GB2134231A

GB2134231A - A hollow-charge warhead

Info

Publication number: GB2134231A
Application number: GB08400078A
Authority: GB
Inventors: Dr Dieter Ludwig; Herman Rosner; Helmut Malnig; Theo Rosendorfer; Heinrich Lechner; Klaus Busse
Original assignee: Messerschmitt Bolkow Blohm AG
Current assignee: Airbus Defence and Space GmbH
Priority date: 1983-01-25
Filing date: 1984-01-04
Publication date: 1984-08-08
Also published as: FR2539865A1; DE3302307A1; DE3302307C2; GB2134231B; FR2539865B1; GB8400078D0

Abstract

For optimal performance, the case 1 consists of thin flow-formed aluminium or fibre-reinforced plastics material, the ballistic cap 8 with the impact contact points for detonation of the charge 2 and the cover plate 7 at the rear end of the warhead are formed from fibre-reinforced plastics material, and the inert insert 4 consists of foamed plastics material. The dimensions of these inert parts are also minimised so that the mass of the effective parts, particularly of the main charge 2, and thus the effectiveness of the warhead are increased. Details of dimensions &c. are given. <IMAGE>

Description

SPECIFICATION A hollow-charge warhead This invention relates to a hollow-charge warhead particularly for a flying body, such as a missle.

The increasing use of modern armour p.lat- ings which cannot be pierced by known hollow-charge warheads or can be pierced only with insufficient residual power requires special measures on the part of antitank defence in order to re-establish equilibrium or to achieve an advantage in their favour.In this respect the term "modern armour platings" is to be understood to mean those of a passive nature which consist, for example, of a combination of armour buckle plates, ceramics elements or multi-layer arrangements It is therefore required of a hollow-charge warhead, particularly for a flying body such as a missile that on the one hand the mass and the dimensions (calibre and length) of the warhead be kept as small as possible in order to ensure munitious manageability and allow use of already existing weapon installations and propulsion means, whilst on the other hand the performance, i.e. the depth of penetration and the hole channel volume, is considerably improved.

The object of the invention is to provide a hollow-charged warhead of dimensions suitable for existing weapon installations, but which has a considerably improved performance compared to hitherto known warheads of this type.

To achieve this the invention provides a hollow-charge warhead particularly for flying bodies, in which a ballistic cap having a contact for detonating an explosive charge funnel-shaped lining, the explosive charge with an inert insert, a booster charge and cover plate are arranged one behind the other, which, with the exception of the ballistic cap, are surrounded by a case, characterised in that the case has a frontal cylindrical portion facing the ballistic cap and having an outside diameter D which corresponds to the calibre, which merges into a rear cylindrical portion enclosing the cover plate and having an outside diameter d, the ratio of the outside diameter d of the rear portion to the outside diameter D of the frontal portion amounting to 0.6 up to 0.8 and the wall thickness of the case amounting to 0.005 up to 0.020 times the outside diameter D of the frontal portion and in that the case consists of aluminium and of fibre-reinforced plastics material.

As a result of the invention, more particularly by optimising the dimensions of the housing parts and of the other inert parts, as well as by using plastics material for these parts, the mass of these parts is reduced in favour of a larger mass of the effective parts of the warhead, in other words of the charge and of the lining.

One exemplified embodiment of the hollowcharge warhead in accordance with the invention will be described herein under with reference to the accompanying drawing, in which: Figure 1 is a longitudinal section through the hollow-charge warhead; and Figure 2 is an enlarged view of a part of the rear portion of the warhead shown in Fig. 1.

The illustrated embodiment of the hollowcharge warhead of the invention consists substantially of the case 1, the main charge 2, the lining 3, the inert insert 4, the booster charge 5, the detonation booster 6, the cover plate 7 and the ballistic cap 8.

The case 1 consists of fibre-reinforced, preferably carbon fibre or glass fibre reinforced, black plastics material with a density of less than 1.6 or of flow-formed, preferably flowspun aluminium of extremely thin wall thickness. A slight and very accurate wall thickness in combination with high strength can be achieved by flow spinning.

The case 1 has a front cylindrical portion 9 facing the ballistic cap 8 and having an outside diameter D (termed the calibre of the warhead), which merges by way of a convex central portion 10 into a cylindrical rear portion 11 the outside diameter d of which is smaller than the outside diameter D of the portion 9 in the ratio d/D of 0.6 up to 0.8, preferably about 0.70.

The front cylindrical portion 9 and the front part of the convex portion 10 of the case 1 extend around the lining 3, whilst the rear cylindrical portion 11 encloses the cover plate 7 nd the booster change 5. The inert insert 4 is/surrounded by the rear cylindrical portion 11 as well as by the rear part of the convex portion 10 of the case 1.

The wall thickness of the case 1 amounts to 0.005 up to 0.020, preferably 0.005 up to 0.011 times the outside diameter D of the front cylindrical portion 9 of the case 1.

By using an extremely thin case made of aluminium or of fibre-reinforced plastics material, not only is a reduction in the weight of the warhead achieved, but also, in this way, the checking of the detonation wave, which occurs particularly in the case of smaller calibres, is effectively countered.

When the case 1 is made of plastics material, as well as a considerable reduction in the mass, the electronic detectability of the warhead is made more difficult and the risk of corrosion damage is precluded. However, the use of plastics material for the case 1 has the potentially disadvantage of the slight mechanical strength of plastics material, particularly when it is of such a slight wall thickness.

Deformation during storage is countered by the inserted effective part, particularly by the cone base of the lining 3. The rear end of the case 1 is stiffened by the cover plate 7 and, optionally, for further stiffening at the rear end of the case 1 an annular aluminium adjoint-piece can be provided.

An electrical flat-band conductor (not shown). which extends from the impact contact points (explained hereinunder) out of the interior of the ballistic cap 8 onto the outside of the case 1, is adhered to the outside of the case 1 and is connected by way of a groove 1 2 on the outside of the lower portion 11 of the case 1 through a slit 1 3 into the interior.

The main charge 2 consists of a conventional explosive, preferably 85 up to 90 percent by weight of octogen and 1 5 to 10 percent by weight of trinitrotoluol. It is cast or chemically worked into the case 1. The main charge 2 encloses the lining 3, with the exception of the base thereof, the inert insert 4 and, by means of an inner cone at its end, the booster charge 5.

The inert insert 4 consists of foamed plastics material, for example foamed polyethylene, having a density of less than 0.05. In this way a further saving in weight is achieved. The inert insert 4 is formed with a rear portion 14 which tapers conically rearwards and is adjacent to the booster charge 5, and a front hemispherical portion 1 5. It is inserted with an oversize interference of 1 up to 2% into a corresponding recess in the base of the main charge 2.

The inert insert 4 has a diameter d1. The overall height of the inert insert 4 is h and the distance between the tip of the hemispherical portion 1 5 of the inert insert 4 and the tip of the funnel-shaped lining 3 is h4.

The ratio d1/d amounts to 0.7 up to 0.8, preferably 0.75 up to 0.80. With a gap between the inert insert 4 and the case 1 which corresponds to a ratio of more than 0.8, i.e. with a very narrow gap, asymmetrical inhomogeneities in the main charge 2, which are an unavoidable result of the production thereof, make themselves too strongly noticeable. On the other hand, with a wide gap, in other words with a ratio of less than 0.75 or even 0.7, adequate detonation wave steering no longer occurs. The ratio h4/h amounts to 0.5 up to 0.7. With a value of the ratio h4/h of more than 0.7 the danger exists of the shock wave, transmitted by way of the inert insert 4, reaching the tip of the inert insert 4 in front of the detonation wave and thereby causing disturbances of the detonation wave.

The conical lining 3 consists of copper of the highest purity, namely having a purity of 99 96 up to 99,99%. The wall thickness of the lining 3 amounts to 0.015 up to 0.020 times the outside diameter D of the front portion 9 of the case 1. With a wall thickness of less than 0.015 D, the sharp point of the lining is found to be too sensitive. On the other hand, with a wall thickness of more than 0.020 D, the mass is such that the tip speed of the sharp point is reduced. The aperture angle of the lining 3 amounts to 50 up to 55 as compared with 60 and more in the case of conventional linings.In this way, an increase in the sharp-point tip speed is achieved, the maximum performance occurring at 8 to 1 2 calibre distance (8 to 1 2 times D) from the target with the sharp point disintegrates only at 1 2 calibre (D).

The conical lining 3 is produced by flow spinning and subsequent recrystallisation annealing in a vacuum. The flow spinning is necessary because copper sheets can no longer be satisfactorily shaped to this base diameter and with such a wall thickness by deepdrawing. As a result of the recrystallisation annealing, the hardness of the copper is further reduced and residual tensions are obviated by this and equally by a texture which has arisen through the flow spinning. Accordingly,overall, a highly-ductile and extremely homogeneous lining 3 is provided, from which a correspondingly effective sharp point is formed.

The booster charge 5, like the main charge 2, consists of a conventional explosive, preferably 85 up to 90 percent by weight of octogen and 1 5 to 10 percent by weight of trinitrotoluol. It is formed by a funnel-shaped plate which is arranged between the cover plate 7 and the inert insert 4 and which is pressed through the cover plate 7 with its conical periphery, widening towards the cover plate 7, projecting into a complementary conical seat of the main charge 2.

The detonation booster 6 is formed by a tetryl compact which has a cylindrical shape of diameter dp and height hp, the ratio of the diameter dp to the diameter d of the rear portion 11 of the case 1 preferably amounting to 0.1 up to 0. 15. The ratio of the diameter d to the height h of the detonation booster 6 (or tetryl compact) preferably amounts to 0.7 upto 1.1.

The detonation booster 6 has a conical or toroidal cavity into which the tip of the booster charge 5 extends whereby punctiform contact therewith irrespective of tolerances and centring-is guaranteed.

The detonation booster 6 is arranged in a tubular adjoint-piece 1 6 on the cover plate 7 and is thereby centred. The cover plate 7 is preferably formed of black, glass-fibre-reinforced plastics material with a density of 1.6 at the most and is provided with reinforcing ribs for absorption of pressure (i.e. strength).

The cover plate 7 is preferably produced by injection moulding. In addition to the adjointpiece 1 6 for the detonation booster 6, receivers 1 7 for balance weights 18, preferably made of lead, are co-moulded or integral with cover plate 7. The balance weights 1 8 each have a bore through which a push-button part 19, which engages in a bore of the relevant receiver 17, is located. The longitudinal groove 1 2 in the lower portion 11 of the case 1 facilitates passage of the electrical flat-band conductor (not shown) through the slit 1 3 to electrical contact plug 20 on the cover plate 7.

The warhead is fastened to the flying body by a connection ring 21 which is arranged on the flying body and is designed as a cap nut.

The rear portion 11 of the case 1 has a bore for a position pin 22 which engages into a corresponding recess in the cover plate 7. The connection ring 21 is fastened to the warhead by a spring ring 23 which engages into an annular groove in the case 1.

The cover plate 7 is protected against torsion by means of a bore (not shown) through the case 1 and the cover plate 7 and a cylindrical pin extending therethrough.

An internal thread is provided on the rear portion 11 of the case 1, possibly on the said annular aluminium adjoint-piece, and a pressure ring 24 is screwed thereon. The pressure ring 24 forces the cover plate 7 against the main charge 2 and the booster charge 5.

The ballistic cap 8 arranged at the front of the hollow charge is bottleneck-shaped in design. The distance between the front tip of the ballistic cap 8 and the base of the lining 3 corresponds to twice, preferably 2.5 times, the calibre D (the outside diamter of the front portion 9 of the case 1). This relatively large spacing ensures a satisfactory sharp-point formation on the warhead. Furthermore, by virtue of the shape, mass and length of the ballistic cap 8, a slight and therewith optimum distance between the aerodynamic pressure point and the centre of gravity of the warhead is guaranteed.

The ballistic cap 8 is formed from black, glass fibre-reinforced plastics material. The ballistic cap 8 has impact contact points for detonating the detonation booster 6. One contact 25 is provided at the tip of the ballistic cap 8 and consists of two thin, concentriacally-arranged, calotte-shaped or hemispherical metal caps. As a result of the bottleneck shape of the ballistic cap 8, it is also possible to mount a second contact in the widened, rear, shoulder-shaped part of the ballistic cap 8. The second contact consists of two conical inner and one complementary conical outer sheet-metal parts 26, 27.Cables 28 and 29 connect the metal cap of the contact 25 at the tip to the conical sheetmetal parts 27, 26 in the rear widened portion of the ballistic cap 8 and, by way of the flat-band conductor on the outside of the case 1, these are connected to the contact plug 20 on the cover plate 7 and thus to the detonation mechanism. The conical outer part 27 is fastened to the ballistic cap 8. The contact formed by the meeting of the sheet-metal parts 26 and 27 in the rear shoulder-shaped part of the ballistic cap 8 becomes effective upon sliding contact of the parts up to a target inclination of 80 .

In the shoulder-shaped rear portion of the ballistic cap 8 there is also a ring 30 which is provided, over its entire periphery, with pockets 31. Balance weights, preferably made from lead, can be placed into the pockets 31 in order, for example, to prevent an imbalance upon rotation of the warhead and to affect the centre of gravity. At the transition between the case 1 and the cap 8, the ring 30 is provided with an aerodynamic covering 32 which snaps into a groove in the case 1. The end part of the second contact is fastened to the ring 30.

Claims

1. A hollow-charge warhead particularly for flying bodies, in which a ballistic cap having a contact for detonating an explosive charge, a funnel-shaped lining, the explosive charge with an inert insert, a booster charge and a cover plate are arranged one behind the other, which, with the exception of the ballistic cap, are surounded by a case, characterised in that the case has a frontal cylindrical portion facing the ballistic cap and having an outside diameter D which corresponds to the calibre, which merges into a rear cylindrical portion enclosing the cover plate and having an outside diameter d, the ratio of the outside diameter d of the rear portion to the outside diameter D of the frontal portion amounting to 0.6 up to 0.8 and the wall thickness of the case amounting to 0.005 up to 0.020 times the outside diameter D of the frontal portion and in that the case consists of aluminium and of fibre-reinforced plastics material.

2. A hollow-charge warhead as claimed in claim 1, characterised in that the inert insert consists of foamed plastics material.

3. A hollow-charge warhead as claimed in claim 1 or 2, characterised in that the inert insert consists of a rear conical portion and a front hemispherical portion.

4. A hollow-charge warhead as claimed in claim 3, characterised in that the ratio of the maximum diameter d, of the case amounts to 0.7 up to 0.8.

5. A hollow-charge warhead as claimed in one of claims 1 to 4, characterised in that the ratio of the distance h4 between the tip of the inert insert and the tip of the funnel-shaped lining to the overall height h of the inert insert amounts to 0.5 up to 0.7.

6. A hollow-charge warhead as claimed in any preceding claim, characterised in that the lining has a wall thickness which amounts to 0.015 up to 0.020 times the outside diameter D of the front portion of the case.

7. A hollow-charge warhead as claimed in claim 6, in which the lining consists of copper and the purity of the copper is 99.96 up to 99.99%.

8. A hollow-charge warhead as claimed in claim 6 or 7, characterised in that the lining is formed of copper which is produced by flow spinning and subsequent recrystallisation an nealing in a vacuum or protective gas.

9. A hollow-charge warhead as claimed in any preceding claim, characterised in that the aperture angle of the lining amounts to 50 up to 55".

10. A hollow-charge warhead as claimed in any preceding claim, characterised in that the booster charge is formed by a funnelshaped plate which projects with a conical tapering into the detonation booster.

11. A hollow-charge warhead as claimed in any preceding claim, characterised in that the cover plate has an integral adjoint-piece for reception of the detonation booster.

1 2. A hollow-charge warhead as claimed in any preceding claim characterised in that the cover plate has integral receivers for balance weights.

1 3. A hollow-charge warhead as claimed in any preceding claim characterised in that a position pin is inserted into the cover plate to prevent rotation of the warhead relative to the flying body.

14. A hollow-charge warhead as claimed in any preceding claim, characterised in that the ballistic cap consists of plastics material.

1 5. A hollow-charge warhead as claimed in any preceding claim, characterised in that the ballistic cap is bottleneck-shaped and is of a length amounting to at least twice the outside diameter D of the front portion of the case.

16. A hollow-charge warhead as claimed in any preceding claim, characterised in that for detonating the detonator, the ballistic cap has a contact on its front tip and a contact in its rear widened portion formed by a conical inner part and a conical outer part.

1 7. A hollow-charge warhead as claimed in any preceding claim, characterised in that arranged in the rear widened portion of the ballistic cap is a ring having pockets for reception of balance weights which are protected by a cover ring.

1 8. A hollow-charge warhead as claimed in any preceding claim, characterised in that the ballistic cap, the cover ring, the cover plate, and optionally the case, consist of black-coloured fibre-reinforced plastics materials.

1 9. A hollow-charge warhead as claimed in any preceding claim, characterised in that the rear portion of the plastics material case has an annular adjoint-piece made of aluminium which is provided with an internal thread for a pressure ring which presses the cover plate against the booster charge and the main charge, and also an outer annular groove for reception of a spring ring which positions the connection ring which provides the connection to the flying body.

20. A hollow-charge warhead as claimed in any preceding claim, characterised in that an electrical flatband conductor is adhered to the outside of the case and is connected by way of a slit in the rear portion of the case to contact plug on the cover plate.

21. A hollow-charge warhead substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.