EP0411243B1 - Fuse for a bomblet - Google Patents

Description

The invention relates to a detonator for an explosive projectile, in particular a submunition projectile (bomblet), according to the preamble of claim 1.

Such a bomblet detonator with an axially unscrewable main firing needle and transversely to the longitudinal direction of the projectile from a securing position into a focusable slide with detonator charge is such. B. is known from EP-A-0 284 923. In the slide, a firing element of a pyrotechnic delay line which can be ignited by a second firing needle is provided for a self-dismantling of the projectile after the detonator has not been triggered in the event of a target impact by the main firing needle. This can e.g. B. happen when such a projectile ejected from a carrier floor (bomblet) lands on soft ground, mud, snow, tree branches or a camouflage net. A disadvantage of the known bomblet construction is the fact that when the ignition device is in focus, the slide protrudes laterally far and unprotected from the igniter housing. As a result, z. B. in rainy weather misfires easily occur in the detonator charge or the exposed ignition element of the delay charge for self-decomposition. Another disadvantage is the arrangement of the second ignition needle for igniting the ignition element on the outer unprotected end of the slide itself, which protrudes far out of the side of the fuse housing. The second ignition needle is provided with a heavy striking piece and is rotatably fastened to the slide by means of a bolt. When focusing by moving the slider out of the side of the detonator housing, the impact piece should go through Centrifugal force from the self-rotation of the bomblet take effect, and the massive firing pin is to move about 90 ° on a pitch circle with a small radius and penetrate into the ignition element. The shape of the ignition needle tip is solidly conical with a flattening on one side, possibly to facilitate penetration into the ignition element on a small circular arc. This detonator construction also has the major disadvantage that large unbalances in rotation and thereby destabilizing forces act on the bomblet due to the slide projecting far out of the detonator housing with an outside heavyweight firing pin impact piece.

From DE-A-33 33 312 another bomb detonator with self-dismantling possibility is known. In this case, a solid, conical second firing needle for activating the firing rate or the delay rate for the self-dismantling of the bomblet is attached to the inner housing wall. A disadvantage of this known bomb detonator is the massive cone-shaped firing pin and the spatial arrangement of the delay set in the detonator housing between the slide and the main explosive charge. This increases the height of the igniter and the igniter is not integrally connected to the delay line, so that the ignition must take place "around the corner", so to speak.
In each ignition element for the delay charge there is a tapping opening covered with a film, into which the tapping or ignition needle penetrates and initiates the charge. The well-known second firing pin with a solid conical shape more or less closes this opening during the ignition process, depending on how deep it penetrates. For a safe ignition, the ignition needle should penetrate as deeply as possible, but then the tap opening is completely closed and the ignition can lead to extinction due to the poor possibility of the combustion gases being emitted.

In this embodiment, a spring tongue is provided to secure the focus of the slider to be moved out of a securing position, which, however, permanently presses on the slider in the securing position. At low speeds of rotation, the centrifugal force or the spring force is often not sufficient to overcome the frictional force between the spring tongue and the slide and to move the slide into focus and to apply the piercing energy that is still necessary.

A further igniter is known from EP-A-0 318 995, which, however, already differs from the generic igniter in that the second ignition needle for igniting an ignition element which in turn can be displaced in the slide is mounted laterally in the slide and not in the igniter housing. This second firing needle is formed from a sheet metal flanged at the outer end of the slide. In order to avoid bending of the ignition needle bent out of the sheet when the ignition delay set is pierced, the sheet must be relatively thick, significantly thicker than 0.8 mm.

The necessary bending stiffness is achieved from a disk-like sheet metal with a thickness of at least 0.8 mm and a corresponding firing needle, but the length of the firing needle is impaired in its overall length. Furthermore, the penetration resistance of this firing needle into the ignition retardation set becomes larger, so that larger centrifugal forces are required for the safe insertion, which, however, are only available to a limited extent due to the narrow installation space. Correct ignition is therefore not possible with a firing needle that is at least 0.8 mm thick, largely due to the high friction, when penetrating into the ignition delay set.

In the case of thinner wall thicknesses of less than 0.8 mm, there is the danger that the firing needle will bend due to the undercut required to produce the pointed firing needle and the small circumferential clamping, so that the piercing area is enlarged and therefore a sufficient penetration depth cannot be achieved in the ignition delay set. The result is that the ignition delay set is not fired, so that the explosive projectile remains as a dud in the event of an impact on soft ground.

From FR-A-2 607 918 an impact detonator for a swirl projectile is known, which, however, is completely different in structure and function from the generic detonator. The ignition is only initiated immediately after a hard impact, with an ignition pin resting directly on the inside of a safety cage carrying a piercing needle. The piercing needle can be part of the sheet-like securing basket, and in this case consists of a tip punched out of the sheet and bent over.

This tip is located centrally in a disk-like plate of the safety cage, which is held at the edges and arranged transversely to the firing pin, as a result of which the disadvantages mentioned for EP-A-0 318 995 can also occur here. In addition, in the ignition position of the firing pin, the large area of the plate carrying the ignition tip largely closes the opening of the ignition charge located in the firing pin, so that little space is available for exhaust gas, and in a further disadvantageous manner the ignition can go out again.

It is an object of the invention to provide an improved detonator for a daughter storey (bomblet) in which the disadvantages described do not occur, reliable ignition being ensured and the overall height of the detonator and the weight or dead load component being able to be reduced.

This object is achieved with the characterizing features of patent claim 1. Due to the extremely flat design of the second ignition needle, an improved emission of the resulting combustion gases of the ignition charge is achieved, since the cross-section of the tap opening is not closed by the flat, pointed ignition needle and the combustion gases can flow out of the ignition opening of the ignition charge unhindered above and below the flat ignition needle . The better exhaust gas also achieves a better, more uniform burn-up and, in particular, constant or equally long delay times with simultaneous ignition / activation of a large number of bomblets ejected from a carrier storey are achieved.

Further advantageously, the rear support of the vertical part of the firing needle on the wall of the igniter housing ensures that the firing needle does not bend during the ignition process, so that it can penetrate deeply into the ignition delay set for safe initiation.

The second Zündandel is expediently an integrated component (connected in one piece) of a circular spring plate made of thin sheet metal, which has a strip-like spring tongue in the center, which engages in a recess arranged below the slide in the focus position of the slide and thus prevents the slide from rebounding and prevents it securely fixed in focus position.

Advantageously, the spring tongue is not loaded when the slide is secured, but is only depressed when the slide is displaced transversely and is therefore not subject to signs of fatigue during long storage.

The invention is explained and described in more detail below with reference to an embodiment shown in the drawings.

Figur 1:

Einen Längsschnitt durch ein Bomblet-Zündergehäuse gemäß der Erfindung,

Figur 2:

einen Teilschnitt durch ein Anzündelement einer Verzögerungsstrecke mit zweiter Zündnadel und

Figur 3:

einen Querschnitt durch das Zündergehäuse mit teilgeschnittenem Schieber.

Show it:

Figure 1:

A longitudinal section through a bomblet detonator housing according to the invention,

Figure 2:

a partial section through an ignition element of a delay line with a second firing pin and

Figure 3:

a cross section through the fuse housing with a partially cut slider.

In FIG. 1, the reference number 10 denotes an igniter housing, which is fixed in place on a bomblet housing 12 by means of a retaining ring 14. Arranged within the detonator housing 10 is a slide 16 with detonator charge 18 which can be moved transversely to the central axis A of the bomblet floor.
The illustration shows the slide 16 in a secured position, the detonator charge 18 being shifted laterally out of the straight line between a main firing needle 20 and an amplifier charge 22 arranged in the upper bomblet housing 12 in order to ignite the main explosive charge 24.
The centrally arranged main firing needle 20 is connected via a screw connection to a sleeve 26, which serves as an additional impact mass and can be displaced axially in the igniter housing 10. In the safety position shown, the firing needle 20 is screwed into the sleeve 26, so that it is supported upwards or backwards against a shoulder of the igniter housing 10. At the front, the tip 28 of the main ignition needle 20 projects into a recess (blind hole) arranged on the upper side of the slide 16 and thus fixes the slide 16 in the securing position.

A folded stabilizing band 30 is attached to the end of the main firing needle 20 protruding from the igniter housing 10. On the outside of the igniter housing 10 and surrounding the upper diameter-reduced area of the igniter housing 10 are two radially outwardly pivotable, semicircularly curved swirl brake vanes 32, e.g. B. made of thin sheet steel. A wrapping band 34 is placed around the swirl brake vanes 32 that are folded in. The winding tape 34 and the stabilizing tape 30 are held in their wound position by a hood-like, two-part plastic clip 36, which in turn is held in position by a spring steel retaining ring 38.

When they are transported to a target area by means of a large-caliber carrier floor that can be closed over long distances (e.g. 30 km), the daughter floors are stacked one inside the other in a space-saving manner as columns. Such a neighboring bomb 60, which completely covers the detonator housing 10, is indicated in FIG. The detonator housing 10 extends far into the conical free space of the shaped charge insert of the adjacent bomblet 60.

When the daughter storeys are ejected from the carrier storey by means of an ejection charge over a target area, after the stack arrangement has been lifted, several steps take place in succession within a predeterminable period of time from the securing position of the bomb detonator until it is focused:
First, the stabilizing band 30 is pulled out of its folded rest position and unfolded. The plastic clip 36 with the retaining ring 38 jumps off the igniter housing 10 and releases the winding tape 34. Thereafter, the detachable winding tape 34 unwinds and releases the swirl brake blades 32, which swivel out due to the centrifugal forces caused by the rotation and reduce the swirl of the now stabilized falling bomblet projectile.

After the stabilizing band 30 is unfolded, a torque acts on the firing needle 20, which turns a little to the rear out of the sleeve 26, the tip 28 of the firing needle 20 lifts out of the recess in the slide 16 and the slide can jerkily - if it has been released for this by additional safety devices acting separately - move it into its focus position.
For this purpose, the center of gravity of the slide 16 is set so that it is arranged in the securing position (on the left in FIG. 1) next to the central axis A, as a result of which the centrifugal forces push the slide 16 (to the left) against the force of a compression spring 40 in the event of a high swirl. As soon as the swirl or the centrifugal forces are somewhat reduced by the swirl brake vanes 32, the pressure force of the spring predominates and shifts the slide somewhat to the right in the direction of a second firing needle 42. As soon as the center of gravity reaches beyond the central axis A (to the right in FIG. 1) is, the slide 16 by the pressure of the spring 40 and the centrifugal force now effective again in its focus position.

The second ignition needle 42 arranged laterally within the detonator housing 10 for initiating an ignition element 44 of a pyrotechnic delay line 46 with a reinforcement set 48 and an explosive explosive charge 50 is designed in a sheet-metal strip-like manner with a pointed cone-shaped cut so that it can penetrate deeply into the ignition set 44 for safe initiation without flowing out to obstruct the resulting combustion gases.

The second firing needle 42 represents an integrated tongue-like bent sheet metal strip part of a flat spring plate disk 52, which is arranged in the direct vicinity of the slide 16 and covers the entire cross section of the igniter housing 10. The tongue-like bent-up spring which is perpendicular to the spring plate disk 52 is supported Part of the second firing needle 42 on the back on the inner wall of the igniter housing 10. The second firing needle 42 or the spring plate 52 expediently has a material thickness or plate thickness of 0.1 to 0.4 mm. The second firing needle 42 is arranged asymmetrically with respect to the central axis B of the slide 16 in a direct line with the ignition element 44 of the pyrotechnic delay line 46, the end region of which is arranged directly next to the detonator charge 18 with a reinforcement set 48 and an explosive explosive charge 50.

Advantageously, the spring washer 52 has an integrated spring tongue 54, which is in a blocking operative connection with a corresponding recess 56 on the underside of the slide 16 in the arming position of the slide. If the slider 16 is moved into the focus position, it is locked by the spring tongue 54, which latches into the recess 56 on the underside of the slider 16.

By attaching a beveled step in front of the recess 56 and lowering or deepening the recess 56 in the underside of the slider 16, neither the slider 16 nor the spring tongue 54 is loaded in a safe manner. The slider 16 only presses the spring tongue 54 down during the displacement movement in the arming position. In the focus position, the spring tongue 54 then jumps into the recess 56 of the slide 16 and then prevents it from running out of this focus position.

The spring washer 52 is fixed to the igniter housing 10 by a thin-walled covering hood 58 that overlaps the igniter housing 10. The covering hood 58 expediently has the same sheet thickness as the spring sheet metal disk 52.

As soon as the slide 16 has reached its focusing position, the ignition element 44 being ignited by the second firing needle 42, the spring tongue 54 engages in the recess 56 and fixes the slide 16 in this position. The detonator charge 18 is now arranged in a line exactly below the tip 28 of the main ignition needle 20, which in the normal case initiates the detonator charge 18 in the event of a hard target impact, which brings the booster charge 22 and thus the main explosive charge 24 to ignition and detonation.
For the trouble-free ignition of the detonator charge 18 onto the booster charge 22 in the bomblet housing 12, the spring plate disk 52 and / or the thin cover hood 58 can have a central bore.

If after a fall time of z. B. 15 seconds after ejection from the carrier storey, the detonator charge is not ignited by the main firing needle 20 when the target area hits softly, the delay set 46 burns after z. B. 20 seconds and ignites the reinforcement set 46, which develops a high combustion temperature, and the explosive powder containing explosive charge 50, which nevertheless activate the detonator charge 18 arranged next to it in a short way.

The inventive construction of the bomb detonator ensures a trouble-free ignition of the igniter element for subsequent self-destruction or detonation of the bomb in any case while reducing the height and weight of the detonator.

Claims (2)

1. Detonator for an explosive projectile, particularly a sub-ammunition projectile (bomblet), with an axially displaceable main firing pin (20) and with a slide (16) which is displaceable transversally in relation to the longitudinal direction of the projectile or to the median axis (A) and which has a detonator charge (18), the slide (16) containing a detonating element (44) associated with a pyrotechnical delay section (46) for self-disintegration of the projectile and which is ignitable by a second firing pin (42) positioned laterally in the detonator housing (10), characterised by the fact that the second firing pin (42) comprises a sheet-metal strip part associated with a thin flat sheet-metal plate which is bent upwards to form a tongue and which does not obstruct the discharge of the combustion gases and which is positioned in the immediate vicinity of the slide (16) and which covers the entire cross section of the detonator housing (10), while that part of the second firing pin (42) which is bent upwards to form a tongue and positioned perpendicularly to the sheet-metal plate (52) is supported at the rear against the inner wall of the detonator housing (10), and that the sheet-metal plate (52) has an integrated flexible tongue (54) which, when the slide (16) is in the armed position, is operatively connected, with a blocking effect, with a corresponding recess (56) on the lower side of the said slide (16).
2. Detonator in accordance with Claim 1, characterised by the fact that the material or sheet metal of the second firing pin (42) or sheet-metal plate (52) has a thickness of 0.1 to 0.4 mm.

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