Projectile

Abstract

The invention relates to a projectile (10) with a projectile casing (12) extending along a central longitudinal axis (M) and having a projectile front (14), wherein the projectile casing (12) has an opening (30) along the central longitudinal axis (M) facing away from the projectile front (14), at which the projectile casing (12) is provided with an internal thread (32), wherein a projectile base insert (36) is provided which has a first external thread (38) with which the projectile base insert (36) can be screwed into the internal thread (32), wherein the projectile base insert (36) closes the opening (30) when screwed in, wherein a retaining ring (40) is provided which has a second external thread (42) and which secures the projectile base insert (36) screwed into the internal thread (32) to the projectile front (14). the opposite side of the floor insert (36) can be screwed into the opening (30),wherein the retaining ring (40) rests against the floor base insert (36) when screwed in.

Description

[0001] The invention relates to a projectile having the features of the preamble of claim 1.

[0002] Projectiles of the type mentioned above are known from the prior art, for example in the form of an artillery shell. Projectiles are propellants that are fired by means of a gun barrel and obtain their kinetic energy from a propellant charge. Thus, after the propellant charge is ignited, the projectile is accelerated in the gun barrel (internal ballistic phase) until it leaves the gun barrel after passing through the muzzle and flies along a ballistic trajectory towards a target (external ballistic phase).

[0003] Some projectile types require an opening on the bottom side of the shell (facing away from the front) to allow for internal work on the shell or the insertion of projectile components, such as a payload, into the shell. After the components are inserted, the opening can be closed with a base insert. This insert is screwed into the base of the shell. A secure fit of the base insert is crucial for the safe firing of the projectile.

[0004] Military projectiles can be subjected to high stresses throughout their service life. In addition to the stresses of firing (the initiated propellant charge accelerates the projectile), they are subjected to logistical stresses such as drop loads (e.g., from heights greater than 2 meters) or vibrations during transport by land, sea, or air. The temperature range to which the projectiles are exposed spans from > 60 °C to < -40 °C. These extreme operating conditions can cause the projectile base insert to detach. This can be exacerbated by the degradation of materials within the projectile's internal structure at high storage temperatures or by the ingress of degradation products (e.g., silicone) into the threads of the base insert. A projectile base insert without a locking mechanism therefore offers only limited stability.

[0005] Various methods for securing the projectile base insert have been attempted in the prior art, such as the use of thread-locking compound or welding the base insert to the projectile casing. The effectiveness of thread-locking compound depends heavily on correct dosage during assembly and can be significantly reduced, for example, if decomposition products enter the threaded area. Welding can lead to distortion of the projectile casing and, due to the payload already contained within the casing (e.g., explosive charge), poses a potential hazard.

[0006] Pinning the projectile base insert to the projectile casing is another option, for example, using transverse pins inserted laterally or radially that partially penetrate the casing and the base insert. Pinning with longitudinal pins aligned along the projectile's length, inserted between the casing and the base insert, is also conceivable. However, pinning requires drilling into the projectile casing, which is already filled with a payload, posing a potential hazard during manufacturing. Furthermore, pinned connections are susceptible to damage during assembly, and pinned components are difficult to disassemble (e.g., due to chips in the threaded area). Therefore, there is room for improvement.

[0007] The invention is based on the objective of enabling a robust and manufacturable securing mechanism for the base of a projectile using simple design means. It is desirable that this securing mechanism be suitable for the mass production of projectiles.

[0008] The invention solves this problem by means of a projectile with the features of claim 1.

[0009] The projectile has a casing that extends along a central longitudinal axis and forms a front (at the front in the direction of fire). The casing encloses an interior space (projectile cavity) and can be rotationally symmetrical. The casing may taper towards the front.

[0010] The projectile casing has an opening (at the bottom) along the central longitudinal axis, facing away from the projectile front (at the rear in the direction of firing), at which the projectile casing is provided with an internal thread.

[0011] A base insert is provided, featuring an external thread that allows it to be screwed into the internal thread of the projectile casing. When screwed in, the base insert seals the opening.

[0012] Furthermore, a retaining ring is provided, which has a second external thread and can be screwed into the opening on the side of the projectile base insert facing away from the projectile front (rear in the direction of fire) to secure the projectile base insert screwed into the internal thread. When screwed in, the retaining ring rests against the projectile base insert, particularly with a defined torque. The projectile base insert and the retaining ring are screwed into the internal thread of the projectile casing one after the other (first the projectile base insert and then the retaining ring).

[0013] The retaining ring, which rests against the projectile base insert, secures the insert against unintentional loosening from the internal thread of the projectile casing in a structurally simple and reliable manner. This reliable securing mechanism reduces the potential for injury to personnel and equipment throughout the projectile's entire lifespan. The simple installation of the retaining ring contributes to reduced labor and inspection effort, as well as high process reliability. The proposed retaining ring system is suitable for high-volume production and also for future weapon systems with increased performance. The retaining ring also allows for disassembly. Tool wear is comparatively low, for example, compared to pinning (which causes high drill wear).

[0014] The retaining ring can be ring-shaped and have a rectangular cross-section. It can have a first end face, a second end face opposite it, an inner surface (inner circumferential surface), and an outer surface (outer circumferential surface). The second external thread can be formed on the outer surface. Regardless of its shape, the retaining ring can also be called a lock ring.

[0015] The projectile may be a projectile with a screwed-in base at the rear, e.g. with a caliber of 105 mm, 152 mm or 155 mm (millimeters).

[0016] The projectile can be designed as a spin-stabilized projectile. In this case, the thread rotation direction of the internal thread for the projectile base insert (and also the external thread on the projectile base insert) preferably corresponds to the opposite spin direction of the firearm designed and intended for firing the projectile.

[0017] Therefore, if a right-hand twist barrel is used, the internal thread for the bullet base insert (and also the external thread on the bullet base insert) has a left-hand rotation direction (left-hand thread). During the firing of the right-hand twist bullet, which is applied by the bullet casing via the externally mounted driving bands and the rifling profile of the weapon, the left-hand threaded bullet base insert is screwed into the bullet casing against the thread stop due to its inertia. As already indicated above, the secure fit of the bullet base insert and all other attached components is a crucial requirement to ensure the reliable firing of the bullet.

[0018] In a preferred embodiment, the projectile base insert can have a radially outwardly projecting projection, and the projectile casing can have a radially inwardly projecting shoulder. When the projectile base insert is screwed in, the projection can rest against the shoulder. The shoulder thus forms a defined stop for the projection and for the projectile base insert as a whole. The shoulder can be located in the projectile casing, adjacent to the internal thread in the screw-in direction (towards the projectile front). The projection and / or the shoulder can each be circumferential. When screwed in, the projectile base insert is tightened or screwed in against the shoulder inside the projectile casing with a precisely defined torque. As mentioned above, the retaining ring is also tightened or screwed in against the projectile base insert with a precisely defined torque.The external thread of the floor insert (first external thread) can be formed on the outwardly projecting projection.

[0019] In principle, it is conceivable that the retaining ring rests against the rear of the projectile base insert, with the retaining ring and the projectile base insert not overlapping axially (along the aforementioned central longitudinal axis). This contributes to a simpler design of the projectile base insert. A large contact area between the projectile base insert and the retaining ring can be achieved. Optionally, the retaining ring can be designed as a retaining disc (without a central opening).

[0020] The retaining ring can be advantageously positioned at the rear (on the side of the projectile base insert facing away from the projectile's front) against the base insert, with the retaining ring and a tapered section of the base insert overlapping axially (along the aforementioned central longitudinal axis). This results in a comparatively short axial length for both the base insert and the retaining ring. Consequently, a large amount of space is available on or within the projectile casing for a payload and / or a rear insert component. Specifically, the retaining ring can rest against the outwardly projecting protrusion of the base insert at the rear. By matching the inner contour (e.g., inner diameter) of the retaining ring to the outer contour (e.g., outer diameter) of the tapered section of the base insert, the retaining ring and the base insert can abut each other.

[0021] The floor insert can have several axial sections: A first axial section facing the floor front. This first axial section can be adjacent to the payload. The floor insert can have a second axial section, where the outwardly projecting extension of the floor insert is located. The third axial section faces away from the floor front and is formed by the tapered section of the floor insert. The second axial section can have the largest external dimension, e.g., the largest external diameter (the first external thread can also be located there). The third axial section can have the smallest external dimension, e.g., the smallest external diameter. The first axial section can have an external dimension, e.g., an external diameter, that lies between the first and third external dimensions (average external dimension or average external diameter).

[0022] Advantageously, the retaining ring and the tapered section of the bullet base insert can be matched in such a way that, when screwed in, the retaining ring does not protrude beyond the bullet base insert along the central longitudinal axis away from the bullet front (rearward in the direction of fire). This contributes to compact dimensions along the central longitudinal axis. Furthermore, this allows for a flat surface at the rear of the retaining ring and bullet base insert.

[0023] In a preferred embodiment, a payload can be arranged in the projectile casing on one side of the projectile base insert facing the projectile's front (front in the direction of fire). This allows the projectile to deliver a payload in a controlled manner. The payload can be located, in particular, directly adjacent to the projectile base insert. The payload can be an explosive charge, submunition, an illuminating device, a smoke grenade, or a combination thereof.

[0024] Advantageously, the internal thread can be formed throughout with a uniform nominal dimension, with the internal thread, the first external thread, and the second external thread all having the same nominal dimension. This simplifies manufacturing, as the internal thread can be formed continuously, possibly in a single operation. The first external thread and the second external thread can also be easily formed with identical nominal dimensions. This reduces the number of tools required to manufacture the projectile. The internal thread and both external threads are all formed with the same thread rotation direction, e.g., all right-hand threads or all left-hand threads (opposite to the twist direction of the barrel of the weapon firing the projectile).

[0025] Alternatively, the internal thread can have a first internal thread section with a first nominal dimension that corresponds to the nominal dimension of the first external thread (base insert), and / or the internal thread can have a second internal thread section with a second nominal dimension that is larger than the first nominal dimension and corresponds to the nominal dimension of the second external thread (retaining ring). By having the second internal thread section and the second external thread with a larger nominal dimension, a higher preload can be generated with the retaining ring. This contributes to a high level of safety. It is also conceivable that the first internal thread section and the first external thread have a thread rotation direction that is opposite to the thread rotation direction of the second internal thread section and the second external thread.Preferably, the first internal thread section, the first external thread, the second internal thread section and the second external thread have the same direction of thread rotation, e.g., all as right-hand threads or all as left-hand threads (opposite to the twist direction of the barrel of the projectile-firing weapon).

[0026] In one possible design, the floor insert itself can form the rear of the floor. This contributes to an axially compact construction with comparatively few components.

[0027] In an alternative design, a rear section can be provided on the side of the projectile base facing away from the projectile's front, which is screwed to the projectile casing. This rear section can provide a streamlined seal to the rear of the projectile and contribute to improved aerodynamics.

[0028] In a preferred embodiment, the rear section of the projectile can have an (integrated) gas generator. This contributes to an increase in range by reducing the downward suction effect on the projectile ("base bleed").

[0029] The invention is explained below with reference to the figures, where identical or functionally equivalent elements are provided with identical reference numerals. The figures show: Fig. 1 shows an embodiment of the projectile in a longitudinal section; and Fig. 2 shows an enlarged partial view of the projectile. Figure 1 in the area of ​​the floor slab, in Figure 1 characterized by a rectangle II.

[0030] Figure 1 Figure 1 shows a longitudinal section of an embodiment of a projectile, the projectile as a whole being designated by reference numeral 10.

[0031] The projectile 10 has a projectile casing 12 that extends along a central longitudinal axis M and has a projectile front 14 (at the front in the direction of fire S). The projectile casing 12 defines an interior projectile space 16 and is rotationally symmetrical in this example.

[0032] The projectile casing 12 tapers towards the projectile front 14. In this example, an opening 18 formed on the projectile front 14 is closed by means of a locking screw 20. The locking screw 20 has a hook section 22, over which the projectile 10 can be handled.

[0033] Guide and / or sealing rings 24 are arranged in the rear section of the projectile casing 12. A projectile tail section 26 is provided on the side facing away from the projectile front 14, which is screwed to the projectile casing 12. The projectile tail section 26 forms the projectile tail. Optionally, the projectile tail section 26 can have an (integrated) gas generator 27, as explained above.

[0034] The further construction of floor 10 will be described based on Figure 2 described.

[0035] The projectile casing 12 has an opening 30 along its central longitudinal axis M, facing away from the projectile front 14 (at the rear in the direction of fire S), at which the projectile casing 12 is provided with an internal thread 32. At the rear of the internal thread 32 (at the rear in the direction of fire S), a further internal thread 34 is provided for attaching the projectile tail section 26.

[0036] A projectile base insert 36 is provided, which has a first external thread 38 that corresponds to the internal thread 32 of the projectile casing 12. The projectile base insert 36 is screwed into the internal thread 32 and closes the opening 30.

[0037] Furthermore, a retaining ring 40 is provided, which has a second external thread 42 that corresponds to the internal thread 32 in this example. To secure the projectile base insert 36, which is screwed into the internal thread 32, the retaining ring 40 is screwed into the opening 30 or the internal thread 32 on the side of the projectile base insert 36 facing away from the projectile front 14 (rear in the firing direction S). When screwed in, the retaining ring 40 rests against the projectile base insert 36 with a defined torque. The projectile base insert 36 and the retaining ring 40 are screwed into the internal thread 32 of the projectile casing 12 one after the other (first the projectile base insert 36 and then the retaining ring 40).

[0038] As explained above, the retaining ring 40 is ring-shaped and has a rectangular profile cross-section. Specifically, the retaining ring has a first end face at the front in the direction of travel S, a second end face at the rear in the direction of travel S, an inner circumferential surface, and an outer circumferential surface on which, in this example, the second external thread 42 is formed (for clarity, the sides of the retaining ring 40 are not individually labelled).

[0039] The projectile base insert 36 has a radially outwardly projecting projection 44. The projectile casing 12 has a radially inwardly projecting shoulder 46. When the projectile base insert is screwed in, the projection 44 rests against the shoulder 46. In this example, the shoulder 46 is located in the projectile casing 12 adjacent to the internal thread 32 in the screw-in direction (S at the front in the firing direction). Both the projection 44 and the shoulder 46 are continuous.

[0040] The retaining ring 40 rests against the rear side (on the side of the projectile base insert 36 facing away from the projectile front 14), with the retaining ring 40 and a (rear-side) tapered section 48 of the projectile base insert overlapping axially (along the central longitudinal axis M). In this example, the retaining ring 40 rests against the outwardly projecting projection 44 of the projectile base insert 36 at its rear.

[0041] The projectile base insert 36 has several axial sections: A first axial section 50, which faces the projectile front 14 (front in the direction of fire S). In this example, section 50 borders a payload 52, which is designed as an explosive charge. The projectile base insert 36 further has a second axial section 54, on which the outwardly projecting projection 44 of the projectile base insert 36 is located. The third axial section faces away from the projectile front 14 and is formed by the tapered section 48 of the projectile base insert 36. The external dimensions of the sections can be configured as described above.

[0042] The retaining ring 40 and the tapered section 48 of the projectile base insert 36 are in such a way that the retaining ring 40, when screwed in, does not protrude beyond the projectile base insert 36 along the central longitudinal axis M away from the projectile front 14 (at the rear in the direction of fire S).

[0043] As explained above, it is conceivable that the internal thread 32 has several internal thread sections with different nominal dimensions. In the example, the internal thread 32 is consistently formed with a uniform nominal dimension, whereby the internal thread 32, the first external thread 38, and the second external thread 42 all have the same nominal dimension. The internal thread 32 and the two external threads 38 and 42 are all formed with the same thread rotation direction, e.g., all as right-hand threads or all as left-hand threads (opposite to the twist direction of the barrel of the weapon firing the projectile 10).

Claims

1. Projectile (10), with a projectile casing (12) extending along a central longitudinal axis (M) and having a projectile front (14), wherein the projectile casing (12) has an opening (30) along the central longitudinal axis (M) facing away from the projectile front (14), at which the projectile casing (12) is provided with an internal thread (32), wherein a projectile base insert (36) is provided which has a first external thread (38), with which the projectile base insert (36) can be screwed into the internal thread (32), wherein the projectile base insert (36) closes the opening (30) when screwed in, characterized by the fact thata retaining ring (40) is provided which has a second external thread (42) and which can be screwed into the opening (30) on the side of the floor insert (36) facing away from the floor front (14) to secure the floor insert (36) screwed into the internal thread (32), wherein the retaining ring (40) rests against the floor insert (36) when screwed in. 2nd floor (10) according to claim 1, characterized by the fact that a projecting outwards projection (44) is formed on the projectile base insert (36) and an inwards projection shoulder (46) is formed in the projectile casing (12), wherein the projection (44) rests against the shoulder (46) when the projectile base insert (36) is screwed in.

3. Floor (10) according to claim 1 or 2, characterized by the fact that the retaining ring (40) rests against the rear of the projectile base insert (36), with the retaining ring (40) and a tapered section (48) of the projectile base insert (36) overlapping axially. 4th floor (10) according to claim 3, characterized by the fact that the retaining ring (40) and the tapered section (48) of the shell base insert (36) are matched in such a way that the retaining ring (40), when screwed in, does not protrude beyond the shell base insert (36) along the central longitudinal axis (M) away from the shell front (14).

5. Floor (10) according to one of the preceding claims, characterized by the fact that a payload (52) is arranged in the floor shell (12) on one side of the floor front (14) of the floor floor insert (36).

6. Floor (10) according to one of the preceding claims, characterized by the fact that the internal thread (32) is formed throughout with a uniform nominal dimension, wherein the internal thread (32), the first external thread (38) and the second external thread (42) are identical in their nominal dimension.

7. Floor (10) according to any one of claims 1 to 5, characterized by the fact thatthe internal thread (32) has a first internal thread section with a first nominal dimension which corresponds to the nominal dimension of the first external thread (38), and / or that the internal thread (32) has a second internal thread section with a second nominal dimension which is larger than the first nominal dimension and which corresponds to the nominal dimension of the second external thread (42).

8. Floor (10) according to one of the preceding claims, characterized by the fact that the projectile base insert (36) forms the projectile tail.

9. Floor (10) according to any one of claims 1 to 7, characterized by the fact that On the side of the projectile base insert (36) facing away from the projectile front (14) a projectile rear part (26) is provided, which is screwed to the projectile casing (12). 10th floor (10) according to claim 9, characterized by the fact that the rear part of the projectile (26) has a gas generator (27).

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