXTERIOR WRAPPING THAT PRODUCES FRAGMENTS AND PROCEDURE FOR MANUFACTURING. - Google Patents

Abstract

Projectile with an outer envelope (2) that produces fragments and a plastic sheet (3) that adheres inside to the outer envelope (2), in which an explosive charge is arranged, presenting the plastic sheet (3) a structured area (5) provided with roof-shaped cavities (4) and at least one flat area (7, 8) that adheres laterally to the structured area (5) and that is dragged into the inner wall ( 6) of the outer envelope (2); and the structured area (5) of the plastic sheet (3) being made of a rigid deformation plastic material, characterized in that the smooth zone (7, 8) is composed of an elastic plastic material.

Description

Projectile with an outer shell that produces fragments and procedure for its manufacture.

The invention relates to a projectile with a outer shell that produces fragments and a plastic sheet that adheres inside to the outer envelope, in which It has an explosive charge. The invention further relates to procedure for the manufacture of such a projectile. A projectile of this type and its manufacturing process are known thanks to the document US-A-5690867, which serves as the basis for the preamble of claims 1, 4 and 5.

Such a projectile is known, for example, thanks to DE-AS1812462. In it, the plastic sheet has a structured area, which is provided with roof-shaped cavities directed inwards and arranged with equal distribution throughout the contour, the cavities of adjacent rows being arranged alternately with each other. At least one smooth area of the sheet adheres laterally to the structured area of the plastic sheet, with which the sheet is dragged into the inner wall of the outer shell. To the extent that it is known to the applicant, an elastic propylene (propylene provided with an elastic additive such as rubber) is used as the material for the entire plastic sheet, that is, comprising both
zones.

The tests performed by the applicant, in special with high acceleration projectiles (such as, for example, used in modern artillery and tank ammunition), have had as a result that the use of such plastic sheets is not in any advisable case when these projectiles contain a explosive bonded with plastic, since it tends to deform with high accelerations Therefore, in an elastic laminated material, the explosive presses the roof-shaped bumps toward outside. Therefore, cracks can arise in the explosive, which can lead to an involuntary transformation of the explosive and therefore represent a security risk.

The invention is based on the objective of ensuring that, with a projectile of the type mentioned at the beginning and with the use of explosive bonded with plastic, no cracking occurs explosive during the acceleration phase of the projectile. Also I know will make known the manufacturing procedures of a projectile of this type.

This objective is achieved in accordance with the invention, by the features of claim 1 in in relation to the projectile and by claims 4 and 5 in relationship with the procedure Subordinate claims give to know other especially advantageous configurations of the invention.

The invention is based on the idea of using as plastic sheet a sheet that at least consists of two zones of different characteristics in terms of resistance. In the zone structured, the plastic sheet is composed of a rigid material to deformation, which avoids a pressure into the roof-shaped cavities during the acceleration phase of the projectile produced by the explosive. In the smooth zone, by the Otherwise, the plastic sheet is composed of a plastic material elastic, so that the sheet is pressed in this area elastically and dragging against the inner wall of the outer wrap

For the manufacture of the plastic sheet for the projectile according to the invention, the areas of plastic material Rigid to deformation and elastic plastic material can be manufactured separately by means of a blowing method of hollow bodies and then heat-welded together, glued or melted together in liquid state by fusion.

But it is also possible by blowing hollow bodies fabricate in a segmented way first different materials of the same base as flexible tube of a piece, that through a blow mold you will receive your final contour. As the Flexible tube production process consisting of segments of different material runs in the blowing machine so computerized, exact reproduction is guaranteed for different areas during this economical procedure.

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As the base material for the plastic sheet, it has been shown again that polypropylene is advantageous. By means of the corresponding additives a material very rigid to deformation is obtained on the one hand and, on the other hand, (for example, by an elastic additive) a correspondingly material

 \ hbox {elastic.} 

Other particularities and advantages of the invention they emerge from the exemplary embodiment explained by a figure.

The side view is reflected in the figure partially represented in section of an explosive projectile, which fires by means of artillery weapon, before the explosive charge and that the front hole is closed with a detonator.

Thus, the projectile is called 1, which comprises an outer wrap 2 of steel, which produces fragments. Within the wrap 2 is a plastic sheet 3, in which arrange the explosive not shown.

The plastic sheet 3 has an area structured 5 provided with cavities 4 with roof form. In this structured area 5 adheres in front and behind respectively a smooth zone 7, 8 that is dragged on the inner wall 6 of the outer shell 2.

According to the invention, the structured area 5 of the plastic sheet 3 is composed of a plastic material rigid to deformation, for example, of polypropylene, reinforced if necessary with fiberglass, while the smooth zone 7, 8 of the plastic sheet 3 is composed respectively of a plastic elastic material, for example of a polypropylene provided with an elastic additive.

In the embodiment shown, the plastic sheet 3 for projectile 1 according to the invention is composed of separate partial sheets, corresponding to the zones 5, 7, 8 and heat-welded together in the areas designated with 9, 10, for example with the help of ultrasound.

Of course, the invention is not limited to exemplary embodiment described previously. So for example It can also be used as a material for the plastic sheet another base material instead of polypropylene, in which they fit the required resistance requirements through the corresponding additives.

Reference List

       \ dotable {\ tabskip \ tabcolsep # \ hfil \ + # \ hfil \ tabskip0ptplus1fil \ dddarstrut \ cr} {
 1 \ + projectile \ cr 2 \ + envelope \ cr 3 \ + plastic sheet \ cr 4
\ + cavity \ cr 5 \ + structured area, zone \ cr 6 \ + wall
interior \ cr 7, 8 \ + smooth zone, zone \ cr 9, 10 \ +
zones \ cr}
    

Claims (5)

1. Projectile with an outer envelope (2) that produces fragments and a plastic sheet (3) that adheres inside to the outer envelope (2), in which an explosive charge is arranged, presenting the plastic sheet (3 ) a structured area (5) provided with roof-shaped cavities (4) and at least one flat area (7, 8) that adheres laterally to the structured area (5) and that is dragged into the wall inside (6) of the outer envelope (2); and the structured area (5) of the plastic sheet (3) being composed of a rigid deformation plastic material, characterized in that the smooth zone (7, 8) is composed of an elastic plastic material. 2. Projectile according to claim 1, characterized in that the plastic elastic material is polypropylene, which is provided with an elastic additive such as rubber. 3. Projectile according to claim 1 or 2, characterized in that the rigid deformation plastic material is polypropylene. 4. Process for the manufacture of a projectile (1), according to one of claims 1 to 3, characterized in that for the manufacture of the plastic sheet (3) the area (5) is made of deformation rigid plastic material and , separately, the zone (7, 8) of elastic plastic material; and because the partial sheets corresponding to these zones (5, 7, 8) are heat-welded, glued together or joined by liquid blow molding. 5. Process for the manufacture of a projectile (1), according to one of claims 1 to 3, characterized in that for the manufacture of the plastic sheet (3) by blowing of empty bodies a flexible tube of a first piece composed of different materials corresponding to the same base, which then obtains its final contour in a blow mold.