GB2460290A

GB2460290A - Directed warhead

Info

Publication number: GB2460290A
Application number: GB8234546A
Authority: GB
Inventors: Jacques Malavergne; Jean-Louis Chieze; Michel Kabrunie
Original assignee: Direction General pour lArmement DGA; Etat Francais
Current assignee: Direction General pour lArmement DGA; Etat Francais
Priority date: 1981-06-26
Filing date: 1982-06-24
Publication date: 2009-12-02
Anticipated expiration: 2002-06-24
Also published as: FR2678723A1; GB8234546D0; IT8320224A0; FR2678723B1; GB2460290B

Abstract

A warhead comprises a proximity fuze and a fragmentation casing 12 which, upon detection of a target 4, is rotated relative to a main explosive charge 2 to align a fragmentation portion 13 of the casing with the target. The fragmentation effect may be enhanced by the provision of an annular charge 13a. The fragmentation casing is caused to rotate by firing several peripheral longitudinal strips ofexplosive which eject metal bars, or by firing a propellant charge within, or by introducing gas into, the annular space devoid of the charge 13a.

Description

The technical area of the present invention is that of explosive projectiles, in particular anti-aircraft defence missiles.

These missiles, which may be of the guided missile type, comprise an explosive charge whose efficiency against an air-target is to be improved. Thus charges of this type with an axis of effects focussed in a pre-determined direction, are known. The firing of these charges can be controlled by target proximity detection means, for example a Doppler effect radio-electric transceiver.

Of course it is known to adapt the structure of an explosive charge to obtain damaging effects focussed against an air-target. For example, US patent 3 949 674 describes a cylindrical charge, radially cornpartmentalised. US patent 3 565 009 also describes a cylindrical charge with four segments that may be fired according to their position with regard to the target direction. Patent 3 985 077 describes a charge whose structure of diEferent explosives is such that this charge has a preferred axis of effect.

Most of these charges-being situated inside an envelope revolving about the missile axis, advantage can be taken of the structure or the deformation of this envelope to obtain the focussed effects sought. For example US patent 4 026 213 describes a ring-shaped explosive charge located between two cylindrical envelopes, the outer one of which is thin and easily deformable by the charge which is fired at a point diametrically opposite with respect to the target.

It has been proposed to set the explosive charge in rotation and to fire it by means of target-proximity detection means.

Certificate of Utility FR 2 388 468 describes a missile -which is set into slow rotation, and includes a revolution envelope containing an explosive charge. This missile comprises envelope flattening means roughly arranged around the envelope periphery and covering at least one segment -angularly limited with respect to the axis, and means for detecting the direction of the target with respect to the axis, associated with the flattening means so as to cause in a selective way a flattening f the envelope arid of the charge approximately facing the target, the means for detecting the poximity of the target arid the means for detecting its direction being combined with co-ordinationand delay means to enure the above-mentioned flattening before the explosion of the charge.

The flattenngof the envelope and of the charge ensures that the fragments of the flattened area of the envelope are projected in a direction perpendicular to this flattening.

This therefore ensures the desired concentration of the fragments in the direction of the target, since the flattening has been carried out facing this.

These various missiles have the disadvantage of a limited number of preferred directions since this number depends on the limited number of firing points.

It was then suggested that the explosive charge be set in rotation and fired by means of the targe,t proximity detection means.

So, patent DE 2 519 507 describes a charge which can have several predefined directed effects, therefore a limited number, and which is set in rotation by a motor. US patent 4 157 685 describes a missile whose charge and proximity fuse are mounted on a gimbalsystem to produce an omnidirectional focussed effects axis.

The disadvantage of these two known solutions is to rotate, in a very short time, the heavy assembly of the explosive charge and therefore to necessitate high energy consumption.

Another drawback of the known missiles of this type is the.

fact that they have segments that have no damaging effects since they' function according to a principle of energy or material transfer to preferred directions.

The purpose of the invention is to remedy these preceding drawbacks and to increase si;riificantly the efficiency of missiles of the above-mentioned type, whilst allowing the concentration, in an unlimited number of preferred directions and at rninimuni energy cost, of a great proportion of the energy of the explosive charge and the damaging means that it projects, by improving the synchronisation of the firing at the moment of coincidence of the rotating axis of focussed effects of the charge with the direction of the target.

The aim of the invention, therefore, is an explosive missile, in particular an anti-aircraft missile, comprising a rotary, dilectional effect charge having a main explosive charge projecting focussable damaging means, and a proximity fuse with a capacity for azimuthal discrimination of a target, a missile that is characterised in that the focussable damaging means are mounted rotatably round the main fixed explosive charge to produce a rotary axis of focussed effects, and in that it ctrnprises means for the detection of the coincidence of the rotary axis of focussed effects with the direction of the target, for firing the charge.

The explosive charge is preferably cylindrical and firing means for the explosive charge are. mounted rotatably around this charge which itself is surrounded by a metal tube.

According to a first variant, the missile of the invention is characterised in that the focussable damaging means are constituted by a rotor comprising an annular fragmentation body surrounding an annular explosive charge, one segment of which is provided with a group of preformed or predetermined fragments, means for firing the annular explosive charge and the main explosive charge, and several peripheral longitudinal explosive strips for the ejection of metal bars for causing the rotor to be set in rotation.

It can be seen that the missile according to the invention has th following simultaneous advantages -taking advantage of the auxiliary orientation device for causing initial damage to the target (ejection of metal bars) -infinite number of preferred directions which can be obtained by virtue of the continuous rotation of the fragmentation body (rotor) and, -the fact that the choice of the direction of focussed effectis not made at the moment of detection but at the actual moment of firing. In fact, although the delay elapsing between detection and firing is generally very short -a few milliseconds -it may happen that the target changes its azimuthal direction with respect to the missile.

According to a second variant, the aim of the invention is a missile as described above, in which the focussable damaging means are constituted by a rotor comprising an annular fragmentation body, one segment of which is provided with a group of preformed or predetermined fragments, the * additional segment being hollowed out and partially surrounding the fixed cylindrical main charge, one part of this hollowed-out segment being occupied by a propulsive powder.

charge initiated by an igniter for setting in rotation the * annular body.

Another aim of the invention is a missile as described above, characterised in that the focussable damaging means are constituted by a group of preformed or predetermined fragments, projected in rotation along an annular path comprised between two fragmentable concentric envelopes surrounding the.

explosive charge. The groupof preformed fragments can be projected in rotation by a powder charge, or by gas under pressure.

According to another variant which comprises an omnidirectional proximity fuse, the rotor includes in addition a narrow lobe proximity fuse centred according to the focussed effects axis, the coincidence of the latter with the direction of the target initiating the firing of the main explosive charge.

With regard to the first variant, these four last modes of construction do not include a double-effect charge, but the latter combines all the advantages of rotating charges (infinite number of preferred directions to produce a focussed effects axis, and insensitivity to rapid changes in the missile-target azimuthal direction), added t.o the improvement in the efficiency of the charge due to the better synchronisation between the coincidence of the focussed effects axis with the target direction, for the firing Of the charge.

Other advantages of the invention will become clear from the following description of several embodiments, given by way of non-limitative example, with reference to the drawing in which: -Figure 1 is a -schematic view in axial section of a missile of the invention, -Figure 2 is a cross section along 11-11 of Figure 1, -Figure 3 is a section along 111-Ill of Figure 1, -Figure 4 is a section along IV-IV of this same figure, -Figure 5 is a schematic axial section of a second variant of a missile according to the invention, -Figure 6is a section along VI-VI of Figure 5, -Figure 7 is a schematic axialsectionOf a third variant of a missile according to the invention, -Figure 8 is a section along Vill-Vill of Figure 7, -Figure 9 shows schematically the axial section of a fourth variant of the invention, -Figure 10 is a section along X-X of Figure 9, finally Figure 11 is a schematic view in axial section of a missile according to a fifth variant, -whilst Figure 12 is a crosS section along XII-XII of Figure 11.

In the embodiments described below,the anti-aircraft defence explosive missile is, for example, self-propelled. It comprises an envelope I preferably made of light material (light metal like aluminium alloy or fibre-resin compound), revolvtnground a Z-V axis and containing a main explosive charge 2, for example a charge of hexolite. Firing means are provided to cause the explosiOn -of the charge 2 around the Z-Z' axis, which pulls off the envelope I and projects damaging devices focussed alony the XX' axis. In a front profiled cap 3 the missile comprises air target 4 proximity detection means to control the firing means and cause the charge 2 to explode.

In known fashion the target 4 proximity detection means or proximity fuse may have a capacity for azimuthal discrimination and comprise a radio-electric transceiver unit 5, operating, for example, in centimetric waves in short and close pulses.

tssociated with the unit 5 is a computer sensitive to the algebraic difference existing between the frequency of the radiation emitted by the unit 5 and the frequency of the radiation received after reflection on the target 4. The computer actuates a relay (not shown) to cause the functioning of the firing means when the above-mentioned difference tends to become cancelled to change its sign, indicating the proximity of the target 4.

In the first four modes of construction (Figures 1, 5, 7 and 9), the sectOrial discrimination proximity fuse 5 emits eight detection lobes 6i to 68 which can detect the target 4 independently from one another. The fifth mode of embodiment (Figure 11) is equipped with a conventional omnidirectional proximity fuse 37. The detection means are electrically linked to a firing box.

The missiles of the invention are generally equipped with means for taking into account the rotation round the main charge of the focussable damaging devices. These devices are electrically linked to a comparator 9 of the angular position of the damaging means with respect to the nose of the missile in which is found the proximity fuse. In ths nose of the missile there is also housed a firing box 10 of the main charge.

In Figires 1, 3 and 4 a missile of the invention has an explosive charge composed of a fixed part (stator) and a part rotating round the latter (rotor).

The fixed part is the cylindrical main explosive charge 2, housed in a metal tube 11, for example of light alloy, which ensures the mechanical connection between the rear of the missile and its cap 3, inside which are disposed the proximity fuse 5, a possible auto-director and the above-mentioned firing components.

*The rotating part essentially consists of the annular fragrnntation body 1.2 of the main charge 2. This body is, for example, made of steel prefragrnented by electronic bombardment. A segment 13 of this ring has additional preformed fragments, for example in steel, intended to be projected towards the target during adequate orientation of the rotating part. These fragments constitute partially the focussable damaging means. The explosive charge is completed by the secondary explosive 13a in the tubular section where there are no preformed fragments, and comprises two firing points 14 and 15 of the main charge, disposed for example at 22.5° on either side of the focussed effect axis, and of course, diametrically opposed to the segment of preformed fragments. These firing means consist of electrical detonators and reinforcing pellets.

The rotating part further comprises, on its periphery, eight longitudinal explosive strips 16i to 168 for the ejection of eight metal bars 17i to 178, for example of steel. These bars are fired by eight explosive channels 18i to 188 linked to a relay 19, fixed and housed in the nose of the missile, itself linked to a firing box 20 controlled by the proximity fuse.

The following description of the functioning of this first variant of missile according to the invention shows the double effect of the explosive charge with which it is equipped: in a first step it ejects the metal bars, which causes it to be orientated, by means of a "pyrotechnic spinning" effect, in a predetermined direction so that in a second step it focusses fragments on the target.

The sectorial discrimination proximity fuse emits eight detection lobes 6 to 68 which can detect the target 4 independently of one another. As soon as the target is detected, an electric order is transmitted to the firing box 20 *which controls the firing of the relay 19, itself connected to the eight explosive channels 18i to 188 which ensure the firing of the eight explosive strips 16 to 16. The eight 1 8 detonation of these...strips causes the ejection of the eight metal bars 172 to 178 which, through a conservation of the amount of movement effect, produce fast rotation (in the order of 500 revolutions per second) of the covering of the charge 12, and of its accessories 14, 15, 13 and 13a in reverse order.

When the eight strips are detonated, the external covering I of the missile is pulled off.

A rotation pick-up 21 (poteritiometric, for example), fixed both on the front of the missile and on the rotatably moving fragmentation body, permanently informs the comparator 9 of the angular position of the fragmentation body with respect to the nose of the missile in which is housed the fuse 5.

As soon as the angle 22 which separates the directed effect axis X'X from the detecting lobe axis Y'Y becomes zero, the comparator 9 emits an electric order towards the main firing box 10 which controls the initiation of the two relays 14 and 15 and thus ensures the firing of the secondary explosive 13a which itself transmits the detonation to the central explosive charge2. The transmission of the firing pulse between 10 and 14 or 15 can be ensured either by means of a brush and collector system or by means of a flexible wire connection with sufficient slack to allow at least one complete turn. This system of pulse transmission is not shown on the drawing.

The variant shown on Figures 5 and 6 does not comprise a "pyrotechnic spinning" technique. The equipment in the missile, nose, however, is identical to that of the first variant. The rotor comprises an annular fragmentation body 23, comprised between the cylindrical tube 11 surrounding the main charge 2, and the envelope I of the missile.

In this body there is formed an annular hollow 23a, one part of which is occupied by a propulsive powder charge 24.

This powder is initiated by. an igniter 25 and linked to the firing box 20 controlled by the proximity fuse, a key 25a is used as a breech for propelling the fragmentation body between the envelopes 11 and 1. The angular position of the axis of focussed effects is marked by at least one rotation pick-up 21.

In the other variants below, only the group of preformed or predetermined fragments is set in rotation in a "circular gun", which may lead to better performances than in the preceding cases where the whole assembly of the rotating covering is propelled.

Figures 7 and 8 illustrate a charge comprising a cylindrical main explosive charge 2, surrounded by two concentric fragmentab)-envelopes 26 and 27 of steel. An annular path 28 is formed between these envelopes for guiding a group of preformed steel fragments 13 having the form of a segment of about 450 An auxiliary propulsive powder charge 29 is initiated by an igniter 30 which, by means of a part 30a, is used both for rigidity and centering of the concentric envelopes. This igniter is linked to the firing box 20. Position detectors 31i to.315 of the fragments segment are disposed on the middle part of the envelope, and are electrically linked to the comparator 9, itself linked to the firing box 10 of the main charge 2.

Functioning is, therefore, as follows. As soon as the target is detected, an electric order is transmitted to the firing box 20 which controls the firing of the igniter 30, thus ensuring the combustion of the propulsive powder 29 which propels the group of preformed fragments 13 in a circular movement between the two concentric fragmentation bodies 26 and 27. The part 30a is used both as a circular gun breech and as a housing for the igniter 30. Discrete position pick-ups 31i to 315, the number of which is not limited, or any other known position pick-up, permanently inform the comparator 9 of the angular position of 13 with 1.0 respect to the missile nose in which is housed the fuse 5.

As soon as the angle 32 separating the movable X'X axis of the group of preformed fragments from the Y'Y axis of the detecting lobe becomes zero, an electric order is transmitted to the firing box 10 which causes firing of the relay 33 and consequently, of the main explosive charge2.

In the variant shown in Figures 9 and 10, the circular gun is fed. with a gas under pressure. The structure of the missile in its detection and rotating charge parts is similar to that of the preceding example. The means for rotating the group of preformed fragments are different. There is a tank 34 for storing gas under very high pressure, housed in the missile cap. The opening of this tank is controlled * by the firing box 20 by means of a pyrotechnic valve 35 which releases the gas into a duct 36. The latter opens into the annular space formed between the concentric envelopes 26 and 27. The gas expansion behind the preformed fragments sector 13 ensures the propulsion of the latter,and the missile functions as the previous one.

* Figures 11 and 12 show another variant of a military head equipped with a charge with a rotating covering and with a rotating proximity fuse. The explosive charge can be either of the "pyrotechnic spinning" type or the "circular gun" type.

A conventional omnidirectional proximity fuse 37 allows the target 4 to be detected as soon as it enters the lobe 38.

Then immediately 8.n electric order is transmitted to the firing box 20 which causes the procedure of setting in rotation the rotating covering 39 and a second narrow lobe proximity fuse 40 secured at 39 and centred on the axis of increased effect X'X. As soon as the target 4 enters the narrowlobe 41 an electric signal is transmitted to the firing box 10 which initiates the relay 33, thus causing the detonation of the main explosive charge 2.

Claims

Claims 1. Explosive missile, in particular an anti-aircraft missile, comprising a rotary, directional effect charge having a main explosive charge projecting focussable damaging means, and a proximity fuse with a capacity for azimuthal discrimination of a target, a missile that is chàracterised in that the focussable damaging means are mounted rotatably round the main fixed explosive charge to produce a rotary axis of focussed effects, and in that it comprises means for the detection of the coincidence of the rotary axis of focussed effects with the direction of the target, for firing the charge.
2. Missile according to claim 1, characterised in that the explosive charge is cylindrical.
3. Missile according to claim I or 2, characterised in that firing means for the explosive charge are mounted rotatably round this charge which itself is surrounded by a metal tube.
4. Missile according to one of claimsI to3, characterised in that the focussable damaging means are constituted by a rotor comprising an annular fragmentation body surrounding an annular explosive char4e, one segment of which is provided with a group of preformed or predetermined fragments, means for firing the annular explosive charge and the main explosive charge, and several peripheral longitudinal explosive strips for the ejection of metal bars for causing the rotor to be set in rotation.
5* Missile according to one of claims lto3, characterised in that the focussable damaging means are constituted by a rotor comprising an annular fragmentation body, one segment of which is provided with a group of preformed or predetermined fragments, the additional segment being hollowed out and partially surrounding the fixed * cylindrical main charge, one part of this hollowed-out segment being occupied by a propulsive powder charge initiated by an igniter for setting in rotation the annular body. * 12
6. Missile according to claim I or 2, characterised in that the focussable damaging means are constituted by a group of preformed or predetermined fragments, projected in rotation along an annular path comprised between two fragmentable concentric envelopes surrounding the explosive charge.
7. Missile according to claim 6, characterised in that the group of fragments is project,ed in rotation by a * powder charge.
8. Missile according to claim 6, characterised in that the group of fragments is projected in rotation by a gas under pressure.
9. Missile according to one of claims I to 8, characterised in that it comprises at least one fragments group position detector, fixed on the outer envelOpe of the missile, and co-operating with the detection means of the coincidence of the rotary axis of focussed effects with the direction of the target.
10. Missile according to one of claims 6 to 9, characterised in that it comprises an igniter housed in a part ensuring the rigidity and centering of the concentric envelopes.
11. Missile according to claims 4 or 5, comprising an omnidirectional proximity fuse, characterised in that the rotor comprises a second narrow lobe proximity fuse centred along the axis of focussed effects, the coincidence of the latter with the direction of the target initiating the firing of the main-explosive charge.
12. Missile according to claim 5, characterised in that the fixed main charge has a key used as a breech for the propulsion of the annular body.Amendments to the claims have been filed as follows 1. An explosive missile comprising a main explosive charge capable of projecting damaging means (for example steel fragments) towards a target, and a proximity fuse capable of azimuthal discrimination of a target, wherein a body which is adapted to provide said damaging means is mounted so as to rotate around the main explosive charge thereby to produce a rotary blast axis substantially along which the damaging means will be directed when the mairxplosive charge explodes, and the missile comprises detection means for detecting coincidence of the rotary blast axis with the direction of the target, for enabling firing, of the main charge when such coincidence is detected and when the proximity fuse responds.2. A missile according to claim 1, wherein the main explosive charge is cylindrical.3. A missile according to claim 1 or 2, wherein firing means for the main explosive charge are mounted rotatably around this charge which itself is surrounded by a metal tube.4. A missile according to any preceding claim, wherein said body extends along an annular path surrounding the main explosive charge, and is housed so as to constrain it to move along said path thereby to rotate around the main explosive charge.5. A missile according to claim 4, wherein said body is an annular body comprising a segment which is adapted to provide said damaging means.6. A missile according to claim 4 or 5, comprising an auxiliary annular explosive charge which extends about the main explosive charge between it and said body, said auxiliary charge being arranged to rotate with said body thereby to provide a rotor.7. A missile according to claim 6, wherein the rotor comprises firing means for the auxiliary and main charges. c8. A missile according to claim 4, 5, 6 or 7, wherein said body comprises a plurality of peripherally-arranged longitudinal explosive strips for ejecting metal bars from the body thereby to rotate the body.9. A missile according to claim 4 or 5, comprising driving means arranged to act directly on said body to drive it along said path.10. A missile according to claim 9 when appended to claim 5, wherein the annular body comprises a hollow region adjacent said segment, and said driving means is arranged to act in said hollow region.11. A missile according to claim 4, or claim 9 when appended to claim 4, wherein said body as a whole is adapted to provide said damaging means and has a limited circumferential extent, the body being housed between two fragmentable concentric envelopes surrounding the main explosive charge.12. A missile according to claim 9 or 10, or claim 11 when appended to claim 9, wherein said driving means is an explosive charge.
13. A missile according to claim 9 or 10, or claim 11 when appended to claim 9, wherein said driving means is pressurised gas.
14. A missile according to any preceding claim, and comprising detector means for detecting the rotary position of the blast axis by detecting the rotary position of the damaging means, this detector being cooperable with said proximity fuse to enable firing when the blast axis coincides with the direction of a target.i* A missile according to claim 12 when appended to claim 11, or claim 14 when appended thereto, and comprising an igniter, for said driving explosive charge, housed ma part providing rigidity and centering for the concentric envelopes.16. A missile according to any preceding claim, wherein said proximity fuse is a narrow lobe proximityVfuse arranged to rotate with the rotary blast axis, firing being initiated when the proximity fuse senses a target thereby indicating that the blast axis coincides with the direction of the target.17. A missile according to claim 16, further comprising an omnidirectional proximity fuse to initiate rotation of the first-mentioned proximity fuse when the omnidirectional proximity fuse detects a target.18. A missile according to claims 12 and 10 combined, wherein the main explosive charge comprises a key used as a breech for the propulsion of the annular body.19. A missile according to any preceding claim, which is an anti-aircraft missile.20. An explosive missile substantially as hereinbefore described with reference to Figures 1 to 4, or Figures 5 and 6, or Figures 7 and 8, or Figures 9 and 10, or Figures 11 and 12, of the accompanying drawings.