DK3036501T3

DK3036501T3 - Pyrotechnic delay device for an ammunition detonator and mortar grenade with such delay device

Info

Publication number: DK3036501T3
Application number: DK14744313.9T
Authority: DK
Inventors: Alexander Paesch
Original assignee: Rheinmetall Waffe Munition Gmbh
Priority date: 2013-08-20
Filing date: 2014-07-24
Publication date: 2018-06-14
Also published as: WO2015024730A1; PL3036501T3; NO3032209T3; EP3036501A1; ES2672309T3; DE102013013705A1; EP3036501B1

Description

Pyrotechnic delay device for an ammunition fuse, and mortar grenade with such a delay device

DESCRIPTION

The invention relates to a pyrotechnic delay device for an ammunition fuse with a pyrotechnic delay element, which is ignited upon firing the ammunition and which after a given delay time ignites a main charge, a propellant charge, or the like. In particular, the invention relates to a (multi)stage-adjustable, firing-initiated pyrotechnic delay device for the initiating and expediting of red phosphorus (RF), for example, as a smoke compound in or from a (Fly-k) mortar shell, in particular. Moreover, the invention relates to a mortar grenade with such a delay device.

Pyrotechnic delay devices for ammunition fuses have long been known. FR1258386A1 discloses such a delay device.

They are used, for example, to ignite explosive charges of ammunition after a precisely predetermined delay time, possibly above a target region. But smoke or light generating materials may also be expelled from corresponding missiles after the delay time counts down. Finally, the known pyrotechnic delay devices may involve safety devices which directly destroy the corresponding shell after a given delay time or cause it to crash.

Besides pyrotechnic delay devices, electronic or mechanical delay devices are also known.

Thus, DE 1 114 125 B describes a pyrotechnic fuse triggered by current, which is only connected to the current source when fired. Furthermore, a self-destruct device for ammunition is disclosed in DE 11 2005 001 081 B4.

This self-destruct device is formed by an electro-pyrotechnic device which in turn is connected with a time delay to an energy reserve after a predetermined time. With DE 60 2004 003 544 T2 another electronic delay is also published for the igniting of a pyrotechnic component. DE 28 38 055 C deals with an electrical fuse with an electronic percussion delay. A mechanically adjustable delay element can be found in DE 10 2012 014 149 B3. The mechanical adjustment consists of at least one tube, a sleeve, and a chemical charge as the delay charge, which is located in the tube. A shifting of the sleeve on the tube in the axial direction produces a releasing of the delay charge toward the ignition charge and thus an adjusting of the delay time.

The unpublished DE 10 2012 014 150.5 contains a pressure-controlled delay element for ammunition and the like with an ignition charge. The delay element described therein comprises a tube, a sleeve, a preloading, and a chemical delay charge arranged in the tube. The tube has an axial slot along a portion of its length and is mounted in the sleeve able to move axially, and preloaded by the preloading. A narrow annular surface of the sleeve closes off the end of the slot at the firing side. At the moment of firing, a peak pressure present at that instant is stored in a pressure storing chamber of the ammunition. This pressure is the regulating quantity for the pressure-controlled delay element. The gas pressure acts on the end face of the tube and pushes it against the preloading in order to adjust the equilibrium of forces. If the gas pressure stored here is higher than the originally set preloading, the tube is pushed against the preloading. In this process, the slot in the tube and the annular surface of the sleeve are pushed toward each other. A portion of the covered slot is freed up and the delay charge comes into contact with the ignition charge in this area - the delay time is shortened.

Unlike electronic or mechanical delay devices, the delay time of pyrotechnic delay devices is generally not adjustable. Instead, to change the delay time the particular delay element has to be replaced with a different delay element.

The problem which the invention proposes to solve is to indicate a pyrotechnic delay device with adjustable delay or delay time, without this requiring a replacement of the delay element. Moreover, a mortar grenade with an ammunition fuse having such a delay device should be disclosed.

This problem is solved in regard to the delay device by the features of Claim 1 and in regard to the mortar grenade by the features of Claim 9. Other, particularly advantageous embodiments of the invention are disclosed by the dependent claims.

The invention is based essentially on the notion that the initiating of the reactively acting payload of the shell is brought about by a pyrotechnically acting delay unit present at the shell side, especially one which is also adjustable in stages by the shooter before the firing. Such a function claim is often found in light mortar cargo ammunition, wherein by contrast with traditional mortar grenades the primary action at the target is produced not by the grenade itself, but by its independently acting payload, which is ejected in the vicinity of the target.

In the implementing of this notion or idea, the delay device according to the invention comprises, in addition to the pyrotechnic delay element with fixedly preset delay time (maximum delay time), a bypass element with a pyrotechnic transfer charge, having a significantly higher bum rate than the material of the pyrotechnic delay element.

In order to realize the delay device, the pyrotechnic delay element is arranged in a hollow cylindrical first housing, which is enclosed at least in a partial region by a hollow cylindrical second housing, the first and the second housing being able to turn relative to each other about a common longitudinal axis in order to adjust the delay time.

At least one bypass bore extends in the side wall region of the second housing, parallel to the first housing, being connected to at least two axially spaced radial bores, directed toward the first housing, the first bore being arranged at the side of the bypass bore facing the main or propellant charge or the like.

The side wall of the first housing furthermore has at least one third and one fourth radial bore, which are arranged such that they are aligned with the first and second radial bores arranged in the second housing by a predeterminable angle of rotation with respect to this housing. The bypass bore and the radial bores of the first and second housing are filled with the pyrotechnic transfer charge, so that when the radial bores of the first and second housing are aligned the delay time between the igniting of the delay element and the igniting of the main or propellant charge or the like is shortened by a length of time dictated by the axial position of the fourth (and thus also the second) radial bore.

Thanks to this design, the claim of achieving several delay times within only a single delay period is fulfilled. A maximum delay time is set. If, now, a delay time needs to be set with the delay device which is less than the maximum delay time, the bypass element is activated after the burning off of a predeterminable first segment of the delay element, so that the remaining second segment of the delay element is bridged over by the bypass element and the corresponding main or propellant charge or the like is ignited immediately after the burn-off of the first segment. On the other hand, if the ignition of the main charge is supposed to occur after the maximum adjustable delay time from the igniting of the pyrotechnic delay element, the two housings are turned relative to each other about the longitudinal axis so that the radial bores are not aligned, so that the bypass is deactivated and it no longer brings about an early burn-through of the pyrotechnic delay period.

If more than two different delay times need to be adjustable with the delay device according to the invention, the number of radial bores in the first and second housing must be increased accordingly in the axial direction and arranged with a relative displacement to one another on the circumference. The associated radial bores in the two housings are then once more aligned in order to set the particular delay time.

Preferably, the angles of rotation at which the radial bores are aligned with each other and therefore produce defined shorter delay times can be set in each case by a releasable detent connection, where the detent element may be a spring-loaded ball arranged in the side wall of the second housing, which can be pressed radially into a blind bore of the outer wall of the first housing.

In the case of a mortar grenade with a tail section and an adjoining front shell section, containing an active charge, it has proven to be advantageous for the easy adjusting of the delay time prior to the firing of the grenade to have the first housing of the delay device and the adjoining explosive or ejection charge connected by force locking and/or form fitting to the tail section, and to have the second housing of the ignition element connected by force locking and/or form fitting to the front shell section of the mortar grenade, so that by rotating the front shell section relative to the tail section the delay time of the delay device of the ammunition fuse can be adjusted.

Further details and benefits of the invention will emerge from the following sample embodiments, explained with the aid of figures. There are shown:

Fig. 1, a longitudinal section through a schematically represented ammunition fuse with pyrotechnic delay device according to the invention, wherein the delay device is adjusted such that it requires its maximum delay time in order to activate a main charge after its ignition,

Fig. 2, the ammunition fuse shown in Fig. 1, wherein the delay device is adjusted so that the delay time in order to activate the main charge is around 50% of the maximum delay time, and

Fig. 3, the schematic representation of a mortar grenade with an ammunition fuse with delay device according to the invention.

Figure 1 represents schematically as 1 an ammunition fuse, consisting of an ignition element 2 of a pyrotechnic delay device 3 and a main charge 4, such as one for igniting an explosive charge, not shown. The ignition element 2 may be, for example, a percussion cap, which is ignited by means of a striker, or it may also be an electrically ignited element.

The pyrotechnic delay device 3 according to the invention comprises a pyrotechnic delay element 5, which is arranged in a hollow cylindrical or tubular first housing 6.

This first housing 6 is enclosed in part by a hollow cylindrical or tubular second housing 7. The first and the second housing 6 and 7 are able to turn relative to each other about a common longitudinal axis 100. A bypass bore 9 extends in the side wall 8 of the second housing 7, parallel to the longitudinal axis 100. This bypass bore 9 is connected to two axially spaced radial bores 10, 11, directed toward the first housing 6, the first bore 10 being arranged at the side of the bypass bore 9 facing the main charge 4 and the second bore 11 being arranged roughly in the middle between the ignition element 2 and the main charge 4.

The side wall 12 of the first housing 6 has a third and a fourth radial bore 13, 14, which are located on the side of the first housing 6 facing away from the observer in Fig. 1. These bores 13 and 14 are arranged such that they are aligned with the first and second radial bores 10, 11 arranged in this housing 7 by a rotation of the first housing with respect to the second housing 7 by 45° (Fig. 2).

Both the bypass bore 9 and the radial bores 13, 14 of the first housing 6 and the radial bores 10, 11 of the second housing 7 are filled with a pyrotechnic transfer charge 15, having a significantly higher burn rate than that of the pyrotechnic delay element 5.

If, now, the igniting of the main charge 4 should occur only after the maximum adjustable delay time after the igniting of the pyrotechnic delay element 5, the two housings 6 and 7 are turned relative to each other about the longitudinal axis 100 so that the radial bores 10 and 13 as well as 11 and 14 are not aligned and an arrangement results as depicted in Fig. 1, for example.

On the other hand, if an igniting of the main charge 4 should occur after around half of the maximum adjustable delay time, the two housings 6 and 7 are turned relative to each other about the longitudinal axis 100 so that the arrangement depicted in Fig. 2 results. In this case, after the bum-off in the first segment of the pyrotechnic delay element 5 extending as far as the radial bore 14, an activation of the transfer charge 15 occurs, so that the remaining segment of the delay element 5 between the radial bores 14 and 13 is bridged over by the transfer charge 15 in the bypass bore 9 and the main charge 4 is ignited much faster than if the igniting of the main charge 4 occurs only after the burn-off of the entire delay element 5.

Figure 3 shows schematically a mortar grenade 16, being for example a mortar grenade which can be fired from a spigot mortar. The mortar grenade 16 comprises a front shell section 17 containing an active charge 18 (such as of a smoke generating material) and a tail section 19 adjoining it at the rear. The ammunition fuse 1 activating the active charge 18 corresponds to the ammunition fuse 1 described above with the aid of Fig. 1 and 2, while the ignition element 2 can be activated by a striker element 20. In order to adjust the delay time, it is provided that the front shell section 17 can be rotated relative to the adjoining tail section 19 about the longitudinal axis 100 of the mortar grenade 16.

The first housing 6 of the pyrotechnic delay device 3 with the ignition element 2 as well as the adjoining main charge 4 are therefore connected by force locking and/or form fitting to the tail section 19. On the other hand, the second housing 7 of the delay device 3 is connected by force locking and/or form fitting to the front shell section 17 of the mortar grenade 16 containing the active charge 18.

Of course, the invention is not limited to the sample embodiments described above.

Thus, for a rapid and reproducible adjusting of the predetermined delay time, it may be provided that the angles of rotation at which the radial bores 10 and 13 as well as 11 and 14 are aligned with each other are set in each case by releasable detent connections. For this, spring-loaded balls may be provided as the detent elements, for example, arranged in the side wall 8 of the second housing, which can be pressed radially into corresponding blind bores of the side wall 12 of the first housing.

In order to adjust the delay device for more than two different delay times, the number of radial bores in the first and second housing must be increased accordingly in the axial direction and arranged on the circumference so that each time only one aligned arrangement of radial bores in the first and second housing, corresponding to the particular delay time, are connected to each other in an aligned manner at the entry side (i.e., at the rear in the firing direction) and the exit side (i.e., at the front in the firing direction).

List of reference numbers 1 ammunition fuse 2 ignition element 3 pyrotechnic delay device 4 main charge 5 (pyrotechnic) delay element 6 (first) housing 7 (second) housing 8 side wall (second housing) 9 bypass bore 10 (first) bore 11 (second) bore 12 side wall (of first housing) 13,14 radial bores 15 (pyrotechnic) transfer charge 16 mortar grenade 17 front shell section 18 active charge 19 tail section 20 striker element 100 longitudinal axis

Claims

A pyrotechnic delay device (3) for an ammunition detonator (1) with a pyrotechnic delay element (5) which, after a predetermined delay time, ignites a main charge (4), an expulsion charge or the like. similarly, wherein the pyrotechnic delay device (3) is mechanically adjusted, the pyrotechnic delay element (5) being in a hollow cylinder-shaped first housing (6) enclosed at least in a sub-region by a second housing (7), second housing (6 and 7) is rotatable relative to each other on a common longitudinal axis (100), characterized in that a bypass element (9) is integrated with a transfer charge (15), so that when rotating the two housings ( 6, 7) can be induced to change the delay time by activating or deactivating the bypass element (9).

The pyrotechnic delay device according to claim 1, characterized in that the bypass element (9) is at least one bypass bore extending in the side wall (8) of the second housing (7) parallel to the longitudinal axis (100) and connected to at least two axial spacing and directed to the first housing (6) radial bores (10, 11).

Pyrotechnic delay device according to claim 2, characterized in that the first bore (10) is arranged on the side of the bypass bore (9) facing the main charge (4) or the like. like.

A pyrotechnic delay device according to claim 2 or 3, characterized in that a third and a fourth radially bore (13, 14) disposed between the side wall (12) of the first housing (6) are provided. such that they align at a predetermined angle of rotation with respect to the second housing (7) with the first and second radial bores (10, 11) disposed in this housing (7).

Pyrotechnic delay device according to claim 4, characterized in that the bypass bore (9) and the radial bores (10, 11 and 13, 14) in the first and second housing (6 and 7) are filled with a pyrotechnic transfer charge (15), whose burnout rate is substantially higher than that of the pyrotechnic delay element (5) such that when the radial bores (10, 13 and 11, 14) of the first and second housings (6 and 7) are flush, the delay time between ignition of the delay element ( 5) and ignition of the main charge (4) or like. is shortened by one of the axial positions of the predetermined period of the second and fourth radial bores (11 and 14).

Delay device according to one of claims 1 to 5, characterized in that for adjusting the delay device (3) to more than two different delay times, the number of the radial bores in the first and second housing (6 and 7) is correspondingly increased axially and applied to the circumferential side such that only a flushing arrangement of the radial bores in the first housing (6 and 7) corresponding to the respective delay time is connected to each other, respectively. the entry and exit side.

Delay device according to one of Claims 1 to 6, characterized in that the angles of rotation where the radial bores (10 and 13 and 11 and 14) align with each other and consequently defined shortened delay times can each be fixed via a detachable stop connection.

Delay device according to claim 7, characterized in that as a stop element there is provided, as a stop element, in the side wall (8) of the second housing (7) a spring-impacted ball which can be radially pressed into a blind bore in the side wall (12) of the first housing. (6).

Mortar grenade with a front projectile member (17) containing an active charge (18) and an adjacent tail portion (19) on the rear, characterized in that the mortar grenade (16) comprises an ammunition detonator (1) with a delay device ( 3) according to one of claims 1 to 8, wherein the first housing (6) of the delay device (3) and the adjacent main charge or the like. like. is connected forcefully and / or formally to the tail part (19), and wherein the second housing (7) of the delay device (3) is connected force and / or shape finally to the front projectile part (17) of the mortar grenade (16), thus the delay time of the delay device (3) of the ammunition detonator (1) can be set by rotating the front projectile part (17) relative to the tail part (19).

Mortar grenade according to claim 9, characterized in that the active charge (18) in the mortar grenade (16) is a material which produces fog.