EP2846124B1 - Shell - Google Patents

Description

The invention relates to a projectile, comprising a projectile casing with explosives received therein into which a projectile tip containing an igniter is inserted.

A projectile of the type in question consists of a projectile casing in which the actual explosive is added. In this mostly hollow cylindrical projectile casing, the projectile nose containing the igniter is usually screwed in with high torque. If such a projectile is exposed to high temperatures, for example in case of fire, then the explosive begins to outgas due to the increased temperature inside the projectile. It thus forms a high internal pressure, which, since the projectile nose is firmly screwed into the projectile casing and thus given a tight connection, can not be degraded by the escape of the forming gas. The explosive is therefore very heavily dammed up. At a critical temperature, the reaction temperature of the explosive, the explosive is reversed, resulting in an explosion. Due to the high internal pressure, this reaction is very violent, associated with environmental hazards. Sometimes it comes also due to pressure to a separation of the projectile tip of the projectile casing, so that the projectile falls into several parts. However, due to the high temperature, there is a risk that the explosive will react and endanger the environment as a result of the parts flying around when the explosive reacts.

To counteract this is known as "insensitive ammunition", short IM-capable projectiles. In such a projectile precautions are taken to specifically reduce the high internal pressure resulting from temperature increase, so that the probability of accidental ignition of the explosive containing high functional reliability by external influences such as fire, shelling, splintering or other accidents is reduced and thus the risk from Collateral damage to the weapon station, weapon carriers and even personnel is reduced. An example of such an IM-capable ammunition is from the US 2010/0024675 A1 and from the US 7,353,755 B2 known. In the US 7,353,755 B2 the igniter is housed in a component having predetermined breaking points. Furthermore, several leading to the outside venting channels are provided, which are closed by Kunststoffpfropfen. If, due to an increase in temperature, there is an outgassing of the explosive absorbed in the projectile casing, the predetermined breaking points on the component break as soon as a defined minimum internal pressure is reached, so that the pressure can escape in the direction of the venting channels closed via the plastic plugs. The plastic stoppers, which are only slightly held, are pushed outwards by the high pressure, so that the venting channels are opened and the pressure can be reduced. On the one hand so here are items, namely the Kunststoffpfropfen ago, on the other hand, it is not excluded that at very high internal pressure of the igniter respectively the bullet tip but not from the projectile casing dissolves, especially if for whatever reason, the predetermined breaking point does not open or not completely ,

The invention is therefore based on the object to provide a projectile, on the one hand, the possibility of venting and thus the pressure reduction, on the other hand, however, prevents a separation of the projectile nose from the projectile casing.

This object is achieved by a projectile according to claim 1. Advantageous embodiments of the invention are indicated in the dependent claims.

The projectile according to the invention, which may be of any type of projectile and also of a warhead, is characterized by the fact that a pressure-related defined axial relative mobility of projectile nose is provided to the projectile casing. On the one hand, this relative mobility leads to the defined opening of at least one ventilation channel, via which the high internal pressure can be reduced. On the other hand, this movement is defined stop-limited, ie, the projectile nose is only a defined axial piece movable and then runs against a stop. Since there is already a pressure reduction as a result of the opening of the vent channel, the projectile tip is securely held over the stop, so it can not separate from the projectile casing. The projectile according to the invention is therefore characterized by the integration of a additional mechanical coupling, which makes it possible to combine the vent as well as the retention of the bullet tip and the detonator on the projectile casing together. A separation or seizure of any items is therefore excluded in the projectile according to the invention.

To realize the limited axial mobility, it is inventively provided that the projectile nose has an external thread on which a female thread exhibiting a first ring is screwed, which has an external thread which is screwed into an internal thread of the projectile casing, and that at the projectile nose a stop element is provided, which runs to limit the axial movement, which is made possible by a pressure-induced shearing of the threaded connection of the ring with the projectile nose, against the stop. The axial mobility is realized in accordance with this embodiment of the invention in that with the external thread of the projectile nose and screwed thereon internal thread of the ring, a threaded connection is designed which is designed so that it generates a defined axially directed force, which is generated by the high internal pressure , shears, so therefore the threaded connection is destroyed. Because of this then no longer given axial fixation of the projectile nose on the ring, which in turn is bolted to the bullet sleeve, the projectile nose can move a short distance axially pressure driven until the stop element of the projectile nose runs against the stop. Consequently, this thread connection constitutes a kind of "predetermined breaking point" of the system. To enable shearing, different embodiments of the threaded connection are conceivable, for example, the intermeshing threads may be made relatively flat, ie. h. that both have a small thread depth and consequently only slightly mesh. It is also conceivable to weaken the respective threads by axial cutouts, so that the engagement surface is reduced overall and the like. The aim of the design of the threaded connection is that a relatively low pressure on the bullet tip or the igniter is sufficient to shear the thread flanks.

As described, a stop element is provided on the nose tip side, which runs against a stop that is fixed in position with the projectile casing. This stop element may be embodied in a further development of the invention as a second ring, which is screwed with an internal thread on the external thread of the projectile nose. On this bullet tip side external thread so two rings are screwed according to this invention embodiment, namely, on the one hand, the first ring, which receives the defined, can be sheared threaded connection with the projectile nose, on the other hand, a second ring, which constitutes the stop element. The threaded connection, which enters the internal thread of the second ring with the external thread of the projectile nose, is designed mechanically much stronger than the peelable threaded connection. Because this second threaded connection should never be damaged due to pressure, but it should be so stable that the projectile nose, when it runs against the stop, is securely fixed. For this reason, it must never come at a time to solve or damage this threaded connection. It is conceivable to cut deeper the external thread of the projectile nose in this area, so that the correspondingly cut internal thread engages deeper and consequently the thread flanks lie over a larger area. If the external thread of the projectile nose is consistently the same, and if it is locally removed, for example by longitudinal milling in the threaded connection to the first ring, then it can be continuous in the region of the connection to the second ring, so that a comparatively larger threaded engagement surface is provided.

In a further development of the invention may finally be provided that one or more, preferably equidistantly distributed around the circumference of the ring arranged radial projections are provided on the second ring, with which or which the second ring runs against the stop. The second ring thus has one or more radial projections, which serve as quasi as abutment sections and strike in the defined end position to the stop. The stop itself is preferably formed by the front edge of the first ring, d. e., that the first ring, which is bolted to the housing shell, which is a Wegbegrenzende element while, if provided, the second ring is the second wegbegrenzende element.

To enable a compact construction, it is expedient if the first ring has a first ring section having the internal thread and an adjoining second annular section with an enlarged inner diameter, with which the first ring radially overlaps the second ring in sections. In other words, the second ring is screwed somewhat below the first ring, so that sufficiently long thread engagements result, but at the same time a compact construction is also provided. Acts the first ring with his End edge as a stop and proposes the second ring, for example, on the radial projections or on the front edge, it can be defined defined by appropriately wide screwing of the second ring and thus moving under the first ring of the axial gap between the radial projections and the front edge, consequently, also the axial mobility.

As described, at least one venting channel is opened by moving respectively at the latest when reaching the end position of the projectile nose after shearing off the threaded connection. Since, as described, the projectile tip moves axially away from the projectile shell, a radially outwardly open annular channel is thus opened in this case, which makes it possible to reduce the overpressure. In order to make this possible, the external thread of the projectile nose and / or the internal thread of the first ring is expediently provided with at least one longitudinal groove which forms the venting channel or a part thereof and which opens in an annular gap which opens outwards when the stopper position is reached between projectile nose and projectile casing , The threaded connection, which is sheared off at overpressure, is thus provided with a, preferably with a plurality of equidistant and distributed around the circumference arranged longitudinal grooves which form the respective ventilation ducts or parts thereof. These also serve at the same time the weakening of the thread to allow a defined shearing. In the assembly position, when the projectile nose is firmly and tightly bolted to the projectile casing, the entire interior is completely sealed, consequently, this or these venting channels are closed. Now builds up a high internal pressure and it comes to shearing off the thread, so the projectile tip moves a short distance axially away from the threaded sheath, it opens a radially outwardly open annular gap in which or the thread connection side longitudinal grooves, so the ventilation channels , flow. The interior communicates in a suitable manner with the longitudinal grooves or grooves, so that the overpressure can escape into the annular channel. The overpressure is reduced, however, the bullet tip is safely trapped in the bullet casing over the stop.

In order to guide the overpressure or the gas produced in the one or more longitudinal grooves, it is expedient if the first ring engages over the second ring with a radial distance, so that an annular gap is formed, which circumferentially distributed with the at least one longitudinal groove respectively the plurality of provided longitudinal grooves and the projectile interior communicates. D. h. That the forming gas ultimately coming from the projectile interior in the annular gap between the first and the second ring flows and flows from there into the one or more longitudinal grooves, from where it is discharged into the opening radial gap. Of course, it would also be conceivable to guide the gas directly into the longitudinal groove (s), for example, if no second ring is provided and manufacturing technology integrally provided on the projectile nose one or more stop elements radially projecting. Because then, after the first ring axially adjacent to the interior of the envelope, the access to the venting grooves would be open anyway.

Fig. 1

eine Prinzipdarstellung eines erfindungsgemäßen Geschosses,

Fig. 2

eine perspektivische Schnittansicht durch die Geschossspitze enthaltend respektive darstellend den Zünder,

Fig. 3

eine Perspektivansicht des Zündverstärkerträgers,

Fig. 4

eine Stirnseitenansicht des Zündverstärkerträgers aus Fig. 3,

Fig. 5

eine Schnittansicht des Zündverstärkerträgers aus Fig. 3,

Fig. 6

eine Perspektivansicht der Geschossspitze lediglich mit montiertem Zündverstärkerträger,

Fig. 7

die Geschossspitze aus Fig. 6 mit aufgeschraubtem ersten Ring,

Fig. 8

eine Schnittansicht durch den ersten Ring,

Fig. 9

eine Perspektivansicht der Geschossspitze aus Fig. 7 mit aufgeschraubtem zweiten Ring,

Fig. 10

eine Schnittansicht durch den zweiten Ring,

Fig. 11

eine Perspektivansicht des zweiten Rings,

Fig. 12

eine Teilansicht eines erfindungsgemäßen Geschosses mit Schnittdarstellung des Verbindungsbereichs von Geschossspitze zu Geschosshülle in der Grundstellung, und

Fig. 13

die Darstellung aus Fig. 12 mit druckbedingter Axialverschiebung der Geschossspitze relativ zur Geschosshülle.

Further advantages, features and details of the invention will become apparent from the embodiments described below and from the drawing. Showing:

Fig. 1

a schematic diagram of a projectile according to the invention,

Fig. 2

a perspective sectional view through the projectile tip containing respectively representing the detonator,

Fig. 3

a perspective view of the Zündverstärkerträgers,

Fig. 4

an end view of the Zündverstärkerträgers Fig. 3 .

Fig. 5

a sectional view of the Zündverstärkerträgers Fig. 3 .

Fig. 6

a perspective view of the projectile nose only with mounted Zündverstärkerträger,

Fig. 7

the bullet point Fig. 6 with screwed on first ring,

Fig. 8

a sectional view through the first ring,

Fig. 9

a perspective view of the projectile tip Fig. 7 with screwed on second ring,

Fig. 10

a sectional view through the second ring,

Fig. 11

a perspective view of the second ring,

Fig. 12

a partial view of a projectile according to the invention with a sectional view of the connecting portion of bullet tip to projectile casing in the normal position, and

Fig. 13

the presentation Fig. 12 with pressure-induced axial displacement of the projectile tip relative to the projectile casing.

Fig. 1 shows in the form of a pure schematic representation of a projectile according to the invention 1, consisting of a projectile casing 2, in which the actual explosive 3 is added, and one attached to the projectile casing 2 via a screw projectile nose 4, which has an igniter 5, the defined ignition of Explosives 3 serves. The basic structure of such a bullet, which is an ammunition, for example, the caliber 76 mm x 636, but also to a warhead or the like, is well known.

The projectile 1 according to the invention is characterized in that the projectile nose 4 is defined relative to the projectile casing 2 and axially movable limited stop, wherein the axial movement is initiated solely by an overpressure caused in the interior of the projectile by outgassing of the explosive 3, and means are provided in order to reduce the overpressure as a result of the axial movement.

The projectile tip 4 is in a sectional view in Fig. 2 shown. It comprises on the one hand a housing 6, which can also be addressed as an igniter housing. In this case 6, a Zündverstärkerträger 7 is screwed tight, including the housing 6 has an internal thread 8 and the Zündverstärkerträger 7 on a pin 9 has an external thread 10. At Zündverstärkerträger 7, the actual igniter unit 11 comprising an SAD (safety & arming device) and one or more booster (= booster), etc. added. The projectile tip is thus formed by the housing 6, the ignition amplifier carrier 7 and the igniter unit 11.

To enable axial mobility, the ignition amplifier carrier 7, as part of the projectile nose, see Fig. 3 to 5 , designed in a special way. The Zündverstärkerträger 7 and thus the projectile nose 4 has an external thread 12, which is interrupted over a plurality of circumferentially equidistantly distributed longitudinal grooves 13, the venting channels respectively parts of venting channels, and this is ultimately weakened defined. The longitudinal grooves 13 go in continuing Grooves 14, so that ultimately this section has a plurality of individual ventilation channels 15. The front view according to Fig. 4 clearly shows the individual adjacent venting channels 15.

This section is followed by a second external thread 16, which, see Fig. 5 , is slightly smaller in diameter than the first external thread 12, which, like Fig. 5 shows, is raised, while the external thread 16 is worked out recessed. These different external threads 12 and 16 are used to accommodate separate rings, which will be discussed below.

Fig. 6 shows a perspective view of the projectile nose 4, on which the Zündverstärkerträger 7 is mounted together with ignition unit 11. On the first external thread 12 is (see Fig. 7 ) now a first ring 17, the, see Fig. 8 , having an internal thread 18, screwed. It is screwed on until it rests against a radial flange 31 of the Zündverstärkerträgers 7. Due to the formation of the longitudinal grooves 13 in conjunction with the fact that the external thread 12 is axially seen relatively short and results from screwing of internal thread 18 and external thread 12, a relatively weak threaded connection that holds no too large axial forces. This is important in the present case, as on this one hand, the projectile nose 4 is axially fixed relative to the projectile casing 2, on the other hand, however, this threaded connection can be solved due to pressure to move the projectile tip 4 of the threaded sleeve 2 for venting purposes. This will be discussed below.

As Fig. 8 shows, the first ring 17 on an enlarged diameter portion 19. This section 19 makes it possible to see a second ring 20, which Fig. 10 , an internal thread 21, to screw on the second external thread 16 and at the same time to guide under the first ring 17, see Fig. 9 , D. h., That the first ring 17 axially overlaps the second ring 20 slightly, in which case an annular gap 22 is formed. The external thread 16 and the internal thread 21 are a substantially stronger mechanical connection, as the external thread 12 and the internal thread 18. For it is to ensure that the second ring 20 and the Zündverstärkerträger 7 are fixed and undetachably connected to each other under pressure.

On the second ring 20 are, see Fig. 11 , a plurality of radial projections 23 are provided, which form the second ring 20 as a stop element. Because these radial projections 23 beat when the projectile nose 4 is moved axially due to pressure, against a stop 24, formed over the end edge 25 of the first ring 17, and thus limit the axial movement, which will be discussed below. Since the radial projections 23 are circumferentially spaced from each other and thus given a radially lower intermediate region 26 between each two radial projections 23, there is consequently, see Fig. 9 , an immediate access to the annular gap 22 and via this to the venting channels 15th

If the second ring 20 is screwed, the projectile tip 4 can be screwed into the projectile casing 2. For this purpose, the projectile casing 2 has an internal thread 27 into which an external thread 28 provided on the first ring 17 is screwed. This threaded connection is also designed to be very strong mechanically, so that it is ensured that it is axially stable when pressure is applied to the projectile nose 4 and is not deformed.

There are thus given a total of three threaded connections after screwing the projectile nose, namely on the one hand, the weakened and provided for shearing threaded connection of external thread 12 and internal thread 18 between the first ring 17 and the projectile nose 4 and the Zündverstärkerträgers 7, also the second, mechanically fixed threaded connection External thread 16 of the Zündverstärkerträgers 7 and inner thread 21 of the second ring 20, and as a third threaded connection which also mechanically very strong connection between the external thread 28 and internal thread 27 of the projectile casing. 2

Fig. 12 on the other hand shows the annular gap 22 between the first ring 17 and second ring 20, as well as the axial gap 29 between the end edge 25 of the first ring and the leading edge of the radial projections 23 of the second ring 20th

Fig. 12 shows the mounting position, in which consequently a firm and tight connection between the projectile nose 4 and projectile casing 2 is given. Obviously, the leading end edge 30 of the projectile casing 2 is fixed and tight against the opposite end face 32 of the housing 6 and the radial flange 31 of the Zündverstärkerträgers 7.

If, due to the temperature, the gassing of the explosive 3 in the projectile casing 2 and thus to a high internal pressure occurs, this will have an immediate effect As long as the internal pressure and the resulting axial force acting on the first threaded connection between the external thread 12 of the Zündverstärkerträgers 7 and internal thread 18 of the first ring 17, is still sufficiently low that the threaded connection they still picks up, it remains at the in Fig. 12 shown position of bullet 4 and projectile casing 2. However, the pressure continues to increase, so the axial force increases. Is it sufficiently large, holds the threaded connection between the first ring 17 and 7 Zündverstärkerträger no longer stand, the threads respectively thread flanks are sheared off. It comes now, see Fig. 13 , For an axial movement of the projectile nose 4 relatively projectile casing 2, as a result of the sheared thread, the projectile nose 4 is axially no longer firmly connected to the projectile casing 2. This axial movement is stop-limited, ie, the projectile tip 4 moves so far until the radial projections 23 of the second ring 20 abut against the end edge 25 of the first ring 17. Another movement is excluded. On the one hand, the threaded connection of the second ring 20 to the ignition amplifier carrier 7 and thus to the projectile nose 4 is intact, on the other hand, the threaded connection between the projectile casing 2 and the first ring 17 is also intact.

With the shearing off of the threaded connection between the first ring 17 and the ignition amplifier carrier 7, respectively the projectile nose 4, and the resulting axial movement, an annular gap 33 opens radially outwardly. In this annular gap 33 all the longitudinal grooves 13 respectively venting passages 15. Since on the one hand the radial projections 23 are circumferentially spaced and open intermediate portions 26 are given, and on the other hand, there is also an annular gap 22 between the two rings 17 and 20 which leads into the venting channels 15, thus a complete venting path is given, from the interior of the projectile casing 2 in the annular gap 33 and from there leads to the outside. The high internal pressure, which has already been partially reduced by the axial movement is now completely reduced, it comes to vent the bullet interior on the Zündverstärkerträger 7, respectively the bullet tip 4. At the same time a secure retention of the projectile nose 4 respectively of the igniter is given, it comes So not to a separation of the various parts. This is made possible in the specific embodiment by the use of the first ring 17 and the second ring 20 and the corresponding formation of the respective outer and inner threads on the rings 17, 20 respectively of the projectile nose 4 and the Zündverstärkerträger 7 and the projectile casing. 2

Claims (10)

1. Projectile comprising a projectile casing (2) having explosive (3) contained therein, into which a projectile tip (4) containing a detonator (5) is inserted,
   wherein
   the projectile tip (4) can be moved axially against a stop (24) by a gas pressure building up inside the projectile (1) relative to the projectile casing (2), while opening at least one venting duct (16) connecting the inside of the projectile casing (2) to the environment,
   wherein the projectile tip (4) has an external thread (12) onto which a first ring (17) with an internal thread (18) is screwed, which first ring has an external thread (28) which is screwed into an internal thread (27) of the projectile casing (2), and wherein a stop member (20) is provided at the projectile tip (4) which runs against the stop (24) to limit the axial movement made possible by a pressure-induced shearing of the threaded connection of the ring (17) to the projectile tip (4) .
2. Projectile according to Claim 1,
   characterized in that
   the stop element is a second ring (20) which is screwed with an internal thread (21) onto the or a further external thread (15) of the projectile tip (4) .
3. Projectile according to Claim 2,
   characterized in that
   on the second ring (20) one or a plurality of radial projections (23), preferably arranged equidistantly about the periphery of the ring, is/are provided, with which the second ring (20) runs against the stop (24).
4. Projectile according to Claim 2 or 3,
   characterized in that
   the first ring (17) and the second ring (20) are screwed onto a booster carrier (7) which is part of the projectile tip (4) and which comprises the external thread or threads (12, 15).
5. Projectile according to one of the preceding claims,
   characterized in that
   the stop (24) is formed by the front edge (25) of the first ring (17).
6. Projectile according to Claim 5,
   characterized in that
   the first ring (17) has a first ring section exhibiting the internal thread (18) and a second ring section (19) attached thereto with an enlarged internal diameter, with which the first ring (17) radially overlaps the second ring (20) sectionally from an axial viewpoint.
7. Projectile according to one of the preceding claims,
   characterized in that
   the external thread (12) of the projectile tip (4) and/or the internal thread (18) of the first ring (17) comprises with at least one longitudinal groove (13) which forms the vent duct (16) or a part thereof and which opens into an outwardly opening annular gap (33) between the projectile tip (4) and the projectile casing (2) when the stop position is reached.
8. Projectile according to Claim 7,
   characterized in that
   a plurality of longitudinal grooves (13) arranged equidistantly about the periphery is provided on the external thread (12) and/or on the internal thread (18).
9. Projectile according to Claim 6 and 7,
   characterized in that
   the first ring (17) overlaps the second ring (20) at a radial distance and the annular gap (22) created communicates with the at least one longitudinal groove (13) and the inside of the projectile.
10. Projectile according to one of the preceding claims,
    characterized in that
    the axial movability is at least 1 mm, preferably at least 2 mm.

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