EP1154223A2 - Spin stablised projectile provided with brake fins - Google Patents

Abstract

The projectile has an aerodynamic brake unit in its front area, which can be moved outwards along its flight path into an axially symmetrical radially extended work position. The projectile tip (14) has support points for flap-shaped ring sectors (24) around its central cross-section plane. The ring sectors can be pivoted outwards from a position flat against the projectile to a working position transverse to the projectile longitudinal axis.

Description

The invention relates to a spin-stabilized projectile according to the preamble of the claim 1.

The generic projectile is known from WO 98/01719 A1. There is provided semi-circular plates in the parting plane between the projectile body and the projectile tip to be arranged, which, axially overlapping one another, azimuthally around the longitudinal axis of the projectile are offset from each other. You can radially with respect to this longitudinal axis from its position within the contour of the projectile in its axially symmetrical operative position be pushed out, then due to an increase in aerodynamic drag shorten the ballistic trajectory. Installation of the mechanism for the relocation of the plates between their two positions and the stable bracket of the extended Position due to the inflow, particularly in the stressed plates construction and function critical level of the transition from the tip into the body However, the projectile is associated with considerable construction risks, especially since this Cross-sectional plane per se with the detonator components engaging into the body from the tip is already fully occupied.

In contrast, it is known from DE 36 08 109 A1 as a braking device for a spin-stabilized projectile in the center area a peripherally extending puncture To provide stowage chambers for a cloth that is radial by releasing centrifugal masses can be thrown into an annular brake sail around the projectile jacket surface is stretched radially around. Its position in the course of the projectile body basically opens up greater constructive freedom for accommodation the braking device not yet deployed into the active position and its drive elements for the centrifugal force bringing into the active position; but these. arrangement requires a complete redesign of the projectile due to serious interventions into the load-bearing structure and its useful cargo space. Another disadvantage is that the textile In the case of an asymmetrical flow, the shape is not guaranteed.

The technical problem of the present invention lies in the knowledge of these circumstances based on a projectile of the generic type with an easily activated, uncontrolled (i.e. having two-point behavior) and yet very effective, functionally reliable equip aerodynamic braking device.

According to the invention this task is according to the characterizing part of the main claim essentially solved in that as an aerodynamic braking device approximately in the middle the projectile tip on from the transfer position, against the inflow, can be swung out into a geometrically defined operative position Flap system is provided, which there in a circumferential recess on the wall of the igniter housing is articulated. Because in the top of the large-caliber ones of interest here Ammunition for the tube artillery is housed the detonator, is the complete tip for designed for disassembly, that is, easily replaceable on the body of the projectile supported. As a result, the conventional, imported ammunition can also be retrofitted can be equipped with this braking device for influencing the trajectory by simply the conventional projectile tip is replaced by another with the brake elements becomes.

To that extent, it is known from DE 1 98 45 611 A1 to use a path control with swirled and to carry out arrow-stabilized projectiles by using correction elements axially asymmetrical more or less far from a separate correction unit, from which Projectile body or extended from the detonator; but for those there Constant control of the correction elements and their actuating force application is a very considerable one Installation space is required, even in the event of a major redesign introduced igniter systems is hardly available.

In contrast, in the context of the present invention, the centrifugal force acts on the spin-stabilized Projectile swinging the flap-shaped swing out without braking Sectors of the braking device into a star-shaped, approximately radially oriented operative position, due to the equilibrium of forces of the centrifugal and dynamic pressure forces are given. This eliminates the need for the inside of the projectile tip Construction elements for an active release of the braking device take effect allow; so this braking system is relatively far forward around the tapered area of the tip can be articulated where the aerodynamic braking effect is greatest and therefore the brake flaps can be relatively short. The location as far as possible in front of the parting plane to the projectile body is also useful because there is practically no inside of the tip is required for detonator functions and because this area is also of no significance for the design for the overall rigidity of the projectile, that is, a weakening of the Ignition housing through radial recesses for mounting the swivel shafts for the brake flaps quite tolerated. The individual flap-shaped brake sectors not swung out against a stop fixed to the housing, because that is there - especially with possibly in the direction of flow acting flow - raise critical stability problems would. With low swirl ammunition, the brake elements can be opened through deposited between the brake elements and the housing of the projectile tip clamped leg springs are promoted. It is expedient in any case a simple latching to prevent the swinging freely swinging back into its operative position Folding sectors of the braking device are provided so that the braking device their geometrically defined position of action once achieved is stable in the interest Braking behavior immediately and reliably even under changing inflow conditions maintains.

When the movement position is folded into the housing, the flap-shaped brake elements carry hardly radial. Therefore, they must not be so wide that they e.g. At her Project the linkage laterally over the surface of the igniter tip. Therefore are comparative narrow flaps offset circumferentially against each other at asymmetrical mounted bolt-shaped swivel shafts. Under two each other Adjacent flaps can be arranged around the entire circumference the top, thanks to mutual support, a uniform set-up to promote all valves.

The in their movement position parallel to the outer surface of the hood to the igniter housing embossed flap-shaped brake elements in the form of ring disc sectors cannot overlap each other so far in the circumferential direction of the igniter housing, that they are in the radially deployed position in the front view a closed, radial Open a wide ring around the top, which is why there are none when it is on display uninterrupted ring disc results, but a broad spoke-shaped structure. However, their aerodynamic braking effect is compared to a closed one Ring disc only slightly reduced because of vortex losses at the transitions from the closed sectors to the gaping cutouts resulting in additional braking effects to have. However, the braking effect can be increased by the gaps be bridged between the ring disk sectors by flexible elements, for example through textile cut-outs, which arise when the flaps are set up between the sectors span. This results in a simpler articulation in terms of geometry and mechanics stable structure for the braking device when the flap-shaped washer sectors to be narrowed to thin spokes, which are ring-shaped exhibited textile structures in the manner of an umbrella due to radial bracing Give geometric stability even under changing aerodynamic influences. The textile ring that is braced by the spokes can then still be braced by an unsupported one circumferential edge are enlarged to the braking surface for the incoming flow to optimize.

If, on the other hand, the essentially textile continuous structure of the braking device due to a mechanically more stable because it is metallically closed in the direction of flow Ring surface should be replaced, as yes by the width of the flap-shaped sectors alone cannot be reached without gaps, then these braking elements can be radial on themselves extending sector longitudinal edges equipped on both sides with triangular spring plates be the one another in the folded state of the sectors with elastic adjustment overlap alternately on the lateral surface curvature of the projectile tip and in stretched unfolded state, the free cutouts between the flaps just cover in pairs.

Fig. 1

einen Artillerie-Zünder mit inaktiver Bremseinrichtung in Ansicht,

Fig. 2

den Zünder gemäß Fig. 1 in abgebrochener Achsial-Längsschnittdarstellung,

Fig. 3

den Zünder gemäß Fig. 1 bei aktivierter Bremseinrichtung in Ansicht,

Fig. 4

den Zünder gemäß Fig. 3 in abgebrochener Achsial-Längsschnittdarstellung und

Fig. 5

einen Zünder, dessen radial ausgestellte Bremseinrichtung eine in Anströmrichtung geschlossene metallische Ringscheibenstruktur aufweist.

With regard to additional advantages, alternatives and further developments, reference is made not only to the subclaims but also to the following description of a preferred implementation example, which is illustrated in the drawing in a highly abstracted manner, but limited to the functional essentials, as well as the use of a spin-stabilized projectile with such an aerodynamic braking device to avoid Repetitions of the full content of our older German patent application "Procedure for target-specific correction of a ballistic trajectory", file number 19957363.8 from November 29, 1999, expressly referred to. In the present drawing:

Fig. 1

an artillery detonator with inactive braking device in view,

Fig. 2

1 in a broken axial longitudinal sectional view,

Fig. 3

1 with the braking device activated in view,

Fig. 4

3 in broken axial longitudinal section and

Fig. 5

an igniter, the radially flared braking device of which has a closed metallic annular disc structure in the direction of flow.

A spin-stabilized artillery projectile 11 consists essentially of a straight one hollow cylindrical body 12, in which a removable detonator 13 engages frontally. The Detonator 13 is thus part of the tip 14 of the projectile 11, the contour of which is essentially is determined by their ballistic hood 15.

The igniter 13 is detachably connected to the body 12 via a coaxial screw connection 16. It then protrudes through the parting plane 17 between the tip 14 and body 12 of the Projectile 11 with at least one ignition amplifier or transmitter charge 18 together with securing device 19 into the front area of the body 12. Before that lies approximately in the division level 17, e.g. Navigation unit based on satellite navigation 20 behind a battery 21 in the base of the projectile tip 14. Between this and the evaluation electronics 22 in the front area of the igniter 13 is an ignition electronics 23 arranged approximately in the axial center plane.

In their jacket area are flap-shaped elements of the braking device Washer sectors 24 to the front - that is, against the flow - under the action of centrifugal force Swing-out without any stops. Each of the flap-shaped sectors 24 is therefor a pin 25 oriented tangentially in the jacket area as a short bearing and Assigned swivel shaft. The bolts 25 lie in radial incisions 26, which are approximately in the center transverse plane of the tip 14 is introduced into the igniter housing 27 in the circumferential direction are. The beginning and end, i.e. the bearing points, of the circumferential in a cross-sectional plane However, the sequence of bolts 25 does not lie on one that is concentric with the longitudinal axis 28 of the project Circle, but radially asymmetrical, namely with one end inside and radially offset with the other end outside this circle, so that the Bolts 25 adjacent on both sides in the circumferential direction are mounted radially in front of or behind them are. This pivoting from the direction of the secants in the above-mentioned Circle and thus the asymmetrical orientation of the bolts with respect to the axis 28 25 makes it possible to carry out their bearings on both sides identically for all bolts 25 and thereby a symmetrical installation behavior of each other in the circumferential direction to promote neighboring sectors 24.

The relatively narrow sectors 24 are profiled so as to be curved around their longitudinal axes folded or movement state according to Fig. 1 / Fig. 2 the contours on the one hand inside of the housing 27 and on the other hand outside of the rear continuation of the here deposited to adapt ballistic hood 15 as well as possible. In this state of movement can over the hammered flaps (ring sectors 24) one (dashed lines in Fig. 2) considered) bracket sleeve 29 to be put on to continue in the rear the shortened hood 15 to define its lateral surface contour, that is, the aerodynamic ensure smooth geometry and compared to the surface of the conventional Projectile tip 14 not to be changed. To fold out the sectors 24 into the active position the brake device this sleeve 29 is e.g. with ripping along predetermined breaking points blown pyrotechnically. That is with a cuff 29 because of the attacking Centrifugal forces and especially the inflow can be realized more easily than blasting an aerodynamic hood, hermetically sealed in the direction of flight, which Within the scope of the present invention, however, it can also be used over the engaged sectors 24 would.

By removing the retainer collar 29 (or by axially sliding a crown latch - Not shown) are the sectors 24 for centrifugal unfolding released around the bolts 25, which is done by means of integral or adapted leg bending springs (not shown) still supported against the housing 27 can be. To synchronize the unfolding these are now released peripherally to promote adjacent sectors 24 despite approximately asymmetrical flow instead of voluminous leg springs in the hinged pin 25 also simply radially short cantilevered spring supports can be arranged, each over at least two each other neighboring sectors 24 extend (not taken into account in the drawing).

For the reasons already mentioned, it is inevitable that the braking device from the set up, relatively narrow individual annular disk sectors 24 spokes-like gaps. To increase the braking effect these gaping cutouts 32 (FIG. 3) can close one between two adjacent sectors 24 flexible bridging 33 may be provided, which in the course of setting up the sectors 24 is spanned, as shown in Fig. 3 on the left. This bridging 33 of the sectored Brake ring disc can consist of textile fabric that is folded in State of the sectors 24 is folded radially below them. The sectors 24 can then can also be thinned to narrow radial spokes, the suspension of which on short Bolt 25 constructively less problematic than the folding suspension of the wider sectors 24 and is in the issued state an umbrella-like stiffening then bring the overall textile disk-shaped braking device.

If, on the other hand, a metallic annular disc that is as complete as possible in the direction of flow is desired as a braking device, then the individual sectors 24 are radial on their extending longitudinal edges with welded or riveted triangular edged spring plates 34, which are preferably in the warped state the braking device under the sleeve 29 alternately above and below each other come to rest. This is promoted when the spring plates 34 of a sector 24 in connect mutually offset levels to it, as can be seen from FIG. 5. This Arrangement also promotes a rapidly rolling out unfolding of the sectors 24 to their functional positions, in which the neighboring, now relaxed in levels Spring plates 34 just overlap each other to form a closed ring.

A swirl-stabilized artillery projectile 11 can therefore be simply with an axially symmetrical aerodynamic braking device to shorten the ballistic trajectory retrofit if the equipped with the igniter 13 from the projectile body 12 without any problems Removable tip 14 at about half height with articulated hinged under centrifugal force Sectors 24 is populated, which are in the conical in their transfer position Nest the shape of the outer surface and in the operative position to a gaping or closed issued radial ring are unfolded. The unique time-discrete use with a fixed manipulated variable through the targeted increase in aerodynamic drag - with Change the braking effect on the trajectory by adjusting the time the issuance of the braking device - the result for an explosive projectile Possibility of shortening the trajectory, for a bomblet projectile also with the Adjustment of the time of ejection is another possibility to intervene in the function.

Claims (9)

Swirl-stabilized projectile (11) with an aerodynamic braking device which can be set up radially along its trajectory from a displacement position into the axially symmetrical active position,
characterized in that its tip (14) is equipped in approximately its central cross-sectional plane with bearing points for flap-shaped annular disk sectors (24) which can be pivoted out of a movement position in the lateral surface area of the tip (14) into an operative position approximately transversely to the longitudinal axis (28) of the projectile are. Projectile according to claim 1,
characterized in that the sectors (24) can be pivoted out about bolts (25) into the operative position, which are mounted in a housing incision (26) oriented transversely to the longitudinal axis (28). Projectile according to claim 2,
characterized in that the bolts (25) are each pivoted asymmetrically from a secant orientation such that one end of a bolt (25) is at a greater distance from the longitudinal axis (28) than the other end, that of the bolt which adjoins in the circumferential direction (25) with its larger spaced end is engaged radially with respect to the longitudinal axis (28) of the projectile. Projectile according to one of the preceding claims,
characterized in that the sectors (24) are suspended with leg bending springs around the bolts (25) which are supported radially opposite the sectors (24) against the igniter housing (27). Projectile according to one of the preceding claims,
characterized in that the width of the sectors (24) which overlap one another in their movement position provides, in their operative position, a ring with gaps in cutouts approximately transversely to the longitudinal axis of the projectile (28). Projectile according to the preceding claim,
characterized in that the gaps (32) are spanned by flexible bridges (33) clamped between adjacent sectors (24) in the circumferential direction. Projectile according to the preceding claim,
characterized in that the sectors (24) are narrow spokes. Projectile according to one of claims 1 to 4,
characterized in that the sectors (24) are laterally equipped with triangular spring plates (34) which overlap in the movement state and in the unfolded operative position close the gaps (32) between the sectors (24) to form a closed ring. Projectile according to the preceding claim,
characterized in that the spring plates (34) are fastened to the sector (24) on both sides of a sector (24) in a mutually offset projectile-axial position.

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