Percussion fuse

Abstract

A percussion fuse (10) for a shell has a fuse body (12), a detonator system with a priming charge (16) in the bottom section (12c) of the fuse body (12), and a firing pin (24) in the head section (12a) of the fuse body (12). The firing pin (24) has a pin rod (26), with a piercing tip (27), and a pin head (25), wherein the firing pin (24) can be moved in the direction of the detonator system (16) in the case of the percussion fuse (20) striking a target, in order that the piercing tip (27) of the firing pin (24) pierces the priming charge in the detonator system (16). In order to improve impact sensing, in particular even in the case of striking a target at a shallow angle, the percussion fuse (10) additionally has a pressure element which is arranged loosely between the head end (12b) of the fuse body (12) and the pin head (25) of the firing pin (24), and is configured and arranged in the head section (12a) of the fuse body (12) in such a way that it can tilt relative to the fuse body (12) and relative to the pin head (25) of the firing pin (24), with the result that, in the case of a deformation of the head section (12a) of the fuse body (12) during striking of a target, it presses in a straight line on the pin head (25) of the firing pin, without tilting the pin head relative to the longitudinal axis (18) of the fuse body (12).

Description

[0001] The present invention relates to an impact fuse for a projectile.

[0002] Impact fuzes for projectiles typically have a fuze body that can be mounted on a projectile and contains a detonator system with an ignition charge for igniting a main charge of the projectile and an ignition needle for piercing the ignition charge of the detonator system upon impact with a target. Such impact fuzes are known, for example, from US 2 415 262 A, DE 15 78 498 A1, and GB 130 017 A. In all three cases, one or more spherical elements interact with an ignition needle to transmit force.

[0003] When impacting a target at a relatively vertical angle, the head of the detonator body presses on the firing pin and moves it toward the detonator system, puncturing the ignition charge. However, when impacting a target at a flat angle, the detonator body is usually deformed, which can destroy the firing pin and prevent the firing pin from moving toward the detonator system to pierce the ignition charge. This problem with a conventional impact detonator is exemplified in Figur 3 illustrated. As shown, the firing needle in the igniter body 12 has a needle head 25 and a needle bar 26, wherein the needle head 25 is arranged in the front region of the igniter body 12 behind a cover plate 21 and the needle bar 26 has a piercing tip 27 at the rear end for piercing the ignition charge in the detonator system 16. As illustrated in the partial figure sequence A, B, C, D, a flat impact, i.e. an impact of the detonator at a flat - in particular as opposed to an acute - angle on a target body causes a partial deformation of the front part of the detonator body 12, which results in a tilting of the needle head 25 in the direction of the impact surface, which in turn can cause a bending and / or jamming of the needle bar 26 in the detonator body 12, so that the needle bar 26 is no longer properly pressed in the direction of the detonator system 16 and consequently can no longer pierce the ignition charge in the detonator system.This of course also prevents the detonation of the main charge of the projectile.

[0004] It is therefore an object of the invention to provide an improved impact detonator which can cause the ignition charge to be pierced by the ignition needle even when it impacts flatly on a target body.

[0005] This object is achieved by an impact fuse for a projectile having the features of claim 1. Particularly advantageous embodiments and further developments of the invention are the subject of the dependent claims.

[0006] The impact fuze of the invention comprises a fuze body that can be mounted on a projectile, the fuze body having a head portion facing away from the projectile, a base portion facing the projectile, and a longitudinal axis, and a detonator system with an ignition charge in the base portion of the fuze body. The impact fuze further comprises an ignition needle in the head portion of the fuze body, the ignition needle having a needle rod, a needle head at an end of the needle rod facing the head end of the fuze body, and a piercing tip at an end of the needle rod facing the detonator system. The ignition needle is movable toward the detonator system upon impact of the impact fuze on a target body, so that the piercing tip of the ignition needle pierces the ignition charge in the detonator system.According to the invention, a pressure element is also provided which is loosely (in the sense of not fixed) arranged in the head section of the igniter body between the head end of the igniter body and the needle head of the ignition needle, wherein the pressure element is designed and arranged in the head section of the igniter body in such a way that it can tilt relative to the igniter body and relative to the needle head of the ignition needle, so that when the head section of the igniter body is deformed upon impact with a target body, it can press on the needle head of the ignition needle without tilting the needle head relative to the longitudinal axis of the igniter body.

[0007] The additional pressure element is tilted if the head section of the fuze body is deformed, but by being decoupled from the needle head, it maintains the alignment of the needle head and thus also of the needle bar. This prevents, for example, tilting of the needle head and the resulting bending or jamming of the needle bar. This additional pressure element therefore ensures that the firing needle remains functional and the ignition charge in the detonator system can pierce even if the impact fuze strikes a target body with a flat surface. This guarantee of the functional capability of the impact fuze, even if it strikes a target body with a flat surface, can be achieved by means of the additional pressure element and a simple, cost-effective design.In many conventional design variants of impact detonators, a simple insertion of the special pressure element is sufficient without the need for significant modification of the detonator body and the firing needle.

[0008] The impact fuze of the invention is generally applicable to any type of projectile. Furthermore, the impact fuze of the invention is not limited to any specific detonator system with a primer charge.

[0009] According to the invention, the pressure element has a rear side facing the firing needle, which is dome-shaped. In this way, the rear side of the pressure element can remain in contact with the needle head of the firing needle even when the pressure element is tilted (i.e. both when impacting vertically and when impacting flat against a target body), preferably even in the region of the central longitudinal axis of the detonator body, along which the firing needle can be moved towards the detonator system. The dome or its curvature can be spherical or aspherical. According to the invention, the curvature rises above an elliptical or angular base area. The base area can in particular be circular or square. According to the invention, the curvature comprises a flat region in the region above the center of gravity of the base area.The flat area is preferably located symmetrically around the theoretically highest point of the dome, if the dome would not include a flat area. Advantageously, the flat area of ​​the rear side—or in other words, the flat area of ​​the dome-shaped surface of the rear side—makes up less than 30%, in particular less than 25%, of the total area of ​​the dome-shaped surface. The spherical or aspherical surface profile of the rear side of the printing element can also be formed by a plurality of flat elements, so that the dome-shaped rear side is formed by a polyhedron.

[0010] According to the invention, the side of the needle head of the firing needle facing the pressure element is essentially flat. In this way, the tilting of the pressure element relative to the needle head can be better ensured: Due to the dome-shaped design of the rear side of the pressure element and the flat design of the side of the needle head facing the pressure element, when the detonator strikes a target body at a shallow angle, the pressure element, due to its loose or unfixed arrangement, can essentially roll on the side of the needle head facing the pressure element while simultaneously exerting pressure on the needle head - or in other words, while simultaneously transmitting the deformation of the head section of the detonator body in a straight line, i.e., in the direction of the longitudinal axis of the detonator body, via the pressure element to the needle head.If, according to the invention, the rear side of the pressure element has a flat area as described above, a flat contact can be established between the pressure element and the side of the needle head facing the pressure element, despite the loose arrangement of the pressure element, so that the pressure element only tilts when the detonator hits a target body at a shallow angle.

[0011] According to the invention, the front side of the pressure element facing the head end of the igniter body is designed to be substantially flat. In this case, the pressure element can be designed, for example, as a hemisphere or quasi-lens-shaped with a flat surface as the front side and an aspherical, spherical, or faceted surface as the rear side, with both the "hemisphere" and the "lens" comprising a flat region on their rear side, as described above.

[0012] In an alternative according to the invention, the front side of the printing element comprises two planar areas, one planar area being planar relative to the other

[0013] Area is raised in a stepped manner. The stepped, flat area of ​​the front side can be located opposite a previously described flat area of ​​the rear side, or in other words: regardless of whether the rear side comprises a flat area or not, the stepped, flat area of ​​the front side is preferably arranged opposite the (theoretically) highest point of the dome-shaped rear side, wherein the area is aligned in particular symmetrically with respect to this point. The stepped, flat area can create a contact area between the head end of the igniter body and the pressure body, which, however, offers the advantage compared to an essentially completely flat front side that a certain contact can be created between the head end, although this contact is smaller in area, so that a tilting movement of the pressure element is easier when the igniter impacts flat.

[0014] However, the front side of the pressure element facing the head end of the igniter body can also be designed analogously to one of the previously described rear sides of the pressure element. This makes it possible, for example, for the pressure element to have a spherical shape, an elliptical shape, an oval shape, the shape of a polyhedron on both the rear and front sides, or various combinations, such as a spherical shape on the front side and an elliptical or aspherical shape on the rear side, etc.

[0015] The pressure element preferably has a solid molded body made of a metallic material. This ensures that the pressure element is dimensionally stable and can maintain its shape and thus its functionality even when the detonator body deforms upon impact with a target. For weight reasons, the pressure element is made of aluminum, for example.

[0016] In one embodiment of the invention, the igniter body has a channel in its head section in which the ignition needle is arranged and guided and in which the pressure element is also located. If the needle bar has a smaller width than the needle head of the ignition needle, this channel preferably has a first channel section for guiding the needle head and the pressure element and a second channel section for guiding the needle bar, wherein the second channel section is narrower than the first channel section. Furthermore, the ignition needle and the channel preferably run essentially coaxially to the central longitudinal axis of the igniter body. The channel or its first and second channel sections are preferably essentially cylindrical in shape, preferably essentially coaxially to the longitudinal axis of the igniter body.

[0017] In order to ensure the free mobility of the pressure element even when the head section of the igniter body is deformed, the pressure element is preferably designed such that the diameters of the pressure element are smaller than the width of the channel in all directions.

[0018] In one embodiment of the invention, the igniter body has an access opening at its head end for mounting the firing needle, wherein the access opening is closed by a cover plate after the firing needle has been inserted into the igniter body. The pressure element is also inserted into the igniter body through this access opening and is then loosely arranged between the cover plate and the needle head of the firing needle.

[0019] The above and other features and advantages of the invention will become more apparent from the following description of a preferred, non-limiting embodiment with reference to the accompanying drawings, in which: Fig. 1 shows a longitudinal sectional view of an impact fuse according to an embodiment of the invention; Fig. 2 shows four sketches to illustrate the deformation profile of the impact fuse of Fig. 1 upon oblique impact on a target body; and Fig. 3 four sketches illustrating the deformation curve of a conventional impact fuze upon oblique impact on a target body.

[0020] Fig. 1 illustrates the structure of an impact fuse using the example of an explosive projectile. Fig. 1 shows the structure in the resting state or in the flight state of the impact fuse 10, ie before the impact fuse 10 hits a target body.

[0021] The impact fuze 10 has a fuze body 12, which is made, for example, of aluminum. The fuze body 12 has a front head section 12a with a head end 12b in the direction of flight 13 and a rear base section 12c in the direction of flight 13. A fastening device 14 is provided on the base section 12c of the fuze body 12, with which the fuze body 12 can be attached to the body of the projectile. As shown in Fig. 1 As indicated, the fastening device 14 has, for example, a thread for screwing the fuze body 12 into a projectile cavity. Depending on the type of projectile, the fastening device 14 of the fuze body 12 can also be designed differently.

[0022] The fuze body 12 has a central longitudinal axis 18, which also defines an axial direction of the fuze body 12. The flight direction 13 of the projectile and the impact fuze 10 is essentially parallel or coaxial to this longitudinal axis 18.

[0023] In the base section 12c of the fuze body 12, an ignition charge chamber 15 is provided, which is, for example, substantially cylindrical in shape and arranged substantially coaxially with the longitudinal direction 18. A detonator system with an ignition charge 16 is accommodated in this ignition charge chamber 15. The detonator system 16 has, for example, a detonation chain. The ignition charge of the detonator system 16 can be mechanically triggered through a tapping opening 17, wherein the tapping opening 17 is provided in the region of the longitudinal axis 18 on the side of the detonator system 16 facing the head section 12a. The triggered ignition charge of the detonator system 16 can then trigger the main charge of the projectile.

[0024] A channel 22 is provided in the head portion 12a of the igniter body 12, which is arranged substantially coaxially with the longitudinal direction 18 and serves to receive and guide an ignition needle 24. The ignition needle 24 has a needle bar 26, a needle head 25 at the end of the needle bar 26 facing the head end 12b of the igniter body 12, and a piercing tip 27 at the end of the needle bar 26 facing the detonator system 16. The piercing tip 17 serves to trigger the ignition charge by piercing the piercing opening 17 of the detonator system 16. The needle head 25 of the ignition needle 24 is wider than the needle bar 26 in this embodiment. The channel 22 in the head section 12a of the ignition body 12 therefore has a wider first channel section 22a for receiving and guiding the needle head 25 and a narrower second channel section 22b for receiving and guiding the needle bar 26. The first and second channel sections 22a, 22b are both essentially hollow-cylindrical in shape.The firing needle 24 and the channel 22 are each aligned substantially coaxially with the longitudinal axis 18. The firing needle 24 is movable in the channel along the longitudinal axis 18, so that when the impact detonator 10 strikes a target body, it can be moved toward the detonator system 16 by pressure on the needle head 25, so that the piercing tip 27 penetrates the piercing opening 17 of the detonator system 16 to trigger the ignition charge.

[0025] As in Fig. 1 As shown, the head portion 12a of the igniter body 12 has an access opening 20 at its head end 12b through which the firing needle 24 can be inserted into the channel 22 of the igniter body 12. After the firing needle 24 has been installed, this access opening 20 is then closed and sealed by a cover plate 21.

[0026] A pressure element 28 is also inserted into the channel 22 through the access opening 20. The pressure element 28 is then arranged between the needle head 25 and the cover plate 21 in the first channel section 22a. The pressure element 28 is loosely arranged in the first channel section 22a, i.e., it is not fixed to any element of the cover plate 21, igniter body 12, and needle head 25, so that it can tilt within the first channel section 22a relative to the igniter body 12 and relative to the needle head 25 of the ignition needle 24, as indicated by the curved arrows 29 in Fig. 1 indicated.

[0027] In the example of Fig. 1 The pressure element 28 is configured in the shape of a hemisphere. This means that the pressure element 28 has a front side 28a facing the cover plate 21, which is essentially flat, and a rear side 28b facing the needle head 25, which is dome-shaped, in this case spherical. In other embodiments of the invention, the front side 28a of the pressure element 28 can also be dome-shaped, for example spherical, so that the pressure element 28 is spherical.

[0028] The side of the needle head 25 facing the pressure element 28 is preferably substantially flat. Fig. 1 the pressure element 28 is in contact with the needle head 25.

[0029] The pressure element is also preferably a solid (i.e., not hollow) molded part, for example, made of aluminum. The pressure element 28 is arranged substantially coaxially with the longitudinal axis 18. Furthermore, all diameters of the pressure element 28 are smaller in all orientations than the width of the first channel section 22a in the head section 12a of the igniter body 12.

[0030] In the event of impact of the impact detonator 10 somewhat perpendicularly onto a target body, i.e., essentially parallel to the longitudinal axis 18, the head end 12b of the detonator body 12 is pressed in, so that the pressure element 21 presses with its rear side 28b against the needle head 25. As a result, the firing needle 24 is moved in the direction of the detonator system 16 and ultimately pierces the piercing tip 27 into the piercing opening of the detonator system 16 to trigger the ignition charge in the detonator system 16. As in Fig. 1 As can be seen, the pressure element 28 presses against the needle head 25 in the central region of the longitudinal axis 18 due to its dome-shaped rear side 28b, so that the pressure effect is rectilinear, thereby supporting the axial movement of the ignition needle 24 through the channel 22 along the longitudinal axis 18.

[0031] The functionality of the impact fuse 10 in the case of a flat impact on a target body is described in Fig. 2 The advantage of the inventive design of the impact fuse 10 is particularly evident by comparing Fig. 2 with the above-described Fig. 3 for a conventional impact fuse.

[0032] How the sequence of the subfigures A, B, C, D of Fig. 2 illustrated, the head section 12a of the igniter body 12 in the region of the head end 12b is similar to Fig. 3 continues to deform. In contrast to the conventional design, however, this deformation of the igniter body 12, due to the additional pressure element 28, does not cause the needle head 25 to tilt and thus does not cause the needle bar 26 to bend or jam, so that the ignition needle 24 remains functional and the ignition charge in the detonator system 16 can pierce.

[0033] Due to the deformation of the igniter body 12, the pressure element 28 is tilted within the first channel section 22a such that its flat front side 28a is aligned with the target body. Furthermore, the pressure element 28 is moved slightly toward the bottom section 12c of the igniter body 12 by the impact during the deformation of the igniter body 12. However, since the pressure element 28 is loosely located in the first channel section 22a, the tilting of the pressure element 28 does not cause any deformation of the first channel section 22 and, in particular, does not cause any tilting of the needle head 25 relative to the longitudinal axis 18. As can be seen from Fig. 2 Instead, as can be seen, the dome-shaped rear side 28b of the pressure element 28 remains in contact with the flat upper side of the needle head 25 in the central region of the longitudinal axis 18 during the deformation of the igniter body 12. As a result, the pressure element 28 always presses essentially centrally against the needle head 25 and essentially in a straight line along the longitudinal axis 18 during the deformation of the igniter body 12. In this way, the ignition needle 24 is moved along the longitudinal direction 18 through the channel 22 in the direction of the detonator system 16, without tilting in any way transverse to the longitudinal axis 18.

[0034] The additional pressure element 28 in the fuze body 12 allows the impact sensing of the impact fuze 10 to be improved or maintained even when impacting a target body with a shallow impact. The functionality of the impact fuze and thus the operational capability of the projectile can thus be significantly improved. List of reference symbols

[0035] 10 Impact fuze 12 Fuze body 12a Head section of the fuze body 12b Head end of the fuze body 12c Bottom section of the fuze body 13 Direction of flight 14 Fastening device 15 Ignition charge chamber 16 Detonator system with ignition charge 17 Piercing opening 18 Longitudinal axis (defines axial direction) 20 Access opening for assembly 21 Cover plate 22 Channel 22a First channel section 22b Second channel section 24 Firing needle 25 Needle head 26 Needle rod 27 Piercing tip 28 Pressure element 28a Front of the pressure element 28b Rear of the pressure element 29 Tilting option of the pressure element

Claims

1. Percussion fuse (10) for a shell, having: a) a fuse body (12), which can be mounted on a shell, wherein the fuse body (12) has a head portion (12a), which faces away from the shell and has a head end (12b), a base portion (12c), which faces the shell, and a longitudinal axis (18); b) a detonator system having a priming charge (16) in the base portion (12c) of the fuse body (12); and c) a firing pin (24) in the head portion (12a) of the fuse body (12), wherein the firing pin (24) has a pin rod (26), a pin head (25) at an end of the pin rod (26) facing the head end (12b) of the fuse body (12) and a piercing tip (27) at an end of the pin rod (26) facing the detonator system (16), wherein the firing pin (24) can be moved in the direction towards the detonator system (16) when the percussion fuse (10) strikes a target, so that the piercing tip (27) of the firing pin (24) pierces the priming charge in the detonator system (16), d) a pressure element (28), which is arranged loosely in the head portion (12a) of the fuse body (12) between the head end (12b) of the fuse body (12) and the pin head (25) of the firing pin (24), wherein - the pressure element (28) is configured and arranged in the head portion (12a) of the fuse body (12) in such a manner that it can tilt relative to the fuse body (12) and relative to the pin head (25) of the firing pin (24), so that, in the event of a deformation of the head portion (12a) of the fuse body (12) when striking a target, it can press on the pin head (25) of the firing pin without tilting the pin head relative to the longitudinal axis (18) of the fuse body (12), - the pressure element (28) has a front side (28b), which faces the head end (12b) of the fuse body (12) and is configured in a substantially planar manner or comprises two planar regions, wherein one planar region is raised in a stepped manner with respect to the other planar region, - a side, facing the pressure element (28), of the pin head (25) of the firing pin (24) is formed in a planar manner, - the pressure element (28) has a rear side (28b), which faces the firing pin (24) and is configured in a dome-like manner, wherein the curvature of the dome-like rear side rises over an elliptical or angular base surface and the curvature comprises a planar region in the region above the centroid of the area of the base surface, so that a planar contact between the rear side (28b) of the pressure element (28) and the side, facing the pressure element (28), of the pin head (25) of the firing pin (24) can be produced, so that the pressure element (28) is tilted only when the percussion fuse (10) strikes a target at a shallow angle.

2. Percussion fuse (10) according to Claim 1, in which the pressure element (28) has a solid shaped body made of a metal material.

3. Percussion fuse (10) according to either of the preceding claims, in which the fuse body (12) has in the head portion (12a) thereof a channel (22), in which the firing pin (24) is arranged and guided and in which the pressure element (28) is also located.

4. Percussion fuse (10) according to Claim 3, in which the pin rod (26) has a smaller width than the pin head (25) of the firing pin (24), and the channel (22) has a first channel portion (22a) for guiding the pin head (25) and the pressure element (28) and a second channel portion (22b) for guiding the pin rod (26), wherein the second channel portion (22b) is narrower than the first channel portion (22a).

5. Percussion fuse (10) according to Claim 3 or 4, in which the firing pin (24) and the channel (22) extend coaxially relative to the central longitudinal axis (18) of the fuse body (12).

6. Percussion fuse (10) according to one of Claims 3 to 5, in which the pressure element (28) is configured in such a manner that the diameters of the pressure element (28) in all directions are smaller than the width of the channel (22).

7. Percussion fuse (10) according to one of the preceding claims, in which the fuse body (12) has at the head end (12b) thereof an access opening (20) for mounting the firing pin (24), wherein the access opening is closed by a covering plate (21), and wherein the pressure element (28) is arranged loosely between the covering plate (21) and the pin head (25) of the firing pin (24).

Images