EP0392533B1 - Disintegrating igniter device - Google Patents

Abstract

What is described is a disintegrating igniter device for projectiles, grenades, cartridges, missiles and the like, consisting of a thin-walled aluminium sleeve, of a disintegrating ignition charge arranged in this, if appropriate of an ignition aid located in this charge, and of a flange piece arranged at the head end of the aluminium sleeve and having an axial bore, the aluminium sleeve being covered with a thin-walled plastic casing which is preferably produced from a shrinkable tube. Furthermore, there is preferably also a specially designed ignition aid which consists of ignition particles randomly distributed in the disintegrating igniter charge. Such a disintegrating igniter device is characterised by an especially clear-cut and reliable functioning, since its function pattern remains virtually unchanged even under the effects of a high load, such as occurs with the use of devices into which such disintegrating igniter devices are installed.

Description

The invention relates to an ignition disassembly device for projectiles, grenades, cartridges, projectiles and the like, consisting of a thin-walled aluminum sleeve, an ignition disassembly charge arranged therein, optionally an ignition aid arranged in this charge, and a flange piece arranged at the head end of the aluminum sleeve and having an axial bore.

Such an ignition disassembly device is usually arranged axially in projectiles, grenades, cartridges, throwing objects and the like and normally penetrates them more or less overall in the area which contains the active charges of such devices, so that the igniter disassembly device is generally completely embedded in the respective active charge . The active charge is normally an ignitable and combustible charge, such as an ignitable and combustible throwing means of known type, which, after more or less complete reaction of the igniter charge contained in the igniter device, which is initiated via an ignition delay piece arranged in the axial bore of the flange piece, and tearing open Aluminum sleeve ensures a spontaneous and comprehensive ignition of the active charge and subsequent disassembly of the container containing this charge. In the case of the known throwing bodies, the active charge can consist, for example, of conventional sentences based on red phosphorus or also of flammable thin leaflets which are ignited by the igniter charge of the igniter device and are distributed in the desired manner in the environment after the wall of the respective container has been disassembled.

From DE-B 35 15 166 a throwing body for the representation of an infrared surface radiator is known, the flammable thin flakes present as throwing material are ignited with a burning layer consisting of a fire paste via an igniter device of the above type and after disassembling the throwing agent container to the desired infrared surface radiator This ignition disassembly device accordingly also consists of a thin-walled aluminum sleeve, at the head end of which an axial bore for receiving an ignition delay piece has a flange piece, the ignition disassembly charge located in the sleeve being axially penetrated by an ignition liner as an ignition aid. A corresponding throwing body is also known from DE-B 28 11 016, but its igniter device does not contain an igniter core.

The known ignition disassembly devices, and in particular also those with an ignition core as ignition aid, fulfill their purpose in principle, but have the disadvantage of insufficient mechanical strength. When firing with a high launch acceleration, as can be the case especially with projectiles and grenades, where accelerations of 15,000 to 20,000 g and above are to be expected, there is therefore a strong deformation and premature tearing of the thin-walled Aluminum sleeve, which brings various undesirable and even very disruptive consequences. The deformation-related occasional tearing of the aluminum sleeve leads, for example, to a trickle of the igniter charge. If the active charge surrounding the ignition disassembly device (payload) is sensitive to friction and / or impact, such as, for example, in the case of a payload containing red phosphorus, then the friction on the aluminum sleeve can cause the active charge to ignite prematurely and thus also ignite the sprinkled ignition disassembly charge come. The consequence of this is a premature detonation of the igniter charge and thus also a disassembly of the payload and the body housing the payload. All of this can also be initiated by the influence of the impact on the possible ignition aid, in particular an ignition liner, which in turn ultimately leads to undesired premature or at least irregular disassembly. A strong deformation or even tearing of the aluminum sleeve naturally has the overall disadvantage of weakening this sleeve at certain points, with the result that the aluminum sleeve is not disassembled evenly, practically at the same time and over its entire circumference, when the igniter charge reacts through.

The problem of insufficient mechanical strength of the aluminum sleeve of the ignition disassembly device could in principle be eliminated with a thick-walled aluminum sleeve, but such a more insulated aluminum sleeve would not result in a functionally correct solution to the problem at hand. For the desired ignition, disassembly and distribution of the payload, an ignition disassembly device with comparatively low mechanical strength is indispensable, since, for example, if the aluminum sleeve containing the ignition disassembly charge is too high, the payload would be distributed into particles that are too small or else the payload would be damaged in some other way.

The invention has for its object to provide a lighter breakdown device that remains fully functional even at high shot loads, such as occur at accelerations of 15,000 to 20,000 g or even higher, so that its functional image corresponds to a lighter breakdown device with an essentially intact aluminum sleeve .

This object is achieved according to the invention in an ignition disassembly device of the type mentioned at the outset in that the aluminum sleeve is covered with a thin-walled plastic jacket.

The plastic jacket on the aluminum sleeve is preferably made of a shrink tube, which advantageously also has an inner adhesive coating. Such a shrink tube expediently has a shrinking temperature of 100 to 200 ° C., preferably 125 to 175 ° C. It can therefore be easily attached as a piece of tubing with the required length to the aluminum sleeve of the fully ignited ignition disassembly device and then fixed to it by heating to the respective shrinking temperature, for example to 125 ° C., the inner adhesive coating preferably present on the shrinking tube for a further improvement of such a composite of the aluminum sleeve and the plastic jacket produced thereon by shrinking the shrink tube.

Shrink sleeves are products familiar to the person skilled in the art, which are based on a wide variety of cold-stretched thermoplastic materials, which return to their original stress-free arrangement when heat-treated. This is a consequence of the so-called memory or elastic shape memory of the plastic molecules from which such shrink sleeves are made. In addition to the various plastics that form the basis, such shrink tubes as well as other plastic compositions, which can also be used to produce a thin-walled plastic jacket on the aluminum sleeve of the present igniter device, can optionally contain conventional additives, such as fillers, extenders and in particular reinforcing agents of various types, or else Pigments.

Shrink sleeves, as can also be used here, are already used in electrical engineering, for example, in order to isolate and protect cable bundles. Shrink sleeves based on polyethylene are available, for example, from T & B, Thomas & Betts GmbH, D-6073 Egelsbach, under the various type designations PLG (Shrink-Kon).

The thin-walled plastic jacket present as an essential element in the ignition disassembly device according to the invention as a coating on its aluminum sleeve can either be produced from a shrink tube in the preferred manner or it can, if under some circumstances, also be made from liquid preparations of the respective plastics, for example by immersion, Brushing, spraying or rolling on and then curing the applied liquid plastic preparation in the usual way. Of course, the liquid plastic preparations to be used here may also contain conventional fillers, extenders and reinforcing agents or other auxiliaries, including crosslinking agents and polymerization catalysts. The formation of thin-walled plastic shells on the respective aluminum sleeves based on liquid plastic compositions is therefore within the scope of the usual professional skill.

The thin-walled plastic jacket present on the aluminum sleeve of the ignition disassembly device according to the invention, be it made from a shrink tube or a liquid plastic preparation, is preferably based on any thermoplastic material, polyolefins or copolymers thereof being preferred. Examples of suitable plastics are polyethylene, which is particularly preferred, polypropylene, polyisobutylene, polybutene or Copolymers thereof or also polyethylene terephthalate or polyvinyl chloride. Instead of this, of course, any other plastics, such as silicones, can also be used, which ensure that the aluminum sleeve is equipped in such a way that the functional appearance of the ignition disassembly device according to the invention is almost unchanged when disassembled by the respective thin-walled plastic jacket. The decomposition temperature of such a plastic jacket must of course be far below the temperature that occurs during the function of the igniter charge and the disassembly of the aluminum sleeve, which means that the thermal and mechanical effects on the payload by the igniter device must not be changed significantly by the thin-walled plastic jacket . When the respective body is fired, however, the plastic sheath should result in such an improvement in the strength of the aluminum sleeve that this sleeve preferably no longer tears open or that any weak points or cracks do not allow the igniter charge to trickle into the surrounding payload. The plastic jacket present on the aluminum sleeve as a coating should therefore in any case also prevent contact between the igniter charge located in the igniter device and the surrounding payload if the aluminum sleeve should become defective at all. The plastic sheath, which is much softer than the aluminum of the aluminum sleeve, is also said to significantly reduce the risk of ignition of the payload due to friction or impact, such as occurs with relatively high launch loads and can then lead to premature ignition and reaction. The plastic jacket is also intended to protect the aluminum sleeve against corrosion by the action of the components of the payload.

The thin-walled plastic jacket present on the aluminum sleeve of the ignition disassembly device according to the invention suitably has a tensile strength of 700 to 1,300 N / cm², and preferably 1,000 to 1,100 N / cm², and suitably has an elongation at break of 200 to 400%, preferably of 250 to 350%. It generally has a wall thickness of 0.2 to 1.5 mm, preferably 0.3 to 0.8 mm. Furthermore, this plastic jacket should not melt, be well resistant to the chemicals of the respective payload and have a temperature resistance of generally from -40 ° C to +120 ° C, preferably from -30 ° C to +70 ° C.

The wall thickness of the aluminum sleeve of the ignition disassembly device according to the invention is of course dependent on the particular device in which it is used, but is generally 0.1 to 1.5 mm, and preferably 0.2 to 0.8 mm. Such aluminum sleeves are usually produced by conventional extrusion from an aluminum molded body.

The ignition disintegration charge present in the aluminum sleeve can be based on any powder set that is customary for this purpose and is preferably based on a powder set consisting of magnesium and barium nitrate, in which these two components are present in particular in a weight ratio of approximately 30:70%, this set also expediently also approximately 1 % Contains aluminum oxide. It is therefore a relatively insensitive powder batch.

As already mentioned, the essential element of the ignition disassembly device according to the invention is the coating made of a thin-walled plastic jacket arranged on the aluminum sleeve. In addition to this, it is also essential for the special function of this ignition disassembly device that the existing ignition disassembly charge reacts reliably at the speed required for disassembly.

It is therefore advantageous if an ignition aid is also arranged in the igniter charge of the igniter device according to the invention, which improves the reaction pattern of the igniter charge in the desired manner. The ignition aid must of course be much more sensitive than the igniter charge, since the igniter should ensure that the igniter charge is ignited and reacted as quickly as possible. Nitrocellulose powder is preferably used for this.

It has now been shown that the ignition disassembly device according to the invention has a practically optimal spectrum of action especially when its aluminum sleeve is not only covered with a thin-walled plastic jacket, but when an ignition aid is also arranged in its ignition disassembly charge, which can be designed in different ways. Such a special embodiment is achieved according to the invention in that ignition particles are arranged in a statistically distributed manner in the igniter charge, preferably based on nitrocellulose powder. These ignition particles are preferably granules or cut extrudates based on the respective ignition charge, which have a grain size of approximately 0.5 to 2.5 mm, preferably approximately 1 to 2 mm. Such ignition particles, which are statistically distributed in the igniter charge, ensure a rapid and reliable through-reaction of the igniter charge and, particularly in comparison to a likewise possible ignition core based on the respective ignition charge, which penetrates the igniter charge axially, have the further advantage that the embedding of the highly inflammable particles in the ignition disassembly kit makes this less sensitive to impact compared to a kit with a continuous ignition core. The risk of inflammation caused by the launch shock, which is relatively low anyway, is thereby further reduced. The combined The use of a plastic jacket and of ignition particles, which are statistically distributed in the ignition disassembly charge, thus represents a particularly preferred embodiment of the ignition disassembly device according to the invention.

As already mentioned, however, the firing aid can also consist of a firing core which axially penetrates the firing splitter charge, as is already provided, for example, in the firing splitter device of the throwing body described in DE-B 35 15 166.

The amount of igniter, based on the amount by weight of the igniter charge, is generally 2 to 7 percent by weight and preferably 3 to 5 percent by weight.

The advantages that can be achieved with the invention are, in particular, that the strength and resilience of the aluminum sleeve of the present ignition disassembly device can be increased in a metered manner by the thin-walled plastic jacket present on the aluminum sleeve, without this resulting in a substantial increase in the insulation of this sleeve with the result of a uncontrolled and violent disassembly of the sleeve and thus the throwing body provided with such an igniter device. The possible, in principle, pure increase in the wall thickness of the aluminum sleeve would therefore not lead to the desired goal. When the ignition disassembly device and thus the aluminum sleeve are loaded, for example by impact or shock, no sharp folds or kinks form in the aluminum sleeve, and blind sections have therefore only shown round and softly drawn faults on them. Any damage to the aluminum sleeve is covered and supported by the plastic jacket. Even if the sleeve were injured, no igniter charge would trickle out. The danger of ignition of the payload by the Friction on the aluminum sleeve during firing is significantly reduced by the plastic jacket. In addition, the plastic jacket forms a corrosion protection against the active mass, which is particularly advantageous with chemically aggressive active material sets. Corrosion of the aluminum sleeve by the components of the active set surrounding it is therefore largely ruled out. The particular advantages resulting from the thin-walled plastic sheath on the aluminum sleeve and mentioned above are further promoted by the arrangement according to the invention of statistically distributed ignition particles in the igniter charge, since the impact sensitivity of the igniter charge as a result of this is also possible compared to the arrangement of an ignition core axially penetrating the igniter charge is additionally reduced.

In principle, the invention can be used with all projectiles, grenades, cartridges, projectiles and the like, and the igniter decomposition device according to the invention can therefore, for example, only be based on an incandescent charge, an igniter charge or a decomposer charge, with devices in which this igniter decomposition device is used can be, for example 60 mm mortar grenades, 81 mm mortar grandsons, 120 mm mortar cartridges, 105 mm bullets, 155 mm bullets or corresponding small devices, such as hand flame cartridges and in particular projectiles. The use of the device according to the invention therefore arises automatically for the person skilled in the art.

Figur 1

einen Längsschnitt durch eine erfindungsgemäße Anzündzerlegervorrichtung mit in der Anzündzerlegerladung statistisch verteilten Anzündpartikeln und

Figur 2

einen teilweisen Längsschnitt durch eine erfindungsgemäße Anzündzerlegervorrichtung (Figur 1) mit einer die Anzündzerlegerladung axial durchsetzenden Anzündseele.

Two preferred exemplary embodiments of the invention are shown in the drawing and are described in more detail below. Show in it

Figure 1

a longitudinal section through an ignition disassembly device according to the invention with ignition particles statistically distributed in the ignition disassembly charge and

Figure 2

a partial longitudinal section through an ignition disassembly device according to the invention (Figure 1) with an ignition core axially penetrating the ignition disassembly charge.

In detail, FIG. 1 shows an ignition disassembling device 1 (for a projectile) made of a thin-walled aluminum sleeve 3, which is a sleeve produced by extrusion with a wall thickness of approximately 0.35 mm, a base thickness of approximately 1.5 mm and an outer diameter of approximately 12 mm and a length of about 180 mm, and of a flange piece 7 arranged at the head end of the aluminum sleeve 3, which is also made of aluminum and which has an annular groove 15 on its neck piece, via which it is connected to the aluminum sleeve 3 by a crank. The flange piece 7 has a threaded axial bore 17 into which an ignition delay piece, not shown, can be screwed. An existing external thread 19 on the neck piece of the flange piece 7 is used for fixing in the bottom part of a projectile, also not shown.

The aluminum sleeve 3 of the ignition disassembly device 1 is covered with a thin-walled plastic jacket 9, which has a wall thickness of approximately 0.35 mm and is made from a shrink tube with an inner adhesive coating. The shrink tube used for this is a plastic tube made by extrusion and cross-linked and modified by radiation and modified on the basis of polyethylene, the shrinking temperature of which starts at approximately 125 ° C. and which has a tensile strength of at least 1,000 N / cm² and an elongation at break of at least 250%. This shrink tube can be used in a temperature range from -55 ° C to +115 ° C and does not melt. It has a specific weight of maximum 1.25 and shows a radial shrinkage of about 50% and under the influence of heat (125 ° C to 200 ° C) a maximum longitudinal shrinkage of 10%. Shrink tubes of this type are available, for example, from T & B, Thomas & Betts GmbH, D-6073 Egelsbach, under the type designations PLG (Shrink-Kon), a shrink tube with the product number PLG 500-XY being used in the present case is.

The interior of the aluminum sleeve 3 is filled with an ignition decomposition charge 5, which is a common and relatively insensitive powder set based on magnesium and barium nitrate in a mixing ratio of 30:70 parts by weight, which still contains about 1 percent by weight of aluminum oxide. In this ignition disintegration charge 5, ignition particles 11 based on nitrocellulose powder, which consist of a cut extrudate of the mass of the ignition aid, are arranged in statistical distribution as ignition aid. Instead, the ignition particles 11 can of course also be produced in any other suitable manner and, for example, also represent a more or less coarse-grained granulate. The igniter charge 5 is about 18 g, while the amount of igniter particles 11 is about 0.6 g and thus makes up about 3.3% by weight of the igniter charge 5.

FIG. 2 shows an ignition disassembly device 1 (for a throwing body), which differs from the ignition disassembly device shown in FIG. 1 only in that, instead of the ignition particles 11 as ignition aid, an ignition core 13 which penetrates the ignition disassembly charge 5 axially, again on the basis of nitrocellulose powder, is present . This kindling consists of an extrudate of the mass of the kindling aid which, in contrast to the kindling particles 11 in FIG. 1, is therefore not cut. Instead, the igniter core 13 can of course also be produced in any other suitable manner.

Claims (16)

1. Disintegrating igniter device (1) for shells, grenades, bullets, projectiles etc, consisting of a thin-walled aluminium case (3), a disintegrating igniter charge (5) positioned in this case, an auxiliary igniter (11, 13) positioned in this charge (5) and a flange piece (7) positioned on the head of the aluminium case (3) presenting an axial bore hole (17),
   characterized in that the aluminium case (3) is covered with a thin-walled plastic coating (9).
2. Disintegrating igniter device according to Claim 1, characterized in that the plastic coating (9) is produced from a heat-shrinkable sleeve.
3. Disintegrating igniter device according to Claim 2, characterized in that the heat-shrinkable sleeve possesses an internal adhesive layer.
4. Disintegrating igniter device according to Claims 2 or 3, characterized in that the heat-shrinkable sleeve used possesses a shrinkage temperature of 100 to 200 °C, preferably 125 to 175 °C.
5. Disintegrating igniter device according to one of the previous Claims, characterized in that the plastic coating (9) is made of a thermoplastic.
6. Disintegrating igniter device according to Claim 5, characterized in that the plastic coating (9) consists of a polyolefin or a polyolefin copolymer.
7. Disintegrating igniter device according to Claim 5, characterized in that the plastic coating (9) consists of a polyethylene, polypropylene, polyisobutylene, polybutene or a copolymer of the above.
8. Disintegrating igniter device according to Claim 5, characterized in that the plastic coating (9) consists of a polyethylene terephthalate or a polyvinyl chloride.
9. Disintegrating igniter device according to one of the previous Claims, characterized in that the plastic coating (9) possesses a tensile strength of 700 to 1300 N/cm■ and an elongation at break of 200 to 400 %.
10. Disintegrating igniter device according to one of the previous Claims, characterized in that the plastic coating (9) possesses a wall-thickness of 0.2 to 1.5 mm, preferably from 0.3 to 0.8 mm.
11. Disintegrating igniter device according to one of the previous Claims, characterized in that the aluminium case (3) possesses a wall-thickness of 0.1 to 1.5 mm, preferably from 0.2 to 0.8 mm.
12. Disintegrating igniter device according to one of the previous Claims, characterized in that the disintegrating igniter charge (5) is composed of a powder compound based on magnesium and barium nitrate.
13. Disintegrating igniter device according to one of the previous Claims, characterized in that the auxiliary igniter (11, 13) is composed of a compound based on nitrocellulose powder.
14. Disintegrating igniter device according to Claim 13, characterized in that the auxiliary igniter (11) consists of igniter particles (11) based on nitrocellulose powder which are statistically distributed in the disintegrating igniter charge (5).
15. Disintegrating igniter device according to Claim 13, characterized in that the auxiliary igniter (13) consists of an igniter core (13) based on nitrocellulose powder which axially penetrates the disintegrating igniter charge (5).
16. Disintegrating igniter device according to Claims 13, 14 or 15, characterized in that the quantity of auxiliary igniter (11, 13) makes up 2 to 7 per cent by weight of the quantity by weight of the disintegrating igniter charge (5).

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